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 #include <linux/delay.h>
  29
  30
  31 #include "udlfb.h"
  32
  33 static struct fb_fix_screeninfo dlfb_fix = {
  34         .id =           "udlfb",
  35         .type =         FB_TYPE_PACKED_PIXELS,
  36         .visual =       FB_VISUAL_TRUECOLOR,
  37         .xpanstep =     0,
  38         .ypanstep =     0,
  39         .ywrapstep =    0,
  40         .accel =        FB_ACCEL_NONE,
  41 };
  42
  43 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
  44 #ifdef FBINFO_VIRTFB
  45                 FBINFO_VIRTFB |
  46 #endif
  47                 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
  48                 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
  49
  50 /*
  51  * There are many DisplayLink-based products, all with unique PIDs. We are able
  52  * to support all volume ones (circa 2009) with a single driver, so we match
  53  * globally on VID. TODO: Probe() needs to detect when we might be running
  54  * "future" chips, and bail on those, so a compatible driver can match.
  55  */
  56 static struct usb_device_id id_table[] = {
  57         {.idVendor = 0x17e9, .match_flags = USB_DEVICE_ID_MATCH_VENDOR,},
  58         {},
  59 };
  60 MODULE_DEVICE_TABLE(usb, id_table);
  61
  62 #ifndef CONFIG_FB_DEFERRED_IO
  63 #warning Please set CONFIG_FB_DEFFERRED_IO option to support generic fbdev apps
  64 #endif
  65
  66 #ifndef CONFIG_FB_SYS_IMAGEBLIT
  67 #ifndef CONFIG_FB_SYS_IMAGEBLIT_MODULE
  68 #warning Please set CONFIG_FB_SYS_IMAGEBLIT option to support fb console
  69 #endif
  70 #endif
  71
  72 #ifndef CONFIG_FB_MODE_HELPERS
  73 #warning CONFIG_FB_MODE_HELPERS required. Expect build break
  74 #endif
  75
  76 /* dlfb keeps a list of urbs for efficient bulk transfers */
  77 static void dlfb_urb_completion(struct urb *urb);
  78 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
  79 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
  80 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
  81 static void dlfb_free_urb_list(struct dlfb_data *dev);
  82
  83 /* other symbols with dependents */
  84 #ifdef CONFIG_FB_DEFERRED_IO
  85 static struct fb_deferred_io dlfb_defio;
  86 #endif
  87
  88 /*
  89  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  90  * All operations are written to buffers which then later get sent to device
  91  */
  92 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
  93 {
  94         *buf++ = 0xAF;
  95         *buf++ = 0x20;
  96         *buf++ = reg;
  97         *buf++ = val;
  98         return buf;
  99 }
 100
 101 static char *dlfb_vidreg_lock(char *buf)
 102 {
 103         return dlfb_set_register(buf, 0xFF, 0x00);
 104 }
 105
 106 static char *dlfb_vidreg_unlock(char *buf)
 107 {
 108         return dlfb_set_register(buf, 0xFF, 0xFF);
 109 }
 110
 111 /*
 112  * On/Off for driving the DisplayLink framebuffer to the display
 113  *  0x00 H and V sync on
 114  *  0x01 H and V sync off (screen blank but powered)
 115  *  0x07 DPMS powerdown (requires modeset to come back)
 116  */
 117 static char *dlfb_enable_hvsync(char *buf, bool enable)
 118 {
 119         if (enable)
 120                 return dlfb_set_register(buf, 0x1F, 0x00);
 121         else
 122                 return dlfb_set_register(buf, 0x1F, 0x07);
 123 }
 124
 125 static char *dlfb_set_color_depth(char *buf, u8 selection)
 126 {
 127         return dlfb_set_register(buf, 0x00, selection);
 128 }
 129
 130 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 131 {
 132         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 133         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 134         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 135         return dlfb_set_register(wrptr, 0x22, base);
 136 }
 137
 138 /*
 139  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 140  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 141  */
 142 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 143 {
 144         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 145         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 146         return dlfb_set_register(wrptr, 0x28, base);
 147 }
 148
 149 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 150 {
 151         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 152         return dlfb_set_register(wrptr, reg+1, value);
 153 }
 154
 155 /*
 156  * This is kind of weird because the controller takes some
 157  * register values in a different byte order than other registers.
 158  */
 159 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 160 {
 161         wrptr = dlfb_set_register(wrptr, reg, value);
 162         return dlfb_set_register(wrptr, reg+1, value >> 8);
 163 }
 164
 165 /*
 166  * LFSR is linear feedback shift register. The reason we have this is
 167  * because the display controller needs to minimize the clock depth of
 168  * various counters used in the display path. So this code reverses the
 169  * provided value into the lfsr16 value by counting backwards to get
 170  * the value that needs to be set in the hardware comparator to get the
 171  * same actual count. This makes sense once you read above a couple of
 172  * times and think about it from a hardware perspective.
 173  */
 174 static u16 dlfb_lfsr16(u16 actual_count)
 175 {
 176         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 177
 178         while (actual_count--) {
 179                 lv =     ((lv << 1) |
 180                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 181                         & 0xFFFF;
 182         }
 183
 184         return (u16) lv;
 185 }
 186
 187 /*
 188  * This does LFSR conversion on the value that is to be written.
 189  * See LFSR explanation above for more detail.
 190  */
 191 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 192 {
 193         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 194 }
 195
 196 /*
 197  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 198  * details and converts them into the DisplayLink equivalent register commands.
 199  */
 200 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 201 {
 202         u16 xds, yds;
 203         u16 xde, yde;
 204         u16 yec;
 205
 206         /* x display start */
 207         xds = var->left_margin + var->hsync_len;
 208         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 209         /* x display end */
 210         xde = xds + var->xres;
 211         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 212
 213         /* y display start */
 214         yds = var->upper_margin + var->vsync_len;
 215         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 216         /* y display end */
 217         yde = yds + var->yres;
 218         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 219
 220         /* x end count is active + blanking - 1 */
 221         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 222                         xde + var->right_margin - 1);
 223
 224         /* libdlo hardcodes hsync start to 1 */
 225         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 226
 227         /* hsync end is width of sync pulse + 1 */
 228         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 229
 230         /* hpixels is active pixels */
 231         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 232
 233         /* yendcount is vertical active + vertical blanking */
 234         yec = var->yres + var->upper_margin + var->lower_margin +
 235                         var->vsync_len;
 236         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 237
 238         /* libdlo hardcodes vsync start to 0 */
 239         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 240
 241         /* vsync end is width of vsync pulse */
 242         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 243
 244         /* vpixels is active pixels */
 245         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 246
 247         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 248         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 249                         200*1000*1000/var->pixclock);
 250
 251         return wrptr;
 252 }
 253
 254 /*
 255  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 256  * and then generates the appropriate command sequence that then drives the
 257  * display controller.
