diff --git a/drivers/staging/udlfb/udlfb.c b/drivers/staging/udlfb/udlfb.c index f5416af1e90..b01e73311d4 100644 --- a/drivers/staging/udlfb/udlfb.c +++ b/drivers/staging/udlfb/udlfb.c @@ -1,17 +1,20 @@ -/***************************************************************************** - * DLFB Kernel Driver * - * Version 0.2 (udlfb) * - * (C) 2009 Roberto De Ioris * - * * - * This file is licensed under the GPLv2. See COPYING in the package. * - * Based on the amazing work of Florian Echtler and libdlo 0.1 * - * * - * * - * 10.06.09 release 0.2.3 (edid ioctl, fallback for unsupported modes) * - * 05.06.09 release 0.2.2 (real screen blanking, rle compression, double buffer) * - * 31.05.09 release 0.2 * - * 22.05.09 First public (ugly) release * - *****************************************************************************/ +/* + * udlfb.c -- Framebuffer driver for DisplayLink USB controller + * + * Copyright (C) 2009 Roberto De Ioris + * Copyright (C) 2009 Jaya Kumar + * Copyright (C) 2009 Bernie Thompson + * + * 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. + * + * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven, + * usb-skeleton by GregKH. + * + * Device-specific portions based on information from Displaylink, with work + * from Florian Echtler, Henrik Bjerregaard Pedersen, and others. + */ #include #include @@ -20,66 +23,280 @@ #include #include #include -#include #include +#include +#include +#include #include "udlfb.h" -#define DRIVER_VERSION "DLFB 0.2" +static struct fb_fix_screeninfo dlfb_fix = { + .id = "udlfb", + .type = FB_TYPE_PACKED_PIXELS, + .visual = FB_VISUAL_TRUECOLOR, + .xpanstep = 0, + .ypanstep = 0, + .ywrapstep = 0, + .accel = FB_ACCEL_NONE, +}; -/* memory functions taken from vfb */ +static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST | +#ifdef FBINFO_VIRTFB + FBINFO_VIRTFB | +#endif + FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT | + FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR; -static void *rvmalloc(unsigned long size) +/* + * There are many DisplayLink-based products, all with unique PIDs. We are able + * to support all volume ones (circa 2009) with a single driver, so we match + * globally on VID. TODO: Probe() needs to detect when we might be running + * "future" chips, and bail on those, so a compatible driver can match. + */ +static struct usb_device_id id_table[] = { + {.idVendor = 0x17e9, .match_flags = USB_DEVICE_ID_MATCH_VENDOR,}, + {}, +}; +MODULE_DEVICE_TABLE(usb, id_table); + +/* module options */ +static int console; /* Optionally allow fbcon to consume first framebuffer */ +static int fb_defio; /* Optionally enable experimental fb_defio mmap support */ + +/* dlfb keeps a list of urbs for efficient bulk transfers */ +static void dlfb_urb_completion(struct urb *urb); +static struct urb *dlfb_get_urb(struct dlfb_data *dev); +static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len); +static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size); +static void dlfb_free_urb_list(struct dlfb_data *dev); + +/* + * All DisplayLink bulk operations start with 0xAF, followed by specific code + * All operations are written to buffers which then later get sent to device + */ +static char *dlfb_set_register(char *buf, u8 reg, u8 val) { - 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; + *buf++ = 0xAF; + *buf++ = 0x20; + *buf++ = reg; + *buf++ = val; + return buf; } -static void rvfree(void *mem, unsigned long size) +static char *dlfb_vidreg_lock(char *buf) { - 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); + return dlfb_set_register(buf, 0xFF, 0x00); } -static int dlfb_mmap(struct fb_info *info, struct vm_area_struct *vma) +static char *dlfb_vidreg_unlock(char *buf) +{ + return dlfb_set_register(buf, 0xFF, 0xFF); +} + +/* + * On/Off for driving the DisplayLink framebuffer to the display + * 0x00 H and V sync on + * 0x01 H and V sync off (screen blank but powered) + * 0x07 DPMS powerdown (requires modeset to come back) + */ +static char *dlfb_enable_hvsync(char *buf, bool enable) +{ + if (enable) + return dlfb_set_register(buf, 0x1F, 0x00); + else + return dlfb_set_register(buf, 0x1F, 0x07); +} + +static char *dlfb_set_color_depth(char *buf, u8 selection) +{ + return dlfb_set_register(buf, 0x00, selection); +} + +static char *dlfb_set_base16bpp(char *wrptr, u32 base) +{ + /* the base pointer is 16 bits wide, 0x20 is hi byte. */ + wrptr = dlfb_set_register(wrptr, 0x20, base >> 16); + wrptr = dlfb_set_register(wrptr, 0x21, base >> 8); + return dlfb_set_register(wrptr, 0x22, base); +} + +/* + * DisplayLink HW has separate 16bpp and 8bpp framebuffers. + * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer + */ +static char *dlfb_set_base8bpp(char *wrptr, u32 base) +{ + wrptr = dlfb_set_register(wrptr, 0x26, base >> 16); + wrptr = dlfb_set_register(wrptr, 0x27, base >> 8); + return dlfb_set_register(wrptr, 0x28, base); +} + +static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value) +{ + wrptr = dlfb_set_register(wrptr, reg, value >> 8); + return dlfb_set_register(wrptr, reg+1, value); +} + +/* + * This is kind of weird because the controller takes some + * register values in a different byte order than other registers. + */ +static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value) +{ + wrptr = dlfb_set_register(wrptr, reg, value); + return dlfb_set_register(wrptr, reg+1, value >> 8); +} + +/* + * LFSR is linear feedback shift register. The reason we have this is + * because the display controller needs to minimize the clock depth of + * various counters used in the display path. So this code reverses the + * provided value into the lfsr16 value by counting backwards to get + * the value that needs to be set in the hardware comparator to get the + * same actual count. This makes sense once you read above a couple of + * times and think about it from a hardware perspective. + */ +static u16 dlfb_lfsr16(u16 actual_count) +{ + u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */ + + while (actual_count--) { + lv = ((lv << 1) | + (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1)) + & 0xFFFF; + } + + return (u16) lv; +} + +/* + * This does LFSR conversion on the value that is to be written. + * See LFSR explanation above for more detail. + */ +static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value) +{ + return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value)); +} + +/* + * This takes a standard fbdev screeninfo struct and all of its monitor mode + * details and converts them into the DisplayLink equivalent register commands. + */ +static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var) +{ + u16 xds, yds; + u16 xde, yde; + u16 yec; + + /* x display start */ + xds = var->left_margin + var->hsync_len; + wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds); + /* x display end */ + xde = xds + var->xres; + wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde); + + /* y display start */ + yds = var->upper_margin + var->vsync_len; + wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds); + /* y display end */ + yde = yds + var->yres; + wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde); + + /* x end count is active + blanking - 1 */ + wrptr = dlfb_set_register_lfsr16(wrptr, 0x09, + xde + var->right_margin - 1); + + /* libdlo hardcodes hsync start to 1 */ + wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1); + + /* hsync end is width of sync pulse + 1 */ + wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1); + + /* hpixels is active pixels */ + wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres); + + /* yendcount is vertical