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 */
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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"
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 };
45 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
46 FBINFO_VIRTFB |
47 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
48 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
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 |
63 USB_DEVICE_ID_MATCH_INT_CLASS |
64 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
65 USB_DEVICE_ID_MATCH_INT_PROTOCOL,
66 },
67 {},
68 };
69 MODULE_DEVICE_TABLE(usb, id_table);
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 */
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);
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 }
97 static char *dlfb_vidreg_lock(char *buf)
98 {
99 return dlfb_set_register(buf, 0xFF, 0x00);
100 }
102 static char *dlfb_vidreg_unlock(char *buf)
103 {
104 return dlfb_set_register(buf, 0xFF, 0xFF);
105 }
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;
121 switch (fb_blank) {
122 case FB_BLANK_POWERDOWN:
123 reg = 0x07;
124 break;
125 case FB_BLANK_HSYNC_SUSPEND:
126 reg = 0x05;
127 break;
128 case FB_BLANK_VSYNC_SUSPEND:
129 reg = 0x03;
130 break;
131 case FB_BLANK_NORMAL:
132 reg = 0x01;
133 break;
134 default:
135 reg = 0x00;
136 }
138 buf = dlfb_set_register(buf, 0x1F, reg);
140 return buf;
141 }
143 static char *dlfb_set_color_depth(char *buf, u8 selection)
144 {
145 return dlfb_set_register(buf, 0x00, selection);
146 }
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 }
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 }
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 }
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 }
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 */
196 while (actual_count--) {
197 lv = ((lv << 1) |
198 (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
199 & 0xFFFF;
200 }
202 return (u16) lv;
203 }
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 }
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;
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);
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);
238 /* x end count is active + blanking - 1 */
239 wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
240 xde + var->right_margin - 1);
242 /* libdlo hardcodes hsync start to 1 */
243 wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
245 /* hsync end is width of sync pulse + 1 */
246 wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
248 /* hpixels is active pixels */
249 wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
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);
256 /* libdlo hardcodes vsync start to 0 */
257 wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
259 /* vsync end is width of vsync pulse */
260 wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
262 /* vpixels is active pixels */
263 wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
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);
269 return wrptr;
270 }
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;
286 if (!atomic_read(&dev->usb_active))
287 return -EPERM;
289 urb = dlfb_get_urb(dev);
290 if (!urb)
291 return -ENOMEM;
293 buf = (char *) urb->transfer_buffer;
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);
307 wrptr = dlfb_set_vid_cmds(wrptr, var);
308 wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
309 wrptr = dlfb_vidreg_unlock(wrptr);
311 writesize = wrptr - buf;
313 retval = dlfb_submit_urb(dev, urb, writesize);
315 dev->blank_mode = FB_BLANK_UNBLANK;
317 return retval;
318 }
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;
327 if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
328 return -EINVAL;
329 if (size > info->fix.smem_len)
330 return -EINVAL;
331 if (offset > info->fix.smem_len - size)
332 return -EINVAL;
334 pos = (unsigned long)info->fix.smem_start + offset;
336 pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
337 pos, size);
339 while (size > 0) {
340 page = vmalloc_to_pfn((void *)pos);
341 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
342 return -EAGAIN;
344 start += PAGE_SIZE;
345 pos += PAGE_SIZE;
346 if (size > PAGE_SIZE)
347 size -= PAGE_SIZE;
348 else
349 size = 0;
350 }
352 return 0;
353 }
355 /*
356 * Trims identical data from front and back of line
357 * Sets new front buffer address and width
358 * And returns byte count of identical pixels
359 * Assumes CPU natural alignment (unsigned long)
360 * for back and front buffer ptrs and width
361 */
362 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
363 {
364 int j, k;
365 const unsigned long *back = (const unsigned long *) bback;
366 const unsigned long *front = (const unsigned long *) *bfront;
367 const int width = *width_bytes / sizeof(unsigned long);
368 int identical = width;
369 int start = width;
370 int end = width;
372 prefetch((void *) front);
373 prefetch((void *) back);
375 for (j = 0; j < width; j++) {
376 if (back[j] != front[j]) {
377 start = j;
378 break;
379 }
380 }
382 for (k = width - 1; k > j; k--) {
383 if (back[k] != front[k]) {
384 end = k+1;
385 break;
386 }
387 }
389 identical = start + (width - end);
390 *bfront = (u8 *) &front[start];
391 *width_bytes = (end - start) * sizeof(unsigned long);
393 return identical * sizeof(unsigned long);
394 }
396 /*
397 * Render a command stream for an encoded horizontal line segment of pixels.
398 *
399 * A command buffer holds several commands.
400 * It always begins with a fresh command header
401 * (the protocol doesn't require this, but we enforce it to allow
402 * multiple buffers to be potentially encoded and sent in parallel).
403 * A single command encodes one contiguous horizontal line of pixels
404 *
405 * The function relies on the client to do all allocation, so that
406 * rendering can be done directly to output buffers (e.g. USB URBs).
407 * The function fills the supplied command buffer, providing information
408 * on where it left off, so the client may call in again with additional
409 * buffers if the line will take several buffers to complete.
410 *
411 * A single command can transmit a maximum of 256 pixels,
412 * regardless of the compression ratio (protocol design limit).
413 * To the hardware, 0 for a size byte means 256
414 *
415 * Rather than 256 pixel commands which are either rl or raw encoded,
416 * the rlx command simply assumes alternating raw and rl spans within one cmd.
417 * This has a slightly larger header overhead, but produces more even results.
418 * It also processes all data (read and write) in a single pass.
419 * Performance benchmarks of common cases show it having just slightly better
420 * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
421 * But for very rl friendly data, will compress not quite as well.
