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 message "kernel 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 message "FB_SYS_* in kernel or module option to support fb console"
  67 #endif
  68 #endif
  69
  70 #ifndef CONFIG_FB_MODE_HELPERS
  71 #warning message "kernel 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 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 606 static void dlfb_ops_copyarea(struct fb_info *info,
 607                                 const struct fb_copyarea *area)
 608 {
 609
 610         struct dlfb_data *dev = info->par;
 611
 612 #if defined CONFIG_FB_SYS_COPYAREA || defined CONFIG_FB_SYS_COPYAREA_MODULE
 613
 614         sys_copyarea(info, area);
 615
 616         dlfb_handle_damage(dev, area->dx, area->dy,
 617                         area->width, area->height, info->screen_base);
 618 #endif
 619         atomic_inc(&dev->copy_count);
 620
 621 }
 622
 623 static void dlfb_ops_imageblit(struct fb_info *info,
 624                                 const struct fb_image *image)
 625 {
 626         struct dlfb_data *dev = info->par;
 627
 628 #if defined CONFIG_FB_SYS_IMAGEBLIT || defined CONFIG_FB_SYS_IMAGEBLIT_MODULE
 629
 630         sys_imageblit(info, image);
 631
 632         dlfb_handle_damage(dev, image->dx, image->dy,
 633                         image->width, image->height, info->screen_base);
 634
 635 #endif
 636
 637         atomic_inc(&dev->blit_count);
 638 }
 639
 640 static void dlfb_ops_fillrect(struct fb_info *info,
 641                           const struct fb_fillrect *rect)
 642 {
 643         struct dlfb_data *dev = info->par;
 644
 645 #if defined CONFIG_FB_SYS_FILLRECT || defined CONFIG_FB_SYS_FILLRECT_MODULE
 646
 647         sys_fillrect(info, rect);
 648
 649         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
 650                               rect->height, info->screen_base);
 651 #endif
 652
 653         atomic_inc(&dev->fill_count);
 654
 655 }
 656
 657 static void dlfb_get_edid(struct dlfb_data *dev)
 658 {
 659         int i;
 660         int ret;
 661         char rbuf[2];
 662
 663         for (i = 0; i < sizeof(dev->edid); i++) {
 664                 ret = usb_control_msg(dev->udev,
 665                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 666                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 667                                     0);
 668                 dev->edid[i] = rbuf[1];
 669         }
 670 }
 671
 672 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 673                                 unsigned long arg)
 674 {
 675
 676         struct dlfb_data *dev = info->par;
 677         struct dloarea *area = NULL;
 678
 679         if (!atomic_read(&dev->usb_active))
 680                 return 0;
 681
 682         /* TODO: Update X server to get this from sysfs instead */
 683         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 684                 char *edid = (char *)arg;
 685                 dlfb_get_edid(dev);
 686                 if (copy_to_user(edid, dev->edid, sizeof(dev->edid)))
 687                         return -EFAULT;
 688                 return 0;
 689         }
 690
 691         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 692         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 693
 694                 area = (struct dloarea *)arg;
 695
 696                 if (area->x < 0)
 697                         area->x = 0;
 698
 699                 if (area->x > info->var.xres)
 700                         area->x = info->var.xres;
 701
 702                 if (area->y < 0)
 703                         area->y = 0;
 704
 705                 if (area->y > info->var.yres)
 706                         area->y = info->var.yres;
 707
 708                 atomic_set(&dev->use_defio, 0);
 709
 710                 dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
 711                            info->screen_base);
 712                 atomic_inc(&dev->damage_count);
 713         }
 714
 715         return 0;
 716 }
 717
 718 /* taken from vesafb */
 719 static int
 720 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 721                unsigned blue, unsigned transp, struct fb_info *info)
 722 {
 723         int err = 0;
 724
 725         if (regno >= info->cmap.len)
 726                 return 1;
 727
 728         if (regno < 16) {
 729                 if (info->var.red.offset == 10) {
 730                         /* 1:5:5:5 */
 731                         ((u32 *) (info->pseudo_palette))[regno] =
 732                             ((red & 0xf800) >> 1) |
 733                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 734                 } else {
 735                         /* 0:5:6:5 */
 736                         ((u32 *) (info->pseudo_palette))[regno] =
 737                             ((red & 0xf800)) |
 738                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 739                 }
 740         }
 741
 742         return err;
 743 }
 744
 745 /*
 746  * It's common for several clients to have framebuffer open simultaneously.
