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
  31 #include "udlfb.h"
  32
  33 static struct fb_fix_screeninfo dlfb_fix = {
  34         .id =           "udlfb",
  35         .type =         FB_TYPE_PACKED_PIXELS,
  36         .visual =       FB_VISUAL_TRUECOLOR,
  37         .xpanstep =     0,
  38         .ypanstep =     0,
  39         .ywrapstep =    0,
  40         .accel =        FB_ACCEL_NONE,
  41 };
  42
  43 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
  44 #ifdef FBINFO_VIRTFB
  45                 FBINFO_VIRTFB |
  46 #endif
  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 #ifndef CONFIG_FB_DEFERRED_IO
  63 #warning Please set CONFIG_FB_DEFFERRED_IO option to support generic fbdev apps
  64 #endif
  65
  66 #ifndef CONFIG_FB_SYS_IMAGEBLIT
  67 #ifndef CONFIG_FB_SYS_IMAGEBLIT_MODULE
  68 #warning Please set CONFIG_FB_SYS_IMAGEBLIT option to support fb console
  69 #endif
  70 #endif
  71
  72 #ifndef CONFIG_FB_MODE_HELPERS
  73 #warning CONFIG_FB_MODE_HELPERS required. Expect build break
  74 #endif
  75
  76 /* dlfb keeps a list of urbs for efficient bulk transfers */
  77 static void dlfb_urb_completion(struct urb *urb);
  78 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
  79 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
  80 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
  81 static void dlfb_free_urb_list(struct dlfb_data *dev);
  82
  83 /* other symbols with dependents */
  84 #ifdef CONFIG_FB_DEFERRED_IO
  85 static struct fb_deferred_io dlfb_defio;
  86 #endif
  87
  88 /*
  89  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  90  * All operations are written to buffers which then later get sent to device
  91  */
  92 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
  93 {
  94         *buf++ = 0xAF;
  95         *buf++ = 0x20;
  96         *buf++ = reg;
  97         *buf++ = val;
  98         return buf;
  99 }
 100
 101 static char *dlfb_vidreg_lock(char *buf)
 102 {
 103         return dlfb_set_register(buf, 0xFF, 0x00);
 104 }
 105
 106 static char *dlfb_vidreg_unlock(char *buf)
 107 {
 108         return dlfb_set_register(buf, 0xFF, 0xFF);
 109 }
 110
 111 /*
 112  * On/Off for driving the DisplayLink framebuffer to the display
 113  *  0x00 H and V sync on
 114  *  0x01 H and V sync off (screen blank but powered)
 115  *  0x07 DPMS powerdown (requires modeset to come back)
 116  */
 117 static char *dlfb_enable_hvsync(char *buf, bool enable)
 118 {
 119         if (enable)
 120                 return dlfb_set_register(buf, 0x1F, 0x00);
 121         else
 122                 return dlfb_set_register(buf, 0x1F, 0x07);
 123 }
 124
 125 static char *dlfb_set_color_depth(char *buf, u8 selection)
 126 {
 127         return dlfb_set_register(buf, 0x00, selection);
 128 }
 129
 130 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 131 {
 132         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 133         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 134         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 135         return dlfb_set_register(wrptr, 0x22, base);
 136 }
 137
 138 /*
 139  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 140  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 141  */
 142 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 143 {
 144         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 145         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 146         return dlfb_set_register(wrptr, 0x28, base);
 147 }
 148
 149 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 150 {
 151         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 152         return dlfb_set_register(wrptr, reg+1, value);
 153 }
 154
 155 /*
 156  * This is kind of weird because the controller takes some
 157  * register values in a different byte order than other registers.
 158  */
 159 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 160 {
 161         wrptr = dlfb_set_register(wrptr, reg, value);
 162         return dlfb_set_register(wrptr, reg+1, value >> 8);
 163 }
 164
 165 /*
 166  * LFSR is linear feedback shift register. The reason we have this is
 167  * because the display controller needs to minimize the clock depth of
 168  * various counters used in the display path. So this code reverses the
 169  * provided value into the lfsr16 value by counting backwards to get
 170  * the value that needs to be set in the hardware comparator to get the
 171  * same actual count. This makes sense once you read above a couple of
 172  * times and think about it from a hardware perspective.
 173  */
 174 static u16 dlfb_lfsr16(u16 actual_count)
 175 {
 176         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 177
 178         while (actual_count--) {
 179                 lv =     ((lv << 1) |
 180                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 181                         & 0xFFFF;
 182         }
 183
 184         return (u16) lv;
 185 }
 186
 187 /*
 188  * This does LFSR conversion on the value that is to be written.
 189  * See LFSR explanation above for more detail.
 190  */
 191 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 192 {
 193         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 194 }
 195
 196 /*
 197  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 198  * details and converts them into the DisplayLink equivalent register commands.
 199  */
 200 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 201 {
 202         u16 xds, yds;
 203         u16 xde, yde;
 204         u16 yec;
 205
 206         /* x display start */
 207         xds = var->left_margin + var->hsync_len;
 208         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 209         /* x display end */
 210         xde = xds + var->xres;
 211         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 212
 213         /* y display start */
 214         yds = var->upper_margin + var->vsync_len;
 215         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 216         /* y display end */
 217         yde = yds + var->yres;
 218         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 219
 220         /* x end count is active + blanking - 1 */
 221         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 222                         xde + var->right_margin - 1);
 223
 224         /* libdlo hardcodes hsync start to 1 */
 225         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 226
 227         /* hsync end is width of sync pulse + 1 */
 228         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 229
 230         /* hpixels is active pixels */
 231         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 232
 233         /* yendcount is vertical active + vertical blanking */
 234         yec = var->yres + var->upper_margin + var->lower_margin +
 235                         var->vsync_len;
 236         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 237
 238         /* libdlo hardcodes vsync start to 0 */
 239         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 240
 241         /* vsync end is width of vsync pulse */
 242         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 243
 244         /* vpixels is active pixels */
 245         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 246
 247         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 248         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 249                         200*1000*1000/var->pixclock);
 250
 251         return wrptr;
 252 }
 253
 254 /*
 255  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 256  * and then generates the appropriate command sequence that then drives the
 257  * display controller.
 258  */
 259 static int dlfb_set_video_mode(struct dlfb_data *dev,
 260                                 struct fb_var_screeninfo *var)
 261 {
 262         char *buf;
 263         char *wrptr;
 264         int retval = 0;
 265         int writesize;
 266         struct urb *urb;
 267
 268         if (!atomic_read(&dev->usb_active))
 269                 return -EPERM;
 270
 271         urb = dlfb_get_urb(dev);
 272         if (!urb)
 273                 return -ENOMEM;
 274         buf = (char *) urb->transfer_buffer;
 275
 276         /*
 277         * This first section has to do with setting the base address on the
 278         * controller * associated with the display. There are 2 base
 279         * pointers, currently, we only * use the 16 bpp segment.