 258  */
 259 static int dlfb_set_video_mode(struct dlfb_data *dev,
 260                                 struct fb_var_screeninfo *var)
 261 {
 262         char *buf;
 263         char *wrptr;
 264         int retval = 0;
 265         int writesize;
 266         struct urb *urb;
 267
 268         if (!atomic_read(&dev->usb_active))
 269                 return -EPERM;
 270
 271         urb = dlfb_get_urb(dev);
 272         if (!urb)
 273                 return -ENOMEM;
 274         buf = (char *) urb->transfer_buffer;
 275
 276         /*
 277         * This first section has to do with setting the base address on the
 278         * controller * associated with the display. There are 2 base
 279         * pointers, currently, we only * use the 16 bpp segment.
 280         */
 281         wrptr = dlfb_vidreg_lock(buf);
 282         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 283         /* set base for 16bpp segment to 0 */
 284         wrptr = dlfb_set_base16bpp(wrptr, 0);
 285         /* set base for 8bpp segment to end of fb */
 286         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
 287
 288         wrptr = dlfb_set_vid_cmds(wrptr, var);
 289         wrptr = dlfb_enable_hvsync(wrptr, true);
 290         wrptr = dlfb_vidreg_unlock(wrptr);
 291
 292         writesize = wrptr - buf;
 293
 294         retval = dlfb_submit_urb(dev, urb, writesize);
 295
 296         return retval;
 297 }
 298
 299 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 300 {
 301         unsigned long start = vma->vm_start;
 302         unsigned long size = vma->vm_end - vma->vm_start;
 303         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 304         unsigned long page, pos;
 305
 306         dl_notice("MMAP: %lu %u\n", offset + size, info->fix.smem_len);
 307
 308         if (offset + size > info->fix.smem_len)
 309                 return -EINVAL;
 310
 311         pos = (unsigned long)info->fix.smem_start + offset;
 312
 313         while (size > 0) {
 314                 page = vmalloc_to_pfn((void *)pos);
 315                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 316                         return -EAGAIN;
 317
 318                 start += PAGE_SIZE;
 319                 pos += PAGE_SIZE;
 320                 if (size > PAGE_SIZE)
 321                         size -= PAGE_SIZE;
 322                 else
 323                         size = 0;
 324         }
 325
 326         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 327         return 0;
 328
 329 }
 330
 331 /*
 332  * Trims identical data from front and back of line
 333  * Sets new front buffer address and width
 334  * And returns byte count of identical pixels
 335  * Assumes CPU natural alignment (unsigned long)
 336  * for back and front buffer ptrs and width
 337  */
 338 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 339 {
 340         int j, k;
 341         const unsigned long *back = (const unsigned long *) bback;
 342         const unsigned long *front = (const unsigned long *) *bfront;
 343         const int width = *width_bytes / sizeof(unsigned long);
 344         int identical = width;
 345         int start = width;
 346         int end = width;
 347
 348         prefetch((void *) front);
 349         prefetch((void *) back);
 350
 351         for (j = 0; j < width; j++) {
 352                 if (back[j] != front[j]) {
 353                         start = j;
 354                         break;
 355                 }
 356         }
 357
 358         for (k = width - 1; k > j; k--) {
 359                 if (back[k] != front[k]) {
 360                         end = k+1;
 361                         break;
 362                 }
 363         }
 364
 365         identical = start + (width - end);
 366         *bfront = (u8 *) &front[start];
 367         *width_bytes = (end - start) * sizeof(unsigned long);
 368
 369         return identical * sizeof(unsigned long);
 370 }
 371
 372 /*
 373  * Render a command stream for an encoded horizontal line segment of pixels.
 374  *
 375  * A command buffer holds several commands.
 376  * It always begins with a fresh command header
 377  * (the protocol doesn't require this, but we enforce it to allow
 378  * multiple buffers to be potentially encoded and sent in parallel).
 379  * A single command encodes one contiguous horizontal line of pixels
 380  *
 381  * The function relies on the client to do all allocation, so that
 382  * rendering can be done directly to output buffers (e.g. USB URBs).
 383  * The function fills the supplied command buffer, providing information
 384  * on where it left off, so the client may call in again with additional
 385  * buffers if the line will take several buffers to complete.
 386  *
 387  * A single command can transmit a maximum of 256 pixels,
 388  * regardless of the compression ratio (protocol design limit).
 389  * To the hardware, 0 for a size byte means 256
 390  *
 391  * Rather than 256 pixel commands which are either rl or raw encoded,
 392  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 393  * This has a slightly larger header overhead, but produces more even results.
 394  * It also processes all data (read and write) in a single pass.
 395  * Performance benchmarks of common cases show it having just slightly better
 396  * compression than 256 pixel raw -or- rle commands, with similar CPU consumpion.
 397  * But for very rl friendly data, will compress not quite as well.