 747  * e.g. both fbcon and X. Makes things interesting.
 748  */
 749 static int dlfb_ops_open(struct fb_info *info, int user)
 750 {
 751         struct dlfb_data *dev = info->par;
 752
 753 /*      if (user == 0)
 754  *              We could special case kernel mode clients (fbcon) here
 755  */
 756
 757         mutex_lock(&dev->fb_open_lock);
 758
 759         dev->fb_count++;
 760
 761 #ifdef CONFIG_FB_DEFERRED_IO
 762         if ((atomic_read(&dev->use_defio)) && (info->fbdefio == NULL)) {
 763                 /* enable defio */
 764                 info->fbdefio = &dlfb_defio;
 765                 fb_deferred_io_init(info);
 766         }
 767 #endif
 768
 769         dl_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 770             info->node, user, info, dev->fb_count);
 771
 772         mutex_unlock(&dev->fb_open_lock);
 773
 774         return 0;
 775 }
 776
 777 static int dlfb_ops_release(struct fb_info *info, int user)
 778 {
 779         struct dlfb_data *dev = info->par;
 780
 781         mutex_lock(&dev->fb_open_lock);
 782
 783         dev->fb_count--;
 784
 785 #ifdef CONFIG_FB_DEFERRED_IO
 786         if ((dev->fb_count == 0) && (info->fbdefio)) {
 787                 fb_deferred_io_cleanup(info);
 788                 info->fbdefio = NULL;
 789                 info->fbops->fb_mmap = dlfb_ops_mmap;
 790         }
 791 #endif
 792
 793         dl_notice("release /dev/fb%d user=%d count=%d\n",
 794                   info->node, user, dev->fb_count);
 795
 796         mutex_unlock(&dev->fb_open_lock);
 797
 798         return 0;
 799 }
 800
 801 /*
 802  * Called when all client interfaces to start transactions have been disabled,
 803  * and all references to our device instance (dlfb_data) are released.
 804  * Every transaction must have a reference, so we know are fully spun down
 805  */
 806 static void dlfb_delete(struct kref *kref)
 807 {
 808         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 809
 810         if (dev->backing_buffer)
 811                 vfree(dev->backing_buffer);
 812
 813         mutex_destroy(&dev->fb_open_lock);
 814
 815         kfree(dev);
 816 }
 817
 818 /*
 819  * Called by fbdev as last part of unregister_framebuffer() process
 820  * No new clients can open connections. Deallocate everything fb_info.
 821  */
 822 static void dlfb_ops_destroy(struct fb_info *info)
 823 {
 824         struct dlfb_data *dev = info->par;
 825
 826         if (info->cmap.len != 0)
 827                 fb_dealloc_cmap(&info->cmap);
 828         if (info->monspecs.modedb)
 829                 fb_destroy_modedb(info->monspecs.modedb);
 830         if (info->screen_base)
 831                 vfree(info->screen_base);
 832
 833         fb_destroy_modelist(&info->modelist);
 834
 835         framebuffer_release(info);
 836
 837         /* ref taken before register_framebuffer() for dlfb_data clients */
 838         kref_put(&dev->kref, dlfb_delete);
 839 }
 840
 841 /*
 842  * Check whether a video mode is supported by the DisplayLink chip
 843  * We start from monitor's modes, so don't need to filter that here
 844  */
 845 static int dlfb_is_valid_mode(struct fb_videomode *mode,
 846                 struct fb_info *info)
 847 {
 848         struct dlfb_data *dev = info->par;
 849
 850         if (mode->xres * mode->yres > dev->sku_pixel_limit)
 851                 return 0;
 852
 853         return 1;
 854 }
 855
 856 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
 857 {
 858         const struct fb_bitfield red = { 11, 5, 0 };
 859         const struct fb_bitfield green = { 5, 6, 0 };
 860         const struct fb_bitfield blue = { 0, 5, 0 };
 861
 862         var->bits_per_pixel = 16;
 863         var->red = red;
 864         var->green = green;
 865         var->blue = blue;
 866 }
 867
 868 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
 869                                 struct fb_info *info)
 870 {
 871         struct fb_videomode mode;
 872
 873         /* TODO: support dynamically changing framebuffer size */
 874         if ((var->xres * var->yres * 2) > info->fix.smem_len)
 875                 return -EINVAL;
 876
