[v10,2/2] media: V3s: Add support for Allwinner CSI.

Commit Message

yong May 4, 2018, 7:09 a.m. UTC

Allwinner V3s SoC features two CSI module. CSI0 is used for MIPI CSI-2
interface and CSI1 is used for parallel interface. This is not
documented in datasheet but by test and guess.

This patch implement a v4l2 framework driver for it.

Currently, the driver only support the parallel interface. MIPI-CSI2,
ISP's support are not included in this patch.

Reviewed-by: Hans Verkuil <[e-mail]>
Reviewed-by: Maxime Ripard <[e-mail]>
Tested-by: Maxime Ripard <[e-mail]>
Signed-off-by: Yong Deng <[e-mail]>
---
 MAINTAINERS                                        |   8 +
 drivers/media/platform/Kconfig                     |   1 +
 drivers/media/platform/Makefile                    |   2 +
 drivers/media/platform/sunxi/sun6i-csi/Kconfig     |   9 +
 drivers/media/platform/sunxi/sun6i-csi/Makefile    |   3 +
 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 932 +++++++++++++++++++++
 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h | 145 ++++
 .../media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h | 196 +++++
 .../media/platform/sunxi/sun6i-csi/sun6i_video.c   | 767 +++++++++++++++++
 .../media/platform/sunxi/sun6i-csi/sun6i_video.h   |  53 ++
 10 files changed, 2116 insertions(+)
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/Kconfig
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/Makefile
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h

Comments

Sakari Ailus June 26, 2018, 11:08 a.m. UTC | #1

Hi Yong,

My apologies for taking so long to review the set. A few comments below.

On Fri, May 04, 2018 at 03:09:05PM +0800, Yong Deng wrote:
> Allwinner V3s SoC features two CSI module. CSI0 is used for MIPI CSI-2
> interface and CSI1 is used for parallel interface. This is not
> documented in datasheet but by test and guess.
> 
> This patch implement a v4l2 framework driver for it.
> 
> Currently, the driver only support the parallel interface. MIPI-CSI2,
> ISP's support are not included in this patch.
> 
> Reviewed-by: Hans Verkuil <[e-mail]>
> Reviewed-by: Maxime Ripard <[e-mail]>
> Tested-by: Maxime Ripard <[e-mail]>
> Signed-off-by: Yong Deng <[e-mail]>
> ---
>  MAINTAINERS                                        |   8 +
>  drivers/media/platform/Kconfig                     |   1 +
>  drivers/media/platform/Makefile                    |   2 +
>  drivers/media/platform/sunxi/sun6i-csi/Kconfig     |   9 +
>  drivers/media/platform/sunxi/sun6i-csi/Makefile    |   3 +
>  drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 932 +++++++++++++++++++++
>  drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h | 145 ++++
>  .../media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h | 196 +++++
>  .../media/platform/sunxi/sun6i-csi/sun6i_video.c   | 767 +++++++++++++++++
>  .../media/platform/sunxi/sun6i-csi/sun6i_video.h   |  53 ++
>  10 files changed, 2116 insertions(+)
>  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/Kconfig
>  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/Makefile
>  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
>  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
>  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h
>  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
>  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0a1410d5a621..a8f9fe91dd14 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3771,6 +3771,14 @@ M:	Jaya Kumar <[e-mail]>
>  S:	Maintained
>  F:	sound/pci/cs5535audio/
>  
> +CSI DRIVERS FOR ALLWINNER V3s
> +M:	Yong Deng <[e-mail]>
> +L:	[e-mail]
> +T:	git git://linuxtv.org/media_tree.git
> +S:	Maintained
> +F:	drivers/media/platform/sunxi/sun6i-csi/
> +F:	Documentation/devicetree/bindings/media/sun6i-csi.txt
> +
>  CW1200 WLAN driver
>  M:	Solomon Peachy <[e-mail]>
>  S:	Maintained
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index e3229f7baed1..43f25c9c05e1 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -138,6 +138,7 @@ source "drivers/media/platform/am437x/Kconfig"
>  source "drivers/media/platform/xilinx/Kconfig"
>  source "drivers/media/platform/rcar-vin/Kconfig"
>  source "drivers/media/platform/atmel/Kconfig"
> +source "drivers/media/platform/sunxi/sun6i-csi/Kconfig"
>  
>  config VIDEO_TI_CAL
>  	tristate "TI CAL (Camera Adaptation Layer) driver"
> diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> index 932515df4477..69472cbfa360 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -92,3 +92,5 @@ obj-$(CONFIG_VIDEO_QCOM_CAMSS)		+= qcom/camss-8x16/
>  obj-$(CONFIG_VIDEO_QCOM_VENUS)		+= qcom/venus/
>  
>  obj-y					+= meson/
> +
> +obj-$(CONFIG_VIDEO_SUN6I_CSI)		+= sunxi/sun6i-csi/
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/Kconfig b/drivers/media/platform/sunxi/sun6i-csi/Kconfig
> new file mode 100644
> index 000000000000..018e3ec788c0
> --- /dev/null
> +++ b/drivers/media/platform/sunxi/sun6i-csi/Kconfig
> @@ -0,0 +1,9 @@
> +config VIDEO_SUN6I_CSI
> +	tristate "Allwinner V3s Camera Sensor Interface driver"
> +	depends on VIDEO_V4L2 && COMMON_CLK && VIDEO_V4L2_SUBDEV_API && HAS_DMA
> +	depends on ARCH_SUNXI || COMPILE_TEST
> +	select VIDEOBUF2_DMA_CONTIG
> +	select REGMAP_MMIO
> +	select V4L2_FWNODE
> +	help
> +	   Support for the Allwinner Camera Sensor Interface Controller on V3s.
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/Makefile b/drivers/media/platform/sunxi/sun6i-csi/Makefile
> new file mode 100644
> index 000000000000..213cb6be9e9c
> --- /dev/null
> +++ b/drivers/media/platform/sunxi/sun6i-csi/Makefile
> @@ -0,0 +1,3 @@
> +sun6i-csi-y += sun6i_video.o sun6i_csi.o
> +
> +obj-$(CONFIG_VIDEO_SUN6I_CSI) += sun6i-csi.o
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> new file mode 100644
> index 000000000000..d03a367dad44
> --- /dev/null
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> @@ -0,0 +1,932 @@
> +// SPDX-License-Identifier: GPL-2.0

Doesn't match MODULE_LICENSE at the end. Which one is it?

> +/*
> + * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
> + * All rights reserved.
> + * Author: Yong Deng <[e-mail]>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/fs.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/ioctl.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +#include <linux/sched.h>
> +#include <linux/sizes.h>
> +#include <linux/slab.h>
> +
> +#include "sun6i_csi.h"
> +#include "sun6i_csi_reg.h"
> +
> +#define MODULE_NAME	"sun6i-csi"
> +
> +struct sun6i_csi_dev {
> +	struct sun6i_csi		csi;
> +	struct device			*dev;
> +
> +	struct regmap			*regmap;
> +	struct clk			*clk_mod;
> +	struct clk			*clk_ram;
> +	struct reset_control		*rstc_bus;
> +
> +	int				planar_offset[3];
> +};
> +
> +static const u32 supported_pixformats[] = {
> +	V4L2_PIX_FMT_SBGGR8,
> +	V4L2_PIX_FMT_SGBRG8,
> +	V4L2_PIX_FMT_SGRBG8,
> +	V4L2_PIX_FMT_SRGGB8,
> +	V4L2_PIX_FMT_SBGGR10,
> +	V4L2_PIX_FMT_SGBRG10,
> +	V4L2_PIX_FMT_SGRBG10,
> +	V4L2_PIX_FMT_SRGGB10,
> +	V4L2_PIX_FMT_SBGGR12,
> +	V4L2_PIX_FMT_SGBRG12,
> +	V4L2_PIX_FMT_SGRBG12,
> +	V4L2_PIX_FMT_SRGGB12,
> +	V4L2_PIX_FMT_YUYV,
> +	V4L2_PIX_FMT_YVYU,
> +	V4L2_PIX_FMT_UYVY,
> +	V4L2_PIX_FMT_VYUY,
> +	V4L2_PIX_FMT_HM12,
> +	V4L2_PIX_FMT_NV12,
> +	V4L2_PIX_FMT_NV21,
> +	V4L2_PIX_FMT_YUV420,
> +	V4L2_PIX_FMT_YVU420,
> +	V4L2_PIX_FMT_NV16,
> +	V4L2_PIX_FMT_NV61,
> +	V4L2_PIX_FMT_YUV422P,
> +};
> +
> +static inline struct sun6i_csi_dev *sun6i_csi_to_dev(struct sun6i_csi *csi)
> +{
> +	return container_of(csi, struct sun6i_csi_dev, csi);
> +}
> +
> +int sun6i_csi_get_supported_pixformats(struct sun6i_csi *csi,
> +				       const u32 **pixformats)
> +{
> +	if (pixformats != NULL)
> +		*pixformats = supported_pixformats;
> +
> +	return ARRAY_SIZE(supported_pixformats);
> +}

This is only relevant in the context of in-memory formats (same goes for
supported_formats) --- how about moving them to the other file?

> +
> +/* TODO add 10&12 bit YUV, RGB support */
> +bool sun6i_csi_is_format_supported(struct sun6i_csi *csi,
> +				 u32 pixformat, u32 mbus_code)
> +{
> +	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
> +
> +	/*
> +	 * Some video receivers have the ability to be compatible with
> +	 * 8bit and 16bit bus width.
> +	 * Identify the media bus format from device tree.
> +	 */
> +	if ((sdev->csi.v4l2_ep.bus_type == V4L2_MBUS_PARALLEL
> +	      || sdev->csi.v4l2_ep.bus_type == V4L2_MBUS_BT656)
> +	     && sdev->csi.v4l2_ep.bus.parallel.bus_width == 16) {
> +		switch (pixformat) {
> +		case V4L2_PIX_FMT_HM12:
> +		case V4L2_PIX_FMT_NV12:
> +		case V4L2_PIX_FMT_NV21:
> +		case V4L2_PIX_FMT_NV16:
> +		case V4L2_PIX_FMT_NV61:
> +		case V4L2_PIX_FMT_YUV420:
> +		case V4L2_PIX_FMT_YVU420:
> +		case V4L2_PIX_FMT_YUV422P:
> +			switch (mbus_code) {
> +			case MEDIA_BUS_FMT_UYVY8_1X16:
> +			case MEDIA_BUS_FMT_VYUY8_1X16:
> +			case MEDIA_BUS_FMT_YUYV8_1X16:
> +			case MEDIA_BUS_FMT_YVYU8_1X16:
> +				return true;
> +			default:
> +				dev_dbg(sdev->dev, "Unsupported mbus code: 0x%x\n",
> +					mbus_code);
> +				break;
> +			}
> +			break;
> +		default:
> +			dev_dbg(sdev->dev, "Unsupported pixformat: 0x%x\n",
> +				pixformat);
> +			break;
> +		}
> +		return false;
> +	}
> +
> +	switch (pixformat) {
> +	case V4L2_PIX_FMT_SBGGR8:
> +		return (mbus_code == MEDIA_BUS_FMT_SBGGR8_1X8);
> +	case V4L2_PIX_FMT_SGBRG8:
> +		return (mbus_code == MEDIA_BUS_FMT_SGBRG8_1X8);
> +	case V4L2_PIX_FMT_SGRBG8:
> +		return (mbus_code == MEDIA_BUS_FMT_SGRBG8_1X8);
> +	case V4L2_PIX_FMT_SRGGB8:
> +		return (mbus_code == MEDIA_BUS_FMT_SRGGB8_1X8);
> +	case V4L2_PIX_FMT_SBGGR10:
> +		return (mbus_code == MEDIA_BUS_FMT_SBGGR10_1X10);
> +	case V4L2_PIX_FMT_SGBRG10:
> +		return (mbus_code == MEDIA_BUS_FMT_SGBRG10_1X10);
> +	case V4L2_PIX_FMT_SGRBG10:
> +		return (mbus_code == MEDIA_BUS_FMT_SGRBG10_1X10);
> +	case V4L2_PIX_FMT_SRGGB10:
> +		return (mbus_code == MEDIA_BUS_FMT_SRGGB10_1X10);
> +	case V4L2_PIX_FMT_SBGGR12:
> +		return (mbus_code == MEDIA_BUS_FMT_SBGGR12_1X12);
> +	case V4L2_PIX_FMT_SGBRG12:
> +		return (mbus_code == MEDIA_BUS_FMT_SGBRG12_1X12);
> +	case V4L2_PIX_FMT_SGRBG12:
> +		return (mbus_code == MEDIA_BUS_FMT_SGRBG12_1X12);
> +	case V4L2_PIX_FMT_SRGGB12:
> +		return (mbus_code == MEDIA_BUS_FMT_SRGGB12_1X12);
> +
> +	case V4L2_PIX_FMT_YUYV:
> +		return (mbus_code == MEDIA_BUS_FMT_YUYV8_2X8);
> +	case V4L2_PIX_FMT_YVYU:
> +		return (mbus_code == MEDIA_BUS_FMT_YVYU8_2X8);
> +	case V4L2_PIX_FMT_UYVY:
> +		return (mbus_code == MEDIA_BUS_FMT_UYVY8_2X8);
> +	case V4L2_PIX_FMT_VYUY:
> +		return (mbus_code == MEDIA_BUS_FMT_VYUY8_2X8);
> +
> +	case V4L2_PIX_FMT_HM12:
> +	case V4L2_PIX_FMT_NV12:
> +	case V4L2_PIX_FMT_NV21:
> +	case V4L2_PIX_FMT_NV16:
> +	case V4L2_PIX_FMT_NV61:
> +	case V4L2_PIX_FMT_YUV420:
> +	case V4L2_PIX_FMT_YVU420:
> +	case V4L2_PIX_FMT_YUV422P:
> +		switch (mbus_code) {
> +		case MEDIA_BUS_FMT_UYVY8_2X8:
> +		case MEDIA_BUS_FMT_VYUY8_2X8:
> +		case MEDIA_BUS_FMT_YUYV8_2X8:
> +		case MEDIA_BUS_FMT_YVYU8_2X8:
> +			return true;
> +		default:
> +			dev_dbg(sdev->dev, "Unsupported mbus code: 0x%x\n",
> +				mbus_code);
> +			break;
> +		}
> +		break;
> +	default:
> +		dev_dbg(sdev->dev, "Unsupported pixformat: 0x%x\n", pixformat);
> +		break;
> +	}
> +
> +	return false;
> +}
> +
> +int sun6i_csi_set_power(struct sun6i_csi *csi, bool enable)
> +{
> +	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
> +	struct regmap *regmap = sdev->regmap;
> +	int ret;
> +
> +	if (!enable) {
> +		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
> +
> +		clk_disable_unprepare(sdev->clk_ram);
> +		clk_disable_unprepare(sdev->clk_mod);
> +		reset_control_assert(sdev->rstc_bus);
> +		return 0;
> +	}
> +
> +	ret = clk_prepare_enable(sdev->clk_mod);
> +	if (ret) {
> +		dev_err(sdev->dev, "Enable csi clk err %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(sdev->clk_ram);
> +	if (ret) {
> +		dev_err(sdev->dev, "Enable clk_dram_csi clk err %d\n", ret);
> +		return ret;
> +	}

You could use clk_bulk_prepare_enable() (and clk_bulk_disable_unprepare()
above). Either way, you need to unprepare and disable sdev->clk_mod here if
preparing or enabling  sdev->clk_ram fails above. Same for reset below.

