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  */
 112 static char *dlfb_enable_hvsync(char *buf, bool enable)
 113 {
 114         if (enable)
 115                 return dlfb_set_register(buf, 0x1F, 0x00);
 116         else
 117                 return dlfb_set_register(buf, 0x1F, 0x01);
 118 }
 119
 120 static char *dlfb_set_color_depth(char *buf, u8 selection)
 121 {
 122         return dlfb_set_register(buf, 0x00, selection);
 123 }
 124
 125 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 126 {
 127         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 128         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 129         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 130         return dlfb_set_register(wrptr, 0x22, base);
 131 }
 132
 133 /*
 134  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 135  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 136  */
 137 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 138 {
 139         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 140         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 141         return dlfb_set_register(wrptr, 0x28, base);
 142 }
 143
 144 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 145 {
 146         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 147         return dlfb_set_register(wrptr, reg+1, value);
 148 }
 149
 150 /*
 151  * This is kind of weird because the controller takes some
 152  * register values in a different byte order than other registers.
 153  */
 154 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 155 {
 156         wrptr = dlfb_set_register(wrptr, reg, value);
 157         return dlfb_set_register(wrptr, reg+1, value >> 8);
 158 }
 159
 160 /*
 161  * LFSR is linear feedback shift register. The reason we have this is
 162  * because the display controller needs to minimize the clock depth of
 163  * various counters used in the display path. So this code reverses the
 164  * provided value into the lfsr16 value by counting backwards to get
 165  * the value that needs to be set in the hardware comparator to get the
 166  * same actual count. This makes sense once you read above a couple of
 167  * times and think about it from a hardware perspective.
 168  */
 169 static u16 dlfb_lfsr16(u16 actual_count)
 170 {
 171         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 172
 173         while (actual_count--) {
 174                 lv =     ((lv << 1) |
 175                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 176                         & 0xFFFF;
 177         }
 178
 179         return (u16) lv;
 180 }
 181
 182 /*
 183  * This does LFSR conversion on the value that is to be written.
 184  * See LFSR explanation above for more detail.
 185  */
 186 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 187 {
 188         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 189 }
 190
 191 /*
 192  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 193  * details and converts them into the DisplayLink equivalent register commands.
 194  */
 195 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 196 {
 197         u16 xds, yds;
 198         u16 xde, yde;
 199         u16 yec;
 200
 201         /* x display start */
 202         xds = var->left_margin + var->hsync_len;
 203         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 204         /* x display end */
 205         xde = xds + var->xres;
 206         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 207
 208         /* y display start */
 209         yds = var->upper_margin + var->vsync_len;
 210         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 211         /* y display end */
 212         yde = yds + var->yres;
 213         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 214
 215         /* x end count is active + blanking - 1 */
 216         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 217                         xde + var->right_margin - 1);
 218
 219         /* libdlo hardcodes hsync start to 1 */
 220         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 221
 222         /* hsync end is width of sync pulse + 1 */
 223         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 224
 225         /* hpixels is active pixels */
 226         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 227
 228         /* yendcount is vertical active + vertical blanking */
 229         yec = var->yres + var->upper_margin + var->lower_margin +
 230                         var->vsync_len;
 231         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 232
 233         /* libdlo hardcodes vsync start to 0 */
 234         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 235
 236         /* vsync end is width of vsync pulse */
 237         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 238
 239         /* vpixels is active pixels */
 240         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 241
 242         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 243         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 244                         200*1000*1000/var->pixclock);
 245
 246         return wrptr;
 247 }
 248
 249 /*
 250  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 251  * and then generates the appropriate command sequence that then drives the
 252  * display controller.
 253  */
 254 static int dlfb_set_video_mode(struct dlfb_data *dev,
 255                                 struct fb_var_screeninfo *var)
 256 {
 257         char *buf;
 258         char *wrptr;
 259         int retval = 0;
 260         int writesize;
 261         struct urb *urb;
 262
 263         if (!atomic_read(&dev->usb_active))
 264                 return -EPERM;
 265
 266         urb = dlfb_get_urb(dev);
 267         if (!urb)
 268                 return -ENOMEM;
 269         buf = (char *) urb->transfer_buffer;
 270
 271         /*
 272         * This first section has to do with setting the base address on the
 273         * controller * associated with the display. There are 2 base
 274         * pointers, currently, we only * use the 16 bpp segment.
 275         */
 276         wrptr = dlfb_vidreg_lock(buf);
 277         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 278         /* set base for 16bpp segment to 0 */
 279         wrptr = dlfb_set_base16bpp(wrptr, 0);
 280         /* set base for 8bpp segment to end of fb */
 281         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
 282
 283         wrptr = dlfb_set_vid_cmds(wrptr, var);
 284         wrptr = dlfb_enable_hvsync(wrptr, true);
 285         wrptr = dlfb_vidreg_unlock(wrptr);
 286
 287         writesize = wrptr - buf;
 288
 289         retval = dlfb_submit_urb(dev, urb, writesize);
 290
 291         return retval;
 292 }
 293
 294 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 295 {
 296         unsigned long start = vma->vm_start;
 297         unsigned long size = vma->vm_end - vma->vm_start;
 298         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 299         unsigned long page, pos;
 300         struct dlfb_data *dev = info->par;
 301
 302         dl_notice("MMAP: %lu %u\n", offset + size, info->fix.smem_len);
 303
 304         if (offset + size > info->fix.smem_len)
 305                 return -EINVAL;
 306
 307         pos = (unsigned long)info->fix.smem_start + offset;
 308
 309         while (size > 0) {
 310                 page = vmalloc_to_pfn((void *)pos);
 311                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 312                         return -EAGAIN;
 313
 314                 start += PAGE_SIZE;
 315                 pos += PAGE_SIZE;
 316                 if (size > PAGE_SIZE)
 317                         size -= PAGE_SIZE;
 318                 else
 319                         size = 0;
 320         }
 321
 322         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 323         return 0;
 324
 325 }
 326
 327 /*
 328  * Trims identical data from front and back of line
 329  * Sets new front buffer address and width
 330  * And returns byte count of identical pixels
 331  * Assumes CPU natural alignment (unsigned long)
 332  * for back and front buffer ptrs and width
 333  */
 334 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 335 {
 336         int j, k;
 337         const unsigned long *back = (const unsigned long *) bback;
 338         const unsigned long *front = (const unsigned long *) *bfront;
 339         const int width = *width_bytes / sizeof(unsigned long);
 340         int identical = width;
 341         int start = width;
 342         int end = width;
 343
 344         prefetch((void *) front);
 345         prefetch((void *) back);
 346
 347         for (j = 0; j < width; j++) {
 348                 if (back[j] != front[j]) {
 349                         start = j;
 350                         break;
 351                 }
 352         }
 353
 354         for (k = width - 1; k > j; k--) {
 355                 if (back[k] != front[k]) {
 356                         end = k+1;
 357                         break;
 358                 }
 359         }
 360
 361         identical = start + (width - end);
 362         *bfront = (u8 *) &front[start];
 363         *width_bytes = (end - start) * sizeof(unsigned long);
 364
 365         return identical * sizeof(unsigned long);
 366 }
 367
 368 /*
 369  * Render a command stream for an encoded horizontal line segment of pixels.
