drivers/staging/udlfb/udlfb.c

   1 /*
   2  * udlfb.c -- Framebuffer driver for DisplayLink USB controller
   3  *
   4  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
   5  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
   6  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License v2. See the file COPYING in the main directory of this archive for
  10  * more details.
  11  *
  12  * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
  13  * usb-skeleton by GregKH.
  14  *
  15  * Device-specific portions based on information from Displaylink, with work
  16  * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/usb.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/mm.h>
  25 #include <linux/fb.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/slab.h>
  28 #include <linux/delay.h>
  29
  30 #include "udlfb.h"
  31
  32 static struct fb_fix_screeninfo dlfb_fix = {
  33         .id =           "udlfb",
  34         .type =         FB_TYPE_PACKED_PIXELS,
  35         .visual =       FB_VISUAL_TRUECOLOR,
  36         .xpanstep =     0,
  37         .ypanstep =     0,
  38         .ywrapstep =    0,
  39         .accel =        FB_ACCEL_NONE,
  40 };
  41
  42 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
  43 #ifdef FBINFO_VIRTFB
  44                 FBINFO_VIRTFB |
  45 #endif
  46                 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
  47                 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
  48
  49 /*
  50  * There are many DisplayLink-based products, all with unique PIDs. We are able
  51  * to support all volume ones (circa 2009) with a single driver, so we match
  52  * globally on VID. TODO: Probe() needs to detect when we might be running
  53  * "future" chips, and bail on those, so a compatible driver can match.
  54  */
  55 static struct usb_device_id id_table[] = {
  56         {.idVendor = 0x17e9, .match_flags = USB_DEVICE_ID_MATCH_VENDOR,},
  57         {},
  58 };
  59 MODULE_DEVICE_TABLE(usb, id_table);
  60
  61 /* module options */
  62 static int console;   /* Optionally allow fbcon to consume first framebuffer */
  63 static int fb_defio;  /* Optionally enable experimental fb_defio mmap support */
  64
  65 /* dlfb keeps a list of urbs for efficient bulk transfers */
  66 static void dlfb_urb_completion(struct urb *urb);
  67 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
  68 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
  69 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
  70 static void dlfb_free_urb_list(struct dlfb_data *dev);
  71
  72 /*
  73  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  74  * All operations are written to buffers which then later get sent to device
  75  */
  76 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
  77 {
  78         *buf++ = 0xAF;
  79         *buf++ = 0x20;
  80         *buf++ = reg;
  81         *buf++ = val;
  82         return buf;
  83 }
  84
  85 static char *dlfb_vidreg_lock(char *buf)
  86 {
  87         return dlfb_set_register(buf, 0xFF, 0x00);
  88 }
  89
  90 static char *dlfb_vidreg_unlock(char *buf)
  91 {
  92         return dlfb_set_register(buf, 0xFF, 0xFF);
  93 }
  94
  95 /*
  96  * On/Off for driving the DisplayLink framebuffer to the display
  97  *  0x00 H and V sync on
  98  *  0x01 H and V sync off (screen blank but powered)
  99  *  0x07 DPMS powerdown (requires modeset to come back)
 100  */
 101 static char *dlfb_enable_hvsync(char *buf, bool enable)
 102 {
 103         if (enable)
 104                 return dlfb_set_register(buf, 0x1F, 0x00);
 105         else
 106                 return dlfb_set_register(buf, 0x1F, 0x07);
 107 }
 108
 109 static char *dlfb_set_color_depth(char *buf, u8 selection)
 110 {
 111         return dlfb_set_register(buf, 0x00, selection);
 112 }
 113
 114 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 115 {
 116         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 117         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 118         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 119         return dlfb_set_register(wrptr, 0x22, base);
 120 }
 121
 122 /*
 123  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 124  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 125  */
 126 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 127 {
 128         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 129         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 130         return dlfb_set_register(wrptr, 0x28, base);
 131 }
 132
 133 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 134 {
 135         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 136         return dlfb_set_register(wrptr, reg+1, value);
 137 }
 138
 139 /*
 140  * This is kind of weird because the controller takes some
 141  * register values in a different byte order than other registers.
 142  */
 143 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 144 {
 145         wrptr = dlfb_set_register(wrptr, reg, value);
 146         return dlfb_set_register(wrptr, reg+1, value >> 8);
 147 }
 148
 149 /*
 150  * LFSR is linear feedback shift register. The reason we have this is
 151  * because the display controller needs to minimize the clock depth of
 152  * various counters used in the display path. So this code reverses the
 153  * provided value into the lfsr16 value by counting backwards to get
 154  * the value that needs to be set in the hardware comparator to get the
 155  * same actual count. This makes sense once you read above a couple of
 156  * times and think about it from a hardware perspective.
 157  */
 158 static u16 dlfb_lfsr16(u16 actual_count)
 159 {
 160         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 161
 162         while (actual_count--) {
 163                 lv =     ((lv << 1) |
 164                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 165                         & 0xFFFF;
 166         }
 167
 168         return (u16) lv;
 169 }
 170
 171 /*
 172  * This does LFSR conversion on the value that is to be written.
 173  * See LFSR explanation above for more detail.
 174  */
 175 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 176 {
 177         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 178 }
 179
 180 /*
 181  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 182  * details and converts them into the DisplayLink equivalent register commands.
 183  */
 184 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 185 {
 186         u16 xds, yds;
 187         u16 xde, yde;
 188         u16 yec;
 189
 190         /* x display start */
 191         xds = var->left_margin + var->hsync_len;
 192         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 193         /* x display end */
 194         xde = xds + var->xres;
 195         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 196
 197         /* y display start */
 198         yds = var->upper_margin + var->vsync_len;
 199         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 200         /* y display end */
 201         yde = yds + var->yres;
 202         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 203
 204         /* x end count is active + blanking - 1 */
 205         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 206                         xde + var->right_margin - 1);
 207
 208         /* libdlo hardcodes hsync start to 1 */
 209         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 210
 211         /* hsync end is width of sync pulse + 1 */
 212         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 213
 214         /* hpixels is active pixels */
 215         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 216
 217         /* yendcount is vertical active + vertical blanking */
 218         yec = var->yres + var->upper_margin + var->lower_margin +
 219                         var->vsync_len;
 220         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 221
 222         /* libdlo hardcodes vsync start to 0 */
 223         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 224
 225         /* vsync end is width of vsync pulse */
 226         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 227
 228         /* vpixels is active pixels */
 229         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 230
 231         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 232         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 233                         200*1000*1000/var->pixclock);
 234
 235         return wrptr;
 236 }
 237
 238 /*
 239  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 240  * and then generates the appropriate command sequence that then drives the
 241  * display controller.
 242  */
 243 static int dlfb_set_video_mode(struct dlfb_data *dev,
 244                                 struct fb_var_screeninfo *var)
 245 {
 246         char *buf;
 247         char *wrptr;
 248         int retval = 0;
 249         int writesize;
 250         struct urb *urb;
 251
 252         if (!atomic_read(&dev->usb_active))
 253                 return -EPERM;
 254
 255         urb = dlfb_get_urb(dev);
 256         if (!urb)
 257                 return -ENOMEM;
 258
 259         buf = (char *) urb->transfer_buffer;
 260
 261         /*
 262         * This first section has to do with setting the base address on the
 263         * controller * associated with the display. There are 2 base
 264         * pointers, currently, we only * use the 16 bpp segment.