 877         /* set device-specific elements of var unrelated to mode */
 878         dlfb_var_color_format(var);
 879
 880         fb_var_to_videomode(&mode, var);
 881
 882         if (!dlfb_is_valid_mode(&mode, info))
 883                 return -EINVAL;
 884
 885         return 0;
 886 }
 887
 888 static int dlfb_ops_set_par(struct fb_info *info)
 889 {
 890         struct dlfb_data *dev = info->par;
 891
 892         dl_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
 893
 894         return dlfb_set_video_mode(dev, &info->var);
 895 }
 896
 897 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
 898 {
 899         struct dlfb_data *dev = info->par;
 900         char *bufptr;
 901         struct urb *urb;
 902
 903         urb = dlfb_get_urb(dev);
 904         if (!urb)
 905                 return 0;
 906         bufptr = (char *) urb->transfer_buffer;
 907
 908         /* overloading usb_active.  UNBLANK can conflict with teardown */
 909
 910         bufptr = dlfb_vidreg_lock(bufptr);
 911         if (blank_mode != FB_BLANK_UNBLANK) {
 912                 atomic_set(&dev->usb_active, 0);
 913                 bufptr = dlfb_enable_hvsync(bufptr, false);
 914         } else {
 915                 atomic_set(&dev->usb_active, 1);
 916                 bufptr = dlfb_enable_hvsync(bufptr, true);
 917         }
 918         bufptr = dlfb_vidreg_unlock(bufptr);
 919
 920         dlfb_submit_urb(dev, urb, bufptr - (char *) urb->transfer_buffer);
 921
 922         return 0;
 923 }
 924
 925 static struct fb_ops dlfb_ops = {
 926         .owner = THIS_MODULE,
 927         .fb_setcolreg = dlfb_ops_setcolreg,
 928         .fb_fillrect = dlfb_ops_fillrect,
 929         .fb_copyarea = dlfb_ops_copyarea,
 930         .fb_imageblit = dlfb_ops_imageblit,
 931         .fb_mmap = dlfb_ops_mmap,
 932         .fb_ioctl = dlfb_ops_ioctl,
 933         .fb_open = dlfb_ops_open,
 934         .fb_release = dlfb_ops_release,
 935         .fb_blank = dlfb_ops_blank,
 936         .fb_check_var = dlfb_ops_check_var,
 937         .fb_set_par = dlfb_ops_set_par,
 938 };
 939
 940 /*
 941  * Calls dlfb_get_edid() to query the EDID of attached monitor via usb cmds
 942  * Then parses EDID into three places used by various parts of fbdev:
 943  * fb_var_screeninfo contains the timing of the monitor's preferred mode
 944  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
 945  * fb_info.modelist is a linked list of all monitor & VESA modes which work
 946  *
 947  * If EDID is not readable/valid, then modelist is all VESA modes,
 948  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
 949  * Returns 0 if EDID parses successfully
 950  */
 951 static int dlfb_parse_edid(struct dlfb_data *dev,
 952                             struct fb_var_screeninfo *var,
 953                             struct fb_info *info)
 954 {
 955         int i;
 956         const struct fb_videomode *default_vmode = NULL;
 957         int result = 0;
 958
 959         fb_destroy_modelist(&info->modelist);
 960         memset(&info->monspecs, 0, sizeof(info->monspecs));
 961
 962         dlfb_get_edid(dev);
 963         fb_edid_to_monspecs(dev->edid, &info->monspecs);
 964
 965         if (info->monspecs.modedb_len > 0) {
 966
 967                 for (i = 0; i < info->monspecs.modedb_len; i++) {
 968                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
 969                                 fb_add_videomode(&info->monspecs.modedb[i],
 970                                         &info->modelist);
 971                 }
 972
 973                 default_vmode = fb_find_best_display(&info->monspecs,
 974                                                      &info->modelist);
 975         } else {
 976                 struct fb_videomode fb_vmode = {0};
 977
 978                 dl_err("Unable to get valid EDID from device/display\n");
 979                 result = 1;
 980
 981                 /*
 982                  * Add the standard VESA modes to our modelist
 983                  * Since we don't have EDID, there may be modes that
 984                  * overspec monitor and/or are incorrect aspect ratio, etc.