 280         */
 281         wrptr = dlfb_vidreg_lock(buf);
 282         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 283         /* set base for 16bpp segment to 0 */
 284         wrptr = dlfb_set_base16bpp(wrptr, 0);
 285         /* set base for 8bpp segment to end of fb */
 286         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
 287
 288         wrptr = dlfb_set_vid_cmds(wrptr, var);
 289         wrptr = dlfb_enable_hvsync(wrptr, true);
 290         wrptr = dlfb_vidreg_unlock(wrptr);
 291
 292         writesize = wrptr - buf;
 293
 294         retval = dlfb_submit_urb(dev, urb, writesize);
 295
 296         return retval;
 297 }
 298
 299 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 300 {
 301         unsigned long start = vma->vm_start;
 302         unsigned long size = vma->vm_end - vma->vm_start;
 303         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 304         unsigned long page, pos;
 305
 306         dl_notice("MMAP: %lu %u\n", offset + size, info->fix.smem_len);
 307
 308         if (offset + size > info->fix.smem_len)
 309                 return -EINVAL;
 310
 311         pos = (unsigned long)info->fix.smem_start + offset;
 312
 313         while (size > 0) {
 314                 page = vmalloc_to_pfn((void *)pos);
 315                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 316                         return -EAGAIN;
 317
 318                 start += PAGE_SIZE;
 319                 pos += PAGE_SIZE;
 320                 if (size > PAGE_SIZE)
 321                         size -= PAGE_SIZE;
 322                 else
 323                         size = 0;
 324         }
 325
 326         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 327         return 0;
 328
 329 }
 330
 331 /*
 332  * Trims identical data from front and back of line
 333  * Sets new front buffer address and width
 334  * And returns byte count of identical pixels
 335  * Assumes CPU natural alignment (unsigned long)
 336  * for back and front buffer ptrs and width
 337  */
 338 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 339 {
 340         int j, k;
 341         const unsigned long *back = (const unsigned long *) bback;
 342         const unsigned long *front = (const unsigned long *) *bfront;
 343         const int width = *width_bytes / sizeof(unsigned long);
 344         int identical = width;
 345         int start = width;
 346         int end = width;
 347
 348         prefetch((void *) front);
 349         prefetch((void *) back);
 350
 351         for (j = 0; j < width; j++) {
 352                 if (back[j] != front[j]) {
 353                         start = j;
 354                         break;
 355                 }
 356         }
 357
 358         for (k = width - 1; k > j; k--) {
 359                 if (back[k] != front[k]) {
 360                         end = k+1;
 361                         break;
 362                 }
 363         }
 364
 365         identical = start + (width - end);
 366         *bfront = (u8 *) &front[start];
 367         *width_bytes = (end - start) * sizeof(unsigned long);
 368
 369         return identical * sizeof(unsigned long);
 370 }
 371
 372 /*
 373  * Render a command stream for an encoded horizontal line segment of pixels.
 374  *
 375  * A command buffer holds several commands.
 376  * It always begins with a fresh command header
 377  * (the protocol doesn't require this, but we enforce it to allow
 378  * multiple buffers to be potentially encoded and sent in parallel).
 379  * A single command encodes one contiguous horizontal line of pixels
 380  *
 381  * The function relies on the client to do all allocation, so that
 382  * rendering can be done directly to output buffers (e.g. USB URBs).
 383  * The function fills the supplied command buffer, providing information
 384  * on where it left off, so the client may call in again with additional
 385  * buffers if the line will take several buffers to complete.
 386  *
 387  * A single command can transmit a maximum of 256 pixels,
 388  * regardless of the compression ratio (protocol design limit).
 389  * To the hardware, 0 for a size byte means 256
 390  *
 391  * Rather than 256 pixel commands which are either rl or raw encoded,
 392  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 393  * This has a slightly larger header overhead, but produces more even results.
 394  * It also processes all data (read and write) in a single pass.
 395  * Performance benchmarks of common cases show it having just slightly better
 396  * compression than 256 pixel raw -or- rle commands, with similar CPU consumpion.
 397  * But for very rl friendly data, will compress not quite as well.
 398  */
 399 static void dlfb_compress_hline(
 400         const uint16_t **pixel_start_ptr,
 401         const uint16_t *const pixel_end,
 402         uint32_t *device_address_ptr,
 403         uint8_t **command_buffer_ptr,
 404         const uint8_t *const cmd_buffer_end)
 405 {
 406         const uint16_t *pixel = *pixel_start_ptr;
 407         uint32_t dev_addr  = *device_address_ptr;
 408         uint8_t *cmd = *command_buffer_ptr;
 409         const int bpp = 2;
 410
 411         while ((pixel_end > pixel) &&
 412                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 413                 uint8_t *raw_pixels_count_byte = 0;
 414                 uint8_t *cmd_pixels_count_byte = 0;
 415                 const uint16_t *raw_pixel_start = 0;
 416                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
 417                 const uint32_t be_dev_addr = cpu_to_be32(dev_addr);
 418
 419                 prefetchw((void *) cmd); /* pull in one cache line at least */
 420
 421                 *cmd++ = 0xAF;
 422                 *cmd++ = 0x6B;
 423                 *cmd++ = (uint8_t) ((be_dev_addr >> 8) & 0xFF);
 424                 *cmd++ = (uint8_t) ((be_dev_addr >> 16) & 0xFF);
 425                 *cmd++ = (uint8_t) ((be_dev_addr >> 24) & 0xFF);
 426
 427                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
 428                 cmd_pixel_start = pixel;
 429
 430                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
 431                 raw_pixel_start = pixel;
 432
 433                 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
 434                         min((int)(pixel_end - pixel),
 435                             (int)(cmd_buffer_end - cmd) / bpp));
 436
 437                 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
 438
 439                 while (pixel < cmd_pixel_end) {
 440                         const uint16_t * const repeating_pixel = pixel;
 441
 442                         *(uint16_t *)cmd = cpu_to_be16p(pixel);
 443                         cmd += 2;
 444                         pixel++;
 445
 446                         if (unlikely((pixel < cmd_pixel_end) &&
 447                                      (*pixel == *repeating_pixel))) {
 448                                 /* go back and fill in raw pixel count */
 449                                 *raw_pixels_count_byte = ((repeating_pixel -
 450                                                 raw_pixel_start) + 1) & 0xFF;
 451
 452                                 while ((pixel < cmd_pixel_end)
 453                                        && (*pixel == *repeating_pixel)) {
 454                                         pixel++;
 455                                 }
 456
 457                                 /* immediately after raw data is repeat byte */
 458                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
 459
 460                                 /* Then start another raw pixel span */
 461                                 raw_pixel_start = pixel;
 462                                 raw_pixels_count_byte = cmd++;
 463                         }
 464                 }
 465
 466                 if (pixel > raw_pixel_start) {
 467                         /* finalize last RAW span */
 468                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
 469                 }
 470
 471                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
 472                 dev_addr += (pixel - cmd_pixel_start) * bpp;
 473         }
 474
 475         if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
 476                 /* Fill leftover bytes with no-ops */
 477                 if (cmd_buffer_end > cmd)
 478                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
 479                 cmd = (uint8_t *) cmd_buffer_end;
 480         }
 481
 482         *command_buffer_ptr = cmd;
 483         *pixel_start_ptr = pixel;
 484         *device_address_ptr = dev_addr;
 485
 486         return;
 487 }
 488
 489 /*
 490  * There are 3 copies of every pixel: The front buffer that the fbdev
 491  * client renders to, the actual framebuffer across the USB bus in hardware
 492  * (that we can only write to, slowly, and can never read), and (optionally)
 493  * our shadow copy that tracks what's been sent to that hardware buffer.
