drivers/video/fbdev/udlfb.c

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This source file includes following definitions.
dlfb_set_register
dlfb_vidreg_lock
dlfb_vidreg_unlock
dlfb_blanking
dlfb_set_color_depth
dlfb_set_base16bpp
dlfb_set_base8bpp
dlfb_set_register_16
dlfb_set_register_16be
dlfb_lfsr16
dlfb_set_register_lfsr16
dlfb_set_vid_cmds
dlfb_set_video_mode
dlfb_ops_mmap
dlfb_trim_hline
dlfb_compress_hline
dlfb_render_hline
dlfb_handle_damage
dlfb_init_damage
dlfb_damage_work
dlfb_offload_damage
dlfb_ops_write
dlfb_ops_copyarea
dlfb_ops_imageblit
dlfb_ops_fillrect
dlfb_dpy_deferred_io
dlfb_get_edid
dlfb_ops_ioctl
dlfb_ops_setcolreg
dlfb_ops_open
dlfb_ops_destroy
dlfb_ops_release
dlfb_is_valid_mode
dlfb_var_color_format
dlfb_ops_check_var
dlfb_ops_set_par
dlfb_dummy_render
dlfb_ops_blank
dlfb_deferred_vfree
dlfb_realloc_framebuffer
dlfb_setup_modes
metrics_bytes_rendered_show
metrics_bytes_identical_show
metrics_bytes_sent_show
metrics_cpu_kcycles_used_show
edid_show
edid_store
metrics_reset_store
dlfb_select_std_channel
dlfb_parse_vendor_descriptor
dlfb_usb_probe
dlfb_usb_disconnect
dlfb_urb_completion
dlfb_free_urb_list
dlfb_alloc_urb_list
dlfb_get_urb
dlfb_submit_urb
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * udlfb.c -- Framebuffer driver for DisplayLink USB controller
   4  *
   5  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
   6  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
   7  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
   8  *
   9  * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
  10  * usb-skeleton by GregKH.
  11  *
  12  * Device-specific portions based on information from Displaylink, with work
  13  * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
  14  */
  15 
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/usb.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/mm.h>
  22 #include <linux/fb.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/delay.h>
  26 #include <asm/unaligned.h>
  27 #include <video/udlfb.h>
  28 #include "edid.h"
  29 
  30 static const struct fb_fix_screeninfo dlfb_fix = {
  31         .id =           "udlfb",
  32         .type =         FB_TYPE_PACKED_PIXELS,
  33         .visual =       FB_VISUAL_TRUECOLOR,
  34         .xpanstep =     0,
  35         .ypanstep =     0,
  36         .ywrapstep =    0,
  37         .accel =        FB_ACCEL_NONE,
  38 };
  39 
  40 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
  41                 FBINFO_VIRTFB |
  42                 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
  43                 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
  44 
  45 /*
  46  * There are many DisplayLink-based graphics products, all with unique PIDs.
  47  * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
  48  * We also require a match on SubClass (0x00) and Protocol (0x00),
  49  * which is compatible with all known USB 2.0 era graphics chips and firmware,
  50  * but allows DisplayLink to increment those for any future incompatible chips
  51  */
  52 static const struct usb_device_id id_table[] = {
  53         {.idVendor = 0x17e9,
  54          .bInterfaceClass = 0xff,
  55          .bInterfaceSubClass = 0x00,
  56          .bInterfaceProtocol = 0x00,
  57          .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
  58                 USB_DEVICE_ID_MATCH_INT_CLASS |
  59                 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
  60                 USB_DEVICE_ID_MATCH_INT_PROTOCOL,
  61         },
  62         {},
  63 };
  64 MODULE_DEVICE_TABLE(usb, id_table);
  65 
  66 /* module options */
  67 static bool console = 1; /* Allow fbcon to open framebuffer */
  68 static bool fb_defio = 1;  /* Detect mmap writes using page faults */
  69 static bool shadow = 1; /* Optionally disable shadow framebuffer */
  70 static int pixel_limit; /* Optionally force a pixel resolution limit */
  71 
  72 struct dlfb_deferred_free {
  73         struct list_head list;
  74         void *mem;
  75 };
  76 
  77 static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len);
  78 
  79 /* dlfb keeps a list of urbs for efficient bulk transfers */
  80 static void dlfb_urb_completion(struct urb *urb);
  81 static struct urb *dlfb_get_urb(struct dlfb_data *dlfb);
  82 static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb * urb, size_t len);
  83 static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size);
  84 static void dlfb_free_urb_list(struct dlfb_data *dlfb);
  85 
  86 /*
  87  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  88  * All operations are written to buffers which then later get sent to device
  89  */
  90 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
  91 {
  92         *buf++ = 0xAF;
  93         *buf++ = 0x20;
  94         *buf++ = reg;
  95         *buf++ = val;
  96         return buf;
  97 }
  98 
  99 static char *dlfb_vidreg_lock(char *buf)
 100 {
 101         return dlfb_set_register(buf, 0xFF, 0x00);
 102 }
 103 
 104 static char *dlfb_vidreg_unlock(char *buf)
 105 {
 106         return dlfb_set_register(buf, 0xFF, 0xFF);
 107 }
 108 
 109 /*
 110  * Map FB_BLANK_* to DisplayLink register
 111  * DLReg FB_BLANK_*
 112  * ----- -----------------------------
 113  *  0x00 FB_BLANK_UNBLANK (0)
 114  *  0x01 FB_BLANK (1)
 115  *  0x03 FB_BLANK_VSYNC_SUSPEND (2)
 116  *  0x05 FB_BLANK_HSYNC_SUSPEND (3)
 117  *  0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
 118  */
 119 static char *dlfb_blanking(char *buf, int fb_blank)
 120 {
 121         u8 reg;
 122 
 123         switch (fb_blank) {
 124         case FB_BLANK_POWERDOWN:
 125                 reg = 0x07;
 126                 break;
 127         case FB_BLANK_HSYNC_SUSPEND:
 128                 reg = 0x05;
 129                 break;
 130         case FB_BLANK_VSYNC_SUSPEND:
 131                 reg = 0x03;
 132                 break;
 133         case FB_BLANK_NORMAL:
 134                 reg = 0x01;
 135                 break;
 136         default:
 137                 reg = 0x00;
 138         }
 139 
 140         buf = dlfb_set_register(buf, 0x1F, reg);
 141 
 142         return buf;
 143 }
 144 
 145 static char *dlfb_set_color_depth(char *buf, u8 selection)
 146 {
 147         return dlfb_set_register(buf, 0x00, selection);
 148 }
 149 
 150 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 151 {
 152         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 153         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 154         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 155         return dlfb_set_register(wrptr, 0x22, base);
 156 }
 157 
 158 /*
 159  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 160  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 161  */
 162 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 163 {
 164         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 165         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 166         return dlfb_set_register(wrptr, 0x28, base);
 167 }
 168 
 169 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 170 {
 171         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 172         return dlfb_set_register(wrptr, reg+1, value);
 173 }
 174 
 175 /*
 176  * This is kind of weird because the controller takes some
 177  * register values in a different byte order than other registers.
 178  */
 179 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 180 {
 181         wrptr = dlfb_set_register(wrptr, reg, value);
 182         return dlfb_set_register(wrptr, reg+1, value >> 8);
 183 }
 184 
 185 /*
 186  * LFSR is linear feedback shift register. The reason we have this is
 187  * because the display controller needs to minimize the clock depth of
 188  * various counters used in the display path. So this code reverses the
 189  * provided value into the lfsr16 value by counting backwards to get
 190  * the value that needs to be set in the hardware comparator to get the
 191  * same actual count. This makes sense once you read above a couple of
 192  * times and think about it from a hardware perspective.
 193  */
 194 static u16 dlfb_lfsr16(u16 actual_count)
 195 {
 196         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 197 
 198         while (actual_count--) {
 199                 lv =     ((lv << 1) |
 200                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 201                         & 0xFFFF;
 202         }
 203 
 204         return (u16) lv;
 205 }
 206 
 207 /*
 208  * This does LFSR conversion on the value that is to be written.
 209  * See LFSR explanation above for more detail.
 210  */
 211 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 212 {
 213         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 214 }
 215 
 216 /*
 217  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 218  * details and converts them into the DisplayLink equivalent register commands.