 985                  * But at least the user has a chance to choose
 986                  */
 987                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
 988                         if (dlfb_is_valid_mode((struct fb_videomode *)
 989                                                 &vesa_modes[i], info))
 990                                 fb_add_videomode(&vesa_modes[i],
 991                                                  &info->modelist);
 992                 }
 993
 994                 /*
 995                  * default to resolution safe for projectors
 996                  * (since they are most common case without EDID)
 997                  */
 998                 fb_vmode.xres = 800;
 999                 fb_vmode.yres = 600;
1000                 fb_vmode.refresh = 60;
1001                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1002                                                      &info->modelist);
1003         }
1004
1005         fb_videomode_to_var(var, default_vmode);
1006         dlfb_var_color_format(var);
1007
1008         return result;
1009 }
1010
1011 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1012                                    struct device_attribute *a, char *buf) {
1013         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1014         struct dlfb_data *dev = fb_info->par;
1015         return snprintf(buf, PAGE_SIZE, "%u\n",
1016                         atomic_read(&dev->bytes_rendered));
1017 }
1018
1019 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1020                                    struct device_attribute *a, char *buf) {
1021         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1022         struct dlfb_data *dev = fb_info->par;
1023         return snprintf(buf, PAGE_SIZE, "%u\n",
1024                         atomic_read(&dev->bytes_identical));
1025 }
1026
1027 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1028                                    struct device_attribute *a, char *buf) {
1029         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1030         struct dlfb_data *dev = fb_info->par;
1031         return snprintf(buf, PAGE_SIZE, "%u\n",
1032                         atomic_read(&dev->bytes_sent));
1033 }
1034
1035 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1036                                    struct device_attribute *a, char *buf) {
1037         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1038         struct dlfb_data *dev = fb_info->par;
1039         return snprintf(buf, PAGE_SIZE, "%u\n",
1040                         atomic_read(&dev->cpu_kcycles_used));
1041 }
1042
1043 static ssize_t metrics_misc_show(struct device *fbdev,
1044                                    struct device_attribute *a, char *buf) {
1045         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1046         struct dlfb_data *dev = fb_info->par;
1047         return snprintf(buf, PAGE_SIZE,
1048                         "Calls to\ndamage: %u\nblit: %u\n"
1049                         "defio faults: %u\ncopy: %u\n"
1050                         "fill: %u\n\n"
1051                         "active framebuffer clients: %d\n"
1052                         "urbs available %d(%d)\n"
1053                         "Shadow framebuffer in use? %s\n"
1054                         "Any lost pixels? %s\n",
1055                         atomic_read(&dev->damage_count),
1056                         atomic_read(&dev->blit_count),
1057                         atomic_read(&dev->defio_fault_count),
1058                         atomic_read(&dev->copy_count),
1059                         atomic_read(&dev->fill_count),
1060                         dev->fb_count,
1061                         dev->urbs.available, dev->urbs.limit_sem.count,
1062                         (dev->backing_buffer) ? "yes" : "no",
1063                         atomic_read(&dev->lost_pixels) ? "yes" : "no");
1064 }
1065
1066 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
1067                          struct bin_attribute *a,
1068                          char *buf, loff_t off, size_t count) {
1069         struct device *fbdev = container_of(kobj, struct device, kobj);
1070         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1071         struct dlfb_data *dev = fb_info->par;
1072         char *edid = &dev->edid[0];
1073         const size_t size = sizeof(dev->edid);
1074
1075         if (dlfb_parse_edid(dev, &fb_info->var, fb_info))
1076                 return 0;
1077
1078         if (off >= size)
1079                 return 0;
1080
1081         if (off + count > size)
1082                 count = size - off;
1083         memcpy(buf, edid + off, count);
1084
1085         return count;
1086 }
1087
1088
1089 static ssize_t metrics_reset_store(struct device *fbdev,
