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_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 (info->fbdefio) 332 return fb_deferred_io_mmap(info, vma); 333 334 if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) 335 return -EINVAL; 336 if (size > info->fix.smem_len) 337 return -EINVAL; 338 if (offset > info->fix.smem_len - size) 339 return -EINVAL; 340 341 pos = (unsigned long)info->fix.smem_start + offset; 342 343 dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n", 344 pos, size); 345 346 while (size > 0) { 347 page = vmalloc_to_pfn((void *)pos); 348 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) 349 return -EAGAIN; 350 351 start += PAGE_SIZE; 352 pos += PAGE_SIZE; 353 if (size > PAGE_SIZE) 354 size -= PAGE_SIZE; 355 else 356 size = 0; 357 } 358 359 return 0; 360} 361 362/* 363 * Trims identical data from front and back of line 364 * Sets new front buffer address and width 365 * And returns byte count of identical pixels 366 * Assumes CPU natural alignment (unsigned long) 367 * for back and front buffer ptrs and width 368 */ 369static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes) 370{ 371 int j, k; 372 const unsigned long *back = (const unsigned long *) bback; 373 const unsigned long *front = (const unsigned long *) *bfront; 374 const int width = *width_bytes / sizeof(unsigned long); 375 int identical; 376 int start = width; 377 int end = width; 378 379 for (j = 0; j < width; j++) { 380 if (back[j] != front[j]) { 381 start = j; 382 break; 383 } 384 } 385 386 for (k = width - 1; k > j; k--) { 387 if (back[k] != front[k]) { 388 end = k+1; 389 break; 390 } 391 } 392 393 identical = start + (width - end); 394 *bfront = (u8 *) &front[start]; 395 *width_bytes = (end - start) * sizeof(unsigned long); 396 397 return identical * sizeof(unsigned long); 398} 399 400/* 401 * Render a command stream for an encoded horizontal line segment of pixels. 402 * 403 * A command buffer holds several commands. 404 * It always begins with a fresh command header 405 * (the protocol doesn't require this, but we enforce it to allow 406 * multiple buffers to be potentially encoded and sent in parallel). 407 * A single command encodes one contiguous horizontal line of pixels 408 * 409 * The function relies on the client to do all allocation, so that 410 * rendering can be done directly to output buffers (e.g. USB URBs). 411 * The function fills the supplied command buffer, providing information 412 * on where it left off, so the client may call in again with additional 413 * buffers if the line will take several buffers to complete. 414 * 415 * A single command can transmit a maximum of 256 pixels, 416 * regardless of the compression ratio (protocol design limit). 417 * To the hardware, 0 for a size byte means 256 418 * 419 * Rather than 256 pixel commands which are either rl or raw encoded, 420 * the rlx command simply assumes alternating raw and rl spans within one cmd. 421 * This has a slightly larger header overhead, but produces more even results. 422 * It also processes all data (read and write) in a single pass. 423 * Performance benchmarks of common cases show it having just slightly better 424 * compression than 256 pixel raw or rle commands, with similar CPU consumpion. 425 * But for very rl friendly data, will compress not quite as well. 426 */ 427static void dlfb_compress_hline( 428 const uint16_t **pixel_start_ptr, 429 const uint16_t *const pixel_end, 430 uint32_t *device_address_ptr, 431 uint8_t **command_buffer_ptr, 432 const uint8_t *const cmd_buffer_end, 433 unsigned long back_buffer_offset, 434 int *ident_ptr) 435{ 436 const uint16_t *pixel = *pixel_start_ptr; 437 uint32_t dev_addr = *device_address_ptr; 438 uint8_t *cmd = *command_buffer_ptr; 439 440 while ((pixel_end > pixel) && 441 (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) { 442 uint8_t *raw_pixels_count_byte = NULL; 443 uint8_t *cmd_pixels_count_byte = NULL; 444 const uint16_t *raw_pixel_start = NULL; 445 const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL; 446 447 if (back_buffer_offset && 448 *pixel == *(u16 *)((u8 *)pixel + back_buffer_offset)) { 449 pixel++; 450 dev_addr += BPP; 451 (*ident_ptr)++; 452 continue; 453 } 454 455 *cmd++ = 0xAF; 456 *cmd++ = 0x6B; 457 *cmd++ = dev_addr >> 16; 458 *cmd++ = dev_addr >> 8; 459 *cmd++ = dev_addr; 460 461 cmd_pixels_count_byte = cmd++; /* we'll know this later */ 462 cmd_pixel_start = pixel; 463 464 raw_pixels_count_byte = cmd++; /* we'll know this later */ 465 raw_pixel_start = pixel; 466 467 cmd_pixel_end = pixel + min3(MAX_CMD_PIXELS + 1UL, 468 (unsigned long)(pixel_end - pixel), 469 (unsigned long)(cmd_buffer_end - 1 - cmd) / BPP); 470 471 if (back_buffer_offset) { 472 /* note: the framebuffer may change under us, so we must test for underflow */ 473 while (cmd_pixel_end - 1 > pixel && 474 *(cmd_pixel_end - 1) == *(u16 *)((u8 *)(cmd_pixel_end - 1) + back_buffer_offset)) 475 cmd_pixel_end--; 476 } 477 478 while (pixel < cmd_pixel_end) { 479 const uint16_t * const repeating_pixel = pixel; 480 u16 pixel_value = *pixel; 481 482 put_unaligned_be16(pixel_value, cmd); 483 if (back_buffer_offset) 484 *(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value; 485 cmd += 2; 486 pixel++; 487 488 if (unlikely((pixel < cmd_pixel_end) && 489 (*pixel == pixel_value))) { 490 /* go back and fill in raw pixel count */ 491 *raw_pixels_count_byte = ((repeating_pixel - 492 raw_pixel_start) + 1) & 