diff mbox

media: Support Intersil/Techwell TW686x-based video capture cards

Message ID 1451183213-2733-1-git-send-email-ezequiel@vanguardiasur.com.ar (mailing list archive)
State New, archived
Headers show

Commit Message

Ezequiel Garcia Dec. 27, 2015, 2:26 a.m. UTC
This commit introduces the support for the Techwell TW686x video
capture IC. This hardware supports a few DMA modes, including
scatter-gather and frame (contiguous).

This commit supports only DMA frame (contiguous) mode.
DMA scatter-gather mode support may be added in the future.

Currently supported chips:
- TW6864 (4 video channels),
- TW6865 (4 video channels, not tested, second generation chip),
- TW6868 (8 video channels but only 4 first channels using
           built-in video decoder are supported, not tested),
- TW6869 (8 video channels, second generation chip).

Cc: Krzysztof Ha?asa <khalasa@piap.pl>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
---
This patchset superseeds Krzysztof's original patch:
https://patchwork.linuxtv.org/patch/30448/

Tested on a custom TW6869-based capture card.
Latest v4l2-compliance test pass:

$ /usr/bin/v4l2-compliance -f -s
Driver Info:
	Driver name   : tw686x
	Card type     : tw6869
	Bus info      : PCI:0000:04:00.0
	Driver version: 4.4.0
	Capabilities  : 0x85200001
		Video Capture
		Read/Write
		Streaming
		Extended Pix Format
		Device Capabilities
	Device Caps   : 0x05200001
		Video Capture
		Read/Write
		Streaming
		Extended Pix Format

Compliance test for device /dev/video0 (not using libv4l2):

[..]
Test input 0:

Streaming ioctls:
	test read/write: OK
	test MMAP: OK
	test USERPTR: OK (Not Supported)
	test DMABUF: Cannot test, specify --expbuf-device

Stream using all formats:
	test MMAP for Format UYVY, Frame Size 360x240:
		Stride 720, Field Interlaced: OK
	test MMAP for Format UYVY, Frame Size 720x480:
		Stride 1440, Field Interlaced: OK
	test MMAP for Format RGBP, Frame Size 360x240:
		Stride 720, Field Interlaced: OK
	test MMAP for Format RGBP, Frame Size 720x480:
		Stride 1440, Field Interlaced: OK
	test MMAP for Format YUYV, Frame Size 360x240:
		Stride 720, Field Interlaced: OK
	test MMAP for Format YUYV, Frame Size 720x480:
		Stride 1440, Field Interlaced: OK

Total: 114, Succeeded: 114, Failed: 0, Warnings: 0
---
 MAINTAINERS                             |   8 +
 drivers/media/pci/Kconfig               |   1 +
 drivers/media/pci/Makefile              |   1 +
 drivers/media/pci/tw686x/Kconfig        |  18 +
 drivers/media/pci/tw686x/Makefile       |   3 +
 drivers/media/pci/tw686x/tw686x-audio.c | 379 +++++++++++++
 drivers/media/pci/tw686x/tw686x-core.c  | 356 ++++++++++++
 drivers/media/pci/tw686x/tw686x-regs.h  | 118 ++++
 drivers/media/pci/tw686x/tw686x-video.c | 953 ++++++++++++++++++++++++++++++++
 drivers/media/pci/tw686x/tw686x.h       | 189 +++++++
 10 files changed, 2026 insertions(+)
 create mode 100644 drivers/media/pci/tw686x/Kconfig
 create mode 100644 drivers/media/pci/tw686x/Makefile
 create mode 100644 drivers/media/pci/tw686x/tw686x-audio.c
 create mode 100644 drivers/media/pci/tw686x/tw686x-core.c
 create mode 100644 drivers/media/pci/tw686x/tw686x-regs.h
 create mode 100644 drivers/media/pci/tw686x/tw686x-video.c
 create mode 100644 drivers/media/pci/tw686x/tw686x.h

Comments

Hans Verkuil Jan. 18, 2016, 1:02 p.m. UTC | #1
Hi Ezequiel,

Thanks for working on this! Do you know where I can get a board tw686x board?
I always like to have hardware to test the driver, if at all possible.

See below for a review of this driver.

On 12/27/2015 03:26 AM, Ezequiel Garcia wrote:
> This commit introduces the support for the Techwell TW686x video
> capture IC. This hardware supports a few DMA modes, including
> scatter-gather and frame (contiguous).
> 
> This commit supports only DMA frame (contiguous) mode.
> DMA scatter-gather mode support may be added in the future.
> 
> Currently supported chips:
> - TW6864 (4 video channels),
> - TW6865 (4 video channels, not tested, second generation chip),
> - TW6868 (8 video channels but only 4 first channels using
>            built-in video decoder are supported, not tested),
> - TW6869 (8 video channels, second generation chip).
> 
> Cc: Krzysztof Ha?asa <khalasa@piap.pl>
> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
> ---
> This patchset superseeds Krzysztof's original patch:
> https://patchwork.linuxtv.org/patch/30448/
> 
> Tested on a custom TW6869-based capture card.
> Latest v4l2-compliance test pass:
> 
> $ /usr/bin/v4l2-compliance -f -s
> Driver Info:
> 	Driver name   : tw686x
> 	Card type     : tw6869
> 	Bus info      : PCI:0000:04:00.0
> 	Driver version: 4.4.0
> 	Capabilities  : 0x85200001
> 		Video Capture
> 		Read/Write
> 		Streaming
> 		Extended Pix Format
> 		Device Capabilities
> 	Device Caps   : 0x05200001
> 		Video Capture
> 		Read/Write
> 		Streaming
> 		Extended Pix Format
> 
> Compliance test for device /dev/video0 (not using libv4l2):
> 
> [..]
> Test input 0:
> 
> Streaming ioctls:
> 	test read/write: OK
> 	test MMAP: OK
> 	test USERPTR: OK (Not Supported)
> 	test DMABUF: Cannot test, specify --expbuf-device
> 
> Stream using all formats:
> 	test MMAP for Format UYVY, Frame Size 360x240:
> 		Stride 720, Field Interlaced: OK
> 	test MMAP for Format UYVY, Frame Size 720x480:
> 		Stride 1440, Field Interlaced: OK
> 	test MMAP for Format RGBP, Frame Size 360x240:
> 		Stride 720, Field Interlaced: OK
> 	test MMAP for Format RGBP, Frame Size 720x480:
> 		Stride 1440, Field Interlaced: OK
> 	test MMAP for Format YUYV, Frame Size 360x240:
> 		Stride 720, Field Interlaced: OK
> 	test MMAP for Format YUYV, Frame Size 720x480:
> 		Stride 1440, Field Interlaced: OK
> 
> Total: 114, Succeeded: 114, Failed: 0, Warnings: 0
> ---
>  MAINTAINERS                             |   8 +
>  drivers/media/pci/Kconfig               |   1 +
>  drivers/media/pci/Makefile              |   1 +
>  drivers/media/pci/tw686x/Kconfig        |  18 +
>  drivers/media/pci/tw686x/Makefile       |   3 +
>  drivers/media/pci/tw686x/tw686x-audio.c | 379 +++++++++++++
>  drivers/media/pci/tw686x/tw686x-core.c  | 356 ++++++++++++
>  drivers/media/pci/tw686x/tw686x-regs.h  | 118 ++++
>  drivers/media/pci/tw686x/tw686x-video.c | 953 ++++++++++++++++++++++++++++++++
>  drivers/media/pci/tw686x/tw686x.h       | 189 +++++++
>  10 files changed, 2026 insertions(+)
>  create mode 100644 drivers/media/pci/tw686x/Kconfig
>  create mode 100644 drivers/media/pci/tw686x/Makefile
>  create mode 100644 drivers/media/pci/tw686x/tw686x-audio.c
>  create mode 100644 drivers/media/pci/tw686x/tw686x-core.c
>  create mode 100644 drivers/media/pci/tw686x/tw686x-regs.h
>  create mode 100644 drivers/media/pci/tw686x/tw686x-video.c
>  create mode 100644 drivers/media/pci/tw686x/tw686x.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4635e1d14612..9308f8242cd3 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10846,6 +10846,14 @@ W:	https://linuxtv.org
>  S:	Odd Fixes
>  F:	drivers/media/pci/tw68/
>  
> +TW686X VIDEO4LINUX DRIVER
> +M:	Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
> +L:	linux-media@vger.kernel.org
> +T:	git git://linuxtv.org/media_tree.git
> +W:	http://linuxtv.org
> +S:	Maintained
> +F:	drivers/media/pci/tw686x/
> +
>  TPM DEVICE DRIVER
>  M:	Peter Huewe <peterhuewe@gmx.de>
>  M:	Marcel Selhorst <tpmdd@selhorst.net>
> diff --git a/drivers/media/pci/Kconfig b/drivers/media/pci/Kconfig
> index 48a611bc3e18..4f6467fbaeb4 100644
> --- a/drivers/media/pci/Kconfig
> +++ b/drivers/media/pci/Kconfig
> @@ -14,6 +14,7 @@ source "drivers/media/pci/meye/Kconfig"
>  source "drivers/media/pci/solo6x10/Kconfig"
>  source "drivers/media/pci/sta2x11/Kconfig"
>  source "drivers/media/pci/tw68/Kconfig"
> +source "drivers/media/pci/tw686x/Kconfig"
>  source "drivers/media/pci/zoran/Kconfig"
>  endif
>  
> diff --git a/drivers/media/pci/Makefile b/drivers/media/pci/Makefile
> index 5f8aacb8b9b8..2e54c36441f7 100644
> --- a/drivers/media/pci/Makefile
> +++ b/drivers/media/pci/Makefile
> @@ -25,6 +25,7 @@ obj-$(CONFIG_VIDEO_BT848) += bt8xx/
>  obj-$(CONFIG_VIDEO_SAA7134) += saa7134/
>  obj-$(CONFIG_VIDEO_SAA7164) += saa7164/
>  obj-$(CONFIG_VIDEO_TW68) += tw68/
> +obj-$(CONFIG_VIDEO_TW686X) += tw686x/
>  obj-$(CONFIG_VIDEO_DT3155) += dt3155/
>  obj-$(CONFIG_VIDEO_MEYE) += meye/
>  obj-$(CONFIG_STA2X11_VIP) += sta2x11/
> diff --git a/drivers/media/pci/tw686x/Kconfig b/drivers/media/pci/tw686x/Kconfig
> new file mode 100644
> index 000000000000..bd73d3dd25b4
> --- /dev/null
> +++ b/drivers/media/pci/tw686x/Kconfig
> @@ -0,0 +1,18 @@
> +config VIDEO_TW686X
> +	tristate "Intersil/Techwell TW686x video capture cards"
> +	depends on PCI && VIDEO_DEV && VIDEO_V4L2 && SND
> +	depends on HAS_DMA
> +	select VIDEOBUF2_DMA_CONTIG
> +	select SND_PCM
> +	help
> +	  Support for Intersil/Techwell TW686x-based frame grabber cards.
> +
> +	  Currently supported chips:
> +	  - TW6864 (4 video channels),
> +	  - TW6865 (4 video channels, not tested, second generation chip),
> +	  - TW6868 (8 video channels but only 4 first channels using
> +	    built-in video decoder are supported, not tested),
> +	  - TW6869 (8 video channels, second generation chip).
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be named tw686x.
> diff --git a/drivers/media/pci/tw686x/Makefile b/drivers/media/pci/tw686x/Makefile
> new file mode 100644
> index 000000000000..99819542b733
> --- /dev/null
> +++ b/drivers/media/pci/tw686x/Makefile
> @@ -0,0 +1,3 @@
> +tw686x-objs := tw686x-core.o tw686x-video.o tw686x-audio.o
> +
> +obj-$(CONFIG_VIDEO_TW686X) += tw686x.o
> diff --git a/drivers/media/pci/tw686x/tw686x-audio.c b/drivers/media/pci/tw686x/tw686x-audio.c
> new file mode 100644
> index 000000000000..2295d2d1a945
> --- /dev/null
> +++ b/drivers/media/pci/tw686x/tw686x-audio.c
> @@ -0,0 +1,379 @@
> +/*
> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
> + *
> + * Based on the audio support from the tw6869 driver:
> + * Copyright 2015 www.starterkit.ru <info@starterkit.ru>
> + *
> + * Based on:
> + * Driver for Intersil|Techwell TW6869 based DVR cards
> + * (c) 2011-12 liran <jli11@intersil.com> [Intersil|Techwell China]
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of version 2 of the GNU General Public License
> + * as published by the Free Software Foundation.
> + */
> +
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/kmod.h>
> +#include <linux/mutex.h>
> +#include <linux/pci.h>
> +#include <linux/delay.h>
> +
> +#include <sound/core.h>
> +#include <sound/initval.h>
> +#include <sound/pcm.h>
> +#include <sound/control.h>
> +#include "tw686x.h"
> +#include "tw686x-regs.h"
> +
> +#define AUDIO_CHANNEL_OFFSET 8
> +
> +void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
> +		      unsigned int pb_status)
> +{
> +	unsigned long flags;
> +	unsigned int ch, pb;
> +
> +	for_each_set_bit(ch, &requests, max_channels(dev)) {
> +

Remove this empty line.

> +		struct tw686x_audio_channel *ac = &dev->audio_channels[ch];
> +		struct tw686x_audio_buf *done = NULL;
> +		struct tw686x_audio_buf *next = NULL;
> +		struct tw686x_dma_desc *desc;
> +
> +		pb = !!(pb_status & BIT(AUDIO_CHANNEL_OFFSET + ch));
> +
> +		spin_lock_irqsave(&ac->lock, flags);
> +
> +		/* Sanity check */
> +		if (!ac->ss || !ac->curr_bufs[0] || !ac->curr_bufs[1]) {
> +			spin_unlock_irqrestore(&ac->lock, flags);
> +			continue;
> +		}
> +
> +		if (!list_empty(&ac->buf_list)) {
> +			next = list_first_entry(&ac->buf_list,
> +					struct tw686x_audio_buf, list);
> +			list_move_tail(&next->list, &ac->buf_list);
> +			done = ac->curr_bufs[!pb];
> +			ac->curr_bufs[pb] = next;
> +		}
> +		spin_unlock_irqrestore(&ac->lock, flags);
> +
> +		desc = &ac->dma_descs[pb];
> +		if (done && next && desc->virt) {
> +			memcpy(done->virt, desc->virt, desc->size);
> +			ac->ptr = done->dma - ac->buf[0].dma;
> +			snd_pcm_period_elapsed(ac->ss);
> +		}
> +	}
> +}
> +
> +static int tw686x_pcm_hw_params(struct snd_pcm_substream *ss,
> +				struct snd_pcm_hw_params *hw_params)
> +{
> +	return snd_pcm_lib_malloc_pages(ss, params_buffer_bytes(hw_params));
> +}
> +
> +static int tw686x_pcm_hw_free(struct snd_pcm_substream *ss)
> +{
> +	return snd_pcm_lib_free_pages(ss);
> +}
> +
> +static const struct snd_pcm_hardware tw686x_capture_hw = {
> +	.info			= (SNDRV_PCM_INFO_MMAP |
> +				   SNDRV_PCM_INFO_INTERLEAVED |
> +				   SNDRV_PCM_INFO_BLOCK_TRANSFER |
> +				   SNDRV_PCM_INFO_MMAP_VALID),
> +	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
> +	.rates			= SNDRV_PCM_RATE_8000_48000,
> +	.rate_min		= 8000,
> +	.rate_max		= 48000,
> +	.channels_min		= 1,
> +	.channels_max		= 1,
> +	.buffer_bytes_max	= TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE,
> +	.period_bytes_min	= TW686X_PAGE_SIZE,
> +	.period_bytes_max	= TW686X_PAGE_SIZE,
> +	.periods_min		= 2,
> +	.periods_max		= TW686X_AUDIO_PAGE_MAX,
> +};
> +
> +static int tw686x_pcm_open(struct snd_pcm_substream *ss)
> +{
> +	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
> +	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
> +	struct snd_pcm_runtime *rt = ss->runtime;
> +	int err;
> +
> +	ac->ss = ss;
> +	rt->hw = tw686x_capture_hw;
> +
> +	err = snd_pcm_hw_constraint_integer(rt, SNDRV_PCM_HW_PARAM_PERIODS);
> +	if (err < 0)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static int tw686x_pcm_close(struct snd_pcm_substream *ss)
> +{
> +	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
> +	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
> +
> +	ac->ss = NULL;
> +	return 0;
> +}
> +
> +static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
> +{
> +	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
> +	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
> +	struct snd_pcm_runtime *rt = ss->runtime;
> +	unsigned int period_size = snd_pcm_lib_period_bytes(ss);
> +	struct tw686x_audio_buf *p_buf, *b_buf;
> +	unsigned long flags;
> +	int i;
> +
> +	spin_lock_irqsave(&dev->lock, flags);
> +	tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +
> +	if (dev->audio_rate != rt->rate) {
> +		u32 reg;
> +
> +		dev->audio_rate = rt->rate;
> +		reg = ((125000000 / rt->rate) << 16) +
> +		       ((125000000 % rt->rate) << 16) / rt->rate;
> +
> +		reg_write(dev, AUDIO_CONTROL2, reg);
> +	}
> +
> +	if ((period_size != TW686X_PAGE_SIZE) ||
> +	    (rt->periods < 2) || (rt->periods > TW686X_AUDIO_PAGE_MAX)) {

There is no need for the extra parenthesis around simple comparisons.

> +		return -EINVAL;
> +	}
> +
> +	spin_lock_irqsave(&ac->lock, flags);
> +	INIT_LIST_HEAD(&ac->buf_list);
> +
> +	for (i = 0; i < rt->periods; i++) {
> +		ac->buf[i].dma = rt->dma_addr + period_size * i;
> +		ac->buf[i].virt = rt->dma_area + period_size * i;
> +		INIT_LIST_HEAD(&ac->buf[i].list);
> +		list_add_tail(&ac->buf[i].list, &ac->buf_list);
> +	}
> +
> +	p_buf =	list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
> +	list_move_tail(&p_buf->list, &ac->buf_list);
> +
> +	b_buf =	list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
> +	list_move_tail(&b_buf->list, &ac->buf_list);
> +
> +	ac->curr_bufs[0] = p_buf;
> +	ac->curr_bufs[1] = b_buf;
> +	ac->ptr = 0;
> +	spin_unlock_irqrestore(&ac->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
> +{
> +	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
> +	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
> +	unsigned long flags;
> +	int err = 0;
> +
> +	switch (cmd) {
> +	case SNDRV_PCM_TRIGGER_START:
> +		if (ac->curr_bufs[0] && ac->curr_bufs[1]) {
> +			spin_lock_irqsave(&dev->lock, flags);
> +			tw686x_enable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
> +			spin_unlock_irqrestore(&dev->lock, flags);
> +
> +			mod_timer(&dev->dma_delay_timer,
> +				  jiffies + msecs_to_jiffies(100));
> +		} else {
> +			err = -EIO;
> +		}
> +		break;
> +	case SNDRV_PCM_TRIGGER_STOP:
> +		spin_lock_irqsave(&dev->lock, flags);
> +		tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
> +		spin_unlock_irqrestore(&dev->lock, flags);
> +
> +		spin_lock_irqsave(&ac->lock, flags);
> +		ac->curr_bufs[0] = NULL;
> +		ac->curr_bufs[1] = NULL;
> +		spin_unlock_irqrestore(&ac->lock, flags);
> +		break;
> +	default:
> +		err = -EINVAL;
> +	}
> +	return err;
> +}
> +
> +static snd_pcm_uframes_t tw686x_pcm_pointer(struct snd_pcm_substream *ss)
> +{
> +	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
> +	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
> +
> +	return bytes_to_frames(ss->runtime, ac->ptr);
> +}
> +
> +static struct snd_pcm_ops tw686x_pcm_ops = {
> +	.open = tw686x_pcm_open,
> +	.close = tw686x_pcm_close,
> +	.ioctl = snd_pcm_lib_ioctl,
> +	.hw_params = tw686x_pcm_hw_params,
> +	.hw_free = tw686x_pcm_hw_free,
> +	.prepare = tw686x_pcm_prepare,
> +	.trigger = tw686x_pcm_trigger,
> +	.pointer = tw686x_pcm_pointer,
> +};
> +
> +static int tw686x_snd_pcm_init(struct tw686x_dev *dev)
> +{
> +	struct snd_card *card = dev->snd_card;
> +	struct snd_pcm *pcm;
> +	struct snd_pcm_substream *ss;
> +	unsigned int i;
> +	int err;
> +
> +	err = snd_pcm_new(card, card->driver, 0, 0, max_channels(dev), &pcm);
> +	if (err < 0)
> +		return err;
> +
> +	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &tw686x_pcm_ops);
> +	snd_pcm_chip(pcm) = dev;
> +	pcm->info_flags = 0;
> +	strcpy(pcm->name, "tw686x PCM");

strlcpy

> +
> +	for (i = 0, ss = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
> +	     ss; ss = ss->next, i++)
> +		sprintf(ss->name, "vch%u audio", i);

snprintf

> +
> +	return snd_pcm_lib_preallocate_pages_for_all(pcm,
> +				SNDRV_DMA_TYPE_DEV,
> +				snd_dma_pci_data(dev->pci_dev),
> +				TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE,
> +				TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE);
> +}
> +
> +static void tw686x_audio_dma_free(struct tw686x_dev *dev,
> +				  struct tw686x_audio_channel *ac)
> +{
> +	int pb;
> +
> +	for (pb = 0; pb < 2; pb++) {
> +		if (!ac->dma_descs[pb].virt)
> +			continue;
> +		pci_free_consistent(dev->pci_dev, ac->dma_descs[pb].size,
> +				    ac->dma_descs[pb].virt,
> +				    ac->dma_descs[pb].phys);
> +		ac->dma_descs[pb].virt = NULL;
> +	}
> +}
> +
> +static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
> +				  struct tw686x_audio_channel *ac)
> +{
> +	int pb;
> +
> +	for (pb = 0; pb < 2; pb++) {
> +		u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch];
> +		void *virt;
> +
> +		virt = pci_alloc_consistent(dev->pci_dev, TW686X_PAGE_SIZE,
> +					    &ac->dma_descs[pb].phys);
> +		if (!virt) {
> +			dev_err(&dev->pci_dev->dev,
> +				"dma%d: unable to allocate audio DMA %s-buffer\n",
> +				ac->ch, pb ? "B" : "P");
> +			return -ENOMEM;
> +		}
> +		ac->dma_descs[pb].virt = virt;
> +		ac->dma_descs[pb].size = TW686X_PAGE_SIZE;
> +		reg_write(dev, reg, ac->dma_descs[pb].phys);
> +	}
> +	return 0;
> +}
> +
> +void tw686x_audio_free(struct tw686x_dev *dev)
> +{
> +	unsigned long flags;
> +	u32 dma_ch_mask;
> +	u32 dma_cmd;
> +
> +	spin_lock_irqsave(&dev->lock, flags);
> +	dma_cmd = reg_read(dev, DMA_CMD);
> +	dma_ch_mask = reg_read(dev, DMA_CHANNEL_ENABLE);
> +	reg_write(dev, DMA_CMD, dma_cmd & ~0xff00);
> +	reg_write(dev, DMA_CHANNEL_ENABLE, dma_ch_mask & ~0xff00);
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +
> +	if (!dev->snd_card)
> +		return;
> +	snd_card_free(dev->snd_card);
> +	dev->snd_card = NULL;
> +}
> +
> +int tw686x_audio_init(struct tw686x_dev *dev)
> +{
> +	struct pci_dev *pci_dev = dev->pci_dev;
> +	struct snd_card *card;
> +	int err, ch;
> +
> +	/*
> +	 * AUDIO_CONTROL1
> +	 * DMA byte length [31:19] = 4096 (i.e. ALSA period)
> +	 * External audio enable [0] = enabled
> +	 */
> +	reg_write(dev, AUDIO_CONTROL1, 0x80000001);
> +
> +	err = snd_card_new(&pci_dev->dev, SNDRV_DEFAULT_IDX1,
> +			   SNDRV_DEFAULT_STR1,
> +			   THIS_MODULE, 0, &card);
> +	if (err < 0)
> +		return err;
> +
> +	dev->snd_card = card;
> +	strcpy(card->driver, "tw686x");
> +	strcpy(card->shortname, "tw686x");
> +	sprintf(card->longname, "%s", pci_name(pci_dev));

Use strlcpy and snprintf.

> +	snd_card_set_dev(card, &pci_dev->dev);
> +
> +	for (ch = 0; ch < max_channels(dev); ch++) {
> +		struct tw686x_audio_channel *ac;
> +
> +		ac = &dev->audio_channels[ch];
> +		spin_lock_init(&ac->lock);
> +		ac->dev = dev;
> +		ac->ch = ch;
> +
> +		err = tw686x_audio_dma_alloc(dev, ac);
> +		if (err < 0)
> +			goto err_cleanup;
> +	}
> +
> +	err = tw686x_snd_pcm_init(dev);
> +	if (err < 0)
> +		goto err_cleanup;
> +
> +	err = snd_card_register(card);
> +	if (!err)
> +		return 0;
> +
> +err_cleanup:
> +	for (ch = 0; ch < max_channels(dev); ch++) {
> +		if (!dev->audio_channels[ch].dev)
> +			continue;
> +		tw686x_audio_dma_free(dev, &dev->audio_channels[ch]);
> +	}
> +	snd_card_free(card);
> +	dev->snd_card = NULL;
> +	return err;
> +}
> diff --git a/drivers/media/pci/tw686x/tw686x-core.c b/drivers/media/pci/tw686x/tw686x-core.c
> new file mode 100644
> index 000000000000..8774facb29d5
> --- /dev/null
> +++ b/drivers/media/pci/tw686x/tw686x-core.c
> @@ -0,0 +1,356 @@
> +/*
> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
> + *
> + * Based on original driver by Krzysztof Ha?asa:
> + * Copyright (C) 2015 Industrial Research Institute for Automation
> + * and Measurements PIAP
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of version 2 of the GNU General Public License
> + * as published by the Free Software Foundation.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pci_ids.h>
> +#include <linux/slab.h>
> +#include <linux/timer.h>
> +
> +#include "tw686x.h"
> +#include "tw686x-regs.h"
> +
> +static u32 dma_interval = 0x00098968;
> +module_param(dma_interval, int, 0444);
> +MODULE_PARM_DESC(dma_interval, "Minimum time span for DMA interrupting host");
> +
> +/*
> + * The purpose of this awful hack is to avoid
> + * enabling the DMA channels "too fast" which seems
> + * to make some TW686x devices _very_ angry and freeze the CPU.
> + */
> +static void tw686x_dma_delay(unsigned long data)
> +{
> +        struct tw686x_dev *dev = (struct tw686x_dev *) data;

Weird indentation, spaces instead of tab. Remove space after cast.

> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&dev->lock, flags);
> +
> +	reg_write(dev, DMA_CHANNEL_ENABLE, dev->pending_dma_en);
> +	reg_write(dev, DMA_CMD, dev->pending_dma_cmd);
> +	dev->pending_dma_en = 0;
> +	dev->pending_dma_cmd = 0;
> +
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +}
> +
> +static void tw686x_reset_channels(struct tw686x_dev *dev, unsigned int ch_mask)
> +{
> +	u32 dma_en, dma_cmd;
> +
> +	dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
> +	dma_cmd = reg_read(dev, DMA_CMD);
> +
> +	/*
> +	 * Save pending register status, the timer will
> +	 * restore them.
> +	 */
> +	dev->pending_dma_en |= dma_en;
> +	dev->pending_dma_cmd |= dma_cmd;
> +
> +	/* Disable the reset channels */
> +	reg_write(dev, DMA_CHANNEL_ENABLE, dma_en & ~ch_mask);
> +
> +	if ((dma_en & ~ch_mask) == 0) {
> +		dev_dbg(&dev->pci_dev->dev, "reset: stopping DMA\n");
> +		dma_cmd &= ~BIT(31);
> +	}
> +	reg_write(dev, DMA_CMD, dma_cmd & ~ch_mask);
> +}
> +
> +static irqreturn_t tw686x_irq(int irq, void *dev_id)
> +{
> +	struct tw686x_dev *dev = (struct tw686x_dev *)dev_id;
> +	unsigned int video_requests, audio_requests, reset_ch;
> +	u32 fifo_status, fifo_signal, fifo_ov, fifo_bad, fifo_errors;
> +	u32 int_status, dma_en, video_en, pb_status;
> +	unsigned long flags;
> +
> +	int_status = reg_read(dev, INT_STATUS); /* cleared on read */
> +	fifo_status = reg_read(dev, VIDEO_FIFO_STATUS);
> +
> +	/* INT_STATUS does not include FIFO_STATUS errors! */
> +	if (!int_status && !TW686X_FIFO_ERROR(fifo_status))
> +		return IRQ_NONE;
> +
> +	if (int_status & BIT(17)) {

Either use a define for BIT(17) or add a comment so I know what bit 17 is.

> +		dev_dbg(&dev->pci_dev->dev,
> +			"DMA timeout. Resetting DMA for all channels\n");
> +		reset_ch = ~0;
> +		goto reset_channels;
> +	}
> +
> +	spin_lock_irqsave(&dev->lock, flags);
> +	dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +
> +	video_en = dma_en & 0xff;
> +	fifo_signal = ~(fifo_status & 0xff) & video_en;
> +	fifo_ov = fifo_status >> 24;
> +	fifo_bad = fifo_status >> 16;
> +
> +	/* Mask of channels with signal and FIFO errors */
> +	fifo_errors = fifo_signal & (fifo_ov | fifo_bad);
> +
> +	reset_ch = 0;
> +	pb_status = reg_read(dev, PB_STATUS);
> +
> +	/* Coalesce video frame/error events */
> +	video_requests = (int_status & video_en) | fifo_errors;
> +	audio_requests = (int_status & dma_en) >> 8;
> +
> +	if (video_requests)
> +		tw686x_video_irq(dev, video_requests, pb_status,
> +				 fifo_status, &reset_ch);
> +	if (audio_requests)
> +		tw686x_audio_irq(dev, audio_requests, pb_status);
> +
> +reset_channels:
> +	if (reset_ch) {
> +		spin_lock_irqsave(&dev->lock, flags);
> +		tw686x_reset_channels(dev, reset_ch);
> +		spin_unlock_irqrestore(&dev->lock, flags);
> +		mod_timer(&dev->dma_delay_timer,
> +			  jiffies + msecs_to_jiffies(100));
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void tw686x_dev_release(struct v4l2_device *v4l2_dev)
> +{
> +        struct tw686x_dev *dev = container_of(v4l2_dev, struct tw686x_dev,
> +					      v4l2_dev);
> +	unsigned int ch;
> +
> +	for (ch = 0; ch < max_channels(dev); ch++)
> +		v4l2_ctrl_handler_free(&dev->video_channels[ch].ctrl_handler);
> +
> +	v4l2_device_unregister(&dev->v4l2_dev);
> +
> +	kfree(dev->audio_channels);
> +	kfree(dev->video_channels);
> +	kfree(dev);
> +}
> +
> +static int tw686x_probe(struct pci_dev *pci_dev,
> +			const struct pci_device_id *pci_id)
> +{
> +	struct tw686x_dev *dev;
> +	int err;
> +
> +	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> +	if (!dev)
> +		return -ENOMEM;
> +	dev->type = pci_id->driver_data;
> +	sprintf(dev->name, "tw%04X", pci_dev->device);
> +
> +	dev->video_channels = kcalloc(max_channels(dev),
> +		sizeof(*dev->video_channels), GFP_KERNEL);
> +	if (!dev->video_channels) {
> +		err = -ENOMEM;
> +		goto free_dev;
> +	}
> +
> +	dev->audio_channels = kcalloc(max_channels(dev),
> +		sizeof(*dev->audio_channels), GFP_KERNEL);
> +	if (!dev->audio_channels) {
> +		err = -ENOMEM;
> +		goto free_video;
> +	}
> +
> +	pr_info("%s: PCI %s, IRQ %d, MMIO 0x%lx\n", dev->name,
> +		pci_name(pci_dev), pci_dev->irq,
> +		(unsigned long)pci_resource_start(pci_dev, 0));
> +
> +	dev->pci_dev = pci_dev;
> +	if (pci_enable_device(pci_dev)) {
> +		err = -EIO;
> +		goto free_audio;
> +	}
> +
> +	pci_set_master(pci_dev);
> +	err = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
> +	if (err) {
> +		dev_err(&pci_dev->dev, "32-bit PCI DMA not supported\n");
> +		err = -EIO;
> +		goto disable_pci;
> +	}
> +
> +	err = pci_request_regions(pci_dev, dev->name);
> +	if (err) {
> +		dev_err(&pci_dev->dev, "unable to request PCI region\n");
> +		goto disable_pci;
> +	}
> +
> +	dev->mmio = pci_ioremap_bar(pci_dev, 0);
> +	if (!dev->mmio) {
> +		dev_err(&pci_dev->dev, "unable to remap PCI region\n");
> +		err = -ENOMEM;
> +		goto free_region;
> +	}
> +
> +	/* Reset all subsystems */
> +	reg_write(dev, SYS_SOFT_RST, 0x0F);

The codingstyle for the kernel is to use lower case hex values, so 0x0f.

Please change this throughout the source code.

> +	mdelay(1);
> +
> +	reg_write(dev, SRST[0], 0x3F);
> +	if (max_channels(dev) > 4)
> +		reg_write(dev, SRST[1], 0x3F);
> +
> +	/* Disable the DMA engine */
> +	reg_write(dev, DMA_CMD, 0);
> +	reg_write(dev, DMA_CHANNEL_ENABLE, 0);
> +
> +	/* Enable DMA FIFO overflow and pointer check */
> +	reg_write(dev, DMA_CONFIG, 0xFFFFFF04);
> +	reg_write(dev, DMA_CHANNEL_TIMEOUT, 0x140C8584);
> +	reg_write(dev, DMA_TIMER_INTERVAL, dma_interval);
> +
> +	spin_lock_init(&dev->lock);
> +
> +	err = request_irq(pci_dev->irq, tw686x_irq, IRQF_SHARED,
> +			  dev->name, dev);
> +	if (err < 0) {
> +		dev_err(&pci_dev->dev, "unable to request interrupt\n");
> +		goto iounmap;
> +	}
> +
> +	setup_timer(&dev->dma_delay_timer,
> +		    tw686x_dma_delay, (unsigned long) dev);
> +
> +	/*
> +	 * This must be set right before initializing v4l2_dev.
> +	 * It's used to release resources after the last handle
> +	 * held is released.
> +	 */
> +	dev->v4l2_dev.release = tw686x_dev_release;
> +	err = tw686x_video_init(dev);
> +	if (err) {
> +		dev_err(&pci_dev->dev, "can't register video\n");
> +		goto free_irq;
> +	}
> +
> +	err = tw686x_audio_init(dev);
> +	if (err) {
> +		dev_warn(&pci_dev->dev, "can't register audio\n");
> +	}
> +
> +	pci_set_drvdata(pci_dev, dev);
> +	return 0;
> +
> +free_irq:
> +	free_irq(pci_dev->irq, dev);
> +iounmap:
> +	pci_iounmap(pci_dev, dev->mmio);
> +free_region:
> +	pci_release_regions(pci_dev);
> +disable_pci:
> +	pci_disable_device(pci_dev);
> +free_audio:
> +	kfree(dev->audio_channels);
> +free_video:
> +	kfree(dev->video_channels);
> +free_dev:
> +	kfree(dev);
> +	return err;
> +}
> +
> +static void tw686x_remove(struct pci_dev *pci_dev)
> +{
> +	struct tw686x_dev *dev = pci_get_drvdata(pci_dev);
> +	unsigned long flags;
> +
> +	/* This guarantees the IRQ handler is no longer running,
> +	 * which means we can kiss good-bye some resources.
> +	 */
> +	free_irq(pci_dev->irq, dev);
> +
> +	tw686x_video_free(dev);
> +	tw686x_audio_free(dev);
> +	del_timer_sync(&dev->dma_delay_timer);
> +
> +	pci_iounmap(pci_dev, dev->mmio);
> +	pci_release_regions(pci_dev);
> +	pci_disable_device(pci_dev);
> +
> +	/*
> +	 * This allows to detect device is not here,
> +	 * and will be used by vb2_ops. The lock is really
> +	 * important here.
> +	 */
> +	spin_lock_irqsave(&dev->lock, flags);
> +	dev->pci_dev = NULL;
> +	spin_unlock_irqrestore(&dev->lock, flags);

As you sure this is needed? Normally you can only come here if the module
is removed, which isn't possible as long as userspace is using it. And if
the module is removed, then vb2 shouldn't be called at all.

