drivers/staging/udlfb/udlfb.c

   1 /*
   2  * udlfb.c -- Framebuffer driver for DisplayLink USB controller
   3  *
   4  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
   5  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
   6  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License v2. See the file COPYING in the main directory of this archive for
  10  * more details.
  11  *
  12  * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
  13  * usb-skeleton by GregKH.
  14  *
  15  * Device-specific portions based on information from Displaylink, with work
  16  * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/usb.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/mm.h>
  25 #include <linux/fb.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/slab.h>
  28
  29 #include "udlfb.h"
  30
  31 static struct fb_fix_screeninfo dlfb_fix = {
  32         .id =           "udlfb",
  33         .type =         FB_TYPE_PACKED_PIXELS,
  34         .visual =       FB_VISUAL_TRUECOLOR,
  35         .xpanstep =     0,
  36         .ypanstep =     0,
  37         .ywrapstep =    0,
  38         .accel =        FB_ACCEL_NONE,
  39 };
  40
  41 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
  42 #ifdef FBINFO_VIRTFB
  43                 FBINFO_VIRTFB |
  44 #endif
  45                 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
  46                 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
  47
  48 /*
  49  * There are many DisplayLink-based products, all with unique PIDs. We are able
  50  * to support all volume ones (circa 2009) with a single driver, so we match
  51  * globally on VID. TODO: Probe() needs to detect when we might be running
  52  * "future" chips, and bail on those, so a compatible driver can match.
  53  */
  54 static struct usb_device_id id_table[] = {
  55         {.idVendor = 0x17e9, .match_flags = USB_DEVICE_ID_MATCH_VENDOR,},
  56         {},
  57 };
  58 MODULE_DEVICE_TABLE(usb, id_table);
  59
  60 #ifndef CONFIG_FB_DEFERRED_IO
  61 #warning Please set CONFIG_FB_DEFFERRED_IO option to support generic fbdev apps
  62 #endif
  63
  64 #ifndef CONFIG_FB_SYS_IMAGEBLIT
  65 #ifndef CONFIG_FB_SYS_IMAGEBLIT_MODULE
  66 #warning Please set CONFIG_FB_SYS_IMAGEBLIT option to support fb console
  67 #endif
  68 #endif
  69
  70 #ifndef CONFIG_FB_MODE_HELPERS
  71 #warning CONFIG_FB_MODE_HELPERS required. Expect build break
  72 #endif
  73
  74 /* dlfb keeps a list of urbs for efficient bulk transfers */
  75 static void dlfb_urb_completion(struct urb *urb);
  76 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
  77 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
  78 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
  79 static void dlfb_free_urb_list(struct dlfb_data *dev);
  80
  81 /* other symbols with dependents */
  82 #ifdef CONFIG_FB_DEFERRED_IO
  83 static struct fb_deferred_io dlfb_defio;
  84 #endif
  85
  86 /*
  87  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  88  * All operations are written to buffers which then later get sent to device
  89  */
  90 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
  91 {
  92         *buf++ = 0xAF;
  93         *buf++ = 0x20;
  94         *buf++ = reg;
  95         *buf++ = val;
  96         return buf;
  97 }
  98
  99 static char *dlfb_vidreg_lock(char *buf)
 100 {
 101         return dlfb_set_register(buf, 0xFF, 0x00);
 102 }
 103
 104 static char *dlfb_vidreg_unlock(char *buf)
 105 {
 106         return dlfb_set_register(buf, 0xFF, 0xFF);
 107 }
 108
 109 /*
 110  * On/Off for driving the DisplayLink framebuffer to the display
 111  *  0x00 H and V sync on
 112  *  0x01 H and V sync off (screen blank but powered)
 113  *  0x07 DPMS powerdown (requires modeset to come back)
 114  */
 115 static char *dlfb_enable_hvsync(char *buf, bool enable)
 116 {
 117         if (enable)
 118                 return dlfb_set_register(buf, 0x1F, 0x00);
 119         else
 120                 return dlfb_set_register(buf, 0x1F, 0x07);
 121 }
 122
 123 static char *dlfb_set_color_depth(char *buf, u8 selection)
 124 {
 125         return dlfb_set_register(buf, 0x00, selection);
 126 }
 127
 128 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 129 {
 130         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 131         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 132         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 133         return dlfb_set_register(wrptr, 0x22, base);
 134 }
 135
 136 /*
 137  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 138  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 139  */
 140 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 141 {
 142         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 143         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 144         return dlfb_set_register(wrptr, 0x28, base);
 145 }
 146
 147 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 148 {
 149         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 150         return dlfb_set_register(wrptr, reg+1, value);
 151 }
 152
 153 /*
 154  * This is kind of weird because the controller takes some
 155  * register values in a different byte order than other registers.
 156  */
 157 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 158 {
 159         wrptr = dlfb_set_register(wrptr, reg, value);
 160         return dlfb_set_register(wrptr, reg+1, value >> 8);
 161 }
 162
 163 /*
 164  * LFSR is linear feedback shift register. The reason we have this is
 165  * because the display controller needs to minimize the clock depth of
 166  * various counters used in the display path. So this code reverses the
 167  * provided value into the lfsr16 value by counting backwards to get
 168  * the value that needs to be set in the hardware comparator to get the
 169  * same actual count. This makes sense once you read above a couple of
 170  * times and think about it from a hardware perspective.
 171  */
 172 static u16 dlfb_lfsr16(u16 actual_count)
 173 {
 174         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 175
 176         while (actual_count--) {
 177                 lv =     ((lv << 1) |
 178                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 179                         & 0xFFFF;
 180         }
 181
 182         return (u16) lv;
 183 }
 184
 185 /*
 186  * This does LFSR conversion on the value that is to be written.
 187  * See LFSR explanation above for more detail.
 188  */
 189 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 190 {
 191         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 192 }
 193
 194 /*
 195  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 196  * details and converts them into the DisplayLink equivalent register commands.
 197  */
 198 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 199 {
 200         u16 xds, yds;
 201         u16 xde, yde;
 202         u16 yec;
 203
 204         /* x display start */
 205         xds = var->left_margin + var->hsync_len;
 206         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 207         /* x display end */
 208         xde = xds + var->xres;
 209         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 210
 211         /* y display start */
 212         yds = var->upper_margin + var->vsync_len;
 213         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 214         /* y display end */
 215         yde = yds + var->yres;
 216         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 217
 218         /* x end count is active + blanking - 1 */
 219         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 220                         xde + var->right_margin - 1);
 221
 222         /* libdlo hardcodes hsync start to 1 */
 223         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 224
 225         /* hsync end is width of sync pulse + 1 */
 226         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 227
 228         /* hpixels is active pixels */
 229         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 230
 231         /* yendcount is vertical active + vertical blanking */
 232         yec = var->yres + var->upper_margin + var->lower_margin +
 233                         var->vsync_len;
 234         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 235
 236         /* libdlo hardcodes vsync start to 0 */
 237         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 238
 239         /* vsync end is width of vsync pulse */
 240         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 241
 242         /* vpixels is active pixels */
 243         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 244
 245         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 246         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 247                         200*1000*1000/var->pixclock);
 248
 249         return wrptr;
 250 }
 251
 252 /*
 253  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 254  * and then generates the appropriate command sequence that then drives the
 255  * display controller.