 398  */
 399 static void dlfb_compress_hline(
 400         const uint16_t **pixel_start_ptr,
 401         const uint16_t *const pixel_end,
 402         uint32_t *device_address_ptr,
 403         uint8_t **command_buffer_ptr,
 404         const uint8_t *const cmd_buffer_end)
 405 {
 406         const uint16_t *pixel = *pixel_start_ptr;
 407         uint32_t dev_addr  = *device_address_ptr;
 408         uint8_t *cmd = *command_buffer_ptr;
 409         const int bpp = 2;
 410
 411         while ((pixel_end > pixel) &&
 412                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 413                 uint8_t *raw_pixels_count_byte = 0;
 414                 uint8_t *cmd_pixels_count_byte = 0;
 415                 const uint16_t *raw_pixel_start = 0;
 416                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
 417
 418                 prefetchw((void *) cmd); /* pull in one cache line at least */
 419
 420                 *cmd++ = 0xAF;
 421                 *cmd++ = 0x6B;
 422                 *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
 423                 *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
 424                 *cmd++ = (uint8_t) ((dev_addr) & 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 int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
 699 {
 700         int i;
 701         int ret;
 702         char *rbuf;
 703
 704         rbuf = kmalloc(2, GFP_KERNEL);
 705         if (!rbuf)
 706                 return 0;
 707
 708         for (i = 0; i < len; i++) {
 709                 ret = usb_control_msg(dev->udev,
 710                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 711                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 712                                     HZ);
 713                 if (ret < 1) {
 714                         dl_err("Read EDID byte %d failed err %x\n", i, ret);
 715                         i--;
 716                         break;
 717                 }
 718                 edid[i] = rbuf[1];
 719         }
 720
 721         kfree(rbuf);
 722
 723         return i;
 724 }
 725
 726 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 727                                 unsigned long arg)
 728 {
 729
 730         struct dlfb_data *dev = info->par;
 731         struct dloarea *area = NULL;
 732
 733         if (!atomic_read(&dev->usb_active))
 734                 return 0;
 735
 736         /* TODO: Update X server to get this from sysfs instead */
 737         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 738                 char *edid = (char *)arg;
 739                 if (copy_to_user(edid, dev->edid, dev->edid_size))
 740                         return -EFAULT;
 741                 return 0;
 742         }
 743
 744         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 745         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 746
 747                 area = (struct dloarea *)arg;
 748
 749                 if (area->x < 0)
 750                         area->x = 0;
 751
 752                 if (area->x > info->var.xres)
 753                         area->x = info->var.xres;
 754
 755                 if (area->y < 0)
 756                         area->y = 0;
 757
 758                 if (area->y > info->var.yres)
 759                         area->y = info->var.yres;
 760
 761                 atomic_set(&dev->use_defio, 0);
 762
 763                 dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
 764                            info->screen_base);
 765         }
 766
 767         return 0;
 768 }
 769
 770 /* taken from vesafb */
 771 static int
 772 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 773                unsigned blue, unsigned transp, struct fb_info *info)
 774 {
 775         int err = 0;
 776
 777         if (regno >= info->cmap.len)
 778                 return 1;
 779
 780         if (regno < 16) {
 781                 if (info->var.red.offset == 10) {
 782                         /* 1:5:5:5 */
 783                         ((u32 *) (info->pseudo_palette))[regno] =
 784                             ((red & 0xf800) >> 1) |
 785                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 786                 } else {
 787                         /* 0:5:6:5 */
 788                         ((u32 *) (info->pseudo_palette))[regno] =
 789                             ((red & 0xf800)) |
 790                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 791                 }
 792         }
 793
 794         return err;
 795 }
 796
 797 /*
 798  * It's common for several clients to have framebuffer open simultaneously.
 799  * e.g. both fbcon and X. Makes things interesting.
 800  * Assumes caller is holding info->lock (for open and release at least)
 801  */
 802 static int dlfb_ops_open(struct fb_info *info, int user)
 803 {
 804         struct dlfb_data *dev = info->par;
 805
 806 /*      if (user == 0)
 807  *              We could special case kernel mode clients (fbcon) here
 808  */
 809
 810         /* If the USB device is gone, we don't accept new opens */
 811         if (dev->virtualized)
 812                 return -ENODEV;
 813
 814         dev->fb_count++;
 815
 816         kref_get(&dev->kref);
 817
 818 #ifdef CONFIG_FB_DEFERRED_IO
 819         if ((atomic_read(&dev->use_defio)) && (info->fbdefio == NULL)) {
 820                 /* enable defio */
 821                 info->fbdefio = &dlfb_defio;
 822                 fb_deferred_io_init(info);
 823         }
 824 #endif
 825
 826         dl_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 827             info->node, user, info, dev->fb_count);
 828
 829         return 0;
 830 }
 831
 832 /*
 833  * Called when all client interfaces to start transactions have been disabled,
 834  * and all references to our device instance (dlfb_data) are released.
 835  * Every transaction must have a reference, so we know are fully spun down
 836  */
 837 static void dlfb_free(struct kref *kref)
 838 {
 839         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 840
 841         /* this function will wait for all in-flight urbs to complete */
 842         if (dev->urbs.count > 0)
 843                 dlfb_free_urb_list(dev);
 844
 845         if (dev->backing_buffer)
 846                 vfree(dev->backing_buffer);
 847
 848         kfree(dev->edid);
 849
 850         dl_warn("freeing dlfb_data %p\n", dev);
 851
 852         kfree(dev);
 853 }
 854
 855
 856 static void dlfb_free_framebuffer_work(struct work_struct *work)
 857 {
 858         struct dlfb_data *dev = container_of(work, struct dlfb_data,
 859                                              free_framebuffer_work.work);
 860         struct fb_info *info = dev->info;
 861         int node = info->node;
 862
 863         unregister_framebuffer(info);
 864
 865         if (info->cmap.len != 0)
 866                 fb_dealloc_cmap(&info->cmap);
 867         if (info->monspecs.modedb)
 868                 fb_destroy_modedb(info->monspecs.modedb);
 869         if (info->screen_base)
 870                 vfree(info->screen_base);
 871
