Add support for SMSC UFX6000/7000 USB display adapters

Commit Message

Steve Glendinning Aug. 12, 2011, 12:07 p.m. UTC

This patch adds framebuffer suport for SMSC's UFX6000 (USB 2.0) and
UFX7000 (USB 3.0) display adapters.

Signed-off-by: Steve Glendinning <[e-mail]>
---
 MAINTAINERS             |    6 +
 drivers/video/Kconfig   |   16 +
 drivers/video/Makefile  |    1 +
 drivers/video/smscufx.c | 2009 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 2032 insertions(+), 0 deletions(-)
 create mode 100644 drivers/video/smscufx.c

Comments

Greg Kroah-Hartman Aug. 12, 2011, 3:56 p.m. UTC | #1

On Fri, Aug 12, 2011 at 01:07:03PM +0100, Steve Glendinning wrote:
> This patch adds framebuffer suport for SMSC's UFX6000 (USB 2.0) and
> UFX7000 (USB 3.0) display adapters.
> 
> Signed-off-by: Steve Glendinning <[e-mail]>

Very nice job, I only have one very minor suggestion for this code from
a USB/driver core standpoint (I can't verify that the framebuffer api is
being used properly as I don't know that at all.):

> +/* sets analog bit PLL configuration values */
> +static int ufx_config_pix_clk(struct ufx_data *dev, u32 pixclock)
> +{
> +	struct pll_values asic_pll = {0};
> +	u32 value, clk_pixel, clk_pixel_pll;
> +	int status;
> +
> +	/* convert pixclock (in ps) to frequency (in Hz) */
> +	clk_pixel = PICOS2KHZ(pixclock) * 1000;
> +	pr_info("pixclock %d ps = clk_pixel %d Hz", pixclock, clk_pixel);

Use call pr_info() a bunch, (especially in your probe() call chain)
which will get noisy in the kernel log.  How about using dev_dbg()
instead, which allows you to dynamically turn on/off messages like this,
and it provides the needed information so that the reader of the
messages can tell exactly which device is sending the messages (very
helpful when you attach more than one.)

You can do the same for your calls to pr_debug() and other pr_* calls.
If you note in the header file for those functions, it suggests that
drivers should always call the dev_* versions instead of teh "raw" pr_*
functions, as you do have access to a struct device within your driver.

thanks,

greg k-h
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Greg Kroah-Hartman Aug. 12, 2011, 7:34 p.m. UTC | #2

On Fri, Aug 12, 2011 at 12:06:55PM -0700, Bernie Thompson wrote:
> On Fri, Aug 12, 2011 at 8:56 AM, Greg KH <[e-mail]> wrote:
> 
>     You can do the same for your calls to pr_debug() and other pr_* calls.
>     If you note in the header file for those functions, it suggests that
>     drivers should always call the dev_* versions instead of teh "raw" pr_*
>     functions, as you do have access to a struct device within your driver.
> 
> 
> A little background from udlfb: we weren't able to stick with dev_* calls 100%,
> because udlfb needed to survive USB device removal and the freeing of the
> USB-initiated device structure. This is because the framebuffer device needed
> to outlive it if a client was holding on to it.  In other words, it's born a
> two-headed beast (usb and fbdev), but the two faces of the device are killed
> off independently based on remaining ref counts.  So there are prints in there
> which will fault if converted to dev_* without this in mind.
> 
> Because of this, we had originally created our own dl_* wrapper around the pr_
> macros.
> 
> Then a later patch initiated by Paul (fbdev maintainer) changed those to
> uncustomized pr_ macros with a goal of uniformity with other drivers.  And that
> code is what SMSC started from.
> 
> So there's some complexity behind the choices here.  It might be good to keep
> common strategies between udlfb and smsc's driver, as the issues to consider
> are the same.

Ok, thanks for the background information, that makes sense.

But for stuff like the usb probe() call, that should always be dev_* as
you really do have a proper pointer.  So when you do have a valid struct
device, you should use it.

Although a lot of the pr_info() calls should be downgraded to pr_debug()
I imagine, to keep things from being so noisy.

thanks,

greg k-h
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Florian Tobias Schandinat Aug. 16, 2011, 10:17 a.m. UTC | #3

Hi,

On 08/12/2011 12:07 PM, Steve Glendinning wrote:
> This patch adds framebuffer suport for SMSC's UFX6000 (USB 2.0) and
> UFX7000 (USB 3.0) display adapters.
> 
> Signed-off-by: Steve Glendinning <[e-mail]>
> ---
>  MAINTAINERS             |    6 +
>  drivers/video/Kconfig   |   16 +
>  drivers/video/Makefile  |    1 +
>  drivers/video/smscufx.c | 2009 +++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 2032 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/video/smscufx.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1e55e1e..80d5555 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5920,6 +5920,12 @@ L:	[e-mail]
>  S:	Supported
>  F:	drivers/net/smsc9420.*
>  
> +SMSC UFX6000 and UFX7000 USB to VGA DRIVER
> +M:	Steve Glendinning <[e-mail]>
> +L:	[e-mail]
> +S:	Supported
> +F:	drivers/video/smscufx.c
> +
>  SN-IA64 (Itanium) SUB-PLATFORM
>  M:	Jes Sorensen <[e-mail]>
>  L:	[e-mail]
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> index 549b960..8bfb387 100644
> --- a/drivers/video/Kconfig
> +++ b/drivers/video/Kconfig
> @@ -2110,6 +2110,22 @@ config FB_SM501
>  
>  	  If unsure, say N.
>  
> +config FB_SMSCUFX
> +	tristate "SMSC UFX6000/7000 USB Framebuffer support"
> +	depends on FB && USB
> +	select FB_MODE_HELPERS
> +	select FB_SYS_FILLRECT
> +	select FB_SYS_COPYAREA
> +	select FB_SYS_IMAGEBLIT
> +	select FB_SYS_FOPS
> +	select FB_DEFERRED_IO
> +	---help---
> +	  This is a kernel framebuffer driver for SMSC UFX USB devices.
> +	  Supports fbdev clients like xf86-video-fbdev, kdrive, fbi, and
> +	  mplayer -vo fbdev. Supports both UFX6000 (USB 2.0) and UFX7000
> +	  (USB 3.0) devices.
> +	  To compile as a module, choose M here: the module name is smscufx.
> +
>  config FB_UDL
>  	tristate "Displaylink USB Framebuffer support"
>  	depends on FB && USB
> diff --git a/drivers/video/Makefile b/drivers/video/Makefile
> index 8b83129..f3546ec 100644
> --- a/drivers/video/Makefile
> +++ b/drivers/video/Makefile
> @@ -127,6 +127,7 @@ obj-$(CONFIG_FB_IBM_GXT4500)	  += gxt4500.o
>  obj-$(CONFIG_FB_PS3)		  += ps3fb.o
>  obj-$(CONFIG_FB_SM501)            += sm501fb.o
>  obj-$(CONFIG_FB_UDL)		  += udlfb.o
> +obj-$(CONFIG_FB_SMSCUFX)	  += smscufx.o
>  obj-$(CONFIG_FB_XILINX)           += xilinxfb.o
>  obj-$(CONFIG_SH_MIPI_DSI)	  += sh_mipi_dsi.o
>  obj-$(CONFIG_FB_SH_MOBILE_HDMI)	  += sh_mobile_hdmi.o
> diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
> new file mode 100644
> index 0000000..2d1a7b2
> --- /dev/null
> +++ b/drivers/video/smscufx.c
> @@ -0,0 +1,2009 @@
> +/*
> + * smscufx.c -- Framebuffer driver for SMSC UFX USB controller
> + *
> + * Copyright (C) 2011 Steve Glendinning <[e-mail]>
> + * Copyright (C) 2009 Roberto De Ioris <[e-mail]>
> + * Copyright (C) 2009 Jaya Kumar <[e-mail]>
> + * Copyright (C) 2009 Bernie Thompson <[e-mail]>
> + *
> + * This file is subject to the terms and conditions of the GNU General Public
> + * License v2. See the file COPYING in the main directory of this archive for
> + * more details.
> + *
> + * Based on udlfb, with work from Florian Echtler, Henrik Bjerregaard Pedersen,
> + * and others.
> + *
> + * Works well with Bernie Thompson's X DAMAGE patch to xf86-video-fbdev
> + * available from http://git.plugable.com
> + *
> + * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
> + * usb-skeleton by GregKH.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/usb.h>
> +#include <linux/uaccess.h>
> +#include <linux/mm.h>
> +#include <linux/fb.h>
> +#include <linux/vmalloc.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include "edid.h"
> +
> +#define check_warn(status, fmt, args...) \
> +	({ if (status < 0) pr_warn(fmt, ##args); })
> +
> +#define check_warn_return(status, fmt, args...) \
> +	({ if (status < 0) { pr_warn(fmt, ##args); return status; } })
> +
> +#define check_warn_goto_error(status, fmt, args...) \
> +	({ if (status < 0) { pr_warn(fmt, ##args); goto error; } })
> +
> +#define all_bits_set(x, bits) (((x) & (bits)) == (bits))
> +
> +#define USB_VENDOR_REQUEST_WRITE_REGISTER	0xA0
> +#define USB_VENDOR_REQUEST_READ_REGISTER	0xA1
> +
> +/*
> + * TODO: Propose standard fb.h ioctl for reporting damage,
> + * using _IOWR() and one of the existing area structs from fb.h
> + * Consider these ioctls deprecated, but they're still used by the
> + * DisplayLink X server as yet - need both to be modified in tandem
> + * when new ioctl(s) are ready.
> + */
> +#define UFX_IOCTL_RETURN_EDID	(0xAD)
> +#define UFX_IOCTL_REPORT_DAMAGE	(0xAA)

Why don't we solve this now? So what do you need?
An IOCTL, a struct like
struct dloarea {
	int x, y;
	int w, h;
};
and I don't think any of the existing structs in fb.h would fit. I'd just prefer
to have those int's replaced by something of known size, probably __u32 to make
it consistent with fb_var_screeninfo?
Maybe this should be also reported by the capability field that Laurent's API
extension will likely add.

> +
> +/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
> +#define BULK_SIZE		(512)
> +#define MAX_TRANSFER		(PAGE_SIZE*16 - BULK_SIZE)
> +#define WRITES_IN_FLIGHT	(4)
> +
> +#define GET_URB_TIMEOUT		(HZ)
> +#define FREE_URB_TIMEOUT	(HZ*2)
> +
> +#define BPP			2
> +
> +#define UFX_DEFIO_WRITE_DELAY	5 /* fb_deferred_io.delay in jiffies */
> +#define UFX_DEFIO_WRITE_DISABLE	(HZ*60) /* "disable" with long delay */
> +
> +struct dloarea {
> +	int x, y;
> +	int w, h;
> +};
> +
> +struct urb_node {
> +	struct list_head entry;
> +	struct ufx_data *dev;
> +	struct delayed_work release_urb_work;
> +	struct urb *urb;
> +};
> +
> +struct urb_list {
> +	struct list_head list;
> +	spinlock_t lock;
> +	struct semaphore limit_sem;
> +	int available;
> +	int count;
> +	size_t size;
> +};
> +
> +struct ufx_data {
> +	struct usb_device *udev;
> +	struct device *gdev; /* &udev->dev */
> +	struct fb_info *info;
> +	struct urb_list urbs;
> +	struct kref kref;
> +	int fb_count;
> +	bool virtualized; /* true when physical usb device not present */
> +	struct delayed_work free_framebuffer_work;
> +	atomic_t usb_active; /* 0 = update virtual buffer, but no usb traffic */
> +	atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */
> +	char *edid; /* null until we read edid from hw or get from sysfs */
> +	size_t edid_size;
> +	u32 pseudo_palette[256];
> +};
> +
> +static struct fb_fix_screeninfo ufx_fix = {
> +	.id =           "smscufx",
> +	.type =         FB_TYPE_PACKED_PIXELS,
> +	.visual =       FB_VISUAL_TRUECOLOR,
> +	.xpanstep =     0,
> +	.ypanstep =     0,
> +	.ywrapstep =    0,
> +	.accel =        FB_ACCEL_NONE,
> +};
> +
> +static const u32 smscufx_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
> +	FBINFO_VIRTFB |	FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
> +	FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
> +
> +static struct usb_device_id id_table[] = {
> +	{USB_DEVICE(0x0424, 0x9d00),},
> +	{USB_DEVICE(0x0424, 0x9d01),},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(usb, id_table);
> +
> +/* module options */
> +static int console;   /* Optionally allow fbcon to consume first framebuffer */
> +static int fb_defio = true;  /* Optionally enable fb_defio mmap support */
> +
> +/* ufx keeps a list of urbs for efficient bulk transfers */
> +static void ufx_urb_completion(struct urb *urb);
> +static struct urb *ufx_get_urb(struct ufx_data *dev);
> +static int ufx_submit_urb(struct ufx_data *dev, struct urb * urb, size_t len);
> +static int ufx_alloc_urb_list(struct ufx_data *dev, int count, size_t size);
> +static void ufx_free_urb_list(struct ufx_data *dev);
> +
> +/* reads a control register */
> +static int ufx_reg_read(struct ufx_data *dev, u32 index, u32 *data)
> +{
> +	u32 *buf = kmalloc(4, GFP_KERNEL);
> +	int ret;
> +
> +	BUG_ON(!dev);
> +
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
> +		USB_VENDOR_REQUEST_READ_REGISTER,
> +		USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> +		00, index, buf, 4, USB_CTRL_GET_TIMEOUT);
> +
> +	le32_to_cpus(buf);
> +	*data = *buf;
> +	kfree(buf);
> +
> +	if (unlikely(ret < 0))
> +		pr_warn("Failed to read register index 0x%08x\n", index);
> +
> +	return ret;
> +}
> +
> +/* writes a control register */
> +static int ufx_reg_write(struct ufx_data *dev, u32 index, u32 data)
> +{
> +	u32 *buf = kmalloc(4, GFP_KERNEL);
> +	int ret;
> +
> +	BUG_ON(!dev);
> +
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	*buf = data;
> +	cpu_to_le32s(buf);
> +
> +	ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
> +		USB_VENDOR_REQUEST_WRITE_REGISTER,
> +		USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> +		00, index, buf, 4, USB_CTRL_SET_TIMEOUT);
> +
> +	kfree(buf);
> +
> +	if (unlikely(ret < 0))
> +		pr_warn("Failed to write register index 0x%08x with value "
> +			"0x%08x\n", index, data);
> +
> +	return ret;
> +}
> +
> +static int ufx_reg_clear_and_set_bits(struct ufx_data *dev, u32 index,
> +	u32 bits_to_clear, u32 bits_to_set)
> +{
> +	u32 data;
> +	int status = ufx_reg_read(dev, index, &data);
> +	check_warn_return(status, "ufx_reg_clear_and_set_bits error reading "
> +		"0x%x", index);
> +
> +	data &= (~bits_to_clear);
> +	data |= bits_to_set;
> +
> +	status = ufx_reg_write(dev, index, data);
> +	check_warn_return(status, "ufx_reg_clear_and_set_bits error writing "
> +		"0x%x", index);
> +
> +	return 0;
> +}
> +
> +static int ufx_reg_set_bits(struct ufx_data *dev, u32 index, u32 bits)
> +{
> +	return ufx_reg_clear_and_set_bits(dev, index, 0, bits);
> +}
> +
> +static int ufx_reg_clear_bits(struct ufx_data *dev, u32 index, u32 bits)
> +{
> +	return ufx_reg_clear_and_set_bits(dev, index, bits, 0);
> +}
> +
> +static int ufx_lite_reset(struct ufx_data *dev)
> +{
> +	int status;
> +	u32 value;
> +
> +	status = ufx_reg_write(dev, 0x3008, 0x00000001);
> +	check_warn_return(status, "ufx_lite_reset error writing 0x3008");
> +
> +	status = ufx_reg_read(dev, 0x3008, &value);
> +	check_warn_return(status, "ufx_lite_reset error reading 0x3008");
> +
> +	return (value == 0) ? 0 : -EIO;
> +}
> +
> +/* If display is unblanked, then blank it */
> +static int ufx_blank(struct ufx_data *dev, bool wait)
> +{
> +	u32 dc_ctrl, dc_sts;
> +	int i;
> +
> +	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +	check_warn_return(status, "ufx_blank error reading 0x2004");
> +
> +	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
> +	check_warn_return(status, "ufx_blank error reading 0x2000");
> +
> +	/* return success if display is already blanked */
> +	if ((dc_sts & 0x00000100) || (dc_ctrl & 0x00000100))
> +		return 0;
> +
> +	/* request the DC to blank the display */
> +	dc_ctrl |= 0x00000100;
> +	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
> +	check_warn_return(status, "ufx_blank error writing 0x2000");
> +
> +	/* return success immediately if we don't have to wait */
> +	if (!wait)
> +		return 0;
> +
> +	for (i = 0; i < 250; i++) {
> +		status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +		check_warn_return(status, "ufx_blank error reading 0x2004");
> +
> +		if (dc_sts & 0x00000100)
> +			return 0;
> +	}
> +
> +	/* timed out waiting for display to blank */
> +	return -EIO;
> +}
> +
> +/* If display is blanked, then unblank it */
> +static int ufx_unblank(struct ufx_data *dev, bool wait)
> +{
> +	u32 dc_ctrl, dc_sts;
> +	int i;
> +
> +	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +	check_warn_return(status, "ufx_unblank error reading 0x2004");
> +
> +	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
> +	check_warn_return(status, "ufx_unblank error reading 0x2000");
> +
> +	/* return success if display is already unblanked */
> +	if (((dc_sts & 0x00000100) == 0) || ((dc_ctrl & 0x00000100) == 0))
> +		return 0;
> +
> +	/* request the DC to unblank the display */
> +	dc_ctrl &= ~0x00000100;
> +	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
> +	check_warn_return(status, "ufx_unblank error writing 0x2000");
> +
> +	/* return success immediately if we don't have to wait */
> +	if (!wait)
> +		return 0;
> +
> +	for (i = 0; i < 250; i++) {
> +		status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +		check_warn_return(status, "ufx_unblank error reading 0x2004");
> +
> +		if ((dc_sts & 0x00000100) == 0)
> +			return 0;
> +	}
> +
> +	/* timed out waiting for display to unblank */
> +	return -EIO;
> +}
> +
> +/* If display is enabled, then disable it */
> +static int ufx_disable(struct ufx_data *dev, bool wait)
> +{
> +	u32 dc_ctrl, dc_sts;
> +	int i;
> +
> +	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +	check_warn_return(status, "ufx_disable error reading 0x2004");
> +
> +	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
> +	check_warn_return(status, "ufx_disable error reading 0x2000");
> +
> +	/* return success if display is already disabled */
> +	if (((dc_sts & 0x00000001) == 0) || ((dc_ctrl & 0x00000001) == 0))
> +		return 0;
> +
> +	/* request the DC to disable the display */
> +	dc_ctrl &= ~(0x00000001);
> +	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
> +	check_warn_return(status, "ufx_disable error writing 0x2000");
> +
> +	/* return success immediately if we don't have to wait */
> +	if (!wait)
> +		return 0;
> +
> +	for (i = 0; i < 250; i++) {
> +		status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +		check_warn_return(status, "ufx_disable error reading 0x2004");
> +
> +		if ((dc_sts & 0x00000001) == 0)
> +			return 0;
> +	}
> +
> +	/* timed out waiting for display to disable */
> +	return -EIO;
> +}
> +
> +/* If display is disabled, then enable it */
> +static int ufx_enable(struct ufx_data *dev, bool wait)
> +{
> +	u32 dc_ctrl, dc_sts;
> +	int i;
> +
> +	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +	check_warn_return(status, "ufx_enable error reading 0x2004");
> +
> +	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
> +	check_warn_return(status, "ufx_enable error reading 0x2000");
> +
> +	/* return success if display is already enabled */
> +	if ((dc_sts & 0x00000001) || (dc_ctrl & 0x00000001))
> +		return 0;
> +
> +	/* request the DC to enable the display */
> +	dc_ctrl |= 0x00000001;
> +	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
> +	check_warn_return(status, "ufx_enable error writing 0x2000");
> +
> +	/* return success immediately if we don't have to wait */
> +	if (!wait)
> +		return 0;
> +
> +	for (i = 0; i < 250; i++) {
> +		status = ufx_reg_read(dev, 0x2004, &dc_sts);
> +		check_warn_return(status, "ufx_enable error reading 0x2004");
> +
> +		if (dc_sts & 0x00000001)
> +			return 0;
> +	}
> +
> +	/* timed out waiting for display to enable */
> +	return -EIO;
> +}
> +
> +static int ufx_config_sys_clk(struct ufx_data *dev)
> +{
> +	int status = ufx_reg_write(dev, 0x700C, 0x8000000F);
> +	check_warn_return(status, "error writing 0x700C");
> +
> +	status = ufx_reg_write(dev, 0x7014, 0x0010024F);
> +	check_warn_return(status, "error writing 0x7014");
> +
> +	status = ufx_reg_write(dev, 0x7010, 0x00000000);
> +	check_warn_return(status, "error writing 0x7010");
> +
> +	status = ufx_reg_clear_bits(dev, 0x700C, 0x0000000A);
> +	check_warn_return(status, "error clearing PLL1 bypass in 0x700C");
> +	msleep(1);
> +
> +	status = ufx_reg_clear_bits(dev, 0x700C, 0x80000000);
> +	check_warn_return(status, "error clearing output gate in 0x700C");
> +
> +	return 0;
> +}
> +
> +static int ufx_config_ddr2(struct ufx_data *dev)
> +{
> +	int status, i = 0;
> +	u32 tmp;
> +
> +	status = ufx_reg_write(dev, 0x0004, 0x001F0F77);
> +	check_warn_return(status, "error writing 0x0004");
> +
> +	status = ufx_reg_write(dev, 0x0008, 0xFFF00000);
> +	check_warn_return(status, "error writing 0x0008");
> +
> +	status = ufx_reg_write(dev, 0x000C, 0x0FFF2222);
> +	check_warn_return(status, "error writing 0x000C");
> +
> +	status = ufx_reg_write(dev, 0x0010, 0x00030814);
> +	check_warn_return(status, "error writing 0x0010");
> +
> +	status = ufx_reg_write(dev, 0x0014, 0x00500019);
> +	check_warn_return(status, "error writing 0x0014");
> +
> +	status = ufx_reg_write(dev, 0x0018, 0x020D0F15);
> +	check_warn_return(status, "error writing 0x0018");
> +
> +	status = ufx_reg_write(dev, 0x001C, 0x02532305);
> +	check_warn_return(status, "error writing 0x001C");
> +
> +	status = ufx_reg_write(dev, 0x0020, 0x0B030905);
> +	check_warn_return(status, "error writing 0x0020");
> +
> +	status = ufx_reg_write(dev, 0x0024, 0x00000827);
> +	check_warn_return(status, "error writing 0x0024");
> +
> +	status = ufx_reg_write(dev, 0x0028, 0x00000000);
> +	check_warn_return(status, "error writing 0x0028");
> +
> +	status = ufx_reg_write(dev, 0x002C, 0x00000042);
> +	check_warn_return(status, "error writing 0x002C");
> +
> +	status = ufx_reg_write(dev, 0x0030, 0x09520000);
> +	check_warn_return(status, "error writing 0x0030");
> +
> +	status = ufx_reg_write(dev, 0x0034, 0x02223314);
> +	check_warn_return(status, "error writing 0x0034");
> +
> +	status = ufx_reg_write(dev, 0x0038, 0x00430043);
> +	check_warn_return(status, "error writing 0x0038");
> +
> +	status = ufx_reg_write(dev, 0x003C, 0xF00F000F);
> +	check_warn_return(status, "error writing 0x003C");
> +
> +	status = ufx_reg_write(dev, 0x0040, 0xF380F00F);
> +	check_warn_return(status, "error writing 0x0040");
> +
> +	status = ufx_reg_write(dev, 0x0044, 0xF00F0496);
> +	check_warn_return(status, "error writing 0x0044");
> +
> +	status = ufx_reg_write(dev, 0x0048, 0x03080406);
> +	check_warn_return(status, "error writing 0x0048");
> +
> +	status = ufx_reg_write(dev, 0x004C, 0x00001000);
> +	check_warn_return(status, "error writing 0x004C");
> +
> +	status = ufx_reg_write(dev, 0x005C, 0x00000007);
> +	check_warn_return(status, "error writing 0x005C");
> +
> +	status = ufx_reg_write(dev, 0x0100, 0x54F00012);
> +	check_warn_return(status, "error writing 0x0100");
> +
> +	status = ufx_reg_write(dev, 0x0104, 0x00004012);
> +	check_warn_return(status, "error writing 0x0104");
> +
> +	status = ufx_reg_write(dev, 0x0118, 0x40404040);
> +	check_warn_return(status, "error writing 0x0118");
> +
> +	status = ufx_reg_write(dev, 0x0000, 0x00000001);
> +	check_warn_return(status, "error writing 0x0000");