> +
> +	ret = reset_control_deassert(sdev->rstc_bus);
> +	if (ret) {
> +		dev_err(sdev->dev, "reset err %d\n", ret);
> +		return ret;
> +	}
> +
> +	regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, CSI_EN_CSI_EN);
> +
> +	return 0;
> +}
> +
> +static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_dev *sdev,
> +					       u32 mbus_code, u32 pixformat)
> +{
> +	/* bayer */
> +	if ((mbus_code & 0xF000) == 0x3000)
> +		return CSI_INPUT_FORMAT_RAW;
> +
> +	switch (pixformat) {
> +	case V4L2_PIX_FMT_YUYV:
> +	case V4L2_PIX_FMT_YVYU:
> +	case V4L2_PIX_FMT_UYVY:
> +	case V4L2_PIX_FMT_VYUY:
> +		return CSI_INPUT_FORMAT_RAW;
> +	default:
> +		break;
> +	}
> +
> +	/* not support YUV420 input format yet */
> +	dev_dbg(sdev->dev, "Select YUV422 as default input format of CSI.\n");
> +	return CSI_INPUT_FORMAT_YUV422;
> +}
> +
> +static enum csi_output_fmt get_csi_output_format(struct sun6i_csi_dev *sdev,
> +						 u32 pixformat, u32 field)
> +{
> +	bool buf_interlaced = false;
> +
> +	if (field == V4L2_FIELD_INTERLACED
> +	    || field == V4L2_FIELD_INTERLACED_TB
> +	    || field == V4L2_FIELD_INTERLACED_BT)
> +		buf_interlaced = true;
> +
> +	switch (pixformat) {
> +	case V4L2_PIX_FMT_SBGGR8:
> +	case V4L2_PIX_FMT_SGBRG8:
> +	case V4L2_PIX_FMT_SGRBG8:
> +	case V4L2_PIX_FMT_SRGGB8:
> +		return buf_interlaced ? CSI_FRAME_RAW_8 : CSI_FIELD_RAW_8;
> +	case V4L2_PIX_FMT_SBGGR10:
> +	case V4L2_PIX_FMT_SGBRG10:
> +	case V4L2_PIX_FMT_SGRBG10:
> +	case V4L2_PIX_FMT_SRGGB10:
> +		return buf_interlaced ? CSI_FRAME_RAW_10 : CSI_FIELD_RAW_10;
> +	case V4L2_PIX_FMT_SBGGR12:
> +	case V4L2_PIX_FMT_SGBRG12:
> +	case V4L2_PIX_FMT_SGRBG12:
> +	case V4L2_PIX_FMT_SRGGB12:
> +		return buf_interlaced ? CSI_FRAME_RAW_12 : CSI_FIELD_RAW_12;
> +
> +	case V4L2_PIX_FMT_YUYV:
> +	case V4L2_PIX_FMT_YVYU:
> +	case V4L2_PIX_FMT_UYVY:
> +	case V4L2_PIX_FMT_VYUY:
> +		return buf_interlaced ? CSI_FRAME_RAW_8 : CSI_FIELD_RAW_8;
> +
> +	case V4L2_PIX_FMT_HM12:
> +		return buf_interlaced ? CSI_FRAME_MB_YUV420 :
> +					CSI_FIELD_MB_YUV420;
> +	case V4L2_PIX_FMT_NV12:
> +	case V4L2_PIX_FMT_NV21:
> +		return buf_interlaced ? CSI_FRAME_UV_CB_YUV420 :
> +					CSI_FIELD_UV_CB_YUV420;
> +	case V4L2_PIX_FMT_YUV420:
> +	case V4L2_PIX_FMT_YVU420:
> +		return buf_interlaced ? CSI_FRAME_PLANAR_YUV420 :
> +					CSI_FIELD_PLANAR_YUV420;
> +	case V4L2_PIX_FMT_NV16:
> +	case V4L2_PIX_FMT_NV61:
> +		return buf_interlaced ? CSI_FRAME_UV_CB_YUV422 :
> +					CSI_FIELD_UV_CB_YUV422;
> +	case V4L2_PIX_FMT_YUV422P:
> +		return buf_interlaced ? CSI_FRAME_PLANAR_YUV422 :
> +					CSI_FIELD_PLANAR_YUV422;
> +	default:
> +		dev_warn(sdev->dev, "Unsupported pixformat: 0x%x\n", pixformat);
> +		break;
> +	}
> +
> +	return CSI_FIELD_RAW_8;
> +}
> +
> +static enum csi_input_seq get_csi_input_seq(struct sun6i_csi_dev *sdev,
> +					    u32 mbus_code, u32 pixformat)
> +{
> +
> +	switch (pixformat) {
> +	case V4L2_PIX_FMT_HM12:
> +	case V4L2_PIX_FMT_NV12:
> +	case V4L2_PIX_FMT_NV16:
> +	case V4L2_PIX_FMT_YUV420:
> +	case V4L2_PIX_FMT_YUV422P:
> +		switch (mbus_code) {
> +		case MEDIA_BUS_FMT_UYVY8_2X8:
> +		case MEDIA_BUS_FMT_UYVY8_1X16:
> +			return CSI_INPUT_SEQ_UYVY;
> +		case MEDIA_BUS_FMT_VYUY8_2X8:
> +		case MEDIA_BUS_FMT_VYUY8_1X16:
> +			return CSI_INPUT_SEQ_VYUY;
> +		case MEDIA_BUS_FMT_YUYV8_2X8:
> +		case MEDIA_BUS_FMT_YUYV8_1X16:
> +			return CSI_INPUT_SEQ_YUYV;
> +		case MEDIA_BUS_FMT_YVYU8_1X16:
> +		case MEDIA_BUS_FMT_YVYU8_2X8:
> +			return CSI_INPUT_SEQ_YVYU;
> +		default:
> +			dev_warn(sdev->dev, "Unsupported mbus code: 0x%x\n",
> +				 mbus_code);
> +			break;
> +		}
> +		break;
> +	case V4L2_PIX_FMT_NV21:
> +	case V4L2_PIX_FMT_NV61:
> +	case V4L2_PIX_FMT_YVU420:
> +		switch (mbus_code) {
> +		case MEDIA_BUS_FMT_UYVY8_2X8:
> +		case MEDIA_BUS_FMT_UYVY8_1X16:
> +			return CSI_INPUT_SEQ_VYUY;
> +		case MEDIA_BUS_FMT_VYUY8_2X8:
> +		case MEDIA_BUS_FMT_VYUY8_1X16:
> +			return CSI_INPUT_SEQ_UYVY;
> +		case MEDIA_BUS_FMT_YUYV8_2X8:
> +		case MEDIA_BUS_FMT_YUYV8_1X16:
> +			return CSI_INPUT_SEQ_YVYU;
> +		case MEDIA_BUS_FMT_YVYU8_1X16:
> +		case MEDIA_BUS_FMT_YVYU8_2X8:
> +			return CSI_INPUT_SEQ_YUYV;
> +		default:
> +			dev_warn(sdev->dev, "Unsupported mbus code: 0x%x\n",
> +				 mbus_code);
> +			break;
> +		}
> +		break;
> +
> +	case V4L2_PIX_FMT_YUYV:
> +		return CSI_INPUT_SEQ_YUYV;
> +
> +	default:
> +		dev_warn(sdev->dev, "Unsupported pixformat: 0x%x, defaulting to YUYV\n",
> +			 pixformat);
> +		break;
> +	}
> +
> +	return CSI_INPUT_SEQ_YUYV;
> +}
> +
> +static void sun6i_csi_setup_bus(struct sun6i_csi_dev *sdev)
> +{
> +	struct v4l2_fwnode_endpoint *endpoint = &sdev->csi.v4l2_ep;
> +	unsigned char bus_width;
> +	u32 flags;
> +	u32 cfg;
> +
> +	bus_width = endpoint->bus.parallel.bus_width;
> +
> +	regmap_read(sdev->regmap, CSI_IF_CFG_REG, &cfg);
> +
> +	cfg &= ~(CSI_IF_CFG_CSI_IF_MASK | CSI_IF_CFG_MIPI_IF_MASK |
> +		 CSI_IF_CFG_IF_DATA_WIDTH_MASK |
> +		 CSI_IF_CFG_CLK_POL_MASK | CSI_IF_CFG_VREF_POL_MASK |
> +		 CSI_IF_CFG_HREF_POL_MASK | CSI_IF_CFG_FIELD_MASK);
> +
> +	switch (endpoint->bus_type) {
> +	case V4L2_MBUS_PARALLEL:
> +		cfg |= CSI_IF_CFG_MIPI_IF_CSI;
> +
> +		flags = endpoint->bus.parallel.flags;
> +
> +		cfg |= (bus_width == 16) ? CSI_IF_CFG_CSI_IF_YUV422_16BIT :
> +					   CSI_IF_CFG_CSI_IF_YUV422_INTLV;
> +
> +		if (flags & V4L2_MBUS_FIELD_EVEN_LOW)
> +			cfg |= CSI_IF_CFG_FIELD_POSITIVE;
> +
> +		if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
> +			cfg |= CSI_IF_CFG_VREF_POL_POSITIVE;
> +		if (flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)
> +			cfg |= CSI_IF_CFG_HREF_POL_POSITIVE;
> +
> +		if (flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
> +			cfg |= CSI_IF_CFG_CLK_POL_FALLING_EDGE;
> +		break;
> +	case V4L2_MBUS_BT656:
> +		cfg |= CSI_IF_CFG_MIPI_IF_CSI;
> +
> +		flags = endpoint->bus.parallel.flags;
> +
> +		cfg |= (bus_width == 16) ? CSI_IF_CFG_CSI_IF_BT1120 :
> +					   CSI_IF_CFG_CSI_IF_BT656;
> +
> +		if (flags & V4L2_MBUS_FIELD_EVEN_LOW)
> +			cfg |= CSI_IF_CFG_FIELD_POSITIVE;
> +
> +		if (flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
> +			cfg |= CSI_IF_CFG_CLK_POL_FALLING_EDGE;
> +		break;
> +	default:
> +		dev_warn(sdev->dev, "Unsupported bus type: %d\n",
> +			 endpoint->bus_type);
> +		break;
> +	}
> +
> +	switch (bus_width) {
> +	case 8:
> +		cfg |= CSI_IF_CFG_IF_DATA_WIDTH_8BIT;
> +		break;
> +	case 10:
> +		cfg |= CSI_IF_CFG_IF_DATA_WIDTH_10BIT;
> +		break;
> +	case 12:
> +		cfg |= CSI_IF_CFG_IF_DATA_WIDTH_12BIT;
> +		break;
> +	case 16: /* No need to configure DATA_WIDTH for 16bit */
> +		break;
> +	default:
> +		dev_warn(sdev->dev, "Unsupported bus width: %d\n", bus_width);
> +		break;
> +	}
> +
> +	regmap_write(sdev->regmap, CSI_IF_CFG_REG, cfg);
> +}
> +
> +static void sun6i_csi_set_format(struct sun6i_csi_dev *sdev)
> +{
> +	struct sun6i_csi *csi = &sdev->csi;
> +	u32 cfg;
> +	u32 val;
> +
> +	regmap_read(sdev->regmap, CSI_CH_CFG_REG, &cfg);
> +
> +	cfg &= ~(CSI_CH_CFG_INPUT_FMT_MASK |
> +		 CSI_CH_CFG_OUTPUT_FMT_MASK | CSI_CH_CFG_VFLIP_EN |
> +		 CSI_CH_CFG_HFLIP_EN | CSI_CH_CFG_FIELD_SEL_MASK |
> +		 CSI_CH_CFG_INPUT_SEQ_MASK);
> +
> +	val = get_csi_input_format(sdev, csi->config.code,
> +				   csi->config.pixelformat);
> +	cfg |= CSI_CH_CFG_INPUT_FMT(val);
> +
> +	val = get_csi_output_format(sdev, csi->config.pixelformat,
> +				    csi->config.field);
> +	cfg |= CSI_CH_CFG_OUTPUT_FMT(val);
> +
> +	val = get_csi_input_seq(sdev, csi->config.code,
> +				csi->config.pixelformat);
> +	cfg |= CSI_CH_CFG_INPUT_SEQ(val);
> +
> +	if (csi->config.field == V4L2_FIELD_TOP)
> +		cfg |= CSI_CH_CFG_FIELD_SEL_FIELD0;
> +	else if (csi->config.field == V4L2_FIELD_BOTTOM)
> +		cfg |= CSI_CH_CFG_FIELD_SEL_FIELD1;
> +	else
> +		cfg |= CSI_CH_CFG_FIELD_SEL_BOTH;
> +
> +	regmap_write(sdev->regmap, CSI_CH_CFG_REG, cfg);
> +}
> +
> +static void sun6i_csi_set_window(struct sun6i_csi_dev *sdev)
> +{
> +	struct sun6i_csi_config *config = &sdev->csi.config;
> +	u32 bytesperline_y;
> +	u32 bytesperline_c;
> +	int *planar_offset = sdev->planar_offset;
> +	u32 width = config->width;
> +	u32 height = config->height;
> +	u32 hor_len = width;
> +
> +	switch (config->pixelformat) {
> +	case V4L2_PIX_FMT_YUYV:
> +	case V4L2_PIX_FMT_YVYU:
> +	case V4L2_PIX_FMT_UYVY:
> +	case V4L2_PIX_FMT_VYUY:
> +		dev_dbg(sdev->dev,
> +			"Horizontal length should be 2 times of width for packed YUV formats!\n");
> +		hor_len = width * 2;
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	regmap_write(sdev->regmap, CSI_CH_HSIZE_REG,
> +		     CSI_CH_HSIZE_HOR_LEN(hor_len) |
> +		     CSI_CH_HSIZE_HOR_START(0));
> +	regmap_write(sdev->regmap, CSI_CH_VSIZE_REG,
> +		     CSI_CH_VSIZE_VER_LEN(height) |
> +		     CSI_CH_VSIZE_VER_START(0));
> +
> +	planar_offset[0] = 0;
> +	switch (config->pixelformat) {
> +	case V4L2_PIX_FMT_HM12:
> +	case V4L2_PIX_FMT_NV12:
> +	case V4L2_PIX_FMT_NV21:
> +	case V4L2_PIX_FMT_NV16:
> +	case V4L2_PIX_FMT_NV61:
> +		bytesperline_y = width;
> +		bytesperline_c = width;
> +		planar_offset[1] = bytesperline_y * height;
> +		planar_offset[2] = -1;
> +		break;
> +	case V4L2_PIX_FMT_YUV420:
> +	case V4L2_PIX_FMT_YVU420:
> +		bytesperline_y = width;
> +		bytesperline_c = width / 2;
> +		planar_offset[1] = bytesperline_y * height;
> +		planar_offset[2] = planar_offset[1] +
> +				bytesperline_c * height / 2;
> +		break;
> +	case V4L2_PIX_FMT_YUV422P:
> +		bytesperline_y = width;
> +		bytesperline_c = width / 2;
> +		planar_offset[1] = bytesperline_y * height;
> +		planar_offset[2] = planar_offset[1] +
> +				bytesperline_c * height;
> +		break;
> +	default: /* raw */
> +		dev_dbg(sdev->dev,
> +			"Calculating pixelformat(0x%x)'s bytesperline as a packed format\n",
> +			config->pixelformat);
> +		bytesperline_y = (sun6i_csi_get_bpp(config->pixelformat) *
> +				  config->width) / 8;
> +		bytesperline_c = 0;
> +		planar_offset[1] = -1;
> +		planar_offset[2] = -1;
> +		break;
> +	}
> +
> +	regmap_write(sdev->regmap, CSI_CH_BUF_LEN_REG,
> +		     CSI_CH_BUF_LEN_BUF_LEN_C(bytesperline_c) |
> +		     CSI_CH_BUF_LEN_BUF_LEN_Y(bytesperline_y));
> +}
> +
> +int sun6i_csi_update_config(struct sun6i_csi *csi,
> +			    struct sun6i_csi_config *config)
> +{
> +	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
> +
> +	if (config == NULL)
> +		return -EINVAL;
> +
> +	memcpy(&csi->config, config, sizeof(csi->config));
> +
> +	sun6i_csi_setup_bus(sdev);
> +	sun6i_csi_set_format(sdev);
> +	sun6i_csi_set_window(sdev);
> +
> +	return 0;
> +}
> +
> +void sun6i_csi_update_buf_addr(struct sun6i_csi *csi, dma_addr_t addr)
> +{
> +	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
> +
> +	regmap_write(sdev->regmap, CSI_CH_F0_BUFA_REG,
> +		     (addr + sdev->planar_offset[0]) >> 2);
> +	if (sdev->planar_offset[1] != -1)
> +		regmap_write(sdev->regmap, CSI_CH_F1_BUFA_REG,
> +			     (addr + sdev->planar_offset[1]) >> 2);
> +	if (sdev->planar_offset[2] != -1)
> +		regmap_write(sdev->regmap, CSI_CH_F2_BUFA_REG,
> +			     (addr + sdev->planar_offset[2]) >> 2);
> +}
> +
> +void sun6i_csi_set_stream(struct sun6i_csi *csi, bool enable)
> +{
> +	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
> +	struct regmap *regmap = sdev->regmap;
> +
> +	if (!enable) {
> +		regmap_update_bits(regmap, CSI_CAP_REG, CSI_CAP_CH0_VCAP_ON, 0);
> +		regmap_write(regmap, CSI_CH_INT_EN_REG, 0);
> +		return;
> +	}
> +
> +	regmap_write(regmap, CSI_CH_INT_STA_REG, 0xFF);
> +	regmap_write(regmap, CSI_CH_INT_EN_REG,
> +		     CSI_CH_INT_EN_HB_OF_INT_EN |
> +		     CSI_CH_INT_EN_FIFO2_OF_INT_EN |
> +		     CSI_CH_INT_EN_FIFO1_OF_INT_EN |
> +		     CSI_CH_INT_EN_FIFO0_OF_INT_EN |
> +		     CSI_CH_INT_EN_FD_INT_EN |
> +		     CSI_CH_INT_EN_CD_INT_EN);
> +
> +	regmap_update_bits(regmap, CSI_CAP_REG, CSI_CAP_CH0_VCAP_ON,
> +			   CSI_CAP_CH0_VCAP_ON);
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Media Controller and V4L2
> + */
> +static int sun6i_csi_link_entity(struct sun6i_csi *csi,
> +				 struct media_entity *entity,
> +				 struct fwnode_handle *fwnode)
> +{
> +	struct media_entity *sink;
> +	struct media_pad *sink_pad;
> +	struct media_link *link;
> +	int src_pad_index;
> +	int ret;
> +
> +	ret = media_entity_get_fwnode_pad(entity, fwnode, MEDIA_PAD_FL_SOURCE);
> +	if (ret < 0) {
> +		dev_err(csi->dev, "%s: no source pad in external entity %s\n",
> +			__func__, entity->name);
> +		return -EINVAL;
> +	}
> +
> +	src_pad_index = ret;
> +
> +	sink = &csi->video.vdev.entity;
> +	sink_pad = &csi->video.pad;
> +
> +	dev_dbg(csi->dev, "creating %s:%u -> %s:%u link\n",
> +		entity->name, src_pad_index, sink->name, sink_pad->index);
> +	ret = media_create_pad_link(entity, src_pad_index, sink,
> +				    sink_pad->index, 0);
> +	if (ret < 0) {
> +		dev_err(csi->dev, "failed to create %s:%u -> %s:%u link\n",
> +			entity->name, src_pad_index,
> +			sink->name, sink_pad->index);
> +		return ret;
> +	}
> +
> +	link = media_entity_find_link(&entity->pads[src_pad_index], sink_pad);
> +	return media_entity_setup_link(link, MEDIA_LNK_FL_ENABLED);

No need for link setup here; just set the ENABLED flag when you create the
link. If there's no use case for disabling it, you should also set the
IMMUTABLE flag.

> +}
> +
> +static int sun6i_subdev_notify_complete(struct v4l2_async_notifier *notifier)
> +{
> +	struct sun6i_csi *csi = container_of(notifier, struct sun6i_csi,
> +					     notifier);
> +	struct v4l2_device *v4l2_dev = &csi->v4l2_dev;
> +	struct v4l2_subdev *sd;
> +	int ret;
> +
> +	dev_dbg(csi->dev, "notify complete, all subdevs registered\n");
> +
> +	if (notifier->num_subdevs != 1)
> +		return -EINVAL;
> +
> +	sd = list_first_entry(&v4l2_dev->subdevs, struct v4l2_subdev, list);
> +	if (sd == NULL)
> +		return -EINVAL;
> +
> +	ret = sun6i_csi_link_entity(csi, &sd->entity, sd->fwnode);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = v4l2_device_register_subdev_nodes(&csi->v4l2_dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	return media_device_register(&csi->media_dev);
> +}
> +
> +static const struct v4l2_async_notifier_operations sun6i_csi_async_ops = {
> +	.complete = sun6i_subdev_notify_complete,
> +};
> +
> +static int sun6i_csi_fwnode_parse(struct device *dev,
> +				  struct v4l2_fwnode_endpoint *vep,
> +				  struct v4l2_async_subdev *asd)
> +{
> +	struct sun6i_csi *csi = dev_get_drvdata(dev);
> +
> +	if (vep->base.port || vep->base.id) {
> +		dev_warn(dev, "Only support a single port with one endpoint\n");
> +		return -ENOTCONN;
> +	}
> +
> +	switch (vep->bus_type) {
> +	case V4L2_MBUS_PARALLEL:
> +	case V4L2_MBUS_BT656:
> +		csi->v4l2_ep = *vep;
> +		return 0;
> +	default:
> +		dev_err(dev, "Unsupported media bus type\n");
> +		return -ENOTCONN;
> +	}
> +}
> +
> +static void sun6i_csi_v4l2_cleanup(struct sun6i_csi *csi)
> +{
> +	v4l2_async_notifier_cleanup(&csi->notifier);
> +	v4l2_async_notifier_unregister(&csi->notifier);

The other way. First unregister, then cleanup.