 370  *
 371  * A command buffer holds several commands.
 372  * It always begins with a fresh command header
 373  * (the protocol doesn't require this, but we enforce it to allow
 374  * multiple buffers to be potentially encoded and sent in parallel).
 375  * A single command encodes one contiguous horizontal line of pixels
 376  *
 377  * The function relies on the client to do all allocation, so that
 378  * rendering can be done directly to output buffers (e.g. USB URBs).
 379  * The function fills the supplied command buffer, providing information
 380  * on where it left off, so the client may call in again with additional
 381  * buffers if the line will take several buffers to complete.
 382  *
 383  * A single command can transmit a maximum of 256 pixels,
 384  * regardless of the compression ratio (protocol design limit).
 385  * To the hardware, 0 for a size byte means 256
 386  *
 387  * Rather than 256 pixel commands which are either rl or raw encoded,
 388  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 389  * This has a slightly larger header overhead, but produces more even results.
 390  * It also processes all data (read and write) in a single pass.
 391  * Performance benchmarks of common cases show it having just slightly better
 392  * compression than 256 pixel raw -or- rle commands, with similar CPU consumpion.
 393  * But for very rl friendly data, will compress not quite as well.
 394  */
 395 static void dlfb_compress_hline(
 396         const uint16_t **pixel_start_ptr,
 397         const uint16_t *const pixel_end,
 398         uint32_t *device_address_ptr,
 399         uint8_t **command_buffer_ptr,
 400         const uint8_t *const cmd_buffer_end)
 401 {
 402         const uint16_t *pixel = *pixel_start_ptr;
 403         uint32_t dev_addr  = *device_address_ptr;
 404         uint8_t *cmd = *command_buffer_ptr;
 405         const int bpp = 2;
 406
 407         while ((pixel_end > pixel) &&
 408                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 409                 uint8_t *raw_pixels_count_byte = 0;
 410                 uint8_t *cmd_pixels_count_byte = 0;
 411                 const uint16_t *raw_pixel_start = 0;
 412                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
 413                 const uint32_t be_dev_addr = cpu_to_be32(dev_addr);
 414
 415                 prefetchw((void *) cmd); /* pull in one cache line at least */
 416
 417                 *cmd++ = 0xAF;
 418                 *cmd++ = 0x6B;
 419                 *cmd++ = (uint8_t) ((be_dev_addr >> 8) & 0xFF);
 420                 *cmd++ = (uint8_t) ((be_dev_addr >> 16) & 0xFF);
 421                 *cmd++ = (uint8_t) ((be_dev_addr >> 24) & 0xFF);
 422
 423                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
 424                 cmd_pixel_start = pixel;
 425
 426                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
 427                 raw_pixel_start = pixel;
 428
 429                 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
 430                         min((int)(pixel_end - pixel),
 431                             (int)(cmd_buffer_end - cmd) / bpp));
 432
 433                 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
 434
 435                 while (pixel < cmd_pixel_end) {
 436                         const uint16_t * const repeating_pixel = pixel;
 437
 438                         *(uint16_t *)cmd = cpu_to_be16p(pixel);
 439                         cmd += 2;
 440                         pixel++;
 441
 442                         if (unlikely((pixel < cmd_pixel_end) &&
 443                                      (*pixel == *repeating_pixel))) {
 444                                 /* go back and fill in raw pixel count */
 445                                 *raw_pixels_count_byte = ((repeating_pixel -
 446                                                 raw_pixel_start) + 1) & 0xFF;
 447
 448                                 while ((pixel < cmd_pixel_end)
 449                                        && (*pixel == *repeating_pixel)) {
 450                                         pixel++;
 451                                 }
 452
 453                                 /* immediately after raw data is repeat byte */
 454                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
 455
 456                                 /* Then start another raw pixel span */
 457                                 raw_pixel_start = pixel;
 458                                 raw_pixels_count_byte = cmd++;
 459                         }
 460                 }
 461
 462                 if (pixel > raw_pixel_start) {
 463                         /* finalize last RAW span */
 464                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
 465                 }
 466
 467                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
 468                 dev_addr += (pixel - cmd_pixel_start) * bpp;
 469         }
 470
 471         if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
 472                 /* Fill leftover bytes with no-ops */
 473                 if (cmd_buffer_end > cmd)
 474                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
 475                 cmd = (uint8_t *) cmd_buffer_end;
 476         }
 477
 478         *command_buffer_ptr = cmd;
 479         *pixel_start_ptr = pixel;
 480         *device_address_ptr = dev_addr;
 481
 482         return;
 483 }
 484
 485 /*
 486  * There are 3 copies of every pixel: The front buffer that the fbdev
 487  * client renders to, the actual framebuffer across the USB bus in hardware
 488  * (that we can only write to, slowly, and can never read), and (optionally)
 489  * our shadow copy that tracks what's been sent to that hardware buffer.