These are a lot of magic values above (including ufx_config_sys_clk). If they
have any useful meaning and are not just magic please document what they do to
allow others to understand it.

> +
> +	while (i++ < 500) {
> +		status = ufx_reg_read(dev, 0x0000, &tmp);
> +		check_warn_return(status, "error reading 0x0000");
> +
> +		if (all_bits_set(tmp, 0xC0000000))
> +			return 0;
> +	}
> +
> +	pr_err("DDR2 initialisation timed out, reg 0x0000=0x%08x", tmp);
> +	return -ETIMEDOUT;
> +}
> +
> +struct pll_values {
> +	u32 div_r0;
> +	u32 div_f0;
> +	u32 div_q0;
> +	u32 range0;
> +	u32 div_r1;
> +	u32 div_f1;
> +	u32 div_q1;
> +	u32 range1;
> +};
> +
> +static u32 ufx_calc_range(u32 ref_freq)
> +{
> +	if (ref_freq >= 88000000)
> +		return 7;
> +
> +	if (ref_freq >= 54000000)
> +		return 6;
> +
> +	if (ref_freq >= 34000000)
> +		return 5;
> +
> +	if (ref_freq >= 21000000)
> +		return 4;
> +
> +	if (ref_freq >= 13000000)
> +		return 3;
> +
> +	if (ref_freq >= 8000000)
> +		return 2;
> +
> +	return 1;
> +}
> +
> +/* calculates PLL divider settings for a desired target frequency */
> +static void ufx_calc_pll_values(const u32 clk_pixel_pll, struct pll_values *asic_pll)
> +{
> +	const u32 ref_clk = 25000000;
> +	u32 div_r0, div_f0, div_q0, div_r1, div_f1, div_q1;
> +	u32 min_error = clk_pixel_pll;
> +
> +	for (div_r0 = 1; div_r0 <= 32; div_r0++) {
> +		u32 ref_freq0 = ref_clk / div_r0;
> +		if (ref_freq0 < 5000000)
> +			break;
> +
> +		if (ref_freq0 > 200000000)
> +			continue;
> +
> +		for (div_f0 = 1; div_f0 <= 256; div_f0++) {
> +			u32 vco_freq0 = ref_freq0 * div_f0;
> +
> +			if (vco_freq0 < 350000000)
> +				continue;
> +
> +			if (vco_freq0 > 700000000)
> +				break;
> +
> +			for (div_q0 = 0; div_q0 < 7; div_q0++) {
> +				u32 pllout_freq0 = vco_freq0 / (1 << div_q0);
> +
> +				if (pllout_freq0 < 5000000)
> +					break;
> +
> +				if (pllout_freq0 > 200000000)
> +					continue;
> +
> +				for (div_r1 = 1; div_r1 <= 32; div_r1++) {
> +					u32 ref_freq1 = pllout_freq0 / div_r1;
> +
> +					if (ref_freq1 < 5000000)
> +						break;
> +
> +					for (div_f1 = 1; div_f1 <= 256; div_f1++) {
> +						u32 vco_freq1 = ref_freq1 * div_f1;
> +
> +						if (vco_freq1 < 350000000)
> +							continue;
> +
> +						if (vco_freq1 > 700000000)
> +							break;
> +
> +						for (div_q1 = 0; div_q1 < 7; div_q1++) {
> +							u32 pllout_freq1 = vco_freq1 / (1 << div_q1);
> +							int error = abs(pllout_freq1 - clk_pixel_pll);
> +
> +							if (pllout_freq1 < 5000000)
> +								break;
> +
> +							if (pllout_freq1 > 700000000)
> +								continue;
> +
> +							if (error < min_error) {
> +								min_error = error;
> +
> +								/* final returned value is equal to calculated value - 1
> +								 * because a value of 0 = divide by 1 */
> +								asic_pll->div_r0 = div_r0 - 1;
> +								asic_pll->div_f0 = div_f0 - 1;
> +								asic_pll->div_q0 = div_q0;
> +								asic_pll->div_r1 = div_r1 - 1;
> +								asic_pll->div_f1 = div_f1 - 1;
> +								asic_pll->div_q1 = div_q1;
> +
> +								asic_pll->range0 = ufx_calc_range(ref_freq0);
> +								asic_pll->range1 = ufx_calc_range(ref_freq1);
> +
> +								if (min_error == 0)
> +									return;

Ugh, 6 nested loops. It's good that you do the calculation of PLL vlaues so
transparent but isn't there a way to do it more efficient than trying all
possible combinations (in theory 2^32 if I calculated correct, probably much
less due to the breaks and continues). At least it would be an improvement, I
think, if you calculated the min and max value for each loop instead of relying
on break and continue.

> +							}
> +						}
> +					}
> +				}
> +			}
> +		}
> +	}
> +}
> +
> +/* sets analog bit PLL configuration values */
> +static int ufx_config_pix_clk(struct ufx_data *dev, u32 pixclock)
> +{
> +	struct pll_values asic_pll = {0};
> +	u32 value, clk_pixel, clk_pixel_pll;
> +	int status;
> +
> +	/* convert pixclock (in ps) to frequency (in Hz) */
> +	clk_pixel = PICOS2KHZ(pixclock) * 1000;
> +	pr_info("pixclock %d ps = clk_pixel %d Hz", pixclock, clk_pixel);
> +
> +	/* clk_pixel = 1/2 clk_pixel_pll */
> +	clk_pixel_pll = clk_pixel * 2;
> +
> +	ufx_calc_pll_values(clk_pixel_pll, &asic_pll);
> +
> +	/* Keep BYPASS and RESET signals asserted until configured */
> +	status = ufx_reg_write(dev, 0x7000, 0x8000000F);
> +	check_warn_return(status, "error writing 0x7000");
> +
> +	value = (asic_pll.div_f1 | (asic_pll.div_r1 << 8) |
> +		(asic_pll.div_q1 << 16) | (asic_pll.range1 << 20));
> +	status = ufx_reg_write(dev, 0x7008, value);
> +	check_warn_return(status, "error writing 0x7008");
> +
> +	value = (asic_pll.div_f0 | (asic_pll.div_r0 << 8) |
> +		(asic_pll.div_q0 << 16) | (asic_pll.range0 << 20));
> +	status = ufx_reg_write(dev, 0x7004, value);
> +	check_warn_return(status, "error writing 0x7004");
> +
> +	status = ufx_reg_clear_bits(dev, 0x7000, 0x00000005);
> +	check_warn_return(status,
> +		"error clearing PLL0 bypass bits in 0x7000");
> +	msleep(1);
> +
> +	status = ufx_reg_clear_bits(dev, 0x7000, 0x0000000A);
> +	check_warn_return(status,
> +		"error clearing PLL1 bypass bits in 0x7000");
> +	msleep(1);
> +
> +	status = ufx_reg_clear_bits(dev, 0x7000, 0x80000000);
> +	check_warn_return(status, "error clearing gate bits in 0x7000");
> +
> +	return 0;
> +}
> +
> +static int ufx_set_vid_mode(struct ufx_data *dev, struct fb_var_screeninfo *var)
> +{
> +	u32 temp;
> +	u16 h_total, h_active, h_blank_start, h_blank_end, h_sync_start, h_sync_end;
> +	u16 v_total, v_active, v_blank_start, v_blank_end, v_sync_start, v_sync_end;
> +
> +	int status = ufx_reg_write(dev, 0x8028, 0);
> +	check_warn_return(status, "ufx_set_vid_mode error disabling RGB pad");
> +
> +	status = ufx_reg_write(dev, 0x8024, 0);
> +	check_warn_return(status, "ufx_set_vid_mode error disabling VDAC");
> +
> +	/* shut everything down before changing timing */
> +	status = ufx_blank(dev, true);
> +	check_warn_return(status, "ufx_set_vid_mode error blanking display");
> +
> +	status = ufx_disable(dev, true);
> +	check_warn_return(status, "ufx_set_vid_mode error disabling display");
> +
> +	status = ufx_config_pix_clk(dev, var->pixclock);
> +	check_warn_return(status, "ufx_set_vid_mode error configuring pixclock");
> +
> +	status = ufx_reg_write(dev, 0x2000, 0x00000104);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2000");
> +
> +	/* set horizontal timings */
> +	h_total = var->xres + var->right_margin + var->hsync_len + var->left_margin;
> +	h_active = var->xres;
> +	h_blank_start = var->xres + var->right_margin;
> +	h_blank_end = var->xres + var->right_margin + var->hsync_len;
> +	h_sync_start = var->xres + var->right_margin;
> +	h_sync_end = var->xres + var->right_margin + var->hsync_len;
> +
> +	temp = ((h_total - 1) << 16) | (h_active - 1);
> +	status = ufx_reg_write(dev, 0x2008, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2008");
> +
> +	temp = ((h_blank_start - 1) << 16) | (h_blank_end - 1);
> +	status = ufx_reg_write(dev, 0x200C, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x200C");
> +
> +	temp = ((h_sync_start - 1) << 16) | (h_sync_end - 1);
> +	status = ufx_reg_write(dev, 0x2010, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2010");
> +
> +	/* set vertical timings */
> +	v_total = var->upper_margin + var->yres + var->lower_margin + var->vsync_len;
> +	v_active = var->yres;
> +	v_blank_start = var->yres + var->lower_margin;
> +	v_blank_end = var->yres + var->lower_margin + var->vsync_len;
> +	v_sync_start = var->yres + var->lower_margin;
> +	v_sync_end = var->yres + var->lower_margin + var->vsync_len;
> +
> +	temp = ((v_total - 1) << 16) | (v_active - 1);
> +	status = ufx_reg_write(dev, 0x2014, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2014");
> +
> +	temp = ((v_blank_start - 1) << 16) | (v_blank_end - 1);
> +	status = ufx_reg_write(dev, 0x2018, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2018");
> +
> +	temp = ((v_sync_start - 1) << 16) | (v_sync_end - 1);
> +	status = ufx_reg_write(dev, 0x201C, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x201C");
> +
> +	status = ufx_reg_write(dev, 0x2020, 0x00000000);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2020");
> +
> +	status = ufx_reg_write(dev, 0x2024, 0x00000000);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2024");
> +
> +	/* Set the frame length register (#pix * 2 bytes/pixel) */
> +	temp = var->xres * var->yres * 2;
> +	temp = (temp + 7) & (~0x7);
> +	status = ufx_reg_write(dev, 0x2028, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2028");
> +
> +	/* enable desired output interface & disable others */
> +	status = ufx_reg_write(dev, 0x2040, 0);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2040");
> +
> +	status = ufx_reg_write(dev, 0x2044, 0);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2044");
> +
> +	status = ufx_reg_write(dev, 0x2048, 0);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2048");
> +
> +	/* set the sync polarities & enable bit */
> +	temp = 0x00000001;
> +	if (var->sync & FB_SYNC_HOR_HIGH_ACT)
> +		temp |= 0x00000010;
> +
> +	if (var->sync & FB_SYNC_VERT_HIGH_ACT)
> +		temp |= 0x00000008;
> +
> +	status = ufx_reg_write(dev, 0x2040, temp);
> +	check_warn_return(status, "ufx_set_vid_mode error writing 0x2040");
> +
> +	/* start everything back up */
> +	status = ufx_enable(dev, true);
> +	check_warn_return(status, "ufx_set_vid_mode error enabling display");
> +
> +	/* Unblank the display */
> +	status = ufx_unblank(dev, true);
> +	check_warn_return(status, "ufx_set_vid_mode error unblanking display");
> +
> +	/* enable RGB pad */
> +	status = ufx_reg_write(dev, 0x8028, 0x00000003);
> +	check_warn_return(status, "ufx_set_vid_mode error enabling RGB pad");
> +
> +	/* enable VDAC */
> +	status = ufx_reg_write(dev, 0x8024, 0x00000007);
> +	check_warn_return(status, "ufx_set_vid_mode error enabling VDAC");
> +
> +	return 0;
> +}
> +
> +static int ufx_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
> +{
> +	unsigned long start = vma->vm_start;
> +	unsigned long size = vma->vm_end - vma->vm_start;
> +	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
> +	unsigned long page, pos;
> +
> +	if (offset + size > info->fix.smem_len)
> +		return -EINVAL;
> +
> +	pos = (unsigned long)info->fix.smem_start + offset;
> +
> +	pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
> +		  pos, size);
> +
> +	while (size > 0) {
> +		page = vmalloc_to_pfn((void *)pos);
> +		if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
> +			return -EAGAIN;
> +
> +		start += PAGE_SIZE;
> +		pos += PAGE_SIZE;
> +		if (size > PAGE_SIZE)
> +			size -= PAGE_SIZE;
> +		else
> +			size = 0;
> +	}
> +
> +	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
> +	return 0;
> +}
> +
> +static char *ufx_raw_rect(struct ufx_data *dev, char *cmd, int x, int y,
> +	int width, int height)
> +{
> +	size_t packed_line_len = ALIGN((width * 2), 4);
> +	size_t packed_rect_len = packed_line_len * height;
> +	int i;
> +
> +	BUG_ON(!dev);
> +	BUG_ON(!dev->info);
> +
> +	/* command word */
> +	*cmd = 0x01;
> +	cmd += 4;

That looks strange. You dereference a char* (1 byte) but add 4? So the 3 bytes
after the one written contain old data, maybe this is intentional, just asking.