0xFF; 493 494 do { 495 if (back_buffer_offset) 496 *(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value; 497 pixel++; 498 } while ((pixel < cmd_pixel_end) && 499 (*pixel == pixel_value)); 500 501 /* immediately after raw data is repeat byte */ 502 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF; 503 504 /* Then start another raw pixel span */ 505 raw_pixel_start = pixel; 506 raw_pixels_count_byte = cmd++; 507 } 508 } 509 510 if (pixel > raw_pixel_start) { 511 /* finalize last RAW span */ 512 *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF; 513 } else { 514 /* undo unused byte */ 515 cmd--; 516 } 517 518 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF; 519 dev_addr += (u8 *)pixel - (u8 *)cmd_pixel_start; 520 } 521 522 if (cmd_buffer_end - MIN_RLX_CMD_BYTES <= cmd) { 523 /* Fill leftover bytes with no-ops */ 524 if (cmd_buffer_end > cmd) 525 memset(cmd, 0xAF, cmd_buffer_end - cmd); 526 cmd = (uint8_t *) cmd_buffer_end; 527 } 528 529 *command_buffer_ptr = cmd; 530 *pixel_start_ptr = pixel; 531 *device_address_ptr = dev_addr; 532} 533 534/* 535 * There are 3 copies of every pixel: The front buffer that the fbdev 536 * client renders to, the actual framebuffer across the USB bus in hardware 537 * (that we can only write to, slowly, and can never read), and (optionally) 538 * our shadow copy that tracks what's been sent to that hardware buffer. 539 */ 540static int dlfb_render_hline(struct dlfb_data *dlfb, struct urb **urb_ptr, 541 const char *front, char **urb_buf_ptr, 542 u32 byte_offset, u32 byte_width, 543 int *ident_ptr, int *sent_ptr) 544{ 545 const u8 *line_start, *line_end, *next_pixel; 546 u32 dev_addr = dlfb->base16 + byte_offset; 547 struct urb *urb = *urb_ptr; 548 u8 *cmd = *urb_buf_ptr; 549 u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length; 550 unsigned long back_buffer_offset = 0; 551 552 line_start = (u8 *) (front + byte_offset); 553 next_pixel = line_start; 554 line_end = next_pixel + byte_width; 555 556 if (dlfb->backing_buffer) { 557 int offset; 558 const u8 *back_start = (u8 *) (dlfb->backing_buffer 559 + byte_offset); 560 561 back_buffer_offset = (unsigned long)back_start - (unsigned long)line_start; 562 563 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel, 564 &byte_width); 565 566 offset = next_pixel - line_start; 567 line_end = next_pixel + byte_width; 568 dev_addr += offset; 569 back_start += offset; 570 line_start += offset; 571 } 572 573 while (next_pixel < line_end) { 574 575 dlfb_compress_hline((const uint16_t **) &next_pixel, 576 (const uint16_t *) line_end, &dev_addr, 577 (u8 **) &cmd, (u8 *) cmd_end, back_buffer_offset, 578 ident_ptr); 579 580 if (cmd >= cmd_end) { 581 int len = cmd - (u8 *) urb->transfer_buffer; 582 if (dlfb_submit_urb(dlfb, urb, len)) 583 return 1; /* lost pixels is set */ 584 *sent_ptr += len; 585 urb = dlfb_get_urb(dlfb); 586 if (!urb) 587 return 1; /* lost_pixels is set */ 588 *urb_ptr = urb; 589 cmd = urb->transfer_buffer; 590 cmd_end = &cmd[urb->transfer_buffer_length]; 591 } 592 } 593 594 *urb_buf_ptr = cmd; 595 596 return 0; 597} 598 599static int dlfb_handle_damage(struct dlfb_data *dlfb, int x, int y, int width, int height) 600{ 601 int i, ret; 602 char *cmd; 603 cycles_t start_cycles, end_cycles; 604 int bytes_sent = 0; 605 int bytes_identical = 0; 606 struct urb *urb; 607 int aligned_x; 608 609 start_cycles = get_cycles(); 610 611 mutex_lock(&dlfb->render_mutex); 612 613 aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long)); 614 width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long)); 615 x = aligned_x; 616 617 if ((width <= 0) || 618 (x + width > dlfb->info->var.xres) || 619 (y + height > dlfb->info->var.yres)) { 620 ret = -EINVAL; 621 goto unlock_ret; 622 } 623 624 if (!atomic_read(&dlfb->usb_active)) { 625 ret = 0; 626 goto unlock_ret; 627 } 628 629 urb = dlfb_get_urb(dlfb); 630 if (!urb) { 631 ret = 0; 632 goto unlock_ret; 633 } 634 cmd = urb->transfer_buffer; 635 636 for (i = y; i < y + height ; i++) { 637 const int line_offset = dlfb->info->fix.line_length * i; 638 const int byte_offset = line_offset + (x * BPP); 639 640 if (dlfb_render_hline(dlfb, &urb, 641 (char *) dlfb->info->fix.smem_start, 642 &cmd, byte_offset, width * BPP, 643 &bytes_identical, &bytes_sent)) 644 goto error; 645 } 646 647 if (cmd > (char *) urb->transfer_buffer) { 648 int len; 649 if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length) 650 *cmd++ = 0xAF; 651 /* Send partial buffer remaining before exiting */ 652 len = cmd - (char *) urb->transfer_buffer; 653 dlfb_submit_urb(dlfb, urb, len); 654 bytes_sent += len; 655 } else 656 dlfb_urb_completion(urb); 657 658error: 659 atomic_add(bytes_sent, &dlfb->bytes_sent); 660 atomic_add(bytes_identical, &dlfb->bytes_identical); 661 atomic_add(width*height*2, &dlfb->bytes_rendered); 662 end_cycles = get_cycles(); 663 atomic_add(((unsigned int) ((end_cycles - start_cycles) 664 >> 10)), /* Kcycles */ 665 &dlfb->cpu_kcycles_used); 666 667 ret = 0; 668 669unlock_ret: 670 mutex_unlock(&dlfb->render_mutex); 671 return ret; 672} 673 674static void dlfb_init_damage(struct dlfb_data *dlfb) 675{ 676 dlfb->damage_x = INT_MAX; 677 dlfb->damage_x2 = 0; 678 dlfb->damage_y = INT_MAX; 679 dlfb->damage_y2 = 0; 680} 681 682static void dlfb_damage_work(struct work_struct *w) 683{ 684 struct dlfb_data *dlfb = container_of(w, struct dlfb_data, damage_work); 685 int x, x2, y, y2; 686 687 spin_lock_irq(&dlfb->damage_lock); 