Merge branch 'staging-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[linux-2.6.git] / drivers / video / udlfb.c
1 /*
2  * udlfb.c -- Framebuffer driver for DisplayLink USB controller
3  *
4  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
5  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
6  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License v2. See the file COPYING in the main directory of this archive for
10  * more details.
11  *
12  * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
13  * usb-skeleton by GregKH.
14  *
15  * Device-specific portions based on information from Displaylink, with work
16  * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
17  */
18
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/init.h>
24 #include <linux/usb.h>
25 #include <linux/uaccess.h>
26 #include <linux/mm.h>
27 #include <linux/fb.h>
28 #include <linux/vmalloc.h>
29 #include <linux/slab.h>
30 #include <linux/delay.h>
31 #include <video/udlfb.h>
32 #include "edid.h"
33
34 static struct fb_fix_screeninfo dlfb_fix = {
35         .id =           "udlfb",
36         .type =         FB_TYPE_PACKED_PIXELS,
37         .visual =       FB_VISUAL_TRUECOLOR,
38         .xpanstep =     0,
39         .ypanstep =     0,
40         .ywrapstep =    0,
41         .accel =        FB_ACCEL_NONE,
42 };
43
44 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
45                 FBINFO_VIRTFB |
46                 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
47                 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
48
49 /*
50  * There are many DisplayLink-based products, all with unique PIDs. We are able
51  * to support all volume ones (circa 2009) with a single driver, so we match
52  * globally on VID. TODO: Probe() needs to detect when we might be running
53  * "future" chips, and bail on those, so a compatible driver can match.
54  */
55 static struct usb_device_id id_table[] = {
56         {.idVendor = 0x17e9, .match_flags = USB_DEVICE_ID_MATCH_VENDOR,},
57         {},
58 };
59 MODULE_DEVICE_TABLE(usb, id_table);
60
61 /* module options */
62 static int console;   /* Optionally allow fbcon to consume first framebuffer */
63 static int fb_defio;  /* Optionally enable experimental fb_defio mmap support */
64
65 /* dlfb keeps a list of urbs for efficient bulk transfers */
66 static void dlfb_urb_completion(struct urb *urb);
67 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
68 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
69 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
70 static void dlfb_free_urb_list(struct dlfb_data *dev);
71
72 /*
73  * All DisplayLink bulk operations start with 0xAF, followed by specific code
74  * All operations are written to buffers which then later get sent to device
75  */
76 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
77 {
78         *buf++ = 0xAF;
79         *buf++ = 0x20;
80         *buf++ = reg;
81         *buf++ = val;
82         return buf;
83 }
84
85 static char *dlfb_vidreg_lock(char *buf)
86 {
87         return dlfb_set_register(buf, 0xFF, 0x00);
88 }
89
90 static char *dlfb_vidreg_unlock(char *buf)
91 {
92         return dlfb_set_register(buf, 0xFF, 0xFF);
93 }
94
95 /*
96  * On/Off for driving the DisplayLink framebuffer to the display
97  *  0x00 H and V sync on
98  *  0x01 H and V sync off (screen blank but powered)
99  *  0x07 DPMS powerdown (requires modeset to come back)
100  */
101 static char *dlfb_enable_hvsync(char *buf, bool enable)
102 {
103         if (enable)
104                 return dlfb_set_register(buf, 0x1F, 0x00);
105         else
106                 return dlfb_set_register(buf, 0x1F, 0x07);
107 }
108
109 static char *dlfb_set_color_depth(char *buf, u8 selection)
110 {
111         return dlfb_set_register(buf, 0x00, selection);
112 }
113
114 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
115 {
116         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
117         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
118         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
119         return dlfb_set_register(wrptr, 0x22, base);
120 }
121
122 /*
123  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
124  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
125  */
126 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
127 {
128         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
129         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
130         return dlfb_set_register(wrptr, 0x28, base);
131 }
132
133 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
134 {
135         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
136         return dlfb_set_register(wrptr, reg+1, value);
137 }
138
139 /*
140  * This is kind of weird because the controller takes some
141  * register values in a different byte order than other registers.
142  */
143 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
144 {
145         wrptr = dlfb_set_register(wrptr, reg, value);
146         return dlfb_set_register(wrptr, reg+1, value >> 8);
147 }
148
149 /*
150  * LFSR is linear feedback shift register. The reason we have this is
151  * because the display controller needs to minimize the clock depth of
152  * various counters used in the display path. So this code reverses the
153  * provided value into the lfsr16 value by counting backwards to get
154  * the value that needs to be set in the hardware comparator to get the
155  * same actual count. This makes sense once you read above a couple of
156  * times and think about it from a hardware perspective.
157  */
158 static u16 dlfb_lfsr16(u16 actual_count)
159 {
160         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
161
162         while (actual_count--) {
163                 lv =     ((lv << 1) |
164                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
165                         & 0xFFFF;
166         }
167
168         return (u16) lv;
169 }
170
171 /*
172  * This does LFSR conversion on the value that is to be written.
173  * See LFSR explanation above for more detail.
174  */
175 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
176 {
177         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
178 }
179
180 /*
181  * This takes a standard fbdev screeninfo struct and all of its monitor mode
182  * details and converts them into the DisplayLink equivalent register commands.
183  */
184 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
185 {
186         u16 xds, yds;
187         u16 xde, yde;
188         u16 yec;
189
190         /* x display start */
191         xds = var->left_margin + var->hsync_len;
192         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
193         /* x display end */
194         xde = xds + var->xres;
195         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
196
197         /* y display start */
198         yds = var->upper_margin + var->vsync_len;
199         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
200         /* y display end */
201         yde = yds + var->yres;
202         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
203
204         /* x end count is active + blanking - 1 */
205         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
206                         xde + var->right_margin - 1);
207
208         /* libdlo hardcodes hsync start to 1 */
209         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
210
211         /* hsync end is width of sync pulse + 1 */
212         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
213
214         /* hpixels is active pixels */
215         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
216
217         /* yendcount is vertical active + vertical blanking */
218         yec = var->yres + var->upper_margin + var->lower_margin +
219                         var->vsync_len;
220         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
221
222         /* libdlo hardcodes vsync start to 0 */
223         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
224
225         /* vsync end is width of vsync pulse */
226         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
227
228         /* vpixels is active pixels */
229         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
230
231         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
232         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
233                         200*1000*1000/var->pixclock);
234
235         return wrptr;
236 }
237
238 /*
239  * This takes a standard fbdev screeninfo struct that was fetched or prepared
240  * and then generates the appropriate command sequence that then drives the
241  * display controller.
242  */
243 static int dlfb_set_video_mode(struct dlfb_data *dev,
244                                 struct fb_var_screeninfo *var)
245 {
246         char *buf;
247         char *wrptr;
248         int retval = 0;
249         int writesize;
250         struct urb *urb;
251
252         if (!atomic_read(&dev->usb_active))
253                 return -EPERM;
254
255         urb = dlfb_get_urb(dev);
256         if (!urb)
257                 return -ENOMEM;
258
259         buf = (char *) urb->transfer_buffer;
260
261         /*
262         * This first section has to do with setting the base address on the
263         * controller * associated with the display. There are 2 base
264         * pointers, currently, we only * use the 16 bpp segment.