 872         fb_destroy_modelist(&info->modelist);
 873
 874         dev->info = 0;
 875
 876         /* Assume info structure is freed after this point */
 877         framebuffer_release(info);
 878
 879         dl_warn("fb_info for /dev/fb%d has been freed\n", node);
 880
 881         /* ref taken in probe() as part of registering framebfufer */
 882         kref_put(&dev->kref, dlfb_free);
 883 }
 884
 885 /*
 886  * Assumes caller is holding info->lock mutex (for open and release at least)
 887  */
 888 static int dlfb_ops_release(struct fb_info *info, int user)
 889 {
 890         struct dlfb_data *dev = info->par;
 891
 892         dev->fb_count--;
 893
 894         /* We can't free fb_info here - fbmem will touch it when we return */
 895         if (dev->virtualized && (dev->fb_count == 0))
 896                 schedule_delayed_work(&dev->free_framebuffer_work, HZ);
 897
 898 #ifdef CONFIG_FB_DEFERRED_IO
 899         if ((dev->fb_count == 0) && (info->fbdefio)) {
 900                 fb_deferred_io_cleanup(info);
 901                 kfree(info->fbdefio);
 902                 info->fbdefio = NULL;
 903                 info->fbops->fb_mmap = dlfb_ops_mmap;
 904         }
 905 #endif
 906
 907         dl_warn("released /dev/fb%d user=%d count=%d\n",
 908                   info->node, user, dev->fb_count);
 909
 910         kref_put(&dev->kref, dlfb_free);
 911
 912         return 0;
 913 }
 914
 915 /*
 916  * Check whether a video mode is supported by the DisplayLink chip
 917  * We start from monitor's modes, so don't need to filter that here
 918  */
 919 static int dlfb_is_valid_mode(struct fb_videomode *mode,
 920                 struct fb_info *info)
 921 {
 922         struct dlfb_data *dev = info->par;
 923
 924         if (mode->xres * mode->yres > dev->sku_pixel_limit) {
 925                 dl_warn("%dx%d beyond chip capabilities\n",
 926                        mode->xres, mode->yres);
 927                 return 0;
 928         }
 929
 930         dl_info("%dx%d valid mode\n", mode->xres, mode->yres);
 931
 932         return 1;
 933 }
 934
 935 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
 936 {
 937         const struct fb_bitfield red = { 11, 5, 0 };
 938         const struct fb_bitfield green = { 5, 6, 0 };
 939         const struct fb_bitfield blue = { 0, 5, 0 };
 940
 941         var->bits_per_pixel = 16;
 942         var->red = red;
 943         var->green = green;
 944         var->blue = blue;
 945 }
 946
 947 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
 948                                 struct fb_info *info)
 949 {
 950         struct fb_videomode mode;
 951
 952         /* TODO: support dynamically changing framebuffer size */
 953         if ((var->xres * var->yres * 2) > info->fix.smem_len)
 954                 return -EINVAL;
 955
 956         /* set device-specific elements of var unrelated to mode */
 957         dlfb_var_color_format(var);
 958
 959         fb_var_to_videomode(&mode, var);
 960
 961         if (!dlfb_is_valid_mode(&mode, info))
 962                 return -EINVAL;
 963
 964         return 0;
 965 }
 966
 967 static int dlfb_ops_set_par(struct fb_info *info)
 968 {
 969         struct dlfb_data *dev = info->par;
 970         int result;
 971         u16 *pix_framebuffer;
 972         int i;
 973
 974         dl_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
 975
 976         result = dlfb_set_video_mode(dev, &info->var);
 977
 978         if ((result == 0) && (dev->fb_count == 0)) {
 979
 980                 /* paint greenscreen */
 981
 982                 pix_framebuffer = (u16 *) info->screen_base;
 983                 for (i = 0; i < info->fix.smem_len / 2; i++)
 984                         pix_framebuffer[i] = 0x37e6;
 985
 986                 dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
 987                                    info->screen_base);
 988         }
 989
 990         return result;
 991 }
 992
 993 /*
 994  * In order to come back from full DPMS off, we need to set the mode again
 995  */
 996 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
 997 {
 998         struct dlfb_data *dev = info->par;
 999
1000         if (blank_mode != FB_BLANK_UNBLANK) {
1001                 char *bufptr;
1002                 struct urb *urb;
1003
1004                 urb = dlfb_get_urb(dev);
1005                 if (!urb)
1006                         return 0;
1007
1008                 bufptr = (char *) urb->transfer_buffer;
1009                 bufptr = dlfb_vidreg_lock(bufptr);
1010                 bufptr = dlfb_enable_hvsync(bufptr, false);
1011                 bufptr = dlfb_vidreg_unlock(bufptr);
1012
1013                 dlfb_submit_urb(dev, urb, bufptr -
1014                                 (char *) urb->transfer_buffer);
1015         } else {
1016                 dlfb_set_video_mode(dev, &info->var);
1017         }
1018
1019         return 0;
1020 }
1021
1022 static struct fb_ops dlfb_ops = {
1023         .owner = THIS_MODULE,
1024         .fb_read = dlfb_ops_read,
1025         .fb_write = dlfb_ops_write,
1026         .fb_setcolreg = dlfb_ops_setcolreg,
1027         .fb_fillrect = dlfb_ops_fillrect,
1028         .fb_copyarea = dlfb_ops_copyarea,
1029         .fb_imageblit = dlfb_ops_imageblit,
1030         .fb_mmap = dlfb_ops_mmap,
1031         .fb_ioctl = dlfb_ops_ioctl,
1032         .fb_open = dlfb_ops_open,
1033         .fb_release = dlfb_ops_release,
1034         .fb_blank = dlfb_ops_blank,
1035         .fb_check_var = dlfb_ops_check_var,
1036         .fb_set_par = dlfb_ops_set_par,
1037 };
1038
1039
1040 /*
1041  * Assumes &info->lock held by caller
1042  * Assumes no active clients have framebuffer open
1043  */
1044 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1045 {
1046         int retval = -ENOMEM;
1047         int old_len = info->fix.smem_len;
1048         int new_len;
1049         unsigned char *old_fb = info->screen_base;
1050         unsigned char *new_fb;
1051         unsigned char *new_back;
1052
1053         dl_warn("Reallocating framebuffer. Addresses will change!\n");
1054
1055         new_len = info->fix.line_length * info->var.yres;
1056
1057         if (PAGE_ALIGN(new_len) > old_len) {
1058                 /*
1059                  * Alloc system memory for virtual framebuffer
1060                  */
1061                 new_fb = vmalloc(new_len);
1062                 if (!new_fb) {
1063                         dl_err("Virtual framebuffer alloc failed\n");
1064                         goto error;
1065                 }
1066
1067                 if (info->screen_base) {
1068                         memcpy(new_fb, old_fb, old_len);
1069                         vfree(info->screen_base);
1070                 }
1071
1072                 info->screen_base = new_fb;
1073                 info->fix.smem_len = PAGE_ALIGN(new_len);
1074                 info->fix.smem_start = (unsigned long) new_fb;
1075                 info->flags = udlfb_info_flags;
1076
1077                 /*
1078                  * Second framebuffer copy to mirror the framebuffer state
1079                  * on the physical USB device. We can function without this.