 256  */
 257 static int dlfb_set_video_mode(struct dlfb_data *dev,
 258                                 struct fb_var_screeninfo *var)
 259 {
 260         char *buf;
 261         char *wrptr;
 262         int retval = 0;
 263         int writesize;
 264         struct urb *urb;
 265
 266         if (!atomic_read(&dev->usb_active))
 267                 return -EPERM;
 268
 269         urb = dlfb_get_urb(dev);
 270         if (!urb)
 271                 return -ENOMEM;
 272         buf = (char *) urb->transfer_buffer;
 273
 274         /*
 275         * This first section has to do with setting the base address on the
 276         * controller * associated with the display. There are 2 base
 277         * pointers, currently, we only * use the 16 bpp segment.
 278         */
 279         wrptr = dlfb_vidreg_lock(buf);
 280         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 281         /* set base for 16bpp segment to 0 */
 282         wrptr = dlfb_set_base16bpp(wrptr, 0);
 283         /* set base for 8bpp segment to end of fb */
 284         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
 285
 286         wrptr = dlfb_set_vid_cmds(wrptr, var);
 287         wrptr = dlfb_enable_hvsync(wrptr, true);
 288         wrptr = dlfb_vidreg_unlock(wrptr);
 289
 290         writesize = wrptr - buf;
 291
 292         retval = dlfb_submit_urb(dev, urb, writesize);
 293
 294         return retval;
 295 }
 296
 297 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 298 {
 299         unsigned long start = vma->vm_start;
 300         unsigned long size = vma->vm_end - vma->vm_start;
 301         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 302         unsigned long page, pos;
 303         struct dlfb_data *dev = info->par;
 304
 305         dl_notice("MMAP: %lu %u\n", offset + size, info->fix.smem_len);
 306
 307         if (offset + size > info->fix.smem_len)
 308                 return -EINVAL;
 309
 310         pos = (unsigned long)info->fix.smem_start + offset;
 311
 312         while (size > 0) {
 313                 page = vmalloc_to_pfn((void *)pos);
 314                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 315                         return -EAGAIN;
 316
 317                 start += PAGE_SIZE;
 318                 pos += PAGE_SIZE;
 319                 if (size > PAGE_SIZE)
 320                         size -= PAGE_SIZE;
 321                 else
 322                         size = 0;
 323         }
 324
 325         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 326         return 0;
 327
 328 }
 329
 330 /*
 331  * Trims identical data from front and back of line
 332  * Sets new front buffer address and width
 333  * And returns byte count of identical pixels
 334  * Assumes CPU natural alignment (unsigned long)
 335  * for back and front buffer ptrs and width
 336  */
 337 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 338 {
 339         int j, k;
 340         const unsigned long *back = (const unsigned long *) bback;
 341         const unsigned long *front = (const unsigned long *) *bfront;
 342         const int width = *width_bytes / sizeof(unsigned long);
 343         int identical = width;
 344         int start = width;
 345         int end = width;
 346
 347         prefetch((void *) front);
 348         prefetch((void *) back);
 349
 350         for (j = 0; j < width; j++) {
 351                 if (back[j] != front[j]) {
 352                         start = j;
 353                         break;
 354                 }
 355         }
 356
 357         for (k = width - 1; k > j; k--) {
 358                 if (back[k] != front[k]) {
 359                         end = k+1;
 360                         break;
 361                 }
 362         }
 363
 364         identical = start + (width - end);
 365         *bfront = (u8 *) &front[start];
 366         *width_bytes = (end - start) * sizeof(unsigned long);
 367
 368         return identical * sizeof(unsigned long);
 369 }
 370
 371 /*
 372  * Render a command stream for an encoded horizontal line segment of pixels.
 373  *
 374  * A command buffer holds several commands.
 375  * It always begins with a fresh command header
 376  * (the protocol doesn't require this, but we enforce it to allow
 377  * multiple buffers to be potentially encoded and sent in parallel).
 378  * A single command encodes one contiguous horizontal line of pixels
 379  *
 380  * The function relies on the client to do all allocation, so that
 381  * rendering can be done directly to output buffers (e.g. USB URBs).
 382  * The function fills the supplied command buffer, providing information
 383  * on where it left off, so the client may call in again with additional
 384  * buffers if the line will take several buffers to complete.
 385  *
 386  * A single command can transmit a maximum of 256 pixels,
 387  * regardless of the compression ratio (protocol design limit).
 388  * To the hardware, 0 for a size byte means 256
 389  *
 390  * Rather than 256 pixel commands which are either rl or raw encoded,
 391  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 392  * This has a slightly larger header overhead, but produces more even results.
 393  * It also processes all data (read and write) in a single pass.
 394  * Performance benchmarks of common cases show it having just slightly better
 395  * compression than 256 pixel raw -or- rle commands, with similar CPU consumpion.
 396  * But for very rl friendly data, will compress not quite as well.