> +	sun6i_video_cleanup(&csi->video);
> +	v4l2_device_unregister(&csi->v4l2_dev);
> +	media_device_unregister(&csi->media_dev);
> +	media_device_cleanup(&csi->media_dev);
> +}
> +
> +static int sun6i_csi_v4l2_init(struct sun6i_csi *csi)
> +{
> +	int ret;
> +
> +	csi->media_dev.dev = csi->dev;
> +	strlcpy(csi->media_dev.model, "Allwinner Video Capture Device",
> +		sizeof(csi->media_dev.model));
> +	csi->media_dev.hw_revision = 0;
> +
> +	media_device_init(&csi->media_dev);
> +
> +	ret = v4l2_ctrl_handler_init(&csi->ctrl_handler, 0);
> +	if (ret) {
> +		dev_err(csi->dev, "V4L2 controls handler init failed (%d)\n",
> +			ret);
> +		goto clean_media;
> +	}
> +
> +	csi->v4l2_dev.mdev = &csi->media_dev;
> +	csi->v4l2_dev.ctrl_handler = &csi->ctrl_handler;
> +	ret = v4l2_device_register(csi->dev, &csi->v4l2_dev);
> +	if (ret) {
> +		dev_err(csi->dev, "V4L2 device registration failed (%d)\n",
> +			ret);
> +		goto clean_media;
> +	}
> +
> +	ret = sun6i_video_init(&csi->video, csi, "sun6i-csi");
> +	if (ret)
> +		goto unreg_v4l2;
> +
> +	ret = v4l2_async_notifier_parse_fwnode_endpoints(
> +		csi->dev, &csi->notifier, sizeof(struct v4l2_async_subdev),
> +		sun6i_csi_fwnode_parse);
> +	if (ret)
> +		goto clean_video;
> +
> +	csi->notifier.ops = &sun6i_csi_async_ops;
> +
> +	ret = v4l2_async_notifier_register(&csi->v4l2_dev, &csi->notifier);
> +	if (ret) {
> +		dev_err(csi->dev, "notifier registration failed\n");
> +		goto clean_notifier;
> +	}
> +
> +	return 0;
> +
> +clean_notifier:
> +	v4l2_async_notifier_cleanup(&csi->notifier);
> +clean_video:
> +	sun6i_video_cleanup(&csi->video);
> +unreg_v4l2:
> +	v4l2_device_unregister(&csi->v4l2_dev);
> +clean_media:
> +	media_device_cleanup(&csi->media_dev);
> +
> +	return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Resources and IRQ
> + */
> +static irqreturn_t sun6i_csi_isr(int irq, void *dev_id)
> +{
> +	struct sun6i_csi_dev *sdev = (struct sun6i_csi_dev *)dev_id;
> +	struct regmap *regmap = sdev->regmap;
> +	u32 status;
> +
> +	regmap_read(regmap, CSI_CH_INT_STA_REG, &status);
> +
> +	if (!(status & 0xFF))
> +		return IRQ_NONE;
> +
> +	if ((status & CSI_CH_INT_STA_FIFO0_OF_PD) ||
> +	    (status & CSI_CH_INT_STA_FIFO1_OF_PD) ||
> +	    (status & CSI_CH_INT_STA_FIFO2_OF_PD) ||
> +	    (status & CSI_CH_INT_STA_HB_OF_PD)) {
> +		regmap_write(regmap, CSI_CH_INT_STA_REG, status);
> +		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
> +		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN,
> +				   CSI_EN_CSI_EN);
> +		return IRQ_HANDLED;
> +	}
> +
> +	if (status & CSI_CH_INT_STA_FD_PD)
> +		sun6i_video_frame_done(&sdev->csi.video);
> +
> +	regmap_write(regmap, CSI_CH_INT_STA_REG, status);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct regmap_config sun6i_csi_regmap_config = {
> +	.reg_bits       = 32,
> +	.reg_stride     = 4,
> +	.val_bits       = 32,
> +	.max_register	= 0x1000,
> +};
> +
> +static int sun6i_csi_resource_request(struct sun6i_csi_dev *sdev,
> +				      struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	void __iomem *io_base;
> +	int ret;
> +	int irq;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	io_base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(io_base))
> +		return PTR_ERR(io_base);
> +
> +	sdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "bus", io_base,
> +					    &sun6i_csi_regmap_config);
> +	if (IS_ERR(sdev->regmap)) {
> +		dev_err(&pdev->dev, "Failed to init register map\n");
> +		return PTR_ERR(sdev->regmap);
> +	}
> +
> +	sdev->clk_mod = devm_clk_get(&pdev->dev, "mod");
> +	if (IS_ERR(sdev->clk_mod)) {
> +		dev_err(&pdev->dev, "Unable to acquire csi clock\n");
> +		return PTR_ERR(sdev->clk_mod);
> +	}
> +
> +	sdev->clk_ram = devm_clk_get(&pdev->dev, "ram");
> +	if (IS_ERR(sdev->clk_ram)) {
> +		dev_err(&pdev->dev, "Unable to acquire dram-csi clock\n");
> +		return PTR_ERR(sdev->clk_ram);
> +	}
> +
> +	sdev->rstc_bus = devm_reset_control_get_shared(&pdev->dev, NULL);
> +	if (IS_ERR(sdev->rstc_bus)) {
> +		dev_err(&pdev->dev, "Cannot get reset controller\n");
> +		return PTR_ERR(sdev->rstc_bus);
> +	}
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		dev_err(&pdev->dev, "No csi IRQ specified\n");
> +		ret = -ENXIO;
> +		return ret;
> +	}
> +
> +	ret = devm_request_irq(&pdev->dev, irq, sun6i_csi_isr, 0, MODULE_NAME,
> +			       sdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Cannot request csi IRQ\n");
> +		return ret;
> +	}
> +	return 0;
> +}
> +
> +/*
> + * PHYS_OFFSET isn't available on all architectures. In order to
> + * accomodate for COMPILE_TEST, let's define it to something dumb.
> + */
> +#ifndef PHYS_OFFSET
> +#define PHYS_OFFSET 0
> +#endif
> +
> +static int sun6i_csi_probe(struct platform_device *pdev)
> +{
> +	struct sun6i_csi_dev *sdev;
> +	int ret;
> +
> +	sdev = devm_kzalloc(&pdev->dev, sizeof(*sdev), GFP_KERNEL);
> +	if (!sdev)
> +		return -ENOMEM;
> +
> +	sdev->dev = &pdev->dev;
> +	/* The DMA bus has the memory mapped at 0 */
> +	sdev->dev->dma_pfn_offset = PHYS_OFFSET >> PAGE_SHIFT;
> +
> +	ret = sun6i_csi_resource_request(sdev, pdev);
> +	if (ret)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, sdev);
> +
> +	sdev->csi.dev = &pdev->dev;
> +	ret = sun6i_csi_v4l2_init(&sdev->csi);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int sun6i_csi_remove(struct platform_device *pdev)
> +{
> +	struct sun6i_csi_dev *sdev = platform_get_drvdata(pdev);
> +
> +	sun6i_csi_v4l2_cleanup(&sdev->csi);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id sun6i_csi_of_match[] = {
> +	{ .compatible = "allwinner,sun8i-v3s-csi", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, sun6i_csi_of_match);
> +
> +static struct platform_driver sun6i_csi_platform_driver = {
> +	.probe = sun6i_csi_probe,
> +	.remove = sun6i_csi_remove,
> +	.driver = {
> +		.name = MODULE_NAME,
> +		.of_match_table = of_match_ptr(sun6i_csi_of_match),
> +	},
> +};
> +module_platform_driver(sun6i_csi_platform_driver);
> +
> +MODULE_DESCRIPTION("Allwinner V3s Camera Sensor Interface driver");
> +MODULE_AUTHOR("Yong Deng <[e-mail]>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
> new file mode 100644
> index 000000000000..44a7d50805bc
> --- /dev/null
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
> @@ -0,0 +1,145 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
> + * All rights reserved.
> + * Author: Yong Deng <[e-mail]>
> + */
> +
> +#ifndef __SUN6I_CSI_H__
> +#define __SUN6I_CSI_H__
> +
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +
> +#include "sun6i_video.h"
> +
> +struct sun6i_csi;
> +
> +/**
> + * struct sun6i_csi_config - configs for sun6i csi
> + * @pixelformat: v4l2 pixel format (V4L2_PIX_FMT_*)
> + * @code:	media bus format code (MEDIA_BUS_FMT_*)
> + * @field:	used interlacing type (enum v4l2_field)
> + * @width:	frame width
> + * @height:	frame height
> + */
> +struct sun6i_csi_config {
> +	u32		pixelformat;
> +	u32		code;
> +	u32		field;
> +	u32		width;
> +	u32		height;
> +};
> +
> +struct sun6i_csi {
> +	struct device			*dev;
> +	struct v4l2_ctrl_handler	ctrl_handler;
> +	struct v4l2_device		v4l2_dev;
> +	struct media_device		media_dev;
> +
> +	struct v4l2_async_notifier	notifier;
> +
> +	/* video port settings */
> +	struct v4l2_fwnode_endpoint	v4l2_ep;
> +
> +	struct sun6i_csi_config		config;
> +
> +	struct sun6i_video		video;
> +};
> +
> +/**
> + * sun6i_csi_get_supported_pixformats() - get csi supported pixformats
> + * @csi:	pointer to the csi
> + * @pixformats:	supported pixformats return from csi
> + *
> + * @return the count of pixformats or error(< 0)
> + */
> +int sun6i_csi_get_supported_pixformats(struct sun6i_csi *csi,
> +				       const u32 **pixformats);
> +
> +/**
> + * sun6i_csi_is_format_supported() - check if the format supported by csi
> + * @csi:	pointer to the csi
> + * @pixformat:	v4l2 pixel format (V4L2_PIX_FMT_*)
> + * @mbus_code:	media bus format code (MEDIA_BUS_FMT_*)
> + */
> +bool sun6i_csi_is_format_supported(struct sun6i_csi *csi, u32 pixformat,
> +				 u32 mbus_code);
> +
> +/**
> + * sun6i_csi_set_power() - power on/off the csi
> + * @csi:	pointer to the csi
> + * @enable:	on/off
> + */
> +int sun6i_csi_set_power(struct sun6i_csi *csi, bool enable);
> +
> +/**
> + * sun6i_csi_update_config() - update the csi register setttings
> + * @csi:	pointer to the csi
> + * @config:	see struct sun6i_csi_config
> + */
> +int sun6i_csi_update_config(struct sun6i_csi *csi,
> +			    struct sun6i_csi_config *config);
> +
> +/**
> + * sun6i_csi_update_buf_addr() - update the csi frame buffer address
> + * @csi:	pointer to the csi
> + * @addr:	frame buffer's physical address
> + */
> +void sun6i_csi_update_buf_addr(struct sun6i_csi *csi, dma_addr_t addr);
> +
> +/**
> + * sun6i_csi_set_stream() - start/stop csi streaming
> + * @csi:	pointer to the csi
> + * @enable:	start/stop
> + */
> +void sun6i_csi_set_stream(struct sun6i_csi *csi, bool enable);
> +
> +/* get bpp form v4l2 pixformat */
> +static inline int sun6i_csi_get_bpp(unsigned int pixformat)
> +{
> +	switch (pixformat) {
> +	case V4L2_PIX_FMT_SBGGR8:
> +	case V4L2_PIX_FMT_SGBRG8:
> +	case V4L2_PIX_FMT_SGRBG8:
> +	case V4L2_PIX_FMT_SRGGB8:
> +		return 8;
> +	case V4L2_PIX_FMT_SBGGR10:
> +	case V4L2_PIX_FMT_SGBRG10:
> +	case V4L2_PIX_FMT_SGRBG10:
> +	case V4L2_PIX_FMT_SRGGB10:
> +		return 10;
> +	case V4L2_PIX_FMT_SBGGR12:
> +	case V4L2_PIX_FMT_SGBRG12:
> +	case V4L2_PIX_FMT_SGRBG12:
> +	case V4L2_PIX_FMT_SRGGB12:
> +	case V4L2_PIX_FMT_HM12:
> +	case V4L2_PIX_FMT_NV12:
> +	case V4L2_PIX_FMT_NV21:
> +	case V4L2_PIX_FMT_YUV420:
> +	case V4L2_PIX_FMT_YVU420:
> +		return 12;
> +	case V4L2_PIX_FMT_YUYV:
> +	case V4L2_PIX_FMT_YVYU:
> +	case V4L2_PIX_FMT_UYVY:
> +	case V4L2_PIX_FMT_VYUY:
> +	case V4L2_PIX_FMT_NV16:
> +	case V4L2_PIX_FMT_NV61:
> +	case V4L2_PIX_FMT_YUV422P:
> +		return 16;
> +	case V4L2_PIX_FMT_RGB24:
> +	case V4L2_PIX_FMT_BGR24:
> +		return 24;
> +	case V4L2_PIX_FMT_RGB32:
> +	case V4L2_PIX_FMT_BGR32:
> +		return 32;
> +	default:
> +		WARN(1, "Unsupported pixformat: 0x%x\n", pixformat);
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +#endif /* __SUN6I_CSI_H__ */
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h
> new file mode 100644
> index 000000000000..00798b4d20f2
> --- /dev/null
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h
> @@ -0,0 +1,196 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
> + * All rights reserved.
> + * Author: Yong Deng <[e-mail]>
> + */
> +
> +#ifndef __SUN6I_CSI_REG_H__
> +#define __SUN6I_CSI_REG_H__
> +
> +#include <linux/kernel.h>
> +
> +#define CSI_EN_REG			0x0
> +#define CSI_EN_VER_EN				BIT(30)
> +#define CSI_EN_CSI_EN				BIT(0)
> +
> +#define CSI_IF_CFG_REG			0x4
> +#define CSI_IF_CFG_SRC_TYPE_MASK		BIT(21)
> +#define CSI_IF_CFG_SRC_TYPE_PROGRESSED		((0 << 21) & CSI_IF_CFG_SRC_TYPE_MASK)
> +#define CSI_IF_CFG_SRC_TYPE_INTERLACED		((1 << 21) & CSI_IF_CFG_SRC_TYPE_MASK)
> +#define CSI_IF_CFG_FPS_DS_EN			BIT(20)
> +#define CSI_IF_CFG_FIELD_MASK			BIT(19)
> +#define CSI_IF_CFG_FIELD_NEGATIVE		((0 << 19) & CSI_IF_CFG_FIELD_MASK)
> +#define CSI_IF_CFG_FIELD_POSITIVE		((1 << 19) & CSI_IF_CFG_FIELD_MASK)
> +#define CSI_IF_CFG_VREF_POL_MASK		BIT(18)
> +#define CSI_IF_CFG_VREF_POL_NEGATIVE		((0 << 18) & CSI_IF_CFG_VREF_POL_MASK)
> +#define CSI_IF_CFG_VREF_POL_POSITIVE		((1 << 18) & CSI_IF_CFG_VREF_POL_MASK)
> +#define CSI_IF_CFG_HREF_POL_MASK		BIT(17)
> +#define CSI_IF_CFG_HREF_POL_NEGATIVE		((0 << 17) & CSI_IF_CFG_HREF_POL_MASK)
> +#define CSI_IF_CFG_HREF_POL_POSITIVE		((1 << 17) & CSI_IF_CFG_HREF_POL_MASK)
> +#define CSI_IF_CFG_CLK_POL_MASK			BIT(16)
> +#define CSI_IF_CFG_CLK_POL_RISING_EDGE		((0 << 16) & CSI_IF_CFG_CLK_POL_MASK)
> +#define CSI_IF_CFG_CLK_POL_FALLING_EDGE		((1 << 16) & CSI_IF_CFG_CLK_POL_MASK)
> +#define CSI_IF_CFG_IF_DATA_WIDTH_MASK		GENMASK(10, 8)
> +#define CSI_IF_CFG_IF_DATA_WIDTH_8BIT		((0 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
> +#define CSI_IF_CFG_IF_DATA_WIDTH_10BIT		((1 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
> +#define CSI_IF_CFG_IF_DATA_WIDTH_12BIT		((2 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
> +#define CSI_IF_CFG_MIPI_IF_MASK			BIT(7)
> +#define CSI_IF_CFG_MIPI_IF_CSI			(0 << 7)
> +#define CSI_IF_CFG_MIPI_IF_MIPI			(1 << 7)
> +#define CSI_IF_CFG_CSI_IF_MASK			GENMASK(4, 0)
> +#define CSI_IF_CFG_CSI_IF_YUV422_INTLV		((0 << 0) & CSI_IF_CFG_CSI_IF_MASK)
> +#define CSI_IF_CFG_CSI_IF_YUV422_16BIT		((1 << 0) & CSI_IF_CFG_CSI_IF_MASK)
> +#define CSI_IF_CFG_CSI_IF_BT656			((4 << 0) & CSI_IF_CFG_CSI_IF_MASK)
> +#define CSI_IF_CFG_CSI_IF_BT1120		((5 << 0) & CSI_IF_CFG_CSI_IF_MASK)
> +
> +#define CSI_CAP_REG			0x8
> +#define CSI_CAP_CH0_CAP_MASK_MASK		GENMASK(5, 2)
> +#define CSI_CAP_CH0_CAP_MASK(count)		((count << 2) & CSI_CAP_CH0_CAP_MASK_MASK)
> +#define CSI_CAP_CH0_VCAP_ON			BIT(1)
> +#define CSI_CAP_CH0_SCAP_ON			BIT(0)
> +
> +#define CSI_SYNC_CNT_REG		0xc
> +#define CSI_FIFO_THRS_REG		0x10
> +#define CSI_BT656_HEAD_CFG_REG		0x14
> +#define CSI_PTN_LEN_REG			0x30
> +#define CSI_PTN_ADDR_REG		0x34
> +#define CSI_VER_REG			0x3c
> +
> +#define CSI_CH_CFG_REG			0x44
> +#define CSI_CH_CFG_INPUT_FMT_MASK		GENMASK(23, 20)
> +#define CSI_CH_CFG_INPUT_FMT(fmt)		((fmt << 20) & CSI_CH_CFG_INPUT_FMT_MASK)
> +#define CSI_CH_CFG_OUTPUT_FMT_MASK		GENMASK(19, 16)
> +#define CSI_CH_CFG_OUTPUT_FMT(fmt)		((fmt << 16) & CSI_CH_CFG_OUTPUT_FMT_MASK)
> +#define CSI_CH_CFG_VFLIP_EN			BIT(13)
> +#define CSI_CH_CFG_HFLIP_EN			BIT(12)
> +#define CSI_CH_CFG_FIELD_SEL_MASK		GENMASK(11, 10)
> +#define CSI_CH_CFG_FIELD_SEL_FIELD0		((0 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
> +#define CSI_CH_CFG_FIELD_SEL_FIELD1		((1 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
> +#define CSI_CH_CFG_FIELD_SEL_BOTH		((2 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
> +#define CSI_CH_CFG_INPUT_SEQ_MASK		GENMASK(9, 8)
> +#define CSI_CH_CFG_INPUT_SEQ(seq)		((seq << 8) & CSI_CH_CFG_INPUT_SEQ_MASK)
> +
> +#define CSI_CH_SCALE_REG		0x4c
> +#define CSI_CH_SCALE_QUART_EN			BIT(0)
> +
> +#define CSI_CH_F0_BUFA_REG		0x50
> +
> +#define CSI_CH_F1_BUFA_REG		0x58
> +
> +#define CSI_CH_F2_BUFA_REG		0x60
> +
> +#define CSI_CH_STA_REG			0x6c
> +#define CSI_CH_STA_FIELD_STA_MASK		BIT(2)
> +#define CSI_CH_STA_FIELD_STA_FIELD0		((0 << 2) & CSI_CH_STA_FIELD_STA_MASK)
> +#define CSI_CH_STA_FIELD_STA_FIELD1		((1 << 2) & CSI_CH_STA_FIELD_STA_MASK)
> +#define CSI_CH_STA_VCAP_STA			BIT(1)
> +#define CSI_CH_STA_SCAP_STA			BIT(0)
> +
> +#define CSI_CH_INT_EN_REG		0x70
> +#define CSI_CH_INT_EN_VS_INT_EN			BIT(7)
> +#define CSI_CH_INT_EN_HB_OF_INT_EN		BIT(6)
> +#define CSI_CH_INT_EN_MUL_ERR_INT_EN		BIT(5)
> +#define CSI_CH_INT_EN_FIFO2_OF_INT_EN		BIT(4)
> +#define CSI_CH_INT_EN_FIFO1_OF_INT_EN		BIT(3)
> +#define CSI_CH_INT_EN_FIFO0_OF_INT_EN		BIT(2)
> +#define CSI_CH_INT_EN_FD_INT_EN			BIT(1)
> +#define CSI_CH_INT_EN_CD_INT_EN			BIT(0)
> +
> +#define CSI_CH_INT_STA_REG		0x74
> +#define CSI_CH_INT_STA_VS_PD			BIT(7)
> +#define CSI_CH_INT_STA_HB_OF_PD			BIT(6)
> +#define CSI_CH_INT_STA_MUL_ERR_PD		BIT(5)
> +#define CSI_CH_INT_STA_FIFO2_OF_PD		BIT(4)
> +#define CSI_CH_INT_STA_FIFO1_OF_PD		BIT(3)
> +#define CSI_CH_INT_STA_FIFO0_OF_PD		BIT(2)
> +#define CSI_CH_INT_STA_FD_PD			BIT(1)
> +#define CSI_CH_INT_STA_CD_PD			BIT(0)
> +
> +#define CSI_CH_FLD1_VSIZE_REG		0x78
> +
> +#define CSI_CH_HSIZE_REG		0x80
> +#define CSI_CH_HSIZE_HOR_LEN_MASK		GENMASK(28, 16)
> +#define CSI_CH_HSIZE_HOR_LEN(len)		((len << 16) & CSI_CH_HSIZE_HOR_LEN_MASK)
> +#define CSI_CH_HSIZE_HOR_START_MASK		GENMASK(12, 0)
> +#define CSI_CH_HSIZE_HOR_START(start)		((start << 0) & CSI_CH_HSIZE_HOR_START_MASK)
> +
> +#define CSI_CH_VSIZE_REG		0x84
> +#define CSI_CH_VSIZE_VER_LEN_MASK		GENMASK(28, 16)
> +#define CSI_CH_VSIZE_VER_LEN(len)		((len << 16) & CSI_CH_VSIZE_VER_LEN_MASK)
> +#define CSI_CH_VSIZE_VER_START_MASK		GENMASK(12, 0)
> +#define CSI_CH_VSIZE_VER_START(start)		((start << 0) & CSI_CH_VSIZE_VER_START_MASK)
> +
> +#define CSI_CH_BUF_LEN_REG		0x88
> +#define CSI_CH_BUF_LEN_BUF_LEN_C_MASK		GENMASK(29, 16)
> +#define CSI_CH_BUF_LEN_BUF_LEN_C(len)		((len << 16) & CSI_CH_BUF_LEN_BUF_LEN_C_MASK)
> +#define CSI_CH_BUF_LEN_BUF_LEN_Y_MASK		GENMASK(13, 0)
> +#define CSI_CH_BUF_LEN_BUF_LEN_Y(len)		((len << 0) & CSI_CH_BUF_LEN_BUF_LEN_Y_MASK)
> +
> +#define CSI_CH_FLIP_SIZE_REG		0x8c
> +#define CSI_CH_FLIP_SIZE_VER_LEN_MASK		GENMASK(28, 16)
> +#define CSI_CH_FLIP_SIZE_VER_LEN(len)		((len << 16) & CSI_CH_FLIP_SIZE_VER_LEN_MASK)
> +#define CSI_CH_FLIP_SIZE_VALID_LEN_MASK		GENMASK(12, 0)
> +#define CSI_CH_FLIP_SIZE_VALID_LEN(len)		((len << 0) & CSI_CH_FLIP_SIZE_VALID_LEN_MASK)
> +
> +#define CSI_CH_FRM_CLK_CNT_REG		0x90
> +#define CSI_CH_ACC_ITNL_CLK_CNT_REG	0x94
> +#define CSI_CH_FIFO_STAT_REG		0x98
> +#define CSI_CH_PCLK_STAT_REG		0x9c
> +
> +/*
> + * csi input data format
> + */
> +enum csi_input_fmt {
> +	CSI_INPUT_FORMAT_RAW		= 0,
> +	CSI_INPUT_FORMAT_YUV422		= 3,
> +	CSI_INPUT_FORMAT_YUV420		= 4,
> +};
> +
> +/*
> + * csi output data format
> + */
> +enum csi_output_fmt {
> +	/* only when input format is RAW */
> +	CSI_FIELD_RAW_8			= 0,
> +	CSI_FIELD_RAW_10		= 1,
> +	CSI_FIELD_RAW_12		= 2,
> +	CSI_FIELD_RGB565		= 4,
> +	CSI_FIELD_RGB888		= 5,
> +	CSI_FIELD_PRGB888		= 6,
> +	CSI_FRAME_RAW_8			= 8,
> +	CSI_FRAME_RAW_10		= 9,
> +	CSI_FRAME_RAW_12		= 10,
> +	CSI_FRAME_RGB565		= 12,
> +	CSI_FRAME_RGB888		= 13,
> +	CSI_FRAME_PRGB888		= 14,
> +
> +	/* only when input format is YUV422 */
> +	CSI_FIELD_PLANAR_YUV422		= 0,
> +	CSI_FIELD_PLANAR_YUV420		= 1,
> +	CSI_FRAME_PLANAR_YUV420		= 2,
> +	CSI_FRAME_PLANAR_YUV422		= 3,
> +	CSI_FIELD_UV_CB_YUV422		= 4,
> +	CSI_FIELD_UV_CB_YUV420		= 5,
> +	CSI_FRAME_UV_CB_YUV420		= 6,
> +	CSI_FRAME_UV_CB_YUV422		= 7,
> +	CSI_FIELD_MB_YUV422		= 8,
> +	CSI_FIELD_MB_YUV420		= 9,
> +	CSI_FRAME_MB_YUV420		= 10,
> +	CSI_FRAME_MB_YUV422		= 11,
> +	CSI_FIELD_UV_CB_YUV422_10	= 12,
> +	CSI_FIELD_UV_CB_YUV420_10	= 13,
> +};
> +
> +/*
> + * csi YUV input data sequence
> + */
> +enum csi_input_seq {
> +	/* only when input format is YUV422 */
> +	CSI_INPUT_SEQ_YUYV = 0,
> +	CSI_INPUT_SEQ_YVYU,
> +	CSI_INPUT_SEQ_UYVY,
> +	CSI_INPUT_SEQ_VYUY,
> +};
> +
> +#endif /* __SUN6I_CSI_REG_H__ */
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
> new file mode 100644
> index 000000000000..9bd662b08236
> --- /dev/null
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
> @@ -0,0 +1,767 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
> + * All rights reserved.
> + * Author: Yong Deng <[e-mail]>
> + */
> +
> +#include <linux/of.h>
> +
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/v4l2-mc.h>
> +#include <media/videobuf2-dma-contig.h>
> +#include <media/videobuf2-v4l2.h>
> +
> +#include "sun6i_csi.h"
> +#include "sun6i_video.h"
> +
> +struct sun6i_csi_buffer {
> +	struct vb2_v4l2_buffer		vb;
> +	struct list_head		list;
> +
> +	dma_addr_t			dma_addr;
> +	bool				queued_to_csi;
> +};
> +
> +static struct sun6i_csi_format *
> +find_format_by_pixformat(struct sun6i_video *video, unsigned int pixformat)
> +{
> +	unsigned int num_formats = video->num_formats;
> +	struct sun6i_csi_format *fmt;
> +	unsigned int i;
> +
> +	for (i = 0; i < num_formats; i++) {
> +		fmt = &video->formats[i];
> +		if (fmt->pixformat == pixformat)
> +			return fmt;
> +	}
> +
> +	return NULL;
> +}
> +
> +static struct v4l2_subdev *
> +sun6i_video_remote_subdev(struct sun6i_video *video, u32 *pad)
> +{
> +	struct media_pad *remote;
> +
> +	remote = media_entity_remote_pad(&video->pad);
> +
> +	if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
> +		return NULL;
> +
> +	if (pad)
> +		*pad = remote->index;
> +
> +	return media_entity_to_v4l2_subdev(remote->entity);

If you changed this to return the pad instead of the subdev, you could omit
the pad argument. Up to you.

> +}
> +
> +static int sun6i_video_queue_setup(struct vb2_queue *vq,
> +				 unsigned int *nbuffers, unsigned int *nplanes,
> +				 unsigned int sizes[],
> +				 struct device *alloc_devs[])
> +{
> +	struct sun6i_video *video = vb2_get_drv_priv(vq);
> +	unsigned int size = video->fmt.fmt.pix.sizeimage;
> +
> +	if (*nplanes)
> +		return sizes[0] < size ? -EINVAL : 0;
> +
> +	*nplanes = 1;
> +	sizes[0] = size;
> +
> +	return 0;
> +}
> +
> +static int sun6i_video_buffer_prepare(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct sun6i_csi_buffer *buf =
> +			container_of(vbuf, struct sun6i_csi_buffer, vb);
> +	struct sun6i_video *video = vb2_get_drv_priv(vb->vb2_queue);
> +	unsigned long size = video->fmt.fmt.pix.sizeimage;
> +
> +	if (vb2_plane_size(vb, 0) < size) {
> +		v4l2_err(video->vdev.v4l2_dev, "buffer too small (%lu < %lu)\n",
> +			 vb2_plane_size(vb, 0), size);
> +		return -EINVAL;
> +	}
> +
> +	vb2_set_plane_payload(vb, 0, size);
> +
> +	buf->dma_addr = vb2_dma_contig_plane_dma_addr(vb, 0);
> +
> +	vbuf->field = video->fmt.fmt.pix.field;
> +
> +	return 0;
> +}
> +
> +static int sun6i_pipeline_set_stream(struct sun6i_video *video, bool enable)
> +{
> +	struct media_entity *entity;
> +	struct media_pad *pad;
> +	struct v4l2_subdev *subdev;
> +	int ret;
> +
> +	entity = &video->vdev.entity;
> +	while (1) {
> +		pad = &entity->pads[0];
> +		if (!(pad->flags & MEDIA_PAD_FL_SINK))
> +			break;
> +
> +		pad = media_entity_remote_pad(pad);
> +		if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
> +			break;
> +
> +		entity = pad->entity;
> +		subdev = media_entity_to_v4l2_subdev(entity);
> +
> +		ret = v4l2_subdev_call(subdev, video, s_stream, enable);
> +		if (enable && ret < 0 && ret != -ENOIOCTLCMD)
> +			return ret;

You'll need to end the loop when you encounter the first sub-device which
is not controlled by this driver. The order in which other drivers control
streaming on their upstream sub-devices is specific to that driver (and is
not known here).

> +	}
> +
> +	return 0;
> +}
> +
> +static int sun6i_video_start_streaming(struct vb2_queue *vq, unsigned int count)
> +{
> +	struct sun6i_video *video = vb2_get_drv_priv(vq);
> +	struct sun6i_csi_buffer *buf;
> +	struct sun6i_csi_buffer *next_buf;
> +	struct sun6i_csi_config config;
> +	unsigned long flags;
> +	int ret;
> +
> +	video->sequence = 0;
> +
> +	if (!video->current_fmt)
> +		return -ENXIO;
> +
> +	ret = media_pipeline_start(&video->vdev.entity, &video->vdev.pipe);
> +	if (ret < 0)
> +		goto clear_dma_queue;
> +
> +	config.pixelformat = video->fmt.fmt.pix.pixelformat;
> +	config.code = video->current_fmt->mbus_code;
> +	config.field = video->fmt.fmt.pix.field;
> +	config.width = video->fmt.fmt.pix.width;
> +	config.height = video->fmt.fmt.pix.height;
> +
> +	ret = sun6i_csi_update_config(video->csi, &config);
> +	if (ret < 0)
> +		goto stop_media_pipeline;
> +
> +	spin_lock_irqsave(&video->dma_queue_lock, flags);
> +
> +	buf = list_first_entry(&video->dma_queue,
> +			       struct sun6i_csi_buffer, list);
> +	buf->queued_to_csi = true;
> +	sun6i_csi_update_buf_addr(video->csi, buf->dma_addr);
> +
> +	sun6i_csi_set_stream(video->csi, true);
> +
> +	/*
> +	 * CSI will lookup the next dma buffer for next frame before the
> +	 * the current frame done IRQ triggered. This is not documented
> +	 * but reported by Ondřej Jirman.
> +	 * The BSP code has workaround for this too. It skip to mark the
> +	 * first buffer as frame done for VB2 and pass the second buffer
> +	 * to CSI in the first frame done ISR call. Then in second frame
> +	 * done ISR call, it mark the first buffer as frame done for VB2
> +	 * and pass the third buffer to CSI. And so on. The bad thing is
> +	 * that the first buffer will be written twice and the first frame
> +	 * is dropped even the queued buffer is sufficient.
> +	 * So, I make some improvement here. Pass the next buffer to CSI
> +	 * just follow starting the CSI. In this case, the first frame
> +	 * will be stored in first buffer, second frame in second buffer.
> +	 * This method is used to avoid dropping the first frame, it
> +	 * would also drop frame when lacking of queued buffer.
> +	 */
> +	next_buf = list_next_entry(buf, list);
> +	next_buf->queued_to_csi = true;
> +	sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
> +
> +	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
> +
> +	ret = sun6i_pipeline_set_stream(video, true);
> +	if (ret < 0)
> +		goto stop_csi_stream;
> +
> +	return 0;
> +
> +stop_csi_stream:
> +	sun6i_csi_set_stream(video->csi, false);
> +stop_media_pipeline:
> +	media_pipeline_stop(&video->vdev.entity);
> +clear_dma_queue:
> +	spin_lock_irqsave(&video->dma_queue_lock, flags);
> +	list_for_each_entry(buf, &video->dma_queue, list)
> +		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
> +	INIT_LIST_HEAD(&video->dma_queue);
> +	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
> +
> +	return ret;
> +}
> +
> +static void sun6i_video_stop_streaming(struct vb2_queue *vq)
> +{
> +	struct sun6i_video *video = vb2_get_drv_priv(vq);
> +	unsigned long flags;
> +	struct sun6i_csi_buffer *buf;
> +
> +	sun6i_pipeline_set_stream(video, false);
> +
> +	sun6i_csi_set_stream(video->csi, false);
> +
> +	media_pipeline_stop(&video->vdev.entity);
> +
> +	/* Release all active buffers */
> +	spin_lock_irqsave(&video->dma_queue_lock, flags);
> +	list_for_each_entry(buf, &video->dma_queue, list)
> +		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
> +	INIT_LIST_HEAD(&video->dma_queue);
> +	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
> +}
> +
> +static void sun6i_video_buffer_queue(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct sun6i_csi_buffer *buf =
> +			container_of(vbuf, struct sun6i_csi_buffer, vb);
> +	struct sun6i_video *video = vb2_get_drv_priv(vb->vb2_queue);
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&video->dma_queue_lock, flags);
> +	buf->queued_to_csi = false;
> +	list_add_tail(&buf->list, &video->dma_queue);
> +	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
> +}
> +
> +void sun6i_video_frame_done(struct sun6i_video *video)
> +{
> +	struct sun6i_csi_buffer *buf;
> +	struct sun6i_csi_buffer *next_buf;
> +	struct vb2_v4l2_buffer *vbuf;
> +
> +	spin_lock(&video->dma_queue_lock);

I'm not sure I'd rely on interrupts being disabled here. How about
spin_lock_irqsave()?