 265         */
 266         wrptr = dlfb_vidreg_lock(buf);
 267         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 268         /* set base for 16bpp segment to 0 */
 269         wrptr = dlfb_set_base16bpp(wrptr, 0);
 270         /* set base for 8bpp segment to end of fb */
 271         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
 272
 273         wrptr = dlfb_set_vid_cmds(wrptr, var);
 274         wrptr = dlfb_enable_hvsync(wrptr, true);
 275         wrptr = dlfb_vidreg_unlock(wrptr);
 276
 277         writesize = wrptr - buf;
 278
 279         retval = dlfb_submit_urb(dev, urb, writesize);
 280
 281         return retval;
 282 }
 283
 284 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 285 {
 286         unsigned long start = vma->vm_start;
 287         unsigned long size = vma->vm_end - vma->vm_start;
 288         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 289         unsigned long page, pos;
 290
 291         if (offset + size > info->fix.smem_len)
 292                 return -EINVAL;
 293
 294         pos = (unsigned long)info->fix.smem_start + offset;
 295
 296         dl_notice("mmap() framebuffer addr:%lu size:%lu\n",
 297                   pos, size);
 298
 299         while (size > 0) {
 300                 page = vmalloc_to_pfn((void *)pos);
 301                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 302                         return -EAGAIN;
 303
 304                 start += PAGE_SIZE;
 305                 pos += PAGE_SIZE;
 306                 if (size > PAGE_SIZE)
 307                         size -= PAGE_SIZE;
 308                 else
 309                         size = 0;
 310         }
 311
 312         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 313         return 0;
 314 }
 315
 316 /*
 317  * Trims identical data from front and back of line
 318  * Sets new front buffer address and width
 319  * And returns byte count of identical pixels
 320  * Assumes CPU natural alignment (unsigned long)
 321  * for back and front buffer ptrs and width
 322  */
 323 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 324 {
 325         int j, k;
 326         const unsigned long *back = (const unsigned long *) bback;
 327         const unsigned long *front = (const unsigned long *) *bfront;
 328         const int width = *width_bytes / sizeof(unsigned long);
 329         int identical = width;
 330         int start = width;
 331         int end = width;
 332
 333         prefetch((void *) front);
 334         prefetch((void *) back);
 335
 336         for (j = 0; j < width; j++) {
 337                 if (back[j] != front[j]) {
 338                         start = j;
 339                         break;
 340                 }
 341         }
 342
 343         for (k = width - 1; k > j; k--) {
 344                 if (back[k] != front[k]) {
 345                         end = k+1;
 346                         break;
 347                 }
 348         }
 349
 350         identical = start + (width - end);
 351         *bfront = (u8 *) &front[start];
 352         *width_bytes = (end - start) * sizeof(unsigned long);
 353
 354         return identical * sizeof(unsigned long);
 355 }
 356
 357 /*
 358  * Render a command stream for an encoded horizontal line segment of pixels.
 359  *
 360  * A command buffer holds several commands.
 361  * It always begins with a fresh command header
 362  * (the protocol doesn't require this, but we enforce it to allow
 363  * multiple buffers to be potentially encoded and sent in parallel).
 364  * A single command encodes one contiguous horizontal line of pixels
 365  *
 366  * The function relies on the client to do all allocation, so that
 367  * rendering can be done directly to output buffers (e.g. USB URBs).
 368  * The function fills the supplied command buffer, providing information
 369  * on where it left off, so the client may call in again with additional
 370  * buffers if the line will take several buffers to complete.
 371  *
 372  * A single command can transmit a maximum of 256 pixels,
 373  * regardless of the compression ratio (protocol design limit).
 374  * To the hardware, 0 for a size byte means 256
 375  *
 376  * Rather than 256 pixel commands which are either rl or raw encoded,
 377  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 378  * This has a slightly larger header overhead, but produces more even results.
 379  * It also processes all data (read and write) in a single pass.
 380  * Performance benchmarks of common cases show it having just slightly better
 381  * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
 382  * But for very rl friendly data, will compress not quite as well.
 383  */
 384 static void dlfb_compress_hline(
 385         const uint16_t **pixel_start_ptr,
 386         const uint16_t *const pixel_end,
 387         uint32_t *device_address_ptr,
 388         uint8_t **command_buffer_ptr,
 389         const uint8_t *const cmd_buffer_end)
 390 {
 391         const uint16_t *pixel = *pixel_start_ptr;
 392         uint32_t dev_addr  = *device_address_ptr;
 393         uint8_t *cmd = *command_buffer_ptr;
 394         const int bpp = 2;
 395
 396         while ((pixel_end > pixel) &&
 397                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 398                 uint8_t *raw_pixels_count_byte = 0;
 399                 uint8_t *cmd_pixels_count_byte = 0;
 400                 const uint16_t *raw_pixel_start = 0;
 401                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
 402
 403                 prefetchw((void *) cmd); /* pull in one cache line at least */
 404
 405                 *cmd++ = 0xAF;
 406                 *cmd++ = 0x6B;
 407                 *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
 408                 *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
 409                 *cmd++ = (uint8_t) ((dev_addr) & 0xFF);
 410
 411                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
 412                 cmd_pixel_start = pixel;
 413
 414                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
 415                 raw_pixel_start = pixel;
 416
 417                 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
 418                         min((int)(pixel_end - pixel),
 419                             (int)(cmd_buffer_end - cmd) / bpp));
 420
 421                 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
 422
 423                 while (pixel < cmd_pixel_end) {
 424                         const uint16_t * const repeating_pixel = pixel;
 425
 426                         *(uint16_t *)cmd = cpu_to_be16p(pixel);
 427                         cmd += 2;
 428                         pixel++;
 429
 430                         if (unlikely((pixel < cmd_pixel_end) &&
 431                                      (*pixel == *repeating_pixel))) {
 432                                 /* go back and fill in raw pixel count */
 433                                 *raw_pixels_count_byte = ((repeating_pixel -
 434                                                 raw_pixel_start) + 1) & 0xFF;
 435
 436                                 while ((pixel < cmd_pixel_end)
 437                                        && (*pixel == *repeating_pixel)) {
 438                                         pixel++;
 439                                 }
 440
 441                                 /* immediately after raw data is repeat byte */
 442                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
 443
 444                                 /* Then start another raw pixel span */
 445                                 raw_pixel_start = pixel;
 446                                 raw_pixels_count_byte = cmd++;
 447                         }
 448                 }
 449
 450                 if (pixel > raw_pixel_start) {
 451                         /* finalize last RAW span */
 452                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
 453                 }
 454
 455                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
 456                 dev_addr += (pixel - cmd_pixel_start) * bpp;
 457         }
 458
 459         if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
 460                 /* Fill leftover bytes with no-ops */
 461                 if (cmd_buffer_end > cmd)
 462                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
 463                 cmd = (uint8_t *) cmd_buffer_end;
 464         }
 465
 466         *command_buffer_ptr = cmd;
 467         *pixel_start_ptr = pixel;
 468         *device_address_ptr = dev_addr;
 469
 470         return;
 471 }
 472
 473 /*
 474  * There are 3 copies of every pixel: The front buffer that the fbdev
 475  * client renders to, the actual framebuffer across the USB bus in hardware
 476  * (that we can only write to, slowly, and can never read), and (optionally)
 477  * our shadow copy that tracks what's been sent to that hardware buffer.