 397  */
 398 static void dlfb_compress_hline(
 399         const uint16_t **pixel_start_ptr,
 400         const uint16_t *const pixel_end,
 401         uint32_t *device_address_ptr,
 402         uint8_t **command_buffer_ptr,
 403         const uint8_t *const cmd_buffer_end)
 404 {
 405         const uint16_t *pixel = *pixel_start_ptr;
 406         uint32_t dev_addr  = *device_address_ptr;
 407         uint8_t *cmd = *command_buffer_ptr;
 408         const int bpp = 2;
 409
 410         while ((pixel_end > pixel) &&
 411                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 412                 uint8_t *raw_pixels_count_byte = 0;
 413                 uint8_t *cmd_pixels_count_byte = 0;
 414                 const uint16_t *raw_pixel_start = 0;
 415                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
 416                 const uint32_t be_dev_addr = cpu_to_be32(dev_addr);
 417
 418                 prefetchw((void *) cmd); /* pull in one cache line at least */
 419
 420                 *cmd++ = 0xAF;
 421                 *cmd++ = 0x6B;
 422                 *cmd++ = (uint8_t) ((be_dev_addr >> 8) & 0xFF);
 423                 *cmd++ = (uint8_t) ((be_dev_addr >> 16) & 0xFF);
 424                 *cmd++ = (uint8_t) ((be_dev_addr >> 24) & 0xFF);
 425
 426                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
 427                 cmd_pixel_start = pixel;
 428
 429                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
 430                 raw_pixel_start = pixel;
 431
 432                 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
 433                         min((int)(pixel_end - pixel),
 434                             (int)(cmd_buffer_end - cmd) / bpp));
 435
 436                 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
 437
 438                 while (pixel < cmd_pixel_end) {
 439                         const uint16_t * const repeating_pixel = pixel;
 440
 441                         *(uint16_t *)cmd = cpu_to_be16p(pixel);
 442                         cmd += 2;
 443                         pixel++;
 444
 445                         if (unlikely((pixel < cmd_pixel_end) &&
 446                                      (*pixel == *repeating_pixel))) {
 447                                 /* go back and fill in raw pixel count */
 448                                 *raw_pixels_count_byte = ((repeating_pixel -
 449                                                 raw_pixel_start) + 1) & 0xFF;
 450
 451                                 while ((pixel < cmd_pixel_end)
 452                                        && (*pixel == *repeating_pixel)) {
 453                                         pixel++;
 454                                 }
 455
 456                                 /* immediately after raw data is repeat byte */
 457                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
 458
 459                                 /* Then start another raw pixel span */
 460                                 raw_pixel_start = pixel;
 461                                 raw_pixels_count_byte = cmd++;
 462                         }
 463                 }
 464
 465                 if (pixel > raw_pixel_start) {
 466                         /* finalize last RAW span */
 467                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
 468                 }
 469
 470                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
 471                 dev_addr += (pixel - cmd_pixel_start) * bpp;
 472         }
 473
 474         if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
 475                 /* Fill leftover bytes with no-ops */
 476                 if (cmd_buffer_end > cmd)
 477                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
 478                 cmd = (uint8_t *) cmd_buffer_end;
 479         }
 480
 481         *command_buffer_ptr = cmd;
 482         *pixel_start_ptr = pixel;
 483         *device_address_ptr = dev_addr;
 484
 485         return;
 486 }
 487
 488 /*
 489  * There are 3 copies of every pixel: The front buffer that the fbdev
 490  * client renders to, the actual framebuffer across the USB bus in hardware
 491  * (that we can only write to, slowly, and can never read), and (optionally)
 492  * our shadow copy that tracks what's been sent to that hardware buffer.
 493  */
 494 static void dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
 495                               const char *front, char **urb_buf_ptr,
 496                               u32 byte_offset, u32 byte_width,
 497                               int *ident_ptr, int *sent_ptr)
 498 {
 499         const u8 *line_start, *line_end, *next_pixel;
 500         u32 dev_addr = dev->base16 + byte_offset;
 501         struct urb *urb = *urb_ptr;
 502         u8 *cmd = *urb_buf_ptr;
 503         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
 504
 505         line_start = (u8 *) (front + byte_offset);
 506         next_pixel = line_start;
 507         line_end = next_pixel + byte_width;
 508
 509         if (dev->backing_buffer) {
 510                 int offset;
 511                 const u8 *back_start = (u8 *) (dev->backing_buffer
 512                                                 + byte_offset);
 513
 514                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
 515                         &byte_width);
 516
 517                 offset = next_pixel - line_start;
 518                 line_end = next_pixel + byte_width;
 519                 dev_addr += offset;
 520                 back_start += offset;
 521                 line_start += offset;
 522
 523                 memcpy((char *)back_start, (char *) line_start,
 524                        byte_width);
 525         }
 526
 527         while (next_pixel < line_end) {
 528
 529                 dlfb_compress_hline((const uint16_t **) &next_pixel,
 530                              (const uint16_t *) line_end, &dev_addr,
 531                         (u8 **) &cmd, (u8 *) cmd_end);
 532
 533                 if (cmd >= cmd_end) {
 534                         int len = cmd - (u8 *) urb->transfer_buffer;
 535                         if (dlfb_submit_urb(dev, urb, len))
 536                                 return; /* lost pixels is set */
 537                         *sent_ptr += len;
 538                         urb = dlfb_get_urb(dev);
 539                         if (!urb)
 540                                 return; /* lost_pixels is set */
 541                         *urb_ptr = urb;
 542                         cmd = urb->transfer_buffer;
 543                         cmd_end = &cmd[urb->transfer_buffer_length];
 544                 }
 545         }
 546
 547         *urb_buf_ptr = cmd;
 548 }
 549
 550 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
 551                int width, int height, char *data)
 552 {
 553         int i, ret;
 554         char *cmd;
 555         cycles_t start_cycles, end_cycles;
 556         int bytes_sent = 0;
 557         int bytes_identical = 0;
 558         struct urb *urb;
 559         int aligned_x;
 560
 561         start_cycles = get_cycles();
 562
 563         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 564         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 565         x = aligned_x;
 566
 567         if ((width <= 0) ||
 568             (x + width > dev->info->var.xres) ||
 569             (y + height > dev->info->var.yres))
 570                 return -EINVAL;
 571
 572         if (!atomic_read(&dev->usb_active))
 573                 return 0;
 574
 575         urb = dlfb_get_urb(dev);
 576         if (!urb)
 577                 return 0;
 578         cmd = urb->transfer_buffer;
 579
 580         for (i = y; i < y + height ; i++) {
 581                 const int line_offset = dev->info->fix.line_length * i;
 582                 const int byte_offset = line_offset + (x * BPP);
 583
 584                 dlfb_render_hline(dev, &urb, (char *) dev->info->fix.smem_start,
 585                                   &cmd, byte_offset, width * BPP,
 586                                   &bytes_identical, &bytes_sent);
 587         }
 588
 589         if (cmd > (char *) urb->transfer_buffer) {
 590                 /* Send partial buffer remaining before exiting */
 591                 int len = cmd - (char *) urb->transfer_buffer;
 592                 ret = dlfb_submit_urb(dev, urb, len);
 593                 bytes_sent += len;
 594         } else
 595                 dlfb_urb_completion(urb);
 596
 597         atomic_add(bytes_sent, &dev->bytes_sent);
 598         atomic_add(bytes_identical, &dev->bytes_identical);
 599         atomic_add(width*height*2, &dev->bytes_rendered);
 600         end_cycles = get_cycles();
 601         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 602                     >> 10)), /* Kcycles */
 603                    &dev->cpu_kcycles_used);
 604
 605         return 0;
 606 }
 607
 608 static ssize_t dlfb_ops_read(struct fb_info *info, char __user *buf,
 609                          size_t count, loff_t *ppos)
 610 {
 611         ssize_t result = -ENOSYS;
 612
 613 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 614         result = fb_sys_read(info, buf, count, ppos);
 615 #endif
 616
 617         return result;
 618 }
 619
 620 /*
 621  * Path triggered by usermode clients who write to filesystem
 622  * e.g. cat filename > /dev/fb1
 623  * Not used by X Windows or text-mode console. But useful for testing.