> +
> +	buf = list_first_entry(&video->dma_queue,
> +			       struct sun6i_csi_buffer, list);
> +	if (list_is_last(&buf->list, &video->dma_queue)) {
> +		dev_dbg(video->csi->dev, "Frame droped!\n");
> +		goto unlock;
> +	}
> +
> +	next_buf = list_next_entry(buf, list);
> +	/* If a new buffer (#next_buf) had not been queued to CSI, the old
> +	 * buffer (#buf) is still holding by CSI for storing the next
> +	 * frame. So, we queue a new buffer (#next_buf) to CSI then wait
> +	 * for next ISR call.
> +	 */
> +	if (!next_buf->queued_to_csi) {
> +		next_buf->queued_to_csi = true;
> +		sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
> +		dev_dbg(video->csi->dev, "Frame droped!\n");
> +		goto unlock;
> +	}
> +
> +	list_del(&buf->list);
> +	vbuf = &buf->vb;
> +	vbuf->vb2_buf.timestamp = ktime_get_ns();
> +	vbuf->sequence = video->sequence;
> +	vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_DONE);
> +
> +	/* Prepare buffer for next frame but one.  */
> +	if (!list_is_last(&next_buf->list, &video->dma_queue)) {
> +		next_buf = list_next_entry(next_buf, list);
> +		next_buf->queued_to_csi = true;
> +		sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
> +	} else {
> +		dev_dbg(video->csi->dev, "Next frame will be dropped!\n");
> +	}
> +
> +unlock:
> +	video->sequence++;
> +	spin_unlock(&video->dma_queue_lock);
> +}
> +
> +static const struct vb2_ops sun6i_csi_vb2_ops = {
> +	.queue_setup		= sun6i_video_queue_setup,
> +	.wait_prepare		= vb2_ops_wait_prepare,
> +	.wait_finish		= vb2_ops_wait_finish,
> +	.buf_prepare		= sun6i_video_buffer_prepare,
> +	.start_streaming	= sun6i_video_start_streaming,
> +	.stop_streaming		= sun6i_video_stop_streaming,
> +	.buf_queue		= sun6i_video_buffer_queue,
> +};
> +
> +static int vidioc_querycap(struct file *file, void *priv,
> +				struct v4l2_capability *cap)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +
> +	strlcpy(cap->driver, "sun6i-video", sizeof(cap->driver));
> +	strlcpy(cap->card, video->vdev.name, sizeof(cap->card));
> +	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
> +		 video->csi->dev->of_node->name);
> +
> +	return 0;
> +}
> +
> +static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
> +				   struct v4l2_fmtdesc *f)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +	u32 index = f->index;
> +
> +	if (index >= video->num_formats)
> +		return -EINVAL;
> +
> +	f->pixelformat = video->formats[index].pixformat;
> +
> +	return 0;
> +}
> +
> +static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
> +				struct v4l2_format *fmt)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +
> +	*fmt = video->fmt;
> +
> +	return 0;
> +}
> +
> +
> +static int sun6i_video_try_fmt_source(struct sun6i_video *video,
> +				      u32 which,
> +				      struct v4l2_pix_format *pixfmt,
> +				      struct sun6i_csi_format *csi_fmt)
> +{
> +	struct v4l2_subdev *subdev;
> +	struct v4l2_subdev_pad_config *pad_cfg;
> +	struct v4l2_subdev_format format = {
> +		.which = which,
> +	};
> +	u32 pad;
> +	int ret;
> +
> +	subdev = sun6i_video_remote_subdev(video, &pad);
> +	if (subdev == NULL)
> +		return -ENXIO;
> +
> +	v4l2_fill_mbus_format(&format.format, pixfmt, csi_fmt->mbus_code);
> +
> +	pad_cfg = v4l2_subdev_alloc_pad_config(subdev);
> +	if (pad_cfg == NULL)
> +		return -ENOMEM;
> +
> +	format.pad = pad;
> +	ret = v4l2_subdev_call(subdev, pad, set_fmt, pad_cfg, &format);
> +	if (ret)
> +		goto done;

If the driver exposes format configuration through the V4L2 sub-device API,
trying the format on the video node should limit to the DMA engine only.
I.e. what the upstream sub-device can (or cannot) do is not relevant here.

The pipeline there may well be longer than just an image sensor
represented by just a single sub-device.

> +
> +	v4l2_fill_pix_format(pixfmt, &format.format);
> +
> +done:
> +	v4l2_subdev_free_pad_config(pad_cfg);
> +	return ret;
> +}
> +
> +static int sun6i_video_try_fmt(struct sun6i_video *video, u32 which,
> +			       struct v4l2_format *f,
> +			       struct sun6i_csi_format **current_fmt)
> +{
> +	struct sun6i_csi_format *csi_fmt;
> +	struct v4l2_pix_format *pixfmt = &f->fmt.pix;
> +	int ret;
> +
> +	csi_fmt = find_format_by_pixformat(video, pixfmt->pixelformat);
> +	if (csi_fmt == NULL) {
> +		if (video->num_formats > 0) {
> +			csi_fmt = &video->formats[0];
> +			pixfmt->pixelformat = csi_fmt->pixformat;
> +		} else
> +			return -EINVAL;
> +	}
> +
> +	ret = sun6i_video_try_fmt_source(video, which, pixfmt, csi_fmt);
> +	if (ret)
> +		return ret;
> +
> +	pixfmt->bytesperline = (pixfmt->width * csi_fmt->bpp) >> 3;
> +	pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
> +
> +	if (current_fmt)
> +		*current_fmt = csi_fmt;
> +
> +	return 0;
> +}
> +
> +static int sun6i_video_set_fmt(struct sun6i_video *video, struct v4l2_format *f)
> +{
> +	struct sun6i_csi_format *current_fmt;
> +	int ret;
> +
> +	ret = sun6i_video_try_fmt(video, V4L2_SUBDEV_FORMAT_ACTIVE, f,
> +				  &current_fmt);
> +	if (ret)
> +		return ret;
> +
> +	video->fmt = *f;
> +	video->current_fmt = current_fmt;
> +
> +	return 0;
> +}
> +
> +static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
> +				struct v4l2_format *f)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +
> +	if (vb2_is_busy(&video->vb2_vidq))
> +		return -EBUSY;
> +
> +	return sun6i_video_set_fmt(video, f);
> +}
> +
> +static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
> +				  struct v4l2_format *f)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +
> +	return sun6i_video_try_fmt(video, V4L2_SUBDEV_FORMAT_TRY, f, NULL);
> +}
> +
> +static int vidioc_enum_input(struct file *file, void *fh,
> +			 struct v4l2_input *inp)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +	struct v4l2_subdev *subdev;
> +	u32 pad;
> +	int ret;
> +
> +	if (inp->index != 0)
> +		return -EINVAL;
> +
> +	subdev = sun6i_video_remote_subdev(video, &pad);
> +	if (subdev == NULL)
> +		return -ENXIO;
> +
> +	ret = v4l2_subdev_call(subdev, video, g_input_status, &inp->status);

What's the intent here? Below, g_input and s_input both support zero only
(i.e. whatever is connected).

> +	if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV)
> +		return ret;
> +
> +	inp->type = 0;
> +
> +	inp->capabilities = 0;
> +	inp->std = 0;
> +	if (v4l2_subdev_has_op(subdev, pad, dv_timings_cap))
> +		inp->capabilities = V4L2_IN_CAP_DV_TIMINGS;
> +
> +	strlcpy(inp->name, subdev->name, sizeof(inp->name));
> +
> +	return 0;
> +}
> +
> +static int vidioc_g_input(struct file *file, void *fh, unsigned int *i)
> +{
> +	*i = 0;
> +
> +	return 0;
> +}
> +
> +static int vidioc_s_input(struct file *file, void *fh, unsigned int i)
> +{
> +	if (i != 0)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ioctl_ops sun6i_video_ioctl_ops = {
> +	.vidioc_querycap		= vidioc_querycap,
> +	.vidioc_enum_fmt_vid_cap	= vidioc_enum_fmt_vid_cap,
> +	.vidioc_g_fmt_vid_cap		= vidioc_g_fmt_vid_cap,
> +	.vidioc_s_fmt_vid_cap		= vidioc_s_fmt_vid_cap,
> +	.vidioc_try_fmt_vid_cap		= vidioc_try_fmt_vid_cap,
> +
> +	.vidioc_enum_input		= vidioc_enum_input,
> +	.vidioc_s_input			= vidioc_s_input,
> +	.vidioc_g_input			= vidioc_g_input,
> +
> +	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
> +	.vidioc_querybuf		= vb2_ioctl_querybuf,
> +	.vidioc_qbuf			= vb2_ioctl_qbuf,
> +	.vidioc_expbuf			= vb2_ioctl_expbuf,
> +	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
> +	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
> +	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
> +	.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,
> +
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 file operations
> + */
> +static int sun6i_video_open(struct file *file)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +	int ret;
> +
> +	if (mutex_lock_interruptible(&video->lock))
> +		return -ERESTARTSYS;
> +
> +	ret = v4l2_fh_open(file);
> +	if (ret < 0)
> +		goto unlock;
> +
> +	ret = v4l2_pipeline_pm_use(&video->vdev.entity, 1);
> +	if (ret < 0)
> +		goto fh_release;
> +
> +	/* check if already powered */
> +	if (!v4l2_fh_is_singular_file(file))
> +		goto unlock;
> +
> +	ret = sun6i_csi_set_power(video->csi, true);
> +	if (ret < 0)
> +		goto fh_release;
> +
> +	mutex_unlock(&video->lock);
> +	return 0;
> +
> +fh_release:
> +	v4l2_fh_release(file);
> +unlock:
> +	mutex_unlock(&video->lock);
> +	return ret;
> +}
> +
> +static int sun6i_video_close(struct file *file)
> +{
> +	struct sun6i_video *video = video_drvdata(file);
> +	bool last_fh;
> +
> +	mutex_lock(&video->lock);
> +
> +	last_fh = v4l2_fh_is_singular_file(file);
> +
> +	_vb2_fop_release(file, NULL);
> +
> +	v4l2_pipeline_pm_use(&video->vdev.entity, 0);
> +
> +	if (last_fh)
> +		sun6i_csi_set_power(video->csi, false);
> +
> +	mutex_unlock(&video->lock);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_file_operations sun6i_video_fops = {
> +	.owner		= THIS_MODULE,
> +	.open		= sun6i_video_open,
> +	.release	= sun6i_video_close,
> +	.unlocked_ioctl	= video_ioctl2,
> +	.mmap		= vb2_fop_mmap,
> +	.poll		= vb2_fop_poll
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Media Operations
> + */
> +static int sun6i_video_formats_init(struct sun6i_video *video,
> +				    const struct media_pad *remote)
> +{
> +	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
> +	struct sun6i_csi *csi = video->csi;
> +	struct v4l2_format format;
> +	struct v4l2_subdev *subdev;
> +	u32 pad;
> +	const u32 *pixformats;
> +	int pixformat_count = 0;
> +	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
> +	int codes_count = 0;
> +	int num_fmts = 0;
> +	int i, j;
> +
> +	pad = remote->index;
> +	subdev = media_entity_to_v4l2_subdev(remote->entity);
> +	if (subdev == NULL)
> +		return -ENXIO;
> +
> +	/* Get supported pixformats of CSI */
> +	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
> +	if (pixformat_count <= 0)
> +		return -ENXIO;
> +
> +	/* Get subdev formats codes */
> +	mbus_code.pad = pad;
> +	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> +	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
> +				 &mbus_code)) {

The formats supported by the external sub-device may depend on horizontal
and vertical flipping. You shouldn't assume any particular configuration
here: instead, bridge drivers generally just need to make sure the formats
match in link validation when streaming is started. At least the CSI-2
receiver driver and the DMA engine driver (video device) should check the
configuration is valid. See e.g. the IPU3 driver:
drivers/media/pci/intel/ipu3/ipu3-cio2.c .

> +		if (codes_count >= ARRAY_SIZE(subdev_codes)) {
> +			dev_warn(video->csi->dev,
> +				 "subdev_codes array is full!\n");
> +			break;
> +		}
> +		subdev_codes[codes_count] = mbus_code.code;
> +		codes_count++;
> +		mbus_code.index++;
> +	}
> +
> +	if (!codes_count)
> +		return -ENXIO;
> +
> +	/* Get supported formats count */
> +	for (i = 0; i < codes_count; i++) {
> +		for (j = 0; j < pixformat_count; j++) {
> +			if (!sun6i_csi_is_format_supported(csi, pixformats[j],
> +					subdev_codes[i])) {
> +				continue;
> +			}
> +			num_fmts++;
> +		}
> +	}
> +
> +	if (!num_fmts)
> +		return -ENXIO;
> +
> +	video->num_formats = num_fmts;
> +	video->formats = devm_kcalloc(video->csi->dev, num_fmts,
> +			sizeof(struct sun6i_csi_format), GFP_KERNEL);
> +	if (!video->formats)
> +		return -ENOMEM;
> +
> +	/* Get supported formats */
> +	num_fmts = 0;
> +	for (i = 0; i < codes_count; i++) {
> +		for (j = 0; j < pixformat_count; j++) {
> +			if (!sun6i_csi_is_format_supported(csi, pixformats[j],
> +					subdev_codes[i])) {
> +				continue;
> +			}
> +
> +			video->formats[num_fmts].pixformat = pixformats[j];
> +			video->formats[num_fmts].mbus_code = subdev_codes[i];
> +			video->formats[num_fmts].bpp =
> +					sun6i_csi_get_bpp(pixformats[j]);
> +			num_fmts++;
> +		}
> +	}
> +
> +	/* setup default format */
> +	format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	format.fmt.pix.width = 1280;
> +	format.fmt.pix.height = 720;
> +	format.fmt.pix.pixelformat = video->formats[0].pixformat;
> +	sun6i_video_set_fmt(video, &format);
> +
> +	return 0;
> +}
> +
> +static int sun6i_video_link_setup(struct media_entity *entity,
> +				  const struct media_pad *local,
> +				  const struct media_pad *remote, u32 flags)
> +{
> +	struct video_device *vdev = media_entity_to_video_device(entity);
> +	struct sun6i_video *video = video_get_drvdata(vdev);
> +
> +	if (WARN_ON(video == NULL))
> +		return 0;
> +
> +	if ((flags & MEDIA_LNK_FL_ENABLED) == 0)
> +		return 0;
> +
> +	return sun6i_video_formats_init(video, remote);
> +}
> +
> +static const struct media_entity_operations sun6i_video_media_ops = {
> +	.link_setup = sun6i_video_link_setup,
> +};
> +
> +int sun6i_video_init(struct sun6i_video *video, struct sun6i_csi *csi,
> +		     const char *name)
> +{
> +	struct video_device *vdev = &video->vdev;
> +	struct vb2_queue *vidq = &video->vb2_vidq;
> +	int ret;
> +
> +	video->csi = csi;
> +
> +	/* Initialize the media entity... */
> +	video->pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
> +	vdev->entity.ops = &sun6i_video_media_ops;
> +	ret = media_entity_pads_init(&vdev->entity, 1, &video->pad);
> +	if (ret < 0)
> +		return ret;
> +
> +	mutex_init(&video->lock);
> +
> +	INIT_LIST_HEAD(&video->dma_queue);
> +	spin_lock_init(&video->dma_queue_lock);
> +
> +	video->sequence = 0;
> +	video->num_formats = 0;
> +
> +	/* Initialize videobuf2 queue */
> +	vidq->type			= V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	vidq->io_modes			= VB2_MMAP | VB2_DMABUF;
> +	vidq->drv_priv			= video;
> +	vidq->buf_struct_size		= sizeof(struct sun6i_csi_buffer);
> +	vidq->ops			= &sun6i_csi_vb2_ops;
> +	vidq->mem_ops			= &vb2_dma_contig_memops;
> +	vidq->timestamp_flags		= V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> +	vidq->lock			= &video->lock;
> +	/* Make sure non-dropped frame */
> +	vidq->min_buffers_needed	= 3;
> +	vidq->dev			= csi->dev;
> +
> +	ret = vb2_queue_init(vidq);
> +	if (ret) {
> +		v4l2_err(&csi->v4l2_dev, "vb2_queue_init failed: %d\n", ret);
> +		goto error;
> +	}
> +
> +	/* Register video device */
> +	strlcpy(vdev->name, name, sizeof(vdev->name));
> +	vdev->release		= video_device_release_empty;
> +	vdev->fops		= &sun6i_video_fops;
> +	vdev->ioctl_ops		= &sun6i_video_ioctl_ops;
> +	vdev->vfl_type		= VFL_TYPE_GRABBER;
> +	vdev->vfl_dir		= VFL_DIR_RX;
> +	vdev->v4l2_dev		= &csi->v4l2_dev;
> +	vdev->queue		= vidq;
> +	vdev->lock		= &video->lock;
> +	vdev->device_caps	= V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_CAPTURE;
> +	video_set_drvdata(vdev, video);
> +
> +	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
> +	if (ret < 0) {
> +		v4l2_err(&csi->v4l2_dev,
> +			 "video_register_device failed: %d\n", ret);
> +		goto error;
> +	}
> +
> +	return 0;
> +
> +error:
> +	sun6i_video_cleanup(video);
> +	return ret;
> +}
> +
> +void sun6i_video_cleanup(struct sun6i_video *video)
> +{
> +	if (video_is_registered(&video->vdev))
> +		video_unregister_device(&video->vdev);
> +
> +	media_entity_cleanup(&video->vdev.entity);
> +}
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h
> new file mode 100644
> index 000000000000..2301f184c986
> --- /dev/null
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h
> @@ -0,0 +1,53 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
> + * All rights reserved.
> + * Author: Yong Deng <[e-mail]>
> + */
> +
> +#ifndef __SUN6I_VIDEO_H__
> +#define __SUN6I_VIDEO_H__
> +
> +#include <media/v4l2-dev.h>
> +#include <media/videobuf2-core.h>
> +
> +/*
> + * struct sun6i_csi_format - CSI media bus format information
> + * @pixformat: V4l2 pixformat for this format
> + * @mbus_code: V4L2 media bus format code.
> + * @bpp: Bytes per pixel (when stored in memory)
> + */
> +struct sun6i_csi_format {
> +	u32				pixformat;
> +	u32				mbus_code;
> +	u8				bpp;
> +};
> +
> +struct sun6i_csi;
> +
> +struct sun6i_video {
> +	struct video_device		vdev;
> +	struct media_pad		pad;
> +	struct sun6i_csi		*csi;
> +
> +	struct mutex			lock;
> +
> +	struct vb2_queue		vb2_vidq;
> +	spinlock_t			dma_queue_lock;
> +	struct list_head		dma_queue;
> +
> +	unsigned int			sequence;
> +
> +	struct sun6i_csi_format		*formats;
> +	unsigned int			num_formats;
> +	struct sun6i_csi_format		*current_fmt;
> +	struct v4l2_format		fmt;
> +};
> +
> +int sun6i_video_init(struct sun6i_video *video, struct sun6i_csi *csi,
> +		     const char *name);
> +void sun6i_video_cleanup(struct sun6i_video *video);
> +
> +void sun6i_video_frame_done(struct sun6i_video *video);
> +
> +#endif /* __SUN6I_VIDEO_H__ */

yong July 5, 2018, 7:48 a.m. UTC | #2

Hi Sakari,

On Tue, 26 Jun 2018 14:08:21 +0300
Sakari Ailus <[e-mail]> wrote:

> Hi Yong,
> 
> My apologies for taking so long to review the set. A few comments below.
> 
> On Fri, May 04, 2018 at 03:09:05PM +0800, Yong Deng wrote:
> > Allwinner V3s SoC features two CSI module. CSI0 is used for MIPI CSI-2
> > interface and CSI1 is used for parallel interface. This is not
> > documented in datasheet but by test and guess.
> > 
> > This patch implement a v4l2 framework driver for it.
> > 
> > Currently, the driver only support the parallel interface. MIPI-CSI2,
> > ISP's support are not included in this patch.
> > 
> > Reviewed-by: Hans Verkuil <[e-mail]>
> > Reviewed-by: Maxime Ripard <[e-mail]>
> > Tested-by: Maxime Ripard <[e-mail]>
> > Signed-off-by: Yong Deng <[e-mail]>
> > ---
> >  MAINTAINERS                                        |   8 +
> >  drivers/media/platform/Kconfig                     |   1 +
> >  drivers/media/platform/Makefile                    |   2 +
> >  drivers/media/platform/sunxi/sun6i-csi/Kconfig     |   9 +
> >  drivers/media/platform/sunxi/sun6i-csi/Makefile    |   3 +
> >  drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 932 +++++++++++++++++++++
> >  drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h | 145 ++++
> >  .../media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h | 196 +++++
> >  .../media/platform/sunxi/sun6i-csi/sun6i_video.c   | 767 +++++++++++++++++
> >  .../media/platform/sunxi/sun6i-csi/sun6i_video.h   |  53 ++
> >  10 files changed, 2116 insertions(+)
> >  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/Kconfig
> >  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/Makefile
> >  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> >  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
> >  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h
> >  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
> >  create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h
> > 

... 

> > +
> > +static int sun6i_video_try_fmt_source(struct sun6i_video *video,
> > +				      u32 which,
> > +				      struct v4l2_pix_format *pixfmt,
> > +				      struct sun6i_csi_format *csi_fmt)
> > +{
> > +	struct v4l2_subdev *subdev;
> > +	struct v4l2_subdev_pad_config *pad_cfg;
> > +	struct v4l2_subdev_format format = {
> > +		.which = which,
> > +	};
> > +	u32 pad;
> > +	int ret;
> > +
> > +	subdev = sun6i_video_remote_subdev(video, &pad);
> > +	if (subdev == NULL)
> > +		return -ENXIO;
> > +
> > +	v4l2_fill_mbus_format(&format.format, pixfmt, csi_fmt->mbus_code);
> > +
> > +	pad_cfg = v4l2_subdev_alloc_pad_config(subdev);
> > +	if (pad_cfg == NULL)
> > +		return -ENOMEM;
> > +
> > +	format.pad = pad;
> > +	ret = v4l2_subdev_call(subdev, pad, set_fmt, pad_cfg, &format);
> > +	if (ret)
> > +		goto done;
> 
> If the driver exposes format configuration through the V4L2 sub-device API,
> trying the format on the video node should limit to the DMA engine only.
> I.e. what the upstream sub-device can (or cannot) do is not relevant here.
> 
> The pipeline there may well be longer than just an image sensor
> represented by just a single sub-device.

OK. I will check the formats in link validation when streaming is started.

> 
> > +
> > +	v4l2_fill_pix_format(pixfmt, &format.format);
> > +
> > +done:
> > +	v4l2_subdev_free_pad_config(pad_cfg);
> > +	return ret;
> > +}
> > +
> > +static int sun6i_video_try_fmt(struct sun6i_video *video, u32 which,
> > +			       struct v4l2_format *f,
> > +			       struct sun6i_csi_format **current_fmt)
> > +{
> > +	struct sun6i_csi_format *csi_fmt;
> > +	struct v4l2_pix_format *pixfmt = &f->fmt.pix;
> > +	int ret;
> > +
> > +	csi_fmt = find_format_by_pixformat(video, pixfmt->pixelformat);
> > +	if (csi_fmt == NULL) {
> > +		if (video->num_formats > 0) {
> > +			csi_fmt = &video->formats[0];
> > +			pixfmt->pixelformat = csi_fmt->pixformat;
> > +		} else
> > +			return -EINVAL;
> > +	}
> > +
> > +	ret = sun6i_video_try_fmt_source(video, which, pixfmt, csi_fmt);
> > +	if (ret)
> > +		return ret;
> > +
> > +	pixfmt->bytesperline = (pixfmt->width * csi_fmt->bpp) >> 3;
> > +	pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
> > +
> > +	if (current_fmt)
> > +		*current_fmt = csi_fmt;
> > +
> > +	return 0;
> > +}
> > +

...

> > +
> > +/* -----------------------------------------------------------------------------
> > + * Media Operations
> > + */
> > +static int sun6i_video_formats_init(struct sun6i_video *video,
> > +				    const struct media_pad *remote)
> > +{
> > +	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
> > +	struct sun6i_csi *csi = video->csi;
> > +	struct v4l2_format format;
> > +	struct v4l2_subdev *subdev;
> > +	u32 pad;
> > +	const u32 *pixformats;
> > +	int pixformat_count = 0;
> > +	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
> > +	int codes_count = 0;
> > +	int num_fmts = 0;
> > +	int i, j;
> > +
> > +	pad = remote->index;
> > +	subdev = media_entity_to_v4l2_subdev(remote->entity);
> > +	if (subdev == NULL)
> > +		return -ENXIO;
> > +
> > +	/* Get supported pixformats of CSI */
> > +	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
> > +	if (pixformat_count <= 0)
> > +		return -ENXIO;
> > +
> > +	/* Get subdev formats codes */
> > +	mbus_code.pad = pad;
> > +	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > +	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
> > +				 &mbus_code)) {
> 
> The formats supported by the external sub-device may depend on horizontal
> and vertical flipping. You shouldn't assume any particular configuration
> here: instead, bridge drivers generally just need to make sure the formats
> match in link validation when streaming is started. At least the CSI-2
> receiver driver and the DMA engine driver (video device) should check the
> configuration is valid. See e.g. the IPU3 driver:
> drivers/media/pci/intel/ipu3/ipu3-cio2.c .