> +
> +	/* length word */
> +	*((u32 *)cmd) = cpu_to_le32(packed_rect_len + 16);
> +	cmd += 4;
> +
> +	*((u16 *)cmd) = cpu_to_le16(x);
> +	cmd += 2;
> +
> +	*((u16 *)cmd) = cpu_to_le16(y);
> +	cmd += 2;
> +
> +	*((u16 *)cmd) = cpu_to_le16(width);
> +	cmd += 2;
> +
> +	*((u16 *)cmd) = cpu_to_le16(height);
> +	cmd += 2;
> +
> +	/* frame base address */
> +	*((u32 *)cmd) = cpu_to_le32(0 & 0xffffff80);
> +	cmd += 4;
> +
> +	/* color mode and horizontal resolution */
> +	*((u16 *)cmd) = cpu_to_le16(0x4000 | dev->info->var.xres);
> +	cmd += 2;
> +
> +	/* vertical resolution */
> +	*((u16 *)cmd) = cpu_to_le16(dev->info->var.yres);
> +	cmd += 2;

Isn't there a way to avoid this amount of casts and pointer increments?
I guess it could help if you used u16* as base type and then
*((u32*)&cmd[2]) =
cmd[4] =
cmd[5] =

> +
> +	/* packed data */
> +	for (i = y; i < y + height ; i++) {
> +		const int line_offset = dev->info->fix.line_length * i;
> +		const int byte_offset = line_offset + (x * BPP);
> +		memcpy(cmd, (char *) dev->info->fix.smem_start + byte_offset, (width * BPP));
> +
> +		/* include line padding */
> +		cmd += packed_line_len;
> +	}
> +
> +	return cmd;
> +}
> +
> +int ufx_handle_damage(struct ufx_data *dev, int x, int y,
> +	int width, int height)
> +{
> +	size_t packed_line_len = ALIGN((width * 2), 4);
> +	int len, status, urb_lines, start_line = 0;
> +	char *cmd;
> +
> +	if ((width <= 0) || (height <= 0) ||
> +	    (x + width > dev->info->var.xres) ||
> +	    (y + height > dev->info->var.yres))
> +		return -EINVAL;
> +
> +	if (!atomic_read(&dev->usb_active))
> +		return 0;
> +
> +	while (start_line < height) {
> +		struct urb *urb = ufx_get_urb(dev);
> +		if (!urb) {
> +			pr_warn("ufx_handle_damage unable to get urb");
> +			return 0;
> +		}
> +
> +		/* assume we have enough space to transfer at least one line */
> +		BUG_ON(urb->transfer_buffer_length < (24 + (width * 2)));
> +
> +		/* calculate the maximum number of lines we could fit in */
> +		urb_lines = (urb->transfer_buffer_length - 24) / packed_line_len;
> +
> +		/* but we might not need this many */
> +		urb_lines = min(urb_lines, (height - start_line));
> +
> +		memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
> +
> +		cmd = ufx_raw_rect(dev, urb->transfer_buffer, x, (y + start_line), width, urb_lines);
> +
> +		len = cmd - (char *) urb->transfer_buffer;
> +		BUG_ON(len != (24 + (packed_line_len * urb_lines)));
> +
> +		status = ufx_submit_urb(dev, urb, len);
> +		check_warn_return(status, "Error submitting URB");
> +
> +		start_line += urb_lines;
> +	}
> +
> +	return 0;
> +}
> +
> +/* Path triggered by usermode clients who write to filesystem
> + * e.g. cat filename > /dev/fb1
> + * Not used by X Windows or text-mode console. But useful for testing.
> + * Slow because of extra copy and we must assume all pixels dirty. */
> +static ssize_t ufx_ops_write(struct fb_info *info, const char __user *buf,
> +			  size_t count, loff_t *ppos)
> +{
> +	ssize_t result;
> +	struct ufx_data *dev = info->par;
> +	u32 offset = (u32) *ppos;
> +
> +	result = fb_sys_write(info, buf, count, ppos);
> +
> +	if (result > 0) {
> +		int start = max((int)(offset / info->fix.line_length) - 1, 0);
> +		int lines = min((u32)((result / info->fix.line_length) + 1),
> +				(u32)info->var.yres);
> +
> +		ufx_handle_damage(dev, 0, start, info->var.xres, lines);
> +	}
> +
> +	return result;
> +}
> +
> +static void ufx_ops_copyarea(struct fb_info *info,
> +				const struct fb_copyarea *area)
> +{
> +
> +	struct ufx_data *dev = info->par;
> +
> +	sys_copyarea(info, area);
> +
> +	ufx_handle_damage(dev, area->dx, area->dy,
> +			area->width, area->height);
> +}
> +
> +static void ufx_ops_imageblit(struct fb_info *info,
> +				const struct fb_image *image)
> +{
> +	struct ufx_data *dev = info->par;
> +
> +	sys_imageblit(info, image);
> +
> +	ufx_handle_damage(dev, image->dx, image->dy,
> +			image->width, image->height);
> +}
> +
> +static void ufx_ops_fillrect(struct fb_info *info,
> +			  const struct fb_fillrect *rect)
> +{
> +	struct ufx_data *dev = info->par;
> +
> +	sys_fillrect(info, rect);
> +
> +	ufx_handle_damage(dev, rect->dx, rect->dy, rect->width,
> +			      rect->height);
> +}
> +
> +/* NOTE: fb_defio.c is holding info->fbdefio.mutex
> + *   Touching ANY framebuffer memory that triggers a page fault
> + *   in fb_defio will cause a deadlock, when it also tries to
> + *   grab the same mutex. */
> +static void ufx_dpy_deferred_io(struct fb_info *info,
> +				struct list_head *pagelist)
> +{
> +	struct page *cur;
> +	struct fb_deferred_io *fbdefio = info->fbdefio;
> +	struct ufx_data *dev = info->par;
> +
> +	if (!fb_defio)
> +		return;
> +
> +	if (!atomic_read(&dev->usb_active))
> +		return;
> +
> +	/* walk the written page list and render each to device */
> +	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
> +		/* create a rectangle of full screen width that encloses the
> +		 * entire dirty framebuffer page */
> +		const int x = 0;
> +		const int width = dev->info->var.xres;
> +		const int y = (cur->index << PAGE_SHIFT) / (width * 2);
> +		int height = (PAGE_SIZE / (width * 2)) + 1;
> +		height = min(height, (int)(dev->info->var.yres - y));
> +
> +		BUG_ON(y >= dev->info->var.yres);
> +		BUG_ON((y + height) > dev->info->var.yres);
> +
> +		ufx_handle_damage(dev, x, y, width, height);
> +	}
> +}
> +
> +static int ufx_ops_ioctl(struct fb_info *info, unsigned int cmd,
> +			 unsigned long arg)
> +{
> +	struct ufx_data *dev = info->par;
> +	struct dloarea *area = NULL;
> +
> +	if (!atomic_read(&dev->usb_active))
> +		return 0;
> +
> +	/* TODO: Update X server to get this from sysfs instead */
> +	if (cmd == UFX_IOCTL_RETURN_EDID) {
> +		char *edid = (char *)arg;
> +		if (copy_to_user(edid, dev->edid, dev->edid_size))
> +			return -EFAULT;
> +		return 0;
> +	}
> +
> +	/* TODO: Help propose a standard fb.h ioctl to report mmap damage */
> +	if (cmd == UFX_IOCTL_REPORT_DAMAGE) {
> +		/* If we have a damage-aware client, turn fb_defio "off"
> +		 * To avoid perf imact of unecessary page fault handling.
> +		 * Done by resetting the delay for this fb_info to a very
> +		 * long period. Pages will become writable and stay that way.
> +		 * Reset to normal value when all clients have closed this fb.
> +		 */

I think you should reset when fb_set_par is called as probably all users do when
they are activated. Otherwise things get broken if any client that supports this
extension and any other is run at the same time so it won't be resetted if you
switch between them.

> +		if (info->fbdefio)
> +			info->fbdefio->delay = UFX_DEFIO_WRITE_DISABLE;
> +
> +		area = (struct dloarea *)arg;
> +
> +		if (area->x < 0)
> +			area->x = 0;
> +
> +		if (area->x > info->var.xres)
> +			area->x = info->var.xres;
> +
> +		if (area->y < 0)
> +			area->y = 0;
> +
> +		if (area->y > info->var.yres)
> +			area->y = info->var.yres;
> +
> +		ufx_handle_damage(dev, area->x, area->y, area->w, area->h);
> +	}
> +
> +	return 0;
> +}
> +
> +/* taken from vesafb */
> +static int
> +ufx_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
> +	       unsigned blue, unsigned transp, struct fb_info *info)
> +{
> +	int err = 0;
> +
> +	if (regno >= info->cmap.len)
> +		return 1;
> +
> +	if (regno < 16) {
> +		if (info->var.red.offset == 10) {
> +			/* 1:5:5:5 */
> +			((u32 *) (info->pseudo_palette))[regno] =
> +			    ((red & 0xf800) >> 1) |
> +			    ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
> +		} else {
> +			/* 0:5:6:5 */
> +			((u32 *) (info->pseudo_palette))[regno] =
> +			    ((red & 0xf800)) |
> +			    ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
> +		}
> +	}
> +
> +	return err;
> +}
> +
> +/* It's common for several clients to have framebuffer open simultaneously.
> + * e.g. both fbcon and X. Makes things interesting.
> + * Assumes caller is holding info->lock (for open and release at least) */
> +static int ufx_ops_open(struct fb_info *info, int user)
> +{
> +	struct ufx_data *dev = info->par;
> +
> +	/* fbcon aggressively connects to first framebuffer it finds,
> +	 * preventing other clients (X) from working properly. Usually
> +	 * not what the user wants. Fail by default with option to enable. */

Not really, otherwise we'd see this problem more often. If an application
changed the VT to KD_GRAPHICS it works well. I assume that if this problem
occured X was stared with --shared-vt (or what the option was called) which does
not do this correctly.

> +	if ((user == 0) & (!console))

You want a && here and you can also drop the inner ().