The only exception would be if this is a hot-pluggable device, which is
quite unlikely for a PCI device. I don't believe any of the pci drivers
support that.

Dubious code.

> +
> +        /*
> +         * This calls tw686x_dev_release if it's the last reference.
> +         * therwise, release is posponed until there are no users left.

Typo: Otherwise ... postponed

> +         */
> +        v4l2_device_put(&dev->v4l2_dev);

Again, spaces instead of tabs.

> +}
> +
> +/*
> + * On TW6864 and TW6868, all channels share the pair of video DMA SG tables,
> + * with 10-bit start_idx and end_idx determining start and end of frame buffer
> + * for particular channel.
> + * TW6868 with all its 8 channels would be problematic (only 127 SG entries per
> + * channel) but we support only 4 channels on this chip anyway (the first
> + * 4 channels are driven with internal video decoder, the other 4 would require
> + * an external TW286x part).
> + *
> + * On TW6865 and TW6869, each channel has its own DMA SG table, with indexes
> + * starting with 0. Both chips have complete sets of internal video decoders
> + * (respectively 4 or 8-channel).
> + *
> + * All chips have separate SG tables for two video frames.
> + */
> +
> +/* driver_data is number of A/V channels */
> +static const struct pci_device_id tw686x_pci_tbl[] = {
> +	{
> +		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6864),
> +		.driver_data = 4
> +	},
> +	{
> +		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6865), /* not tested */
> +		.driver_data = 4 | TYPE_SECOND_GEN
> +	},
> +	/*
> +	 * TW6868 supports 8 A/V channels with an external TW2865 chip;
> +	 * not supported by the driver.
> +	 */
> +	{
> +		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6868), /* not tested */
> +		.driver_data = 4
> +	},
> +	{
> +		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6869),
> +		.driver_data = 8 | TYPE_SECOND_GEN},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(pci, tw686x_pci_tbl);
> +
> +static struct pci_driver tw686x_pci_driver = {
> +	.name = "tw686x",
> +	.id_table = tw686x_pci_tbl,
> +	.probe = tw686x_probe,
> +	.remove = tw686x_remove,
> +};
> +module_pci_driver(tw686x_pci_driver);
> +
> +MODULE_DESCRIPTION("Driver for video frame grabber cards based on Intersil/Techwell TW686[4589]");
> +MODULE_AUTHOR("Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/media/pci/tw686x/tw686x-regs.h b/drivers/media/pci/tw686x/tw686x-regs.h
> new file mode 100644
> index 000000000000..92c331ceb065
> --- /dev/null
> +++ b/drivers/media/pci/tw686x/tw686x-regs.h
> @@ -0,0 +1,118 @@
> +/* DMA controller registers */
> +#define REG8_1(a0) ((const u16[8]){a0, a0 + 1, a0 + 2, a0 + 3,		\
> +				   a0 + 4, a0 + 5, a0 + 6, a0 + 7})
> +#define REG8_2(a0) ((const u16[8]){a0, a0 + 2, a0 + 4, a0 + 6,		\
> +				   a0 + 8, a0 + 0xA, a0 + 0xC, a0 + 0xE})
> +#define REG8_8(a0) ((const u16[8]){a0, a0 + 8, a0 + 0x10, a0 + 0x18,	\
> +				   a0 + 0x20, a0 + 0x28, a0 + 0x30, a0 + 0x38})
> +#define INT_STATUS		0x00
> +#define PB_STATUS		0x01
> +#define DMA_CMD			0x02
> +#define VIDEO_FIFO_STATUS	0x03
> +#define VIDEO_CHANNEL_ID	0x04
> +#define VIDEO_PARSER_STATUS	0x05
> +#define SYS_SOFT_RST		0x06
> +#define DMA_PAGE_TABLE0_ADDR	((const u16[8]){0x08, 0xD0, 0xD2, 0xD4,	\
> +						0xD6, 0xD8, 0xDA, 0xDC})
> +#define DMA_PAGE_TABLE1_ADDR	((const u16[8]){0x09, 0xD1, 0xD3, 0xD5,	\
> +						0xD7, 0xD9, 0xDB, 0xDD})
> +#define DMA_CHANNEL_ENABLE	0x0a
> +#define DMA_CONFIG		0x0b
> +#define DMA_TIMER_INTERVAL	0x0c
> +#define DMA_CHANNEL_TIMEOUT	0x0d
> +#define VDMA_CHANNEL_CONFIG	REG8_1(0x10)
> +#define ADMA_P_ADDR		REG8_2(0x18)
> +#define ADMA_B_ADDR		REG8_2(0x19)
> +#define DMA10_P_ADDR		0x28 /* ??? */
> +#define DMA10_B_ADDR		0x29
> +#define VIDEO_CONTROL1		0x2A
> +#define VIDEO_CONTROL2		0x2B
> +#define AUDIO_CONTROL1		0x2C
> +#define AUDIO_CONTROL2		0x2D
> +#define PHASE_REF		0x2E
> +#define GPIO_REG		0x2F
> +#define INTL_HBAR_CTRL		REG8_1(0x30)
> +#define AUDIO_CONTROL3		0x38
> +#define VIDEO_FIELD_CTRL	REG8_1(0x39)
> +#define HSCALER_CTRL		REG8_1(0x42)
> +#define VIDEO_SIZE		REG8_1(0x4A)
> +#define VIDEO_SIZE_F2		REG8_1(0x52)
> +#define MD_CONF			REG8_1(0x60)
> +#define MD_INIT			REG8_1(0x68)
> +#define MD_MAP0			REG8_1(0x70)
> +#define VDMA_P_ADDR		REG8_8(0x80) /* not used in DMA SG mode */
> +#define VDMA_WHP		REG8_8(0x81)
> +#define VDMA_B_ADDR		REG8_8(0x82)
> +#define VDMA_F2_P_ADDR		REG8_8(0x84)
> +#define VDMA_F2_WHP		REG8_8(0x85)
> +#define VDMA_F2_B_ADDR		REG8_8(0x86)
> +#define EP_REG_ADDR		0xFE
> +#define EP_REG_DATA		0xFF
> +
> +/* Video decoder registers */
> +#define VDREG8(a0) ((const u16[8]){			\
> +	a0 + 0x000, a0 + 0x010, a0 + 0x020, a0 + 0x030,	\
> +	a0 + 0x100, a0 + 0x110, a0 + 0x120, a0 + 0x130})
> +#define VIDSTAT			VDREG8(0x100)
> +#define BRIGHT			VDREG8(0x101)
> +#define CONTRAST		VDREG8(0x102)
> +#define SHARPNESS		VDREG8(0x103)
> +#define SAT_U			VDREG8(0x104)
> +#define SAT_V			VDREG8(0x105)
> +#define HUE			VDREG8(0x106)
> +#define CROP_HI			VDREG8(0x107)
> +#define VDELAY_LO		VDREG8(0x108)
> +#define VACTIVE_LO		VDREG8(0x109)
> +#define HDELAY_LO		VDREG8(0x10A)
> +#define HACTIVE_LO		VDREG8(0x10B)
> +#define MVSN			VDREG8(0x10C)
> +#define STATUS2			VDREG8(0x10C)
> +#define SDT			VDREG8(0x10E)
> +#define SDT_EN			VDREG8(0x10F)
> +
> +#define VSCALE_LO		VDREG8(0x144)
> +#define SCALE_HI		VDREG8(0x145)
> +#define HSCALE_LO		VDREG8(0x146)
> +#define F2CROP_HI		VDREG8(0x147)
> +#define F2VDELAY_LO		VDREG8(0x148)
> +#define F2VACTIVE_LO		VDREG8(0x149)
> +#define F2HDELAY_LO		VDREG8(0x14A)
> +#define F2HACTIVE_LO		VDREG8(0x14B)
> +#define F2VSCALE_LO		VDREG8(0x14C)
> +#define F2SCALE_HI		VDREG8(0x14D)
> +#define F2HSCALE_LO		VDREG8(0x14E)
> +#define F2CNT			VDREG8(0x14F)
> +
> +#define VDREG2(a0) ((const u16[2]){a0, a0 + 0x100})
> +#define SRST			VDREG2(0x180)
> +#define ACNTL			VDREG2(0x181)
> +#define ACNTL2			VDREG2(0x182)
> +#define CNTRL1			VDREG2(0x183)
> +#define CKHY			VDREG2(0x184)
> +#define SHCOR			VDREG2(0x185)
> +#define CORING			VDREG2(0x186)
> +#define CLMPG			VDREG2(0x187)
> +#define IAGC			VDREG2(0x188)
> +#define VCTRL1			VDREG2(0x18F)
> +#define MISC1			VDREG2(0x194)
> +#define LOOP			VDREG2(0x195)
> +#define MISC2			VDREG2(0x196)
> +
> +#define CLMD			VDREG2(0x197)
> +#define ANPWRDOWN		VDREG2(0x1ce)
> +#define AIGAIN			((const u16[8]){0x1D0, 0x1D1, 0x1D2, 0x1D3, \
> +						0x2D0, 0x2D1, 0x2D2, 0x2D3})
> +
> +#define SYS_MODE_DMA_SHIFT	13
> +#define TW686X_VIDSTAT_HLOCK	BIT(6)
> +#define TW686X_VIDSTAT_VDLOSS	BIT(7)
> +
> +#define TW686X_STD_NTSC_M	0
> +#define TW686X_STD_PAL		1
> +#define TW686X_STD_SECAM	2
> +#define TW686X_STD_NTSC_443	3
> +#define TW686X_STD_PAL_M	4
> +#define TW686X_STD_PAL_CN	5
> +#define TW686X_STD_PAL_60	6
> +
> +#define TW686X_FIFO_ERROR(x)	(x & ~(0xFF))
> diff --git a/drivers/media/pci/tw686x/tw686x-video.c b/drivers/media/pci/tw686x/tw686x-video.c
> new file mode 100644
> index 000000000000..7287a9de7a1a
> --- /dev/null
> +++ b/drivers/media/pci/tw686x/tw686x-video.c
> @@ -0,0 +1,953 @@
> +/*
> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
> + *
> + * Based on original driver by Krzysztof Ha?asa:
> + * Copyright (C) 2015 Industrial Research Institute for Automation
> + * and Measurements PIAP
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of version 2 of the GNU General Public License
> + * as published by the Free Software Foundation.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/delay.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-event.h>
> +#include <media/videobuf2-vmalloc.h>
> +#include "tw686x.h"
> +#include "tw686x-regs.h"
> +
> +#define TW686X_INPUTS_PER_CH		4
> +#define TW686X_VIDEO_WIDTH		720
> +#define TW686X_VIDEO_HEIGHT(id)		((id & V4L2_STD_625_50) ? 576 : 480)
> +
> +static const struct tw686x_format formats[] = {
> +	{
> +		.name = "4:2:2 packed, UYVY",
> +		.fourcc = V4L2_PIX_FMT_UYVY,
> +		.mode = 0,
> +		.depth = 16,
> +	}, {
> +		.name = "16 bpp RGB",
> +		.fourcc = V4L2_PIX_FMT_RGB565,
> +		.mode = 5,
> +		.depth = 16,
> +	}, {
> +		.name = "4:2:2 packed, YUYV",

Drop name: these days this is filled in by the v4l2 core to ensure
consistent naming.

> +		.fourcc = V4L2_PIX_FMT_YUYV,
> +		.mode = 6,
> +		.depth = 16,
> +	}
> +};
> +
> +static unsigned int tw686x_fields_map(v4l2_std_id std, unsigned int fps)
> +{
> +	unsigned int map[15] = {
> +		0x00000000, 0x00000001, 0x00004001, 0x00104001, 0x00404041,
> +		0x01041041, 0x01104411, 0x01111111, 0x04444445, 0x04511445,
> +		0x05145145, 0x05151515, 0x05515455, 0x05551555, 0x05555555
> +	};
> +
> +	unsigned int std_625_50[26] = {
> +		0, 1, 1, 2,  3,  3,  4,  4,  5,  5,  6,  7,  7,
> +		   8, 8, 9, 10, 10, 11, 11, 12, 13, 13, 14, 14, 0
> +	};
> +
> +	unsigned int std_525_60[31] = {
> +		0, 1, 1, 1, 2,  2,  3,  3,  4,  4,  5,  5,  6,  6, 7, 7,
> +		   8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 0, 0
> +	};

This can all be static const.

> +
> +	unsigned int i =
> +		(std & V4L2_STD_625_50) ? std_625_50[fps] : std_525_60[fps];
> +
> +	return map[i];
> +}
> +
> +static void tw686x_set_framerate(struct tw686x_video_channel *vc,
> +				 unsigned int fps)
> +{
> +	unsigned int map;
> +
> +	if (vc->fps == fps)
> +		return;
> +
> +	map = tw686x_fields_map(vc->video_standard, fps) << 1;
> +	map |= map << 1;
> +	if (map > 0)
> +		map |= BIT(31);
> +	reg_write(vc->dev, VIDEO_FIELD_CTRL[vc->ch], map);
> +	vc->fps = fps;
> +}
> +
> +static const struct tw686x_format *format_by_fourcc(unsigned fourcc)
> +{
> +	unsigned cnt;
> +
> +	for (cnt = 0; cnt < ARRAY_SIZE(formats); cnt++)
> +		if (formats[cnt].fourcc == fourcc)
> +			return &formats[cnt];
> +	return NULL;
> +}
> +
> +static int tw686x_queue_setup(struct vb2_queue *vq,
> +			      unsigned int *nbuffers, unsigned int *nplanes,
> +			      unsigned int sizes[], void *alloc_ctxs[])
> +{
> +	struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
> +	unsigned int szimage =
> +		(vc->width * vc->height * vc->format->depth) >> 3;
> +
> +	/*
> +	 * Let's request at least three buffers: two for the
> +	 * DMA engine and one for userspace.
> +	 */
> +	if (vq->num_buffers + *nbuffers < 3)
> +		*nbuffers = 3 - vq->num_buffers;
> +
> +	if (*nplanes) {
> +		if (*nplanes != 1 || sizes[0] < szimage)
> +			return -EINVAL;
> +		return 0;
> +	}
> +
> +	sizes[0] = szimage;
> +	*nplanes = 1;
> +	return 0;
> +}
> +
> +static void tw686x_buf_queue(struct vb2_buffer *vb)
> +{
> +	struct tw686x_video_channel *vc = vb2_get_drv_priv(vb->vb2_queue);
> +	struct tw686x_dev *dev = vc->dev;
> +	struct pci_dev *pci_dev;
> +	unsigned long flags;
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct tw686x_v4l2_buf *buf =
> +		container_of(vbuf, struct tw686x_v4l2_buf, vb);
> +
> +	/* Check device presence */
> +	spin_lock_irqsave(&dev->lock, flags);
> +	pci_dev = dev->pci_dev;
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +	if (!pci_dev) {
> +		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
> +		return;
> +	}
> +
> +	spin_lock_irqsave(&vc->qlock, flags);
> +	list_add_tail(&buf->list, &vc->vidq_queued);
> +	spin_unlock_irqrestore(&vc->qlock, flags);
> +}
> +
> +/*
> + * We can call this even when alloc_dma failed for the given channel
> + */
> +static void tw686x_free_dma(struct tw686x_video_channel *vc, unsigned int pb)
> +{
> +	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
> +	struct tw686x_dev *dev = vc->dev;
> +	struct pci_dev *pci_dev;
> +	unsigned long flags;
> +
> +	/* Check device presence. Shouldn't really happen! */
> +	spin_lock_irqsave(&dev->lock, flags);
> +	pci_dev = dev->pci_dev;
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +	if (!pci_dev) {
> +		WARN(1, "trying to deallocate on missing device\n");
> +		return;
> +	}

Dubious code, as mentioned earlier.

> +
> +	if (desc->virt) {
> +		pci_free_consistent(dev->pci_dev, desc->size,
> +				    desc->virt, desc->phys);
> +		desc->virt = NULL;
> +	}
> +}
> +
> +static int tw686x_alloc_dma(struct tw686x_video_channel *vc, unsigned int pb)
> +{
> +	struct tw686x_dev *dev = vc->dev;
> +	u32 reg = pb ? VDMA_B_ADDR[vc->ch] : VDMA_P_ADDR[vc->ch];
> +	unsigned int len;
> +	void *virt;
> +
> +	WARN(vc->dma_descs[pb].virt,
> +	     "Allocating buffer but previous still here\n");
> +
> +	len = (vc->width * vc->height * vc->format->depth) >> 3;
> +	virt = pci_alloc_consistent(dev->pci_dev, len,
> +				    &vc->dma_descs[pb].phys);
> +	if (!virt) {
> +		v4l2_err(&dev->v4l2_dev, "dma%d: unable to allocate %s-buffer\n",
> +			 vc->ch, pb ? "B" : "P");
> +		return -ENOMEM;
> +	}
> +	vc->dma_descs[pb].size = len;
> +	vc->dma_descs[pb].virt = virt;
> +	reg_write(dev, reg, vc->dma_descs[pb].phys);
> +
> +	return 0;
> +}
> +
> +static void tw686x_buffer_refill(struct tw686x_video_channel *vc, unsigned int pb)
> +{
> +	struct tw686x_v4l2_buf *buf;
> +
> +	while (!list_empty(&vc->vidq_queued)) {
> +
> +		buf = list_first_entry(&vc->vidq_queued,
> +			struct tw686x_v4l2_buf, list);
> +		list_del(&buf->list);
> +
> +		vc->curr_bufs[pb] = buf;
> +		return;
> +	}
> +	vc->curr_bufs[pb] = NULL;
> +}
> +
> +static void tw686x_clear_queue(struct tw686x_video_channel *vc)
> +{
> +	unsigned int pb;
> +
> +	while (!list_empty(&vc->vidq_queued)) {
> +		struct tw686x_v4l2_buf *buf;
> +
> +		buf = list_first_entry(&vc->vidq_queued,
> +			struct tw686x_v4l2_buf, list);
> +		list_del(&buf->list);
> +		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
> +	}
> +
> +	for (pb = 0; pb < 2; pb++) {
> +		if (vc->curr_bufs[pb])
> +			vb2_buffer_done(&vc->curr_bufs[pb]->vb.vb2_buf,
> +					VB2_BUF_STATE_ERROR);
> +		vc->curr_bufs[pb] = NULL;
> +	}
> +}
> +
> +static int tw686x_start_streaming(struct vb2_queue *vq, unsigned int count)
> +{
> +	struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
> +	struct tw686x_dev *dev = vc->dev;
> +	struct pci_dev *pci_dev;
> +	unsigned long flags;
> +	int pb;
> +
> +	/* Check device presence */
> +	spin_lock_irqsave(&dev->lock, flags);
> +	pci_dev = dev->pci_dev;
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +	if (!pci_dev)
> +		return -ENODEV;
> +
> +	spin_lock_irqsave(&vc->qlock, flags);
> +
> +	/* Sanity check */
> +	if (!vc->dma_descs[0].virt || !vc->dma_descs[1].virt) {
> +		spin_unlock_irqrestore(&vc->qlock, flags);
> +		v4l2_err(&dev->v4l2_dev, "video%d: refusing to start without DMA buffers\n",
> +			 vc->num);
> +		return -ENOMEM;

If start_streaming fails with an error, then you need to call vb2_buffer_done
with status VB2_BUF_STATE_QUEUED for all buffers.

> +	}
> +
> +	for (pb = 0; pb < 2; pb++)
> +		tw686x_buffer_refill(vc, pb);
> +	spin_unlock_irqrestore(&vc->qlock, flags);
> +
> +	vc->sequence = 0;
> +	vc->pb = 0;
> +
> +	spin_lock_irqsave(&dev->lock, flags);
> +	tw686x_enable_channel(dev, vc->ch);
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +
> +	mod_timer(&dev->dma_delay_timer, jiffies + msecs_to_jiffies(100));
> +
> +	return 0;
> +}
> +
> +static void tw686x_stop_streaming(struct vb2_queue *vq)
> +{
> +	struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
> +	struct tw686x_dev *dev = vc->dev;
> +	struct pci_dev *pci_dev;
> +	unsigned long flags;
> +
> +	/* Check device presence */
> +	spin_lock_irqsave(&dev->lock, flags);
> +	pci_dev = dev->pci_dev;
> +	spin_unlock_irqrestore(&dev->lock, flags);
> +	if (pci_dev)
> +		tw686x_disable_channel(dev, vc->ch);
> +
> +	spin_lock_irqsave(&vc->qlock, flags);
> +	tw686x_clear_queue(vc);
> +	spin_unlock_irqrestore(&vc->qlock, flags);
> +}
> +
> +static int tw686x_buf_prepare(struct vb2_buffer *vb)
> +{
> +	struct tw686x_video_channel *vc = vb2_get_drv_priv(vb->vb2_queue);
> +	unsigned int size =
> +		(vc->width * vc->height * vc->format->depth) >> 3;
> +
> +	if (vb2_plane_size(vb, 0) < size)
> +		return -EINVAL;
> +	vb2_set_plane_payload(vb, 0, size);
> +	return 0;
> +}
> +
> +static struct vb2_ops tw686x_video_qops = {
> +	.queue_setup		= tw686x_queue_setup,
> +	.buf_queue		= tw686x_buf_queue,
> +	.buf_prepare		= tw686x_buf_prepare,
> +	.start_streaming	= tw686x_start_streaming,
> +	.stop_streaming		= tw686x_stop_streaming,
> +	.wait_prepare		= vb2_ops_wait_prepare,
> +	.wait_finish		= vb2_ops_wait_finish,
> +};
> +
> +static int tw686x_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct tw686x_video_channel *vc;
> +	struct tw686x_dev *dev;
> +	unsigned ch;
> +
> +	vc = container_of(ctrl->handler, struct tw686x_video_channel,
> +			  ctrl_handler);
> +	dev = vc->dev;
> +	ch = vc->ch;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_BRIGHTNESS:
> +		reg_write(dev, BRIGHT[ch], ctrl->val & 0xFF);
> +		return 0;
> +
> +	case V4L2_CID_CONTRAST:
> +		reg_write(dev, CONTRAST[ch], ctrl->val);
> +		return 0;
> +
> +	case V4L2_CID_SATURATION:
> +		reg_write(dev, SAT_U[ch], ctrl->val);
> +		reg_write(dev, SAT_V[ch], ctrl->val);
> +		return 0;
> +
> +	case V4L2_CID_HUE:
> +		reg_write(dev, HUE[ch], ctrl->val & 0xFF);
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct v4l2_ctrl_ops ctrl_ops = {
> +	.s_ctrl = tw686x_s_ctrl,
> +};
> +
> +static int tw686x_g_fmt_vid_cap(struct file *file, void *priv,
> +				struct v4l2_format *f)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +
> +	f->fmt.pix.width = vc->width;
> +	f->fmt.pix.height = vc->height;
> +	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
> +	f->fmt.pix.pixelformat = vc->format->fourcc;
> +	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
> +	f->fmt.pix.bytesperline = (f->fmt.pix.width * vc->format->depth) / 8;
> +	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
> +	return 0;
> +}
> +
> +static int tw686x_try_fmt_vid_cap(struct file *file, void *priv,
> +				  struct v4l2_format *f)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	unsigned int video_height = TW686X_VIDEO_HEIGHT(vc->video_standard);
> +	const struct tw686x_format *format;
> +
> +	format = format_by_fourcc(f->fmt.pix.pixelformat);
> +	if (!format) {
> +		format = &formats[0];
> +		f->fmt.pix.pixelformat = format->fourcc;
> +	}
> +
> +	if (f->fmt.pix.width <= TW686X_VIDEO_WIDTH / 2)
> +		f->fmt.pix.width = TW686X_VIDEO_WIDTH / 2;
> +	else
> +		f->fmt.pix.width = TW686X_VIDEO_WIDTH;
> +
> +	if (f->fmt.pix.height <= video_height / 2)
> +		f->fmt.pix.height = video_height / 2;
> +	else
> +		f->fmt.pix.height = video_height;
> +
> +	f->fmt.pix.bytesperline = (f->fmt.pix.width * format->depth) / 8;
> +	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
> +	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
> +	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
> +
> +	return 0;
> +}
> +
> +static int tw686x_s_fmt_vid_cap(struct file *file, void *priv,
> +				struct v4l2_format *f)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	u32 val, width, line_width, height;
> +	unsigned long bitsperframe;
> +	int err, pb;
> +
> +	if (vb2_is_busy(&vc->vidq))
> +		return -EBUSY;
> +
> +	bitsperframe = vc->width * vc->height * vc->format->depth;
> +	err = tw686x_try_fmt_vid_cap(file, priv, f);
> +	if (err)
> +		return err;
> +
> +	vc->format = format_by_fourcc(f->fmt.pix.pixelformat);
> +	vc->width = f->fmt.pix.width;
> +	vc->height = f->fmt.pix.height;
> +
> +	/* We need new DMA buffers if the framesize has changed */
> +	if (bitsperframe != vc->width * vc->height * vc->format->depth) {
> +

Remove empty line.

> +		for (pb = 0; pb < 2; pb++)
> +			tw686x_free_dma(vc, pb);
> +
> +		for (pb = 0; pb < 2; pb++) {
> +			err = tw686x_alloc_dma(vc, pb);
> +			if (err) {
> +				if (pb > 0)
> +					tw686x_free_dma(vc, 0);
> +				return err;
> +			}
> +		}
> +	}
> +
> +	val = reg_read(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch]);
> +
> +	if (vc->width <= TW686X_VIDEO_WIDTH / 2)
> +		val |= BIT(23);
> +	else
> +		val &= ~BIT(23);
> +
> +	if (vc->height <= TW686X_VIDEO_HEIGHT(vc->video_standard) / 2)
> +		val |= BIT(24);
> +	else
> +		val &= ~BIT(24);
> +
> +	val &= ~(0x7 << 20);
> +	val |= vc->format->mode << 20;
> +	reg_write(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch], val);
> +
> +	/* Program the DMA frame size */
> +	width = (vc->width * 2) & 0x7ff;
> +	height = vc->height / 2;
> +	line_width = (vc->width * 2) & 0x7ff;
> +	val = (height << 22) | (line_width << 11)  | width;
> +	reg_write(vc->dev, VDMA_WHP[vc->ch], val);
> +	return 0;
> +}
> +
> +static int tw686x_querycap(struct file *file, void *priv,
> +			   struct v4l2_capability *cap)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	struct tw686x_dev *dev = vc->dev;
> +
> +	strcpy(cap->driver, "tw686x");
> +	strcpy(cap->card, dev->name);
> +	sprintf(cap->bus_info, "PCI:%s", pci_name(dev->pci_dev));

strlcpy and snprintf

> +	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
> +			   V4L2_CAP_READWRITE;
> +	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
> +	return 0;
> +}
> +
> +static int tw686x_s_std(struct file *file, void *priv, v4l2_std_id id)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	struct v4l2_format f;
> +	u32 val, ret;
> +
> +	if (vc->video_standard == id)
> +		return 0;
> +
> +	if (vb2_is_busy(&vc->vidq))
> +		return -EBUSY;
> +
> +	if (id & V4L2_STD_NTSC)
> +		val = 0;
> +	else if (id & V4L2_STD_PAL)
> +		val = 1;
> +	else if (id & V4L2_STD_SECAM)
> +		val = 2;
> +	else if (id & V4L2_STD_NTSC_443)
> +		val = 3;
> +	else if (id & V4L2_STD_PAL_M)
> +		val = 4;
> +	else if (id & V4L2_STD_PAL_Nc)
> +		val = 5;
> +	else if (id & V4L2_STD_PAL_60)
> +		val = 6;
> +	else
> +		return -EINVAL;
> +
> +	vc->video_standard = id;
> +	reg_write(vc->dev, SDT[vc->ch], val);
> +
> +	val = reg_read(vc->dev, VIDEO_CONTROL1);
> +	if (id & V4L2_STD_625_50)
> +		val |= (1 << (SYS_MODE_DMA_SHIFT + vc->ch));
> +	else
> +		val &= ~(1 << (SYS_MODE_DMA_SHIFT + vc->ch));
> +	reg_write(vc->dev, VIDEO_CONTROL1, val);
> +
> +	/*
> +	 * Adjust format after V4L2_STD_525_60/V4L2_STD_625_50 change,
> +	 * calling g_fmt and s_fmt will sanitize the height
> +	 * according to the standard.
> +	 */
> +	ret = tw686x_g_fmt_vid_cap(file, priv, &f);
> +	if (!ret)
> +		tw686x_s_fmt_vid_cap(file, priv, &f);
> +	return 0;
> +}
> +
> +static int tw686x_querystd(struct file *file, void *priv, v4l2_std_id *std)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	struct tw686x_dev *dev = vc->dev;
> +	unsigned int old_std, detected_std = 0;
> +	unsigned long end;
> +
> +	if (vb2_is_streaming(&vc->vidq))
> +		return -EBUSY;
> +
> +	/* Enable and start standard detection */
> +	old_std = reg_read(dev, SDT[vc->ch]);
> +	reg_write(dev, SDT[vc->ch], 0x7);
> +	reg_write(dev, SDT_EN[vc->ch], 0xff);
> +
> +	end = jiffies + msecs_to_jiffies(500);
> +	while (time_is_after_jiffies(end)) {
> +
> +		detected_std = reg_read(dev, SDT[vc->ch]);
> +		if (!(detected_std & BIT(7)))
> +			break;
> +		msleep(100);
> +	}
> +	reg_write(dev, SDT[vc->ch], old_std);
> +
> +	/* Exit if still busy */
> +	if (detected_std & BIT(7))
> +		return 0;
> +
> +	detected_std = (detected_std >> 4) & 0x7;
> +	switch (detected_std) {
> +	case TW686X_STD_NTSC_M:
> +		*std &= V4L2_STD_NTSC;
> +		break;
> +	case TW686X_STD_NTSC_443:
> +		*std &= V4L2_STD_NTSC_443;
> +		break;
> +	case TW686X_STD_PAL_M:
> +		*std &= V4L2_STD_PAL_M;
> +		break;
> +	case TW686X_STD_PAL_60:
> +		*std &= V4L2_STD_PAL_60;
> +		break;
> +	case TW686X_STD_PAL:
> +		*std &= V4L2_STD_PAL;
> +		break;
> +	case TW686X_STD_PAL_CN:
> +		*std &= V4L2_STD_PAL_Nc;
> +		break;
> +	case TW686X_STD_SECAM:
> +		*std &= V4L2_STD_SECAM;
> +		break;
> +	default:
> +		*std = 0;
> +	}
> +	return 0;
> +}
> +
> +static int tw686x_g_std(struct file *file, void *priv, v4l2_std_id *id)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +
> +	*id = vc->video_standard;
> +	return 0;
> +}
> +
> +static int tw686x_enum_fmt_vid_cap(struct file *file, void *priv,
> +				   struct v4l2_fmtdesc *f)
> +{
> +	if (f->index >= ARRAY_SIZE(formats))
> +		return -EINVAL;
> +
> +	strlcpy(f->description, formats[f->index].name, sizeof(f->description));

Drop this line, this is now done by the v4l2 core.

> +	f->pixelformat = formats[f->index].fourcc;
> +	return 0;
> +}
> +
> +static int tw686x_g_parm(struct file *file, void *priv,
> +			 struct v4l2_streamparm *sp)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	struct v4l2_captureparm *cp = &sp->parm.capture;
> +
> +	if (sp->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +	sp->parm.capture.readbuffers = 3;
> +
> +	cp->capability = V4L2_CAP_TIMEPERFRAME;
> +	cp->timeperframe.numerator = 1;
> +	cp->timeperframe.denominator = vc->fps;
> +	return 0;
> +}
> +
> +static int tw686x_s_parm(struct file *file, void *priv,
> +			 struct v4l2_streamparm *sp)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	struct v4l2_captureparm *cp = &sp->parm.capture;
> +	unsigned int denominator = cp->timeperframe.denominator;
> +	unsigned int numerator = cp->timeperframe.numerator;
> +	unsigned int fps;
> +
> +	if (vb2_is_busy(&vc->vidq))
> +		return -EBUSY;
> +
> +	fps = (!numerator || !denominator) ? 0 : denominator / numerator;
> +	if (vc->video_standard & V4L2_STD_625_50)
> +		fps = (!fps || fps > 25) ? 25 : fps;
> +	else
> +		fps = (!fps || fps > 30) ? 30 : fps;
> +	tw686x_set_framerate(vc, fps);
> +
> +	return tw686x_g_parm(file, priv, sp);
> +}

Why do you need to implement g/s_parm? This is not typically done for SDTV
capture devices since you cannot set it. And the v4l2 core will provide a
default g_parm implementation that does the right thing. I think you can
just delete these two functions.