 494  */
 495 static void dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
 496                               const char *front, char **urb_buf_ptr,
 497                               u32 byte_offset, u32 byte_width,
 498                               int *ident_ptr, int *sent_ptr)
 499 {
 500         const u8 *line_start, *line_end, *next_pixel;
 501         u32 dev_addr = dev->base16 + byte_offset;
 502         struct urb *urb = *urb_ptr;
 503         u8 *cmd = *urb_buf_ptr;
 504         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
 505
 506         line_start = (u8 *) (front + byte_offset);
 507         next_pixel = line_start;
 508         line_end = next_pixel + byte_width;
 509
 510         if (dev->backing_buffer) {
 511                 int offset;
 512                 const u8 *back_start = (u8 *) (dev->backing_buffer
 513                                                 + byte_offset);
 514
 515                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
 516                         &byte_width);
 517
 518                 offset = next_pixel - line_start;
 519                 line_end = next_pixel + byte_width;
 520                 dev_addr += offset;
 521                 back_start += offset;
 522                 line_start += offset;
 523
 524                 memcpy((char *)back_start, (char *) line_start,
 525                        byte_width);
 526         }
 527
 528         while (next_pixel < line_end) {
 529
 530                 dlfb_compress_hline((const uint16_t **) &next_pixel,
 531                              (const uint16_t *) line_end, &dev_addr,
 532                         (u8 **) &cmd, (u8 *) cmd_end);
 533
 534                 if (cmd >= cmd_end) {
 535                         int len = cmd - (u8 *) urb->transfer_buffer;
 536                         if (dlfb_submit_urb(dev, urb, len))
 537                                 return; /* lost pixels is set */
 538                         *sent_ptr += len;
 539                         urb = dlfb_get_urb(dev);
 540                         if (!urb)
 541                                 return; /* lost_pixels is set */
 542                         *urb_ptr = urb;
 543                         cmd = urb->transfer_buffer;
 544                         cmd_end = &cmd[urb->transfer_buffer_length];
 545                 }
 546         }
 547
 548         *urb_buf_ptr = cmd;
 549 }
 550
 551 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
 552                int width, int height, char *data)
 553 {
 554         int i, ret;
 555         char *cmd;
 556         cycles_t start_cycles, end_cycles;
 557         int bytes_sent = 0;
 558         int bytes_identical = 0;
 559         struct urb *urb;
 560         int aligned_x;
 561
 562         start_cycles = get_cycles();
 563
 564         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 565         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 566         x = aligned_x;
 567
 568         if ((width <= 0) ||
 569             (x + width > dev->info->var.xres) ||
 570             (y + height > dev->info->var.yres))
 571                 return -EINVAL;
 572
 573         if (!atomic_read(&dev->usb_active))
 574                 return 0;
 575
 576         urb = dlfb_get_urb(dev);
 577         if (!urb)
 578                 return 0;
 579         cmd = urb->transfer_buffer;
 580
 581         for (i = y; i < y + height ; i++) {
 582                 const int line_offset = dev->info->fix.line_length * i;
 583                 const int byte_offset = line_offset + (x * BPP);
 584
 585                 dlfb_render_hline(dev, &urb, (char *) dev->info->fix.smem_start,
 586                                   &cmd, byte_offset, width * BPP,
 587                                   &bytes_identical, &bytes_sent);
 588         }
 589
 590         if (cmd > (char *) urb->transfer_buffer) {
 591                 /* Send partial buffer remaining before exiting */
 592                 int len = cmd - (char *) urb->transfer_buffer;
 593                 ret = dlfb_submit_urb(dev, urb, len);
 594                 bytes_sent += len;
 595         } else
 596                 dlfb_urb_completion(urb);
 597
 598         atomic_add(bytes_sent, &dev->bytes_sent);
 599         atomic_add(bytes_identical, &dev->bytes_identical);
 600         atomic_add(width*height*2, &dev->bytes_rendered);
 601         end_cycles = get_cycles();
 602         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 603                     >> 10)), /* Kcycles */
 604                    &dev->cpu_kcycles_used);
 605
 606         return 0;
 607 }
 608
 609 static ssize_t dlfb_ops_read(struct fb_info *info, char __user *buf,
 610                          size_t count, loff_t *ppos)
 611 {
 612         ssize_t result = -ENOSYS;
 613
 614 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 615         result = fb_sys_read(info, buf, count, ppos);
 616 #endif
 617
 618         return result;
 619 }
 620
 621 /*
 622  * Path triggered by usermode clients who write to filesystem
 623  * e.g. cat filename > /dev/fb1
 624  * Not used by X Windows or text-mode console. But useful for testing.
 625  * Slow because of extra copy and we must assume all pixels dirty.
 626  */
 627 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
 628                           size_t count, loff_t *ppos)
 629 {
 630         ssize_t result = -ENOSYS;
 631         struct dlfb_data *dev = info->par;
 632         u32 offset = (u32) *ppos;
 633
 634 #if defined CONFIG_FB_SYS_FOPS || defined CONFIG_FB_SYS_FOPS_MODULE
 635
 636         result = fb_sys_write(info, buf, count, ppos);
 637
 638         if (result > 0) {
 639                 int start = max((int)(offset / info->fix.line_length) - 1, 0);
 640                 int lines = min((u32)((result / info->fix.line_length) + 1),
 641                                 (u32)info->var.yres);
 642
 643                 dlfb_handle_damage(dev, 0, start, info->var.xres,
 644                         lines, info->screen_base);
 645         }
 646 #endif
 647
 648         return result;
 649 }
 650
 651 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 652 static void dlfb_ops_copyarea(struct fb_info *info,
 653                                 const struct fb_copyarea *area)
 654 {
 655
 656         struct dlfb_data *dev = info->par;
 657
 658 #if defined CONFIG_FB_SYS_COPYAREA || defined CONFIG_FB_SYS_COPYAREA_MODULE
 659
 660         sys_copyarea(info, area);
 661
 662         dlfb_handle_damage(dev, area->dx, area->dy,
 663                         area->width, area->height, info->screen_base);
 664 #endif
 665
 666 }
 667
 668 static void dlfb_ops_imageblit(struct fb_info *info,
 669                                 const struct fb_image *image)
 670 {
 671         struct dlfb_data *dev = info->par;
 672
 673 #if defined CONFIG_FB_SYS_IMAGEBLIT || defined CONFIG_FB_SYS_IMAGEBLIT_MODULE
 674
 675         sys_imageblit(info, image);
 676
 677         dlfb_handle_damage(dev, image->dx, image->dy,
 678                         image->width, image->height, info->screen_base);
 679
 680 #endif
 681
 682 }
 683
 684 static void dlfb_ops_fillrect(struct fb_info *info,
 685                           const struct fb_fillrect *rect)
 686 {
 687         struct dlfb_data *dev = info->par;
 688
 689 #if defined CONFIG_FB_SYS_FILLRECT || defined CONFIG_FB_SYS_FILLRECT_MODULE
 690
 691         sys_fillrect(info, rect);
 692
 693         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
 694                               rect->height, info->screen_base);
 695 #endif
 696
 697 }
 698
 699 static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
 700 {
 701         int i;
 702         int ret;
 703         char *rbuf;
 704
 705         rbuf = kmalloc(2, GFP_KERNEL);
 706         if (!rbuf)
 707                 return 0;
 708
 709         for (i = 0; i < len; i++) {
 710                 ret = usb_control_msg(dev->udev,
 711                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 712                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 713                                     HZ);
 714                 if (ret < 1) {
 715                         dl_err("Read EDID byte %d failed err %x\n", i, ret);
 716                         i--;
 717                         break;
 718                 }
 719                 edid[i] = rbuf[1];
 720         }
 721
 722         kfree(rbuf);
 723
 724         return i;
 725 }
 726
 727 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 728                                 unsigned long arg)
 729 {
 730
 731         struct dlfb_data *dev = info->par;
 732         struct dloarea *area = NULL;
 733
 734         if (!atomic_read(&dev->usb_active))
 735                 return 0;
 736
 737         /* TODO: Update X server to get this from sysfs instead */
 738         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 739                 char *edid = (char *)arg;
 740                 if (copy_to_user(edid, dev->edid, dev->edid_size))
 741                         return -EFAULT;
 742                 return 0;
 743         }
 744
 745         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 746         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 747
 748                 area = (struct dloarea *)arg;
 749
 750                 if (area->x < 0)
 751                         area->x = 0;
 752
 753                 if (area->x > info->var.xres)
 754                         area->x = info->var.xres;
 755
 756                 if (area->y < 0)
 757                         area->y = 0;
 758
 759                 if (area->y > info->var.yres)
 760                         area->y = info->var.yres;
 761
 762                 atomic_set(&dev->use_defio, 0);
 763
 764                 dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
 765                            info->screen_base);
 766         }
 767
 768         return 0;
 769 }
 770
 771 /* taken from vesafb */
 772 static int
 773 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 774                unsigned blue, unsigned transp, struct fb_info *info)
 775 {
 776         int err = 0;
 777
 778         if (regno >= info->cmap.len)
 779                 return 1;
 780
 781         if (regno < 16) {
 782                 if (info->var.red.offset == 10) {
 783                         /* 1:5:5:5 */
 784                         ((u32 *) (info->pseudo_palette))[regno] =
 785                             ((red & 0xf800) >> 1) |
 786                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 787                 } else {
 788                         /* 0:5:6:5 */
 789                         ((u32 *) (info->pseudo_palette))[regno] =
 790                             ((red & 0xf800)) |
 791                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 792                 }
 793         }
 794
 795         return err;
 796 }
 797
 798 /*
 799  * It's common for several clients to have framebuffer open simultaneously.