 219  */
 220 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 221 {
 222         u16 xds, yds;
 223         u16 xde, yde;
 224         u16 yec;
 225 
 226         /* x display start */
 227         xds = var->left_margin + var->hsync_len;
 228         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 229         /* x display end */
 230         xde = xds + var->xres;
 231         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 232 
 233         /* y display start */
 234         yds = var->upper_margin + var->vsync_len;
 235         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 236         /* y display end */
 237         yde = yds + var->yres;
 238         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 239 
 240         /* x end count is active + blanking - 1 */
 241         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 242                         xde + var->right_margin - 1);
 243 
 244         /* libdlo hardcodes hsync start to 1 */
 245         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 246 
 247         /* hsync end is width of sync pulse + 1 */
 248         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 249 
 250         /* hpixels is active pixels */
 251         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 252 
 253         /* yendcount is vertical active + vertical blanking */
 254         yec = var->yres + var->upper_margin + var->lower_margin +
 255                         var->vsync_len;
 256         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 257 
 258         /* libdlo hardcodes vsync start to 0 */
 259         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 260 
 261         /* vsync end is width of vsync pulse */
 262         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 263 
 264         /* vpixels is active pixels */
 265         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 266 
 267         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 268         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 269                         200*1000*1000/var->pixclock);
 270 
 271         return wrptr;
 272 }
 273 
 274 /*
 275  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 276  * and then generates the appropriate command sequence that then drives the
 277  * display controller.
 278  */
 279 static int dlfb_set_video_mode(struct dlfb_data *dlfb,
 280                                 struct fb_var_screeninfo *var)
 281 {
 282         char *buf;
 283         char *wrptr;
 284         int retval;
 285         int writesize;
 286         struct urb *urb;
 287 
 288         if (!atomic_read(&dlfb->usb_active))
 289                 return -EPERM;
 290 
 291         urb = dlfb_get_urb(dlfb);
 292         if (!urb)
 293                 return -ENOMEM;
 294 
 295         buf = (char *) urb->transfer_buffer;
 296 
 297         /*
 298         * This first section has to do with setting the base address on the
 299         * controller * associated with the display. There are 2 base
 300         * pointers, currently, we only * use the 16 bpp segment.
 301         */
 302         wrptr = dlfb_vidreg_lock(buf);
 303         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 304         /* set base for 16bpp segment to 0 */
 305         wrptr = dlfb_set_base16bpp(wrptr, 0);
 306         /* set base for 8bpp segment to end of fb */
 307         wrptr = dlfb_set_base8bpp(wrptr, dlfb->info->fix.smem_len);
 308 
 309         wrptr = dlfb_set_vid_cmds(wrptr, var);
 310         wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
 311         wrptr = dlfb_vidreg_unlock(wrptr);
 312 
 313         writesize = wrptr - buf;
 314 
 315         retval = dlfb_submit_urb(dlfb, urb, writesize);
 316 
 317         dlfb->blank_mode = FB_BLANK_UNBLANK;
 318 
 319         return retval;
 320 }
 321 
 322 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 323 {
 324         unsigned long start = vma->vm_start;
 325         unsigned long size = vma->vm_end - vma->vm_start;
 326         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 327         unsigned long page, pos;
 328 
 329         if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
 330                 return -EINVAL;
 331         if (size > info->fix.smem_len)
 332                 return -EINVAL;
 333         if (offset > info->fix.smem_len - size)
 334                 return -EINVAL;
 335 
 336         pos = (unsigned long)info->fix.smem_start + offset;
 337 
 338         dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n",
 339                 pos, size);
 340 
 341         while (size > 0) {
 342                 page = vmalloc_to_pfn((void *)pos);
 343                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 344                         return -EAGAIN;
 345 
 346                 start += PAGE_SIZE;
 347                 pos += PAGE_SIZE;
 348                 if (size > PAGE_SIZE)
 349                         size -= PAGE_SIZE;
 350                 else
 351                         size = 0;
 352         }
 353 
 354         return 0;
 355 }
 356 
 357 /*
 358  * Trims identical data from front and back of line
 359  * Sets new front buffer address and width
 360  * And returns byte count of identical pixels
 361  * Assumes CPU natural alignment (unsigned long)
 362  * for back and front buffer ptrs and width
 363  */
 364 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 365 {
 366         int j, k;
 367         const unsigned long *back = (const unsigned long *) bback;
 368         const unsigned long *front = (const unsigned long *) *bfront;
 369         const int width = *width_bytes / sizeof(unsigned long);
 370         int identical = width;
 371         int start = width;
 372         int end = width;
 373 
 374         for (j = 0; j < width; j++) {
 375                 if (back[j] != front[j]) {
 376                         start = j;
 377                         break;
 378                 }
 379         }
 380 
 381         for (k = width - 1; k > j; k--) {
 382                 if (back[k] != front[k]) {
 383                         end = k+1;
 384                         break;
 385                 }
 386         }
 387 
 388         identical = start + (width - end);
 389         *bfront = (u8 *) &front[start];
 390         *width_bytes = (end - start) * sizeof(unsigned long);
 391 
 392         return identical * sizeof(unsigned long);
 393 }
 394 
 395 /*
 396  * Render a command stream for an encoded horizontal line segment of pixels.
 397  *
 398  * A command buffer holds several commands.
 399  * It always begins with a fresh command header
 400  * (the protocol doesn't require this, but we enforce it to allow
 401  * multiple buffers to be potentially encoded and sent in parallel).
 402  * A single command encodes one contiguous horizontal line of pixels
 403  *
 404  * The function relies on the client to do all allocation, so that
 405  * rendering can be done directly to output buffers (e.g. USB URBs).
 406  * The function fills the supplied command buffer, providing information
 407  * on where it left off, so the client may call in again with additional
 408  * buffers if the line will take several buffers to complete.
 409  *
 410  * A single command can transmit a maximum of 256 pixels,
 411  * regardless of the compression ratio (protocol design limit).
 412  * To the hardware, 0 for a size byte means 256
 413  *
 414  * Rather than 256 pixel commands which are either rl or raw encoded,
 415  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 416  * This has a slightly larger header overhead, but produces more even results.
 417  * It also processes all data (read and write) in a single pass.
 418  * Performance benchmarks of common cases show it having just slightly better
 419  * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
 420  * But for very rl friendly data, will compress not quite as well.
 421  */
 422 static void dlfb_compress_hline(
 423         const uint16_t **pixel_start_ptr,
 424         const uint16_t *const pixel_end,
 425         uint32_t *device_address_ptr,
 426         uint8_t **command_buffer_ptr,
 427         const uint8_t *const cmd_buffer_end,
 428         unsigned long back_buffer_offset,
 429         int *ident_ptr)
 430 {
 431         const uint16_t *pixel = *pixel_start_ptr;
 432         uint32_t dev_addr  = *device_address_ptr;
 433         uint8_t *cmd = *command_buffer_ptr;
 434 
 435         while ((pixel_end > pixel) &&
 436                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 437                 uint8_t *raw_pixels_count_byte = NULL;
 438                 uint8_t *cmd_pixels_count_byte = NULL;
 439                 const uint16_t *raw_pixel_start = NULL;
 440                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL;
 441 
 442                 if (back_buffer_offset &&
 443                     *pixel == *(u16 *)((u8 *)pixel + back_buffer_offset)) {
 444                         pixel++;
 445                         dev_addr += BPP;
 446                         (*ident_ptr)++;
 447                         continue;
 448                 }
 449 
 450                 *cmd++ = 0xAF;
 451                 *cmd++ = 0x6B;
 452                 *cmd++ = dev_addr >> 16;
 453                 *cmd++ = dev_addr >> 8;
 454                 *cmd++ = dev_addr;
 455 
 456                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
 457                 cmd_pixel_start = pixel;
 458 
 459                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
 460                 raw_pixel_start = pixel;
 461 
 462                 cmd_pixel_end = pixel + min3(MAX_CMD_PIXELS + 1UL,
 463                                         (unsigned long)(pixel_end - pixel),
 464                                         (unsigned long)(cmd_buffer_end - 1 - cmd) / BPP);
 465 
 466                 if (back_buffer_offset) {
 467                         /* note: the framebuffer may change under us, so we must test for underflow */
 468                         while (cmd_pixel_end - 1 > pixel &&
 469                                *(cmd_pixel_end - 1) == *(u16 *)((u8 *)(cmd_pixel_end - 1) + back_buffer_offset))
 470                                 cmd_pixel_end--;
 471                 }
 472 
 473                 while (pixel < cmd_pixel_end) {
 474                         const uint16_t * const repeating_pixel = pixel;
 475                         u16 pixel_value = *pixel;
 476 
 477                         put_unaligned_be16(pixel_value, cmd);
 478                         if (back_buffer_offset)
 479                                 *(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value;
 480                         cmd += 2;
 481                         pixel++;
 482 
 483                         if (unlikely((pixel < cmd_pixel_end) &&
 484                                      (*pixel == pixel_value))) {
 485                                 /* go back and fill in raw pixel count */
 486                                 *raw_pixels_count_byte = ((repeating_pixel -
 487                                                 raw_pixel_start) + 1) & 0xFF;
 488 
 489                                 do {
 490                                         if (back_buffer_offset)
 491                                                 *(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value;
 492                                         pixel++;
 493                                 } while ((pixel < cmd_pixel_end) &&
 494                                          (*pixel == pixel_value));
 495 
 496                                 /* immediately after raw data is repeat byte */
 497                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
 498 
 499                                 /* Then start another raw pixel span */
 500                                 raw_pixel_start = pixel;
 501                                 raw_pixels_count_byte = cmd++;
 502                         }
 503                 }
 504 
 505                 if (pixel > raw_pixel_start) {
 506                         /* finalize last RAW span */
 507                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
 508                 } else {
 509                         /* undo unused byte */
 510                         cmd--;
 511                 }
 512 
 513                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
 514                 dev_addr += (u8 *)pixel - (u8 *)cmd_pixel_start;
 515         }
 516 
 517         if (cmd_buffer_end - MIN_RLX_CMD_BYTES <= cmd) {
 518                 /* Fill leftover bytes with no-ops */
 519                 if (cmd_buffer_end > cmd)
 520                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
 521                 cmd = (uint8_t *) cmd_buffer_end;
 522         }
 523 
 524         *command_buffer_ptr = cmd;
 525         *pixel_start_ptr = pixel;
 526         *device_address_ptr = dev_addr;
 527 }
 528 
 529 /*
 530  * There are 3 copies of every pixel: The front buffer that the fbdev
 531  * client renders to, the actual framebuffer across the USB bus in hardware
 532  * (that we can only write to, slowly, and can never read), and (optionally)
 533  * our shadow copy that tracks what's been sent to that hardware buffer.
