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/prefetch.h>
31#include <linux/delay.h>
32#include <video/udlfb.h>
33#include "edid.h"
34
35static struct fb_fix_screeninfo dlfb_fix = {
36	.id =           "udlfb",
37	.type =         FB_TYPE_PACKED_PIXELS,
38	.visual =       FB_VISUAL_TRUECOLOR,
39	.xpanstep =     0,
40	.ypanstep =     0,
41	.ywrapstep =    0,
42	.accel =        FB_ACCEL_NONE,
43};
44
45static 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;
49
50/*
51 * There are many DisplayLink-based graphics products, all with unique PIDs.
52 * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
53 * We also require a match on SubClass (0x00) and Protocol (0x00),
54 * which is compatible with all known USB 2.0 era graphics chips and firmware,
55 * but allows DisplayLink to increment those for any future incompatible chips
56 */
57static 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};
69MODULE_DEVICE_TABLE(usb, id_table);
70
71/* module options */
72static bool console = 1; /* Allow fbcon to open framebuffer */
73static bool fb_defio = 1;  /* Detect mmap writes using page faults */
74static bool shadow = 1; /* Optionally disable shadow framebuffer */
75static int pixel_limit; /* Optionally force a pixel resolution limit */
76
77/* dlfb keeps a list of urbs for efficient bulk transfers */
78static void dlfb_urb_completion(struct urb *urb);
79static struct urb *dlfb_get_urb(struct dlfb_data *dev);
80static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
81static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
82static void dlfb_free_urb_list(struct dlfb_data *dev);
83
84/*
85 * All DisplayLink bulk operations start with 0xAF, followed by specific code
86 * All operations are written to buffers which then later get sent to device
87 */
88static char *dlfb_set_register(char *buf, u8 reg, u8 val)
89{
90	*buf++ = 0xAF;
91	*buf++ = 0x20;
92	*buf++ = reg;
93	*buf++ = val;
94	return buf;
95}
96
97static char *dlfb_vidreg_lock(char *buf)
98{
99	return dlfb_set_register(buf, 0xFF, 0x00);
100}
101
102static char *dlfb_vidreg_unlock(char *buf)
103{
104	return dlfb_set_register(buf, 0xFF, 0xFF);
105}
106
107/*
108 * Map FB_BLANK_* to DisplayLink register
109 * DLReg FB_BLANK_*
110 * ----- -----------------------------
111 *  0x00 FB_BLANK_UNBLANK (0)
112 *  0x01 FB_BLANK (1)
113 *  0x03 FB_BLANK_VSYNC_SUSPEND (2)
114 *  0x05 FB_BLANK_HSYNC_SUSPEND (3)
115 *  0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
116 */
117static char *dlfb_blanking(char *buf, int fb_blank)
118{
119	u8 reg;
120
121	switch (fb_blank) {
122	case FB_BLANK_POWERDOWN:
123		reg = 0x07;
124		break;
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	}
137
138	buf = dlfb_set_register(buf, 0x1F, reg);
139
140	return buf;
141}
142
143static char *dlfb_set_color_depth(char *buf, u8 selection)
144{
145	return dlfb_set_register(buf, 0x00, selection);
146}
147
148static char *dlfb_set_base16bpp(char *wrptr, u32 base)
149{
150	/* the base pointer is 16 bits wide, 0x20 is hi byte. */
151	wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
152	wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
153	return dlfb_set_register(wrptr, 0x22, base);
154}
155
156/*
157 * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
158 * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
159 */
160static char *dlfb_set_base8bpp(char *wrptr, u32 base)
161{
162	wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
163	wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
164	return dlfb_set_register(wrptr, 0x28, base);
165}
166
167static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
168{
169	wrptr = dlfb_set_register(wrptr, reg, value >> 8);
170	return dlfb_set_register(wrptr, reg+1, value);
171}
172
173/*
174 * This is kind of weird because the controller takes some
175 * register values in a different byte order than other registers.
176 */
177static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
178{
179	wrptr = dlfb_set_register(wrptr, reg, value);
180	return dlfb_set_register(wrptr, reg+1, value >> 8);
181}
182
183/*
184 * LFSR is linear feedback shift register. The reason we have this is
185 * because the display controller needs to minimize the clock depth of
186 * various counters used in the display path. So this code reverses the
187 * provided value into the lfsr16 value by counting backwards to get
188 * the value that needs to be set in the hardware comparator to get the
189 * same actual count. This makes sense once you read above a couple of
190 * times and think about it from a hardware perspective.