> +
> +static int tw686x_s_input(struct file *file, void *priv, unsigned int i)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	u32 val;
> +
> +	if (i >= TW686X_INPUTS_PER_CH)
> +		return -EINVAL;
> +

I would add this here:

	if (i == vc->input)
		return 0;

> +	/*
> +	 * Not sure we are able to support on the fly input change
> +	 */
> +	if (vb2_is_busy(&vc->vidq))
> +		return -EBUSY;
> +
> +	vc->input = i;
> +
> +	val = reg_read(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch]);
> +	val &= ~(0x3 << 30);
> +	val |= i << 30;
> +	reg_write(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch], val);
> +	return 0;
> +}
> +
> +static int tw686x_g_input(struct file *file, void *priv, unsigned int *i)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +
> +	*i = vc->input;
> +	return 0;
> +}
> +
> +static int tw686x_enum_input(struct file *file, void *priv,
> +			     struct v4l2_input *i)
> +{
> +	struct tw686x_video_channel *vc = video_drvdata(file);
> +	unsigned int vidstat;
> +
> +	if (i->index >= TW686X_INPUTS_PER_CH)
> +		return -EINVAL;
> +
> +	sprintf(i->name, "Composite%d", i->index);
> +	i->type = V4L2_INPUT_TYPE_CAMERA;
> +	i->std = vc->device->tvnorms;
> +	i->capabilities = V4L2_IN_CAP_STD;
> +
> +	vidstat = reg_read(vc->dev, VIDSTAT[vc->ch]);
> +	i->status = 0;
> +	if (vidstat & TW686X_VIDSTAT_VDLOSS)
> +		i->status |= V4L2_IN_ST_NO_SIGNAL;
> +	if (!(vidstat & TW686X_VIDSTAT_HLOCK))
> +		i->status |= V4L2_IN_ST_NO_H_LOCK;
> +
> +	return 0;
> +}
> +
> +const struct v4l2_file_operations tw686x_video_fops = {
> +	.owner		= THIS_MODULE,
> +	.open		= v4l2_fh_open,
> +	.unlocked_ioctl	= video_ioctl2,
> +	.release	= vb2_fop_release,
> +	.poll		= vb2_fop_poll,
> +	.read		= vb2_fop_read,
> +	.mmap		= vb2_fop_mmap,
> +};
> +
> +const struct v4l2_ioctl_ops tw686x_video_ioctl_ops = {
> +	.vidioc_querycap		= tw686x_querycap,
> +	.vidioc_g_fmt_vid_cap		= tw686x_g_fmt_vid_cap,
> +	.vidioc_s_fmt_vid_cap		= tw686x_s_fmt_vid_cap,
> +	.vidioc_enum_fmt_vid_cap	= tw686x_enum_fmt_vid_cap,
> +	.vidioc_try_fmt_vid_cap		= tw686x_try_fmt_vid_cap,
> +
> +	.vidioc_querystd		= tw686x_querystd,
> +	.vidioc_g_std			= tw686x_g_std,
> +	.vidioc_s_std			= tw686x_s_std,
> +
> +	.vidioc_g_parm			= tw686x_g_parm,
> +	.vidioc_s_parm			= tw686x_s_parm,
> +
> +	.vidioc_enum_input		= tw686x_enum_input,
> +	.vidioc_g_input			= tw686x_g_input,
> +	.vidioc_s_input			= tw686x_s_input,
> +
> +	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
> +	.vidioc_querybuf		= vb2_ioctl_querybuf,
> +	.vidioc_qbuf			= vb2_ioctl_qbuf,
> +	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
> +	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
> +	.vidioc_streamon		= vb2_ioctl_streamon,
> +	.vidioc_streamoff		= vb2_ioctl_streamoff,
> +
> +	.vidioc_log_status		= v4l2_ctrl_log_status,
> +	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
> +	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
> +};
> +
> +static void tw686x_buffer_copy(struct tw686x_video_channel *vc,
> +			       unsigned int pb, struct vb2_v4l2_buffer *vb)
> +{
> +	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
> +	struct vb2_buffer *vb2_buf = &vb->vb2_buf;
> +
> +	vb->field = V4L2_FIELD_INTERLACED;
> +	vb->sequence = vc->sequence++;
> +
> +	memcpy(vb2_plane_vaddr(vb2_buf, 0), desc->virt, desc->size);
> +	vb2_buf->timestamp = ktime_get_ns();
> +	vb2_buffer_done(vb2_buf, VB2_BUF_STATE_DONE);
> +}
> +
> +void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
> +		      unsigned int pb_status, unsigned int fifo_status,
> +		      unsigned int *reset_ch)
> +{
> +	struct tw686x_video_channel *vc;
> +	struct vb2_v4l2_buffer *vb;
> +	unsigned long flags;
> +	unsigned int ch, pb;
> +
> +	for_each_set_bit(ch, &requests, max_channels(dev)) {
> +

Remove empty line.

> +		vc = &dev->video_channels[ch];
> +
> +		/*
> +		 * This can either be a blue frame (with signal-lost bit set)
> +		 * or a good frame (with signal-lost bit clear). If we have just
> +		 * got signal, then this channel needs resetting.
> +		 */
> +		if (vc->no_signal && !(fifo_status & BIT(ch))) {
> +			v4l2_printk(KERN_DEBUG, &dev->v4l2_dev,
> +				    "video%d: signal recovered\n", vc->num);
> +			vc->no_signal = false;
> +			*reset_ch |= BIT(ch);
> +			vc->pb = 0;
> +			continue;
> +		}
> +		vc->no_signal = !!(fifo_status & BIT(ch));
> +
> +		/* Check FIFO errors only if there's signal */
> +		if (!vc->no_signal) {
> +			u32 fifo_ov, fifo_bad;
> +
> +			fifo_ov = (fifo_status >> 24) & BIT(ch);
> +			fifo_bad = (fifo_status >> 16) & BIT(ch);
> +			if (fifo_ov || fifo_bad) {
> +				/* Mark this channel for reset */
> +				v4l2_printk(KERN_DEBUG, &dev->v4l2_dev, "video%d: FIFO error\n", vc->num);
> +				*reset_ch |= BIT(ch);
> +				vc->pb = 0;
> +				continue;
> +			}
> +		}
> +
> +		pb = !!(pb_status & BIT(ch));
> +		if (vc->pb != pb) {
> +			/* Mark this channel for reset */
> +			v4l2_printk(KERN_DEBUG, &dev->v4l2_dev,
> +				    "video%d: unexpected p-b buffer!\n", vc->num);
> +			*reset_ch |= BIT(ch);
> +			vc->pb = 0;
> +			continue;
> +		}
> +
> +		/* handle video stream */
> +		spin_lock_irqsave(&vc->qlock, flags);
> +		if (vc->curr_bufs[pb]) {
> +			vb = &vc->curr_bufs[pb]->vb;
> +			tw686x_buffer_copy(vc, pb, vb);

You have to copy the data? It's not possible the program the DMA so that
it DMAs into the buffer itself? That's quite unusual for a PCI device.

> +		}
> +		vc->pb = !pb;
> +		tw686x_buffer_refill(vc, pb);
> +		spin_unlock_irqrestore(&vc->qlock, flags);
> +	}
> +}
> +
> +void tw686x_video_free(struct tw686x_dev *dev)
> +{
> +	unsigned int ch, pb;
> +
> +	for (ch = 0; ch < max_channels(dev); ch++) {
> +		struct tw686x_video_channel *vc = &dev->video_channels[ch];
> +
> +		if (vc->device)
> +			video_unregister_device(vc->device);
> +
> +		for (pb = 0; pb < 2; pb++)
> +			tw686x_free_dma(vc, pb);
> +	}
> +}
> +
> +int tw686x_video_init(struct tw686x_dev *dev)
> +{
> +	unsigned int ch, val, pb;
> +	int err;
> +
> +	err = v4l2_device_register(&dev->pci_dev->dev, &dev->v4l2_dev);
> +	if (err)
> +		return err;
> +
> +	for (ch = 0; ch < max_channels(dev); ch++) {
> +		struct tw686x_video_channel *vc = &dev->video_channels[ch];
> +		struct video_device *vdev;
> +
> +		mutex_init(&vc->vb_mutex);
> +		spin_lock_init(&vc->qlock);
> +		INIT_LIST_HEAD(&vc->vidq_queued);
> +
> +		vc->dev = dev;
> +		vc->ch = ch;
> +
> +		/* default settings */
> +		vc->format = &formats[0];
> +		vc->video_standard = V4L2_STD_NTSC;
> +		vc->width = TW686X_VIDEO_WIDTH;
> +		vc->height = TW686X_VIDEO_HEIGHT(vc->video_standard);
> +		vc->input = 0;
> +
> +		reg_write(vc->dev, SDT[ch], 0);
> +		tw686x_set_framerate(vc, 30);
> +
> +		reg_write(dev, VDELAY_LO[ch], 0x14);
> +		reg_write(dev, HACTIVE_LO[ch], 0xD0);
> +		reg_write(dev, VIDEO_SIZE[ch], 0);
> +
> +		for (pb = 0; pb < 2; pb++) {
> +			err = tw686x_alloc_dma(vc, pb);
> +			if (err)
> +				goto error;
> +		}
> +
> +		vdev = video_device_alloc();
> +		if (!vdev) {
> +			v4l2_err(&dev->v4l2_dev, "dma%d: unable to allocate device\n", ch);
> +			err = -ENOMEM;
> +			goto error;
> +		}
> +
> +		vc->vidq.io_modes = VB2_READ | VB2_MMAP | VB2_DMABUF;
> +		vc->vidq.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +		vc->vidq.drv_priv = vc;
> +		vc->vidq.buf_struct_size = sizeof(struct tw686x_v4l2_buf);
> +		vc->vidq.ops = &tw686x_video_qops;
> +		vc->vidq.mem_ops = &vb2_vmalloc_memops;
> +		vc->vidq.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> +		vc->vidq.min_buffers_needed = 2;
> +		vc->vidq.lock = &vc->vb_mutex;
> +
> +		err = vb2_queue_init(&vc->vidq);
> +		if (err)
> +			goto error;
> +
> +		snprintf(vdev->name, sizeof(vdev->name), "%s video", dev->name);
> +		vdev->fops = &tw686x_video_fops;
> +		vdev->ioctl_ops = &tw686x_video_ioctl_ops;
> +		vdev->release = video_device_release;
> +		vdev->v4l2_dev = &dev->v4l2_dev;
> +		vdev->queue = &vc->vidq;
> +		vdev->tvnorms = V4L2_STD_525_60 | V4L2_STD_625_50;
> +		vdev->minor = -1;
> +		vdev->lock = &vc->vb_mutex;
> +		vc->device = vdev;
> +		video_set_drvdata(vdev, vc);
> +		err = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
> +		if (err < 0)
> +			goto error;

Move this down to the end of the loop. Userspace can use the video device
as soon as it is created, so it is wise to create it only after everything
else has been configured.

> +		vc->num = vdev->num;
> +
> +		err = v4l2_ctrl_handler_init(&vc->ctrl_handler, 4);
> +		if (err) {
> +			v4l2_err(&dev->v4l2_dev,
> +				 "video%d: cannot init ctrl handler\n",
> +				 vc->num);
> +			goto error;
> +		}
> +		vdev->ctrl_handler = &vc->ctrl_handler;
> +		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
> +				  V4L2_CID_BRIGHTNESS, -128, 127, 1, 0);
> +		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
> +				  V4L2_CID_CONTRAST, 0, 255, 1, 100);
> +		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
> +				  V4L2_CID_SATURATION, 0, 255, 1, 128);
> +		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
> +				  V4L2_CID_HUE, -128, 127, 1, 0);
> +		err = vc->ctrl_handler.error;
> +		if (err)
> +			goto error;
> +
> +		err = v4l2_ctrl_handler_setup(&vc->ctrl_handler);
> +		if (err)
> +			goto error;
> +	}
> +
> +	/* Set DMA frame mode on all channels. Only supported mode for now. */
> +	val = TW686X_DEF_PHASE_REF;
> +	for (ch = 0; ch < max_channels(dev); ch++)
> +		val |= TW686X_FRAME_MODE << (16 + ch * 2);
> +	reg_write(dev, PHASE_REF, val);
> +
> +	reg_write(dev, MISC2[0], 0xE7);
> +	reg_write(dev, VCTRL1[0], 0xCC);
> +	reg_write(dev, LOOP[0], 0xA5);
> +	if (max_channels(dev) > 4) {
> +		reg_write(dev, VCTRL1[1], 0xCC);
> +		reg_write(dev, LOOP[1], 0xA5);
> +		reg_write(dev, MISC2[1], 0xE7);
> +	}
> +	return 0;
> +
> +error:
> +	tw686x_video_free(dev);
> +	return err;
> +}
> diff --git a/drivers/media/pci/tw686x/tw686x.h b/drivers/media/pci/tw686x/tw686x.h
> new file mode 100644
> index 000000000000..0ffb0be84aa2
> --- /dev/null
> +++ b/drivers/media/pci/tw686x/tw686x.h
> @@ -0,0 +1,189 @@
> +/*
> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
> + *
> + * Copyright (C) 2015 Industrial Research Institute for Automation
> + * and Measurements PIAP
> + * Written by Krzysztof Ha?asa
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of version 2 of the GNU General Public License
> + * as published by the Free Software Foundation.
> + */
> +
> +#include <linux/mutex.h>
> +#include <linux/pci.h>
> +#include <linux/timer.h>
> +#include <linux/videodev2.h>
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/videobuf2-v4l2.h>
> +#include <sound/pcm.h>
> +
> +#include "tw686x-regs.h"
> +
> +#define TYPE_MAX_CHANNELS	0x0F
> +#define TYPE_SECOND_GEN		0x10
> +#define TW686X_DEF_PHASE_REF	0x1518
> +
> +#define TW686X_FIELD_MODE	0x3
> +#define TW686X_FRAME_MODE	0x2
> +/* 0x1 is reserved */
> +#define TW686X_SG_MODE		0x0
> +
> +#define TW686X_PAGE_SIZE	4096
> +#define TW686X_AUDIO_PAGE_MAX	16
> +
> +struct tw686x_format {
> +	char *name;
> +	unsigned fourcc;
> +	unsigned depth;
> +	unsigned mode;
> +};
> +
> +struct tw686x_dma_desc {
> +	dma_addr_t phys;
> +	void *virt;
> +	unsigned size;
> +};
> +
> +struct tw686x_audio_buf {
> +	dma_addr_t dma;
> +	void *virt;
> +	struct list_head list;
> +};
> +
> +struct tw686x_v4l2_buf {
> +	struct vb2_v4l2_buffer vb;
> +	struct list_head list;
> +};
> +
> +struct tw686x_audio_channel {
> +	struct tw686x_dev *dev;
> +	struct snd_pcm_substream *ss;
> +	unsigned int ch;
> +	struct tw686x_audio_buf *curr_bufs[2];
> +	struct tw686x_dma_desc dma_descs[2];
> +	dma_addr_t ptr;
> +
> +	struct tw686x_audio_buf buf[TW686X_AUDIO_PAGE_MAX];
> +	struct list_head buf_list;
> +	spinlock_t lock;
> +};
> +
> +struct tw686x_video_channel {
> +	struct tw686x_dev *dev;
> +
> +	struct vb2_queue vidq;
> +	struct list_head vidq_queued;
> +	struct video_device *device;
> +	struct tw686x_v4l2_buf *curr_bufs[2];
> +	struct tw686x_dma_desc dma_descs[2];
> +
> +	struct v4l2_ctrl_handler ctrl_handler;
> +	const struct tw686x_format *format;
> +	struct mutex vb_mutex;
> +	spinlock_t qlock;
> +	v4l2_std_id video_standard;
> +	unsigned int width, height;
> +	unsigned int h_halve, v_halve;
> +	unsigned int ch;
> +	unsigned int num;
> +	unsigned int fps;
> +	unsigned int input;
> +	unsigned int sequence;
> +	unsigned int pb;
> +	bool no_signal;
> +};
> +
> +/**
> + * struct tw686x_dev - global device status
> + * @lock: spinlock controlling access to the
> + *        shared device registers (DMA enable/disable).
> + */
> +struct tw686x_dev {
> +	spinlock_t lock;
> +
> +	struct v4l2_device v4l2_dev;
> +	struct snd_card *snd_card;
> +
> +	char name[32];
> +	unsigned int type;
> +	struct pci_dev *pci_dev;
> +	__u32 __iomem *mmio;
> +
> +	void *alloc_ctx;
> +
> +	struct tw686x_video_channel *video_channels;
> +	struct tw686x_audio_channel *audio_channels;
> +
> +	int audio_rate; /* per-device value */
> +
> +	struct timer_list dma_delay_timer;
> +	u32 pending_dma_en; /* must be protected by lock */
> +	u32 pending_dma_cmd; /* must be protected by lock */
> +};
> +
> +static inline uint32_t reg_read(struct tw686x_dev *dev, unsigned reg)
> +{
> +	return readl(dev->mmio + reg);
> +}
> +
> +static inline void reg_write(struct tw686x_dev *dev, unsigned reg,
> +			     uint32_t value)
> +{
> +	writel(value, dev->mmio + reg);
> +}
> +
> +static inline void tw686x_disable_channel(struct tw686x_dev *dev,
> +					  unsigned int channel)
> +{
> +	u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
> +	u32 dma_cmd = reg_read(dev, DMA_CMD);
> +
> +	dma_en &= ~BIT(channel);
> +	dma_cmd &= ~BIT(channel);
> +
> +	/* Must remove it from pending too */
> +	dev->pending_dma_en &= ~BIT(channel);
> +	dev->pending_dma_cmd &= ~BIT(channel);
> +
> +	/* Stop DMA if no channels are enabled */
> +	if (!dma_en)
> +		dma_cmd = 0;
> +	reg_write(dev, DMA_CHANNEL_ENABLE, dma_en);
> +	reg_write(dev, DMA_CMD, dma_cmd);
> +}
> +
> +static inline void tw686x_enable_channel(struct tw686x_dev *dev,
> +					 unsigned int channel)
> +{
> +	u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
> +	u32 dma_cmd = reg_read(dev, DMA_CMD);
> +
> +	dev->pending_dma_en |= dma_en | BIT(channel);
> +	dev->pending_dma_cmd |= dma_cmd | BIT(31) | BIT(channel);
> +}

I think these should be normal functions. I see no reason for en/disabling
channel to be inline.

> +
> +static inline unsigned max_channels(struct tw686x_dev *dev)
> +{
> +	return dev->type & TYPE_MAX_CHANNELS; /* 4 or 8 channels */
> +}
> +
> +static inline unsigned is_second_gen(struct tw686x_dev *dev)
> +{
> +	/* each channel has its own DMA SG table */
> +	return dev->type & TYPE_SECOND_GEN;
> +}
> +
> +int tw686x_video_init(struct tw686x_dev *dev);
> +void tw686x_video_free(struct tw686x_dev *dev);
> +void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
> +		      unsigned int pb_status, unsigned int fifo_status,
> +		      unsigned int *reset_ch);
> +
> +int tw686x_audio_init(struct tw686x_dev *dev);
> +void tw686x_audio_free(struct tw686x_dev *dev);
> +void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
> +		      unsigned int pb_status);
> 

Regards,

	Hans
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Ezequiel Garcia Jan. 18, 2016, 3:20 p.m. UTC | #2
Hi Hans,

On 18 January 2016 at 10:02, Hans Verkuil <hverkuil@xs4all.nl> wrote:
> Hi Ezequiel,
>
> Thanks for working on this! Do you know where I can get a board tw686x board?
> I always like to have hardware to test the driver, if at all possible.
>

No, I don't know. I have one to spare, and I could send it to you.

> See below for a review of this driver.
>
> On 12/27/2015 03:26 AM, Ezequiel Garcia wrote:
>> This commit introduces the support for the Techwell TW686x video
>> capture IC. This hardware supports a few DMA modes, including
>> scatter-gather and frame (contiguous).
>>
>> This commit supports only DMA frame (contiguous) mode.
>> DMA scatter-gather mode support may be added in the future.
>>
>> Currently supported chips:
>> - TW6864 (4 video channels),
>> - TW6865 (4 video channels, not tested, second generation chip),
>> - TW6868 (8 video channels but only 4 first channels using
>>            built-in video decoder are supported, not tested),
>> - TW6869 (8 video channels, second generation chip).
>>
>> Cc: Krzysztof Ha?asa <khalasa@piap.pl>
>> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
>> ---
>> This patchset superseeds Krzysztof's original patch:
>> https://patchwork.linuxtv.org/patch/30448/
>>
>> Tested on a custom TW6869-based capture card.
>> Latest v4l2-compliance test pass:
>>
>> $ /usr/bin/v4l2-compliance -f -s
>> Driver Info:
>>       Driver name   : tw686x
>>       Card type     : tw6869
>>       Bus info      : PCI:0000:04:00.0
>>       Driver version: 4.4.0
>>       Capabilities  : 0x85200001
>>               Video Capture
>>               Read/Write
>>               Streaming
>>               Extended Pix Format
>>               Device Capabilities
>>       Device Caps   : 0x05200001
>>               Video Capture
>>               Read/Write
>>               Streaming
>>               Extended Pix Format
>>
>> Compliance test for device /dev/video0 (not using libv4l2):
>>
>> [..]
>> Test input 0:
>>
>> Streaming ioctls:
>>       test read/write: OK
>>       test MMAP: OK
>>       test USERPTR: OK (Not Supported)
>>       test DMABUF: Cannot test, specify --expbuf-device
>>
>> Stream using all formats:
>>       test MMAP for Format UYVY, Frame Size 360x240:
>>               Stride 720, Field Interlaced: OK
>>       test MMAP for Format UYVY, Frame Size 720x480:
>>               Stride 1440, Field Interlaced: OK
>>       test MMAP for Format RGBP, Frame Size 360x240:
>>               Stride 720, Field Interlaced: OK
>>       test MMAP for Format RGBP, Frame Size 720x480:
>>               Stride 1440, Field Interlaced: OK
>>       test MMAP for Format YUYV, Frame Size 360x240:
>>               Stride 720, Field Interlaced: OK
>>       test MMAP for Format YUYV, Frame Size 720x480:
>>               Stride 1440, Field Interlaced: OK
>>
>> Total: 114, Succeeded: 114, Failed: 0, Warnings: 0
>> ---
>>  MAINTAINERS                             |   8 +
>>  drivers/media/pci/Kconfig               |   1 +
>>  drivers/media/pci/Makefile              |   1 +
>>  drivers/media/pci/tw686x/Kconfig        |  18 +
>>  drivers/media/pci/tw686x/Makefile       |   3 +
>>  drivers/media/pci/tw686x/tw686x-audio.c | 379 +++++++++++++
>>  drivers/media/pci/tw686x/tw686x-core.c  | 356 ++++++++++++
>>  drivers/media/pci/tw686x/tw686x-regs.h  | 118 ++++
>>  drivers/media/pci/tw686x/tw686x-video.c | 953 ++++++++++++++++++++++++++++++++
>>  drivers/media/pci/tw686x/tw686x.h       | 189 +++++++
>>  10 files changed, 2026 insertions(+)
>>  create mode 100644 drivers/media/pci/tw686x/Kconfig
>>  create mode 100644 drivers/media/pci/tw686x/Makefile
>>  create mode 100644 drivers/media/pci/tw686x/tw686x-audio.c
>>  create mode 100644 drivers/media/pci/tw686x/tw686x-core.c
>>  create mode 100644 drivers/media/pci/tw686x/tw686x-regs.h
>>  create mode 100644 drivers/media/pci/tw686x/tw686x-video.c
>>  create mode 100644 drivers/media/pci/tw686x/tw686x.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 4635e1d14612..9308f8242cd3 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10846,6 +10846,14 @@ W:   https://linuxtv.org
>>  S:   Odd Fixes
>>  F:   drivers/media/pci/tw68/
>>
>> +TW686X VIDEO4LINUX DRIVER
>> +M:   Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
>> +L:   linux-media@vger.kernel.org
>> +T:   git git://linuxtv.org/media_tree.git
>> +W:   http://linuxtv.org
>> +S:   Maintained
>> +F:   drivers/media/pci/tw686x/
>> +
>>  TPM DEVICE DRIVER
>>  M:   Peter Huewe <peterhuewe@gmx.de>
>>  M:   Marcel Selhorst <tpmdd@selhorst.net>
>> diff --git a/drivers/media/pci/Kconfig b/drivers/media/pci/Kconfig
>> index 48a611bc3e18..4f6467fbaeb4 100644
>> --- a/drivers/media/pci/Kconfig
>> +++ b/drivers/media/pci/Kconfig
>> @@ -14,6 +14,7 @@ source "drivers/media/pci/meye/Kconfig"
>>  source "drivers/media/pci/solo6x10/Kconfig"
>>  source "drivers/media/pci/sta2x11/Kconfig"
>>  source "drivers/media/pci/tw68/Kconfig"
>> +source "drivers/media/pci/tw686x/Kconfig"
>>  source "drivers/media/pci/zoran/Kconfig"
>>  endif
>>
>> diff --git a/drivers/media/pci/Makefile b/drivers/media/pci/Makefile
>> index 5f8aacb8b9b8..2e54c36441f7 100644
>> --- a/drivers/media/pci/Makefile
>> +++ b/drivers/media/pci/Makefile
>> @@ -25,6 +25,7 @@ obj-$(CONFIG_VIDEO_BT848) += bt8xx/
>>  obj-$(CONFIG_VIDEO_SAA7134) += saa7134/
>>  obj-$(CONFIG_VIDEO_SAA7164) += saa7164/
>>  obj-$(CONFIG_VIDEO_TW68) += tw68/
>> +obj-$(CONFIG_VIDEO_TW686X) += tw686x/
>>  obj-$(CONFIG_VIDEO_DT3155) += dt3155/
>>  obj-$(CONFIG_VIDEO_MEYE) += meye/
>>  obj-$(CONFIG_STA2X11_VIP) += sta2x11/
>> diff --git a/drivers/media/pci/tw686x/Kconfig b/drivers/media/pci/tw686x/Kconfig
>> new file mode 100644
>> index 000000000000..bd73d3dd25b4
>> --- /dev/null
>> +++ b/drivers/media/pci/tw686x/Kconfig
>> @@ -0,0 +1,18 @@
>> +config VIDEO_TW686X
>> +     tristate "Intersil/Techwell TW686x video capture cards"
>> +     depends on PCI && VIDEO_DEV && VIDEO_V4L2 && SND
>> +     depends on HAS_DMA
>> +     select VIDEOBUF2_DMA_CONTIG
>> +     select SND_PCM
>> +     help
>> +       Support for Intersil/Techwell TW686x-based frame grabber cards.
>> +
>> +       Currently supported chips:
>> +       - TW6864 (4 video channels),
>> +       - TW6865 (4 video channels, not tested, second generation chip),
>> +       - TW6868 (8 video channels but only 4 first channels using
>> +         built-in video decoder are supported, not tested),
>> +       - TW6869 (8 video channels, second generation chip).
>> +
>> +       To compile this driver as a module, choose M here: the module
>> +       will be named tw686x.
>> diff --git a/drivers/media/pci/tw686x/Makefile b/drivers/media/pci/tw686x/Makefile
>> new file mode 100644
>> index 000000000000..99819542b733
>> --- /dev/null
>> +++ b/drivers/media/pci/tw686x/Makefile
>> @@ -0,0 +1,3 @@
>> +tw686x-objs := tw686x-core.o tw686x-video.o tw686x-audio.o
>> +
>> +obj-$(CONFIG_VIDEO_TW686X) += tw686x.o
>> diff --git a/drivers/media/pci/tw686x/tw686x-audio.c b/drivers/media/pci/tw686x/tw686x-audio.c
>> new file mode 100644
>> index 000000000000..2295d2d1a945
>> --- /dev/null
>> +++ b/drivers/media/pci/tw686x/tw686x-audio.c
>> @@ -0,0 +1,379 @@
>> +/*
>> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
>> + *
>> + * Based on the audio support from the tw6869 driver:
>> + * Copyright 2015 www.starterkit.ru <info@starterkit.ru>
>> + *
>> + * Based on:
>> + * Driver for Intersil|Techwell TW6869 based DVR cards
>> + * (c) 2011-12 liran <jli11@intersil.com> [Intersil|Techwell China]
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms of version 2 of the GNU General Public License
>> + * as published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/types.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/init.h>
>> +#include <linux/kmod.h>
>> +#include <linux/mutex.h>
>> +#include <linux/pci.h>
>> +#include <linux/delay.h>
>> +
>> +#include <sound/core.h>
>> +#include <sound/initval.h>
>> +#include <sound/pcm.h>
>> +#include <sound/control.h>
>> +#include "tw686x.h"
>> +#include "tw686x-regs.h"
>> +
>> +#define AUDIO_CHANNEL_OFFSET 8
>> +
>> +void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
>> +                   unsigned int pb_status)
>> +{
>> +     unsigned long flags;
>> +     unsigned int ch, pb;
>> +
>> +     for_each_set_bit(ch, &requests, max_channels(dev)) {
>> +
>
> Remove this empty line.
>

Sure.

>> +             struct tw686x_audio_channel *ac = &dev->audio_channels[ch];
>> +             struct tw686x_audio_buf *done = NULL;
>> +             struct tw686x_audio_buf *next = NULL;
>> +             struct tw686x_dma_desc *desc;
>> +
>> +             pb = !!(pb_status & BIT(AUDIO_CHANNEL_OFFSET + ch));
>> +
>> +             spin_lock_irqsave(&ac->lock, flags);
>> +
>> +             /* Sanity check */
>> +             if (!ac->ss || !ac->curr_bufs[0] || !ac->curr_bufs[1]) {
>> +                     spin_unlock_irqrestore(&ac->lock, flags);
>> +                     continue;
>> +             }
>> +
>> +             if (!list_empty(&ac->buf_list)) {
>> +                     next = list_first_entry(&ac->buf_list,
>> +                                     struct tw686x_audio_buf, list);
>> +                     list_move_tail(&next->list, &ac->buf_list);
>> +                     done = ac->curr_bufs[!pb];
>> +                     ac->curr_bufs[pb] = next;
>> +             }
>> +             spin_unlock_irqrestore(&ac->lock, flags);
>> +
>> +             desc = &ac->dma_descs[pb];
>> +             if (done && next && desc->virt) {
>> +                     memcpy(done->virt, desc->virt, desc->size);
>> +                     ac->ptr = done->dma - ac->buf[0].dma;
>> +                     snd_pcm_period_elapsed(ac->ss);
>> +             }
>> +     }
>> +}
>> +
>> +static int tw686x_pcm_hw_params(struct snd_pcm_substream *ss,
>> +                             struct snd_pcm_hw_params *hw_params)
>> +{
>> +     return snd_pcm_lib_malloc_pages(ss, params_buffer_bytes(hw_params));
>> +}
>> +
>> +static int tw686x_pcm_hw_free(struct snd_pcm_substream *ss)
>> +{
>> +     return snd_pcm_lib_free_pages(ss);
>> +}
>> +
>> +static const struct snd_pcm_hardware tw686x_capture_hw = {
>> +     .info                   = (SNDRV_PCM_INFO_MMAP |
>> +                                SNDRV_PCM_INFO_INTERLEAVED |
>> +                                SNDRV_PCM_INFO_BLOCK_TRANSFER |
>> +                                SNDRV_PCM_INFO_MMAP_VALID),
>> +     .formats                = SNDRV_PCM_FMTBIT_S16_LE,
>> +     .rates                  = SNDRV_PCM_RATE_8000_48000,
>> +     .rate_min               = 8000,
>> +     .rate_max               = 48000,
>> +     .channels_min           = 1,
>> +     .channels_max           = 1,
>> +     .buffer_bytes_max       = TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE,
>> +     .period_bytes_min       = TW686X_PAGE_SIZE,
>> +     .period_bytes_max       = TW686X_PAGE_SIZE,
>> +     .periods_min            = 2,
>> +     .periods_max            = TW686X_AUDIO_PAGE_MAX,
>> +};
>> +
>> +static int tw686x_pcm_open(struct snd_pcm_substream *ss)
>> +{
>> +     struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
>> +     struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
>> +     struct snd_pcm_runtime *rt = ss->runtime;
>> +     int err;
>> +
>> +     ac->ss = ss;
>> +     rt->hw = tw686x_capture_hw;
>> +
>> +     err = snd_pcm_hw_constraint_integer(rt, SNDRV_PCM_HW_PARAM_PERIODS);
>> +     if (err < 0)
>> +             return err;
>> +
>> +     return 0;
>> +}
>> +
>> +static int tw686x_pcm_close(struct snd_pcm_substream *ss)
>> +{
>> +     struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
>> +     struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
>> +
>> +     ac->ss = NULL;
>> +     return 0;
>> +}
>> +
>> +static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
>> +{
>> +     struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
>> +     struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
>> +     struct snd_pcm_runtime *rt = ss->runtime;
>> +     unsigned int period_size = snd_pcm_lib_period_bytes(ss);
>> +     struct tw686x_audio_buf *p_buf, *b_buf;
>> +     unsigned long flags;
>> +     int i;
>> +
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +
>> +     if (dev->audio_rate != rt->rate) {
>> +             u32 reg;
>> +
>> +             dev->audio_rate = rt->rate;
>> +             reg = ((125000000 / rt->rate) << 16) +
>> +                    ((125000000 % rt->rate) << 16) / rt->rate;
>> +
>> +             reg_write(dev, AUDIO_CONTROL2, reg);
>> +     }
>> +
>> +     if ((period_size != TW686X_PAGE_SIZE) ||
>> +         (rt->periods < 2) || (rt->periods > TW686X_AUDIO_PAGE_MAX)) {
>
> There is no need for the extra parenthesis around simple comparisons.
>

OK.

>> +             return -EINVAL;
>> +     }
>> +
>> +     spin_lock_irqsave(&ac->lock, flags);
>> +     INIT_LIST_HEAD(&ac->buf_list);
>> +
>> +     for (i = 0; i < rt->periods; i++) {
>> +             ac->buf[i].dma = rt->dma_addr + period_size * i;
>> +             ac->buf[i].virt = rt->dma_area + period_size * i;
>> +             INIT_LIST_HEAD(&ac->buf[i].list);
>> +             list_add_tail(&ac->buf[i].list, &ac->buf_list);
>> +     }
>> +
>> +     p_buf = list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
>> +     list_move_tail(&p_buf->list, &ac->buf_list);
>> +
>> +     b_buf = list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
>> +     list_move_tail(&b_buf->list, &ac->buf_list);
>> +
>> +     ac->curr_bufs[0] = p_buf;
>> +     ac->curr_bufs[1] = b_buf;
>> +     ac->ptr = 0;
>> +     spin_unlock_irqrestore(&ac->lock, flags);
>> +
>> +     return 0;
>> +}
>> +
>> +static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
>> +{
>> +     struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
>> +     struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
>> +     unsigned long flags;
>> +     int err = 0;
>> +
>> +     switch (cmd) {
>> +     case SNDRV_PCM_TRIGGER_START:
>> +             if (ac->curr_bufs[0] && ac->curr_bufs[1]) {
>> +                     spin_lock_irqsave(&dev->lock, flags);
>> +                     tw686x_enable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
>> +                     spin_unlock_irqrestore(&dev->lock, flags);
>> +
>> +                     mod_timer(&dev->dma_delay_timer,
>> +                               jiffies + msecs_to_jiffies(100));
>> +             } else {
>> +                     err = -EIO;
>> +             }
>> +             break;
>> +     case SNDRV_PCM_TRIGGER_STOP:
>> +             spin_lock_irqsave(&dev->lock, flags);
>> +             tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
>> +             spin_unlock_irqrestore(&dev->lock, flags);
>> +
>> +             spin_lock_irqsave(&ac->lock, flags);
>> +             ac->curr_bufs[0] = NULL;
>> +             ac->curr_bufs[1] = NULL;
>> +             spin_unlock_irqrestore(&ac->lock, flags);
>> +             break;
>> +     default:
>> +             err = -EINVAL;
>> +     }
>> +     return err;
>> +}
>> +
>> +static snd_pcm_uframes_t tw686x_pcm_pointer(struct snd_pcm_substream *ss)
>> +{
>> +     struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
>> +     struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
>> +
>> +     return bytes_to_frames(ss->runtime, ac->ptr);
>> +}
>> +
>> +static struct snd_pcm_ops tw686x_pcm_ops = {
>> +     .open = tw686x_pcm_open,
>> +     .close = tw686x_pcm_close,
>> +     .ioctl = snd_pcm_lib_ioctl,
>> +     .hw_params = tw686x_pcm_hw_params,
>> +     .hw_free = tw686x_pcm_hw_free,
>> +     .prepare = tw686x_pcm_prepare,
>> +     .trigger = tw686x_pcm_trigger,
>> +     .pointer = tw686x_pcm_pointer,
>> +};
>> +
>> +static int tw686x_snd_pcm_init(struct tw686x_dev *dev)
>> +{
>> +     struct snd_card *card = dev->snd_card;
>> +     struct snd_pcm *pcm;
>> +     struct snd_pcm_substream *ss;
>> +     unsigned int i;
>> +     int err;
>> +
>> +     err = snd_pcm_new(card, card->driver, 0, 0, max_channels(dev), &pcm);
>> +     if (err < 0)
>> +             return err;
>> +
>> +     snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &tw686x_pcm_ops);
>> +     snd_pcm_chip(pcm) = dev;
>> +     pcm->info_flags = 0;
>> +     strcpy(pcm->name, "tw686x PCM");
>
> strlcpy
>

OK.