 534  */
 535 static int dlfb_render_hline(struct dlfb_data *dlfb, struct urb **urb_ptr,
 536                               const char *front, char **urb_buf_ptr,
 537                               u32 byte_offset, u32 byte_width,
 538                               int *ident_ptr, int *sent_ptr)
 539 {
 540         const u8 *line_start, *line_end, *next_pixel;
 541         u32 dev_addr = dlfb->base16 + byte_offset;
 542         struct urb *urb = *urb_ptr;
 543         u8 *cmd = *urb_buf_ptr;
 544         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
 545         unsigned long back_buffer_offset = 0;
 546 
 547         line_start = (u8 *) (front + byte_offset);
 548         next_pixel = line_start;
 549         line_end = next_pixel + byte_width;
 550 
 551         if (dlfb->backing_buffer) {
 552                 int offset;
 553                 const u8 *back_start = (u8 *) (dlfb->backing_buffer
 554                                                 + byte_offset);
 555 
 556                 back_buffer_offset = (unsigned long)back_start - (unsigned long)line_start;
 557 
 558                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
 559                         &byte_width);
 560 
 561                 offset = next_pixel - line_start;
 562                 line_end = next_pixel + byte_width;
 563                 dev_addr += offset;
 564                 back_start += offset;
 565                 line_start += offset;
 566         }
 567 
 568         while (next_pixel < line_end) {
 569 
 570                 dlfb_compress_hline((const uint16_t **) &next_pixel,
 571                              (const uint16_t *) line_end, &dev_addr,
 572                         (u8 **) &cmd, (u8 *) cmd_end, back_buffer_offset,
 573                         ident_ptr);
 574 
 575                 if (cmd >= cmd_end) {
 576                         int len = cmd - (u8 *) urb->transfer_buffer;
 577                         if (dlfb_submit_urb(dlfb, urb, len))
 578                                 return 1; /* lost pixels is set */
 579                         *sent_ptr += len;
 580                         urb = dlfb_get_urb(dlfb);
 581                         if (!urb)
 582                                 return 1; /* lost_pixels is set */
 583                         *urb_ptr = urb;
 584                         cmd = urb->transfer_buffer;
 585                         cmd_end = &cmd[urb->transfer_buffer_length];
 586                 }
 587         }
 588 
 589         *urb_buf_ptr = cmd;
 590 
 591         return 0;
 592 }
 593 
 594 static int dlfb_handle_damage(struct dlfb_data *dlfb, int x, int y, int width, int height)
 595 {
 596         int i, ret;
 597         char *cmd;
 598         cycles_t start_cycles, end_cycles;
 599         int bytes_sent = 0;
 600         int bytes_identical = 0;
 601         struct urb *urb;
 602         int aligned_x;
 603 
 604         start_cycles = get_cycles();
 605 
 606         mutex_lock(&dlfb->render_mutex);
 607 
 608         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 609         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 610         x = aligned_x;
 611 
 612         if ((width <= 0) ||
 613             (x + width > dlfb->info->var.xres) ||
 614             (y + height > dlfb->info->var.yres)) {
 615                 ret = -EINVAL;
 616                 goto unlock_ret;
 617         }
 618 
 619         if (!atomic_read(&dlfb->usb_active)) {
 620                 ret = 0;
 621                 goto unlock_ret;
 622         }
 623 
 624         urb = dlfb_get_urb(dlfb);
 625         if (!urb) {
 626                 ret = 0;
 627                 goto unlock_ret;
 628         }
 629         cmd = urb->transfer_buffer;
 630 
 631         for (i = y; i < y + height ; i++) {
 632                 const int line_offset = dlfb->info->fix.line_length * i;
 633                 const int byte_offset = line_offset + (x * BPP);
 634 
 635                 if (dlfb_render_hline(dlfb, &urb,
 636                                       (char *) dlfb->info->fix.smem_start,
 637                                       &cmd, byte_offset, width * BPP,
 638                                       &bytes_identical, &bytes_sent))
 639                         goto error;
 640         }
 641 
 642         if (cmd > (char *) urb->transfer_buffer) {
 643                 int len;
 644                 if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length)
 645                         *cmd++ = 0xAF;
 646                 /* Send partial buffer remaining before exiting */
 647                 len = cmd - (char *) urb->transfer_buffer;
 648                 dlfb_submit_urb(dlfb, urb, len);
 649                 bytes_sent += len;
 650         } else
 651                 dlfb_urb_completion(urb);
 652 
 653 error:
 654         atomic_add(bytes_sent, &dlfb->bytes_sent);
 655         atomic_add(bytes_identical, &dlfb->bytes_identical);
 656         atomic_add(width*height*2, &dlfb->bytes_rendered);
 657         end_cycles = get_cycles();
 658         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 659                     >> 10)), /* Kcycles */
 660                    &dlfb->cpu_kcycles_used);
 661 
 662         ret = 0;
 663 
 664 unlock_ret:
 665         mutex_unlock(&dlfb->render_mutex);
 666         return ret;
 667 }
 668 
 669 static void dlfb_init_damage(struct dlfb_data *dlfb)
 670 {
 671         dlfb->damage_x = INT_MAX;
 672         dlfb->damage_x2 = 0;
 673         dlfb->damage_y = INT_MAX;
 674         dlfb->damage_y2 = 0;
 675 }
 676 
 677 static void dlfb_damage_work(struct work_struct *w)
 678 {
 679         struct dlfb_data *dlfb = container_of(w, struct dlfb_data, damage_work);
 680         int x, x2, y, y2;
 681 
 682         spin_lock_irq(&dlfb->damage_lock);
 683         x = dlfb->damage_x;
 684         x2 = dlfb->damage_x2;
 685         y = dlfb->damage_y;
 686         y2 = dlfb->damage_y2;
 687         dlfb_init_damage(dlfb);
 688         spin_unlock_irq(&dlfb->damage_lock);
 689 
 690         if (x < x2 && y < y2)
 691                 dlfb_handle_damage(dlfb, x, y, x2 - x, y2 - y);
 692 }
 693 
 694 static void dlfb_offload_damage(struct dlfb_data *dlfb, int x, int y, int width, int height)
 695 {
 696         unsigned long flags;
 697         int x2 = x + width;
 698         int y2 = y + height;
 699 
 700         if (x >= x2 || y >= y2)
 701                 return;
 702 
 703         spin_lock_irqsave(&dlfb->damage_lock, flags);
 704         dlfb->damage_x = min(x, dlfb->damage_x);
 705         dlfb->damage_x2 = max(x2, dlfb->damage_x2);
 706         dlfb->damage_y = min(y, dlfb->damage_y);
 707         dlfb->damage_y2 = max(y2, dlfb->damage_y2);
 708         spin_unlock_irqrestore(&dlfb->damage_lock, flags);
 709 
 710         schedule_work(&dlfb->damage_work);
 711 }
 712 
 713 /*
 714  * Path triggered by usermode clients who write to filesystem
 715  * e.g. cat filename > /dev/fb1
 716  * Not used by X Windows or text-mode console. But useful for testing.
 717  * Slow because of extra copy and we must assume all pixels dirty.
