Staging: add udlfb driver

This adds the udlfb driver, a framebuffer driver for DisplayLink devices.


From: Roberto De Ioris <roberto@unbit.it>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/udlfb/udlfb.c

@@ -0,0 +1,773 @@
+/*****************************************************************************
+ *                          DLFB Kernel Driver                               *
+ *                            Version 0.2 (udlfb)                            *
+ *             (C) 2009 Roberto De Ioris <roberto@unbit.it>                  *
+ *                                                                           *
+ *     This file is licensed under the GPLv2. See COPYING in the package.    *
+ * Based on the amazing work of Florian Echtler and libdlo 0.1               *
+ *                                                                           *
+ *                                                                           *
+ * 31.05.09 release 0.2                                                      *
+ * 22.05.09 First public (ugly) release                                      *
+ *****************************************************************************/
+
+#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/mutex.h>
+
+#include "udlfb.h"
+
+#define DRIVER_VERSION "DLFB 0.2"
+
+// memory functions taken from vfb
+
+static void *rvmalloc(unsigned long size)
+{
+	void *mem;
+	unsigned long adr;
+
+	size = PAGE_ALIGN(size);
+	mem = vmalloc_32(size);
+	if (!mem)
+		return NULL;
+
+	memset(mem, 0, size);	/* Clear the ram out, no junk to the user */
+	adr = (unsigned long)mem;
+	while (size > 0) {
+		SetPageReserved(vmalloc_to_page((void *)adr));
+		adr += PAGE_SIZE;
+		size -= PAGE_SIZE;
+	}
+
+	return mem;
+}
+
+static void rvfree(void *mem, unsigned long size)
+{
+	unsigned long adr;
+
+	if (!mem)
+		return;
+
+	adr = (unsigned long)mem;
+	while ((long)size > 0) {
+		ClearPageReserved(vmalloc_to_page((void *)adr));
+		adr += PAGE_SIZE;
+		size -= PAGE_SIZE;
+	}
+	vfree(mem);
+}
+
+static int dlfb_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;
+
+	printk("MMAP: %lu %u\n", offset + size, info->fix.smem_len);
+
+	if (offset + size > info->fix.smem_len) {
+		return -EINVAL;
+	}
+
+	pos = (unsigned long)info->fix.smem_start + offset;
+
+	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;
+
+}
+
+//
+
+//ioctl structure
+struct dloarea {
+	int x, y;
+	int w, h;
+};
+
+/*
+
+static struct usb_device_id id_table [] = {
+	{ USB_DEVICE(0x17e9, 0x023d) },
+        { }
+};
+
+*/
+
+static struct usb_device_id id_table[] = {
+	{.idVendor = 0x17e9,.match_flags = USB_DEVICE_ID_MATCH_VENDOR,},
+	{},
+};
+
+MODULE_DEVICE_TABLE(usb, id_table);
+
+static struct usb_driver dlfb_driver;
+
+static int
+image_blit(struct dlfb_data *dev_info, int x, int y, int width, int height,
+	   char *data)
+{
+
+	int i, j, base;
+	int rem = width;
+	int ret;
+
+	int diff;
+
+	char *bufptr;
+
+	if (x + width > dev_info->info->var.xres) {
+		return -EINVAL;
+	}
+
+	if (y + height > dev_info->info->var.yres) {
+		return -EINVAL;
+	}
+
+	mutex_lock(&dev_info->bulk_mutex);
+
+	base = dev_info->base16 + (dev_info->info->var.xres * 2 * y) + (x * 2);
+