>> +
>> +     for (i = 0, ss = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
>> +          ss; ss = ss->next, i++)
>> +             sprintf(ss->name, "vch%u audio", i);
>
> snprintf
>

OK.

>> +
>> +     return snd_pcm_lib_preallocate_pages_for_all(pcm,
>> +                             SNDRV_DMA_TYPE_DEV,
>> +                             snd_dma_pci_data(dev->pci_dev),
>> +                             TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE,
>> +                             TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE);
>> +}
>> +
>> +static void tw686x_audio_dma_free(struct tw686x_dev *dev,
>> +                               struct tw686x_audio_channel *ac)
>> +{
>> +     int pb;
>> +
>> +     for (pb = 0; pb < 2; pb++) {
>> +             if (!ac->dma_descs[pb].virt)
>> +                     continue;
>> +             pci_free_consistent(dev->pci_dev, ac->dma_descs[pb].size,
>> +                                 ac->dma_descs[pb].virt,
>> +                                 ac->dma_descs[pb].phys);
>> +             ac->dma_descs[pb].virt = NULL;
>> +     }
>> +}
>> +
>> +static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
>> +                               struct tw686x_audio_channel *ac)
>> +{
>> +     int pb;
>> +
>> +     for (pb = 0; pb < 2; pb++) {
>> +             u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch];
>> +             void *virt;
>> +
>> +             virt = pci_alloc_consistent(dev->pci_dev, TW686X_PAGE_SIZE,
>> +                                         &ac->dma_descs[pb].phys);
>> +             if (!virt) {
>> +                     dev_err(&dev->pci_dev->dev,
>> +                             "dma%d: unable to allocate audio DMA %s-buffer\n",
>> +                             ac->ch, pb ? "B" : "P");
>> +                     return -ENOMEM;
>> +             }
>> +             ac->dma_descs[pb].virt = virt;
>> +             ac->dma_descs[pb].size = TW686X_PAGE_SIZE;
>> +             reg_write(dev, reg, ac->dma_descs[pb].phys);
>> +     }
>> +     return 0;
>> +}
>> +
>> +void tw686x_audio_free(struct tw686x_dev *dev)
>> +{
>> +     unsigned long flags;
>> +     u32 dma_ch_mask;
>> +     u32 dma_cmd;
>> +
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     dma_cmd = reg_read(dev, DMA_CMD);
>> +     dma_ch_mask = reg_read(dev, DMA_CHANNEL_ENABLE);
>> +     reg_write(dev, DMA_CMD, dma_cmd & ~0xff00);
>> +     reg_write(dev, DMA_CHANNEL_ENABLE, dma_ch_mask & ~0xff00);
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +
>> +     if (!dev->snd_card)
>> +             return;
>> +     snd_card_free(dev->snd_card);
>> +     dev->snd_card = NULL;
>> +}
>> +
>> +int tw686x_audio_init(struct tw686x_dev *dev)
>> +{
>> +     struct pci_dev *pci_dev = dev->pci_dev;
>> +     struct snd_card *card;
>> +     int err, ch;
>> +
>> +     /*
>> +      * AUDIO_CONTROL1
>> +      * DMA byte length [31:19] = 4096 (i.e. ALSA period)
>> +      * External audio enable [0] = enabled
>> +      */
>> +     reg_write(dev, AUDIO_CONTROL1, 0x80000001);
>> +
>> +     err = snd_card_new(&pci_dev->dev, SNDRV_DEFAULT_IDX1,
>> +                        SNDRV_DEFAULT_STR1,
>> +                        THIS_MODULE, 0, &card);
>> +     if (err < 0)
>> +             return err;
>> +
>> +     dev->snd_card = card;
>> +     strcpy(card->driver, "tw686x");
>> +     strcpy(card->shortname, "tw686x");
>> +     sprintf(card->longname, "%s", pci_name(pci_dev));
>
> Use strlcpy and snprintf.
>

OK.

>> +     snd_card_set_dev(card, &pci_dev->dev);
>> +
>> +     for (ch = 0; ch < max_channels(dev); ch++) {
>> +             struct tw686x_audio_channel *ac;
>> +
>> +             ac = &dev->audio_channels[ch];
>> +             spin_lock_init(&ac->lock);
>> +             ac->dev = dev;
>> +             ac->ch = ch;
>> +
>> +             err = tw686x_audio_dma_alloc(dev, ac);
>> +             if (err < 0)
>> +                     goto err_cleanup;
>> +     }
>> +
>> +     err = tw686x_snd_pcm_init(dev);
>> +     if (err < 0)
>> +             goto err_cleanup;
>> +
>> +     err = snd_card_register(card);
>> +     if (!err)
>> +             return 0;
>> +
>> +err_cleanup:
>> +     for (ch = 0; ch < max_channels(dev); ch++) {
>> +             if (!dev->audio_channels[ch].dev)
>> +                     continue;
>> +             tw686x_audio_dma_free(dev, &dev->audio_channels[ch]);
>> +     }
>> +     snd_card_free(card);
>> +     dev->snd_card = NULL;
>> +     return err;
>> +}
>> diff --git a/drivers/media/pci/tw686x/tw686x-core.c b/drivers/media/pci/tw686x/tw686x-core.c
>> new file mode 100644
>> index 000000000000..8774facb29d5
>> --- /dev/null
>> +++ b/drivers/media/pci/tw686x/tw686x-core.c
>> @@ -0,0 +1,356 @@
>> +/*
>> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
>> + *
>> + * Based on original driver by Krzysztof Ha?asa:
>> + * Copyright (C) 2015 Industrial Research Institute for Automation
>> + * and Measurements PIAP
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms of version 2 of the GNU General Public License
>> + * as published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/delay.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/pci_ids.h>
>> +#include <linux/slab.h>
>> +#include <linux/timer.h>
>> +
>> +#include "tw686x.h"
>> +#include "tw686x-regs.h"
>> +
>> +static u32 dma_interval = 0x00098968;
>> +module_param(dma_interval, int, 0444);
>> +MODULE_PARM_DESC(dma_interval, "Minimum time span for DMA interrupting host");
>> +
>> +/*
>> + * The purpose of this awful hack is to avoid
>> + * enabling the DMA channels "too fast" which seems
>> + * to make some TW686x devices _very_ angry and freeze the CPU.
>> + */
>> +static void tw686x_dma_delay(unsigned long data)
>> +{
>> +        struct tw686x_dev *dev = (struct tw686x_dev *) data;
>
> Weird indentation, spaces instead of tab. Remove space after cast.
>

Ouch, I'll fix it.

>> +     unsigned long flags;
>> +
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +
>> +     reg_write(dev, DMA_CHANNEL_ENABLE, dev->pending_dma_en);
>> +     reg_write(dev, DMA_CMD, dev->pending_dma_cmd);
>> +     dev->pending_dma_en = 0;
>> +     dev->pending_dma_cmd = 0;
>> +
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +}
>> +
>> +static void tw686x_reset_channels(struct tw686x_dev *dev, unsigned int ch_mask)
>> +{
>> +     u32 dma_en, dma_cmd;
>> +
>> +     dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
>> +     dma_cmd = reg_read(dev, DMA_CMD);
>> +
>> +     /*
>> +      * Save pending register status, the timer will
>> +      * restore them.
>> +      */
>> +     dev->pending_dma_en |= dma_en;
>> +     dev->pending_dma_cmd |= dma_cmd;
>> +
>> +     /* Disable the reset channels */
>> +     reg_write(dev, DMA_CHANNEL_ENABLE, dma_en & ~ch_mask);
>> +
>> +     if ((dma_en & ~ch_mask) == 0) {
>> +             dev_dbg(&dev->pci_dev->dev, "reset: stopping DMA\n");
>> +             dma_cmd &= ~BIT(31);
>> +     }
>> +     reg_write(dev, DMA_CMD, dma_cmd & ~ch_mask);
>> +}
>> +
>> +static irqreturn_t tw686x_irq(int irq, void *dev_id)
>> +{
>> +     struct tw686x_dev *dev = (struct tw686x_dev *)dev_id;
>> +     unsigned int video_requests, audio_requests, reset_ch;
>> +     u32 fifo_status, fifo_signal, fifo_ov, fifo_bad, fifo_errors;
>> +     u32 int_status, dma_en, video_en, pb_status;
>> +     unsigned long flags;
>> +
>> +     int_status = reg_read(dev, INT_STATUS); /* cleared on read */
>> +     fifo_status = reg_read(dev, VIDEO_FIFO_STATUS);
>> +
>> +     /* INT_STATUS does not include FIFO_STATUS errors! */
>> +     if (!int_status && !TW686X_FIFO_ERROR(fifo_status))
>> +             return IRQ_NONE;
>> +
>> +     if (int_status & BIT(17)) {
>
> Either use a define for BIT(17) or add a comment so I know what bit 17 is.
>

Sure, I'll define it.

>> +             dev_dbg(&dev->pci_dev->dev,
>> +                     "DMA timeout. Resetting DMA for all channels\n");
>> +             reset_ch = ~0;
>> +             goto reset_channels;
>> +     }
>> +
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +
>> +     video_en = dma_en & 0xff;
>> +     fifo_signal = ~(fifo_status & 0xff) & video_en;
>> +     fifo_ov = fifo_status >> 24;
>> +     fifo_bad = fifo_status >> 16;
>> +
>> +     /* Mask of channels with signal and FIFO errors */
>> +     fifo_errors = fifo_signal & (fifo_ov | fifo_bad);
>> +
>> +     reset_ch = 0;
>> +     pb_status = reg_read(dev, PB_STATUS);
>> +
>> +     /* Coalesce video frame/error events */
>> +     video_requests = (int_status & video_en) | fifo_errors;
>> +     audio_requests = (int_status & dma_en) >> 8;
>> +
>> +     if (video_requests)
>> +             tw686x_video_irq(dev, video_requests, pb_status,
>> +                              fifo_status, &reset_ch);
>> +     if (audio_requests)
>> +             tw686x_audio_irq(dev, audio_requests, pb_status);
>> +
>> +reset_channels:
>> +     if (reset_ch) {
>> +             spin_lock_irqsave(&dev->lock, flags);
>> +             tw686x_reset_channels(dev, reset_ch);
>> +             spin_unlock_irqrestore(&dev->lock, flags);
>> +             mod_timer(&dev->dma_delay_timer,
>> +                       jiffies + msecs_to_jiffies(100));
>> +     }
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +static void tw686x_dev_release(struct v4l2_device *v4l2_dev)
>> +{
>> +        struct tw686x_dev *dev = container_of(v4l2_dev, struct tw686x_dev,
>> +                                           v4l2_dev);
>> +     unsigned int ch;
>> +
>> +     for (ch = 0; ch < max_channels(dev); ch++)
>> +             v4l2_ctrl_handler_free(&dev->video_channels[ch].ctrl_handler);
>> +
>> +     v4l2_device_unregister(&dev->v4l2_dev);
>> +
>> +     kfree(dev->audio_channels);
>> +     kfree(dev->video_channels);
>> +     kfree(dev);
>> +}
>> +
>> +static int tw686x_probe(struct pci_dev *pci_dev,
>> +                     const struct pci_device_id *pci_id)
>> +{
>> +     struct tw686x_dev *dev;
>> +     int err;
>> +
>> +     dev = kzalloc(sizeof(*dev), GFP_KERNEL);
>> +     if (!dev)
>> +             return -ENOMEM;
>> +     dev->type = pci_id->driver_data;
>> +     sprintf(dev->name, "tw%04X", pci_dev->device);
>> +
>> +     dev->video_channels = kcalloc(max_channels(dev),
>> +             sizeof(*dev->video_channels), GFP_KERNEL);
>> +     if (!dev->video_channels) {
>> +             err = -ENOMEM;
>> +             goto free_dev;
>> +     }
>> +
>> +     dev->audio_channels = kcalloc(max_channels(dev),
>> +             sizeof(*dev->audio_channels), GFP_KERNEL);
>> +     if (!dev->audio_channels) {
>> +             err = -ENOMEM;
>> +             goto free_video;
>> +     }
>> +
>> +     pr_info("%s: PCI %s, IRQ %d, MMIO 0x%lx\n", dev->name,
>> +             pci_name(pci_dev), pci_dev->irq,
>> +             (unsigned long)pci_resource_start(pci_dev, 0));
>> +
>> +     dev->pci_dev = pci_dev;
>> +     if (pci_enable_device(pci_dev)) {
>> +             err = -EIO;
>> +             goto free_audio;
>> +     }
>> +
>> +     pci_set_master(pci_dev);
>> +     err = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
>> +     if (err) {
>> +             dev_err(&pci_dev->dev, "32-bit PCI DMA not supported\n");
>> +             err = -EIO;
>> +             goto disable_pci;
>> +     }
>> +
>> +     err = pci_request_regions(pci_dev, dev->name);
>> +     if (err) {
>> +             dev_err(&pci_dev->dev, "unable to request PCI region\n");
>> +             goto disable_pci;
>> +     }
>> +
>> +     dev->mmio = pci_ioremap_bar(pci_dev, 0);
>> +     if (!dev->mmio) {
>> +             dev_err(&pci_dev->dev, "unable to remap PCI region\n");
>> +             err = -ENOMEM;
>> +             goto free_region;
>> +     }
>> +
>> +     /* Reset all subsystems */
>> +     reg_write(dev, SYS_SOFT_RST, 0x0F);
>
> The codingstyle for the kernel is to use lower case hex values, so 0x0f.
>
> Please change this throughout the source code.
>

Sure.

>> +     mdelay(1);
>> +
>> +     reg_write(dev, SRST[0], 0x3F);
>> +     if (max_channels(dev) > 4)
>> +             reg_write(dev, SRST[1], 0x3F);
>> +
>> +     /* Disable the DMA engine */
>> +     reg_write(dev, DMA_CMD, 0);
>> +     reg_write(dev, DMA_CHANNEL_ENABLE, 0);
>> +
>> +     /* Enable DMA FIFO overflow and pointer check */
>> +     reg_write(dev, DMA_CONFIG, 0xFFFFFF04);
>> +     reg_write(dev, DMA_CHANNEL_TIMEOUT, 0x140C8584);
>> +     reg_write(dev, DMA_TIMER_INTERVAL, dma_interval);
>> +
>> +     spin_lock_init(&dev->lock);
>> +
>> +     err = request_irq(pci_dev->irq, tw686x_irq, IRQF_SHARED,
>> +                       dev->name, dev);
>> +     if (err < 0) {
>> +             dev_err(&pci_dev->dev, "unable to request interrupt\n");
>> +             goto iounmap;
>> +     }
>> +
>> +     setup_timer(&dev->dma_delay_timer,
>> +                 tw686x_dma_delay, (unsigned long) dev);
>> +
>> +     /*
>> +      * This must be set right before initializing v4l2_dev.
>> +      * It's used to release resources after the last handle
>> +      * held is released.
>> +      */
>> +     dev->v4l2_dev.release = tw686x_dev_release;
>> +     err = tw686x_video_init(dev);
>> +     if (err) {
>> +             dev_err(&pci_dev->dev, "can't register video\n");
>> +             goto free_irq;
>> +     }
>> +
>> +     err = tw686x_audio_init(dev);
>> +     if (err) {
>> +             dev_warn(&pci_dev->dev, "can't register audio\n");
>> +     }
>> +
>> +     pci_set_drvdata(pci_dev, dev);
>> +     return 0;
>> +
>> +free_irq:
>> +     free_irq(pci_dev->irq, dev);
>> +iounmap:
>> +     pci_iounmap(pci_dev, dev->mmio);
>> +free_region:
>> +     pci_release_regions(pci_dev);
>> +disable_pci:
>> +     pci_disable_device(pci_dev);
>> +free_audio:
>> +     kfree(dev->audio_channels);
>> +free_video:
>> +     kfree(dev->video_channels);
>> +free_dev:
>> +     kfree(dev);
>> +     return err;
>> +}
>> +
>> +static void tw686x_remove(struct pci_dev *pci_dev)
>> +{
>> +     struct tw686x_dev *dev = pci_get_drvdata(pci_dev);
>> +     unsigned long flags;
>> +
>> +     /* This guarantees the IRQ handler is no longer running,
>> +      * which means we can kiss good-bye some resources.
>> +      */
>> +     free_irq(pci_dev->irq, dev);
>> +
>> +     tw686x_video_free(dev);
>> +     tw686x_audio_free(dev);
>> +     del_timer_sync(&dev->dma_delay_timer);
>> +
>> +     pci_iounmap(pci_dev, dev->mmio);
>> +     pci_release_regions(pci_dev);
>> +     pci_disable_device(pci_dev);
>> +
>> +     /*
>> +      * This allows to detect device is not here,
>> +      * and will be used by vb2_ops. The lock is really
>> +      * important here.
>> +      */
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     dev->pci_dev = NULL;
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>
> As you sure this is needed? Normally you can only come here if the module
> is removed, which isn't possible as long as userspace is using it. And if
> the module is removed, then vb2 shouldn't be called at all.
>
> The only exception would be if this is a hot-pluggable device, which is
> quite unlikely for a PCI device. I don't believe any of the pci drivers
> support that.
>

A previous version of the driver didn't have that. However, under certain
stress testing it was observed that the PCIe link goes down. I still have the
traces for that:

[..]
[21833.389031] pciehp 0000:13:01.0:pcie24: pcie_isr: intr_loc 100
[21833.389035] pciehp 0000:13:01.0:pcie24: Data Link Layer State change
[21833.389038] pciehp 0000:13:01.0:pcie24: slot(1-5): Link Down event
[21833.389076] pciehp 0000:13:01.0:pcie24: Disabling
domain:bus:device=0000:14:00
[21833.389078] pciehp 0000:13:01.0:pcie24: pciehp_unconfigure_device:
domain:bus:dev = 0000:14:00
[21833.389103] TW686x 0000:14:00.0: removing
[21833.416557] TW686x 0000:14:00.0: removed
[..]

I have no idea why the link goes down (hardware issue?),
but it's better to handle it gracefully :)

> Dubious code.
>
>> +
>> +        /*
>> +         * This calls tw686x_dev_release if it's the last reference.
>> +         * therwise, release is posponed until there are no users left.
>
> Typo: Otherwise ... postponed
>

Right.

>> +         */
>> +        v4l2_device_put(&dev->v4l2_dev);
>
> Again, spaces instead of tabs.
>

Will fix.

>> +}
>> +
>> +/*
>> + * On TW6864 and TW6868, all channels share the pair of video DMA SG tables,
>> + * with 10-bit start_idx and end_idx determining start and end of frame buffer
>> + * for particular channel.
>> + * TW6868 with all its 8 channels would be problematic (only 127 SG entries per
>> + * channel) but we support only 4 channels on this chip anyway (the first
>> + * 4 channels are driven with internal video decoder, the other 4 would require
>> + * an external TW286x part).
>> + *
>> + * On TW6865 and TW6869, each channel has its own DMA SG table, with indexes
>> + * starting with 0. Both chips have complete sets of internal video decoders
>> + * (respectively 4 or 8-channel).
>> + *
>> + * All chips have separate SG tables for two video frames.
>> + */
>> +
>> +/* driver_data is number of A/V channels */
>> +static const struct pci_device_id tw686x_pci_tbl[] = {
>> +     {
>> +             PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6864),
>> +             .driver_data = 4
>> +     },
>> +     {
>> +             PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6865), /* not tested */
>> +             .driver_data = 4 | TYPE_SECOND_GEN
>> +     },
>> +     /*
>> +      * TW6868 supports 8 A/V channels with an external TW2865 chip;
>> +      * not supported by the driver.
>> +      */
>> +     {
>> +             PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6868), /* not tested */
>> +             .driver_data = 4
>> +     },
>> +     {
>> +             PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6869),
>> +             .driver_data = 8 | TYPE_SECOND_GEN},
>> +     {}
>> +};
>> +MODULE_DEVICE_TABLE(pci, tw686x_pci_tbl);
>> +
>> +static struct pci_driver tw686x_pci_driver = {
>> +     .name = "tw686x",
>> +     .id_table = tw686x_pci_tbl,
>> +     .probe = tw686x_probe,
>> +     .remove = tw686x_remove,
>> +};
>> +module_pci_driver(tw686x_pci_driver);
>> +
>> +MODULE_DESCRIPTION("Driver for video frame grabber cards based on Intersil/Techwell TW686[4589]");
>> +MODULE_AUTHOR("Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>");
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/media/pci/tw686x/tw686x-regs.h b/drivers/media/pci/tw686x/tw686x-regs.h
>> new file mode 100644
>> index 000000000000..92c331ceb065
>> --- /dev/null
>> +++ b/drivers/media/pci/tw686x/tw686x-regs.h
>> @@ -0,0 +1,118 @@
>> +/* DMA controller registers */
>> +#define REG8_1(a0) ((const u16[8]){a0, a0 + 1, a0 + 2, a0 + 3,               \
>> +                                a0 + 4, a0 + 5, a0 + 6, a0 + 7})
>> +#define REG8_2(a0) ((const u16[8]){a0, a0 + 2, a0 + 4, a0 + 6,               \
>> +                                a0 + 8, a0 + 0xA, a0 + 0xC, a0 + 0xE})
>> +#define REG8_8(a0) ((const u16[8]){a0, a0 + 8, a0 + 0x10, a0 + 0x18, \
>> +                                a0 + 0x20, a0 + 0x28, a0 + 0x30, a0 + 0x38})
>> +#define INT_STATUS           0x00
>> +#define PB_STATUS            0x01
>> +#define DMA_CMD                      0x02
>> +#define VIDEO_FIFO_STATUS    0x03
>> +#define VIDEO_CHANNEL_ID     0x04
>> +#define VIDEO_PARSER_STATUS  0x05
>> +#define SYS_SOFT_RST         0x06
>> +#define DMA_PAGE_TABLE0_ADDR ((const u16[8]){0x08, 0xD0, 0xD2, 0xD4, \
>> +                                             0xD6, 0xD8, 0xDA, 0xDC})
>> +#define DMA_PAGE_TABLE1_ADDR ((const u16[8]){0x09, 0xD1, 0xD3, 0xD5, \
>> +                                             0xD7, 0xD9, 0xDB, 0xDD})
>> +#define DMA_CHANNEL_ENABLE   0x0a
>> +#define DMA_CONFIG           0x0b
>> +#define DMA_TIMER_INTERVAL   0x0c
>> +#define DMA_CHANNEL_TIMEOUT  0x0d
>> +#define VDMA_CHANNEL_CONFIG  REG8_1(0x10)
>> +#define ADMA_P_ADDR          REG8_2(0x18)
>> +#define ADMA_B_ADDR          REG8_2(0x19)
>> +#define DMA10_P_ADDR         0x28 /* ??? */
>> +#define DMA10_B_ADDR         0x29
>> +#define VIDEO_CONTROL1               0x2A
>> +#define VIDEO_CONTROL2               0x2B
>> +#define AUDIO_CONTROL1               0x2C
>> +#define AUDIO_CONTROL2               0x2D
>> +#define PHASE_REF            0x2E
>> +#define GPIO_REG             0x2F
>> +#define INTL_HBAR_CTRL               REG8_1(0x30)
>> +#define AUDIO_CONTROL3               0x38
>> +#define VIDEO_FIELD_CTRL     REG8_1(0x39)
>> +#define HSCALER_CTRL         REG8_1(0x42)
>> +#define VIDEO_SIZE           REG8_1(0x4A)
>> +#define VIDEO_SIZE_F2                REG8_1(0x52)
>> +#define MD_CONF                      REG8_1(0x60)
>> +#define MD_INIT                      REG8_1(0x68)
>> +#define MD_MAP0                      REG8_1(0x70)
>> +#define VDMA_P_ADDR          REG8_8(0x80) /* not used in DMA SG mode */
>> +#define VDMA_WHP             REG8_8(0x81)
>> +#define VDMA_B_ADDR          REG8_8(0x82)
>> +#define VDMA_F2_P_ADDR               REG8_8(0x84)
>> +#define VDMA_F2_WHP          REG8_8(0x85)
>> +#define VDMA_F2_B_ADDR               REG8_8(0x86)
>> +#define EP_REG_ADDR          0xFE
>> +#define EP_REG_DATA          0xFF
>> +
>> +/* Video decoder registers */
>> +#define VDREG8(a0) ((const u16[8]){                  \
>> +     a0 + 0x000, a0 + 0x010, a0 + 0x020, a0 + 0x030, \
>> +     a0 + 0x100, a0 + 0x110, a0 + 0x120, a0 + 0x130})
>> +#define VIDSTAT                      VDREG8(0x100)
>> +#define BRIGHT                       VDREG8(0x101)
>> +#define CONTRAST             VDREG8(0x102)
>> +#define SHARPNESS            VDREG8(0x103)
>> +#define SAT_U                        VDREG8(0x104)
>> +#define SAT_V                        VDREG8(0x105)
>> +#define HUE                  VDREG8(0x106)
>> +#define CROP_HI                      VDREG8(0x107)
>> +#define VDELAY_LO            VDREG8(0x108)
>> +#define VACTIVE_LO           VDREG8(0x109)
>> +#define HDELAY_LO            VDREG8(0x10A)
>> +#define HACTIVE_LO           VDREG8(0x10B)
>> +#define MVSN                 VDREG8(0x10C)
>> +#define STATUS2                      VDREG8(0x10C)
>> +#define SDT                  VDREG8(0x10E)
>> +#define SDT_EN                       VDREG8(0x10F)
>> +
>> +#define VSCALE_LO            VDREG8(0x144)
>> +#define SCALE_HI             VDREG8(0x145)
>> +#define HSCALE_LO            VDREG8(0x146)
>> +#define F2CROP_HI            VDREG8(0x147)
>> +#define F2VDELAY_LO          VDREG8(0x148)
>> +#define F2VACTIVE_LO         VDREG8(0x149)
>> +#define F2HDELAY_LO          VDREG8(0x14A)
>> +#define F2HACTIVE_LO         VDREG8(0x14B)
>> +#define F2VSCALE_LO          VDREG8(0x14C)
>> +#define F2SCALE_HI           VDREG8(0x14D)
>> +#define F2HSCALE_LO          VDREG8(0x14E)
>> +#define F2CNT                        VDREG8(0x14F)
>> +
>> +#define VDREG2(a0) ((const u16[2]){a0, a0 + 0x100})
>> +#define SRST                 VDREG2(0x180)
>> +#define ACNTL                        VDREG2(0x181)
>> +#define ACNTL2                       VDREG2(0x182)
>> +#define CNTRL1                       VDREG2(0x183)
>> +#define CKHY                 VDREG2(0x184)
>> +#define SHCOR                        VDREG2(0x185)
>> +#define CORING                       VDREG2(0x186)
>> +#define CLMPG                        VDREG2(0x187)
>> +#define IAGC                 VDREG2(0x188)
>> +#define VCTRL1                       VDREG2(0x18F)
>> +#define MISC1                        VDREG2(0x194)
>> +#define LOOP                 VDREG2(0x195)
>> +#define MISC2                        VDREG2(0x196)
>> +
>> +#define CLMD                 VDREG2(0x197)
>> +#define ANPWRDOWN            VDREG2(0x1ce)
>> +#define AIGAIN                       ((const u16[8]){0x1D0, 0x1D1, 0x1D2, 0x1D3, \
>> +                                             0x2D0, 0x2D1, 0x2D2, 0x2D3})
>> +
>> +#define SYS_MODE_DMA_SHIFT   13
>> +#define TW686X_VIDSTAT_HLOCK BIT(6)
>> +#define TW686X_VIDSTAT_VDLOSS        BIT(7)
>> +
>> +#define TW686X_STD_NTSC_M    0
>> +#define TW686X_STD_PAL               1
>> +#define TW686X_STD_SECAM     2
>> +#define TW686X_STD_NTSC_443  3
>> +#define TW686X_STD_PAL_M     4
>> +#define TW686X_STD_PAL_CN    5
>> +#define TW686X_STD_PAL_60    6
>> +
>> +#define TW686X_FIFO_ERROR(x) (x & ~(0xFF))
>> diff --git a/drivers/media/pci/tw686x/tw686x-video.c b/drivers/media/pci/tw686x/tw686x-video.c
>> new file mode 100644
>> index 000000000000..7287a9de7a1a
>> --- /dev/null
>> +++ b/drivers/media/pci/tw686x/tw686x-video.c
>> @@ -0,0 +1,953 @@
>> +/*
>> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
>> + *
>> + * Based on original driver by Krzysztof Ha?asa:
>> + * Copyright (C) 2015 Industrial Research Institute for Automation
>> + * and Measurements PIAP
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms of version 2 of the GNU General Public License
>> + * as published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/init.h>
>> +#include <linux/delay.h>
>> +#include <linux/list.h>
>> +#include <linux/module.h>
>> +#include <linux/kernel.h>
>> +#include <linux/slab.h>
>> +#include <media/v4l2-common.h>
>> +#include <media/v4l2-event.h>
>> +#include <media/videobuf2-vmalloc.h>
>> +#include "tw686x.h"
>> +#include "tw686x-regs.h"
>> +
>> +#define TW686X_INPUTS_PER_CH         4
>> +#define TW686X_VIDEO_WIDTH           720
>> +#define TW686X_VIDEO_HEIGHT(id)              ((id & V4L2_STD_625_50) ? 576 : 480)
>> +
>> +static const struct tw686x_format formats[] = {
>> +     {
>> +             .name = "4:2:2 packed, UYVY",
>> +             .fourcc = V4L2_PIX_FMT_UYVY,
>> +             .mode = 0,
>> +             .depth = 16,
>> +     }, {
>> +             .name = "16 bpp RGB",
>> +             .fourcc = V4L2_PIX_FMT_RGB565,
>> +             .mode = 5,
>> +             .depth = 16,
>> +     }, {
>> +             .name = "4:2:2 packed, YUYV",
>
> Drop name: these days this is filled in by the v4l2 core to ensure
> consistent naming.
>

OK.

>> +             .fourcc = V4L2_PIX_FMT_YUYV,
>> +             .mode = 6,
>> +             .depth = 16,
>> +     }
>> +};
>> +
>> +static unsigned int tw686x_fields_map(v4l2_std_id std, unsigned int fps)
>> +{
>> +     unsigned int map[15] = {
>> +             0x00000000, 0x00000001, 0x00004001, 0x00104001, 0x00404041,
>> +             0x01041041, 0x01104411, 0x01111111, 0x04444445, 0x04511445,
>> +             0x05145145, 0x05151515, 0x05515455, 0x05551555, 0x05555555
>> +     };
>> +
>> +     unsigned int std_625_50[26] = {
>> +             0, 1, 1, 2,  3,  3,  4,  4,  5,  5,  6,  7,  7,
>> +                8, 8, 9, 10, 10, 11, 11, 12, 13, 13, 14, 14, 0
>> +     };
>> +
>> +     unsigned int std_525_60[31] = {
>> +             0, 1, 1, 1, 2,  2,  3,  3,  4,  4,  5,  5,  6,  6, 7, 7,
>> +                8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 0, 0
>> +     };
>
> This can all be static const.
>

OK.

>> +
>> +     unsigned int i =
>> +             (std & V4L2_STD_625_50) ? std_625_50[fps] : std_525_60[fps];
>> +
>> +     return map[i];
>> +}
>> +
>> +static void tw686x_set_framerate(struct tw686x_video_channel *vc,
>> +                              unsigned int fps)
>> +{
>> +     unsigned int map;
>> +
>> +     if (vc->fps == fps)
>> +             return;
>> +
>> +     map = tw686x_fields_map(vc->video_standard, fps) << 1;
>> +     map |= map << 1;
>> +     if (map > 0)
>> +             map |= BIT(31);
>> +     reg_write(vc->dev, VIDEO_FIELD_CTRL[vc->ch], map);
>> +     vc->fps = fps;
>> +}
>> +
>> +static const struct tw686x_format *format_by_fourcc(unsigned fourcc)
>> +{
>> +     unsigned cnt;
>> +
>> +     for (cnt = 0; cnt < ARRAY_SIZE(formats); cnt++)
>> +             if (formats[cnt].fourcc == fourcc)
>> +                     return &formats[cnt];
>> +     return NULL;
>> +}
>> +
>> +static int tw686x_queue_setup(struct vb2_queue *vq,
>> +                           unsigned int *nbuffers, unsigned int *nplanes,
>> +                           unsigned int sizes[], void *alloc_ctxs[])
>> +{
>> +     struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
>> +     unsigned int szimage =
>> +             (vc->width * vc->height * vc->format->depth) >> 3;
>> +
>> +     /*
>> +      * Let's request at least three buffers: two for the
>> +      * DMA engine and one for userspace.
>> +      */
>> +     if (vq->num_buffers + *nbuffers < 3)
>> +             *nbuffers = 3 - vq->num_buffers;
>> +
>> +     if (*nplanes) {
>> +             if (*nplanes != 1 || sizes[0] < szimage)
>> +                     return -EINVAL;
>> +             return 0;
>> +     }
>> +
>> +     sizes[0] = szimage;
>> +     *nplanes = 1;
>> +     return 0;
>> +}
>> +
>> +static void tw686x_buf_queue(struct vb2_buffer *vb)
>> +{
>> +     struct tw686x_video_channel *vc = vb2_get_drv_priv(vb->vb2_queue);
>> +     struct tw686x_dev *dev = vc->dev;
>> +     struct pci_dev *pci_dev;
>> +     unsigned long flags;
>> +     struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>> +     struct tw686x_v4l2_buf *buf =
>> +             container_of(vbuf, struct tw686x_v4l2_buf, vb);
>> +
>> +     /* Check device presence */
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     pci_dev = dev->pci_dev;
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +     if (!pci_dev) {
>> +             vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
>> +             return;
>> +     }
>> +
>> +     spin_lock_irqsave(&vc->qlock, flags);
>> +     list_add_tail(&buf->list, &vc->vidq_queued);
>> +     spin_unlock_irqrestore(&vc->qlock, flags);
>> +}
>> +
>> +/*
>> + * We can call this even when alloc_dma failed for the given channel
>> + */
>> +static void tw686x_free_dma(struct tw686x_video_channel *vc, unsigned int pb)
>> +{
>> +     struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
>> +     struct tw686x_dev *dev = vc->dev;
>> +     struct pci_dev *pci_dev;
>> +     unsigned long flags;
>> +
>> +     /* Check device presence. Shouldn't really happen! */
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     pci_dev = dev->pci_dev;
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +     if (!pci_dev) {
>> +             WARN(1, "trying to deallocate on missing device\n");
>> +             return;
>> +     }
>
> Dubious code, as mentioned earlier.
>
>> +
>> +     if (desc->virt) {
>> +             pci_free_consistent(dev->pci_dev, desc->size,
>> +                                 desc->virt, desc->phys);
>> +             desc->virt = NULL;
>> +     }
>> +}
>> +
>> +static int tw686x_alloc_dma(struct tw686x_video_channel *vc, unsigned int pb)
>> +{
>> +     struct tw686x_dev *dev = vc->dev;
>> +     u32 reg = pb ? VDMA_B_ADDR[vc->ch] : VDMA_P_ADDR[vc->ch];
>> +     unsigned int len;
>> +     void *virt;
>> +
>> +     WARN(vc->dma_descs[pb].virt,
>> +          "Allocating buffer but previous still here\n");
>> +
>> +     len = (vc->width * vc->height * vc->format->depth) >> 3;
>> +     virt = pci_alloc_consistent(dev->pci_dev, len,
>> +                                 &vc->dma_descs[pb].phys);
>> +     if (!virt) {
>> +             v4l2_err(&dev->v4l2_dev, "dma%d: unable to allocate %s-buffer\n",
>> +                      vc->ch, pb ? "B" : "P");
>> +             return -ENOMEM;
>> +     }
>> +     vc->dma_descs[pb].size = len;
>> +     vc->dma_descs[pb].virt = virt;
>> +     reg_write(dev, reg, vc->dma_descs[pb].phys);
>> +
>> +     return 0;
>> +}
>> +
>> +static void tw686x_buffer_refill(struct tw686x_video_channel *vc, unsigned int pb)
>> +{
>> +     struct tw686x_v4l2_buf *buf;
>> +
>> +     while (!list_empty(&vc->vidq_queued)) {
>> +
>> +             buf = list_first_entry(&vc->vidq_queued,
>> +                     struct tw686x_v4l2_buf, list);
>> +             list_del(&buf->list);
>> +
>> +             vc->curr_bufs[pb] = buf;
>> +             return;
>> +     }
>> +     vc->curr_bufs[pb] = NULL;
>> +}
>> +
>> +static void tw686x_clear_queue(struct tw686x_video_channel *vc)
>> +{
>> +     unsigned int pb;
>> +
>> +     while (!list_empty(&vc->vidq_queued)) {
>> +             struct tw686x_v4l2_buf *buf;
>> +
>> +             buf = list_first_entry(&vc->vidq_queued,
>> +                     struct tw686x_v4l2_buf, list);
>> +             list_del(&buf->list);
>> +             vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
>> +     }
>> +
>> +     for (pb = 0; pb < 2; pb++) {
>> +             if (vc->curr_bufs[pb])
>> +                     vb2_buffer_done(&vc->curr_bufs[pb]->vb.vb2_buf,
>> +                                     VB2_BUF_STATE_ERROR);
>> +             vc->curr_bufs[pb] = NULL;
>> +     }
>> +}
>> +
>> +static int tw686x_start_streaming(struct vb2_queue *vq, unsigned int count)
>> +{
>> +     struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
>> +     struct tw686x_dev *dev = vc->dev;
>> +     struct pci_dev *pci_dev;
>> +     unsigned long flags;
>> +     int pb;
>> +
>> +     /* Check device presence */
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     pci_dev = dev->pci_dev;
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +     if (!pci_dev)
>> +             return -ENODEV;
>> +
>> +     spin_lock_irqsave(&vc->qlock, flags);
>> +
>> +     /* Sanity check */
>> +     if (!vc->dma_descs[0].virt || !vc->dma_descs[1].virt) {
>> +             spin_unlock_irqrestore(&vc->qlock, flags);
>> +             v4l2_err(&dev->v4l2_dev, "video%d: refusing to start without DMA buffers\n",
>> +                      vc->num);
>> +             return -ENOMEM;
>
> If start_streaming fails with an error, then you need to call vb2_buffer_done
> with status VB2_BUF_STATE_QUEUED for all buffers.
>

Ah, OK. Will fix it.