422 */
423 static void dlfb_compress_hline(
424 const uint16_t **pixel_start_ptr,
425 const uint16_t *const pixel_end,
426 uint32_t *device_address_ptr,
427 uint8_t **command_buffer_ptr,
428 const uint8_t *const cmd_buffer_end)
429 {
430 const uint16_t *pixel = *pixel_start_ptr;
431 uint32_t dev_addr = *device_address_ptr;
432 uint8_t *cmd = *command_buffer_ptr;
433 const int bpp = 2;
435 while ((pixel_end > pixel) &&
436 (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
437 uint8_t *raw_pixels_count_byte = NULL;
438 uint8_t *cmd_pixels_count_byte = NULL;
439 const uint16_t *raw_pixel_start = NULL;
440 const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL;
442 prefetchw((void *) cmd); /* pull in one cache line at least */
444 *cmd++ = 0xAF;
445 *cmd++ = 0x6B;
446 *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
447 *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
448 *cmd++ = (uint8_t) ((dev_addr) & 0xFF);
450 cmd_pixels_count_byte = cmd++; /* we'll know this later */
451 cmd_pixel_start = pixel;
453 raw_pixels_count_byte = cmd++; /* we'll know this later */
454 raw_pixel_start = pixel;
456 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
457 min((int)(pixel_end - pixel),
458 (int)(cmd_buffer_end - cmd) / bpp));
460 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
462 while (pixel < cmd_pixel_end) {
463 const uint16_t * const repeating_pixel = pixel;
465 *(uint16_t *)cmd = cpu_to_be16p(pixel);
466 cmd += 2;
467 pixel++;
469 if (unlikely((pixel < cmd_pixel_end) &&
470 (*pixel == *repeating_pixel))) {
471 /* go back and fill in raw pixel count */
472 *raw_pixels_count_byte = ((repeating_pixel -
473 raw_pixel_start) + 1) & 0xFF;
475 while ((pixel < cmd_pixel_end)
476 && (*pixel == *repeating_pixel)) {
477 pixel++;
478 }
480 /* immediately after raw data is repeat byte */
481 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
483 /* Then start another raw pixel span */
484 raw_pixel_start = pixel;
485 raw_pixels_count_byte = cmd++;
486 }
487 }
489 if (pixel > raw_pixel_start) {
490 /* finalize last RAW span */
491 *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
492 }
494 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
495 dev_addr += (pixel - cmd_pixel_start) * bpp;
496 }
498 if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
499 /* Fill leftover bytes with no-ops */
500 if (cmd_buffer_end > cmd)
501 memset(cmd, 0xAF, cmd_buffer_end - cmd);
502 cmd = (uint8_t *) cmd_buffer_end;
503 }
505 *command_buffer_ptr = cmd;
506 *pixel_start_ptr = pixel;
507 *device_address_ptr = dev_addr;
509 return;
510 }
512 /*
513 * There are 3 copies of every pixel: The front buffer that the fbdev
514 * client renders to, the actual framebuffer across the USB bus in hardware
515 * (that we can only write to, slowly, and can never read), and (optionally)
516 * our shadow copy that tracks what's been sent to that hardware buffer.
517 */
518 static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
519 const char *front, char **urb_buf_ptr,
520 u32 byte_offset, u32 byte_width,
521 int *ident_ptr, int *sent_ptr)
522 {
523 const u8 *line_start, *line_end, *next_pixel;
524 u32 dev_addr = dev->base16 + byte_offset;
525 struct urb *urb = *urb_ptr;
526 u8 *cmd = *urb_buf_ptr;
527 u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
529 line_start = (u8 *) (front + byte_offset);
530 next_pixel = line_start;
531 line_end = next_pixel + byte_width;
533 if (dev->backing_buffer) {
534 int offset;
535 const u8 *back_start = (u8 *) (dev->backing_buffer
536 + byte_offset);
538 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
539 &byte_width);
541 offset = next_pixel - line_start;
542 line_end = next_pixel + byte_width;
543 dev_addr += offset;
544 back_start += offset;
545 line_start += offset;
547 memcpy((char *)back_start, (char *) line_start,
548 byte_width);
549 }
551 while (next_pixel < line_end) {
553 dlfb_compress_hline((const uint16_t **) &next_pixel,
554 (const uint16_t *) line_end, &dev_addr,
555 (u8 **) &cmd, (u8 *) cmd_end);
557 if (cmd >= cmd_end) {
558 int len = cmd - (u8 *) urb->transfer_buffer;
559 if (dlfb_submit_urb(dev, urb, len))
560 return 1; /* lost pixels is set */
561 *sent_ptr += len;
562 urb = dlfb_get_urb(dev);
563 if (!urb)
564 return 1; /* lost_pixels is set */
565 *urb_ptr = urb;
566 cmd = urb->transfer_buffer;
567 cmd_end = &cmd[urb->transfer_buffer_length];
568 }
569 }
571 *urb_buf_ptr = cmd;
573 return 0;
574 }
576 static int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
577 int width, int height, char *data)
578 {
579 int i, ret;
580 char *cmd;
581 cycles_t start_cycles, end_cycles;
582 int bytes_sent = 0;
583 int bytes_identical = 0;
584 struct urb *urb;
585 int aligned_x;
587 start_cycles = get_cycles();
589 aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
590 width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
591 x = aligned_x;
593 if ((width <= 0) ||
594 (x + width > dev->info->var.xres) ||
595 (y + height > dev->info->var.yres))
596 return -EINVAL;
598 if (!atomic_read(&dev->usb_active))
599 return 0;
601 urb = dlfb_get_urb(dev);
602 if (!urb)
603 return 0;
604 cmd = urb->transfer_buffer;
606 for (i = y; i < y + height ; i++) {
607 const int line_offset = dev->info->fix.line_length * i;
608 const int byte_offset = line_offset + (x * BPP);
610 if (dlfb_render_hline(dev, &urb,
611 (char *) dev->info->fix.smem_start,
612 &cmd, byte_offset, width * BPP,
613 &bytes_identical, &bytes_sent))
614 goto error;
615 }
617 if (cmd > (char *) urb->transfer_buffer) {
618 /* Send partial buffer remaining before exiting */
619 int len = cmd - (char *) urb->transfer_buffer;
620 ret = dlfb_submit_urb(dev, urb, len);
621 bytes_sent += len;
622 } else
623 dlfb_urb_completion(urb);
625 error:
626 atomic_add(bytes_sent, &dev->bytes_sent);
627 atomic_add(bytes_identical, &dev->bytes_identical);
628 atomic_add(width*height*2, &dev->bytes_rendered);
629 end_cycles = get_cycles();
630 atomic_add(((unsigned int) ((end_cycles - start_cycles)
631 >> 10)), /* Kcycles */
632 &dev->cpu_kcycles_used);
634 return 0;
635 }
637 /*
638 * Path triggered by usermode clients who write to filesystem
639 * e.g. cat filename > /dev/fb1
640 * Not used by X Windows or text-mode console. But useful for testing.
641 * Slow because of extra copy and we must assume all pixels dirty.