191 */
192static u16 dlfb_lfsr16(u16 actual_count)
193{
194	u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
195
196	while (actual_count--) {
197		lv =	 ((lv << 1) |
198			(((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
199			& 0xFFFF;
200	}
201
202	return (u16) lv;
203}
204
205/*
206 * This does LFSR conversion on the value that is to be written.
207 * See LFSR explanation above for more detail.
208 */
209static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
210{
211	return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
212}
213
214/*
215 * This takes a standard fbdev screeninfo struct and all of its monitor mode
216 * details and converts them into the DisplayLink equivalent register commands.
217 */
218static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
219{
220	u16 xds, yds;
221	u16 xde, yde;
222	u16 yec;
223
224	/* x display start */
225	xds = var->left_margin + var->hsync_len;
226	wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
227	/* x display end */
228	xde = xds + var->xres;
229	wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
230
231	/* y display start */
232	yds = var->upper_margin + var->vsync_len;
233	wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
234	/* y display end */
235	yde = yds + var->yres;
236	wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
237
238	/* x end count is active + blanking - 1 */
239	wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
240			xde + var->right_margin - 1);
241
242	/* libdlo hardcodes hsync start to 1 */
243	wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
244
245	/* hsync end is width of sync pulse + 1 */
246	wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
247
248	/* hpixels is active pixels */
249	wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
250
251	/* yendcount is vertical active + vertical blanking */
252	yec = var->yres + var->upper_margin + var->lower_margin +
253			var->vsync_len;
254	wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
255
256	/* libdlo hardcodes vsync start to 0 */
257	wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
258
259	/* vsync end is width of vsync pulse */
260	wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
261
262	/* vpixels is active pixels */
263	wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
264
265	/* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
266	wrptr = dlfb_set_register_16be(wrptr, 0x1B,
267			200*1000*1000/var->pixclock);
268
269	return wrptr;
270}
271
272/*
273 * This takes a standard fbdev screeninfo struct that was fetched or prepared
274 * and then generates the appropriate command sequence that then drives the
275 * display controller.
276 */
277static 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;
283	int writesize;
284	struct urb *urb;
285
286	if (!atomic_read(&dev->usb_active))
287		return -EPERM;
288
289	urb = dlfb_get_urb(dev);
290	if (!urb)
291		return -ENOMEM;
292
293	buf = (char *) urb->transfer_buffer;
294
295	/*
296	* This first section has to do with setting the base address on the
297	* controller * associated with the display. There are 2 base
298	* pointers, currently, we only * use the 16 bpp segment.
299	*/
300	wrptr = dlfb_vidreg_lock(buf);
301	wrptr = dlfb_set_color_depth(wrptr, 0x00);
302	/* set base for 16bpp segment to 0 */
303	wrptr = dlfb_set_base16bpp(wrptr, 0);
304	/* set base for 8bpp segment to end of fb */
305	wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
306
307	wrptr = dlfb_set_vid_cmds(wrptr, var);
308	wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
309	wrptr = dlfb_vidreg_unlock(wrptr);
310
311	writesize = wrptr - buf;
312
313	retval = dlfb_submit_urb(dev, urb, writesize);
314
315	dev->blank_mode = FB_BLANK_UNBLANK;
316
317	return retval;
318}
319
320static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
321{
322	unsigned long start = vma->vm_start;
323	unsigned long size = vma->vm_end - vma->vm_start;
324	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
325	unsigned long page, pos;
326
327	if (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;
333
