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