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#define OUT_EP_NUM 1 /* The endpoint number we will use */ 31 32static const struct fb_fix_screeninfo dlfb_fix = { 33 .id = "udlfb", 34 .type = FB_TYPE_PACKED_PIXELS, 35 .visual = FB_VISUAL_TRUECOLOR, 36 .xpanstep = 0, 37 .ypanstep = 0, 38 .ywrapstep = 0, 39 .accel = FB_ACCEL_NONE, 40}; 41 42static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST | 43 FBINFO_VIRTFB | 44 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT | 45 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR; 46 47/* 48 * There are many DisplayLink-based graphics products, all with unique PIDs. 49 * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff) 50 * We also require a match on SubClass (0x00) and Protocol (0x00), 51 * which is compatible with all known USB 2.0 era graphics chips and firmware, 52 * but allows DisplayLink to increment those for any future incompatible chips 53 */ 54static const struct usb_device_id id_table[] = { 55 {.idVendor = 0x17e9, 56 .bInterfaceClass = 0xff, 57 .bInterfaceSubClass = 0x00, 58 .bInterfaceProtocol = 0x00, 59 .match_flags = USB_DEVICE_ID_MATCH_VENDOR | 60 USB_DEVICE_ID_MATCH_INT_CLASS | 61 USB_DEVICE_ID_MATCH_INT_SUBCLASS | 62 USB_DEVICE_ID_MATCH_INT_PROTOCOL, 63 }, 64 {}, 65}; 66MODULE_DEVICE_TABLE(usb, id_table); 67 68/* module options */ 69static bool console = true; /* Allow fbcon to open framebuffer */ 70static bool fb_defio = true; /* Detect mmap writes using page faults */ 71static bool shadow = true; /* Optionally disable shadow framebuffer */ 72static int pixel_limit; /* Optionally force a pixel resolution limit */ 73 74struct dlfb_deferred_free { 75 struct list_head list; 76 void *mem; 77}; 78 79static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len); 80 81/* dlfb keeps a list of urbs for efficient bulk transfers */ 82static void dlfb_urb_completion(struct urb *urb); 83static struct urb *dlfb_get_urb(struct dlfb_data *dlfb); 84static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb * urb, size_t len); 85static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size); 86static void dlfb_free_urb_list(struct dlfb_data *dlfb); 87 88/* 89 * All DisplayLink bulk operations start with 0xAF, followed by specific code 90 * All operations are written to buffers which then later get sent to device 91 */ 92static char *dlfb_set_register(char *buf, u8 reg, u8 val) 93{ 94 *buf++ = 0xAF; 95 *buf++ = 0x20; 96 *buf++ = reg; 97 *buf++ = val; 98 return buf; 99} 100 101static char *dlfb_vidreg_lock(char *buf) 102{ 103 return dlfb_set_register(buf, 0xFF, 0x00); 104} 105 106static char *dlfb_vidreg_unlock(char *buf) 107{ 108 return dlfb_set_register(buf, 0xFF, 0xFF); 109} 110 111/* 112 * Map FB_BLANK_* to DisplayLink register 113 * DLReg FB_BLANK_* 114 * ----- ----------------------------- 115 * 0x00 FB_BLANK_UNBLANK (0) 116 * 0x01 FB_BLANK (1) 117 * 0x03 FB_BLANK_VSYNC_SUSPEND (2) 118 * 0x05 FB_BLANK_HSYNC_SUSPEND (3) 119 * 0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back 120 */ 121static char *dlfb_blanking(char *buf, int fb_blank) 122{ 123 u8 reg; 124 125 switch (fb_blank) { 126 case FB_BLANK_POWERDOWN: 127 reg = 0x07; 128 break; 129 case FB_BLANK_HSYNC_SUSPEND: 130 reg = 0x05; 131 break; 132 case FB_BLANK_VSYNC_SUSPEND: 133 reg = 0x03; 134 break; 135 case FB_BLANK_NORMAL: 136 reg = 0x01; 137 break; 138 default: 139 reg = 0x00; 140 } 141 142 buf = dlfb_set_register(buf, 0x1F, reg); 143 144 return buf; 145} 146 147static char *dlfb_set_color_depth(char *buf, u8 selection) 148{ 149 return dlfb_set_register(buf, 0x00, selection); 150} 151 152static char *dlfb_set_base16bpp(char *wrptr, u32 base) 153{ 154 /* the base pointer is 16 bits wide, 0x20 is hi byte. */ 155 wrptr = dlfb_set_register(wrptr, 0x20, base >> 16); 156 wrptr = dlfb_set_register(wrptr, 0x21, base >> 8); 157 return dlfb_set_register(wrptr, 0x22, base); 158} 159 160/* 161 * DisplayLink HW has separate 16bpp and 8bpp framebuffers. 162 * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer 163 */ 164static char *dlfb_set_base8bpp(char *wrptr, u32 base) 165{ 166 wrptr = dlfb_set_register(wrptr, 0x26, base >> 16); 167 wrptr = dlfb_set_register(wrptr, 0x27, base >> 8); 168 return dlfb_set_register(wrptr, 0x28, base); 169} 170 171static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value) 172{ 173 wrptr = dlfb_set_register(wrptr, reg, value >> 8); 174 return dlfb_set_register(wrptr, reg+1, value); 175} 176 177/* 178 * This is kind of weird because the controller takes some 179 * register values in a different byte order than other registers. 180 */ 181static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value) 182{ 183 wrptr = dlfb_set_register(wrptr, reg, value); 184 return dlfb_set_register(wrptr, reg+1, value >> 8); 185} 186 187/* 188 * LFSR is linear feedback shift register. The reason we have this is 189 * because the display controller needs to minimize the clock depth of 190 * various counters used in the display path. So this code reverses the 191 * provided value into the lfsr16 value by counting backwards to get 192 * the value that needs to be set in the hardware comparator to get the 193 * same actual count. This makes sense once you read above a couple of 194 * times and think about it from a hardware perspective. 195 */ 196static u16 dlfb_lfsr16(u16 actual_count) 197{ 198 u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */ 199 200 while (actual_count--) { 201 lv = ((lv << 1) | 202 (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1)) 203 & 0xFFFF; 204 } 205 206 return (u16) lv; 207} 208 209/* 210 * This does LFSR conversion on the value that is to be written. 211 * See LFSR explanation above for more detail. 212 */ 213static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value) 214{ 215 return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value)); 216} 217 218/* 219 * This takes a standard fbdev screeninfo struct and all of its monitor mode 220 * details and converts them into the DisplayLink equivalent register commands. 221 */ 222static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var) 223{ 224 u16 xds, yds; 225 u16 xde, yde; 226 u16 yec; 227 228 /* x display start */ 229 xds = var->left_margin + var->hsync_len; 230 wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds); 231 /* x display end */ 232 xde = xds + var->xres; 233 wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde); 234 235 /* y display start */ 236 yds = var->upper_margin + var->vsync_len; 237 wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds); 238 /* y display end */ 239 yde = yds + var->yres; 240 wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde); 241 242 /* x end count is active + blanking - 1 */ 243 wrptr = dlfb_set_register_lfsr16(wrptr, 0x09, 244 xde + var->right_margin - 1); 245 246 /* libdlo hardcodes hsync start to 1 */ 247 wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1); 248 249 /* hsync end is width of sync pulse + 1 */ 250 wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1); 251 252 /* hpixels is active pixels */ 253 wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres); 254 255 /* yendcount is vertical active + vertical blanking */ 256 yec = var->yres + var->upper_margin + var->lower_margin + 257 var->vsync_len; 258 wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec); 259 260 /* libdlo hardcodes vsync start to 0 */ 261 wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0); 262 263 /* vsync end is width of vsync pulse */ 264 wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len); 265 266 /* vpixels is active pixels */ 267 wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres); 268 269 /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */ 270 wrptr = dlfb_set_register_16be(wrptr, 0x1B, 271 200*1000*1000/var->pixclock); 272 273 return wrptr; 274} 275 276/* 277 * This takes a standard fbdev screeninfo struct that was fetched or prepared 278 * and then generates the appropriate command sequence that then drives the 279 * display controller. 