642 */
643 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
644 size_t count, loff_t *ppos)
645 {
646 ssize_t result;
647 struct dlfb_data *dev = info->par;
648 u32 offset = (u32) *ppos;
650 result = fb_sys_write(info, buf, count, ppos);
652 if (result > 0) {
653 int start = max((int)(offset / info->fix.line_length), 0);
654 int lines = min((u32)((result / info->fix.line_length) + 1),
655 (u32)info->var.yres);
657 dlfb_handle_damage(dev, 0, start, info->var.xres,
658 lines, info->screen_base);
659 }
661 return result;
662 }
664 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
665 static void dlfb_ops_copyarea(struct fb_info *info,
666 const struct fb_copyarea *area)
667 {
669 struct dlfb_data *dev = info->par;
671 sys_copyarea(info, area);
673 dlfb_handle_damage(dev, area->dx, area->dy,
674 area->width, area->height, info->screen_base);
675 }
677 static void dlfb_ops_imageblit(struct fb_info *info,
678 const struct fb_image *image)
679 {
680 struct dlfb_data *dev = info->par;
682 sys_imageblit(info, image);
684 dlfb_handle_damage(dev, image->dx, image->dy,
685 image->width, image->height, info->screen_base);
686 }
688 static void dlfb_ops_fillrect(struct fb_info *info,
689 const struct fb_fillrect *rect)
690 {
691 struct dlfb_data *dev = info->par;
693 sys_fillrect(info, rect);
695 dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
696 rect->height, info->screen_base);
697 }
699 /*
700 * NOTE: fb_defio.c is holding info->fbdefio.mutex
701 * Touching ANY framebuffer memory that triggers a page fault
702 * in fb_defio will cause a deadlock, when it also tries to
703 * grab the same mutex.
704 */
705 static void dlfb_dpy_deferred_io(struct fb_info *info,
706 struct list_head *pagelist)
707 {
708 struct page *cur;
709 struct fb_deferred_io *fbdefio = info->fbdefio;
710 struct dlfb_data *dev = info->par;
711 struct urb *urb;
712 char *cmd;
713 cycles_t start_cycles, end_cycles;
714 int bytes_sent = 0;
715 int bytes_identical = 0;
716 int bytes_rendered = 0;
718 if (!fb_defio)
719 return;
721 if (!atomic_read(&dev->usb_active))
722 return;
724 start_cycles = get_cycles();
726 urb = dlfb_get_urb(dev);
727 if (!urb)
728 return;
730 cmd = urb->transfer_buffer;
732 /* walk the written page list and render each to device */
733 list_for_each_entry(cur, &fbdefio->pagelist, lru) {
735 if (dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
736 &cmd, cur->index << PAGE_SHIFT,
737 PAGE_SIZE, &bytes_identical, &bytes_sent))
738 goto error;
739 bytes_rendered += PAGE_SIZE;
740 }
742 if (cmd > (char *) urb->transfer_buffer) {
743 /* Send partial buffer remaining before exiting */
744 int len = cmd - (char *) urb->transfer_buffer;
745 dlfb_submit_urb(dev, urb, len);
746 bytes_sent += len;
747 } else
748 dlfb_urb_completion(urb);
750 error:
751 atomic_add(bytes_sent, &dev->bytes_sent);
752 atomic_add(bytes_identical, &dev->bytes_identical);
753 atomic_add(bytes_rendered, &dev->bytes_rendered);
754 end_cycles = get_cycles();
755 atomic_add(((unsigned int) ((end_cycles - start_cycles)
756 >> 10)), /* Kcycles */
757 &dev->cpu_kcycles_used);
758 }
760 static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
761 {
762 int i;
763 int ret;
764 char *rbuf;
766 rbuf = kmalloc(2, GFP_KERNEL);
767 if (!rbuf)
768 return 0;
770 for (i = 0; i < len; i++) {
771 ret = usb_control_msg(dev->udev,
772 usb_rcvctrlpipe(dev->udev, 0), (0x02),
773 (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
774 HZ);
775 if (ret < 1) {
776 pr_err("Read EDID byte %d failed err %x\n", i, ret);
777 i--;
778 break;
779 }
780 edid[i] = rbuf[1];
781 }
783 kfree(rbuf);
785 return i;
786 }
788 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
789 unsigned long arg)
790 {
792 struct dlfb_data *dev = info->par;
794 if (!atomic_read(&dev->usb_active))
795 return 0;
797 /* TODO: Update X server to get this from sysfs instead */
798 if (cmd == DLFB_IOCTL_RETURN_EDID) {
799 void __user *edid = (void __user *)arg;
800 if (copy_to_user(edid, dev->edid, dev->edid_size))
801 return -EFAULT;
802 return 0;
803 }
805 /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
806 if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
807 struct dloarea area;
809 if (copy_from_user(&area, (void __user *)arg,
810 sizeof(struct dloarea)))
811 return -EFAULT;
813 /*
814 * If we have a damage-aware client, turn fb_defio "off"
815 * To avoid perf imact of unnecessary page fault handling.
816 * Done by resetting the delay for this fb_info to a very
817 * long period. Pages will become writable and stay that way.
818 * Reset to normal value when all clients have closed this fb.
819 */
820 if (info->fbdefio)
821 info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
823 if (area.x < 0)
824 area.x = 0;
826 if (area.x > info->var.xres)
827 area.x = info->var.xres;
829 if (area.y < 0)
830 area.y = 0;
832 if (area.y > info->var.yres)
833 area.y = info->var.yres;
835 dlfb_handle_damage(dev, area.x, area.y, area.w, area.h,
836 info->screen_base);
837 }
839 return 0;
840 }
842 /* taken from vesafb */
843 static int
844 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
845 unsigned blue, unsigned transp, struct fb_info *info)
846 {
847 int err = 0;
849 if (regno >= info->cmap.len)
850 return 1;
852 if (regno < 16) {
853 if (info->var.red.offset == 10) {
854 /* 1:5:5:5 */
855 ((u32 *) (info->pseudo_palette))[regno] =
856 ((red & 0xf800) >> 1) |
857 ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
858 } else {
859 /* 0:5:6:5 */
860 ((u32 *) (info->pseudo_palette))[regno] =
861 ((red & 0xf800)) |
862 ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
863 }
864 }
866 return err;
867 }
869 /*
870 * It's common for several clients to have framebuffer open simultaneously.
871 * e.g. both fbcon and X. Makes things interesting.
872 * Assumes caller is holding info->lock (for open and release at least)
873 */
874 static int dlfb_ops_open(struct fb_info *info, int user)
875 {
876 struct dlfb_data *dev = info->par;
878 /*
879 * fbcon aggressively connects to first framebuffer it finds,
880 * preventing other clients (X) from working properly. Usually
881 * not what the user wants. Fail by default with option to enable.
882 */
883 if ((user == 0) && (!console))
884 return -EBUSY;
886 /* If the USB device is gone, we don't accept new opens */
887 if (dev->virtualized)
888 return -ENODEV;
890 dev->fb_count++;
892 kref_get(&dev->kref);
894 if (fb_defio && (info->fbdefio == NULL)) {
895 /* enable defio at last moment if not disabled by client */
897 struct fb_deferred_io *fbdefio;
899 fbdefio = kzalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
901 if (fbdefio) {
902 fbdefio->delay = DL_DEFIO_WRITE_DELAY;
903 fbdefio->deferred_io = dlfb_dpy_deferred_io;
904 }
906 info->fbdefio = fbdefio;
907 fb_deferred_io_init(info);
908 }
910 pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
911 info->node, user, info, dev->fb_count);
913 return 0;
914 }
916 /*
917 * Called when all client interfaces to start transactions have been disabled,
918 * and all references to our device instance (dlfb_data) are released.