 718  */
 719 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
 720                           size_t count, loff_t *ppos)
 721 {
 722         ssize_t result;
 723         struct dlfb_data *dlfb = info->par;
 724         u32 offset = (u32) *ppos;
 725 
 726         result = fb_sys_write(info, buf, count, ppos);
 727 
 728         if (result > 0) {
 729                 int start = max((int)(offset / info->fix.line_length), 0);
 730                 int lines = min((u32)((result / info->fix.line_length) + 1),
 731                                 (u32)info->var.yres);
 732 
 733                 dlfb_handle_damage(dlfb, 0, start, info->var.xres,
 734                         lines);
 735         }
 736 
 737         return result;
 738 }
 739 
 740 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 741 static void dlfb_ops_copyarea(struct fb_info *info,
 742                                 const struct fb_copyarea *area)
 743 {
 744 
 745         struct dlfb_data *dlfb = info->par;
 746 
 747         sys_copyarea(info, area);
 748 
 749         dlfb_offload_damage(dlfb, area->dx, area->dy,
 750                         area->width, area->height);
 751 }
 752 
 753 static void dlfb_ops_imageblit(struct fb_info *info,
 754                                 const struct fb_image *image)
 755 {
 756         struct dlfb_data *dlfb = info->par;
 757 
 758         sys_imageblit(info, image);
 759 
 760         dlfb_offload_damage(dlfb, image->dx, image->dy,
 761                         image->width, image->height);
 762 }
 763 
 764 static void dlfb_ops_fillrect(struct fb_info *info,
 765                           const struct fb_fillrect *rect)
 766 {
 767         struct dlfb_data *dlfb = info->par;
 768 
 769         sys_fillrect(info, rect);
 770 
 771         dlfb_offload_damage(dlfb, rect->dx, rect->dy, rect->width,
 772                               rect->height);
 773 }
 774 
 775 /*
 776  * NOTE: fb_defio.c is holding info->fbdefio.mutex
 777  *   Touching ANY framebuffer memory that triggers a page fault
 778  *   in fb_defio will cause a deadlock, when it also tries to
 779  *   grab the same mutex.
 780  */
 781 static void dlfb_dpy_deferred_io(struct fb_info *info,
 782                                 struct list_head *pagelist)
 783 {
 784         struct page *cur;
 785         struct fb_deferred_io *fbdefio = info->fbdefio;
 786         struct dlfb_data *dlfb = info->par;
 787         struct urb *urb;
 788         char *cmd;
 789         cycles_t start_cycles, end_cycles;
 790         int bytes_sent = 0;
 791         int bytes_identical = 0;
 792         int bytes_rendered = 0;
 793 
 794         mutex_lock(&dlfb->render_mutex);
 795 
 796         if (!fb_defio)
 797                 goto unlock_ret;
 798 
 799         if (!atomic_read(&dlfb->usb_active))
 800                 goto unlock_ret;
 801 
 802         start_cycles = get_cycles();
 803 
 804         urb = dlfb_get_urb(dlfb);
 805         if (!urb)
 806                 goto unlock_ret;
 807 
 808         cmd = urb->transfer_buffer;
 809 
 810         /* walk the written page list and render each to device */
 811         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
 812 
 813                 if (dlfb_render_hline(dlfb, &urb, (char *) info->fix.smem_start,
 814                                   &cmd, cur->index << PAGE_SHIFT,
 815                                   PAGE_SIZE, &bytes_identical, &bytes_sent))
 816                         goto error;
 817                 bytes_rendered += PAGE_SIZE;
 818         }
 819 
 820         if (cmd > (char *) urb->transfer_buffer) {
 821                 int len;
 822                 if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length)
 823                         *cmd++ = 0xAF;
 824                 /* Send partial buffer remaining before exiting */
 825                 len = cmd - (char *) urb->transfer_buffer;
 826                 dlfb_submit_urb(dlfb, urb, len);
 827                 bytes_sent += len;
 828         } else
 829                 dlfb_urb_completion(urb);
 830 
 831 error:
 832         atomic_add(bytes_sent, &dlfb->bytes_sent);
 833         atomic_add(bytes_identical, &dlfb->bytes_identical);
 834         atomic_add(bytes_rendered, &dlfb->bytes_rendered);
 835         end_cycles = get_cycles();
 836         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 837                     >> 10)), /* Kcycles */
 838                    &dlfb->cpu_kcycles_used);
 839 unlock_ret:
 840         mutex_unlock(&dlfb->render_mutex);
 841 }
 842 
 843 static int dlfb_get_edid(struct dlfb_data *dlfb, char *edid, int len)
 844 {
 845         int i, ret;
 846         char *rbuf;
 847 
 848         rbuf = kmalloc(2, GFP_KERNEL);
 849         if (!rbuf)
 850                 return 0;
 851 
 852         for (i = 0; i < len; i++) {
 853                 ret = usb_control_msg(dlfb->udev,
 854                                       usb_rcvctrlpipe(dlfb->udev, 0), 0x02,
 855                                       (0x80 | (0x02 << 5)), i << 8, 0xA1,
 856                                       rbuf, 2, USB_CTRL_GET_TIMEOUT);
 857                 if (ret < 2) {
 858                         dev_err(&dlfb->udev->dev,
 859                                 "Read EDID byte %d failed: %d\n", i, ret);
 860                         i--;
 861                         break;
 862                 }
 863                 edid[i] = rbuf[1];
 864         }
 865 
 866         kfree(rbuf);
 867 
 868         return i;
 869 }
 870 
 871 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 872                                 unsigned long arg)
 873 {
 874 
 875         struct dlfb_data *dlfb = info->par;
 876 
 877         if (!atomic_read(&dlfb->usb_active))
 878                 return 0;
 879 
 880         /* TODO: Update X server to get this from sysfs instead */
 881         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 882                 void __user *edid = (void __user *)arg;
 883                 if (copy_to_user(edid, dlfb->edid, dlfb->edid_size))
 884                         return -EFAULT;
 885                 return 0;
 886         }
 887 
 888         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 889         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 890                 struct dloarea area;
 891 
 892                 if (copy_from_user(&area, (void __user *)arg,
 893                                   sizeof(struct dloarea)))
 894                         return -EFAULT;
 895 
 896                 /*
 897                  * If we have a damage-aware client, turn fb_defio "off"
 898                  * To avoid perf imact of unnecessary page fault handling.
 899                  * Done by resetting the delay for this fb_info to a very
 900                  * long period. Pages will become writable and stay that way.
 901                  * Reset to normal value when all clients have closed this fb.
 902                  */
 903                 if (info->fbdefio)
 904                         info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
 905 
 906                 if (area.x < 0)
 907                         area.x = 0;
 908 
 909                 if (area.x > info->var.xres)
 910                         area.x = info->var.xres;
 911 
 912                 if (area.y < 0)
 913                         area.y = 0;
 914 
 915                 if (area.y > info->var.yres)
 916                         area.y = info->var.yres;
 917 
 918                 dlfb_handle_damage(dlfb, area.x, area.y, area.w, area.h);
 919         }
 920 
 921         return 0;
 922 }
 923 
 924 /* taken from vesafb */
 925 static int
 926 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 927                unsigned blue, unsigned transp, struct fb_info *info)
 928 {
 929         int err = 0;
 930 
 931         if (regno >= info->cmap.len)
 932                 return 1;
 933 
 934         if (regno < 16) {
 935                 if (info->var.red.offset == 10) {
 936                         /* 1:5:5:5 */
 937                         ((u32 *) (info->pseudo_palette))[regno] =
 938                             ((red & 0xf800) >> 1) |
 939                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 940                 } else {
 941                         /* 0:5:6:5 */
 942                         ((u32 *) (info->pseudo_palette))[regno] =
 943                             ((red & 0xf800)) |
 944                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 945                 }
 946         }
 947 
 948         return err;
 949 }
 950 
 951 /*
 952  * It's common for several clients to have framebuffer open simultaneously.
 953  * e.g. both fbcon and X. Makes things interesting.
 954  * Assumes caller is holding info->lock (for open and release at least)
 955  */
 956 static int dlfb_ops_open(struct fb_info *info, int user)
 957 {
 958         struct dlfb_data *dlfb = info->par;
 959 
 960         /*
 961          * fbcon aggressively connects to first framebuffer it finds,
 962          * preventing other clients (X) from working properly. Usually
 963          * not what the user wants. Fail by default with option to enable.