280 */ 281static int dlfb_set_video_mode(struct dlfb_data *dlfb, 282 struct fb_var_screeninfo *var) 283{ 284 char *buf; 285 char *wrptr; 286 int retval; 287 int writesize; 288 struct urb *urb; 289 290 if (!atomic_read(&dlfb->usb_active)) 291 return -EPERM; 292 293 urb = dlfb_get_urb(dlfb); 294 if (!urb) 295 return -ENOMEM; 296 297 buf = (char *) urb->transfer_buffer; 298 299 /* 300 * This first section has to do with setting the base address on the 301 * controller * associated with the display. There are 2 base 302 * pointers, currently, we only * use the 16 bpp segment. 303 */ 304 wrptr = dlfb_vidreg_lock(buf); 305 wrptr = dlfb_set_color_depth(wrptr, 0x00); 306 /* set base for 16bpp segment to 0 */ 307 wrptr = dlfb_set_base16bpp(wrptr, 0); 308 /* set base for 8bpp segment to end of fb */ 309 wrptr = dlfb_set_base8bpp(wrptr, dlfb->info->fix.smem_len); 310 311 wrptr = dlfb_set_vid_cmds(wrptr, var); 312 wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK); 313 wrptr = dlfb_vidreg_unlock(wrptr); 314 315 writesize = wrptr - buf; 316 317 retval = dlfb_submit_urb(dlfb, urb, writesize); 318 319 dlfb->blank_mode = FB_BLANK_UNBLANK; 320 321 return retval; 322} 323 324static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma) 325{ 326 unsigned long start = vma->vm_start; 327 unsigned long size = vma->vm_end - vma->vm_start; 328 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; 329 unsigned long page, pos; 330 331 if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) 332 return -EINVAL; 333 if (size > info->fix.smem_len) 334 return -EINVAL; 335 if (offset > info->fix.smem_len - size) 336 return -EINVAL; 337 338 pos = (unsigned long)info->fix.smem_start + offset; 339 340 dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n", 341 pos, size); 342 343 while (size > 0) { 344 page = vmalloc_to_pfn((void *)pos); 345 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) 346 return -EAGAIN; 347 348 start += PAGE_SIZE; 349 pos += PAGE_SIZE; 350 if (size > PAGE_SIZE) 351 size -= PAGE_SIZE; 352 else 353 size = 0; 354 } 355 356 return 0; 357} 358 359/* 360 * Trims identical data from front and back of line 361 * Sets new front buffer address and width 362 * And returns byte count of identical pixels 363 * Assumes CPU natural alignment (unsigned long) 364 * for back and front buffer ptrs and width 365 */ 366static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes) 367{ 368 int j, k; 369 const unsigned long *back = (const unsigned long *) bback; 370 const unsigned long *front = (const unsigned long *) *bfront; 371 const int width = *width_bytes / sizeof(unsigned long); 372 int identical = width; 373 int start = width; 374 int end = width; 375 376 for (j = 0; j < width; j++) { 377 if (back[j] != front[j]) { 378 start = j; 379 break; 380 } 381 } 382 383 for (k = width - 1; k > j; k--) { 384 if (back[k] != front[k]) { 385 end = k+1; 386 break; 387 } 388 } 389 390 identical = start + (width - end); 391 *bfront = (u8 *) &front[start]; 392 *width_bytes = (end - start) * sizeof(unsigned long); 393 394 return identical * sizeof(unsigned long); 395} 396 397/* 398 * Render a command stream for an encoded horizontal line segment of pixels. 399 * 400 * A command buffer holds several commands. 401 * It always begins with a fresh command header 402 * (the protocol doesn't require this, but we enforce it to allow 403 * multiple buffers to be potentially encoded and sent in parallel). 404 * A single command encodes one contiguous horizontal line of pixels 405 * 406 * The function relies on the client to do all allocation, so that 407 * rendering can be done directly to output buffers (e.g. USB URBs). 408 * The function fills the supplied command buffer, providing information 409 * on where it left off, so the client may call in again with additional 410 * buffers if the line will take several buffers to complete. 411 * 412 * A single command can transmit a maximum of 256 pixels, 413 * regardless of the compression ratio (protocol design limit). 414 * To the hardware, 0 for a size byte means 256 415 * 416 * Rather than 256 pixel commands which are either rl or raw encoded, 417 * the rlx command simply assumes alternating raw and rl spans within one cmd. 418 * This has a slightly larger header overhead, but produces more even results. 419 * It also processes all data (read and write) in a single pass. 420 * Performance benchmarks of common cases show it having just slightly better 421 * compression than 256 pixel raw or rle commands, with similar CPU consumpion. 422 * But for very rl friendly data, will compress not quite as well. 423 */ 424static void dlfb_compress_hline( 425 const uint16_t **pixel_start_ptr, 426 const uint16_t *const pixel_end, 427 uint32_t *device_address_ptr, 428 uint8_t **command_buffer_ptr, 429 const uint8_t *const cmd_buffer_end, 430 unsigned long back_buffer_offset, 431 int *ident_ptr) 432{ 433 const uint16_t *pixel = *pixel_start_ptr; 434 uint32_t dev_addr = *device_address_ptr; 435 uint8_t *cmd = *command_buffer_ptr; 436 437 while ((pixel_end > pixel) && 438 (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) { 439 uint8_t *raw_pixels_count_byte = NULL; 440 uint8_t *cmd_pixels_count_byte = NULL; 441 const uint16_t *raw_pixel_start = NULL; 442 const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL; 443 444 if (back_buffer_offset && 445 *pixel == *(u16 *)((u8 *)pixel + back_buffer_offset)) { 446 pixel++; 447 dev_addr += BPP; 448 (*ident_ptr)++; 449 continue; 450 } 451 452 *cmd++ = 0xAF; 453 *cmd++ = 0x6B; 454 *cmd++ = dev_addr >> 16; 455 *cmd++ = dev_addr >> 8; 456 *cmd++ = dev_addr; 457 458 cmd_pixels_count_byte = cmd++; /* we'll know this later */ 459 cmd_pixel_start = pixel; 460 461 raw_pixels_count_byte = cmd++; /* we'll know this later */ 462 raw_pixel_start = pixel; 463 464 cmd_pixel_end = pixel + min3(MAX_CMD_PIXELS + 1UL, 465 (unsigned long)(pixel_end - pixel), 466 (unsigned long)(cmd_buffer_end - 1 - cmd) / BPP); 467 468 if (back_buffer_offset) { 469 /* note: the framebuffer may change under us, so we must test for underflow */ 470 while (cmd_pixel_end - 1 > pixel && 471 *(cmd_pixel_end - 1) == *(u16 *)((u8 *)(cmd_pixel_end - 1) + back_buffer_offset)) 472 cmd_pixel_end--; 473 } 474 475 while (pixel < cmd_pixel_end) { 476 const uint16_t * const repeating_pixel = pixel; 477 u16 pixel_value = *pixel; 478 479 put_unaligned_be16(pixel_value, cmd); 