Can mbus_code be added dynamically ?
The code here only enum the mbus code and get the possible supported
pairs of pixformat and mbus by SoC. Not try to check if the formats
(width height ...) is valid or not. The formats validation will be 
in link validation when streaming is started as per your advise. 

> 
> > +		if (codes_count >= ARRAY_SIZE(subdev_codes)) {
> > +			dev_warn(video->csi->dev,
> > +				 "subdev_codes array is full!\n");
> > +			break;
> > +		}
> > +		subdev_codes[codes_count] = mbus_code.code;
> > +		codes_count++;
> > +		mbus_code.index++;
> > +	}
> > +
> > +	if (!codes_count)
> > +		return -ENXIO;
> > +
> > +	/* Get supported formats count */
> > +	for (i = 0; i < codes_count; i++) {
> > +		for (j = 0; j < pixformat_count; j++) {
> > +			if (!sun6i_csi_is_format_supported(csi, pixformats[j],
> > +					subdev_codes[i])) {
> > +				continue;
> > +			}
> > +			num_fmts++;
> > +		}
> > +	}
> > +
> > +	if (!num_fmts)
> > +		return -ENXIO;
> > +
> > +	video->num_formats = num_fmts;
> > +	video->formats = devm_kcalloc(video->csi->dev, num_fmts,
> > +			sizeof(struct sun6i_csi_format), GFP_KERNEL);
> > +	if (!video->formats)
> > +		return -ENOMEM;
> > +
> > +	/* Get supported formats */
> > +	num_fmts = 0;
> > +	for (i = 0; i < codes_count; i++) {
> > +		for (j = 0; j < pixformat_count; j++) {
> > +			if (!sun6i_csi_is_format_supported(csi, pixformats[j],
> > +					subdev_codes[i])) {
> > +				continue;
> > +			}
> > +
> > +			video->formats[num_fmts].pixformat = pixformats[j];
> > +			video->formats[num_fmts].mbus_code = subdev_codes[i];
> > +			video->formats[num_fmts].bpp =
> > +					sun6i_csi_get_bpp(pixformats[j]);
> > +			num_fmts++;
> > +		}
> > +	}
> > +
> > +	/* setup default format */
> > +	format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> > +	format.fmt.pix.width = 1280;
> > +	format.fmt.pix.height = 720;
> > +	format.fmt.pix.pixelformat = video->formats[0].pixformat;
> > +	sun6i_video_set_fmt(video, &format);
> > +
> > +	return 0;
> > +}
> > +

...

> 
> -- 
> Kind regards,
> 
> Sakari Ailus
> e-mail: [e-mail]


Thanks,
Yong

Maxime Ripard July 11, 2018, 11:12 a.m. UTC | #3

Hi Sakari,

On Thu, Jul 05, 2018 at 03:48:02PM +0800, Yong wrote:
> > > +
> > > +/* -----------------------------------------------------------------------------
> > > + * Media Operations
> > > + */
> > > +static int sun6i_video_formats_init(struct sun6i_video *video,
> > > +				    const struct media_pad *remote)
> > > +{
> > > +	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
> > > +	struct sun6i_csi *csi = video->csi;
> > > +	struct v4l2_format format;
> > > +	struct v4l2_subdev *subdev;
> > > +	u32 pad;
> > > +	const u32 *pixformats;
> > > +	int pixformat_count = 0;
> > > +	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
> > > +	int codes_count = 0;
> > > +	int num_fmts = 0;
> > > +	int i, j;
> > > +
> > > +	pad = remote->index;
> > > +	subdev = media_entity_to_v4l2_subdev(remote->entity);
> > > +	if (subdev == NULL)
> > > +		return -ENXIO;
> > > +
> > > +	/* Get supported pixformats of CSI */
> > > +	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
> > > +	if (pixformat_count <= 0)
> > > +		return -ENXIO;
> > > +
> > > +	/* Get subdev formats codes */
> > > +	mbus_code.pad = pad;
> > > +	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > > +	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
> > > +				 &mbus_code)) {
> > 
> > The formats supported by the external sub-device may depend on horizontal
> > and vertical flipping. You shouldn't assume any particular configuration
> > here: instead, bridge drivers generally just need to make sure the formats
> > match in link validation when streaming is started. At least the CSI-2
> > receiver driver and the DMA engine driver (video device) should check the
> > configuration is valid. See e.g. the IPU3 driver:
> > drivers/media/pci/intel/ipu3/ipu3-cio2.c .
> 
> Can mbus_code be added dynamically ?
> The code here only enum the mbus code and get the possible supported
> pairs of pixformat and mbus by SoC. Not try to check if the formats
> (width height ...) is valid or not. The formats validation will be 
> in link validation when streaming is started as per your advise. 

Can you reply to this so that Yong has a chance to resubmit his serie
before the 4.19 merge window starts?

Or alternatively, is this something we can fix later on, once it's
merged?

Thanks!
Maxime

Sakari Ailus July 18, 2018, 9:55 a.m. UTC | #4

Hi Yong,

On Thu, Jul 05, 2018 at 03:48:02PM +0800, Yong wrote:
> > > +
> > > +/* -----------------------------------------------------------------------------
> > > + * Media Operations
> > > + */
> > > +static int sun6i_video_formats_init(struct sun6i_video *video,
> > > +				    const struct media_pad *remote)
> > > +{
> > > +	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
> > > +	struct sun6i_csi *csi = video->csi;
> > > +	struct v4l2_format format;
> > > +	struct v4l2_subdev *subdev;
> > > +	u32 pad;
> > > +	const u32 *pixformats;
> > > +	int pixformat_count = 0;
> > > +	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
> > > +	int codes_count = 0;
> > > +	int num_fmts = 0;
> > > +	int i, j;
> > > +
> > > +	pad = remote->index;
> > > +	subdev = media_entity_to_v4l2_subdev(remote->entity);
> > > +	if (subdev == NULL)
> > > +		return -ENXIO;
> > > +
> > > +	/* Get supported pixformats of CSI */
> > > +	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
> > > +	if (pixformat_count <= 0)
> > > +		return -ENXIO;
> > > +
> > > +	/* Get subdev formats codes */
> > > +	mbus_code.pad = pad;
> > > +	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > > +	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
> > > +				 &mbus_code)) {
> > 
> > The formats supported by the external sub-device may depend on horizontal
> > and vertical flipping. You shouldn't assume any particular configuration
> > here: instead, bridge drivers generally just need to make sure the formats
> > match in link validation when streaming is started. At least the CSI-2
> > receiver driver and the DMA engine driver (video device) should check the
> > configuration is valid. See e.g. the IPU3 driver:
> > drivers/media/pci/intel/ipu3/ipu3-cio2.c .
> 
> Can mbus_code be added dynamically ?
> The code here only enum the mbus code and get the possible supported
> pairs of pixformat and mbus by SoC. Not try to check if the formats
> (width height ...) is valid or not. The formats validation will be 
> in link validation when streaming is started as per your advise. 

The formats that can be enumerated from the sensor here are those settable
using SUBDEV_S_FMT. The enumeration will change on raw sensors if you use
the flipping controls. As the bridge driver implements MC as well as subdev
APIs, generally the sensor configuration is out of scope of this driver
since it's directly configured from the user space.

Just check that the pipeline is valid before starting streaming in your
driver.

yong July 19, 2018, 3:43 a.m. UTC | #5

On Wed, 18 Jul 2018 12:55:14 +0300
Sakari Ailus <[e-mail]> wrote:

> Hi Yong,
> 
> On Thu, Jul 05, 2018 at 03:48:02PM +0800, Yong wrote:
> > > > +
> > > > +/* -----------------------------------------------------------------------------
> > > > + * Media Operations
> > > > + */
> > > > +static int sun6i_video_formats_init(struct sun6i_video *video,
> > > > +				    const struct media_pad *remote)
> > > > +{
> > > > +	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
> > > > +	struct sun6i_csi *csi = video->csi;
> > > > +	struct v4l2_format format;
> > > > +	struct v4l2_subdev *subdev;
> > > > +	u32 pad;
> > > > +	const u32 *pixformats;
> > > > +	int pixformat_count = 0;
> > > > +	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
> > > > +	int codes_count = 0;
> > > > +	int num_fmts = 0;
> > > > +	int i, j;
> > > > +
> > > > +	pad = remote->index;
> > > > +	subdev = media_entity_to_v4l2_subdev(remote->entity);
> > > > +	if (subdev == NULL)
> > > > +		return -ENXIO;
> > > > +
> > > > +	/* Get supported pixformats of CSI */
> > > > +	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
> > > > +	if (pixformat_count <= 0)
> > > > +		return -ENXIO;
> > > > +
> > > > +	/* Get subdev formats codes */
> > > > +	mbus_code.pad = pad;
> > > > +	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > > > +	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
> > > > +				 &mbus_code)) {
> > > 
> > > The formats supported by the external sub-device may depend on horizontal
> > > and vertical flipping. You shouldn't assume any particular configuration
> > > here: instead, bridge drivers generally just need to make sure the formats
> > > match in link validation when streaming is started. At least the CSI-2
> > > receiver driver and the DMA engine driver (video device) should check the
> > > configuration is valid. See e.g. the IPU3 driver:
> > > drivers/media/pci/intel/ipu3/ipu3-cio2.c .
> > 
> > Can mbus_code be added dynamically ?
> > The code here only enum the mbus code and get the possible supported
> > pairs of pixformat and mbus by SoC. Not try to check if the formats
> > (width height ...) is valid or not. The formats validation will be 
> > in link validation when streaming is started as per your advise. 
> 
> The formats that can be enumerated from the sensor here are those settable
> using SUBDEV_S_FMT. The enumeration will change on raw sensors if you use
> the flipping controls. As the bridge driver implements MC as well as subdev
> APIs, generally the sensor configuration is out of scope of this driver
> since it's directly configured from the user space.
> 
> Just check that the pipeline is valid before starting streaming in your
> driver.

OK. I will take some time to change these code.

> 
> -- 
> Kind regards,
> 
> Sakari Ailus
> [e-mail]


Thanks,
Yong

yong July 25, 2018, 10:42 a.m. UTC | #6

Hi Sakari,

On Wed, 18 Jul 2018 12:55:14 +0300
Sakari Ailus <[e-mail]> wrote:

> Hi Yong,
> 
> On Thu, Jul 05, 2018 at 03:48:02PM +0800, Yong wrote:
> > > > +
> > > > +/* -----------------------------------------------------------------------------
> > > > + * Media Operations
> > > > + */
> > > > +static int sun6i_video_formats_init(struct sun6i_video *video,
> > > > +				    const struct media_pad *remote)
> > > > +{
> > > > +	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
> > > > +	struct sun6i_csi *csi = video->csi;
> > > > +	struct v4l2_format format;
> > > > +	struct v4l2_subdev *subdev;
> > > > +	u32 pad;
> > > > +	const u32 *pixformats;
> > > > +	int pixformat_count = 0;
> > > > +	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
> > > > +	int codes_count = 0;
> > > > +	int num_fmts = 0;
> > > > +	int i, j;
> > > > +
> > > > +	pad = remote->index;
> > > > +	subdev = media_entity_to_v4l2_subdev(remote->entity);
> > > > +	if (subdev == NULL)
> > > > +		return -ENXIO;
> > > > +
> > > > +	/* Get supported pixformats of CSI */
> > > > +	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
> > > > +	if (pixformat_count <= 0)
> > > > +		return -ENXIO;
> > > > +
> > > > +	/* Get subdev formats codes */
> > > > +	mbus_code.pad = pad;
> > > > +	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > > > +	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
> > > > +				 &mbus_code)) {
> > > 
> > > The formats supported by the external sub-device may depend on horizontal
> > > and vertical flipping. You shouldn't assume any particular configuration
> > > here: instead, bridge drivers generally just need to make sure the formats
> > > match in link validation when streaming is started. At least the CSI-2
> > > receiver driver and the DMA engine driver (video device) should check the
> > > configuration is valid. See e.g. the IPU3 driver:
> > > drivers/media/pci/intel/ipu3/ipu3-cio2.c .
> > 
> > Can mbus_code be added dynamically ?
> > The code here only enum the mbus code and get the possible supported
> > pairs of pixformat and mbus by SoC. Not try to check if the formats
> > (width height ...) is valid or not. The formats validation will be 
> > in link validation when streaming is started as per your advise. 
> 
> The formats that can be enumerated from the sensor here are those settable
> using SUBDEV_S_FMT. The enumeration will change on raw sensors if you use
> the flipping controls. As the bridge driver implements MC as well as subdev
> APIs, generally the sensor configuration is out of scope of this driver
> since it's directly configured from the user space.
> 
> Just check that the pipeline is valid before starting streaming in your
> driver.

Sorry. I am still confused.
As the CSI driver does not enum the formats supported by sensor.
How to get a valid format if I do not want to open the subdev? 
Many applications still only open /dev/video*.

> 
> -- 
> Kind regards,
> 
> Sakari Ailus
> [e-mail]


Thanks,
Yong

Sakari Ailus July 25, 2018, 11:43 a.m. UTC | #7

Hi Yong,

On Wed, Jul 25, 2018 at 06:42:24PM +0800, Yong wrote:
> Hi Sakari,
> 
> On Wed, 18 Jul 2018 12:55:14 +0300
> Sakari Ailus <[e-mail]> wrote:
> 
> > Hi Yong,
> > 
> > On Thu, Jul 05, 2018 at 03:48:02PM +0800, Yong wrote:
> > > > > +
> > > > > +/* -----------------------------------------------------------------------------
> > > > > + * Media Operations
> > > > > + */
> > > > > +static int sun6i_video_formats_init(struct sun6i_video *video,
> > > > > +				    const struct media_pad *remote)
> > > > > +{
> > > > > +	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
> > > > > +	struct sun6i_csi *csi = video->csi;
> > > > > +	struct v4l2_format format;
> > > > > +	struct v4l2_subdev *subdev;
> > > > > +	u32 pad;
> > > > > +	const u32 *pixformats;
> > > > > +	int pixformat_count = 0;
> > > > > +	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
> > > > > +	int codes_count = 0;
> > > > > +	int num_fmts = 0;
> > > > > +	int i, j;
> > > > > +
> > > > > +	pad = remote->index;
> > > > > +	subdev = media_entity_to_v4l2_subdev(remote->entity);
> > > > > +	if (subdev == NULL)
> > > > > +		return -ENXIO;
> > > > > +
> > > > > +	/* Get supported pixformats of CSI */
> > > > > +	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
> > > > > +	if (pixformat_count <= 0)
> > > > > +		return -ENXIO;
> > > > > +
> > > > > +	/* Get subdev formats codes */
> > > > > +	mbus_code.pad = pad;
> > > > > +	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > > > > +	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
> > > > > +				 &mbus_code)) {
> > > > 
> > > > The formats supported by the external sub-device may depend on horizontal
> > > > and vertical flipping. You shouldn't assume any particular configuration
> > > > here: instead, bridge drivers generally just need to make sure the formats
> > > > match in link validation when streaming is started. At least the CSI-2
> > > > receiver driver and the DMA engine driver (video device) should check the
> > > > configuration is valid. See e.g. the IPU3 driver:
> > > > drivers/media/pci/intel/ipu3/ipu3-cio2.c .
> > > 
> > > Can mbus_code be added dynamically ?
> > > The code here only enum the mbus code and get the possible supported
> > > pairs of pixformat and mbus by SoC. Not try to check if the formats
> > > (width height ...) is valid or not. The formats validation will be 
> > > in link validation when streaming is started as per your advise. 
> > 
> > The formats that can be enumerated from the sensor here are those settable
> > using SUBDEV_S_FMT. The enumeration will change on raw sensors if you use
> > the flipping controls. As the bridge driver implements MC as well as subdev
> > APIs, generally the sensor configuration is out of scope of this driver
> > since it's directly configured from the user space.
> > 
> > Just check that the pipeline is valid before starting streaming in your
> > driver.
> 
> Sorry. I am still confused.
> As the CSI driver does not enum the formats supported by sensor.
> How to get a valid format if I do not want to open the subdev? 

For MC-enabled drivers that expose the pipeline, the user is responsible
for configuring the pipeline.

There are bridge drivers that do not expose the pipeline but that will
exclude the use of e.g. some sensor drivers with those bridge drivers.

> Many applications still only open /dev/video*.

That's true, and this is indeed a known gap:

<URL:https://www.spinics.net/lists/linux-media/msg137668.html>

So in other words, there is no solution for that issue right now, but this
is in no way specific to your driver, and it is known that this needs to be
addressed.

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 0a1410d5a621..a8f9fe91dd14 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3771,6 +3771,14 @@  M:	Jaya Kumar <[e-mail]>
 S:	Maintained
 F:	sound/pci/cs5535audio/
 
+CSI DRIVERS FOR ALLWINNER V3s
+M:	Yong Deng <[e-mail]>
+L:	[e-mail]
+T:	git git://linuxtv.org/media_tree.git
+S:	Maintained
+F:	drivers/media/platform/sunxi/sun6i-csi/
+F:	Documentation/devicetree/bindings/media/sun6i-csi.txt
+
 CW1200 WLAN driver
 M:	Solomon Peachy <[e-mail]>
 S:	Maintained
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index e3229f7baed1..43f25c9c05e1 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -138,6 +138,7 @@  source "drivers/media/platform/am437x/Kconfig"
 source "drivers/media/platform/xilinx/Kconfig"
 source "drivers/media/platform/rcar-vin/Kconfig"
 source "drivers/media/platform/atmel/Kconfig"
+source "drivers/media/platform/sunxi/sun6i-csi/Kconfig"
 
 config VIDEO_TI_CAL
 	tristate "TI CAL (Camera Adaptation Layer) driver"
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 932515df4477..69472cbfa360 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -92,3 +92,5 @@  obj-$(CONFIG_VIDEO_QCOM_CAMSS)		+= qcom/camss-8x16/
 obj-$(CONFIG_VIDEO_QCOM_VENUS)		+= qcom/venus/
 