 478  */
 479 static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
 480                               const char *front, char **urb_buf_ptr,
 481                               u32 byte_offset, u32 byte_width,
 482                               int *ident_ptr, int *sent_ptr)
 483 {
 484         const u8 *line_start, *line_end, *next_pixel;
 485         u32 dev_addr = dev->base16 + byte_offset;
 486         struct urb *urb = *urb_ptr;
 487         u8 *cmd = *urb_buf_ptr;
 488         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
 489
 490         line_start = (u8 *) (front + byte_offset);
 491         next_pixel = line_start;
 492         line_end = next_pixel + byte_width;
 493
 494         if (dev->backing_buffer) {
 495                 int offset;
 496                 const u8 *back_start = (u8 *) (dev->backing_buffer
 497                                                 + byte_offset);
 498
 499                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
 500                         &byte_width);
 501
 502                 offset = next_pixel - line_start;
 503                 line_end = next_pixel + byte_width;
 504                 dev_addr += offset;
 505                 back_start += offset;
 506                 line_start += offset;
 507
 508                 memcpy((char *)back_start, (char *) line_start,
 509                        byte_width);
 510         }
 511
 512         while (next_pixel < line_end) {
 513
 514                 dlfb_compress_hline((const uint16_t **) &next_pixel,
 515                              (const uint16_t *) line_end, &dev_addr,
 516                         (u8 **) &cmd, (u8 *) cmd_end);
 517
 518                 if (cmd >= cmd_end) {
 519                         int len = cmd - (u8 *) urb->transfer_buffer;
 520                         if (dlfb_submit_urb(dev, urb, len))
 521                                 return 1; /* lost pixels is set */
 522                         *sent_ptr += len;
 523                         urb = dlfb_get_urb(dev);
 524                         if (!urb)
 525                                 return 1; /* lost_pixels is set */
 526                         *urb_ptr = urb;
 527                         cmd = urb->transfer_buffer;
 528                         cmd_end = &cmd[urb->transfer_buffer_length];
 529                 }
 530         }
 531
 532         *urb_buf_ptr = cmd;
 533
 534         return 0;
 535 }
 536
 537 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
 538                int width, int height, char *data)
 539 {
 540         int i, ret;
 541         char *cmd;
 542         cycles_t start_cycles, end_cycles;
 543         int bytes_sent = 0;
 544         int bytes_identical = 0;
 545         struct urb *urb;
 546         int aligned_x;
 547
 548         start_cycles = get_cycles();
 549
 550         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 551         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 552         x = aligned_x;
 553
 554         if ((width <= 0) ||
 555             (x + width > dev->info->var.xres) ||
 556             (y + height > dev->info->var.yres))
 557                 return -EINVAL;
 558
 559         if (!atomic_read(&dev->usb_active))
 560                 return 0;
 561
 562         urb = dlfb_get_urb(dev);
 563         if (!urb)
 564                 return 0;
 565         cmd = urb->transfer_buffer;
 566
 567         for (i = y; i < y + height ; i++) {
 568                 const int line_offset = dev->info->fix.line_length * i;
 569                 const int byte_offset = line_offset + (x * BPP);
 570
 571                 if (dlfb_render_hline(dev, &urb,
 572                                       (char *) dev->info->fix.smem_start,
 573                                       &cmd, byte_offset, width * BPP,
 574                                       &bytes_identical, &bytes_sent))
 575                         goto error;
 576         }
 577
 578         if (cmd > (char *) urb->transfer_buffer) {
 579                 /* Send partial buffer remaining before exiting */
 580                 int len = cmd - (char *) urb->transfer_buffer;
 581                 ret = dlfb_submit_urb(dev, urb, len);
 582                 bytes_sent += len;
 583         } else
 584                 dlfb_urb_completion(urb);
 585
 586 error:
 587         atomic_add(bytes_sent, &dev->bytes_sent);
 588         atomic_add(bytes_identical, &dev->bytes_identical);
 589         atomic_add(width*height*2, &dev->bytes_rendered);
 590         end_cycles = get_cycles();
 591         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 592                     >> 10)), /* Kcycles */
 593                    &dev->cpu_kcycles_used);
 594
 595         return 0;
 596 }
 597
 598 static ssize_t dlfb_ops_read(struct fb_info *info, char __user *buf,
 599                          size_t count, loff_t *ppos)
 600 {
 601         ssize_t result = -ENOSYS;
 602
 603 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 604         result = fb_sys_read(info, buf, count, ppos);
 605 #endif
 606
 607         return result;
 608 }
 609
 610 /*
 611  * Path triggered by usermode clients who write to filesystem
 612  * e.g. cat filename > /dev/fb1
 613  * Not used by X Windows or text-mode console. But useful for testing.
 614  * Slow because of extra copy and we must assume all pixels dirty.
 615  */
 616 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
 617                           size_t count, loff_t *ppos)
 618 {
 619         ssize_t result = -ENOSYS;
 620         struct dlfb_data *dev = info->par;
 621         u32 offset = (u32) *ppos;
 622
 623 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 624
 625         result = fb_sys_write(info, buf, count, ppos);
 626
 627         if (result > 0) {
 628                 int start = max((int)(offset / info->fix.line_length) - 1, 0);
 629                 int lines = min((u32)((result / info->fix.line_length) + 1),
 630                                 (u32)info->var.yres);
 631
 632                 dlfb_handle_damage(dev, 0, start, info->var.xres,
 633                         lines, info->screen_base);
 634         }
 635 #endif
 636
 637         return result;
 638 }
 639
 640 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 641 static void dlfb_ops_copyarea(struct fb_info *info,
 642                                 const struct fb_copyarea *area)
 643 {
 644
 645         struct dlfb_data *dev = info->par;
 646
 647 #if defined CONFIG_FB_SYS_COPYAREA || defined CONFIG_FB_SYS_COPYAREA_MODULE
 648
 649         sys_copyarea(info, area);
 650
 651         dlfb_handle_damage(dev, area->dx, area->dy,
 652                         area->width, area->height, info->screen_base);
 653 #endif
 654
 655 }
 656
 657 static void dlfb_ops_imageblit(struct fb_info *info,
 658                                 const struct fb_image *image)
 659 {
 660         struct dlfb_data *dev = info->par;
 661
 662 #if defined CONFIG_FB_SYS_IMAGEBLIT || defined CONFIG_FB_SYS_IMAGEBLIT_MODULE
 663
 664         sys_imageblit(info, image);
 665
 666         dlfb_handle_damage(dev, image->dx, image->dy,
 667                         image->width, image->height, info->screen_base);
 668
 669 #endif
 670
 671 }
 672
 673 static void dlfb_ops_fillrect(struct fb_info *info,
 674                           const struct fb_fillrect *rect)
 675 {
 676         struct dlfb_data *dev = info->par;
 677
 678 #if defined CONFIG_FB_SYS_FILLRECT || defined CONFIG_FB_SYS_FILLRECT_MODULE
 679
 680         sys_fillrect(info, rect);
 681
 682         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
 683                               rect->height, info->screen_base);
 684 #endif
 685
 686 }
 687
 688 #ifdef CONFIG_FB_DEFERRED_IO
 689 /*
 690  * NOTE: fb_defio.c is holding info->fbdefio.mutex
 691  *   Touching ANY framebuffer memory that triggers a page fault
 692  *   in fb_defio will cause a deadlock, when it also tries to
 693  *   grab the same mutex.
