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udlfb.c
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1 /*
2  * udlfb.c -- Framebuffer driver for DisplayLink USB controller
3  *
4  * Copyright (C) 2009 Roberto De Ioris <[email protected]>
5  * Copyright (C) 2009 Jaya Kumar <[email protected]>
6  * Copyright (C) 2009 Bernie Thompson <[email protected]>
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License v2. See the file COPYING in the main directory of this archive for
10  * more details.
11  *
12  * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
13  * usb-skeleton by GregKH.
14  *
15  * Device-specific portions based on information from Displaylink, with work
16  * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
17  */
18 
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/init.h>
24 #include <linux/usb.h>
25 #include <linux/uaccess.h>
26 #include <linux/mm.h>
27 #include <linux/fb.h>
28 #include <linux/vmalloc.h>
29 #include <linux/slab.h>
30 #include <linux/prefetch.h>
31 #include <linux/delay.h>
32 #include <video/udlfb.h>
33 #include "edid.h"
34 
35 static struct fb_fix_screeninfo dlfb_fix = {
36  .id = "udlfb",
37  .type = FB_TYPE_PACKED_PIXELS,
38  .visual = FB_VISUAL_TRUECOLOR,
39  .xpanstep = 0,
40  .ypanstep = 0,
41  .ywrapstep = 0,
42  .accel = FB_ACCEL_NONE,
43 };
44 
45 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
49 
50 /*
51  * There are many DisplayLink-based graphics products, all with unique PIDs.
52  * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
53  * We also require a match on SubClass (0x00) and Protocol (0x00),
54  * which is compatible with all known USB 2.0 era graphics chips and firmware,
55  * but allows DisplayLink to increment those for any future incompatible chips
56  */
57 static struct usb_device_id id_table[] = {
58  {.idVendor = 0x17e9,
59  .bInterfaceClass = 0xff,
60  .bInterfaceSubClass = 0x00,
61  .bInterfaceProtocol = 0x00,
62  .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
66  },
67  {},
68 };
69 MODULE_DEVICE_TABLE(usb, id_table);
70 
71 /* module options */
72 static bool console = 1; /* Allow fbcon to open framebuffer */
73 static bool fb_defio = 1; /* Detect mmap writes using page faults */
74 static bool shadow = 1; /* Optionally disable shadow framebuffer */
75 static int pixel_limit; /* Optionally force a pixel resolution limit */
76 
77 /* dlfb keeps a list of urbs for efficient bulk transfers */
78 static void dlfb_urb_completion(struct urb *urb);
79 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
80 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
81 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
82 static void dlfb_free_urb_list(struct dlfb_data *dev);
83 
84 /*
85  * All DisplayLink bulk operations start with 0xAF, followed by specific code
86  * All operations are written to buffers which then later get sent to device
87  */
88 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
89 {
90  *buf++ = 0xAF;
91  *buf++ = 0x20;
92  *buf++ = reg;
93  *buf++ = val;
94  return buf;
95 }
96 
97 static char *dlfb_vidreg_lock(char *buf)
98 {
99  return dlfb_set_register(buf, 0xFF, 0x00);
100 }
101 
102 static char *dlfb_vidreg_unlock(char *buf)
103 {
104  return dlfb_set_register(buf, 0xFF, 0xFF);
105 }
106 
107 /*
108  * Map FB_BLANK_* to DisplayLink register
109  * DLReg FB_BLANK_*
110  * ----- -----------------------------
111  * 0x00 FB_BLANK_UNBLANK (0)
112  * 0x01 FB_BLANK (1)
113  * 0x03 FB_BLANK_VSYNC_SUSPEND (2)
114  * 0x05 FB_BLANK_HSYNC_SUSPEND (3)
115  * 0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
116  */
117 static char *dlfb_blanking(char *buf, int fb_blank)
118 {
119  u8 reg;
120 
121  switch (fb_blank) {
122  case FB_BLANK_POWERDOWN:
123  reg = 0x07;
124  break;
126  reg = 0x05;
127  break;
129  reg = 0x03;
130  break;
131  case FB_BLANK_NORMAL:
132  reg = 0x01;
133  break;
134  default:
135  reg = 0x00;
136  }
137 
138  buf = dlfb_set_register(buf, 0x1F, reg);
139 
140  return buf;
141 }
142 
143 static char *dlfb_set_color_depth(char *buf, u8 selection)
144 {
145  return dlfb_set_register(buf, 0x00, selection);
146 }
147 
148 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
149 {
150  /* the base pointer is 16 bits wide, 0x20 is hi byte. */
151  wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
152  wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
153  return dlfb_set_register(wrptr, 0x22, base);
154 }
155 
156 /*
157  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
158  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
159  */
160 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
161 {
162  wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
163  wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
164  return dlfb_set_register(wrptr, 0x28, base);
165 }
166 
167 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
168 {
169  wrptr = dlfb_set_register(wrptr, reg, value >> 8);
170  return dlfb_set_register(wrptr, reg+1, value);
171 }
172 
173 /*
174  * This is kind of weird because the controller takes some
175  * register values in a different byte order than other registers.
176  */
177 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
178 {
179  wrptr = dlfb_set_register(wrptr, reg, value);
180  return dlfb_set_register(wrptr, reg+1, value >> 8);
181 }
182 
183 /*
184  * LFSR is linear feedback shift register. The reason we have this is
185  * because the display controller needs to minimize the clock depth of
186  * various counters used in the display path. So this code reverses the
187  * provided value into the lfsr16 value by counting backwards to get
188  * the value that needs to be set in the hardware comparator to get the
189  * same actual count. This makes sense once you read above a couple of
190  * times and think about it from a hardware perspective.
191  */
192 static u16 dlfb_lfsr16(u16 actual_count)
193 {
194  u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
195 
196  while (actual_count--) {
197  lv = ((lv << 1) |
198  (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
199  & 0xFFFF;
200  }
201 
202  return (u16) lv;
203 }
204 
205 /*
206  * This does LFSR conversion on the value that is to be written.
207  * See LFSR explanation above for more detail.
208  */
209 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
210 {
211  return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
212 }
213 
214 /*
215  * This takes a standard fbdev screeninfo struct and all of its monitor mode
216  * details and converts them into the DisplayLink equivalent register commands.
217  */
218 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
219 {
220  u16 xds, yds;
221  u16 xde, yde;
222  u16 yec;
223 
224  /* x display start */
225  xds = var->left_margin + var->hsync_len;
226  wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
227  /* x display end */
228  xde = xds + var->xres;
229  wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
230 
231  /* y display start */
232  yds = var->upper_margin + var->vsync_len;
233  wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
234  /* y display end */
235  yde = yds + var->yres;
236  wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
237 
238  /* x end count is active + blanking - 1 */
239  wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
240  xde + var->right_margin - 1);
241 
242  /* libdlo hardcodes hsync start to 1 */
243  wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
244 
245  /* hsync end is width of sync pulse + 1 */
246  wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
247 
248  /* hpixels is active pixels */
249  wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
250 
251  /* yendcount is vertical active + vertical blanking */
252  yec = var->yres + var->upper_margin + var->lower_margin +
253  var->vsync_len;
254  wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
255 
256  /* libdlo hardcodes vsync start to 0 */
257  wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
258 
259  /* vsync end is width of vsync pulse */
260  wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
261 
262  /* vpixels is active pixels */
263  wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
264 
265  /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
266  wrptr = dlfb_set_register_16be(wrptr, 0x1B,
267  200*1000*1000/var->pixclock);
268 
269  return wrptr;
270 }
271 
272 /*
273  * This takes a standard fbdev screeninfo struct that was fetched or prepared
274  * and then generates the appropriate command sequence that then drives the
275  * display controller.