480 if (back_buffer_offset) 481 *(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value; 482 cmd += 2; 483 pixel++; 484 485 if (unlikely((pixel < cmd_pixel_end) && 486 (*pixel == pixel_value))) { 487 /* go back and fill in raw pixel count */ 488 *raw_pixels_count_byte = ((repeating_pixel - 489 raw_pixel_start) + 1) & 0xFF; 490 491 do { 492 if (back_buffer_offset) 493 *(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value; 494 pixel++; 495 } while ((pixel < cmd_pixel_end) && 496 (*pixel == pixel_value)); 497 498 /* immediately after raw data is repeat byte */ 499 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF; 500 501 /* Then start another raw pixel span */ 502 raw_pixel_start = pixel; 503 raw_pixels_count_byte = cmd++; 504 } 505 } 506 507 if (pixel > raw_pixel_start) { 508 /* finalize last RAW span */ 509 *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF; 510 } else { 511 /* undo unused byte */ 512 cmd--; 513 } 514 515 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF; 516 dev_addr += (u8 *)pixel - (u8 *)cmd_pixel_start; 517 } 518 519 if (cmd_buffer_end - MIN_RLX_CMD_BYTES <= cmd) { 520 /* Fill leftover bytes with no-ops */ 521 if (cmd_buffer_end > cmd) 522 memset(cmd, 0xAF, cmd_buffer_end - cmd); 523 cmd = (uint8_t *) cmd_buffer_end; 524 } 525 526 *command_buffer_ptr = cmd; 527 *pixel_start_ptr = pixel; 528 *device_address_ptr = dev_addr; 529} 530 531/* 532 * There are 3 copies of every pixel: The front buffer that the fbdev 533 * client renders to, the actual framebuffer across the USB bus in hardware 534 * (that we can only write to, slowly, and can never read), and (optionally) 535 * our shadow copy that tracks what's been sent to that hardware buffer. 536 */ 537static int dlfb_render_hline(struct dlfb_data *dlfb, struct urb **urb_ptr, 538 const char *front, char **urb_buf_ptr, 539 u32 byte_offset, u32 byte_width, 540 int *ident_ptr, int *sent_ptr) 541{ 542 const u8 *line_start, *line_end, *next_pixel; 543 u32 dev_addr = dlfb->base16 + byte_offset; 544 struct urb *urb = *urb_ptr; 545 u8 *cmd = *urb_buf_ptr; 546 u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length; 547 unsigned long back_buffer_offset = 0; 548 549 line_start = (u8 *) (front + byte_offset); 550 next_pixel = line_start; 551 line_end = next_pixel + byte_width; 552 553 if (dlfb->backing_buffer) { 554 int offset; 555 const u8 *back_start = (u8 *) (dlfb->backing_buffer 556 + byte_offset); 557 558 back_buffer_offset = (unsigned long)back_start - (unsigned long)line_start; 559 560 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel, 561 &byte_width); 562 563 offset = next_pixel - line_start; 564 line_end = next_pixel + byte_width; 565 dev_addr += offset; 566 back_start += offset; 567 line_start += offset; 568 } 569 570 while (next_pixel < line_end) { 571 572 dlfb_compress_hline((const uint16_t **) &next_pixel, 573 (const uint16_t *) line_end, &dev_addr, 574 (u8 **) &cmd, (u8 *) cmd_end, back_buffer_offset, 575 ident_ptr); 576 577 if (cmd >= cmd_end) { 578 int len = cmd - (u8 *) urb->transfer_buffer; 579 if (dlfb_submit_urb(dlfb, urb, len)) 580 return 1; /* lost pixels is set */ 581 *sent_ptr += len; 582 urb = dlfb_get_urb(dlfb); 583 if (!urb) 584 return 1; /* lost_pixels is set */ 585 *urb_ptr = urb; 586 cmd = urb->transfer_buffer; 587 cmd_end = &cmd[urb->transfer_buffer_length]; 588 } 589 } 590 591 *urb_buf_ptr = cmd; 592 593 return 0; 594} 595 596static int dlfb_handle_damage(struct dlfb_data *dlfb, int x, int y, int width, int height) 597{ 598 int i, ret; 599 char *cmd; 600 cycles_t start_cycles, end_cycles; 601 int bytes_sent = 0; 602 int bytes_identical = 0; 603 struct urb *urb; 604 int aligned_x; 605 606 start_cycles = get_cycles(); 607 608 mutex_lock(&dlfb->render_mutex); 609 610 aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long)); 611 width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long)); 612 x = aligned_x; 613 614 if ((width <= 0) || 615 (x + width > dlfb->info->var.xres) || 616 (y + height > dlfb->info->var.yres)) { 617 ret = -EINVAL; 618 goto unlock_ret; 619 } 620 621 if (!atomic_read(&dlfb->usb_active)) { 622 ret = 0; 623 goto unlock_ret; 624 } 625 626 urb = dlfb_get_urb(dlfb); 627 if (!urb) { 628 ret = 0; 629 goto unlock_ret; 630 } 631 cmd = urb->transfer_buffer; 632 633 for (i = y; i < y + height ; i++) { 634 const int line_offset = dlfb->info->fix.line_length * i; 635 const int byte_offset = line_offset + (x * BPP); 636 637 if (dlfb_render_hline(dlfb, &urb, 638 (char *) dlfb->info->fix.smem_start, 639 &cmd, byte_offset, width * BPP, 640 &bytes_identical, &bytes_sent)) 641 goto error; 642 } 643 644 if (cmd > (char *) urb->transfer_buffer) { 645 int len; 646 if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length) 647 *cmd++ = 0xAF; 648 /* Send partial buffer remaining before exiting */ 649 len = cmd - (char *) urb->transfer_buffer; 650 dlfb_submit_urb(dlfb, urb, len); 651 bytes_sent += len; 652 } else 653 dlfb_urb_completion(urb); 654 655error: 656 atomic_add(bytes_sent, &dlfb->bytes_sent); 657 atomic_add(bytes_identical, &dlfb->bytes_identical); 658 atomic_add(width*height*2, &dlfb->bytes_rendered); 659 end_cycles = get_cycles(); 660 atomic_add(((unsigned int) ((end_cycles - start_cycles) 661 >> 10)), /* Kcycles */ 662 &dlfb->cpu_kcycles_used); 663 664 ret = 0; 665 666unlock_ret: 667 mutex_unlock(&dlfb->render_mutex); 668 return ret; 669} 670 671static void dlfb_init_damage(struct dlfb_data *dlfb) 672{ 673 dlfb->damage_x = INT_MAX; 674 dlfb->damage_x2 = 0; 675 dlfb->damage_y = INT_MAX; 676 dlfb->damage_y2 = 0; 677} 678 679static void dlfb_damage_work(struct work_struct *w) 680{ 681 struct dlfb_data *dlfb = container_of(w, struct dlfb_data, damage_work); 682 int x, x2, y, y2; 683 684 spin_lock_irq(&dlfb->damage_lock); 685 x = dlfb->damage_x; 686 x2 = dlfb->damage_x2; 687 y = dlfb->damage_y; 688 y2 = dlfb->damage_y2; 689 dlfb_init_damage(dlfb); 690 spin_unlock_irq(&dlfb->damage_lock); 691 692 if (x < x2 && y < y2) 693 dlfb_handle_damage(dlfb, x, y, x2 - x, y2 - y); 694} 695 696static void dlfb_offload_damage(struct dlfb_data *dlfb, int x, int y, int width, int height) 697{ 698 unsigned long flags; 699 int x2 = x + width; 700 int y2 = y + height; 701 702 if (x >= x2 || y >= y2) 703 return; 704 705 spin_lock_irqsave(&dlfb->damage_lock, flags); 706 dlfb->damage_x = min(x, dlfb->damage_x); 707 dlfb->damage_x2 = max(x2, dlfb->damage_x2); 708 dlfb->damage_y = min(y, dlfb->damage_y); 709 dlfb->damage_y2 = max(y2, dlfb->damage_y2); 710 spin_unlock_irqrestore(&dlfb->damage_lock, flags); 711 712 schedule_work(&dlfb->damage_work); 713} 714 715/* 716 * Path triggered by usermode clients who write to filesystem 717 * e.g. cat filename > /dev/fb1 718 * Not used by X Windows or text-mode console. But useful for testing. 719 * Slow because of extra copy and we must assume all pixels dirty. 