>> +     }
>> +
>> +     for (pb = 0; pb < 2; pb++)
>> +             tw686x_buffer_refill(vc, pb);
>> +     spin_unlock_irqrestore(&vc->qlock, flags);
>> +
>> +     vc->sequence = 0;
>> +     vc->pb = 0;
>> +
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     tw686x_enable_channel(dev, vc->ch);
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +
>> +     mod_timer(&dev->dma_delay_timer, jiffies + msecs_to_jiffies(100));
>> +
>> +     return 0;
>> +}
>> +
>> +static void tw686x_stop_streaming(struct vb2_queue *vq)
>> +{
>> +     struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
>> +     struct tw686x_dev *dev = vc->dev;
>> +     struct pci_dev *pci_dev;
>> +     unsigned long flags;
>> +
>> +     /* Check device presence */
>> +     spin_lock_irqsave(&dev->lock, flags);
>> +     pci_dev = dev->pci_dev;
>> +     spin_unlock_irqrestore(&dev->lock, flags);
>> +     if (pci_dev)
>> +             tw686x_disable_channel(dev, vc->ch);
>> +
>> +     spin_lock_irqsave(&vc->qlock, flags);
>> +     tw686x_clear_queue(vc);
>> +     spin_unlock_irqrestore(&vc->qlock, flags);
>> +}
>> +
>> +static int tw686x_buf_prepare(struct vb2_buffer *vb)
>> +{
>> +     struct tw686x_video_channel *vc = vb2_get_drv_priv(vb->vb2_queue);
>> +     unsigned int size =
>> +             (vc->width * vc->height * vc->format->depth) >> 3;
>> +
>> +     if (vb2_plane_size(vb, 0) < size)
>> +             return -EINVAL;
>> +     vb2_set_plane_payload(vb, 0, size);
>> +     return 0;
>> +}
>> +
>> +static struct vb2_ops tw686x_video_qops = {
>> +     .queue_setup            = tw686x_queue_setup,
>> +     .buf_queue              = tw686x_buf_queue,
>> +     .buf_prepare            = tw686x_buf_prepare,
>> +     .start_streaming        = tw686x_start_streaming,
>> +     .stop_streaming         = tw686x_stop_streaming,
>> +     .wait_prepare           = vb2_ops_wait_prepare,
>> +     .wait_finish            = vb2_ops_wait_finish,
>> +};
>> +
>> +static int tw686x_s_ctrl(struct v4l2_ctrl *ctrl)
>> +{
>> +     struct tw686x_video_channel *vc;
>> +     struct tw686x_dev *dev;
>> +     unsigned ch;
>> +
>> +     vc = container_of(ctrl->handler, struct tw686x_video_channel,
>> +                       ctrl_handler);
>> +     dev = vc->dev;
>> +     ch = vc->ch;
>> +
>> +     switch (ctrl->id) {
>> +     case V4L2_CID_BRIGHTNESS:
>> +             reg_write(dev, BRIGHT[ch], ctrl->val & 0xFF);
>> +             return 0;
>> +
>> +     case V4L2_CID_CONTRAST:
>> +             reg_write(dev, CONTRAST[ch], ctrl->val);
>> +             return 0;
>> +
>> +     case V4L2_CID_SATURATION:
>> +             reg_write(dev, SAT_U[ch], ctrl->val);
>> +             reg_write(dev, SAT_V[ch], ctrl->val);
>> +             return 0;
>> +
>> +     case V4L2_CID_HUE:
>> +             reg_write(dev, HUE[ch], ctrl->val & 0xFF);
>> +             return 0;
>> +     }
>> +
>> +     return -EINVAL;
>> +}
>> +
>> +static const struct v4l2_ctrl_ops ctrl_ops = {
>> +     .s_ctrl = tw686x_s_ctrl,
>> +};
>> +
>> +static int tw686x_g_fmt_vid_cap(struct file *file, void *priv,
>> +                             struct v4l2_format *f)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +
>> +     f->fmt.pix.width = vc->width;
>> +     f->fmt.pix.height = vc->height;
>> +     f->fmt.pix.field = V4L2_FIELD_INTERLACED;
>> +     f->fmt.pix.pixelformat = vc->format->fourcc;
>> +     f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
>> +     f->fmt.pix.bytesperline = (f->fmt.pix.width * vc->format->depth) / 8;
>> +     f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
>> +     return 0;
>> +}
>> +
>> +static int tw686x_try_fmt_vid_cap(struct file *file, void *priv,
>> +                               struct v4l2_format *f)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     unsigned int video_height = TW686X_VIDEO_HEIGHT(vc->video_standard);
>> +     const struct tw686x_format *format;
>> +
>> +     format = format_by_fourcc(f->fmt.pix.pixelformat);
>> +     if (!format) {
>> +             format = &formats[0];
>> +             f->fmt.pix.pixelformat = format->fourcc;
>> +     }
>> +
>> +     if (f->fmt.pix.width <= TW686X_VIDEO_WIDTH / 2)
>> +             f->fmt.pix.width = TW686X_VIDEO_WIDTH / 2;
>> +     else
>> +             f->fmt.pix.width = TW686X_VIDEO_WIDTH;
>> +
>> +     if (f->fmt.pix.height <= video_height / 2)
>> +             f->fmt.pix.height = video_height / 2;
>> +     else
>> +             f->fmt.pix.height = video_height;
>> +
>> +     f->fmt.pix.bytesperline = (f->fmt.pix.width * format->depth) / 8;
>> +     f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
>> +     f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
>> +     f->fmt.pix.field = V4L2_FIELD_INTERLACED;
>> +
>> +     return 0;
>> +}
>> +
>> +static int tw686x_s_fmt_vid_cap(struct file *file, void *priv,
>> +                             struct v4l2_format *f)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     u32 val, width, line_width, height;
>> +     unsigned long bitsperframe;
>> +     int err, pb;
>> +
>> +     if (vb2_is_busy(&vc->vidq))
>> +             return -EBUSY;
>> +
>> +     bitsperframe = vc->width * vc->height * vc->format->depth;
>> +     err = tw686x_try_fmt_vid_cap(file, priv, f);
>> +     if (err)
>> +             return err;
>> +
>> +     vc->format = format_by_fourcc(f->fmt.pix.pixelformat);
>> +     vc->width = f->fmt.pix.width;
>> +     vc->height = f->fmt.pix.height;
>> +
>> +     /* We need new DMA buffers if the framesize has changed */
>> +     if (bitsperframe != vc->width * vc->height * vc->format->depth) {
>> +
>
> Remove empty line.
>

OK.

>> +             for (pb = 0; pb < 2; pb++)
>> +                     tw686x_free_dma(vc, pb);
>> +
>> +             for (pb = 0; pb < 2; pb++) {
>> +                     err = tw686x_alloc_dma(vc, pb);
>> +                     if (err) {
>> +                             if (pb > 0)
>> +                                     tw686x_free_dma(vc, 0);
>> +                             return err;
>> +                     }
>> +             }
>> +     }
>> +
>> +     val = reg_read(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch]);
>> +
>> +     if (vc->width <= TW686X_VIDEO_WIDTH / 2)
>> +             val |= BIT(23);
>> +     else
>> +             val &= ~BIT(23);
>> +
>> +     if (vc->height <= TW686X_VIDEO_HEIGHT(vc->video_standard) / 2)
>> +             val |= BIT(24);
>> +     else
>> +             val &= ~BIT(24);
>> +
>> +     val &= ~(0x7 << 20);
>> +     val |= vc->format->mode << 20;
>> +     reg_write(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch], val);
>> +
>> +     /* Program the DMA frame size */
>> +     width = (vc->width * 2) & 0x7ff;
>> +     height = vc->height / 2;
>> +     line_width = (vc->width * 2) & 0x7ff;
>> +     val = (height << 22) | (line_width << 11)  | width;
>> +     reg_write(vc->dev, VDMA_WHP[vc->ch], val);
>> +     return 0;
>> +}
>> +
>> +static int tw686x_querycap(struct file *file, void *priv,
>> +                        struct v4l2_capability *cap)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     struct tw686x_dev *dev = vc->dev;
>> +
>> +     strcpy(cap->driver, "tw686x");
>> +     strcpy(cap->card, dev->name);
>> +     sprintf(cap->bus_info, "PCI:%s", pci_name(dev->pci_dev));
>
> strlcpy and snprintf
>

Will fix.

>> +     cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
>> +                        V4L2_CAP_READWRITE;
>> +     cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
>> +     return 0;
>> +}
>> +
>> +static int tw686x_s_std(struct file *file, void *priv, v4l2_std_id id)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     struct v4l2_format f;
>> +     u32 val, ret;
>> +
>> +     if (vc->video_standard == id)
>> +             return 0;
>> +
>> +     if (vb2_is_busy(&vc->vidq))
>> +             return -EBUSY;
>> +
>> +     if (id & V4L2_STD_NTSC)
>> +             val = 0;
>> +     else if (id & V4L2_STD_PAL)
>> +             val = 1;
>> +     else if (id & V4L2_STD_SECAM)
>> +             val = 2;
>> +     else if (id & V4L2_STD_NTSC_443)
>> +             val = 3;
>> +     else if (id & V4L2_STD_PAL_M)
>> +             val = 4;
>> +     else if (id & V4L2_STD_PAL_Nc)
>> +             val = 5;
>> +     else if (id & V4L2_STD_PAL_60)
>> +             val = 6;
>> +     else
>> +             return -EINVAL;
>> +
>> +     vc->video_standard = id;
>> +     reg_write(vc->dev, SDT[vc->ch], val);
>> +
>> +     val = reg_read(vc->dev, VIDEO_CONTROL1);
>> +     if (id & V4L2_STD_625_50)
>> +             val |= (1 << (SYS_MODE_DMA_SHIFT + vc->ch));
>> +     else
>> +             val &= ~(1 << (SYS_MODE_DMA_SHIFT + vc->ch));
>> +     reg_write(vc->dev, VIDEO_CONTROL1, val);
>> +
>> +     /*
>> +      * Adjust format after V4L2_STD_525_60/V4L2_STD_625_50 change,
>> +      * calling g_fmt and s_fmt will sanitize the height
>> +      * according to the standard.
>> +      */
>> +     ret = tw686x_g_fmt_vid_cap(file, priv, &f);
>> +     if (!ret)
>> +             tw686x_s_fmt_vid_cap(file, priv, &f);
>> +     return 0;
>> +}
>> +
>> +static int tw686x_querystd(struct file *file, void *priv, v4l2_std_id *std)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     struct tw686x_dev *dev = vc->dev;
>> +     unsigned int old_std, detected_std = 0;
>> +     unsigned long end;
>> +
>> +     if (vb2_is_streaming(&vc->vidq))
>> +             return -EBUSY;
>> +
>> +     /* Enable and start standard detection */
>> +     old_std = reg_read(dev, SDT[vc->ch]);
>> +     reg_write(dev, SDT[vc->ch], 0x7);
>> +     reg_write(dev, SDT_EN[vc->ch], 0xff);
>> +
>> +     end = jiffies + msecs_to_jiffies(500);
>> +     while (time_is_after_jiffies(end)) {
>> +
>> +             detected_std = reg_read(dev, SDT[vc->ch]);
>> +             if (!(detected_std & BIT(7)))
>> +                     break;
>> +             msleep(100);
>> +     }
>> +     reg_write(dev, SDT[vc->ch], old_std);
>> +
>> +     /* Exit if still busy */
>> +     if (detected_std & BIT(7))
>> +             return 0;
>> +
>> +     detected_std = (detected_std >> 4) & 0x7;
>> +     switch (detected_std) {
>> +     case TW686X_STD_NTSC_M:
>> +             *std &= V4L2_STD_NTSC;
>> +             break;
>> +     case TW686X_STD_NTSC_443:
>> +             *std &= V4L2_STD_NTSC_443;
>> +             break;
>> +     case TW686X_STD_PAL_M:
>> +             *std &= V4L2_STD_PAL_M;
>> +             break;
>> +     case TW686X_STD_PAL_60:
>> +             *std &= V4L2_STD_PAL_60;
>> +             break;
>> +     case TW686X_STD_PAL:
>> +             *std &= V4L2_STD_PAL;
>> +             break;
>> +     case TW686X_STD_PAL_CN:
>> +             *std &= V4L2_STD_PAL_Nc;
>> +             break;
>> +     case TW686X_STD_SECAM:
>> +             *std &= V4L2_STD_SECAM;
>> +             break;
>> +     default:
>> +             *std = 0;
>> +     }
>> +     return 0;
>> +}
>> +
>> +static int tw686x_g_std(struct file *file, void *priv, v4l2_std_id *id)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +
>> +     *id = vc->video_standard;
>> +     return 0;
>> +}
>> +
>> +static int tw686x_enum_fmt_vid_cap(struct file *file, void *priv,
>> +                                struct v4l2_fmtdesc *f)
>> +{
>> +     if (f->index >= ARRAY_SIZE(formats))
>> +             return -EINVAL;
>> +
>> +     strlcpy(f->description, formats[f->index].name, sizeof(f->description));
>
> Drop this line, this is now done by the v4l2 core.
>

OK.

>> +     f->pixelformat = formats[f->index].fourcc;
>> +     return 0;
>> +}
>> +
>> +static int tw686x_g_parm(struct file *file, void *priv,
>> +                      struct v4l2_streamparm *sp)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     struct v4l2_captureparm *cp = &sp->parm.capture;
>> +
>> +     if (sp->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>> +             return -EINVAL;
>> +     sp->parm.capture.readbuffers = 3;
>> +
>> +     cp->capability = V4L2_CAP_TIMEPERFRAME;
>> +     cp->timeperframe.numerator = 1;
>> +     cp->timeperframe.denominator = vc->fps;
>> +     return 0;
>> +}
>> +
>> +static int tw686x_s_parm(struct file *file, void *priv,
>> +                      struct v4l2_streamparm *sp)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     struct v4l2_captureparm *cp = &sp->parm.capture;
>> +     unsigned int denominator = cp->timeperframe.denominator;
>> +     unsigned int numerator = cp->timeperframe.numerator;
>> +     unsigned int fps;
>> +
>> +     if (vb2_is_busy(&vc->vidq))
>> +             return -EBUSY;
>> +
>> +     fps = (!numerator || !denominator) ? 0 : denominator / numerator;
>> +     if (vc->video_standard & V4L2_STD_625_50)
>> +             fps = (!fps || fps > 25) ? 25 : fps;
>> +     else
>> +             fps = (!fps || fps > 30) ? 30 : fps;
>> +     tw686x_set_framerate(vc, fps);
>> +
>> +     return tw686x_g_parm(file, priv, sp);
>> +}
>
> Why do you need to implement g/s_parm? This is not typically done for SDTV
> capture devices since you cannot set it. And the v4l2 core will provide a
> default g_parm implementation that does the right thing. I think you can
> just delete these two functions.
>

Hm, I think it's a left over from the code this driver is based. I haven't
really used this ioctl.

>> +
>> +static int tw686x_s_input(struct file *file, void *priv, unsigned int i)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     u32 val;
>> +
>> +     if (i >= TW686X_INPUTS_PER_CH)
>> +             return -EINVAL;
>> +
>
> I would add this here:
>
>         if (i == vc->input)
>                 return 0;
>

Ah, right.

>> +     /*
>> +      * Not sure we are able to support on the fly input change
>> +      */
>> +     if (vb2_is_busy(&vc->vidq))
>> +             return -EBUSY;
>> +
>> +     vc->input = i;
>> +
>> +     val = reg_read(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch]);
>> +     val &= ~(0x3 << 30);
>> +     val |= i << 30;
>> +     reg_write(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch], val);
>> +     return 0;
>> +}
>> +
>> +static int tw686x_g_input(struct file *file, void *priv, unsigned int *i)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +
>> +     *i = vc->input;
>> +     return 0;
>> +}
>> +
>> +static int tw686x_enum_input(struct file *file, void *priv,
>> +                          struct v4l2_input *i)
>> +{
>> +     struct tw686x_video_channel *vc = video_drvdata(file);
>> +     unsigned int vidstat;
>> +
>> +     if (i->index >= TW686X_INPUTS_PER_CH)
>> +             return -EINVAL;
>> +
>> +     sprintf(i->name, "Composite%d", i->index);
>> +     i->type = V4L2_INPUT_TYPE_CAMERA;
>> +     i->std = vc->device->tvnorms;
>> +     i->capabilities = V4L2_IN_CAP_STD;
>> +
>> +     vidstat = reg_read(vc->dev, VIDSTAT[vc->ch]);
>> +     i->status = 0;
>> +     if (vidstat & TW686X_VIDSTAT_VDLOSS)
>> +             i->status |= V4L2_IN_ST_NO_SIGNAL;
>> +     if (!(vidstat & TW686X_VIDSTAT_HLOCK))
>> +             i->status |= V4L2_IN_ST_NO_H_LOCK;
>> +
>> +     return 0;
>> +}
>> +
>> +const struct v4l2_file_operations tw686x_video_fops = {
>> +     .owner          = THIS_MODULE,
>> +     .open           = v4l2_fh_open,
>> +     .unlocked_ioctl = video_ioctl2,
>> +     .release        = vb2_fop_release,
>> +     .poll           = vb2_fop_poll,
>> +     .read           = vb2_fop_read,
>> +     .mmap           = vb2_fop_mmap,
>> +};
>> +
>> +const struct v4l2_ioctl_ops tw686x_video_ioctl_ops = {
>> +     .vidioc_querycap                = tw686x_querycap,
>> +     .vidioc_g_fmt_vid_cap           = tw686x_g_fmt_vid_cap,
>> +     .vidioc_s_fmt_vid_cap           = tw686x_s_fmt_vid_cap,
>> +     .vidioc_enum_fmt_vid_cap        = tw686x_enum_fmt_vid_cap,
>> +     .vidioc_try_fmt_vid_cap         = tw686x_try_fmt_vid_cap,
>> +
>> +     .vidioc_querystd                = tw686x_querystd,
>> +     .vidioc_g_std                   = tw686x_g_std,
>> +     .vidioc_s_std                   = tw686x_s_std,
>> +
>> +     .vidioc_g_parm                  = tw686x_g_parm,
>> +     .vidioc_s_parm                  = tw686x_s_parm,
>> +
>> +     .vidioc_enum_input              = tw686x_enum_input,
>> +     .vidioc_g_input                 = tw686x_g_input,
>> +     .vidioc_s_input                 = tw686x_s_input,
>> +
>> +     .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
>> +     .vidioc_querybuf                = vb2_ioctl_querybuf,
>> +     .vidioc_qbuf                    = vb2_ioctl_qbuf,
>> +     .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
>> +     .vidioc_create_bufs             = vb2_ioctl_create_bufs,
>> +     .vidioc_streamon                = vb2_ioctl_streamon,
>> +     .vidioc_streamoff               = vb2_ioctl_streamoff,
>> +
>> +     .vidioc_log_status              = v4l2_ctrl_log_status,
>> +     .vidioc_subscribe_event         = v4l2_ctrl_subscribe_event,
>> +     .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
>> +};
>> +
>> +static void tw686x_buffer_copy(struct tw686x_video_channel *vc,
>> +                            unsigned int pb, struct vb2_v4l2_buffer *vb)
>> +{
>> +     struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
>> +     struct vb2_buffer *vb2_buf = &vb->vb2_buf;
>> +
>> +     vb->field = V4L2_FIELD_INTERLACED;
>> +     vb->sequence = vc->sequence++;
>> +
>> +     memcpy(vb2_plane_vaddr(vb2_buf, 0), desc->virt, desc->size);
>> +     vb2_buf->timestamp = ktime_get_ns();
>> +     vb2_buffer_done(vb2_buf, VB2_BUF_STATE_DONE);
>> +}
>> +
>> +void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
>> +                   unsigned int pb_status, unsigned int fifo_status,
>> +                   unsigned int *reset_ch)
>> +{
>> +     struct tw686x_video_channel *vc;
>> +     struct vb2_v4l2_buffer *vb;
>> +     unsigned long flags;
>> +     unsigned int ch, pb;
>> +
>> +     for_each_set_bit(ch, &requests, max_channels(dev)) {
>> +
>
> Remove empty line.
>

OK.

>> +             vc = &dev->video_channels[ch];
>> +
>> +             /*
>> +              * This can either be a blue frame (with signal-lost bit set)
>> +              * or a good frame (with signal-lost bit clear). If we have just
>> +              * got signal, then this channel needs resetting.
>> +              */
>> +             if (vc->no_signal && !(fifo_status & BIT(ch))) {
>> +                     v4l2_printk(KERN_DEBUG, &dev->v4l2_dev,
>> +                                 "video%d: signal recovered\n", vc->num);
>> +                     vc->no_signal = false;
>> +                     *reset_ch |= BIT(ch);
>> +                     vc->pb = 0;
>> +                     continue;
>> +             }
>> +             vc->no_signal = !!(fifo_status & BIT(ch));
>> +
>> +             /* Check FIFO errors only if there's signal */
>> +             if (!vc->no_signal) {
>> +                     u32 fifo_ov, fifo_bad;
>> +
>> +                     fifo_ov = (fifo_status >> 24) & BIT(ch);
>> +                     fifo_bad = (fifo_status >> 16) & BIT(ch);
>> +                     if (fifo_ov || fifo_bad) {
>> +                             /* Mark this channel for reset */
>> +                             v4l2_printk(KERN_DEBUG, &dev->v4l2_dev, "video%d: FIFO error\n", vc->num);
>> +                             *reset_ch |= BIT(ch);
>> +                             vc->pb = 0;
>> +                             continue;
>> +                     }
>> +             }
>> +
>> +             pb = !!(pb_status & BIT(ch));
>> +             if (vc->pb != pb) {
>> +                     /* Mark this channel for reset */
>> +                     v4l2_printk(KERN_DEBUG, &dev->v4l2_dev,
>> +                                 "video%d: unexpected p-b buffer!\n", vc->num);
>> +                     *reset_ch |= BIT(ch);
>> +                     vc->pb = 0;
>> +                     continue;
>> +             }
>> +
>> +             /* handle video stream */
>> +             spin_lock_irqsave(&vc->qlock, flags);
>> +             if (vc->curr_bufs[pb]) {
>> +                     vb = &vc->curr_bufs[pb]->vb;
>> +                     tw686x_buffer_copy(vc, pb, vb);
>
> You have to copy the data? It's not possible the program the DMA so that
> it DMAs into the buffer itself? That's quite unusual for a PCI device.
>

Yes, it's possible and I spent an enormous amount of time trying to make it work
(originally using scatter-gather mode, and then with frame mode).

However, despite my many efforts it always stucked (sooner or later in
the tests)
into a hard machine freeze. There are two apparent sources for the freeze:

(1) To make the above work you need to program the registers so the chip DMAs
into a new buffer each time the current DMA buffer is completed.

(2) Also, when a signal error is detected and/or signal is lost and recovered,
the DMA channels are re-programmed as well.

It was only when all the registers write got removed and minimized to the bare
minimum (registers are written before streaming starts and then stay mostly
untouched) that I got a stable driver working fine for several weeks.

The ugly delay timer is meant to mitigate (2). And the buffer copy is
to workaround (1).

Chip and board vendors couldn't provide any explanation for this
behavior. I have
two different boards (one with 1-chip, one with 2-chips and a PCIe switch),
and the issues are present on both.

In any case, the vendor's Windows driver does the similar buffer-copy.

I understand that on some platforms this implementation could be too
costly (it's
completely cheap on any modern x86), and I intend to provide some option
to provide "frame DMA-to-buffer" and "scatter-gather DMA".

However, I wanted to get this basic version merged first.

(Sorry, I should have included all this in the cover letter since
it was pretty obvious you would ask :)

>> +             }
>> +             vc->pb = !pb;
>> +             tw686x_buffer_refill(vc, pb);
>> +             spin_unlock_irqrestore(&vc->qlock, flags);
>> +     }
>> +}
>> +
>> +void tw686x_video_free(struct tw686x_dev *dev)
>> +{
>> +     unsigned int ch, pb;
>> +
>> +     for (ch = 0; ch < max_channels(dev); ch++) {
>> +             struct tw686x_video_channel *vc = &dev->video_channels[ch];
>> +
>> +             if (vc->device)
>> +                     video_unregister_device(vc->device);
>> +
>> +             for (pb = 0; pb < 2; pb++)
>> +                     tw686x_free_dma(vc, pb);
>> +     }
>> +}
>> +
>> +int tw686x_video_init(struct tw686x_dev *dev)
>> +{
>> +     unsigned int ch, val, pb;
>> +     int err;
>> +
>> +     err = v4l2_device_register(&dev->pci_dev->dev, &dev->v4l2_dev);
>> +     if (err)
>> +             return err;
>> +
>> +     for (ch = 0; ch < max_channels(dev); ch++) {
>> +             struct tw686x_video_channel *vc = &dev->video_channels[ch];
>> +             struct video_device *vdev;
>> +
>> +             mutex_init(&vc->vb_mutex);
>> +             spin_lock_init(&vc->qlock);
>> +             INIT_LIST_HEAD(&vc->vidq_queued);
>> +
>> +             vc->dev = dev;
>> +             vc->ch = ch;
>> +
>> +             /* default settings */
>> +             vc->format = &formats[0];
>> +             vc->video_standard = V4L2_STD_NTSC;
>> +             vc->width = TW686X_VIDEO_WIDTH;
>> +             vc->height = TW686X_VIDEO_HEIGHT(vc->video_standard);
>> +             vc->input = 0;
>> +
>> +             reg_write(vc->dev, SDT[ch], 0);
>> +             tw686x_set_framerate(vc, 30);
>> +
>> +             reg_write(dev, VDELAY_LO[ch], 0x14);
>> +             reg_write(dev, HACTIVE_LO[ch], 0xD0);
>> +             reg_write(dev, VIDEO_SIZE[ch], 0);
>> +
>> +             for (pb = 0; pb < 2; pb++) {
>> +                     err = tw686x_alloc_dma(vc, pb);
>> +                     if (err)
>> +                             goto error;
>> +             }
>> +
>> +             vdev = video_device_alloc();
>> +             if (!vdev) {
>> +                     v4l2_err(&dev->v4l2_dev, "dma%d: unable to allocate device\n", ch);
>> +                     err = -ENOMEM;
>> +                     goto error;
>> +             }
>> +
>> +             vc->vidq.io_modes = VB2_READ | VB2_MMAP | VB2_DMABUF;
>> +             vc->vidq.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
>> +             vc->vidq.drv_priv = vc;
>> +             vc->vidq.buf_struct_size = sizeof(struct tw686x_v4l2_buf);
>> +             vc->vidq.ops = &tw686x_video_qops;
>> +             vc->vidq.mem_ops = &vb2_vmalloc_memops;
>> +             vc->vidq.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
>> +             vc->vidq.min_buffers_needed = 2;
>> +             vc->vidq.lock = &vc->vb_mutex;
>> +
>> +             err = vb2_queue_init(&vc->vidq);
>> +             if (err)
>> +                     goto error;
>> +
>> +             snprintf(vdev->name, sizeof(vdev->name), "%s video", dev->name);
>> +             vdev->fops = &tw686x_video_fops;
>> +             vdev->ioctl_ops = &tw686x_video_ioctl_ops;
>> +             vdev->release = video_device_release;
>> +             vdev->v4l2_dev = &dev->v4l2_dev;
>> +             vdev->queue = &vc->vidq;
>> +             vdev->tvnorms = V4L2_STD_525_60 | V4L2_STD_625_50;
>> +             vdev->minor = -1;
>> +             vdev->lock = &vc->vb_mutex;
>> +             vc->device = vdev;
>> +             video_set_drvdata(vdev, vc);
>> +             err = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
>> +             if (err < 0)
>> +                     goto error;
>
> Move this down to the end of the loop. Userspace can use the video device
> as soon as it is created, so it is wise to create it only after everything
> else has been configured.
>

OK.