 490  */
 491 static void dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
 492                               const char *front, char **urb_buf_ptr,
 493                               u32 byte_offset, u32 byte_width,
 494                               int *ident_ptr, int *sent_ptr)
 495 {
 496         const u8 *line_start, *line_end, *next_pixel;
 497         u32 dev_addr = dev->base16 + byte_offset;
 498         struct urb *urb = *urb_ptr;
 499         u8 *cmd = *urb_buf_ptr;
 500         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
 501
 502         line_start = (u8 *) (front + byte_offset);
 503         next_pixel = line_start;
 504         line_end = next_pixel + byte_width;
 505
 506         if (dev->backing_buffer) {
 507                 int offset;
 508                 const u8 *back_start = (u8 *) (dev->backing_buffer
 509                                                 + byte_offset);
 510
 511                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
 512                         &byte_width);
 513
 514                 offset = next_pixel - line_start;
 515                 line_end = next_pixel + byte_width;
 516                 dev_addr += offset;
 517                 back_start += offset;
 518                 line_start += offset;
 519
 520                 memcpy((char *)back_start, (char *) line_start,
 521                        byte_width);
 522         }
 523
 524         while (next_pixel < line_end) {
 525
 526                 dlfb_compress_hline((const uint16_t **) &next_pixel,
 527                              (const uint16_t *) line_end, &dev_addr,
 528                         (u8 **) &cmd, (u8 *) cmd_end);
 529
 530                 if (cmd >= cmd_end) {
 531                         int len = cmd - (u8 *) urb->transfer_buffer;
 532                         if (dlfb_submit_urb(dev, urb, len))
 533                                 return; /* lost pixels is set */
 534                         *sent_ptr += len;
 535                         urb = dlfb_get_urb(dev);
 536                         if (!urb)
 537                                 return; /* lost_pixels is set */
 538                         *urb_ptr = urb;
 539                         cmd = urb->transfer_buffer;
 540                         cmd_end = &cmd[urb->transfer_buffer_length];
 541                 }
 542         }
 543
 544         *urb_buf_ptr = cmd;
 545 }
 546
 547 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
 548                int width, int height, char *data)
 549 {
 550         int i, ret;
 551         char *cmd;
 552         cycles_t start_cycles, end_cycles;
 553         int bytes_sent = 0;
 554         int bytes_identical = 0;
 555         struct urb *urb;
 556         int aligned_x;
 557
 558         start_cycles = get_cycles();
 559
 560         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 561         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 562         x = aligned_x;
 563
 564         if ((width <= 0) ||
 565             (x + width > dev->info->var.xres) ||
 566             (y + height > dev->info->var.yres))
 567                 return -EINVAL;
 568
 569         if (!atomic_read(&dev->usb_active))
 570                 return 0;
 571
 572         urb = dlfb_get_urb(dev);
 573         if (!urb)
 574                 return 0;
 575         cmd = urb->transfer_buffer;
 576
 577         for (i = y; i < y + height ; i++) {
 578                 const int line_offset = dev->info->fix.line_length * i;
 579                 const int byte_offset = line_offset + (x * BPP);
 580
 581                 dlfb_render_hline(dev, &urb, (char *) dev->info->fix.smem_start,
 582                                   &cmd, byte_offset, width * BPP,
 583                                   &bytes_identical, &bytes_sent);
 584         }
 585
 586         if (cmd > (char *) urb->transfer_buffer) {
 587                 /* Send partial buffer remaining before exiting */
 588                 int len = cmd - (char *) urb->transfer_buffer;
 589                 ret = dlfb_submit_urb(dev, urb, len);
 590                 bytes_sent += len;
 591         } else
 592                 dlfb_urb_completion(urb);
 593
 594         atomic_add(bytes_sent, &dev->bytes_sent);
 595         atomic_add(bytes_identical, &dev->bytes_identical);
 596         atomic_add(width*height*2, &dev->bytes_rendered);
 597         end_cycles = get_cycles();
 598         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 599                     >> 10)), /* Kcycles */
 600                    &dev->cpu_kcycles_used);
 601
 602         return 0;
 603 }
 604
 605 static ssize_t dlfb_ops_read(struct fb_info *info, char __user *buf,
 606                          size_t count, loff_t *ppos)
 607 {
 608         ssize_t result = -ENOSYS;
 609
 610 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 611         result = fb_sys_read(info, buf, count, ppos);
 612 #endif
 613
 614         return result;
 615 }
 616
 617 /*
 618  * Path triggered by usermode clients who write to filesystem
 619  * e.g. cat filename > /dev/fb1
 620  * Not used by X Windows or text-mode console. But useful for testing.
 621  * Slow because of extra copy and we must assume all pixels dirty.
 622  */
 623 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
 624                           size_t count, loff_t *ppos)
 625 {
 626         ssize_t result = -ENOSYS;
 627         struct dlfb_data *dev = info->par;
 628         u32 offset = (u32) *ppos;
 629
 630 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 631
 632         result = fb_sys_write(info, buf, count, ppos);
 633
 634         if (result > 0) {
 635                 int start = max((int)(offset / info->fix.line_length) - 1, 0);
 636                 int lines = min((u32)((result / info->fix.line_length) + 1),
 637                                 (u32)info->var.yres);
 638
 639                 dlfb_handle_damage(dev, 0, start, info->var.xres,
 640                         lines, info->screen_base);
 641         }
 642 #endif
 643
 644         return result;
 645 }
 646
 647 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 648 static void dlfb_ops_copyarea(struct fb_info *info,
 649                                 const struct fb_copyarea *area)
 650 {
 651
 652         struct dlfb_data *dev = info->par;
 653
 654 #if defined CONFIG_FB_SYS_COPYAREA || defined CONFIG_FB_SYS_COPYAREA_MODULE
 655
 656         sys_copyarea(info, area);
 657
 658         dlfb_handle_damage(dev, area->dx, area->dy,
 659                         area->width, area->height, info->screen_base);