 964          */
 965         if ((user == 0) && (!console))
 966                 return -EBUSY;
 967 
 968         /* If the USB device is gone, we don't accept new opens */
 969         if (dlfb->virtualized)
 970                 return -ENODEV;
 971 
 972         dlfb->fb_count++;
 973 
 974         if (fb_defio && (info->fbdefio == NULL)) {
 975                 /* enable defio at last moment if not disabled by client */
 976 
 977                 struct fb_deferred_io *fbdefio;
 978 
 979                 fbdefio = kzalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
 980 
 981                 if (fbdefio) {
 982                         fbdefio->delay = DL_DEFIO_WRITE_DELAY;
 983                         fbdefio->deferred_io = dlfb_dpy_deferred_io;
 984                 }
 985 
 986                 info->fbdefio = fbdefio;
 987                 fb_deferred_io_init(info);
 988         }
 989 
 990         dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n",
 991                 user, info, dlfb->fb_count);
 992 
 993         return 0;
 994 }
 995 
 996 static void dlfb_ops_destroy(struct fb_info *info)
 997 {
 998         struct dlfb_data *dlfb = info->par;
 999 
1000         cancel_work_sync(&dlfb->damage_work);
1001 
1002         mutex_destroy(&dlfb->render_mutex);
1003 
1004         if (info->cmap.len != 0)
1005                 fb_dealloc_cmap(&info->cmap);
1006         if (info->monspecs.modedb)
1007                 fb_destroy_modedb(info->monspecs.modedb);
1008         vfree(info->screen_base);
1009 
1010         fb_destroy_modelist(&info->modelist);
1011 
1012         while (!list_empty(&dlfb->deferred_free)) {
1013                 struct dlfb_deferred_free *d = list_entry(dlfb->deferred_free.next, struct dlfb_deferred_free, list);
1014                 list_del(&d->list);
1015                 vfree(d->mem);
1016                 kfree(d);
1017         }
1018         vfree(dlfb->backing_buffer);
1019         kfree(dlfb->edid);
1020         usb_put_dev(dlfb->udev);
1021         kfree(dlfb);
1022 
1023         /* Assume info structure is freed after this point */
1024         framebuffer_release(info);
1025 }
1026 
1027 /*
1028  * Assumes caller is holding info->lock mutex (for open and release at least)
1029  */
1030 static int dlfb_ops_release(struct fb_info *info, int user)
1031 {
1032         struct dlfb_data *dlfb = info->par;
1033 
1034         dlfb->fb_count--;
1035 
1036         if ((dlfb->fb_count == 0) && (info->fbdefio)) {
1037                 fb_deferred_io_cleanup(info);
1038                 kfree(info->fbdefio);
1039                 info->fbdefio = NULL;
1040                 info->fbops->fb_mmap = dlfb_ops_mmap;
1041         }
1042 
1043         dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count);
1044 
1045         return 0;
1046 }
1047 
1048 /*
1049  * Check whether a video mode is supported by the DisplayLink chip
1050  * We start from monitor's modes, so don't need to filter that here
1051  */
1052 static int dlfb_is_valid_mode(struct fb_videomode *mode, struct dlfb_data *dlfb)
1053 {
1054         if (mode->xres * mode->yres > dlfb->sku_pixel_limit)
1055                 return 0;
1056 
1057         return 1;
1058 }
1059 
1060 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1061 {
1062         const struct fb_bitfield red = { 11, 5, 0 };
1063         const struct fb_bitfield green = { 5, 6, 0 };
1064         const struct fb_bitfield blue = { 0, 5, 0 };
1065 
1066         var->bits_per_pixel = 16;
1067         var->red = red;
1068         var->green = green;
1069         var->blue = blue;
1070 }
1071 
1072 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1073                                 struct fb_info *info)
1074 {
1075         struct fb_videomode mode;
1076         struct dlfb_data *dlfb = info->par;
1077 
1078         /* set device-specific elements of var unrelated to mode */
1079         dlfb_var_color_format(var);
1080 
1081         fb_var_to_videomode(&mode, var);
1082 
1083         if (!dlfb_is_valid_mode(&mode, dlfb))
1084                 return -EINVAL;
1085 
1086         return 0;
1087 }
1088 
1089 static int dlfb_ops_set_par(struct fb_info *info)
1090 {
1091         struct dlfb_data *dlfb = info->par;
1092         int result;
1093         u16 *pix_framebuffer;
1094         int i;
1095         struct fb_var_screeninfo fvs;
1096         u32 line_length = info->var.xres * (info->var.bits_per_pixel / 8);
1097 
1098         /* clear the activate field because it causes spurious miscompares */
1099         fvs = info->var;
1100         fvs.activate = 0;
1101         fvs.vmode &= ~FB_VMODE_SMOOTH_XPAN;
1102 
1103         if (!memcmp(&dlfb->current_mode, &fvs, sizeof(struct fb_var_screeninfo)))
1104                 return 0;
1105 
1106         result = dlfb_realloc_framebuffer(dlfb, info, info->var.yres * line_length);
1107         if (result)
1108                 return result;
1109 
1110         result = dlfb_set_video_mode(dlfb, &info->var);
1111 
1112         if (result)
1113                 return result;
1114 
1115         dlfb->current_mode = fvs;
1116         info->fix.line_length = line_length;
1117 
1118         if (dlfb->fb_count == 0) {
1119 
1120                 /* paint greenscreen */
1121 
1122                 pix_framebuffer = (u16 *) info->screen_base;
1123                 for (i = 0; i < info->fix.smem_len / 2; i++)
1124                         pix_framebuffer[i] = 0x37e6;
1125         }
1126 
1127         dlfb_handle_damage(dlfb, 0, 0, info->var.xres, info->var.yres);
1128 
1129         return 0;
1130 }
1131 
1132 /* To fonzi the jukebox (e.g. make blanking changes take effect) */
1133 static char *dlfb_dummy_render(char *buf)
1134 {
1135         *buf++ = 0xAF;
1136         *buf++ = 0x6A; /* copy */
1137         *buf++ = 0x00; /* from address*/
1138         *buf++ = 0x00;
1139         *buf++ = 0x00;
1140         *buf++ = 0x01; /* one pixel */
1141         *buf++ = 0x00; /* to address */
1142         *buf++ = 0x00;
1143         *buf++ = 0x00;
1144         return buf;
1145 }
1146 
1147 /*
1148  * In order to come back from full DPMS off, we need to set the mode again
1149  */
1150 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1151 {
1152         struct dlfb_data *dlfb = info->par;
1153         char *bufptr;
1154         struct urb *urb;
1155 
1156         dev_dbg(info->dev, "blank, mode %d --> %d\n",
1157                 dlfb->blank_mode, blank_mode);
1158 
1159         if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) &&
1160             (blank_mode != FB_BLANK_POWERDOWN)) {
1161 
1162                 /* returning from powerdown requires a fresh modeset */
1163                 dlfb_set_video_mode(dlfb, &info->var);
1164         }
1165 
1166         urb = dlfb_get_urb(dlfb);
1167         if (!urb)
1168                 return 0;
1169 
1170         bufptr = (char *) urb->transfer_buffer;
1171         bufptr = dlfb_vidreg_lock(bufptr);
1172         bufptr = dlfb_blanking(bufptr, blank_mode);
1173         bufptr = dlfb_vidreg_unlock(bufptr);
1174 
1175         /* seems like a render op is needed to have blank change take effect */
1176         bufptr = dlfb_dummy_render(bufptr);
1177 
1178         dlfb_submit_urb(dlfb, urb, bufptr -
1179                         (char *) urb->transfer_buffer);
1180 
1181         dlfb->blank_mode = blank_mode;
1182 
1183         return 0;
1184 }
1185 
1186 static const struct fb_ops dlfb_ops = {
1187         .owner = THIS_MODULE,
1188         .fb_read = fb_sys_read,
1189         .fb_write = dlfb_ops_write,
1190         .fb_setcolreg = dlfb_ops_setcolreg,
1191         .fb_fillrect = dlfb_ops_fillrect,
1192         .fb_copyarea = dlfb_ops_copyarea,
1193         .fb_imageblit = dlfb_ops_imageblit,
1194         .fb_mmap = dlfb_ops_mmap,
1195         .fb_ioctl = dlfb_ops_ioctl,
1196         .fb_open = dlfb_ops_open,
1197         .fb_release = dlfb_ops_release,
1198         .fb_blank = dlfb_ops_blank,
1199         .fb_check_var = dlfb_ops_check_var,
1200         .fb_set_par = dlfb_ops_set_par,
1201         .fb_destroy = dlfb_ops_destroy,
1202 };
1203 
1204 
1205 static void dlfb_deferred_vfree(struct dlfb_data *dlfb, void *mem)
1206 {
1207         struct dlfb_deferred_free *d = kmalloc(sizeof(struct dlfb_deferred_free), GFP_KERNEL);
1208         if (!d)
1209                 return;
1210         d->mem = mem;
1211         list_add(&d->list, &dlfb->deferred_free);
1212 }
1213 
1214 /*
1215  * Assumes &info->lock held by caller
1216  * Assumes no active clients have framebuffer open
1217  */
1218 static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len)
1219 {
1220         u32 old_len = info->fix.smem_len;
1221         const void *old_fb = (const void __force *)info->screen_base;
1222         unsigned char *new_fb;
1223         unsigned char *new_back = NULL;
1224 
1225         new_len = PAGE_ALIGN(new_len);
1226 
1227         if (new_len > old_len) {
1228                 /*
1229                  * Alloc system memory for virtual framebuffer
1230                  */
1231                 new_fb = vmalloc(new_len);
1232                 if (!new_fb) {
1233                         dev_err(info->dev, "Virtual framebuffer alloc failed\n");
1234                         return -ENOMEM;
1235                 }
1236                 memset(new_fb, 0xff, new_len);
1237 
1238                 if (info->screen_base) {
1239                         memcpy(new_fb, old_fb, old_len);
1240                         dlfb_deferred_vfree(dlfb, (void __force *)info->screen_base);
1241                 }
1242 
1243                 info->screen_base = (char __iomem *)new_fb;
1244                 info->fix.smem_len = new_len;
1245                 info->fix.smem_start = (unsigned long) new_fb;
1246                 info->flags = udlfb_info_flags;
1247 
1248                 /*
1249                  * Second framebuffer copy to mirror the framebuffer state
1250                  * on the physical USB device. We can function without this.