>> +             vc->num = vdev->num;
>> +
>> +             err = v4l2_ctrl_handler_init(&vc->ctrl_handler, 4);
>> +             if (err) {
>> +                     v4l2_err(&dev->v4l2_dev,
>> +                              "video%d: cannot init ctrl handler\n",
>> +                              vc->num);
>> +                     goto error;
>> +             }
>> +             vdev->ctrl_handler = &vc->ctrl_handler;
>> +             v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
>> +                               V4L2_CID_BRIGHTNESS, -128, 127, 1, 0);
>> +             v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
>> +                               V4L2_CID_CONTRAST, 0, 255, 1, 100);
>> +             v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
>> +                               V4L2_CID_SATURATION, 0, 255, 1, 128);
>> +             v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
>> +                               V4L2_CID_HUE, -128, 127, 1, 0);
>> +             err = vc->ctrl_handler.error;
>> +             if (err)
>> +                     goto error;
>> +
>> +             err = v4l2_ctrl_handler_setup(&vc->ctrl_handler);
>> +             if (err)
>> +                     goto error;
>> +     }
>> +
>> +     /* Set DMA frame mode on all channels. Only supported mode for now. */
>> +     val = TW686X_DEF_PHASE_REF;
>> +     for (ch = 0; ch < max_channels(dev); ch++)
>> +             val |= TW686X_FRAME_MODE << (16 + ch * 2);
>> +     reg_write(dev, PHASE_REF, val);
>> +
>> +     reg_write(dev, MISC2[0], 0xE7);
>> +     reg_write(dev, VCTRL1[0], 0xCC);
>> +     reg_write(dev, LOOP[0], 0xA5);
>> +     if (max_channels(dev) > 4) {
>> +             reg_write(dev, VCTRL1[1], 0xCC);
>> +             reg_write(dev, LOOP[1], 0xA5);
>> +             reg_write(dev, MISC2[1], 0xE7);
>> +     }
>> +     return 0;
>> +
>> +error:
>> +     tw686x_video_free(dev);
>> +     return err;
>> +}
>> diff --git a/drivers/media/pci/tw686x/tw686x.h b/drivers/media/pci/tw686x/tw686x.h
>> new file mode 100644
>> index 000000000000..0ffb0be84aa2
>> --- /dev/null
>> +++ b/drivers/media/pci/tw686x/tw686x.h
>> @@ -0,0 +1,189 @@
>> +/*
>> + * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
>> + *
>> + * Copyright (C) 2015 Industrial Research Institute for Automation
>> + * and Measurements PIAP
>> + * Written by Krzysztof Ha?asa
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms of version 2 of the GNU General Public License
>> + * as published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/mutex.h>
>> +#include <linux/pci.h>
>> +#include <linux/timer.h>
>> +#include <linux/videodev2.h>
>> +#include <media/v4l2-common.h>
>> +#include <media/v4l2-ctrls.h>
>> +#include <media/v4l2-device.h>
>> +#include <media/v4l2-ioctl.h>
>> +#include <media/videobuf2-v4l2.h>
>> +#include <sound/pcm.h>
>> +
>> +#include "tw686x-regs.h"
>> +
>> +#define TYPE_MAX_CHANNELS    0x0F
>> +#define TYPE_SECOND_GEN              0x10
>> +#define TW686X_DEF_PHASE_REF 0x1518
>> +
>> +#define TW686X_FIELD_MODE    0x3
>> +#define TW686X_FRAME_MODE    0x2
>> +/* 0x1 is reserved */
>> +#define TW686X_SG_MODE               0x0
>> +
>> +#define TW686X_PAGE_SIZE     4096
>> +#define TW686X_AUDIO_PAGE_MAX        16
>> +
>> +struct tw686x_format {
>> +     char *name;
>> +     unsigned fourcc;
>> +     unsigned depth;
>> +     unsigned mode;
>> +};
>> +
>> +struct tw686x_dma_desc {
>> +     dma_addr_t phys;
>> +     void *virt;
>> +     unsigned size;
>> +};
>> +
>> +struct tw686x_audio_buf {
>> +     dma_addr_t dma;
>> +     void *virt;
>> +     struct list_head list;
>> +};
>> +
>> +struct tw686x_v4l2_buf {
>> +     struct vb2_v4l2_buffer vb;
>> +     struct list_head list;
>> +};
>> +
>> +struct tw686x_audio_channel {
>> +     struct tw686x_dev *dev;
>> +     struct snd_pcm_substream *ss;
>> +     unsigned int ch;
>> +     struct tw686x_audio_buf *curr_bufs[2];
>> +     struct tw686x_dma_desc dma_descs[2];
>> +     dma_addr_t ptr;
>> +
>> +     struct tw686x_audio_buf buf[TW686X_AUDIO_PAGE_MAX];
>> +     struct list_head buf_list;
>> +     spinlock_t lock;
>> +};
>> +
>> +struct tw686x_video_channel {
>> +     struct tw686x_dev *dev;
>> +
>> +     struct vb2_queue vidq;
>> +     struct list_head vidq_queued;
>> +     struct video_device *device;
>> +     struct tw686x_v4l2_buf *curr_bufs[2];
>> +     struct tw686x_dma_desc dma_descs[2];
>> +
>> +     struct v4l2_ctrl_handler ctrl_handler;
>> +     const struct tw686x_format *format;
>> +     struct mutex vb_mutex;
>> +     spinlock_t qlock;
>> +     v4l2_std_id video_standard;
>> +     unsigned int width, height;
>> +     unsigned int h_halve, v_halve;
>> +     unsigned int ch;
>> +     unsigned int num;
>> +     unsigned int fps;
>> +     unsigned int input;
>> +     unsigned int sequence;
>> +     unsigned int pb;
>> +     bool no_signal;
>> +};
>> +
>> +/**
>> + * struct tw686x_dev - global device status
>> + * @lock: spinlock controlling access to the
>> + *        shared device registers (DMA enable/disable).
>> + */
>> +struct tw686x_dev {
>> +     spinlock_t lock;
>> +
>> +     struct v4l2_device v4l2_dev;
>> +     struct snd_card *snd_card;
>> +
>> +     char name[32];
>> +     unsigned int type;
>> +     struct pci_dev *pci_dev;
>> +     __u32 __iomem *mmio;
>> +
>> +     void *alloc_ctx;
>> +
>> +     struct tw686x_video_channel *video_channels;
>> +     struct tw686x_audio_channel *audio_channels;
>> +
>> +     int audio_rate; /* per-device value */
>> +
>> +     struct timer_list dma_delay_timer;
>> +     u32 pending_dma_en; /* must be protected by lock */
>> +     u32 pending_dma_cmd; /* must be protected by lock */
>> +};
>> +
>> +static inline uint32_t reg_read(struct tw686x_dev *dev, unsigned reg)
>> +{
>> +     return readl(dev->mmio + reg);
>> +}
>> +
>> +static inline void reg_write(struct tw686x_dev *dev, unsigned reg,
>> +                          uint32_t value)
>> +{
>> +     writel(value, dev->mmio + reg);
>> +}
>> +
>> +static inline void tw686x_disable_channel(struct tw686x_dev *dev,
>> +                                       unsigned int channel)
>> +{
>> +     u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
>> +     u32 dma_cmd = reg_read(dev, DMA_CMD);
>> +
>> +     dma_en &= ~BIT(channel);
>> +     dma_cmd &= ~BIT(channel);
>> +
>> +     /* Must remove it from pending too */
>> +     dev->pending_dma_en &= ~BIT(channel);
>> +     dev->pending_dma_cmd &= ~BIT(channel);
>> +
>> +     /* Stop DMA if no channels are enabled */
>> +     if (!dma_en)
>> +             dma_cmd = 0;
>> +     reg_write(dev, DMA_CHANNEL_ENABLE, dma_en);
>> +     reg_write(dev, DMA_CMD, dma_cmd);
>> +}
>> +
>> +static inline void tw686x_enable_channel(struct tw686x_dev *dev,
>> +                                      unsigned int channel)
>> +{
>> +     u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
>> +     u32 dma_cmd = reg_read(dev, DMA_CMD);
>> +
>> +     dev->pending_dma_en |= dma_en | BIT(channel);
>> +     dev->pending_dma_cmd |= dma_cmd | BIT(31) | BIT(channel);
>> +}
>
> I think these should be normal functions. I see no reason for en/disabling
> channel to be inline.
>

OK.

>> +
>> +static inline unsigned max_channels(struct tw686x_dev *dev)
>> +{
>> +     return dev->type & TYPE_MAX_CHANNELS; /* 4 or 8 channels */
>> +}
>> +
>> +static inline unsigned is_second_gen(struct tw686x_dev *dev)
>> +{
>> +     /* each channel has its own DMA SG table */
>> +     return dev->type & TYPE_SECOND_GEN;
>> +}
>> +
>> +int tw686x_video_init(struct tw686x_dev *dev);
>> +void tw686x_video_free(struct tw686x_dev *dev);
>> +void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
>> +                   unsigned int pb_status, unsigned int fifo_status,
>> +                   unsigned int *reset_ch);
>> +
>> +int tw686x_audio_init(struct tw686x_dev *dev);
>> +void tw686x_audio_free(struct tw686x_dev *dev);
>> +void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
>> +                   unsigned int pb_status);
>>
>
> Regards,
>
>         Hans

Thanks a lot for the thorough review!
Hans Verkuil Jan. 18, 2016, 3:28 p.m. UTC | #3
On 01/18/2016 04:20 PM, Ezequiel Garcia wrote:
> Hi Hans,
> 
> On 18 January 2016 at 10:02, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>> Hi Ezequiel,
>>
>> Thanks for working on this! Do you know where I can get a board tw686x board?
>> I always like to have hardware to test the driver, if at all possible.
>>
> 
> No, I don't know. I have one to spare, and I could send it to you.
> 
>> See below for a review of this driver.

<snip>

>>> +     /*
>>> +      * This allows to detect device is not here,
>>> +      * and will be used by vb2_ops. The lock is really
>>> +      * important here.
>>> +      */
>>> +     spin_lock_irqsave(&dev->lock, flags);
>>> +     dev->pci_dev = NULL;
>>> +     spin_unlock_irqrestore(&dev->lock, flags);
>>
>> As you sure this is needed? Normally you can only come here if the module
>> is removed, which isn't possible as long as userspace is using it. And if
>> the module is removed, then vb2 shouldn't be called at all.
>>
>> The only exception would be if this is a hot-pluggable device, which is
>> quite unlikely for a PCI device. I don't believe any of the pci drivers
>> support that.
>>
> 
> A previous version of the driver didn't have that. However, under certain
> stress testing it was observed that the PCIe link goes down. I still have the
> traces for that:
> 
> [..]
> [21833.389031] pciehp 0000:13:01.0:pcie24: pcie_isr: intr_loc 100
> [21833.389035] pciehp 0000:13:01.0:pcie24: Data Link Layer State change
> [21833.389038] pciehp 0000:13:01.0:pcie24: slot(1-5): Link Down event
> [21833.389076] pciehp 0000:13:01.0:pcie24: Disabling
> domain:bus:device=0000:14:00
> [21833.389078] pciehp 0000:13:01.0:pcie24: pciehp_unconfigure_device:
> domain:bus:dev = 0000:14:00
> [21833.389103] TW686x 0000:14:00.0: removing
> [21833.416557] TW686x 0000:14:00.0: removed
> [..]
> 
> I have no idea why the link goes down (hardware issue?),
> but it's better to handle it gracefully :)

This definitely needs to be documented.

<snip>

>>> +             /* handle video stream */
>>> +             spin_lock_irqsave(&vc->qlock, flags);
>>> +             if (vc->curr_bufs[pb]) {
>>> +                     vb = &vc->curr_bufs[pb]->vb;
>>> +                     tw686x_buffer_copy(vc, pb, vb);
>>
>> You have to copy the data? It's not possible the program the DMA so that
>> it DMAs into the buffer itself? That's quite unusual for a PCI device.
>>
> 
> Yes, it's possible and I spent an enormous amount of time trying to make it work
> (originally using scatter-gather mode, and then with frame mode).
> 
> However, despite my many efforts it always stucked (sooner or later in
> the tests)
> into a hard machine freeze. There are two apparent sources for the freeze:
> 
> (1) To make the above work you need to program the registers so the chip DMAs
> into a new buffer each time the current DMA buffer is completed.
> 
> (2) Also, when a signal error is detected and/or signal is lost and recovered,
> the DMA channels are re-programmed as well.
> 
> It was only when all the registers write got removed and minimized to the bare
> minimum (registers are written before streaming starts and then stay mostly
> untouched) that I got a stable driver working fine for several weeks.
> 
> The ugly delay timer is meant to mitigate (2). And the buffer copy is
> to workaround (1).
> 
> Chip and board vendors couldn't provide any explanation for this
> behavior. I have
> two different boards (one with 1-chip, one with 2-chips and a PCIe switch),
> and the issues are present on both.
> 
> In any case, the vendor's Windows driver does the similar buffer-copy.
> 
> I understand that on some platforms this implementation could be too
> costly (it's
> completely cheap on any modern x86), and I intend to provide some option
> to provide "frame DMA-to-buffer" and "scatter-gather DMA".
> 
> However, I wanted to get this basic version merged first.
> 
> (Sorry, I should have included all this in the cover letter since
> it was pretty obvious you would ask :)

This too definitely needs to be documented in the code.

For both issues it is not enough to document that in the cover letter,
since future maintainers of the code will not see that. It really has to
be in the code itself.

These are typical workarounds for weird hardware behavior that isn't documented
anywhere and that future developers are inclined to remove if it isn't clearly
stated why they are needed.

Regards,

	Hans
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Ezequiel Garcia Jan. 18, 2016, 3:31 p.m. UTC | #4
On 18 January 2016 at 12:28, Hans Verkuil <hverkuil@xs4all.nl> wrote:
> On 01/18/2016 04:20 PM, Ezequiel Garcia wrote:
>> Hi Hans,
>>
>> On 18 January 2016 at 10:02, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>>> Hi Ezequiel,
>>>
>>> Thanks for working on this! Do you know where I can get a board tw686x board?
>>> I always like to have hardware to test the driver, if at all possible.
>>>
>>
>> No, I don't know. I have one to spare, and I could send it to you.
>>
>>> See below for a review of this driver.
>
> <snip>
>
>>>> +     /*
>>>> +      * This allows to detect device is not here,
>>>> +      * and will be used by vb2_ops. The lock is really
>>>> +      * important here.
>>>> +      */
>>>> +     spin_lock_irqsave(&dev->lock, flags);
>>>> +     dev->pci_dev = NULL;
>>>> +     spin_unlock_irqrestore(&dev->lock, flags);
>>>
>>> As you sure this is needed? Normally you can only come here if the module
>>> is removed, which isn't possible as long as userspace is using it. And if
>>> the module is removed, then vb2 shouldn't be called at all.
>>>
>>> The only exception would be if this is a hot-pluggable device, which is
>>> quite unlikely for a PCI device. I don't believe any of the pci drivers
>>> support that.
>>>
>>
>> A previous version of the driver didn't have that. However, under certain
>> stress testing it was observed that the PCIe link goes down. I still have the
>> traces for that:
>>
>> [..]
>> [21833.389031] pciehp 0000:13:01.0:pcie24: pcie_isr: intr_loc 100
>> [21833.389035] pciehp 0000:13:01.0:pcie24: Data Link Layer State change
>> [21833.389038] pciehp 0000:13:01.0:pcie24: slot(1-5): Link Down event
>> [21833.389076] pciehp 0000:13:01.0:pcie24: Disabling
>> domain:bus:device=0000:14:00
>> [21833.389078] pciehp 0000:13:01.0:pcie24: pciehp_unconfigure_device:
>> domain:bus:dev = 0000:14:00
>> [21833.389103] TW686x 0000:14:00.0: removing
>> [21833.416557] TW686x 0000:14:00.0: removed
>> [..]
>>
>> I have no idea why the link goes down (hardware issue?),
>> but it's better to handle it gracefully :)
>
> This definitely needs to be documented.
>
> <snip>
>
>>>> +             /* handle video stream */
>>>> +             spin_lock_irqsave(&vc->qlock, flags);
>>>> +             if (vc->curr_bufs[pb]) {
>>>> +                     vb = &vc->curr_bufs[pb]->vb;
>>>> +                     tw686x_buffer_copy(vc, pb, vb);
>>>
>>> You have to copy the data? It's not possible the program the DMA so that
>>> it DMAs into the buffer itself? That's quite unusual for a PCI device.
>>>
>>
>> Yes, it's possible and I spent an enormous amount of time trying to make it work
>> (originally using scatter-gather mode, and then with frame mode).
>>
>> However, despite my many efforts it always stucked (sooner or later in
>> the tests)
>> into a hard machine freeze. There are two apparent sources for the freeze:
>>
>> (1) To make the above work you need to program the registers so the chip DMAs
>> into a new buffer each time the current DMA buffer is completed.
>>
>> (2) Also, when a signal error is detected and/or signal is lost and recovered,
>> the DMA channels are re-programmed as well.
>>
>> It was only when all the registers write got removed and minimized to the bare
>> minimum (registers are written before streaming starts and then stay mostly
>> untouched) that I got a stable driver working fine for several weeks.
>>
>> The ugly delay timer is meant to mitigate (2). And the buffer copy is
>> to workaround (1).
>>
>> Chip and board vendors couldn't provide any explanation for this
>> behavior. I have
>> two different boards (one with 1-chip, one with 2-chips and a PCIe switch),
>> and the issues are present on both.
>>
>> In any case, the vendor's Windows driver does the similar buffer-copy.
>>
>> I understand that on some platforms this implementation could be too
>> costly (it's
>> completely cheap on any modern x86), and I intend to provide some option
>> to provide "frame DMA-to-buffer" and "scatter-gather DMA".
>>
>> However, I wanted to get this basic version merged first.
>>
>> (Sorry, I should have included all this in the cover letter since
>> it was pretty obvious you would ask :)
>
> This too definitely needs to be documented in the code.
>
> For both issues it is not enough to document that in the cover letter,
> since future maintainers of the code will not see that. It really has to
> be in the code itself.
>
> These are typical workarounds for weird hardware behavior that isn't documented
> anywhere and that future developers are inclined to remove if it isn't clearly
> stated why they are needed.
>

No problem.

Thanks,
Krzysztof Hałasa Jan. 25, 2016, 9:40 a.m. UTC | #5
Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:

> A previous version of the driver didn't have that. However, under certain
> stress testing it was observed that the PCIe link goes down. I still have the
> traces for that:
>
> [..]
> [21833.389031] pciehp 0000:13:01.0:pcie24: pcie_isr: intr_loc 100
> [21833.389035] pciehp 0000:13:01.0:pcie24: Data Link Layer State change
> [21833.389038] pciehp 0000:13:01.0:pcie24: slot(1-5): Link Down event
> [21833.389076] pciehp 0000:13:01.0:pcie24: Disabling
> domain:bus:device=0000:14:00
> [21833.389078] pciehp 0000:13:01.0:pcie24: pciehp_unconfigure_device:
> domain:bus:dev = 0000:14:00
> [21833.389103] TW686x 0000:14:00.0: removing
> [21833.416557] TW686x 0000:14:00.0: removed
> [..]
>
> I have no idea why the link goes down (hardware issue?),
> but it's better to handle it gracefully :)

Could be hw issue indeed, FWIW I have never observed this problem on my
hw (which is ARM-based and includes TW6869).

> I understand that on some platforms this implementation could be too
> costly (it's
> completely cheap on any modern x86), and I intend to provide some option
> to provide "frame DMA-to-buffer" and "scatter-gather DMA".

Though I'm using the driver that I posted several months ago, with
SG DMA field-only mode (SG DMA engine doesn't support frame mode and
while non-SG DMA (field or frame) mode is certainly possible with CMA,
copying the buffers is out of the question here).

I wonder if that driver works for you (which would suggest a sw bug)
or if the problems are the same (hw issue - system, power, or the chip
itself).


BTW adding incremental patches on top of the driver I posted would seem
preferable to me. It would enable us to pinpoint (and not include)
changes which tend to break something. For now, it seems I'll be stuck
with my version, since I have to do DMA to buffers (though I could use
the frame mode).

Incremental patches are generally how it is done in Linux.
Perhaps we should merge my driver first and you'd add your changes on
top of it (preserving the existing functionality)?

This is very easy with git.
Ezequiel Garcia Jan. 25, 2016, 12:03 p.m. UTC | #6
On 25 January 2016 at 06:40, Krzysztof Ha?asa <khalasa@piap.pl> wrote:
> Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:
>
>> A previous version of the driver didn't have that. However, under certain
>> stress testing it was observed that the PCIe link goes down. I still have the
>> traces for that:
>>
>> [..]
>> [21833.389031] pciehp 0000:13:01.0:pcie24: pcie_isr: intr_loc 100
>> [21833.389035] pciehp 0000:13:01.0:pcie24: Data Link Layer State change
>> [21833.389038] pciehp 0000:13:01.0:pcie24: slot(1-5): Link Down event
>> [21833.389076] pciehp 0000:13:01.0:pcie24: Disabling
>> domain:bus:device=0000:14:00
>> [21833.389078] pciehp 0000:13:01.0:pcie24: pciehp_unconfigure_device:
>> domain:bus:dev = 0000:14:00
>> [21833.389103] TW686x 0000:14:00.0: removing
>> [21833.416557] TW686x 0000:14:00.0: removed
>> [..]
>>
>> I have no idea why the link goes down (hardware issue?),
>> but it's better to handle it gracefully :)
>
> Could be hw issue indeed, FWIW I have never observed this problem on my
> hw (which is ARM-based and includes TW6869).
>
>> I understand that on some platforms this implementation could be too
>> costly (it's
>> completely cheap on any modern x86), and I intend to provide some option
>> to provide "frame DMA-to-buffer" and "scatter-gather DMA".
>
> Though I'm using the driver that I posted several months ago, with
> SG DMA field-only mode (SG DMA engine doesn't support frame mode and
> while non-SG DMA (field or frame) mode is certainly possible with CMA,
> copying the buffers is out of the question here).
>
> I wonder if that driver works for you (which would suggest a sw bug)
> or if the problems are the same (hw issue - system, power, or the chip
> itself).
>

No, it didn't. Using SG mode suffers from the same issues here.

>
> BTW adding incremental patches on top of the driver I posted would seem
> preferable to me. It would enable us to pinpoint (and not include)
> changes which tend to break something. For now, it seems I'll be stuck
> with my version, since I have to do DMA to buffers (though I could use
> the frame mode).
>
> Incremental patches are generally how it is done in Linux.
> Perhaps we should merge my driver first and you'd add your changes on
> top of it (preserving the existing functionality)?
>
> This is very easy with git.

Well, I plan to add SG mode as soon as this driver is merged, so hopefully you
won't have to use an out of tree driver anymore.
Krzysztof Hałasa Jan. 26, 2016, 11:16 a.m. UTC | #7
Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:

> Well, I plan to add SG mode as soon as this driver is merged, so hopefully you
> won't have to use an out of tree driver anymore.

So why don't you want to do it the normal way, i.e., add your specific
changes on top of my driver?

This way you don't have to add SG mode. It's already there. Also, this
means I (and others) don't have to hope. And, your changes can be much
better examined, bisected etc.

For now, there is no in-tree driver, all versions are out of tree.

At the moment, from my POV it all looks this way:
- I have written a driver and posted it for inclusion
- it works on my systems, complies with the LK, V4L standards etc.,
  though it probably still needs some small changes
- you took it, (I guess) added the needed changes (and others), removed
  the critical functionality, and want it merged instead of the
  original, working version.

I can only see two ways out (which make sense) from this. The first is:
we add my driver first and then your specific changes on top of it.

The other one: I add required changes (e.g. the one that sets default
mode on start, or something alike, I don't remember exactly) and then we
add the driver. Then I'll also add the non-SG CMA DMA frame and field
mode (DMA to buffers), since it seems I will need it (and it was a bit
overlooked).
Ezequiel Garcia Jan. 26, 2016, 12:35 p.m. UTC | #8
On 26 January 2016 at 08:16, Krzysztof Ha?asa <khalasa@piap.pl> wrote:
> Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:
>
>> Well, I plan to add SG mode as soon as this driver is merged, so hopefully you
>> won't have to use an out of tree driver anymore.
>
> So why don't you want to do it the normal way, i.e., add your specific
> changes on top of my driver?
>

As far as I can see, you sent a driver back in July:

https://patchwork.linuxtv.org/patch/30448/

I reviewed the driver as soon as it was sent, and planned to submit
changes to support my setup once your driver was merged, but that
never happened.

Since you never submitted a v2, I sincerely thought that after six
months you had lost the interest.
There is no "your" driver vs. "my" driver, it's the same driver, as
the copyright note explains.

> This way you don't have to add SG mode. It's already there. Also, this
> means I (and others) don't have to hope. And, your changes can be much
> better examined, bisected etc.
>
> For now, there is no in-tree driver, all versions are out of tree.
>
> At the moment, from my POV it all looks this way:
> - I have written a driver and posted it for inclusion
> - it works on my systems, complies with the LK, V4L standards etc.,
>   though it probably still needs some small changes
> - you took it, (I guess) added the needed changes (and others), removed
>   the critical functionality, and want it merged instead of the
>   original, working version.
>
> I can only see two ways out ( which make sense) from this. The first is:
> we add my driver first and then your specific changes on top of it.
>

If you want your driver merged, then you would have to submit it
again, addressing
my review comments. However, I have just posted a v2 and it would be nice if
you can review it and test it.

Thanks,
Krzysztof Hałasa Jan. 26, 2016, 3 p.m. UTC | #9
Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:

> I reviewed the driver as soon as it was sent, and planned to submit
> changes to support my setup once your driver was merged, but that
> never happened.

This was because you, shortly thereafter, stated:

> I'm working on an improved version of the tw686x driver. I've started
> with the patches
> you posted and made a significant number of changes:

> * Handling events in the top-half (removed bottom halves).
> * Audio support
> * Added CIF and D1 size support
> * some other goodies
> * a lot of code refactoring

> I'm now working on supporting both S-G and frame modes,
> so the driver will support INTERLACED and SEQ frames, and the
> user will have both options.

> I'll post a patchset as soon as it's working. Since I've started with
> your patch,
> your authorship will be retained and I'll add only my Signed-off-by.

And, when I asked about merging the combined work properly:

> Problem is I've re-written the driver, taking yours as a starting point
> and reference.

> In other words, I don't have a proper git branch with a history, starting
> from the patch you submitted. Instead, I would be submitting a new
> patch for Hans and Mauro to review.

> This patch is based in yours, so AFAIK should have your signature.

The latter was obviously not true - the code may retain the original
authors and copyrights (if it hasn't been rewritten completely), but
you have to remove the original S-O-B when you are submitting heavily
modified code - see the rules. Signature is not copyright/authorship,
it's who posts the code.


This is also why separating the work helps (especially in such
non-trivial cases) - the original code bears the original signature,
and the subsequent changes have their own. These things are invented
for a reason.


I really thought you have rewritten the driver from scratch, so my
inferior driver was of no use. In this situation submitting v2 didn't
make sense, though obviously I haven't written a driver for nothing -
I'm using it for my purposes.


What other options did I have at that time?

> If you want your driver merged, then you would have to submit it
> again, addressing
> my review comments.

Well, then this is something I can do. I wonder if it would be better
to post the raw code as a single patch, or to repost the original
version (already reviewed) and the subsequent patches (much smaller)
instead. Hans?

> However, I have just posted a v2 and it would be nice if
> you can review it and test it.

I can review it, however I can't really test it, because my ARM-based
systems require DMA to buffer functionality. Also, please not I'm not
a V4L2 expert, though I have a bit of experience with low level hw.


However, it would be much easier if you had posted an incremental patch
set instead. Also, WRT the merging, since this turns out to be in fact
my driver with your subsequent modifications (most of them very
valuable, I'm sure), I'd really think we should merge the original
driver first, and add the modifications, perhaps one-by-one, next.


This doesn't mean it has to wait. I can even do it all myself, simply
send your patches against my code and I'll merge them properly in my git
tree once they are positively reviewed. Hans could then merge it all
easily.


Does this make any sense?

Thanks in advance.
Ezequiel Garcia Jan. 27, 2016, 12:14 p.m. UTC | #10
On 26 January 2016 at 12:00, Krzysztof Ha?asa <khalasa@piap.pl> wrote:
> Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:
>
>> I reviewed the driver as soon as it was sent, and planned to submit
>> changes to support my setup once your driver was merged, but that
>> never happened.
>
> This was because you, shortly thereafter, stated:
>
>> I'm working on an improved version of the tw686x driver. I've started
>> with the patches
>> you posted and made a significant number of changes:
>
>> * Handling events in the top-half (removed bottom halves).
>> * Audio support
>> * Added CIF and D1 size support
>> * some other goodies
>> * a lot of code refactoring
>
>> I'm now working on supporting both S-G and frame modes,
>> so the driver will support INTERLACED and SEQ frames, and the
>> user will have both options.
>
>> I'll post a patchset as soon as it's working. Since I've started with
>> your patch,
>> your authorship will be retained and I'll add only my Signed-off-by.
>
> And, when I asked about merging the combined work properly:
>
>> Problem is I've re-written the driver, taking yours as a starting point
>> and reference.
>
>> In other words, I don't have a proper git branch with a history, starting
>> from the patch you submitted. Instead, I would be submitting a new
>> patch for Hans and Mauro to review.
>
>> This patch is based in yours, so AFAIK should have your signature.
>
> The latter was obviously not true - the code may retain the original
> authors and copyrights (if it hasn't been rewritten completely), but
> you have to remove the original S-O-B when you are submitting heavily
> modified code - see the rules. Signature is not copyright/authorship,
> it's who posts the code.
>
>
> This is also why separating the work helps (especially in such
> non-trivial cases) - the original code bears the original signature,
> and the subsequent changes have their own. These things are invented
> for a reason.
>
>
> I really thought you have rewritten the driver from scratch, so my
> inferior driver was of no use. In this situation submitting v2 didn't
> make sense, though obviously I haven't written a driver for nothing -
> I'm using it for my purposes.
>

Well, I kept the general organization, kept the registers definitions,
the rest was probably changed or re-written, mostly to meet
CodingStyle or to fix bugs. In any case it's hard to say, as it took
me 2 months to get that driver in a stable shape, and the
implementation changed a lot until it was stable.

On my setup, the requirement was to support an array of 2-chip cards
(16 ch per card). Ideally, it would be able to stream up to 96
channels simultaneously, in a single x86 box.

On those machines DMA scatter-gather wouldn't work because it ran out
of s-g resources (don't have the exact error here). Then I tried DMA
frame mode, which seemed to work fine until I found those unexplained
machine freezing.

As you can see in this patch, I had to use a very annoying memcpy to
avoid writing to the DMA, and also a timer to avoid resetting
registers too often.

This version of the driver passed all stress testing, and it's
installed on a lot of boxes running with long uptime.

Since I have no idea if this is a tw6869 issue or a card issue (it's
definitely not a software issue), I thought it would be important to
keep this workarounds in the mainline driver (interestingly, the
"official" windows driver also copies the buffers from the DMA buffer
to the buffer returned to the user).

>
> What other options did I have at that time?
>
>> If you want your driver merged, then you would have to submit it
>> again, addressing
>> my review comments.
>
> Well, then this is something I can do. I wonder if it would be better
> to post the raw code as a single patch, or to repost the original
> version (already reviewed) and the subsequent patches (much smaller)
> instead. Hans?
>
>> However, I have just posted a v2 and it would be nice if
>> you can review it and test it.
>
> I can review it, however I can't really test it, because my ARM-based
> systems require DMA to buffer functionality. Also, please not I'm not
> a V4L2 expert, though I have a bit of experience with low level hw.
>
>
> However, it would be much easier if you had posted an incremental patch
> set instead. Also, WRT the merging, since this turns out to be in fact
> my driver with your subsequent modifications (most of them very
> valuable, I'm sure), I'd really think we should merge the original
> driver first, and add the modifications, perhaps one-by-one, next.
>

Since your driver is not merged, there's no real benefit in my sending
me patches against it.

Also, notice that your driver from July needs a lot of work. Aside
from the review I provided back in July, you need to get rid of your
kthread, port it to the new API, and add audio.

Since I just submitted a v2 driver that seems to be ready to be
merged, how about I just add DMA s-g support so you get all the
functionality you need?

This option sounds much easier than you going through all the pain of
cleaning up your driver.

How does it sound?
Krzysztof Hałasa Jan. 28, 2016, 7:25 a.m. UTC | #11
Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:

> Since your driver is not merged, there's no real benefit in my sending
> me patches against it.

And it's not merged because you stated that you have produced
a rewritten driver, using my driver just as a reference, and I was naive
enough to believe it and let it go.

> Since I just submitted a v2 driver that seems to be ready to be
> merged, how about I just add DMA s-g support so you get all the
> functionality you need?
>
> This option sounds much easier than you going through all the pain of
> cleaning up your driver.

Do I really have to answer such questions?

One can't simply take someone's code, replace the MODULE_AUTHOR,
twist a bit to suit his needs, and send it as his own.

In my country, it wouldn't be even legal.



I have at least one similar situation here. I'm using frame grabber
drivers for an I.MX6 processor on-chip feature. The problem is, the
author hasn't yet managed (for years now) to have this functionality
merged into the official tree. Obviously, I'm putting some considerable
work in it. Does this mean I'm free to grab it as my own and request
that it is to be merged instead? No, I have to wait until the original
work is merged, and only then I can ask for my patches to be applied
(in the form of changes, not a raw driver code).
Hans Verkuil Jan. 28, 2016, 7:43 a.m. UTC | #12
On 01/28/2016 08:25 AM, Krzysztof Ha?asa wrote:
> Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:
> 
>> Since your driver is not merged, there's no real benefit in my sending
>> me patches against it.
> 
> And it's not merged because you stated that you have produced
> a rewritten driver, using my driver just as a reference, and I was naive
> enough to believe it and let it go.
> 
>> Since I just submitted a v2 driver that seems to be ready to be
>> merged, how about I just add DMA s-g support so you get all the
>> functionality you need?
>>
>> This option sounds much easier than you going through all the pain of
>> cleaning up your driver.
> 
> Do I really have to answer such questions?
> 
> One can't simply take someone's code, replace the MODULE_AUTHOR,
> twist a bit to suit his needs, and send it as his own.

As long as copyright notices are retained (and that also includes a
MODULE_AUTHOR: Ezequiel, if you removed that than you should put it
back and add a second MODULE_AUTHOR with your name), then you are free
to do so if the code is licensed under a GPL.

> In my country, it wouldn't be even legal.

It's legal for the GPL license since that gives explicit permission.

> 
> 
> 
> I have at least one similar situation here. I'm using frame grabber
> drivers for an I.MX6 processor on-chip feature. The problem is, the
> author hasn't yet managed (for years now) to have this functionality
> merged into the official tree. Obviously, I'm putting some considerable
> work in it. Does this mean I'm free to grab it as my own and request
> that it is to be merged instead? No, I have to wait until the original
> work is merged, and only then I can ask for my patches to be applied
> (in the form of changes, not a raw driver code).

Wrong. As long as the original code is distributed as GPL you can
certainly take it, fix it and ask for it to be merged.

This happens all the time if the original author has left the scene, or has
no time or interest to follow-up on his patches.

From the point of view as a reviewer and all things being equal the first
who comes up with a decent driver that passes the quality tests will get
merged.

In this particular case I've asked Ezequiel to put back the functionality
that he removed, since I thought that was a reasonable compromise (i.e.
you're both unhappy, so that's only half the misery for each :-) ).

For future reference: if someone posts code to a kernel mailinglist and does
not fix any comments made on the code in, let's say, 1-2 months, then
someone else might just step in. Once posted you lose control over your
code (they are kernel drivers, so always GPL). Normally nobody wants to
take over the code unless no visible progress is made for a few months.

Anyway, what's done is done.

Regards,

	Hans
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Krzysztof Hałasa Jan. 28, 2016, 8:51 a.m. UTC | #13
Hans Verkuil <hverkuil@xs4all.nl> writes:

>> In my country, it wouldn't be even legal.
>
> It's legal for the GPL license since that gives explicit permission.

In my country, claiming authorship (not co-authorship) of someone's code
is illegal. Even if done with author's permission.

>> I have at least one similar situation here. I'm using frame grabber
>> drivers for an I.MX6 processor on-chip feature. The problem is, the
>> author hasn't yet managed (for years now) to have this functionality
>> merged into the official tree. Obviously, I'm putting some considerable
>> work in it. Does this mean I'm free to grab it as my own and request
>> that it is to be merged instead? No, I have to wait until the original
>> work is merged, and only then I can ask for my patches to be applied
>> (in the form of changes, not a raw driver code).
>
> Wrong. As long as the original code is distributed as GPL you can
> certainly take it, fix it and ask for it to be merged.
>
> This happens all the time if the original author has left the scene, or has
> no time or interest to follow-up on his patches.

This doesn't seem to be applicable in either case.

> For future reference: if someone posts code to a kernel mailinglist and does
> not fix any comments made on the code in, let's say, 1-2 months, then
> someone else might just step in.

Oh, come on. I let it go because Ezequiel wrote he had rewritten the
driver and wanted to merge it instead. I first asked for diffs vs. my
code, but in case of a rewrite such diffs don't make sense.


I don't say nobody is allowed to take my work and add his own on top.
Actually, this was what I proposed at least twice.