1080                  * But with imperfect damage info we may send pixels over USB
1081                  * that were, in fact, unchanged - wasting limited USB bandwidth
1082                  */
1083                 new_back = vmalloc(new_len);
1084                 if (!new_back)
1085                         dl_info("No shadow/backing buffer allcoated\n");
1086                 else {
1087                         if (dev->backing_buffer)
1088                                 vfree(dev->backing_buffer);
1089                         dev->backing_buffer = new_back;
1090                         memset(dev->backing_buffer, 0, new_len);
1091                 }
1092         }
1093
1094         retval = 0;
1095
1096 error:
1097         return retval;
1098 }
1099
1100 /*
1101  * 1) Get EDID from hw, or use sw default
1102  * 2) Parse into various fb_info structs
1103  * 3) Allocate virtual framebuffer memory to back highest res mode
1104  *
1105  * Parses EDID into three places used by various parts of fbdev:
1106  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1107  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1108  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1109  *
1110  * If EDID is not readable/valid, then modelist is all VESA modes,
1111  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1112  * Returns 0 if successful
1113  */
1114 static int dlfb_setup_modes(struct dlfb_data *dev,
1115                            struct fb_info *info,
1116                            char *default_edid, size_t default_edid_size)
1117 {
1118         int i;
1119         const struct fb_videomode *default_vmode = NULL;
1120         int result = 0;
1121         char *edid;
1122         int tries = 3;
1123
1124         if (info->dev) /* only use mutex if info has been registered */
1125                 mutex_lock(&info->lock);
1126
1127         edid = kmalloc(MAX_EDID_SIZE, GFP_KERNEL);
1128         if (!edid) {
1129                 result = -ENOMEM;
1130                 goto error;
1131         }
1132
1133         fb_destroy_modelist(&info->modelist);
1134         memset(&info->monspecs, 0, sizeof(info->monspecs));
1135
1136         /*
1137          * Try to (re)read EDID from hardware first
1138          * EDID data may return, but not parse as valid
1139          * Try again a few times, in case of e.g. analog cable noise
1140          */
1141         while (tries--) {
1142
1143                 i = dlfb_get_edid(dev, edid, MAX_EDID_SIZE);
1144
1145                 if (i >= MIN_EDID_SIZE)
1146                         fb_edid_to_monspecs(edid, &info->monspecs);
1147
1148                 if (info->monspecs.modedb_len > 0) {
1149                         dev->edid = edid;
1150                         dev->edid_size = i;
1151                         break;
1152                 }
1153         }
1154
1155         /* If that fails, use a previously returned EDID if available */
1156         if (info->monspecs.modedb_len == 0) {
1157
1158                 dl_err("Unable to get valid EDID from device/display\n");
1159
1160                 if (dev->edid) {
1161                         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1162                         if (info->monspecs.modedb_len > 0)
1163                                 dl_err("Using previously queried EDID\n");
1164                 }
1165         }
1166
1167         /* If that fails, use the default EDID we were handed */
1168         if (info->monspecs.modedb_len == 0) {
1169                 if (default_edid_size >= MIN_EDID_SIZE) {
1170                         fb_edid_to_monspecs(default_edid, &info->monspecs);
1171                         if (info->monspecs.modedb_len > 0) {
1172                                 memcpy(edid, default_edid, default_edid_size);
1173                                 dev->edid = edid;
1174                                 dev->edid_size = default_edid_size;
1175                                 dl_err("Using default/backup EDID\n");
1176                         }
1177                 }
1178         }
1179
1180         /* If we've got modes, let's pick a best default mode */
1181         if (info->monspecs.modedb_len > 0) {
1182
1183                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1184                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1185                                 fb_add_videomode(&info->monspecs.modedb[i],
1186                                         &info->modelist);
1187                         else /* if we've removed top/best mode */
1188                                 info->monspecs.misc &= ~FB_MISC_1ST_DETAIL;
1189                 }
1190
1191                 default_vmode = fb_find_best_display(&info->monspecs,
1192                                                      &info->modelist);
1193         }
1194
1195         /* If everything else has failed, fall back to safe default mode */
1196         if (default_vmode == NULL) {
1197
1198                 struct fb_videomode fb_vmode = {0};
1199
1200                 /*
1201                  * Add the standard VESA modes to our modelist
1202                  * Since we don't have EDID, there may be modes that
1203                  * overspec monitor and/or are incorrect aspect ratio, etc.
1204                  * But at least the user has a chance to choose
1205                  */
1206                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1207                         if (dlfb_is_valid_mode((struct fb_videomode *)
1208                                                 &vesa_modes[i], info))
1209                                 fb_add_videomode(&vesa_modes[i],
1210                                                  &info->modelist);
1211                 }
1212
1213                 /*
1214                  * default to resolution safe for projectors
1215                  * (since they are most common case without EDID)
1216                  */
1217                 fb_vmode.xres = 800;
1218                 fb_vmode.yres = 600;
1219                 fb_vmode.refresh = 60;
1220                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1221                                                      &info->modelist);
1222         }
1223
1224         /* If we have good mode and no active clients*/
1225         if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1226
1227                 fb_videomode_to_var(&info->var, default_vmode);
1228                 dlfb_var_color_format(&info->var);
1229
1230                 /*
1231                  * with mode size info, we can now alloc our framebuffer.