1090                            struct device_attribute *attr,
1091                            const char *buf, size_t count)
1092 {
1093         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1094         struct dlfb_data *dev = fb_info->par;
1095
1096         atomic_set(&dev->bytes_rendered, 0);
1097         atomic_set(&dev->bytes_identical, 0);
1098         atomic_set(&dev->bytes_sent, 0);
1099         atomic_set(&dev->cpu_kcycles_used, 0);
1100         atomic_set(&dev->blit_count, 0);
1101         atomic_set(&dev->copy_count, 0);
1102         atomic_set(&dev->fill_count, 0);
1103         atomic_set(&dev->defio_fault_count, 0);
1104         atomic_set(&dev->damage_count, 0);
1105
1106         return count;
1107 }
1108
1109 static ssize_t use_defio_show(struct device *fbdev,
1110                                    struct device_attribute *a, char *buf) {
1111         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1112         struct dlfb_data *dev = fb_info->par;
1113         return snprintf(buf, PAGE_SIZE, "%d\n",
1114                         atomic_read(&dev->use_defio));
1115 }
1116
1117 static ssize_t use_defio_store(struct device *fbdev,
1118                            struct device_attribute *attr,
1119                            const char *buf, size_t count)
1120 {
1121         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1122         struct dlfb_data *dev = fb_info->par;
1123
1124         if (count > 0) {
1125                 if (buf[0] == '0')
1126                         atomic_set(&dev->use_defio, 0);
1127                 if (buf[0] == '1')
1128                         atomic_set(&dev->use_defio, 1);
1129         }
1130         return count;
1131 }
1132
1133 static struct bin_attribute edid_attr = {
1134         .attr.name = "edid",
1135         .attr.mode = 0444,
1136         .size = 128,
1137         .read = edid_show,
1138 };
1139
1140 static struct device_attribute fb_device_attrs[] = {
1141         __ATTR_RO(metrics_bytes_rendered),
1142         __ATTR_RO(metrics_bytes_identical),
1143         __ATTR_RO(metrics_bytes_sent),
1144         __ATTR_RO(metrics_cpu_kcycles_used),
1145         __ATTR_RO(metrics_misc),
1146         __ATTR(metrics_reset, S_IWUGO, NULL, metrics_reset_store),
1147         __ATTR_RW(use_defio),
1148 };
1149
1150 #ifdef CONFIG_FB_DEFERRED_IO
1151 static void dlfb_dpy_deferred_io(struct fb_info *info,
1152                                 struct list_head *pagelist)
1153 {
1154         struct page *cur;
1155         struct fb_deferred_io *fbdefio = info->fbdefio;
1156         struct dlfb_data *dev = info->par;
1157         struct urb *urb;
1158         char *cmd;
1159         cycles_t start_cycles, end_cycles;
1160         int bytes_sent = 0;
1161         int bytes_identical = 0;
1162         int bytes_rendered = 0;
1163         int fault_count = 0;
1164
1165         if (!atomic_read(&dev->use_defio))
1166                 return;
1167
1168         if (!atomic_read(&dev->usb_active))
1169                 return;
1170
1171         start_cycles = get_cycles();
1172
1173         urb = dlfb_get_urb(dev);
1174         if (!urb)
1175                 return;
1176         cmd = urb->transfer_buffer;
1177
1178         /* walk the written page list and render each to device */
1179         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
1180                 dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
1181                                   &cmd, cur->index << PAGE_SHIFT,
1182                                   PAGE_SIZE, &bytes_identical, &bytes_sent);
1183                 bytes_rendered += PAGE_SIZE;
1184                 fault_count++;
1185         }
1186
1187         if (cmd > (char *) urb->transfer_buffer) {
1188                 /* Send partial buffer remaining before exiting */
1189                 int len = cmd - (char *) urb->transfer_buffer;
1190                 dlfb_submit_urb(dev, urb, len);
1191                 bytes_sent += len;
1192         } else
1193                 dlfb_urb_completion(urb);
1194
1195         atomic_add(fault_count, &dev->defio_fault_count);
1196         atomic_add(bytes_sent, &dev->bytes_sent);
1197         atomic_add(bytes_identical, &dev->bytes_identical);
1198         atomic_add(bytes_rendered, &dev->bytes_rendered);
1199         end_cycles = get_cycles();
1200         atomic_add(((unsigned int) ((end_cycles - start_cycles)
1201                     >> 10)), /* Kcycles */
1202                    &dev->cpu_kcycles_used);
1203 }
1204
1205 static struct fb_deferred_io dlfb_defio = {
1206         .delay          = 5,
1207         .deferred_io    = dlfb_dpy_deferred_io,
1208 };
1209
1210 #endif
1211
1212 /*
1213  * This is necessary before we can communicate with the display controller.