active + vertical blanking */ + yec = var->yres + var->upper_margin + var->lower_margin + + var->vsync_len; + wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec); + + /* libdlo hardcodes vsync start to 0 */ + wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0); + + /* vsync end is width of vsync pulse */ + wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len); + + /* vpixels is active pixels */ + wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres); + + /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */ + wrptr = dlfb_set_register_16be(wrptr, 0x1B, + 200*1000*1000/var->pixclock); + + return wrptr; +} + +/* + * This takes a standard fbdev screeninfo struct that was fetched or prepared + * and then generates the appropriate command sequence that then drives the + * display controller. + */ +static int dlfb_set_video_mode(struct dlfb_data *dev, + struct fb_var_screeninfo *var) +{ + char *buf; + char *wrptr; + int retval = 0; + int writesize; + struct urb *urb; + + if (!atomic_read(&dev->usb_active)) + return -EPERM; + + urb = dlfb_get_urb(dev); + if (!urb) + return -ENOMEM; + + buf = (char *) urb->transfer_buffer; + + /* + * This first section has to do with setting the base address on the + * controller * associated with the display. There are 2 base + * pointers, currently, we only * use the 16 bpp segment. + */ + wrptr = dlfb_vidreg_lock(buf); + wrptr = dlfb_set_color_depth(wrptr, 0x00); + /* set base for 16bpp segment to 0 */ + wrptr = dlfb_set_base16bpp(wrptr, 0); + /* set base for 8bpp segment to end of fb */ + wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len); + + wrptr = dlfb_set_vid_cmds(wrptr, var); + wrptr = dlfb_enable_hvsync(wrptr, true); + wrptr = dlfb_vidreg_unlock(wrptr); + + writesize = wrptr - buf; + + retval = dlfb_submit_urb(dev, urb, writesize); + + return retval; +} + +static int dlfb_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; - 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; + dl_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)) @@ -95,531 +312,502 @@ static int dlfb_mmap(struct fb_info *info, struct vm_area_struct *vma) vma->vm_flags |= VM_RESERVED; /* avoid to swap out this VMA */ return 0; - -} - -/* ioctl structure */ -struct dloarea { - int x, y; - int w, h; - int x2, y2; -}; - -/* -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; - -// thanks to Henrik Bjerregaard Pedersen for this function -static char *rle_compress16(uint16_t * src, char *dst, int rem) -{ - - int rl; - uint16_t pix0; - char *end_if_raw = dst + 6 + 2 * rem; - - dst += 6; // header will be filled in if RLE is worth it - - while (rem && dst < end_if_raw) { - char *start = (char *)src; - - pix0 = *src++; - rl = 1; - rem--; - while (rem && *src == pix0) - rem--, rl++, src++; - *dst++ = rl; - *dst++ = start[1]; - *dst++ = start[0]; - } - - return dst; } /* -Thanks to Henrik Bjerregaard Pedersen for rle implementation and code refactoring. -Next step is huffman compression. -*/ - -static int -image_blit(struct dlfb_data *dev_info, int x, int y, int width, int height, - char *data) + * Trims identical data from front and back of line + * Sets new front buffer address and width + * And returns byte count of identical pixels + * Assumes CPU natural alignment (unsigned long) + * for back and front buffer ptrs and width + */ +static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes) { + int j, k; + const unsigned long *back = (const unsigned long *) bback; + const unsigned long *front = (const unsigned long *) *bfront; + const int width = *width_bytes / sizeof(unsigned long); + int identical = width; + int start = width; + int end = width; - int i, j, base; - int rem = width; - int ret; + prefetch((void *) front); + prefetch((void *) back); - int firstdiff, thistime; - - 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; + for (j = 0; j < width; j++) { + if (back[j] != front[j]) { + start = j; + break; } + } - rem = width; + for (k = width - 1; k > j; k--) { + if (back[k] != front[k]) { + end = k+1; + break; + } + } - /* printk("WRITING LINE %d\n", i); */ + identical = start + (width - end); + *bfront = (u8 *) &front[start]; + *width_bytes = (end - start) * sizeof(unsigned long); - while (rem) { + return identical * sizeof(unsigned long); +} - if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) { - ret = - dlfb_bulk_msg(dev_info, - bufptr - dev_info->buf); - bufptr = dev_info->buf; - } - // number of pixels to consider this time - thistime = rem; - if (thistime > 255) - thistime = 255; +/* + * Render a command stream for an encoded horizontal line segment of pixels. + * + * A command buffer holds several commands. + * It always begins with a fresh command header + * (the protocol doesn't require this, but we enforce it to allow + * multiple buffers to be potentially encoded and sent in parallel). + * A single command encodes one contiguous horizontal line of pixels + * + * The function relies on the client to do all allocation, so that + * rendering can be done directly to output buffers (e.g. USB URBs). + * The function fills the supplied command buffer, providing information + * on where it left off, so the client may call in again with additional + * buffers if the line will take several buffers to complete. + * + * A single command can transmit a maximum of 256 pixels, + * regardless of the compression ratio (protocol design limit). + * To the hardware, 0 for a size byte means 256 + * + * Rather than 256 pixel commands which are either rl or raw encoded, + * the rlx command simply assumes alternating raw and rl spans within one cmd. + * This has a slightly larger header overhead, but produces more even results. + * It also processes all data (read and write) in a single pass. + * Performance benchmarks of common cases show it having just slightly better + * compression than 256 pixel raw or rle commands, with similar CPU consumpion. + * But for very rl friendly data, will compress not quite as well. + */ +static void dlfb_compress_hline( + const uint16_t **pixel_start_ptr, + const uint16_t *const pixel_end, + uint32_t *device_address_ptr, + uint8_t **command_buffer_ptr, + const uint8_t *const cmd_buffer_end) +{ + const uint16_t *pixel = *pixel_start_ptr; + uint32_t dev_addr = *device_address_ptr; + uint8_t *cmd = *command_buffer_ptr; + const int bpp = 2; - // find position of first pixel that has changed - firstdiff = -1; - for (j = 0; j < thistime * 2; j++) { - if (dev_info->backing_buffer - [base - dev_info->base16 + j] != data[j]) { - firstdiff = j / 2; - break; + while ((pixel_end > pixel) && + (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) { + uint8_t *raw_pixels_count_byte = 0; + uint8_t *cmd_pixels_count_byte = 0; + const uint16_t *raw_pixel_start = 0; + const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0; + + prefetchw((void *) cmd); /* pull in one cache line at least */ + + *cmd++ = 0xAF; + *cmd++ = 0x6B; + *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF); + *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF); + *cmd++ = (uint8_t) ((dev_addr) & 0xFF); + + cmd_pixels_count_byte = cmd++; /* we'll know this later */ + cmd_pixel_start = pixel; + + raw_pixels_count_byte = cmd++; /* we'll know this later */ + raw_pixel_start = pixel; + + cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1, + min((int)(pixel_end - pixel), + (int)(cmd_buffer_end - cmd) / bpp)); + + prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp); + + while (pixel < cmd_pixel_end) { + const uint16_t * const repeating_pixel = pixel; + + *(uint16_t *)cmd = cpu_to_be16p(pixel); + cmd += 2; + pixel++; + + if (unlikely((pixel < cmd_pixel_end) && + (*pixel == *repeating_pixel))) { + /* go back and fill in raw pixel count */ + *raw_pixels_count_byte = ((repeating_pixel - + raw_pixel_start) + 1) & 0xFF; + + while ((pixel < cmd_pixel_end) + && (*pixel == *repeating_pixel)) { + pixel++; } + + /* immediately after raw data is repeat byte */ + *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF; + + /* Then start another raw pixel span */ + raw_pixel_start = pixel; + raw_pixels_count_byte = cmd++; } - - if (firstdiff >= 0) { - char *end_of_rle; - - end_of_rle = - rle_compress16((uint16_t *) (data + - firstdiff * 2), - bufptr, - thistime - firstdiff); - - if (end_of_rle < - bufptr + 6 + 2 * (thistime - firstdiff)) { - bufptr[0] = 0xAF; - bufptr[1] = 0x69; - - bufptr[2] = - (char)((base + - firstdiff * 2) >> 16); - bufptr[3] = - (char)((base + firstdiff * 2) >> 8); - bufptr[4] = - (char)(base + firstdiff * 2); - bufptr[5] = thistime - firstdiff; - - bufptr = end_of_rle; - - } else { - // fallback to raw (or some other encoding?) - *bufptr++ = 0xAF; - *bufptr++ = 0x68; - - *bufptr++ = - (char)((base + - firstdiff * 2) >> 16); - *bufptr++ = - (char)((base + firstdiff * 2) >> 8); - *bufptr++ = - (char)(base + firstdiff * 2); - *bufptr++ = thistime - firstdiff; - // PUT COMPRESSION HERE - for (j = firstdiff * 2; - j < thistime * 2; j += 2) { - *bufptr++ = data[j + 1]; - *bufptr++ = data[j]; - } - } - } - - base += thistime * 2; - data += thistime * 2; - rem -= thistime; } - memcpy(dev_info->backing_buffer + (base - dev_info->base16) - - (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 (pixel > raw_pixel_start) { + /* finalize last RAW span */ + *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF; + } + *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF; + dev_addr += (pixel - cmd_pixel_start) * bpp; } - if (bufptr > dev_info->buf) { - ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf); + if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) { + /* Fill leftover bytes with no-ops */ + if (cmd_buffer_end > cmd) + memset(cmd, 0xAF, cmd_buffer_end - cmd); + cmd = (uint8_t *) cmd_buffer_end; } - mutex_unlock(&dev_info->bulk_mutex); - - return base; + *command_buffer_ptr = cmd; + *pixel_start_ptr = pixel; + *device_address_ptr = dev_addr; + return; } -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) +/* + * There are 3 copies of every pixel: The front buffer that the fbdev + * client renders to, the actual framebuffer across the USB bus in hardware + * (that we can only write to, slowly, and can never read), and (optionally) + * our shadow copy that tracks what's been sent to that hardware buffer. + */ +static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr, + const char *front, char **urb_buf_ptr, + u32 byte_offset, u32 byte_width, + int *ident_ptr, int *sent_ptr) { + const u8 *line_start, *line_end, *next_pixel; + u32 dev_addr = dev->base16 + byte_offset; + struct urb *urb = *urb_ptr; + u8 *cmd = *urb_buf_ptr; + u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length; - int i, j, base; - int ret; - unsigned short col = - (((((red) & 0xF8) | ((green) >> 5)) & 0xFF) << 8) + - (((((green) & 0x1C) << 3) | ((blue) >> 3)) & 0xFF); - int rem = width; + line_start = (u8 *) (front + byte_offset); + next_pixel = line_start; + line_end = next_pixel + byte_width; - char *bufptr; + if (dev->backing_buffer) { + int offset; + const u8 *back_start = (u8 *) (dev->backing_buffer + + byte_offset); - if (x + width > dev_info->info->var.xres) - return -EINVAL; + *ident_ptr += dlfb_trim_hline(back_start, &next_pixel, + &byte_width); - 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 - dev_info->base16 + j] = - (char)(col >> 8); - dev_info->backing_buffer[base - dev_info->base16 + 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); + offset = next_pixel - line_start; + line_end = next_pixel + byte_width; + dev_addr += offset; + back_start += offset; + line_start += offset; + memcpy((char *)back_start, (char *) line_start, + byte_width); } - if (bufptr > dev_info->buf) - ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf); + while (next_pixel < line_end) { - mutex_unlock(&dev_info->bulk_mutex); + dlfb_compress_hline((const uint16_t **) &next_pixel, + (const uint16_t *) line_end, &dev_addr, + (u8 **) &cmd, (u8 *) cmd_end); - return 1; + if (cmd >= cmd_end) { + int len = cmd - (u8 *) urb->transfer_buffer; + if (dlfb_submit_urb(dev, urb, len)) + return 1; /* lost pixels is set */ + *sent_ptr += len; + urb = dlfb_get_urb(dev); + if (!urb) + return 1; /* lost_pixels is set */ + *urb_ptr = urb; + cmd = urb->transfer_buffer; + cmd_end = &cmd[urb->transfer_buffer_length]; + } + } + + *urb_buf_ptr = cmd; + + return 0; } -static void swapfb(struct dlfb_data *dev_info) +int dlfb_handle_damage(struct dlfb_data *dev, int x, int y, + int width, int height, char *data) { - - int tmpbase; - char *bufptr; - - mutex_lock(&dev_info->bulk_mutex); - - tmpbase = dev_info->base16; - - dev_info->base16 = dev_info->base16d; - dev_info->base16d = tmpbase; - - bufptr = dev_info->buf; - - 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, 0xFF, 0x00); - - dlfb_bulk_msg(dev_info, bufptr - dev_info->buf); - - mutex_unlock(&dev_info->bulk_mutex); -} - -static int copyfb(struct dlfb_data *dev_info) -{ - int base; - int source; - int rem; int i, ret; + char *cmd; + cycles_t start_cycles, end_cycles; + int bytes_sent = 0; + int bytes_identical = 0; + struct urb *urb; + int aligned_x; - char *bufptr; + start_cycles = get_cycles(); - base = dev_info->base16d; + aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long)); + width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long)); + x = aligned_x; - mutex_lock(&dev_info->bulk_mutex); + if ((width <= 0) || + (x + width > dev->info->var.xres) || + (y + height > dev->info->var.yres)) + return -EINVAL; - source = dev_info->base16; + if (!atomic_read(&dev->usb_active)) + return 0; - bufptr = dev_info->buf; + urb = dlfb_get_urb(dev); + if (!urb) + return 0; + cmd = urb->transfer_buffer; - for (i = 0; i < dev_info->info->var.yres; i++) { + 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); - if (dev_info->bufend - bufptr < BUF_HIGH_WATER_MARK) { - ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf); - bufptr = dev_info->buf; - } - - rem = dev_info->info->var.xres; - - 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; - } - } + if (dlfb_render_hline(dev, &urb, + (char *) dev->info->fix.smem_start, + &cmd, byte_offset, width * BPP, + &bytes_identical, &bytes_sent)) + goto error; } - if (bufptr > dev_info->buf) - ret = dlfb_bulk_msg(dev_info, bufptr - dev_info->buf); + if (cmd > (char *) urb->transfer_buffer) { + /* Send partial buffer remaining before exiting */ + int len = cmd - (char *) urb->transfer_buffer; + ret = dlfb_submit_urb(dev, urb, len); + bytes_sent += len; + } else + dlfb_urb_completion(urb); - mutex_unlock(&dev_info->bulk_mutex); - - return 1; +error: + atomic_add(bytes_sent, &dev->bytes_sent); + atomic_add(bytes_identical, &dev->bytes_identical); + atomic_add(width*height*2, &dev->bytes_rendered); + end_cycles = get_cycles(); + atomic_add(((unsigned int) ((end_cycles - start_cycles) + >> 10)), /* Kcycles */ + &dev->cpu_kcycles_used); + return 0; } -static int -copyarea(struct dlfb_data *dev_info, int dx, int dy, int sx, int sy, - int width, int height) +static ssize_t dlfb_ops_read(struct fb_info *info, char __user *buf, + size_t count, loff_t *ppos) { - int base; - int source; - int rem; - int i, ret; + ssize_t result = -ENOSYS; - char *bufptr; +#if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE + result = fb_sys_read(info, buf, count, ppos); +#endif - 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->base16, - 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; + return result; } -static void dlfb_copyarea(struct fb_info *info, const struct fb_copyarea *area) +/* + * 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 dlfb_ops_write(struct fb_info *info, const char __user *buf, + size_t count, loff_t *ppos) +{ + ssize_t result = -ENOSYS; + struct dlfb_data *dev = info->par; + u32 offset = (u32) *ppos; + +#if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE + + 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); + + dlfb_handle_damage(dev, 0, start, info->var.xres, + lines, info->screen_base); + } +#endif + + return result; +} + +/* hardware has native COPY command (see libdlo), but not worth it for fbcon */ +static void dlfb_ops_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); +#if defined CONFIG_FB_SYS_COPYAREA || defined CONFIG_FB_SYS_COPYAREA_MODULE - /* printk("COPY AREA %d %d %d %d %d %d !!!