276  */
277 static int dlfb_set_video_mode(struct dlfb_data *dev,
278  struct fb_var_screeninfo *var)
279 {
280  char *buf;
281  char *wrptr;
282  int retval = 0;
283  int writesize;
284  struct urb *urb;
285 
286  if (!atomic_read(&dev->usb_active))
287  return -EPERM;
288 
289  urb = dlfb_get_urb(dev);
290  if (!urb)
291  return -ENOMEM;
292 
293  buf = (char *) urb->transfer_buffer;
294 
295  /*
296  * This first section has to do with setting the base address on the
297  * controller * associated with the display. There are 2 base
298  * pointers, currently, we only * use the 16 bpp segment.
299  */
300  wrptr = dlfb_vidreg_lock(buf);
301  wrptr = dlfb_set_color_depth(wrptr, 0x00);
302  /* set base for 16bpp segment to 0 */
303  wrptr = dlfb_set_base16bpp(wrptr, 0);
304  /* set base for 8bpp segment to end of fb */
305  wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
306 
307  wrptr = dlfb_set_vid_cmds(wrptr, var);
308  wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
309  wrptr = dlfb_vidreg_unlock(wrptr);
310 
311  writesize = wrptr - buf;
312 
313  retval = dlfb_submit_urb(dev, urb, writesize);
314 
316 
317  return retval;
318 }
319 
320 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
321 {
322  unsigned long start = vma->vm_start;
323  unsigned long size = vma->vm_end - vma->vm_start;
324  unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
325  unsigned long page, pos;
326 
327  if (offset + size > info->fix.smem_len)
328  return -EINVAL;
329 
330  pos = (unsigned long)info->fix.smem_start + offset;
331 
332  pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
333  pos, size);
334 
335  while (size > 0) {
336  page = vmalloc_to_pfn((void *)pos);
337  if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
338  return -EAGAIN;
339 
340  start += PAGE_SIZE;
341  pos += PAGE_SIZE;
342  if (size > PAGE_SIZE)
343  size -= PAGE_SIZE;
344  else
345  size = 0;
346  }
347 
348  return 0;
349 }
350 
351 /*
352  * Trims identical data from front and back of line
353  * Sets new front buffer address and width
354  * And returns byte count of identical pixels
355  * Assumes CPU natural alignment (unsigned long)
356  * for back and front buffer ptrs and width
357  */
358 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
359 {
360  int j, k;
361  const unsigned long *back = (const unsigned long *) bback;
362  const unsigned long *front = (const unsigned long *) *bfront;
363  const int width = *width_bytes / sizeof(unsigned long);
364  int identical = width;
365  int start = width;
366  int end = width;
367 
368  prefetch((void *) front);
369  prefetch((void *) back);
370 
371  for (j = 0; j < width; j++) {
372  if (back[j] != front[j]) {
373  start = j;
374  break;
375  }
376  }
377 
378  for (k = width - 1; k > j; k--) {
379  if (back[k] != front[k]) {
380  end = k+1;
381  break;
382  }
383  }
384 
385  identical = start + (width - end);
386  *bfront = (u8 *) &front[start];
387  *width_bytes = (end - start) * sizeof(unsigned long);
388 
389  return identical * sizeof(unsigned long);
390 }
391 
392 /*
393  * Render a command stream for an encoded horizontal line segment of pixels.
394  *
395  * A command buffer holds several commands.
396  * It always begins with a fresh command header
397  * (the protocol doesn't require this, but we enforce it to allow
398  * multiple buffers to be potentially encoded and sent in parallel).
399  * A single command encodes one contiguous horizontal line of pixels
400  *
401  * The function relies on the client to do all allocation, so that
402  * rendering can be done directly to output buffers (e.g. USB URBs).
403  * The function fills the supplied command buffer, providing information
404  * on where it left off, so the client may call in again with additional
405  * buffers if the line will take several buffers to complete.
406  *
407  * A single command can transmit a maximum of 256 pixels,
408  * regardless of the compression ratio (protocol design limit).
409  * To the hardware, 0 for a size byte means 256
410  *
411  * Rather than 256 pixel commands which are either rl or raw encoded,
412  * the rlx command simply assumes alternating raw and rl spans within one cmd.
413  * This has a slightly larger header overhead, but produces more even results.
414  * It also processes all data (read and write) in a single pass.
415  * Performance benchmarks of common cases show it having just slightly better
416  * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
417  * But for very rl friendly data, will compress not quite as well.
418  */
419 static void dlfb_compress_hline(
420  const uint16_t **pixel_start_ptr,
421  const uint16_t *const pixel_end,
422  uint32_t *device_address_ptr,
423  uint8_t **command_buffer_ptr,
424  const uint8_t *const cmd_buffer_end)
425 {
426  const uint16_t *pixel = *pixel_start_ptr;
427  uint32_t dev_addr = *device_address_ptr;
428  uint8_t *cmd = *command_buffer_ptr;
429  const int bpp = 2;
430 
431  while ((pixel_end > pixel) &&
432  (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
433  uint8_t *raw_pixels_count_byte = 0;
434  uint8_t *cmd_pixels_count_byte = 0;
435  const uint16_t *raw_pixel_start = 0;
436  const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
437 
438  prefetchw((void *) cmd); /* pull in one cache line at least */
439 
440  *cmd++ = 0xAF;
441  *cmd++ = 0x6B;
442  *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
443  *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
444  *cmd++ = (uint8_t) ((dev_addr) & 0xFF);
445 
446  cmd_pixels_count_byte = cmd++; /* we'll know this later */
447  cmd_pixel_start = pixel;
448 
449  raw_pixels_count_byte = cmd++; /* we'll know this later */
450  raw_pixel_start = pixel;
451 
452  cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
453  min((int)(pixel_end - pixel),
454  (int)(cmd_buffer_end - cmd) / bpp));
455 
456  prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
457 
458  while (pixel < cmd_pixel_end) {
459  const uint16_t * const repeating_pixel = pixel;
460 
461  *(uint16_t *)cmd = cpu_to_be16p(pixel);
462  cmd += 2;
463  pixel++;
464 
465  if (unlikely((pixel < cmd_pixel_end) &&
466  (*pixel == *repeating_pixel))) {
467  /* go back and fill in raw pixel count */
468  *raw_pixels_count_byte = ((repeating_pixel -
469  raw_pixel_start) + 1) & 0xFF;
470 
471  while ((pixel < cmd_pixel_end)
472  && (*pixel == *repeating_pixel)) {
473  pixel++;
474  }
475 
476  /* immediately after raw data is repeat byte */
477  *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
478 
479  /* Then start another raw pixel span */
480  raw_pixel_start = pixel;
481  raw_pixels_count_byte = cmd++;
482  }
483  }
484 
485  if (pixel > raw_pixel_start) {
486  /* finalize last RAW span */
487  *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
488  }
489 
490  *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
491  dev_addr += (pixel - cmd_pixel_start) * bpp;
492  }
493 
494  if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
495  /* Fill leftover bytes with no-ops */
496  if (cmd_buffer_end > cmd)
497  memset(cmd, 0xAF, cmd_buffer_end - cmd);
498  cmd = (uint8_t *) cmd_buffer_end;
499  }
500 
501  *command_buffer_ptr = cmd;
502  *pixel_start_ptr = pixel;
503  *device_address_ptr = dev_addr;
504 
505  return;
506 }
507 
508 /*
509  * There are 3 copies of every pixel: The front buffer that the fbdev
510  * client renders to, the actual framebuffer across the USB bus in hardware
511  * (that we can only write to, slowly, and can never read), and (optionally)
512  * our shadow copy that tracks what's been sent to that hardware buffer.