 624  * Slow because of extra copy and we must assume all pixels dirty.
 625  */
 626 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
 627                           size_t count, loff_t *ppos)
 628 {
 629         ssize_t result = -ENOSYS;
 630         struct dlfb_data *dev = info->par;
 631         u32 offset = (u32) *ppos;
 632
 633 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 634
 635         result = fb_sys_write(info, buf, count, ppos);
 636
 637         if (result > 0) {
 638                 int start = max((int)(offset / info->fix.line_length) - 1, 0);
 639                 int lines = min((u32)((result / info->fix.line_length) + 1),
 640                                 (u32)info->var.yres);
 641
 642                 dlfb_handle_damage(dev, 0, start, info->var.xres,
 643                         lines, info->screen_base);
 644         }
 645 #endif
 646
 647         return result;
 648 }
 649
 650 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 651 static void dlfb_ops_copyarea(struct fb_info *info,
 652                                 const struct fb_copyarea *area)
 653 {
 654
 655         struct dlfb_data *dev = info->par;
 656
 657 #if defined CONFIG_FB_SYS_COPYAREA || defined CONFIG_FB_SYS_COPYAREA_MODULE
 658
 659         sys_copyarea(info, area);
 660
 661         dlfb_handle_damage(dev, area->dx, area->dy,
 662                         area->width, area->height, info->screen_base);
 663 #endif
 664
 665 }
 666
 667 static void dlfb_ops_imageblit(struct fb_info *info,
 668                                 const struct fb_image *image)
 669 {
 670         struct dlfb_data *dev = info->par;
 671
 672 #if defined CONFIG_FB_SYS_IMAGEBLIT || defined CONFIG_FB_SYS_IMAGEBLIT_MODULE
 673
 674         sys_imageblit(info, image);
 675
 676         dlfb_handle_damage(dev, image->dx, image->dy,
 677                         image->width, image->height, info->screen_base);
 678
 679 #endif
 680
 681 }
 682
 683 static void dlfb_ops_fillrect(struct fb_info *info,
 684                           const struct fb_fillrect *rect)
 685 {
 686         struct dlfb_data *dev = info->par;
 687
 688 #if defined CONFIG_FB_SYS_FILLRECT || defined CONFIG_FB_SYS_FILLRECT_MODULE
 689
 690         sys_fillrect(info, rect);
 691
 692         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
 693                               rect->height, info->screen_base);
 694 #endif
 695
 696 }
 697
 698 static void dlfb_get_edid(struct dlfb_data *dev)
 699 {
 700         int i;
 701         int ret;
 702         char rbuf[2];
 703
 704         for (i = 0; i < sizeof(dev->edid); i++) {
 705                 ret = usb_control_msg(dev->udev,
 706                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 707                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 708                                     0);
 709                 dev->edid[i] = rbuf[1];
 710         }
 711 }
 712
 713 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 714                                 unsigned long arg)
 715 {
 716
 717         struct dlfb_data *dev = info->par;
 718         struct dloarea *area = NULL;
 719
 720         if (!atomic_read(&dev->usb_active))
 721                 return 0;
 722
 723         /* TODO: Update X server to get this from sysfs instead */
 724         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 725                 char *edid = (char *)arg;
 726                 dlfb_get_edid(dev);
 727                 if (copy_to_user(edid, dev->edid, sizeof(dev->edid)))
 728                         return -EFAULT;
 729                 return 0;
 730         }
 731
 732         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 733         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 734
 735                 area = (struct dloarea *)arg;
 736
 737                 if (area->x < 0)
 738                         area->x = 0;
 739
 740                 if (area->x > info->var.xres)
 741                         area->x = info->var.xres;
 742
 743                 if (area->y < 0)
 744                         area->y = 0;
 745
 746                 if (area->y > info->var.yres)
 747                         area->y = info->var.yres;
 748
 749                 atomic_set(&dev->use_defio, 0);
 750
 751                 dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
 752                            info->screen_base);
 753         }
 754
 755         return 0;
 756 }
 757
 758 /* taken from vesafb */
 759 static int
 760 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 761                unsigned blue, unsigned transp, struct fb_info *info)
 762 {
 763         int err = 0;
 764
 765         if (regno >= info->cmap.len)
 766                 return 1;
 767
 768         if (regno < 16) {
 769                 if (info->var.red.offset == 10) {
 770                         /* 1:5:5:5 */
 771                         ((u32 *) (info->pseudo_palette))[regno] =
 772                             ((red & 0xf800) >> 1) |
 773                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 774                 } else {
 775                         /* 0:5:6:5 */
 776                         ((u32 *) (info->pseudo_palette))[regno] =
 777                             ((red & 0xf800)) |
 778                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 779                 }
 780         }
 781
 782         return err;
 783 }
 784
 785 /*
 786  * It's common for several clients to have framebuffer open simultaneously.
 787  * e.g. both fbcon and X. Makes things interesting.
 788  */
 789 static int dlfb_ops_open(struct fb_info *info, int user)
 790 {
 791         struct dlfb_data *dev = info->par;
 792
 793 /*      if (user == 0)
 794  *              We could special case kernel mode clients (fbcon) here
 795  */
 796
 797         mutex_lock(&dev->fb_open_lock);
 798
 799         dev->fb_count++;
 800
 801 #ifdef CONFIG_FB_DEFERRED_IO
 802         if ((atomic_read(&dev->use_defio)) && (info->fbdefio == NULL)) {
 803                 /* enable defio */
 804                 info->fbdefio = &dlfb_defio;
 805                 fb_deferred_io_init(info);
 806         }
 807 #endif
 808
 809         dl_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 810             info->node, user, info, dev->fb_count);
 811
 812         mutex_unlock(&dev->fb_open_lock);
 813
 814         return 0;
 815 }
 816
 817 static int dlfb_ops_release(struct fb_info *info, int user)
 818 {
 819         struct dlfb_data *dev = info->par;
 820
 821         mutex_lock(&dev->fb_open_lock);
 822
 823         dev->fb_count--;
 824
 825 #ifdef CONFIG_FB_DEFERRED_IO
 826         if ((dev->fb_count == 0) && (info->fbdefio)) {
 827                 fb_deferred_io_cleanup(info);
 828                 info->fbdefio = NULL;
 829                 info->fbops->fb_mmap = dlfb_ops_mmap;
 830         }
 831 #endif
 832
 833         dl_notice("release /dev/fb%d user=%d count=%d\n",
 834                   info->node, user, dev->fb_count);
 835
 836         mutex_unlock(&dev->fb_open_lock);
 837
 838         return 0;
 839 }
 840
 841 /*
 842  * Called when all client interfaces to start transactions have been disabled,
 843  * and all references to our device instance (dlfb_data) are released.