334	pos = (unsigned long)info->fix.smem_start + offset;
335
336	pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
337		  pos, size);
338
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;
343
344		start += PAGE_SIZE;
345		pos += PAGE_SIZE;
346		if (size > PAGE_SIZE)
347			size -= PAGE_SIZE;
348		else
349			size = 0;
350	}
351
352	return 0;
353}
354
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 */
362static 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;
371
372	prefetch((void *) front);
373	prefetch((void *) back);
374
375	for (j = 0; j < width; j++) {
376		if (back[j] != front[j]) {
377			start = j;
378			break;
379		}
380	}
381
382	for (k = width - 1; k > j; k--) {
383		if (back[k] != front[k]) {
384			end = k+1;
385			break;
386		}
387	}
388
389	identical = start + (width - end);
390	*bfront = (u8 *) &front[start];
391	*width_bytes = (end - start) * sizeof(unsigned long);
392
393	return identical * sizeof(unsigned long);
394}
395
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 */
423static 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;
434
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;
441
442		prefetchw((void *) cmd); /* pull in one cache line at least */
443
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);
449
450		cmd_pixels_count_byte = cmd++; /*  we'll know this later */
451		cmd_pixel_start = pixel;
452
453		raw_pixels_count_byte = cmd++; /*  we'll know this later */
454		raw_pixel_start = pixel;
455
456		cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
457			min((int)(pixel_end - pixel),
458			    (int)(cmd_buffer_end - cmd) / bpp));
459
460		prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
461
462		while (pixel < cmd_pixel_end) {
463			const uint16_t * const repeating_pixel = pixel;
464
465			*(uint16_t *)cmd = cpu_to_be16p(pixel);
466			cmd += 2;
467			pixel++;
468
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;
474
475				while ((pixel < cmd_pixel_end)
476				       && (*pixel == *repeating_pixel)) {
477					pixel++;
478				}
479
480				/* immediately after raw data is repeat byte */
481				*cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
482
483				/* Then start another raw pixel span */
484				raw_pixel_start = pixel;
485				raw_pixels_count_byte = cmd++;
486			}
487		}
488
489		if (pixel > raw_pixel_start) {
490			/* finalize last RAW span */
491			*raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
492		}
493
494		*cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
495		dev_addr += (pixel - cmd_pixel_start) * bpp;
496	}
497
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	}
504
505	*command_buffer_ptr = cmd;
506	*pixel_start_ptr = pixel;
507	*device_address_ptr = dev_addr;
508
509	return;
510}
511
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 */
518static 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;
528
529	line_start = (u8 *) (front + byte_offset);
530	next_pixel = line_start;
531	line_end = next_pixel + byte_width;
532
533	if (dev->backing_buffer) {
534		int offset;
535		const u8 *back_start = (u8 *) (dev->backing_buffer
536						+ byte_offset);
537
538		*ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
539			&byte_width);
540
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;
546
547		memcpy((char *)back_start, (char *) line_start,
548		       byte_width);
549	}
550
551	while (next_pixel < line_end) {
552
553		dlfb_compress_hline((const uint16_t **) &next_pixel,
554			     (const uint16_t *) line_end, &dev_addr,
555			(u8 **) &cmd, (u8 *) cmd_end);
556
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	}
570
571	*urb_buf_ptr = cmd;
572
573	return 0;
574}
575
576static 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;
586
587	start_cycles = get_cycles();
588
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;
592
593	if ((width <= 0) ||
594	    (x + width > dev->info->var.xres) ||
595	    (y + height > dev->info->var.yres))
596		return -EINVAL;
597
598	if (!atomic_read(&dev->usb_active))
599		return 0;
600
601	urb = dlfb_get_urb(dev);
602	if (!urb)
603		return 0;
604	cmd = urb->transfer_buffer;
605