513  */
514 static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
515  const char *front, char **urb_buf_ptr,
516  u32 byte_offset, u32 byte_width,
517  int *ident_ptr, int *sent_ptr)
518 {
519  const u8 *line_start, *line_end, *next_pixel;
520  u32 dev_addr = dev->base16 + byte_offset;
521  struct urb *urb = *urb_ptr;
522  u8 *cmd = *urb_buf_ptr;
523  u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
524 
525  line_start = (u8 *) (front + byte_offset);
526  next_pixel = line_start;
527  line_end = next_pixel + byte_width;
528 
529  if (dev->backing_buffer) {
530  int offset;
531  const u8 *back_start = (u8 *) (dev->backing_buffer
532  + byte_offset);
533 
534  *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
535  &byte_width);
536 
537  offset = next_pixel - line_start;
538  line_end = next_pixel + byte_width;
539  dev_addr += offset;
540  back_start += offset;
541  line_start += offset;
542 
543  memcpy((char *)back_start, (char *) line_start,
544  byte_width);
545  }
546 
547  while (next_pixel < line_end) {
548 
549  dlfb_compress_hline((const uint16_t **) &next_pixel,
550  (const uint16_t *) line_end, &dev_addr,
551  (u8 **) &cmd, (u8 *) cmd_end);
552 
553  if (cmd >= cmd_end) {
554  int len = cmd - (u8 *) urb->transfer_buffer;
555  if (dlfb_submit_urb(dev, urb, len))
556  return 1; /* lost pixels is set */
557  *sent_ptr += len;
558  urb = dlfb_get_urb(dev);
559  if (!urb)
560  return 1; /* lost_pixels is set */
561  *urb_ptr = urb;
562  cmd = urb->transfer_buffer;
563  cmd_end = &cmd[urb->transfer_buffer_length];
564  }
565  }
566 
567  *urb_buf_ptr = cmd;
568 
569  return 0;
570 }
571 
572 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
573  int width, int height, char *data)
574 {
575  int i, ret;
576  char *cmd;
577  cycles_t start_cycles, end_cycles;
578  int bytes_sent = 0;
579  int bytes_identical = 0;
580  struct urb *urb;
581  int aligned_x;
582 
583  start_cycles = get_cycles();
584 
585  aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
586  width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
587  x = aligned_x;
588 
589  if ((width <= 0) ||
590  (x + width > dev->info->var.xres) ||
591  (y + height > dev->info->var.yres))
592  return -EINVAL;
593 
594  if (!atomic_read(&dev->usb_active))
595  return 0;
596 
597  urb = dlfb_get_urb(dev);
598  if (!urb)
599  return 0;
600  cmd = urb->transfer_buffer;
601 
602  for (i = y; i < y + height ; i++) {
603  const int line_offset = dev->info->fix.line_length * i;
604  const int byte_offset = line_offset + (x * BPP);
605 
606  if (dlfb_render_hline(dev, &urb,
607  (char *) dev->info->fix.smem_start,
608  &cmd, byte_offset, width * BPP,
609  &bytes_identical, &bytes_sent))
610  goto error;
611  }
612 
613  if (cmd > (char *) urb->transfer_buffer) {
614  /* Send partial buffer remaining before exiting */
615  int len = cmd - (char *) urb->transfer_buffer;
616  ret = dlfb_submit_urb(dev, urb, len);
617  bytes_sent += len;
618  } else
619  dlfb_urb_completion(urb);
620 
621 error:
622  atomic_add(bytes_sent, &dev->bytes_sent);
623  atomic_add(bytes_identical, &dev->bytes_identical);
624  atomic_add(width*height*2, &dev->bytes_rendered);
625  end_cycles = get_cycles();
626  atomic_add(((unsigned int) ((end_cycles - start_cycles)
627  >> 10)), /* Kcycles */
628  &dev->cpu_kcycles_used);
629 
630  return 0;
631 }
632 
633 /*
634  * Path triggered by usermode clients who write to filesystem
635  * e.g. cat filename > /dev/fb1
636  * Not used by X Windows or text-mode console. But useful for testing.
637  * Slow because of extra copy and we must assume all pixels dirty.
638  */
639 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
640  size_t count, loff_t *ppos)
641 {
642  ssize_t result;
643  struct dlfb_data *dev = info->par;
644  u32 offset = (u32) *ppos;
645 
646  result = fb_sys_write(info, buf, count, ppos);
647 
648  if (result > 0) {
649  int start = max((int)(offset / info->fix.line_length), 0);
650  int lines = min((u32)((result / info->fix.line_length) + 1),
651  (u32)info->var.yres);
652 
653  dlfb_handle_damage(dev, 0, start, info->var.xres,
654  lines, info->screen_base);
655  }
656 
657  return result;
658 }
659 
660 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
661 static void dlfb_ops_copyarea(struct fb_info *info,
662  const struct fb_copyarea *area)
663 {
664 
665  struct dlfb_data *dev = info->par;
666 
667  sys_copyarea(info, area);
668 
669  dlfb_handle_damage(dev, area->dx, area->dy,
670  area->width, area->height, info->screen_base);
671 }
672 
673 static void dlfb_ops_imageblit(struct fb_info *info,
674  const struct fb_image *image)
675 {
676  struct dlfb_data *dev = info->par;
677 
678  sys_imageblit(info, image);
679 
680  dlfb_handle_damage(dev, image->dx, image->dy,
681  image->width, image->height, info->screen_base);
682 }
683 
684 static void dlfb_ops_fillrect(struct fb_info *info,
685  const struct fb_fillrect *rect)
686 {
687  struct dlfb_data *dev = info->par;
688 
689  sys_fillrect(info, rect);
690 
691  dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
692  rect->height, info->screen_base);
693 }
694 
695 /*
696  * NOTE: fb_defio.c is holding info->fbdefio.mutex
697  * Touching ANY framebuffer memory that triggers a page fault
698  * in fb_defio will cause a deadlock, when it also tries to
699  * grab the same mutex.
700  */
701 static void dlfb_dpy_deferred_io(struct fb_info *info,
702  struct list_head *pagelist)
703 {
704  struct page *cur;
705  struct fb_deferred_io *fbdefio = info->fbdefio;
706  struct dlfb_data *dev = info->par;
707  struct urb *urb;
708  char *cmd;
709  cycles_t start_cycles, end_cycles;
710  int bytes_sent = 0;
711  int bytes_identical = 0;
712  int bytes_rendered = 0;
713 
714  if (!fb_defio)
715  return;
716 
717  if (!atomic_read(&dev->usb_active))
718  return;
719 
720  start_cycles = get_cycles();
721 
722  urb = dlfb_get_urb(dev);
723  if (!urb)
724  return;
725 
726  cmd = urb->transfer_buffer;
727 
728  /* walk the written page list and render each to device */
729  list_for_each_entry(cur, &fbdefio->pagelist, lru) {
730 
731  if (dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
732  &cmd, cur->index << PAGE_SHIFT,
733  PAGE_SIZE, &bytes_identical, &bytes_sent))
734  goto error;
735  bytes_rendered += PAGE_SIZE;
736  }
737 
738  if (cmd > (char *) urb->transfer_buffer) {
739  /* Send partial buffer remaining before exiting */
740  int len = cmd - (char *) urb->transfer_buffer;
741  dlfb_submit_urb(dev, urb, len);
742  bytes_sent += len;
743  } else
744  dlfb_urb_completion(urb);
745 
746 error:
747  atomic_add(bytes_sent, &dev->bytes_sent);
748  atomic_add(bytes_identical, &dev->bytes_identical);
749  atomic_add(bytes_rendered, &dev->bytes_rendered);
750  end_cycles = get_cycles();
751  atomic_add(((unsigned int) ((end_cycles - start_cycles)
752  >> 10)), /* Kcycles */
753  &dev->cpu_kcycles_used);
754 }
755 
756 static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
757 {
758  int i;
759  int ret;
760  char *rbuf;
761 
762  rbuf = kmalloc(2, GFP_KERNEL);
763  if (!rbuf)
764  return 0;
765 
766  for (i = 0; i < len; i++) {
767  ret = usb_control_msg(dev->udev,
768  usb_rcvctrlpipe(dev->udev, 0), (0x02),
769  (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
770  HZ);
771  if (ret < 1) {
772  pr_err("Read EDID byte %d failed err %x\n", i, ret);
773  i--;
774  break;
775  }
776  edid[i] = rbuf[1];
777  }
778 
779  kfree(rbuf);
780 
781  return i;
782 }
783 
784 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
785  unsigned long arg)
786 {
787 
788  struct dlfb_data *dev = info->par;
789 
790  if (!atomic_read(&dev->usb_active))
791  return 0;
792 
793  /* TODO: Update X server to get this from sysfs instead */
794  if (cmd == DLFB_IOCTL_RETURN_EDID) {
795  void __user *edid = (void __user *)arg;
796  if (copy_to_user(edid, dev->edid, dev->edid_size))
797  return -EFAULT;
798  return 0;
799  }
800 
801  /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
802  if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
803  struct dloarea area;
804 
805  if (copy_from_user(&area, (void __user *)arg,
806  sizeof(struct dloarea)))
807  return -EFAULT;
808 
809  /*
810  * If we have a damage-aware client, turn fb_defio "off"
811  * To avoid perf imact of unnecessary page fault handling.