 844  * Every transaction must have a reference, so we know are fully spun down
 845  */
 846 static void dlfb_delete(struct kref *kref)
 847 {
 848         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 849
 850         if (dev->backing_buffer)
 851                 vfree(dev->backing_buffer);
 852
 853         mutex_destroy(&dev->fb_open_lock);
 854
 855         kfree(dev);
 856 }
 857
 858 /*
 859  * Called by fbdev as last part of unregister_framebuffer() process
 860  * No new clients can open connections. Deallocate everything fb_info.
 861  */
 862 static void dlfb_ops_destroy(struct fb_info *info)
 863 {
 864         struct dlfb_data *dev = info->par;
 865
 866         if (info->cmap.len != 0)
 867                 fb_dealloc_cmap(&info->cmap);
 868         if (info->monspecs.modedb)
 869                 fb_destroy_modedb(info->monspecs.modedb);
 870         if (info->screen_base)
 871                 vfree(info->screen_base);
 872
 873         fb_destroy_modelist(&info->modelist);
 874
 875         framebuffer_release(info);
 876
 877         /* ref taken before register_framebuffer() for dlfb_data clients */
 878         kref_put(&dev->kref, dlfb_delete);
 879 }
 880
 881 /*
 882  * Check whether a video mode is supported by the DisplayLink chip
 883  * We start from monitor's modes, so don't need to filter that here
 884  */
 885 static int dlfb_is_valid_mode(struct fb_videomode *mode,
 886                 struct fb_info *info)
 887 {
 888         struct dlfb_data *dev = info->par;
 889
 890         if (mode->xres * mode->yres > dev->sku_pixel_limit)
 891                 return 0;
 892
 893         return 1;
 894 }
 895
 896 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
 897 {
 898         const struct fb_bitfield red = { 11, 5, 0 };
 899         const struct fb_bitfield green = { 5, 6, 0 };
 900         const struct fb_bitfield blue = { 0, 5, 0 };
 901
 902         var->bits_per_pixel = 16;
 903         var->red = red;
 904         var->green = green;
 905         var->blue = blue;
 906 }
 907
 908 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
 909                                 struct fb_info *info)
 910 {
 911         struct fb_videomode mode;
 912
 913         /* TODO: support dynamically changing framebuffer size */
 914         if ((var->xres * var->yres * 2) > info->fix.smem_len)
 915                 return -EINVAL;
 916
 917         /* set device-specific elements of var unrelated to mode */
 918         dlfb_var_color_format(var);
 919
 920         fb_var_to_videomode(&mode, var);
 921
 922         if (!dlfb_is_valid_mode(&mode, info))
 923                 return -EINVAL;
 924
 925         return 0;
 926 }
 927
 928 static int dlfb_ops_set_par(struct fb_info *info)
 929 {
 930         struct dlfb_data *dev = info->par;
 931
 932         dl_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
 933
 934         return dlfb_set_video_mode(dev, &info->var);
 935 }
 936
 937 /*
 938  * In order to come back from full DPMS off, we need to set the mode again
 939  */
 940 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
 941 {
 942         struct dlfb_data *dev = info->par;
 943
 944         if (blank_mode != FB_BLANK_UNBLANK) {
 945                 char *bufptr;
 946                 struct urb *urb;
 947
 948                 urb = dlfb_get_urb(dev);
 949                 if (!urb)
 950                         return 0;
 951
 952                 bufptr = (char *) urb->transfer_buffer;
 953                 bufptr = dlfb_vidreg_lock(bufptr);
 954                 bufptr = dlfb_enable_hvsync(bufptr, false);
 955                 bufptr = dlfb_vidreg_unlock(bufptr);
 956
 957                 dlfb_submit_urb(dev, urb, bufptr -
 958                                 (char *) urb->transfer_buffer);
 959         } else {
 960                 dlfb_set_video_mode(dev, &info->var);
 961         }
 962
 963         return 0;
 964 }
 965
 966 static struct fb_ops dlfb_ops = {
 967         .owner = THIS_MODULE,
 968         .fb_read = dlfb_ops_read,
 969         .fb_write = dlfb_ops_write,
 970         .fb_setcolreg = dlfb_ops_setcolreg,
 971         .fb_fillrect = dlfb_ops_fillrect,
 972         .fb_copyarea = dlfb_ops_copyarea,
 973         .fb_imageblit = dlfb_ops_imageblit,
 974         .fb_mmap = dlfb_ops_mmap,
 975         .fb_ioctl = dlfb_ops_ioctl,
 976         .fb_open = dlfb_ops_open,
 977         .fb_release = dlfb_ops_release,
 978         .fb_blank = dlfb_ops_blank,
 979         .fb_check_var = dlfb_ops_check_var,
 980         .fb_set_par = dlfb_ops_set_par,
 981 };
 982
 983 /*
 984  * Calls dlfb_get_edid() to query the EDID of attached monitor via usb cmds
 985  * Then parses EDID into three places used by various parts of fbdev:
 986  * fb_var_screeninfo contains the timing of the monitor's preferred mode
 987  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
 988  * fb_info.modelist is a linked list of all monitor & VESA modes which work
 989  *
 990  * If EDID is not readable/valid, then modelist is all VESA modes,
 991  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
 992  * Returns 0 if EDID parses successfully
 993  */
 994 static int dlfb_parse_edid(struct dlfb_data *dev,
 995                             struct fb_var_screeninfo *var,
 996                             struct fb_info *info)
 997 {
 998         int i;
 999         const struct fb_videomode *default_vmode = NULL;
1000         int result = 0;
1001
1002         fb_destroy_modelist(&info->modelist);
1003         memset(&info->monspecs, 0, sizeof(info->monspecs));
1004
1005         dlfb_get_edid(dev);
1006         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1007
1008         if (info->monspecs.modedb_len > 0) {
1009
1010                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1011                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1012                                 fb_add_videomode(&info->monspecs.modedb[i],
1013                                         &info->modelist);
1014                 }
1015
1016                 default_vmode = fb_find_best_display(&info->monspecs,
1017                                                      &info->modelist);
1018         } else {
1019                 struct fb_videomode fb_vmode = {0};
1020
1021                 dl_err("Unable to get valid EDID from device/display\n");
1022                 result = 1;
1023
1024                 /*
1025                  * Add the standard VESA modes to our modelist
1026                  * Since we don't have EDID, there may be modes that
1027                  * overspec monitor and/or are incorrect aspect ratio, etc.