1232                  */
1233                 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1234                 info->fix.line_length = info->var.xres *
1235                         (info->var.bits_per_pixel / 8);
1236
1237                 result = dlfb_realloc_framebuffer(dev, info);
1238
1239         } else
1240                 result = -EINVAL;
1241
1242 error:
1243         if (edid && (dev->edid != edid))
1244                 kfree(edid);
1245
1246         if (info->dev)
1247                 mutex_unlock(&info->lock);
1248
1249         return result;
1250 }
1251
1252 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1253                                    struct device_attribute *a, char *buf) {
1254         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1255         struct dlfb_data *dev = fb_info->par;
1256         return snprintf(buf, PAGE_SIZE, "%u\n",
1257                         atomic_read(&dev->bytes_rendered));
1258 }
1259
1260 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1261                                    struct device_attribute *a, char *buf) {
1262         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1263         struct dlfb_data *dev = fb_info->par;
1264         return snprintf(buf, PAGE_SIZE, "%u\n",
1265                         atomic_read(&dev->bytes_identical));
1266 }
1267
1268 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1269                                    struct device_attribute *a, char *buf) {
1270         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1271         struct dlfb_data *dev = fb_info->par;
1272         return snprintf(buf, PAGE_SIZE, "%u\n",
1273                         atomic_read(&dev->bytes_sent));
1274 }
1275
1276 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1277                                    struct device_attribute *a, char *buf) {
1278         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1279         struct dlfb_data *dev = fb_info->par;
1280         return snprintf(buf, PAGE_SIZE, "%u\n",
1281                         atomic_read(&dev->cpu_kcycles_used));
1282 }
1283
1284 static ssize_t edid_show(
1285                         struct file *filp,
1286                         struct kobject *kobj, struct bin_attribute *a,
1287                          char *buf, loff_t off, size_t count) {
1288         struct device *fbdev = container_of(kobj, struct device, kobj);
1289         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1290         struct dlfb_data *dev = fb_info->par;
1291
1292         if (dev->edid == NULL)
1293                 return 0;
1294
1295         if ((off >= dev->edid_size) || (count > dev->edid_size))
1296                 return 0;
1297
1298         if (off + count > dev->edid_size)
1299                 count = dev->edid_size - off;
1300
1301         dl_info("sysfs edid copy %p to %p, %d bytes\n",
1302                 dev->edid, buf, (int) count);
1303
1304         memcpy(buf, dev->edid, count);
1305
1306         return count;
1307 }
1308
1309
1310 static ssize_t metrics_reset_store(struct device *fbdev,
1311                            struct device_attribute *attr,
1312                            const char *buf, size_t count)
1313 {
1314         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1315         struct dlfb_data *dev = fb_info->par;
1316
1317         atomic_set(&dev->bytes_rendered, 0);
1318         atomic_set(&dev->bytes_identical, 0);
1319         atomic_set(&dev->bytes_sent, 0);
1320         atomic_set(&dev->cpu_kcycles_used, 0);
1321
1322         return count;
1323 }
1324
1325 static ssize_t use_defio_show(struct device *fbdev,
1326                                    struct device_attribute *a, char *buf) {
1327         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1328         struct dlfb_data *dev = fb_info->par;
1329         return snprintf(buf, PAGE_SIZE, "%d\n",
1330                         atomic_read(&dev->use_defio));
1331 }
1332
1333 static ssize_t use_defio_store(struct device *fbdev,
1334                            struct device_attribute *attr,
1335                            const char *buf, size_t count)
1336 {
1337         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1338         struct dlfb_data *dev = fb_info->par;
1339
1340         if (count > 0) {
1341                 if (buf[0] == '0')
1342                         atomic_set(&dev->use_defio, 0);
1343                 if (buf[0] == '1')
1344                         atomic_set(&dev->use_defio, 1);
1345         }
1346         return count;
1347 }
1348
1349 static struct bin_attribute edid_attr = {
1350         .attr.name = "edid",
1351         .attr.mode = 0444,
1352         .size = 128,
1353         .read = edid_show,
1354 };
1355
1356 static struct device_attribute fb_device_attrs[] = {
1357         __ATTR_RO(metrics_bytes_rendered),
1358         __ATTR_RO(metrics_bytes_identical),
1359         __ATTR_RO(metrics_bytes_sent),
1360         __ATTR_RO(metrics_cpu_kcycles_used),
1361         __ATTR(metrics_reset, S_IWUGO, NULL, metrics_reset_store),
1362         __ATTR_RW(use_defio),
1363 };
1364
1365 #ifdef CONFIG_FB_DEFERRED_IO
1366 static void dlfb_dpy_deferred_io(struct fb_info *info,
1367                                 struct list_head *pagelist)
1368 {
1369         struct page *cur;
1370         struct fb_deferred_io *fbdefio = info->fbdefio;
1371         struct dlfb_data *dev = info->par;
1372         struct urb *urb;
1373         char *cmd;
1374         cycles_t start_cycles, end_cycles;
1375         int bytes_sent = 0;
1376         int bytes_identical = 0;
1377         int bytes_rendered = 0;
1378
1379         if (!atomic_read(&dev->use_defio))
1380                 return;
1381
1382         if (!atomic_read(&dev->usb_active))
1383                 return;
1384
1385         start_cycles = get_cycles();
1386
1387         urb = dlfb_get_urb(dev);
1388         if (!urb)
1389                 return;
1390         cmd = urb->transfer_buffer;
1391
1392         /* walk the written page list and render each to device */
1393         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
1394                 dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
1395                                   &cmd, cur->index << PAGE_SHIFT,
1396                                   PAGE_SIZE, &bytes_identical, &bytes_sent);
1397                 bytes_rendered += PAGE_SIZE;
1398         }
1399
1400         if (cmd > (char *) urb->transfer_buffer) {
1401                 /* Send partial buffer remaining before exiting */
1402                 int len = cmd - (char *) urb->transfer_buffer;
1403                 dlfb_submit_urb(dev, urb, len);
1404                 bytes_sent += len;
1405         } else
1406                 dlfb_urb_completion(urb);
1407
1408         atomic_add(bytes_sent, &dev->bytes_sent);
1409         atomic_add(bytes_identical, &dev->bytes_identical);
1410         atomic_add(bytes_rendered, &dev->bytes_rendered);
1411         end_cycles = get_cycles();
1412         atomic_add(((unsigned int) ((end_cycles - start_cycles)
1413                     >> 10)), /* Kcycles */
1414                    &dev->cpu_kcycles_used);
1415 }
1416
1417 static struct fb_deferred_io dlfb_defio = {
1418         .delay          = 5,
1419         .deferred_io    = dlfb_dpy_deferred_io,
1420 };
1421
1422 #endif
1423
1424 /*
1425  * This is necessary before we can communicate with the display controller.