 694  */
 695 static void dlfb_dpy_deferred_io(struct fb_info *info,
 696                                 struct list_head *pagelist)
 697 {
 698         struct page *cur;
 699         struct fb_deferred_io *fbdefio = info->fbdefio;
 700         struct dlfb_data *dev = info->par;
 701         struct urb *urb;
 702         char *cmd;
 703         cycles_t start_cycles, end_cycles;
 704         int bytes_sent = 0;
 705         int bytes_identical = 0;
 706         int bytes_rendered = 0;
 707
 708         if (!fb_defio)
 709                 return;
 710
 711         if (!atomic_read(&dev->usb_active))
 712                 return;
 713
 714         start_cycles = get_cycles();
 715
 716         urb = dlfb_get_urb(dev);
 717         if (!urb)
 718                 return;
 719
 720         cmd = urb->transfer_buffer;
 721
 722         /* walk the written page list and render each to device */
 723         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
 724
 725                 if (dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
 726                                   &cmd, cur->index << PAGE_SHIFT,
 727                                   PAGE_SIZE, &bytes_identical, &bytes_sent))
 728                         goto error;
 729                 bytes_rendered += PAGE_SIZE;
 730         }
 731
 732         if (cmd > (char *) urb->transfer_buffer) {
 733                 /* Send partial buffer remaining before exiting */
 734                 int len = cmd - (char *) urb->transfer_buffer;
 735                 dlfb_submit_urb(dev, urb, len);
 736                 bytes_sent += len;
 737         } else
 738                 dlfb_urb_completion(urb);
 739
 740 error:
 741         atomic_add(bytes_sent, &dev->bytes_sent);
 742         atomic_add(bytes_identical, &dev->bytes_identical);
 743         atomic_add(bytes_rendered, &dev->bytes_rendered);
 744         end_cycles = get_cycles();
 745         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 746                     >> 10)), /* Kcycles */
 747                    &dev->cpu_kcycles_used);
 748 }
 749
 750 #endif
 751
 752 static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
 753 {
 754         int i;
 755         int ret;
 756         char *rbuf;
 757
 758         rbuf = kmalloc(2, GFP_KERNEL);
 759         if (!rbuf)
 760                 return 0;
 761
 762         for (i = 0; i < len; i++) {
 763                 ret = usb_control_msg(dev->udev,
 764                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 765                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 766                                     HZ);
 767                 if (ret < 1) {
 768                         dl_err("Read EDID byte %d failed err %x\n", i, ret);
 769                         i--;
 770                         break;
 771                 }
 772                 edid[i] = rbuf[1];
 773         }
 774
 775         kfree(rbuf);
 776
 777         return i;
 778 }
 779
 780 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 781                                 unsigned long arg)
 782 {
 783
 784         struct dlfb_data *dev = info->par;
 785         struct dloarea *area = NULL;
 786
 787         if (!atomic_read(&dev->usb_active))
 788                 return 0;
 789
 790         /* TODO: Update X server to get this from sysfs instead */
 791         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 792                 char *edid = (char *)arg;
 793                 if (copy_to_user(edid, dev->edid, dev->edid_size))
 794                         return -EFAULT;
 795                 return 0;
 796         }
 797
 798         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 799         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 800
 801                 /*
 802                  * If we have a damage-aware client, turn fb_defio "off"
 803                  * To avoid perf imact of unecessary page fault handling.
 804                  * Done by resetting the delay for this fb_info to a very
 805                  * long period. Pages will become writable and stay that way.
 806                  * Reset to normal value when all clients have closed this fb.
 807                  */
 808                 if (info->fbdefio)
 809                         info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
 810
 811                 area = (struct dloarea *)arg;
 812
 813                 if (area->x < 0)
 814                         area->x = 0;
 815
 816                 if (area->x > info->var.xres)
 817                         area->x = info->var.xres;
 818
 819                 if (area->y < 0)
 820                         area->y = 0;
 821
 822                 if (area->y > info->var.yres)
 823                         area->y = info->var.yres;
 824
 825                 dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
 826                            info->screen_base);
 827         }
 828
 829         return 0;
 830 }
 831
 832 /* taken from vesafb */
 833 static int
 834 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 835                unsigned blue, unsigned transp, struct fb_info *info)
 836 {
 837         int err = 0;
 838
 839         if (regno >= info->cmap.len)
 840                 return 1;
 841
 842         if (regno < 16) {
 843                 if (info->var.red.offset == 10) {
 844                         /* 1:5:5:5 */
 845                         ((u32 *) (info->pseudo_palette))[regno] =
 846                             ((red & 0xf800) >> 1) |
 847                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 848                 } else {
 849                         /* 0:5:6:5 */
 850                         ((u32 *) (info->pseudo_palette))[regno] =
 851                             ((red & 0xf800)) |
 852                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 853                 }
 854         }
 855
 856         return err;
 857 }
 858
 859 /*
 860  * It's common for several clients to have framebuffer open simultaneously.
 861  * e.g. both fbcon and X. Makes things interesting.
 862  * Assumes caller is holding info->lock (for open and release at least)
 863  */
 864 static int dlfb_ops_open(struct fb_info *info, int user)
 865 {
 866         struct dlfb_data *dev = info->par;
 867
 868         /*
 869          * fbcon aggressively connects to first framebuffer it finds,
 870          * preventing other clients (X) from working properly. Usually
 871          * not what the user wants. Fail by default with option to enable.
 872          */
 873         if ((user == 0) & (!console))
 874                 return -EBUSY;
 875
 876         /* If the USB device is gone, we don't accept new opens */
 877         if (dev->virtualized)
 878                 return -ENODEV;
 879
 880         dev->fb_count++;
 881
 882         kref_get(&dev->kref);
 883
 884 #ifdef CONFIG_FB_DEFERRED_IO
 885         if (fb_defio && (info->fbdefio == NULL)) {
 886                 /* enable defio at last moment if not disabled by client */
 887
 888                 struct fb_deferred_io *fbdefio;
 889
 890                 fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
 891
 892                 if (fbdefio) {
 893                         fbdefio->delay = DL_DEFIO_WRITE_DELAY;
 894                         fbdefio->deferred_io = dlfb_dpy_deferred_io;
 895                 }
 896
 897                 info->fbdefio = fbdefio;
 898                 fb_deferred_io_init(info);
 899         }
 900 #endif
 901
 902         dl_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 903             info->node, user, info, dev->fb_count);
 904
 905         return 0;
 906 }
 907
 908 /*
 909  * Called when all client interfaces to start transactions have been disabled,
 910  * and all references to our device instance (dlfb_data) are released.