265         */
266         wrptr = dlfb_vidreg_lock(buf);
267         wrptr = dlfb_set_color_depth(wrptr, 0x00);
268         /* set base for 16bpp segment to 0 */
269         wrptr = dlfb_set_base16bpp(wrptr, 0);
270         /* set base for 8bpp segment to end of fb */
271         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
272
273         wrptr = dlfb_set_vid_cmds(wrptr, var);
274         wrptr = dlfb_enable_hvsync(wrptr, true);
275         wrptr = dlfb_vidreg_unlock(wrptr);
276
277         writesize = wrptr - buf;
278
279         retval = dlfb_submit_urb(dev, urb, writesize);
280
281         return retval;
282 }
283
284 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
285 {
286         unsigned long start = vma->vm_start;
287         unsigned long size = vma->vm_end - vma->vm_start;
288         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
289         unsigned long page, pos;
290
291         if (offset + size > info->fix.smem_len)
292                 return -EINVAL;
293
294         pos = (unsigned long)info->fix.smem_start + offset;
295
296         pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
297                   pos, size);
298
299         while (size > 0) {
300                 page = vmalloc_to_pfn((void *)pos);
301                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
302                         return -EAGAIN;
303
304                 start += PAGE_SIZE;
305                 pos += PAGE_SIZE;
306                 if (size > PAGE_SIZE)
307                         size -= PAGE_SIZE;
308                 else
309                         size = 0;
310         }
311
312         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
313         return 0;
314 }
315
316 /*
317  * Trims identical data from front and back of line
318  * Sets new front buffer address and width
319  * And returns byte count of identical pixels
320  * Assumes CPU natural alignment (unsigned long)
321  * for back and front buffer ptrs and width
322  */
323 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
324 {
325         int j, k;
326         const unsigned long *back = (const unsigned long *) bback;
327         const unsigned long *front = (const unsigned long *) *bfront;
328         const int width = *width_bytes / sizeof(unsigned long);
329         int identical = width;
330         int start = width;
331         int end = width;
332
333         prefetch((void *) front);
334         prefetch((void *) back);
335
336         for (j = 0; j < width; j++) {
337                 if (back[j] != front[j]) {
338                         start = j;
339                         break;
340                 }
341         }
342
343         for (k = width - 1; k > j; k--) {
344                 if (back[k] != front[k]) {
345                         end = k+1;
346                         break;
347                 }
348         }
349
350         identical = start + (width - end);
351         *bfront = (u8 *) &front[start];
352         *width_bytes = (end - start) * sizeof(unsigned long);
353
354         return identical * sizeof(unsigned long);
355 }
356
357 /*
358  * Render a command stream for an encoded horizontal line segment of pixels.
359  *
360  * A command buffer holds several commands.
361  * It always begins with a fresh command header
362  * (the protocol doesn't require this, but we enforce it to allow
363  * multiple buffers to be potentially encoded and sent in parallel).
364  * A single command encodes one contiguous horizontal line of pixels
365  *
366  * The function relies on the client to do all allocation, so that
367  * rendering can be done directly to output buffers (e.g. USB URBs).
368  * The function fills the supplied command buffer, providing information
369  * on where it left off, so the client may call in again with additional
370  * buffers if the line will take several buffers to complete.
371  *
372  * A single command can transmit a maximum of 256 pixels,
373  * regardless of the compression ratio (protocol design limit).
374  * To the hardware, 0 for a size byte means 256
375  *
376  * Rather than 256 pixel commands which are either rl or raw encoded,
377  * the rlx command simply assumes alternating raw and rl spans within one cmd.
378  * This has a slightly larger header overhead, but produces more even results.
379  * It also processes all data (read and write) in a single pass.
380  * Performance benchmarks of common cases show it having just slightly better
381  * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
382  * But for very rl friendly data, will compress not quite as well.
383  */
384 static void dlfb_compress_hline(
385         const uint16_t **pixel_start_ptr,
386         const uint16_t *const pixel_end,
387         uint32_t *device_address_ptr,
388         uint8_t **command_buffer_ptr,
389         const uint8_t *const cmd_buffer_end)
390 {
391         const uint16_t *pixel = *pixel_start_ptr;
392         uint32_t dev_addr  = *device_address_ptr;
393         uint8_t *cmd = *command_buffer_ptr;
394         const int bpp = 2;
395
396         while ((pixel_end > pixel) &&
397                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
398                 uint8_t *raw_pixels_count_byte = 0;
399                 uint8_t *cmd_pixels_count_byte = 0;
400                 const uint16_t *raw_pixel_start = 0;
401                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
402
403                 prefetchw((void *) cmd); /* pull in one cache line at least */
404
405                 *cmd++ = 0xAF;
406                 *cmd++ = 0x6B;
407                 *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
408                 *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
409                 *cmd++ = (uint8_t) ((dev_addr) & 0xFF);
410
411                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
412                 cmd_pixel_start = pixel;
413
414                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
415                 raw_pixel_start = pixel;
416
417                 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
418                         min((int)(pixel_end - pixel),
419                             (int)(cmd_buffer_end - cmd) / bpp));
420
421                 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
422
423                 while (pixel < cmd_pixel_end) {
424                         const uint16_t * const repeating_pixel = pixel;
425
426                         *(uint16_t *)cmd = cpu_to_be16p(pixel);
427                         cmd += 2;
428                         pixel++;
429
430                         if (unlikely((pixel < cmd_pixel_end) &&
431                                      (*pixel == *repeating_pixel))) {
432                                 /* go back and fill in raw pixel count */
433                                 *raw_pixels_count_byte = ((repeating_pixel -
434                                                 raw_pixel_start) + 1) & 0xFF;
435
436                                 while ((pixel < cmd_pixel_end)
437                                        && (*pixel == *repeating_pixel)) {
438                                         pixel++;
439                                 }
440
441                                 /* immediately after raw data is repeat byte */
442                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
443
444                                 /* Then start another raw pixel span */
445                                 raw_pixel_start = pixel;
446                                 raw_pixels_count_byte = cmd++;
447                         }
448                 }
449
450                 if (pixel > raw_pixel_start) {
451                         /* finalize last RAW span */
452                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
453                 }
454
455                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
456                 dev_addr += (pixel - cmd_pixel_start) * bpp;
457         }
458
459         if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
460                 /* Fill leftover bytes with no-ops */
461                 if (cmd_buffer_end > cmd)
462                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
463                 cmd = (uint8_t *) cmd_buffer_end;
464         }
465
466         *command_buffer_ptr = cmd;
467         *pixel_start_ptr = pixel;
468         *device_address_ptr = dev_addr;
469
470         return;
471 }
472
473 /*
474  * There are 3 copies of every pixel: The front buffer that the fbdev
475  * client renders to, the actual framebuffer across the USB bus in hardware
476  * (that we can only write to, slowly, and can never read), and (optionally)
477  * our shadow copy that tracks what's been sent to that hardware buffer.