 obj-y					+= meson/
+
+obj-$(CONFIG_VIDEO_SUN6I_CSI)		+= sunxi/sun6i-csi/
diff --git a/drivers/media/platform/sunxi/sun6i-csi/Kconfig b/drivers/media/platform/sunxi/sun6i-csi/Kconfig
new file mode 100644
index 000000000000..018e3ec788c0
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/Kconfig
@@ -0,0 +1,9 @@ 
+config VIDEO_SUN6I_CSI
+	tristate "Allwinner V3s Camera Sensor Interface driver"
+	depends on VIDEO_V4L2 && COMMON_CLK && VIDEO_V4L2_SUBDEV_API && HAS_DMA
+	depends on ARCH_SUNXI || COMPILE_TEST
+	select VIDEOBUF2_DMA_CONTIG
+	select REGMAP_MMIO
+	select V4L2_FWNODE
+	help
+	   Support for the Allwinner Camera Sensor Interface Controller on V3s.
diff --git a/drivers/media/platform/sunxi/sun6i-csi/Makefile b/drivers/media/platform/sunxi/sun6i-csi/Makefile
new file mode 100644
index 000000000000..213cb6be9e9c
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/Makefile
@@ -0,0 +1,3 @@ 
+sun6i-csi-y += sun6i_video.o sun6i_csi.o
+
+obj-$(CONFIG_VIDEO_SUN6I_CSI) += sun6i-csi.o
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
new file mode 100644
index 000000000000..d03a367dad44
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
@@ -0,0 +1,932 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <[e-mail]>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioctl.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#include "sun6i_csi.h"
+#include "sun6i_csi_reg.h"
+
+#define MODULE_NAME	"sun6i-csi"
+
+struct sun6i_csi_dev {
+	struct sun6i_csi		csi;
+	struct device			*dev;
+
+	struct regmap			*regmap;
+	struct clk			*clk_mod;
+	struct clk			*clk_ram;
+	struct reset_control		*rstc_bus;
+
+	int				planar_offset[3];
+};
+
+static const u32 supported_pixformats[] = {
+	V4L2_PIX_FMT_SBGGR8,
+	V4L2_PIX_FMT_SGBRG8,
+	V4L2_PIX_FMT_SGRBG8,
+	V4L2_PIX_FMT_SRGGB8,
+	V4L2_PIX_FMT_SBGGR10,
+	V4L2_PIX_FMT_SGBRG10,
+	V4L2_PIX_FMT_SGRBG10,
+	V4L2_PIX_FMT_SRGGB10,
+	V4L2_PIX_FMT_SBGGR12,
+	V4L2_PIX_FMT_SGBRG12,
+	V4L2_PIX_FMT_SGRBG12,
+	V4L2_PIX_FMT_SRGGB12,
+	V4L2_PIX_FMT_YUYV,
+	V4L2_PIX_FMT_YVYU,
+	V4L2_PIX_FMT_UYVY,
+	V4L2_PIX_FMT_VYUY,
+	V4L2_PIX_FMT_HM12,
+	V4L2_PIX_FMT_NV12,
+	V4L2_PIX_FMT_NV21,
+	V4L2_PIX_FMT_YUV420,
+	V4L2_PIX_FMT_YVU420,
+	V4L2_PIX_FMT_NV16,
+	V4L2_PIX_FMT_NV61,
+	V4L2_PIX_FMT_YUV422P,
+};
+
+static inline struct sun6i_csi_dev *sun6i_csi_to_dev(struct sun6i_csi *csi)
+{
+	return container_of(csi, struct sun6i_csi_dev, csi);
+}
+
+int sun6i_csi_get_supported_pixformats(struct sun6i_csi *csi,
+				       const u32 **pixformats)
+{
+	if (pixformats != NULL)
+		*pixformats = supported_pixformats;
+
+	return ARRAY_SIZE(supported_pixformats);
+}
+
+/* TODO add 10&12 bit YUV, RGB support */
+bool sun6i_csi_is_format_supported(struct sun6i_csi *csi,
+				 u32 pixformat, u32 mbus_code)
+{
+	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
+
+	/*
+	 * Some video receivers have the ability to be compatible with
+	 * 8bit and 16bit bus width.
+	 * Identify the media bus format from device tree.
+	 */
+	if ((sdev->csi.v4l2_ep.bus_type == V4L2_MBUS_PARALLEL
+	      || sdev->csi.v4l2_ep.bus_type == V4L2_MBUS_BT656)
+	     && sdev->csi.v4l2_ep.bus.parallel.bus_width == 16) {
+		switch (pixformat) {
+		case V4L2_PIX_FMT_HM12:
+		case V4L2_PIX_FMT_NV12:
+		case V4L2_PIX_FMT_NV21:
+		case V4L2_PIX_FMT_NV16:
+		case V4L2_PIX_FMT_NV61:
+		case V4L2_PIX_FMT_YUV420:
+		case V4L2_PIX_FMT_YVU420:
+		case V4L2_PIX_FMT_YUV422P:
+			switch (mbus_code) {
+			case MEDIA_BUS_FMT_UYVY8_1X16:
+			case MEDIA_BUS_FMT_VYUY8_1X16:
+			case MEDIA_BUS_FMT_YUYV8_1X16:
+			case MEDIA_BUS_FMT_YVYU8_1X16:
+				return true;
+			default:
+				dev_dbg(sdev->dev, "Unsupported mbus code: 0x%x\n",
+					mbus_code);
+				break;
+			}
+			break;
+		default:
+			dev_dbg(sdev->dev, "Unsupported pixformat: 0x%x\n",
+				pixformat);
+			break;
+		}
+		return false;
+	}
+
+	switch (pixformat) {
+	case V4L2_PIX_FMT_SBGGR8:
+		return (mbus_code == MEDIA_BUS_FMT_SBGGR8_1X8);
+	case V4L2_PIX_FMT_SGBRG8:
+		return (mbus_code == MEDIA_BUS_FMT_SGBRG8_1X8);
+	case V4L2_PIX_FMT_SGRBG8:
+		return (mbus_code == MEDIA_BUS_FMT_SGRBG8_1X8);
+	case V4L2_PIX_FMT_SRGGB8:
+		return (mbus_code == MEDIA_BUS_FMT_SRGGB8_1X8);
+	case V4L2_PIX_FMT_SBGGR10:
+		return (mbus_code == MEDIA_BUS_FMT_SBGGR10_1X10);
+	case V4L2_PIX_FMT_SGBRG10:
+		return (mbus_code == MEDIA_BUS_FMT_SGBRG10_1X10);
+	case V4L2_PIX_FMT_SGRBG10:
+		return (mbus_code == MEDIA_BUS_FMT_SGRBG10_1X10);
+	case V4L2_PIX_FMT_SRGGB10:
+		return (mbus_code == MEDIA_BUS_FMT_SRGGB10_1X10);
+	case V4L2_PIX_FMT_SBGGR12:
+		return (mbus_code == MEDIA_BUS_FMT_SBGGR12_1X12);
+	case V4L2_PIX_FMT_SGBRG12:
+		return (mbus_code == MEDIA_BUS_FMT_SGBRG12_1X12);
+	case V4L2_PIX_FMT_SGRBG12:
+		return (mbus_code == MEDIA_BUS_FMT_SGRBG12_1X12);
+	case V4L2_PIX_FMT_SRGGB12:
+		return (mbus_code == MEDIA_BUS_FMT_SRGGB12_1X12);
+
+	case V4L2_PIX_FMT_YUYV:
+		return (mbus_code == MEDIA_BUS_FMT_YUYV8_2X8);
+	case V4L2_PIX_FMT_YVYU:
+		return (mbus_code == MEDIA_BUS_FMT_YVYU8_2X8);
+	case V4L2_PIX_FMT_UYVY:
+		return (mbus_code == MEDIA_BUS_FMT_UYVY8_2X8);
+	case V4L2_PIX_FMT_VYUY:
+		return (mbus_code == MEDIA_BUS_FMT_VYUY8_2X8);
+
+	case V4L2_PIX_FMT_HM12:
+	case V4L2_PIX_FMT_NV12:
+	case V4L2_PIX_FMT_NV21:
+	case V4L2_PIX_FMT_NV16:
+	case V4L2_PIX_FMT_NV61:
+	case V4L2_PIX_FMT_YUV420:
+	case V4L2_PIX_FMT_YVU420:
+	case V4L2_PIX_FMT_YUV422P:
+		switch (mbus_code) {
+		case MEDIA_BUS_FMT_UYVY8_2X8:
+		case MEDIA_BUS_FMT_VYUY8_2X8:
+		case MEDIA_BUS_FMT_YUYV8_2X8:
+		case MEDIA_BUS_FMT_YVYU8_2X8:
+			return true;
+		default:
+			dev_dbg(sdev->dev, "Unsupported mbus code: 0x%x\n",
+				mbus_code);
+			break;
+		}
+		break;
+	default:
+		dev_dbg(sdev->dev, "Unsupported pixformat: 0x%x\n", pixformat);
+		break;
+	}
+
+	return false;
+}
+
+int sun6i_csi_set_power(struct sun6i_csi *csi, bool enable)
+{
+	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
+	struct regmap *regmap = sdev->regmap;
+	int ret;
+
+	if (!enable) {
+		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
+
+		clk_disable_unprepare(sdev->clk_ram);
+		clk_disable_unprepare(sdev->clk_mod);
+		reset_control_assert(sdev->rstc_bus);
+		return 0;
+	}
+
+	ret = clk_prepare_enable(sdev->clk_mod);
+	if (ret) {
+		dev_err(sdev->dev, "Enable csi clk err %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(sdev->clk_ram);
+	if (ret) {
+		dev_err(sdev->dev, "Enable clk_dram_csi clk err %d\n", ret);
+		return ret;
+	}
+
+	ret = reset_control_deassert(sdev->rstc_bus);
+	if (ret) {
+		dev_err(sdev->dev, "reset err %d\n", ret);
+		return ret;
+	}
+
+	regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, CSI_EN_CSI_EN);
+
+	return 0;
+}
+
+static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_dev *sdev,
+					       u32 mbus_code, u32 pixformat)
+{
+	/* bayer */
+	if ((mbus_code & 0xF000) == 0x3000)
+		return CSI_INPUT_FORMAT_RAW;
+
+	switch (pixformat) {
+	case V4L2_PIX_FMT_YUYV:
+	case V4L2_PIX_FMT_YVYU:
+	case V4L2_PIX_FMT_UYVY:
+	case V4L2_PIX_FMT_VYUY:
+		return CSI_INPUT_FORMAT_RAW;
+	default:
+		break;
+	}
+
+	/* not support YUV420 input format yet */
+	dev_dbg(sdev->dev, "Select YUV422 as default input format of CSI.\n");
+	return CSI_INPUT_FORMAT_YUV422;
+}
+
+static enum csi_output_fmt get_csi_output_format(struct sun6i_csi_dev *sdev,
+						 u32 pixformat, u32 field)
+{
+	bool buf_interlaced = false;
+
+	if (field == V4L2_FIELD_INTERLACED
+	    || field == V4L2_FIELD_INTERLACED_TB
+	    || field == V4L2_FIELD_INTERLACED_BT)
+		buf_interlaced = true;
+
+	switch (pixformat) {
+	case V4L2_PIX_FMT_SBGGR8:
+	case V4L2_PIX_FMT_SGBRG8:
+	case V4L2_PIX_FMT_SGRBG8:
+	case V4L2_PIX_FMT_SRGGB8:
+		return buf_interlaced ? CSI_FRAME_RAW_8 : CSI_FIELD_RAW_8;
+	case V4L2_PIX_FMT_SBGGR10:
+	case V4L2_PIX_FMT_SGBRG10:
+	case V4L2_PIX_FMT_SGRBG10:
+	case V4L2_PIX_FMT_SRGGB10:
+		return buf_interlaced ? CSI_FRAME_RAW_10 : CSI_FIELD_RAW_10;
+	case V4L2_PIX_FMT_SBGGR12:
+	case V4L2_PIX_FMT_SGBRG12:
+	case V4L2_PIX_FMT_SGRBG12:
+	case V4L2_PIX_FMT_SRGGB12:
+		return buf_interlaced ? CSI_FRAME_RAW_12 : CSI_FIELD_RAW_12;
+
+	case V4L2_PIX_FMT_YUYV:
+	case V4L2_PIX_FMT_YVYU:
+	case V4L2_PIX_FMT_UYVY:
+	case V4L2_PIX_FMT_VYUY:
+		return buf_interlaced ? CSI_FRAME_RAW_8 : CSI_FIELD_RAW_8;
+
+	case V4L2_PIX_FMT_HM12:
+		return buf_interlaced ? CSI_FRAME_MB_YUV420 :
+					CSI_FIELD_MB_YUV420;
+	case V4L2_PIX_FMT_NV12:
+	case V4L2_PIX_FMT_NV21:
+		return buf_interlaced ? CSI_FRAME_UV_CB_YUV420 :
+					CSI_FIELD_UV_CB_YUV420;
+	case V4L2_PIX_FMT_YUV420:
+	case V4L2_PIX_FMT_YVU420:
+		return buf_interlaced ? CSI_FRAME_PLANAR_YUV420 :
+					CSI_FIELD_PLANAR_YUV420;
+	case V4L2_PIX_FMT_NV16:
+	case V4L2_PIX_FMT_NV61:
+		return buf_interlaced ? CSI_FRAME_UV_CB_YUV422 :
+					CSI_FIELD_UV_CB_YUV422;
+	case V4L2_PIX_FMT_YUV422P:
+		return buf_interlaced ? CSI_FRAME_PLANAR_YUV422 :
+					CSI_FIELD_PLANAR_YUV422;
+	default:
+		dev_warn(sdev->dev, "Unsupported pixformat: 0x%x\n", pixformat);
+		break;
+	}
+
+	return CSI_FIELD_RAW_8;
+}
+
+static enum csi_input_seq get_csi_input_seq(struct sun6i_csi_dev *sdev,
+					    u32 mbus_code, u32 pixformat)
+{
+
+	switch (pixformat) {
+	case V4L2_PIX_FMT_HM12:
+	case V4L2_PIX_FMT_NV12:
+	case V4L2_PIX_FMT_NV16:
+	case V4L2_PIX_FMT_YUV420:
+	case V4L2_PIX_FMT_YUV422P:
+		switch (mbus_code) {
+		case MEDIA_BUS_FMT_UYVY8_2X8:
+		case MEDIA_BUS_FMT_UYVY8_1X16:
+			return CSI_INPUT_SEQ_UYVY;
+		case MEDIA_BUS_FMT_VYUY8_2X8:
+		case MEDIA_BUS_FMT_VYUY8_1X16:
+			return CSI_INPUT_SEQ_VYUY;
+		case MEDIA_BUS_FMT_YUYV8_2X8:
+		case MEDIA_BUS_FMT_YUYV8_1X16:
+			return CSI_INPUT_SEQ_YUYV;
+		case MEDIA_BUS_FMT_YVYU8_1X16:
+		case MEDIA_BUS_FMT_YVYU8_2X8:
+			return CSI_INPUT_SEQ_YVYU;
+		default:
+			dev_warn(sdev->dev, "Unsupported mbus code: 0x%x\n",
+				 mbus_code);
+			break;
+		}
+		break;
+	case V4L2_PIX_FMT_NV21:
+	case V4L2_PIX_FMT_NV61:
+	case V4L2_PIX_FMT_YVU420:
+		switch (mbus_code) {
+		case MEDIA_BUS_FMT_UYVY8_2X8:
+		case MEDIA_BUS_FMT_UYVY8_1X16:
+			return CSI_INPUT_SEQ_VYUY;
+		case MEDIA_BUS_FMT_VYUY8_2X8:
+		case MEDIA_BUS_FMT_VYUY8_1X16:
+			return CSI_INPUT_SEQ_UYVY;
+		case MEDIA_BUS_FMT_YUYV8_2X8:
+		case MEDIA_BUS_FMT_YUYV8_1X16:
+			return CSI_INPUT_SEQ_YVYU;
+		case MEDIA_BUS_FMT_YVYU8_1X16:
+		case MEDIA_BUS_FMT_YVYU8_2X8:
+			return CSI_INPUT_SEQ_YUYV;
+		default:
+			dev_warn(sdev->dev, "Unsupported mbus code: 0x%x\n",
+				 mbus_code);
+			break;
+		}
+		break;
+
+	case V4L2_PIX_FMT_YUYV:
+		return CSI_INPUT_SEQ_YUYV;
+
+	default:
+		dev_warn(sdev->dev, "Unsupported pixformat: 0x%x, defaulting to YUYV\n",
+			 pixformat);
+		break;
+	}
+
+	return CSI_INPUT_SEQ_YUYV;
+}
+
+static void sun6i_csi_setup_bus(struct sun6i_csi_dev *sdev)
+{
+	struct v4l2_fwnode_endpoint *endpoint = &sdev->csi.v4l2_ep;
+	unsigned char bus_width;
+	u32 flags;
+	u32 cfg;
+
+	bus_width = endpoint->bus.parallel.bus_width;
+
+	regmap_read(sdev->regmap, CSI_IF_CFG_REG, &cfg);
+
+	cfg &= ~(CSI_IF_CFG_CSI_IF_MASK | CSI_IF_CFG_MIPI_IF_MASK |
+		 CSI_IF_CFG_IF_DATA_WIDTH_MASK |
+		 CSI_IF_CFG_CLK_POL_MASK | CSI_IF_CFG_VREF_POL_MASK |
+		 CSI_IF_CFG_HREF_POL_MASK | CSI_IF_CFG_FIELD_MASK);
+
+	switch (endpoint->bus_type) {
+	case V4L2_MBUS_PARALLEL:
+		cfg |= CSI_IF_CFG_MIPI_IF_CSI;
+
+		flags = endpoint->bus.parallel.flags;
+
+		cfg |= (bus_width == 16) ? CSI_IF_CFG_CSI_IF_YUV422_16BIT :
+					   CSI_IF_CFG_CSI_IF_YUV422_INTLV;
+
+		if (flags & V4L2_MBUS_FIELD_EVEN_LOW)
+			cfg |= CSI_IF_CFG_FIELD_POSITIVE;
+
+		if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
+			cfg |= CSI_IF_CFG_VREF_POL_POSITIVE;
+		if (flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)
+			cfg |= CSI_IF_CFG_HREF_POL_POSITIVE;
+
+		if (flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
+			cfg |= CSI_IF_CFG_CLK_POL_FALLING_EDGE;
+		break;
+	case V4L2_MBUS_BT656:
+		cfg |= CSI_IF_CFG_MIPI_IF_CSI;
+
+		flags = endpoint->bus.parallel.flags;
+
+		cfg |= (bus_width == 16) ? CSI_IF_CFG_CSI_IF_BT1120 :
+					   CSI_IF_CFG_CSI_IF_BT656;
+
+		if (flags & V4L2_MBUS_FIELD_EVEN_LOW)
+			cfg |= CSI_IF_CFG_FIELD_POSITIVE;
+
+		if (flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
+			cfg |= CSI_IF_CFG_CLK_POL_FALLING_EDGE;
+		break;
+	default:
+		dev_warn(sdev->dev, "Unsupported bus type: %d\n",
+			 endpoint->bus_type);
+		break;
+	}
+
+	switch (bus_width) {
+	case 8:
+		cfg |= CSI_IF_CFG_IF_DATA_WIDTH_8BIT;
+		break;
+	case 10:
+		cfg |= CSI_IF_CFG_IF_DATA_WIDTH_10BIT;
+		break;
+	case 12:
+		cfg |= CSI_IF_CFG_IF_DATA_WIDTH_12BIT;
+		break;
+	case 16: /* No need to configure DATA_WIDTH for 16bit */
+		break;
+	default:
+		dev_warn(sdev->dev, "Unsupported bus width: %d\n", bus_width);
+		break;
+	}
+
+	regmap_write(sdev->regmap, CSI_IF_CFG_REG, cfg);
+}
+
+static void sun6i_csi_set_format(struct sun6i_csi_dev *sdev)
+{
+	struct sun6i_csi *csi = &sdev->csi;
+	u32 cfg;
+	u32 val;
+
+	regmap_read(sdev->regmap, CSI_CH_CFG_REG, &cfg);
+
+	cfg &= ~(CSI_CH_CFG_INPUT_FMT_MASK |
+		 CSI_CH_CFG_OUTPUT_FMT_MASK | CSI_CH_CFG_VFLIP_EN |
+		 CSI_CH_CFG_HFLIP_EN | CSI_CH_CFG_FIELD_SEL_MASK |
+		 CSI_CH_CFG_INPUT_SEQ_MASK);
+
+	val = get_csi_input_format(sdev, csi->config.code,
+				   csi->config.pixelformat);
+	cfg |= CSI_CH_CFG_INPUT_FMT(val);
+
+	val = get_csi_output_format(sdev, csi->config.pixelformat,
+				    csi->config.field);
+	cfg |= CSI_CH_CFG_OUTPUT_FMT(val);
+
+	val = get_csi_input_seq(sdev, csi->config.code,
+				csi->config.pixelformat);
+	cfg |= CSI_CH_CFG_INPUT_SEQ(val);
+
+	if (csi->config.field == V4L2_FIELD_TOP)
+		cfg |= CSI_CH_CFG_FIELD_SEL_FIELD0;
+	else if (csi->config.field == V4L2_FIELD_BOTTOM)
+		cfg |= CSI_CH_CFG_FIELD_SEL_FIELD1;
+	else
+		cfg |= CSI_CH_CFG_FIELD_SEL_BOTH;
+
+	regmap_write(sdev->regmap, CSI_CH_CFG_REG, cfg);
+}
+
+static void sun6i_csi_set_window(struct sun6i_csi_dev *sdev)
+{
+	struct sun6i_csi_config *config = &sdev->csi.config;
+	u32 bytesperline_y;
+	u32 bytesperline_c;
+	int *planar_offset = sdev->planar_offset;
+	u32 width = config->width;
+	u32 height = config->height;
+	u32 hor_len = width;
+
+	switch (config->pixelformat) {
+	case V4L2_PIX_FMT_YUYV:
+	case V4L2_PIX_FMT_YVYU:
+	case V4L2_PIX_FMT_UYVY:
+	case V4L2_PIX_FMT_VYUY:
+		dev_dbg(sdev->dev,
+			"Horizontal length should be 2 times of width for packed YUV formats!\n");
+		hor_len = width * 2;
+		break;
+	default:
+		break;
+	}
+
+	regmap_write(sdev->regmap, CSI_CH_HSIZE_REG,
+		     CSI_CH_HSIZE_HOR_LEN(hor_len) |
+		     CSI_CH_HSIZE_HOR_START(0));
+	regmap_write(sdev->regmap, CSI_CH_VSIZE_REG,
+		     CSI_CH_VSIZE_VER_LEN(height) |
+		     CSI_CH_VSIZE_VER_START(0));
+
+	planar_offset[0] = 0;
+	switch (config->pixelformat) {
+	case V4L2_PIX_FMT_HM12:
+	case V4L2_PIX_FMT_NV12:
+	case V4L2_PIX_FMT_NV21:
+	case V4L2_PIX_FMT_NV16:
+	case V4L2_PIX_FMT_NV61:
+		bytesperline_y = width;
+		bytesperline_c = width;
+		planar_offset[1] = bytesperline_y * height;
+		planar_offset[2] = -1;
+		break;
+	case V4L2_PIX_FMT_YUV420:
+	case V4L2_PIX_FMT_YVU420:
+		bytesperline_y = width;
+		bytesperline_c = width / 2;
+		planar_offset[1] = bytesperline_y * height;
+		planar_offset[2] = planar_offset[1] +
+				bytesperline_c * height / 2;
+		break;
+	case V4L2_PIX_FMT_YUV422P:
+		bytesperline_y = width;
+		bytesperline_c = width / 2;
+		planar_offset[1] = bytesperline_y * height;
+		planar_offset[2] = planar_offset[1] +
+				bytesperline_c * height;
+		break;
+	default: /* raw */
+		dev_dbg(sdev->dev,
+			"Calculating pixelformat(0x%x)'s bytesperline as a packed format\n",
+			config->pixelformat);
+		bytesperline_y = (sun6i_csi_get_bpp(config->pixelformat) *
+				  config->width) / 8;
+		bytesperline_c = 0;
+		planar_offset[1] = -1;
+		planar_offset[2] = -1;
+		break;
+	}
+
+	regmap_write(sdev->regmap, CSI_CH_BUF_LEN_REG,
+		     CSI_CH_BUF_LEN_BUF_LEN_C(bytesperline_c) |
+		     CSI_CH_BUF_LEN_BUF_LEN_Y(bytesperline_y));
+}
+
+int sun6i_csi_update_config(struct sun6i_csi *csi,
+			    struct sun6i_csi_config *config)
+{
+	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
+
+	if (config == NULL)
+		return -EINVAL;
+
+	memcpy(&csi->config, config, sizeof(csi->config));
+
+	sun6i_csi_setup_bus(sdev);
+	sun6i_csi_set_format(sdev);
+	sun6i_csi_set_window(sdev);
+
+	return 0;
+}
+
+void sun6i_csi_update_buf_addr(struct sun6i_csi *csi, dma_addr_t addr)
+{
+	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
+
+	regmap_write(sdev->regmap, CSI_CH_F0_BUFA_REG,
+		     (addr + sdev->planar_offset[0]) >> 2);
+	if (sdev->planar_offset[1] != -1)
+		regmap_write(sdev->regmap, CSI_CH_F1_BUFA_REG,
+			     (addr + sdev->planar_offset[1]) >> 2);
+	if (sdev->planar_offset[2] != -1)
+		regmap_write(sdev->regmap, CSI_CH_F2_BUFA_REG,
+			     (addr + sdev->planar_offset[2]) >> 2);
+}
+
+void sun6i_csi_set_stream(struct sun6i_csi *csi, bool enable)
+{
+	struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi);
+	struct regmap *regmap = sdev->regmap;
+
+	if (!enable) {
+		regmap_update_bits(regmap, CSI_CAP_REG, CSI_CAP_CH0_VCAP_ON, 0);
+		regmap_write(regmap, CSI_CH_INT_EN_REG, 0);
+		return;
+	}
+
+	regmap_write(regmap, CSI_CH_INT_STA_REG, 0xFF);
+	regmap_write(regmap, CSI_CH_INT_EN_REG,
+		     CSI_CH_INT_EN_HB_OF_INT_EN |
+		     CSI_CH_INT_EN_FIFO2_OF_INT_EN |
+		     CSI_CH_INT_EN_FIFO1_OF_INT_EN |
+		     CSI_CH_INT_EN_FIFO0_OF_INT_EN |
+		     CSI_CH_INT_EN_FD_INT_EN |
+		     CSI_CH_INT_EN_CD_INT_EN);
+
+	regmap_update_bits(regmap, CSI_CAP_REG, CSI_CAP_CH0_VCAP_ON,
+			   CSI_CAP_CH0_VCAP_ON);
+}
+
+/* -----------------------------------------------------------------------------
+ * Media Controller and V4L2
+ */
+static int sun6i_csi_link_entity(struct sun6i_csi *csi,
+				 struct media_entity *entity,
+				 struct fwnode_handle *fwnode)
+{
+	struct media_entity *sink;
+	struct media_pad *sink_pad;
+	struct media_link *link;
+	int src_pad_index;
+	int ret;
+
+	ret = media_entity_get_fwnode_pad(entity, fwnode, MEDIA_PAD_FL_SOURCE);
+	if (ret < 0) {
+		dev_err(csi->dev, "%s: no source pad in external entity %s\n",
+			__func__, entity->name);
+		return -EINVAL;
+	}
+
+	src_pad_index = ret;
+
+	sink = &csi->video.vdev.entity;
+	sink_pad = &csi->video.pad;
+
+	dev_dbg(csi->dev, "creating %s:%u -> %s:%u link\n",
+		entity->name, src_pad_index, sink->name, sink_pad->index);
+	ret = media_create_pad_link(entity, src_pad_index, sink,
+				    sink_pad->index, 0);
+	if (ret < 0) {
+		dev_err(csi->dev, "failed to create %s:%u -> %s:%u link\n",
+			entity->name, src_pad_index,
+			sink->name, sink_pad->index);
+		return ret;
+	}
+
+	link = media_entity_find_link(&entity->pads[src_pad_index], sink_pad);
+	return media_entity_setup_link(link, MEDIA_LNK_FL_ENABLED);
+}
+
+static int sun6i_subdev_notify_complete(struct v4l2_async_notifier *notifier)
+{
+	struct sun6i_csi *csi = container_of(notifier, struct sun6i_csi,
+					     notifier);
+	struct v4l2_device *v4l2_dev = &csi->v4l2_dev;
+	struct v4l2_subdev *sd;
+	int ret;
+
+	dev_dbg(csi->dev, "notify complete, all subdevs registered\n");
+
+	if (notifier->num_subdevs != 1)
+		return -EINVAL;
+
+	sd = list_first_entry(&v4l2_dev->subdevs, struct v4l2_subdev, list);
+	if (sd == NULL)
+		return -EINVAL;
+
+	ret = sun6i_csi_link_entity(csi, &sd->entity, sd->fwnode);
+	if (ret < 0)
+		return ret;
+
+	ret = v4l2_device_register_subdev_nodes(&csi->v4l2_dev);
+	if (ret < 0)
+		return ret;
+
+	return media_device_register(&csi->media_dev);
+}
+
+static const struct v4l2_async_notifier_operations sun6i_csi_async_ops = {
+	.complete = sun6i_subdev_notify_complete,
+};
+
+static int sun6i_csi_fwnode_parse(struct device *dev,
+				  struct v4l2_fwnode_endpoint *vep,