 911  * Every transaction must have a reference, so we know are fully spun down
 912  */
 913 static void dlfb_free(struct kref *kref)
 914 {
 915         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 916
 917         /* this function will wait for all in-flight urbs to complete */
 918         if (dev->urbs.count > 0)
 919                 dlfb_free_urb_list(dev);
 920
 921         if (dev->backing_buffer)
 922                 vfree(dev->backing_buffer);
 923
 924         kfree(dev->edid);
 925
 926         dl_warn("freeing dlfb_data %p\n", dev);
 927
 928         kfree(dev);
 929 }
 930
 931 static void dlfb_release_urb_work(struct work_struct *work)
 932 {
 933         struct urb_node *unode = container_of(work, struct urb_node,
 934                                               release_urb_work.work);
 935
 936         up(&unode->dev->urbs.limit_sem);
 937 }
 938
 939 static void dlfb_free_framebuffer_work(struct work_struct *work)
 940 {
 941         struct dlfb_data *dev = container_of(work, struct dlfb_data,
 942                                              free_framebuffer_work.work);
 943         struct fb_info *info = dev->info;
 944         int node = info->node;
 945
 946         unregister_framebuffer(info);
 947
 948         if (info->cmap.len != 0)
 949                 fb_dealloc_cmap(&info->cmap);
 950         if (info->monspecs.modedb)
 951                 fb_destroy_modedb(info->monspecs.modedb);
 952         if (info->screen_base)
 953                 vfree(info->screen_base);
 954
 955         fb_destroy_modelist(&info->modelist);
 956
 957         dev->info = 0;
 958
 959         /* Assume info structure is freed after this point */
 960         framebuffer_release(info);
 961
 962         dl_warn("fb_info for /dev/fb%d has been freed\n", node);
 963
 964         /* ref taken in probe() as part of registering framebfufer */
 965         kref_put(&dev->kref, dlfb_free);
 966 }
 967
 968 /*
 969  * Assumes caller is holding info->lock mutex (for open and release at least)
 970  */
 971 static int dlfb_ops_release(struct fb_info *info, int user)
 972 {
 973         struct dlfb_data *dev = info->par;
 974
 975         dev->fb_count--;
 976
 977         /* We can't free fb_info here - fbmem will touch it when we return */
 978         if (dev->virtualized && (dev->fb_count == 0))
 979                 schedule_delayed_work(&dev->free_framebuffer_work, HZ);
 980
 981 #ifdef CONFIG_FB_DEFERRED_IO
 982         if ((dev->fb_count == 0) && (info->fbdefio)) {
 983                 fb_deferred_io_cleanup(info);
 984                 kfree(info->fbdefio);
 985                 info->fbdefio = NULL;
 986                 info->fbops->fb_mmap = dlfb_ops_mmap;
 987         }
 988 #endif
 989
 990         dl_warn("released /dev/fb%d user=%d count=%d\n",
 991                   info->node, user, dev->fb_count);
 992
 993         kref_put(&dev->kref, dlfb_free);
 994
 995         return 0;
 996 }
 997
 998 /*
 999  * Check whether a video mode is supported by the DisplayLink chip
1000  * We start from monitor's modes, so don't need to filter that here
1001  */
1002 static int dlfb_is_valid_mode(struct fb_videomode *mode,
1003                 struct fb_info *info)
1004 {
1005         struct dlfb_data *dev = info->par;
1006
1007         if (mode->xres * mode->yres > dev->sku_pixel_limit) {
1008                 dl_warn("%dx%d beyond chip capabilities\n",
1009                        mode->xres, mode->yres);
1010                 return 0;
1011         }
1012
1013         dl_info("%dx%d valid mode\n", mode->xres, mode->yres);
1014
1015         return 1;
1016 }
1017
1018 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1019 {
1020         const struct fb_bitfield red = { 11, 5, 0 };
1021         const struct fb_bitfield green = { 5, 6, 0 };
1022         const struct fb_bitfield blue = { 0, 5, 0 };
1023
1024         var->bits_per_pixel = 16;
1025         var->red = red;
1026         var->green = green;
1027         var->blue = blue;
1028 }
1029
1030 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1031                                 struct fb_info *info)
1032 {
1033         struct fb_videomode mode;
1034
1035         /* TODO: support dynamically changing framebuffer size */
1036         if ((var->xres * var->yres * 2) > info->fix.smem_len)
1037                 return -EINVAL;
1038
1039         /* set device-specific elements of var unrelated to mode */
1040         dlfb_var_color_format(var);
1041
1042         fb_var_to_videomode(&mode, var);
1043
1044         if (!dlfb_is_valid_mode(&mode, info))
1045                 return -EINVAL;
1046
1047         return 0;
1048 }
1049
1050 static int dlfb_ops_set_par(struct fb_info *info)
1051 {
1052         struct dlfb_data *dev = info->par;
1053         int result;
1054         u16 *pix_framebuffer;
1055         int i;
1056
1057         dl_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
1058
1059         result = dlfb_set_video_mode(dev, &info->var);
1060
1061         if ((result == 0) && (dev->fb_count == 0)) {
1062
1063                 /* paint greenscreen */
1064
1065                 pix_framebuffer = (u16 *) info->screen_base;
1066                 for (i = 0; i < info->fix.smem_len / 2; i++)
1067                         pix_framebuffer[i] = 0x37e6;
1068
1069                 dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1070                                    info->screen_base);
1071         }
1072
1073         return result;
1074 }
1075
1076 /*
1077  * In order to come back from full DPMS off, we need to set the mode again
1078  */
1079 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1080 {
1081         struct dlfb_data *dev = info->par;
1082
1083         if (blank_mode != FB_BLANK_UNBLANK) {
1084                 char *bufptr;
1085                 struct urb *urb;
1086
1087                 urb = dlfb_get_urb(dev);
1088                 if (!urb)
1089                         return 0;
1090
1091                 bufptr = (char *) urb->transfer_buffer;
1092                 bufptr = dlfb_vidreg_lock(bufptr);
1093                 bufptr = dlfb_enable_hvsync(bufptr, false);
1094                 bufptr = dlfb_vidreg_unlock(bufptr);
1095
1096                 dlfb_submit_urb(dev, urb, bufptr -
1097                                 (char *) urb->transfer_buffer);
1098         } else {
1099                 dlfb_set_video_mode(dev, &info->var);
1100         }
1101
1102         return 0;
1103 }
1104
1105 static struct fb_ops dlfb_ops = {
1106         .owner = THIS_MODULE,
1107         .fb_read = dlfb_ops_read,
1108         .fb_write = dlfb_ops_write,
1109         .fb_setcolreg = dlfb_ops_setcolreg,
1110         .fb_fillrect = dlfb_ops_fillrect,
1111         .fb_copyarea = dlfb_ops_copyarea,
1112         .fb_imageblit = dlfb_ops_imageblit,
1113         .fb_mmap = dlfb_ops_mmap,
1114         .fb_ioctl = dlfb_ops_ioctl,
1115         .fb_open = dlfb_ops_open,
1116         .fb_release = dlfb_ops_release,
1117         .fb_blank = dlfb_ops_blank,
1118         .fb_check_var = dlfb_ops_check_var,
1119         .fb_set_par = dlfb_ops_set_par,
1120 };
1121
1122
1123 /*
1124  * Assumes &info->lock held by caller
1125  * Assumes no active clients have framebuffer open
1126  */
1127 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1128 {
1129         int retval = -ENOMEM;
1130         int old_len = info->fix.smem_len;
1131         int new_len;
1132         unsigned char *old_fb = info->screen_base;
1133         unsigned char *new_fb;
1134         unsigned char *new_back;
1135
1136         dl_warn("Reallocating framebuffer. Addresses will change!\n");
1137
1138         new_len = info->fix.line_length * info->var.yres;
1139
1140         if (PAGE_ALIGN(new_len) > old_len) {
1141                 /*
1142                  * Alloc system memory for virtual framebuffer
1143                  */
1144                 new_fb = vmalloc(new_len);
1145                 if (!new_fb) {
1146                         dl_err("Virtual framebuffer alloc failed\n");
1147                         goto error;
1148                 }
1149
1150                 if (info->screen_base) {
1151                         memcpy(new_fb, old_fb, old_len);
1152                         vfree(info->screen_base);
1153                 }
1154
1155                 info->screen_base = new_fb;
1156                 info->fix.smem_len = PAGE_ALIGN(new_len);
1157                 info->fix.smem_start = (unsigned long) new_fb;
1158                 info->flags = udlfb_info_flags;
1159
1160                 /*
1161                  * Second framebuffer copy to mirror the framebuffer state
1162                  * on the physical USB device. We can function without this.