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);
609
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	}
616
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);
624
625error:
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);
633
634	return 0;
635}
636
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 */
643static 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;
649
650	result = fb_sys_write(info, buf, count, ppos);
651
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);
656
657		dlfb_handle_damage(dev, 0, start, info->var.xres,
658			lines, info->screen_base);
659	}
660
661	return result;
662}
663
664/* hardware has native COPY command (see libdlo), but not worth it for fbcon */
665static void dlfb_ops_copyarea(struct fb_info *info,
666				const struct fb_copyarea *area)
667{
668
669	struct dlfb_data *dev = info->par;
670
671	sys_copyarea(info, area);
672
673	dlfb_handle_damage(dev, area->dx, area->dy,
674			area->width, area->height, info->screen_base);
675}
676
677static void dlfb_ops_imageblit(struct fb_info *info,
678				const struct fb_image *image)
679{
680	struct dlfb_data *dev = info->par;
681
682	sys_imageblit(info, image);
683
684	dlfb_handle_damage(dev, image->dx, image->dy,
685			image->width, image->height, info->screen_base);
686}
687
688static void dlfb_ops_fillrect(struct fb_info *info,
689			  const struct fb_fillrect *rect)
690{
691	struct dlfb_data *dev = info->par;
692
693	sys_fillrect(info, rect);
694
695	dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
696			      rect->height, info->screen_base);
697}
698
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 */
705static 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;
717
718	if (!fb_defio)
719		return;
720
721	if (!atomic_read(&dev->usb_active))
722		return;
723
724	start_cycles = get_cycles();
725
726	urb = dlfb_get_urb(dev);
727	if (!urb)
728		return;
729
730	cmd = urb->transfer_buffer;
731
732	/* walk the written page list and render each to device */
733	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
734
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	}
741
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);
749
750error:
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}
759
760static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
761{
762	int i;
763	int ret;
764	char *rbuf;
765
766	rbuf = kmalloc(2, GFP_KERNEL);
767	if (!rbuf)
768		return 0;
769
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	}
782
783	kfree(rbuf);
784
785	return i;
786}
787
788static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
789				unsigned long arg)
790{
791
792	struct dlfb_data *dev = info->par;
793
794	if (!atomic_read(&dev->usb_active))
795		return 0;
796
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	}
804
805	/* TODO: Help propose a standard fb.h ioctl to report mmap damage */
806	if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
807		struct dloarea area;
808
809		if (copy_from_user(&area, (void __user *)arg,
810				  sizeof(struct dloarea)))
811			return -EFAULT;
812
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;
822
823		if (area.x < 0)
824			area.x = 0;
825
826		if (area.x > info->var.xres)
827			area.x = info->var.xres;
828
829		if (area.y < 0)
830			area.y = 0;
831
832		if (area.y > info->var.yres)
833			area.y = info->var.yres;
834
835		dlfb_handle_damage(dev, area.x, area.y, area.w, area.h,
836			   info->screen_base);
837	}
838
839	return 0;
840}
841
842/* taken from vesafb */
843static int
844dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
845	       unsigned blue, unsigned transp, struct fb_info *info)
846{
847	int err = 0;
848
849	if (regno >= info->cmap.len)
850		return 1;
851
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	}
865
866	return err;
867}
868
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 */
874static int dlfb_ops_open(struct fb_info *info, int user)
875{
876	struct dlfb_data *dev = info->par;
877
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;
885
886	/* If the USB device is gone, we don't accept new opens */
887	if (dev->virtualized)