 660 #endif
 661         atomic_inc(&dev->copy_count);
 662
 663 }
 664
 665 static void dlfb_ops_imageblit(struct fb_info *info,
 666                                 const struct fb_image *image)
 667 {
 668         struct dlfb_data *dev = info->par;
 669
 670 #if defined CONFIG_FB_SYS_IMAGEBLIT || defined CONFIG_FB_SYS_IMAGEBLIT_MODULE
 671
 672         sys_imageblit(info, image);
 673
 674         dlfb_handle_damage(dev, image->dx, image->dy,
 675                         image->width, image->height, info->screen_base);
 676
 677 #endif
 678
 679         atomic_inc(&dev->blit_count);
 680 }
 681
 682 static void dlfb_ops_fillrect(struct fb_info *info,
 683                           const struct fb_fillrect *rect)
 684 {
 685         struct dlfb_data *dev = info->par;
 686
 687 #if defined CONFIG_FB_SYS_FILLRECT || defined CONFIG_FB_SYS_FILLRECT_MODULE
 688
 689         sys_fillrect(info, rect);
 690
 691         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
 692                               rect->height, info->screen_base);
 693 #endif
 694
 695         atomic_inc(&dev->fill_count);
 696
 697 }
 698
 699 static void dlfb_get_edid(struct dlfb_data *dev)
 700 {
 701         int i;
 702         int ret;
 703         char rbuf[2];
 704
 705         for (i = 0; i < sizeof(dev->edid); i++) {
 706                 ret = usb_control_msg(dev->udev,
 707                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 708                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 709                                     0);
 710                 dev->edid[i] = rbuf[1];
 711         }
 712 }
 713
 714 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 715                                 unsigned long arg)
 716 {
 717
 718         struct dlfb_data *dev = info->par;
 719         struct dloarea *area = NULL;
 720
 721         if (!atomic_read(&dev->usb_active))
 722                 return 0;
 723
 724         /* TODO: Update X server to get this from sysfs instead */
 725         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 726                 char *edid = (char *)arg;
 727                 dlfb_get_edid(dev);
 728                 if (copy_to_user(edid, dev->edid, sizeof(dev->edid)))
 729                         return -EFAULT;
 730                 return 0;
 731         }
 732
 733         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 734         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 735
 736                 area = (struct dloarea *)arg;
 737
 738                 if (area->x < 0)
 739                         area->x = 0;
 740
 741                 if (area->x > info->var.xres)
 742                         area->x = info->var.xres;
 743
 744                 if (area->y < 0)
 745                         area->y = 0;
 746
 747                 if (area->y > info->var.yres)
 748                         area->y = info->var.yres;
 749
 750                 atomic_set(&dev->use_defio, 0);
 751
 752                 dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
 753                            info->screen_base);
 754                 atomic_inc(&dev->damage_count);
 755         }
 756
 757         return 0;
 758 }
 759
 760 /* taken from vesafb */
 761 static int
 762 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 763                unsigned blue, unsigned transp, struct fb_info *info)
 764 {
 765         int err = 0;
 766
 767         if (regno >= info->cmap.len)
 768                 return 1;
 769
 770         if (regno < 16) {
 771                 if (info->var.red.offset == 10) {
 772                         /* 1:5:5:5 */
 773                         ((u32 *) (info->pseudo_palette))[regno] =
 774                             ((red & 0xf800) >> 1) |
 775                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 776                 } else {
 777                         /* 0:5:6:5 */
 778                         ((u32 *) (info->pseudo_palette))[regno] =
 779                             ((red & 0xf800)) |
 780                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 781                 }
 782         }
 783
 784         return err;
 785 }
 786
 787 /*
 788  * It's common for several clients to have framebuffer open simultaneously.
 789  * e.g. both fbcon and X. Makes things interesting.
 790  */
 791 static int dlfb_ops_open(struct fb_info *info, int user)
 792 {
 793         struct dlfb_data *dev = info->par;
 794
 795 /*      if (user == 0)
 796  *              We could special case kernel mode clients (fbcon) here
 797  */
 798
 799         mutex_lock(&dev->fb_open_lock);
 800
 801         dev->fb_count++;
 802
 803 #ifdef CONFIG_FB_DEFERRED_IO
 804         if ((atomic_read(&dev->use_defio)) && (info->fbdefio == NULL)) {
 805                 /* enable defio */
 806                 info->fbdefio = &dlfb_defio;
 807                 fb_deferred_io_init(info);
 808         }
 809 #endif
 810
 811         dl_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 812             info->node, user, info, dev->fb_count);
 813
 814         mutex_unlock(&dev->fb_open_lock);
 815
 816         return 0;
 817 }
 818
 819 static int dlfb_ops_release(struct fb_info *info, int user)
 820 {
 821         struct dlfb_data *dev = info->par;
 822
 823         mutex_lock(&dev->fb_open_lock);
 824
 825         dev->fb_count--;
 826
 827 #ifdef CONFIG_FB_DEFERRED_IO
 828         if ((dev->fb_count == 0) && (info->fbdefio)) {
 829                 fb_deferred_io_cleanup(info);
 830                 info->fbdefio = NULL;
 831                 info->fbops->fb_mmap = dlfb_ops_mmap;
 832         }
 833 #endif
 834
 835         dl_notice("release /dev/fb%d user=%d count=%d\n",
 836                   info->node, user, dev->fb_count);
 837
 838         mutex_unlock(&dev->fb_open_lock);
 839
 840         return 0;
 841 }
 842
 843 /*
 844  * Called when all client interfaces to start transactions have been disabled,
 845  * and all references to our device instance (dlfb_data) are released.
 846  * Every transaction must have a reference, so we know are fully spun down
 847  */
 848 static void dlfb_delete(struct kref *kref)
 849 {
 850         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 851
 852         if (dev->backing_buffer)
 853                 vfree(dev->backing_buffer);
 854
 855         mutex_destroy(&dev->fb_open_lock);
 856
 857         kfree(dev);
 858 }
 859
 860 /*
 861  * Called by fbdev as last part of unregister_framebuffer() process
 862  * No new clients can open connections. Deallocate everything fb_info.