1028                  * But at least the user has a chance to choose
1029                  */
1030                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1031                         if (dlfb_is_valid_mode((struct fb_videomode *)
1032                                                 &vesa_modes[i], info))
1033                                 fb_add_videomode(&vesa_modes[i],
1034                                                  &info->modelist);
1035                 }
1036
1037                 /*
1038                  * default to resolution safe for projectors
1039                  * (since they are most common case without EDID)
1040                  */
1041                 fb_vmode.xres = 800;
1042                 fb_vmode.yres = 600;
1043                 fb_vmode.refresh = 60;
1044                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1045                                                      &info->modelist);
1046         }
1047
1048         fb_videomode_to_var(var, default_vmode);
1049         dlfb_var_color_format(var);
1050
1051         return result;
1052 }
1053
1054 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1055                                    struct device_attribute *a, char *buf) {
1056         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1057         struct dlfb_data *dev = fb_info->par;
1058         return snprintf(buf, PAGE_SIZE, "%u\n",
1059                         atomic_read(&dev->bytes_rendered));
1060 }
1061
1062 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1063                                    struct device_attribute *a, char *buf) {
1064         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1065         struct dlfb_data *dev = fb_info->par;
1066         return snprintf(buf, PAGE_SIZE, "%u\n",
1067                         atomic_read(&dev->bytes_identical));
1068 }
1069
1070 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1071                                    struct device_attribute *a, char *buf) {
1072         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1073         struct dlfb_data *dev = fb_info->par;
1074         return snprintf(buf, PAGE_SIZE, "%u\n",
1075                         atomic_read(&dev->bytes_sent));
1076 }
1077
1078 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1079                                    struct device_attribute *a, char *buf) {
1080         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1081         struct dlfb_data *dev = fb_info->par;
1082         return snprintf(buf, PAGE_SIZE, "%u\n",
1083                         atomic_read(&dev->cpu_kcycles_used));
1084 }
1085
1086 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
1087                          struct bin_attribute *a,
1088                          char *buf, loff_t off, size_t count) {
1089         struct device *fbdev = container_of(kobj, struct device, kobj);
1090         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1091         struct dlfb_data *dev = fb_info->par;
1092         char *edid = &dev->edid[0];
1093         const size_t size = sizeof(dev->edid);
1094
1095         if (dlfb_parse_edid(dev, &fb_info->var, fb_info))
1096                 return 0;
1097
1098         if (off >= size)
1099                 return 0;
1100
1101         if (off + count > size)
1102                 count = size - off;
1103         memcpy(buf, edid + off, count);
1104
1105         return count;
1106 }
1107
1108
1109 static ssize_t metrics_reset_store(struct device *fbdev,
1110                            struct device_attribute *attr,
1111                            const char *buf, size_t count)
1112 {
1113         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1114         struct dlfb_data *dev = fb_info->par;
1115
1116         atomic_set(&dev->bytes_rendered, 0);
1117         atomic_set(&dev->bytes_identical, 0);
1118         atomic_set(&dev->bytes_sent, 0);
1119         atomic_set(&dev->cpu_kcycles_used, 0);
1120
1121         return count;
1122 }
1123
1124 static ssize_t use_defio_show(struct device *fbdev,
1125                                    struct device_attribute *a, char *buf) {
1126         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1127         struct dlfb_data *dev = fb_info->par;
1128         return snprintf(buf, PAGE_SIZE, "%d\n",
1129                         atomic_read(&dev->use_defio));
1130 }
1131
1132 static ssize_t use_defio_store(struct device *fbdev,
1133                            struct device_attribute *attr,
1134                            const char *buf, size_t count)
1135 {
1136         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1137         struct dlfb_data *dev = fb_info->par;
1138
1139         if (count > 0) {
1140                 if (buf[0] == '0')
1141                         atomic_set(&dev->use_defio, 0);
1142                 if (buf[0] == '1')
1143                         atomic_set(&dev->use_defio, 1);
1144         }
1145         return count;
1146 }
1147
1148 static struct bin_attribute edid_attr = {
1149         .attr.name = "edid",
1150         .attr.mode = 0444,
1151         .size = 128,
1152         .read = edid_show,
1153 };
1154
1155 static struct device_attribute fb_device_attrs[] = {
1156         __ATTR_RO(metrics_bytes_rendered),
1157         __ATTR_RO(metrics_bytes_identical),
1158         __ATTR_RO(metrics_bytes_sent),
1159         __ATTR_RO(metrics_cpu_kcycles_used),
1160         __ATTR(metrics_reset, S_IWUGO, NULL, metrics_reset_store),
1161         __ATTR_RW(use_defio),
1162 };
1163
1164 #ifdef CONFIG_FB_DEFERRED_IO
1165 static void dlfb_dpy_deferred_io(struct fb_info *info,
1166                                 struct list_head *pagelist)
1167 {
1168         struct page *cur;
1169         struct fb_deferred_io *fbdefio = info->fbdefio;
1170         struct dlfb_data *dev = info->par;
1171         struct urb *urb;
1172         char *cmd;
1173         cycles_t start_cycles, end_cycles;
1174         int bytes_sent = 0;
1175         int bytes_identical = 0;
1176         int bytes_rendered = 0;
1177
1178         if (!atomic_read(&dev->use_defio))
1179                 return;
1180
1181         if (!atomic_read(&dev->usb_active))
1182                 return;
1183
1184         start_cycles = get_cycles();
1185
1186         urb = dlfb_get_urb(dev);
1187         if (!urb)
1188                 return;
1189         cmd = urb->transfer_buffer;
1190
1191         /* walk the written page list and render each to device */
1192         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
1193                 dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
1194                                   &cmd, cur->index << PAGE_SHIFT,
1195                                   PAGE_SIZE, &bytes_identical, &bytes_sent);
1196                 bytes_rendered += PAGE_SIZE;
1197         }
1198
1199         if (cmd > (char *) urb->transfer_buffer) {
1200                 /* Send partial buffer remaining before exiting */
1201                 int len = cmd - (char *) urb->transfer_buffer;
1202                 dlfb_submit_urb(dev, urb, len);
1203                 bytes_sent += len;
1204         } else
1205                 dlfb_urb_completion(urb);
1206
1207         atomic_add(bytes_sent, &dev->bytes_sent);
1208         atomic_add(bytes_identical, &dev->bytes_identical);
1209         atomic_add(bytes_rendered, &dev->bytes_rendered);
1210         end_cycles = get_cycles();
1211         atomic_add(((unsigned int) ((end_cycles - start_cycles)
1212                     >> 10)), /* Kcycles */
1213                    &dev->cpu_kcycles_used);
1214 }
1215
1216 static struct fb_deferred_io dlfb_defio = {
1217         .delay          = 5,
1218         .deferred_io    = dlfb_dpy_deferred_io,
1219 };
1220
1221 #endif
1222
1223 /*
1224  * This is necessary before we can communicate with the display controller.