> +		return -EBUSY;
> +
> +	/* If the USB device is gone, we don't accept new opens */
> +	if (dev->virtualized)
> +		return -ENODEV;
> +
> +	dev->fb_count++;
> +
> +	kref_get(&dev->kref);
> +
> +	if (fb_defio && (info->fbdefio == NULL)) {
> +		/* enable defio at last moment if not disabled by client */
> +
> +		struct fb_deferred_io *fbdefio;
> +
> +		fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
> +
> +		if (fbdefio) {
> +			fbdefio->delay = UFX_DEFIO_WRITE_DELAY;
> +			fbdefio->deferred_io = ufx_dpy_deferred_io;
> +		}
> +
> +		info->fbdefio = fbdefio;
> +		fb_deferred_io_init(info);
> +	}
> +
> +	pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d",
> +		info->node, user, info, dev->fb_count);
> +
> +	return 0;
> +}
> +
> +/*
> + * Called when all client interfaces to start transactions have been disabled,
> + * and all references to our device instance (ufx_data) are released.
> + * Every transaction must have a reference, so we know are fully spun down
> + */
> +static void ufx_free(struct kref *kref)
> +{
> +	struct ufx_data *dev = container_of(kref, struct ufx_data, kref);
> +
> +	/* this function will wait for all in-flight urbs to complete */
> +	if (dev->urbs.count > 0)
> +		ufx_free_urb_list(dev);
> +
> +	pr_warn("freeing ufx_data %p", dev);
> +
> +	kfree(dev);
> +}
> +
> +static void ufx_release_urb_work(struct work_struct *work)
> +{
> +	struct urb_node *unode = container_of(work, struct urb_node,
> +					      release_urb_work.work);
> +
> +	up(&unode->dev->urbs.limit_sem);
> +}
> +
> +static void ufx_free_framebuffer_work(struct work_struct *work)
> +{
> +	struct ufx_data *dev = container_of(work, struct ufx_data,
> +					    free_framebuffer_work.work);
> +	struct fb_info *info = dev->info;
> +	int node = info->node;
> +
> +	unregister_framebuffer(info);
> +
> +	if (info->cmap.len != 0)
> +		fb_dealloc_cmap(&info->cmap);
> +	if (info->monspecs.modedb)
> +		fb_destroy_modedb(info->monspecs.modedb);
> +	if (info->screen_base)
> +		vfree(info->screen_base);
> +
> +	fb_destroy_modelist(&info->modelist);
> +
> +	dev->info = 0;
> +
> +	/* Assume info structure is freed after this point */
> +	framebuffer_release(info);
> +
> +	pr_warn("fb_info for /dev/fb%d has been freed", node);
> +
> +	/* ref taken in probe() as part of registering framebfufer */
> +	kref_put(&dev->kref, ufx_free);
> +}
> +
> +/*
> + * Assumes caller is holding info->lock mutex (for open and release at least)
> + */
> +static int ufx_ops_release(struct fb_info *info, int user)
> +{
> +	struct ufx_data *dev = info->par;
> +
> +	dev->fb_count--;
> +
> +	/* We can't free fb_info here - fbmem will touch it when we return */
> +	if (dev->virtualized && (dev->fb_count == 0))
> +		schedule_delayed_work(&dev->free_framebuffer_work, HZ);
> +
> +	if ((dev->fb_count == 0) && (info->fbdefio)) {
> +		fb_deferred_io_cleanup(info);
> +		kfree(info->fbdefio);
> +		info->fbdefio = NULL;
> +		info->fbops->fb_mmap = ufx_ops_mmap;
> +	}
> +
> +	pr_warn("released /dev/fb%d user=%d count=%d",
> +		  info->node, user, dev->fb_count);
> +
> +	kref_put(&dev->kref, ufx_free);
> +
> +	return 0;
> +}
> +
> +/* Check whether a video mode is supported by the chip
> + * We start from monitor's modes, so don't need to filter that here */
> +static int ufx_is_valid_mode(struct fb_videomode *mode,
> +		struct fb_info *info)
> +{
> +	if ((mode->xres * mode->yres) > (2048 * 1152)) {
> +		pr_warn("%dx%d too many pixels",
> +		       mode->xres, mode->yres);
> +		return 0;
> +	}
> +
> +	if (mode->pixclock < 5000) {
> +		pr_warn("%dx%d %dps pixel clock too fast",
> +		       mode->xres, mode->yres, mode->pixclock);
> +		return 0;
> +	}
> +
> +	pr_info("%dx%d (pixclk %dps %dMHz) valid mode", mode->xres, mode->yres,
> +		mode->pixclock, (1000000 / mode->pixclock));
> +	return 1;
> +}
> +
> +static void ufx_var_color_format(struct fb_var_screeninfo *var)
> +{
> +	const struct fb_bitfield red = { 11, 5, 0 };
> +	const struct fb_bitfield green = { 5, 6, 0 };
> +	const struct fb_bitfield blue = { 0, 5, 0 };
> +
> +	var->bits_per_pixel = 16;
> +	var->red = red;
> +	var->green = green;
> +	var->blue = blue;
> +}
> +
> +static int ufx_ops_check_var(struct fb_var_screeninfo *var,
> +				struct fb_info *info)
> +{
> +	struct fb_videomode mode;
> +
> +	/* TODO: support dynamically changing framebuffer size */
> +	if ((var->xres * var->yres * 2) > info->fix.smem_len)
> +		return -EINVAL;
> +
> +	/* set device-specific elements of var unrelated to mode */
> +	ufx_var_color_format(var);
> +
> +	fb_var_to_videomode(&mode, var);
> +
> +	if (!ufx_is_valid_mode(&mode, info))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int ufx_ops_set_par(struct fb_info *info)
> +{
> +	struct ufx_data *dev = info->par;
> +	int result;
> +	u16 *pix_framebuffer;
> +	int i;
> +
> +	pr_notice("set_par mode %dx%d", info->var.xres, info->var.yres);
> +	result = ufx_set_vid_mode(dev, &info->var);
> +
> +	if ((result == 0) && (dev->fb_count == 0)) {
> +		/* paint greenscreen */
> +		pix_framebuffer = (u16 *) info->screen_base;
> +		for (i = 0; i < info->fix.smem_len / 2; i++)
> +			pix_framebuffer[i] = 0x37e6;
> +
> +		ufx_handle_damage(dev, 0, 0, info->var.xres, info->var.yres);
> +	}
> +
> +	return result;
> +}
> +
> +/* In order to come back from full DPMS off, we need to set the mode again */
> +static int ufx_ops_blank(int blank_mode, struct fb_info *info)
> +{
> +	struct ufx_data *dev = info->par;
> +	ufx_set_vid_mode(dev, &info->var);
> +	return 0;
> +}
> +
> +static struct fb_ops ufx_ops = {
> +	.owner = THIS_MODULE,
> +	.fb_read = fb_sys_read,
> +	.fb_write = ufx_ops_write,
> +	.fb_setcolreg = ufx_ops_setcolreg,
> +	.fb_fillrect = ufx_ops_fillrect,
> +	.fb_copyarea = ufx_ops_copyarea,
> +	.fb_imageblit = ufx_ops_imageblit,
> +	.fb_mmap = ufx_ops_mmap,
> +	.fb_ioctl = ufx_ops_ioctl,
> +	.fb_open = ufx_ops_open,
> +	.fb_release = ufx_ops_release,
> +	.fb_blank = ufx_ops_blank,
> +	.fb_check_var = ufx_ops_check_var,
> +	.fb_set_par = ufx_ops_set_par,
> +};
> +
> +/* Assumes &info->lock held by caller
> + * Assumes no active clients have framebuffer open */
> +static int ufx_realloc_framebuffer(struct ufx_data *dev, struct fb_info *info)
> +{
> +	int retval = -ENOMEM;
> +	int old_len = info->fix.smem_len;
> +	int new_len;
> +	unsigned char *old_fb = info->screen_base;
> +	unsigned char *new_fb;
> +
> +	pr_warn("Reallocating framebuffer. Addresses will change!");
> +
> +	new_len = info->fix.line_length * info->var.yres;
> +
> +	if (PAGE_ALIGN(new_len) > old_len) {
> +		/*
> +		 * Alloc system memory for virtual framebuffer
> +		 */
> +		new_fb = vmalloc(new_len);
> +		if (!new_fb) {
> +			pr_err("Virtual framebuffer alloc failed");
> +			goto error;
> +		}
> +
> +		if (info->screen_base) {
> +			memcpy(new_fb, old_fb, old_len);
> +			vfree(info->screen_base);
> +		}
> +
> +		info->screen_base = new_fb;
> +		info->fix.smem_len = PAGE_ALIGN(new_len);
> +		info->fix.smem_start = (unsigned long) new_fb;
> +		info->flags = smscufx_info_flags;
> +	}
> +
> +	retval = 0;
> +
> +error:
> +	return retval;
> +}
> +
> +/* sets up I2C Controller for 100 Kbps, std. speed, 7-bit addr, master,
> + * restart enabled, but no start byte, enable controller */
> +static int ufx_i2c_init(struct ufx_data *dev)
> +{
> +	u32 tmp;
> +
> +	/* disable the controller before it can be reprogrammed */
> +	int status = ufx_reg_write(dev, 0x106C, 0x00);
> +	check_warn_return(status, "failed to disable I2C");
> +
> +	/* Setup the clock count registers
> +	 * (12+1) = 13 clks @ 2.5 MHz = 5.2 uS */
> +	status = ufx_reg_write(dev, 0x1018, 12);
> +	check_warn_return(status, "error writing 0x1018");
> +
> +	/* (6+8) = 14 clks @ 2.5 MHz = 5.6 uS */
> +	status = ufx_reg_write(dev, 0x1014, 6);
> +	check_warn_return(status, "error writing 0x1014");
> +
> +	status = ufx_reg_read(dev, 0x1000, &tmp);
> +	check_warn_return(status, "error reading 0x1000");
> +
> +	/* set speed to std mode */
> +	tmp &= ~(0x06);
> +	tmp |= 0x02;
> +
> +	/* 7-bit (not 10-bit) addressing */
> +	tmp &= ~(0x10);
> +
> +	/* enable restart conditions and master mode */
> +	tmp |= 0x21;
> +
> +	status = ufx_reg_write(dev, 0x1000, tmp);
> +	check_warn_return(status, "error writing 0x1000");
> +
> +	/* Set normal tx using target address 0 */
> +	status = ufx_reg_clear_and_set_bits(dev, 0x1004, 0xC00, 0x000);
> +	check_warn_return(status, "error setting TX mode bits in 0x1004");
> +
> +	/* Enable the controller */
> +	status = ufx_reg_write(dev, 0x106C, 0x01);
> +	check_warn_return(status, "failed to enable I2C");
> +
> +	return 0;
> +}
> +
> +/* sets the I2C port mux and target address */
> +static int ufx_i2c_configure(struct ufx_data *dev)
> +{
> +	int status = ufx_reg_write(dev, 0x106C, 0x00);
> +	check_warn_return(status, "failed to disable I2C");
> +
> +	status = ufx_reg_write(dev, 0x3010, 0x00000000);
> +	check_warn_return(status, "failed to write 0x3010");
> +
> +	/* A0h is std for any EDID, right shifted by one */
> +	status = ufx_reg_clear_and_set_bits(dev, 0x1004, 0x3FF,	(0xA0 >> 1));
> +	check_warn_return(status, "failed to set TAR bits in 0x1004");
> +
> +	status = ufx_reg_write(dev, 0x106C, 0x01);
> +	check_warn_return(status, "failed to enable I2C");
> +
> +	return 0;
> +}
> +
> +/* wait for BUSY to clear, with a timeout of 50ms with 10ms sleeps. if no
> + * monitor is connected, there is no error except for timeout */
> +static int ufx_i2c_wait_busy(struct ufx_data *dev)
> +{
> +	u32 tmp;
> +	int i, status;
> +
> +	for (i = 0; i < 15; i++) {
> +		status = ufx_reg_read(dev, 0x1100, &tmp);
> +		check_warn_return(status, "0x1100 read failed");
> +
> +		/* if BUSY is clear, check for error */
> +		if ((tmp & 0x80000000) == 0) {
> +			if (tmp & 0x20000000) {
> +				pr_warn("I2C read failed, 0x1100=0x%08x", tmp);
> +				return -EIO;
> +			}
> +
> +			return 0;
> +		}
> +
> +		/* perform the first 10 retries without delay */
> +		if (i >= 10)
> +			msleep(10);
> +	}
> +
> +	pr_warn("I2C access timed out, resetting I2C hardware");
> +	status =  ufx_reg_write(dev, 0x1100, 0x40000000);
> +	check_warn_return(status, "0x1100 write failed");
> +
> +	return -ETIMEDOUT;
> +}
> +
> +/* reads a 128-byte EDID block from the currently selected port and TAR */
> +static int ufx_read_edid(struct ufx_data *dev, char *edid, int edid_len)
> +{
> +	int i, j, status;
> +	u32 *edid_u32 = (u32 *)edid;
> +
> +	BUG_ON(edid_len != EDID_LENGTH);
> +
> +	status = ufx_i2c_configure(dev);
> +	if (status < 0) {
> +		pr_err("ufx_i2c_configure failed");
> +		return status;
> +	}
> +
> +	memset(edid, 0xff, EDID_LENGTH);
> +
> +	/* Read the 128-byte EDID as 2 bursts of 64 bytes */
> +	for (i = 0; i < 2; i++) {
> +		u32 temp = 0x28070000 | (63 << 20) | (((u32)(i * 64)) << 8);
> +		status = ufx_reg_write(dev, 0x1100, temp);
> +		check_warn_return(status, "Failed to write 0x1100");
> +
> +		temp |= 0x80000000;
> +		status = ufx_reg_write(dev, 0x1100, temp);
> +		check_warn_return(status, "Failed to write 0x1100");
> +
> +		status = ufx_i2c_wait_busy(dev);
> +		check_warn_return(status, "Timeout waiting for I2C BUSY to clear");
> +
> +		for (j = 0; j < 16; j++) {
> +			u32 data_reg_addr = 0x1110 + (j * 4);
> +			status = ufx_reg_read(dev, data_reg_addr, edid_u32++);
> +			check_warn_return(status, "Error reading i2c data");
> +		}
> +	}
> +
> +	/* all FF's in the first 16 bytes indicates nothing is connected */
> +	for (i = 0; i < 16; i++) {
> +		if (edid[i] != 0xFF) {
> +			pr_info("edid data read succesfully");
> +			return EDID_LENGTH;
> +		}
> +	}
> +
> +	pr_warn("edid data contains all 0xff");
> +	return -ETIMEDOUT;
> +}
> +
> +/* 1) use sw default
> + * 2) Parse into various fb_info structs
> + * 3) Allocate virtual framebuffer memory to back highest res mode
> + *
> + * Parses EDID into three places used by various parts of fbdev:
> + * fb_var_screeninfo contains the timing of the monitor's preferred mode
> + * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
> + * fb_info.modelist is a linked list of all monitor & VESA modes which work
> + *
> + * If EDID is not readable/valid, then modelist is all VESA modes,
> + * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
> + * Returns 0 if successful */
> +static int ufx_setup_modes(struct ufx_data *dev, struct fb_info *info,
> +	char *default_edid, size_t default_edid_size)
> +{
> +	const struct fb_videomode *default_vmode = NULL;
> +	char *edid;
> +	int i, result = 0, tries = 3;
> +
> +	if (info->dev) /* only use mutex if info has been registered */
> +		mutex_lock(&info->lock);
> +
> +	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
> +	if (!edid) {
> +		result = -ENOMEM;
> +		goto error;
> +	}
> +
> +	fb_destroy_modelist(&info->modelist);
> +	memset(&info->monspecs, 0, sizeof(info->monspecs));
> +
> +	/* Try to (re)read EDID from hardware first
> +	 * EDID data may return, but not parse as valid
> +	 * Try again a few times, in case of e.g. analog cable noise */
> +	while (tries--) {
> +		i = ufx_read_edid(dev, edid, EDID_LENGTH);
> +
> +		if (i >= EDID_LENGTH)
> +			fb_edid_to_monspecs(edid, &info->monspecs);
> +
> +		if (info->monspecs.modedb_len > 0) {
> +			dev->edid = edid;
> +			dev->edid_size = i;
> +			break;
> +		}
> +	}
> +
> +	/* If that fails, use a previously returned EDID if available */
> +	if (info->monspecs.modedb_len == 0) {
> +
> +		pr_err("Unable to get valid EDID from device/display\n");
> +
> +		if (dev->edid) {
> +			fb_edid_to_monspecs(dev->edid, &info->monspecs);
> +			if (info->monspecs.modedb_len > 0)
> +				pr_err("Using previously queried EDID\n");
> +		}
> +	}
> +
> +	/* If that fails, use the default EDID we were handed */
> +	if (info->monspecs.modedb_len == 0) {
> +		if (default_edid_size >= EDID_LENGTH) {
> +			fb_edid_to_monspecs(default_edid, &info->monspecs);
> +			if (info->monspecs.modedb_len > 0) {
> +				memcpy(edid, default_edid, default_edid_size);
> +				dev->edid = edid;
> +				dev->edid_size = default_edid_size;
> +				pr_err("Using default/backup EDID\n");
> +			}
> +		}
> +	}
> +
> +	/* If we've got modes, let's pick a best default mode */
> +	if (info->monspecs.modedb_len > 0) {
> +
> +		for (i = 0; i < info->monspecs.modedb_len; i++) {
> +			if (ufx_is_valid_mode(&info->monspecs.modedb[i], info))
> +				fb_add_videomode(&info->monspecs.modedb[i],
> +					&info->modelist);
> +			else /* if we've removed top/best mode */
> +				info->monspecs.misc &= ~FB_MISC_1ST_DETAIL;
> +		}
> +
> +		default_vmode = fb_find_best_display(&info->monspecs,
> +						     &info->modelist);
> +	}
> +
> +	/* If everything else has failed, fall back to safe default mode */
> +	if (default_vmode == NULL) {
> +
> +		struct fb_videomode fb_vmode = {0};
> +
> +		/* Add the standard VESA modes to our modelist
> +		 * Since we don't have EDID, there may be modes that
> +		 * overspec monitor and/or are incorrect aspect ratio, etc.
> +		 * But at least the user has a chance to choose
> +		 */
> +		for (i = 0; i < VESA_MODEDB_SIZE; i++) {
> +			if (ufx_is_valid_mode((struct fb_videomode *)
> +						&vesa_modes[i], info))
> +				fb_add_videomode(&vesa_modes[i],
> +						 &info->modelist);
> +		}
> +
> +		/* default to resolution safe for projectors
> +		 * (since they are most common case without EDID)
> +		 */
> +		fb_vmode.xres = 800;
> +		fb_vmode.yres = 600;
> +		fb_vmode.refresh = 60;
> +		default_vmode = fb_find_nearest_mode(&fb_vmode,
> +						     &info->modelist);
> +	}
> +
> +	/* If we have good mode and no active clients */
> +	if ((default_vmode != NULL) && (dev->fb_count == 0)) {
> +
> +		fb_videomode_to_var(&info->var, default_vmode);
> +		ufx_var_color_format(&info->var);
> +
> +		/* with mode size info, we can now alloc our framebuffer */
> +		memcpy(&info->fix, &ufx_fix, sizeof(ufx_fix));
> +		info->fix.line_length = info->var.xres *
> +			(info->var.bits_per_pixel / 8);
> +
> +		result = ufx_realloc_framebuffer(dev, info);
> +
> +	} else
> +		result = -EINVAL;
> +
> +error:
> +	if (edid && (dev->edid != edid))
> +		kfree(edid);
> +
> +	if (info->dev)
> +		mutex_unlock(&info->lock);
> +
> +	return result;
> +}
> +
> +static int ufx_usb_probe(struct usb_interface *interface,
> +			const struct usb_device_id *id)
> +{
> +	struct usb_device *usbdev;
> +	struct ufx_data *dev = 0;
> +	struct fb_info *info = 0;
> +	int retval = -ENOMEM;
> +	u32 id_rev, fpga_rev;
> +
> +	/* usb initialization */
> +	usbdev = interface_to_usbdev(interface);
> +
> +	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> +	if (dev == NULL) {
> +		err("ufx_usb_probe: failed alloc of dev struct\n");
> +		goto error;
> +	}
> +
> +	/* we need to wait for both usb and fbdev to spin down on disconnect */
> +	kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
> +	kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
> +
> +	dev->udev = usbdev;
> +	dev->gdev = &usbdev->dev; /* our generic struct device * */
> +	usb_set_intfdata(interface, dev);
> +
> +	pr_info("%s %s - serial #%s\n",
> +		usbdev->manufacturer, usbdev->product, usbdev->serial);
> +	pr_info("vid_%04x&pid_%04x&rev_%04x driver's ufx_data struct at %p\n",
> +		usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
> +		usbdev->descriptor.bcdDevice, dev);
> +	pr_info("console enable=%d\n", console);
> +	pr_info("fb_defio enable=%d\n", fb_defio);
> +
> +	if (!ufx_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
> +		retval = -ENOMEM;
> +		pr_err("ufx_alloc_urb_list failed\n");
> +		goto error;
> +	}
> +
> +	/* We don't register a new USB class. Our client interface is fbdev */
> +
> +	/* allocates framebuffer driver structure, not framebuffer memory */
> +	info = framebuffer_alloc(0, &usbdev->dev);
> +	if (!info) {
> +		retval = -ENOMEM;
> +		pr_err("framebuffer_alloc failed\n");
> +		goto error;
> +	}
> +
> +	dev->info = info;
> +	info->par = dev;
> +	info->pseudo_palette = dev->pseudo_palette;
> +	info->fbops = &ufx_ops;
> +
> +	retval = fb_alloc_cmap(&info->cmap, 256, 0);
> +	if (retval < 0) {
> +		pr_err("fb_alloc_cmap failed %x\n", retval);
> +		goto error;
> +	}
> +
> +	INIT_DELAYED_WORK(&dev->free_framebuffer_work,
> +			  ufx_free_framebuffer_work);
> +
> +	INIT_LIST_HEAD(&info->modelist);
> +
> +	retval = ufx_reg_read(dev, 0x3000, &id_rev);
> +	check_warn_goto_error(retval, "error %d reading 0x3000 register from device", retval);
> +	pr_info("ID_REV register value 0x%08x", id_rev);
> +
> +	retval = ufx_reg_read(dev, 0x3004, &fpga_rev);
> +	check_warn_goto_error(retval, "error %d reading 0x3004 register from device", retval);
> +	pr_info("FPGA_REV register value 0x%08x", fpga_rev);
> +
> +	pr_info("resetting device");
> +	retval = ufx_lite_reset(dev);
> +	check_warn_goto_error(retval, "error %d resetting device", retval);
> +
> +	pr_info("configuring system clock");
> +	retval = ufx_config_sys_clk(dev);
> +	check_warn_goto_error(retval, "error %d configuring system clock", retval);
> +
> +	pr_info("configuring DDR2 controller");
> +	retval = ufx_config_ddr2(dev);
> +	check_warn_goto_error(retval, "error %d initialising DDR2 controller", retval);
> +
> +	pr_info("configuring I2C controller");
> +	retval = ufx_i2c_init(dev);
> +	check_warn_goto_error(retval, "error %d initialising I2C controller", retval);
> +
> +	pr_info("selecting display mode");
> +	retval = ufx_setup_modes(dev, info, NULL, 0);
> +	check_warn_goto_error(retval, "unable to find common mode for display and adapter");
> +
> +	retval = ufx_reg_set_bits(dev, 0x4000, 0x00000001);
> +	check_warn_goto_error(retval, "error %d enabling graphics engine", retval);
> +
> +	/* ready to begin using device */
> +	atomic_set(&dev->usb_active, 1);
> +
> +	pr_info("checking var");
> +	retval = ufx_ops_check_var(&info->var, info);
> +	check_warn_goto_error(retval, "error %d ufx_ops_check_var", retval);
> +
> +	pr_info("setting par");
> +	retval = ufx_ops_set_par(info);
> +	check_warn_goto_error(retval, "error %d ufx_ops_set_par", retval);
> +
> +	pr_info("registering framebuffer");
> +	retval = register_framebuffer(info);
> +	check_warn_goto_error(retval, "error %d register_framebuffer", retval);
> +
> +	pr_info("SMSC UDX USB device /dev/fb%d attached. %dx%d resolution."
> +		" Using %dK framebuffer memory\n", info->node,
> +		info->var.xres, info->var.yres, info->fix.smem_len >> 10);
> +
> +	return 0;
> +
> +error:
> +	if (dev) {
> +		if (info) {
> +			if (info->cmap.len != 0)
> +				fb_dealloc_cmap(&info->cmap);
> +			if (info->monspecs.modedb)
> +				fb_destroy_modedb(info->monspecs.modedb);
> +			if (info->screen_base)
> +				vfree(info->screen_base);
> +
> +			fb_destroy_modelist(&info->modelist);
> +
> +			framebuffer_release(info);
> +		}
> +
> +		kref_put(&dev->kref, ufx_free); /* ref for framebuffer */
> +		kref_put(&dev->kref, ufx_free); /* last ref from kref_init */
> +
> +		/* dev has been deallocated. Do not dereference */
> +	}
> +
> +	return retval;
> +}
> +
> +static void ufx_usb_disconnect(struct usb_interface *interface)
> +{
> +	struct ufx_data *dev;
> +	struct fb_info *info;
> +
> +	dev = usb_get_intfdata(interface);
> +	info = dev->info;
> +
> +	pr_info("USB disconnect starting\n");
> +
> +	/* we virtualize until all fb clients release. Then we free */
> +	dev->virtualized = true;
> +
> +	/* When non-active we'll update virtual framebuffer, but no new urbs */
> +	atomic_set(&dev->usb_active, 0);
> +
> +	usb_set_intfdata(interface, NULL);
> +
> +	/* if clients still have us open, will be freed on last close */
> +	if (dev->fb_count == 0)
> +		schedule_delayed_work(&dev->free_framebuffer_work, 0);
> +
> +	/* release reference taken by kref_init in probe() */
> +	kref_put(&dev->kref, ufx_free);
> +
> +	/* consider ufx_data freed */
> +}
> +
> +static struct usb_driver ufx_driver = {
> +	.name = "smscufx",
> +	.probe = ufx_usb_probe,
> +	.disconnect = ufx_usb_disconnect,
> +	.id_table = id_table,
> +};
> +
> +static int __init ufx_module_init(void)
> +{
> +	int res;
> +
> +	res = usb_register(&ufx_driver);
> +	if (res)
> +		err("usb_register failed. Error number %d", res);
> +
> +	return res;
> +}
> +
> +static void __exit ufx_module_exit(void)
> +{
> +	usb_deregister(&ufx_driver);
> +}
> +
> +module_init(ufx_module_init);
> +module_exit(ufx_module_exit);
> +
> +static void ufx_urb_completion(struct urb *urb)
> +{
> +	struct urb_node *unode = urb->context;
> +	struct ufx_data *dev = unode->dev;
> +	unsigned long flags;
> +
> +	/* sync/async unlink faults aren't errors */
> +	if (urb->status) {
> +		if (!(urb->status == -ENOENT ||
> +		    urb->status == -ECONNRESET ||
> +		    urb->status == -ESHUTDOWN)) {
> +			pr_err("%s - nonzero write bulk status received: %d\n",
> +				__func__, urb->status);
> +			atomic_set(&dev->lost_pixels, 1);
> +		}
> +	}
> +
> +	urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
> +
> +	spin_lock_irqsave(&dev->urbs.lock, flags);
> +	list_add_tail(&unode->entry, &dev->urbs.list);
> +	dev->urbs.available++;
> +	spin_unlock_irqrestore(&dev->urbs.lock, flags);
> +
> +	/* When using fb_defio, we deadlock if up() is called
> +	 * while another is waiting. So queue to another process */
> +	if (fb_defio)
> +		schedule_delayed_work(&unode->release_urb_work, 0);
> +	else
> +		up(&dev->urbs.limit_sem);
> +}
> +
> +static void ufx_free_urb_list(struct ufx_data *dev)
> +{
> +	int count = dev->urbs.count;
> +	struct list_head *node;
> +	struct urb_node *unode;
> +	struct urb *urb;
> +	int ret;
> +	unsigned long flags;
> +
> +	pr_notice("Waiting for completes and freeing all render urbs\n");
> +
> +	/* keep waiting and freeing, until we've got 'em all */
> +	while (count--) {
> +		/* Getting interrupted means a leak, but ok at shutdown*/
> +		ret = down_interruptible(&dev->urbs.limit_sem);
> +		if (ret)
> +			break;
> +
> +		spin_lock_irqsave(&dev->urbs.lock, flags);
> +
> +		node = dev->urbs.list.next; /* have reserved one with sem */
> +		list_del_init(node);
> +
> +		spin_unlock_irqrestore(&dev->urbs.lock, flags);
> +
> +		unode = list_entry(node, struct urb_node, entry);
> +		urb = unode->urb;
> +
> +		/* Free each separately allocated piece */
> +		usb_free_coherent(urb->dev, dev->urbs.size,
> +				  urb->transfer_buffer, urb->transfer_dma);
> +		usb_free_urb(urb);
> +		kfree(node);
> +	}
> +}
> +
> +static int ufx_alloc_urb_list(struct ufx_data *dev, int count, size_t size)
> +{
> +	int i = 0;
> +	struct urb *urb;
> +	struct urb_node *unode;
> +	char *buf;
> +
> +	spin_lock_init(&dev->urbs.lock);
> +
> +	dev->urbs.size = size;
> +	INIT_LIST_HEAD(&dev->urbs.list);
> +
> +	while (i < count) {
> +		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
> +		if (!unode)
> +			break;
> +		unode->dev = dev;
> +
> +		INIT_DELAYED_WORK(&unode->release_urb_work,
> +			  ufx_release_urb_work);
> +
> +		urb = usb_alloc_urb(0, GFP_KERNEL);
> +		if (!urb) {
> +			kfree(unode);
> +			break;
> +		}
> +		unode->urb = urb;
> +
> +		buf = usb_alloc_coherent(dev->udev, size, GFP_KERNEL,
> +					 &urb->transfer_dma);
> +		if (!buf) {
> +			kfree(unode);
> +			usb_free_urb(urb);
> +			break;
> +		}
> +
> +		/* urb->transfer_buffer_length set to actual before submit */
> +		usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
> +			buf, size, ufx_urb_completion, unode);
> +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +
> +		list_add_tail(&unode->entry, &dev->urbs.list);
> +
> +		i++;
> +	}
> +
> +	sema_init(&dev->urbs.limit_sem, i);
> +	dev->urbs.count = i;
> +	dev->urbs.available = i;
> +
> +	pr_notice("allocated %d %d byte urbs\n", i, (int) size);
> +
> +	return i;
> +}
> +
> +static struct urb *ufx_get_urb(struct ufx_data *dev)
> +{
> +	int ret = 0;
> +	struct list_head *entry;
> +	struct urb_node *unode;
> +	struct urb *urb = NULL;
> +	unsigned long flags;
> +
> +	/* Wait for an in-flight buffer to complete and get re-queued */
> +	ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
> +	if (ret) {
> +		atomic_set(&dev->lost_pixels, 1);
> +		pr_warn("wait for urb interrupted: %x available: %d\n",
> +		       ret, dev->urbs.available);
> +		goto error;
> +	}
> +
> +	spin_lock_irqsave(&dev->urbs.lock, flags);
> +
> +	BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
> +	entry = dev->urbs.list.next;
> +	list_del_init(entry);
> +	dev->urbs.available--;
> +
> +	spin_unlock_irqrestore(&dev->urbs.lock, flags);
> +
> +	unode = list_entry(entry, struct urb_node, entry);
> +	urb = unode->urb;
> +
> +error:
> +	return urb;
> +}
> +
> +static int ufx_submit_urb(struct ufx_data *dev, struct urb *urb, size_t len)
> +{
> +	int ret;
> +
> +	BUG_ON(len > dev->urbs.size);
> +
> +	urb->transfer_buffer_length = len; /* set to actual payload len */
> +	ret = usb_submit_urb(urb, GFP_KERNEL);
> +	if (ret) {
> +		ufx_urb_completion(urb); /* because no one else will */
> +		atomic_set(&dev->lost_pixels, 1);
> +		pr_err("usb_submit_urb error %x\n", ret);
> +	}
> +	return ret;
> +}
> +
> +module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
> +MODULE_PARM_DESC(console, "Allow fbcon to consume first framebuffer found");

The description is not really correct. It's more like
Allow fbcon to be used on this display.
Whether or not your module is the first framebuffer and therefore the one fbcon
tries to use with default settings depends on module load order and such things.