1214  */
1215 static int dlfb_select_std_channel(struct dlfb_data *dev)
1216 {
1217         int ret;
1218         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1219                                 0x1C, 0x88, 0x5E, 0x15,
1220                                 0x60, 0xFE, 0xC6, 0x97,
1221                                 0x16, 0x3D, 0x47, 0xF2  };
1222
1223         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1224                         NR_USB_REQUEST_CHANNEL,
1225                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1226                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1227         return ret;
1228 }
1229
1230
1231 static int dlfb_usb_probe(struct usb_interface *interface,
1232                         const struct usb_device_id *id)
1233 {
1234         struct usb_device *usbdev;
1235         struct dlfb_data *dev;
1236         struct fb_info *info;
1237         int videomemorysize;
1238         int i;
1239         unsigned char *videomemory;
1240         int retval = -ENOMEM;
1241         struct fb_var_screeninfo *var;
1242         int registered = 0;
1243         u16 *pix_framebuffer;
1244
1245         /* usb initialization */
1246
1247         usbdev = interface_to_usbdev(interface);
1248
1249         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1250         if (dev == NULL) {
1251                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1252                 goto error;
1253         }
1254
1255         /* we need to wait for both usb and fbdev to spin down on disconnect */
1256         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1257         kref_get(&dev->kref); /* matching kref_put in .fb_destroy function*/
1258
1259         dev->udev = usbdev;
1260         dev->gdev = &usbdev->dev; /* our generic struct device * */
1261         usb_set_intfdata(interface, dev);
1262
1263         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1264                 retval = -ENOMEM;
1265                 dl_err("dlfb_alloc_urb_list failed\n");
1266                 goto error;
1267         }
1268
1269         mutex_init(&dev->fb_open_lock);
1270
1271         /* We don't register a new USB class. Our client interface is fbdev */
1272
1273         /* allocates framebuffer driver structure, not framebuffer memory */
1274         info = framebuffer_alloc(0, &usbdev->dev);
1275         if (!info) {
1276                 retval = -ENOMEM;
1277                 dl_err("framebuffer_alloc failed\n");
1278                 goto error;
1279         }
1280         dev->info = info;
1281         info->par = dev;
1282         info->pseudo_palette = dev->pseudo_palette;
1283         info->fbops = &dlfb_ops;
1284
1285         var = &info->var;
1286
1287         /* TODO set limit based on actual SKU detection */
1288         dev->sku_pixel_limit = 2048 * 1152;
1289
1290         INIT_LIST_HEAD(&info->modelist);
1291         dlfb_parse_edid(dev, var, info);
1292
1293         /*
1294          * ok, now that we've got the size info, we can alloc our framebuffer.
1295          */
1296         info->fix = dlfb_fix;
1297         info->fix.line_length = var->xres * (var->bits_per_pixel / 8);
1298         videomemorysize = info->fix.line_length * var->yres;
1299
1300         /*
1301          * The big chunk of system memory we use as a virtual framebuffer.
1302          * TODO: Handle fbcon cursor code calling blit in interrupt context
1303          */
1304         videomemory = vmalloc(videomemorysize);
1305         if (!videomemory) {
1306                 retval = -ENOMEM;
1307                 dl_err("Virtual framebuffer alloc failed\n");
1308                 goto error;
1309         }
1310
1311         info->screen_base = videomemory;
1312         info->fix.smem_len = PAGE_ALIGN(videomemorysize);
1313         info->fix.smem_start = (unsigned long) videomemory;
1314         info->flags = udlfb_info_flags;
1315
1316
1317         /*
1318          * Second framebuffer copy, mirroring the state of the framebuffer
1319          * on the physical USB device. We can function without this.
1320          * But with imperfect damage info we may end up sending pixels over USB
1321          * that were, in fact, unchanged -- wasting limited USB bandwidth
1322          */
1323         dev->backing_buffer = vmalloc(videomemorysize);
1324         if (!dev->backing_buffer)
1325                 dl_warn("No shadow/backing buffer allcoated\n");
1326         else
1327                 memset(dev->backing_buffer, 0, videomemorysize);
1328
1329         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1330         if (retval < 0) {
1331                 dl_err("fb_alloc_cmap failed %x\n", retval);
1332                 goto error;
1333         }
1334
1335         /* ready to begin using device */
1336
1337 #ifdef CONFIG_FB_DEFERRED_IO
1338         atomic_set(&dev->use_defio, 1);
1339 #endif
1340         atomic_set(&dev->usb_active, 1);
1341         dlfb_select_std_channel(dev);
1342
1343         dlfb_ops_check_var(var, info);
1344         dlfb_ops_set_par(info);
1345
1346         /* paint greenscreen */
1347         pix_framebuffer = (u16 *) videomemory;
1348         for (i = 0; i < videomemorysize / 2; i++)
1349                 pix_framebuffer[i] = 0x37e6;
1350
1351         dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1352                                 videomemory);
1353
1354         retval = register_framebuffer(info);
1355         if (retval < 0) {
1356                 dl_err("register_framebuffer failed %d\n", retval);
1357                 goto error;
1358         }
1359         registered = 1;
1360
1361         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1362                 device_create_file(info->dev, &fb_device_attrs[i]);
1363
1364         device_create_bin_file(info->dev, &edid_attr);
1365
1366         dl_err("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1367                         " Using %dK framebuffer memory\n", info->node,
1368                         var->xres, var->yres,
1369                         ((dev->backing_buffer) ?