812  * Done by resetting the delay for this fb_info to a very
813  * long period. Pages will become writable and stay that way.
814  * Reset to normal value when all clients have closed this fb.
815  */
816  if (info->fbdefio)
817  info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
818 
819  if (area.x < 0)
820  area.x = 0;
821 
822  if (area.x > info->var.xres)
823  area.x = info->var.xres;
824 
825  if (area.y < 0)
826  area.y = 0;
827 
828  if (area.y > info->var.yres)
829  area.y = info->var.yres;
830 
831  dlfb_handle_damage(dev, area.x, area.y, area.w, area.h,
832  info->screen_base);
833  }
834 
835  return 0;
836 }
837 
838 /* taken from vesafb */
839 static int
840 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
841  unsigned blue, unsigned transp, struct fb_info *info)
842 {
843  int err = 0;
844 
845  if (regno >= info->cmap.len)
846  return 1;
847 
848  if (regno < 16) {
849  if (info->var.red.offset == 10) {
850  /* 1:5:5:5 */
851  ((u32 *) (info->pseudo_palette))[regno] =
852  ((red & 0xf800) >> 1) |
853  ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
854  } else {
855  /* 0:5:6:5 */
856  ((u32 *) (info->pseudo_palette))[regno] =
857  ((red & 0xf800)) |
858  ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
859  }
860  }
861 
862  return err;
863 }
864 
865 /*
866  * It's common for several clients to have framebuffer open simultaneously.
867  * e.g. both fbcon and X. Makes things interesting.
868  * Assumes caller is holding info->lock (for open and release at least)
869  */
870 static int dlfb_ops_open(struct fb_info *info, int user)
871 {
872  struct dlfb_data *dev = info->par;
873 
874  /*
875  * fbcon aggressively connects to first framebuffer it finds,
876  * preventing other clients (X) from working properly. Usually
877  * not what the user wants. Fail by default with option to enable.
878  */
879  if ((user == 0) && (!console))
880  return -EBUSY;
881 
882  /* If the USB device is gone, we don't accept new opens */
883  if (dev->virtualized)
884  return -ENODEV;
885 
886  dev->fb_count++;
887 
888  kref_get(&dev->kref);
889 
890  if (fb_defio && (info->fbdefio == NULL)) {
891  /* enable defio at last moment if not disabled by client */
892 
893  struct fb_deferred_io *fbdefio;
894 
895  fbdefio = kzalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
896 
897  if (fbdefio) {
898  fbdefio->delay = DL_DEFIO_WRITE_DELAY;
899  fbdefio->deferred_io = dlfb_dpy_deferred_io;
900  }
901 
902  info->fbdefio = fbdefio;
903  fb_deferred_io_init(info);
904  }
905 
906  pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
907  info->node, user, info, dev->fb_count);
908 
909  return 0;
910 }
911 
912 /*
913  * Called when all client interfaces to start transactions have been disabled,
914  * and all references to our device instance (dlfb_data) are released.
915  * Every transaction must have a reference, so we know are fully spun down
916  */
917 static void dlfb_free(struct kref *kref)
918 {
919  struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
920 
921  if (dev->backing_buffer)
922  vfree(dev->backing_buffer);
923 
924  kfree(dev->edid);
925 
926  pr_warn("freeing dlfb_data %p\n", dev);
927 
928  kfree(dev);
929 }
930 
931 static void dlfb_release_urb_work(struct work_struct *work)
932 {
933  struct urb_node *unode = container_of(work, struct urb_node,
934  release_urb_work.work);
935 
936  up(&unode->dev->urbs.limit_sem);
937 }
938 
939 static void dlfb_free_framebuffer(struct dlfb_data *dev)
940 {
941  struct fb_info *info = dev->info;
942 
943  if (info) {
944  int node = info->node;
945 
947 
948  if (info->cmap.len != 0)
949  fb_dealloc_cmap(&info->cmap);
950  if (info->monspecs.modedb)
951  fb_destroy_modedb(info->monspecs.modedb);
952  if (info->screen_base)
953  vfree(info->screen_base);
954 
956 
957  dev->info = NULL;
958 
959  /* Assume info structure is freed after this point */
960  framebuffer_release(info);
961 
962  pr_warn("fb_info for /dev/fb%d has been freed\n", node);
963  }
964 
965  /* ref taken in probe() as part of registering framebfufer */
966  kref_put(&dev->kref, dlfb_free);
967 }
968 
969 static void dlfb_free_framebuffer_work(struct work_struct *work)
970 {
971  struct dlfb_data *dev = container_of(work, struct dlfb_data,
972  free_framebuffer_work.work);
973  dlfb_free_framebuffer(dev);
974 }
975 /*
976  * Assumes caller is holding info->lock mutex (for open and release at least)
977  */
978 static int dlfb_ops_release(struct fb_info *info, int user)
979 {
980  struct dlfb_data *dev = info->par;
981 
982  dev->fb_count--;
983 
984  /* We can't free fb_info here - fbmem will touch it when we return */
985  if (dev->virtualized && (dev->fb_count == 0))
987 
988  if ((dev->fb_count == 0) && (info->fbdefio)) {
990  kfree(info->fbdefio);
991  info->fbdefio = NULL;
992  info->fbops->fb_mmap = dlfb_ops_mmap;
993  }
994 
995  pr_warn("released /dev/fb%d user=%d count=%d\n",
996  info->node, user, dev->fb_count);
997 
998  kref_put(&dev->kref, dlfb_free);
999 
1000  return 0;
1001 }
1002 
1003 /*
1004  * Check whether a video mode is supported by the DisplayLink chip
1005  * We start from monitor's modes, so don't need to filter that here
1006  */
1007 static int dlfb_is_valid_mode(struct fb_videomode *mode,