688 x = dlfb->damage_x; 689 x2 = dlfb->damage_x2; 690 y = dlfb->damage_y; 691 y2 = dlfb->damage_y2; 692 dlfb_init_damage(dlfb); 693 spin_unlock_irq(&dlfb->damage_lock); 694 695 if (x < x2 && y < y2) 696 dlfb_handle_damage(dlfb, x, y, x2 - x, y2 - y); 697} 698 699static void dlfb_offload_damage(struct dlfb_data *dlfb, int x, int y, int width, int height) 700{ 701 unsigned long flags; 702 int x2 = x + width; 703 int y2 = y + height; 704 705 if (x >= x2 || y >= y2) 706 return; 707 708 spin_lock_irqsave(&dlfb->damage_lock, flags); 709 dlfb->damage_x = min(x, dlfb->damage_x); 710 dlfb->damage_x2 = max(x2, dlfb->damage_x2); 711 dlfb->damage_y = min(y, dlfb->damage_y); 712 dlfb->damage_y2 = max(y2, dlfb->damage_y2); 713 spin_unlock_irqrestore(&dlfb->damage_lock, flags); 714 715 schedule_work(&dlfb->damage_work); 716} 717 718/* 719 * Path triggered by usermode clients who write to filesystem 720 * e.g. cat filename > /dev/fb1 721 * Not used by X Windows or text-mode console. But useful for testing. 722 * Slow because of extra copy and we must assume all pixels dirty. 723 */ 724static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf, 725 size_t count, loff_t *ppos) 726{ 727 ssize_t result; 728 struct dlfb_data *dlfb = info->par; 729 u32 offset = (u32) *ppos; 730 731 result = fb_sys_write(info, buf, count, ppos); 732 733 if (result > 0) { 734 int start = max((int)(offset / info->fix.line_length), 0); 735 int lines = min((u32)((result / info->fix.line_length) + 1), 736 (u32)info->var.yres); 737 738 dlfb_handle_damage(dlfb, 0, start, info->var.xres, 739 lines); 740 } 741 742 return result; 743} 744 745/* hardware has native COPY command (see libdlo), but not worth it for fbcon */ 746static void dlfb_ops_copyarea(struct fb_info *info, 747 const struct fb_copyarea *area) 748{ 749 750 struct dlfb_data *dlfb = info->par; 751 752 sys_copyarea(info, area); 753 754 dlfb_offload_damage(dlfb, area->dx, area->dy, 755 area->width, area->height); 756} 757 758static void dlfb_ops_imageblit(struct fb_info *info, 759 const struct fb_image *image) 760{ 761 struct dlfb_data *dlfb = info->par; 762 763 sys_imageblit(info, image); 764 765 dlfb_offload_damage(dlfb, image->dx, image->dy, 766 image->width, image->height); 767} 768 769static void dlfb_ops_fillrect(struct fb_info *info, 770 const struct fb_fillrect *rect) 771{ 772 struct dlfb_data *dlfb = info->par; 773 774 sys_fillrect(info, rect); 775 776 dlfb_offload_damage(dlfb, rect->dx, rect->dy, rect->width, 777 rect->height); 778} 779 780/* 781 * NOTE: fb_defio.c is holding info->fbdefio.mutex 782 * Touching ANY framebuffer memory that triggers a page fault 783 * in fb_defio will cause a deadlock, when it also tries to 784 * grab the same mutex. 785 */ 786static void dlfb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist) 787{ 788 struct fb_deferred_io_pageref *pageref; 789 struct dlfb_data *dlfb = info->par; 790 struct urb *urb; 791 char *cmd; 792 cycles_t start_cycles, end_cycles; 793 int bytes_sent = 0; 794 int bytes_identical = 0; 795 int bytes_rendered = 0; 796 797 mutex_lock(&dlfb->render_mutex); 798 799 if (!fb_defio) 800 goto unlock_ret; 801 802 if (!atomic_read(&dlfb->usb_active)) 803 goto unlock_ret; 804 805 start_cycles = get_cycles(); 806 807 urb = dlfb_get_urb(dlfb); 808 if (!urb) 809 goto unlock_ret; 810 811 cmd = urb->transfer_buffer; 812 813 /* walk the written page list and render each to device */ 814 list_for_each_entry(pageref, pagereflist, list) { 815 if (dlfb_render_hline(dlfb, &urb, (char *) info->fix.smem_start, 816 &cmd, pageref->offset, PAGE_SIZE, 817 &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->sort_pagereflist = true; 986 fbdefio->deferred_io = dlfb_dpy_deferred_io; 987 } 988 989 info->fbdefio = fbdefio; 990 fb_deferred_io_init(info); 991 } 992 993 dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n", 994 user, info, dlfb->fb_count); 995 996 return 0; 997} 998 999static void dlfb_ops_destroy(struct fb_info *info) 1000{ 1001 struct dlfb_data *dlfb = info->par; 1002 1003 cancel_work_sync(&dlfb->damage_work); 1004 1005 mutex_destroy(&dlfb->render_mutex); 1006 1007 if (info->cmap.len != 0) 1008 fb_dealloc_cmap(&info->cmap); 1009 if (info->monspecs.modedb) 1010 fb_destroy_modedb(info->monspecs.modedb); 1011 vfree(info->screen_buffer); 1012 1013 fb_destroy_modelist(&info->modelist); 1014 1015 while (!list_empty(&dlfb->deferred_free)) { 1016 struct dlfb_deferred_free *d = list_entry(dlfb->deferred_free.next, struct dlfb_deferred_free, list); 1017 list_del(&d->list); 1018 vfree(d->mem); 1019 kfree(d); 1020 } 1021 vfree(dlfb->backing_buffer); 1022 kfree(dlfb->edid); 1023 dlfb_free_urb_list(dlfb); 1024 usb_put_dev(dlfb->udev); 1025 kfree(dlfb); 1026 1027 /* Assume info structure is freed after this point */ 1028 framebuffer_release(info); 1029} 1030 1031/* 1032 * Assumes caller is holding info->lock mutex (for open and release at least) 1033 */ 1034static int dlfb_ops_release(struct fb_info *info, int user) 1035{ 1036 struct dlfb_data *dlfb = info->par; 1037 1038 dlfb->fb_count--; 1039 1040 if ((dlfb->fb_count == 0) && (info->fbdefio)) { 1041 fb_deferred_io_cleanup(info); 1042 kfree(info->fbdefio); 1043 info->fbdefio = NULL; 1044 } 1045 1046 dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count); 1047 1048 return 0; 1049} 1050 1051/* 1052 * Check whether a video mode is supported by the DisplayLink chip 1053 * We start from monitor's modes, so don't need