 863  */
 864 static void dlfb_ops_destroy(struct fb_info *info)
 865 {
 866         struct dlfb_data *dev = info->par;
 867
 868         if (info->cmap.len != 0)
 869                 fb_dealloc_cmap(&info->cmap);
 870         if (info->monspecs.modedb)
 871                 fb_destroy_modedb(info->monspecs.modedb);
 872         if (info->screen_base)
 873                 vfree(info->screen_base);
 874
 875         fb_destroy_modelist(&info->modelist);
 876
 877         framebuffer_release(info);
 878
 879         /* ref taken before register_framebuffer() for dlfb_data clients */
 880         kref_put(&dev->kref, dlfb_delete);
 881 }
 882
 883 /*
 884  * Check whether a video mode is supported by the DisplayLink chip
 885  * We start from monitor's modes, so don't need to filter that here
 886  */
 887 static int dlfb_is_valid_mode(struct fb_videomode *mode,
 888                 struct fb_info *info)
 889 {
 890         struct dlfb_data *dev = info->par;
 891
 892         if (mode->xres * mode->yres > dev->sku_pixel_limit)
 893                 return 0;
 894
 895         return 1;
 896 }
 897
 898 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
 899 {
 900         const struct fb_bitfield red = { 11, 5, 0 };
 901         const struct fb_bitfield green = { 5, 6, 0 };
 902         const struct fb_bitfield blue = { 0, 5, 0 };
 903
 904         var->bits_per_pixel = 16;
 905         var->red = red;
 906         var->green = green;
 907         var->blue = blue;
 908 }
 909
 910 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
 911                                 struct fb_info *info)
 912 {
 913         struct fb_videomode mode;
 914
 915         /* TODO: support dynamically changing framebuffer size */
 916         if ((var->xres * var->yres * 2) > info->fix.smem_len)
 917                 return -EINVAL;
 918
 919         /* set device-specific elements of var unrelated to mode */
 920         dlfb_var_color_format(var);
 921
 922         fb_var_to_videomode(&mode, var);
 923
 924         if (!dlfb_is_valid_mode(&mode, info))
 925                 return -EINVAL;
 926
 927         return 0;
 928 }
 929
 930 static int dlfb_ops_set_par(struct fb_info *info)
 931 {
 932         struct dlfb_data *dev = info->par;
 933
 934         dl_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
 935
 936         return dlfb_set_video_mode(dev, &info->var);
 937 }
 938
 939 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
 940 {
 941         struct dlfb_data *dev = info->par;
 942         char *bufptr;
 943         struct urb *urb;
 944
 945         urb = dlfb_get_urb(dev);
 946         if (!urb)
 947                 return 0;
 948         bufptr = (char *) urb->transfer_buffer;
 949
 950         /* overloading usb_active.  UNBLANK can conflict with teardown */
 951
 952         bufptr = dlfb_vidreg_lock(bufptr);
 953         if (blank_mode != FB_BLANK_UNBLANK) {
 954                 atomic_set(&dev->usb_active, 0);
 955                 bufptr = dlfb_enable_hvsync(bufptr, false);
 956         } else {
 957                 atomic_set(&dev->usb_active, 1);
 958                 bufptr = dlfb_enable_hvsync(bufptr, true);
 959         }
 960         bufptr = dlfb_vidreg_unlock(bufptr);
 961
 962         dlfb_submit_urb(dev, urb, bufptr - (char *) urb->transfer_buffer);
 963
 964         return 0;
 965 }
 966
 967 static struct fb_ops dlfb_ops = {
 968         .owner = THIS_MODULE,
 969         .fb_read = dlfb_ops_read,
 970         .fb_write = dlfb_ops_write,
 971         .fb_setcolreg = dlfb_ops_setcolreg,
 972         .fb_fillrect = dlfb_ops_fillrect,
 973         .fb_copyarea = dlfb_ops_copyarea,
 974         .fb_imageblit = dlfb_ops_imageblit,
 975         .fb_mmap = dlfb_ops_mmap,
 976         .fb_ioctl = dlfb_ops_ioctl,
 977         .fb_open = dlfb_ops_open,
 978         .fb_release = dlfb_ops_release,
 979         .fb_blank = dlfb_ops_blank,
 980         .fb_check_var = dlfb_ops_check_var,
 981         .fb_set_par = dlfb_ops_set_par,
 982 };
 983
 984 /*
 985  * Calls dlfb_get_edid() to query the EDID of attached monitor via usb cmds
 986  * Then parses EDID into three places used by various parts of fbdev:
 987  * fb_var_screeninfo contains the timing of the monitor's preferred mode
 988  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
 989  * fb_info.modelist is a linked list of all monitor & VESA modes which work
 990  *
 991  * If EDID is not readable/valid, then modelist is all VESA modes,
 992  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
 993  * Returns 0 if EDID parses successfully
 994  */
 995 static int dlfb_parse_edid(struct dlfb_data *dev,
 996                             struct fb_var_screeninfo *var,
 997                             struct fb_info *info)
 998 {
 999         int i;
1000         const struct fb_videomode *default_vmode = NULL;
1001         int result = 0;
1002
1003         fb_destroy_modelist(&info->modelist);
1004         memset(&info->monspecs, 0, sizeof(info->monspecs));
1005
1006         dlfb_get_edid(dev);
1007         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1008
1009         if (info->monspecs.modedb_len > 0) {
1010
1011                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1012                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1013                                 fb_add_videomode(&info->monspecs.modedb[i],
1014                                         &info->modelist);
1015                 }
1016
1017                 default_vmode = fb_find_best_display(&info->monspecs,
1018                                                      &info->modelist);
1019         } else {
1020                 struct fb_videomode fb_vmode = {0};
1021
1022                 dl_err("Unable to get valid EDID from device/display\n");
1023                 result = 1;
1024
1025                 /*
1026                  * Add the standard VESA modes to our modelist
1027                  * Since we don't have EDID, there may be modes that
1028                  * overspec monitor and/or are incorrect aspect ratio, etc.
1029                  * But at least the user has a chance to choose
1030                  */
1031                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1032                         if (dlfb_is_valid_mode((struct fb_videomode *)
1033                                                 &vesa_modes[i], info))
1034                                 fb_add_videomode(&vesa_modes[i],
1035                                                  &info->modelist);
1036                 }
1037
1038                 /*
1039                  * default to resolution safe for projectors
1040                  * (since they are most common case without EDID)
1041                  */
1042                 fb_vmode.xres = 800;
1043                 fb_vmode.yres = 600;
1044                 fb_vmode.refresh = 60;
1045                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1046                                                      &info->modelist);
1047         }
1048
1049         fb_videomode_to_var(var, default_vmode);
1050         dlfb_var_color_format(var);
1051
1052         return result;
1053 }
1054
1055 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1056                                    struct device_attribute *a, char *buf) {
1057         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1058         struct dlfb_data *dev = fb_info->par;
1059         return snprintf(buf, PAGE_SIZE, "%u\n",
1060                         atomic_read(&dev->bytes_rendered));
1061 }
1062
1063 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1064                                    struct device_attribute *a, char *buf) {
1065         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1066         struct dlfb_data *dev = fb_info->par;