\n", area->dx, area->dy, area->sx, area->sy, area->width, area->height); */ + sys_copyarea(info, area); + + dlfb_handle_damage(dev, area->dx, area->dy, + area->width, area->height, info->screen_base); +#endif } -static void dlfb_imageblit(struct fb_info *info, const struct fb_image *image) +static void dlfb_ops_imageblit(struct fb_info *info, + const struct fb_image *image) { + struct dlfb_data *dev = info->par; +#if defined CONFIG_FB_SYS_IMAGEBLIT || defined CONFIG_FB_SYS_IMAGEBLIT_MODULE + + sys_imageblit(info, image); + + dlfb_handle_damage(dev, image->dx, image->dy, + image->width, image->height, info->screen_base); + +#endif + +} + +static void dlfb_ops_fillrect(struct fb_info *info, + const struct fb_fillrect *rect) +{ + struct dlfb_data *dev = info->par; + +#if defined CONFIG_FB_SYS_FILLRECT || defined CONFIG_FB_SYS_FILLRECT_MODULE + + sys_fillrect(info, rect); + + dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width, + rect->height, info->screen_base); +#endif + +} + +#ifdef CONFIG_FB_DEFERRED_IO +/* + * 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 dlfb_dpy_deferred_io(struct fb_info *info, + struct list_head *pagelist) +{ + struct page *cur; + struct fb_deferred_io *fbdefio = info->fbdefio; + struct dlfb_data *dev = info->par; + struct urb *urb; + char *cmd; + cycles_t start_cycles, end_cycles; + int bytes_sent = 0; + int bytes_identical = 0; + int bytes_rendered = 0; + + if (!fb_defio) + return; + + if (!atomic_read(&dev->usb_active)) + return; + + start_cycles = get_cycles(); + + urb = dlfb_get_urb(dev); + if (!urb) + return; + + cmd = urb->transfer_buffer; + + /* walk the written page list and render each to device */ + list_for_each_entry(cur, &fbdefio->pagelist, lru) { + + if (dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start, + &cmd, cur->index << PAGE_SHIFT, + PAGE_SIZE, &bytes_identical, &bytes_sent)) + goto error; + bytes_rendered += PAGE_SIZE; + } + + if (cmd > (char *) urb->transfer_buffer) { + /* Send partial buffer remaining before exiting */ + int len = cmd - (char *) urb->transfer_buffer; + dlfb_submit_urb(dev, urb, len); + bytes_sent += len; + } else + dlfb_urb_completion(urb); + +error: + atomic_add(bytes_sent, &dev->bytes_sent); + atomic_add(bytes_identical, &dev->bytes_identical); + atomic_add(bytes_rendered, &dev->bytes_rendered); + end_cycles = get_cycles(); + atomic_add(((unsigned int) ((end_cycles - start_cycles) + >> 10)), /* Kcycles */ + &dev->cpu_kcycles_used); +} + +#endif + +static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len) +{ + int i; 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); */ + char *rbuf; + + rbuf = kmalloc(2, GFP_KERNEL); + if (!rbuf) + return 0; + + for (i = 0; i < len; i++) { + ret = usb_control_msg(dev->udev, + usb_rcvctrlpipe(dev->udev, 0), (0x02), + (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2, + HZ); + if (ret < 1) { + dl_err("Read EDID byte %d failed err %x\n", i, ret); + i--; + break; + } + edid[i] = rbuf[1]; + } + + kfree(rbuf); + + return i; } -static void dlfb_fillrect(struct fb_info *info, - const struct fb_fillrect *region) +static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd, + unsigned long arg) { - unsigned char red, green, blue; struct dlfb_data *dev = info->par; - - memcpy(&red, ®ion->color, 1); - memcpy(&green, ®ion->color + 1, 1); - memcpy(&blue, ®ion->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 = NULL; - if (cmd == 0xAD) { + if (!atomic_read(&dev->usb_active)) + return 0; + + /* TODO: Update X server to get this from sysfs instead */ + if (cmd == DLFB_IOCTL_RETURN_EDID) { char *edid = (char *)arg; - dlfb_edid(dev_info); - if (copy_to_user(edid, dev_info->edid, 128)) { + if (copy_to_user(edid, dev->edid, dev->edid_size)) return -EFAULT; - } return 0; } - if (cmd == 0xAA || cmd == 0xAB || cmd == 0xAC) { + /* TODO: Help propose a standard fb.h ioctl to report mmap damage */ + if (cmd == DLFB_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 = DL_DEFIO_WRITE_DISABLE; area = (struct dloarea *)arg; @@ -634,36 +822,17 @@ static int dlfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg) if (area->y > info->var.yres) area->y = info->var.yres; - } - if (cmd == 0xAA) { - image_blit(dev_info, area->x, area->y, area->w, area->h, + dlfb_handle_damage(dev, area->x, area->y, area->w, area->h, info->screen_base); } - if (cmd == 0xAC) { - copyfb(dev_info); - image_blit(dev_info, area->x, area->y, area->w, area->h, - info->screen_base); - swapfb(dev_info); - } else if (cmd == 0xAB) { - if (area->x2 < 0) - area->x2 = 0; - - if (area->y2 < 0) - area->y2 = 0; - - copyarea(dev_info, - area->x2, area->y2, area->x, area->y, area->w, - area->h); - } return 0; } /* taken from vesafb */ - static int -dlfb_setcolreg(unsigned regno, unsigned red, unsigned green, +dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info) { int err = 0; @@ -688,251 +857,1072 @@ dlfb_setcolreg(unsigned regno, unsigned red, unsigned green, return err; } -static int dlfb_release(struct fb_info *info, int user) +/* + * 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 dlfb_ops_open(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); + struct dlfb_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); + +#ifdef CONFIG_FB_DEFERRED_IO + 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 = DL_DEFIO_WRITE_DELAY; + fbdefio->deferred_io = dlfb_dpy_deferred_io; + } + + info->fbdefio = fbdefio; + fb_deferred_io_init(info); + } +#endif + + dl_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n", + info->node, user, info, dev->fb_count); + return 0; } -static int dlfb_blank(int blank_mode, struct fb_info *info) +/* + * Called when all client interfaces to start transactions have been disabled, + * and all references to our device instance (dlfb_data) are released. + * Every transaction must have a reference, so we know are fully spun down + */ +static void dlfb_free(struct kref *kref) { - struct dlfb_data *dev_info = info->par; - char *bufptr = dev_info->buf; + struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref); - bufptr = dlfb_set_register(bufptr, 0xFF, 0x00); - if (blank_mode != FB_BLANK_UNBLANK) { - bufptr = dlfb_set_register(bufptr, 0x1F, 0x01); - } else { - bufptr = dlfb_set_register(bufptr, 0x1F, 0x00); + /* this function will wait for all in-flight urbs to complete */ + if (dev->urbs.count > 0) + dlfb_free_urb_list(dev); + + if (dev->backing_buffer) + vfree(dev->backing_buffer); + + kfree(dev->edid); + + dl_warn("freeing dlfb_data %p\n", dev); + + kfree(dev); +} + +static void dlfb_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 dlfb_free_framebuffer_work(struct