to filter that here 1054 */ 1055static int dlfb_is_valid_mode(struct fb_videomode *mode, struct dlfb_data *dlfb) 1056{ 1057 if (mode->xres * mode->yres > dlfb->sku_pixel_limit) 1058 return 0; 1059 1060 return 1; 1061} 1062 1063static void dlfb_var_color_format(struct fb_var_screeninfo *var) 1064{ 1065 const struct fb_bitfield red = { 11, 5, 0 }; 1066 const struct fb_bitfield green = { 5, 6, 0 }; 1067 const struct fb_bitfield blue = { 0, 5, 0 }; 1068 1069 var->bits_per_pixel = 16; 1070 var->red = red; 1071 var->green = green; 1072 var->blue = blue; 1073} 1074 1075static int dlfb_ops_check_var(struct fb_var_screeninfo *var, 1076 struct fb_info *info) 1077{ 1078 struct fb_videomode mode; 1079 struct dlfb_data *dlfb = info->par; 1080 1081 /* set device-specific elements of var unrelated to mode */ 1082 dlfb_var_color_format(var); 1083 1084 fb_var_to_videomode(&mode, var); 1085 1086 if (!dlfb_is_valid_mode(&mode, dlfb)) 1087 return -EINVAL; 1088 1089 return 0; 1090} 1091 1092static int dlfb_ops_set_par(struct fb_info *info) 1093{ 1094 struct dlfb_data *dlfb = info->par; 1095 int result; 1096 u16 *pix_framebuffer; 1097 int i; 1098 struct fb_var_screeninfo fvs; 1099 u32 line_length = info->var.xres * (info->var.bits_per_pixel / 8); 1100 1101 /* clear the activate field because it causes spurious miscompares */ 1102 fvs = info->var; 1103 fvs.activate = 0; 1104 fvs.vmode &= ~FB_VMODE_SMOOTH_XPAN; 1105 1106 if (!memcmp(&dlfb->current_mode, &fvs, sizeof(struct fb_var_screeninfo))) 1107 return 0; 1108 1109 result = dlfb_realloc_framebuffer(dlfb, info, info->var.yres * line_length); 1110 if (result) 1111 return result; 1112 1113 result = dlfb_set_video_mode(dlfb, &info->var); 1114 1115 if (result) 1116 return result; 1117 1118 dlfb->current_mode = fvs; 1119 info->fix.line_length = line_length; 1120 1121 if (dlfb->fb_count == 0) { 1122 1123 /* paint greenscreen */ 1124 1125 pix_framebuffer = (u16 *)info->screen_buffer; 1126 for (i = 0; i < info->fix.smem_len / 2; i++) 1127 pix_framebuffer[i] = 0x37e6; 1128 } 1129 1130 dlfb_handle_damage(dlfb, 0, 0, info->var.xres, info->var.yres); 1131 1132 return 0; 1133} 1134 1135/* To fonzi the jukebox (e.g. make blanking changes take effect) */ 1136static char *dlfb_dummy_render(char *buf) 1137{ 1138 *buf++ = 0xAF; 1139 *buf++ = 0x6A; /* copy */ 1140 *buf++ = 0x00; /* from address*/ 1141 *buf++ = 0x00; 1142 *buf++ = 0x00; 1143 *buf++ = 0x01; /* one pixel */ 1144 *buf++ = 0x00; /* to address */ 1145 *buf++ = 0x00; 1146 *buf++ = 0x00; 1147 return buf; 1148} 1149 1150/* 1151 * In order to come back from full DPMS off, we need to set the mode again 1152 */ 1153static int dlfb_ops_blank(int blank_mode, struct fb_info *info) 1154{ 1155 struct dlfb_data *dlfb = info->par; 1156 char *bufptr; 1157 struct urb *urb; 1158 1159 dev_dbg(info->dev, "blank, mode %d --> %d\n", 1160 dlfb->blank_mode, blank_mode); 1161 1162 if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) && 1163 (blank_mode != FB_BLANK_POWERDOWN)) { 1164 1165 /* returning from powerdown requires a fresh modeset */ 1166 dlfb_set_video_mode(dlfb, &info->var); 1167 } 1168 1169 urb = dlfb_get_urb(dlfb); 1170 if (!urb) 1171 return 0; 1172 1173 bufptr = (char *) urb->transfer_buffer; 1174 bufptr = dlfb_vidreg_lock(bufptr); 1175 bufptr = dlfb_blanking(bufptr, blank_mode); 1176 bufptr = dlfb_vidreg_unlock(bufptr); 1177 1178 /* seems like a render op is needed to have blank change take effect */ 1179 bufptr = dlfb_dummy_render(bufptr); 1180 1181 dlfb_submit_urb(dlfb, urb, bufptr - 1182 (char *) urb->transfer_buffer); 1183 1184 dlfb->blank_mode = blank_mode; 1185 1186 return 0; 1187} 1188 1189static const struct fb_ops dlfb_ops = { 1190 .owner = THIS_MODULE, 1191 .fb_read = fb_sys_read, 1192 .fb_write = dlfb_ops_write, 1193 .fb_setcolreg = dlfb_ops_setcolreg, 1194 .fb_fillrect = dlfb_ops_fillrect, 1195 .fb_copyarea = dlfb_ops_copyarea, 1196 .fb_imageblit = dlfb_ops_imageblit, 1197 .fb_mmap = dlfb_ops_mmap, 1198 .fb_ioctl = dlfb_ops_ioctl, 1199 .fb_open = dlfb_ops_open, 1200 .fb_release = dlfb_ops_release, 1201 .fb_blank = dlfb_ops_blank, 1202 .fb_check_var = dlfb_ops_check_var, 1203 .fb_set_par = dlfb_ops_set_par, 1204 .fb_destroy = dlfb_ops_destroy, 1205}; 1206 1207 1208static void dlfb_deferred_vfree(struct dlfb_data *dlfb, void *mem) 1209{ 1210 struct dlfb_deferred_free *d = kmalloc(sizeof(struct dlfb_deferred_free), GFP_KERNEL); 1211 if (!d) 1212 return; 1213 d->mem = mem; 1214 list_add(&d->list, &dlfb->deferred_free); 1215} 1216 1217/* 1218 * Assumes &info->lock held by caller 1219 * Assumes no active clients have framebuffer open 1220 */ 1221static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len) 1222{ 1223 u32 old_len = info->fix.smem_len; 1224 const void *old_fb = info->screen_buffer; 1225 unsigned char *new_fb; 1226 unsigned char *new_back = NULL; 1227 1228 new_len = PAGE_ALIGN(new_len); 1229 1230 if (new_len > old_len) { 1231 /* 1232 * Alloc system memory for virtual framebuffer 1233 */ 1234 new_fb = vmalloc(new_len); 1235 if (!new_fb) { 1236 dev_err(info->dev, "Virtual framebuffer alloc failed\n"); 1237 return -ENOMEM; 1238 } 1239 memset(new_fb, 0xff, new_len); 1240 1241 if (info->screen_buffer) { 1242 memcpy(new_fb, old_fb, old_len); 1243 dlfb_deferred_vfree(dlfb, info->screen_buffer); 1244 } 1245 1246 info->screen_buffer = new_fb; 1247 info->fix.smem_len = new_len; 1248 info->fix.smem_start = (unsigned long) new_fb; 1249 info->flags = udlfb_info_flags; 