 800  * e.g. both fbcon and X. Makes things interesting.
 801  * Assumes caller is holding info->lock (for open and release at least)
 802  */
 803 static int dlfb_ops_open(struct fb_info *info, int user)
 804 {
 805         struct dlfb_data *dev = info->par;
 806
 807 /*      if (user == 0)
 808  *              We could special case kernel mode clients (fbcon) here
 809  */
 810
 811         /* If the USB device is gone, we don't accept new opens */
 812         if (dev->virtualized)
 813                 return -ENODEV;
 814
 815         dev->fb_count++;
 816
 817         kref_get(&dev->kref);
 818
 819 #ifdef CONFIG_FB_DEFERRED_IO
 820         if ((atomic_read(&dev->use_defio)) && (info->fbdefio == NULL)) {
 821                 /* enable defio */
 822                 info->fbdefio = &dlfb_defio;
 823                 fb_deferred_io_init(info);
 824         }
 825 #endif
 826
 827         dl_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 828             info->node, user, info, dev->fb_count);
 829
 830         return 0;
 831 }
 832
 833 /*
 834  * Called when all client interfaces to start transactions have been disabled,
 835  * and all references to our device instance (dlfb_data) are released.
 836  * Every transaction must have a reference, so we know are fully spun down
 837  */
 838 static void dlfb_free(struct kref *kref)
 839 {
 840         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 841
 842         /* this function will wait for all in-flight urbs to complete */
 843         if (dev->urbs.count > 0)
 844                 dlfb_free_urb_list(dev);
 845
 846         if (dev->backing_buffer)
 847                 vfree(dev->backing_buffer);
 848
 849         kfree(dev->edid);
 850
 851         dl_warn("freeing dlfb_data %p\n", dev);
 852
 853         kfree(dev);
 854 }
 855
 856
 857 static void dlfb_free_framebuffer_work(struct work_struct *work)
 858 {
 859         struct dlfb_data *dev = container_of(work, struct dlfb_data,
 860                                              free_framebuffer_work.work);
 861         struct fb_info *info = dev->info;
 862         int node = info->node;
 863
 864         unregister_framebuffer(info);
 865
 866         if (info->cmap.len != 0)
 867                 fb_dealloc_cmap(&info->cmap);
 868         if (info->monspecs.modedb)
 869                 fb_destroy_modedb(info->monspecs.modedb);
 870         if (info->screen_base)
 871                 vfree(info->screen_base);
 872
 873         fb_destroy_modelist(&info->modelist);
 874
 875         dev->info = 0;
 876
 877         /* Assume info structure is freed after this point */
 878         framebuffer_release(info);
 879
 880         dl_warn("fb_info for /dev/fb%d has been freed\n", node);
 881
 882         /* ref taken in probe() as part of registering framebfufer */
 883         kref_put(&dev->kref, dlfb_free);
 884 }
 885
 886 /*
 887  * Assumes caller is holding info->lock mutex (for open and release at least)
 888  */
 889 static int dlfb_ops_release(struct fb_info *info, int user)
 890 {
 891         struct dlfb_data *dev = info->par;
 892
 893         dev->fb_count--;
 894
 895         /* We can't free fb_info here - fbmem will touch it when we return */
 896         if (dev->virtualized && (dev->fb_count == 0))
 897                 schedule_delayed_work(&dev->free_framebuffer_work, HZ);
 898
 899 #ifdef CONFIG_FB_DEFERRED_IO
 900         if ((dev->fb_count == 0) && (info->fbdefio)) {
 901                 fb_deferred_io_cleanup(info);
 902                 kfree(info->fbdefio);
 903                 info->fbdefio = NULL;
 904                 info->fbops->fb_mmap = dlfb_ops_mmap;
 905         }
 906 #endif
 907
 908         dl_warn("released /dev/fb%d user=%d count=%d\n",
 909                   info->node, user, dev->fb_count);
 910
 911         kref_put(&dev->kref, dlfb_free);
 912
 913         return 0;
 914 }
 915
 916 /*
 917  * Check whether a video mode is supported by the DisplayLink chip
 918  * We start from monitor's modes, so don't need to filter that here
 919  */
 920 static int dlfb_is_valid_mode(struct fb_videomode *mode,
 921                 struct fb_info *info)
 922 {
 923         struct dlfb_data *dev = info->par;
 924
 925         if (mode->xres * mode->yres > dev->sku_pixel_limit) {
 926                 dl_warn("%dx%d beyond chip capabilities\n",
 927                        mode->xres, mode->yres);
 928                 return 0;
 929         }
 930
 931         dl_info("%dx%d valid mode\n", mode->xres, mode->yres);
 932
 933         return 1;
 934 }
 935
 936 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
 937 {
 938         const struct fb_bitfield red = { 11, 5, 0 };
 939         const struct fb_bitfield green = { 5, 6, 0 };
 940         const struct fb_bitfield blue = { 0, 5, 0 };
 941
 942         var->bits_per_pixel = 16;
 943         var->red = red;
 944         var->green = green;
 945         var->blue = blue;
 946 }
 947
 948 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
 949                                 struct fb_info *info)
 950 {
 951         struct fb_videomode mode;
 952
 953         /* TODO: support dynamically changing framebuffer size */
 954         if ((var->xres * var->yres * 2) > info->fix.smem_len)
 955                 return -EINVAL;
 956
 957         /* set device-specific elements of var unrelated to mode */
 958         dlfb_var_color_format(var);
 959
 960         fb_var_to_videomode(&mode, var);
 961
 962         if (!dlfb_is_valid_mode(&mode, info))
 963                 return -EINVAL;
 964
 965         return 0;
 966 }
 967
 968 static int dlfb_ops_set_par(struct fb_info *info)
 969 {
 970         struct dlfb_data *dev = info->par;
 971         int result;
 972         u16 *pix_framebuffer;
 973         int i;
 974
 975         dl_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
 976
 977         result = dlfb_set_video_mode(dev, &info->var);
 978
 979         if ((result == 0) && (dev->fb_count == 0)) {
 980
 981                 /* paint greenscreen */
 982
 983                 pix_framebuffer = (u16 *) info->screen_base;
 984                 for (i = 0; i < info->fix.smem_len / 2; i++)
 985                         pix_framebuffer[i] = 0x37e6;
 986
 987                 dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
 988                                    info->screen_base);
 989         }
 990
 991         return result;
 992 }
 993
 994 /*
 995  * In order to come back from full DPMS off, we need to set the mode again
 996  */
 997 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
 998 {
 999         struct dlfb_data *dev = info->par;
1000
1001         if (blank_mode != FB_BLANK_UNBLANK) {
1002                 char *bufptr;
1003                 struct urb *urb;
1004
1005                 urb = dlfb_get_urb(dev);
1006                 if (!urb)
1007                         return 0;
1008
1009                 bufptr = (char *) urb->transfer_buffer;
1010                 bufptr = dlfb_vidreg_lock(bufptr);
1011                 bufptr = dlfb_enable_hvsync(bufptr, false);
1012                 bufptr = dlfb_vidreg_unlock(bufptr);
1013
1014                 dlfb_submit_urb(dev, urb, bufptr -
1015                                 (char *) urb->transfer_buffer);
1016         } else {
1017                 dlfb_set_video_mode(dev, &info->var);
1018         }
1019
1020         return 0;
1021 }
1022
1023 static struct fb_ops dlfb_ops = {