+				  struct v4l2_async_subdev *asd)
+{
+	struct sun6i_csi *csi = dev_get_drvdata(dev);
+
+	if (vep->base.port || vep->base.id) {
+		dev_warn(dev, "Only support a single port with one endpoint\n");
+		return -ENOTCONN;
+	}
+
+	switch (vep->bus_type) {
+	case V4L2_MBUS_PARALLEL:
+	case V4L2_MBUS_BT656:
+		csi->v4l2_ep = *vep;
+		return 0;
+	default:
+		dev_err(dev, "Unsupported media bus type\n");
+		return -ENOTCONN;
+	}
+}
+
+static void sun6i_csi_v4l2_cleanup(struct sun6i_csi *csi)
+{
+	v4l2_async_notifier_cleanup(&csi->notifier);
+	v4l2_async_notifier_unregister(&csi->notifier);
+	sun6i_video_cleanup(&csi->video);
+	v4l2_device_unregister(&csi->v4l2_dev);
+	media_device_unregister(&csi->media_dev);
+	media_device_cleanup(&csi->media_dev);
+}
+
+static int sun6i_csi_v4l2_init(struct sun6i_csi *csi)
+{
+	int ret;
+
+	csi->media_dev.dev = csi->dev;
+	strlcpy(csi->media_dev.model, "Allwinner Video Capture Device",
+		sizeof(csi->media_dev.model));
+	csi->media_dev.hw_revision = 0;
+
+	media_device_init(&csi->media_dev);
+
+	ret = v4l2_ctrl_handler_init(&csi->ctrl_handler, 0);
+	if (ret) {
+		dev_err(csi->dev, "V4L2 controls handler init failed (%d)\n",
+			ret);
+		goto clean_media;
+	}
+
+	csi->v4l2_dev.mdev = &csi->media_dev;
+	csi->v4l2_dev.ctrl_handler = &csi->ctrl_handler;
+	ret = v4l2_device_register(csi->dev, &csi->v4l2_dev);
+	if (ret) {
+		dev_err(csi->dev, "V4L2 device registration failed (%d)\n",
+			ret);
+		goto clean_media;
+	}
+
+	ret = sun6i_video_init(&csi->video, csi, "sun6i-csi");
+	if (ret)
+		goto unreg_v4l2;
+
+	ret = v4l2_async_notifier_parse_fwnode_endpoints(
+		csi->dev, &csi->notifier, sizeof(struct v4l2_async_subdev),
+		sun6i_csi_fwnode_parse);
+	if (ret)
+		goto clean_video;
+
+	csi->notifier.ops = &sun6i_csi_async_ops;
+
+	ret = v4l2_async_notifier_register(&csi->v4l2_dev, &csi->notifier);
+	if (ret) {
+		dev_err(csi->dev, "notifier registration failed\n");
+		goto clean_notifier;
+	}
+
+	return 0;
+
+clean_notifier:
+	v4l2_async_notifier_cleanup(&csi->notifier);
+clean_video:
+	sun6i_video_cleanup(&csi->video);
+unreg_v4l2:
+	v4l2_device_unregister(&csi->v4l2_dev);
+clean_media:
+	media_device_cleanup(&csi->media_dev);
+
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * Resources and IRQ
+ */
+static irqreturn_t sun6i_csi_isr(int irq, void *dev_id)
+{
+	struct sun6i_csi_dev *sdev = (struct sun6i_csi_dev *)dev_id;
+	struct regmap *regmap = sdev->regmap;
+	u32 status;
+
+	regmap_read(regmap, CSI_CH_INT_STA_REG, &status);
+
+	if (!(status & 0xFF))
+		return IRQ_NONE;
+
+	if ((status & CSI_CH_INT_STA_FIFO0_OF_PD) ||
+	    (status & CSI_CH_INT_STA_FIFO1_OF_PD) ||
+	    (status & CSI_CH_INT_STA_FIFO2_OF_PD) ||
+	    (status & CSI_CH_INT_STA_HB_OF_PD)) {
+		regmap_write(regmap, CSI_CH_INT_STA_REG, status);
+		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
+		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN,
+				   CSI_EN_CSI_EN);
+		return IRQ_HANDLED;
+	}
+
+	if (status & CSI_CH_INT_STA_FD_PD)
+		sun6i_video_frame_done(&sdev->csi.video);
+
+	regmap_write(regmap, CSI_CH_INT_STA_REG, status);
+
+	return IRQ_HANDLED;
+}
+
+static const struct regmap_config sun6i_csi_regmap_config = {
+	.reg_bits       = 32,
+	.reg_stride     = 4,
+	.val_bits       = 32,
+	.max_register	= 0x1000,
+};
+
+static int sun6i_csi_resource_request(struct sun6i_csi_dev *sdev,
+				      struct platform_device *pdev)
+{
+	struct resource *res;
+	void __iomem *io_base;
+	int ret;
+	int irq;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	io_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	sdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "bus", io_base,
+					    &sun6i_csi_regmap_config);
+	if (IS_ERR(sdev->regmap)) {
+		dev_err(&pdev->dev, "Failed to init register map\n");
+		return PTR_ERR(sdev->regmap);
+	}
+
+	sdev->clk_mod = devm_clk_get(&pdev->dev, "mod");
+	if (IS_ERR(sdev->clk_mod)) {
+		dev_err(&pdev->dev, "Unable to acquire csi clock\n");
+		return PTR_ERR(sdev->clk_mod);
+	}
+
+	sdev->clk_ram = devm_clk_get(&pdev->dev, "ram");
+	if (IS_ERR(sdev->clk_ram)) {
+		dev_err(&pdev->dev, "Unable to acquire dram-csi clock\n");
+		return PTR_ERR(sdev->clk_ram);
+	}
+
+	sdev->rstc_bus = devm_reset_control_get_shared(&pdev->dev, NULL);
+	if (IS_ERR(sdev->rstc_bus)) {
+		dev_err(&pdev->dev, "Cannot get reset controller\n");
+		return PTR_ERR(sdev->rstc_bus);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "No csi IRQ specified\n");
+		ret = -ENXIO;
+		return ret;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, sun6i_csi_isr, 0, MODULE_NAME,
+			       sdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot request csi IRQ\n");
+		return ret;
+	}
+	return 0;
+}
+
+/*
+ * PHYS_OFFSET isn't available on all architectures. In order to
+ * accomodate for COMPILE_TEST, let's define it to something dumb.
+ */
+#ifndef PHYS_OFFSET
+#define PHYS_OFFSET 0
+#endif
+
+static int sun6i_csi_probe(struct platform_device *pdev)
+{
+	struct sun6i_csi_dev *sdev;
+	int ret;
+
+	sdev = devm_kzalloc(&pdev->dev, sizeof(*sdev), GFP_KERNEL);
+	if (!sdev)
+		return -ENOMEM;
+
+	sdev->dev = &pdev->dev;
+	/* The DMA bus has the memory mapped at 0 */
+	sdev->dev->dma_pfn_offset = PHYS_OFFSET >> PAGE_SHIFT;
+
+	ret = sun6i_csi_resource_request(sdev, pdev);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, sdev);
+
+	sdev->csi.dev = &pdev->dev;
+	ret = sun6i_csi_v4l2_init(&sdev->csi);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int sun6i_csi_remove(struct platform_device *pdev)
+{
+	struct sun6i_csi_dev *sdev = platform_get_drvdata(pdev);
+
+	sun6i_csi_v4l2_cleanup(&sdev->csi);
+
+	return 0;
+}
+
+static const struct of_device_id sun6i_csi_of_match[] = {
+	{ .compatible = "allwinner,sun8i-v3s-csi", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sun6i_csi_of_match);
+
+static struct platform_driver sun6i_csi_platform_driver = {
+	.probe = sun6i_csi_probe,
+	.remove = sun6i_csi_remove,
+	.driver = {
+		.name = MODULE_NAME,
+		.of_match_table = of_match_ptr(sun6i_csi_of_match),
+	},
+};
+module_platform_driver(sun6i_csi_platform_driver);
+
+MODULE_DESCRIPTION("Allwinner V3s Camera Sensor Interface driver");
+MODULE_AUTHOR("Yong Deng <[e-mail]>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
new file mode 100644
index 000000000000..44a7d50805bc
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
@@ -0,0 +1,145 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <[e-mail]>
+ */
+
+#ifndef __SUN6I_CSI_H__
+#define __SUN6I_CSI_H__
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+
+#include "sun6i_video.h"
+
+struct sun6i_csi;
+
+/**
+ * struct sun6i_csi_config - configs for sun6i csi
+ * @pixelformat: v4l2 pixel format (V4L2_PIX_FMT_*)
+ * @code:	media bus format code (MEDIA_BUS_FMT_*)
+ * @field:	used interlacing type (enum v4l2_field)
+ * @width:	frame width
+ * @height:	frame height
+ */
+struct sun6i_csi_config {
+	u32		pixelformat;
+	u32		code;
+	u32		field;
+	u32		width;
+	u32		height;
+};
+
+struct sun6i_csi {
+	struct device			*dev;
+	struct v4l2_ctrl_handler	ctrl_handler;
+	struct v4l2_device		v4l2_dev;
+	struct media_device		media_dev;
+
+	struct v4l2_async_notifier	notifier;
+
+	/* video port settings */
+	struct v4l2_fwnode_endpoint	v4l2_ep;
+
+	struct sun6i_csi_config		config;
+
+	struct sun6i_video		video;
+};
+
+/**
+ * sun6i_csi_get_supported_pixformats() - get csi supported pixformats
+ * @csi:	pointer to the csi
+ * @pixformats:	supported pixformats return from csi
+ *
+ * @return the count of pixformats or error(< 0)
+ */
+int sun6i_csi_get_supported_pixformats(struct sun6i_csi *csi,
+				       const u32 **pixformats);
+
+/**
+ * sun6i_csi_is_format_supported() - check if the format supported by csi
+ * @csi:	pointer to the csi
+ * @pixformat:	v4l2 pixel format (V4L2_PIX_FMT_*)
+ * @mbus_code:	media bus format code (MEDIA_BUS_FMT_*)
+ */
+bool sun6i_csi_is_format_supported(struct sun6i_csi *csi, u32 pixformat,
+				 u32 mbus_code);
+
+/**
+ * sun6i_csi_set_power() - power on/off the csi
+ * @csi:	pointer to the csi
+ * @enable:	on/off
+ */
+int sun6i_csi_set_power(struct sun6i_csi *csi, bool enable);
+
+/**
+ * sun6i_csi_update_config() - update the csi register setttings
+ * @csi:	pointer to the csi
+ * @config:	see struct sun6i_csi_config
+ */
+int sun6i_csi_update_config(struct sun6i_csi *csi,
+			    struct sun6i_csi_config *config);
+
+/**
+ * sun6i_csi_update_buf_addr() - update the csi frame buffer address
+ * @csi:	pointer to the csi
+ * @addr:	frame buffer's physical address
+ */
+void sun6i_csi_update_buf_addr(struct sun6i_csi *csi, dma_addr_t addr);
+
+/**
+ * sun6i_csi_set_stream() - start/stop csi streaming
+ * @csi:	pointer to the csi
+ * @enable:	start/stop
+ */
+void sun6i_csi_set_stream(struct sun6i_csi *csi, bool enable);
+
+/* get bpp form v4l2 pixformat */
+static inline int sun6i_csi_get_bpp(unsigned int pixformat)
+{
+	switch (pixformat) {
+	case V4L2_PIX_FMT_SBGGR8:
+	case V4L2_PIX_FMT_SGBRG8:
+	case V4L2_PIX_FMT_SGRBG8:
+	case V4L2_PIX_FMT_SRGGB8:
+		return 8;
+	case V4L2_PIX_FMT_SBGGR10:
+	case V4L2_PIX_FMT_SGBRG10:
+	case V4L2_PIX_FMT_SGRBG10:
+	case V4L2_PIX_FMT_SRGGB10:
+		return 10;
+	case V4L2_PIX_FMT_SBGGR12:
+	case V4L2_PIX_FMT_SGBRG12:
+	case V4L2_PIX_FMT_SGRBG12:
+	case V4L2_PIX_FMT_SRGGB12:
+	case V4L2_PIX_FMT_HM12:
+	case V4L2_PIX_FMT_NV12:
+	case V4L2_PIX_FMT_NV21:
+	case V4L2_PIX_FMT_YUV420:
+	case V4L2_PIX_FMT_YVU420:
+		return 12;
+	case V4L2_PIX_FMT_YUYV:
+	case V4L2_PIX_FMT_YVYU:
+	case V4L2_PIX_FMT_UYVY:
+	case V4L2_PIX_FMT_VYUY:
+	case V4L2_PIX_FMT_NV16:
+	case V4L2_PIX_FMT_NV61:
+	case V4L2_PIX_FMT_YUV422P:
+		return 16;
+	case V4L2_PIX_FMT_RGB24:
+	case V4L2_PIX_FMT_BGR24:
+		return 24;
+	case V4L2_PIX_FMT_RGB32:
+	case V4L2_PIX_FMT_BGR32:
+		return 32;
+	default:
+		WARN(1, "Unsupported pixformat: 0x%x\n", pixformat);
+		break;
+	}
+
+	return 0;
+}
+
+#endif /* __SUN6I_CSI_H__ */
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h
new file mode 100644
index 000000000000..00798b4d20f2
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h
@@ -0,0 +1,196 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <[e-mail]>
+ */
+
+#ifndef __SUN6I_CSI_REG_H__
+#define __SUN6I_CSI_REG_H__
+
+#include <linux/kernel.h>
+
+#define CSI_EN_REG			0x0
+#define CSI_EN_VER_EN				BIT(30)
+#define CSI_EN_CSI_EN				BIT(0)
+
+#define CSI_IF_CFG_REG			0x4
+#define CSI_IF_CFG_SRC_TYPE_MASK		BIT(21)
+#define CSI_IF_CFG_SRC_TYPE_PROGRESSED		((0 << 21) & CSI_IF_CFG_SRC_TYPE_MASK)
+#define CSI_IF_CFG_SRC_TYPE_INTERLACED		((1 << 21) & CSI_IF_CFG_SRC_TYPE_MASK)
+#define CSI_IF_CFG_FPS_DS_EN			BIT(20)
+#define CSI_IF_CFG_FIELD_MASK			BIT(19)
+#define CSI_IF_CFG_FIELD_NEGATIVE		((0 << 19) & CSI_IF_CFG_FIELD_MASK)
+#define CSI_IF_CFG_FIELD_POSITIVE		((1 << 19) & CSI_IF_CFG_FIELD_MASK)
+#define CSI_IF_CFG_VREF_POL_MASK		BIT(18)
+#define CSI_IF_CFG_VREF_POL_NEGATIVE		((0 << 18) & CSI_IF_CFG_VREF_POL_MASK)
+#define CSI_IF_CFG_VREF_POL_POSITIVE		((1 << 18) & CSI_IF_CFG_VREF_POL_MASK)
+#define CSI_IF_CFG_HREF_POL_MASK		BIT(17)
+#define CSI_IF_CFG_HREF_POL_NEGATIVE		((0 << 17) & CSI_IF_CFG_HREF_POL_MASK)
+#define CSI_IF_CFG_HREF_POL_POSITIVE		((1 << 17) & CSI_IF_CFG_HREF_POL_MASK)
+#define CSI_IF_CFG_CLK_POL_MASK			BIT(16)
+#define CSI_IF_CFG_CLK_POL_RISING_EDGE		((0 << 16) & CSI_IF_CFG_CLK_POL_MASK)
+#define CSI_IF_CFG_CLK_POL_FALLING_EDGE		((1 << 16) & CSI_IF_CFG_CLK_POL_MASK)
+#define CSI_IF_CFG_IF_DATA_WIDTH_MASK		GENMASK(10, 8)
+#define CSI_IF_CFG_IF_DATA_WIDTH_8BIT		((0 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
+#define CSI_IF_CFG_IF_DATA_WIDTH_10BIT		((1 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
+#define CSI_IF_CFG_IF_DATA_WIDTH_12BIT		((2 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
+#define CSI_IF_CFG_MIPI_IF_MASK			BIT(7)
+#define CSI_IF_CFG_MIPI_IF_CSI			(0 << 7)
+#define CSI_IF_CFG_MIPI_IF_MIPI			(1 << 7)
+#define CSI_IF_CFG_CSI_IF_MASK			GENMASK(4, 0)
+#define CSI_IF_CFG_CSI_IF_YUV422_INTLV		((0 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+#define CSI_IF_CFG_CSI_IF_YUV422_16BIT		((1 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+#define CSI_IF_CFG_CSI_IF_BT656			((4 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+#define CSI_IF_CFG_CSI_IF_BT1120		((5 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+
+#define CSI_CAP_REG			0x8
+#define CSI_CAP_CH0_CAP_MASK_MASK		GENMASK(5, 2)
+#define CSI_CAP_CH0_CAP_MASK(count)		((count << 2) & CSI_CAP_CH0_CAP_MASK_MASK)
+#define CSI_CAP_CH0_VCAP_ON			BIT(1)
+#define CSI_CAP_CH0_SCAP_ON			BIT(0)
+
+#define CSI_SYNC_CNT_REG		0xc
+#define CSI_FIFO_THRS_REG		0x10
+#define CSI_BT656_HEAD_CFG_REG		0x14
+#define CSI_PTN_LEN_REG			0x30
+#define CSI_PTN_ADDR_REG		0x34
+#define CSI_VER_REG			0x3c
+
+#define CSI_CH_CFG_REG			0x44
+#define CSI_CH_CFG_INPUT_FMT_MASK		GENMASK(23, 20)
+#define CSI_CH_CFG_INPUT_FMT(fmt)		((fmt << 20) & CSI_CH_CFG_INPUT_FMT_MASK)
+#define CSI_CH_CFG_OUTPUT_FMT_MASK		GENMASK(19, 16)
+#define CSI_CH_CFG_OUTPUT_FMT(fmt)		((fmt << 16) & CSI_CH_CFG_OUTPUT_FMT_MASK)
+#define CSI_CH_CFG_VFLIP_EN			BIT(13)
+#define CSI_CH_CFG_HFLIP_EN			BIT(12)
+#define CSI_CH_CFG_FIELD_SEL_MASK		GENMASK(11, 10)
+#define CSI_CH_CFG_FIELD_SEL_FIELD0		((0 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
+#define CSI_CH_CFG_FIELD_SEL_FIELD1		((1 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
+#define CSI_CH_CFG_FIELD_SEL_BOTH		((2 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
+#define CSI_CH_CFG_INPUT_SEQ_MASK		GENMASK(9, 8)
+#define CSI_CH_CFG_INPUT_SEQ(seq)		((seq << 8) & CSI_CH_CFG_INPUT_SEQ_MASK)
+
+#define CSI_CH_SCALE_REG		0x4c
+#define CSI_CH_SCALE_QUART_EN			BIT(0)
+
+#define CSI_CH_F0_BUFA_REG		0x50
+
+#define CSI_CH_F1_BUFA_REG		0x58
+
+#define CSI_CH_F2_BUFA_REG		0x60
+
+#define CSI_CH_STA_REG			0x6c
+#define CSI_CH_STA_FIELD_STA_MASK		BIT(2)
+#define CSI_CH_STA_FIELD_STA_FIELD0		((0 << 2) & CSI_CH_STA_FIELD_STA_MASK)
+#define CSI_CH_STA_FIELD_STA_FIELD1		((1 << 2) & CSI_CH_STA_FIELD_STA_MASK)
+#define CSI_CH_STA_VCAP_STA			BIT(1)
+#define CSI_CH_STA_SCAP_STA			BIT(0)
+
+#define CSI_CH_INT_EN_REG		0x70
+#define CSI_CH_INT_EN_VS_INT_EN			BIT(7)
+#define CSI_CH_INT_EN_HB_OF_INT_EN		BIT(6)
+#define CSI_CH_INT_EN_MUL_ERR_INT_EN		BIT(5)
+#define CSI_CH_INT_EN_FIFO2_OF_INT_EN		BIT(4)
+#define CSI_CH_INT_EN_FIFO1_OF_INT_EN		BIT(3)
+#define CSI_CH_INT_EN_FIFO0_OF_INT_EN		BIT(2)
+#define CSI_CH_INT_EN_FD_INT_EN			BIT(1)
+#define CSI_CH_INT_EN_CD_INT_EN			BIT(0)
+
+#define CSI_CH_INT_STA_REG		0x74
+#define CSI_CH_INT_STA_VS_PD			BIT(7)
+#define CSI_CH_INT_STA_HB_OF_PD			BIT(6)
+#define CSI_CH_INT_STA_MUL_ERR_PD		BIT(5)
+#define CSI_CH_INT_STA_FIFO2_OF_PD		BIT(4)
+#define CSI_CH_INT_STA_FIFO1_OF_PD		BIT(3)
+#define CSI_CH_INT_STA_FIFO0_OF_PD		BIT(2)
+#define CSI_CH_INT_STA_FD_PD			BIT(1)
+#define CSI_CH_INT_STA_CD_PD			BIT(0)
+
+#define CSI_CH_FLD1_VSIZE_REG		0x78
+
+#define CSI_CH_HSIZE_REG		0x80
+#define CSI_CH_HSIZE_HOR_LEN_MASK		GENMASK(28, 16)
+#define CSI_CH_HSIZE_HOR_LEN(len)		((len << 16) & CSI_CH_HSIZE_HOR_LEN_MASK)
+#define CSI_CH_HSIZE_HOR_START_MASK		GENMASK(12, 0)
+#define CSI_CH_HSIZE_HOR_START(start)		((start << 0) & CSI_CH_HSIZE_HOR_START_MASK)
+
+#define CSI_CH_VSIZE_REG		0x84
+#define CSI_CH_VSIZE_VER_LEN_MASK		GENMASK(28, 16)
+#define CSI_CH_VSIZE_VER_LEN(len)		((len << 16) & CSI_CH_VSIZE_VER_LEN_MASK)
+#define CSI_CH_VSIZE_VER_START_MASK		GENMASK(12, 0)
+#define CSI_CH_VSIZE_VER_START(start)		((start << 0) & CSI_CH_VSIZE_VER_START_MASK)
+
+#define CSI_CH_BUF_LEN_REG		0x88
+#define CSI_CH_BUF_LEN_BUF_LEN_C_MASK		GENMASK(29, 16)
+#define CSI_CH_BUF_LEN_BUF_LEN_C(len)		((len << 16) & CSI_CH_BUF_LEN_BUF_LEN_C_MASK)
+#define CSI_CH_BUF_LEN_BUF_LEN_Y_MASK		GENMASK(13, 0)
+#define CSI_CH_BUF_LEN_BUF_LEN_Y(len)		((len << 0) & CSI_CH_BUF_LEN_BUF_LEN_Y_MASK)
+
+#define CSI_CH_FLIP_SIZE_REG		0x8c
+#define CSI_CH_FLIP_SIZE_VER_LEN_MASK		GENMASK(28, 16)
+#define CSI_CH_FLIP_SIZE_VER_LEN(len)		((len << 16) & CSI_CH_FLIP_SIZE_VER_LEN_MASK)
+#define CSI_CH_FLIP_SIZE_VALID_LEN_MASK		GENMASK(12, 0)
+#define CSI_CH_FLIP_SIZE_VALID_LEN(len)		((len << 0) & CSI_CH_FLIP_SIZE_VALID_LEN_MASK)
+
+#define CSI_CH_FRM_CLK_CNT_REG		0x90
+#define CSI_CH_ACC_ITNL_CLK_CNT_REG	0x94
+#define CSI_CH_FIFO_STAT_REG		0x98
+#define CSI_CH_PCLK_STAT_REG		0x9c
+
+/*
+ * csi input data format
+ */
+enum csi_input_fmt {
+	CSI_INPUT_FORMAT_RAW		= 0,
+	CSI_INPUT_FORMAT_YUV422		= 3,
+	CSI_INPUT_FORMAT_YUV420		= 4,
+};
+
+/*
+ * csi output data format
+ */
+enum csi_output_fmt {
+	/* only when input format is RAW */
+	CSI_FIELD_RAW_8			= 0,
+	CSI_FIELD_RAW_10		= 1,
+	CSI_FIELD_RAW_12		= 2,
+	CSI_FIELD_RGB565		= 4,
+	CSI_FIELD_RGB888		= 5,
+	CSI_FIELD_PRGB888		= 6,
+	CSI_FRAME_RAW_8			= 8,
+	CSI_FRAME_RAW_10		= 9,
+	CSI_FRAME_RAW_12		= 10,
+	CSI_FRAME_RGB565		= 12,
+	CSI_FRAME_RGB888		= 13,
+	CSI_FRAME_PRGB888		= 14,
+
+	/* only when input format is YUV422 */
+	CSI_FIELD_PLANAR_YUV422		= 0,
+	CSI_FIELD_PLANAR_YUV420		= 1,
+	CSI_FRAME_PLANAR_YUV420		= 2,
+	CSI_FRAME_PLANAR_YUV422		= 3,
+	CSI_FIELD_UV_CB_YUV422		= 4,
+	CSI_FIELD_UV_CB_YUV420		= 5,
+	CSI_FRAME_UV_CB_YUV420		= 6,
+	CSI_FRAME_UV_CB_YUV422		= 7,
+	CSI_FIELD_MB_YUV422		= 8,
+	CSI_FIELD_MB_YUV420		= 9,
+	CSI_FRAME_MB_YUV420		= 10,
+	CSI_FRAME_MB_YUV422		= 11,
+	CSI_FIELD_UV_CB_YUV422_10	= 12,
+	CSI_FIELD_UV_CB_YUV420_10	= 13,
+};
+
+/*
+ * csi YUV input data sequence
+ */
+enum csi_input_seq {
+	/* only when input format is YUV422 */
+	CSI_INPUT_SEQ_YUYV = 0,
+	CSI_INPUT_SEQ_YVYU,
+	CSI_INPUT_SEQ_UYVY,
+	CSI_INPUT_SEQ_VYUY,
+};
+
+#endif /* __SUN6I_CSI_REG_H__ */
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
new file mode 100644
index 000000000000..9bd662b08236
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
@@ -0,0 +1,767 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <[e-mail]>
+ */
+
+#include <linux/of.h>
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mc.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "sun6i_csi.h"
+#include "sun6i_video.h"
+
+struct sun6i_csi_buffer {
+	struct vb2_v4l2_buffer		vb;
+	struct list_head		list;
+
+	dma_addr_t			dma_addr;
+	bool				queued_to_csi;
+};
+
+static struct sun6i_csi_format *
+find_format_by_pixformat(struct sun6i_video *video, unsigned int pixformat)
+{
+	unsigned int num_formats = video->num_formats;
+	struct sun6i_csi_format *fmt;
+	unsigned int i;
+
+	for (i = 0; i < num_formats; i++) {
+		fmt = &video->formats[i];
+		if (fmt->pixformat == pixformat)
+			return fmt;
+	}
+
+	return NULL;
+}
+
+static struct v4l2_subdev *
+sun6i_video_remote_subdev(struct sun6i_video *video, u32 *pad)
+{
+	struct media_pad *remote;
+
+	remote = media_entity_remote_pad(&video->pad);
+
+	if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
+		return NULL;
+
+	if (pad)
+		*pad = remote->index;
+
+	return media_entity_to_v4l2_subdev(remote->entity);
+}
+
+static int sun6i_video_queue_setup(struct vb2_queue *vq,
+				 unsigned int *nbuffers, unsigned int *nplanes,
+				 unsigned int sizes[],
+				 struct device *alloc_devs[])
+{
+	struct sun6i_video *video = vb2_get_drv_priv(vq);
+	unsigned int size = video->fmt.fmt.pix.sizeimage;
+
+	if (*nplanes)
+		return sizes[0] < size ? -EINVAL : 0;
+
+	*nplanes = 1;
+	sizes[0] = size;
+
+	return 0;
+}
+
+static int sun6i_video_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct sun6i_csi_buffer *buf =
+			container_of(vbuf, struct sun6i_csi_buffer, vb);
+	struct sun6i_video *video = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long size = video->fmt.fmt.pix.sizeimage;
+
+	if (vb2_plane_size(vb, 0) < size) {