1250 1251 /* 1252 * Second framebuffer copy to mirror the framebuffer state 1253 * on the physical USB device. We can function without this. 1254 * But with imperfect damage info we may send pixels over USB 1255 * that were, in fact, unchanged - wasting limited USB bandwidth 1256 */ 1257 if (shadow) 1258 new_back = vzalloc(new_len); 1259 if (!new_back) 1260 dev_info(info->dev, 1261 "No shadow/backing buffer allocated\n"); 1262 else { 1263 dlfb_deferred_vfree(dlfb, dlfb->backing_buffer); 1264 dlfb->backing_buffer = new_back; 1265 } 1266 } 1267 return 0; 1268} 1269 1270/* 1271 * 1) Get EDID from hw, or use sw default 1272 * 2) Parse into various fb_info structs 1273 * 3) Allocate virtual framebuffer memory to back highest res mode 1274 * 1275 * Parses EDID into three places used by various parts of fbdev: 1276 * fb_var_screeninfo contains the timing of the monitor's preferred mode 1277 * fb_info.monspecs is full parsed EDID info, including monspecs.modedb 1278 * fb_info.modelist is a linked list of all monitor & VESA modes which work 1279 * 1280 * If EDID is not readable/valid, then modelist is all VESA modes, 1281 * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode 1282 * Returns 0 if successful 1283 */ 1284static int dlfb_setup_modes(struct dlfb_data *dlfb, 1285 struct fb_info *info, 1286 char *default_edid, size_t default_edid_size) 1287{ 1288 char *edid; 1289 int i, result = 0, tries = 3; 1290 struct device *dev = info->device; 1291 struct fb_videomode *mode; 1292 const struct fb_videomode *default_vmode = NULL; 1293 1294 if (info->dev) { 1295 /* only use mutex if info has been registered */ 1296 mutex_lock(&info->lock); 1297 /* parent device is used otherwise */ 1298 dev = info->dev; 1299 } 1300 1301 edid = kmalloc(EDID_LENGTH, GFP_KERNEL); 1302 if (!edid) { 1303 result = -ENOMEM; 1304 goto error; 1305 } 1306 1307 fb_destroy_modelist(&info->modelist); 1308 memset(&info->monspecs, 0, sizeof(info->monspecs)); 1309 1310 /* 1311 * Try to (re)read EDID from hardware first 1312 * EDID data may return, but not parse as valid 1313 * Try again a few times, in case of e.g. analog cable noise 1314 */ 1315 while (tries--) { 1316 1317 i = dlfb_get_edid(dlfb, edid, EDID_LENGTH); 1318 1319 if (i >= EDID_LENGTH) 1320 fb_edid_to_monspecs(edid, &info->monspecs); 1321 1322 if (info->monspecs.modedb_len > 0) { 1323 dlfb->edid = edid; 1324 dlfb->edid_size = i; 1325 break; 1326 } 1327 } 1328 1329 /* If that fails, use a previously returned EDID if available */ 1330 if (info->monspecs.modedb_len == 0) { 1331 dev_err(dev, "Unable to get valid EDID from device/display\n"); 1332 1333 if (dlfb->edid) { 1334 fb_edid_to_monspecs(dlfb->edid, &info->monspecs); 1335 if (info->monspecs.modedb_len > 0) 1336 dev_err(dev, "Using previously queried EDID\n"); 1337 } 1338 } 1339 1340 /* If that fails, use the default EDID we were handed */ 1341 if (info->monspecs.modedb_len == 0) { 1342 if (default_edid_size >= EDID_LENGTH) { 1343 fb_edid_to_monspecs(default_edid, &info->monspecs); 1344 if (info->monspecs.modedb_len > 0) { 1345 memcpy(edid, default_edid, default_edid_size); 1346 dlfb->edid = edid; 1347 dlfb->edid_size = default_edid_size; 1348 dev_err(dev, "Using default/backup EDID\n"); 1349 } 1350 } 1351 } 1352 1353 /* If we've got modes, let's pick a best default mode */ 1354 if (info->monspecs.modedb_len > 0) { 1355 1356 for (i = 0; i < info->monspecs.modedb_len; i++) { 1357 mode = &info->monspecs.modedb[i]; 1358 if (dlfb_is_valid_mode(mode, dlfb)) { 1359 fb_add_videomode(mode, &info->modelist); 1360 } else { 1361 dev_dbg(dev, "Specified mode %dx%d too big\n", 1362 mode->xres, mode->yres); 1363 if (i == 0) 1364 /* if we've removed top/best mode */ 1365 info->monspecs.misc 1366 &= ~FB_MISC_1ST_DETAIL; 1367 } 1368 } 1369 1370 default_vmode = fb_find_best_display(&info->monspecs, 1371 &info->modelist); 1372 } 1373 1374 /* If everything else has failed, fall back to safe default mode */ 1375 if (default_vmode == NULL) { 1376 1377 struct fb_videomode fb_vmode = {0}; 1378 1379 /* 1380 * Add the standard VESA modes to our modelist 1381 * Since we don't have EDID, there may be modes that 1382 * overspec monitor and/or are incorrect aspect ratio, etc. 1383 * But at least the user has a chance to choose 1384 */ 1385 for (i = 0; i < VESA_MODEDB_SIZE; i++) { 1386 mode = (struct fb_videomode *)&vesa_modes[i]; 1387 if (dlfb_is_valid_mode(mode, dlfb)) 1388 fb_add_videomode(mode, &info->modelist); 1389 else 1390 dev_dbg(dev, "VESA mode %dx%d too big\n", 1391 mode->xres, mode->yres); 1392 } 1393 1394 /* 1395 * default to resolution safe for projectors 1396 * (since they are most common case without EDID) 1397 */ 1398 fb_vmode.xres = 800; 1399 fb_vmode.yres = 600; 1400 fb_vmode.refresh = 60; 1401 default_vmode = fb_find_nearest_mode(&fb_vmode, 1402 &info->modelist); 1403 } 1404 1405 /* If we have good mode and no active clients*/ 1406 if ((default_vmode != NULL) && (dlfb->fb_count == 0)) { 1407 1408 fb_videomode_to_var(&info->var, default_vmode); 1409 dlfb_var_color_format(&info->var); 1410 1411 /* 1412 * with mode size info, we can now alloc our framebuffer. 