Add support for SMSC UFX6000/7000 USB display adapters

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

Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

1 files changed, 1994 insertions, 0 deletions

diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
new file mode 100644
index 000000000000..c6b86e7beb98
--- /dev/null
+++ b/drivers/video/smscufx.c
@@ -0,0 +1,1994 @@
+/*
+ * smscufx.c -- Framebuffer driver for SMSC UFX USB controller
+ *
+ * Copyright (C) 2011 Steve Glendinning <steve.glendinning@smsc.com>
+ * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
+ * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
+ * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
+ *
+ * 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_debug("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_debug("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 void 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 line;
+
+	BUG_ON(!dev);
+	BUG_ON(!dev->info);
+
+	/* command word */
+	*((u32 *)&cmd[0]) = cpu_to_le32(0x01);
+
+	/* length word */
+	*((u32 *)&cmd[4]) = cpu_to_le32(packed_rect_len + 16);
+
+	*((u16 *)&cmd[8]) = cpu_to_le16(x);
+	*((u16 *)&cmd[10]) = cpu_to_le16(y);
+	*((u16 *)&cmd[12]) = cpu_to_le16(width);
+	*((u16 *)&cmd[14]) = cpu_to_le16(height);
+
+	/* frame base address */
+	*((u32 *)&cmd[16]) = cpu_to_le32(0 & 0xffffff80);
+
+	/* color mode and horizontal resolution */
+	*((u16 *)&cmd[20]) = cpu_to_le16(0x4000 | dev->info->var.xres);
+
+	/* vertical resolution */
+	*((u16 *)&cmd[22]) = cpu_to_le16(dev->info->var.yres);
+
+	/* packed data */
+	for (line = 0; line < height; line++) {
+		const int line_offset = dev->info->fix.line_length * (y + line);
+		const int byte_offset = line_offset + (x * BPP);
+		memcpy(&cmd[24 + (packed_line_len * line)],
+			(char *)dev->info->fix.smem_start + byte_offset, width * BPP);
+	}
+}
+
+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;
+
+	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);
+
+		ufx_raw_rect(dev, urb->transfer_buffer, x, (y + start_line), width, urb_lines);
+		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_debug("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_debug("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_debug("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_debug("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_debug("%dx%d too many pixels",
+		       mode->xres, mode->yres);
+		return 0;
+	}
+
+	if (mode->pixclock < 5000) {
+		pr_debug("%dx%d %dps pixel clock too fast",
+		       mode->xres, mode->yres, mode->pixclock);
+		return 0;
+	}
+
+	pr_debug("%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_debug("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);
+	}
+
+	/* re-enable defio if previously disabled by damage tracking */
+	if (info->fbdefio)
+		info->fbdefio->delay = UFX_DEFIO_WRITE_DELAY;
+
+	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_debug("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_debug("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;
+	struct fb_info *info = 0;
+	int retval = -ENOMEM;
+	u32 id_rev, fpga_rev;
+
+	/* usb initialization */
+	usbdev = interface_to_usbdev(interface);
+	BUG_ON(!usbdev);
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL) {
+		dev_err(&usbdev->dev, "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);
+
+	dev_dbg(dev->gdev, "%s %s - serial #%s\n",
+		usbdev->manufacturer, usbdev->product, usbdev->serial);
+	dev_dbg(dev->gdev, "vid_%04x&pid_%04x&rev_%04x driver's ufx_data struct at %p\n",
+		usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
+		usbdev->descriptor.bcdDevice, dev);
+	dev_dbg(dev->gdev, "console enable=%d\n", console);
+	dev_dbg(dev->gdev, "fb_defio enable=%d\n", fb_defio);
+
+	if (!ufx_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
+		retval = -ENOMEM;
+		dev_err(dev->gdev, "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;
+		dev_err(dev->gdev, "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) {
+		dev_err(dev->gdev, "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);
+	dev_dbg(dev->gdev, "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);
+	dev_dbg(dev->gdev, "FPGA_REV register value 0x%08x", fpga_rev);
+
+	dev_dbg(dev->gdev, "resetting device");
+	retval = ufx_lite_reset(dev);
+	check_warn_goto_error(retval, "error %d resetting device", retval);
+
+	dev_dbg(dev->gdev, "configuring system clock");
+	retval = ufx_config_sys_clk(dev);
+	check_warn_goto_error(retval, "error %d configuring system clock", retval);
+
+	dev_dbg(dev->gdev, "configuring DDR2 controller");
+	retval = ufx_config_ddr2(dev);
+	check_warn_goto_error(retval, "error %d initialising DDR2 controller", retval);
+
+	dev_dbg(dev->gdev, "configuring I2C controller");
+	retval = ufx_i2c_init(dev);
+	check_warn_goto_error(retval, "error %d initialising I2C controller", retval);
+
+	dev_dbg(dev->gdev, "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);
+
+	dev_dbg(dev->gdev, "checking var");
+	retval = ufx_ops_check_var(&info->var, info);
+	check_warn_goto_error(retval, "error %d ufx_ops_check_var", retval);
+
+	dev_dbg(dev->gdev, "setting par");
+	retval = ufx_ops_set_par(info);
+	check_warn_goto_error(retval, "error %d ufx_ops_set_par", retval);
+
+	dev_dbg(dev->gdev, "registering framebuffer");
+	retval = register_framebuffer(info);
+	check_warn_goto_error(retval, "error %d register_framebuffer", retval);
+
+	dev_info(dev->gdev, "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_debug("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_debug("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_debug("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 be used on this display");
+
+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 <steve.glendinning@smsc.com>");
+MODULE_DESCRIPTION("SMSC UFX kernel framebuffer driver");
+MODULE_LICENSE("GPL");