+	data += (dev_info->info->var.xres * 2 * y) + (x * 2);
+
+	//printk("IMAGE_BLIT\n");
+
+	bufptr = dev_info->buf;
+
+	for (i = y; i < y + height; i++) {
+
+		if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) {
+			ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf);
+			bufptr = dev_info->buf;
+		}
+
+		rem = width;
+
+		//printk("WRITING LINE %d\n", i);
+
+		while (rem) {
+
+			if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) {
+				ret =
+				    dlfb_bulk_msg(dev_info,
+						  bufptr - dev_info->buf);
+				bufptr = dev_info->buf;
+			}
+
+			if (rem > 255) {
+
+				diff = 0;
+				for (j = 0; j < 510; j++) {
+					if (dev_info->
+					    backing_buffer[base + j] !=
+					    data[j]) {
+						diff = 1;
+						break;
+					}
+				}
+
+				if (diff == 1) {
+					*bufptr++ = 0xAF;
+					*bufptr++ = 0x68;
+
+					*bufptr++ = (char)(base >> 16);
+					*bufptr++ = (char)(base >> 8);
+					*bufptr++ = (char)(base);
+					*bufptr++ = 255;
+					// PUT COMPRESSION HERE
+					for (j = 0; j < 510; j += 2) {
+						bufptr[j] = data[j + 1];
+						bufptr[j + 1] = data[j];
+					}
+					bufptr += 510;
+				}
+
+				rem -= 255;
+				base += 510;
+				data += 510;
+			} else {
+
+				diff = 0;
+
+				for (j = 0; j < rem * 2; j++) {
+					if (dev_info->
+					    backing_buffer[base + j] !=
+					    data[j]) {
+						diff = 1;
+						break;
+					}
+				}
+
+				if (diff == 1) {
+
+					*bufptr++ = 0xAF;
+					*bufptr++ = 0x68;
+
+					*bufptr++ = (char)(base >> 16);
+					*bufptr++ = (char)(base >> 8);
+					*bufptr++ = (char)(base);
+					*bufptr++ = rem;
+					// PUT COMPRESSION HERE
+					for (j = 0; j < rem * 2; j += 2) {
+						bufptr[j] = data[j + 1];
+						bufptr[j + 1] = data[j];
+					}
+					bufptr += rem * 2;
+
+				}
+
+				base += rem * 2;
+				data += rem * 2;
+				rem = 0;
+			}
+
+		}
+
+		memcpy(dev_info->backing_buffer + base - (width * 2),
+		       data - (width * 2), width * 2);
+
+		base += (dev_info->info->var.xres * 2) - (width * 2);
+		data += (dev_info->info->var.xres * 2) - (width * 2);
+
+	}
+
+	if (bufptr > dev_info->buf) {
+		ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf);
+	}
+
+	mutex_unlock(&dev_info->bulk_mutex);
+
+	return base;
+
+}
+
+static int
+draw_rect(struct dlfb_data *dev_info, int x, int y, int width, int height,
+	  unsigned char red, unsigned char green, unsigned char blue)
+{
+
+	int i, j, base;
+	int ret;
+	unsigned short col =
+	    (((((red) & 0xF8) | ((green) >> 5)) & 0xFF) << 8) +
+	    (((((green) & 0x1C) << 3) | ((blue) >> 3)) & 0xFF);
+	int rem = width;
+
+	char *bufptr;
+
+	if (x + width > dev_info->info->var.xres) {
+		return -EINVAL;
+	}
+
+	if (y + height > dev_info->info->var.yres) {
+		return -EINVAL;
+	}
+
+	mutex_lock(&dev_info->bulk_mutex);
+
+	base = dev_info->base16 + (dev_info->info->var.xres * 2 * y) + (x * 2);
+
+	bufptr = dev_info->buf;
+
+	for (i = y; i < y + height; i++) {
+
+		for (j = 0; j < width * 2; j += 2) {
+			dev_info->backing_buffer[base + j] = (char)(col >> 8);
+			dev_info->backing_buffer[base + j + 1] = (char)(col);
+		}
+		if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) {
+			ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf);
+			bufptr = dev_info->buf;
+		}
+