1163                  * But with imperfect damage info we may send pixels over USB
1164                  * that were, in fact, unchanged - wasting limited USB bandwidth
1165                  */
1166                 new_back = vmalloc(new_len);
1167                 if (!new_back)
1168                         dl_info("No shadow/backing buffer allcoated\n");
1169                 else {
1170                         if (dev->backing_buffer)
1171                                 vfree(dev->backing_buffer);
1172                         dev->backing_buffer = new_back;
1173                         memset(dev->backing_buffer, 0, new_len);
1174                 }
1175         }
1176
1177         retval = 0;
1178
1179 error:
1180         return retval;
1181 }
1182
1183 /*
1184  * 1) Get EDID from hw, or use sw default
1185  * 2) Parse into various fb_info structs
1186  * 3) Allocate virtual framebuffer memory to back highest res mode
1187  *
1188  * Parses EDID into three places used by various parts of fbdev:
1189  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1190  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1191  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1192  *
1193  * If EDID is not readable/valid, then modelist is all VESA modes,
1194  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1195  * Returns 0 if successful
1196  */
1197 static int dlfb_setup_modes(struct dlfb_data *dev,
1198                            struct fb_info *info,
1199                            char *default_edid, size_t default_edid_size)
1200 {
1201         int i;
1202         const struct fb_videomode *default_vmode = NULL;
1203         int result = 0;
1204         char *edid;
1205         int tries = 3;
1206
1207         if (info->dev) /* only use mutex if info has been registered */
1208                 mutex_lock(&info->lock);
1209
1210         edid = kmalloc(MAX_EDID_SIZE, GFP_KERNEL);
1211         if (!edid) {
1212                 result = -ENOMEM;
1213                 goto error;
1214         }
1215
1216         fb_destroy_modelist(&info->modelist);
1217         memset(&info->monspecs, 0, sizeof(info->monspecs));
1218
1219         /*
1220          * Try to (re)read EDID from hardware first
1221          * EDID data may return, but not parse as valid
1222          * Try again a few times, in case of e.g. analog cable noise
1223          */
1224         while (tries--) {
1225
1226                 i = dlfb_get_edid(dev, edid, MAX_EDID_SIZE);
1227
1228                 if (i >= MIN_EDID_SIZE)
1229                         fb_edid_to_monspecs(edid, &info->monspecs);
1230
1231                 if (info->monspecs.modedb_len > 0) {
1232                         dev->edid = edid;
1233                         dev->edid_size = i;
1234                         break;
1235                 }
1236         }
1237
1238         /* If that fails, use a previously returned EDID if available */
1239         if (info->monspecs.modedb_len == 0) {
1240
1241                 dl_err("Unable to get valid EDID from device/display\n");
1242
1243                 if (dev->edid) {
1244                         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1245                         if (info->monspecs.modedb_len > 0)
1246                                 dl_err("Using previously queried EDID\n");
1247                 }
1248         }
1249
1250         /* If that fails, use the default EDID we were handed */
1251         if (info->monspecs.modedb_len == 0) {
1252                 if (default_edid_size >= MIN_EDID_SIZE) {
1253                         fb_edid_to_monspecs(default_edid, &info->monspecs);
1254                         if (info->monspecs.modedb_len > 0) {
1255                                 memcpy(edid, default_edid, default_edid_size);
1256                                 dev->edid = edid;
1257                                 dev->edid_size = default_edid_size;
1258                                 dl_err("Using default/backup EDID\n");
1259                         }
1260                 }
1261         }
1262
1263         /* If we've got modes, let's pick a best default mode */
1264         if (info->monspecs.modedb_len > 0) {
1265
1266                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1267                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1268                                 fb_add_videomode(&info->monspecs.modedb[i],
1269                                         &info->modelist);
1270                         else /* if we've removed top/best mode */
1271                                 info->monspecs.misc &= ~FB_MISC_1ST_DETAIL;
1272                 }
1273
1274                 default_vmode = fb_find_best_display(&info->monspecs,
1275                                                      &info->modelist);
1276         }
1277
1278         /* If everything else has failed, fall back to safe default mode */
1279         if (default_vmode == NULL) {
1280
1281                 struct fb_videomode fb_vmode = {0};
1282
1283                 /*
1284                  * Add the standard VESA modes to our modelist
1285                  * Since we don't have EDID, there may be modes that
1286                  * overspec monitor and/or are incorrect aspect ratio, etc.
1287                  * But at least the user has a chance to choose
1288                  */
1289                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1290                         if (dlfb_is_valid_mode((struct fb_videomode *)
1291                                                 &vesa_modes[i], info))
1292                                 fb_add_videomode(&vesa_modes[i],
1293                                                  &info->modelist);
1294                 }
1295
1296                 /*
1297                  * default to resolution safe for projectors
1298                  * (since they are most common case without EDID)
1299                  */
1300                 fb_vmode.xres = 800;
1301                 fb_vmode.yres = 600;
1302                 fb_vmode.refresh = 60;
1303                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1304                                                      &info->modelist);
1305         }
1306
1307         /* If we have good mode and no active clients*/
1308         if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1309
1310                 fb_videomode_to_var(&info->var, default_vmode);
1311                 dlfb_var_color_format(&info->var);
1312
1313                 /*
1314                  * with mode size info, we can now alloc our framebuffer.
1315                  */
1316                 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1317                 info->fix.line_length = info->var.xres *
1318                         (info->var.bits_per_pixel / 8);
1319
1320                 result = dlfb_realloc_framebuffer(dev, info);
1321
1322         } else
1323                 result = -EINVAL;
1324
1325 error:
1326         if (edid && (dev->edid != edid))
1327                 kfree(edid);
1328
1329         if (info->dev)
1330                 mutex_unlock(&info->lock);
1331
1332         return result;
1333 }
1334
1335 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1336                                    struct device_attribute *a, char *buf) {
1337         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1338         struct dlfb_data *dev = fb_info->par;
1339         return snprintf(buf, PAGE_SIZE, "%u\n",
1340                         atomic_read(&dev->bytes_rendered));
1341 }
1342
1343 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1344                                    struct device_attribute *a, char *buf) {
1345         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1346         struct dlfb_data *dev = fb_info->par;
1347         return snprintf(buf, PAGE_SIZE, "%u\n",
1348                         atomic_read(&dev->bytes_identical));
1349 }
1350
1351 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1352                                    struct device_attribute *a, char *buf) {
1353         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1354         struct dlfb_data *dev = fb_info->par;
1355         return snprintf(buf, PAGE_SIZE, "%u\n",
1356                         atomic_read(&dev->bytes_sent));
1357 }
1358
1359 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1360                                    struct device_attribute *a, char *buf) {
1361         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1362         struct dlfb_data *dev = fb_info->par;
1363         return snprintf(buf, PAGE_SIZE, "%u\n",
1364                         atomic_read(&dev->cpu_kcycles_used));
1365 }
1366
1367 static ssize_t edid_show(
1368                         struct file *filp,
1369                         struct kobject *kobj, struct bin_attribute *a,
1370                          char *buf, loff_t off, size_t count) {
1371         struct device *fbdev = container_of(kobj, struct device, kobj);
1372         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1373         struct dlfb_data *dev = fb_info->par;
1374
1375         if (dev->edid == NULL)
1376                 return 0;
1377
1378         if ((off >= dev->edid_size) || (count > dev->edid_size))
1379                 return 0;
1380
1381         if (off + count > dev->edid_size)
1382                 count = dev->edid_size - off;
1383
1384         dl_info("sysfs edid copy %p to %p, %d bytes\n",
1385                 dev->edid, buf, (int) count);
1386
1387         memcpy(buf, dev->edid, count);
1388
1389         return count;
1390 }
1391
1392 static ssize_t edid_store(
1393                         struct file *filp,
1394                         struct kobject *kobj, struct bin_attribute *a,
1395                         char *src, loff_t src_off, size_t src_size) {
1396         struct device *fbdev = container_of(kobj, struct device, kobj);
1397         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1398         struct dlfb_data *dev = fb_info->par;
1399
1400         /* We only support write of entire EDID at once, no offset*/
1401         if ((src_size < MIN_EDID_SIZE) ||
1402             (src_size > MAX_EDID_SIZE) ||
1403             (src_off != 0))
1404                 return 0;
1405
1406         dlfb_setup_modes(dev, fb_info, src, src_size);
1407
1408         if (dev->edid && (memcmp(src, dev->edid, src_size) == 0)) {
1409                 dl_info("sysfs written EDID is new default\n");
1410                 dlfb_ops_set_par(fb_info);
1411                 return src_size;
1412         } else
1413                 return 0;
1414 }
1415
1416 static ssize_t metrics_reset_store(struct device *fbdev,
1417                            struct device_attribute *attr,
1418                            const char *buf, size_t count)
1419 {
1420         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1421         struct dlfb_data *dev = fb_info->par;
1422
1423         atomic_set(&dev->bytes_rendered, 0);
1424         atomic_set(&dev->bytes_identical, 0);
1425         atomic_set(&dev->bytes_sent, 0);
1426         atomic_set(&dev->cpu_kcycles_used, 0);
1427
1428         return count;
1429 }
1430
1431 static struct bin_attribute edid_attr = {
1432         .attr.name = "edid",
1433         .attr.mode = 0666,
1434         .size = MAX_EDID_SIZE,
1435         .read = edid_show,
1436         .write = edid_store
1437 };
1438
1439 static struct device_attribute fb_device_attrs[] = {
1440         __ATTR_RO(metrics_bytes_rendered),
1441         __ATTR_RO(metrics_bytes_identical),
1442         __ATTR_RO(metrics_bytes_sent),
1443         __ATTR_RO(metrics_cpu_kcycles_used),
1444         __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1445 };
1446
1447 /*
1448  * This is necessary before we can communicate with the display controller.