1426  */
1427 static int dlfb_select_std_channel(struct dlfb_data *dev)
1428 {
1429         int ret;
1430         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1431                                 0x1C, 0x88, 0x5E, 0x15,
1432                                 0x60, 0xFE, 0xC6, 0x97,
1433                                 0x16, 0x3D, 0x47, 0xF2  };
1434
1435         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1436                         NR_USB_REQUEST_CHANNEL,
1437                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1438                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1439         return ret;
1440 }
1441
1442 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1443                                         struct usb_device *usbdev)
1444 {
1445         char *desc;
1446         char *buf;
1447         char *desc_end;
1448
1449         u8 total_len = 0;
1450
1451         buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1452         if (!buf)
1453                 return false;
1454         desc = buf;
1455
1456         total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
1457                                     0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1458         if (total_len > 5) {
1459                 dl_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1460                         "%02x %02x %02x %02x %02x %02x %02x\n",
1461                         total_len, desc[0],
1462                         desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1463                         desc[7], desc[8], desc[9], desc[10]);
1464
1465                 if ((desc[0] != total_len) || /* descriptor length */
1466                     (desc[1] != 0x5f) ||   /* vendor descriptor type */
1467                     (desc[2] != 0x01) ||   /* version (2 bytes) */
1468                     (desc[3] != 0x00) ||
1469                     (desc[4] != total_len - 2)) /* length after type */
1470                         goto unrecognized;
1471
1472                 desc_end = desc + total_len;
1473                 desc += 5; /* the fixed header we've already parsed */
1474
1475                 while (desc < desc_end) {
1476                         u8 length;
1477                         u16 key;
1478
1479                         key = *((u16 *) desc);
1480                         desc += sizeof(u16);
1481                         length = *desc;
1482                         desc++;
1483
1484                         switch (key) {
1485                         case 0x0200: { /* max_area */
1486                                 u32 max_area;
1487                                 max_area = le32_to_cpu(*((u32 *)desc));
1488                                 dl_warn("DL chip limited to %d pixel modes\n",
1489                                         max_area);
1490                                 dev->sku_pixel_limit = max_area;
1491                                 break;
1492                         }
1493                         default:
1494                                 break;
1495                         }
1496                         desc += length;
1497                 }
1498         }
1499
1500         goto success;
1501
1502 unrecognized:
1503         /* allow udlfb to load for now even if firmware unrecognized */
1504         dl_err("Unrecognized vendor firmware descriptor\n");
1505
1506 success:
1507         kfree(buf);
1508         return true;
1509 }
1510 static int dlfb_usb_probe(struct usb_interface *interface,
1511                         const struct usb_device_id *id)
1512 {
1513         struct usb_device *usbdev;
1514         struct dlfb_data *dev = 0;
1515         struct fb_info *info = 0;
1516         int i;
1517         int retval = -ENOMEM;
1518
1519         /* usb initialization */
1520
1521         usbdev = interface_to_usbdev(interface);
1522
1523         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1524         if (dev == NULL) {
1525                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1526                 goto error;
1527         }
1528
1529         /* we need to wait for both usb and fbdev to spin down on disconnect */
1530         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1531         kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1532
1533         dev->udev = usbdev;
1534         dev->gdev = &usbdev->dev; /* our generic struct device * */
1535         usb_set_intfdata(interface, dev);
1536
1537         dl_info("%s %s - serial #%s\n",
1538                 usbdev->manufacturer, usbdev->product, usbdev->serial);
1539         dl_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1540                 usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1541                 usbdev->descriptor.bcdDevice, dev);
1542
1543         dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1544
1545         if (!dlfb_parse_vendor_descriptor(dev, usbdev)) {
1546                 dl_err("firmware not recognized. Assume incompatible device\n");
1547                 goto error;
1548         }
1549
1550         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1551                 retval = -ENOMEM;
1552                 dl_err("dlfb_alloc_urb_list failed\n");
1553                 goto error;
1554         }
1555
1556         /* We don't register a new USB class. Our client interface is fbdev */
1557
1558         /* allocates framebuffer driver structure, not framebuffer memory */
1559         info = framebuffer_alloc(0, &usbdev->dev);
1560         if (!info) {
1561                 retval = -ENOMEM;
1562                 dl_err("framebuffer_alloc failed\n");
1563                 goto error;
1564         }
1565
1566         dev->info = info;
1567         info->par = dev;
1568         info->pseudo_palette = dev->pseudo_palette;
1569         info->fbops = &dlfb_ops;
1570
1571         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1572         if (retval < 0) {
1573                 dl_err("fb_alloc_cmap failed %x\n", retval);
1574                 goto error;
1575         }
1576
1577         INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1578                           dlfb_free_framebuffer_work);
1579
1580         INIT_LIST_HEAD(&info->modelist);
1581
1582         retval = dlfb_setup_modes(dev, info, NULL, 0);
1583         if (retval != 0) {
1584                 dl_err("unable to find common mode for display and adapter\n");
1585                 goto error;
1586         }
1587
1588         /* ready to begin using device */
1589
1590 #ifdef CONFIG_FB_DEFERRED_IO
1591         atomic_set(&dev->use_defio, 1);
1592 #endif
1593         atomic_set(&dev->usb_active, 1);
1594         dlfb_select_std_channel(dev);
1595
1596         dlfb_ops_check_var(&info->var, info);
1597         dlfb_ops_set_par(info);
1598
1599         retval = register_framebuffer(info);
1600         if (retval < 0) {
1601                 dl_err("register_framebuffer failed %d\n", retval);
1602                 goto error;
1603         }
1604
1605         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1606                 device_create_file(info->dev, &fb_device_attrs[i]);
1607
1608         device_create_bin_file(info->dev, &edid_attr);
1609
1610         dl_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1611                         " Using %dK framebuffer memory\n", info->node,
1612                         info->var.xres, info->var.yres,
1613                         ((dev->backing_buffer) ?