478  */
479 static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
480                               const char *front, char **urb_buf_ptr,
481                               u32 byte_offset, u32 byte_width,
482                               int *ident_ptr, int *sent_ptr)
483 {
484         const u8 *line_start, *line_end, *next_pixel;
485         u32 dev_addr = dev->base16 + byte_offset;
486         struct urb *urb = *urb_ptr;
487         u8 *cmd = *urb_buf_ptr;
488         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
489
490         line_start = (u8 *) (front + byte_offset);
491         next_pixel = line_start;
492         line_end = next_pixel + byte_width;
493
494         if (dev->backing_buffer) {
495                 int offset;
496                 const u8 *back_start = (u8 *) (dev->backing_buffer
497                                                 + byte_offset);
498
499                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
500                         &byte_width);
501
502                 offset = next_pixel - line_start;
503                 line_end = next_pixel + byte_width;
504                 dev_addr += offset;
505                 back_start += offset;
506                 line_start += offset;
507
508                 memcpy((char *)back_start, (char *) line_start,
509                        byte_width);
510         }
511
512         while (next_pixel < line_end) {
513
514                 dlfb_compress_hline((const uint16_t **) &next_pixel,
515                              (const uint16_t *) line_end, &dev_addr,
516                         (u8 **) &cmd, (u8 *) cmd_end);
517
518                 if (cmd >= cmd_end) {
519                         int len = cmd - (u8 *) urb->transfer_buffer;
520                         if (dlfb_submit_urb(dev, urb, len))
521                                 return 1; /* lost pixels is set */
522                         *sent_ptr += len;
523                         urb = dlfb_get_urb(dev);
524                         if (!urb)
525                                 return 1; /* lost_pixels is set */
526                         *urb_ptr = urb;
527                         cmd = urb->transfer_buffer;
528                         cmd_end = &cmd[urb->transfer_buffer_length];
529                 }
530         }
531
532         *urb_buf_ptr = cmd;
533
534         return 0;
535 }
536
537 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
538                int width, int height, char *data)
539 {
540         int i, ret;
541         char *cmd;
542         cycles_t start_cycles, end_cycles;
543         int bytes_sent = 0;
544         int bytes_identical = 0;
545         struct urb *urb;
546         int aligned_x;
547
548         start_cycles = get_cycles();
549
550         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
551         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
552         x = aligned_x;
553
554         if ((width <= 0) ||
555             (x + width > dev->info->var.xres) ||
556             (y + height > dev->info->var.yres))
557                 return -EINVAL;
558
559         if (!atomic_read(&dev->usb_active))
560                 return 0;
561
562         urb = dlfb_get_urb(dev);
563         if (!urb)
564                 return 0;
565         cmd = urb->transfer_buffer;
566
567         for (i = y; i < y + height ; i++) {
568                 const int line_offset = dev->info->fix.line_length * i;
569                 const int byte_offset = line_offset + (x * BPP);
570
571                 if (dlfb_render_hline(dev, &urb,
572                                       (char *) dev->info->fix.smem_start,
573                                       &cmd, byte_offset, width * BPP,
574                                       &bytes_identical, &bytes_sent))
575                         goto error;
576         }
577
578         if (cmd > (char *) urb->transfer_buffer) {
579                 /* Send partial buffer remaining before exiting */
580                 int len = cmd - (char *) urb->transfer_buffer;
581                 ret = dlfb_submit_urb(dev, urb, len);
582                 bytes_sent += len;
583         } else
584                 dlfb_urb_completion(urb);
585
586 error:
587         atomic_add(bytes_sent, &dev->bytes_sent);
588         atomic_add(bytes_identical, &dev->bytes_identical);
589         atomic_add(width*height*2, &dev->bytes_rendered);
590         end_cycles = get_cycles();
591         atomic_add(((unsigned int) ((end_cycles - start_cycles)
592                     >> 10)), /* Kcycles */
593                    &dev->cpu_kcycles_used);
594
595         return 0;
596 }
597
598 /*
599  * Path triggered by usermode clients who write to filesystem
600  * e.g. cat filename > /dev/fb1
601  * Not used by X Windows or text-mode console. But useful for testing.
602  * Slow because of extra copy and we must assume all pixels dirty.
603  */
604 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
605                           size_t count, loff_t *ppos)
606 {
607         ssize_t result;
608         struct dlfb_data *dev = info->par;
609         u32 offset = (u32) *ppos;
610
611         result = fb_sys_write(info, buf, count, ppos);
612
613         if (result > 0) {
614                 int start = max((int)(offset / info->fix.line_length) - 1, 0);
615                 int lines = min((u32)((result / info->fix.line_length) + 1),
616                                 (u32)info->var.yres);
617
618                 dlfb_handle_damage(dev, 0, start, info->var.xres,
619                         lines, info->screen_base);
620         }
621
622         return result;
623 }
624
625 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
626 static void dlfb_ops_copyarea(struct fb_info *info,
627                                 const struct fb_copyarea *area)
628 {
629
630         struct dlfb_data *dev = info->par;
631
632         sys_copyarea(info, area);
633
634         dlfb_handle_damage(dev, area->dx, area->dy,
635                         area->width, area->height, info->screen_base);
636 }
637
638 static void dlfb_ops_imageblit(struct fb_info *info,
639                                 const struct fb_image *image)
640 {
641         struct dlfb_data *dev = info->par;
642
643         sys_imageblit(info, image);
644
645         dlfb_handle_damage(dev, image->dx, image->dy,
646                         image->width, image->height, info->screen_base);
647 }
648
649 static void dlfb_ops_fillrect(struct fb_info *info,
650                           const struct fb_fillrect *rect)
651 {
652         struct dlfb_data *dev = info->par;
653
654         sys_fillrect(info, rect);
655
656         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
657                               rect->height, info->screen_base);
658 }
659
660 /*
661  * NOTE: fb_defio.c is holding info->fbdefio.mutex
662  *   Touching ANY framebuffer memory that triggers a page fault
663  *   in fb_defio will cause a deadlock, when it also tries to
664  *   grab the same mutex.
665  */
666 static void dlfb_dpy_deferred_io(struct fb_info *info,
667                                 struct list_head *pagelist)
668 {
669         struct page *cur;
670         struct fb_deferred_io *fbdefio = info->fbdefio;
671         struct dlfb_data *dev = info->par;
672         struct urb *urb;
673         char *cmd;
674         cycles_t start_cycles, end_cycles;
675         int bytes_sent = 0;
676         int bytes_identical = 0;
677         int bytes_rendered = 0;
678
679         if (!fb_defio)
680                 return;
681
682         if (!atomic_read(&dev->usb_active))
683                 return;
684
685         start_cycles = get_cycles();
686
687         urb = dlfb_get_urb(dev);
688         if (!urb)
689                 return;
690
691         cmd = urb->transfer_buffer;
692
693         /* walk the written page list and render each to device */
694         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
695
696                 if (dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
697                                   &cmd, cur->index << PAGE_SHIFT,
698                                   PAGE_SIZE, &bytes_identical, &bytes_sent))
699                         goto error;
700                 bytes_rendered += PAGE_SIZE;
701         }
702
703         if (cmd > (char *) urb->transfer_buffer) {
704                 /* Send partial buffer remaining before exiting */
705                 int len = cmd - (char *) urb->transfer_buffer;
706                 dlfb_submit_urb(dev, urb, len);
707                 bytes_sent += len;
708         } else
709                 dlfb_urb_completion(urb);
710
711 error:
712         atomic_add(bytes_sent, &dev->bytes_sent);
713         atomic_add(bytes_identical, &dev->bytes_identical);
714         atomic_add(bytes_rendered, &dev->bytes_rendered);
715         end_cycles = get_cycles();
716         atomic_add(((unsigned int) ((end_cycles - start_cycles)
717                     >> 10)), /* Kcycles */
718                    &dev->cpu_kcycles_used);
719 }
720
721 static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
722 {
723         int i;
724         int ret;
725         char *rbuf;
726
727         rbuf = kmalloc(2, GFP_KERNEL);
728         if (!rbuf)
729                 return 0;
730
731         for (i = 0; i < len; i++) {
732                 ret = usb_control_msg(dev->udev,
733                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
734                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
735                                     HZ);
736                 if (ret < 1) {
737                         pr_err("Read EDID byte %d failed err %x\n", i, ret);
738                         i--;
739                         break;
740                 }
741                 edid[i] = rbuf[1];
742         }
743
744         kfree(rbuf);
745
746         return i;
747 }
748
749 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
750                                 unsigned long arg)
751 {
752
753         struct dlfb_data *dev = info->par;
754         struct dloarea *area = NULL;
755
756         if (!atomic_read(&dev->usb_active))
757                 return 0;
758
759         /* TODO: Update X server to get this from sysfs instead */
760         if (cmd == DLFB_IOCTL_RETURN_EDID) {
761                 char *edid = (char *)arg;
762                 if (copy_to_user(edid, dev->edid, dev->edid_size))
763                         return -EFAULT;
764                 return 0;
765         }
766
767         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
768         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
769
770                 /*
771                  * If we have a damage-aware client, turn fb_defio "off"
772                  * To avoid perf imact of unecessary page fault handling.