888		return -ENODEV;
889
890	dev->fb_count++;
891
892	kref_get(&dev->kref);
893
894	if (fb_defio && (info->fbdefio == NULL)) {
895		/* enable defio at last moment if not disabled by client */
896
897		struct fb_deferred_io *fbdefio;
898
899		fbdefio = kzalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
900
901		if (fbdefio) {
902			fbdefio->delay = DL_DEFIO_WRITE_DELAY;
903			fbdefio->deferred_io = dlfb_dpy_deferred_io;
904		}
905
906		info->fbdefio = fbdefio;
907		fb_deferred_io_init(info);
908	}
909
910	pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
911	    info->node, user, info, dev->fb_count);
912
913	return 0;
914}
915
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 */
921static void dlfb_free(struct kref *kref)
922{
923	struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
924
925	vfree(dev->backing_buffer);
926
927	kfree(dev->edid);
928
929	pr_warn("freeing dlfb_data %p\n", dev);
930
931	kfree(dev);
932}
933
934static void dlfb_release_urb_work(struct work_struct *work)
935{
936	struct urb_node *unode = container_of(work, struct urb_node,
937					      release_urb_work.work);
938
939	up(&unode->dev->urbs.limit_sem);
940}
941
942static void dlfb_free_framebuffer(struct dlfb_data *dev)
943{
944	struct fb_info *info = dev->info;
945
946	if (info) {
947		int node = info->node;
948
949		unregister_framebuffer(info);
950
951		if (info->cmap.len != 0)
952			fb_dealloc_cmap(&info->cmap);
953		if (info->monspecs.modedb)
954			fb_destroy_modedb(info->monspecs.modedb);
955		vfree(info->screen_base);
956
957		fb_destroy_modelist(&info->modelist);
958
959		dev->info = NULL;
960
961		/* Assume info structure is freed after this point */
962		framebuffer_release(info);
963
964		pr_warn("fb_info for /dev/fb%d has been freed\n", node);
965	}
966
967	/* ref taken in probe() as part of registering framebfufer */
968	kref_put(&dev->kref, dlfb_free);
969}
970
971static void dlfb_free_framebuffer_work(struct work_struct *work)
972{
973	struct dlfb_data *dev = container_of(work, struct dlfb_data,
974					     free_framebuffer_work.work);
975	dlfb_free_framebuffer(dev);
976}
977/*
978 * Assumes caller is holding info->lock mutex (for open and release at least)
979 */
980static int dlfb_ops_release(struct fb_info *info, int user)
981{
982	struct dlfb_data *dev = info->par;
983
984	dev->fb_count--;
985
986	/* We can't free fb_info here - fbmem will touch it when we return */
987	if (dev->virtualized && (dev->fb_count == 0))
988		schedule_delayed_work(&dev->free_framebuffer_work, HZ);
989
990	if ((dev->fb_count == 0) && (info->fbdefio)) {
991		fb_deferred_io_cleanup(info);
992		kfree(info->fbdefio);
993		info->fbdefio = NULL;
994		info->fbops->fb_mmap = dlfb_ops_mmap;
995	}
996
997	pr_warn("released /dev/fb%d user=%d count=%d\n",
998		  info->node, user, dev->fb_count);
999
1000	kref_put(&dev->kref, dlfb_free);
1001
1002	return 0;
1003}
1004
1005/*
1006 * Check whether a video mode is supported by the DisplayLink chip
1007 * We start from monitor's modes, so don't need to filter that here
1008 */
1009static int dlfb_is_valid_mode(struct fb_videomode *mode,
1010		struct fb_info *info)
1011{
1012	struct dlfb_data *dev = info->par;
1013
1014	if (mode->xres * mode->yres > dev->sku_pixel_limit) {
1015		pr_warn("%dx%d beyond chip capabilities\n",
1016		       mode->xres, mode->yres);
1017		return 0;
1018	}
1019
1020	pr_info("%dx%d @ %d Hz valid mode\n", mode->xres, mode->yres,
1021		mode->refresh);
1022
1023	return 1;
1024}
1025
1026static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1027{
1028	const struct fb_bitfield red = { 11, 5, 0 };
1029	const struct fb_bitfield green = { 5, 6, 0 };
1030	const struct fb_bitfield blue = { 0, 5, 0 };
1031
1032	var->bits_per_pixel = 16;
1033	var->red = red;
1034	var->green = green;
1035	var->blue = blue;
1036}
1037
1038static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1039				struct fb_info *info)
1040{
1041	struct fb_videomode mode;
1042
1043	/* TODO: support dynamically changing framebuffer size */
1044	if ((var->xres * var->yres * 2) > info->fix.smem_len)
1045		return -EINVAL;
1046