1614                         info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1615         return 0;
1616
1617 error:
1618         if (dev) {
1619
1620                 if (info) {
1621                         if (info->cmap.len != 0)
1622                                 fb_dealloc_cmap(&info->cmap);
1623                         if (info->monspecs.modedb)
1624                                 fb_destroy_modedb(info->monspecs.modedb);
1625                         if (info->screen_base)
1626                                 vfree(info->screen_base);
1627
1628                         fb_destroy_modelist(&info->modelist);
1629
1630                         framebuffer_release(info);
1631                 }
1632
1633                 if (dev->backing_buffer)
1634                         vfree(dev->backing_buffer);
1635
1636                 kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1637                 kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1638
1639                 /* dev has been deallocated. Do not dereference */
1640         }
1641
1642         return retval;
1643 }
1644
1645 static void dlfb_usb_disconnect(struct usb_interface *interface)
1646 {
1647         struct dlfb_data *dev;
1648         struct fb_info *info;
1649         int i;
1650
1651         dev = usb_get_intfdata(interface);
1652         info = dev->info;
1653
1654         dl_info("USB disconnect starting\n");
1655
1656         /* we virtualize until all fb clients release. Then we free */
1657         dev->virtualized = true;
1658
1659         /* When non-active we'll update virtual framebuffer, but no new urbs */
1660         atomic_set(&dev->usb_active, 0);
1661
1662         /* remove udlfb's sysfs interfaces */
1663         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1664                 device_remove_file(info->dev, &fb_device_attrs[i]);
1665         device_remove_bin_file(info->dev, &edid_attr);
1666
1667         usb_set_intfdata(interface, NULL);
1668
1669         /* if clients still have us open, will be freed on last close */
1670         if (dev->fb_count == 0)
1671                 schedule_delayed_work(&dev->free_framebuffer_work, 0);
1672
1673         /* release reference taken by kref_init in probe() */
1674         kref_put(&dev->kref, dlfb_free);
1675
1676         /* consider dlfb_data freed */
1677
1678         return;
1679 }
1680
1681 static struct usb_driver dlfb_driver = {
1682         .name = "udlfb",
1683         .probe = dlfb_usb_probe,
1684         .disconnect = dlfb_usb_disconnect,
1685         .id_table = id_table,
1686 };
1687
1688 static int __init dlfb_module_init(void)
1689 {
1690         int res;
1691
1692         res = usb_register(&dlfb_driver);
1693         if (res)
1694                 err("usb_register failed. Error number %d", res);
1695
1696         return res;
1697 }
1698
1699 static void __exit dlfb_module_exit(void)
1700 {
1701         usb_deregister(&dlfb_driver);
1702 }
1703
1704 module_init(dlfb_module_init);
1705 module_exit(dlfb_module_exit);
1706
1707 static void dlfb_urb_completion(struct urb *urb)
1708 {
1709         struct urb_node *unode = urb->context;
1710         struct dlfb_data *dev = unode->dev;
1711         unsigned long flags;
1712
1713         /* sync/async unlink faults aren't errors */
1714         if (urb->status) {
1715                 if (!(urb->status == -ENOENT ||
1716                     urb->status == -ECONNRESET ||
1717                     urb->status == -ESHUTDOWN)) {
1718                         dl_err("%s - nonzero write bulk status received: %d\n",
1719                                 __func__, urb->status);
1720                         atomic_set(&dev->lost_pixels, 1);
1721                 }
1722         }
1723
1724         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1725
1726         spin_lock_irqsave(&dev->urbs.lock, flags);
1727         list_add_tail(&unode->entry, &dev->urbs.list);
1728         dev->urbs.available++;
1729         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1730
1731         up(&dev->urbs.limit_sem);
1732 }
1733
1734 static void dlfb_free_urb_list(struct dlfb_data *dev)
1735 {
1736         int count = dev->urbs.count;
1737         struct list_head *node;
1738         struct urb_node *unode;
1739         struct urb *urb;
1740         int ret;
1741         unsigned long flags;
1742
1743         dl_notice("Waiting for completes and freeing all render urbs\n");
1744
1745         /* keep waiting and freeing, until we've got 'em all */
1746         while (count--) {
1747
1748                 /* Getting interrupted means a leak, but ok at shutdown*/
1749                 ret = down_interruptible(&dev->urbs.limit_sem);
1750                 if (ret)
1751                         break;
1752
1753                 spin_lock_irqsave(&dev->urbs.lock, flags);
1754
1755                 node = dev->urbs.list.next; /* have reserved one with sem */
1756                 list_del_init(node);
1757
1758                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1759
1760                 unode = list_entry(node, struct urb_node, entry);
1761                 urb = unode->urb;
1762
1763                 /* Free each separately allocated piece */
1764                 usb_free_coherent(urb->dev, dev->urbs.size,
1765                                   urb->transfer_buffer, urb->transfer_dma);
1766                 usb_free_urb(urb);
1767                 kfree(node);
1768         }
1769
1770 }
1771
1772 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1773 {
1774         int i = 0;
1775         struct urb *urb;
1776         struct urb_node *unode;
1777         char *buf;
1778
1779         spin_lock_init(&dev->urbs.lock);
1780
1781         dev->urbs.size = size;
1782         INIT_LIST_HEAD(&dev->urbs.list);
1783
1784         while (i < count) {
1785                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1786                 if (!unode)
1787                         break;
1788                 unode->dev = dev;
1789
1790                 urb = usb_alloc_urb(0, GFP_KERNEL);
1791                 if (!urb) {
1792                         kfree(unode);
1793                         break;
1794                 }
1795                 unode->urb = urb;
1796
1797                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1798                                          &urb->transfer_dma);
1799                 if (!buf) {
1800                         kfree(unode);
1801                         usb_free_urb(urb);
1802                         break;
1803                 }
1804
1805                 /* urb->transfer_buffer_length set to actual before submit */
1806                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1807                         buf, size, dlfb_urb_completion, unode);
1808                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1809
1810                 list_add_tail(&unode->entry, &dev->urbs.list);
1811
1812                 i++;
1813         }
1814
1815         sema_init(&dev->urbs.limit_sem, i);
1816         dev->urbs.count = i;
1817         dev->urbs.available = i;
1818
1819         dl_notice("allocated %d %d byte urbs\n", i, (int) size);
1820
1821         return i;
1822 }
1823
1824 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1825 {
1826         int ret = 0;
1827         struct list_head *entry;
1828         struct urb_node *unode;
1829         struct urb *urb = NULL;
1830         unsigned long flags;
1831
1832         /* Wait for an in-flight buffer to complete and get re-queued */
1833         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1834         if (ret) {
1835                 atomic_set(&dev->lost_pixels, 1);
1836                 dl_err("wait for urb interrupted: %x\n", ret);
1837                 goto error;
1838         }
1839
1840         spin_lock_irqsave(&dev->urbs.lock, flags);
1841
1842         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1843         entry = dev->urbs.list.next;
1844         list_del_init(entry);
1845         dev->urbs.available--;
1846
1847         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1848
1849         unode = list_entry(entry, struct urb_node, entry);
1850         urb = unode->urb;
1851
1852 error:
1853         return urb;
1854 }
1855
1856 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1857 {
1858         int ret;
1859
1860         BUG_ON(len > dev->urbs.size);
1861
1862         urb->transfer_buffer_length = len; /* set to actual payload len */
1863         ret = usb_submit_urb(urb, GFP_KERNEL);
1864         if (ret) {
1865                 dlfb_urb_completion(urb); /* because no one else will */
1866                 atomic_set(&dev->lost_pixels, 1);
1867                 dl_err("usb_submit_urb error %x\n", ret);
1868         }
1869         return ret;
1870 }
1871
1872 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1873               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1874               "Bernie Thompson <bernie@plugable.com>");
1875 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1876 MODULE_LICENSE("GPL");
1877