773                  * Done by resetting the delay for this fb_info to a very
774                  * long period. Pages will become writable and stay that way.
775                  * Reset to normal value when all clients have closed this fb.
776                  */
777                 if (info->fbdefio)
778                         info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
779
780                 area = (struct dloarea *)arg;
781
782                 if (area->x < 0)
783                         area->x = 0;
784
785                 if (area->x > info->var.xres)
786                         area->x = info->var.xres;
787
788                 if (area->y < 0)
789                         area->y = 0;
790
791                 if (area->y > info->var.yres)
792                         area->y = info->var.yres;
793
794                 dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
795                            info->screen_base);
796         }
797
798         return 0;
799 }
800
801 /* taken from vesafb */
802 static int
803 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
804                unsigned blue, unsigned transp, struct fb_info *info)
805 {
806         int err = 0;
807
808         if (regno >= info->cmap.len)
809                 return 1;
810
811         if (regno < 16) {
812                 if (info->var.red.offset == 10) {
813                         /* 1:5:5:5 */
814                         ((u32 *) (info->pseudo_palette))[regno] =
815                             ((red & 0xf800) >> 1) |
816                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
817                 } else {
818                         /* 0:5:6:5 */
819                         ((u32 *) (info->pseudo_palette))[regno] =
820                             ((red & 0xf800)) |
821                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
822                 }
823         }
824
825         return err;
826 }
827
828 /*
829  * It's common for several clients to have framebuffer open simultaneously.
830  * e.g. both fbcon and X. Makes things interesting.
831  * Assumes caller is holding info->lock (for open and release at least)
832  */
833 static int dlfb_ops_open(struct fb_info *info, int user)
834 {
835         struct dlfb_data *dev = info->par;
836
837         /*
838          * fbcon aggressively connects to first framebuffer it finds,
839          * preventing other clients (X) from working properly. Usually
840          * not what the user wants. Fail by default with option to enable.
841          */
842         if ((user == 0) & (!console))
843                 return -EBUSY;
844
845         /* If the USB device is gone, we don't accept new opens */
846         if (dev->virtualized)
847                 return -ENODEV;
848
849         dev->fb_count++;
850
851         kref_get(&dev->kref);
852
853         if (fb_defio && (info->fbdefio == NULL)) {
854                 /* enable defio at last moment if not disabled by client */
855
856                 struct fb_deferred_io *fbdefio;
857
858                 fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
859
860                 if (fbdefio) {
861                         fbdefio->delay = DL_DEFIO_WRITE_DELAY;
862                         fbdefio->deferred_io = dlfb_dpy_deferred_io;
863                 }
864
865                 info->fbdefio = fbdefio;
866                 fb_deferred_io_init(info);
867         }
868
869         pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
870             info->node, user, info, dev->fb_count);
871
872         return 0;
873 }
874
875 /*
876  * Called when all client interfaces to start transactions have been disabled,
877  * and all references to our device instance (dlfb_data) are released.
878  * Every transaction must have a reference, so we know are fully spun down
879  */
880 static void dlfb_free(struct kref *kref)
881 {
882         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
883
884         /* this function will wait for all in-flight urbs to complete */
885         if (dev->urbs.count > 0)
886                 dlfb_free_urb_list(dev);
887
888         if (dev->backing_buffer)
889                 vfree(dev->backing_buffer);
890
891         kfree(dev->edid);
892
893         pr_warn("freeing dlfb_data %p\n", dev);
894
895         kfree(dev);
896 }
897
898 static void dlfb_release_urb_work(struct work_struct *work)
899 {
900         struct urb_node *unode = container_of(work, struct urb_node,
901                                               release_urb_work.work);
902
903         up(&unode->dev->urbs.limit_sem);
904 }
905
906 static void dlfb_free_framebuffer_work(struct work_struct *work)
907 {
908         struct dlfb_data *dev = container_of(work, struct dlfb_data,
909                                              free_framebuffer_work.work);
910         struct fb_info *info = dev->info;
911         int node = info->node;
912
913         unregister_framebuffer(info);
914
915         if (info->cmap.len != 0)
916                 fb_dealloc_cmap(&info->cmap);
917         if (info->monspecs.modedb)
918                 fb_destroy_modedb(info->monspecs.modedb);
919         if (info->screen_base)
920                 vfree(info->screen_base);
921
922         fb_destroy_modelist(&info->modelist);
923
924         dev->info = 0;
925
926         /* Assume info structure is freed after this point */
927         framebuffer_release(info);
928
929         pr_warn("fb_info for /dev/fb%d has been freed\n", node);
930
931         /* ref taken in probe() as part of registering framebfufer */
932         kref_put(&dev->kref, dlfb_free);
933 }
934
935 /*
936  * Assumes caller is holding info->lock mutex (for open and release at least)
937  */
938 static int dlfb_ops_release(struct fb_info *info, int user)
939 {
940         struct dlfb_data *dev = info->par;
941
942         dev->fb_count--;
943
944         /* We can't free fb_info here - fbmem will touch it when we return */
945         if (dev->virtualized && (dev->fb_count == 0))
946                 schedule_delayed_work(&dev->free_framebuffer_work, HZ);
947
948         if ((dev->fb_count == 0) && (info->fbdefio)) {