1251                  * But with imperfect damage info we may send pixels over USB
1252                  * that were, in fact, unchanged - wasting limited USB bandwidth
1253                  */
1254                 if (shadow)
1255                         new_back = vzalloc(new_len);
1256                 if (!new_back)
1257                         dev_info(info->dev,
1258                                  "No shadow/backing buffer allocated\n");
1259                 else {
1260                         dlfb_deferred_vfree(dlfb, dlfb->backing_buffer);
1261                         dlfb->backing_buffer = new_back;
1262                 }
1263         }
1264         return 0;
1265 }
1266 
1267 /*
1268  * 1) Get EDID from hw, or use sw default
1269  * 2) Parse into various fb_info structs
1270  * 3) Allocate virtual framebuffer memory to back highest res mode
1271  *
1272  * Parses EDID into three places used by various parts of fbdev:
1273  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1274  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1275  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1276  *
1277  * If EDID is not readable/valid, then modelist is all VESA modes,
1278  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1279  * Returns 0 if successful
1280  */
1281 static int dlfb_setup_modes(struct dlfb_data *dlfb,
1282                            struct fb_info *info,
1283                            char *default_edid, size_t default_edid_size)
1284 {
1285         char *edid;
1286         int i, result = 0, tries = 3;
1287         struct device *dev = info->device;
1288         struct fb_videomode *mode;
1289         const struct fb_videomode *default_vmode = NULL;
1290 
1291         if (info->dev) {
1292                 /* only use mutex if info has been registered */
1293                 mutex_lock(&info->lock);
1294                 /* parent device is used otherwise */
1295                 dev = info->dev;
1296         }
1297 
1298         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1299         if (!edid) {
1300                 result = -ENOMEM;
1301                 goto error;
1302         }
1303 
1304         fb_destroy_modelist(&info->modelist);
1305         memset(&info->monspecs, 0, sizeof(info->monspecs));
1306 
1307         /*
1308          * Try to (re)read EDID from hardware first
1309          * EDID data may return, but not parse as valid
1310          * Try again a few times, in case of e.g. analog cable noise
1311          */
1312         while (tries--) {
1313 
1314                 i = dlfb_get_edid(dlfb, edid, EDID_LENGTH);
1315 
1316                 if (i >= EDID_LENGTH)
1317                         fb_edid_to_monspecs(edid, &info->monspecs);
1318 
1319                 if (info->monspecs.modedb_len > 0) {
1320                         dlfb->edid = edid;
1321                         dlfb->edid_size = i;
1322                         break;
1323                 }
1324         }
1325 
1326         /* If that fails, use a previously returned EDID if available */
1327         if (info->monspecs.modedb_len == 0) {
1328                 dev_err(dev, "Unable to get valid EDID from device/display\n");
1329 
1330                 if (dlfb->edid) {
1331                         fb_edid_to_monspecs(dlfb->edid, &info->monspecs);
1332                         if (info->monspecs.modedb_len > 0)
1333                                 dev_err(dev, "Using previously queried EDID\n");
1334                 }
1335         }
1336 
1337         /* If that fails, use the default EDID we were handed */
1338         if (info->monspecs.modedb_len == 0) {
1339                 if (default_edid_size >= EDID_LENGTH) {
1340                         fb_edid_to_monspecs(default_edid, &info->monspecs);
1341                         if (info->monspecs.modedb_len > 0) {
1342                                 memcpy(edid, default_edid, default_edid_size);
1343                                 dlfb->edid = edid;
1344                                 dlfb->edid_size = default_edid_size;
1345                                 dev_err(dev, "Using default/backup EDID\n");
1346                         }
1347                 }
1348         }
1349 
1350         /* If we've got modes, let's pick a best default mode */
1351         if (info->monspecs.modedb_len > 0) {
1352 
1353                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1354                         mode = &info->monspecs.modedb[i];
1355                         if (dlfb_is_valid_mode(mode, dlfb)) {
1356                                 fb_add_videomode(mode, &info->modelist);
1357                         } else {
1358                                 dev_dbg(dev, "Specified mode %dx%d too big\n",
1359                                         mode->xres, mode->yres);
1360                                 if (i == 0)
1361                                         /* if we've removed top/best mode */
1362                                         info->monspecs.misc
1363                                                 &= ~FB_MISC_1ST_DETAIL;
1364                         }
1365                 }
1366 
1367                 default_vmode = fb_find_best_display(&info->monspecs,
1368                                                      &info->modelist);
1369         }
1370 
1371         /* If everything else has failed, fall back to safe default mode */
1372         if (default_vmode == NULL) {
1373 
1374                 struct fb_videomode fb_vmode = {0};
1375 
1376                 /*
1377                  * Add the standard VESA modes to our modelist
1378                  * Since we don't have EDID, there may be modes that
1379                  * overspec monitor and/or are incorrect aspect ratio, etc.
1380                  * But at least the user has a chance to choose
1381                  */
1382                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1383                         mode = (struct fb_videomode *)&vesa_modes[i];
1384                         if (dlfb_is_valid_mode(mode, dlfb))
1385                                 fb_add_videomode(mode, &info->modelist);
1386                         else
1387                                 dev_dbg(dev, "VESA mode %dx%d too big\n",
1388                                         mode->xres, mode->yres);
1389                 }
1390 
1391                 /*
1392                  * default to resolution safe for projectors
1393                  * (since they are most common case without EDID)
1394                  */
1395                 fb_vmode.xres = 800;
1396                 fb_vmode.yres = 600;
1397                 fb_vmode.refresh = 60;
1398                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1399                                                      &info->modelist);
1400         }
1401 
1402         /* If we have good mode and no active clients*/
1403         if ((default_vmode != NULL) && (dlfb->fb_count == 0)) {
1404 
1405                 fb_videomode_to_var(&info->var, default_vmode);
1406                 dlfb_var_color_format(&info->var);
1407 
1408                 /*
1409                  * with mode size info, we can now alloc our framebuffer.
1410                  */
1411                 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1412         } else
1413                 result = -EINVAL;
1414 
1415 error:
1416         if (edid && (dlfb->edid != edid))
1417                 kfree(edid);
1418 
1419         if (info->dev)
1420                 mutex_unlock(&info->lock);
1421 
1422         return result;
1423 }
1424 
1425 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1426                                    struct device_attribute *a, char *buf) {
1427         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1428         struct dlfb_data *dlfb = fb_info->par;
1429         return snprintf(buf, PAGE_SIZE, "%u\n",
1430                         atomic_read(&dlfb->bytes_rendered));
1431 }
1432 
1433 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1434                                    struct device_attribute *a, char *buf) {
1435         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1436         struct dlfb_data *dlfb = fb_info->par;
1437         return snprintf(buf, PAGE_SIZE, "%u\n",
1438                         atomic_read(&dlfb->bytes_identical));
1439 }
1440 
1441 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1442                                    struct device_attribute *a, char *buf) {
1443         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1444         struct dlfb_data *dlfb = fb_info->par;
1445         return snprintf(buf, PAGE_SIZE, "%u\n",
1446                         atomic_read(&dlfb->bytes_sent));
1447 }
1448 
1449 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1450                                    struct device_attribute *a, char *buf) {
1451         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1452         struct dlfb_data *dlfb = fb_info->par;
1453         return snprintf(buf, PAGE_SIZE, "%u\n",
1454                         atomic_read(&dlfb->cpu_kcycles_used));
1455 }
1456 
1457 static ssize_t edid_show(
1458                         struct file *filp,
1459                         struct kobject *kobj, struct bin_attribute *a,
1460                          char *buf, loff_t off, size_t count) {
1461         struct device *fbdev = container_of(kobj, struct device, kobj);
1462         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1463         struct dlfb_data *dlfb = fb_info->par;
1464 
1465         if (dlfb->edid == NULL)
1466                 return 0;
1467 
1468         if ((off >= dlfb->edid_size) || (count > dlfb->edid_size))
1469                 return 0;
1470 
1471         if (off + count > dlfb->edid_size)
1472                 count = dlfb->edid_size - off;
1473 
1474         memcpy(buf, dlfb->edid, count);
1475 
1476         return count;
1477 }
1478 
1479 static ssize_t edid_store(
1480                         struct file *filp,
1481                         struct kobject *kobj, struct bin_attribute *a,
1482                         char *src, loff_t src_off, size_t src_size) {
1483         struct device *fbdev = container_of(kobj, struct device, kobj);
1484         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1485         struct dlfb_data *dlfb = fb_info->par;
1486         int ret;
1487 
1488         /* We only support write of entire EDID at once, no offset*/
1489         if ((src_size != EDID_LENGTH) || (src_off != 0))
1490                 return -EINVAL;
1491 
1492         ret = dlfb_setup_modes(dlfb, fb_info, src, src_size);
1493         if (ret)
1494                 return ret;
1495 
1496         if (!dlfb->edid || memcmp(src, dlfb->edid, src_size))
1497                 return -EINVAL;
1498 
1499         ret = dlfb_ops_set_par(fb_info);
1500         if (ret)
1501                 return ret;
1502 
1503         return src_size;
1504 }
1505 
1506 static ssize_t metrics_reset_store(struct device *fbdev,
1507                            struct device_attribute *attr,
1508                            const char *buf, size_t count)
1509 {
1510         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1511         struct dlfb_data *dlfb = fb_info->par;
1512 
1513         atomic_set(&dlfb->bytes_rendered, 0);
1514         atomic_set(&dlfb->bytes_identical, 0);
1515         atomic_set(&dlfb->bytes_sent, 0);
1516         atomic_set(&dlfb->cpu_kcycles_used, 0);
1517 
1518         return count;
1519 }
1520 
1521 static const struct bin_attribute edid_attr = {
1522         .attr.name = "edid",
1523         .attr.mode = 0666,
1524         .size = EDID_LENGTH,
1525         .read = edid_show,
1526         .write = edid_store
1527 };
1528 
1529 static const struct device_attribute fb_device_attrs[] = {
1530         __ATTR_RO(metrics_bytes_rendered),
1531         __ATTR_RO(metrics_bytes_identical),
1532         __ATTR_RO(metrics_bytes_sent),
1533         __ATTR_RO(metrics_cpu_kcycles_used),
1534         __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1535 };
1536 
1537 /*
1538  * This is necessary before we can communicate with the display controller.