+		rem = width;
+
+		while (rem) {
+
+			if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) {
+				ret =
+				    dlfb_bulk_msg(dev_info,
+						  bufptr - dev_info->buf);
+				bufptr = dev_info->buf;
+			}
+
+			*bufptr++ = 0xAF;
+			*bufptr++ = 0x69;
+
+			*bufptr++ = (char)(base >> 16);
+			*bufptr++ = (char)(base >> 8);
+			*bufptr++ = (char)(base);
+
+			if (rem > 255) {
+				*bufptr++ = 255;
+				*bufptr++ = 255;
+				rem -= 255;
+				base += 255 * 2;
+			} else {
+				*bufptr++ = rem;
+				*bufptr++ = rem;
+				base += rem * 2;
+				rem = 0;
+			}
+
+			*bufptr++ = (char)(col >> 8);
+			*bufptr++ = (char)(col);
+
+		}
+
+		base += (dev_info->info->var.xres * 2) - (width * 2);
+
+	}
+
+	if (bufptr > dev_info->buf) {
+		ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf);
+	}
+
+	mutex_unlock(&dev_info->bulk_mutex);
+
+	return 1;
+}
+
+static int
+copyarea(struct dlfb_data *dev_info, int dx, int dy, int sx, int sy,
+	 int width, int height)
+{
+
+	int base;
+	int source;
+	int rem;
+	int i, ret;
+
+	char *bufptr;
+
+	if (dx + width > dev_info->info->var.xres) {
+		return -EINVAL;
+	}
+
+	if (dy + height > dev_info->info->var.yres) {
+		return -EINVAL;
+	}
+
+	mutex_lock(&dev_info->bulk_mutex);
+
+	base =
+	    dev_info->base16 + (dev_info->info->var.xres * 2 * dy) + (dx * 2);
+	source = (dev_info->info->var.xres * 2 * sy) + (sx * 2);
+
+	bufptr = dev_info->buf;
+
+	for (i = sy; i < sy + height; i++) {
+
+		memcpy(dev_info->backing_buffer + base,
+		       dev_info->backing_buffer + source, width * 2);
+
+		if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) {
+			ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf);
+			bufptr = dev_info->buf;
+		}
+
+		rem = width;
+
+		while (rem) {
+
+			if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) {
+				ret =
+				    dlfb_bulk_msg(dev_info,
+						  bufptr - dev_info->buf);
+				bufptr = dev_info->buf;
+			}
+
+			*bufptr++ = 0xAF;
+			*bufptr++ = 0x6A;
+
+			*bufptr++ = (char)(base >> 16);
+			*bufptr++ = (char)(base >> 8);
+			*bufptr++ = (char)(base);
+
+			if (rem > 255) {
+				*bufptr++ = 255;
+				*bufptr++ = (char)(source >> 16);
+				*bufptr++ = (char)(source >> 8);
+				*bufptr++ = (char)(source);
+
+				rem -= 255;
+				base += 255 * 2;
+				source += 255 * 2;
+
+			} else {
+				*bufptr++ = rem;
+				*bufptr++ = (char)(source >> 16);
+				*bufptr++ = (char)(source >> 8);
+				*bufptr++ = (char)(source);
+
+				base += rem * 2;
+				source += rem * 2;
+				rem = 0;
+			}
+
+		}
+
+		base += (dev_info->info->var.xres * 2) - (width * 2);
+		source += (dev_info->info->var.xres * 2) - (width * 2);
+
+	}
+
+	if (bufptr > dev_info->buf) {
+		ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf);
+	}
+
+	mutex_unlock(&dev_info->bulk_mutex);
+
+	return 1;
+}
+
+void dlfb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+
+	struct dlfb_data *dev = info->par;
+
+	copyarea(dev, area->dx, area->dy, area->sx, area->sy, area->width,
+		 area->height);
+
+	//printk("COPY AREA %d %d %d %d %d %d !!!\n", area->dx, area->dy, area->sx, area->sy, area->width, area->height);
+
+}
+
+void dlfb_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+
+	int ret;
+	struct dlfb_data *dev = info->par;