1047	/* set device-specific elements of var unrelated to mode */
1048	dlfb_var_color_format(var);
1049
1050	fb_var_to_videomode(&mode, var);
1051
1052	if (!dlfb_is_valid_mode(&mode, info))
1053		return -EINVAL;
1054
1055	return 0;
1056}
1057
1058static int dlfb_ops_set_par(struct fb_info *info)
1059{
1060	struct dlfb_data *dev = info->par;
1061	int result;
1062	u16 *pix_framebuffer;
1063	int i;
1064
1065	pr_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
1066
1067	result = dlfb_set_video_mode(dev, &info->var);
1068
1069	if ((result == 0) && (dev->fb_count == 0)) {
1070
1071		/* paint greenscreen */
1072
1073		pix_framebuffer = (u16 *) info->screen_base;
1074		for (i = 0; i < info->fix.smem_len / 2; i++)
1075			pix_framebuffer[i] = 0x37e6;
1076
1077		dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1078				   info->screen_base);
1079	}
1080
1081	return result;
1082}
1083
1084/* To fonzi the jukebox (e.g. make blanking changes take effect) */
1085static char *dlfb_dummy_render(char *buf)
1086{
1087	*buf++ = 0xAF;
1088	*buf++ = 0x6A; /* copy */
1089	*buf++ = 0x00; /* from address*/
1090	*buf++ = 0x00;
1091	*buf++ = 0x00;
1092	*buf++ = 0x01; /* one pixel */
1093	*buf++ = 0x00; /* to address */
1094	*buf++ = 0x00;
1095	*buf++ = 0x00;
1096	return buf;
1097}
1098
1099/*
1100 * In order to come back from full DPMS off, we need to set the mode again
1101 */
1102static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1103{
1104	struct dlfb_data *dev = info->par;
1105	char *bufptr;
1106	struct urb *urb;
1107
1108	pr_info("/dev/fb%d FB_BLANK mode %d --> %d\n",
1109		info->node, dev->blank_mode, blank_mode);
1110
1111	if ((dev->blank_mode == FB_BLANK_POWERDOWN) &&
1112	    (blank_mode != FB_BLANK_POWERDOWN)) {
1113
1114		/* returning from powerdown requires a fresh modeset */
1115		dlfb_set_video_mode(dev, &info->var);
1116	}
1117
1118	urb = dlfb_get_urb(dev);
1119	if (!urb)
1120		return 0;
1121
1122	bufptr = (char *) urb->transfer_buffer;
1123	bufptr = dlfb_vidreg_lock(bufptr);
1124	bufptr = dlfb_blanking(bufptr, blank_mode);
1125	bufptr = dlfb_vidreg_unlock(bufptr);
1126
1127	/* seems like a render op is needed to have blank change take effect */
1128	bufptr = dlfb_dummy_render(bufptr);
1129
1130	dlfb_submit_urb(dev, urb, bufptr -
1131			(char *) urb->transfer_buffer);
1132
1133	dev->blank_mode = blank_mode;
1134
1135	return 0;
1136}
1137
1138static struct fb_ops dlfb_ops = {
1139	.owner = THIS_MODULE,
1140	.fb_read = fb_sys_read,
1141	.fb_write = dlfb_ops_write,
1142	.fb_setcolreg = dlfb_ops_setcolreg,
1143	.fb_fillrect = dlfb_ops_fillrect,
1144	.fb_copyarea = dlfb_ops_copyarea,
1145	.fb_imageblit = dlfb_ops_imageblit,
1146	.fb_mmap = dlfb_ops_mmap,
1147	.fb_ioctl = dlfb_ops_ioctl,
1148	.fb_open = dlfb_ops_open,
1149	.fb_release = dlfb_ops_release,
1150	.fb_blank = dlfb_ops_blank,
1151	.fb_check_var = dlfb_ops_check_var,
1152	.fb_set_par = dlfb_ops_set_par,
1153};
1154
1155
1156/*
1157 * Assumes &info->lock held by caller
1158 * Assumes no active clients have framebuffer open
1159 */
1160static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1161{
1162	int retval = -ENOMEM;
1163	int old_len = info->fix.smem_len;
1164	int new_len;
1165	unsigned char *old_fb = info->screen_base;
1166	unsigned char *new_fb;
1167	unsigned char *new_back = NULL;
1168
1169	pr_warn("Reallocating framebuffer. Addresses will change!\n");
1170
1171	new_len = info->fix.line_length * info->var.yres;
1172
1173	if (PAGE_ALIGN(new_len) > old_len) {
1174		/*
1175		 * Alloc system memory for virtual framebuffer
1176		 */
1177		new_fb = vmalloc(new_len);
1178		if (!new_fb) {
1179			pr_err("Virtual framebuffer alloc failed\n");
1180			goto error;
1181		}
1182
1183		if (info->screen_base) {
1184			memcpy(new_fb, old_fb, old_len);
1185			vfree(info->screen_base);
1186		}
1187
1188		info->screen_base = new_fb;
1189		info->fix.smem_len = PAGE_ALIGN(new_len);
1190		info->fix.smem_start = (unsigned long) new_fb;
1191		info->flags = udlfb_info_flags;
1192
1193		/*
1194		 * Second framebuffer copy to mirror the framebuffer state
1195		 * on the physical USB device. We can function without this.