1449  */
1450 static int dlfb_select_std_channel(struct dlfb_data *dev)
1451 {
1452         int ret;
1453         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1454                                 0x1C, 0x88, 0x5E, 0x15,
1455                                 0x60, 0xFE, 0xC6, 0x97,
1456                                 0x16, 0x3D, 0x47, 0xF2  };
1457
1458         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1459                         NR_USB_REQUEST_CHANNEL,
1460                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1461                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1462         return ret;
1463 }
1464
1465 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1466                                         struct usb_device *usbdev)
1467 {
1468         char *desc;
1469         char *buf;
1470         char *desc_end;
1471
1472         u8 total_len = 0;
1473
1474         buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1475         if (!buf)
1476                 return false;
1477         desc = buf;
1478
1479         total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
1480                                     0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1481         if (total_len > 5) {
1482                 dl_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1483                         "%02x %02x %02x %02x %02x %02x %02x\n",
1484                         total_len, desc[0],
1485                         desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1486                         desc[7], desc[8], desc[9], desc[10]);
1487
1488                 if ((desc[0] != total_len) || /* descriptor length */
1489                     (desc[1] != 0x5f) ||   /* vendor descriptor type */
1490                     (desc[2] != 0x01) ||   /* version (2 bytes) */
1491                     (desc[3] != 0x00) ||
1492                     (desc[4] != total_len - 2)) /* length after type */
1493                         goto unrecognized;
1494
1495                 desc_end = desc + total_len;
1496                 desc += 5; /* the fixed header we've already parsed */
1497
1498                 while (desc < desc_end) {
1499                         u8 length;
1500                         u16 key;
1501
1502                         key = *((u16 *) desc);
1503                         desc += sizeof(u16);
1504                         length = *desc;
1505                         desc++;
1506
1507                         switch (key) {
1508                         case 0x0200: { /* max_area */
1509                                 u32 max_area;
1510                                 max_area = le32_to_cpu(*((u32 *)desc));
1511                                 dl_warn("DL chip limited to %d pixel modes\n",
1512                                         max_area);
1513                                 dev->sku_pixel_limit = max_area;
1514                                 break;
1515                         }
1516                         default:
1517                                 break;
1518                         }
1519                         desc += length;
1520                 }
1521         }
1522
1523         goto success;
1524
1525 unrecognized:
1526         /* allow udlfb to load for now even if firmware unrecognized */
1527         dl_err("Unrecognized vendor firmware descriptor\n");
1528
1529 success:
1530         kfree(buf);
1531         return true;
1532 }
1533 static int dlfb_usb_probe(struct usb_interface *interface,
1534                         const struct usb_device_id *id)
1535 {
1536         struct usb_device *usbdev;
1537         struct dlfb_data *dev = 0;
1538         struct fb_info *info = 0;
1539         int retval = -ENOMEM;
1540         int i;
1541
1542         /* usb initialization */
1543
1544         usbdev = interface_to_usbdev(interface);
1545
1546         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1547         if (dev == NULL) {
1548                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1549                 goto error;
1550         }
1551
1552         /* we need to wait for both usb and fbdev to spin down on disconnect */
1553         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1554         kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1555
1556         dev->udev = usbdev;
1557         dev->gdev = &usbdev->dev; /* our generic struct device * */
1558         usb_set_intfdata(interface, dev);
1559
1560         dl_info("%s %s - serial #%s\n",
1561                 usbdev->manufacturer, usbdev->product, usbdev->serial);
1562         dl_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1563                 usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1564                 usbdev->descriptor.bcdDevice, dev);
1565         dl_info("console enable=%d\n", console);
1566         dl_info("fb_defio enable=%d\n", fb_defio);
1567
1568         dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1569
1570         if (!dlfb_parse_vendor_descriptor(dev, usbdev)) {
1571                 dl_err("firmware not recognized. Assume incompatible device\n");
1572                 goto error;
1573         }
1574
1575         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1576                 retval = -ENOMEM;
1577                 dl_err("dlfb_alloc_urb_list failed\n");
1578                 goto error;
1579         }
1580
1581         /* We don't register a new USB class. Our client interface is fbdev */
1582
1583         /* allocates framebuffer driver structure, not framebuffer memory */
1584         info = framebuffer_alloc(0, &usbdev->dev);
1585         if (!info) {
1586                 retval = -ENOMEM;
1587                 dl_err("framebuffer_alloc failed\n");
1588                 goto error;
1589         }
1590
1591         dev->info = info;
1592         info->par = dev;
1593         info->pseudo_palette = dev->pseudo_palette;
1594         info->fbops = &dlfb_ops;
1595
1596         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1597         if (retval < 0) {
1598                 dl_err("fb_alloc_cmap failed %x\n", retval);
1599                 goto error;
1600         }
1601
1602         INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1603                           dlfb_free_framebuffer_work);
1604
1605         INIT_LIST_HEAD(&info->modelist);
1606
1607         retval = dlfb_setup_modes(dev, info, NULL, 0);
1608         if (retval != 0) {
1609                 dl_err("unable to find common mode for display and adapter\n");
1610                 goto error;
1611         }
1612
1613         /* ready to begin using device */
1614
1615         atomic_set(&dev->usb_active, 1);
1616         dlfb_select_std_channel(dev);
1617
1618         dlfb_ops_check_var(&info->var, info);
1619         dlfb_ops_set_par(info);
1620
1621         retval = register_framebuffer(info);
1622         if (retval < 0) {
1623                 dl_err("register_framebuffer failed %d\n", retval);
1624                 goto error;
1625         }
1626
1627         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1628                 device_create_file(info->dev, &fb_device_attrs[i]);
1629
1630         device_create_bin_file(info->dev, &edid_attr);
1631
1632         dl_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1633                         " Using %dK framebuffer memory\n", info->node,
1634                         info->var.xres, info->var.yres,
1635                         ((dev->backing_buffer) ?