1067         return snprintf(buf, PAGE_SIZE, "%u\n",
1068                         atomic_read(&dev->bytes_identical));
1069 }
1070
1071 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1072                                    struct device_attribute *a, char *buf) {
1073         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1074         struct dlfb_data *dev = fb_info->par;
1075         return snprintf(buf, PAGE_SIZE, "%u\n",
1076                         atomic_read(&dev->bytes_sent));
1077 }
1078
1079 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1080                                    struct device_attribute *a, char *buf) {
1081         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1082         struct dlfb_data *dev = fb_info->par;
1083         return snprintf(buf, PAGE_SIZE, "%u\n",
1084                         atomic_read(&dev->cpu_kcycles_used));
1085 }
1086
1087 static ssize_t metrics_misc_show(struct device *fbdev,
1088                                    struct device_attribute *a, char *buf) {
1089         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1090         struct dlfb_data *dev = fb_info->par;
1091         return snprintf(buf, PAGE_SIZE,
1092                         "Calls to\ndamage: %u\nblit: %u\n"
1093                         "defio faults: %u\ncopy: %u\n"
1094                         "fill: %u\n\n"
1095                         "active framebuffer clients: %d\n"
1096                         "urbs available %d(%d)\n"
1097                         "Shadow framebuffer in use? %s\n"
1098                         "Any lost pixels? %s\n",
1099                         atomic_read(&dev->damage_count),
1100                         atomic_read(&dev->blit_count),
1101                         atomic_read(&dev->defio_fault_count),
1102                         atomic_read(&dev->copy_count),
1103                         atomic_read(&dev->fill_count),
1104                         dev->fb_count,
1105                         dev->urbs.available, dev->urbs.limit_sem.count,
1106                         (dev->backing_buffer) ? "yes" : "no",
1107                         atomic_read(&dev->lost_pixels) ? "yes" : "no");
1108 }
1109
1110 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
1111                          struct bin_attribute *a,
1112                          char *buf, loff_t off, size_t count) {
1113         struct device *fbdev = container_of(kobj, struct device, kobj);
1114         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1115         struct dlfb_data *dev = fb_info->par;
1116         char *edid = &dev->edid[0];
1117         const size_t size = sizeof(dev->edid);
1118
1119         if (dlfb_parse_edid(dev, &fb_info->var, fb_info))
1120                 return 0;
1121
1122         if (off >= size)
1123                 return 0;
1124
1125         if (off + count > size)
1126                 count = size - off;
1127         memcpy(buf, edid + off, count);
1128
1129         return count;
1130 }
1131
1132
1133 static ssize_t metrics_reset_store(struct device *fbdev,
1134                            struct device_attribute *attr,
1135                            const char *buf, size_t count)
1136 {
1137         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1138         struct dlfb_data *dev = fb_info->par;
1139
1140         atomic_set(&dev->bytes_rendered, 0);
1141         atomic_set(&dev->bytes_identical, 0);
1142         atomic_set(&dev->bytes_sent, 0);
1143         atomic_set(&dev->cpu_kcycles_used, 0);
1144         atomic_set(&dev->blit_count, 0);
1145         atomic_set(&dev->copy_count, 0);
1146         atomic_set(&dev->fill_count, 0);
1147         atomic_set(&dev->defio_fault_count, 0);
1148         atomic_set(&dev->damage_count, 0);
1149
1150         return count;
1151 }
1152
1153 static ssize_t use_defio_show(struct device *fbdev,
1154                                    struct device_attribute *a, char *buf) {
1155         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1156         struct dlfb_data *dev = fb_info->par;
1157         return snprintf(buf, PAGE_SIZE, "%d\n",
1158                         atomic_read(&dev->use_defio));
1159 }
1160
1161 static ssize_t use_defio_store(struct device *fbdev,
1162                            struct device_attribute *attr,
1163                            const char *buf, size_t count)
1164 {
1165         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1166         struct dlfb_data *dev = fb_info->par;
1167
1168         if (count > 0) {
1169                 if (buf[0] == '0')
1170                         atomic_set(&dev->use_defio, 0);
1171                 if (buf[0] == '1')
1172                         atomic_set(&dev->use_defio, 1);
1173         }
1174         return count;
1175 }
1176
1177 static struct bin_attribute edid_attr = {
1178         .attr.name = "edid",
1179         .attr.mode = 0444,
1180         .size = 128,
1181         .read = edid_show,
1182 };
1183
1184 static struct device_attribute fb_device_attrs[] = {
1185         __ATTR_RO(metrics_bytes_rendered),
1186         __ATTR_RO(metrics_bytes_identical),
1187         __ATTR_RO(metrics_bytes_sent),
1188         __ATTR_RO(metrics_cpu_kcycles_used),
1189         __ATTR_RO(metrics_misc),
1190         __ATTR(metrics_reset, S_IWUGO, NULL, metrics_reset_store),
1191         __ATTR_RW(use_defio),
1192 };
1193
1194 #ifdef CONFIG_FB_DEFERRED_IO
1195 static void dlfb_dpy_deferred_io(struct fb_info *info,
1196                                 struct list_head *pagelist)
1197 {
1198         struct page *cur;
1199         struct fb_deferred_io *fbdefio = info->fbdefio;
1200         struct dlfb_data *dev = info->par;
1201         struct urb *urb;
1202         char *cmd;
1203         cycles_t start_cycles, end_cycles;
1204         int bytes_sent = 0;
1205         int bytes_identical = 0;
1206         int bytes_rendered = 0;
1207         int fault_count = 0;
1208
1209         if (!atomic_read(&dev->use_defio))
1210                 return;
1211
1212         if (!atomic_read(&dev->usb_active))
1213                 return;
1214
1215         start_cycles = get_cycles();
1216
1217         urb = dlfb_get_urb(dev);
1218         if (!urb)
1219                 return;
1220         cmd = urb->transfer_buffer;
1221
1222         /* walk the written page list and render each to device */
1223         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
1224                 dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
1225                                   &cmd, cur->index << PAGE_SHIFT,
1226                                   PAGE_SIZE, &bytes_identical, &bytes_sent);
1227                 bytes_rendered += PAGE_SIZE;
1228                 fault_count++;
1229         }
1230
1231         if (cmd > (char *) urb->transfer_buffer) {
1232                 /* Send partial buffer remaining before exiting */
1233                 int len = cmd - (char *) urb->transfer_buffer;
1234                 dlfb_submit_urb(dev, urb, len);
1235                 bytes_sent += len;
1236         } else
1237                 dlfb_urb_completion(urb);
1238
1239         atomic_add(fault_count, &dev->defio_fault_count);
1240         atomic_add(bytes_sent, &dev->bytes_sent);
1241         atomic_add(bytes_identical, &dev->bytes_identical);
1242         atomic_add(bytes_rendered, &dev->bytes_rendered);
1243         end_cycles = get_cycles();
1244         atomic_add(((unsigned int) ((end_cycles - start_cycles)
1245                     >> 10)), /* Kcycles */
1246                    &dev->cpu_kcycles_used);
1247 }
1248
1249 static struct fb_deferred_io dlfb_defio = {
1250         .delay          = 5,
1251         .deferred_io    = dlfb_dpy_deferred_io,
1252 };
1253
1254 #endif
1255
1256 /*
1257  * This is necessary before we can communicate with the display controller.