1225  */
1226 static int dlfb_select_std_channel(struct dlfb_data *dev)
1227 {
1228         int ret;
1229         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1230                                 0x1C, 0x88, 0x5E, 0x15,
1231                                 0x60, 0xFE, 0xC6, 0x97,
1232                                 0x16, 0x3D, 0x47, 0xF2  };
1233
1234         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1235                         NR_USB_REQUEST_CHANNEL,
1236                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1237                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1238         return ret;
1239 }
1240
1241
1242 static int dlfb_usb_probe(struct usb_interface *interface,
1243                         const struct usb_device_id *id)
1244 {
1245         struct usb_device *usbdev;
1246         struct dlfb_data *dev;
1247         struct fb_info *info;
1248         int videomemorysize;
1249         int i;
1250         unsigned char *videomemory;
1251         int retval = -ENOMEM;
1252         struct fb_var_screeninfo *var;
1253         int registered = 0;
1254         u16 *pix_framebuffer;
1255
1256         /* usb initialization */
1257
1258         usbdev = interface_to_usbdev(interface);
1259
1260         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1261         if (dev == NULL) {
1262                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1263                 goto error;
1264         }
1265
1266         /* we need to wait for both usb and fbdev to spin down on disconnect */
1267         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1268         kref_get(&dev->kref); /* matching kref_put in .fb_destroy function*/
1269
1270         dev->udev = usbdev;
1271         dev->gdev = &usbdev->dev; /* our generic struct device * */
1272         usb_set_intfdata(interface, dev);
1273
1274         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1275                 retval = -ENOMEM;
1276                 dl_err("dlfb_alloc_urb_list failed\n");
1277                 goto error;
1278         }
1279
1280         mutex_init(&dev->fb_open_lock);
1281
1282         /* We don't register a new USB class. Our client interface is fbdev */
1283
1284         /* allocates framebuffer driver structure, not framebuffer memory */
1285         info = framebuffer_alloc(0, &usbdev->dev);
1286         if (!info) {
1287                 retval = -ENOMEM;
1288                 dl_err("framebuffer_alloc failed\n");
1289                 goto error;
1290         }
1291         dev->info = info;
1292         info->par = dev;
1293         info->pseudo_palette = dev->pseudo_palette;
1294         info->fbops = &dlfb_ops;
1295
1296         var = &info->var;
1297
1298         /* TODO set limit based on actual SKU detection */
1299         dev->sku_pixel_limit = 2048 * 1152;
1300
1301         INIT_LIST_HEAD(&info->modelist);
1302         dlfb_parse_edid(dev, var, info);
1303
1304         /*
1305          * ok, now that we've got the size info, we can alloc our framebuffer.
1306          */
1307         info->fix = dlfb_fix;
1308         info->fix.line_length = var->xres * (var->bits_per_pixel / 8);
1309         videomemorysize = info->fix.line_length * var->yres;
1310
1311         /*
1312          * The big chunk of system memory we use as a virtual framebuffer.
1313          * TODO: Handle fbcon cursor code calling blit in interrupt context
1314          */
1315         videomemory = vmalloc(videomemorysize);
1316         if (!videomemory) {
1317                 retval = -ENOMEM;
1318                 dl_err("Virtual framebuffer alloc failed\n");
1319                 goto error;
1320         }
1321
1322         info->screen_base = videomemory;
1323         info->fix.smem_len = PAGE_ALIGN(videomemorysize);
1324         info->fix.smem_start = (unsigned long) videomemory;
1325         info->flags = udlfb_info_flags;
1326
1327
1328         /*
1329          * Second framebuffer copy, mirroring the state of the framebuffer
1330          * on the physical USB device. We can function without this.
1331          * But with imperfect damage info we may end up sending pixels over USB
1332          * that were, in fact, unchanged -- wasting limited USB bandwidth
1333          */
1334         dev->backing_buffer = vmalloc(videomemorysize);
1335         if (!dev->backing_buffer)
1336                 dl_warn("No shadow/backing buffer allcoated\n");
1337         else
1338                 memset(dev->backing_buffer, 0, videomemorysize);
1339
1340         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1341         if (retval < 0) {
1342                 dl_err("fb_alloc_cmap failed %x\n", retval);
1343                 goto error;
1344         }
1345
1346         /* ready to begin using device */
1347
1348 #ifdef CONFIG_FB_DEFERRED_IO
1349         atomic_set(&dev->use_defio, 1);
1350 #endif
1351         atomic_set(&dev->usb_active, 1);
1352         dlfb_select_std_channel(dev);
1353
1354         dlfb_ops_check_var(var, info);
1355         dlfb_ops_set_par(info);
1356
1357         /* paint greenscreen */
1358         pix_framebuffer = (u16 *) videomemory;
1359         for (i = 0; i < videomemorysize / 2; i++)
1360                 pix_framebuffer[i] = 0x37e6;
1361
1362         dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1363                                 videomemory);
1364
1365         retval = register_framebuffer(info);
1366         if (retval < 0) {
1367                 dl_err("register_framebuffer failed %d\n", retval);
1368                 goto error;
1369         }
1370         registered = 1;
1371
1372         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1373                 device_create_file(info->dev, &fb_device_attrs[i]);
1374
1375         device_create_bin_file(info->dev, &edid_attr);
1376
1377         dl_err("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1378                         " Using %dK framebuffer memory\n", info->node,
1379                         var->xres, var->yres,
1380                         ((dev->backing_buffer) ?