> +
> +module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
> +MODULE_PARM_DESC(fb_defio, "Enable fb_defio mmap support");
> +
> +MODULE_AUTHOR("Steve Glendinning <[e-mail]>");
> +MODULE_DESCRIPTION("SMSC UFX kernel framebuffer driver");
> +MODULE_LICENSE("GPL");

Otherwise it looks good to me.


Thanks,

Florian Tobias Schandinat
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[e-mail] Aug. 16, 2011, 4:53 p.m. UTC | #4

Hi Florian,

On Tue, Aug 16, 2011 at 3:17 AM, Florian Tobias Schandinat
<[e-mail]> wrote:
>> + * TODO: Propose standard fb.h ioctl for reporting damage,
>> + * using _IOWR() and one of the existing area structs from fb.h
>> + * Consider these ioctls deprecated, but they're still used by the
>> + * DisplayLink X server as yet - need both to be modified in tandem
>> + * when new ioctl(s) are ready.
>> + */
>> +#define UFX_IOCTL_RETURN_EDID        (0xAD)
>> +#define UFX_IOCTL_REPORT_DAMAGE      (0xAA)
>
> Why don't we solve this now? So what do you need?

It would be wonderful to solve this now.  This capability is needed
for any device which doesn't have a directly mmapable hardware
framebuffer (e.g. any USB graphics device, but also remote
framebuffers, devices like eink controllers, etc.)

If we define the standard interface, we'll also modify udlfb (the
DisplayLink driver) to match, so we'll have several clients of the
interface in the tree from day one.

And we also have a patch to the xorg fbdev driver to be a client of
this interface -- to pass X DAMAGE protocol notifications to the
kernel framebuffer, allowing all these devices to work with common
clients (whereas they can't today, without fb_defio or some other
trick to detect framebuffer writes).

Here is the xorg fbdev patch that can be updated to the new interface:
http://git.plugable.com/gitphp/index.php?p=xf86-video-fbdev&a=commitdiff&h=dbfe3f839ee00135a7cccf13db5926fb1019abde

> An IOCTL, a struct like
> struct dloarea {
>        int x, y;
>        int w, h;
> };
> and I don't think any of the existing structs in fb.h would fit. I'd just prefer
> to have those int's replaced by something of known size, probably __u32 to make
> it consistent with fb_var_screeninfo?

Yes. that'd be perfect.   Could be as simple as

struct fb_rect {
	__u32_t x;
	__u32_t y;
	__u32_t width;
	__u32_t height;
};
#define FBIOPUT_DAMAGE _IOW('F', 0x1A, struct fb_rect)

(with the 1A ordinal being out of date now).  But anything similarly
simple is fine.

> Maybe this should be also reported by the capability field that Laurent's API
> extension will likely add.

Definitely.  In addition to the above, the only other thing needed is
capability negotiation between the fbdev client (say, xorg) and the
fbdev driver.  The negotiation has to be two-step:

The fbdev client tells the driver that it's damage-aware (A)
The fbdev driver returns to the client whether it requires damage (B)

If A and B, then the client will send damage and the driver will rely
on it (and not use fb_defio, timers, or other backup)
If A but not B, then the client should avoid unncessary overhead of
sending damage notifications that the driver isn't listening to.
If not A, then the driver must use fb_defio, timers, or some of the
other (less-efficient) backup mechanisms to make the mmap client's
framebuffer writes get noticed.

Timing: When the driver doesn't have a damage-aware client, they often
fall back to using fb_defio.  fb_defio requires special setup
(framebuffer mmap with pages set to fault on writes), that has
complexities that are best avoided if possible.  So we want step (A)
to happen before mmap, at least, and we should define the API to make
it happen at the earliest point we can define.

You can see the xorg driver patch above, and the smsc and displaylink
drivers doing this today, but in not the prettiest way (as soon as the
driver gets the first damage notification, it tries to stop using
fb_defio).  But an explicit capability negotiation, defined to happen
at the earliest point, would be cleaner.

I don't know Laurent's API.  Do we have the tools in the interface to
do a two-step negotiation to figure out whether (both) client and
driver support this new damage reporting interface?

All the pieces are close. It would be great to get this standardized!
Thanks for stepping in to help lead this.

Best wishes,
Bernie
http://plugable.com/
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Florian Tobias Schandinat Aug. 16, 2011, 5:32 p.m. UTC | #5

Hi Bernie,

On 08/16/2011 04:53 PM, Bernie Thompson wrote:
> Hi Florian,
> 
> On Tue, Aug 16, 2011 at 3:17 AM, Florian Tobias Schandinat
> <[e-mail]> wrote:
>>> + * TODO: Propose standard fb.h ioctl for reporting damage,
>>> + * using _IOWR() and one of the existing area structs from fb.h
>>> + * Consider these ioctls deprecated, but they're still used by the
>>> + * DisplayLink X server as yet - need both to be modified in tandem
>>> + * when new ioctl(s) are ready.
>>> + */
>>> +#define UFX_IOCTL_RETURN_EDID        (0xAD)
>>> +#define UFX_IOCTL_REPORT_DAMAGE      (0xAA)
>>
>> Why don't we solve this now? So what do you need?
> 
> It would be wonderful to solve this now.  This capability is needed
> for any device which doesn't have a directly mmapable hardware
> framebuffer (e.g. any USB graphics device, but also remote
> framebuffers, devices like eink controllers, etc.)
> 
> If we define the standard interface, we'll also modify udlfb (the
> DisplayLink driver) to match, so we'll have several clients of the
> interface in the tree from day one.
> 
> And we also have a patch to the xorg fbdev driver to be a client of
> this interface -- to pass X DAMAGE protocol notifications to the
> kernel framebuffer, allowing all these devices to work with common
> clients (whereas they can't today, without fb_defio or some other
> trick to detect framebuffer writes).
> 
> Here is the xorg fbdev patch that can be updated to the new interface:
> http://git.plugable.com/gitphp/index.php?p=xf86-video-fbdev&a=commitdiff&h=dbfe3f839ee00135a7cccf13db5926fb1019abde
> 
>> An IOCTL, a struct like
>> struct dloarea {
>>        int x, y;
>>        int w, h;
>> };
>> and I don't think any of the existing structs in fb.h would fit. I'd just prefer
>> to have those int's replaced by something of known size, probably __u32 to make
>> it consistent with fb_var_screeninfo?
> 
> Yes. that'd be perfect.   Could be as simple as
> 
> struct fb_rect {
> 	__u32_t x;
> 	__u32_t y;
> 	__u32_t width;
> 	__u32_t height;
> };
> #define FBIOPUT_DAMAGE _IOW('F', 0x1A, struct fb_rect)
> 
> (with the 1A ordinal being out of date now).  But anything similarly
> simple is fine.

Yes, I think we can add this to fb.h without any problems.

>> Maybe this should be also reported by the capability field that Laurent's API
>> extension will likely add.
> 
> Definitely.  In addition to the above, the only other thing needed is
> capability negotiation between the fbdev client (say, xorg) and the
> fbdev driver.  The negotiation has to be two-step:
> 
> The fbdev client tells the driver that it's damage-aware (A)
> The fbdev driver returns to the client whether it requires damage (B)
> 
> If A and B, then the client will send damage and the driver will rely
> on it (and not use fb_defio, timers, or other backup)
> If A but not B, then the client should avoid unncessary overhead of
> sending damage notifications that the driver isn't listening to.
> If not A, then the driver must use fb_defio, timers, or some of the
> other (less-efficient) backup mechanisms to make the mmap client's
> framebuffer writes get noticed.
> 
> Timing: When the driver doesn't have a damage-aware client, they often
> fall back to using fb_defio.  fb_defio requires special setup
> (framebuffer mmap with pages set to fault on writes), that has
> complexities that are best avoided if possible.  So we want step (A)
> to happen before mmap, at least, and we should define the API to make
> it happen at the earliest point we can define.
> 
> You can see the xorg driver patch above, and the smsc and displaylink
> drivers doing this today, but in not the prettiest way (as soon as the
> driver gets the first damage notification, it tries to stop using
> fb_defio).  But an explicit capability negotiation, defined to happen
> at the earliest point, would be cleaner.

What's the problem with the way you do it now? (aside that you should IMHO reset
the flag whether the client does use damage or not on set_par/mode change)
The extension I proposed and is part of Laurent's patches is a capability
reporting from the driver to the client, that would solve (B). Sure we could
think of anything to make the other way (A) possible but I doubt that it would
be worth it as I think you have to keep defio support around anyway for
applications that do not support damage reporting. I think implementing (A)
would just needlessly add complexity to the drivers as it would be some sort of
alternative mmap IOCTL. Or we could try to find yet another flag inside var that
is unused for it but that is difficult.

> All the pieces are close. It would be great to get this standardized!
> Thanks for stepping in to help lead this.

Sure, all the nice features will just be used if they are easy usable from user
space, so providing an API instead of requiring user space to know individual
drivers is a good thing.


Best regards,

Florian Tobias Schandinat
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Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 1e55e1e..80d5555 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5920,6 +5920,12 @@  L:	[e-mail]
 S:	Supported
 F:	drivers/net/smsc9420.*
 
+SMSC UFX6000 and UFX7000 USB to VGA DRIVER
+M:	Steve Glendinning <[e-mail]>
+L:	[e-mail]
+S:	Supported
+F:	drivers/video/smscufx.c
+
 SN-IA64 (Itanium) SUB-PLATFORM
 M:	Jes Sorensen <[e-mail]>
 L:	[e-mail]
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 549b960..8bfb387 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -2110,6 +2110,22 @@  config FB_SM501
 
 	  If unsure, say N.
 
