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