919 * Every transaction must have a reference, so we know are fully spun down
920 */
921 static void dlfb_free(struct kref *kref)
922 {
923 struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
925 if (dev->backing_buffer)
926 vfree(dev->backing_buffer);
928 kfree(dev->edid);
930 pr_warn("freeing dlfb_data %p\n", dev);
932 kfree(dev);
933 }
935 static void dlfb_release_urb_work(struct work_struct *work)
936 {
937 struct urb_node *unode = container_of(work, struct urb_node,
938 release_urb_work.work);
940 up(&unode->dev->urbs.limit_sem);
941 }
943 static void dlfb_free_framebuffer(struct dlfb_data *dev)
944 {
945 struct fb_info *info = dev->info;
947 if (info) {
948 int node = info->node;
950 unregister_framebuffer(info);
952 if (info->cmap.len != 0)
953 fb_dealloc_cmap(&info->cmap);
954 if (info->monspecs.modedb)
955 fb_destroy_modedb(info->monspecs.modedb);
956 if (info->screen_base)
957 vfree(info->screen_base);
959 fb_destroy_modelist(&info->modelist);
961 dev->info = NULL;
963 /* Assume info structure is freed after this point */
964 framebuffer_release(info);
966 pr_warn("fb_info for /dev/fb%d has been freed\n", node);
967 }
969 /* ref taken in probe() as part of registering framebfufer */
970 kref_put(&dev->kref, dlfb_free);
971 }
973 static void dlfb_free_framebuffer_work(struct work_struct *work)
974 {
975 struct dlfb_data *dev = container_of(work, struct dlfb_data,
976 free_framebuffer_work.work);
977 dlfb_free_framebuffer(dev);
978 }
979 /*
980 * Assumes caller is holding info->lock mutex (for open and release at least)
981 */
982 static int dlfb_ops_release(struct fb_info *info, int user)
983 {
984 struct dlfb_data *dev = info->par;
986 dev->fb_count--;
988 /* We can't free fb_info here - fbmem will touch it when we return */
989 if (dev->virtualized && (dev->fb_count == 0))
990 schedule_delayed_work(&dev->free_framebuffer_work, HZ);
992 if ((dev->fb_count == 0) && (info->fbdefio)) {
993 fb_deferred_io_cleanup(info);
994 kfree(info->fbdefio);
995 info->fbdefio = NULL;
996 info->fbops->fb_mmap = dlfb_ops_mmap;
997 }
999 pr_warn("released /dev/fb%d user=%d count=%d\n",
1000 info->node, user, dev->fb_count);
1002 kref_put(&dev->kref, dlfb_free);
1004 return 0;
1005 }
1007 /*
1008 * Check whether a video mode is supported by the DisplayLink chip
1009 * We start from monitor's modes, so don't need to filter that here
1010 */
1011 static int dlfb_is_valid_mode(struct fb_videomode *mode,
1012 struct fb_info *info)
1013 {
1014 struct dlfb_data *dev = info->par;
1016 if (mode->xres * mode->yres > dev->sku_pixel_limit) {
1017 pr_warn("%dx%d beyond chip capabilities\n",
1018 mode->xres, mode->yres);
1019 return 0;
1020 }
1022 pr_info("%dx%d @ %d Hz valid mode\n", mode->xres, mode->yres,
1023 mode->refresh);
1025 return 1;
1026 }
1028 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1029 {
1030 const struct fb_bitfield red = { 11, 5, 0 };
1031 const struct fb_bitfield green = { 5, 6, 0 };
1032 const struct fb_bitfield blue = { 0, 5, 0 };
1034 var->bits_per_pixel = 16;
1035 var->red = red;
1036 var->green = green;
1037 var->blue = blue;
1038 }
1040 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1041 struct fb_info *info)
1042 {
1043 struct fb_videomode mode;
1045 /* TODO: support dynamically changing framebuffer size */
1046 if ((var->xres * var->yres * 2) > info->fix.smem_len)
1047 return -EINVAL;
1049 /* set device-specific elements of var unrelated to mode */
1050 dlfb_var_color_format(var);
1052 fb_var_to_videomode(&mode, var);
1054 if (!dlfb_is_valid_mode(&mode, info))
1055 return -EINVAL;
1057 return 0;
1058 }
1060 static int dlfb_ops_set_par(struct fb_info *info)
1061 {
1062 struct dlfb_data *dev = info->par;
1063 int result;
1064 u16 *pix_framebuffer;
1065 int i;
1067 pr_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
1069 result = dlfb_set_video_mode(dev, &info->var);
1071 if ((result == 0) && (dev->fb_count == 0)) {
1073 /* paint greenscreen */
1075 pix_framebuffer = (u16 *) info->screen_base;
1076 for (i = 0; i < info->fix.smem_len / 2; i++)
1077 pix_framebuffer[i] = 0x37e6;
1079 dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1080 info->screen_base);
1081 }
1083 return result;
1084 }
1086 /* To fonzi the jukebox (e.g. make blanking changes take effect) */
1087 static char *dlfb_dummy_render(char *buf)
1088 {
1089 *buf++ = 0xAF;
1090 *buf++ = 0x6A; /* copy */
1091 *buf++ = 0x00; /* from address*/
1092 *buf++ = 0x00;
1093 *buf++ = 0x00;
1094 *buf++ = 0x01; /* one pixel */
1095 *buf++ = 0x00; /* to address */
1096 *buf++ = 0x00;
1097 *buf++ = 0x00;
1098 return buf;
1099 }
1101 /*
1102 * In order to come back from full DPMS off, we need to set the mode again
1103 */
1104 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1105 {
1106 struct dlfb_data *dev = info->par;
1107 char *bufptr;
1108 struct urb *urb;
1110 pr_info("/dev/fb%d FB_BLANK mode %d --> %d\n",
1111 info->node, dev->blank_mode, blank_mode);
1113 if ((dev->blank_mode == FB_BLANK_POWERDOWN) &&
1114 (blank_mode != FB_BLANK_POWERDOWN)) {
1116 /* returning from powerdown requires a fresh modeset */
1117 dlfb_set_video_mode(dev, &info->var);
1118 }
1120 urb = dlfb_get_urb(dev);
1121 if (!urb)
1122 return 0;
1124 bufptr = (char *) urb->transfer_buffer;
1125 bufptr = dlfb_vidreg_lock(bufptr);
1126 bufptr = dlfb_blanking(bufptr, blank_mode);
1127 bufptr = dlfb_vidreg_unlock(bufptr);
1129 /* seems like a render op is needed to have blank change take effect */
1130 bufptr = dlfb_dummy_render(bufptr);
1132 dlfb_submit_urb(dev, urb, bufptr -