+	//printk("IMAGE BLIT (1) %d %d %d %d DEPTH %d {%p}!!!\n", image->dx, image->dy, image->width, image->height, image->depth, dev->udev);
+	cfb_imageblit(info, image);
+	ret =
+	    image_blit(dev, image->dx, image->dy, image->width, image->height,
+		       info->screen_base);
+	//printk("IMAGE BLIT (2) %d %d %d %d DEPTH %d {%p} %d!!!\n", image->dx, image->dy, image->width, image->height, image->depth, dev->udev, ret);
+}
+
+void dlfb_fillrect(struct fb_info *info, const struct fb_fillrect *region)
+{
+
+	unsigned char red, green, blue;
+	struct dlfb_data *dev = info->par;
+
+	memcpy(&red, &region->color, 1);
+	memcpy(&green, &region->color + 1, 1);
+	memcpy(&blue, &region->color + 2, 1);
+	draw_rect(dev, region->dx, region->dy, region->width, region->height,
+		  red, green, blue);
+	//printk("FILL RECT %d %d !!!\n", region->dx, region->dy);
+
+}
+
+static int dlfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
+{
+
+	struct dlfb_data *dev_info = info->par;
+	struct dloarea *area;
+
+	if (cmd == 0xAA) {
+
+		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;
+
+		image_blit(dev_info, area->x, area->y, area->w, area->h,
+			   info->screen_base);
+	}
+	return 0;
+}
+
+// taken from vesafb
+
+static int
+dlfb_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;
+}
+
+static int dlfb_release(struct fb_info *info, int user)
+{
+	struct dlfb_data *dev_info = info->par;
+	image_blit(dev_info, 0, 0, info->var.xres, info->var.yres,
+		   info->screen_base);
+	return 0;
+}
+
+static int dlfb_blank(int blank_mode, struct fb_info *info) {
+	return 0;
+}
+
+static struct fb_ops dlfb_ops = {
+
+	.fb_setcolreg = dlfb_setcolreg,
+	.fb_fillrect = dlfb_fillrect,
+	.fb_copyarea = dlfb_copyarea,
+	.fb_imageblit = dlfb_imageblit,
+	.fb_mmap = dlfb_mmap,
+	.fb_ioctl = dlfb_ioctl,
+	.fb_release = dlfb_release,
+	.fb_blank = dlfb_blank,
+};
+
+static int
+dlfb_probe(struct usb_interface *interface, const struct usb_device_id *id)
+{
+	struct dlfb_data *dev_info;
+	struct fb_info *info;
+	int i;
+
+	int ret;
+	char rbuf[4];
+
+	dev_info = kzalloc(sizeof(*dev_info), GFP_KERNEL);
+	if (dev_info == NULL) {
+		printk("cannot allocate dev_info structure.\n");
+		return -ENOMEM;
+	}
+
+	mutex_init(&dev_info->bulk_mutex);
+
+	dev_info->udev = usb_get_dev(interface_to_usbdev(interface));
+	dev_info->interface = interface;
+
+	printk("DisplayLink device attached\n");
+
+	// add framebuffer info to usb interface
+	usb_set_intfdata(interface, dev_info);
+
+	dev_info->buf = kmalloc(BUF_SIZE, GFP_KERNEL);	//usb_buffer_alloc(dev_info->udev, BUF_SIZE , GFP_KERNEL, &dev_info->tx_urb->transfer_dma);
+
+	if (dev_info->buf == NULL) {
+		printk("unable to allocate memory for dlfb commands\n");
+		goto out;
+	}
+	dev_info->bufend = dev_info->buf + BUF_SIZE;
+
+	dev_info->tx_urb = usb_alloc_urb(0, GFP_KERNEL);
+	usb_fill_bulk_urb(dev_info->tx_urb, dev_info->udev,
+			  usb_sndbulkpipe(dev_info->udev, 1), dev_info->buf, 0,
+			  dlfb_bulk_callback, dev_info);
+
+	ret =
+	    usb_control_msg(dev_info->udev, usb_rcvctrlpipe(dev_info->udev, 0),
+			    (0x06), (0x80 | (0x02 << 5)), 0, 0, rbuf, 4, 0);
+	printk("ret control msg 0: %d %x%x%x%x\n", ret, rbuf[0], rbuf[1],
+	       rbuf[2], rbuf[3]);
+