949                 fb_deferred_io_cleanup(info);
950                 kfree(info->fbdefio);
951                 info->fbdefio = NULL;
952                 info->fbops->fb_mmap = dlfb_ops_mmap;
953         }
954
955         pr_warn("released /dev/fb%d user=%d count=%d\n",
956                   info->node, user, dev->fb_count);
957
958         kref_put(&dev->kref, dlfb_free);
959
960         return 0;
961 }
962
963 /*
964  * Check whether a video mode is supported by the DisplayLink chip
965  * We start from monitor's modes, so don't need to filter that here
966  */
967 static int dlfb_is_valid_mode(struct fb_videomode *mode,
968                 struct fb_info *info)
969 {
970         struct dlfb_data *dev = info->par;
971
972         if (mode->xres * mode->yres > dev->sku_pixel_limit) {
973                 pr_warn("%dx%d beyond chip capabilities\n",
974                        mode->xres, mode->yres);
975                 return 0;
976         }
977
978         pr_info("%dx%d valid mode\n", mode->xres, mode->yres);
979
980         return 1;
981 }
982
983 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
984 {
985         const struct fb_bitfield red = { 11, 5, 0 };
986         const struct fb_bitfield green = { 5, 6, 0 };
987         const struct fb_bitfield blue = { 0, 5, 0 };
988
989         var->bits_per_pixel = 16;
990         var->red = red;
991         var->green = green;
992         var->blue = blue;
993 }
994
995 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
996                                 struct fb_info *info)
997 {
998         struct fb_videomode mode;
999
1000         /* TODO: support dynamically changing framebuffer size */
1001         if ((var->xres * var->yres * 2) > info->fix.smem_len)
1002                 return -EINVAL;
1003
1004         /* set device-specific elements of var unrelated to mode */
1005         dlfb_var_color_format(var);
1006
1007         fb_var_to_videomode(&mode, var);
1008
1009         if (!dlfb_is_valid_mode(&mode, info))
1010                 return -EINVAL;
1011
1012         return 0;
1013 }
1014
1015 static int dlfb_ops_set_par(struct fb_info *info)
1016 {
1017         struct dlfb_data *dev = info->par;
1018         int result;
1019         u16 *pix_framebuffer;
1020         int i;
1021
1022         pr_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
1023
1024         result = dlfb_set_video_mode(dev, &info->var);
1025
1026         if ((result == 0) && (dev->fb_count == 0)) {
1027
1028                 /* paint greenscreen */
1029
1030                 pix_framebuffer = (u16 *) info->screen_base;
1031                 for (i = 0; i < info->fix.smem_len / 2; i++)
1032                         pix_framebuffer[i] = 0x37e6;
1033
1034                 dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1035                                    info->screen_base);
1036         }
1037
1038         return result;
1039 }
1040
1041 /*
1042  * In order to come back from full DPMS off, we need to set the mode again
1043  */
1044 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1045 {
1046         struct dlfb_data *dev = info->par;
1047
1048         if (blank_mode != FB_BLANK_UNBLANK) {
1049                 char *bufptr;
1050                 struct urb *urb;
1051
1052                 urb = dlfb_get_urb(dev);
1053                 if (!urb)
1054                         return 0;
1055
1056                 bufptr = (char *) urb->transfer_buffer;
1057                 bufptr = dlfb_vidreg_lock(bufptr);
1058                 bufptr = dlfb_enable_hvsync(bufptr, false);
1059                 bufptr = dlfb_vidreg_unlock(bufptr);
1060
1061                 dlfb_submit_urb(dev, urb, bufptr -
1062                                 (char *) urb->transfer_buffer);
1063         } else {
1064                 dlfb_set_video_mode(dev, &info->var);
1065         }
1066
1067         return 0;
1068 }
1069
1070 static struct fb_ops dlfb_ops = {
1071         .owner = THIS_MODULE,
1072         .fb_read = fb_sys_read,
1073         .fb_write = dlfb_ops_write,
1074         .fb_setcolreg = dlfb_ops_setcolreg,
1075         .fb_fillrect = dlfb_ops_fillrect,
1076         .fb_copyarea = dlfb_ops_copyarea,
1077         .fb_imageblit = dlfb_ops_imageblit,
1078         .fb_mmap = dlfb_ops_mmap,
1079         .fb_ioctl = dlfb_ops_ioctl,
1080         .fb_open = dlfb_ops_open,
1081         .fb_release = dlfb_ops_release,
1082         .fb_blank = dlfb_ops_blank,
1083         .fb_check_var = dlfb_ops_check_var,
1084         .fb_set_par = dlfb_ops_set_par,
1085 };
1086
1087
1088 /*
1089  * Assumes &info->lock held by caller
1090  * Assumes no active clients have framebuffer open
1091  */
1092 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1093 {
1094         int retval = -ENOMEM;
1095         int old_len = info->fix.smem_len;
1096         int new_len;
1097         unsigned char *old_fb = info->screen_base;
1098         unsigned char *new_fb;
1099         unsigned char *new_back;
1100
1101         pr_warn("Reallocating framebuffer. Addresses will change!\n");
1102
1103         new_len = info->fix.line_length * info->var.yres;
1104
1105         if (PAGE_ALIGN(new_len) > old_len) {
1106                 /*
1107                  * Alloc system memory for virtual framebuffer
1108                  */
1109                 new_fb = vmalloc(new_len);
1110                 if (!new_fb) {
1111                         pr_err("Virtual framebuffer alloc failed\n");
1112                         goto error;
1113                 }
1114
1115                 if (info->screen_base) {
1116                         memcpy(new_fb, old_fb, old_len);
1117                         vfree(info->screen_base);
1118                 }
1119
1120                 info->screen_base = new_fb;
1121                 info->fix.smem_len = PAGE_ALIGN(new_len);
1122                 info->fix.smem_start = (unsigned long) new_fb;
1123                 info->flags = udlfb_info_flags;
1124
1125                 /*
1126                  * Second framebuffer copy to mirror the framebuffer state
1127                  * on the physical USB device. We can function without this.