1636                         info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1637         return 0;
1638
1639 error:
1640         if (dev) {
1641
1642                 if (info) {
1643                         if (info->cmap.len != 0)
1644                                 fb_dealloc_cmap(&info->cmap);
1645                         if (info->monspecs.modedb)
1646                                 fb_destroy_modedb(info->monspecs.modedb);
1647                         if (info->screen_base)
1648                                 vfree(info->screen_base);
1649
1650                         fb_destroy_modelist(&info->modelist);
1651
1652                         framebuffer_release(info);
1653                 }
1654
1655                 if (dev->backing_buffer)
1656                         vfree(dev->backing_buffer);
1657
1658                 kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1659                 kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1660
1661                 /* dev has been deallocated. Do not dereference */
1662         }
1663
1664         return retval;
1665 }
1666
1667 static void dlfb_usb_disconnect(struct usb_interface *interface)
1668 {
1669         struct dlfb_data *dev;
1670         struct fb_info *info;
1671         int i;
1672
1673         dev = usb_get_intfdata(interface);
1674         info = dev->info;
1675
1676         dl_info("USB disconnect starting\n");
1677
1678         /* we virtualize until all fb clients release. Then we free */
1679         dev->virtualized = true;
1680
1681         /* When non-active we'll update virtual framebuffer, but no new urbs */
1682         atomic_set(&dev->usb_active, 0);
1683
1684         /* remove udlfb's sysfs interfaces */
1685         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1686                 device_remove_file(info->dev, &fb_device_attrs[i]);
1687         device_remove_bin_file(info->dev, &edid_attr);
1688
1689         usb_set_intfdata(interface, NULL);
1690
1691         /* if clients still have us open, will be freed on last close */
1692         if (dev->fb_count == 0)
1693                 schedule_delayed_work(&dev->free_framebuffer_work, 0);
1694
1695         /* release reference taken by kref_init in probe() */
1696         kref_put(&dev->kref, dlfb_free);
1697
1698         /* consider dlfb_data freed */
1699
1700         return;
1701 }
1702
1703 static struct usb_driver dlfb_driver = {
1704         .name = "udlfb",
1705         .probe = dlfb_usb_probe,
1706         .disconnect = dlfb_usb_disconnect,
1707         .id_table = id_table,
1708 };
1709
1710 static int __init dlfb_module_init(void)
1711 {
1712         int res;
1713
1714         res = usb_register(&dlfb_driver);
1715         if (res)
1716                 err("usb_register failed. Error number %d", res);
1717
1718         return res;
1719 }
1720
1721 static void __exit dlfb_module_exit(void)
1722 {
1723         usb_deregister(&dlfb_driver);
1724 }
1725
1726 module_init(dlfb_module_init);
1727 module_exit(dlfb_module_exit);
1728
1729 static void dlfb_urb_completion(struct urb *urb)
1730 {
1731         struct urb_node *unode = urb->context;
1732         struct dlfb_data *dev = unode->dev;
1733         unsigned long flags;
1734
1735         /* sync/async unlink faults aren't errors */
1736         if (urb->status) {
1737                 if (!(urb->status == -ENOENT ||
1738                     urb->status == -ECONNRESET ||
1739                     urb->status == -ESHUTDOWN)) {
1740                         dl_err("%s - nonzero write bulk status received: %d\n",
1741                                 __func__, urb->status);
1742                         atomic_set(&dev->lost_pixels, 1);
1743                 }
1744         }
1745
1746         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1747
1748         spin_lock_irqsave(&dev->urbs.lock, flags);
1749         list_add_tail(&unode->entry, &dev->urbs.list);
1750         dev->urbs.available++;
1751         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1752
1753         /*
1754          * When using fb_defio, we deadlock if up() is called
1755          * while another is waiting. So queue to another process.
1756          */
1757         if (fb_defio)
1758                 schedule_delayed_work(&unode->release_urb_work, 0);
1759         else
1760                 up(&dev->urbs.limit_sem);
1761 }
1762
1763 static void dlfb_free_urb_list(struct dlfb_data *dev)
1764 {
1765         int count = dev->urbs.count;
1766         struct list_head *node;
1767         struct urb_node *unode;
1768         struct urb *urb;
1769         int ret;
1770         unsigned long flags;
1771
1772         dl_notice("Waiting for completes and freeing all render urbs\n");
1773
1774         /* keep waiting and freeing, until we've got 'em all */
1775         while (count--) {
1776
1777                 /* Getting interrupted means a leak, but ok at shutdown*/
1778                 ret = down_interruptible(&dev->urbs.limit_sem);
1779                 if (ret)
1780                         break;
1781
1782                 spin_lock_irqsave(&dev->urbs.lock, flags);
1783
1784                 node = dev->urbs.list.next; /* have reserved one with sem */
1785                 list_del_init(node);
1786
1787                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1788
1789                 unode = list_entry(node, struct urb_node, entry);
1790                 urb = unode->urb;
1791
1792                 /* Free each separately allocated piece */
1793                 usb_free_coherent(urb->dev, dev->urbs.size,
1794                                   urb->transfer_buffer, urb->transfer_dma);
1795                 usb_free_urb(urb);
1796                 kfree(node);
1797         }
1798
1799 }
1800
1801 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1802 {
1803         int i = 0;
1804         struct urb *urb;
1805         struct urb_node *unode;
1806         char *buf;
1807
1808         spin_lock_init(&dev->urbs.lock);
1809
1810         dev->urbs.size = size;
1811         INIT_LIST_HEAD(&dev->urbs.list);
1812
1813         while (i < count) {
1814                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1815                 if (!unode)
1816                         break;
1817                 unode->dev = dev;
1818
1819                 INIT_DELAYED_WORK(&unode->release_urb_work,
1820                           dlfb_release_urb_work);
1821
1822                 urb = usb_alloc_urb(0, GFP_KERNEL);
1823                 if (!urb) {
1824                         kfree(unode);
1825                         break;
1826                 }
1827                 unode->urb = urb;
1828
1829                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1830                                          &urb->transfer_dma);
1831                 if (!buf) {
1832                         kfree(unode);
1833                         usb_free_urb(urb);
1834                         break;
1835                 }
1836
1837                 /* urb->transfer_buffer_length set to actual before submit */
1838                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1839                         buf, size, dlfb_urb_completion, unode);
1840                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1841
1842                 list_add_tail(&unode->entry, &dev->urbs.list);
1843
1844                 i++;
1845         }
1846
1847         sema_init(&dev->urbs.limit_sem, i);
1848         dev->urbs.count = i;
1849         dev->urbs.available = i;
1850
1851         dl_notice("allocated %d %d byte urbs\n", i, (int) size);
1852
1853         return i;
1854 }
1855
1856 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1857 {
1858         int ret = 0;
1859         struct list_head *entry;
1860         struct urb_node *unode;
1861         struct urb *urb = NULL;
1862         unsigned long flags;
1863
1864         /* Wait for an in-flight buffer to complete and get re-queued */
1865         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1866         if (ret) {
1867                 atomic_set(&dev->lost_pixels, 1);
1868                 dl_warn("wait for urb interrupted: %x available: %d\n",
1869                        ret, dev->urbs.available);
1870                 goto error;
1871         }
1872
1873         spin_lock_irqsave(&dev->urbs.lock, flags);
1874
1875         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1876         entry = dev->urbs.list.next;
1877         list_del_init(entry);
1878         dev->urbs.available--;
1879
1880         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1881
1882         unode = list_entry(entry, struct urb_node, entry);
1883         urb = unode->urb;
1884
1885 error:
1886         return urb;
1887 }
1888
1889 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1890 {
1891         int ret;
1892
1893         BUG_ON(len > dev->urbs.size);
1894
1895         urb->transfer_buffer_length = len; /* set to actual payload len */
1896         ret = usb_submit_urb(urb, GFP_KERNEL);
1897         if (ret) {
1898                 dlfb_urb_completion(urb); /* because no one else will */
1899                 atomic_set(&dev->lost_pixels, 1);
1900                 dl_err("usb_submit_urb error %x\n", ret);
1901         }
1902         return ret;
1903 }
1904
1905 module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1906 MODULE_PARM_DESC(console, "Allow fbcon to consume first framebuffer found");
1907
1908 module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1909 MODULE_PARM_DESC(fb_defio, "Enable fb_defio mmap support. *Experimental*");
1910
1911 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1912               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1913               "Bernie Thompson <bernie@plugable.com>");
1914 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1915 MODULE_LICENSE("GPL");
1916