1133 (char *) urb->transfer_buffer);
1135 dev->blank_mode = blank_mode;
1137 return 0;
1138 }
1140 static struct fb_ops dlfb_ops = {
1141 .owner = THIS_MODULE,
1142 .fb_read = fb_sys_read,
1143 .fb_write = dlfb_ops_write,
1144 .fb_setcolreg = dlfb_ops_setcolreg,
1145 .fb_fillrect = dlfb_ops_fillrect,
1146 .fb_copyarea = dlfb_ops_copyarea,
1147 .fb_imageblit = dlfb_ops_imageblit,
1148 .fb_mmap = dlfb_ops_mmap,
1149 .fb_ioctl = dlfb_ops_ioctl,
1150 .fb_open = dlfb_ops_open,
1151 .fb_release = dlfb_ops_release,
1152 .fb_blank = dlfb_ops_blank,
1153 .fb_check_var = dlfb_ops_check_var,
1154 .fb_set_par = dlfb_ops_set_par,
1155 };
1158 /*
1159 * Assumes &info->lock held by caller
1160 * Assumes no active clients have framebuffer open
1161 */
1162 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1163 {
1164 int retval = -ENOMEM;
1165 int old_len = info->fix.smem_len;
1166 int new_len;
1167 unsigned char *old_fb = info->screen_base;
1168 unsigned char *new_fb;
1169 unsigned char *new_back = NULL;
1171 pr_warn("Reallocating framebuffer. Addresses will change!\n");
1173 new_len = info->fix.line_length * info->var.yres;
1175 if (PAGE_ALIGN(new_len) > old_len) {
1176 /*
1177 * Alloc system memory for virtual framebuffer
1178 */
1179 new_fb = vmalloc(new_len);
1180 if (!new_fb) {
1181 pr_err("Virtual framebuffer alloc failed\n");
1182 goto error;
1183 }
1185 if (info->screen_base) {
1186 memcpy(new_fb, old_fb, old_len);
1187 vfree(info->screen_base);
1188 }
1190 info->screen_base = new_fb;
1191 info->fix.smem_len = PAGE_ALIGN(new_len);
1192 info->fix.smem_start = (unsigned long) new_fb;
1193 info->flags = udlfb_info_flags;
1195 /*
1196 * Second framebuffer copy to mirror the framebuffer state
1197 * on the physical USB device. We can function without this.
1198 * But with imperfect damage info we may send pixels over USB
1199 * that were, in fact, unchanged - wasting limited USB bandwidth
1200 */
1201 if (shadow)
1202 new_back = vzalloc(new_len);
1203 if (!new_back)
1204 pr_info("No shadow/backing buffer allocated\n");
1205 else {
1206 if (dev->backing_buffer)
1207 vfree(dev->backing_buffer);
1208 dev->backing_buffer = new_back;
1209 }
1210 }
1212 retval = 0;
1214 error:
1215 return retval;
1216 }
1218 /*
1219 * 1) Get EDID from hw, or use sw default
1220 * 2) Parse into various fb_info structs
1221 * 3) Allocate virtual framebuffer memory to back highest res mode
1222 *
1223 * Parses EDID into three places used by various parts of fbdev:
1224 * fb_var_screeninfo contains the timing of the monitor's preferred mode
1225 * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1226 * fb_info.modelist is a linked list of all monitor & VESA modes which work
1227 *
1228 * If EDID is not readable/valid, then modelist is all VESA modes,
1229 * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1230 * Returns 0 if successful
1231 */
1232 static int dlfb_setup_modes(struct dlfb_data *dev,
1233 struct fb_info *info,
1234 char *default_edid, size_t default_edid_size)
1235 {
1236 int i;
1237 const struct fb_videomode *default_vmode = NULL;
1238 int result = 0;
1239 char *edid;
1240 int tries = 3;
1242 if (info->dev) /* only use mutex if info has been registered */
1243 mutex_lock(&info->lock);
1245 edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1246 if (!edid) {
1247 result = -ENOMEM;
1248 goto error;
1249 }
1251 fb_destroy_modelist(&info->modelist);
1252 memset(&info->monspecs, 0, sizeof(info->monspecs));
1254 /*
1255 * Try to (re)read EDID from hardware first
1256 * EDID data may return, but not parse as valid
1257 * Try again a few times, in case of e.g. analog cable noise
1258 */
1259 while (tries--) {
1261 i = dlfb_get_edid(dev, edid, EDID_LENGTH);
1263 if (i >= EDID_LENGTH)
1264 fb_edid_to_monspecs(edid, &info->monspecs);
1266 if (info->monspecs.modedb_len > 0) {
1267 dev->edid = edid;
1268 dev->edid_size = i;
1269 break;
1270 }
1271 }
1273 /* If that fails, use a previously returned EDID if available */
1274 if (info->monspecs.modedb_len == 0) {
1276 pr_err("Unable to get valid EDID from device/display\n");
1278 if (dev->edid) {
1279 fb_edid_to_monspecs(dev->edid, &info->monspecs);
1280 if (info->monspecs.modedb_len > 0)
1281 pr_err("Using previously queried EDID\n");
1282 }
1283 }
1285 /* If that fails, use the default EDID we were handed */
1286 if (info->monspecs.modedb_len == 0) {
1287 if (default_edid_size >= EDID_LENGTH) {
1288 fb_edid_to_monspecs(default_edid, &info->monspecs);
1289 if (info->monspecs.modedb_len > 0) {
1290 memcpy(edid, default_edid, default_edid_size);
1291 dev->edid = edid;
1292 dev->edid_size = default_edid_size;
1293 pr_err("Using default/backup EDID\n");
1294 }
1295 }
1296 }
1298 /* If we've got modes, let's pick a best default mode */
1299 if (info->monspecs.modedb_len > 0) {
1301 for (i = 0; i < info->monspecs.modedb_len; i++) {
1302 if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1303 fb_add_videomode(&info->monspecs.modedb[i],
1304 &info->modelist);
1305 else {
1306 if (i == 0)
1307 /* if we've removed top/best mode */
1308 info->monspecs.misc
1309 &= ~FB_MISC_1ST_DETAIL;
1310 }
1311 }
1313 default_vmode = fb_find_best_display(&info->monspecs,
1314 &info->modelist);
1315 }
1317 /* If everything else has failed, fall back to safe default mode */
1318 if (default_vmode == NULL) {
1320 struct fb_videomode fb_vmode = {0};
1322 /*
1323 * Add the standard VESA modes to our modelist
1324 * Since we don't have EDID, there may be modes that
1325 * overspec monitor and/or are incorrect aspect ratio, etc.