+	for (i = 0; i < 128; i++) {
+		ret =
+		    usb_control_msg(dev_info->udev,
+				    usb_rcvctrlpipe(dev_info->udev, 0), (0x02),
+				    (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
+				    0);
+		//printk("ret control msg edid %d: %d [%d]\n",i, ret, rbuf[1]);
+		dev_info->edid[i] = rbuf[1];
+	}
+
+	info = framebuffer_alloc(sizeof(u32) * 256, &dev_info->udev->dev);
+
+	if (!info) {
+		printk("non posso allocare il framebuffer displaylink");
+		goto out;
+	}
+
+	fb_parse_edid(dev_info->edid, &info->var);
+
+	printk("EDID XRES %d YRES %d\n", info->var.xres, info->var.yres);
+
+	if (dlfb_set_video_mode(dev_info, info->var.xres, info->var.yres) != 0) {
+		goto out;
+	}
+
+	printk("found valid mode...%d\n", info->var.pixclock);
+
+	info->pseudo_palette = info->par;
+	info->par = dev_info;
+
+	dev_info->info = info;
+
+	info->flags =
+	    FBINFO_DEFAULT | FBINFO_READS_FAST | FBINFO_HWACCEL_IMAGEBLIT |
+	    FBINFO_HWACCEL_COPYAREA | FBINFO_HWACCEL_FILLRECT;
+	info->fbops = &dlfb_ops;
+	info->screen_base = rvmalloc(dev_info->screen_size);
+
+	if (info->screen_base == NULL) {
+		printk
+		    ("cannot allocate framebuffer virtual memory of %d bytes\n",
+		     dev_info->screen_size);
+		goto out0;
+	}
+
+	printk("screen base allocated !!!\n");
+
+	dev_info->backing_buffer = kzalloc(dev_info->screen_size, GFP_KERNEL);
+
+	if (!dev_info->backing_buffer) {
+		printk("non posso allocare il backing buffer\n");
+	}
+	//info->var = dev_info->si;
+
+	info->var.bits_per_pixel = 16;
+	info->var.activate = FB_ACTIVATE_TEST;
+	info->var.vmode = FB_VMODE_NONINTERLACED;
+
+	info->var.red.offset = 11;
+	info->var.red.length = 5;
+	info->var.red.msb_right = 0;
+
+	info->var.green.offset = 5;
+	info->var.green.length = 6;
+	info->var.green.msb_right = 0;
+
+	info->var.blue.offset = 0;
+	info->var.blue.length = 5;
+	info->var.blue.msb_right = 0;
+
+	//info->var.pixclock =  (10000000 / FB_W * 1000 / FB_H)/2 ;
+
+	info->fix.smem_start = (unsigned long)info->screen_base;
+	info->fix.smem_len = PAGE_ALIGN(dev_info->screen_size);
+	memcpy(info->fix.id, "DisplayLink FB", 14);
+	info->fix.type = FB_TYPE_PACKED_PIXELS;
+	info->fix.visual = FB_VISUAL_TRUECOLOR;
+	info->fix.accel = info->flags;
+	info->fix.line_length = dev_info->line_length;
+
+	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
+		goto out1;
+	}
+
+	printk("colormap allocated\n");
+	if (register_framebuffer(info) < 0) {
+		goto out2;
+	}
+
+	draw_rect(dev_info, 0, 0, dev_info->info->var.xres,
+		  dev_info->info->var.yres, 0x30, 0xff, 0x30);
+
+	return 0;
+
+ out2:
+	fb_dealloc_cmap(&info->cmap);
+ out1:
+	rvfree(info->screen_base, dev_info->screen_size);
+ out0:
+	framebuffer_release(info);
+ out:
+	usb_set_intfdata(interface, NULL);
+	usb_put_dev(dev_info->udev);
+	kfree(dev_info);
+	return -ENOMEM;
+
+}
+
+static void dlfb_disconnect(struct usb_interface *interface)
+{
+	struct dlfb_data *dev_info = usb_get_intfdata(interface);
+
+	mutex_unlock(&dev_info->bulk_mutex);
+
+	usb_kill_urb(dev_info->tx_urb);
+	usb_free_urb(dev_info->tx_urb);
+	usb_set_intfdata(interface, NULL);
+	usb_put_dev(dev_info->udev);
+
+	if (dev_info->info) {
+		unregister_framebuffer(dev_info->info);
+		fb_dealloc_cmap(&dev_info->info->cmap);