work_struct *work) +{ + struct dlfb_data *dev = container_of(work, struct dlfb_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); + + dl_warn("fb_info for /dev/fb%d has been freed\n", node); + + /* ref taken in probe() as part of registering framebfufer */ + kref_put(&dev->kref, dlfb_free); +} + +/* + * Assumes caller is holding info->lock mutex (for open and release at least) + */ +static int dlfb_ops_release(struct fb_info *info, int user) +{ + struct dlfb_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); + +#ifdef CONFIG_FB_DEFERRED_IO + if ((dev->fb_count == 0) && (info->fbdefio)) { + fb_deferred_io_cleanup(info); + kfree(info->fbdefio); + info->fbdefio = NULL; + info->fbops->fb_mmap = dlfb_ops_mmap; } - bufptr = dlfb_set_register(bufptr, 0xFF, 0xFF); +#endif - dlfb_bulk_msg(dev_info, bufptr - dev_info->buf); + dl_warn("released /dev/fb%d user=%d count=%d\n", + info->node, user, dev->fb_count); + + kref_put(&dev->kref, dlfb_free); + + return 0; +} + +/* + * Check whether a video mode is supported by the DisplayLink chip + * We start from monitor's modes, so don't need to filter that here + */ +static int dlfb_is_valid_mode(struct fb_videomode *mode, + struct fb_info *info) +{ + struct dlfb_data *dev = info->par; + + if (mode->xres * mode->yres > dev->sku_pixel_limit) { + dl_warn("%dx%d beyond chip capabilities\n", + mode->xres, mode->yres); + return 0; + } + + dl_info("%dx%d valid mode\n", mode->xres, mode->yres); + + return 1; +} + +static void dlfb_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 dlfb_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 */ + dlfb_var_color_format(var); + + fb_var_to_videomode(&mode, var); + + if (!dlfb_is_valid_mode(&mode, info)) + return -EINVAL; + + return 0; +} + +static int dlfb_ops_set_par(struct fb_info *info) +{ + struct dlfb_data *dev = info->par; + int result; + u16 *pix_framebuffer; + int i; + + dl_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres); + + result = dlfb_set_video_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; + + dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres, + info->screen_base); + } + + return result; +} + +/* + * In order to come back from full DPMS off, we need to set the mode again + */ +static int dlfb_ops_blank(int blank_mode, struct fb_info *info) +{ + struct dlfb_data *dev = info->par; + + if (blank_mode != FB_BLANK_UNBLANK) { + char *bufptr; + struct urb *urb; + + urb = dlfb_get_urb(dev); + if (!urb) + return 0; + + bufptr = (char *) urb->transfer_buffer; + bufptr = dlfb_vidreg_lock(bufptr); + bufptr = dlfb_enable_hvsync(bufptr, false); + bufptr = dlfb_vidreg_unlock(bufptr); + + dlfb_submit_urb(dev, urb, bufptr - + (char *) urb->transfer_buffer); + } else { + dlfb_set_video_mode(dev, &info->var); + } 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, + .owner = THIS_MODULE, + .fb_read = dlfb_ops_read, + .fb_write = dlfb_ops_write, + .fb_setcolreg = dlfb_ops_setcolreg, + .fb_fillrect = dlfb_ops_fillrect, + .fb_copyarea = dlfb_ops_copyarea, + .fb_imageblit = dlfb_ops_imageblit, + .fb_mmap = dlfb_ops_mmap, + .fb_ioctl = dlfb_ops_ioctl, + .fb_open = dlfb_ops_open, + .fb_release = dlfb_ops_release, + .fb_blank = dlfb_ops_blank, + .fb_check_var = dlfb_ops_check_var, + .fb_set_par = dlfb_ops_set_par, }; -static int -dlfb_probe(struct usb_interface *interface, const struct usb_device_id *id) + +/* + * Assumes &info->lock held by caller + * Assumes no active clients have framebuffer open + */ +static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info) { - struct dlfb_data *dev_info; - 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; + unsigned char *new_back; - int ret; - char rbuf[4]; + dl_warn("Reallocating framebuffer. Addresses will change!\n"); - dev_info = kzalloc(sizeof(*dev_info), GFP_KERNEL); - if (dev_info == NULL) { - printk("cannot allocate dev_info structure.\n"); - return -ENOMEM; - } + new_len = info->fix.line_length * info->var.yres; - mutex_init(&dev_info->bulk_mutex); + if (PAGE_ALIGN(new_len) > old_len) { + /* + * Alloc system memory for virtual framebuffer + */ + new_fb = vmalloc(new_len); + if (!new_fb) { + dl_err("Virtual framebuffer alloc failed\n"); + goto error; + } - dev_info->udev = usb_get_dev(interface_to_usbdev(interface)); - dev_info->interface = interface; + if (info->screen_base) { + memcpy(new_fb, old_fb, old_len); + vfree(info->screen_base); + } - printk("DisplayLink device attached\n"); + info->screen_base = new_fb; + info->fix.smem_len = PAGE_ALIGN(new_len); + info->fix.smem_start = (unsigned long) new_fb; + info->flags = udlfb_info_flags; - /* 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]); - - dlfb_edid(dev_info); - - 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) { - info->var.xres = 1280; - info->var.yres = 1024; - if (dlfb_set_video_mode - (dev_info, info->var.xres, info->var.yres) != 0) { - goto out; + /* + * Second framebuffer copy to mirror the framebuffer state + * on the physical USB device. We can function without this. + * But with imperfect damage info we may send pixels over USB + * that were, in fact, unchanged - wasting limited USB bandwidth + */ + new_back = vmalloc(new_len); + if (!new_back) + dl_info("No shadow/backing buffer allcoated\n"); + else { + if (dev->backing_buffer) + vfree(dev->backing_buffer); + dev->backing_buffer = new_back; + memset(dev->backing_buffer, 0, new_len); } } - 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); - if (strlen(dev_info->udev->product) > 15) { - memcpy(info->fix.id, dev_info->udev->product, 15); - } else { - memcpy(info->fix.id, dev_info->udev->product, - strlen(dev_info->udev->product)); - } - 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; + retval = 0; +error: + return retval; } -static void dlfb_disconnect(struct usb_interface *interface) +/* + * 1) Get EDID from hw, or 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 dlfb_setup_modes(struct dlfb_data *dev, + struct fb_info *info, + char *default_edid, size_t default_edid_size) { - struct dlfb_data *dev_info = usb_get_intfdata(interface); + int i; + const struct fb_videomode *default_vmode = NULL; + int result = 0; + char *edid; + int tries = 3; - 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); + if (info->dev) /* only use mutex if info has been registered */ + mutex_lock(&info->lock); + edid = kmalloc(MAX_EDID_SIZE, GFP_KERNEL); + if (!edid) { + result = -ENOMEM; + goto error; } - kfree(dev_info); + fb_destroy_modelist(&info->modelist); + memset(&info->monspecs, 0, sizeof(info->monspecs)); - printk("DisplayLink device disconnected\n"); + /* + * 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 = dlfb_get_edid(dev, edid, MAX_EDID_SIZE); + + if (i >= MIN_EDID_SIZE) + 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) { + + dl_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) + dl_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 >= MIN_EDID_SIZE) { + 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; + dl_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 (dlfb_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 (dlfb_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); + dlfb_var_color_format(&info->var); + + /* + * with mode size info, we can now alloc our framebuffer. + */ + memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix)); + info->fix.line_length = info->var.xres * + (info->var.bits_per_pixel / 8); + + result = dlfb_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 ssize_t metrics_bytes_rendered_show(struct device *fbdev, + struct device_attribute *a, char *buf) { + struct fb_info *fb_info = dev_get_drvdata(fbdev); + struct dlfb_data *dev = fb_info->par; + return snprintf(buf, PAGE_SIZE, "%u\n", + atomic_read(&dev->bytes_rendered)); +} + +static ssize_t metrics_bytes_identical_show(struct device *fbdev, + struct device_attribute *a, char *buf) { + struct fb_info *fb_info = dev_get_drvdata(fbdev); + struct dlfb_data *dev = fb_info->par; + return snprintf(buf, PAGE_SIZE, "%u\n", + atomic_read(&dev->bytes_identical)); +} + +static ssize_t metrics_bytes_sent_show(struct device *fbdev, + struct device_attribute *a, char *buf) { + struct fb_info *fb_info = dev_get_drvdata(fbdev); + struct dlfb_data *dev = fb_info->par; + return snprintf(buf, PAGE_SIZE, "%u\n", + atomic_read(&dev->bytes_sent)); +} + +static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev, + struct device_attribute *a, char *buf) { + struct fb_info *fb_info = dev_get_drvdata(fbdev); + struct dlfb_data *dev = fb_info->par; + return snprintf(buf, PAGE_SIZE, "%u\n", + atomic_read(&dev->cpu_kcycles_used)); +} + +static ssize_t edid_show( + struct file *filp, + struct kobject *kobj, struct bin_attribute *a, + char *buf, loff_t off, size_t count) { + struct device *fbdev = container_of(kobj, struct device, kobj); + struct fb_info *fb_info = dev_get_drvdata(fbdev); + struct dlfb_data *dev = fb_info->par; + + if (dev->edid == NULL) + return 0; + + if ((off >= dev->edid_size) || (count > dev->edid_size)) + return 0; + + if (off + count > dev->edid_size) + count = dev->edid_size - off; + + dl_info("sysfs edid copy %p to %p, %d bytes\n", + dev->edid, buf, (int) count); + + memcpy(buf, dev->edid, count); + + return count; +} + +static ssize_t edid_store( + struct file *filp, + struct kobject *kobj, struct bin_attribute *a, + char *src, loff_t src_off, size_t src_size) { + struct device *fbdev = container_of(kobj, struct device, kobj); + struct fb_info *fb_info = dev_get_drvdata(fbdev); + struct dlfb_data *dev = fb_info->par; + + /* We only support write of entire EDID at once, no offset*/ + if ((src_size < MIN_EDID_SIZE) || + (src_size > MAX_EDID_SIZE) || + (src_off != 0)) + return 0; + + dlfb_setup_modes(dev, fb_info, src, src_size); + + if (dev->edid && (memcmp(src, dev->edid, src_size) == 0)) { + dl_info("sysfs written EDID is new default\n"); + dlfb_ops_set_par(fb_info); + return src_size; + } else + return 0; +} + +static ssize_t metrics_reset_store(struct device *fbdev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct fb_info *fb_info = dev_get_drvdata(fbdev); + struct dlfb_data *dev = fb_info->par; + + atomic_set(&dev->bytes_rendered, 0); + atomic_set(&dev->bytes_identical, 0); + atomic_set(&dev->bytes_sent, 0); + atomic_set(&dev->cpu_kcycles_used, 0); + + return count; +} + +static struct bin_attribute edid_attr = { + .attr.name = "edid", + .attr.mode = 0666, + .size = MAX_EDID_SIZE, + .read = edid_show, + .write = edid_store +}; + +static struct device_attribute fb_device_attrs[] = { + __ATTR_RO(metrics_bytes_rendered), + __ATTR_RO(metrics_bytes_identical), + __ATTR_RO(metrics_bytes_sent), + __ATTR_RO(metrics_cpu_kcycles_used), + __ATTR(metrics_reset, S_IWUGO, NULL, metrics_reset_store), +}; + +/* + * This is necessary before we can communicate with the display controller. + */ +static int dlfb_select_std_channel(struct dlfb_data *dev) +{ + int ret; + u8 set_def_chn[] = { 0x57, 0xCD, 0xDC, 0xA7, + 0x1C, 0x88, 0x5E, 0x15, + 0x60, 0xFE, 0xC6, 0x97, + 0x16, 0x3D, 0x47, 0xF2 }; + + ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), + NR_USB_REQUEST_CHANNEL, + (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0, + set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT); + return ret; +} + +static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev, + struct usb_device *usbdev) +{ + char *desc; + char *buf; + char *desc_end; + + u8 total_len = 0; + + buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL); + if (!buf) + return false; + desc = buf; + + total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */ + 0, desc, MAX_VENDOR_DESCRIPTOR_SIZE); + if (total_len > 5) { + dl_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \ + "%02x %02x %02x %02x %02x %02x %02x\n", + total_len, desc[0], + desc[1], desc[2], desc[3], desc[4], desc[5], desc[6], + desc[7], desc[8], desc[9], desc[10]); + + if ((desc[0] != total_len) || /* descriptor length */ + (desc[1] != 0x5f) || /* vendor descriptor type */ + (desc[2] != 0x01) || /* version (2 bytes) */ + (desc[3] != 0x00) || + (desc[4] != total_len - 2)) /* length after type */ + goto unrecognized; + + desc_end = desc + total_len; + desc += 5; /* the fixed header we've already parsed */ + + while (desc < desc_end) { + u8 length; + u16 key; + + key = *((u16 *) desc); + desc += sizeof(u16); + length = *desc; + desc++; + + switch (key) { + case 0x0200: { /* max_area */ + u32 max_area; + max_area = le32_to_cpu(*((u32 *)desc)); + dl_warn("DL chip limited to %d pixel modes\n", + max_area); + dev->sku_pixel_limit = max_area; + break; + } + default: + break; + } + desc += length; + } + } + + goto success; + +unrecognized: + /* allow udlfb to load for now even if firmware unrecognized */ + dl_err("Unrecognized vendor firmware descriptor\n"); + +success: + kfree(buf); + return true; +} +static int dlfb_usb_probe(struct usb_interface *interface, + const struct usb_device_id *id) +{ + struct usb_device *usbdev; + struct dlfb_data *dev = 0; + struct fb_info *info = 0; + int retval = -ENOMEM; + int i; + + /* usb initialization */ + + usbdev = interface_to_usbdev(interface); + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (dev == NULL) { + err("dlfb_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); + + dl_info("%s %s - serial #%s\n", + usbdev->manufacturer, usbdev->product, usbdev->serial); + dl_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n", + usbdev->descriptor.idVendor, usbdev->descriptor.idProduct, + usbdev->descriptor.bcdDevice, dev); + dl_info("console enable=%d\n", console); + dl_info("fb_defio enable=%d\n", fb_defio); + + dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */ + + if (!dlfb_parse_vendor_descriptor(dev, usbdev)) { + dl_err("firmware not recognized. Assume incompatible device\n"); + goto error; + } + + if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) { + retval = -ENOMEM; + dl_err("dlfb_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; + dl_err("framebuffer_alloc failed\n"); + goto error; + } + + dev->info = info; + info->par = dev; + info->pseudo_palette = dev->pseudo_palette; + info->fbops = &dlfb_ops; + + retval = fb_alloc_cmap(&info->cmap, 256, 0); + if (retval < 0) { + dl_err("fb_alloc_cmap failed %x\n", retval); + goto error; + } + + INIT_DELAYED_WORK(&dev->free_framebuffer_work, + dlfb_free_framebuffer_work); + + INIT_LIST_HEAD(&info->modelist); + + retval = dlfb_setup_modes(dev, info, NULL, 0); + if (retval != 0) { + dl_err("unable to find common mode for display and adapter\n"); + goto error; + } + + /* ready to begin using device */ + + atomic_set(&dev->usb_active, 1); + dlfb_select_std_channel(dev); + + dlfb_ops_check_var(&info->var, info); + dlfb_ops_set_par(info); + + retval = register_framebuffer(info); + if (retval < 0) { + dl_err("register_framebuffer failed %d\n", retval); + goto error; + } + + for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) + device_create_file(info->dev, &fb_device_attrs[i]); + + device_create_bin_file(info->dev, &edid_attr); + + dl_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution." + " Using %dK framebuffer memory\n", info->node, + info->var.xres, info->var.yres, + ((dev->backing_buffer) ? + info->fix.smem_len * 2 : 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); + } + + if (dev->backing_buffer) + vfree(dev->backing_buffer); + + kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */ + kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */ + + /* dev has been deallocated. Do not dereference */ + } + + return retval; +} + +static void dlfb_usb_disconnect(struct usb_interface *interface) +{ + struct dlfb_data *dev; + struct fb_info *info; + int i; + + dev = usb_get_intfdata(interface); + info = dev->info; + + dl_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); + + /* remove udlfb's sysfs interfaces */ + for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) + device_remove_file(info->dev, &fb_device_attrs[i]); + device_remove_bin_file(info->dev, &edid_attr); + + 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, dlfb_free); + + /* consider dlfb_data freed */ + + return; } static struct usb_driver dlfb_driver = { .name = "udlfb", - .probe = dlfb_probe, - .disconnect = dlfb_disconnect, + .probe = dlfb_usb_probe, + .disconnect = dlfb_usb_disconnect, .id_table = id_table, }; -static int __init dlfb_init(void) +static int __init dlfb_module_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) +static void __exit dlfb_module_exit(void) { usb_deregister(&dlfb_driver); } -module_init(dlfb_init); -module_exit(dlfb_exit); +module_init(dlfb_module_init); +module_exit(dlfb_module_exit); -MODULE_AUTHOR("Roberto De Ioris "); -MODULE_DESCRIPTION(DRIVER_VERSION); +static void dlfb_urb_completion(struct urb *urb) +{ + struct urb_node *unode = urb->context; + struct dlfb_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)) { + dl_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 dlfb_free_urb_list(struct dlfb_data *dev) +{ + int count = dev->urbs.count; + struct list_head *node; + struct urb_node *unode; + struct urb *urb; + int ret; + unsigned long flags; + + dl_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 */ +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,34)) + usb_free_coherent(urb->dev, dev->urbs.size, + urb->transfer_buffer, urb->transfer_dma); +#else + usb_buffer_free(urb->dev, dev->urbs.size, + urb->transfer_buffer, urb->transfer_dma); +#endif + usb_free_urb(urb); + kfree(node); + } + +} + +static int dlfb_alloc_urb_list(struct dlfb_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, + dlfb_release_urb_work); + + urb = usb_alloc_urb(0, GFP_KERNEL); + if (!urb) { + kfree(unode); + break; + } + unode->urb = urb; + +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,34)) + buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL, + &urb->transfer_dma); +#else + buf = usb_buffer_alloc(dev->udev, MAX_TRANSFER, GFP_KERNEL, + &urb->transfer_dma); +#endif + + 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, dlfb_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; + + dl_notice("allocated %d %d byte urbs\n", i, (int) size); + + return i; +} + +static struct urb *dlfb_get_urb(struct dlfb_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); + dl_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 dlfb_submit_urb(struct dlfb_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) { + dlfb_urb_completion(urb); /* because no one else will */ + atomic_set(&dev->lost_pixels, 1); + dl_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. *Experimental*"); + +MODULE_AUTHOR("Roberto De Ioris , " + "Jaya Kumar , " + "Bernie Thompson "); +MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver"); MODULE_LICENSE("GPL"); + diff --git a/drivers/staging/udlfb/udlfb.h b/drivers/staging/udlfb/udlfb.h index 08bd671204b..6f9785e9d62 100644 --- a/drivers/staging/udlfb/udlfb.h +++ b/drivers/staging/udlfb/udlfb.h @@ -1,225 +1,117 @@ #ifndef UDLFB_H #define UDLFB_H -#define MAX_VMODES 4 -#define FB_BPP 16 +/* + * 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 DLFB_IOCTL_RETURN_EDID 0xAD +#define DLFB_IOCTL_REPORT_DAMAGE 0xAA +struct dloarea { + int x, y; + int w, h; + int x2, y2; +}; -#define STD_CHANNEL "\x57\xCD\xDC\xA7\x1C\x88\x5E\x15" \ - "\x60\xFE\xC6\x97\x16\x3D\x47\xF2" +struct urb_node { + struct list_head entry; + struct dlfb_data *dev; + struct delayed_work release_urb_work; + struct urb *urb; +}; -/* as libdlo */ -#define BUF_HIGH_WATER_MARK 1024 -#define BUF_SIZE (64*1024) +struct urb_list { + struct list_head list; + spinlock_t lock; + struct semaphore limit_sem; + int available; + int count; + size_t size; +}; struct dlfb_data { struct usb_device *udev; - struct usb_interface *interface; - struct urb *tx_urb, *ctrl_urb; - struct usb_ctrlrequest dr; + struct device *gdev; /* &udev->dev */ struct fb_info *info; - char *buf; - char *bufend; + struct urb_list urbs; + struct kref kref; char *backing_buffer; - struct mutex bulk_mutex; - char edid[128]; - int screen_size; - int line_length; - struct completion done; + 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; + int sku_pixel_limit; int base16; - int base16d; int base8; - int base8d; + u32 pseudo_palette[256]; + /* blit-only rendering path metrics, exposed through sysfs */ + atomic_t bytes_rendered; /* raw pixel-bytes driver asked to render */ + atomic_t bytes_identical; /* saved effort with backbuffer comparison */ + atomic_t bytes_sent; /* to usb, after compression including overhead */ + atomic_t cpu_kcycles_used; /* transpired during pixel processing */ }; -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__)); +#define NR_USB_REQUEST_I2C_SUB_IO 0x02 +#define NR_USB_REQUEST_CHANNEL 0x12 -static struct dlfb_video_mode dlfb_video_modes[MAX_VMODES]; +/* -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) -static void dlfb_bulk_callback(struct urb *urb) -{ - struct dlfb_data *dev_info = urb->context; - complete(&dev_info->done); -} +#define MIN_EDID_SIZE 128 +#define MAX_EDID_SIZE 128 -static void dlfb_edid(struct dlfb_data *dev_info) -{ - int i; - int ret; - char rbuf[2]; +#define MAX_VENDOR_DESCRIPTOR_SIZE 256 - 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]; - } +#define GET_URB_TIMEOUT HZ +#define FREE_URB_TIMEOUT (HZ*2) -} +#define BPP 2 +#define MAX_CMD_PIXELS 255 -static int dlfb_bulk_msg(struct dlfb_data *dev_info, int len) -{ - int ret; +#define RLX_HEADER_BYTES 7 +#define MIN_RLX_PIX_BYTES 4 +#define MIN_RLX_CMD_BYTES (RLX_HEADER_BYTES + MIN_RLX_PIX_BYTES) - init_completion(&dev_info->done); +#define RLE_HEADER_BYTES 6 +#define MIN_RLE_PIX_BYTES 3 +#define MIN_RLE_CMD_BYTES (RLE_HEADER_BYTES + MIN_RLE_PIX_BYTES) - dev_info->tx_urb->actual_length = 0; - dev_info->tx_urb->transfer_buffer_length = len; +#define RAW_HEADER_BYTES 6 +#define MIN_RAW_PIX_BYTES 2 +#define MIN_RAW_CMD_BYTES (RAW_HEADER_BYTES + MIN_RAW_PIX_BYTES) - 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"); - } +#define DL_DEFIO_WRITE_DELAY 5 /* fb_deferred_io.delay in jiffies */ +#define DL_DEFIO_WRITE_DISABLE (HZ*60) /* "disable" with long delay */ - return dev_info->tx_urb->actual_length; -} +/* remove these once align.h patch is taken into kernel */ +#define DL_ALIGN_UP(x, a) ALIGN(x, a) +#define DL_ALIGN_DOWN(x, a) ALIGN(x-(a-1), a) -static 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); +/* remove once this gets added to sysfs.h */ +#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store) - 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); -} - -static char *dlfb_set_register(char *bufptr, uint8_t reg, uint8_t val) -{ - *bufptr++ = 0xAF; - *bufptr++ = 0x20; - *bufptr++ = reg; - *bufptr++ = val; - - return bufptr; -} - -static 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->base16d = width * height * (FB_BPP / 8); - - //dev_info->base8 = width * height * (FB_BPP / 8); - - dev_info->base8 = dev_info->base16; - dev_info->base8d = dev_info->base16d; - - /* 