720 */ 721static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf, 722 size_t count, loff_t *ppos) 723{ 724 ssize_t result; 725 struct dlfb_data *dlfb = info->par; 726 u32 offset = (u32) *ppos; 727 728 result = fb_sys_write(info, buf, count, ppos); 729 730 if (result > 0) { 731 int start = max((int)(offset / info->fix.line_length), 0); 732 int lines = min((u32)((result / info->fix.line_length) + 1), 733 (u32)info->var.yres); 734 735 dlfb_handle_damage(dlfb, 0, start, info->var.xres, 736 lines); 737 } 738 739 return result; 740} 741 742/* hardware has native COPY command (see libdlo), but not worth it for fbcon */ 743static void dlfb_ops_copyarea(struct fb_info *info, 744 const struct fb_copyarea *area) 745{ 746 747 struct dlfb_data *dlfb = info->par; 748 749 sys_copyarea(info, area); 750 751 dlfb_offload_damage(dlfb, area->dx, area->dy, 752 area->width, area->height); 753} 754 755static void dlfb_ops_imageblit(struct fb_info *info, 756 const struct fb_image *image) 757{ 758 struct dlfb_data *dlfb = info->par; 759 760 sys_imageblit(info, image); 761 762 dlfb_offload_damage(dlfb, image->dx, image->dy, 763 image->width, image->height); 764} 765 766static void dlfb_ops_fillrect(struct fb_info *info, 767 const struct fb_fillrect *rect) 768{ 769 struct dlfb_data *dlfb = info->par; 770 771 sys_fillrect(info, rect); 772 773 dlfb_offload_damage(dlfb, rect->dx, rect->dy, rect->width, 774 rect->height); 775} 776 777/* 778 * NOTE: fb_defio.c is holding info->fbdefio.mutex 779 * Touching ANY framebuffer memory that triggers a page fault 780 * in fb_defio will cause a deadlock, when it also tries to 781 * grab the same mutex. 782 */ 783static void dlfb_dpy_deferred_io(struct fb_info *info, 784 struct list_head *pagelist) 785{ 786 struct page *cur; 787 struct fb_deferred_io *fbdefio = info->fbdefio; 788 struct dlfb_data *dlfb = info->par; 789 struct urb *urb; 790 char *cmd; 791 cycles_t start_cycles, end_cycles; 792 int bytes_sent = 0; 793 int bytes_identical = 0; 794 int bytes_rendered = 0; 795 796 mutex_lock(&dlfb->render_mutex); 797 798 if (!fb_defio) 799 goto unlock_ret; 800 801 if (!atomic_read(&dlfb->usb_active)) 802 goto unlock_ret; 803 804 start_cycles = get_cycles(); 805 806 urb = dlfb_get_urb(dlfb); 807 if (!urb) 808 goto unlock_ret; 809 810 cmd = urb->transfer_buffer; 811 812 /* walk the written page list and render each to device */ 813 list_for_each_entry(cur, &fbdefio->pagelist, lru) { 814 815 if (dlfb_render_hline(dlfb, &urb, (char *) info->fix.smem_start, 816 &cmd, cur->index << PAGE_SHIFT, 817 PAGE_SIZE, &bytes_identical, &bytes_sent)) 818 goto error; 819 bytes_rendered += PAGE_SIZE; 820 } 821 822 if (cmd > (char *) urb->transfer_buffer) { 823 int len; 824 if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length) 825 *cmd++ = 0xAF; 826 /* Send partial buffer remaining before exiting */ 827 len = cmd - (char *) urb->transfer_buffer; 828 dlfb_submit_urb(dlfb, urb, len); 829 bytes_sent += len; 830 } else 831 dlfb_urb_completion(urb); 832 833error: 834 atomic_add(bytes_sent, &dlfb->bytes_sent); 835 atomic_add(bytes_identical, &dlfb->bytes_identical); 836 atomic_add(bytes_rendered, &dlfb->bytes_rendered); 837 end_cycles = get_cycles(); 838 atomic_add(((unsigned int) ((end_cycles - start_cycles) 839 >> 10)), /* Kcycles */ 840 &dlfb->cpu_kcycles_used); 841unlock_ret: 842 mutex_unlock(&dlfb->render_mutex); 843} 844 845static int dlfb_get_edid(struct dlfb_data *dlfb, char *edid, int len) 846{ 847 int i, ret; 848 char *rbuf; 849 850 rbuf = kmalloc(2, GFP_KERNEL); 851 if (!rbuf) 852 return 0; 853 854 for (i = 0; i < len; i++) { 855 ret = usb_control_msg(dlfb->udev, 856 usb_rcvctrlpipe(dlfb->udev, 0), 0x02, 857 (0x80 | (0x02 << 5)), i << 8, 0xA1, 858 rbuf, 2, USB_CTRL_GET_TIMEOUT); 859 if (ret < 2) { 860 dev_err(&dlfb->udev->dev, 861 "Read EDID byte %d failed: %d\n", i, ret); 862 i--; 863 break; 864 } 865 edid[i] = rbuf[1]; 866 } 867 868 kfree(rbuf); 869 870 return i; 871} 872 873static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd, 874 unsigned long arg) 875{ 876 877 struct dlfb_data *dlfb = info->par; 878 879 if (!atomic_read(&dlfb->usb_active)) 880 return 0; 881 882 /* TODO: Update X server to get this from sysfs instead */ 883 if (cmd == DLFB_IOCTL_RETURN_EDID) { 884 void __user *edid = (void __user *)arg; 885 if (copy_to_user(edid, dlfb->edid, dlfb->edid_size)) 886 return -EFAULT; 887 return 0; 888 } 889 890 /* TODO: Help propose a standard fb.h ioctl to report mmap damage */ 891 if (cmd == DLFB_IOCTL_REPORT_DAMAGE) { 892 struct dloarea area; 893 894 if (copy_from_user(&area, (void __user *)arg, 895 sizeof(struct dloarea))) 896 return -EFAULT; 897 898 /* 899 * If we have a damage-aware client, turn fb_defio "off" 900 * To avoid perf imact of unnecessary page fault handling. 901 * Done by resetting the delay for this fb_info to a very 902 * long period. Pages will become writable and stay that way. 903 * Reset to normal value when all clients have closed this fb. 904 */ 905 if (info->fbdefio) 906 info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE; 907 908 if (area.x < 0) 909 area.x = 0; 910 911 if (area.x > info->var.xres) 912 area.x = info->var.xres; 913 914 if (area.y < 0) 915 area.y = 0; 916 917 if (area.y > info->var.yres) 918 area.y = info->var.yres; 919 920 dlfb_handle_damage(dlfb, area.x, area.y, area.w, area.h); 921 } 922 923 return 0; 924} 925 926/* taken from vesafb */ 927static int 928dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green, 929 unsigned blue, unsigned transp, struct fb_info *info) 930{ 931 int err = 0; 932 933 if (regno >= info->cmap.len) 934 return 1; 935 936 if (regno < 16) { 937 if (info->var.red.offset == 10) { 938 /* 1:5:5:5 */ 939 ((u32 *) (info->pseudo_palette))[regno] = 940 ((red & 0xf800) >> 1) | 941 ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11); 942 } else { 943 /* 0:5:6:5 */ 944 ((u32 *) (info->pseudo_palette))[regno] = 945 ((red & 0xf800)) | 946 ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11); 947 } 948 } 949 950 return err; 951} 952 953/* 954 * It's common for several clients to have framebuffer open simultaneously. 955 * e.g. both fbcon and X. Makes things interesting. 956 * Assumes caller is holding info->lock (for open and release at least) 957 */ 958static int dlfb_ops_open(struct fb_info *info, int user) 959{ 960 struct dlfb_data *dlfb = info->par; 961 962 /* 963 * fbcon aggressively connects to first framebuffer it finds, 964 * preventing other clients (X) from working properly. Usually 965 * not what the user wants. Fail by default with option to enable. 