+config FB_SMSCUFX
+	tristate "SMSC UFX6000/7000 USB Framebuffer support"
+	depends on FB && USB
+	select FB_MODE_HELPERS
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select FB_SYS_FOPS
+	select FB_DEFERRED_IO
+	---help---
+	  This is a kernel framebuffer driver for SMSC UFX USB devices.
+	  Supports fbdev clients like xf86-video-fbdev, kdrive, fbi, and
+	  mplayer -vo fbdev. Supports both UFX6000 (USB 2.0) and UFX7000
+	  (USB 3.0) devices.
+	  To compile as a module, choose M here: the module name is smscufx.
+
 config FB_UDL
 	tristate "Displaylink USB Framebuffer support"
 	depends on FB && USB
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 8b83129..f3546ec 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -127,6 +127,7 @@  obj-$(CONFIG_FB_IBM_GXT4500)	  += gxt4500.o
 obj-$(CONFIG_FB_PS3)		  += ps3fb.o
 obj-$(CONFIG_FB_SM501)            += sm501fb.o
 obj-$(CONFIG_FB_UDL)		  += udlfb.o
+obj-$(CONFIG_FB_SMSCUFX)	  += smscufx.o
 obj-$(CONFIG_FB_XILINX)           += xilinxfb.o
 obj-$(CONFIG_SH_MIPI_DSI)	  += sh_mipi_dsi.o
 obj-$(CONFIG_FB_SH_MOBILE_HDMI)	  += sh_mobile_hdmi.o
diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
new file mode 100644
index 0000000..2d1a7b2
--- /dev/null
+++ b/drivers/video/smscufx.c
@@ -0,0 +1,2009 @@ 
+/*
+ * smscufx.c -- Framebuffer driver for SMSC UFX USB controller
+ *
+ * Copyright (C) 2011 Steve Glendinning <[e-mail]>
+ * Copyright (C) 2009 Roberto De Ioris <[e-mail]>
+ * Copyright (C) 2009 Jaya Kumar <[e-mail]>
+ * Copyright (C) 2009 Bernie Thompson <[e-mail]>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License v2. See the file COPYING in the main directory of this archive for
+ * more details.
+ *
+ * Based on udlfb, with work from Florian Echtler, Henrik Bjerregaard Pedersen,
+ * and others.
+ *
+ * Works well with Bernie Thompson's X DAMAGE patch to xf86-video-fbdev
+ * available from http://git.plugable.com
+ *
+ * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
+ * usb-skeleton by GregKH.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/uaccess.h>
+#include <linux/mm.h>
+#include <linux/fb.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include "edid.h"
+
+#define check_warn(status, fmt, args...) \
+	({ if (status < 0) pr_warn(fmt, ##args); })
+
+#define check_warn_return(status, fmt, args...) \
+	({ if (status < 0) { pr_warn(fmt, ##args); return status; } })
+
+#define check_warn_goto_error(status, fmt, args...) \
+	({ if (status < 0) { pr_warn(fmt, ##args); goto error; } })
+
+#define all_bits_set(x, bits) (((x) & (bits)) == (bits))
+
+#define USB_VENDOR_REQUEST_WRITE_REGISTER	0xA0
+#define USB_VENDOR_REQUEST_READ_REGISTER	0xA1
+
+/*
+ * TODO: Propose standard fb.h ioctl for reporting damage,
+ * using _IOWR() and one of the existing area structs from fb.h
+ * Consider these ioctls deprecated, but they're still used by the
+ * DisplayLink X server as yet - need both to be modified in tandem
+ * when new ioctl(s) are ready.
+ */
+#define UFX_IOCTL_RETURN_EDID	(0xAD)
+#define UFX_IOCTL_REPORT_DAMAGE	(0xAA)
+
+/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
+#define BULK_SIZE		(512)
+#define MAX_TRANSFER		(PAGE_SIZE*16 - BULK_SIZE)
+#define WRITES_IN_FLIGHT	(4)
+
+#define GET_URB_TIMEOUT		(HZ)
+#define FREE_URB_TIMEOUT	(HZ*2)
+
+#define BPP			2
+
+#define UFX_DEFIO_WRITE_DELAY	5 /* fb_deferred_io.delay in jiffies */
+#define UFX_DEFIO_WRITE_DISABLE	(HZ*60) /* "disable" with long delay */
+
+struct dloarea {
+	int x, y;
+	int w, h;
+};
+
+struct urb_node {
+	struct list_head entry;
+	struct ufx_data *dev;
+	struct delayed_work release_urb_work;
+	struct urb *urb;
+};
+
+struct urb_list {
+	struct list_head list;
+	spinlock_t lock;
+	struct semaphore limit_sem;
+	int available;
+	int count;
+	size_t size;
+};
+
+struct ufx_data {
+	struct usb_device *udev;
+	struct device *gdev; /* &udev->dev */
+	struct fb_info *info;
+	struct urb_list urbs;
+	struct kref kref;
+	int fb_count;
+	bool virtualized; /* true when physical usb device not present */
+	struct delayed_work free_framebuffer_work;
+	atomic_t usb_active; /* 0 = update virtual buffer, but no usb traffic */
+	atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */
+	char *edid; /* null until we read edid from hw or get from sysfs */
+	size_t edid_size;
+	u32 pseudo_palette[256];
+};
+
+static struct fb_fix_screeninfo ufx_fix = {
+	.id =           "smscufx",
+	.type =         FB_TYPE_PACKED_PIXELS,
+	.visual =       FB_VISUAL_TRUECOLOR,
+	.xpanstep =     0,
+	.ypanstep =     0,
+	.ywrapstep =    0,
+	.accel =        FB_ACCEL_NONE,
+};
+
+static const u32 smscufx_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
+	FBINFO_VIRTFB |	FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
+	FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
+
+static struct usb_device_id id_table[] = {
+	{USB_DEVICE(0x0424, 0x9d00),},
+	{USB_DEVICE(0x0424, 0x9d01),},
+	{},
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/* module options */
+static int console;   /* Optionally allow fbcon to consume first framebuffer */
+static int fb_defio = true;  /* Optionally enable fb_defio mmap support */
+
+/* ufx keeps a list of urbs for efficient bulk transfers */
+static void ufx_urb_completion(struct urb *urb);
+static struct urb *ufx_get_urb(struct ufx_data *dev);
+static int ufx_submit_urb(struct ufx_data *dev, struct urb * urb, size_t len);
+static int ufx_alloc_urb_list(struct ufx_data *dev, int count, size_t size);
+static void ufx_free_urb_list(struct ufx_data *dev);
+
+/* reads a control register */
+static int ufx_reg_read(struct ufx_data *dev, u32 index, u32 *data)
+{
+	u32 *buf = kmalloc(4, GFP_KERNEL);
+	int ret;
+
+	BUG_ON(!dev);
+
+	if (!buf)
+		return -ENOMEM;
+
+	ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
+		USB_VENDOR_REQUEST_READ_REGISTER,
+		USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+		00, index, buf, 4, USB_CTRL_GET_TIMEOUT);
+
+	le32_to_cpus(buf);
+	*data = *buf;
+	kfree(buf);
+
+	if (unlikely(ret < 0))
+		pr_warn("Failed to read register index 0x%08x\n", index);
+
+	return ret;
+}
+
+/* writes a control register */
+static int ufx_reg_write(struct ufx_data *dev, u32 index, u32 data)
+{
+	u32 *buf = kmalloc(4, GFP_KERNEL);
+	int ret;
+
+	BUG_ON(!dev);
+
+	if (!buf)
+		return -ENOMEM;
+
+	*buf = data;
+	cpu_to_le32s(buf);
+
+	ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
+		USB_VENDOR_REQUEST_WRITE_REGISTER,
+		USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+		00, index, buf, 4, USB_CTRL_SET_TIMEOUT);
+
+	kfree(buf);
+
+	if (unlikely(ret < 0))
+		pr_warn("Failed to write register index 0x%08x with value "
+			"0x%08x\n", index, data);
+
+	return ret;
+}
+
+static int ufx_reg_clear_and_set_bits(struct ufx_data *dev, u32 index,
+	u32 bits_to_clear, u32 bits_to_set)
+{
+	u32 data;
+	int status = ufx_reg_read(dev, index, &data);
+	check_warn_return(status, "ufx_reg_clear_and_set_bits error reading "
+		"0x%x", index);
+
+	data &= (~bits_to_clear);
+	data |= bits_to_set;
+
+	status = ufx_reg_write(dev, index, data);
+	check_warn_return(status, "ufx_reg_clear_and_set_bits error writing "
+		"0x%x", index);
+
+	return 0;
+}
+
+static int ufx_reg_set_bits(struct ufx_data *dev, u32 index, u32 bits)
+{
+	return ufx_reg_clear_and_set_bits(dev, index, 0, bits);
+}
+
+static int ufx_reg_clear_bits(struct ufx_data *dev, u32 index, u32 bits)
+{
+	return ufx_reg_clear_and_set_bits(dev, index, bits, 0);
+}
+
+static int ufx_lite_reset(struct ufx_data *dev)
+{
+	int status;
+	u32 value;
+
+	status = ufx_reg_write(dev, 0x3008, 0x00000001);
+	check_warn_return(status, "ufx_lite_reset error writing 0x3008");
+
+	status = ufx_reg_read(dev, 0x3008, &value);
+	check_warn_return(status, "ufx_lite_reset error reading 0x3008");
+
+	return (value == 0) ? 0 : -EIO;
+}
+
+/* If display is unblanked, then blank it */
+static int ufx_blank(struct ufx_data *dev, bool wait)
+{
+	u32 dc_ctrl, dc_sts;
+	int i;
+
+	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
+	check_warn_return(status, "ufx_blank error reading 0x2004");
+
+	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
+	check_warn_return(status, "ufx_blank error reading 0x2000");
+
+	/* return success if display is already blanked */
+	if ((dc_sts & 0x00000100) || (dc_ctrl & 0x00000100))
+		return 0;
+
+	/* request the DC to blank the display */
+	dc_ctrl |= 0x00000100;
+	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
+	check_warn_return(status, "ufx_blank error writing 0x2000");
+
+	/* return success immediately if we don't have to wait */
+	if (!wait)
+		return 0;
+
+	for (i = 0; i < 250; i++) {
+		status = ufx_reg_read(dev, 0x2004, &dc_sts);
+		check_warn_return(status, "ufx_blank error reading 0x2004");
+
+		if (dc_sts & 0x00000100)
+			return 0;
+	}
+
+	/* timed out waiting for display to blank */
+	return -EIO;
+}
+
+/* If display is blanked, then unblank it */
+static int ufx_unblank(struct ufx_data *dev, bool wait)
+{
+	u32 dc_ctrl, dc_sts;
+	int i;
+
+	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
+	check_warn_return(status, "ufx_unblank error reading 0x2004");
+
+	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
+	check_warn_return(status, "ufx_unblank error reading 0x2000");
+
+	/* return success if display is already unblanked */
+	if (((dc_sts & 0x00000100) == 0) || ((dc_ctrl & 0x00000100) == 0))
+		return 0;
+
+	/* request the DC to unblank the display */
+	dc_ctrl &= ~0x00000100;
+	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
+	check_warn_return(status, "ufx_unblank error writing 0x2000");
+
+	/* return success immediately if we don't have to wait */
+	if (!wait)
+		return 0;
+
+	for (i = 0; i < 250; i++) {
+		status = ufx_reg_read(dev, 0x2004, &dc_sts);
+		check_warn_return(status, "ufx_unblank error reading 0x2004");
+
+		if ((dc_sts & 0x00000100) == 0)
+			return 0;
+	}
+
+	/* timed out waiting for display to unblank */
+	return -EIO;
+}
+
+/* If display is enabled, then disable it */
+static int ufx_disable(struct ufx_data *dev, bool wait)
+{
+	u32 dc_ctrl, dc_sts;
+	int i;
+
+	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
+	check_warn_return(status, "ufx_disable error reading 0x2004");
+
+	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
+	check_warn_return(status, "ufx_disable error reading 0x2000");
+
+	/* return success if display is already disabled */
+	if (((dc_sts & 0x00000001) == 0) || ((dc_ctrl & 0x00000001) == 0))
+		return 0;
+
+	/* request the DC to disable the display */
+	dc_ctrl &= ~(0x00000001);
+	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
+	check_warn_return(status, "ufx_disable error writing 0x2000");
+
+	/* return success immediately if we don't have to wait */
+	if (!wait)
+		return 0;
+
+	for (i = 0; i < 250; i++) {
+		status = ufx_reg_read(dev, 0x2004, &dc_sts);
+		check_warn_return(status, "ufx_disable error reading 0x2004");
+
+		if ((dc_sts & 0x00000001) == 0)
+			return 0;
+	}
+
+	/* timed out waiting for display to disable */
+	return -EIO;
+}
+
+/* If display is disabled, then enable it */
+static int ufx_enable(struct ufx_data *dev, bool wait)
+{
+	u32 dc_ctrl, dc_sts;
+	int i;
+
+	int status = ufx_reg_read(dev, 0x2004, &dc_sts);
+	check_warn_return(status, "ufx_enable error reading 0x2004");
+
+	status = ufx_reg_read(dev, 0x2000, &dc_ctrl);
+	check_warn_return(status, "ufx_enable error reading 0x2000");
+
+	/* return success if display is already enabled */
+	if ((dc_sts & 0x00000001) || (dc_ctrl & 0x00000001))
+		return 0;
+
+	/* request the DC to enable the display */
+	dc_ctrl |= 0x00000001;
+	status = ufx_reg_write(dev, 0x2000, dc_ctrl);
+	check_warn_return(status, "ufx_enable error writing 0x2000");
+
+	/* return success immediately if we don't have to wait */
+	if (!wait)
+		return 0;
+
+	for (i = 0; i < 250; i++) {
+		status = ufx_reg_read(dev, 0x2004, &dc_sts);
+		check_warn_return(status, "ufx_enable error reading 0x2004");
+
+		if (dc_sts & 0x00000001)
+			return 0;
+	}
+
+	/* timed out waiting for display to enable */
+	return -EIO;
+}
+
+static int ufx_config_sys_clk(struct ufx_data *dev)
+{
+	int status = ufx_reg_write(dev, 0x700C, 0x8000000F);
+	check_warn_return(status, "error writing 0x700C");
+
+	status = ufx_reg_write(dev, 0x7014, 0x0010024F);
+	check_warn_return(status, "error writing 0x7014");
+
+	status = ufx_reg_write(dev, 0x7010, 0x00000000);
+	check_warn_return(status, "error writing 0x7010");
+
+	status = ufx_reg_clear_bits(dev, 0x700C, 0x0000000A);
+	check_warn_return(status, "error clearing PLL1 bypass in 0x700C");
+	msleep(1);
+
+	status = ufx_reg_clear_bits(dev, 0x700C, 0x80000000);
+	check_warn_return(status, "error clearing output gate in 0x700C");
+
+	return 0;
+}
+
+static int ufx_config_ddr2(struct ufx_data *dev)
+{
+	int status, i = 0;
+	u32 tmp;
+
+	status = ufx_reg_write(dev, 0x0004, 0x001F0F77);
+	check_warn_return(status, "error writing 0x0004");
+
+	status = ufx_reg_write(dev, 0x0008, 0xFFF00000);
+	check_warn_return(status, "error writing 0x0008");
+
+	status = ufx_reg_write(dev, 0x000C, 0x0FFF2222);
+	check_warn_return(status, "error writing 0x000C");
+
+	status = ufx_reg_write(dev, 0x0010, 0x00030814);
+	check_warn_return(status, "error writing 0x0010");
+
+	status = ufx_reg_write(dev, 0x0014, 0x00500019);
+	check_warn_return(status, "error writing 0x0014");
+
+	status = ufx_reg_write(dev, 0x0018, 0x020D0F15);
+	check_warn_return(status, "error writing 0x0018");
+
+	status = ufx_reg_write(dev, 0x001C, 0x02532305);
+	check_warn_return(status, "error writing 0x001C");
+
+	status = ufx_reg_write(dev, 0x0020, 0x0B030905);
+	check_warn_return(status, "error writing 0x0020");
+
+	status = ufx_reg_write(dev, 0x0024, 0x00000827);
+	check_warn_return(status, "error writing 0x0024");
+
+	status = ufx_reg_write(dev, 0x0028, 0x00000000);
+	check_warn_return(status, "error writing 0x0028");
+
+	status = ufx_reg_write(dev, 0x002C, 0x00000042);
+	check_warn_return(status, "error writing 0x002C");
+
+	status = ufx_reg_write(dev, 0x0030, 0x09520000);
+	check_warn_return(status, "error writing 0x0030");
+
+	status = ufx_reg_write(dev, 0x0034, 0x02223314);
+	check_warn_return(status, "error writing 0x0034");
+
+	status = ufx_reg_write(dev, 0x0038, 0x00430043);
+	check_warn_return(status, "error writing 0x0038");
+
+	status = ufx_reg_write(dev, 0x003C, 0xF00F000F);
+	check_warn_return(status, "error writing 0x003C");
+
+	status = ufx_reg_write(dev, 0x0040, 0xF380F00F);
+	check_warn_return(status, "error writing 0x0040");
+
+	status = ufx_reg_write(dev, 0x0044, 0xF00F0496);
+	check_warn_return(status, "error writing 0x0044");
+
+	status = ufx_reg_write(dev, 0x0048, 0x03080406);
+	check_warn_return(status, "error writing 0x0048");
+
+	status = ufx_reg_write(dev, 0x004C, 0x00001000);
+	check_warn_return(status, "error writing 0x004C");
+
+	status = ufx_reg_write(dev, 0x005C, 0x00000007);
+	check_warn_return(status, "error writing 0x005C");
+
+	status = ufx_reg_write(dev, 0x0100, 0x54F00012);
+	check_warn_return(status, "error writing 0x0100");
+
+	status = ufx_reg_write(dev, 0x0104, 0x00004012);
+	check_warn_return(status, "error writing 0x0104");
+
+	status = ufx_reg_write(dev, 0x0118, 0x40404040);
+	check_warn_return(status, "error writing 0x0118");
+
+	status = ufx_reg_write(dev, 0x0000, 0x00000001);
+	check_warn_return(status, "error writing 0x0000");
+
+	while (i++ < 500) {
+		status = ufx_reg_read(dev, 0x0000, &tmp);
+		check_warn_return(status, "error reading 0x0000");
+
+		if (all_bits_set(tmp, 0xC0000000))
+			return 0;
+	}
+
+	pr_err("DDR2 initialisation timed out, reg 0x0000=0x%08x", tmp);
+	return -ETIMEDOUT;
+}
+
+struct pll_values {
+	u32 div_r0;
+	u32 div_f0;
+	u32 div_q0;
+	u32 range0;
+	u32 div_r1;
+	u32 div_f1;
+	u32 div_q1;
+	u32 range1;
+};
+
+static u32 ufx_calc_range(u32 ref_freq)
+{
+	if (ref_freq >= 88000000)
+		return 7;
+
+	if (ref_freq >= 54000000)
+		return 6;
+
+	if (ref_freq >= 34000000)
+		return 5;
+
+	if (ref_freq >= 21000000)
+		return 4;
+
+	if (ref_freq >= 13000000)
+		return 3;
+
+	if (ref_freq >= 8000000)
+		return 2;
+
+	return 1;
+}
+
+/* calculates PLL divider settings for a desired target frequency */
+static void ufx_calc_pll_values(const u32 clk_pixel_pll, struct pll_values *asic_pll)
+{
+	const u32 ref_clk = 25000000;
+	u32 div_r0, div_f0, div_q0, div_r1, div_f1, div_q1;
+	u32 min_error = clk_pixel_pll;
+
+	for (div_r0 = 1; div_r0 <= 32; div_r0++) {
+		u32 ref_freq0 = ref_clk / div_r0;
+		if (ref_freq0 < 5000000)
+			break;
+
+		if (ref_freq0 > 200000000)
+			continue;
+
+		for (div_f0 = 1; div_f0 <= 256; div_f0++) {
+			u32 vco_freq0 = ref_freq0 * div_f0;
+
+			if (vco_freq0 < 350000000)
+				continue;
+
+			if (vco_freq0 > 700000000)
+				break;
+
+			for (div_q0 = 0; div_q0 < 7; div_q0++) {
+				u32 pllout_freq0 = vco_freq0 / (1 << div_q0);
+
+				if (pllout_freq0 < 5000000)
+					break;
+
+				if (pllout_freq0 > 200000000)
+					continue;
+
+				for (div_r1 = 1; div_r1 <= 32; div_r1++) {
+					u32 ref_freq1 = pllout_freq0 / div_r1;
+
+					if (ref_freq1 < 5000000)
+						break;
+
+					for (div_f1 = 1; div_f1 <= 256; div_f1++) {
+						u32 vco_freq1 = ref_freq1 * div_f1;
+
+						if (vco_freq1 < 350000000)
+							continue;
+
+						if (vco_freq1 > 700000000)
+							break;
+
+						for (div_q1 = 0; div_q1 < 7; div_q1++) {
+							u32 pllout_freq1 = vco_freq1 / (1 << div_q1);
+							int error = abs(pllout_freq1 - clk_pixel_pll);
+
+							if (pllout_freq1 < 5000000)
+								break;
+
+							if (pllout_freq1 > 700000000)
+								continue;
+
+							if (error < min_error) {
+								min_error = error;
+
+								/* final returned value is equal to calculated value - 1
+								 * because a value of 0 = divide by 1 */
+								asic_pll->div_r0 = div_r0 - 1;
+								asic_pll->div_f0 = div_f0 - 1;
+								asic_pll->div_q0 = div_q0;
+								asic_pll->div_r1 = div_r1 - 1;
+								asic_pll->div_f1 = div_f1 - 1;
+								asic_pll->div_q1 = div_q1;
+
+								asic_pll->range0 = ufx_calc_range(ref_freq0);
+								asic_pll->range1 = ufx_calc_range(ref_freq1);
+
+								if (min_error == 0)
+									return;
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+/* sets analog bit PLL configuration values */
+static int ufx_config_pix_clk(struct ufx_data *dev, u32 pixclock)
+{
+	struct pll_values asic_pll = {0};
+	u32 value, clk_pixel, clk_pixel_pll;
+	int status;
+
+	/* convert pixclock (in ps) to frequency (in Hz) */
+	clk_pixel = PICOS2KHZ(pixclock) * 1000;
+	pr_info("pixclock %d ps = clk_pixel %d Hz", pixclock, clk_pixel);
+
+	/* clk_pixel = 1/2 clk_pixel_pll */
+	clk_pixel_pll = clk_pixel * 2;
+
+	ufx_calc_pll_values(clk_pixel_pll, &asic_pll);
+
+	/* Keep BYPASS and RESET signals asserted until configured */
+	status = ufx_reg_write(dev, 0x7000, 0x8000000F);
+	check_warn_return(status, "error writing 0x7000");
+
+	value = (asic_pll.div_f1 | (asic_pll.div_r1 << 8) |
+		(asic_pll.div_q1 << 16) | (asic_pll.range1 << 20));
+	status = ufx_reg_write(dev, 0x7008, value);
+	check_warn_return(status, "error writing 0x7008");
+
+	value = (asic_pll.div_f0 | (asic_pll.div_r0 << 8) |
+		(asic_pll.div_q0 << 16) | (asic_pll.range0 << 20));
+	status = ufx_reg_write(dev, 0x7004, value);
+	check_warn_return(status, "error writing 0x7004");
+