1539  */
1540 static int dlfb_select_std_channel(struct dlfb_data *dlfb)
1541 {
1542         int ret;
1543         void *buf;
1544         static const u8 set_def_chn[] = {
1545                                 0x57, 0xCD, 0xDC, 0xA7,
1546                                 0x1C, 0x88, 0x5E, 0x15,
1547                                 0x60, 0xFE, 0xC6, 0x97,
1548                                 0x16, 0x3D, 0x47, 0xF2  };
1549 
1550         buf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
1551 
1552         if (!buf)
1553                 return -ENOMEM;
1554 
1555         ret = usb_control_msg(dlfb->udev, usb_sndctrlpipe(dlfb->udev, 0),
1556                         NR_USB_REQUEST_CHANNEL,
1557                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1558                         buf, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1559 
1560         kfree(buf);
1561 
1562         return ret;
1563 }
1564 
1565 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb,
1566                                         struct usb_interface *intf)
1567 {
1568         char *desc;
1569         char *buf;
1570         char *desc_end;
1571         int total_len;
1572 
1573         buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1574         if (!buf)
1575                 return false;
1576         desc = buf;
1577 
1578         total_len = usb_get_descriptor(interface_to_usbdev(intf),
1579                                         0x5f, /* vendor specific */
1580                                         0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1581 
1582         /* if not found, look in configuration descriptor */
1583         if (total_len < 0) {
1584                 if (0 == usb_get_extra_descriptor(intf->cur_altsetting,
1585                         0x5f, &desc))
1586                         total_len = (int) desc[0];
1587         }
1588 
1589         if (total_len > 5) {
1590                 dev_info(&intf->dev,
1591                          "vendor descriptor length: %d data: %11ph\n",
1592                          total_len, desc);
1593 
1594                 if ((desc[0] != total_len) || /* descriptor length */
1595                     (desc[1] != 0x5f) ||   /* vendor descriptor type */
1596                     (desc[2] != 0x01) ||   /* version (2 bytes) */
1597                     (desc[3] != 0x00) ||
1598                     (desc[4] != total_len - 2)) /* length after type */
1599                         goto unrecognized;
1600 
1601                 desc_end = desc + total_len;
1602                 desc += 5; /* the fixed header we've already parsed */
1603 
1604                 while (desc < desc_end) {
1605                         u8 length;
1606                         u16 key;
1607 
1608                         key = *desc++;
1609                         key |= (u16)*desc++ << 8;
1610                         length = *desc++;
1611 
1612                         switch (key) {
1613                         case 0x0200: { /* max_area */
1614                                 u32 max_area = *desc++;
1615                                 max_area |= (u32)*desc++ << 8;
1616                                 max_area |= (u32)*desc++ << 16;
1617                                 max_area |= (u32)*desc++ << 24;
1618                                 dev_warn(&intf->dev,
1619                                          "DL chip limited to %d pixel modes\n",
1620                                          max_area);
1621                                 dlfb->sku_pixel_limit = max_area;
1622                                 break;
1623                         }
1624                         default:
1625                                 break;
1626                         }
1627                         desc += length;
1628                 }
1629         } else {
1630                 dev_info(&intf->dev, "vendor descriptor not available (%d)\n",
1631                          total_len);
1632         }
1633 
1634         goto success;
1635 
1636 unrecognized:
1637         /* allow udlfb to load for now even if firmware unrecognized */
1638         dev_err(&intf->dev, "Unrecognized vendor firmware descriptor\n");
1639 
1640 success:
1641         kfree(buf);
1642         return true;
1643 }
1644 
1645 static int dlfb_usb_probe(struct usb_interface *intf,
1646                           const struct usb_device_id *id)
1647 {
1648         int i;
1649         const struct device_attribute *attr;
1650         struct dlfb_data *dlfb;
1651         struct fb_info *info;
1652         int retval = -ENOMEM;
1653         struct usb_device *usbdev = interface_to_usbdev(intf);
1654 
1655         /* usb initialization */
1656         dlfb = kzalloc(sizeof(*dlfb), GFP_KERNEL);
1657         if (!dlfb) {
1658                 dev_err(&intf->dev, "%s: failed to allocate dlfb\n", __func__);
1659                 return -ENOMEM;
1660         }
1661 
1662         INIT_LIST_HEAD(&dlfb->deferred_free);
1663 
1664         dlfb->udev = usb_get_dev(usbdev);
1665         usb_set_intfdata(intf, dlfb);
1666 
1667         dev_dbg(&intf->dev, "console enable=%d\n", console);
1668         dev_dbg(&intf->dev, "fb_defio enable=%d\n", fb_defio);
1669         dev_dbg(&intf->dev, "shadow enable=%d\n", shadow);
1670 
1671         dlfb->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1672 
1673         if (!dlfb_parse_vendor_descriptor(dlfb, intf)) {
1674                 dev_err(&intf->dev,
1675                         "firmware not recognized, incompatible device?\n");
1676                 goto error;
1677         }
1678 
1679         if (pixel_limit) {
1680                 dev_warn(&intf->dev,
1681                          "DL chip limit of %d overridden to %d\n",
1682                          dlfb->sku_pixel_limit, pixel_limit);
1683                 dlfb->sku_pixel_limit = pixel_limit;
1684         }
1685 
1686 
1687         /* allocates framebuffer driver structure, not framebuffer memory */
1688         info = framebuffer_alloc(0, &dlfb->udev->dev);
1689         if (!info)
1690                 goto error;
1691 
1692         dlfb->info = info;
1693         info->par = dlfb;
1694         info->pseudo_palette = dlfb->pseudo_palette;
1695         dlfb->ops = dlfb_ops;
1696         info->fbops = &dlfb->ops;
1697 
1698         mutex_init(&dlfb->render_mutex);
1699         dlfb_init_damage(dlfb);
1700         spin_lock_init(&dlfb->damage_lock);
1701         INIT_WORK(&dlfb->damage_work, dlfb_damage_work);
1702 
1703         INIT_LIST_HEAD(&info->modelist);
1704 
1705         if (!dlfb_alloc_urb_list(dlfb, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1706                 retval = -ENOMEM;
1707                 dev_err(&intf->dev, "unable to allocate urb list\n");
1708                 goto error;
1709         }
1710 
1711         /* We don't register a new USB class. Our client interface is dlfbev */
1712 
1713         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1714         if (retval < 0) {
1715                 dev_err(info->device, "cmap allocation failed: %d\n", retval);
1716                 goto error;
1717         }
1718 
1719         retval = dlfb_setup_modes(dlfb, info, NULL, 0);
1720         if (retval != 0) {
1721                 dev_err(info->device,
1722                         "unable to find common mode for display and adapter\n");
1723                 goto error;
1724         }
1725 
1726         /* ready to begin using device */
1727 
1728         atomic_set(&dlfb->usb_active, 1);
1729         dlfb_select_std_channel(dlfb);
1730 
1731         dlfb_ops_check_var(&info->var, info);
1732         retval = dlfb_ops_set_par(info);
1733         if (retval)
1734                 goto error;
1735 
1736         retval = register_framebuffer(info);
1737         if (retval < 0) {
1738                 dev_err(info->device, "unable to register framebuffer: %d\n",
1739                         retval);
1740                 goto error;
1741         }
1742 
1743         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
1744                 attr = &fb_device_attrs[i];
1745                 retval = device_create_file(info->dev, attr);
1746                 if (retval)
1747                         dev_warn(info->device,
1748                                  "failed to create '%s' attribute: %d\n",
1749                                  attr->attr.name, retval);
1750         }
1751 
1752         retval = device_create_bin_file(info->dev, &edid_attr);
1753         if (retval)
1754                 dev_warn(info->device, "failed to create '%s' attribute: %d\n",
1755                          edid_attr.attr.name, retval);
1756 
1757         dev_info(info->device,
1758                  "%s is DisplayLink USB device (%dx%d, %dK framebuffer memory)\n",
1759                  dev_name(info->dev), info->var.xres, info->var.yres,
1760                  ((dlfb->backing_buffer) ?