1128                  * But with imperfect damage info we may send pixels over USB
1129                  * that were, in fact, unchanged - wasting limited USB bandwidth
1130                  */
1131                 new_back = vzalloc(new_len);
1132                 if (!new_back)
1133                         pr_info("No shadow/backing buffer allocated\n");
1134                 else {
1135                         if (dev->backing_buffer)
1136                                 vfree(dev->backing_buffer);
1137                         dev->backing_buffer = new_back;
1138                 }
1139         }
1140
1141         retval = 0;
1142
1143 error:
1144         return retval;
1145 }
1146
1147 /*
1148  * 1) Get EDID from hw, or use sw default
1149  * 2) Parse into various fb_info structs
1150  * 3) Allocate virtual framebuffer memory to back highest res mode
1151  *
1152  * Parses EDID into three places used by various parts of fbdev:
1153  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1154  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1155  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1156  *
1157  * If EDID is not readable/valid, then modelist is all VESA modes,
1158  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1159  * Returns 0 if successful
1160  */
1161 static int dlfb_setup_modes(struct dlfb_data *dev,
1162                            struct fb_info *info,
1163                            char *default_edid, size_t default_edid_size)
1164 {
1165         int i;
1166         const struct fb_videomode *default_vmode = NULL;
1167         int result = 0;
1168         char *edid;
1169         int tries = 3;
1170
1171         if (info->dev) /* only use mutex if info has been registered */
1172                 mutex_lock(&info->lock);
1173
1174         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1175         if (!edid) {
1176                 result = -ENOMEM;
1177                 goto error;
1178         }
1179
1180         fb_destroy_modelist(&info->modelist);
1181         memset(&info->monspecs, 0, sizeof(info->monspecs));
1182
1183         /*
1184          * Try to (re)read EDID from hardware first
1185          * EDID data may return, but not parse as valid
1186          * Try again a few times, in case of e.g. analog cable noise
1187          */
1188         while (tries--) {
1189
1190                 i = dlfb_get_edid(dev, edid, EDID_LENGTH);
1191
1192                 if (i >= EDID_LENGTH)
1193                         fb_edid_to_monspecs(edid, &info->monspecs);
1194
1195                 if (info->monspecs.modedb_len > 0) {
1196                         dev->edid = edid;
1197                         dev->edid_size = i;
1198                         break;
1199                 }
1200         }
1201
1202         /* If that fails, use a previously returned EDID if available */
1203         if (info->monspecs.modedb_len == 0) {
1204
1205                 pr_err("Unable to get valid EDID from device/display\n");
1206
1207                 if (dev->edid) {
1208                         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1209                         if (info->monspecs.modedb_len > 0)
1210                                 pr_err("Using previously queried EDID\n");
1211                 }
1212         }
1213
1214         /* If that fails, use the default EDID we were handed */
1215         if (info->monspecs.modedb_len == 0) {
1216                 if (default_edid_size >= EDID_LENGTH) {
1217                         fb_edid_to_monspecs(default_edid, &info->monspecs);
1218                         if (info->monspecs.modedb_len > 0) {
1219                                 memcpy(edid, default_edid, default_edid_size);
1220                                 dev->edid = edid;
1221                                 dev->edid_size = default_edid_size;
1222                                 pr_err("Using default/backup EDID\n");
1223                         }
1224                 }
1225         }
1226
1227         /* If we've got modes, let's pick a best default mode */
1228         if (info->monspecs.modedb_len > 0) {
1229
1230                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1231                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1232                                 fb_add_videomode(&info->monspecs.modedb[i],
1233                                         &info->modelist);
1234                         else /* if we've removed top/best mode */
1235                                 info->monspecs.misc &= ~FB_MISC_1ST_DETAIL;
1236                 }
1237
1238                 default_vmode = fb_find_best_display(&info->monspecs,
1239                                                      &info->modelist);
1240         }
1241
1242         /* If everything else has failed, fall back to safe default mode */
1243         if (default_vmode == NULL) {
1244
1245                 struct fb_videomode fb_vmode = {0};
1246
1247                 /*
1248                  * Add the standard VESA modes to our modelist
1249                  * Since we don't have EDID, there may be modes that
1250                  * overspec monitor and/or are incorrect aspect ratio, etc.
1251                  * But at least the user has a chance to choose
1252                  */
1253                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1254                         if (dlfb_is_valid_mode((struct fb_videomode *)
1255                                                 &vesa_modes[i], info))
1256                                 fb_add_videomode(&vesa_modes[i],
1257                                                  &info->modelist);
1258                 }
1259
1260                 /*
1261                  * default to resolution safe for projectors
1262                  * (since they are most common case without EDID)
1263                  */
1264                 fb_vmode.xres = 800;
1265                 fb_vmode.yres = 600;
1266                 fb_vmode.refresh = 60;
1267                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1268                                                      &info->modelist);
1269         }
1270
1271         /* If we have good mode and no active clients*/
1272         if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1273
1274                 fb_videomode_to_var(&info->var, default_vmode);
1275                 dlfb_var_color_format(&info->var);
1276
1277                 /*
1278                  * with mode size info, we can now alloc our framebuffer.
1279                  */
1280                 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1281                 info->fix.line_length = info->var.xres *
1282                         (info->var.bits_per_pixel / 8);
1283
1284                 result = dlfb_realloc_framebuffer(dev, info);
1285
1286         } else
1287                 result = -EINVAL;
1288
1289 error:
1290         if (edid && (dev->edid != edid))
1291                 kfree(edid);
1292
1293         if (info->dev)
1294                 mutex_unlock(&info->lock);
1295
1296         return result;
1297 }
1298
1299 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1300                                    struct device_attribute *a, char *buf) {
1301         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1302         struct dlfb_data *dev = fb_info->par;
1303         return snprintf(buf, PAGE_SIZE, "%u\n",
1304                         atomic_read(&dev->bytes_rendered));
1305 }
1306
1307 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1308                                    struct device_attribute *a, char *buf) {
1309         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1310         struct dlfb_data *dev = fb_info->par;
1311         return snprintf(buf, PAGE_SIZE, "%u\n",
1312                         atomic_read(&dev->bytes_identical));
1313 }
1314
1315 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1316                                    struct device_attribute *a, char *buf) {
1317         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1318         struct dlfb_data *dev = fb_info->par;
1319         return snprintf(buf, PAGE_SIZE, "%u\n",
1320                         atomic_read(&dev->bytes_sent));
1321 }
1322
1323 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1324                                    struct device_attribute *a, char *buf) {
1325         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1326         struct dlfb_data *dev = fb_info->par;
1327         return snprintf(buf, PAGE_SIZE, "%u\n",
1328                         atomic_read(&dev->cpu_kcycles_used));
1329 }
1330
1331 static ssize_t edid_show(
1332                         struct file *filp,
1333                         struct kobject *kobj, struct bin_attribute *a,
1334                          char *buf, loff_t off, size_t count) {
1335         struct device *fbdev = container_of(kobj, struct device, kobj);
1336         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1337         struct dlfb_data *dev = fb_info->par;
1338
1339         if (dev->edid == NULL)
1340                 return 0;
1341
1342         if ((off >= dev->edid_size) || (count > dev->edid_size))
1343                 return 0;
1344
1345         if (off + count > dev->edid_size)
1346                 count = dev->edid_size - off;
1347
1348         pr_info("sysfs edid copy %p to %p, %d bytes\n",
1349                 dev->edid, buf, (int) count);
1350
1351         memcpy(buf, dev->edid, count);
1352
1353         return count;
1354 }
1355
1356 static ssize_t edid_store(
1357                         struct file *filp,
1358                         struct kobject *kobj, struct bin_attribute *a,
1359                         char *src, loff_t src_off, size_t src_size) {
1360         struct device *fbdev = container_of(kobj, struct device, kobj);
1361         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1362         struct dlfb_data *dev = fb_info->par;
1363
1364         /* We only support write of entire EDID at once, no offset*/
1365         if ((src_size != EDID_LENGTH) || (src_off != 0))
1366                 return 0;
1367
1368         dlfb_setup_modes(dev, fb_info, src, src_size);
1369
1370         if (dev->edid && (memcmp(src, dev->edid, src_size) == 0)) {
1371                 pr_info("sysfs written EDID is new default\n");
1372                 dlfb_ops_set_par(fb_info);
1373                 return src_size;
1374         } else
1375                 return 0;
1376 }
1377
1378 static ssize_t metrics_reset_store(struct device *fbdev,
1379                            struct device_attribute *attr,
1380                            const char *buf, size_t count)
1381 {
1382         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1383         struct dlfb_data *dev = fb_info->par;
1384
1385         atomic_set(&dev->bytes_rendered, 0);
1386         atomic_set(&dev->bytes_identical, 0);
1387         atomic_set(&dev->bytes_sent, 0);
1388         atomic_set(&dev->cpu_kcycles_used, 0);
1389
1390         return count;
1391 }
1392
1393 static struct bin_attribute edid_attr = {
1394         .attr.name = "edid",
1395         .attr.mode = 0666,
1396         .size = EDID_LENGTH,
1397         .read = edid_show,
1398         .write = edid_store
1399 };
1400
1401 static struct device_attribute fb_device_attrs[] = {
1402         __ATTR_RO(metrics_bytes_rendered),
1403         __ATTR_RO(metrics_bytes_identical),
1404         __ATTR_RO(metrics_bytes_sent),
1405         __ATTR_RO(metrics_cpu_kcycles_used),
1406         __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1407 };
1408
1409 /*
1410  * This is necessary before we can communicate with the display controller.