+		rvfree(dev_info->info->screen_base, dev_info->screen_size);
+		kfree(dev_info->backing_buffer);
+		framebuffer_release(dev_info->info);
+
+	}
+
+	kfree(dev_info);
+
+	printk("DisplayLink device disconnected\n");
+}
+
+static struct usb_driver dlfb_driver = {
+	.name = "udlfb",
+	.probe = dlfb_probe,
+	.disconnect = dlfb_disconnect,
+	.id_table = id_table,
+};
+
+static int __init dlfb_init(void)
+{
+	int res;
+
+	dlfb_init_modes();
+
+	res = usb_register(&dlfb_driver);
+	if (res)
+		err("usb_register failed. Error number %d", res);
+
+	printk("VMODES initialized\n");
+
+	return res;
+}
+
+static void __exit dlfb_exit(void)
+{
+	usb_deregister(&dlfb_driver);
+}
+
+module_init(dlfb_init);
+module_exit(dlfb_exit);
+
+MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>");
+MODULE_DESCRIPTION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");

drivers/staging/udlfb/udlfb.h

@@ -0,0 +1,204 @@
+#define MAX_VMODES 4
+#define FB_BPP 16
+
+#define STD_CHANNEL        "\x57\xCD\xDC\xA7\x1C\x88\x5E\x15\x60\xFE\xC6\x97\x16\x3D\x47\xF2"
+
+// as libdlo
+#define BUF_HIGH_WATER_MARK 1024
+#define BUF_SIZE 64*1024
+
+struct dlfb_data {
+	struct usb_device *udev;
+	struct usb_interface *interface;
+	struct urb *tx_urb, *ctrl_urb;
+	struct usb_ctrlrequest dr;
+	struct fb_info *info;
+	char *buf;
+	char *bufend;
+	char *backing_buffer;
+	struct mutex bulk_mutex;
+	char edid[128];
+	int screen_size;
+	int line_length;
+	struct completion done;
+	int base16;
+	int base8;
+};
+
+struct dlfb_video_mode {
+
+	uint8_t col;
+	uint32_t hclock;
+	uint32_t vclock;
+	uint8_t unknown1[6];
+	uint16_t xres;
+	uint8_t unknown2[6];
+	uint16_t yres;
+	uint8_t unknown3[4];
+
+} __attribute__ ((__packed__));
+
+struct dlfb_video_mode dlfb_video_modes[MAX_VMODES];
+
+static void dlfb_bulk_callback(struct urb *urb)
+{
+
+	struct dlfb_data *dev_info = urb->context;
+	complete(&dev_info->done);
+
+}
+
+static int dlfb_bulk_msg(struct dlfb_data *dev_info, int len)
+{
+
+	int ret;
+
+	init_completion(&dev_info->done);
+
+	dev_info->tx_urb->actual_length = 0;
+	dev_info->tx_urb->transfer_buffer_length = len;
+
+	ret = usb_submit_urb(dev_info->tx_urb, GFP_KERNEL);
+	if (!wait_for_completion_timeout(&dev_info->done, 1000)) {
+		usb_kill_urb(dev_info->tx_urb);
+		printk("usb timeout !!!\n");
+	}
+
+	return dev_info->tx_urb->actual_length;
+
+}
+
+void dlfb_init_modes(void)
+{
+
+	dlfb_video_modes[0].col = 0;
+	memcpy(&dlfb_video_modes[0].hclock, "\x20\x3C\x7A\xC9", 4);
+	memcpy(&dlfb_video_modes[0].vclock, "\xF2\x6C\x48\xF9", 4);
+	memcpy(&dlfb_video_modes[0].unknown1, "\x70\x53\xFF\xFF\x21\x27", 6);
+	dlfb_video_modes[0].xres = 800;
+	memcpy(&dlfb_video_modes[0].unknown2, "\x91\xF3\xFF\xFF\xFF\xF9", 6);
+	dlfb_video_modes[0].yres = 480;
+	memcpy(&dlfb_video_modes[0].unknown3, "\x01\x02\xC8\x19", 4);
+
+	dlfb_video_modes[1].col = 0;
+	memcpy(&dlfb_video_modes[1].hclock, "\x36\x18\xD5\x10", 4);
+	memcpy(&dlfb_video_modes[1].vclock, "\x60\xA9\x7B\x33", 4);
+	memcpy(&dlfb_video_modes[1].unknown1, "\xA1\x2B\x27\x32\xFF\xFF", 6);
+	dlfb_video_modes[1].xres = 1024;
+	memcpy(&dlfb_video_modes[1].unknown2, "\xD9\x9A\xFF\xCA\xFF\xFF", 6);
+	dlfb_video_modes[1].yres = 768;
+	memcpy(&dlfb_video_modes[1].unknown3, "\x04\x03\xC8\x32", 4);