1024         .owner = THIS_MODULE,
1025         .fb_read = dlfb_ops_read,
1026         .fb_write = dlfb_ops_write,
1027         .fb_setcolreg = dlfb_ops_setcolreg,
1028         .fb_fillrect = dlfb_ops_fillrect,
1029         .fb_copyarea = dlfb_ops_copyarea,
1030         .fb_imageblit = dlfb_ops_imageblit,
1031         .fb_mmap = dlfb_ops_mmap,
1032         .fb_ioctl = dlfb_ops_ioctl,
1033         .fb_open = dlfb_ops_open,
1034         .fb_release = dlfb_ops_release,
1035         .fb_blank = dlfb_ops_blank,
1036         .fb_check_var = dlfb_ops_check_var,
1037         .fb_set_par = dlfb_ops_set_par,
1038 };
1039
1040
1041 /*
1042  * Assumes &info->lock held by caller
1043  * Assumes no active clients have framebuffer open
1044  */
1045 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1046 {
1047         int retval = -ENOMEM;
1048         int old_len = info->fix.smem_len;
1049         int new_len;
1050         unsigned char *old_fb = info->screen_base;
1051         unsigned char *new_fb;
1052         unsigned char *new_back;
1053
1054         dl_warn("Reallocating framebuffer. Addresses will change!\n");
1055
1056         new_len = info->fix.line_length * info->var.yres;
1057
1058         if (PAGE_ALIGN(new_len) > old_len) {
1059                 /*
1060                  * Alloc system memory for virtual framebuffer
1061                  */
1062                 new_fb = vmalloc(new_len);
1063                 if (!new_fb) {
1064                         dl_err("Virtual framebuffer alloc failed\n");
1065                         goto error;
1066                 }
1067
1068                 if (info->screen_base) {
1069                         memcpy(new_fb, old_fb, old_len);
1070                         vfree(info->screen_base);
1071                 }
1072
1073                 info->screen_base = new_fb;
1074                 info->fix.smem_len = PAGE_ALIGN(new_len);
1075                 info->fix.smem_start = (unsigned long) new_fb;
1076                 info->flags = udlfb_info_flags;
1077
1078                 /*
1079                  * Second framebuffer copy to mirror the framebuffer state
1080                  * on the physical USB device. We can function without this.
1081                  * But with imperfect damage info we may send pixels over USB
1082                  * that were, in fact, unchanged - wasting limited USB bandwidth
1083                  */
1084                 new_back = vmalloc(new_len);
1085                 if (!new_back)
1086                         dl_info("No shadow/backing buffer allcoated\n");
1087                 else {
1088                         if (dev->backing_buffer)
1089                                 vfree(dev->backing_buffer);
1090                         dev->backing_buffer = new_back;
1091                         memset(dev->backing_buffer, 0, new_len);
1092                 }
1093         }
1094
1095         retval = 0;
1096
1097 error:
1098         return retval;
1099 }
1100
1101 /*
1102  * 1) Get EDID from hw, or use sw default
1103  * 2) Parse into various fb_info structs
1104  * 3) Allocate virtual framebuffer memory to back highest res mode
1105  *
1106  * Parses EDID into three places used by various parts of fbdev:
1107  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1108  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1109  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1110  *
1111  * If EDID is not readable/valid, then modelist is all VESA modes,
1112  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1113  * Returns 0 if successful
1114  */
1115 static int dlfb_setup_modes(struct dlfb_data *dev,
1116                            struct fb_info *info,
1117                            char *default_edid, size_t default_edid_size)
1118 {
1119         int i;
1120         const struct fb_videomode *default_vmode = NULL;
1121         int result = 0;
1122         char *edid;
1123         int tries = 3;
1124
1125         if (info->dev) /* only use mutex if info has been registered */
1126                 mutex_lock(&info->lock);
1127
1128         edid = kmalloc(MAX_EDID_SIZE, GFP_KERNEL);
1129         if (!edid) {
1130                 result = -ENOMEM;
1131                 goto error;
1132         }
1133
1134         fb_destroy_modelist(&info->modelist);
1135         memset(&info->monspecs, 0, sizeof(info->monspecs));
1136
1137         /*
1138          * Try to (re)read EDID from hardware first
1139          * EDID data may return, but not parse as valid
1140          * Try again a few times, in case of e.g. analog cable noise
1141          */
1142         while (tries--) {
1143
1144                 i = dlfb_get_edid(dev, edid, MAX_EDID_SIZE);
1145
1146                 if (i >= MIN_EDID_SIZE)
1147                         fb_edid_to_monspecs(edid, &info->monspecs);
1148
1149                 if (info->monspecs.modedb_len > 0) {
1150                         dev->edid = edid;
1151                         dev->edid_size = i;
1152                         break;
1153                 }
1154         }
1155
1156         /* If that fails, use a previously returned EDID if available */
1157         if (info->monspecs.modedb_len == 0) {
1158
1159                 dl_err("Unable to get valid EDID from device/display\n");
1160
1161                 if (dev->edid) {
1162                         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1163                         if (info->monspecs.modedb_len > 0)
1164                                 dl_err("Using previously queried EDID\n");
1165                 }
1166         }
1167
1168         /* If that fails, use the default EDID we were handed */
1169         if (info->monspecs.modedb_len == 0) {
1170                 if (default_edid_size >= MIN_EDID_SIZE) {
1171                         fb_edid_to_monspecs(default_edid, &info->monspecs);
1172                         if (info->monspecs.modedb_len > 0) {
1173                                 memcpy(edid, default_edid, default_edid_size);
1174                                 dev->edid = edid;
1175                                 dev->edid_size = default_edid_size;
1176                                 dl_err("Using default/backup EDID\n");
1177                         }
1178                 }
1179         }
1180
1181         /* If we've got modes, let's pick a best default mode */
1182         if (info->monspecs.modedb_len > 0) {
1183
1184                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1185                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1186                                 fb_add_videomode(&info->monspecs.modedb[i],
1187                                         &info->modelist);
1188                         else /* if we've removed top/best mode */
1189                                 info->monspecs.misc &= ~FB_MISC_1ST_DETAIL;
1190                 }
1191
1192                 default_vmode = fb_find_best_display(&info->monspecs,
1193                                                      &info->modelist);
1194         }
1195
1196         /* If everything else has failed, fall back to safe default mode */
1197         if (default_vmode == NULL) {
1198
1199                 struct fb_videomode fb_vmode = {0};
1200
1201                 /*
1202                  * Add the standard VESA modes to our modelist
1203                  * Since we don't have EDID, there may be modes that
1204                  * overspec monitor and/or are incorrect aspect ratio, etc.