1258  */
1259 static int dlfb_select_std_channel(struct dlfb_data *dev)
1260 {
1261         int ret;
1262         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1263                                 0x1C, 0x88, 0x5E, 0x15,
1264                                 0x60, 0xFE, 0xC6, 0x97,
1265                                 0x16, 0x3D, 0x47, 0xF2  };
1266
1267         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1268                         NR_USB_REQUEST_CHANNEL,
1269                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1270                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1271         return ret;
1272 }
1273
1274
1275 static int dlfb_usb_probe(struct usb_interface *interface,
1276                         const struct usb_device_id *id)
1277 {
1278         struct usb_device *usbdev;
1279         struct dlfb_data *dev;
1280         struct fb_info *info;
1281         int videomemorysize;
1282         int i;
1283         unsigned char *videomemory;
1284         int retval = -ENOMEM;
1285         struct fb_var_screeninfo *var;
1286         int registered = 0;
1287         u16 *pix_framebuffer;
1288
1289         /* usb initialization */
1290
1291         usbdev = interface_to_usbdev(interface);
1292
1293         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1294         if (dev == NULL) {
1295                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1296                 goto error;
1297         }
1298
1299         /* we need to wait for both usb and fbdev to spin down on disconnect */
1300         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1301         kref_get(&dev->kref); /* matching kref_put in .fb_destroy function*/
1302
1303         dev->udev = usbdev;
1304         dev->gdev = &usbdev->dev; /* our generic struct device * */
1305         usb_set_intfdata(interface, dev);
1306
1307         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1308                 retval = -ENOMEM;
1309                 dl_err("dlfb_alloc_urb_list failed\n");
1310                 goto error;
1311         }
1312
1313         mutex_init(&dev->fb_open_lock);
1314
1315         /* We don't register a new USB class. Our client interface is fbdev */
1316
1317         /* allocates framebuffer driver structure, not framebuffer memory */
1318         info = framebuffer_alloc(0, &usbdev->dev);
1319         if (!info) {
1320                 retval = -ENOMEM;
1321                 dl_err("framebuffer_alloc failed\n");
1322                 goto error;
1323         }
1324         dev->info = info;
1325         info->par = dev;
1326         info->pseudo_palette = dev->pseudo_palette;
1327         info->fbops = &dlfb_ops;
1328
1329         var = &info->var;
1330
1331         /* TODO set limit based on actual SKU detection */
1332         dev->sku_pixel_limit = 2048 * 1152;
1333
1334         INIT_LIST_HEAD(&info->modelist);
1335         dlfb_parse_edid(dev, var, info);
1336
1337         /*
1338          * ok, now that we've got the size info, we can alloc our framebuffer.
1339          */
1340         info->fix = dlfb_fix;
1341         info->fix.line_length = var->xres * (var->bits_per_pixel / 8);
1342         videomemorysize = info->fix.line_length * var->yres;
1343
1344         /*
1345          * The big chunk of system memory we use as a virtual framebuffer.
1346          * TODO: Handle fbcon cursor code calling blit in interrupt context
1347          */
1348         videomemory = vmalloc(videomemorysize);
1349         if (!videomemory) {
1350                 retval = -ENOMEM;
1351                 dl_err("Virtual framebuffer alloc failed\n");
1352                 goto error;
1353         }
1354
1355         info->screen_base = videomemory;
1356         info->fix.smem_len = PAGE_ALIGN(videomemorysize);
1357         info->fix.smem_start = (unsigned long) videomemory;
1358         info->flags = udlfb_info_flags;
1359
1360
1361         /*
1362          * Second framebuffer copy, mirroring the state of the framebuffer
1363          * on the physical USB device. We can function without this.
1364          * But with imperfect damage info we may end up sending pixels over USB
1365          * that were, in fact, unchanged -- wasting limited USB bandwidth
1366          */
1367         dev->backing_buffer = vmalloc(videomemorysize);
1368         if (!dev->backing_buffer)
1369                 dl_warn("No shadow/backing buffer allcoated\n");
1370         else
1371                 memset(dev->backing_buffer, 0, videomemorysize);
1372
1373         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1374         if (retval < 0) {
1375                 dl_err("fb_alloc_cmap failed %x\n", retval);
1376                 goto error;
1377         }
1378
1379         /* ready to begin using device */
1380
1381 #ifdef CONFIG_FB_DEFERRED_IO
1382         atomic_set(&dev->use_defio, 1);
1383 #endif
1384         atomic_set(&dev->usb_active, 1);
1385         dlfb_select_std_channel(dev);
1386
1387         dlfb_ops_check_var(var, info);
1388         dlfb_ops_set_par(info);
1389
1390         /* paint greenscreen */
1391         pix_framebuffer = (u16 *) videomemory;
1392         for (i = 0; i < videomemorysize / 2; i++)
1393                 pix_framebuffer[i] = 0x37e6;
1394
1395         dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1396                                 videomemory);
1397
1398         retval = register_framebuffer(info);
1399         if (retval < 0) {
1400                 dl_err("register_framebuffer failed %d\n", retval);
1401                 goto error;
1402         }
1403         registered = 1;
1404
1405         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1406                 device_create_file(info->dev, &fb_device_attrs[i]);
1407
1408         device_create_bin_file(info->dev, &edid_attr);
1409
1410         dl_err("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1411                         " Using %dK framebuffer memory\n", info->node,
1412                         var->xres, var->yres,
1413                         ((dev->backing_buffer) ?