1381                         videomemorysize * 2 : videomemorysize) >> 10);
1382         return 0;
1383
1384 error:
1385         if (dev) {
1386                 if (registered) {
1387                         unregister_framebuffer(info);
1388                         dlfb_ops_destroy(info);
1389                 } else
1390                         kref_put(&dev->kref, dlfb_delete);
1391
1392                 if (dev->urbs.count > 0)
1393                         dlfb_free_urb_list(dev);
1394                 kref_put(&dev->kref, dlfb_delete); /* last ref from kref_init */
1395
1396                 /* dev has been deallocated. Do not dereference */
1397         }
1398
1399         return retval;
1400 }
1401
1402 static void dlfb_usb_disconnect(struct usb_interface *interface)
1403 {
1404         struct dlfb_data *dev;
1405         struct fb_info *info;
1406         int i;
1407
1408         dev = usb_get_intfdata(interface);
1409         info = dev->info;
1410
1411         /* when non-active we'll update virtual framebuffer, but no new urbs */
1412         atomic_set(&dev->usb_active, 0);
1413
1414         usb_set_intfdata(interface, NULL);
1415
1416         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1417                 device_remove_file(info->dev, &fb_device_attrs[i]);
1418
1419         device_remove_bin_file(info->dev, &edid_attr);
1420
1421         /* this function will wait for all in-flight urbs to complete */
1422         dlfb_free_urb_list(dev);
1423
1424         if (info) {
1425                 dl_notice("Detaching /dev/fb%d\n", info->node);
1426                 unregister_framebuffer(info);
1427                 dlfb_ops_destroy(info);
1428         }
1429
1430         /* release reference taken by kref_init in probe() */
1431         kref_put(&dev->kref, dlfb_delete);
1432
1433         /* consider dlfb_data freed */
1434
1435         return;
1436 }
1437
1438 static struct usb_driver dlfb_driver = {
1439         .name = "udlfb",
1440         .probe = dlfb_usb_probe,
1441         .disconnect = dlfb_usb_disconnect,
1442         .id_table = id_table,
1443 };
1444
1445 static int __init dlfb_module_init(void)
1446 {
1447         int res;
1448
1449         res = usb_register(&dlfb_driver);
1450         if (res)
1451                 err("usb_register failed. Error number %d", res);
1452
1453         printk(KERN_INFO "VMODES initialized\n");
1454
1455         return res;
1456 }
1457
1458 static void __exit dlfb_module_exit(void)
1459 {
1460         usb_deregister(&dlfb_driver);
1461 }
1462
1463 module_init(dlfb_module_init);
1464 module_exit(dlfb_module_exit);
1465
1466 static void dlfb_urb_completion(struct urb *urb)
1467 {
1468         struct urb_node *unode = urb->context;
1469         struct dlfb_data *dev = unode->dev;
1470         unsigned long flags;
1471
1472         /* sync/async unlink faults aren't errors */
1473         if (urb->status) {
1474                 if (!(urb->status == -ENOENT ||
1475                     urb->status == -ECONNRESET ||
1476                     urb->status == -ESHUTDOWN)) {
1477                         dl_err("%s - nonzero write bulk status received: %d\n",
1478                                 __func__, urb->status);
1479                         atomic_set(&dev->lost_pixels, 1);
1480                 }
1481         }
1482
1483         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1484
1485         spin_lock_irqsave(&dev->urbs.lock, flags);
1486         list_add_tail(&unode->entry, &dev->urbs.list);
1487         dev->urbs.available++;
1488         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1489
1490         up(&dev->urbs.limit_sem);
1491 }
1492
1493 static void dlfb_free_urb_list(struct dlfb_data *dev)
1494 {
1495         int count = dev->urbs.count;
1496         struct list_head *node;
1497         struct urb_node *unode;
1498         struct urb *urb;
1499         int ret;
1500         unsigned long flags;
1501
1502         dl_notice("Waiting for completes and freeing all render urbs\n");
1503
1504         /* keep waiting and freeing, until we've got 'em all */
1505         while (count--) {
1506                 /* Timeout means a memory leak and/or fault */
1507                 ret = down_timeout(&dev->urbs.limit_sem, FREE_URB_TIMEOUT);
1508                 if (ret) {
1509                         BUG_ON(ret);
1510                         break;
1511                 }
1512                 spin_lock_irqsave(&dev->urbs.lock, flags);
1513
1514                 node = dev->urbs.list.next; /* have reserved one with sem */
1515                 list_del_init(node);
1516
1517                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1518
1519                 unode = list_entry(node, struct urb_node, entry);
1520                 urb = unode->urb;
1521
1522                 /* Free each separately allocated piece */
1523                 usb_free_coherent(urb->dev, dev->urbs.size,
1524                                   urb->transfer_buffer, urb->transfer_dma);
1525                 usb_free_urb(urb);
1526                 kfree(node);
1527         }
1528
1529         kref_put(&dev->kref, dlfb_delete);
1530
1531 }
1532
1533 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1534 {
1535         int i = 0;
1536         struct urb *urb;
1537         struct urb_node *unode;
1538         char *buf;
1539
1540         spin_lock_init(&dev->urbs.lock);
1541
1542         dev->urbs.size = size;
1543         INIT_LIST_HEAD(&dev->urbs.list);
1544
1545         while (i < count) {
1546                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1547                 if (!unode)
1548                         break;
1549                 unode->dev = dev;
1550
1551                 urb = usb_alloc_urb(0, GFP_KERNEL);
1552                 if (!urb) {
1553                         kfree(unode);
1554                         break;
1555                 }
1556                 unode->urb = urb;
1557
1558                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1559                                          &urb->transfer_dma);
1560                 if (!buf) {
1561                         kfree(unode);
1562                         usb_free_urb(urb);
1563                         break;
1564                 }
1565
1566                 /* urb->transfer_buffer_length set to actual before submit */
1567                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1568                         buf, size, dlfb_urb_completion, unode);
1569                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1570
1571                 list_add_tail(&unode->entry, &dev->urbs.list);
1572
1573                 i++;
1574         }
1575
1576         sema_init(&dev->urbs.limit_sem, i);
1577         dev->urbs.count = i;
1578         dev->urbs.available = i;
1579
1580         kref_get(&dev->kref); /* released in free_render_urbs() */
1581
1582         dl_notice("allocated %d %d byte urbs\n", i, (int) size);
1583
1584         return i;
1585 }
1586
1587 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1588 {
1589         int ret = 0;
1590         struct list_head *entry;
1591         struct urb_node *unode;
1592         struct urb *urb = NULL;
1593         unsigned long flags;
1594
1595         /* Wait for an in-flight buffer to complete and get re-queued */
1596         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1597         if (ret) {
1598                 atomic_set(&dev->lost_pixels, 1);
1599                 dl_err("wait for urb interrupted: %x\n", ret);
1600                 goto error;
1601         }
1602
1603         spin_lock_irqsave(&dev->urbs.lock, flags);
1604
1605         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1606         entry = dev->urbs.list.next;
1607         list_del_init(entry);
1608         dev->urbs.available--;
1609
1610         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1611
1612         unode = list_entry(entry, struct urb_node, entry);
1613         urb = unode->urb;
1614
1615 error:
1616         return urb;
1617 }
1618
1619 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1620 {
1621         int ret;
1622
1623         BUG_ON(len > dev->urbs.size);
1624
1625         urb->transfer_buffer_length = len; /* set to actual payload len */
1626         ret = usb_submit_urb(urb, GFP_KERNEL);
1627         if (ret) {
1628                 dlfb_urb_completion(urb); /* because no one else will */
1629                 atomic_set(&dev->lost_pixels, 1);
1630                 dl_err("usb_submit_urb error %x\n", ret);
1631         }
1632         return ret;
1633 }
1634
1635 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1636               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1637               "Bernie Thompson <bernie@plugable.com>");
1638 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1639 MODULE_LICENSE("GPL");
1640