966 */ 967 if ((user == 0) && (!console)) 968 return -EBUSY; 969 970 /* If the USB device is gone, we don't accept new opens */ 971 if (dlfb->virtualized) 972 return -ENODEV; 973 974 dlfb->fb_count++; 975 976 if (fb_defio && (info->fbdefio == NULL)) { 977 /* enable defio at last moment if not disabled by client */ 978 979 struct fb_deferred_io *fbdefio; 980 981 fbdefio = kzalloc(sizeof(struct fb_deferred_io), GFP_KERNEL); 982 983 if (fbdefio) { 984 fbdefio->delay = DL_DEFIO_WRITE_DELAY; 985 fbdefio->deferred_io = dlfb_dpy_deferred_io; 986 } 987 988 info->fbdefio = fbdefio; 989 fb_deferred_io_init(info); 990 } 991 992 dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n", 993 user, info, dlfb->fb_count); 994 995 return 0; 996} 997 998static void dlfb_ops_destroy(struct fb_info *info) 999{ 1000 struct dlfb_data *dlfb = info->par; 1001 1002 cancel_work_sync(&dlfb->damage_work); 1003 1004 mutex_destroy(&dlfb->render_mutex); 1005 1006 if (info->cmap.len != 0) 1007 fb_dealloc_cmap(&info->cmap); 1008 if (info->monspecs.modedb) 1009 fb_destroy_modedb(info->monspecs.modedb); 1010 vfree(info->screen_base); 1011 1012 fb_destroy_modelist(&info->modelist); 1013 1014 while (!list_empty(&dlfb->deferred_free)) { 1015 struct dlfb_deferred_free *d = list_entry(dlfb->deferred_free.next, struct dlfb_deferred_free, list); 1016 list_del(&d->list); 1017 vfree(d->mem); 1018 kfree(d); 1019 } 1020 vfree(dlfb->backing_buffer); 1021 kfree(dlfb->edid); 1022 dlfb_free_urb_list(dlfb); 1023 usb_put_dev(dlfb->udev); 1024 kfree(dlfb); 1025 1026 /* Assume info structure is freed after this point */ 1027 framebuffer_release(info); 1028} 1029 1030/* 1031 * Assumes caller is holding info->lock mutex (for open and release at least) 1032 */ 1033static int dlfb_ops_release(struct fb_info *info, int user) 1034{ 1035 struct dlfb_data *dlfb = info->par; 1036 1037 dlfb->fb_count--; 1038 1039 if ((dlfb->fb_count == 0) && (info->fbdefio)) { 1040 fb_deferred_io_cleanup(info); 1041 kfree(info->fbdefio); 1042 info->fbdefio = NULL; 1043 } 1044 1045 dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count); 1046 1047 return 0; 1048} 1049 1050/* 1051 * Check whether a video mode is supported by the DisplayLink chip 1052 * We start from monitor's modes, so don't need to filter that here 1053 */ 1054static int dlfb_is_valid_mode(struct fb_videomode *mode, struct dlfb_data *dlfb) 1055{ 1056 if (mode->xres * mode->yres > dlfb->sku_pixel_limit) 1057 return 0; 1058 1059 return 1; 1060} 1061 1062static void dlfb_var_color_format(struct fb_var_screeninfo *var) 1063{ 1064 const struct fb_bitfield red = { 11, 5, 0 }; 1065 const struct fb_bitfield green = { 5, 6, 0 }; 1066 const struct fb_bitfield blue = { 0, 5, 0 }; 1067 1068 var->bits_per_pixel = 16; 1069 var->red = red; 1070 var->green = green; 1071 var->blue = blue; 1072} 1073 1074static int dlfb_ops_check_var(struct fb_var_screeninfo *var, 1075 struct fb_info *info) 1076{ 1077 struct fb_videomode mode; 1078 struct dlfb_data *dlfb = info->par; 1079 1080 /* set device-specific elements of var unrelated to mode */ 1081 dlfb_var_color_format(var); 1082 1083 fb_var_to_videomode(&mode, var); 1084 1085 if (!dlfb_is_valid_mode(&mode, dlfb)) 1086 return -EINVAL; 1087 1088 return 0; 1089} 1090 1091static int dlfb_ops_set_par(struct fb_info *info) 1092{ 1093 struct dlfb_data *dlfb = info->par; 1094 int result; 1095 u16 *pix_framebuffer; 1096 int i; 1097 struct fb_var_screeninfo fvs; 1098 u32 line_length = info->var.xres * (info->var.bits_per_pixel / 8); 1099 1100 /* clear the activate field because it causes spurious miscompares */ 1101 fvs = info->var; 1102 fvs.activate = 0; 1103 fvs.vmode &= ~FB_VMODE_SMOOTH_XPAN; 1104 1105 if (!memcmp(&dlfb->current_mode, &fvs, sizeof(struct fb_var_screeninfo))) 1106 return 0; 1107 1108 result = dlfb_realloc_framebuffer(dlfb, info, info->var.yres * line_length); 1109 if (result) 1110 return result; 1111 1112 result = dlfb_set_video_mode(dlfb, &info->var); 1113 1114 if (result) 1115 return result; 1116 1117 dlfb->current_mode = fvs; 1118 info->fix.line_length = line_length; 1119 1120 if (dlfb->fb_count == 0) { 1121 1122 /* paint greenscreen */ 1123 1124 pix_framebuffer = (u16 *) info->screen_base; 1125 for (i = 0; i < info->fix.smem_len / 2; i++) 1126 pix_framebuffer[i] = 0x37e6; 1127 } 1128 1129 dlfb_handle_damage(dlfb, 0, 0, info->var.xres, info->var.yres); 1130 1131 return 0; 1132} 1133 1134/* To fonzi the jukebox (e.g. make blanking changes take effect) */ 1135static char *dlfb_dummy_render(char *buf) 1136{ 1137 *buf++ = 0xAF; 1138 *buf++ = 0x6A; /* copy */ 1139 *buf++ = 0x00; /* from address*/ 1140 *buf++ = 0x00; 1141 *buf++ = 0x00; 1142 *buf++ = 0x01; /* one pixel */ 1143 *buf++ = 0x00; /* to address */ 1144 *buf++ = 0x00; 1145 *buf++ = 0x00; 1146 return buf; 1147} 1148 1149/* 1150 * In order to come back from full DPMS off, we need to set the mode again 1151 */ 1152static int dlfb_ops_blank(int blank_mode, struct fb_info *info) 1153{ 1154 struct dlfb_data *dlfb = info->par; 1155 char *bufptr; 1156 struct urb *urb; 1157 1158 dev_dbg(info->dev, "blank, mode %d --> %d\n", 1159 dlfb->blank_mode, blank_mode); 1160 1161 if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) && 1162 (blank_mode != FB_BLANK_POWERDOWN)) { 1163 1164 /* returning from powerdown requires a fresh modeset */ 1165 dlfb_set_video_mode(dlfb, &info->var); 1166 } 1167 1168 urb = dlfb_get_urb(dlfb); 1169 if (!urb) 1170 return 0; 1171 1172 bufptr = (char *) urb->transfer_buffer; 1173 bufptr = dlfb_vidreg_lock(bufptr); 1174 bufptr = dlfb_blanking(bufptr, blank_mode); 1175 bufptr = dlfb_vidreg_unlock(bufptr); 1176 1177 /* seems like a render op is needed to have blank change take effect */ 1178 bufptr = dlfb_dummy_render(bufptr); 1179 1180 dlfb_submit_urb(dlfb, urb, bufptr - 1181 (char *) urb->transfer_buffer); 1182 1183 dlfb->blank_mode = blank_mode; 1184 1185 return 0; 1186} 1187 1188static const struct fb_ops dlfb_ops = { 1189 .owner = THIS_MODULE, 1190 .fb_read = fb_sys_read, 1191 .fb_write = dlfb_ops_write, 1192 .fb_setcolreg = dlfb_ops_setcolreg, 1193 .fb_fillrect = dlfb_ops_fillrect, 1194 .fb_copyarea = dlfb_ops_copyarea, 1195 .fb_imageblit = dlfb_ops_imageblit, 1196 .fb_mmap = dlfb_ops_mmap, 1197 .fb_ioctl = dlfb_ops_ioctl, 1198 .fb_open = dlfb_ops_open, 1199 .fb_release = dlfb_ops_release, 1200 .fb_blank = dlfb_ops_blank, 1201 .fb_check_var = dlfb_ops_check_var, 1202 .fb_set_par = dlfb_ops_set_par, 1203 .fb_destroy = dlfb_ops_destroy, 1204}; 1205 1206 1207static void dlfb_deferred_vfree(struct dlfb_data *dlfb, void *mem) 1208{ 1209 struct dlfb_deferred_free *d = kmalloc(sizeof(struct dlfb_deferred_free), GFP_KERNEL); 1210 if (!d) 1211 return; 1212 d->mem = mem; 1213 list_add(&d->list, &dlfb->deferred_free); 1214} 1215 1216/* 1217 * Assumes &info->lock held by caller 1218 * Assumes no active clients have framebuffer open 1219 */ 1220static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len) 1221{ 1222 u32 old_len = info->fix.smem_len; 1223 const void *old_fb = (const void __force *)info->screen_base; 1224 unsigned char *new_fb; 1225 unsigned char *new_back = NULL; 1226 1227 new_len = PAGE_ALIGN(new_len); 1228 1229 if (new_len > old_len) { 1230 /* 1231 * Alloc system memory for virtual framebuffer 1232 */ 1233 new_fb = vmalloc(new_len); 1234 if (!new_fb) { 1235 dev_err(info->dev, "Virtual framebuffer alloc failed\n"); 1236 return -ENOMEM; 1237 } 1238 memset(new_fb, 0xff, new_len); 1239 1240 if (info->screen_base) { 1241 memcpy(new_fb, old_fb, old_len); 1242 dlfb_deferred_vfree(dlfb, (void __force *)info->screen_base); 1243 } 1244 1245 info->screen_base = (char __iomem *)new_fb; 1246 info->fix.smem_len = new_len; 1247 info->fix.smem_start = (unsigned long) new_fb; 1248 info->flags = udlfb_info_flags; 1249 1250 /* 1251 * Second framebuffer copy to mirror the framebuffer state 1252 * on the physical USB device. We can function without this. 1253 * But with imperfect damage info we may send pixels over USB 1254 * that were, in fact, unchanged - wasting limited USB bandwidth 1255 */ 1256 if (shadow) 1257 new_back = vzalloc(new_len); 1258 if (!new_back) 1259 dev_info(info->dev, 1260 "No shadow/backing buffer