1414                         videomemorysize * 2 : videomemorysize) >> 10);
1415         return 0;
1416
1417 error:
1418         if (dev) {
1419                 if (registered) {
1420                         unregister_framebuffer(info);
1421                         dlfb_ops_destroy(info);
1422                 } else
1423                         kref_put(&dev->kref, dlfb_delete);
1424
1425                 if (dev->urbs.count > 0)
1426                         dlfb_free_urb_list(dev);
1427                 kref_put(&dev->kref, dlfb_delete); /* last ref from kref_init */
1428
1429                 /* dev has been deallocated. Do not dereference */
1430         }
1431
1432         return retval;
1433 }
1434
1435 static void dlfb_usb_disconnect(struct usb_interface *interface)
1436 {
1437         struct dlfb_data *dev;
1438         struct fb_info *info;
1439         int i;
1440
1441         dev = usb_get_intfdata(interface);
1442         info = dev->info;
1443
1444         /* when non-active we'll update virtual framebuffer, but no new urbs */
1445         atomic_set(&dev->usb_active, 0);
1446
1447         usb_set_intfdata(interface, NULL);
1448
1449         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1450                 device_remove_file(info->dev, &fb_device_attrs[i]);
1451
1452         device_remove_bin_file(info->dev, &edid_attr);
1453
1454         /* this function will wait for all in-flight urbs to complete */
1455         dlfb_free_urb_list(dev);
1456
1457         if (info) {
1458                 dl_notice("Detaching /dev/fb%d\n", info->node);
1459                 unregister_framebuffer(info);
1460                 dlfb_ops_destroy(info);
1461         }
1462
1463         /* release reference taken by kref_init in probe() */
1464         kref_put(&dev->kref, dlfb_delete);
1465
1466         /* consider dlfb_data freed */
1467
1468         return;
1469 }
1470
1471 static struct usb_driver dlfb_driver = {
1472         .name = "udlfb",
1473         .probe = dlfb_usb_probe,
1474         .disconnect = dlfb_usb_disconnect,
1475         .id_table = id_table,
1476 };
1477
1478 static int __init dlfb_module_init(void)
1479 {
1480         int res;
1481
1482         res = usb_register(&dlfb_driver);
1483         if (res)
1484                 err("usb_register failed. Error number %d", res);
1485
1486         printk(KERN_INFO "VMODES initialized\n");
1487
1488         return res;
1489 }
1490
1491 static void __exit dlfb_module_exit(void)
1492 {
1493         usb_deregister(&dlfb_driver);
1494 }
1495
1496 module_init(dlfb_module_init);
1497 module_exit(dlfb_module_exit);
1498
1499 static void dlfb_urb_completion(struct urb *urb)
1500 {
1501         struct urb_node *unode = urb->context;
1502         struct dlfb_data *dev = unode->dev;
1503         unsigned long flags;
1504
1505         /* sync/async unlink faults aren't errors */
1506         if (urb->status) {
1507                 if (!(urb->status == -ENOENT ||
1508                     urb->status == -ECONNRESET ||
1509                     urb->status == -ESHUTDOWN)) {
1510                         dl_err("%s - nonzero write bulk status received: %d\n",
1511                                 __func__, urb->status);
1512                         atomic_set(&dev->lost_pixels, 1);
1513                 }
1514         }
1515
1516         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1517
1518         spin_lock_irqsave(&dev->urbs.lock, flags);
1519         list_add_tail(&unode->entry, &dev->urbs.list);
1520         dev->urbs.available++;
1521         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1522
1523         up(&dev->urbs.limit_sem);
1524 }
1525
1526 static void dlfb_free_urb_list(struct dlfb_data *dev)
1527 {
1528         int count = dev->urbs.count;
1529         struct list_head *node;
1530         struct urb_node *unode;
1531         struct urb *urb;
1532         int ret;
1533         unsigned long flags;
1534
1535         dl_notice("Waiting for completes and freeing all render urbs\n");
1536
1537         /* keep waiting and freeing, until we've got 'em all */
1538         while (count--) {
1539                 /* Timeout means a memory leak and/or fault */
1540                 ret = down_timeout(&dev->urbs.limit_sem, FREE_URB_TIMEOUT);
1541                 if (ret) {
1542                         BUG_ON(ret);
1543                         break;
1544                 }
1545                 spin_lock_irqsave(&dev->urbs.lock, flags);
1546
1547                 node = dev->urbs.list.next; /* have reserved one with sem */
1548                 list_del_init(node);
1549
1550                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1551
1552                 unode = list_entry(node, struct urb_node, entry);
1553                 urb = unode->urb;
1554
1555                 /* Free each separately allocated piece */
1556                 usb_free_coherent(urb->dev, dev->urbs.size,
1557                                   urb->transfer_buffer, urb->transfer_dma);
1558                 usb_free_urb(urb);
1559                 kfree(node);
1560         }
1561
1562         kref_put(&dev->kref, dlfb_delete);
1563
1564 }
1565
1566 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1567 {
1568         int i = 0;
1569         struct urb *urb;
1570         struct urb_node *unode;
1571         char *buf;
1572
1573         spin_lock_init(&dev->urbs.lock);
1574
1575         dev->urbs.size = size;
1576         INIT_LIST_HEAD(&dev->urbs.list);
1577
1578         while (i < count) {
1579                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1580                 if (!unode)
1581                         break;
1582                 unode->dev = dev;
1583
1584                 urb = usb_alloc_urb(0, GFP_KERNEL);
1585                 if (!urb) {
1586                         kfree(unode);
1587                         break;
1588                 }
1589                 unode->urb = urb;
1590
1591                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1592                                          &urb->transfer_dma);
1593                 if (!buf) {
1594                         kfree(unode);
1595                         usb_free_urb(urb);
1596                         break;
1597                 }
1598
1599                 /* urb->transfer_buffer_length set to actual before submit */
1600                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1601                         buf, size, dlfb_urb_completion, unode);
1602                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1603
1604                 list_add_tail(&unode->entry, &dev->urbs.list);
1605
1606                 i++;
1607         }
1608
1609         sema_init(&dev->urbs.limit_sem, i);
1610         dev->urbs.count = i;
1611         dev->urbs.available = i;
1612
1613         kref_get(&dev->kref); /* released in free_render_urbs() */
1614
1615         dl_notice("allocated %d %d byte urbs\n", i, (int) size);
1616
1617         return i;
1618 }
1619
1620 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1621 {
1622         int ret = 0;
1623         struct list_head *entry;
1624         struct urb_node *unode;
1625         struct urb *urb = NULL;
1626         unsigned long flags;
1627
1628         /* Wait for an in-flight buffer to complete and get re-queued */
1629         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1630         if (ret) {
1631                 atomic_set(&dev->lost_pixels, 1);
1632                 dl_err("wait for urb interrupted: %x\n", ret);
1633                 goto error;
1634         }
1635
1636         spin_lock_irqsave(&dev->urbs.lock, flags);
1637
1638         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1639         entry = dev->urbs.list.next;
1640         list_del_init(entry);
1641         dev->urbs.available--;
1642
1643         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1644
1645         unode = list_entry(entry, struct urb_node, entry);
1646         urb = unode->urb;
1647
1648 error:
1649         return urb;
1650 }
1651
1652 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1653 {
1654         int ret;
1655
1656         BUG_ON(len > dev->urbs.size);
1657
1658         urb->transfer_buffer_length = len; /* set to actual payload len */
1659         ret = usb_submit_urb(urb, GFP_KERNEL);
1660         if (ret) {
1661                 dlfb_urb_completion(urb); /* because no one else will */
1662                 atomic_set(&dev->lost_pixels, 1);
1663                 dl_err("usb_submit_urb error %x\n", ret);
1664         }
1665         return ret;
1666 }
1667
1668 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1669               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1670               "Bernie Thompson <bernie@plugable.com>");
1671 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1672 MODULE_LICENSE("GPL");
1673