1008  struct fb_info *info)
1009 {
1010  struct dlfb_data *dev = info->par;
1011 
1012  if (mode->xres * mode->yres > dev->sku_pixel_limit) {
1013  pr_warn("%dx%d beyond chip capabilities\n",
1014  mode->xres, mode->yres);
1015  return 0;
1016  }
1017 
1018  pr_info("%dx%d @ %d Hz valid mode\n", mode->xres, mode->yres,
1019  mode->refresh);
1020 
1021  return 1;
1022 }
1023 
1024 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1025 {
1026  const struct fb_bitfield red = { 11, 5, 0 };
1027  const struct fb_bitfield green = { 5, 6, 0 };
1028  const struct fb_bitfield blue = { 0, 5, 0 };
1029 
1030  var->bits_per_pixel = 16;
1031  var->red = red;
1032  var->green = green;
1033  var->blue = blue;
1034 }
1035 
1036 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1037  struct fb_info *info)
1038 {
1039  struct fb_videomode mode;
1040 
1041  /* TODO: support dynamically changing framebuffer size */
1042  if ((var->xres * var->yres * 2) > info->fix.smem_len)
1043  return -EINVAL;
1044 
1045  /* set device-specific elements of var unrelated to mode */
1046  dlfb_var_color_format(var);
1047 
1048  fb_var_to_videomode(&mode, var);
1049 
1050  if (!dlfb_is_valid_mode(&mode, info))
1051  return -EINVAL;
1052 
1053  return 0;
1054 }
1055 
1056 static int dlfb_ops_set_par(struct fb_info *info)
1057 {
1058  struct dlfb_data *dev = info->par;
1059  int result;
1060  u16 *pix_framebuffer;
1061  int i;
1062 
1063  pr_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
1064 
1065  result = dlfb_set_video_mode(dev, &info->var);
1066 
1067  if ((result == 0) && (dev->fb_count == 0)) {
1068 
1069  /* paint greenscreen */
1070 
1071  pix_framebuffer = (u16 *) info->screen_base;
1072  for (i = 0; i < info->fix.smem_len / 2; i++)
1073  pix_framebuffer[i] = 0x37e6;
1074 
1075  dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1076  info->screen_base);
1077  }
1078 
1079  return result;
1080 }
1081 
1082 /* To fonzi the jukebox (e.g. make blanking changes take effect) */
1083 static char *dlfb_dummy_render(char *buf)
1084 {
1085  *buf++ = 0xAF;
1086  *buf++ = 0x6A; /* copy */
1087  *buf++ = 0x00; /* from address*/
1088  *buf++ = 0x00;
1089  *buf++ = 0x00;
1090  *buf++ = 0x01; /* one pixel */
1091  *buf++ = 0x00; /* to address */
1092  *buf++ = 0x00;
1093  *buf++ = 0x00;
1094  return buf;
1095 }
1096 
1097 /*
1098  * In order to come back from full DPMS off, we need to set the mode again
1099  */
1100 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1101 {
1102  struct dlfb_data *dev = info->par;
1103  char *bufptr;
1104  struct urb *urb;
1105 
1106  pr_info("/dev/fb%d FB_BLANK mode %d --> %d\n",
1107  info->node, dev->blank_mode, blank_mode);
1108 
1109  if ((dev->blank_mode == FB_BLANK_POWERDOWN) &&
1110  (blank_mode != FB_BLANK_POWERDOWN)) {
1111 
1112  /* returning from powerdown requires a fresh modeset */
1113  dlfb_set_video_mode(dev, &info->var);
1114  }
1115 
1116  urb = dlfb_get_urb(dev);
1117  if (!urb)
1118  return 0;
1119 
1120  bufptr = (char *) urb->transfer_buffer;
1121  bufptr = dlfb_vidreg_lock(bufptr);
1122  bufptr = dlfb_blanking(bufptr, blank_mode);
1123  bufptr = dlfb_vidreg_unlock(bufptr);
1124 
1125  /* seems like a render op is needed to have blank change take effect */
1126  bufptr = dlfb_dummy_render(bufptr);
1127 
1128  dlfb_submit_urb(dev, urb, bufptr -
1129  (char *) urb->transfer_buffer);
1130 
1131  dev->blank_mode = blank_mode;
1132 
1133  return 0;
1134 }
1135 
1136 static struct fb_ops dlfb_ops = {
1137  .owner = THIS_MODULE,
1138  .fb_read = fb_sys_read,
1139  .fb_write = dlfb_ops_write,
1140  .fb_setcolreg = dlfb_ops_setcolreg,
1141  .fb_fillrect = dlfb_ops_fillrect,
1142  .fb_copyarea = dlfb_ops_copyarea,
1143  .fb_imageblit = dlfb_ops_imageblit,
1144  .fb_mmap = dlfb_ops_mmap,
1145  .fb_ioctl = dlfb_ops_ioctl,
1146  .fb_open = dlfb_ops_open,
1147  .fb_release = dlfb_ops_release,
1148  .fb_blank = dlfb_ops_blank,
1149  .fb_check_var = dlfb_ops_check_var,
1150  .fb_set_par = dlfb_ops_set_par,
1151 };
1152 
1153 
1154 /*
1155  * Assumes &info->lock held by caller
1156  * Assumes no active clients have framebuffer open
1157  */
1158 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1159 {
1160  int retval = -ENOMEM;
1161  int old_len = info->fix.smem_len;
1162  int new_len;
1163  unsigned char *old_fb = info->screen_base;
1164  unsigned char *new_fb;
1165  unsigned char *new_back = 0;
1166 
1167  pr_warn("Reallocating framebuffer. Addresses will change!\n");
1168 
1169  new_len = info->fix.line_length * info->var.yres;
1170 
1171  if (PAGE_ALIGN(new_len) > old_len) {
1172  /*
1173  * Alloc system memory for virtual framebuffer
1174  */
1175  new_fb = vmalloc(new_len);
1176  if (!new_fb) {
1177  pr_err("Virtual framebuffer alloc failed\n");
1178  goto error;
1179  }
1180 
1181  if (info->screen_base) {
1182  memcpy(new_fb, old_fb, old_len);
1183  vfree(info->screen_base);
1184  }
1185 
1186  info->screen_base = new_fb;
1187  info->fix.smem_len = PAGE_ALIGN(new_len);
1188  info->fix.smem_start = (unsigned long) new_fb;
1189  info->flags = udlfb_info_flags;
1190 
1191  /*
1192  * Second framebuffer copy to mirror the framebuffer state
1193  * on the physical USB device. We can function without this.