1205                  * But at least the user has a chance to choose
1206                  */
1207                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1208                         if (dlfb_is_valid_mode((struct fb_videomode *)
1209                                                 &vesa_modes[i], info))
1210                                 fb_add_videomode(&vesa_modes[i],
1211                                                  &info->modelist);
1212                 }
1213
1214                 /*
1215                  * default to resolution safe for projectors
1216                  * (since they are most common case without EDID)
1217                  */
1218                 fb_vmode.xres = 800;
1219                 fb_vmode.yres = 600;
1220                 fb_vmode.refresh = 60;
1221                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1222                                                      &info->modelist);
1223         }
1224
1225         /* If we have good mode and no active clients*/
1226         if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1227
1228                 fb_videomode_to_var(&info->var, default_vmode);
1229                 dlfb_var_color_format(&info->var);
1230
1231                 /*
1232                  * with mode size info, we can now alloc our framebuffer.
1233                  */
1234                 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1235                 info->fix.line_length = info->var.xres *
1236                         (info->var.bits_per_pixel / 8);
1237
1238                 result = dlfb_realloc_framebuffer(dev, info);
1239
1240         } else
1241                 result = -EINVAL;
1242
1243 error:
1244         if (edid && (dev->edid != edid))
1245                 kfree(edid);
1246
1247         if (info->dev)
1248                 mutex_unlock(&info->lock);
1249
1250         return result;
1251 }
1252
1253 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1254                                    struct device_attribute *a, char *buf) {
1255         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1256         struct dlfb_data *dev = fb_info->par;
1257         return snprintf(buf, PAGE_SIZE, "%u\n",
1258                         atomic_read(&dev->bytes_rendered));
1259 }
1260
1261 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1262                                    struct device_attribute *a, char *buf) {
1263         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1264         struct dlfb_data *dev = fb_info->par;
1265         return snprintf(buf, PAGE_SIZE, "%u\n",
1266                         atomic_read(&dev->bytes_identical));
1267 }
1268
1269 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1270                                    struct device_attribute *a, char *buf) {
1271         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1272         struct dlfb_data *dev = fb_info->par;
1273         return snprintf(buf, PAGE_SIZE, "%u\n",
1274                         atomic_read(&dev->bytes_sent));
1275 }
1276
1277 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1278                                    struct device_attribute *a, char *buf) {
1279         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1280         struct dlfb_data *dev = fb_info->par;
1281         return snprintf(buf, PAGE_SIZE, "%u\n",
1282                         atomic_read(&dev->cpu_kcycles_used));
1283 }
1284
1285 static ssize_t edid_show(
1286                         struct file *filp,
1287                         struct kobject *kobj, struct bin_attribute *a,
1288                          char *buf, loff_t off, size_t count) {
1289         struct device *fbdev = container_of(kobj, struct device, kobj);
1290         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1291         struct dlfb_data *dev = fb_info->par;
1292
1293         if (dev->edid == NULL)
1294                 return 0;
1295
1296         if ((off >= dev->edid_size) || (count > dev->edid_size))
1297                 return 0;
1298
1299         if (off + count > dev->edid_size)
1300                 count = dev->edid_size - off;
1301
1302         dl_info("sysfs edid copy %p to %p, %d bytes\n",
1303                 dev->edid, buf, (int) count);
1304
1305         memcpy(buf, dev->edid, count);
1306
1307         return count;
1308 }
1309
1310
1311 static ssize_t metrics_reset_store(struct device *fbdev,
1312                            struct device_attribute *attr,
1313                            const char *buf, size_t count)
1314 {
1315         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1316         struct dlfb_data *dev = fb_info->par;
1317
1318         atomic_set(&dev->bytes_rendered, 0);
1319         atomic_set(&dev->bytes_identical, 0);
1320         atomic_set(&dev->bytes_sent, 0);
1321         atomic_set(&dev->cpu_kcycles_used, 0);
1322
1323         return count;
1324 }
1325
1326 static ssize_t use_defio_show(struct device *fbdev,
1327                                    struct device_attribute *a, char *buf) {
1328         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1329         struct dlfb_data *dev = fb_info->par;
1330         return snprintf(buf, PAGE_SIZE, "%d\n",
1331                         atomic_read(&dev->use_defio));
1332 }
1333
1334 static ssize_t use_defio_store(struct device *fbdev,
1335                            struct device_attribute *attr,
1336                            const char *buf, size_t count)
1337 {
1338         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1339         struct dlfb_data *dev = fb_info->par;
1340
1341         if (count > 0) {
1342                 if (buf[0] == '0')
1343                         atomic_set(&dev->use_defio, 0);
1344                 if (buf[0] == '1')
1345                         atomic_set(&dev->use_defio, 1);
1346         }
1347         return count;
1348 }
1349
1350 static struct bin_attribute edid_attr = {
1351         .attr.name = "edid",
1352         .attr.mode = 0444,
1353         .size = 128,
1354         .read = edid_show,
1355 };
1356
1357 static struct device_attribute fb_device_attrs[] = {
1358         __ATTR_RO(metrics_bytes_rendered),
1359         __ATTR_RO(metrics_bytes_identical),
1360         __ATTR_RO(metrics_bytes_sent),
1361         __ATTR_RO(metrics_cpu_kcycles_used),
1362         __ATTR(metrics_reset, S_IWUGO, NULL, metrics_reset_store),
1363         __ATTR_RW(use_defio),
1364 };
1365
1366 #ifdef CONFIG_FB_DEFERRED_IO
1367 static void dlfb_dpy_deferred_io(struct fb_info *info,
1368                                 struct list_head *pagelist)
1369 {
1370         struct page *cur;
1371         struct fb_deferred_io *fbdefio = info->fbdefio;
1372         struct dlfb_data *dev = info->par;
1373         struct urb *urb;
1374         char *cmd;
1375         cycles_t start_cycles, end_cycles;
1376         int bytes_sent = 0;
1377         int bytes_identical = 0;
1378         int bytes_rendered = 0;
1379
1380         if (!atomic_read(&dev->use_defio))
1381                 return;
1382
1383         if (!atomic_read(&dev->usb_active))
1384                 return;
1385
1386         start_cycles = get_cycles();
1387
1388         urb = dlfb_get_urb(dev);
1389         if (!urb)
1390                 return;
1391         cmd = urb->transfer_buffer;
1392
1393         /* walk the written page list and render each to device */
1394         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
1395                 dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
1396                                   &cmd, cur->index << PAGE_SHIFT,
1397                                   PAGE_SIZE, &bytes_identical, &bytes_sent);
1398                 bytes_rendered += PAGE_SIZE;
1399         }
1400
1401         if (cmd > (char *) urb->transfer_buffer) {
1402                 /* Send partial buffer remaining before exiting */
1403                 int len = cmd - (char *) urb->transfer_buffer;
1404                 dlfb_submit_urb(dev, urb, len);
1405                 bytes_sent += len;
1406         } else
1407                 dlfb_urb_completion(urb);
1408
1409         atomic_add(bytes_sent, &dev->bytes_sent);
1410         atomic_add(bytes_identical, &dev->bytes_identical);
1411         atomic_add(bytes_rendered, &dev->bytes_rendered);
1412         end_cycles = get_cycles();
1413         atomic_add(((unsigned int) ((end_cycles - start_cycles)
1414                     >> 10)), /* Kcycles */
1415                    &dev->cpu_kcycles_used);
1416 }
1417
1418 static struct fb_deferred_io dlfb_defio = {
1419         .delay          = 5,
1420         .deferred_io    = dlfb_dpy_deferred_io,
1421 };
1422
1423 #endif
1424
1425 /*
1426  * This is necessary before we can communicate with the display controller.