1326 * But at least the user has a chance to choose
1327 */
1328 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1329 if (dlfb_is_valid_mode((struct fb_videomode *)
1330 &vesa_modes[i], info))
1331 fb_add_videomode(&vesa_modes[i],
1332 &info->modelist);
1333 }
1335 /*
1336 * default to resolution safe for projectors
1337 * (since they are most common case without EDID)
1338 */
1339 fb_vmode.xres = 800;
1340 fb_vmode.yres = 600;
1341 fb_vmode.refresh = 60;
1342 default_vmode = fb_find_nearest_mode(&fb_vmode,
1343 &info->modelist);
1344 }
1346 /* If we have good mode and no active clients*/
1347 if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1349 fb_videomode_to_var(&info->var, default_vmode);
1350 dlfb_var_color_format(&info->var);
1352 /*
1353 * with mode size info, we can now alloc our framebuffer.
1354 */
1355 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1356 info->fix.line_length = info->var.xres *
1357 (info->var.bits_per_pixel / 8);
1359 result = dlfb_realloc_framebuffer(dev, info);
1361 } else
1362 result = -EINVAL;
1364 error:
1365 if (edid && (dev->edid != edid))
1366 kfree(edid);
1368 if (info->dev)
1369 mutex_unlock(&info->lock);
1371 return result;
1372 }
1374 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1375 struct device_attribute *a, char *buf) {
1376 struct fb_info *fb_info = dev_get_drvdata(fbdev);
1377 struct dlfb_data *dev = fb_info->par;
1378 return snprintf(buf, PAGE_SIZE, "%u\n",
1379 atomic_read(&dev->bytes_rendered));
1380 }
1382 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1383 struct device_attribute *a, char *buf) {
1384 struct fb_info *fb_info = dev_get_drvdata(fbdev);
1385 struct dlfb_data *dev = fb_info->par;
1386 return snprintf(buf, PAGE_SIZE, "%u\n",
1387 atomic_read(&dev->bytes_identical));
1388 }
1390 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1391 struct device_attribute *a, char *buf) {
1392 struct fb_info *fb_info = dev_get_drvdata(fbdev);
1393 struct dlfb_data *dev = fb_info->par;
1394 return snprintf(buf, PAGE_SIZE, "%u\n",
1395 atomic_read(&dev->bytes_sent));
1396 }
1398 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1399 struct device_attribute *a, char *buf) {
1400 struct fb_info *fb_info = dev_get_drvdata(fbdev);
1401 struct dlfb_data *dev = fb_info->par;
1402 return snprintf(buf, PAGE_SIZE, "%u\n",
1403 atomic_read(&dev->cpu_kcycles_used));
1404 }
1406 static ssize_t edid_show(
1407 struct file *filp,
1408 struct kobject *kobj, struct bin_attribute *a,
1409 char *buf, loff_t off, size_t count) {
1410 struct device *fbdev = container_of(kobj, struct device, kobj);
1411 struct fb_info *fb_info = dev_get_drvdata(fbdev);
1412 struct dlfb_data *dev = fb_info->par;
1414 if (dev->edid == NULL)
1415 return 0;
1417 if ((off >= dev->edid_size) || (count > dev->edid_size))
1418 return 0;
1420 if (off + count > dev->edid_size)
1421 count = dev->edid_size - off;
1423 pr_info("sysfs edid copy %p to %p, %d bytes\n",
1424 dev->edid, buf, (int) count);
1426 memcpy(buf, dev->edid, count);
1428 return count;
1429 }
1431 static ssize_t edid_store(
1432 struct file *filp,
1433 struct kobject *kobj, struct bin_attribute *a,
1434 char *src, loff_t src_off, size_t src_size) {
1435 struct device *fbdev = container_of(kobj, struct device, kobj);
1436 struct fb_info *fb_info = dev_get_drvdata(fbdev);
1437 struct dlfb_data *dev = fb_info->par;
1438 int ret;
1440 /* We only support write of entire EDID at once, no offset*/
1441 if ((src_size != EDID_LENGTH) || (src_off != 0))
1442 return -EINVAL;
1444 ret = dlfb_setup_modes(dev, fb_info, src, src_size);
1445 if (ret)
1446 return ret;
1448 if (!dev->edid || memcmp(src, dev->edid, src_size))
1449 return -EINVAL;
1451 pr_info("sysfs written EDID is new default\n");
1452 dlfb_ops_set_par(fb_info);
1453 return src_size;
1454 }
1456 static ssize_t metrics_reset_store(struct device *fbdev,
1457 struct device_attribute *attr,
1458 const char *buf, size_t count)
1459 {
1460 struct fb_info *fb_info = dev_get_drvdata(fbdev);
1461 struct dlfb_data *dev = fb_info->par;
1463 atomic_set(&dev->bytes_rendered, 0);
1464 atomic_set(&dev->bytes_identical, 0);
1465 atomic_set(&dev->bytes_sent, 0);
1466 atomic_set(&dev->cpu_kcycles_used, 0);
1468 return count;
1469 }
1471 static struct bin_attribute edid_attr = {
1472 .attr.name = "edid",
1473 .attr.mode = 0666,
1474 .size = EDID_LENGTH,
1475 .read = edid_show,
1476 .write = edid_store
1477 };
1479 static struct device_attribute fb_device_attrs[] = {
1480 __ATTR_RO(metrics_bytes_rendered),
1481 __ATTR_RO(metrics_bytes_identical),
1482 __ATTR_RO(metrics_bytes_sent),
1483 __ATTR_RO(metrics_cpu_kcycles_used),
1484 __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1485 };
1487 /*
1488 * This is necessary before we can communicate with the display controller.