1413 */ 1414 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix)); 1415 } else 1416 result = -EINVAL; 1417 1418error: 1419 if (edid && (dlfb->edid != edid)) 1420 kfree(edid); 1421 1422 if (info->dev) 1423 mutex_unlock(&info->lock); 1424 1425 return result; 1426} 1427 1428static ssize_t metrics_bytes_rendered_show(struct device *fbdev, 1429 struct device_attribute *a, char *buf) { 1430 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1431 struct dlfb_data *dlfb = fb_info->par; 1432 return sysfs_emit(buf, "%u\n", 1433 atomic_read(&dlfb->bytes_rendered)); 1434} 1435 1436static ssize_t metrics_bytes_identical_show(struct device *fbdev, 1437 struct device_attribute *a, char *buf) { 1438 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1439 struct dlfb_data *dlfb = fb_info->par; 1440 return sysfs_emit(buf, "%u\n", 1441 atomic_read(&dlfb->bytes_identical)); 1442} 1443 1444static ssize_t metrics_bytes_sent_show(struct device *fbdev, 1445 struct device_attribute *a, char *buf) { 1446 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1447 struct dlfb_data *dlfb = fb_info->par; 1448 return sysfs_emit(buf, "%u\n", 1449 atomic_read(&dlfb->bytes_sent)); 1450} 1451 1452static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev, 1453 struct device_attribute *a, char *buf) { 1454 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1455 struct dlfb_data *dlfb = fb_info->par; 1456 return sysfs_emit(buf, "%u\n", 1457 atomic_read(&dlfb->cpu_kcycles_used)); 1458} 1459 1460static ssize_t edid_show( 1461 struct file *filp, 1462 struct kobject *kobj, struct bin_attribute *a, 1463 char *buf, loff_t off, size_t count) { 1464 struct device *fbdev = kobj_to_dev(kobj); 1465 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1466 struct dlfb_data *dlfb = fb_info->par; 1467 1468 if (dlfb->edid == NULL) 1469 return 0; 1470 1471 if ((off >= dlfb->edid_size) || (count > dlfb->edid_size)) 1472 return 0; 1473 1474 if (off + count > dlfb->edid_size) 1475 count = dlfb->edid_size - off; 1476 1477 memcpy(buf, dlfb->edid, count); 1478 1479 return count; 1480} 1481 1482static ssize_t edid_store( 1483 struct file *filp, 1484 struct kobject *kobj, struct bin_attribute *a, 1485 char *src, loff_t src_off, size_t src_size) { 1486 struct device *fbdev = kobj_to_dev(kobj); 1487 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1488 struct dlfb_data *dlfb = fb_info->par; 1489 int ret; 1490 1491 /* We only support write of entire EDID at once, no offset*/ 1492 if ((src_size != EDID_LENGTH) || (src_off != 0)) 1493 return -EINVAL; 1494 1495 ret = dlfb_setup_modes(dlfb, fb_info, src, src_size); 1496 if (ret) 1497 return ret; 1498 1499 if (!dlfb->edid || memcmp(src, dlfb->edid, src_size)) 1500 return -EINVAL; 1501 1502 ret = dlfb_ops_set_par(fb_info); 1503 if (ret) 1504 return ret; 1505 1506 return src_size; 1507} 1508 1509static ssize_t metrics_reset_store(struct device *fbdev, 1510 struct device_attribute *attr, 1511 const char *buf, size_t count) 1512{ 1513 struct fb_info *fb_info = dev_get_drvdata(fbdev); 1514 struct dlfb_data *dlfb = fb_info->par; 1515 1516 atomic_set(&dlfb->bytes_rendered, 0); 1517 atomic_set(&dlfb->bytes_identical, 0); 1518 atomic_set(&dlfb->bytes_sent, 0); 1519 atomic_set(&dlfb->cpu_kcycles_used, 0); 1520 1521 return count; 1522} 1523 1524static const struct bin_attribute edid_attr = { 1525 .attr.name = "edid", 1526 .attr.mode = 0666, 1527 .size = EDID_LENGTH, 1528 .read = edid_show, 1529 .write = edid_store 1530}; 1531 1532static const struct device_attribute fb_device_attrs[] = { 1533 __ATTR_RO(metrics_bytes_rendered), 1534 __ATTR_RO(metrics_bytes_identical), 1535 __ATTR_RO(metrics_bytes_sent), 1536 __ATTR_RO(metrics_cpu_kcycles_used), 1537 __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store), 1538}; 1539 1540/* 1541 * This is necessary before we can communicate with the display controller. 1542 */ 1543static int dlfb_select_std_channel(struct dlfb_data *dlfb) 1544{ 1545 int ret; 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 ret = usb_control_msg_send(dlfb->udev, 0, NR_USB_REQUEST_CHANNEL, 1553 (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0, 1554 &set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT, 1555 GFP_KERNEL); 1556 1557 return ret; 1558} 1559 1560static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb, 1561 struct usb_interface *intf) 1562{ 1563 char *desc; 1564 char *buf; 1565 char *desc_end; 1566 int total_len; 1567 1568 buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL); 1569 if (!buf) 1570 return false; 1571 desc = buf; 1572 1573 total_len = usb_get_descriptor(interface_to_usbdev(intf), 1574 0x5f, /* vendor specific */ 1575 0, desc, MAX_VENDOR_DESCRIPTOR_SIZE); 1576 1577 /* if not found, look in configuration descriptor */ 1578 if (total_len < 0) { 1579 if (0 == usb_get_extra_descriptor(intf->cur_altsetting, 1580 0x5f, &desc)) 1581 total_len = (int) desc[0]; 1582 } 1583 1584 if (total_len > 5) { 1585 dev_info(&intf->dev, 1586 "vendor descriptor length: %d data: %11ph\n", 1587 total_len, desc); 1588 1589 if ((desc[0] != total_len) || /* descriptor length */ 1590 (desc[1] != 0x5f) || /* vendor descriptor type */ 1591 (desc[2] != 0x01) || /* version (2 bytes) */ 1592 (desc[3] != 0x00) || 1593 (desc[4] != total_len - 2)) /* length after type */ 1594 goto unrecognized; 1595 1596 desc_end = desc + total_len; 1597 desc += 5; /* the fixed header we've already parsed */ 1598 1599 while (desc < desc_end) { 1600 u8 length; 1601 u16 key; 1602 1603 key = *desc++; 1604 key |= (u16)*desc++ << 8; 1605 length = *desc++; 1606 1607 switch (key) { 1608 case 0x0200: { /* max_area */ 1609 u32 max_area = *desc++; 1610 max_area |= (u32)*desc++ << 8; 1611 max_area |= (u32)*desc++ << 16; 1612 max_area |= (u32)*desc++ << 