+		v4l2_err(video->vdev.v4l2_dev, "buffer too small (%lu < %lu)\n",
+			 vb2_plane_size(vb, 0), size);
+		return -EINVAL;
+	}
+
+	vb2_set_plane_payload(vb, 0, size);
+
+	buf->dma_addr = vb2_dma_contig_plane_dma_addr(vb, 0);
+
+	vbuf->field = video->fmt.fmt.pix.field;
+
+	return 0;
+}
+
+static int sun6i_pipeline_set_stream(struct sun6i_video *video, bool enable)
+{
+	struct media_entity *entity;
+	struct media_pad *pad;
+	struct v4l2_subdev *subdev;
+	int ret;
+
+	entity = &video->vdev.entity;
+	while (1) {
+		pad = &entity->pads[0];
+		if (!(pad->flags & MEDIA_PAD_FL_SINK))
+			break;
+
+		pad = media_entity_remote_pad(pad);
+		if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
+			break;
+
+		entity = pad->entity;
+		subdev = media_entity_to_v4l2_subdev(entity);
+
+		ret = v4l2_subdev_call(subdev, video, s_stream, enable);
+		if (enable && ret < 0 && ret != -ENOIOCTLCMD)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int sun6i_video_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct sun6i_video *video = vb2_get_drv_priv(vq);
+	struct sun6i_csi_buffer *buf;
+	struct sun6i_csi_buffer *next_buf;
+	struct sun6i_csi_config config;
+	unsigned long flags;
+	int ret;
+
+	video->sequence = 0;
+
+	if (!video->current_fmt)
+		return -ENXIO;
+
+	ret = media_pipeline_start(&video->vdev.entity, &video->vdev.pipe);
+	if (ret < 0)
+		goto clear_dma_queue;
+
+	config.pixelformat = video->fmt.fmt.pix.pixelformat;
+	config.code = video->current_fmt->mbus_code;
+	config.field = video->fmt.fmt.pix.field;
+	config.width = video->fmt.fmt.pix.width;
+	config.height = video->fmt.fmt.pix.height;
+
+	ret = sun6i_csi_update_config(video->csi, &config);
+	if (ret < 0)
+		goto stop_media_pipeline;
+
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+
+	buf = list_first_entry(&video->dma_queue,
+			       struct sun6i_csi_buffer, list);
+	buf->queued_to_csi = true;
+	sun6i_csi_update_buf_addr(video->csi, buf->dma_addr);
+
+	sun6i_csi_set_stream(video->csi, true);
+
+	/*
+	 * CSI will lookup the next dma buffer for next frame before the
+	 * the current frame done IRQ triggered. This is not documented
+	 * but reported by Ondřej Jirman.
+	 * The BSP code has workaround for this too. It skip to mark the
+	 * first buffer as frame done for VB2 and pass the second buffer
+	 * to CSI in the first frame done ISR call. Then in second frame
+	 * done ISR call, it mark the first buffer as frame done for VB2
+	 * and pass the third buffer to CSI. And so on. The bad thing is
+	 * that the first buffer will be written twice and the first frame
+	 * is dropped even the queued buffer is sufficient.
+	 * So, I make some improvement here. Pass the next buffer to CSI
+	 * just follow starting the CSI. In this case, the first frame
+	 * will be stored in first buffer, second frame in second buffer.
+	 * This method is used to avoid dropping the first frame, it
+	 * would also drop frame when lacking of queued buffer.
+	 */
+	next_buf = list_next_entry(buf, list);
+	next_buf->queued_to_csi = true;
+	sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
+
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+
+	ret = sun6i_pipeline_set_stream(video, true);
+	if (ret < 0)
+		goto stop_csi_stream;
+
+	return 0;
+
+stop_csi_stream:
+	sun6i_csi_set_stream(video->csi, false);
+stop_media_pipeline:
+	media_pipeline_stop(&video->vdev.entity);
+clear_dma_queue:
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+	list_for_each_entry(buf, &video->dma_queue, list)
+		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
+	INIT_LIST_HEAD(&video->dma_queue);
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+
+	return ret;
+}
+
+static void sun6i_video_stop_streaming(struct vb2_queue *vq)
+{
+	struct sun6i_video *video = vb2_get_drv_priv(vq);
+	unsigned long flags;
+	struct sun6i_csi_buffer *buf;
+
+	sun6i_pipeline_set_stream(video, false);
+
+	sun6i_csi_set_stream(video->csi, false);
+
+	media_pipeline_stop(&video->vdev.entity);
+
+	/* Release all active buffers */
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+	list_for_each_entry(buf, &video->dma_queue, list)
+		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+	INIT_LIST_HEAD(&video->dma_queue);
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+}
+
+static void sun6i_video_buffer_queue(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct sun6i_csi_buffer *buf =
+			container_of(vbuf, struct sun6i_csi_buffer, vb);
+	struct sun6i_video *video = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long flags;
+
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+	buf->queued_to_csi = false;
+	list_add_tail(&buf->list, &video->dma_queue);
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+}
+
+void sun6i_video_frame_done(struct sun6i_video *video)
+{
+	struct sun6i_csi_buffer *buf;
+	struct sun6i_csi_buffer *next_buf;
+	struct vb2_v4l2_buffer *vbuf;
+
+	spin_lock(&video->dma_queue_lock);
+
+	buf = list_first_entry(&video->dma_queue,
+			       struct sun6i_csi_buffer, list);
+	if (list_is_last(&buf->list, &video->dma_queue)) {
+		dev_dbg(video->csi->dev, "Frame droped!\n");
+		goto unlock;
+	}
+
+	next_buf = list_next_entry(buf, list);
+	/* If a new buffer (#next_buf) had not been queued to CSI, the old
+	 * buffer (#buf) is still holding by CSI for storing the next
+	 * frame. So, we queue a new buffer (#next_buf) to CSI then wait
+	 * for next ISR call.
+	 */
+	if (!next_buf->queued_to_csi) {
+		next_buf->queued_to_csi = true;
+		sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
+		dev_dbg(video->csi->dev, "Frame droped!\n");
+		goto unlock;
+	}
+
+	list_del(&buf->list);
+	vbuf = &buf->vb;
+	vbuf->vb2_buf.timestamp = ktime_get_ns();
+	vbuf->sequence = video->sequence;
+	vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_DONE);
+
+	/* Prepare buffer for next frame but one.  */
+	if (!list_is_last(&next_buf->list, &video->dma_queue)) {
+		next_buf = list_next_entry(next_buf, list);
+		next_buf->queued_to_csi = true;
+		sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
+	} else {
+		dev_dbg(video->csi->dev, "Next frame will be dropped!\n");
+	}
+
+unlock:
+	video->sequence++;
+	spin_unlock(&video->dma_queue_lock);
+}
+
+static const struct vb2_ops sun6i_csi_vb2_ops = {
+	.queue_setup		= sun6i_video_queue_setup,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+	.buf_prepare		= sun6i_video_buffer_prepare,
+	.start_streaming	= sun6i_video_start_streaming,
+	.stop_streaming		= sun6i_video_stop_streaming,
+	.buf_queue		= sun6i_video_buffer_queue,
+};
+
+static int vidioc_querycap(struct file *file, void *priv,
+				struct v4l2_capability *cap)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	strlcpy(cap->driver, "sun6i-video", sizeof(cap->driver));
+	strlcpy(cap->card, video->vdev.name, sizeof(cap->card));
+	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
+		 video->csi->dev->of_node->name);
+
+	return 0;
+}
+
+static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
+				   struct v4l2_fmtdesc *f)
+{
+	struct sun6i_video *video = video_drvdata(file);
+	u32 index = f->index;
+
+	if (index >= video->num_formats)
+		return -EINVAL;
+
+	f->pixelformat = video->formats[index].pixformat;
+
+	return 0;
+}
+
+static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *fmt)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	*fmt = video->fmt;
+
+	return 0;
+}
+
+
+static int sun6i_video_try_fmt_source(struct sun6i_video *video,
+				      u32 which,
+				      struct v4l2_pix_format *pixfmt,
+				      struct sun6i_csi_format *csi_fmt)
+{
+	struct v4l2_subdev *subdev;
+	struct v4l2_subdev_pad_config *pad_cfg;
+	struct v4l2_subdev_format format = {
+		.which = which,
+	};
+	u32 pad;
+	int ret;
+
+	subdev = sun6i_video_remote_subdev(video, &pad);
+	if (subdev == NULL)
+		return -ENXIO;
+
+	v4l2_fill_mbus_format(&format.format, pixfmt, csi_fmt->mbus_code);
+
+	pad_cfg = v4l2_subdev_alloc_pad_config(subdev);
+	if (pad_cfg == NULL)
+		return -ENOMEM;
+
+	format.pad = pad;
+	ret = v4l2_subdev_call(subdev, pad, set_fmt, pad_cfg, &format);
+	if (ret)
+		goto done;
+
+	v4l2_fill_pix_format(pixfmt, &format.format);
+
+done:
+	v4l2_subdev_free_pad_config(pad_cfg);
+	return ret;
+}
+
+static int sun6i_video_try_fmt(struct sun6i_video *video, u32 which,
+			       struct v4l2_format *f,
+			       struct sun6i_csi_format **current_fmt)
+{
+	struct sun6i_csi_format *csi_fmt;
+	struct v4l2_pix_format *pixfmt = &f->fmt.pix;
+	int ret;
+
+	csi_fmt = find_format_by_pixformat(video, pixfmt->pixelformat);
+	if (csi_fmt == NULL) {
+		if (video->num_formats > 0) {
+			csi_fmt = &video->formats[0];
+			pixfmt->pixelformat = csi_fmt->pixformat;
+		} else
+			return -EINVAL;
+	}
+
+	ret = sun6i_video_try_fmt_source(video, which, pixfmt, csi_fmt);
+	if (ret)
+		return ret;
+
+	pixfmt->bytesperline = (pixfmt->width * csi_fmt->bpp) >> 3;
+	pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
+
+	if (current_fmt)
+		*current_fmt = csi_fmt;
+
+	return 0;
+}
+
+static int sun6i_video_set_fmt(struct sun6i_video *video, struct v4l2_format *f)
+{
+	struct sun6i_csi_format *current_fmt;
+	int ret;
+
+	ret = sun6i_video_try_fmt(video, V4L2_SUBDEV_FORMAT_ACTIVE, f,
+				  &current_fmt);
+	if (ret)
+		return ret;
+
+	video->fmt = *f;
+	video->current_fmt = current_fmt;
+
+	return 0;
+}
+
+static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	if (vb2_is_busy(&video->vb2_vidq))
+		return -EBUSY;
+
+	return sun6i_video_set_fmt(video, f);
+}
+
+static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
+				  struct v4l2_format *f)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	return sun6i_video_try_fmt(video, V4L2_SUBDEV_FORMAT_TRY, f, NULL);
+}
+
+static int vidioc_enum_input(struct file *file, void *fh,
+			 struct v4l2_input *inp)
+{
+	struct sun6i_video *video = video_drvdata(file);
+	struct v4l2_subdev *subdev;
+	u32 pad;
+	int ret;
+
+	if (inp->index != 0)
+		return -EINVAL;
+
+	subdev = sun6i_video_remote_subdev(video, &pad);
+	if (subdev == NULL)
+		return -ENXIO;
+
+	ret = v4l2_subdev_call(subdev, video, g_input_status, &inp->status);
+	if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV)
+		return ret;
+
+	inp->type = 0;
+
+	inp->capabilities = 0;
+	inp->std = 0;
+	if (v4l2_subdev_has_op(subdev, pad, dv_timings_cap))
+		inp->capabilities = V4L2_IN_CAP_DV_TIMINGS;
+
+	strlcpy(inp->name, subdev->name, sizeof(inp->name));
+
+	return 0;
+}
+
+static int vidioc_g_input(struct file *file, void *fh, unsigned int *i)
+{
+	*i = 0;
+
+	return 0;
+}
+
+static int vidioc_s_input(struct file *file, void *fh, unsigned int i)
+{
+	if (i != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops sun6i_video_ioctl_ops = {
+	.vidioc_querycap		= vidioc_querycap,
+	.vidioc_enum_fmt_vid_cap	= vidioc_enum_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap		= vidioc_g_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap		= vidioc_s_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap		= vidioc_try_fmt_vid_cap,
+
+	.vidioc_enum_input		= vidioc_enum_input,
+	.vidioc_s_input			= vidioc_s_input,
+	.vidioc_g_input			= vidioc_g_input,
+
+	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
+	.vidioc_querybuf		= vb2_ioctl_querybuf,
+	.vidioc_qbuf			= vb2_ioctl_qbuf,
+	.vidioc_expbuf			= vb2_ioctl_expbuf,
+	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
+	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
+	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
+	.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,
+
+};
+
+/* -----------------------------------------------------------------------------
+ * V4L2 file operations
+ */
+static int sun6i_video_open(struct file *file)
+{
+	struct sun6i_video *video = video_drvdata(file);
+	int ret;
+
+	if (mutex_lock_interruptible(&video->lock))
+		return -ERESTARTSYS;
+
+	ret = v4l2_fh_open(file);
+	if (ret < 0)
+		goto unlock;
+
+	ret = v4l2_pipeline_pm_use(&video->vdev.entity, 1);
+	if (ret < 0)
+		goto fh_release;
+
+	/* check if already powered */
+	if (!v4l2_fh_is_singular_file(file))
+		goto unlock;
+
+	ret = sun6i_csi_set_power(video->csi, true);
+	if (ret < 0)
+		goto fh_release;
+
+	mutex_unlock(&video->lock);
+	return 0;
+
+fh_release:
+	v4l2_fh_release(file);
+unlock:
+	mutex_unlock(&video->lock);
+	return ret;
+}
+
+static int sun6i_video_close(struct file *file)
+{
+	struct sun6i_video *video = video_drvdata(file);
+	bool last_fh;
+
+	mutex_lock(&video->lock);
+
+	last_fh = v4l2_fh_is_singular_file(file);
+
+	_vb2_fop_release(file, NULL);
+
+	v4l2_pipeline_pm_use(&video->vdev.entity, 0);
+
+	if (last_fh)
+		sun6i_csi_set_power(video->csi, false);
+
+	mutex_unlock(&video->lock);
+
+	return 0;
+}
+
+static const struct v4l2_file_operations sun6i_video_fops = {
+	.owner		= THIS_MODULE,
+	.open		= sun6i_video_open,
+	.release	= sun6i_video_close,
+	.unlocked_ioctl	= video_ioctl2,
+	.mmap		= vb2_fop_mmap,
+	.poll		= vb2_fop_poll
+};
+
+/* -----------------------------------------------------------------------------
+ * Media Operations
+ */
+static int sun6i_video_formats_init(struct sun6i_video *video,
+				    const struct media_pad *remote)
+{
+	struct v4l2_subdev_mbus_code_enum mbus_code = { 0 };
+	struct sun6i_csi *csi = video->csi;
+	struct v4l2_format format;
+	struct v4l2_subdev *subdev;
+	u32 pad;
+	const u32 *pixformats;
+	int pixformat_count = 0;
+	u32 subdev_codes[32]; /* subdev format codes, 32 should be enough */
+	int codes_count = 0;
+	int num_fmts = 0;
+	int i, j;
+
+	pad = remote->index;
+	subdev = media_entity_to_v4l2_subdev(remote->entity);
+	if (subdev == NULL)
+		return -ENXIO;
+
+	/* Get supported pixformats of CSI */
+	pixformat_count = sun6i_csi_get_supported_pixformats(csi, &pixformats);
+	if (pixformat_count <= 0)
+		return -ENXIO;
+
+	/* Get subdev formats codes */
+	mbus_code.pad = pad;
+	mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
+	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL,
+				 &mbus_code)) {
+		if (codes_count >= ARRAY_SIZE(subdev_codes)) {
+			dev_warn(video->csi->dev,
+				 "subdev_codes array is full!\n");
+			break;
+		}
+		subdev_codes[codes_count] = mbus_code.code;
+		codes_count++;
+		mbus_code.index++;
+	}
+
+	if (!codes_count)
+		return -ENXIO;
+
+	/* Get supported formats count */
+	for (i = 0; i < codes_count; i++) {
+		for (j = 0; j < pixformat_count; j++) {
+			if (!sun6i_csi_is_format_supported(csi, pixformats[j],
+					subdev_codes[i])) {
+				continue;
+			}
+			num_fmts++;
+		}
+	}
+
+	if (!num_fmts)
+		return -ENXIO;
+
+	video->num_formats = num_fmts;
+	video->formats = devm_kcalloc(video->csi->dev, num_fmts,
+			sizeof(struct sun6i_csi_format), GFP_KERNEL);
+	if (!video->formats)
+		return -ENOMEM;
+
+	/* Get supported formats */
+	num_fmts = 0;
+	for (i = 0; i < codes_count; i++) {
+		for (j = 0; j < pixformat_count; j++) {
+			if (!sun6i_csi_is_format_supported(csi, pixformats[j],
+					subdev_codes[i])) {
+				continue;
+			}
+
+			video->formats[num_fmts].pixformat = pixformats[j];
+			video->formats[num_fmts].mbus_code = subdev_codes[i];
+			video->formats[num_fmts].bpp =
+					sun6i_csi_get_bpp(pixformats[j]);
+			num_fmts++;
+		}
+	}
+
+	/* setup default format */
+	format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	format.fmt.pix.width = 1280;
+	format.fmt.pix.height = 720;
+	format.fmt.pix.pixelformat = video->formats[0].pixformat;
+	sun6i_video_set_fmt(video, &format);
+
+	return 0;
+}
+
+static int sun6i_video_link_setup(struct media_entity *entity,
+				  const struct media_pad *local,
+				  const struct media_pad *remote, u32 flags)
+{
+	struct video_device *vdev = media_entity_to_video_device(entity);
+	struct sun6i_video *video = video_get_drvdata(vdev);
+
+	if (WARN_ON(video == NULL))
+		return 0;
+
+	if ((flags & MEDIA_LNK_FL_ENABLED) == 0)
+		return 0;
+
+	return sun6i_video_formats_init(video, remote);
+}
+
+static const struct media_entity_operations sun6i_video_media_ops = {
+	.link_setup = sun6i_video_link_setup,
+};
+
+int sun6i_video_init(struct sun6i_video *video, struct sun6i_csi *csi,
+		     const char *name)
+{
+	struct video_device *vdev = &video->vdev;
+	struct vb2_queue *vidq = &video->vb2_vidq;
+	int ret;
+
+	video->csi = csi;
+
+	/* Initialize the media entity... */
+	video->pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
+	vdev->entity.ops = &sun6i_video_media_ops;
+	ret = media_entity_pads_init(&vdev->entity, 1, &video->pad);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&video->lock);
+
+	INIT_LIST_HEAD(&video->dma_queue);
+	spin_lock_init(&video->dma_queue_lock);
+
+	video->sequence = 0;
+	video->num_formats = 0;
+
+	/* Initialize videobuf2 queue */
+	vidq->type			= V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	vidq->io_modes			= VB2_MMAP | VB2_DMABUF;
+	vidq->drv_priv			= video;
+	vidq->buf_struct_size		= sizeof(struct sun6i_csi_buffer);
+	vidq->ops			= &sun6i_csi_vb2_ops;
+	vidq->mem_ops			= &vb2_dma_contig_memops;
+	vidq->timestamp_flags		= V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	vidq->lock			= &video->lock;
+	/* Make sure non-dropped frame */
+	vidq->min_buffers_needed	= 3;
+	vidq->dev			= csi->dev;
+
+	ret = vb2_queue_init(vidq);
+	if (ret) {
+		v4l2_err(&csi->v4l2_dev, "vb2_queue_init failed: %d\n", ret);
+		goto error;
+	}
+
+	/* Register video device */
+	strlcpy(vdev->name, name, sizeof(vdev->name));
+	vdev->release		= video_device_release_empty;
+	vdev->fops		= &sun6i_video_fops;
+	vdev->ioctl_ops		= &sun6i_video_ioctl_ops;
+	vdev->vfl_type		= VFL_TYPE_GRABBER;
+	vdev->vfl_dir		= VFL_DIR_RX;
+	vdev->v4l2_dev		= &csi->v4l2_dev;
+	vdev->queue		= vidq;
+	vdev->lock		= &video->lock;
+	vdev->device_caps	= V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_CAPTURE;
+	video_set_drvdata(vdev, video);
+
+	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
+	if (ret < 0) {
+		v4l2_err(&csi->v4l2_dev,
+			 "video_register_device failed: %d\n", ret);
+		goto error;
+	}
+
+	return 0;
+
+error:
+	sun6i_video_cleanup(video);
+	return ret;
+}
+
+void sun6i_video_cleanup(struct sun6i_video *video)
+{
+	if (video_is_registered(&video->vdev))
+		video_unregister_device(&video->vdev);
+
+	media_entity_cleanup(&video->vdev.entity);
+}
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h
new file mode 100644
index 000000000000..2301f184c986
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h
@@ -0,0 +1,53 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <[e-mail]>
+ */
+
+#ifndef __SUN6I_VIDEO_H__
+#define __SUN6I_VIDEO_H__
+
+#include <media/v4l2-dev.h>
+#include <media/videobuf2-core.h>
+
+/*
+ * struct sun6i_csi_format - CSI media bus format information
+ * @pixformat: V4l2 pixformat for this format
+ * @mbus_code: V4L2 media bus format code.
+ * @bpp: Bytes per pixel (when stored in memory)
+ */
+struct sun6i_csi_format {
+	u32				pixformat;
+	u32				mbus_code;
+	u8				bpp;
+};
+
+struct sun6i_csi;
+
+struct sun6i_video {
+	struct video_device		vdev;
+	struct media_pad		pad;
+	struct sun6i_csi		*csi;
+
+	struct mutex			lock;
+
+	struct vb2_queue		vb2_vidq;
+	spinlock_t			dma_queue_lock;
+	struct list_head		dma_queue;
+
+	unsigned int			sequence;
+
+	struct sun6i_csi_format		*formats;
+	unsigned int			num_formats;
+	struct sun6i_csi_format		*current_fmt;
+	struct v4l2_format		fmt;
+};
+
+int sun6i_video_init(struct sun6i_video *video, struct sun6i_csi *csi,
+		     const char *name);
+void sun6i_video_cleanup(struct sun6i_video *video);
+
+void sun6i_video_frame_done(struct sun6i_video *video);
+
+#endif /* __SUN6I_VIDEO_H__ */