1194  * But with imperfect damage info we may send pixels over USB
1195  * that were, in fact, unchanged - wasting limited USB bandwidth
1196  */
1197  if (shadow)
1198  new_back = vzalloc(new_len);
1199  if (!new_back)
1200  pr_info("No shadow/backing buffer allocated\n");
1201  else {
1202  if (dev->backing_buffer)
1203  vfree(dev->backing_buffer);
1204  dev->backing_buffer = new_back;
1205  }
1206  }
1207 
1208  retval = 0;
1209 
1210 error:
1211  return retval;
1212 }
1213 
1214 /*
1215  * 1) Get EDID from hw, or use sw default
1216  * 2) Parse into various fb_info structs
1217  * 3) Allocate virtual framebuffer memory to back highest res mode
1218  *
1219  * Parses EDID into three places used by various parts of fbdev:
1220  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1221  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1222  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1223  *
1224  * If EDID is not readable/valid, then modelist is all VESA modes,
1225  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1226  * Returns 0 if successful
1227  */
1228 static int dlfb_setup_modes(struct dlfb_data *dev,
1229  struct fb_info *info,
1230  char *default_edid, size_t default_edid_size)
1231 {
1232  int i;
1233  const struct fb_videomode *default_vmode = NULL;
1234  int result = 0;
1235  char *edid;
1236  int tries = 3;
1237 
1238  if (info->dev) /* only use mutex if info has been registered */
1239  mutex_lock(&info->lock);
1240 
1241  edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1242  if (!edid) {
1243  result = -ENOMEM;
1244  goto error;
1245  }
1246 
1247  fb_destroy_modelist(&info->modelist);
1248  memset(&info->monspecs, 0, sizeof(info->monspecs));
1249 
1250  /*
1251  * Try to (re)read EDID from hardware first
1252  * EDID data may return, but not parse as valid
1253  * Try again a few times, in case of e.g. analog cable noise
1254  */
1255  while (tries--) {
1256 
1257  i = dlfb_get_edid(dev, edid, EDID_LENGTH);
1258 
1259  if (i >= EDID_LENGTH)
1260  fb_edid_to_monspecs(edid, &info->monspecs);
1261 
1262  if (info->monspecs.modedb_len > 0) {
1263  dev->edid = edid;
1264  dev->edid_size = i;
1265  break;
1266  }
1267  }
1268 
1269  /* If that fails, use a previously returned EDID if available */
1270  if (info->monspecs.modedb_len == 0) {
1271 
1272  pr_err("Unable to get valid EDID from device/display\n");
1273 
1274  if (dev->edid) {
1275  fb_edid_to_monspecs(dev->edid, &info->monspecs);
1276  if (info->monspecs.modedb_len > 0)
1277  pr_err("Using previously queried EDID\n");
1278  }
1279  }
1280 
1281  /* If that fails, use the default EDID we were handed */
1282  if (info->monspecs.modedb_len == 0) {
1283  if (default_edid_size >= EDID_LENGTH) {
1284  fb_edid_to_monspecs(default_edid, &info->monspecs);
1285  if (info->monspecs.modedb_len > 0) {
1286  memcpy(edid, default_edid, default_edid_size);
1287  dev->edid = edid;
1288  dev->edid_size = default_edid_size;
1289  pr_err("Using default/backup EDID\n");
1290  }
1291  }
1292  }
1293 
1294  /* If we've got modes, let's pick a best default mode */
1295  if (info->monspecs.modedb_len > 0) {
1296 
1297  for (i = 0; i < info->monspecs.modedb_len; i++) {
1298  if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1299  fb_add_videomode(&info->monspecs.modedb[i],
1300  &info->modelist);
1301  else {
1302  if (i == 0)
1303  /* if we've removed top/best mode */
1304  info->monspecs.misc
1305  &= ~FB_MISC_1ST_DETAIL;
1306  }
1307  }
1308 
1309  default_vmode = fb_find_best_display(&info->monspecs,
1310  &info->modelist);
1311  }
1312 
1313  /* If everything else has failed, fall back to safe default mode */
1314  if (default_vmode == NULL) {
1315 
1316  struct fb_videomode fb_vmode = {0};
1317 
1318  /*
1319  * Add the standard VESA modes to our modelist
1320  * Since we don't have EDID, there may be modes that
1321  * overspec monitor and/or are incorrect aspect ratio, etc.
1322  * But at least the user has a chance to choose
1323  */
1324  for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1325  if (dlfb_is_valid_mode((struct fb_videomode *)
1326  &vesa_modes[i], info))
1327  fb_add_videomode(&vesa_modes[i],
1328  &info->modelist);
1329  }
1330 
1331  /*
1332  * default to resolution safe for projectors
1333  * (since they are most common case without EDID)
1334  */
1335  fb_vmode.xres = 800;
1336  fb_vmode.yres = 600;
1337  fb_vmode.refresh = 60;
1338  default_vmode = fb_find_nearest_mode(&fb_vmode,
1339  &info->modelist);
1340  }
1341 
1342  /* If we have good mode and no active clients*/
1343  if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1344 
1345  fb_videomode_to_var(&info->var, default_vmode);
1346  dlfb_var_color_format(&info->var);
1347 
1348  /*
1349  * with mode size info, we can now alloc our framebuffer.
1350  */
1351  memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1352  info->fix.line_length = info->var.xres *
1353  (info->var.bits_per_pixel / 8);
1354 
1355  result = dlfb_realloc_framebuffer(dev, info);
1356 
1357  } else
1358  result = -EINVAL;
1359 
1360 error:
1361  if (edid && (dev->edid != edid))
1362  kfree(edid);
1363 
1364  if (info->dev)
1365  mutex_unlock(&info->lock);
1366 
1367  return result;
1368 }
1369 
1370 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1371  struct device_attribute *a, char *buf) {
1372  struct fb_info *fb_info = dev_get_drvdata(fbdev);
1373  struct dlfb_data *dev = fb_info->par;
1374  return snprintf(buf, PAGE_SIZE, "%u\n",
1375  atomic_read(&dev->bytes_rendered));
1376 }
1377 
1378 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1379  struct device_attribute *a, char *buf) {
1380  struct fb_info *fb_info = dev_get_drvdata(fbdev);
1381  struct dlfb_data *dev = fb_info->par;
1382  return snprintf(buf, PAGE_SIZE, "%u\n",
1383  atomic_read(&dev->bytes_identical));
1384 }
1385 
1386 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1387  struct device_attribute *a, char *buf) {
1388  struct fb_info *fb_info = dev_get_drvdata(fbdev);
1389  struct dlfb_data *dev = fb_info->par;
1390  return snprintf(buf, PAGE_SIZE, "%u\n",
1391  atomic_read(&dev->bytes_sent));
1392 }
1393 
1394 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1395  struct device_attribute *a, char *buf) {
1396  struct fb_info *fb_info = dev_get_drvdata(fbdev);
1397  struct dlfb_data *dev = fb_info->par;
1398  return snprintf(buf, PAGE_SIZE, "%u\n",
1399  atomic_read(&dev->cpu_kcycles_used));
1400 }
1401 
1402 static ssize_t edid_show(
1403  struct file *filp,
1404  struct kobject *kobj, struct bin_attribute *a,
1405  char *buf, loff_t off, size_t count) {
1406  struct device *fbdev = container_of(kobj, struct device, kobj);
1407  struct fb_info *fb_info = dev_get_drvdata(fbdev);
1408  struct dlfb_data *dev = fb_info->par;
1409 
1410  if (dev->edid == NULL)
1411  return 0;
1412 
1413  if ((off >= dev->edid_size) || (count > dev->edid_size))
1414  return 0;
1415 
1416  if (off + count > dev->edid_size)
1417  count = dev->edid_size - off;
1418 
1419  pr_info("sysfs edid copy %p to %p, %d bytes\n",
1420  dev->edid, buf, (int) count);
1421 
1422  memcpy(buf, dev->edid, count);
1423 
1424  return count;
1425 }
1426 
1427 static ssize_t edid_store(
1428  struct file *filp,
1429  struct kobject *kobj, struct bin_attribute *a,
1430  char *src, loff_t src_off, size_t src_size) {
1431  struct device *fbdev = container_of(kobj, struct device, kobj);
1432  struct fb_info *fb_info = dev_get_drvdata(fbdev);
1433  struct dlfb_data *dev = fb_info->par;
1434  int ret;
1435 
1436  /* We only support write of entire EDID at once, no offset*/
1437  if ((src_size != EDID_LENGTH) || (src_off != 0))
1438  return -EINVAL;
1439 
1440  ret = dlfb_setup_modes(dev, fb_info, src, src_size);
1441  if (ret)
1442  return ret;
1443 
1444  if (!dev->edid || memcmp(src, dev->edid, src_size))
1445  return -EINVAL;
1446 
1447  pr_info("sysfs written EDID is new default\n");
1448  dlfb_ops_set_par(fb_info);
1449  return src_size;
1450 }
1451 
1452 static ssize_t metrics_reset_store(struct device *fbdev,
1453  struct device_attribute *attr,
1454  const char *buf, size_t count)
1455 {
1456  struct fb_info *fb_info = dev_get_drvdata(fbdev);
1457  struct dlfb_data *dev = fb_info->par;
1458 
1459  atomic_set(&dev->bytes_rendered, 0);
1460  atomic_set(&dev->bytes_identical, 0);
1461  atomic_set(&dev->bytes_sent, 0);
1462  atomic_set(&dev->cpu_kcycles_used, 0);
1463 
1464  return count;
1465 }
1466 
1467 static struct bin_attribute edid_attr = {
1468  .attr.name = "edid",
1469  .attr.mode = 0666,
1470  .size = EDID_LENGTH,
1471  .read = edid_show,
1472  .write = edid_store
1473 };
1474 
1475 static struct device_attribute fb_device_attrs[] = {
1476  __ATTR_RO(metrics_bytes_rendered),
1477  __ATTR_RO(metrics_bytes_identical),
1478  __ATTR_RO(metrics_bytes_sent),
1479  __ATTR_RO(metrics_cpu_kcycles_used),
1480  __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1481 };
1482 
1483 /*
1484  * This is necessary before we can communicate with the display controller.