Is there a problem with rebasing his work on top of mine, and showing
the real changes? Git makes it easy.
diff mbox

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 4635e1d14612..9308f8242cd3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10846,6 +10846,14 @@  W:	https://linuxtv.org
 S:	Odd Fixes
 F:	drivers/media/pci/tw68/
 
+TW686X VIDEO4LINUX DRIVER
+M:	Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
+L:	linux-media@vger.kernel.org
+T:	git git://linuxtv.org/media_tree.git
+W:	http://linuxtv.org
+S:	Maintained
+F:	drivers/media/pci/tw686x/
+
 TPM DEVICE DRIVER
 M:	Peter Huewe <peterhuewe@gmx.de>
 M:	Marcel Selhorst <tpmdd@selhorst.net>
diff --git a/drivers/media/pci/Kconfig b/drivers/media/pci/Kconfig
index 48a611bc3e18..4f6467fbaeb4 100644
--- a/drivers/media/pci/Kconfig
+++ b/drivers/media/pci/Kconfig
@@ -14,6 +14,7 @@  source "drivers/media/pci/meye/Kconfig"
 source "drivers/media/pci/solo6x10/Kconfig"
 source "drivers/media/pci/sta2x11/Kconfig"
 source "drivers/media/pci/tw68/Kconfig"
+source "drivers/media/pci/tw686x/Kconfig"
 source "drivers/media/pci/zoran/Kconfig"
 endif
 
