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 /* 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(KERN_INFO "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