1370                         videomemorysize * 2 : videomemorysize) >> 10);
1371         return 0;
1372
1373 error:
1374         if (dev) {
1375                 if (registered) {
1376                         unregister_framebuffer(info);
1377                         dlfb_ops_destroy(info);
1378                 } else
1379                         kref_put(&dev->kref, dlfb_delete);
1380
1381                 if (dev->urbs.count > 0)
1382                         dlfb_free_urb_list(dev);
1383                 kref_put(&dev->kref, dlfb_delete); /* last ref from kref_init */
1384
1385                 /* dev has been deallocated. Do not dereference */
1386         }
1387
1388         return retval;
1389 }
1390
1391 static void dlfb_usb_disconnect(struct usb_interface *interface)
1392 {
1393         struct dlfb_data *dev;
1394         struct fb_info *info;
1395         int i;
1396
1397         dev = usb_get_intfdata(interface);
1398         info = dev->info;
1399
1400         /* when non-active we'll update virtual framebuffer, but no new urbs */
1401         atomic_set(&dev->usb_active, 0);
1402
1403         usb_set_intfdata(interface, NULL);
1404
1405         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1406                 device_remove_file(info->dev, &fb_device_attrs[i]);
1407
1408         device_remove_bin_file(info->dev, &edid_attr);
1409
1410         /* this function will wait for all in-flight urbs to complete */
1411         dlfb_free_urb_list(dev);
1412
1413         if (info) {
1414                 dl_notice("Detaching /dev/fb%d\n", info->node);
1415                 unregister_framebuffer(info);
1416                 dlfb_ops_destroy(info);
1417         }
1418
1419         /* release reference taken by kref_init in probe() */
1420         kref_put(&dev->kref, dlfb_delete);
1421
1422         /* consider dlfb_data freed */
1423
1424         return;
1425 }
1426
1427 static struct usb_driver dlfb_driver = {
1428         .name = "udlfb",
1429         .probe = dlfb_usb_probe,
1430         .disconnect = dlfb_usb_disconnect,
1431         .id_table = id_table,
1432 };
1433
1434 static int __init dlfb_module_init(void)
1435 {
1436         int res;
1437
1438         res = usb_register(&dlfb_driver);
1439         if (res)
1440                 err("usb_register failed. Error number %d", res);
1441
1442         printk("VMODES initialized\n");
1443
1444         return res;
1445 }
1446
1447 static void __exit dlfb_module_exit(void)
1448 {
1449         usb_deregister(&dlfb_driver);
1450 }
1451
1452 module_init(dlfb_module_init);
1453 module_exit(dlfb_module_exit);
1454
1455 static void dlfb_urb_completion(struct urb *urb)
1456 {
1457         struct urb_node *unode = urb->context;
1458         struct dlfb_data *dev = unode->dev;
1459         unsigned long flags;
1460
1461         /* sync/async unlink faults aren't errors */
1462         if (urb->status) {
1463                 if (!(urb->status == -ENOENT ||
1464                     urb->status == -ECONNRESET ||
1465                     urb->status == -ESHUTDOWN)) {
1466                         dl_err("%s - nonzero write bulk status received: %d\n",
1467                                 __func__, urb->status);
1468                         atomic_set(&dev->lost_pixels, 1);
1469                 }
1470         }
1471
1472         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1473
1474         spin_lock_irqsave(&dev->urbs.lock, flags);
1475         list_add_tail(&unode->entry, &dev->urbs.list);
1476         dev->urbs.available++;
1477         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1478
1479         up(&dev->urbs.limit_sem);
1480 }
1481
1482 static void dlfb_free_urb_list(struct dlfb_data *dev)
1483 {
1484         int count = dev->urbs.count;
1485         struct list_head *node;
1486         struct urb_node *unode;
1487         struct urb *urb;
1488         int ret;
1489         unsigned long flags;
1490
1491         dl_notice("Waiting for completes and freeing all render urbs\n");
1492
1493         /* keep waiting and freeing, until we've got 'em all */
1494         while (count--) {
1495                 /* Timeout means a memory leak and/or fault */
1496                 ret = down_timeout(&dev->urbs.limit_sem, FREE_URB_TIMEOUT);
1497                 if (ret) {
1498                         BUG_ON(ret);
1499                         break;
1500                 }
1501                 spin_lock_irqsave(&dev->urbs.lock, flags);