allocated\n"); 1261 else { 1262 dlfb_deferred_vfree(dlfb, dlfb->backing_buffer); 1263 dlfb->backing_buffer = new_back; 1264 } 1265 } 1266 return 0; 1267} 1268 1269/* 1270 * 1) Get EDID from hw, or use sw default 1271 * 2) Parse into various fb_info structs 1272 * 3) Allocate virtual framebuffer memory to back highest res mode 1273 * 1274 * Parses EDID into three places used by various parts of fbdev: 1275 * fb_var_screeninfo contains the timing of the monitor's preferred mode 1276 * fb_info.monspecs is full parsed EDID info, including monspecs.modedb 1277 * fb_info.modelist is a linked list of all monitor & VESA modes which work 1278 * 1279 * If EDID is not readable/valid, then modelist is all VESA modes, 1280 * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode 1281 * Returns 0 if successful 1282 */ 1283static int dlfb_setup_modes(struct dlfb_data *dlfb, 1284 struct fb_info *info, 1285 char *default_edid, size_t default_edid_size) 1286{ 1287 char *edid; 1288 int i, result = 0, tries = 3; 1289 struct device *dev = info->device; 1290 struct fb_videomode *mode; 1291 const struct fb_videomode *default_vmode = NULL; 1292 1293 if (info->dev) { 1294 /* only use mutex if info has been registered */ 1295 mutex_lock(&info->lock); 1296 /* parent device is used otherwise */ 1297 dev = info->dev; 1298 } 1299 1300 edid = kmalloc(EDID_LENGTH, GFP_KERNEL); 1301 if (!edid) { 1302 result = -ENOMEM; 1303 goto error; 1304 } 1305 1306 fb_destroy_modelist(&info->modelist); 1307 memset(&info->monspecs, 0, sizeof(info->monspecs)); 1308 1309 /* 1310 * Try to (re)read EDID from hardware first 1311 * EDID data may return, but not parse as valid 1312 * Try again a few times, in case of e.g. analog cable noise 1313 */ 1314 while (tries--) { 1315 1316 i = dlfb_get_edid(dlfb, edid, EDID_LENGTH); 1317 1318 if (i >= EDID_LENGTH) 1319 fb_edid_to_monspecs(edid, &info->monspecs); 1320 1321 if (info->monspecs.modedb_len > 0) { 1322 dlfb->edid = edid; 1323 dlfb->edid_size = i; 1324 break; 1325 } 1326 } 1327 1328 /* If that fails, use a previously returned EDID if available */ 1329 if (info->monspecs.modedb_len == 0) { 1330 dev_err(dev, "Unable to get valid EDID from device/display\n"); 1331 1332 if (dlfb->edid) { 1333 fb_edid_to_monspecs(dlfb->edid, &info->monspecs); 1334 if (info->monspecs.modedb_len > 0) 1335 dev_err(dev, "Using previously queried EDID\n"); 1336 } 1337 } 1338 1339 /* If that fails, use the default EDID we were handed */ 1340 if (info->monspecs.modedb_len == 0) { 1341 if (default_edid_size >= EDID_LENGTH) { 1342 fb_edid_to_monspecs(default_edid, &info->monspecs); 1343 if (info->monspecs.modedb_len > 0) { 1344 memcpy(edid, default_edid, default_edid_size); 1345 dlfb->edid = edid; 1346 dlfb->edid_size = default_edid_size; 1347 dev_err(dev, "Using default/backup EDID\n"); 1348 } 1349 } 1350 } 1351 1352 /* If we've got modes, let's pick a best default mode */ 1353 if (info->monspecs.modedb_len > 0) { 1354 1355 for (i = 0; i < info->monspecs.modedb_len; i++) { 1356 mode = &info->monspecs.modedb[i]; 1357 if (dlfb_is_valid_mode(mode, dlfb)) { 1358 fb_add_videomode(mode, &info->modelist); 1359 } else { 1360 dev_dbg(dev, "Specified mode %dx%d too big\n", 1361 mode->xres, mode->yres); 1362 if (i == 0) 1363 /* if we've removed top/best mode */ 1364 info->monspecs.misc 1365 &= ~FB_MISC_1ST_DETAIL; 1366 } 1367 } 1368 1369 default_vmode = fb_find_best_display(&info->monspecs, 1370 &info->modelist); 1371 } 1372 1373 /* If everything else has failed, fall back to safe default mode */ 1374 if (default_vmode == NULL) { 1375 1376 struct fb_videomode fb_vmode = {0}; 1377 1378 /* 1379 * Add the standard VESA modes to our modelist 1380 * Since we don't have EDID, there may be modes that 1381 * overspec monitor and/or are incorrect aspect ratio, etc. 1382 * But at least the user has a chance to choose 1383 */ 1384 for (i = 0; i < VESA_MODEDB_SIZE; i++) { 1385 mode = (struct fb_videomode *)&vesa_modes[i]; 1386 if (dlfb_is_valid_mode(mode, dlfb)) 1387 fb_add_videomode(mode, &info->modelist); 1388 else 1389 dev_dbg(dev, "VESA mode %dx%d too big\n", 1390 mode->xres, mode->yres); 1391 } 1392 1393 /* 1394 * default to resolution safe for projectors 1395 * (since they are most common case without EDID) 1396 */ 1397 fb_vmode.xres = 800; 1398 fb_vmode.yres = 600; 1399 fb_vmode.refresh = 60; 1400 default_vmode = fb_find_nearest_mode(&fb_vmode, 1401 &info->modelist); 1402 } 1403 1404 /* If we have good mode and no active clients*/ 1405 if ((default_vmode != NULL) && (dlfb->fb_count == 0)) { 1406 1407 fb_videomode_to_var(&info->var, default_vmode); 1408 dlfb_var_color_format(&info->var); 1409 1410 /* 1411 * with mode size info, we can now alloc our framebuffer. 1412 */ 1413 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix)); 1414 } else 1415 result = -EINVAL; 1416 1417error: 1418 if (edid && (dlfb->edid != edid)) 1419 kfree(edid); 1420 1421 if (info->dev) 1422 mutex_unlock(&info->lock); 1423 1424 return result; 1425} 1426 1427static ssize_t metrics_bytes_rendered_show(struct device *fbdev, 1428 struct device_attribute *a, char *buf) { 1429 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1430 struct dlfb_data *dlfb = fb_info->par; 1431 return sysfs_emit(buf, "%u\n", 1432 atomic_read(&dlfb->bytes_rendered)); 1433} 1434 1435static ssize_t metrics_bytes_identical_show(struct device *fbdev, 1436 struct device_attribute *a, char *buf) { 1437 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1438 struct dlfb_data *dlfb = fb_info->par; 1439 return sysfs_emit(buf, "%u\n", 1440 atomic_read(&dlfb->bytes_identical)); 1441} 1442 1443static ssize_t metrics_bytes_sent_show(struct device *fbdev, 1444 struct device_attribute *a, char *buf) { 1445 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1446 struct dlfb_data *dlfb = fb_info->par; 1447 return sysfs_emit(buf, "%u\n", 1448 atomic_read(&dlfb->bytes_sent)); 1449} 1450 1451static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev, 1452 struct device_attribute *a, char *buf) { 1453 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1454 struct dlfb_data *dlfb = fb_info->par; 1455 return sysfs_emit(buf, "%u\n", 1456 atomic_read(&dlfb->cpu_kcycles_used)); 1457} 1458 1459static ssize_t edid_show( 1460 struct file *filp, 1461 struct kobject *kobj, struct bin_attribute *a, 1462 char *buf, loff_t off, size_t count) { 1463 struct device *fbdev = kobj_to_dev(kobj); 1464 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1465 struct dlfb_data *dlfb = fb_info->par; 1466 1467 if (dlfb->edid == NULL) 1468 return 0; 1469 1470 if ((off >= dlfb->edid_size) || (count > dlfb->edid_size)) 1471 return 0; 1472 1473 if (off + count > dlfb->edid_size) 1474 count = dlfb->edid_size - off; 1475 1476 memcpy(buf, dlfb->edid, count); 1477 1478 return count; 1479} 1480 1481static ssize_t edid_store( 1482 struct file *filp, 1483 struct kobject *kobj, struct bin_attribute *a, 1484 char *src, loff_t src_off, size_t src_size) { 1485 struct device *fbdev = kobj_to_dev(kobj); 1486 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1487 struct dlfb_data *dlfb = fb_info->par; 1488 int ret; 1489 1490 /* We only support write of entire EDID at once, no offset*/ 1491 if ((src_size != EDID_LENGTH) || (src_off != 0)) 1492 return -EINVAL; 1493 1494 ret = dlfb_setup_modes(dlfb, fb_info, src, src_size); 1495 if (ret) 1496 return ret; 1497 1498 if (!dlfb->edid || memcmp(src, dlfb->edid, src_size)) 1499 return -EINVAL; 1500 1501 ret = dlfb_ops_set_par(fb_info); 1502 if (ret) 1503 return ret; 1504 1505 return src_size; 1506} 1507 1508static ssize_t metrics_reset_store(struct device *fbdev, 1509 struct device_attribute *attr, 1510 const char *buf, size_t count) 1511{ 1512 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1513 struct dlfb_data *dlfb = fb_info->par; 1514 1515 atomic_set(&dlfb->bytes_rendered, 0); 1516 atomic_set(&dlfb->bytes_identical, 0); 1517 atomic_set(&dlfb->bytes_sent, 0); 1518 atomic_set(&dlfb->cpu_kcycles_used, 0); 1519 1520 return count; 1521} 1522 1523static const struct bin_attribute edid_attr = { 1524 .attr.name = "edid", 1525 .attr.mode = 0666, 1526 .size = EDID_LENGTH, 1527 .read = edid_show, 1528 .write = edid_store 1529}; 1530 1531static const struct device_attribute fb_device_attrs[] = { 1532 __ATTR_RO(metrics_bytes_rendered), 1533 __ATTR_RO(metrics_bytes_identical), 1534 __ATTR_RO(metrics_bytes_sent), 1535 __ATTR_RO(metrics_cpu_kcycles_used), 1536 __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store), 1537}; 1538 1539/* 1540 * This is necessary before we can communicate with the display controller. 1541 */ 1542static int dlfb_select_std_channel(struct dlfb_data *dlfb) 1543{ 1544 int ret; 1545 void *buf; 1546 static const u8 set_def_chn[] = { 1547 0x57, 0xCD, 0xDC, 0xA7, 1548 0x1C, 0x88, 0x5E, 0x15, 1549 0x60, 0xFE, 0xC6, 0x97, 1550 0x16, 0x3D, 0x47, 0xF2 }; 1551 1552 buf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL); 1553 1554 if (!buf) 1555 return -ENOMEM; 1556 1557 ret = usb_control_msg(dlfb->udev, usb_sndctrlpipe(dlfb->udev, 0), 1558 NR_USB_REQUEST_CHANNEL, 1559 (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0, 1560 buf, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT); 1561 1562 kfree(buf); 1563 1564 return ret; 1565} 1566 1567static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb, 1568 struct usb_interface *intf) 1569{ 1570 char *desc; 1571 char *buf; 1572 char *desc_end; 1573 int total_len; 1574 1575 buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL); 1576 if (!buf) 1577 return false; 1578 desc = buf; 1579 1580 total_len = usb_get_descriptor(interface_to_usbdev(intf), 1581 0x5f, /* vendor specific */ 1582 0, desc, MAX_VENDOR_DESCRIPTOR_SIZE); 1583 1584 /* if not found, look in configuration descriptor */ 1585 if (total_len < 0) { 1586 if (0 == usb_get_extra_descriptor(intf->cur_altsetting, 1587 0x5f, &desc)) 1588 total_len = (int) desc[0]; 1589 } 1590 1591 if (total_len > 5) { 1592 dev_info(&intf->dev, 1593 "vendor descriptor length: %d data: %11ph\n", 1594 total_len, desc); 1595 1596 if ((desc[0] != total_len) || /* descriptor length */ 1597 (desc[1] != 0x5f) || /* vendor descriptor type */ 1598 (desc[2] != 0x01) || /* version (2 bytes) */ 1599 (desc[3] != 0x00) || 1600 (desc[4] != total_len - 2)) /* length after type */ 1601 goto unrecognized; 1602 1603 desc_end = desc + total_len; 1604 desc += 5; /* the fixed header we've already parsed */ 1605 1606 while (desc < desc_end) { 1607 u8 length; 1608 u16 key; 1609 1610 key = *desc++; 1611 key |= (u16)*desc++ << 8; 1612 length = *desc++; 1613 1614 switch (key) { 1615 case 0x0200: { /* max_area */ 1616 u32 max_area = *desc++; 1617 max_area |= (u32)*desc++ << 8; 1618 max_area |= (u32)*desc++ << 16; 1619 max_area |= (u32)*desc++ << 24; 1620 dev_warn(&intf->dev, 1621 "DL chip limited to %d pixel modes\n", 1622 max_area); 1623 dlfb->sku_pixel_limit = max_area; 1624 break; 1625 } 1626 default: 1627 break; 1628 } 1629 desc += length; 1630 } 1631 } else { 1632 dev_info(&intf->dev, "vendor descriptor not available (%d)\n", 1633 total_len); 1634 } 1635 1636 goto success; 1637 1638unrecognized: 1639 /* allow udlfb to load for now even if firmware unrecognized */ 1640 dev_err(&intf->dev, "Unrecognized vendor firmware descriptor\n"); 1641 1642success: 1643 kfree(buf); 1644 return true; 1645} 1646 1647static int dlfb_usb_probe(struct usb_interface *intf, 1648 const struct usb_device_id *id) 1649{ 1650 int i; 1651 const struct device_attribute *attr; 1652 struct dlfb_data *dlfb; 1653 struct fb_info *info; 1654 int retval; 1655 struct usb_device *usbdev = interface_to_usbdev(intf); 1656 static u8 out_ep[] = {OUT_EP_NUM + USB_DIR_OUT, 0}; 1657 1658 /* usb initialization */ 1659 dlfb = kzalloc(sizeof(*dlfb), GFP_KERNEL); 1660 if (!dlfb) { 1661 dev_err(&intf->dev, "%s: failed to allocate dlfb\n", __func__); 1662 return -ENOMEM; 1663 } 1664 1665 INIT_LIST_HEAD(&dlfb->deferred_free); 1666 1667 dlfb->udev = usb_get_dev(usbdev); 1668 usb_set_intfdata(intf, dlfb); 1669 1670 if (!usb_check_bulk_endpoints(intf, out_ep)) { 1671 dev_err(&intf->dev, "Invalid DisplayLink device!\n"); 1672 retval = -EINVAL; 1673 goto error; 1674 } 1675 1676 dev_dbg(&intf->dev, "console enable=%d\n", console); 1677 dev_dbg(&intf->dev, "fb_defio enable=%d\n", fb_defio); 1678 dev_dbg(&intf->dev, "shadow enable=%d\n", shadow); 1679 1680 dlfb->sku_pixel_limit = 2048 * 1152; /* default to maximum */ 1681 1682 if (!dlfb_parse_vendor_descriptor(dlfb, intf)) { 1683 dev_err(&intf->dev, 1684 "firmware not recognized, incompatible device?\n"); 1685 retval = -ENODEV; 1686 goto error; 1687 } 1688 1689 if (pixel_limit) { 1690 dev_warn(&intf->dev, 1691 "DL chip limit of %d overridden to %d\n", 1692 dlfb->sku_pixel_limit, pixel_limit); 1693 dlfb->sku_pixel_limit = pixel_limit; 1694 } 1695 1696 1697 /* allocates framebuffer driver structure, not framebuffer memory */ 1698 info = framebuffer_alloc(0, &dlfb->udev->dev); 1699 if (!info) { 1700 retval = -ENOMEM; 1701 goto error; 1702 } 1703 1704 dlfb->info = info; 1705 info->par = dlfb; 1706 info->pseudo_palette = dlfb->pseudo_palette; 1707 dlfb->ops = dlfb_ops; 1708 info->fbops = &dlfb->ops; 1709 1710 mutex_init(&dlfb->render_mutex); 1711 dlfb_init_damage(dlfb); 1712 spin_lock_init(&dlfb->damage_lock); 1713 INIT_WORK(&dlfb->damage_work, dlfb_damage_work); 1714 1715 INIT_LIST_HEAD(&info->modelist); 1716 1717 if (!dlfb_alloc_urb_list(dlfb, WRITES_IN_FLIGHT, MAX_TRANSFER)) { 1718 retval = -ENOMEM; 1719 dev_err(&intf->dev, "unable to allocate urb list\n"); 1720 goto error; 1721 } 1722 1723 /* We don't register a new USB class. Our client interface is dlfbev */ 1724 1725 retval = fb_alloc_cmap(&info->cmap, 256, 0); 1726 if (retval < 0) { 1727 dev_err(info->device, "cmap allocation failed: %d\n", retval); 1728 goto error; 1729 } 1730 1731 retval = dlfb_setup_modes(dlfb, info, NULL, 0); 1732 if (retval != 0) { 1733 dev_err(info->device, 1734 "unable to find common mode for display and adapter\n"); 1735 goto error; 1736 } 1737 1738 /* ready to begin using device */ 1739 1740 atomic_set(&dlfb->usb_active, 1); 1741 dlfb_select_std_channel(dlfb); 1742 1743 dlfb_ops_check_var(&info->var, info); 1744 retval = dlfb_ops_set_par(info); 1745 if (retval) 1746 goto error; 1747 1748 retval = register_framebuffer(info); 1749 if (retval < 0) { 1750 dev_err(info->device, "unable to register framebuffer: %d\n", 1751 retval); 1752 goto error; 1753 } 1754 1755 for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) { 1756 attr = &fb_device_attrs[i]; 1757 retval = device_create_file(info->dev, attr); 1758 if (retval) 1759 dev_warn(info->device, 1760 "failed to create '%s' attribute: %d\n", 1761 attr->attr.name, retval); 1762 } 1763 1764 retval = device_create_bin_file(info->dev, &edid_attr); 1765 if (retval) 1766 dev_warn(info->device, "failed to create '%s' attribute: %d\n", 1767 edid_attr.attr.name, retval); 1768 1769 dev_info(info->device, 1770 "%s is DisplayLink USB device (%dx%d, %dK framebuffer memory)\n", 1771 dev_name(info->dev), info->var.xres, info->var.yres, 1772 ((dlfb->backing_buffer) ? 