24; 1613 dev_warn(&intf->dev, 1614 "DL chip limited to %d pixel modes\n", 1615 max_area); 1616 dlfb->sku_pixel_limit = max_area; 1617 break; 1618 } 1619 default: 1620 break; 1621 } 1622 desc += length; 1623 } 1624 } else { 1625 dev_info(&intf->dev, "vendor descriptor not available (%d)\n", 1626 total_len); 1627 } 1628 1629 goto success; 1630 1631unrecognized: 1632 /* allow udlfb to load for now even if firmware unrecognized */ 1633 dev_err(&intf->dev, "Unrecognized vendor firmware descriptor\n"); 1634 1635success: 1636 kfree(buf); 1637 return true; 1638} 1639 1640static int dlfb_usb_probe(struct usb_interface *intf, 1641 const struct usb_device_id *id) 1642{ 1643 int i; 1644 const struct device_attribute *attr; 1645 struct dlfb_data *dlfb; 1646 struct fb_info *info; 1647 int retval; 1648 struct usb_device *usbdev = interface_to_usbdev(intf); 1649 static u8 out_ep[] = {OUT_EP_NUM + USB_DIR_OUT, 0}; 1650 1651 /* usb initialization */ 1652 dlfb = kzalloc(sizeof(*dlfb), GFP_KERNEL); 1653 if (!dlfb) { 1654 dev_err(&intf->dev, "%s: failed to allocate dlfb\n", __func__); 1655 return -ENOMEM; 1656 } 1657 1658 INIT_LIST_HEAD(&dlfb->deferred_free); 1659 1660 dlfb->udev = usb_get_dev(usbdev); 1661 usb_set_intfdata(intf, dlfb); 1662 1663 if (!usb_check_bulk_endpoints(intf, out_ep)) { 1664 dev_err(&intf->dev, "Invalid DisplayLink device!\n"); 1665 retval = -EINVAL; 1666 goto error; 1667 } 1668 1669 dev_dbg(&intf->dev, "console enable=%d\n", console); 1670 dev_dbg(&intf->dev, "fb_defio enable=%d\n", fb_defio); 1671 dev_dbg(&intf->dev, "shadow enable=%d\n", shadow); 1672 1673 dlfb->sku_pixel_limit = 2048 * 1152; /* default to maximum */ 1674 1675 if (!dlfb_parse_vendor_descriptor(dlfb, intf)) { 1676 dev_err(&intf->dev, 1677 "firmware not recognized, incompatible device?\n"); 1678 retval = -ENODEV; 1679 goto error; 1680 } 1681 1682 if (pixel_limit) { 1683 dev_warn(&intf->dev, 1684 "DL chip limit of %d overridden to %d\n", 1685 dlfb->sku_pixel_limit, pixel_limit); 1686 dlfb->sku_pixel_limit = pixel_limit; 1687 } 1688 1689 1690 /* allocates framebuffer driver structure, not framebuffer memory */ 1691 info = framebuffer_alloc(0, &dlfb->udev->dev); 1692 if (!info) { 1693 retval = -ENOMEM; 1694 goto error; 1695 } 1696 1697 dlfb->info = info; 1698 info->par = dlfb; 1699 info->pseudo_palette = dlfb->pseudo_palette; 1700 dlfb->ops = dlfb_ops; 1701 info->fbops = &dlfb->ops; 1702 1703 mutex_init(&dlfb->render_mutex); 1704 dlfb_init_damage(dlfb); 1705 spin_lock_init(&dlfb->damage_lock); 1706 INIT_WORK(&dlfb->damage_work, dlfb_damage_work); 1707 1708 INIT_LIST_HEAD(&info->modelist); 1709 1710 if (!dlfb_alloc_urb_list(dlfb, WRITES_IN_FLIGHT, MAX_TRANSFER)) { 1711 retval = -ENOMEM; 1712 dev_err(&intf->dev, "unable to allocate urb list\n"); 1713 goto error; 1714 } 1715 1716 /* We don't register a new USB class. Our client interface is dlfbev */ 1717 1718 retval = fb_alloc_cmap(&info->cmap, 256, 0); 1719 if (retval < 0) { 1720 dev_err(info->device, "cmap allocation failed: %d\n", retval); 1721 goto error; 1722 } 1723 1724 retval = dlfb_setup_modes(dlfb, info, NULL, 0); 1725 if (retval != 0) { 1726 dev_err(info->device, 1727 "unable to find common mode for display and adapter\n"); 1728 goto error; 1729 } 1730 1731 /* ready to begin using device */ 1732 1733 atomic_set(&dlfb->usb_active, 1); 1734 dlfb_select_std_channel(dlfb); 1735 1736 dlfb_ops_check_var(&info->var, info); 1737 retval = dlfb_ops_set_par(info); 1738 if (retval) 1739 goto error; 1740 1741 retval = register_framebuffer(info); 1742 if (retval < 0) { 1743 dev_err(info->device, "unable to register framebuffer: %d\n", 1744 retval); 1745 goto error; 1746 } 1747 1748 for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) { 1749 attr = &fb_device_attrs[i]; 1750 retval = device_create_file(info->dev, attr); 1751 if (retval) 1752 dev_warn(info->device, 1753 "failed to create '%s' attribute: %d\n", 1754 attr->attr.name, retval); 1755 } 1756 1757 retval = device_create_bin_file(info->dev, &edid_attr); 1758 if (retval) 1759 dev_warn(info->device, "failed to create '%s' attribute: %d\n", 1760 edid_attr.attr.name, retval); 1761 1762 dev_info(info->device, 1763 "%s is DisplayLink USB device (%dx%d, %dK framebuffer memory)\n", 1764 dev_name(info->dev), info->var.xres, info->var.yres, 1765 ((dlfb->backing_buffer) ? 1766 info->fix.smem_len * 2 : info->fix.smem_len) >> 10); 1767 return 0; 1768 1769error: 1770 if (dlfb->info) { 1771 dlfb_ops_destroy(dlfb->info); 1772 } else { 1773 usb_put_dev(dlfb->udev); 1774 kfree(dlfb); 1775 } 1776 return retval; 1777} 1778 1779static void dlfb_usb_disconnect(struct usb_interface *intf) 1780{ 1781 struct dlfb_data *dlfb; 1782 struct fb_info *info; 1783 int i; 1784 1785 dlfb = usb_get_intfdata(intf); 1786 info = dlfb->info; 1787 1788 dev_dbg(&intf->dev, "USB disconnect starting\n"); 1789 1790 /* we virtualize until all fb clients release. Then we free */ 1791 dlfb->virtualized = true; 1792 1793 /* When non-active we'll update virtual framebuffer, but no new urbs */ 1794 atomic_set(&dlfb->usb_active, 0); 1795 1796 /* this function will wait for all in-flight urbs to complete */ 1797 dlfb_free_urb_list(dlfb); 1798 1799 /* remove udlfb's sysfs interfaces */ 1800 for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) 1801 device_remove_file(info->dev, &fb_device_attrs[i]); 1802 device_remove_bin_file(info->dev, &edid_attr); 1803 1804 unregister_framebuffer(info); 1805} 1806 1807static