+	status = ufx_reg_clear_bits(dev, 0x7000, 0x00000005);
+	check_warn_return(status,
+		"error clearing PLL0 bypass bits in 0x7000");
+	msleep(1);
+
+	status = ufx_reg_clear_bits(dev, 0x7000, 0x0000000A);
+	check_warn_return(status,
+		"error clearing PLL1 bypass bits in 0x7000");
+	msleep(1);
+
+	status = ufx_reg_clear_bits(dev, 0x7000, 0x80000000);
+	check_warn_return(status, "error clearing gate bits in 0x7000");
+
+	return 0;
+}
+
+static int ufx_set_vid_mode(struct ufx_data *dev, struct fb_var_screeninfo *var)
+{
+	u32 temp;
+	u16 h_total, h_active, h_blank_start, h_blank_end, h_sync_start, h_sync_end;
+	u16 v_total, v_active, v_blank_start, v_blank_end, v_sync_start, v_sync_end;
+
+	int status = ufx_reg_write(dev, 0x8028, 0);
+	check_warn_return(status, "ufx_set_vid_mode error disabling RGB pad");
+
+	status = ufx_reg_write(dev, 0x8024, 0);
+	check_warn_return(status, "ufx_set_vid_mode error disabling VDAC");
+
+	/* shut everything down before changing timing */
+	status = ufx_blank(dev, true);
+	check_warn_return(status, "ufx_set_vid_mode error blanking display");
+
+	status = ufx_disable(dev, true);
+	check_warn_return(status, "ufx_set_vid_mode error disabling display");
+
+	status = ufx_config_pix_clk(dev, var->pixclock);
+	check_warn_return(status, "ufx_set_vid_mode error configuring pixclock");
+
+	status = ufx_reg_write(dev, 0x2000, 0x00000104);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2000");
+
+	/* set horizontal timings */
+	h_total = var->xres + var->right_margin + var->hsync_len + var->left_margin;
+	h_active = var->xres;
+	h_blank_start = var->xres + var->right_margin;
+	h_blank_end = var->xres + var->right_margin + var->hsync_len;
+	h_sync_start = var->xres + var->right_margin;
+	h_sync_end = var->xres + var->right_margin + var->hsync_len;
+
+	temp = ((h_total - 1) << 16) | (h_active - 1);
+	status = ufx_reg_write(dev, 0x2008, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2008");
+
+	temp = ((h_blank_start - 1) << 16) | (h_blank_end - 1);
+	status = ufx_reg_write(dev, 0x200C, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x200C");
+
+	temp = ((h_sync_start - 1) << 16) | (h_sync_end - 1);
+	status = ufx_reg_write(dev, 0x2010, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2010");
+
+	/* set vertical timings */
+	v_total = var->upper_margin + var->yres + var->lower_margin + var->vsync_len;
+	v_active = var->yres;
+	v_blank_start = var->yres + var->lower_margin;
+	v_blank_end = var->yres + var->lower_margin + var->vsync_len;
+	v_sync_start = var->yres + var->lower_margin;
+	v_sync_end = var->yres + var->lower_margin + var->vsync_len;
+
+	temp = ((v_total - 1) << 16) | (v_active - 1);
+	status = ufx_reg_write(dev, 0x2014, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2014");
+
+	temp = ((v_blank_start - 1) << 16) | (v_blank_end - 1);
+	status = ufx_reg_write(dev, 0x2018, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2018");
+
+	temp = ((v_sync_start - 1) << 16) | (v_sync_end - 1);
+	status = ufx_reg_write(dev, 0x201C, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x201C");
+
+	status = ufx_reg_write(dev, 0x2020, 0x00000000);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2020");
+
+	status = ufx_reg_write(dev, 0x2024, 0x00000000);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2024");
+
+	/* Set the frame length register (#pix * 2 bytes/pixel) */
+	temp = var->xres * var->yres * 2;
+	temp = (temp + 7) & (~0x7);
+	status = ufx_reg_write(dev, 0x2028, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2028");
+
+	/* enable desired output interface & disable others */
+	status = ufx_reg_write(dev, 0x2040, 0);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2040");
+
+	status = ufx_reg_write(dev, 0x2044, 0);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2044");
+
+	status = ufx_reg_write(dev, 0x2048, 0);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2048");
+
+	/* set the sync polarities & enable bit */
+	temp = 0x00000001;
+	if (var->sync & FB_SYNC_HOR_HIGH_ACT)
+		temp |= 0x00000010;
+
+	if (var->sync & FB_SYNC_VERT_HIGH_ACT)
+		temp |= 0x00000008;
+
+	status = ufx_reg_write(dev, 0x2040, temp);
+	check_warn_return(status, "ufx_set_vid_mode error writing 0x2040");
+
+	/* start everything back up */
+	status = ufx_enable(dev, true);
+	check_warn_return(status, "ufx_set_vid_mode error enabling display");
+
+	/* Unblank the display */
+	status = ufx_unblank(dev, true);
+	check_warn_return(status, "ufx_set_vid_mode error unblanking display");
+
+	/* enable RGB pad */
+	status = ufx_reg_write(dev, 0x8028, 0x00000003);
+	check_warn_return(status, "ufx_set_vid_mode error enabling RGB pad");
+
+	/* enable VDAC */
+	status = ufx_reg_write(dev, 0x8024, 0x00000007);
+	check_warn_return(status, "ufx_set_vid_mode error enabling VDAC");
+
+	return 0;
+}
+
+static int ufx_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	unsigned long start = vma->vm_start;
+	unsigned long size = vma->vm_end - vma->vm_start;
+	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+	unsigned long page, pos;
+
+	if (offset + size > info->fix.smem_len)
+		return -EINVAL;
+
+	pos = (unsigned long)info->fix.smem_start + offset;
+
+	pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
+		  pos, size);
+
+	while (size > 0) {
+		page = vmalloc_to_pfn((void *)pos);
+		if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
+			return -EAGAIN;
+
+		start += PAGE_SIZE;
+		pos += PAGE_SIZE;
+		if (size > PAGE_SIZE)
+			size -= PAGE_SIZE;
+		else
+			size = 0;
+	}
+
+	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
+	return 0;
+}
+
+static char *ufx_raw_rect(struct ufx_data *dev, char *cmd, int x, int y,
+	int width, int height)
+{
+	size_t packed_line_len = ALIGN((width * 2), 4);
+	size_t packed_rect_len = packed_line_len * height;
+	int i;
+
+	BUG_ON(!dev);
+	BUG_ON(!dev->info);
+
+	/* command word */
+	*cmd = 0x01;
+	cmd += 4;
+
+	/* length word */
+	*((u32 *)cmd) = cpu_to_le32(packed_rect_len + 16);
+	cmd += 4;
+
+	*((u16 *)cmd) = cpu_to_le16(x);
+	cmd += 2;
+
+	*((u16 *)cmd) = cpu_to_le16(y);
+	cmd += 2;
+
+	*((u16 *)cmd) = cpu_to_le16(width);
+	cmd += 2;
+
+	*((u16 *)cmd) = cpu_to_le16(height);
+	cmd += 2;
+
+	/* frame base address */
+	*((u32 *)cmd) = cpu_to_le32(0 & 0xffffff80);
+	cmd += 4;
+
+	/* color mode and horizontal resolution */
+	*((u16 *)cmd) = cpu_to_le16(0x4000 | dev->info->var.xres);
+	cmd += 2;
+
+	/* vertical resolution */
+	*((u16 *)cmd) = cpu_to_le16(dev->info->var.yres);
+	cmd += 2;
+
+	/* packed data */
+	for (i = y; i < y + height ; i++) {
+		const int line_offset = dev->info->fix.line_length * i;
+		const int byte_offset = line_offset + (x * BPP);
+		memcpy(cmd, (char *) dev->info->fix.smem_start + byte_offset, (width * BPP));
+
+		/* include line padding */
+		cmd += packed_line_len;
+	}
+
+	return cmd;
+}
+
+int ufx_handle_damage(struct ufx_data *dev, int x, int y,
+	int width, int height)
+{
+	size_t packed_line_len = ALIGN((width * 2), 4);
+	int len, status, urb_lines, start_line = 0;
+	char *cmd;
+
+	if ((width <= 0) || (height <= 0) ||
+	    (x + width > dev->info->var.xres) ||
+	    (y + height > dev->info->var.yres))
+		return -EINVAL;
+
+	if (!atomic_read(&dev->usb_active))
+		return 0;
+
+	while (start_line < height) {
+		struct urb *urb = ufx_get_urb(dev);
+		if (!urb) {
+			pr_warn("ufx_handle_damage unable to get urb");
+			return 0;
+		}
+
+		/* assume we have enough space to transfer at least one line */
+		BUG_ON(urb->transfer_buffer_length < (24 + (width * 2)));
+
+		/* calculate the maximum number of lines we could fit in */
+		urb_lines = (urb->transfer_buffer_length - 24) / packed_line_len;
+
+		/* but we might not need this many */
+		urb_lines = min(urb_lines, (height - start_line));
+
+		memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
+
+		cmd = ufx_raw_rect(dev, urb->transfer_buffer, x, (y + start_line), width, urb_lines);
+
+		len = cmd - (char *) urb->transfer_buffer;
+		BUG_ON(len != (24 + (packed_line_len * urb_lines)));
+
+		status = ufx_submit_urb(dev, urb, len);
+		check_warn_return(status, "Error submitting URB");
+
+		start_line += urb_lines;
+	}
+
+	return 0;
+}
+
+/* Path triggered by usermode clients who write to filesystem
+ * e.g. cat filename > /dev/fb1
+ * Not used by X Windows or text-mode console. But useful for testing.
+ * Slow because of extra copy and we must assume all pixels dirty. */
+static ssize_t ufx_ops_write(struct fb_info *info, const char __user *buf,
+			  size_t count, loff_t *ppos)
+{
+	ssize_t result;
+	struct ufx_data *dev = info->par;
+	u32 offset = (u32) *ppos;
+
+	result = fb_sys_write(info, buf, count, ppos);
+
+	if (result > 0) {
+		int start = max((int)(offset / info->fix.line_length) - 1, 0);
+		int lines = min((u32)((result / info->fix.line_length) + 1),
+				(u32)info->var.yres);
+
+		ufx_handle_damage(dev, 0, start, info->var.xres, lines);
+	}
+
+	return result;
+}
+
+static void ufx_ops_copyarea(struct fb_info *info,
+				const struct fb_copyarea *area)
+{
+
+	struct ufx_data *dev = info->par;
+
+	sys_copyarea(info, area);
+
+	ufx_handle_damage(dev, area->dx, area->dy,
+			area->width, area->height);
+}
+
+static void ufx_ops_imageblit(struct fb_info *info,
+				const struct fb_image *image)
+{
+	struct ufx_data *dev = info->par;
+
+	sys_imageblit(info, image);
+
+	ufx_handle_damage(dev, image->dx, image->dy,
+			image->width, image->height);
+}
+
+static void ufx_ops_fillrect(struct fb_info *info,
+			  const struct fb_fillrect *rect)
+{
+	struct ufx_data *dev = info->par;
+
+	sys_fillrect(info, rect);
+
+	ufx_handle_damage(dev, rect->dx, rect->dy, rect->width,
+			      rect->height);
+}
+
+/* NOTE: fb_defio.c is holding info->fbdefio.mutex
+ *   Touching ANY framebuffer memory that triggers a page fault
+ *   in fb_defio will cause a deadlock, when it also tries to
+ *   grab the same mutex. */
+static void ufx_dpy_deferred_io(struct fb_info *info,
+				struct list_head *pagelist)
+{
+	struct page *cur;
+	struct fb_deferred_io *fbdefio = info->fbdefio;
+	struct ufx_data *dev = info->par;
+
+	if (!fb_defio)
+		return;
+
+	if (!atomic_read(&dev->usb_active))
+		return;
+
+	/* walk the written page list and render each to device */
+	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
+		/* create a rectangle of full screen width that encloses the
+		 * entire dirty framebuffer page */
+		const int x = 0;
+		const int width = dev->info->var.xres;
+		const int y = (cur->index << PAGE_SHIFT) / (width * 2);
+		int height = (PAGE_SIZE / (width * 2)) + 1;
+		height = min(height, (int)(dev->info->var.yres - y));
+
+		BUG_ON(y >= dev->info->var.yres);
+		BUG_ON((y + height) > dev->info->var.yres);
+
+		ufx_handle_damage(dev, x, y, width, height);
+	}
+}
+
+static int ufx_ops_ioctl(struct fb_info *info, unsigned int cmd,
+			 unsigned long arg)
+{
+	struct ufx_data *dev = info->par;
+	struct dloarea *area = NULL;
+
+	if (!atomic_read(&dev->usb_active))
+		return 0;
+
+	/* TODO: Update X server to get this from sysfs instead */
+	if (cmd == UFX_IOCTL_RETURN_EDID) {
+		char *edid = (char *)arg;
+		if (copy_to_user(edid, dev->edid, dev->edid_size))
+			return -EFAULT;
+		return 0;
+	}
+
+	/* TODO: Help propose a standard fb.h ioctl to report mmap damage */
+	if (cmd == UFX_IOCTL_REPORT_DAMAGE) {
+		/* If we have a damage-aware client, turn fb_defio "off"
+		 * To avoid perf imact of unecessary page fault handling.
+		 * Done by resetting the delay for this fb_info to a very
+		 * long period. Pages will become writable and stay that way.
+		 * Reset to normal value when all clients have closed this fb.
+		 */
+		if (info->fbdefio)
+			info->fbdefio->delay = UFX_DEFIO_WRITE_DISABLE;
+
+		area = (struct dloarea *)arg;
+
+		if (area->x < 0)
+			area->x = 0;
+
+		if (area->x > info->var.xres)
+			area->x = info->var.xres;
+
+		if (area->y < 0)
+			area->y = 0;
+
+		if (area->y > info->var.yres)
+			area->y = info->var.yres;
+
+		ufx_handle_damage(dev, area->x, area->y, area->w, area->h);
+	}
+
+	return 0;
+}
+
+/* taken from vesafb */
+static int
+ufx_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
+	       unsigned blue, unsigned transp, struct fb_info *info)
+{
+	int err = 0;
+
+	if (regno >= info->cmap.len)
+		return 1;
+
+	if (regno < 16) {
+		if (info->var.red.offset == 10) {
+			/* 1:5:5:5 */
+			((u32 *) (info->pseudo_palette))[regno] =
+			    ((red & 0xf800) >> 1) |
+			    ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
+		} else {
+			/* 0:5:6:5 */
+			((u32 *) (info->pseudo_palette))[regno] =
+			    ((red & 0xf800)) |
+			    ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
+		}
+	}
+
+	return err;
+}
+
+/* It's common for several clients to have framebuffer open simultaneously.
+ * e.g. both fbcon and X. Makes things interesting.
+ * Assumes caller is holding info->lock (for open and release at least) */
+static int ufx_ops_open(struct fb_info *info, int user)
+{
+	struct ufx_data *dev = info->par;
+
+	/* fbcon aggressively connects to first framebuffer it finds,
+	 * preventing other clients (X) from working properly. Usually
+	 * not what the user wants. Fail by default with option to enable. */
+	if ((user == 0) & (!console))
+		return -EBUSY;
+
+	/* If the USB device is gone, we don't accept new opens */
+	if (dev->virtualized)
+		return -ENODEV;
+
+	dev->fb_count++;
+
+	kref_get(&dev->kref);
+
+	if (fb_defio && (info->fbdefio == NULL)) {
+		/* enable defio at last moment if not disabled by client */
+
+		struct fb_deferred_io *fbdefio;
+
+		fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
+
+		if (fbdefio) {
+			fbdefio->delay = UFX_DEFIO_WRITE_DELAY;
+			fbdefio->deferred_io = ufx_dpy_deferred_io;
+		}
+
+		info->fbdefio = fbdefio;
+		fb_deferred_io_init(info);
+	}
+
+	pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d",
+		info->node, user, info, dev->fb_count);
+
+	return 0;
+}
+
+/*
+ * Called when all client interfaces to start transactions have been disabled,
+ * and all references to our device instance (ufx_data) are released.
+ * Every transaction must have a reference, so we know are fully spun down
+ */
+static void ufx_free(struct kref *kref)
+{
+	struct ufx_data *dev = container_of(kref, struct ufx_data, kref);
+
+	/* this function will wait for all in-flight urbs to complete */
+	if (dev->urbs.count > 0)
+		ufx_free_urb_list(dev);
+
+	pr_warn("freeing ufx_data %p", dev);
+
+	kfree(dev);
+}
+
+static void ufx_release_urb_work(struct work_struct *work)
+{
+	struct urb_node *unode = container_of(work, struct urb_node,
+					      release_urb_work.work);
+
+	up(&unode->dev->urbs.limit_sem);
+}
+
+static void ufx_free_framebuffer_work(struct work_struct *work)
+{
+	struct ufx_data *dev = container_of(work, struct ufx_data,
+					    free_framebuffer_work.work);
+	struct fb_info *info = dev->info;
+	int node = info->node;
+
+	unregister_framebuffer(info);
+
+	if (info->cmap.len != 0)
+		fb_dealloc_cmap(&info->cmap);
+	if (info->monspecs.modedb)
+		fb_destroy_modedb(info->monspecs.modedb);
+	if (info->screen_base)
+		vfree(info->screen_base);
+
+	fb_destroy_modelist(&info->modelist);
+
+	dev->info = 0;
+
+	/* Assume info structure is freed after this point */
+	framebuffer_release(info);
+
+	pr_warn("fb_info for /dev/fb%d has been freed", node);
+
+	/* ref taken in probe() as part of registering framebfufer */
+	kref_put(&dev->kref, ufx_free);
+}
+
+/*
+ * Assumes caller is holding info->lock mutex (for open and release at least)
+ */
+static int ufx_ops_release(struct fb_info *info, int user)
+{
+	struct ufx_data *dev = info->par;
+
+	dev->fb_count--;
+
+	/* We can't free fb_info here - fbmem will touch it when we return */
+	if (dev->virtualized && (dev->fb_count == 0))
+		schedule_delayed_work(&dev->free_framebuffer_work, HZ);
+
+	if ((dev->fb_count == 0) && (info->fbdefio)) {
+		fb_deferred_io_cleanup(info);
+		kfree(info->fbdefio);
+		info->fbdefio = NULL;
+		info->fbops->fb_mmap = ufx_ops_mmap;
+	}
+
+	pr_warn("released /dev/fb%d user=%d count=%d",
+		  info->node, user, dev->fb_count);
+
+	kref_put(&dev->kref, ufx_free);
+
+	return 0;
+}
+
+/* Check whether a video mode is supported by the chip
+ * We start from monitor's modes, so don't need to filter that here */
+static int ufx_is_valid_mode(struct fb_videomode *mode,
+		struct fb_info *info)
+{
+	if ((mode->xres * mode->yres) > (2048 * 1152)) {
+		pr_warn("%dx%d too many pixels",
+		       mode->xres, mode->yres);
+		return 0;
+	}
+
+	if (mode->pixclock < 5000) {
+		pr_warn("%dx%d %dps pixel clock too fast",
+		       mode->xres, mode->yres, mode->pixclock);
+		return 0;
+	}
+
+	pr_info("%dx%d (pixclk %dps %dMHz) valid mode", mode->xres, mode->yres,
+		mode->pixclock, (1000000 / mode->pixclock));
+	return 1;
+}
+
+static void ufx_var_color_format(struct fb_var_screeninfo *var)
+{
+	const struct fb_bitfield red = { 11, 5, 0 };
+	const struct fb_bitfield green = { 5, 6, 0 };
+	const struct fb_bitfield blue = { 0, 5, 0 };
+
+	var->bits_per_pixel = 16;
+	var->red = red;
+	var->green = green;
+	var->blue = blue;
+}
+
+static int ufx_ops_check_var(struct fb_var_screeninfo *var,
+				struct fb_info *info)
+{
+	struct fb_videomode mode;
+
+	/* TODO: support dynamically changing framebuffer size */
+	if ((var->xres * var->yres * 2) > info->fix.smem_len)
+		return -EINVAL;
+
+	/* set device-specific elements of var unrelated to mode */
+	ufx_var_color_format(var);
+
+	fb_var_to_videomode(&mode, var);
+
+	if (!ufx_is_valid_mode(&mode, info))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ufx_ops_set_par(struct fb_info *info)
+{
+	struct ufx_data *dev = info->par;
+	int result;
+	u16 *pix_framebuffer;
+	int i;
+
+	pr_notice("set_par mode %dx%d", info->var.xres, info->var.yres);
+	result = ufx_set_vid_mode(dev, &info->var);
+
+	if ((result == 0) && (dev->fb_count == 0)) {
+		/* paint greenscreen */
+		pix_framebuffer = (u16 *) info->screen_base;
+		for (i = 0; i < info->fix.smem_len / 2; i++)
+			pix_framebuffer[i] = 0x37e6;
+
+		ufx_handle_damage(dev, 0, 0, info->var.xres, info->var.yres);
+	}
+
+	return result;
+}
+
+/* In order to come back from full DPMS off, we need to set the mode again */
+static int ufx_ops_blank(int blank_mode, struct fb_info *info)
+{
+	struct ufx_data *dev = info->par;
+	ufx_set_vid_mode(dev, &info->var);
+	return 0;
+}
+
+static struct fb_ops ufx_ops = {
+	.owner = THIS_MODULE,
+	.fb_read = fb_sys_read,
+	.fb_write = ufx_ops_write,
+	.fb_setcolreg = ufx_ops_setcolreg,
+	.fb_fillrect = ufx_ops_fillrect,
+	.fb_copyarea = ufx_ops_copyarea,
+	.fb_imageblit = ufx_ops_imageblit,
+	.fb_mmap = ufx_ops_mmap,
+	.fb_ioctl = ufx_ops_ioctl,
+	.fb_open = ufx_ops_open,
+	.fb_release = ufx_ops_release,
+	.fb_blank = ufx_ops_blank,
+	.fb_check_var = ufx_ops_check_var,
+	.fb_set_par = ufx_ops_set_par,
+};
+
+/* Assumes &info->lock held by caller
+ * Assumes no active clients have framebuffer open */
+static int ufx_realloc_framebuffer(struct ufx_data *dev, struct fb_info *info)
+{
+	int retval = -ENOMEM;
+	int old_len = info->fix.smem_len;
+	int new_len;
+	unsigned char *old_fb = info->screen_base;
+	unsigned char *new_fb;
+
+	pr_warn("Reallocating framebuffer. Addresses will change!");
+
+	new_len = info->fix.line_length * info->var.yres;
+
+	if (PAGE_ALIGN(new_len) > old_len) {
+		/*