diff --git a/drivers/media/pci/Makefile b/drivers/media/pci/Makefile
index 5f8aacb8b9b8..2e54c36441f7 100644
--- a/drivers/media/pci/Makefile
+++ b/drivers/media/pci/Makefile
@@ -25,6 +25,7 @@  obj-$(CONFIG_VIDEO_BT848) += bt8xx/
 obj-$(CONFIG_VIDEO_SAA7134) += saa7134/
 obj-$(CONFIG_VIDEO_SAA7164) += saa7164/
 obj-$(CONFIG_VIDEO_TW68) += tw68/
+obj-$(CONFIG_VIDEO_TW686X) += tw686x/
 obj-$(CONFIG_VIDEO_DT3155) += dt3155/
 obj-$(CONFIG_VIDEO_MEYE) += meye/
 obj-$(CONFIG_STA2X11_VIP) += sta2x11/
diff --git a/drivers/media/pci/tw686x/Kconfig b/drivers/media/pci/tw686x/Kconfig
new file mode 100644
index 000000000000..bd73d3dd25b4
--- /dev/null
+++ b/drivers/media/pci/tw686x/Kconfig
@@ -0,0 +1,18 @@ 
+config VIDEO_TW686X
+	tristate "Intersil/Techwell TW686x video capture cards"
+	depends on PCI && VIDEO_DEV && VIDEO_V4L2 && SND
+	depends on HAS_DMA
+	select VIDEOBUF2_DMA_CONTIG
+	select SND_PCM
+	help
+	  Support for Intersil/Techwell TW686x-based frame grabber cards.
+
+	  Currently supported chips:
+	  - TW6864 (4 video channels),
+	  - TW6865 (4 video channels, not tested, second generation chip),
+	  - TW6868 (8 video channels but only 4 first channels using
+	    built-in video decoder are supported, not tested),
+	  - TW6869 (8 video channels, second generation chip).
+
+	  To compile this driver as a module, choose M here: the module
+	  will be named tw686x.
diff --git a/drivers/media/pci/tw686x/Makefile b/drivers/media/pci/tw686x/Makefile
new file mode 100644
index 000000000000..99819542b733
--- /dev/null
+++ b/drivers/media/pci/tw686x/Makefile
@@ -0,0 +1,3 @@ 
+tw686x-objs := tw686x-core.o tw686x-video.o tw686x-audio.o
+
+obj-$(CONFIG_VIDEO_TW686X) += tw686x.o
diff --git a/drivers/media/pci/tw686x/tw686x-audio.c b/drivers/media/pci/tw686x/tw686x-audio.c
new file mode 100644
index 000000000000..2295d2d1a945
--- /dev/null
+++ b/drivers/media/pci/tw686x/tw686x-audio.c
@@ -0,0 +1,379 @@ 
+/*
+ * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
+ *
+ * Based on the audio support from the tw6869 driver:
+ * Copyright 2015 www.starterkit.ru <info@starterkit.ru>
+ *
+ * Based on:
+ * Driver for Intersil|Techwell TW6869 based DVR cards
+ * (c) 2011-12 liran <jli11@intersil.com> [Intersil|Techwell China]
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/control.h>
+#include "tw686x.h"
+#include "tw686x-regs.h"
+
+#define AUDIO_CHANNEL_OFFSET 8
+
+void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
+		      unsigned int pb_status)
+{
+	unsigned long flags;
+	unsigned int ch, pb;
+
+	for_each_set_bit(ch, &requests, max_channels(dev)) {
+
+		struct tw686x_audio_channel *ac = &dev->audio_channels[ch];
+		struct tw686x_audio_buf *done = NULL;
+		struct tw686x_audio_buf *next = NULL;
+		struct tw686x_dma_desc *desc;
+
+		pb = !!(pb_status & BIT(AUDIO_CHANNEL_OFFSET + ch));
+
+		spin_lock_irqsave(&ac->lock, flags);
+
+		/* Sanity check */
+		if (!ac->ss || !ac->curr_bufs[0] || !ac->curr_bufs[1]) {
+			spin_unlock_irqrestore(&ac->lock, flags);
+			continue;
+		}
+
+		if (!list_empty(&ac->buf_list)) {
+			next = list_first_entry(&ac->buf_list,
+					struct tw686x_audio_buf, list);
+			list_move_tail(&next->list, &ac->buf_list);
+			done = ac->curr_bufs[!pb];
+			ac->curr_bufs[pb] = next;
+		}
+		spin_unlock_irqrestore(&ac->lock, flags);
+
+		desc = &ac->dma_descs[pb];
+		if (done && next && desc->virt) {
+			memcpy(done->virt, desc->virt, desc->size);
+			ac->ptr = done->dma - ac->buf[0].dma;
+			snd_pcm_period_elapsed(ac->ss);
+		}
+	}
+}
+
+static int tw686x_pcm_hw_params(struct snd_pcm_substream *ss,
+				struct snd_pcm_hw_params *hw_params)
+{
+	return snd_pcm_lib_malloc_pages(ss, params_buffer_bytes(hw_params));
+}
+
+static int tw686x_pcm_hw_free(struct snd_pcm_substream *ss)
+{
+	return snd_pcm_lib_free_pages(ss);
+}
+
+static const struct snd_pcm_hardware tw686x_capture_hw = {
+	.info			= (SNDRV_PCM_INFO_MMAP |
+				   SNDRV_PCM_INFO_INTERLEAVED |
+				   SNDRV_PCM_INFO_BLOCK_TRANSFER |
+				   SNDRV_PCM_INFO_MMAP_VALID),
+	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
+	.rates			= SNDRV_PCM_RATE_8000_48000,
+	.rate_min		= 8000,
+	.rate_max		= 48000,
+	.channels_min		= 1,
+	.channels_max		= 1,
+	.buffer_bytes_max	= TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE,
+	.period_bytes_min	= TW686X_PAGE_SIZE,
+	.period_bytes_max	= TW686X_PAGE_SIZE,
+	.periods_min		= 2,
+	.periods_max		= TW686X_AUDIO_PAGE_MAX,
+};
+
+static int tw686x_pcm_open(struct snd_pcm_substream *ss)
+{
+	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
+	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
+	struct snd_pcm_runtime *rt = ss->runtime;
+	int err;
+
+	ac->ss = ss;
+	rt->hw = tw686x_capture_hw;
+
+	err = snd_pcm_hw_constraint_integer(rt, SNDRV_PCM_HW_PARAM_PERIODS);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int tw686x_pcm_close(struct snd_pcm_substream *ss)
+{
+	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
+	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
+
+	ac->ss = NULL;
+	return 0;
+}
+
+static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
+{
+	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
+	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
+	struct snd_pcm_runtime *rt = ss->runtime;
+	unsigned int period_size = snd_pcm_lib_period_bytes(ss);
+	struct tw686x_audio_buf *p_buf, *b_buf;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (dev->audio_rate != rt->rate) {
+		u32 reg;
+
+		dev->audio_rate = rt->rate;
+		reg = ((125000000 / rt->rate) << 16) +
+		       ((125000000 % rt->rate) << 16) / rt->rate;
+
+		reg_write(dev, AUDIO_CONTROL2, reg);
+	}
+
+	if ((period_size != TW686X_PAGE_SIZE) ||
+	    (rt->periods < 2) || (rt->periods > TW686X_AUDIO_PAGE_MAX)) {
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&ac->lock, flags);
+	INIT_LIST_HEAD(&ac->buf_list);
+
+	for (i = 0; i < rt->periods; i++) {
+		ac->buf[i].dma = rt->dma_addr + period_size * i;
+		ac->buf[i].virt = rt->dma_area + period_size * i;
+		INIT_LIST_HEAD(&ac->buf[i].list);
+		list_add_tail(&ac->buf[i].list, &ac->buf_list);
+	}
+
+	p_buf =	list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
+	list_move_tail(&p_buf->list, &ac->buf_list);
+
+	b_buf =	list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
+	list_move_tail(&b_buf->list, &ac->buf_list);
+
+	ac->curr_bufs[0] = p_buf;
+	ac->curr_bufs[1] = b_buf;
+	ac->ptr = 0;
+	spin_unlock_irqrestore(&ac->lock, flags);
+
+	return 0;
+}
+
+static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
+{
+	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
+	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
+	unsigned long flags;
+	int err = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		if (ac->curr_bufs[0] && ac->curr_bufs[1]) {
+			spin_lock_irqsave(&dev->lock, flags);
+			tw686x_enable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
+			spin_unlock_irqrestore(&dev->lock, flags);
+
+			mod_timer(&dev->dma_delay_timer,
+				  jiffies + msecs_to_jiffies(100));
+		} else {
+			err = -EIO;
+		}
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		spin_lock_irqsave(&dev->lock, flags);
+		tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
+		spin_unlock_irqrestore(&dev->lock, flags);
+
+		spin_lock_irqsave(&ac->lock, flags);
+		ac->curr_bufs[0] = NULL;
+		ac->curr_bufs[1] = NULL;
+		spin_unlock_irqrestore(&ac->lock, flags);
+		break;
+	default:
+		err = -EINVAL;
+	}
+	return err;
+}
+
+static snd_pcm_uframes_t tw686x_pcm_pointer(struct snd_pcm_substream *ss)
+{
+	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
+	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
+
+	return bytes_to_frames(ss->runtime, ac->ptr);
+}
+
+static struct snd_pcm_ops tw686x_pcm_ops = {
+	.open = tw686x_pcm_open,
+	.close = tw686x_pcm_close,
+	.ioctl = snd_pcm_lib_ioctl,
+	.hw_params = tw686x_pcm_hw_params,
+	.hw_free = tw686x_pcm_hw_free,
+	.prepare = tw686x_pcm_prepare,
+	.trigger = tw686x_pcm_trigger,
+	.pointer = tw686x_pcm_pointer,
+};
+
+static int tw686x_snd_pcm_init(struct tw686x_dev *dev)
+{
+	struct snd_card *card = dev->snd_card;
+	struct snd_pcm *pcm;
+	struct snd_pcm_substream *ss;
+	unsigned int i;
+	int err;
+
+	err = snd_pcm_new(card, card->driver, 0, 0, max_channels(dev), &pcm);
+	if (err < 0)
+		return err;
+
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &tw686x_pcm_ops);
+	snd_pcm_chip(pcm) = dev;
+	pcm->info_flags = 0;
+	strcpy(pcm->name, "tw686x PCM");
+
+	for (i = 0, ss = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
+	     ss; ss = ss->next, i++)
+		sprintf(ss->name, "vch%u audio", i);
+
+	return snd_pcm_lib_preallocate_pages_for_all(pcm,
+				SNDRV_DMA_TYPE_DEV,
+				snd_dma_pci_data(dev->pci_dev),
+				TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE,
+				TW686X_AUDIO_PAGE_MAX * TW686X_PAGE_SIZE);
+}
+
+static void tw686x_audio_dma_free(struct tw686x_dev *dev,
+				  struct tw686x_audio_channel *ac)
+{
+	int pb;
+
+	for (pb = 0; pb < 2; pb++) {
+		if (!ac->dma_descs[pb].virt)
+			continue;
+		pci_free_consistent(dev->pci_dev, ac->dma_descs[pb].size,
+				    ac->dma_descs[pb].virt,
+				    ac->dma_descs[pb].phys);
+		ac->dma_descs[pb].virt = NULL;
+	}
+}
+
+static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
+				  struct tw686x_audio_channel *ac)
+{
+	int pb;
+
+	for (pb = 0; pb < 2; pb++) {
+		u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch];
+		void *virt;
+
+		virt = pci_alloc_consistent(dev->pci_dev, TW686X_PAGE_SIZE,
+					    &ac->dma_descs[pb].phys);
+		if (!virt) {
+			dev_err(&dev->pci_dev->dev,
+				"dma%d: unable to allocate audio DMA %s-buffer\n",
+				ac->ch, pb ? "B" : "P");
+			return -ENOMEM;
+		}
+		ac->dma_descs[pb].virt = virt;
+		ac->dma_descs[pb].size = TW686X_PAGE_SIZE;
+		reg_write(dev, reg, ac->dma_descs[pb].phys);
+	}
+	return 0;
+}
+
+void tw686x_audio_free(struct tw686x_dev *dev)
+{
+	unsigned long flags;
+	u32 dma_ch_mask;
+	u32 dma_cmd;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	dma_cmd = reg_read(dev, DMA_CMD);
+	dma_ch_mask = reg_read(dev, DMA_CHANNEL_ENABLE);
+	reg_write(dev, DMA_CMD, dma_cmd & ~0xff00);
+	reg_write(dev, DMA_CHANNEL_ENABLE, dma_ch_mask & ~0xff00);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (!dev->snd_card)
+		return;
+	snd_card_free(dev->snd_card);
+	dev->snd_card = NULL;
+}
+
+int tw686x_audio_init(struct tw686x_dev *dev)
+{
+	struct pci_dev *pci_dev = dev->pci_dev;
+	struct snd_card *card;
+	int err, ch;
+
+	/*
+	 * AUDIO_CONTROL1
+	 * DMA byte length [31:19] = 4096 (i.e. ALSA period)
+	 * External audio enable [0] = enabled
+	 */
+	reg_write(dev, AUDIO_CONTROL1, 0x80000001);
+
+	err = snd_card_new(&pci_dev->dev, SNDRV_DEFAULT_IDX1,
+			   SNDRV_DEFAULT_STR1,
+			   THIS_MODULE, 0, &card);
+	if (err < 0)
+		return err;
+
+	dev->snd_card = card;
+	strcpy(card->driver, "tw686x");
+	strcpy(card->shortname, "tw686x");
+	sprintf(card->longname, "%s", pci_name(pci_dev));
+	snd_card_set_dev(card, &pci_dev->dev);
+
+	for (ch = 0; ch < max_channels(dev); ch++) {
+		struct tw686x_audio_channel *ac;
+
+		ac = &dev->audio_channels[ch];
+		spin_lock_init(&ac->lock);
+		ac->dev = dev;
+		ac->ch = ch;
+
+		err = tw686x_audio_dma_alloc(dev, ac);
+		if (err < 0)
+			goto err_cleanup;
+	}
+
+	err = tw686x_snd_pcm_init(dev);
+	if (err < 0)
+		goto err_cleanup;
+
+	err = snd_card_register(card);
+	if (!err)
+		return 0;
+
+err_cleanup:
+	for (ch = 0; ch < max_channels(dev); ch++) {
+		if (!dev->audio_channels[ch].dev)
+			continue;
+		tw686x_audio_dma_free(dev, &dev->audio_channels[ch]);
+	}
+	snd_card_free(card);
+	dev->snd_card = NULL;
+	return err;
+}
diff --git a/drivers/media/pci/tw686x/tw686x-core.c b/drivers/media/pci/tw686x/tw686x-core.c
new file mode 100644
index 000000000000..8774facb29d5
--- /dev/null
+++ b/drivers/media/pci/tw686x/tw686x-core.c
@@ -0,0 +1,356 @@ 
+/*
+ * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
+ *
+ * Based on original driver by Krzysztof Ha?asa:
+ * Copyright (C) 2015 Industrial Research Institute for Automation
+ * and Measurements PIAP
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci_ids.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+
+#include "tw686x.h"
+#include "tw686x-regs.h"
+
+static u32 dma_interval = 0x00098968;
+module_param(dma_interval, int, 0444);
+MODULE_PARM_DESC(dma_interval, "Minimum time span for DMA interrupting host");
+
+/*
+ * The purpose of this awful hack is to avoid
+ * enabling the DMA channels "too fast" which seems
+ * to make some TW686x devices _very_ angry and freeze the CPU.
+ */
+static void tw686x_dma_delay(unsigned long data)
+{
+        struct tw686x_dev *dev = (struct tw686x_dev *) data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	reg_write(dev, DMA_CHANNEL_ENABLE, dev->pending_dma_en);
+	reg_write(dev, DMA_CMD, dev->pending_dma_cmd);
+	dev->pending_dma_en = 0;
+	dev->pending_dma_cmd = 0;
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+static void tw686x_reset_channels(struct tw686x_dev *dev, unsigned int ch_mask)
+{
+	u32 dma_en, dma_cmd;
+
+	dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
+	dma_cmd = reg_read(dev, DMA_CMD);
+
+	/*
+	 * Save pending register status, the timer will
+	 * restore them.
+	 */
+	dev->pending_dma_en |= dma_en;
+	dev->pending_dma_cmd |= dma_cmd;
+
+	/* Disable the reset channels */
+	reg_write(dev, DMA_CHANNEL_ENABLE, dma_en & ~ch_mask);
+
+	if ((dma_en & ~ch_mask) == 0) {
+		dev_dbg(&dev->pci_dev->dev, "reset: stopping DMA\n");
+		dma_cmd &= ~BIT(31);
+	}
+	reg_write(dev, DMA_CMD, dma_cmd & ~ch_mask);
+}
+
+static irqreturn_t tw686x_irq(int irq, void *dev_id)
+{
+	struct tw686x_dev *dev = (struct tw686x_dev *)dev_id;
+	unsigned int video_requests, audio_requests, reset_ch;
+	u32 fifo_status, fifo_signal, fifo_ov, fifo_bad, fifo_errors;
+	u32 int_status, dma_en, video_en, pb_status;
+	unsigned long flags;
+
+	int_status = reg_read(dev, INT_STATUS); /* cleared on read */
+	fifo_status = reg_read(dev, VIDEO_FIFO_STATUS);
+
+	/* INT_STATUS does not include FIFO_STATUS errors! */
+	if (!int_status && !TW686X_FIFO_ERROR(fifo_status))
+		return IRQ_NONE;
+
+	if (int_status & BIT(17)) {
+		dev_dbg(&dev->pci_dev->dev,
+			"DMA timeout. Resetting DMA for all channels\n");
+		reset_ch = ~0;
+		goto reset_channels;
+	}
+
+	spin_lock_irqsave(&dev->lock, flags);
+	dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	video_en = dma_en & 0xff;
+	fifo_signal = ~(fifo_status & 0xff) & video_en;
+	fifo_ov = fifo_status >> 24;
+	fifo_bad = fifo_status >> 16;
+
+	/* Mask of channels with signal and FIFO errors */
+	fifo_errors = fifo_signal & (fifo_ov | fifo_bad);
+
+	reset_ch = 0;
+	pb_status = reg_read(dev, PB_STATUS);
+
+	/* Coalesce video frame/error events */
+	video_requests = (int_status & video_en) | fifo_errors;
+	audio_requests = (int_status & dma_en) >> 8;
+
+	if (video_requests)
+		tw686x_video_irq(dev, video_requests, pb_status,
+				 fifo_status, &reset_ch);
+	if (audio_requests)
+		tw686x_audio_irq(dev, audio_requests, pb_status);
+
+reset_channels:
+	if (reset_ch) {
+		spin_lock_irqsave(&dev->lock, flags);
+		tw686x_reset_channels(dev, reset_ch);
+		spin_unlock_irqrestore(&dev->lock, flags);
+		mod_timer(&dev->dma_delay_timer,
+			  jiffies + msecs_to_jiffies(100));
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void tw686x_dev_release(struct v4l2_device *v4l2_dev)
+{
+        struct tw686x_dev *dev = container_of(v4l2_dev, struct tw686x_dev,
+					      v4l2_dev);
+	unsigned int ch;
+
+	for (ch = 0; ch < max_channels(dev); ch++)
+		v4l2_ctrl_handler_free(&dev->video_channels[ch].ctrl_handler);
+
+	v4l2_device_unregister(&dev->v4l2_dev);
+
+	kfree(dev->audio_channels);
+	kfree(dev->video_channels);
+	kfree(dev);
+}
+
+static int tw686x_probe(struct pci_dev *pci_dev,
+			const struct pci_device_id *pci_id)
+{
+	struct tw686x_dev *dev;
+	int err;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+	dev->type = pci_id->driver_data;
+	sprintf(dev->name, "tw%04X", pci_dev->device);
+
+	dev->video_channels = kcalloc(max_channels(dev),
+		sizeof(*dev->video_channels), GFP_KERNEL);
+	if (!dev->video_channels) {
+		err = -ENOMEM;
+		goto free_dev;
+	}
+
+	dev->audio_channels = kcalloc(max_channels(dev),
+		sizeof(*dev->audio_channels), GFP_KERNEL);
+	if (!dev->audio_channels) {
+		err = -ENOMEM;
+		goto free_video;
+	}
+
+	pr_info("%s: PCI %s, IRQ %d, MMIO 0x%lx\n", dev->name,
+		pci_name(pci_dev), pci_dev->irq,
+		(unsigned long)pci_resource_start(pci_dev, 0));
+
+	dev->pci_dev = pci_dev;
+	if (pci_enable_device(pci_dev)) {
+		err = -EIO;
+		goto free_audio;
+	}
+
+	pci_set_master(pci_dev);
+	err = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
+	if (err) {
+		dev_err(&pci_dev->dev, "32-bit PCI DMA not supported\n");
+		err = -EIO;
+		goto disable_pci;
+	}
+
+	err = pci_request_regions(pci_dev, dev->name);
+	if (err) {
+		dev_err(&pci_dev->dev, "unable to request PCI region\n");
+		goto disable_pci;
+	}
+
+	dev->mmio = pci_ioremap_bar(pci_dev, 0);
+	if (!dev->mmio) {
+		dev_err(&pci_dev->dev, "unable to remap PCI region\n");
+		err = -ENOMEM;
+		goto free_region;
+	}
+
+	/* Reset all subsystems */
+	reg_write(dev, SYS_SOFT_RST, 0x0F);
+	mdelay(1);
+
+	reg_write(dev, SRST[0], 0x3F);
+	if (max_channels(dev) > 4)
+		reg_write(dev, SRST[1], 0x3F);
+
+	/* Disable the DMA engine */
+	reg_write(dev, DMA_CMD, 0);
+	reg_write(dev, DMA_CHANNEL_ENABLE, 0);
+
+	/* Enable DMA FIFO overflow and pointer check */
+	reg_write(dev, DMA_CONFIG, 0xFFFFFF04);
+	reg_write(dev, DMA_CHANNEL_TIMEOUT, 0x140C8584);
+	reg_write(dev, DMA_TIMER_INTERVAL, dma_interval);
+
+	spin_lock_init(&dev->lock);
+
+	err = request_irq(pci_dev->irq, tw686x_irq, IRQF_SHARED,
+			  dev->name, dev);
+	if (err < 0) {
+		dev_err(&pci_dev->dev, "unable to request interrupt\n");
+		goto iounmap;
+	}
+
+	setup_timer(&dev->dma_delay_timer,
+		    tw686x_dma_delay, (unsigned long) dev);
+
+	/*
+	 * This must be set right before initializing v4l2_dev.
+	 * It's used to release resources after the last handle
+	 * held is released.
+	 */
+	dev->v4l2_dev.release = tw686x_dev_release;
+	err = tw686x_video_init(dev);
+	if (err) {
+		dev_err(&pci_dev->dev, "can't register video\n");
+		goto free_irq;
+	}
+
+	err = tw686x_audio_init(dev);
+	if (err) {
+		dev_warn(&pci_dev->dev, "can't register audio\n");
+	}
+
+	pci_set_drvdata(pci_dev, dev);
+	return 0;
+
+free_irq:
+	free_irq(pci_dev->irq, dev);
+iounmap:
+	pci_iounmap(pci_dev, dev->mmio);
+free_region:
+	pci_release_regions(pci_dev);
+disable_pci:
+	pci_disable_device(pci_dev);
+free_audio:
+	kfree(dev->audio_channels);
+free_video:
+	kfree(dev->video_channels);
+free_dev:
+	kfree(dev);
+	return err;
+}
+
+static void tw686x_remove(struct pci_dev *pci_dev)
+{
+	struct tw686x_dev *dev = pci_get_drvdata(pci_dev);
+	unsigned long flags;
+
+	/* This guarantees the IRQ handler is no longer running,
+	 * which means we can kiss good-bye some resources.
+	 */
+	free_irq(pci_dev->irq, dev);
+
+	tw686x_video_free(dev);
+	tw686x_audio_free(dev);
+	del_timer_sync(&dev->dma_delay_timer);
+
+	pci_iounmap(pci_dev, dev->mmio);
+	pci_release_regions(pci_dev);
+	pci_disable_device(pci_dev);
+
+	/*
+	 * This allows to detect device is not here,
+	 * and will be used by vb2_ops. The lock is really
+	 * important here.
+	 */
+	spin_lock_irqsave(&dev->lock, flags);
+	dev->pci_dev = NULL;
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+        /*
+         * This calls tw686x_dev_release if it's the last reference.
+         * therwise, release is posponed until there are no users left.
+         */
+        v4l2_device_put(&dev->v4l2_dev);
+}
+
+/*
+ * On TW6864 and TW6868, all channels share the pair of video DMA SG tables,
+ * with 10-bit start_idx and end_idx determining start and end of frame buffer
+ * for particular channel.
+ * TW6868 with all its 8 channels would be problematic (only 127 SG entries per
+ * channel) but we support only 4 channels on this chip anyway (the first
+ * 4 channels are driven with internal video decoder, the other 4 would require
+ * an external TW286x part).
+ *
+ * On TW6865 and TW6869, each channel has its own DMA SG table, with indexes
+ * starting with 0. Both chips have complete sets of internal video decoders
+ * (respectively 4 or 8-channel).
+ *
+ * All chips have separate SG tables for two video frames.
+ */
+
+/* driver_data is number of A/V channels */
+static const struct pci_device_id tw686x_pci_tbl[] = {
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6864),
+		.driver_data = 4
+	},
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6865), /* not tested */
+		.driver_data = 4 | TYPE_SECOND_GEN
+	},
+	/*
+	 * TW6868 supports 8 A/V channels with an external TW2865 chip;
+	 * not supported by the driver.
+	 */
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6868), /* not tested */
+		.driver_data = 4
+	},
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6869),
+		.driver_data = 8 | TYPE_SECOND_GEN},
+	{}
+};
+MODULE_DEVICE_TABLE(pci, tw686x_pci_tbl);
+
+static struct pci_driver tw686x_pci_driver = {
+	.name = "tw686x",
+	.id_table = tw686x_pci_tbl,
+	.probe = tw686x_probe,
+	.remove = tw686x_remove,
+};
+module_pci_driver(tw686x_pci_driver);
+
+MODULE_DESCRIPTION("Driver for video frame grabber cards based on Intersil/Techwell TW686[4589]");
+MODULE_AUTHOR("Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/media/pci/tw686x/tw686x-regs.h b/drivers/media/pci/tw686x/tw686x-regs.h
new file mode 100644
index 000000000000..92c331ceb065
--- /dev/null
+++ b/drivers/media/pci/tw686x/tw686x-regs.h
@@ -0,0 +1,118 @@ 
+/* DMA controller registers */
+#define REG8_1(a0) ((const u16[8]){a0, a0 + 1, a0 + 2, a0 + 3,		\
+				   a0 + 4, a0 + 5, a0 + 6, a0 + 7})
+#define REG8_2(a0) ((const u16[8]){a0, a0 + 2, a0 + 4, a0 + 6,		\
+				   a0 + 8, a0 + 0xA, a0 + 0xC, a0 + 0xE})
+#define REG8_8(a0) ((const u16[8]){a0, a0 + 8, a0 + 0x10, a0 + 0x18,	\
+				   a0 + 0x20, a0 + 0x28, a0 + 0x30, a0 + 0x38})
+#define INT_STATUS		0x00
+#define PB_STATUS		0x01
+#define DMA_CMD			0x02
+#define VIDEO_FIFO_STATUS	0x03
+#define VIDEO_CHANNEL_ID	0x04
+#define VIDEO_PARSER_STATUS	0x05
+#define SYS_SOFT_RST		0x06
+#define DMA_PAGE_TABLE0_ADDR	((const u16[8]){0x08, 0xD0, 0xD2, 0xD4,	\
+						0xD6, 0xD8, 0xDA, 0xDC})
+#define DMA_PAGE_TABLE1_ADDR	((const u16[8]){0x09, 0xD1, 0xD3, 0xD5,	\
+						0xD7, 0xD9, 0xDB, 0xDD})
+#define DMA_CHANNEL_ENABLE	0x0a
+#define DMA_CONFIG		0x0b
+#define DMA_TIMER_INTERVAL	0x0c
+#define DMA_CHANNEL_TIMEOUT	0x0d
+#define VDMA_CHANNEL_CONFIG	REG8_1(0x10)
+#define ADMA_P_ADDR		REG8_2(0x18)
+#define ADMA_B_ADDR		REG8_2(0x19)
+#define DMA10_P_ADDR		0x28 /* ??? */
+#define DMA10_B_ADDR		0x29
+#define VIDEO_CONTROL1		0x2A
+#define VIDEO_CONTROL2		0x2B
+#define AUDIO_CONTROL1		0x2C
+#define AUDIO_CONTROL2		0x2D
+#define PHASE_REF		0x2E
+#define GPIO_REG		0x2F
+#define INTL_HBAR_CTRL		REG8_1(0x30)
+#define AUDIO_CONTROL3		0x38
+#define VIDEO_FIELD_CTRL	REG8_1(0x39)
+#define HSCALER_CTRL		REG8_1(0x42)
+#define VIDEO_SIZE		REG8_1(0x4A)
+#define VIDEO_SIZE_F2		REG8_1(0x52)
+#define MD_CONF			REG8_1(0x60)
+#define MD_INIT			REG8_1(0x68)
+#define MD_MAP0			REG8_1(0x70)
+#define VDMA_P_ADDR		REG8_8(0x80) /* not used in DMA SG mode */
+#define VDMA_WHP		REG8_8(0x81)
+#define VDMA_B_ADDR		REG8_8(0x82)
+#define VDMA_F2_P_ADDR		REG8_8(0x84)
+#define VDMA_F2_WHP		REG8_8(0x85)
+#define VDMA_F2_B_ADDR		REG8_8(0x86)
+#define EP_REG_ADDR		0xFE
+#define EP_REG_DATA		0xFF
+
+/* Video decoder registers */
+#define VDREG8(a0) ((const u16[8]){			\
+	a0 + 0x000, a0 + 0x010, a0 + 0x020, a0 + 0x030,	\
+	a0 + 0x100, a0 + 0x110, a0 + 0x120, a0 + 0x130})
+#define VIDSTAT			VDREG8(0x100)
+#define BRIGHT			VDREG8(0x101)
+#define CONTRAST		VDREG8(0x102)
+#define SHARPNESS		VDREG8(0x103)
+#define SAT_U			VDREG8(0x104)
+#define SAT_V			VDREG8(0x105)
+#define HUE			VDREG8(0x106)
+#define CROP_HI			VDREG8(0x107)
+#define VDELAY_LO		VDREG8(0x108)
+#define VACTIVE_LO		VDREG8(0x109)
+#define HDELAY_LO		VDREG8(0x10A)
+#define HACTIVE_LO		VDREG8(0x10B)
+#define MVSN			VDREG8(0x10C)
+#define STATUS2			VDREG8(0x10C)
+#define SDT			VDREG8(0x10E)
+#define SDT_EN			VDREG8(0x10F)
+
+#define VSCALE_LO		VDREG8(0x144)
+#define SCALE_HI		VDREG8(0x145)
+#define HSCALE_LO		VDREG8(0x146)
+#define F2CROP_HI		VDREG8(0x147)
+#define F2VDELAY_LO		VDREG8(0x148)
+#define F2VACTIVE_LO		VDREG8(0x149)
+#define F2HDELAY_LO		VDREG8(0x14A)
+#define F2HACTIVE_LO		VDREG8(0x14B)
+#define F2VSCALE_LO		VDREG8(0x14C)
+#define F2SCALE_HI		VDREG8(0x14D)
+#define F2HSCALE_LO		VDREG8(0x14E)
+#define F2CNT			VDREG8(0x14F)
+
+#define VDREG2(a0) ((const u16[2]){a0, a0 + 0x100})
+#define SRST			VDREG2(0x180)
+#define ACNTL			VDREG2(0x181)
+#define ACNTL2			VDREG2(0x182)
+#define CNTRL1			VDREG2(0x183)
+#define CKHY			VDREG2(0x184)
+#define SHCOR			VDREG2(0x185)
+#define CORING			VDREG2(0x186)
+#define CLMPG			VDREG2(0x187)
+#define IAGC			VDREG2(0x188)
+#define VCTRL1			VDREG2(0x18F)
+#define MISC1			VDREG2(0x194)
+#define LOOP			VDREG2(0x195)
+#define MISC2			VDREG2(0x196)
+
+#define CLMD			VDREG2(0x197)
+#define ANPWRDOWN		VDREG2(0x1ce)
+#define AIGAIN			((const u16[8]){0x1D0, 0x1D1, 0x1D2, 0x1D3, \
+						0x2D0, 0x2D1, 0x2D2, 0x2D3})
+
+#define SYS_MODE_DMA_SHIFT	13
+#define TW686X_VIDSTAT_HLOCK	BIT(6)
+#define TW686X_VIDSTAT_VDLOSS	BIT(7)
+
+#define TW686X_STD_NTSC_M	0
+#define TW686X_STD_PAL		1
+#define TW686X_STD_SECAM	2
+#define TW686X_STD_NTSC_443	3
+#define TW686X_STD_PAL_M	4
+#define TW686X_STD_PAL_CN	5
+#define TW686X_STD_PAL_60	6
+
+#define TW686X_FIFO_ERROR(x)	(x & ~(0xFF))
diff --git a/drivers/media/pci/tw686x/tw686x-video.c b/drivers/media/pci/tw686x/tw686x-video.c
new file mode 100644
index 000000000000..7287a9de7a1a
--- /dev/null
+++ b/drivers/media/pci/tw686x/tw686x-video.c
@@ -0,0 +1,953 @@ 
+/*
+ * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
+ *
+ * Based on original driver by Krzysztof Ha?asa:
+ * Copyright (C) 2015 Industrial Research Institute for Automation
+ * and Measurements PIAP
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-event.h>
+#include <media/videobuf2-vmalloc.h>
+#include "tw686x.h"
+#include "tw686x-regs.h"
+
+#define TW686X_INPUTS_PER_CH		4
+#define TW686X_VIDEO_WIDTH		720
+#define TW686X_VIDEO_HEIGHT(id)		((id & V4L2_STD_625_50) ? 576 : 480)
+
+static const struct tw686x_format formats[] = {
+	{
+		.name = "4:2:2 packed, UYVY",
+		.fourcc = V4L2_PIX_FMT_UYVY,
+		.mode = 0,
+		.depth = 16,
+	}, {
+		.name = "16 bpp RGB",
+		.fourcc = V4L2_PIX_FMT_RGB565,
+		.mode = 5,
+		.depth = 16,
+	}, {
+		.name = "4:2:2 packed, YUYV",
+		.fourcc = V4L2_PIX_FMT_YUYV,
+		.mode = 6,
+		.depth = 16,
+	}
+};
+
+static unsigned int tw686x_fields_map(v4l2_std_id std, unsigned int fps)
+{
+	unsigned int map[15] = {
+		0x00000000, 0x00000001, 0x00004001, 0x00104001, 0x00404041,
+		0x01041041, 0x01104411, 0x01111111, 0x04444445, 0x04511445,
+		0x05145145, 0x05151515, 0x05515455, 0x05551555, 0x05555555
+	};
+
+	unsigned int std_625_50[26] = {
+		0, 1, 1, 2,  3,  3,  4,  4,  5,  5,  6,  7,  7,
+		   8, 8, 9, 10, 10, 11, 11, 12, 13, 13, 14, 14, 0
+	};
+
+	unsigned int std_525_60[31] = {
+		0, 1, 1, 1, 2,  2,  3,  3,  4,  4,  5,  5,  6,  6, 7, 7,
+		   8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 0, 0
+	};
+
+	unsigned int i =
+		(std & V4L2_STD_625_50) ? std_625_50[fps] : std_525_60[fps];
+
+	return map[i];
+}
+
+static void tw686x_set_framerate(struct tw686x_video_channel *vc,
+				 unsigned int fps)
+{
+	unsigned int map;
+
+	if (vc->fps == fps)
+		return;
+
+	map = tw686x_fields_map(vc->video_standard, fps) << 1;
+	map |= map << 1;
+	if (map > 0)
+		map |= BIT(31);
+	reg_write(vc->dev, VIDEO_FIELD_CTRL[vc->ch], map);
+	vc->fps = fps;
+}
+
+static const struct tw686x_format *format_by_fourcc(unsigned fourcc)
+{
+	unsigned cnt;
+
+	for (cnt = 0; cnt < ARRAY_SIZE(formats); cnt++)
+		if (formats[cnt].fourcc == fourcc)
+			return &formats[cnt];
+	return NULL;
+}
+
+static int tw686x_queue_setup(struct vb2_queue *vq,
+			      unsigned int *nbuffers, unsigned int *nplanes,
+			      unsigned int sizes[], void *alloc_ctxs[])
+{
+	struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
+	unsigned int szimage =
+		(vc->width * vc->height * vc->format->depth) >> 3;
+
+	/*
+	 * Let's request at least three buffers: two for the
+	 * DMA engine and one for userspace.
+	 */
+	if (vq->num_buffers + *nbuffers < 3)
+		*nbuffers = 3 - vq->num_buffers;
+
+	if (*nplanes) {
+		if (*nplanes != 1 || sizes[0] < szimage)
+			return -EINVAL;
+		return 0;
+	}
+
+	sizes[0] = szimage;
+	*nplanes = 1;
+	return 0;
+}
+
+static void tw686x_buf_queue(struct vb2_buffer *vb)
+{
+	struct tw686x_video_channel *vc = vb2_get_drv_priv(vb->vb2_queue);
+	struct tw686x_dev *dev = vc->dev;
+	struct pci_dev *pci_dev;
+	unsigned long flags;
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct tw686x_v4l2_buf *buf =
+		container_of(vbuf, struct tw686x_v4l2_buf, vb);
+
+	/* Check device presence */
+	spin_lock_irqsave(&dev->lock, flags);
+	pci_dev = dev->pci_dev;
+	spin_unlock_irqrestore(&dev->lock, flags);
+	if (!pci_dev) {
+		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+		return;
+	}
+
+	spin_lock_irqsave(&vc->qlock, flags);
+	list_add_tail(&buf->list, &vc->vidq_queued);
+	spin_unlock_irqrestore(&vc->qlock, flags);
+}
+
+/*
+ * We can call this even when alloc_dma failed for the given channel
+ */
+static void tw686x_free_dma(struct tw686x_video_channel *vc, unsigned int pb)
+{
+	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
+	struct tw686x_dev *dev = vc->dev;
+	struct pci_dev *pci_dev;
+	unsigned long flags;
+
+	/* Check device presence. Shouldn't really happen! */
+	spin_lock_irqsave(&dev->lock, flags);
+	pci_dev = dev->pci_dev;
+	spin_unlock_irqrestore(&dev->lock, flags);
+	if (!pci_dev) {
+		WARN(1, "trying to deallocate on missing device\n");
+		return;
+	}
+
+	if (desc->virt) {
+		pci_free_consistent(dev->pci_dev, desc->size,
+				    desc->virt, desc->phys);
+		desc->virt = NULL;
+	}
+}
+
+static int tw686x_alloc_dma(struct tw686x_video_channel *vc, unsigned int pb)
+{
+	struct tw686x_dev *dev = vc->dev;
+	u32 reg = pb ? VDMA_B_ADDR[vc->ch] : VDMA_P_ADDR[vc->ch];
+	unsigned int len;
+	void *virt;
+
+	WARN(vc->dma_descs[pb].virt,
+	     "Allocating buffer but previous still here\n");
+
+	len = (vc->width * vc->height * vc->format->depth) >> 3;
+	virt = pci_alloc_consistent(dev->pci_dev, len,
+				    &vc->dma_descs[pb].phys);
+	if (!virt) {
+		v4l2_err(&dev->v4l2_dev, "dma%d: unable to allocate %s-buffer\n",
+			 vc->ch, pb ? "B" : "P");
+		return -ENOMEM;
+	}
+	vc->dma_descs[pb].size = len;
+	vc->dma_descs[pb].virt = virt;
+	reg_write(dev, reg, vc->dma_descs[pb].phys);
+
+	return 0;
+}
+
+static void tw686x_buffer_refill(struct tw686x_video_channel *vc, unsigned int pb)
+{
+	struct tw686x_v4l2_buf *buf;
+
+	while (!list_empty(&vc->vidq_queued)) {
+
+		buf = list_first_entry(&vc->vidq_queued,
+			struct tw686x_v4l2_buf, list);
+		list_del(&buf->list);
+
+		vc->curr_bufs[pb] = buf;
+		return;
+	}
+	vc->curr_bufs[pb] = NULL;
+}
+
+static void tw686x_clear_queue(struct tw686x_video_channel *vc)
+{
+	unsigned int pb;
+
+	while (!list_empty(&vc->vidq_queued)) {
+		struct tw686x_v4l2_buf *buf;
+
+		buf = list_first_entry(&vc->vidq_queued,
+			struct tw686x_v4l2_buf, list);
+		list_del(&buf->list);
+		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+	}
+
+	for (pb = 0; pb < 2; pb++) {
+		if (vc->curr_bufs[pb])
+			vb2_buffer_done(&vc->curr_bufs[pb]->vb.vb2_buf,
+					VB2_BUF_STATE_ERROR);
+		vc->curr_bufs[pb] = NULL;
+	}
+}
+
+static int tw686x_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
+	struct tw686x_dev *dev = vc->dev;
+	struct pci_dev *pci_dev;
+	unsigned long flags;
+	int pb;
+
+	/* Check device presence */
+	spin_lock_irqsave(&dev->lock, flags);
+	pci_dev = dev->pci_dev;
+	spin_unlock_irqrestore(&dev->lock, flags);
+	if (!pci_dev)
+		return -ENODEV;
+
+	spin_lock_irqsave(&vc->qlock, flags);
+
+	/* Sanity check */
+	if (!vc->dma_descs[0].virt || !vc->dma_descs[1].virt) {
+		spin_unlock_irqrestore(&vc->qlock, flags);
+		v4l2_err(&dev->v4l2_dev, "video%d: refusing to start without DMA buffers\n",
+			 vc->num);
+		return -ENOMEM;
+	}
+
+	for (pb = 0; pb < 2; pb++)
+		tw686x_buffer_refill(vc, pb);
+	spin_unlock_irqrestore(&vc->qlock, flags);
+
+	vc->sequence = 0;
+	vc->pb = 0;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	tw686x_enable_channel(dev, vc->ch);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	mod_timer(&dev->dma_delay_timer, jiffies + msecs_to_jiffies(100));
+
+	return 0;
+}
+
+static void tw686x_stop_streaming(struct vb2_queue *vq)
+{
+	struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
+	struct tw686x_dev *dev = vc->dev;
+	struct pci_dev *pci_dev;
+	unsigned long flags;
+
+	/* Check device presence */
+	spin_lock_irqsave(&dev->lock, flags);
+	pci_dev = dev->pci_dev;
+	spin_unlock_irqrestore(&dev->lock, flags);
+	if (pci_dev)
+		tw686x_disable_channel(dev, vc->ch);
+
+	spin_lock_irqsave(&vc->qlock, flags);
+	tw686x_clear_queue(vc);
+	spin_unlock_irqrestore(&vc->qlock, flags);
+}
+
+static int tw686x_buf_prepare(struct vb2_buffer *vb)
+{
+	struct tw686x_video_channel *vc = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned int size =
+		(vc->width * vc->height * vc->format->depth) >> 3;
+
+	if (vb2_plane_size(vb, 0) < size)
+		return -EINVAL;
+	vb2_set_plane_payload(vb, 0, size);
+	return 0;
+}
+
+static struct vb2_ops tw686x_video_qops = {
+	.queue_setup		= tw686x_queue_setup,
+	.buf_queue		= tw686x_buf_queue,
+	.buf_prepare		= tw686x_buf_prepare,
+	.start_streaming	= tw686x_start_streaming,
+	.stop_streaming		= tw686x_stop_streaming,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+};
+
+static int tw686x_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct tw686x_video_channel *vc;
+	struct tw686x_dev *dev;
+	unsigned ch;
+
+	vc = container_of(ctrl->handler, struct tw686x_video_channel,
+			  ctrl_handler);
+	dev = vc->dev;
+	ch = vc->ch;
+
+	switch (ctrl->id) {
+	case V4L2_CID_BRIGHTNESS:
+		reg_write(dev, BRIGHT[ch], ctrl->val & 0xFF);
+		return 0;
+
+	case V4L2_CID_CONTRAST:
+		reg_write(dev, CONTRAST[ch], ctrl->val);
+		return 0;
+
+	case V4L2_CID_SATURATION:
+		reg_write(dev, SAT_U[ch], ctrl->val);
+		reg_write(dev, SAT_V[ch], ctrl->val);
+		return 0;
+
+	case V4L2_CID_HUE:
+		reg_write(dev, HUE[ch], ctrl->val & 0xFF);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static const struct v4l2_ctrl_ops ctrl_ops = {
+	.s_ctrl = tw686x_s_ctrl,
+};
+
+static int tw686x_g_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+
+	f->fmt.pix.width = vc->width;
+	f->fmt.pix.height = vc->height;
+	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
+	f->fmt.pix.pixelformat = vc->format->fourcc;
+	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
+	f->fmt.pix.bytesperline = (f->fmt.pix.width * vc->format->depth) / 8;
+	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
+	return 0;
+}
+
+static int tw686x_try_fmt_vid_cap(struct file *file, void *priv,
+				  struct v4l2_format *f)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	unsigned int video_height = TW686X_VIDEO_HEIGHT(vc->video_standard);
+	const struct tw686x_format *format;
+
+	format = format_by_fourcc(f->fmt.pix.pixelformat);
+	if (!format) {
+		format = &formats[0];
+		f->fmt.pix.pixelformat = format->fourcc;
+	}
+
+	if (f->fmt.pix.width <= TW686X_VIDEO_WIDTH / 2)
+		f->fmt.pix.width = TW686X_VIDEO_WIDTH / 2;
+	else
+		f->fmt.pix.width = TW686X_VIDEO_WIDTH;
+
+	if (f->fmt.pix.height <= video_height / 2)
+		f->fmt.pix.height = video_height / 2;
+	else
+		f->fmt.pix.height = video_height;
+
+	f->fmt.pix.bytesperline = (f->fmt.pix.width * format->depth) / 8;
+	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
+	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
+	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
+
+	return 0;
+}
+
+static int tw686x_s_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	u32 val, width, line_width, height;
+	unsigned long bitsperframe;
+	int err, pb;
+
+	if (vb2_is_busy(&vc->vidq))
+		return -EBUSY;
+
+	bitsperframe = vc->width * vc->height * vc->format->depth;
+	err = tw686x_try_fmt_vid_cap(file, priv, f);
+	if (err)
+		return err;
+
+	vc->format = format_by_fourcc(f->fmt.pix.pixelformat);
+	vc->width = f->fmt.pix.width;
+	vc->height = f->fmt.pix.height;
+
+	/* We need new DMA buffers if the framesize has changed */
+	if (bitsperframe != vc->width * vc->height * vc->format->depth) {
+
+		for (pb = 0; pb < 2; pb++)
+			tw686x_free_dma(vc, pb);
+
+		for (pb = 0; pb < 2; pb++) {
+			err = tw686x_alloc_dma(vc, pb);
+			if (err) {
+				if (pb > 0)
+					tw686x_free_dma(vc, 0);
+				return err;
+			}
+		}
+	}
+
+	val = reg_read(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch]);
+
+	if (vc->width <= TW686X_VIDEO_WIDTH / 2)
+		val |= BIT(23);
+	else
+		val &= ~BIT(23);
+
+	if (vc->height <= TW686X_VIDEO_HEIGHT(vc->video_standard) / 2)
+		val |= BIT(24);
+	else
+		val &= ~BIT(24);
+
+	val &= ~(0x7 << 20);
+	val |= vc->format->mode << 20;
+	reg_write(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch], val);
+
+	/* Program the DMA frame size */
+	width = (vc->width * 2) & 0x7ff;
+	height = vc->height / 2;
+	line_width = (vc->width * 2) & 0x7ff;
+	val = (height << 22) | (line_width << 11)  | width;
+	reg_write(vc->dev, VDMA_WHP[vc->ch], val);
+	return 0;
+}
+
+static int tw686x_querycap(struct file *file, void *priv,
+			   struct v4l2_capability *cap)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct tw686x_dev *dev = vc->dev;
+
+	strcpy(cap->driver, "tw686x");
+	strcpy(cap->card, dev->name);
+	sprintf(cap->bus_info, "PCI:%s", pci_name(dev->pci_dev));
+	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
+			   V4L2_CAP_READWRITE;
+	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
+	return 0;
+}
+
+static int tw686x_s_std(struct file *file, void *priv, v4l2_std_id id)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct v4l2_format f;
+	u32 val, ret;
+
+	if (vc->video_standard == id)
+		return 0;
+
+	if (vb2_is_busy(&vc->vidq))
+		return -EBUSY;
+
+	if (id & V4L2_STD_NTSC)
+		val = 0;
+	else if (id & V4L2_STD_PAL)
+		val = 1;
+	else if (id & V4L2_STD_SECAM)
+		val = 2;
+	else if (id & V4L2_STD_NTSC_443)
+		val = 3;
+	else if (id & V4L2_STD_PAL_M)
+		val = 4;
+	else if (id & V4L2_STD_PAL_Nc)
+		val = 5;
+	else if (id & V4L2_STD_PAL_60)
+		val = 6;
+	else
+		return -EINVAL;
+
+	vc->video_standard = id;
+	reg_write(vc->dev, SDT[vc->ch], val);
+
+	val = reg_read(vc->dev, VIDEO_CONTROL1);
+	if (id & V4L2_STD_625_50)
+		val |= (1 << (SYS_MODE_DMA_SHIFT + vc->ch));
+	else
+		val &= ~(1 << (SYS_MODE_DMA_SHIFT + vc->ch));
+	reg_write(vc->dev, VIDEO_CONTROL1, val);
+
+	/*
+	 * Adjust format after V4L2_STD_525_60/V4L2_STD_625_50 change,
+	 * calling g_fmt and s_fmt will sanitize the height
+	 * according to the standard.
+	 */
+	ret = tw686x_g_fmt_vid_cap(file, priv, &f);
+	if (!ret)
+		tw686x_s_fmt_vid_cap(file, priv, &f);
+	return 0;
+}
+
+static int tw686x_querystd(struct file *file, void *priv, v4l2_std_id *std)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct tw686x_dev *dev = vc->dev;
+	unsigned int old_std, detected_std = 0;
+	unsigned long end;
+
+	if (vb2_is_streaming(&vc->vidq))
+		return -EBUSY;
+
+	/* Enable and start standard detection */
+	old_std = reg_read(dev, SDT[vc->ch]);
+	reg_write(dev, SDT[vc->ch], 0x7);
+	reg_write(dev, SDT_EN[vc->ch], 0xff);
+
+	end = jiffies + msecs_to_jiffies(500);
+	while (time_is_after_jiffies(end)) {
+
+		detected_std = reg_read(dev, SDT[vc->ch]);
+		if (!(detected_std & BIT(7)))
+			break;
+		msleep(100);
+	}
+	reg_write(dev, SDT[vc->ch], old_std);
+
+	/* Exit if still busy */
+	if (detected_std & BIT(7))
+		return 0;
+
+	detected_std = (detected_std >> 4) & 0x7;
+	switch (detected_std) {
+	case TW686X_STD_NTSC_M:
+		*std &= V4L2_STD_NTSC;
+		break;
+	case TW686X_STD_NTSC_443:
+		*std &= V4L2_STD_NTSC_443;
+		break;
+	case TW686X_STD_PAL_M:
+		*std &= V4L2_STD_PAL_M;
+		break;
+	case TW686X_STD_PAL_60:
+		*std &= V4L2_STD_PAL_60;
+		break;
+	case TW686X_STD_PAL:
+		*std &= V4L2_STD_PAL;
+		break;
+	case TW686X_STD_PAL_CN:
+		*std &= V4L2_STD_PAL_Nc;
+		break;
+	case TW686X_STD_SECAM:
+		*std &= V4L2_STD_SECAM;
+		break;
+	default:
+		*std = 0;
+	}
+	return 0;
+}
+
+static int tw686x_g_std(struct file *file, void *priv, v4l2_std_id *id)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+
+	*id = vc->video_standard;
+	return 0;
+}
+
+static int tw686x_enum_fmt_vid_cap(struct file *file, void *priv,
+				   struct v4l2_fmtdesc *f)
+{
+	if (f->index >= ARRAY_SIZE(formats))
+		return -EINVAL;
+
+	strlcpy(f->description, formats[f->index].name, sizeof(f->description));
+	f->pixelformat = formats[f->index].fourcc;
+	return 0;
+}
+
+static int tw686x_g_parm(struct file *file, void *priv,
+			 struct v4l2_streamparm *sp)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct v4l2_captureparm *cp = &sp->parm.capture;
+
+	if (sp->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+	sp->parm.capture.readbuffers = 3;
+
+	cp->capability = V4L2_CAP_TIMEPERFRAME;
+	cp->timeperframe.numerator = 1;
+	cp->timeperframe.denominator = vc->fps;
+	return 0;
+}
+
+static int tw686x_s_parm(struct file *file, void *priv,
+			 struct v4l2_streamparm *sp)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct v4l2_captureparm *cp = &sp->parm.capture;
+	unsigned int denominator = cp->timeperframe.denominator;
+	unsigned int numerator = cp->timeperframe.numerator;
+	unsigned int fps;
+
+	if (vb2_is_busy(&vc->vidq))
+		return -EBUSY;
+
+	fps = (!numerator || !denominator) ? 0 : denominator / numerator;
+	if (vc->video_standard & V4L2_STD_625_50)
+		fps = (!fps || fps > 25) ? 25 : fps;
+	else
+		fps = (!fps || fps > 30) ? 30 : fps;
+	tw686x_set_framerate(vc, fps);
+
+	return tw686x_g_parm(file, priv, sp);
+}
+
+static int tw686x_s_input(struct file *file, void *priv, unsigned int i)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	u32 val;
+
+	if (i >= TW686X_INPUTS_PER_CH)
+		return -EINVAL;
+
+	/*
+	 * Not sure we are able to support on the fly input change
+	 */
+	if (vb2_is_busy(&vc->vidq))
+		return -EBUSY;
+
+	vc->input = i;
+
+	val = reg_read(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch]);
+	val &= ~(0x3 << 30);
+	val |= i << 30;
+	reg_write(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch], val);
+	return 0;
+}
+
+static int tw686x_g_input(struct file *file, void *priv, unsigned int *i)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+
+	*i = vc->input;
+	return 0;
+}
+
+static int tw686x_enum_input(struct file *file, void *priv,
+			     struct v4l2_input *i)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	unsigned int vidstat;
+
+	if (i->index >= TW686X_INPUTS_PER_CH)
+		return -EINVAL;
+
+	sprintf(i->name, "Composite%d", i->index);
+	i->type = V4L2_INPUT_TYPE_CAMERA;
+	i->std = vc->device->tvnorms;
+	i->capabilities = V4L2_IN_CAP_STD;
+
+	vidstat = reg_read(vc->dev, VIDSTAT[vc->ch]);
+	i->status = 0;
+	if (vidstat & TW686X_VIDSTAT_VDLOSS)
+		i->status |= V4L2_IN_ST_NO_SIGNAL;
+	if (!(vidstat & TW686X_VIDSTAT_HLOCK))
+		i->status |= V4L2_IN_ST_NO_H_LOCK;
+
+	return 0;
+}
+
+const struct v4l2_file_operations tw686x_video_fops = {
+	.owner		= THIS_MODULE,
+	.open		= v4l2_fh_open,
+	.unlocked_ioctl	= video_ioctl2,
+	.release	= vb2_fop_release,
+	.poll		= vb2_fop_poll,
+	.read		= vb2_fop_read,
+	.mmap		= vb2_fop_mmap,
+};
+
+const struct v4l2_ioctl_ops tw686x_video_ioctl_ops = {
+	.vidioc_querycap		= tw686x_querycap,
+	.vidioc_g_fmt_vid_cap		= tw686x_g_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap		= tw686x_s_fmt_vid_cap,
+	.vidioc_enum_fmt_vid_cap	= tw686x_enum_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap		= tw686x_try_fmt_vid_cap,
+
+	.vidioc_querystd		= tw686x_querystd,
+	.vidioc_g_std			= tw686x_g_std,
+	.vidioc_s_std			= tw686x_s_std,
+
+	.vidioc_g_parm			= tw686x_g_parm,
+	.vidioc_s_parm			= tw686x_s_parm,
+
+	.vidioc_enum_input		= tw686x_enum_input,
+	.vidioc_g_input			= tw686x_g_input,
+	.vidioc_s_input			= tw686x_s_input,
+
+	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
+	.vidioc_querybuf		= vb2_ioctl_querybuf,
+	.vidioc_qbuf			= vb2_ioctl_qbuf,
+	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
+	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
+	.vidioc_streamon		= vb2_ioctl_streamon,
+	.vidioc_streamoff		= vb2_ioctl_streamoff,
+
+	.vidioc_log_status		= v4l2_ctrl_log_status,
+	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
+};
+
+static void tw686x_buffer_copy(struct tw686x_video_channel *vc,
+			       unsigned int pb, struct vb2_v4l2_buffer *vb)
+{
+	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
+	struct vb2_buffer *vb2_buf = &vb->vb2_buf;
+
+	vb->field = V4L2_FIELD_INTERLACED;
+	vb->sequence = vc->sequence++;
+
+	memcpy(vb2_plane_vaddr(vb2_buf, 0), desc->virt, desc->size);
+	vb2_buf->timestamp = ktime_get_ns();
+	vb2_buffer_done(vb2_buf, VB2_BUF_STATE_DONE);
+}
+
+void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
+		      unsigned int pb_status, unsigned int fifo_status,
+		      unsigned int *reset_ch)
+{
+	struct tw686x_video_channel *vc;
+	struct vb2_v4l2_buffer *vb;
+	unsigned long flags;
+	unsigned int ch, pb;
+
+	for_each_set_bit(ch, &requests, max_channels(dev)) {
+
+		vc = &dev->video_channels[ch];
+
+		/*
+		 * This can either be a blue frame (with signal-lost bit set)
+		 * or a good frame (with signal-lost bit clear). If we have just
+		 * got signal, then this channel needs resetting.
+		 */
+		if (vc->no_signal && !(fifo_status & BIT(ch))) {
+			v4l2_printk(KERN_DEBUG, &dev->v4l2_dev,
+				    "video%d: signal recovered\n", vc->num);
+			vc->no_signal = false;
+			*reset_ch |= BIT(ch);
+			vc->pb = 0;
+			continue;
+		}
+		vc->no_signal = !!(fifo_status & BIT(ch));
+
+		/* Check FIFO errors only if there's signal */
+		if (!vc->no_signal) {
+			u32 fifo_ov, fifo_bad;
+
+			fifo_ov = (fifo_status >> 24) & BIT(ch);
+			fifo_bad = (fifo_status >> 16) & BIT(ch);
+			if (fifo_ov || fifo_bad) {
+				/* Mark this channel for reset */
+				v4l2_printk(KERN_DEBUG, &dev->v4l2_dev, "video%d: FIFO error\n", vc->num);
+				*reset_ch |= BIT(ch);
+				vc->pb = 0;
+				continue;
+			}
+		}
+
+		pb = !!(pb_status & BIT(ch));
+		if (vc->pb != pb) {
+			/* Mark this channel for reset */
+			v4l2_printk(KERN_DEBUG, &dev->v4l2_dev,
+				    "video%d: unexpected p-b buffer!\n", vc->num);
+			*reset_ch |= BIT(ch);
+			vc->pb = 0;
+			continue;
+		}
+
+		/* handle video stream */
+		spin_lock_irqsave(&vc->qlock, flags);
+		if (vc->curr_bufs[pb]) {
+			vb = &vc->curr_bufs[pb]->vb;
+			tw686x_buffer_copy(vc, pb, vb);
+		}
+		vc->pb = !pb;
+		tw686x_buffer_refill(vc, pb);
+		spin_unlock_irqrestore(&vc->qlock, flags);
+	}
+}
+
+void tw686x_video_free(struct tw686x_dev *dev)
+{
+	unsigned int ch, pb;
+
+	for (ch = 0; ch < max_channels(dev); ch++) {
+		struct tw686x_video_channel *vc = &dev->video_channels[ch];
+
+		if (vc->device)
+			video_unregister_device(vc->device);
+
+		for (pb = 0; pb < 2; pb++)
+			tw686x_free_dma(vc, pb);
+	}
+}
+
+int tw686x_video_init(struct tw686x_dev *dev)
+{
+	unsigned int ch, val, pb;
+	int err;
+
+	err = v4l2_device_register(&dev->pci_dev->dev, &dev->v4l2_dev);
+	if (err)
+		return err;
+
+	for (ch = 0; ch < max_channels(dev); ch++) {
+		struct tw686x_video_channel *vc = &dev->video_channels[ch];
+		struct video_device *vdev;
+
+		mutex_init(&vc->vb_mutex);
+		spin_lock_init(&vc->qlock);
+		INIT_LIST_HEAD(&vc->vidq_queued);
+
+		vc->dev = dev;
+		vc->ch = ch;
+
+		/* default settings */
+		vc->format = &formats[0];
+		vc->video_standard = V4L2_STD_NTSC;
+		vc->width = TW686X_VIDEO_WIDTH;
+		vc->height = TW686X_VIDEO_HEIGHT(vc->video_standard);
+		vc->input = 0;
+
+		reg_write(vc->dev, SDT[ch], 0);
+		tw686x_set_framerate(vc, 30);
+
+		reg_write(dev, VDELAY_LO[ch], 0x14);
+		reg_write(dev, HACTIVE_LO[ch], 0xD0);
+		reg_write(dev, VIDEO_SIZE[ch], 0);
+
+		for (pb = 0; pb < 2; pb++) {
+			err = tw686x_alloc_dma(vc, pb);
+			if (err)
+				goto error;
+		}
+
+		vdev = video_device_alloc();
+		if (!vdev) {
+			v4l2_err(&dev->v4l2_dev, "dma%d: unable to allocate device\n", ch);
+			err = -ENOMEM;
+			goto error;
+		}
+
+		vc->vidq.io_modes = VB2_READ | VB2_MMAP | VB2_DMABUF;
+		vc->vidq.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+		vc->vidq.drv_priv = vc;
+		vc->vidq.buf_struct_size = sizeof(struct tw686x_v4l2_buf);
+		vc->vidq.ops = &tw686x_video_qops;
+		vc->vidq.mem_ops = &vb2_vmalloc_memops;
+		vc->vidq.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+		vc->vidq.min_buffers_needed = 2;
+		vc->vidq.lock = &vc->vb_mutex;
+
+		err = vb2_queue_init(&vc->vidq);
+		if (err)
+			goto error;
+
+		snprintf(vdev->name, sizeof(vdev->name), "%s video", dev->name);
+		vdev->fops = &tw686x_video_fops;
+		vdev->ioctl_ops = &tw686x_video_ioctl_ops;
+		vdev->release = video_device_release;
+		vdev->v4l2_dev = &dev->v4l2_dev;
+		vdev->queue = &vc->vidq;
+		vdev->tvnorms = V4L2_STD_525_60 | V4L2_STD_625_50;
+		vdev->minor = -1;
+		vdev->lock = &vc->vb_mutex;
+		vc->device = vdev;
+		video_set_drvdata(vdev, vc);
+		err = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
+		if (err < 0)
+			goto error;
+		vc->num = vdev->num;
+
+		err = v4l2_ctrl_handler_init(&vc->ctrl_handler, 4);
+		if (err) {
+			v4l2_err(&dev->v4l2_dev,
+				 "video%d: cannot init ctrl handler\n",
+				 vc->num);
+			goto error;
+		}
+		vdev->ctrl_handler = &vc->ctrl_handler;
+		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
+				  V4L2_CID_BRIGHTNESS, -128, 127, 1, 0);
+		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
+				  V4L2_CID_CONTRAST, 0, 255, 1, 100);
+		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
+				  V4L2_CID_SATURATION, 0, 255, 1, 128);
+		v4l2_ctrl_new_std(&vc->ctrl_handler, &ctrl_ops,
+				  V4L2_CID_HUE, -128, 127, 1, 0);
+		err = vc->ctrl_handler.error;
+		if (err)
+			goto error;
+
+		err = v4l2_ctrl_handler_setup(&vc->ctrl_handler);
+		if (err)
+			goto error;
+	}
+
+	/* Set DMA frame mode on all channels. Only supported mode for now. */
+	val = TW686X_DEF_PHASE_REF;
+	for (ch = 0; ch < max_channels(dev); ch++)
+		val |= TW686X_FRAME_MODE << (16 + ch * 2);
+	reg_write(dev, PHASE_REF, val);
+
+	reg_write(dev, MISC2[0], 0xE7);
+	reg_write(dev, VCTRL1[0], 0xCC);
+	reg_write(dev, LOOP[0], 0xA5);
+	if (max_channels(dev) > 4) {
+		reg_write(dev, VCTRL1[1], 0xCC);
+		reg_write(dev, LOOP[1], 0xA5);
+		reg_write(dev, MISC2[1], 0xE7);
+	}
+	return 0;
+
+error:
+	tw686x_video_free(dev);
+	return err;
+}
diff --git a/drivers/media/pci/tw686x/tw686x.h b/drivers/media/pci/tw686x/tw686x.h
new file mode 100644
index 000000000000..0ffb0be84aa2
--- /dev/null
+++ b/drivers/media/pci/tw686x/tw686x.h
@@ -0,0 +1,189 @@ 
+/*
+ * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
+ *
+ * Copyright (C) 2015 Industrial Research Institute for Automation
+ * and Measurements PIAP
+ * Written by Krzysztof Ha?asa
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/timer.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-v4l2.h>
+#include <sound/pcm.h>
+
+#include "tw686x-regs.h"
+
+#define TYPE_MAX_CHANNELS	0x0F
+#define TYPE_SECOND_GEN		0x10
+#define TW686X_DEF_PHASE_REF	0x1518
+
+#define TW686X_FIELD_MODE	0x3
+#define TW686X_FRAME_MODE	0x2
+/* 0x1 is reserved */
+#define TW686X_SG_MODE		0x0
+
+#define TW686X_PAGE_SIZE	4096
+#define TW686X_AUDIO_PAGE_MAX	16
+
+struct tw686x_format {
+	char *name;
+	unsigned fourcc;
+	unsigned depth;
+	unsigned mode;
+};
+
+struct tw686x_dma_desc {
+	dma_addr_t phys;
+	void *virt;
+	unsigned size;
+};
+
+struct tw686x_audio_buf {
+	dma_addr_t dma;
+	void *virt;
+	struct list_head list;
+};
+
+struct tw686x_v4l2_buf {
+	struct vb2_v4l2_buffer vb;
+	struct list_head list;
+};
+
+struct tw686x_audio_channel {
+	struct tw686x_dev *dev;
+	struct snd_pcm_substream *ss;
+	unsigned int ch;
+	struct tw686x_audio_buf *curr_bufs[2];
+	struct tw686x_dma_desc dma_descs[2];
+	dma_addr_t ptr;
+
+	struct tw686x_audio_buf buf[TW686X_AUDIO_PAGE_MAX];
+	struct list_head buf_list;
+	spinlock_t lock;
+};
+
+struct tw686x_video_channel {
+	struct tw686x_dev *dev;
+
+	struct vb2_queue vidq;
+	struct list_head vidq_queued;
+	struct video_device *device;
+	struct tw686x_v4l2_buf *curr_bufs[2];
+	struct tw686x_dma_desc dma_descs[2];
+
+	struct v4l2_ctrl_handler ctrl_handler;
+	const struct tw686x_format *format;
+	struct mutex vb_mutex;
+	spinlock_t qlock;
+	v4l2_std_id video_standard;
+	unsigned int width, height;
+	unsigned int h_halve, v_halve;
+	unsigned int ch;
+	unsigned int num;
+	unsigned int fps;
+	unsigned int input;
+	unsigned int sequence;
+	unsigned int pb;
+	bool no_signal;
+};
+
+/**
+ * struct tw686x_dev - global device status
+ * @lock: spinlock controlling access to the
+ *        shared device registers (DMA enable/disable).
+ */
+struct tw686x_dev {
+	spinlock_t lock;
+
+	struct v4l2_device v4l2_dev;
+	struct snd_card *snd_card;
+
+	char name[32];
+	unsigned int type;
+	struct pci_dev *pci_dev;
+	__u32 __iomem *mmio;
+
+	void *alloc_ctx;
+
+	struct tw686x_video_channel *video_channels;
+	struct tw686x_audio_channel *audio_channels;
+
+	int audio_rate; /* per-device value */
+
+	struct timer_list dma_delay_timer;
+	u32 pending_dma_en; /* must be protected by lock */
+	u32 pending_dma_cmd; /* must be protected by lock */
+};
+
+static inline uint32_t reg_read(struct tw686x_dev *dev, unsigned reg)
+{
+	return readl(dev->mmio + reg);
+}
+
+static inline void reg_write(struct tw686x_dev *dev, unsigned reg,
+			     uint32_t value)
+{
+	writel(value, dev->mmio + reg);
+}
+
+static inline void tw686x_disable_channel(struct tw686x_dev *dev,
+					  unsigned int channel)
+{
+	u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
+	u32 dma_cmd = reg_read(dev, DMA_CMD);
+
+	dma_en &= ~BIT(channel);
+	dma_cmd &= ~BIT(channel);
+
+	/* Must remove it from pending too */
+	dev->pending_dma_en &= ~BIT(channel);
+	dev->pending_dma_cmd &= ~BIT(channel);
+
+	/* Stop DMA if no channels are enabled */
+	if (!dma_en)
+		dma_cmd = 0;
+	reg_write(dev, DMA_CHANNEL_ENABLE, dma_en);
+	reg_write(dev, DMA_CMD, dma_cmd);
+}
+
+static inline void tw686x_enable_channel(struct tw686x_dev *dev,
+					 unsigned int channel)
+{
+	u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
+	u32 dma_cmd = reg_read(dev, DMA_CMD);
+
+	dev->pending_dma_en |= dma_en | BIT(channel);
+	dev->pending_dma_cmd |= dma_cmd | BIT(31) | BIT(channel);
+}
+
+static inline unsigned max_channels(struct tw686x_dev *dev)
+{
+	return dev->type & TYPE_MAX_CHANNELS; /* 4 or 8 channels */
+}
+
+static inline unsigned is_second_gen(struct tw686x_dev *dev)
+{
+	/* each channel has its own DMA SG table */
+	return dev->type & TYPE_SECOND_GEN;
+}
+
+int tw686x_video_init(struct tw686x_dev *dev);
+void tw686x_video_free(struct tw686x_dev *dev);
+void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
+		      unsigned int pb_status, unsigned int fifo_status,
+		      unsigned int *reset_ch);
+
+int tw686x_audio_init(struct tw686x_dev *dev);
+void tw686x_audio_free(struct tw686x_dev *dev);
+void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
+		      unsigned int pb_status);