1485  */
1486 static int dlfb_select_std_channel(struct dlfb_data *dev)
1487 {
1488  int ret;
1489  u8 set_def_chn[] = { 0x57, 0xCD, 0xDC, 0xA7,
1490  0x1C, 0x88, 0x5E, 0x15,
1491  0x60, 0xFE, 0xC6, 0x97,
1492  0x16, 0x3D, 0x47, 0xF2 };
1493 
1494  ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1496  (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1497  set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1498  return ret;
1499 }
1500 
1501 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1502  struct usb_interface *interface)
1503 {
1504  char *desc;
1505  char *buf;
1506  char *desc_end;
1507 
1508  int total_len = 0;
1509 
1510  buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1511  if (!buf)
1512  return false;
1513  desc = buf;
1514 
1515  total_len = usb_get_descriptor(interface_to_usbdev(interface),
1516  0x5f, /* vendor specific */
1517  0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1518 
1519  /* if not found, look in configuration descriptor */
1520  if (total_len < 0) {
1521  if (0 == usb_get_extra_descriptor(interface->cur_altsetting,
1522  0x5f, &desc))
1523  total_len = (int) desc[0];
1524  }
1525 
1526  if (total_len > 5) {
1527  pr_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1528  "%02x %02x %02x %02x %02x %02x %02x\n",
1529  total_len, desc[0],
1530  desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1531  desc[7], desc[8], desc[9], desc[10]);
1532 
1533  if ((desc[0] != total_len) || /* descriptor length */
1534  (desc[1] != 0x5f) || /* vendor descriptor type */
1535  (desc[2] != 0x01) || /* version (2 bytes) */
1536  (desc[3] != 0x00) ||
1537  (desc[4] != total_len - 2)) /* length after type */
1538  goto unrecognized;
1539 
1540  desc_end = desc + total_len;
1541  desc += 5; /* the fixed header we've already parsed */
1542 
1543  while (desc < desc_end) {
1544  u8 length;
1545  u16 key;
1546 
1547  key = le16_to_cpu(*((u16 *) desc));
1548  desc += sizeof(u16);
1549  length = *desc;
1550  desc++;
1551 
1552  switch (key) {
1553  case 0x0200: { /* max_area */
1554  u32 max_area;
1555  max_area = le32_to_cpu(*((u32 *)desc));
1556  pr_warn("DL chip limited to %d pixel modes\n",
1557  max_area);
1558  dev->sku_pixel_limit = max_area;
1559  break;
1560  }
1561  default:
1562  break;
1563  }
1564  desc += length;
1565  }
1566  } else {
1567  pr_info("vendor descriptor not available (%d)\n", total_len);
1568  }
1569 
1570  goto success;
1571 
1572 unrecognized:
1573  /* allow udlfb to load for now even if firmware unrecognized */
1574  pr_err("Unrecognized vendor firmware descriptor\n");
1575 
1576 success:
1577  kfree(buf);
1578  return true;
1579 }
1580 
1581 static void dlfb_init_framebuffer_work(struct work_struct *work);
1582 
1583 static int dlfb_usb_probe(struct usb_interface *interface,
1584  const struct usb_device_id *id)
1585 {
1586  struct usb_device *usbdev;
1587  struct dlfb_data *dev = 0;
1588  int retval = -ENOMEM;
1589 
1590  /* usb initialization */
1591 
1592  usbdev = interface_to_usbdev(interface);
1593 
1594  dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1595  if (dev == NULL) {
1596  dev_err(&interface->dev, "dlfb_usb_probe: failed alloc of dev struct\n");
1597  goto error;
1598  }
1599 
1600  kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1601 
1602  dev->udev = usbdev;
1603  dev->gdev = &usbdev->dev; /* our generic struct device * */
1604  usb_set_intfdata(interface, dev);
1605 
1606  pr_info("%s %s - serial #%s\n",
1607  usbdev->manufacturer, usbdev->product, usbdev->serial);
1608  pr_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1609  usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1610  usbdev->descriptor.bcdDevice, dev);
1611  pr_info("console enable=%d\n", console);
1612  pr_info("fb_defio enable=%d\n", fb_defio);
1613  pr_info("shadow enable=%d\n", shadow);
1614 
1615  dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1616 
1617  if (!dlfb_parse_vendor_descriptor(dev, interface)) {
1618  pr_err("firmware not recognized. Assume incompatible device\n");
1619  goto error;
1620  }
1621 
1622  if (pixel_limit) {
1623  pr_warn("DL chip limit of %d overriden"
1624  " by module param to %d\n",
1625  dev->sku_pixel_limit, pixel_limit);
1626  dev->sku_pixel_limit = pixel_limit;
1627  }
1628 
1629 
1630  if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1631  retval = -ENOMEM;
1632  pr_err("dlfb_alloc_urb_list failed\n");
1633  goto error;
1634  }
1635 
1636  kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1637 
1638  /* We don't register a new USB class. Our client interface is fbdev */
1639 
1640  /* Workitem keep things fast & simple during USB enumeration */
1642  dlfb_init_framebuffer_work);
1644 
1645  return 0;
1646 
1647 error:
1648  if (dev) {
1649 
1650  kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1651  kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1652 
1653  /* dev has been deallocated. Do not dereference */
1654  }
1655 
1656  return retval;
1657 }
1658 
1659 static void dlfb_init_framebuffer_work(struct work_struct *work)
1660 {
1661  struct dlfb_data *dev = container_of(work, struct dlfb_data,
1662  init_framebuffer_work.work);
1663  struct fb_info *info;
1664  int retval;
1665  int i;
1666 
1667  /* allocates framebuffer driver structure, not framebuffer memory */
1668  info = framebuffer_alloc(0, dev->gdev);
1669  if (!info) {
1670  retval = -ENOMEM;
1671  pr_err("framebuffer_alloc failed\n");
1672  goto error;
1673  }
1674 
1675  dev->info = info;
1676  info->par = dev;
1677  info->pseudo_palette = dev->pseudo_palette;
1678  info->fbops = &dlfb_ops;
1679 
1680  retval = fb_alloc_cmap(&info->cmap, 256, 0);
1681  if (retval < 0) {
1682  pr_err("fb_alloc_cmap failed %x\n", retval);
1683  goto error;
1684  }
1685 
1687  dlfb_free_framebuffer_work);
1688 
1689  INIT_LIST_HEAD(&info->modelist);
1690 
1691  retval = dlfb_setup_modes(dev, info, NULL, 0);
1692  if (retval != 0) {
1693  pr_err("unable to find common mode for display and adapter\n");
1694  goto error;
1695  }
1696 
1697  /* ready to begin using device */
1698 
1699  atomic_set(&dev->usb_active, 1);
1700  dlfb_select_std_channel(dev);
1701 
1702  dlfb_ops_check_var(&info->var, info);
1703  dlfb_ops_set_par(info);
1704 
1705  retval = register_framebuffer(info);
1706  if (retval < 0) {
1707  pr_err("register_framebuffer failed %d\n", retval);
1708  goto error;
1709  }
1710 
1711  for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
1712  retval = device_create_file(info->dev, &fb_device_attrs[i]);
1713  if (retval) {
1714  pr_warn("device_create_file failed %d\n", retval);
1715  }
1716  }
1717 
1718  retval = device_create_bin_file(info->dev, &edid_attr);
1719  if (retval) {
1720  pr_warn("device_create_bin_file failed %d\n", retval);
1721  }
1722 
1723  pr_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1724  " Using %dK framebuffer memory\n", info->node,
1725  info->var.xres, info->var.yres,
1726  ((dev->backing_buffer) ?