1773 info->fix.smem_len * 2 : info->fix.smem_len) >> 10); 1774 return 0; 1775 1776error: 1777 if (dlfb->info) { 1778 dlfb_ops_destroy(dlfb->info); 1779 } else { 1780 usb_put_dev(dlfb->udev); 1781 kfree(dlfb); 1782 } 1783 return retval; 1784} 1785 1786static void dlfb_usb_disconnect(struct usb_interface *intf) 1787{ 1788 struct dlfb_data *dlfb; 1789 struct fb_info *info; 1790 int i; 1791 1792 dlfb = usb_get_intfdata(intf); 1793 info = dlfb->info; 1794 1795 dev_dbg(&intf->dev, "USB disconnect starting\n"); 1796 1797 /* we virtualize until all fb clients release. Then we free */ 1798 dlfb->virtualized = true; 1799 1800 /* When non-active we'll update virtual framebuffer, but no new urbs */ 1801 atomic_set(&dlfb->usb_active, 0); 1802 1803 /* this function will wait for all in-flight urbs to complete */ 1804 dlfb_free_urb_list(dlfb); 1805 1806 /* remove udlfb's sysfs interfaces */ 1807 for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) 1808 device_remove_file(info->dev, &fb_device_attrs[i]); 1809 device_remove_bin_file(info->dev, &edid_attr); 1810 1811 unregister_framebuffer(info); 1812} 1813 1814static struct usb_driver dlfb_driver = { 1815 .name = "udlfb", 1816 .probe = dlfb_usb_probe, 1817 .disconnect = dlfb_usb_disconnect, 1818 .id_table = id_table, 1819}; 1820 1821module_usb_driver(dlfb_driver); 1822 1823static void dlfb_urb_completion(struct urb *urb) 1824{ 1825 struct urb_node *unode = urb->context; 1826 struct dlfb_data *dlfb = unode->dlfb; 1827 unsigned long flags; 1828 1829 switch (urb->status) { 1830 case 0: 1831 /* success */ 1832 break; 1833 case -ECONNRESET: 1834 case -ENOENT: 1835 case -ESHUTDOWN: 1836 /* sync/async unlink faults aren't errors */ 1837 break; 1838 default: 1839 dev_err(&dlfb->udev->dev, 1840 "%s - nonzero write bulk status received: %d\n", 1841 __func__, urb->status); 1842 atomic_set(&dlfb->lost_pixels, 1); 1843 break; 1844 } 1845 1846 urb->transfer_buffer_length = dlfb->urbs.size; /* reset to actual */ 1847 1848 spin_lock_irqsave(&dlfb->urbs.lock, flags); 1849 list_add_tail(&unode->entry, &dlfb->urbs.list); 1850 dlfb->urbs.available++; 1851 spin_unlock_irqrestore(&dlfb->urbs.lock, flags); 1852 1853 up(&dlfb->urbs.limit_sem); 1854} 1855 1856static void dlfb_free_urb_list(struct dlfb_data *dlfb) 1857{ 1858 int count = dlfb->urbs.count; 1859 struct list_head *node; 1860 struct urb_node *unode; 1861 struct urb *urb; 1862 1863 /* keep waiting and freeing, until we've got 'em all */ 1864 while (count--) { 1865 down(&dlfb->urbs.limit_sem); 1866 1867 spin_lock_irq(&dlfb->urbs.lock); 1868 1869 node = dlfb->urbs.list.next; /* have reserved one with sem */ 1870 list_del_init(node); 1871 1872 spin_unlock_irq(&dlfb->urbs.lock); 1873 1874 unode = list_entry(node, struct urb_node, entry); 1875 urb = unode->urb; 1876 1877 /* Free each separately allocated piece */ 1878 usb_free_coherent(urb->dev, dlfb->urbs.size, 1879 urb->transfer_buffer, urb->transfer_dma); 1880 usb_free_urb(urb); 1881 kfree(node); 1882 } 1883 1884 dlfb->urbs.count = 0; 1885} 1886 1887static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size) 1888{ 1889 struct urb *urb; 1890 struct urb_node *unode; 1891 char *buf; 1892 size_t wanted_size = count * size; 1893 1894 spin_lock_init(&dlfb->urbs.lock); 1895 1896retry: 1897 dlfb->urbs.size = size; 1898 INIT_LIST_HEAD(&dlfb->urbs.list); 1899 1900 sema_init(&dlfb->urbs.limit_sem, 0); 1901 dlfb->urbs.count = 0; 1902 dlfb->urbs.available = 0; 1903 1904 while (dlfb->urbs.count * size < wanted_size) { 1905 unode = kzalloc(sizeof(*unode), GFP_KERNEL); 1906 if (!unode) 1907 break; 1908 unode->dlfb = dlfb; 1909 1910 urb = usb_alloc_urb(0, GFP_KERNEL); 1911 if (!urb) { 1912 kfree(unode); 1913 break; 1914 } 1915 unode->urb = urb; 1916 1917 buf = usb_alloc_coherent(dlfb->udev, size, GFP_KERNEL, 1918 &urb->transfer_dma); 1919 if (!buf) { 1920 kfree(unode); 1921 usb_free_urb(urb); 1922 if (size > PAGE_SIZE) { 1923 size /= 2; 1924 dlfb_free_urb_list(dlfb); 1925 goto retry; 1926 } 1927 break; 1928 } 1929 1930 /* urb->transfer_buffer_length set to actual before submit */ 1931 usb_fill_bulk_urb(urb, dlfb->udev, 1932 usb_sndbulkpipe(dlfb->udev, OUT_EP_NUM), 1933 buf, size, dlfb_urb_completion, unode); 1934 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 1935 1936 list_add_tail(&unode->entry, &dlfb->urbs.list); 1937 1938 up(&dlfb->urbs.limit_sem); 1939 dlfb->urbs.count++; 1940 dlfb->urbs.available++; 1941 } 1942 1943 return dlfb->urbs.count; 1944} 1945 1946static struct urb *dlfb_get_urb(struct dlfb_data *dlfb) 1947{ 1948 int ret; 1949 struct list_head *entry; 1950 struct urb_node *unode; 1951 1952 /* Wait for an in-flight buffer to complete and get re-queued */ 1953 ret = down_timeout(&dlfb->urbs.limit_sem, GET_URB_TIMEOUT); 1954 if (ret) { 1955 atomic_set(&dlfb->lost_pixels, 1); 1956 dev_warn(&dlfb->udev->dev, 1957 "wait for urb interrupted: %d available: %d\n", 1958 ret, dlfb->urbs.available); 1959 return NULL; 1960 } 1961 1962 spin_lock_irq(&dlfb->urbs.lock); 1963 1964 BUG_ON(list_empty(&dlfb->urbs.list)); /* reserved one with limit_sem */ 1965 entry = dlfb->urbs.list.next; 1966 list_del_init(entry); 1967 dlfb->urbs.available--; 1968 1969 spin_unlock_irq(&dlfb->urbs.lock); 1970 1971 unode = list_entry(entry, struct urb_node, entry); 1972 return unode->urb; 1973} 1974 1975static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb *urb, size_t len) 1976{ 1977 int ret; 1978 1979 BUG_ON(len > dlfb->urbs.size); 1980 1981 urb->transfer_buffer_length = len; /* set to actual payload len */ 1982 ret = usb_submit_urb(urb, GFP_KERNEL); 1983 if (ret) { 1984 dlfb_urb_completion(urb); /* because no one else will */ 1985 atomic_set(&dlfb->lost_pixels, 1); 1986 dev_err(&dlfb->udev->dev, "submit urb error: %d\n", ret); 1987 } 1988 return ret; 1989} 1990 1991module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 1992MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer"); 1993 1994module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 1995MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes"); 1996 1997module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 1998MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf"); 1999 2000module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 2001MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)"); 2002 2003MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, " 2004 "Jaya Kumar <jayakumar.lkml@gmail.com>, " 2005 "Bernie Thompson <bernie@plugable.com>"); 2006MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver"); 2007MODULE_LICENSE("GPL"); 2008 2009