1411  */
1412 static int dlfb_select_std_channel(struct dlfb_data *dev)
1413 {
1414         int ret;
1415         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1416                                 0x1C, 0x88, 0x5E, 0x15,
1417                                 0x60, 0xFE, 0xC6, 0x97,
1418                                 0x16, 0x3D, 0x47, 0xF2  };
1419
1420         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1421                         NR_USB_REQUEST_CHANNEL,
1422                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1423                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1424         return ret;
1425 }
1426
1427 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1428                                         struct usb_device *usbdev)
1429 {
1430         char *desc;
1431         char *buf;
1432         char *desc_end;
1433
1434         u8 total_len = 0;
1435
1436         buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1437         if (!buf)
1438                 return false;
1439         desc = buf;
1440
1441         total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
1442                                     0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1443         if (total_len > 5) {
1444                 pr_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1445                         "%02x %02x %02x %02x %02x %02x %02x\n",
1446                         total_len, desc[0],
1447                         desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1448                         desc[7], desc[8], desc[9], desc[10]);
1449
1450                 if ((desc[0] != total_len) || /* descriptor length */
1451                     (desc[1] != 0x5f) ||   /* vendor descriptor type */
1452                     (desc[2] != 0x01) ||   /* version (2 bytes) */
1453                     (desc[3] != 0x00) ||
1454                     (desc[4] != total_len - 2)) /* length after type */
1455                         goto unrecognized;
1456
1457                 desc_end = desc + total_len;
1458                 desc += 5; /* the fixed header we've already parsed */
1459
1460                 while (desc < desc_end) {
1461                         u8 length;
1462                         u16 key;
1463
1464                         key = *((u16 *) desc);
1465                         desc += sizeof(u16);
1466                         length = *desc;
1467                         desc++;
1468
1469                         switch (key) {
1470                         case 0x0200: { /* max_area */
1471                                 u32 max_area;
1472                                 max_area = le32_to_cpu(*((u32 *)desc));
1473                                 pr_warn("DL chip limited to %d pixel modes\n",
1474                                         max_area);
1475                                 dev->sku_pixel_limit = max_area;
1476                                 break;
1477                         }
1478                         default:
1479                                 break;
1480                         }
1481                         desc += length;
1482                 }
1483         }
1484
1485         goto success;
1486
1487 unrecognized:
1488         /* allow udlfb to load for now even if firmware unrecognized */
1489         pr_err("Unrecognized vendor firmware descriptor\n");
1490
1491 success:
1492         kfree(buf);
1493         return true;
1494 }
1495 static int dlfb_usb_probe(struct usb_interface *interface,
1496                         const struct usb_device_id *id)
1497 {
1498         struct usb_device *usbdev;
1499         struct dlfb_data *dev = 0;
1500         struct fb_info *info = 0;
1501         int retval = -ENOMEM;
1502         int i;
1503
1504         /* usb initialization */
1505
1506         usbdev = interface_to_usbdev(interface);
1507
1508         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1509         if (dev == NULL) {
1510                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1511                 goto error;
1512         }
1513
1514         /* we need to wait for both usb and fbdev to spin down on disconnect */
1515         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1516         kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1517
1518         dev->udev = usbdev;
1519         dev->gdev = &usbdev->dev; /* our generic struct device * */
1520         usb_set_intfdata(interface, dev);
1521
1522         pr_info("%s %s - serial #%s\n",
1523                 usbdev->manufacturer, usbdev->product, usbdev->serial);
1524         pr_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1525                 usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1526                 usbdev->descriptor.bcdDevice, dev);
1527         pr_info("console enable=%d\n", console);
1528         pr_info("fb_defio enable=%d\n", fb_defio);
1529
1530         dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1531
1532         if (!dlfb_parse_vendor_descriptor(dev, usbdev)) {
1533                 pr_err("firmware not recognized. Assume incompatible device\n");
1534                 goto error;
1535         }
1536
1537         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1538                 retval = -ENOMEM;
1539                 pr_err("dlfb_alloc_urb_list failed\n");
1540                 goto error;
1541         }
1542
1543         /* We don't register a new USB class. Our client interface is fbdev */
1544
1545         /* allocates framebuffer driver structure, not framebuffer memory */
1546         info = framebuffer_alloc(0, &usbdev->dev);
1547         if (!info) {
1548                 retval = -ENOMEM;
1549                 pr_err("framebuffer_alloc failed\n");
1550                 goto error;
1551         }
1552
1553         dev->info = info;
1554         info->par = dev;
1555         info->pseudo_palette = dev->pseudo_palette;
1556         info->fbops = &dlfb_ops;
1557
1558         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1559         if (retval < 0) {
1560                 pr_err("fb_alloc_cmap failed %x\n", retval);
1561                 goto error;
1562         }
1563
1564         INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1565                           dlfb_free_framebuffer_work);
1566
1567         INIT_LIST_HEAD(&info->modelist);
1568
1569         retval = dlfb_setup_modes(dev, info, NULL, 0);
1570         if (retval != 0) {
1571                 pr_err("unable to find common mode for display and adapter\n");
1572                 goto error;
1573         }
1574
1575         /* ready to begin using device */
1576
1577         atomic_set(&dev->usb_active, 1);
1578         dlfb_select_std_channel(dev);
1579
1580         dlfb_ops_check_var(&info->var, info);
1581         dlfb_ops_set_par(info);
1582
1583         retval = register_framebuffer(info);
1584         if (retval < 0) {
1585                 pr_err("register_framebuffer failed %d\n", retval);
1586                 goto error;
1587         }
1588
1589         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1590                 device_create_file(info->dev, &fb_device_attrs[i]);
1591
1592         device_create_bin_file(info->dev, &edid_attr);
1593
1594         pr_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1595                         " Using %dK framebuffer memory\n", info->node,
1596                         info->var.xres, info->var.yres,
1597                         ((dev->backing_buffer) ?