1489 */
1490 static int dlfb_select_std_channel(struct dlfb_data *dev)
1491 {
1492 int ret;
1493 u8 set_def_chn[] = { 0x57, 0xCD, 0xDC, 0xA7,
1494 0x1C, 0x88, 0x5E, 0x15,
1495 0x60, 0xFE, 0xC6, 0x97,
1496 0x16, 0x3D, 0x47, 0xF2 };
1498 ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1499 NR_USB_REQUEST_CHANNEL,
1500 (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1501 set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1502 return ret;
1503 }
1505 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1506 struct usb_interface *interface)
1507 {
1508 char *desc;
1509 char *buf;
1510 char *desc_end;
1512 int total_len = 0;
1514 buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1515 if (!buf)
1516 return false;
1517 desc = buf;
1519 total_len = usb_get_descriptor(interface_to_usbdev(interface),
1520 0x5f, /* vendor specific */
1521 0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1523 /* if not found, look in configuration descriptor */
1524 if (total_len < 0) {
1525 if (0 == usb_get_extra_descriptor(interface->cur_altsetting,
1526 0x5f, &desc))
1527 total_len = (int) desc[0];
1528 }
1530 if (total_len > 5) {
1531 pr_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1532 "%02x %02x %02x %02x %02x %02x %02x\n",
1533 total_len, desc[0],
1534 desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1535 desc[7], desc[8], desc[9], desc[10]);
1537 if ((desc[0] != total_len) || /* descriptor length */
1538 (desc[1] != 0x5f) || /* vendor descriptor type */
1539 (desc[2] != 0x01) || /* version (2 bytes) */
1540 (desc[3] != 0x00) ||
1541 (desc[4] != total_len - 2)) /* length after type */
1542 goto unrecognized;
1544 desc_end = desc + total_len;
1545 desc += 5; /* the fixed header we've already parsed */
1547 while (desc < desc_end) {
1548 u8 length;
1549 u16 key;
1551 key = le16_to_cpu(*((u16 *) desc));
1552 desc += sizeof(u16);
1553 length = *desc;
1554 desc++;
1556 switch (key) {
1557 case 0x0200: { /* max_area */
1558 u32 max_area;
1559 max_area = le32_to_cpu(*((u32 *)desc));
1560 pr_warn("DL chip limited to %d pixel modes\n",
1561 max_area);
1562 dev->sku_pixel_limit = max_area;
1563 break;
1564 }
1565 default:
1566 break;
1567 }
1568 desc += length;
1569 }
1570 } else {
1571 pr_info("vendor descriptor not available (%d)\n", total_len);
1572 }
1574 goto success;
1576 unrecognized:
1577 /* allow udlfb to load for now even if firmware unrecognized */
1578 pr_err("Unrecognized vendor firmware descriptor\n");
1580 success:
1581 kfree(buf);
1582 return true;
1583 }
1585 static void dlfb_init_framebuffer_work(struct work_struct *work);
1587 static int dlfb_usb_probe(struct usb_interface *interface,
1588 const struct usb_device_id *id)
1589 {
1590 struct usb_device *usbdev;
1591 struct dlfb_data *dev = NULL;
1592 int retval = -ENOMEM;
1594 /* usb initialization */
1596 usbdev = interface_to_usbdev(interface);
1598 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1599 if (dev == NULL) {
1600 dev_err(&interface->dev, "dlfb_usb_probe: failed alloc of dev struct\n");
1601 goto error;
1602 }
1604 kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1606 dev->udev = usbdev;
1607 dev->gdev = &usbdev->dev; /* our generic struct device * */
1608 usb_set_intfdata(interface, dev);
1610 pr_info("%s %s - serial #%s\n",
1611 usbdev->manufacturer, usbdev->product, usbdev->serial);
1612 pr_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1613 usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1614 usbdev->descriptor.bcdDevice, dev);
1615 pr_info("console enable=%d\n", console);
1616 pr_info("fb_defio enable=%d\n", fb_defio);
1617 pr_info("shadow enable=%d\n", shadow);
1619 dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1621 if (!dlfb_parse_vendor_descriptor(dev, interface)) {
1622 pr_err("firmware not recognized. Assume incompatible device\n");
1623 goto error;
1624 }
1626 if (pixel_limit) {
1627 pr_warn("DL chip limit of %d overridden"
1628 " by module param to %d\n",
1629 dev->sku_pixel_limit, pixel_limit);
1630 dev->sku_pixel_limit = pixel_limit;
1631 }
1634 if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1635 retval = -ENOMEM;
1636 pr_err("dlfb_alloc_urb_list failed\n");
1637 goto error;
1638 }
1640 kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1642 /* We don't register a new USB class. Our client interface is fbdev */
1644 /* Workitem keep things fast & simple during USB enumeration */
1645 INIT_DELAYED_WORK(&dev->init_framebuffer_work,
1646 dlfb_init_framebuffer_work);
1647 schedule_delayed_work(&dev->init_framebuffer_work, 0);
1649 return 0;
1651 error:
1652 if (dev) {
1654 kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1655 kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1657 /* dev has been deallocated. Do not dereference */
1658 }
1660 return retval;
1661 }
1663 static void dlfb_init_framebuffer_work(struct work_struct *work)
1664 {
1665 struct dlfb_data *dev = container_of(work, struct dlfb_data,
1666 init_framebuffer_work.work);
1667 struct fb_info *info;
1668 int retval;
1669 int i;
1671 /* allocates framebuffer driver structure, not framebuffer memory */
1672 info = framebuffer_alloc(0, dev->gdev);
1673 if (!info) {
1674 retval = -ENOMEM;
1675 pr_err("framebuffer_alloc failed\n");
1676 goto error;
1677 }
1679 dev->info = info;
1680 info->par = dev;
1681 info->pseudo_palette = dev->pseudo_palette;
1682 info->fbops = &dlfb_ops;
1684 retval = fb_alloc_cmap(&info->cmap, 256, 0);
1685 if (retval < 0) {
1686 pr_err("fb_alloc_cmap failed %x\n", retval);
1687 goto error;
1688 }
1690 INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1691 dlfb_free_framebuffer_work);
1693 INIT_LIST_HEAD(&info->modelist);
1695 retval = dlfb_setup_modes(dev, info, NULL, 0);
1696 if (retval != 0) {
1697 pr_err("unable to find common mode for display and adapter\n");
1698 goto error;
1699 }
1701 /* ready to begin using device */
1703 atomic_set(&dev->usb_active, 1);
1704 dlfb_select_std_channel(dev);
1706 dlfb_ops_check_var(&info->var, info);
1707 dlfb_ops_set_par(info);
1709 retval = register_framebuffer(info);
1710 if (retval < 0) {
1711 pr_err("register_framebuffer failed %d\n", retval);
1712 goto error;
1713 }
1715 for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
1716 retval = device_create_file(info->dev, &fb_device_attrs[i]);
1717 if (retval) {
1718 pr_warn("device_create_file failed %d\n", retval);
1719 }
1720 }
1722 retval = device_create_bin_file(info->dev, &edid_attr);
1723 if (retval) {
1724 pr_warn("device_create_bin_file failed %d\n", retval);
1725 }
1727 pr_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1728 " Using %dK framebuffer memory\n", info->node,
1729 info->var.xres, info->var.yres,
1730 ((dev->backing_buffer) ?