struct usb_driver dlfb_driver = { 1808 .name = "udlfb", 1809 .probe = dlfb_usb_probe, 1810 .disconnect = dlfb_usb_disconnect, 1811 .id_table = id_table, 1812}; 1813 1814module_usb_driver(dlfb_driver); 1815 1816static void dlfb_urb_completion(struct urb *urb) 1817{ 1818 struct urb_node *unode = urb->context; 1819 struct dlfb_data *dlfb = unode->dlfb; 1820 unsigned long flags; 1821 1822 switch (urb->status) { 1823 case 0: 1824 /* success */ 1825 break; 1826 case -ECONNRESET: 1827 case -ENOENT: 1828 case -ESHUTDOWN: 1829 /* sync/async unlink faults aren't errors */ 1830 break; 1831 default: 1832 dev_err(&dlfb->udev->dev, 1833 "%s - nonzero write bulk status received: %d\n", 1834 __func__, urb->status); 1835 atomic_set(&dlfb->lost_pixels, 1); 1836 break; 1837 } 1838 1839 urb->transfer_buffer_length = dlfb->urbs.size; /* reset to actual */ 1840 1841 spin_lock_irqsave(&dlfb->urbs.lock, flags); 1842 list_add_tail(&unode->entry, &dlfb->urbs.list); 1843 dlfb->urbs.available++; 1844 spin_unlock_irqrestore(&dlfb->urbs.lock, flags); 1845 1846 up(&dlfb->urbs.limit_sem); 1847} 1848 1849static void dlfb_free_urb_list(struct dlfb_data *dlfb) 1850{ 1851 int count = dlfb->urbs.count; 1852 struct list_head *node; 1853 struct urb_node *unode; 1854 struct urb *urb; 1855 1856 /* keep waiting and freeing, until we've got 'em all */ 1857 while (count--) { 1858 down(&dlfb->urbs.limit_sem); 1859 1860 spin_lock_irq(&dlfb->urbs.lock); 1861 1862 node = dlfb->urbs.list.next; /* have reserved one with sem */ 1863 list_del_init(node); 1864 1865 spin_unlock_irq(&dlfb->urbs.lock); 1866 1867 unode = list_entry(node, struct urb_node, entry); 1868 urb = unode->urb; 1869 1870 /* Free each separately allocated piece */ 1871 usb_free_coherent(urb->dev, dlfb->urbs.size, 1872 urb->transfer_buffer, urb->transfer_dma); 1873 usb_free_urb(urb); 1874 kfree(node); 1875 } 1876 1877 dlfb->urbs.count = 0; 1878} 1879 1880static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size) 1881{ 1882 struct urb *urb; 1883 struct urb_node *unode; 1884 char *buf; 1885 size_t wanted_size = count * size; 1886 1887 spin_lock_init(&dlfb->urbs.lock); 1888 1889retry: 1890 dlfb->urbs.size = size; 1891 INIT_LIST_HEAD(&dlfb->urbs.list); 1892 1893 sema_init(&dlfb->urbs.limit_sem, 0); 1894 dlfb->urbs.count = 0; 1895 dlfb->urbs.available = 0; 1896 1897 while (dlfb->urbs.count * size < wanted_size) { 1898 unode = kzalloc(sizeof(*unode), GFP_KERNEL); 1899 if (!unode) 1900 break; 1901 unode->dlfb = dlfb; 1902 1903 urb = usb_alloc_urb(0, GFP_KERNEL); 1904 if (!urb) { 1905 kfree(unode); 1906 break; 1907 } 1908 unode->urb = urb; 1909 1910 buf = usb_alloc_coherent(dlfb->udev, size, GFP_KERNEL, 1911 &urb->transfer_dma); 1912 if (!buf) { 1913 kfree(unode); 1914 usb_free_urb(urb); 1915 if (size > PAGE_SIZE) { 1916 size /= 2; 1917 dlfb_free_urb_list(dlfb); 1918 goto retry; 1919 } 1920 break; 1921 } 1922 1923 /* urb->transfer_buffer_length set to actual before submit */ 1924 usb_fill_bulk_urb(urb, dlfb->udev, 1925 usb_sndbulkpipe(dlfb->udev, OUT_EP_NUM), 1926 buf, size, dlfb_urb_completion, unode); 1927 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 1928 1929 list_add_tail(&unode->entry, &dlfb->urbs.list); 1930 1931 up(&dlfb->urbs.limit_sem); 1932 dlfb->urbs.count++; 1933 dlfb->urbs.available++; 1934 } 1935 1936 return dlfb->urbs.count; 1937} 1938 1939static struct urb *dlfb_get_urb(struct dlfb_data *dlfb) 1940{ 1941 int ret; 1942 struct list_head *entry; 1943 struct urb_node *unode; 1944 1945 /* Wait for an in-flight buffer to complete and get re-queued */ 1946 ret = down_timeout(&dlfb->urbs.limit_sem, GET_URB_TIMEOUT); 1947 if (ret) { 1948 atomic_set(&dlfb->lost_pixels, 1); 1949 dev_warn(&dlfb->udev->dev, 1950 "wait for urb interrupted: %d available: %d\n", 1951 ret, dlfb->urbs.available); 1952 return NULL; 1953 } 1954 1955 spin_lock_irq(&dlfb->urbs.lock); 1956 1957 BUG_ON(list_empty(&dlfb->urbs.list)); /* reserved one with limit_sem */ 1958 entry = dlfb->urbs.list.next; 1959 list_del_init(entry); 1960 dlfb->urbs.available--; 1961 1962 spin_unlock_irq(&dlfb->urbs.lock); 1963 1964 unode = list_entry(entry, struct urb_node, entry); 1965 return unode->urb; 1966} 1967 1968static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb *urb, size_t len) 1969{ 1970 int ret; 1971 1972 BUG_ON(len > dlfb->urbs.size); 1973 1974 urb->transfer_buffer_length = len; /* set to actual payload len */ 1975 ret = usb_submit_urb(urb, GFP_KERNEL); 1976 if (ret) { 1977 dlfb_urb_completion(urb); /* because no one else will */ 1978 atomic_set(&dlfb->lost_pixels, 1); 1979 dev_err(&dlfb->udev->dev, "submit urb error: %d\n", ret); 1980 } 1981 return ret; 1982} 1983 1984module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 1985MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer"); 1986 1987module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 1988MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes"); 1989 1990module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 1991MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf"); 1992 1993module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP); 1994MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)"); 1995 1996MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, " 1997 "Jaya Kumar <jayakumar.lkml@gmail.com>, " 1998 "Bernie Thompson <bernie@plugable.com>"); 1999MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver"); 2000MODULE_LICENSE("GPL"); 2001 2002