1427  */
1428 static int dlfb_select_std_channel(struct dlfb_data *dev)
1429 {
1430         int ret;
1431         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1432                                 0x1C, 0x88, 0x5E, 0x15,
1433                                 0x60, 0xFE, 0xC6, 0x97,
1434                                 0x16, 0x3D, 0x47, 0xF2  };
1435
1436         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1437                         NR_USB_REQUEST_CHANNEL,
1438                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1439                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1440         return ret;
1441 }
1442
1443 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1444                                         struct usb_device *usbdev)
1445 {
1446         char *desc;
1447         char *buf;
1448         char *desc_end;
1449
1450         u8 total_len = 0;
1451
1452         buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1453         if (!buf)
1454                 return false;
1455         desc = buf;
1456
1457         total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
1458                                     0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1459         if (total_len > 5) {
1460                 dl_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1461                         "%02x %02x %02x %02x %02x %02x %02x\n",
1462                         total_len, desc[0],
1463                         desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1464                         desc[7], desc[8], desc[9], desc[10]);
1465
1466                 if ((desc[0] != total_len) || /* descriptor length */
1467                     (desc[1] != 0x5f) ||   /* vendor descriptor type */
1468                     (desc[2] != 0x01) ||   /* version (2 bytes) */
1469                     (desc[3] != 0x00) ||
1470                     (desc[4] != total_len - 2)) /* length after type */
1471                         goto unrecognized;
1472
1473                 desc_end = desc + total_len;
1474                 desc += 5; /* the fixed header we've already parsed */
1475
1476                 while (desc < desc_end) {
1477                         u8 length;
1478                         u16 key;
1479
1480                         key = *((u16 *) desc);
1481                         desc += sizeof(u16);
1482                         length = *desc;
1483                         desc++;
1484
1485                         switch (key) {
1486                         case 0x0200: { /* max_area */
1487                                 u32 max_area;
1488                                 max_area = le32_to_cpu(*((u32 *)desc));
1489                                 dl_warn("DL chip limited to %d pixel modes\n",
1490                                         max_area);
1491                                 dev->sku_pixel_limit = max_area;
1492                                 break;
1493                         }
1494                         default:
1495                                 break;
1496                         }
1497                         desc += length;
1498                 }
1499         }
1500
1501         goto success;
1502
1503 unrecognized:
1504         /* allow udlfb to load for now even if firmware unrecognized */
1505         dl_err("Unrecognized vendor firmware descriptor\n");
1506
1507 success:
1508         kfree(buf);
1509         return true;
1510 }
1511 static int dlfb_usb_probe(struct usb_interface *interface,
1512                         const struct usb_device_id *id)
1513 {
1514         struct usb_device *usbdev;
1515         struct dlfb_data *dev = 0;
1516         struct fb_info *info = 0;
1517         int i;
1518         int retval = -ENOMEM;
1519
1520         /* usb initialization */
1521
1522         usbdev = interface_to_usbdev(interface);
1523
1524         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1525         if (dev == NULL) {
1526                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1527                 goto error;
1528         }
1529
1530         /* we need to wait for both usb and fbdev to spin down on disconnect */
1531         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1532         kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1533
1534         dev->udev = usbdev;
1535         dev->gdev = &usbdev->dev; /* our generic struct device * */
1536         usb_set_intfdata(interface, dev);
1537
1538         dl_info("%s %s - serial #%s\n",
1539                 usbdev->manufacturer, usbdev->product, usbdev->serial);
1540         dl_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1541                 usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1542                 usbdev->descriptor.bcdDevice, dev);
1543
1544         dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1545
1546         if (!dlfb_parse_vendor_descriptor(dev, usbdev)) {
1547                 dl_err("firmware not recognized. Assume incompatible device\n");
1548                 goto error;
1549         }
1550
1551         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1552                 retval = -ENOMEM;
1553                 dl_err("dlfb_alloc_urb_list failed\n");
1554                 goto error;
1555         }
1556
1557         /* We don't register a new USB class. Our client interface is fbdev */
1558
1559         /* allocates framebuffer driver structure, not framebuffer memory */
1560         info = framebuffer_alloc(0, &usbdev->dev);
1561         if (!info) {
1562                 retval = -ENOMEM;
1563                 dl_err("framebuffer_alloc failed\n");
1564                 goto error;
1565         }
1566
1567         dev->info = info;
1568         info->par = dev;
1569         info->pseudo_palette = dev->pseudo_palette;
1570         info->fbops = &dlfb_ops;
1571
1572         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1573         if (retval < 0) {
1574                 dl_err("fb_alloc_cmap failed %x\n", retval);
1575                 goto error;
1576         }
1577
1578         INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1579                           dlfb_free_framebuffer_work);
1580
1581         INIT_LIST_HEAD(&info->modelist);
1582
1583         retval = dlfb_setup_modes(dev, info, NULL, 0);
1584         if (retval != 0) {
1585                 dl_err("unable to find common mode for display and adapter\n");
1586                 goto error;
1587         }
1588
1589         /* ready to begin using device */
1590
1591 #ifdef CONFIG_FB_DEFERRED_IO
1592         atomic_set(&dev->use_defio, 1);
1593 #endif
1594         atomic_set(&dev->usb_active, 1);
1595         dlfb_select_std_channel(dev);
1596
1597         dlfb_ops_check_var(&info->var, info);
1598         dlfb_ops_set_par(info);
1599
1600         retval = register_framebuffer(info);
1601         if (retval < 0) {
1602                 dl_err("register_framebuffer failed %d\n", retval);
1603                 goto error;
1604         }
1605
1606         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1607                 device_create_file(info->dev, &fb_device_attrs[i]);
1608
1609         device_create_bin_file(info->dev, &edid_attr);
1610
1611         dl_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1612                         " Using %dK framebuffer memory\n", info->node,
1613                         info->var.xres, info->var.yres,
1614                         ((dev->backing_buffer) ?