1196		 * But with imperfect damage info we may send pixels over USB
1197		 * that were, in fact, unchanged - wasting limited USB bandwidth
1198		 */
1199		if (shadow)
1200			new_back = vzalloc(new_len);
1201		if (!new_back)
1202			pr_info("No shadow/backing buffer allocated\n");
1203		else {
1204			vfree(dev->backing_buffer);
1205			dev->backing_buffer = new_back;
1206		}
1207	}
1208
1209	retval = 0;
1210
1211error:
1212	return retval;
1213}
1214
1215/*
1216 * 1) Get EDID from hw, or use sw default
1217 * 2) Parse into various fb_info structs
1218 * 3) Allocate virtual framebuffer memory to back highest res mode
1219 *
1220 * Parses EDID into three places used by various parts of fbdev:
1221 * fb_var_screeninfo contains the timing of the monitor's preferred mode
1222 * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1223 * fb_info.modelist is a linked list of all monitor & VESA modes which work
1224 *
1225 * If EDID is not readable/valid, then modelist is all VESA modes,
1226 * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1227 * Returns 0 if successful
1228 */
1229static int dlfb_setup_modes(struct dlfb_data *dev,
1230			   struct fb_info *info,
1231			   char *default_edid, size_t default_edid_size)
1232{
1233	int i;
1234	const struct fb_videomode *default_vmode = NULL;
1235	int result = 0;
1236	char *edid;
1237	int tries = 3;
1238
1239	if (info->dev) /* only use mutex if info has been registered */
1240		mutex_lock(&info->lock);
1241
1242	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1243	if (!edid) {
1244		result = -ENOMEM;
1245		goto error;
1246	}
1247
1248	fb_destroy_modelist(&info->modelist);
1249	memset(&info->monspecs, 0, sizeof(info->monspecs));
1250
1251	/*
1252	 * Try to (re)read EDID from hardware first
1253	 * EDID data may return, but not parse as valid
1254	 * Try again a few times, in case of e.g. analog cable noise
1255	 */
1256	while (tries--) {
1257
1258		i = dlfb_get_edid(dev, edid, EDID_LENGTH);
1259
1260		if (i >= EDID_LENGTH)
1261			fb_edid_to_monspecs(edid, &info->monspecs);
1262
1263		if (info->monspecs.modedb_len > 0) {
1264			dev->edid = edid;
1265			dev->edid_size = i;
1266			break;
1267		}
1268	}
1269
1270	/* If that fails, use a previously returned EDID if available */
1271	if (info->monspecs.modedb_len == 0) {
1272
1273		pr_err("Unable to get valid EDID from device/display\n");
1274
1275		if (dev->edid) {
1276			fb_edid_to_monspecs(dev->edid, &info->monspecs);
1277			if (info->monspecs.modedb_len > 0)
1278				pr_err("Using previously queried EDID\n");
1279		}
1280	}
1281
1282	/* If that fails, use the default EDID we were handed */
1283	if (info->monspecs.modedb_len == 0) {
1284		if (default_edid_size >= EDID_LENGTH) {
1285			fb_edid_to_monspecs(default_edid, &info->monspecs);
1286			if (info->monspecs.modedb_len > 0) {
1287				memcpy(edid, default_edid, default_edid_size);
1288				dev->edid = edid;
1289				dev->edid_size = default_edid_size;
1290				pr_err("Using default/backup EDID\n");
1291			}
1292		}
1293	}
1294
1295	/* If we've got modes, let's pick a best default mode */
1296	if (info->monspecs.modedb_len > 0) {
1297
1298		for (i = 0; i < info->monspecs.modedb_len; i++) {
1299			if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1300				fb_add_videomode(&info->monspecs.modedb[i],
1301					&info->modelist);
1302			else {
1303				if (i == 0)
1304					/* if we've removed top/best mode */
1305					info->monspecs.misc
1306						&= ~FB_MISC_1ST_DETAIL;
1307			}
1308		}
1309
1310		default_vmode = fb_find_best_display(&info->monspecs,
1311						     &info->modelist);
1312	}
1313
1314	/* If everything else has failed, fall back to safe default mode */
1315	if (default_vmode == NULL) {
1316
1317		struct fb_videomode fb_vmode = {0};
1318
1319		/*
1320		 * Add the standard VESA modes to our modelist
1321		 * Since we don't have EDID, there may be modes that
1322		 * overspec monitor and/or are incorrect aspect ratio, etc.
1323		 * But at least the user has a chance to choose
1324		 */
1325		for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1326			if (dlfb_is_valid_mode((struct fb_videomode *)
1327						&vesa_modes[i], info))
1328				fb_add_videomode(&vesa_modes[i],
1329						 &info->modelist);
1330		}
1331
1332		/*
1333		 * default to resolution safe for projectors
1334		 * (since they are most common case without EDID)
1335		 */
1336		fb_vmode.xres = 800;
1337		fb_vmode.yres = 600;
1338		fb_vmode.refresh = 60;
1339		default_vmode = fb_find_nearest_mode(&fb_vmode,
1340						     &info->modelist);
1341	}
1342
1343	/* If we have good mode and no active clients*/
1344	if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1345
1346		fb_videomode_to_var(&info->var, default_vmode);
1347		dlfb_var_color_format(&info->var);
1348
1349		/*
1350		 * with mode size info, we can now alloc our framebuffer.