1598                         info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1599         return 0;
1600
1601 error:
1602         if (dev) {
1603
1604                 if (info) {
1605                         if (info->cmap.len != 0)
1606                                 fb_dealloc_cmap(&info->cmap);
1607                         if (info->monspecs.modedb)
1608                                 fb_destroy_modedb(info->monspecs.modedb);
1609                         if (info->screen_base)
1610                                 vfree(info->screen_base);
1611
1612                         fb_destroy_modelist(&info->modelist);
1613
1614                         framebuffer_release(info);
1615                 }
1616
1617                 if (dev->backing_buffer)
1618                         vfree(dev->backing_buffer);
1619
1620                 kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1621                 kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1622
1623                 /* dev has been deallocated. Do not dereference */
1624         }
1625
1626         return retval;
1627 }
1628
1629 static void dlfb_usb_disconnect(struct usb_interface *interface)
1630 {
1631         struct dlfb_data *dev;
1632         struct fb_info *info;
1633         int i;
1634
1635         dev = usb_get_intfdata(interface);
1636         info = dev->info;
1637
1638         pr_info("USB disconnect starting\n");
1639
1640         /* we virtualize until all fb clients release. Then we free */
1641         dev->virtualized = true;
1642
1643         /* When non-active we'll update virtual framebuffer, but no new urbs */
1644         atomic_set(&dev->usb_active, 0);
1645
1646         /* remove udlfb's sysfs interfaces */
1647         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1648                 device_remove_file(info->dev, &fb_device_attrs[i]);
1649         device_remove_bin_file(info->dev, &edid_attr);
1650
1651         usb_set_intfdata(interface, NULL);
1652
1653         /* if clients still have us open, will be freed on last close */
1654         if (dev->fb_count == 0)
1655                 schedule_delayed_work(&dev->free_framebuffer_work, 0);
1656
1657         /* release reference taken by kref_init in probe() */
1658         kref_put(&dev->kref, dlfb_free);
1659
1660         /* consider dlfb_data freed */
1661
1662         return;
1663 }
1664
1665 static struct usb_driver dlfb_driver = {
1666         .name = "udlfb",
1667         .probe = dlfb_usb_probe,
1668         .disconnect = dlfb_usb_disconnect,
1669         .id_table = id_table,
1670 };
1671
1672 static int __init dlfb_module_init(void)
1673 {
1674         int res;
1675
1676         res = usb_register(&dlfb_driver);
1677         if (res)
1678                 err("usb_register failed. Error number %d", res);
1679
1680         return res;
1681 }
1682
1683 static void __exit dlfb_module_exit(void)
1684 {
1685         usb_deregister(&dlfb_driver);
1686 }
1687
1688 module_init(dlfb_module_init);
1689 module_exit(dlfb_module_exit);
1690
1691 static void dlfb_urb_completion(struct urb *urb)
1692 {
1693         struct urb_node *unode = urb->context;
1694         struct dlfb_data *dev = unode->dev;
1695         unsigned long flags;
1696
1697         /* sync/async unlink faults aren't errors */
1698         if (urb->status) {
1699                 if (!(urb->status == -ENOENT ||
1700                     urb->status == -ECONNRESET ||
1701                     urb->status == -ESHUTDOWN)) {
1702                         pr_err("%s - nonzero write bulk status received: %d\n",
1703                                 __func__, urb->status);
1704                         atomic_set(&dev->lost_pixels, 1);
1705                 }
1706         }
1707
1708         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1709
1710         spin_lock_irqsave(&dev->urbs.lock, flags);
1711         list_add_tail(&unode->entry, &dev->urbs.list);
1712         dev->urbs.available++;
1713         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1714
1715         /*
1716          * When using fb_defio, we deadlock if up() is called
1717          * while another is waiting. So queue to another process.
1718          */
1719         if (fb_defio)
1720                 schedule_delayed_work(&unode->release_urb_work, 0);
1721         else
1722                 up(&dev->urbs.limit_sem);
1723 }
1724
1725 static void dlfb_free_urb_list(struct dlfb_data *dev)
1726 {
1727         int count = dev->urbs.count;
1728         struct list_head *node;
1729         struct urb_node *unode;
1730         struct urb *urb;
1731         int ret;
1732         unsigned long flags;
1733
1734         pr_notice("Waiting for completes and freeing all render urbs\n");
1735
1736         /* keep waiting and freeing, until we've got 'em all */
1737         while (count--) {
1738
1739                 /* Getting interrupted means a leak, but ok at shutdown*/
1740                 ret = down_interruptible(&dev->urbs.limit_sem);
1741                 if (ret)
1742                         break;
1743
1744                 spin_lock_irqsave(&dev->urbs.lock, flags);
1745
1746                 node = dev->urbs.list.next; /* have reserved one with sem */
1747                 list_del_init(node);
1748
1749                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1750
1751                 unode = list_entry(node, struct urb_node, entry);
1752                 urb = unode->urb;
1753
1754                 /* Free each separately allocated piece */
1755                 usb_free_coherent(urb->dev, dev->urbs.size,
1756                                   urb->transfer_buffer, urb->transfer_dma);
1757                 usb_free_urb(urb);
1758                 kfree(node);
1759         }
1760
1761 }
1762
1763 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1764 {
1765         int i = 0;
1766         struct urb *urb;
1767         struct urb_node *unode;
1768         char *buf;
1769
1770         spin_lock_init(&dev->urbs.lock);
1771
1772         dev->urbs.size = size;
1773         INIT_LIST_HEAD(&dev->urbs.list);
1774
1775         while (i < count) {
1776                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1777                 if (!unode)
1778                         break;
1779                 unode->dev = dev;
1780
1781                 INIT_DELAYED_WORK(&unode->release_urb_work,
1782                           dlfb_release_urb_work);
1783
1784                 urb = usb_alloc_urb(0, GFP_KERNEL);
1785                 if (!urb) {
1786                         kfree(unode);
1787                         break;
1788                 }
1789                 unode->urb = urb;
1790
1791                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1792                                          &urb->transfer_dma);
1793                 if (!buf) {
1794                         kfree(unode);
1795                         usb_free_urb(urb);
1796                         break;
1797                 }
1798
1799                 /* urb->transfer_buffer_length set to actual before submit */
1800                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1801                         buf, size, dlfb_urb_completion, unode);
1802                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1803
1804                 list_add_tail(&unode->entry, &dev->urbs.list);
1805
1806                 i++;
1807         }
1808
1809         sema_init(&dev->urbs.limit_sem, i);
1810         dev->urbs.count = i;
1811         dev->urbs.available = i;
1812
1813         pr_notice("allocated %d %d byte urbs\n", i, (int) size);
1814
1815         return i;
1816 }
1817
1818 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1819 {
1820         int ret = 0;
1821         struct list_head *entry;
1822         struct urb_node *unode;
1823         struct urb *urb = NULL;
1824         unsigned long flags;
1825
1826         /* Wait for an in-flight buffer to complete and get re-queued */
1827         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1828         if (ret) {
1829                 atomic_set(&dev->lost_pixels, 1);
1830                 pr_warn("wait for urb interrupted: %x available: %d\n",
1831                        ret, dev->urbs.available);
1832                 goto error;
1833         }
1834
1835         spin_lock_irqsave(&dev->urbs.lock, flags);
1836
1837         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1838         entry = dev->urbs.list.next;
1839         list_del_init(entry);
1840         dev->urbs.available--;
1841
1842         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1843
1844         unode = list_entry(entry, struct urb_node, entry);
1845         urb = unode->urb;
1846
1847 error:
1848         return urb;
1849 }
1850
1851 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1852 {
1853         int ret;
1854
1855         BUG_ON(len > dev->urbs.size);
1856
1857         urb->transfer_buffer_length = len; /* set to actual payload len */
1858         ret = usb_submit_urb(urb, GFP_KERNEL);
1859         if (ret) {
1860                 dlfb_urb_completion(urb); /* because no one else will */
1861                 atomic_set(&dev->lost_pixels, 1);
1862                 pr_err("usb_submit_urb error %x\n", ret);
1863         }
1864         return ret;
1865 }
1866
1867 module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1868 MODULE_PARM_DESC(console, "Allow fbcon to consume first framebuffer found");
1869
1870 module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1871 MODULE_PARM_DESC(fb_defio, "Enable fb_defio mmap support. *Experimental*");
1872
1873 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1874               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1875               "Bernie Thompson <bernie@plugable.com>");
1876 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1877 MODULE_LICENSE("GPL");
1878