1761                  info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1762         return 0;
1763 
1764 error:
1765         if (dlfb->info) {
1766                 dlfb_ops_destroy(dlfb->info);
1767         } else {
1768                 usb_put_dev(dlfb->udev);
1769                 kfree(dlfb);
1770         }
1771         return retval;
1772 }
1773 
1774 static void dlfb_usb_disconnect(struct usb_interface *intf)
1775 {
1776         struct dlfb_data *dlfb;
1777         struct fb_info *info;
1778         int i;
1779 
1780         dlfb = usb_get_intfdata(intf);
1781         info = dlfb->info;
1782 
1783         dev_dbg(&intf->dev, "USB disconnect starting\n");
1784 
1785         /* we virtualize until all fb clients release. Then we free */
1786         dlfb->virtualized = true;
1787 
1788         /* When non-active we'll update virtual framebuffer, but no new urbs */
1789         atomic_set(&dlfb->usb_active, 0);
1790 
1791         /* this function will wait for all in-flight urbs to complete */
1792         dlfb_free_urb_list(dlfb);
1793 
1794         /* remove udlfb's sysfs interfaces */
1795         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1796                 device_remove_file(info->dev, &fb_device_attrs[i]);
1797         device_remove_bin_file(info->dev, &edid_attr);
1798 
1799         unregister_framebuffer(info);
1800 }
1801 
1802 static struct usb_driver dlfb_driver = {
1803         .name = "udlfb",
1804         .probe = dlfb_usb_probe,
1805         .disconnect = dlfb_usb_disconnect,
1806         .id_table = id_table,
1807 };
1808 
1809 module_usb_driver(dlfb_driver);
1810 
1811 static void dlfb_urb_completion(struct urb *urb)
1812 {
1813         struct urb_node *unode = urb->context;
1814         struct dlfb_data *dlfb = unode->dlfb;
1815         unsigned long flags;
1816 
1817         switch (urb->status) {
1818         case 0:
1819                 /* success */
1820                 break;
1821         case -ECONNRESET:
1822         case -ENOENT:
1823         case -ESHUTDOWN:
1824                 /* sync/async unlink faults aren't errors */
1825                 break;
1826         default:
1827                 dev_err(&dlfb->udev->dev,
1828                         "%s - nonzero write bulk status received: %d\n",
1829                         __func__, urb->status);
1830                 atomic_set(&dlfb->lost_pixels, 1);
1831                 break;
1832         }
1833 
1834         urb->transfer_buffer_length = dlfb->urbs.size; /* reset to actual */
1835 
1836         spin_lock_irqsave(&dlfb->urbs.lock, flags);
1837         list_add_tail(&unode->entry, &dlfb->urbs.list);
1838         dlfb->urbs.available++;
1839         spin_unlock_irqrestore(&dlfb->urbs.lock, flags);
1840 
1841         up(&dlfb->urbs.limit_sem);
1842 }
1843 
1844 static void dlfb_free_urb_list(struct dlfb_data *dlfb)
1845 {
1846         int count = dlfb->urbs.count;
1847         struct list_head *node;
1848         struct urb_node *unode;
1849         struct urb *urb;
1850 
1851         /* keep waiting and freeing, until we've got 'em all */
1852         while (count--) {
1853                 down(&dlfb->urbs.limit_sem);
1854 
1855                 spin_lock_irq(&dlfb->urbs.lock);
1856 
1857                 node = dlfb->urbs.list.next; /* have reserved one with sem */
1858                 list_del_init(node);
1859 
1860                 spin_unlock_irq(&dlfb->urbs.lock);
1861 
1862                 unode = list_entry(node, struct urb_node, entry);
1863                 urb = unode->urb;
1864 
1865                 /* Free each separately allocated piece */
1866                 usb_free_coherent(urb->dev, dlfb->urbs.size,
1867                                   urb->transfer_buffer, urb->transfer_dma);
1868                 usb_free_urb(urb);
1869                 kfree(node);
1870         }
1871 
1872         dlfb->urbs.count = 0;
1873 }
1874 
1875 static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size)
1876 {
1877         struct urb *urb;
1878         struct urb_node *unode;
1879         char *buf;
1880         size_t wanted_size = count * size;
1881 
1882         spin_lock_init(&dlfb->urbs.lock);
1883 
1884 retry:
1885         dlfb->urbs.size = size;
1886         INIT_LIST_HEAD(&dlfb->urbs.list);
1887 
1888         sema_init(&dlfb->urbs.limit_sem, 0);
1889         dlfb->urbs.count = 0;
1890         dlfb->urbs.available = 0;
1891 
1892         while (dlfb->urbs.count * size < wanted_size) {
1893                 unode = kzalloc(sizeof(*unode), GFP_KERNEL);
1894                 if (!unode)
1895                         break;
1896                 unode->dlfb = dlfb;
1897 
1898                 urb = usb_alloc_urb(0, GFP_KERNEL);
1899                 if (!urb) {
1900                         kfree(unode);
1901                         break;
1902                 }
1903                 unode->urb = urb;
1904 
1905                 buf = usb_alloc_coherent(dlfb->udev, size, GFP_KERNEL,
1906                                          &urb->transfer_dma);
1907                 if (!buf) {
1908                         kfree(unode);
1909                         usb_free_urb(urb);
1910                         if (size > PAGE_SIZE) {
1911                                 size /= 2;
1912                                 dlfb_free_urb_list(dlfb);
1913                                 goto retry;
1914                         }
1915                         break;
1916                 }
1917 
1918                 /* urb->transfer_buffer_length set to actual before submit */
1919                 usb_fill_bulk_urb(urb, dlfb->udev, usb_sndbulkpipe(dlfb->udev, 1),
1920                         buf, size, dlfb_urb_completion, unode);
1921                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1922 
1923                 list_add_tail(&unode->entry, &dlfb->urbs.list);
1924 
1925                 up(&dlfb->urbs.limit_sem);
1926                 dlfb->urbs.count++;
1927                 dlfb->urbs.available++;
1928         }
1929 
1930         return dlfb->urbs.count;
1931 }
1932 
1933 static struct urb *dlfb_get_urb(struct dlfb_data *dlfb)
1934 {
1935         int ret;
1936         struct list_head *entry;
1937         struct urb_node *unode;
1938 
1939         /* Wait for an in-flight buffer to complete and get re-queued */
1940         ret = down_timeout(&dlfb->urbs.limit_sem, GET_URB_TIMEOUT);
1941         if (ret) {
1942                 atomic_set(&dlfb->lost_pixels, 1);
1943                 dev_warn(&dlfb->udev->dev,
1944                          "wait for urb interrupted: %d available: %d\n",
1945                          ret, dlfb->urbs.available);
1946                 return NULL;
1947         }
1948 
1949         spin_lock_irq(&dlfb->urbs.lock);
1950 
1951         BUG_ON(list_empty(&dlfb->urbs.list)); /* reserved one with limit_sem */
1952         entry = dlfb->urbs.list.next;
1953         list_del_init(entry);
1954         dlfb->urbs.available--;
1955 
1956         spin_unlock_irq(&dlfb->urbs.lock);
1957 
1958         unode = list_entry(entry, struct urb_node, entry);
1959         return unode->urb;
1960 }
1961 
1962 static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb *urb, size_t len)
1963 {
1964         int ret;
1965 
1966         BUG_ON(len > dlfb->urbs.size);
1967 
1968         urb->transfer_buffer_length = len; /* set to actual payload len */
1969         ret = usb_submit_urb(urb, GFP_KERNEL);
1970         if (ret) {
1971                 dlfb_urb_completion(urb); /* because no one else will */
1972                 atomic_set(&dlfb->lost_pixels, 1);
1973                 dev_err(&dlfb->udev->dev, "submit urb error: %d\n", ret);
1974         }
1975         return ret;
1976 }
1977 
1978 module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1979 MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
1980 
1981 module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1982 MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
1983 
1984 module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1985 MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
1986 
1987 module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1988 MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)");
1989 
1990 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1991               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1992               "Bernie Thompson <bernie@plugable.com>");
1993 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1994 MODULE_LICENSE("GPL");
1995
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/video/fbdev/udlfb.c

DEFINITIONS