1727  info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1728  return;
1729 
1730 error:
1731  dlfb_free_framebuffer(dev);
1732 }
1733 
1734 static void dlfb_usb_disconnect(struct usb_interface *interface)
1735 {
1736  struct dlfb_data *dev;
1737  struct fb_info *info;
1738  int i;
1739 
1740  dev = usb_get_intfdata(interface);
1741  info = dev->info;
1742 
1743  pr_info("USB disconnect starting\n");
1744 
1745  /* we virtualize until all fb clients release. Then we free */
1746  dev->virtualized = true;
1747 
1748  /* When non-active we'll update virtual framebuffer, but no new urbs */
1749  atomic_set(&dev->usb_active, 0);
1750 
1751  /* this function will wait for all in-flight urbs to complete */
1752  dlfb_free_urb_list(dev);
1753 
1754  if (info) {
1755  /* remove udlfb's sysfs interfaces */
1756  for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1757  device_remove_file(info->dev, &fb_device_attrs[i]);
1758  device_remove_bin_file(info->dev, &edid_attr);
1759  unlink_framebuffer(info);
1760  }
1761 
1762  usb_set_intfdata(interface, NULL);
1763  dev->udev = NULL;
1764  dev->gdev = NULL;
1765 
1766  /* if clients still have us open, will be freed on last close */
1767  if (dev->fb_count == 0)
1769 
1770  /* release reference taken by kref_init in probe() */
1771  kref_put(&dev->kref, dlfb_free);
1772 
1773  /* consider dlfb_data freed */
1774 
1775  return;
1776 }
1777 
1778 static struct usb_driver dlfb_driver = {
1779  .name = "udlfb",
1780  .probe = dlfb_usb_probe,
1781  .disconnect = dlfb_usb_disconnect,
1782  .id_table = id_table,
1783 };
1784 
1785 module_usb_driver(dlfb_driver);
1786 
1787 static void dlfb_urb_completion(struct urb *urb)
1788 {
1789  struct urb_node *unode = urb->context;
1790  struct dlfb_data *dev = unode->dev;
1791  unsigned long flags;
1792 
1793  /* sync/async unlink faults aren't errors */
1794  if (urb->status) {
1795  if (!(urb->status == -ENOENT ||
1796  urb->status == -ECONNRESET ||
1797  urb->status == -ESHUTDOWN)) {
1798  pr_err("%s - nonzero write bulk status received: %d\n",
1799  __func__, urb->status);
1800  atomic_set(&dev->lost_pixels, 1);
1801  }
1802  }
1803 
1804  urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1805 
1806  spin_lock_irqsave(&dev->urbs.lock, flags);
1807  list_add_tail(&unode->entry, &dev->urbs.list);
1808  dev->urbs.available++;
1809  spin_unlock_irqrestore(&dev->urbs.lock, flags);
1810 
1811  /*
1812  * When using fb_defio, we deadlock if up() is called
1813  * while another is waiting. So queue to another process.
1814  */
1815  if (fb_defio)
1817  else
1818  up(&dev->urbs.limit_sem);
1819 }
1820 
1821 static void dlfb_free_urb_list(struct dlfb_data *dev)
1822 {
1823  int count = dev->urbs.count;
1824  struct list_head *node;
1825  struct urb_node *unode;
1826  struct urb *urb;
1827  int ret;
1828  unsigned long flags;
1829 
1830  pr_notice("Freeing all render urbs\n");
1831 
1832  /* keep waiting and freeing, until we've got 'em all */
1833  while (count--) {
1834 
1835  /* Getting interrupted means a leak, but ok at disconnect */
1836  ret = down_interruptible(&dev->urbs.limit_sem);
1837  if (ret)
1838  break;
1839 
1840  spin_lock_irqsave(&dev->urbs.lock, flags);
1841 
1842  node = dev->urbs.list.next; /* have reserved one with sem */
1843  list_del_init(node);
1844 
1845  spin_unlock_irqrestore(&dev->urbs.lock, flags);
1846 
1847  unode = list_entry(node, struct urb_node, entry);
1848  urb = unode->urb;
1849 
1850  /* Free each separately allocated piece */
1851  usb_free_coherent(urb->dev, dev->urbs.size,
1852  urb->transfer_buffer, urb->transfer_dma);
1853  usb_free_urb(urb);
1854  kfree(node);
1855  }
1856 
1857  dev->urbs.count = 0;
1858 }
1859 
1860 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1861 {
1862  int i = 0;
1863  struct urb *urb;
1864  struct urb_node *unode;
1865  char *buf;
1866 
1867  spin_lock_init(&dev->urbs.lock);
1868 
1869  dev->urbs.size = size;
1870  INIT_LIST_HEAD(&dev->urbs.list);
1871 
1872  while (i < count) {
1873  unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1874  if (!unode)
1875  break;
1876  unode->dev = dev;
1877 
1879  dlfb_release_urb_work);
1880 
1881  urb = usb_alloc_urb(0, GFP_KERNEL);
1882  if (!urb) {
1883  kfree(unode);
1884  break;
1885  }
1886  unode->urb = urb;
1887 
1889  &urb->transfer_dma);
1890  if (!buf) {
1891  kfree(unode);
1892  usb_free_urb(urb);
1893  break;
1894  }
1895 
1896  /* urb->transfer_buffer_length set to actual before submit */
1897  usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1898  buf, size, dlfb_urb_completion, unode);
1899  urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1900 
1901  list_add_tail(&unode->entry, &dev->urbs.list);
1902 
1903  i++;
1904  }
1905 
1906  sema_init(&dev->urbs.limit_sem, i);
1907  dev->urbs.count = i;
1908  dev->urbs.available = i;
1909 
1910  pr_notice("allocated %d %d byte urbs\n", i, (int) size);
1911 
1912  return i;
1913 }
1914 
1915 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1916 {
1917  int ret = 0;
1918  struct list_head *entry;
1919  struct urb_node *unode;
1920  struct urb *urb = NULL;
1921  unsigned long flags;
1922 
1923  /* Wait for an in-flight buffer to complete and get re-queued */
1924  ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1925  if (ret) {
1926  atomic_set(&dev->lost_pixels, 1);
1927  pr_warn("wait for urb interrupted: %x available: %d\n",
1928  ret, dev->urbs.available);
1929  goto error;
1930  }
1931 
1932  spin_lock_irqsave(&dev->urbs.lock, flags);
1933 
1934  BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1935  entry = dev->urbs.list.next;
1936  list_del_init(entry);
1937  dev->urbs.available--;
1938 
1939  spin_unlock_irqrestore(&dev->urbs.lock, flags);
1940 
1941  unode = list_entry(entry, struct urb_node, entry);
1942  urb = unode->urb;
1943 
1944 error:
1945  return urb;
1946 }
1947 
1948 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1949 {
1950  int ret;
1951 
1952  BUG_ON(len > dev->urbs.size);
1953 
1954  urb->transfer_buffer_length = len; /* set to actual payload len */
1955  ret = usb_submit_urb(urb, GFP_KERNEL);
1956  if (ret) {
1957  dlfb_urb_completion(urb); /* because no one else will */
1958  atomic_set(&dev->lost_pixels, 1);
1959  pr_err("usb_submit_urb error %x\n", ret);
1960  }
1961  return ret;
1962 }
1963 
1965 MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
1966 
1967 module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1968 MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
1969 
1971 MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
1972 
1973 module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1974 MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)");
1975 
1976 MODULE_AUTHOR("Roberto De Ioris <[email protected]>, "
1977  "Jaya Kumar <[email protected]>, "
1978  "Bernie Thompson <[email protected]>");
1979 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1980 MODULE_LICENSE("GPL");
1981