+		 * Alloc system memory for virtual framebuffer
+		 */
+		new_fb = vmalloc(new_len);
+		if (!new_fb) {
+			pr_err("Virtual framebuffer alloc failed");
+			goto error;
+		}
+
+		if (info->screen_base) {
+			memcpy(new_fb, old_fb, old_len);
+			vfree(info->screen_base);
+		}
+
+		info->screen_base = new_fb;
+		info->fix.smem_len = PAGE_ALIGN(new_len);
+		info->fix.smem_start = (unsigned long) new_fb;
+		info->flags = smscufx_info_flags;
+	}
+
+	retval = 0;
+
+error:
+	return retval;
+}
+
+/* sets up I2C Controller for 100 Kbps, std. speed, 7-bit addr, master,
+ * restart enabled, but no start byte, enable controller */
+static int ufx_i2c_init(struct ufx_data *dev)
+{
+	u32 tmp;
+
+	/* disable the controller before it can be reprogrammed */
+	int status = ufx_reg_write(dev, 0x106C, 0x00);
+	check_warn_return(status, "failed to disable I2C");
+
+	/* Setup the clock count registers
+	 * (12+1) = 13 clks @ 2.5 MHz = 5.2 uS */
+	status = ufx_reg_write(dev, 0x1018, 12);
+	check_warn_return(status, "error writing 0x1018");
+
+	/* (6+8) = 14 clks @ 2.5 MHz = 5.6 uS */
+	status = ufx_reg_write(dev, 0x1014, 6);
+	check_warn_return(status, "error writing 0x1014");
+
+	status = ufx_reg_read(dev, 0x1000, &tmp);
+	check_warn_return(status, "error reading 0x1000");
+
+	/* set speed to std mode */
+	tmp &= ~(0x06);
+	tmp |= 0x02;
+
+	/* 7-bit (not 10-bit) addressing */
+	tmp &= ~(0x10);
+
+	/* enable restart conditions and master mode */
+	tmp |= 0x21;
+
+	status = ufx_reg_write(dev, 0x1000, tmp);
+	check_warn_return(status, "error writing 0x1000");
+
+	/* Set normal tx using target address 0 */
+	status = ufx_reg_clear_and_set_bits(dev, 0x1004, 0xC00, 0x000);
+	check_warn_return(status, "error setting TX mode bits in 0x1004");
+
+	/* Enable the controller */
+	status = ufx_reg_write(dev, 0x106C, 0x01);
+	check_warn_return(status, "failed to enable I2C");
+
+	return 0;
+}
+
+/* sets the I2C port mux and target address */
+static int ufx_i2c_configure(struct ufx_data *dev)
+{
+	int status = ufx_reg_write(dev, 0x106C, 0x00);
+	check_warn_return(status, "failed to disable I2C");
+
+	status = ufx_reg_write(dev, 0x3010, 0x00000000);
+	check_warn_return(status, "failed to write 0x3010");
+
+	/* A0h is std for any EDID, right shifted by one */
+	status = ufx_reg_clear_and_set_bits(dev, 0x1004, 0x3FF,	(0xA0 >> 1));
+	check_warn_return(status, "failed to set TAR bits in 0x1004");
+
+	status = ufx_reg_write(dev, 0x106C, 0x01);
+	check_warn_return(status, "failed to enable I2C");
+
+	return 0;
+}
+
+/* wait for BUSY to clear, with a timeout of 50ms with 10ms sleeps. if no
+ * monitor is connected, there is no error except for timeout */
+static int ufx_i2c_wait_busy(struct ufx_data *dev)
+{
+	u32 tmp;
+	int i, status;
+
+	for (i = 0; i < 15; i++) {
+		status = ufx_reg_read(dev, 0x1100, &tmp);
+		check_warn_return(status, "0x1100 read failed");
+
+		/* if BUSY is clear, check for error */
+		if ((tmp & 0x80000000) == 0) {
+			if (tmp & 0x20000000) {
+				pr_warn("I2C read failed, 0x1100=0x%08x", tmp);
+				return -EIO;
+			}
+
+			return 0;
+		}
+
+		/* perform the first 10 retries without delay */
+		if (i >= 10)
+			msleep(10);
+	}
+
+	pr_warn("I2C access timed out, resetting I2C hardware");
+	status =  ufx_reg_write(dev, 0x1100, 0x40000000);
+	check_warn_return(status, "0x1100 write failed");
+
+	return -ETIMEDOUT;
+}
+
+/* reads a 128-byte EDID block from the currently selected port and TAR */
+static int ufx_read_edid(struct ufx_data *dev, char *edid, int edid_len)
+{
+	int i, j, status;
+	u32 *edid_u32 = (u32 *)edid;
+
+	BUG_ON(edid_len != EDID_LENGTH);
+
+	status = ufx_i2c_configure(dev);
+	if (status < 0) {
+		pr_err("ufx_i2c_configure failed");
+		return status;
+	}
+
+	memset(edid, 0xff, EDID_LENGTH);
+
+	/* Read the 128-byte EDID as 2 bursts of 64 bytes */
+	for (i = 0; i < 2; i++) {
+		u32 temp = 0x28070000 | (63 << 20) | (((u32)(i * 64)) << 8);
+		status = ufx_reg_write(dev, 0x1100, temp);
+		check_warn_return(status, "Failed to write 0x1100");
+
+		temp |= 0x80000000;
+		status = ufx_reg_write(dev, 0x1100, temp);
+		check_warn_return(status, "Failed to write 0x1100");
+
+		status = ufx_i2c_wait_busy(dev);
+		check_warn_return(status, "Timeout waiting for I2C BUSY to clear");
+
+		for (j = 0; j < 16; j++) {
+			u32 data_reg_addr = 0x1110 + (j * 4);
+			status = ufx_reg_read(dev, data_reg_addr, edid_u32++);
+			check_warn_return(status, "Error reading i2c data");
+		}
+	}
+
+	/* all FF's in the first 16 bytes indicates nothing is connected */
+	for (i = 0; i < 16; i++) {
+		if (edid[i] != 0xFF) {
+			pr_info("edid data read succesfully");
+			return EDID_LENGTH;
+		}
+	}
+
+	pr_warn("edid data contains all 0xff");
+	return -ETIMEDOUT;
+}
+
+/* 1) use sw default
+ * 2) Parse into various fb_info structs
+ * 3) Allocate virtual framebuffer memory to back highest res mode
+ *
+ * Parses EDID into three places used by various parts of fbdev:
+ * fb_var_screeninfo contains the timing of the monitor's preferred mode
+ * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
+ * fb_info.modelist is a linked list of all monitor & VESA modes which work
+ *
+ * If EDID is not readable/valid, then modelist is all VESA modes,
+ * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
+ * Returns 0 if successful */
+static int ufx_setup_modes(struct ufx_data *dev, struct fb_info *info,
+	char *default_edid, size_t default_edid_size)
+{
+	const struct fb_videomode *default_vmode = NULL;
+	char *edid;
+	int i, result = 0, tries = 3;
+
+	if (info->dev) /* only use mutex if info has been registered */
+		mutex_lock(&info->lock);
+
+	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
+	if (!edid) {
+		result = -ENOMEM;
+		goto error;
+	}
+
+	fb_destroy_modelist(&info->modelist);
+	memset(&info->monspecs, 0, sizeof(info->monspecs));
+
+	/* Try to (re)read EDID from hardware first
+	 * EDID data may return, but not parse as valid
+	 * Try again a few times, in case of e.g. analog cable noise */
+	while (tries--) {
+		i = ufx_read_edid(dev, edid, EDID_LENGTH);
+
+		if (i >= EDID_LENGTH)
+			fb_edid_to_monspecs(edid, &info->monspecs);
+
+		if (info->monspecs.modedb_len > 0) {
+			dev->edid = edid;
+			dev->edid_size = i;
+			break;
+		}
+	}
+
+	/* If that fails, use a previously returned EDID if available */
+	if (info->monspecs.modedb_len == 0) {
+
+		pr_err("Unable to get valid EDID from device/display\n");
+
+		if (dev->edid) {
+			fb_edid_to_monspecs(dev->edid, &info->monspecs);
+			if (info->monspecs.modedb_len > 0)
+				pr_err("Using previously queried EDID\n");
+		}
+	}
+
+	/* If that fails, use the default EDID we were handed */
+	if (info->monspecs.modedb_len == 0) {
+		if (default_edid_size >= EDID_LENGTH) {
+			fb_edid_to_monspecs(default_edid, &info->monspecs);
+			if (info->monspecs.modedb_len > 0) {
+				memcpy(edid, default_edid, default_edid_size);
+				dev->edid = edid;
+				dev->edid_size = default_edid_size;
+				pr_err("Using default/backup EDID\n");
+			}
+		}
+	}
+
+	/* If we've got modes, let's pick a best default mode */
+	if (info->monspecs.modedb_len > 0) {
+
+		for (i = 0; i < info->monspecs.modedb_len; i++) {
+			if (ufx_is_valid_mode(&info->monspecs.modedb[i], info))
+				fb_add_videomode(&info->monspecs.modedb[i],
+					&info->modelist);
+			else /* if we've removed top/best mode */
+				info->monspecs.misc &= ~FB_MISC_1ST_DETAIL;
+		}
+
+		default_vmode = fb_find_best_display(&info->monspecs,
+						     &info->modelist);
+	}
+
+	/* If everything else has failed, fall back to safe default mode */
+	if (default_vmode == NULL) {
+
+		struct fb_videomode fb_vmode = {0};
+
+		/* Add the standard VESA modes to our modelist
+		 * Since we don't have EDID, there may be modes that
+		 * overspec monitor and/or are incorrect aspect ratio, etc.
+		 * But at least the user has a chance to choose
+		 */
+		for (i = 0; i < VESA_MODEDB_SIZE; i++) {
+			if (ufx_is_valid_mode((struct fb_videomode *)
+						&vesa_modes[i], info))
+				fb_add_videomode(&vesa_modes[i],
+						 &info->modelist);
+		}
+
+		/* default to resolution safe for projectors
+		 * (since they are most common case without EDID)
+		 */
+		fb_vmode.xres = 800;
+		fb_vmode.yres = 600;
+		fb_vmode.refresh = 60;
+		default_vmode = fb_find_nearest_mode(&fb_vmode,
+						     &info->modelist);
+	}
+
+	/* If we have good mode and no active clients */
+	if ((default_vmode != NULL) && (dev->fb_count == 0)) {
+
+		fb_videomode_to_var(&info->var, default_vmode);
+		ufx_var_color_format(&info->var);
+
+		/* with mode size info, we can now alloc our framebuffer */
+		memcpy(&info->fix, &ufx_fix, sizeof(ufx_fix));
+		info->fix.line_length = info->var.xres *
+			(info->var.bits_per_pixel / 8);
+
+		result = ufx_realloc_framebuffer(dev, info);
+
+	} else
+		result = -EINVAL;
+
+error:
+	if (edid && (dev->edid != edid))
+		kfree(edid);
+
+	if (info->dev)
+		mutex_unlock(&info->lock);
+
+	return result;
+}
+
+static int ufx_usb_probe(struct usb_interface *interface,
+			const struct usb_device_id *id)
+{
+	struct usb_device *usbdev;
+	struct ufx_data *dev = 0;
+	struct fb_info *info = 0;
+	int retval = -ENOMEM;
+	u32 id_rev, fpga_rev;
+
+	/* usb initialization */
+	usbdev = interface_to_usbdev(interface);
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL) {
+		err("ufx_usb_probe: failed alloc of dev struct\n");
+		goto error;
+	}
+
+	/* we need to wait for both usb and fbdev to spin down on disconnect */
+	kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
+	kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
+
+	dev->udev = usbdev;
+	dev->gdev = &usbdev->dev; /* our generic struct device * */
+	usb_set_intfdata(interface, dev);
+
+	pr_info("%s %s - serial #%s\n",
+		usbdev->manufacturer, usbdev->product, usbdev->serial);
+	pr_info("vid_%04x&pid_%04x&rev_%04x driver's ufx_data struct at %p\n",
+		usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
+		usbdev->descriptor.bcdDevice, dev);
+	pr_info("console enable=%d\n", console);
+	pr_info("fb_defio enable=%d\n", fb_defio);
+
+	if (!ufx_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
+		retval = -ENOMEM;
+		pr_err("ufx_alloc_urb_list failed\n");
+		goto error;
+	}
+
+	/* We don't register a new USB class. Our client interface is fbdev */
+
+	/* allocates framebuffer driver structure, not framebuffer memory */
+	info = framebuffer_alloc(0, &usbdev->dev);
+	if (!info) {
+		retval = -ENOMEM;
+		pr_err("framebuffer_alloc failed\n");
+		goto error;
+	}
+
+	dev->info = info;
+	info->par = dev;
+	info->pseudo_palette = dev->pseudo_palette;
+	info->fbops = &ufx_ops;
+
+	retval = fb_alloc_cmap(&info->cmap, 256, 0);
+	if (retval < 0) {
+		pr_err("fb_alloc_cmap failed %x\n", retval);
+		goto error;
+	}
+
+	INIT_DELAYED_WORK(&dev->free_framebuffer_work,
+			  ufx_free_framebuffer_work);
+
+	INIT_LIST_HEAD(&info->modelist);
+
+	retval = ufx_reg_read(dev, 0x3000, &id_rev);
+	check_warn_goto_error(retval, "error %d reading 0x3000 register from device", retval);
+	pr_info("ID_REV register value 0x%08x", id_rev);
+
+	retval = ufx_reg_read(dev, 0x3004, &fpga_rev);
+	check_warn_goto_error(retval, "error %d reading 0x3004 register from device", retval);
+	pr_info("FPGA_REV register value 0x%08x", fpga_rev);
+
+	pr_info("resetting device");
+	retval = ufx_lite_reset(dev);
+	check_warn_goto_error(retval, "error %d resetting device", retval);
+
+	pr_info("configuring system clock");
+	retval = ufx_config_sys_clk(dev);
+	check_warn_goto_error(retval, "error %d configuring system clock", retval);
+
+	pr_info("configuring DDR2 controller");
+	retval = ufx_config_ddr2(dev);
+	check_warn_goto_error(retval, "error %d initialising DDR2 controller", retval);
+
+	pr_info("configuring I2C controller");
+	retval = ufx_i2c_init(dev);
+	check_warn_goto_error(retval, "error %d initialising I2C controller", retval);
+
+	pr_info("selecting display mode");
+	retval = ufx_setup_modes(dev, info, NULL, 0);
+	check_warn_goto_error(retval, "unable to find common mode for display and adapter");
+
+	retval = ufx_reg_set_bits(dev, 0x4000, 0x00000001);
+	check_warn_goto_error(retval, "error %d enabling graphics engine", retval);
+
+	/* ready to begin using device */
+	atomic_set(&dev->usb_active, 1);
+
+	pr_info("checking var");
+	retval = ufx_ops_check_var(&info->var, info);
+	check_warn_goto_error(retval, "error %d ufx_ops_check_var", retval);
+
+	pr_info("setting par");
+	retval = ufx_ops_set_par(info);
+	check_warn_goto_error(retval, "error %d ufx_ops_set_par", retval);
+
+	pr_info("registering framebuffer");
+	retval = register_framebuffer(info);
+	check_warn_goto_error(retval, "error %d register_framebuffer", retval);
+
+	pr_info("SMSC UDX USB device /dev/fb%d attached. %dx%d resolution."
+		" Using %dK framebuffer memory\n", info->node,
+		info->var.xres, info->var.yres, info->fix.smem_len >> 10);
+
+	return 0;
+
+error:
+	if (dev) {
+		if (info) {
+			if (info->cmap.len != 0)
+				fb_dealloc_cmap(&info->cmap);
+			if (info->monspecs.modedb)
+				fb_destroy_modedb(info->monspecs.modedb);
+			if (info->screen_base)
+				vfree(info->screen_base);
+
+			fb_destroy_modelist(&info->modelist);
+
+			framebuffer_release(info);
+		}
+
+		kref_put(&dev->kref, ufx_free); /* ref for framebuffer */
+		kref_put(&dev->kref, ufx_free); /* last ref from kref_init */
+
+		/* dev has been deallocated. Do not dereference */
+	}
+
+	return retval;
+}
+
+static void ufx_usb_disconnect(struct usb_interface *interface)
+{
+	struct ufx_data *dev;
+	struct fb_info *info;
+
+	dev = usb_get_intfdata(interface);
+	info = dev->info;
+
+	pr_info("USB disconnect starting\n");
+
+	/* we virtualize until all fb clients release. Then we free */
+	dev->virtualized = true;
+
+	/* When non-active we'll update virtual framebuffer, but no new urbs */
+	atomic_set(&dev->usb_active, 0);
+
+	usb_set_intfdata(interface, NULL);
+
+	/* if clients still have us open, will be freed on last close */
+	if (dev->fb_count == 0)
+		schedule_delayed_work(&dev->free_framebuffer_work, 0);
+
+	/* release reference taken by kref_init in probe() */
+	kref_put(&dev->kref, ufx_free);
+
+	/* consider ufx_data freed */
+}
+
+static struct usb_driver ufx_driver = {
+	.name = "smscufx",
+	.probe = ufx_usb_probe,
+	.disconnect = ufx_usb_disconnect,
+	.id_table = id_table,
+};
+
+static int __init ufx_module_init(void)
+{
+	int res;
+
+	res = usb_register(&ufx_driver);
+	if (res)
+		err("usb_register failed. Error number %d", res);
+
+	return res;
+}
+
+static void __exit ufx_module_exit(void)
+{
+	usb_deregister(&ufx_driver);
+}
+
+module_init(ufx_module_init);
+module_exit(ufx_module_exit);
+
+static void ufx_urb_completion(struct urb *urb)
+{
+	struct urb_node *unode = urb->context;
+	struct ufx_data *dev = unode->dev;
+	unsigned long flags;
+
+	/* sync/async unlink faults aren't errors */
+	if (urb->status) {
+		if (!(urb->status == -ENOENT ||
+		    urb->status == -ECONNRESET ||
+		    urb->status == -ESHUTDOWN)) {
+			pr_err("%s - nonzero write bulk status received: %d\n",
+				__func__, urb->status);
+			atomic_set(&dev->lost_pixels, 1);
+		}
+	}
+
+	urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
+
+	spin_lock_irqsave(&dev->urbs.lock, flags);
+	list_add_tail(&unode->entry, &dev->urbs.list);
+	dev->urbs.available++;
+	spin_unlock_irqrestore(&dev->urbs.lock, flags);
+
+	/* When using fb_defio, we deadlock if up() is called
+	 * while another is waiting. So queue to another process */
+	if (fb_defio)
+		schedule_delayed_work(&unode->release_urb_work, 0);
+	else
+		up(&dev->urbs.limit_sem);
+}
+
+static void ufx_free_urb_list(struct ufx_data *dev)
+{
+	int count = dev->urbs.count;
+	struct list_head *node;
+	struct urb_node *unode;
+	struct urb *urb;
+	int ret;
+	unsigned long flags;
+
+	pr_notice("Waiting for completes and freeing all render urbs\n");
+
+	/* keep waiting and freeing, until we've got 'em all */
+	while (count--) {
+		/* Getting interrupted means a leak, but ok at shutdown*/
+		ret = down_interruptible(&dev->urbs.limit_sem);
+		if (ret)
+			break;
+
+		spin_lock_irqsave(&dev->urbs.lock, flags);
+
+		node = dev->urbs.list.next; /* have reserved one with sem */
+		list_del_init(node);
+
+		spin_unlock_irqrestore(&dev->urbs.lock, flags);
+
+		unode = list_entry(node, struct urb_node, entry);
+		urb = unode->urb;
+
+		/* Free each separately allocated piece */
+		usb_free_coherent(urb->dev, dev->urbs.size,
+				  urb->transfer_buffer, urb->transfer_dma);
+		usb_free_urb(urb);
+		kfree(node);
+	}
+}
+
+static int ufx_alloc_urb_list(struct ufx_data *dev, int count, size_t size)
+{
+	int i = 0;
+	struct urb *urb;
+	struct urb_node *unode;
+	char *buf;
+
+	spin_lock_init(&dev->urbs.lock);
+
+	dev->urbs.size = size;
+	INIT_LIST_HEAD(&dev->urbs.list);
+
+	while (i < count) {
+		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
+		if (!unode)
+			break;
+		unode->dev = dev;
+
+		INIT_DELAYED_WORK(&unode->release_urb_work,
+			  ufx_release_urb_work);
+
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			kfree(unode);
+			break;
+		}
+		unode->urb = urb;
+
+		buf = usb_alloc_coherent(dev->udev, size, GFP_KERNEL,
+					 &urb->transfer_dma);
+		if (!buf) {
+			kfree(unode);
+			usb_free_urb(urb);
+			break;
+		}
+
+		/* urb->transfer_buffer_length set to actual before submit */
+		usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
+			buf, size, ufx_urb_completion, unode);
+		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+		list_add_tail(&unode->entry, &dev->urbs.list);
+
+		i++;
+	}
+
+	sema_init(&dev->urbs.limit_sem, i);
+	dev->urbs.count = i;
+	dev->urbs.available = i;
+
+	pr_notice("allocated %d %d byte urbs\n", i, (int) size);
+
+	return i;
+}
+
+static struct urb *ufx_get_urb(struct ufx_data *dev)
+{
+	int ret = 0;
+	struct list_head *entry;
+	struct urb_node *unode;
+	struct urb *urb = NULL;
+	unsigned long flags;
+
+	/* Wait for an in-flight buffer to complete and get re-queued */
+	ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
+	if (ret) {
+		atomic_set(&dev->lost_pixels, 1);
+		pr_warn("wait for urb interrupted: %x available: %d\n",
+		       ret, dev->urbs.available);
+		goto error;
+	}
+
+	spin_lock_irqsave(&dev->urbs.lock, flags);
+
+	BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
+	entry = dev->urbs.list.next;
+	list_del_init(entry);
+	dev->urbs.available--;
+
+	spin_unlock_irqrestore(&dev->urbs.lock, flags);
+
+	unode = list_entry(entry, struct urb_node, entry);
+	urb = unode->urb;
+
+error:
+	return urb;
+}
+
+static int ufx_submit_urb(struct ufx_data *dev, struct urb *urb, size_t len)
+{
+	int ret;
+
+	BUG_ON(len > dev->urbs.size);
+
+	urb->transfer_buffer_length = len; /* set to actual payload len */
+	ret = usb_submit_urb(urb, GFP_KERNEL);
+	if (ret) {
+		ufx_urb_completion(urb); /* because no one else will */
+		atomic_set(&dev->lost_pixels, 1);
+		pr_err("usb_submit_urb error %x\n", ret);
+	}
+	return ret;
+}
+
+module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
+MODULE_PARM_DESC(console, "Allow fbcon to consume first framebuffer found");
+
+module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
+MODULE_PARM_DESC(fb_defio, "Enable fb_defio mmap support");
+
+MODULE_AUTHOR("Steve Glendinning <[e-mail]>");
+MODULE_DESCRIPTION("SMSC UFX kernel framebuffer driver");
+MODULE_LICENSE("GPL");