1615                         info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1616         return 0;
1617
1618 error:
1619         if (dev) {
1620
1621                 if (info) {
1622                         if (info->cmap.len != 0)
1623                                 fb_dealloc_cmap(&info->cmap);
1624                         if (info->monspecs.modedb)
1625                                 fb_destroy_modedb(info->monspecs.modedb);
1626                         if (info->screen_base)
1627                                 vfree(info->screen_base);
1628
1629                         fb_destroy_modelist(&info->modelist);
1630
1631                         framebuffer_release(info);
1632                 }
1633
1634                 if (dev->backing_buffer)
1635                         vfree(dev->backing_buffer);
1636
1637                 kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1638                 kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1639
1640                 /* dev has been deallocated. Do not dereference */
1641         }
1642
1643         return retval;
1644 }
1645
1646 static void dlfb_usb_disconnect(struct usb_interface *interface)
1647 {
1648         struct dlfb_data *dev;
1649         struct fb_info *info;
1650         int i;
1651
1652         dev = usb_get_intfdata(interface);
1653         info = dev->info;
1654
1655         dl_info("USB disconnect starting\n");
1656
1657         /* we virtualize until all fb clients release. Then we free */
1658         dev->virtualized = true;
1659
1660         /* When non-active we'll update virtual framebuffer, but no new urbs */
1661         atomic_set(&dev->usb_active, 0);
1662
1663         /* remove udlfb's sysfs interfaces */
1664         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1665                 device_remove_file(info->dev, &fb_device_attrs[i]);
1666         device_remove_bin_file(info->dev, &edid_attr);
1667
1668         usb_set_intfdata(interface, NULL);
1669
1670         /* if clients still have us open, will be freed on last close */
1671         if (dev->fb_count == 0)
1672                 schedule_delayed_work(&dev->free_framebuffer_work, 0);
1673
1674         /* release reference taken by kref_init in probe() */
1675         kref_put(&dev->kref, dlfb_free);
1676
1677         /* consider dlfb_data freed */
1678
1679         return;
1680 }
1681
1682 static struct usb_driver dlfb_driver = {
1683         .name = "udlfb",
1684         .probe = dlfb_usb_probe,
1685         .disconnect = dlfb_usb_disconnect,
1686         .id_table = id_table,
1687 };
1688
1689 static int __init dlfb_module_init(void)
1690 {
1691         int res;
1692
1693         res = usb_register(&dlfb_driver);
1694         if (res)
1695                 err("usb_register failed. Error number %d", res);
1696
1697         return res;
1698 }
1699
1700 static void __exit dlfb_module_exit(void)
1701 {
1702         usb_deregister(&dlfb_driver);
1703 }
1704
1705 module_init(dlfb_module_init);
1706 module_exit(dlfb_module_exit);
1707
1708 static void dlfb_urb_completion(struct urb *urb)
1709 {
1710         struct urb_node *unode = urb->context;
1711         struct dlfb_data *dev = unode->dev;
1712         unsigned long flags;
1713
1714         /* sync/async unlink faults aren't errors */
1715         if (urb->status) {
1716                 if (!(urb->status == -ENOENT ||
1717                     urb->status == -ECONNRESET ||
1718                     urb->status == -ESHUTDOWN)) {
1719                         dl_err("%s - nonzero write bulk status received: %d\n",
1720                                 __func__, urb->status);
1721                         atomic_set(&dev->lost_pixels, 1);
1722                 }
1723         }
1724
1725         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1726
1727         spin_lock_irqsave(&dev->urbs.lock, flags);
1728         list_add_tail(&unode->entry, &dev->urbs.list);
1729         dev->urbs.available++;
1730         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1731
1732         up(&dev->urbs.limit_sem);
1733 }
1734
1735 static void dlfb_free_urb_list(struct dlfb_data *dev)
1736 {
1737         int count = dev->urbs.count;
1738         struct list_head *node;
1739         struct urb_node *unode;
1740         struct urb *urb;
1741         int ret;
1742         unsigned long flags;
1743
1744         dl_notice("Waiting for completes and freeing all render urbs\n");
1745
1746         /* keep waiting and freeing, until we've got 'em all */
1747         while (count--) {
1748
1749                 /* Getting interrupted means a leak, but ok at shutdown*/
1750                 ret = down_interruptible(&dev->urbs.limit_sem);
1751                 if (ret)
1752                         break;
1753
1754                 spin_lock_irqsave(&dev->urbs.lock, flags);
1755
1756                 node = dev->urbs.list.next; /* have reserved one with sem */
1757                 list_del_init(node);
1758
1759                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1760
1761                 unode = list_entry(node, struct urb_node, entry);
1762                 urb = unode->urb;
1763
1764                 /* Free each separately allocated piece */
1765                 usb_free_coherent(urb->dev, dev->urbs.size,
1766                                   urb->transfer_buffer, urb->transfer_dma);
1767                 usb_free_urb(urb);
1768                 kfree(node);
1769         }
1770
1771 }
1772
1773 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1774 {
1775         int i = 0;
1776         struct urb *urb;
1777         struct urb_node *unode;
1778         char *buf;
1779
1780         spin_lock_init(&dev->urbs.lock);
1781
1782         dev->urbs.size = size;
1783         INIT_LIST_HEAD(&dev->urbs.list);
1784
1785         while (i < count) {
1786                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1787                 if (!unode)
1788                         break;
1789                 unode->dev = dev;
1790
1791                 urb = usb_alloc_urb(0, GFP_KERNEL);
1792                 if (!urb) {
1793                         kfree(unode);
1794                         break;
1795                 }
1796                 unode->urb = urb;
1797
1798                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1799                                          &urb->transfer_dma);
1800                 if (!buf) {
1801                         kfree(unode);
1802                         usb_free_urb(urb);
1803                         break;
1804                 }
1805
1806                 /* urb->transfer_buffer_length set to actual before submit */
1807                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1808                         buf, size, dlfb_urb_completion, unode);
1809                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1810
1811                 list_add_tail(&unode->entry, &dev->urbs.list);
1812
1813                 i++;
1814         }
1815
1816         sema_init(&dev->urbs.limit_sem, i);
1817         dev->urbs.count = i;
1818         dev->urbs.available = i;
1819
1820         dl_notice("allocated %d %d byte urbs\n", i, (int) size);
1821
1822         return i;
1823 }
1824
1825 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1826 {
1827         int ret = 0;
1828         struct list_head *entry;
1829         struct urb_node *unode;
1830         struct urb *urb = NULL;
1831         unsigned long flags;
1832
1833         /* Wait for an in-flight buffer to complete and get re-queued */
1834         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1835         if (ret) {
1836                 atomic_set(&dev->lost_pixels, 1);
1837                 dl_err("wait for urb interrupted: %x\n", ret);
1838                 goto error;
1839         }
1840
1841         spin_lock_irqsave(&dev->urbs.lock, flags);
1842
1843         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1844         entry = dev->urbs.list.next;
1845         list_del_init(entry);
1846         dev->urbs.available--;
1847
1848         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1849
1850         unode = list_entry(entry, struct urb_node, entry);
1851         urb = unode->urb;
1852
1853 error:
1854         return urb;
1855 }
1856
1857 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1858 {
1859         int ret;
1860
1861         BUG_ON(len > dev->urbs.size);
1862
1863         urb->transfer_buffer_length = len; /* set to actual payload len */
1864         ret = usb_submit_urb(urb, GFP_KERNEL);
1865         if (ret) {
1866                 dlfb_urb_completion(urb); /* because no one else will */
1867                 atomic_set(&dev->lost_pixels, 1);
1868                 dl_err("usb_submit_urb error %x\n", ret);
1869         }
1870         return ret;
1871 }
1872
1873 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1874               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1875               "Bernie Thompson <bernie@plugable.com>");
1876 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1877 MODULE_LICENSE("GPL");
1878