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 color depth */ - bufptr = dlfb_set_register(bufptr, 0x00, 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; -} +/* + * udlfb is both a usb device, and a framebuffer device. + * They may exist at the same time, but during various stages + * inactivity, teardown, or "virtual" operation, only one or the + * other will exist (one will outlive the other). So we can't + * call the dev_*() macros, because we don't have a stable dev object. + */ +#define dl_err(format, arg...) \ + pr_err("udlfb: " format, ## arg) +#define dl_warn(format, arg...) \ + pr_warning("udlfb: " format, ## arg) +#define dl_notice(format, arg...) \ + pr_notice("udlfb: " format, ## arg) +#define dl_info(format, arg...) \ + pr_info("udlfb: " format, ## arg) #endif diff --git a/drivers/staging/udlfb/udlfb.txt b/drivers/staging/udlfb/udlfb.txt new file mode 100644 index 00000000000..7fdde2a02a2 --- /dev/null +++ b/drivers/staging/udlfb/udlfb.txt @@ -0,0 +1,144 @@ + +What is udlfb? +=============== + +This is a driver for DisplayLink USB 2.0 era graphics chips. + +DisplayLink chips provide simple hline/blit operations with some compression, +pairing that with a hardware framebuffer (16MB) on the other end of the +USB wire. That hardware framebuffer is able to drive the VGA, DVI, or HDMI +monitor with no CPU involvement until a pixel has to change. + +The CPU or other local resource does all the rendering; optinally compares the +result with a local shadow of the remote hardware framebuffer to identify +the minimal set of pixels that have changed; and compresses and sends those +pixels line-by-line via USB bulk transfers. + +Because of the efficiency of bulk transfers and a protocol on top that +does not require any acks - the effect is very low latency that +can support surprisingly high resolutions with good performance for +non-gaming and non-video applications. + +Mode setting, EDID read, etc are other bulk or control transfers. Mode +setting is very flexible - able to set nearly arbitrary modes from any timing. + +Advantages of USB graphics in general: + + * Ability to add a nearly arbitrary number of displays to any USB 2.0 + capable system. On Linux, number of displays is limited by fbdev interface + (FB_MAX is currently 32). Of course, all USB devices on the same + host controller share the same 480Mbs USB 2.0 interface. + +Advantages of supporting DisplayLink chips with kernel framebuffer interface: + + * The actual hardware functionality of DisplayLink chips matches nearly + one-to-one with the fbdev interface, making the driver quite small and + tight relative to the functionality it provides. + * X servers and other applications can use the standard fbdev interface + from user mode to talk to the device, without needing to know anything + about USB or DisplayLink's protocol at all. A "displaylink" X driver + and a slightly modified "fbdev" X driver are among those that already do. + +Disadvantages: + + * Fbdev's mmap interface assumes a real hardware framebuffer is mapped. + In the case of USB graphics, it is just an allocated (virtual) buffer. + Writes need to be detected and encoded into USB bulk transfers by the CPU. + Accurate damage/changed area notifications work around this problem. + In the future, hopefully fbdev will be enhanced with an small standard + interface to allow mmap clients to report damage, for the benefit + of virtual or remote framebuffers. + * Fbdev does not arbitrate client ownership of the framebuffer well. + * Fbcon assumes the first framebuffer it finds should be consumed for console. + * It's not clear what the future of fbdev is, given the rise of KMS/DRM. + +How to use it? +============== + +Udlfb, when loaded as a module, will match against all USB 2.0 generation +DisplayLink chips (Alex and Ollie family). It will then attempt to read the EDID +of the monitor, and set the best common mode between the DisplayLink device +and the monitor's capabilities. + +If the DisplayLink device is successful, it will paint a "green screen" which +means that from a hardware and fbdev software perspective, everything is good. + +At that point, a /dev/fb? interface will be present for user-mode applications +to open and begin writing to the framebuffer of the DisplayLink device using +standard fbdev calls. Note that if mmap() is used, by default the user mode +application must send down damage notifcations to trigger repaints of the +changed regions. Alternatively, udlfb can be recompiled with experimental +defio support enabled, to support a page-fault based detection mechanism +that can work without explicit notifcation. + +The most common client of udlfb is xf86-video-displaylink or a modified +xf86-video-fbdev X server. These servers have no real DisplayLink specific +code. They write to the standard framebuffer interface and rely on udlfb +to do its thing. The one extra feature they have is the ability to report +rectangles from the X DAMAGE protocol extension down to udlfb via udlfb's +damage interface (which will hopefully be standardized for all virtual +framebuffers that need damage info). These damage notifications allow +udlfb to efficiently process the changed pixels. + +Module Options +============== + +Special configuration for udlfb is usually unnecessary. There are a few +options, however. + +From the command line, pass options to modprobe +modprobe udlfb defio=1 console=1 + +Or for permanent option, create file like /etc/modprobe.d/options with text +options udlfb defio=1 console=1 + +Accepted options: + +fb_defio Make use of the fb_defio (CONFIG_FB_DEFERRED_IO) kernel + module to track changed areas of the framebuffer by page faults. + Standard fbdev applications that use mmap but that do not + report damage, may be able to work with this enabled. + Disabled by default because of overhead and other issues. + +console Allow fbcon to attach to udlfb provided framebuffers. This + is disabled by default because fbcon will aggressively consume + the first framebuffer it finds, which isn't usually what the + user wants in the case of USB displays. + +Sysfs Attributes +================ + +Udlfb creates several files in /sys/class/graphics/fb? +Where ? is the sequential framebuffer id of the particular DisplayLink device + +edid If a valid EDID blob is written to this file (typically + by a udev rule), then udlfb will use this EDID as a + backup in case reading the actual EDID of the monitor + attached to the DisplayLink device fails. This is + especially useful for fixed panels, etc. that cannot + communicate their capabilities via EDID. Reading + this file returns the current EDID of the attached + monitor (or last backup value written). This is + useful to get the EDID of the attached monitor, + which can be passed to utilities like parse-edid. + +metrics_bytes_rendered 32-bit count of pixel bytes rendered + +metrics_bytes_identical 32-bit count of how many of those bytes were found to be + unchanged, based on a shadow framebuffer check + +metrics_bytes_sent 32-bit count of how many bytes were transferred over + USB to communicate the resulting changed pixels to the + hardware. Includes compression and protocol overhead + +metrics_cpu_kcycles_used 32-bit count of CPU cycles used in processing the + above pixels (in thousands of cycles). + +metrics_reset Write-only. Any write to this file resets all metrics + above to zero. Note that the 32-bit counters above + roll over very quickly. To get reliable results, design + performance tests to start and finish in a very short + period of time (one minute or less is safe). + +-- +Bernie Thompson