1731 info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1732 return;
1734 error:
1735 dlfb_free_framebuffer(dev);
1736 }
1738 static void dlfb_usb_disconnect(struct usb_interface *interface)
1739 {
1740 struct dlfb_data *dev;
1741 struct fb_info *info;
1742 int i;
1744 dev = usb_get_intfdata(interface);
1745 info = dev->info;
1747 pr_info("USB disconnect starting\n");
1749 /* we virtualize until all fb clients release. Then we free */
1750 dev->virtualized = true;
1752 /* When non-active we'll update virtual framebuffer, but no new urbs */
1753 atomic_set(&dev->usb_active, 0);
1755 /* this function will wait for all in-flight urbs to complete */
1756 dlfb_free_urb_list(dev);
1758 if (info) {
1759 /* remove udlfb's sysfs interfaces */
1760 for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1761 device_remove_file(info->dev, &fb_device_attrs[i]);
1762 device_remove_bin_file(info->dev, &edid_attr);
1763 unlink_framebuffer(info);
1764 }
1766 usb_set_intfdata(interface, NULL);
1767 dev->udev = NULL;
1768 dev->gdev = NULL;
1770 /* if clients still have us open, will be freed on last close */
1771 if (dev->fb_count == 0)
1772 schedule_delayed_work(&dev->free_framebuffer_work, 0);
1774 /* release reference taken by kref_init in probe() */
1775 kref_put(&dev->kref, dlfb_free);
1777 /* consider dlfb_data freed */
1779 return;
1780 }
1782 static struct usb_driver dlfb_driver = {
1783 .name = "udlfb",
1784 .probe = dlfb_usb_probe,
1785 .disconnect = dlfb_usb_disconnect,
1786 .id_table = id_table,
1787 };
1789 module_usb_driver(dlfb_driver);
1791 static void dlfb_urb_completion(struct urb *urb)
1792 {
1793 struct urb_node *unode = urb->context;
1794 struct dlfb_data *dev = unode->dev;
1795 unsigned long flags;
1797 /* sync/async unlink faults aren't errors */
1798 if (urb->status) {
1799 if (!(urb->status == -ENOENT ||
1800 urb->status == -ECONNRESET ||
1801 urb->status == -ESHUTDOWN)) {
1802 pr_err("%s - nonzero write bulk status received: %d\n",
1803 __func__, urb->status);
1804 atomic_set(&dev->lost_pixels, 1);
1805 }
1806 }
1808 urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1810 spin_lock_irqsave(&dev->urbs.lock, flags);
1811 list_add_tail(&unode->entry, &dev->urbs.list);
1812 dev->urbs.available++;
1813 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1815 /*
1816 * When using fb_defio, we deadlock if up() is called
1817 * while another is waiting. So queue to another process.
1818 */
1819 if (fb_defio)
1820 schedule_delayed_work(&unode->release_urb_work, 0);
1821 else
1822 up(&dev->urbs.limit_sem);
1823 }
1825 static void dlfb_free_urb_list(struct dlfb_data *dev)
1826 {
1827 int count = dev->urbs.count;
1828 struct list_head *node;
1829 struct urb_node *unode;
1830 struct urb *urb;
1831 int ret;
1832 unsigned long flags;
1834 pr_notice("Freeing all render urbs\n");
1836 /* keep waiting and freeing, until we've got 'em all */
1837 while (count--) {
1839 /* Getting interrupted means a leak, but ok at disconnect */
1840 ret = down_interruptible(&dev->urbs.limit_sem);
1841 if (ret)
1842 break;
1844 spin_lock_irqsave(&dev->urbs.lock, flags);
1846 node = dev->urbs.list.next; /* have reserved one with sem */
1847 list_del_init(node);
1849 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1851 unode = list_entry(node, struct urb_node, entry);
1852 urb = unode->urb;
1854 /* Free each separately allocated piece */
1855 usb_free_coherent(urb->dev, dev->urbs.size,
1856 urb->transfer_buffer, urb->transfer_dma);
1857 usb_free_urb(urb);
1858 kfree(node);
1859 }
1861 dev->urbs.count = 0;
1862 }
1864 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1865 {
1866 int i = 0;
1867 struct urb *urb;
1868 struct urb_node *unode;
1869 char *buf;
1871 spin_lock_init(&dev->urbs.lock);
1873 dev->urbs.size = size;
1874 INIT_LIST_HEAD(&dev->urbs.list);
1876 while (i < count) {
1877 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1878 if (!unode)
1879 break;
1880 unode->dev = dev;
1882 INIT_DELAYED_WORK(&unode->release_urb_work,
1883 dlfb_release_urb_work);
1885 urb = usb_alloc_urb(0, GFP_KERNEL);
1886 if (!urb) {
1887 kfree(unode);
1888 break;
1889 }
1890 unode->urb = urb;
1892 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1893 &urb->transfer_dma);
1894 if (!buf) {
1895 kfree(unode);
1896 usb_free_urb(urb);
1897 break;
1898 }
1900 /* urb->transfer_buffer_length set to actual before submit */
1901 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1902 buf, size, dlfb_urb_completion, unode);
1903 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1905 list_add_tail(&unode->entry, &dev->urbs.list);
1907 i++;
1908 }
1910 sema_init(&dev->urbs.limit_sem, i);
1911 dev->urbs.count = i;
1912 dev->urbs.available = i;
1914 pr_notice("allocated %d %d byte urbs\n", i, (int) size);
1916 return i;
1917 }
1919 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1920 {
1921 int ret = 0;
1922 struct list_head *entry;
1923 struct urb_node *unode;
1924 struct urb *urb = NULL;
1925 unsigned long flags;
1927 /* Wait for an in-flight buffer to complete and get re-queued */
1928 ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1929 if (ret) {
1930 atomic_set(&dev->lost_pixels, 1);
1931 pr_warn("wait for urb interrupted: %x available: %d\n",
1932 ret, dev->urbs.available);
1933 goto error;
1934 }
1936 spin_lock_irqsave(&dev->urbs.lock, flags);
1938 BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1939 entry = dev->urbs.list.next;
1940 list_del_init(entry);
1941 dev->urbs.available--;
1943 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1945 unode = list_entry(entry, struct urb_node, entry);
1946 urb = unode->urb;
1948 error:
1949 return urb;
1950 }
1952 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1953 {
1954 int ret;
1956 BUG_ON(len > dev->urbs.size);
1958 urb->transfer_buffer_length = len; /* set to actual payload len */
1959 ret = usb_submit_urb(urb, GFP_KERNEL);
1960 if (ret) {
1961 dlfb_urb_completion(urb); /* because no one else will */
1962 atomic_set(&dev->lost_pixels, 1);
1963 pr_err("usb_submit_urb error %x\n", ret);
1964 }
1965 return ret;
1966 }
1968 module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1969 MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
1971 module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1972 MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
1974 module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1975 MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
1977 module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1978 MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)");
1980 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1981 "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1982 "Bernie Thompson <bernie@plugable.com>");
1983 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1984 MODULE_LICENSE("GPL");