1502
1503                 node = dev->urbs.list.next; /* have reserved one with sem */
1504                 list_del_init(node);
1505
1506                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1507
1508                 unode = list_entry(node, struct urb_node, entry);
1509                 urb = unode->urb;
1510
1511                 /* Free each separately allocated piece */
1512                 usb_free_coherent(urb->dev, dev->urbs.size,
1513                                   urb->transfer_buffer, urb->transfer_dma);
1514                 usb_free_urb(urb);
1515                 kfree(node);
1516         }
1517
1518         kref_put(&dev->kref, dlfb_delete);
1519
1520 }
1521
1522 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1523 {
1524         int i = 0;
1525         struct urb *urb;
1526         struct urb_node *unode;
1527         char *buf;
1528
1529         spin_lock_init(&dev->urbs.lock);
1530
1531         dev->urbs.size = size;
1532         INIT_LIST_HEAD(&dev->urbs.list);
1533
1534         while (i < count) {
1535                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1536                 if (!unode)
1537                         break;
1538                 unode->dev = dev;
1539
1540                 urb = usb_alloc_urb(0, GFP_KERNEL);
1541                 if (!urb) {
1542                         kfree(unode);
1543                         break;
1544                 }
1545                 unode->urb = urb;
1546
1547                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1548                                          &urb->transfer_dma);
1549                 if (!buf) {
1550                         kfree(unode);
1551                         usb_free_urb(urb);
1552                         break;
1553                 }
1554
1555                 /* urb->transfer_buffer_length set to actual before submit */
1556                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1557                         buf, size, dlfb_urb_completion, unode);
1558                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1559
1560                 list_add_tail(&unode->entry, &dev->urbs.list);
1561
1562                 i++;
1563         }
1564
1565         sema_init(&dev->urbs.limit_sem, i);
1566         dev->urbs.count = i;
1567         dev->urbs.available = i;
1568
1569         kref_get(&dev->kref); /* released in free_render_urbs() */
1570
1571         dl_notice("allocated %d %d byte urbs \n", i, (int) size);
1572
1573         return i;
1574 }
1575
1576 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1577 {
1578         int ret = 0;
1579         struct list_head *entry;
1580         struct urb_node *unode;
1581         struct urb *urb = NULL;
1582         unsigned long flags;
1583
1584         /* Wait for an in-flight buffer to complete and get re-queued */
1585         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1586         if (ret) {
1587                 atomic_set(&dev->lost_pixels, 1);
1588                 dl_err("wait for urb interrupted: %x\n", ret);
1589                 goto error;
1590         }
1591
1592         spin_lock_irqsave(&dev->urbs.lock, flags);
1593
1594         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1595         entry = dev->urbs.list.next;
1596         list_del_init(entry);
1597         dev->urbs.available--;
1598
1599         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1600
1601         unode = list_entry(entry, struct urb_node, entry);
1602         urb = unode->urb;
1603
1604 error:
1605         return urb;
1606 }
1607
1608 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1609 {
1610         int ret;
1611
1612         BUG_ON(len > dev->urbs.size);
1613
1614         urb->transfer_buffer_length = len; /* set to actual payload len */
1615         ret = usb_submit_urb(urb, GFP_KERNEL);
1616         if (ret) {
1617                 dlfb_urb_completion(urb); /* because no one else will */
1618                 atomic_set(&dev->lost_pixels, 1);
1619                 dl_err("usb_submit_urb error %x\n", ret);
1620         }
1621         return ret;
1622 }
1623
1624 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1625               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1626               "Bernie Thompson <bernie@plugable.com>");
1627 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1628 MODULE_LICENSE("GPL");
1629