+
+	dlfb_video_modes[2].col = 0;
+	memcpy(&dlfb_video_modes[2].hclock, "\x98\xF8\x0D\x57", 4);
+	memcpy(&dlfb_video_modes[2].vclock, "\x2A\x55\x4D\x54", 4);
+	memcpy(&dlfb_video_modes[2].unknown1, "\xCA\x0D\xFF\xFF\x94\x43", 6);
+	dlfb_video_modes[2].xres = 1280;
+	memcpy(&dlfb_video_modes[2].unknown2, "\x9A\xA8\xFF\xFF\xFF\xF9", 6);
+	dlfb_video_modes[2].yres = 1024;
+	memcpy(&dlfb_video_modes[2].unknown3, "\x04\x02\x60\x54", 4);
+
+	dlfb_video_modes[3].col = 0;
+	memcpy(&dlfb_video_modes[3].hclock, "\x42\x24\x38\x36", 4);
+	memcpy(&dlfb_video_modes[3].vclock, "\xC1\x52\xD9\x29", 4);
+	memcpy(&dlfb_video_modes[3].unknown1, "\xEA\xB8\x32\x60\xFF\xFF", 6);
+	dlfb_video_modes[3].xres = 1400;
+	memcpy(&dlfb_video_modes[3].unknown2, "\xC9\x4E\xFF\xFF\xFF\xF2", 6);
+	dlfb_video_modes[3].yres = 1050;
+	memcpy(&dlfb_video_modes[3].unknown3, "\x04\x02\x1E\x5F", 4);
+
+}
+
+char *dlfb_set_register(char *bufptr, uint8_t reg, uint8_t val)
+{
+
+	*bufptr++ = 0xAF;
+	*bufptr++ = 0x20;
+	*bufptr++ = reg;
+	*bufptr++ = val;
+
+	return bufptr;
+
+}
+
+int dlfb_set_video_mode(struct dlfb_data *dev_info, int width, int height)
+{
+
+	int i, ret;
+	unsigned char j;
+	char *bufptr = dev_info->buf;
+	uint8_t *vdata;
+
+	for (i = 0; i < MAX_VMODES; i++) {
+		printk("INIT VIDEO %d %d %d\n", i, dlfb_video_modes[i].xres,
+		       dlfb_video_modes[i].yres);
+		if (dlfb_video_modes[i].xres == width
+		    && dlfb_video_modes[i].yres == height) {
+
+			dev_info->base16 = 0;
+
+			dev_info->base8 = width * height * (FB_BPP / 8);;
+
+			// set encryption key (null)
+			memcpy(dev_info->buf, STD_CHANNEL, 16);
+			ret =
+			    usb_control_msg(dev_info->udev,
+					    usb_sndctrlpipe(dev_info->udev, 0),
+					    0x12, (0x02 << 5), 0, 0,
+					    dev_info->buf, 16, 0);
+			printk("ret control msg 1 (STD_CHANNEL): %d\n", ret);
+
+			// set registers
+			bufptr = dlfb_set_register(bufptr, 0xFF, 0x00);
+
+			// set addresses
+			bufptr =
+			    dlfb_set_register(bufptr, 0x20,
+					      (char)(dev_info->base16 >> 16));
+			bufptr =
+			    dlfb_set_register(bufptr, 0x21,
+					      (char)(dev_info->base16 >> 8));
+			bufptr =
+			    dlfb_set_register(bufptr, 0x22,
+					      (char)(dev_info->base16));
+
+			bufptr =
+			    dlfb_set_register(bufptr, 0x26,
+					      (char)(dev_info->base8 >> 16));
+			bufptr =
+			    dlfb_set_register(bufptr, 0x27,
+					      (char)(dev_info->base8 >> 8));
+			bufptr =
+			    dlfb_set_register(bufptr, 0x28,
+					      (char)(dev_info->base8));
+
+			// set video mode
+			vdata = (uint8_t *) & dlfb_video_modes[i];
+			for (j = 0; j < 29; j++) {
+				bufptr = dlfb_set_register(bufptr, j, vdata[j]);
+			}
+
+			// blank
+			bufptr = dlfb_set_register(bufptr, 0x1F, 0x00);
+
+			// end registers
+			bufptr = dlfb_set_register(bufptr, 0xFF, 0xFF);
+
+			// send
+			ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf);
+			printk("ret bulk 2: %d %d\n", ret,
+			       bufptr - dev_info->buf);
+
+			// flush
+			ret = dlfb_bulk_msg(dev_info, 0);
+			printk("ret bulk 3: %d\n", ret);
+
+			dev_info->screen_size = width * height * (FB_BPP / 8);
+			dev_info->line_length = width * (FB_BPP / 8);
+
+			return 0;
+		}
+	}
+
+	return -1;
+}