1351		 */
1352		memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1353		info->fix.line_length = info->var.xres *
1354			(info->var.bits_per_pixel / 8);
1355
1356		result = dlfb_realloc_framebuffer(dev, info);
1357
1358	} else
1359		result = -EINVAL;
1360
1361error:
1362	if (edid && (dev->edid != edid))
1363		kfree(edid);
1364
1365	if (info->dev)
1366		mutex_unlock(&info->lock);
1367
1368	return result;
1369}
1370
1371static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1372				   struct device_attribute *a, char *buf) {
1373	struct fb_info *fb_info = dev_get_drvdata(fbdev);
1374	struct dlfb_data *dev = fb_info->par;
1375	return snprintf(buf, PAGE_SIZE, "%u\n",
1376			atomic_read(&dev->bytes_rendered));
1377}
1378
1379static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1380				   struct device_attribute *a, char *buf) {
1381	struct fb_info *fb_info = dev_get_drvdata(fbdev);
1382	struct dlfb_data *dev = fb_info->par;
1383	return snprintf(buf, PAGE_SIZE, "%u\n",
1384			atomic_read(&dev->bytes_identical));
1385}
1386
1387static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1388				   struct device_attribute *a, char *buf) {
1389	struct fb_info *fb_info = dev_get_drvdata(fbdev);
1390	struct dlfb_data *dev = fb_info->par;
1391	return snprintf(buf, PAGE_SIZE, "%u\n",
1392			atomic_read(&dev->bytes_sent));
1393}
1394
1395static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1396				   struct device_attribute *a, char *buf) {
1397	struct fb_info *fb_info = dev_get_drvdata(fbdev);
1398	struct dlfb_data *dev = fb_info->par;
1399	return snprintf(buf, PAGE_SIZE, "%u\n",
1400			atomic_read(&dev->cpu_kcycles_used));
1401}
1402
1403static ssize_t edid_show(
1404			struct file *filp,
1405			struct kobject *kobj, struct bin_attribute *a,
1406			 char *buf, loff_t off, size_t count) {
1407	struct device *fbdev = container_of(kobj, struct device, kobj);
1408	struct fb_info *fb_info = dev_get_drvdata(fbdev);
1409	struct dlfb_data *dev = fb_info->par;
1410
1411	if (dev->edid == NULL)
1412		return 0;
1413
1414	if ((off >= dev->edid_size) || (count > dev->edid_size))
1415		return 0;
1416
1417	if (off + count > dev->edid_size)
1418		count = dev->edid_size - off;
1419
1420	pr_info("sysfs edid copy %p to %p, %d bytes\n",
1421		dev->edid, buf, (int) count);
1422
1423	memcpy(buf, dev->edid, count);
1424
1425	return count;
1426}
1427
1428static ssize_t edid_store(
1429			struct file *filp,
1430			struct kobject *kobj, struct bin_attribute *a,
1431			char *src, loff_t src_off, size_t src_size) {
1432	struct device *fbdev = container_of(kobj, struct device, kobj);
1433	struct fb_info *fb_info = dev_get_drvdata(fbdev);
1434	struct dlfb_data *dev = fb_info->par;
1435	int ret;
1436
1437	/* We only support write of entire EDID at once, no offset*/
1438	if ((src_size != EDID_LENGTH) || (src_off != 0))
1439		return -EINVAL;
1440
1441	ret = dlfb_setup_modes(dev, fb_info, src, src_size);
1442	if (ret)
1443		return ret;
1444
1445	if (!dev->edid || memcmp(src, dev->edid, src_size))
1446		return -EINVAL;
1447
1448	pr_info("sysfs written EDID is new default\n");
1449	dlfb_ops_set_par(fb_info);
1450	return src_size;
1451}
1452
1453static ssize_t metrics_reset_store(struct device *fbdev,
1454			   struct device_attribute *attr,
1455			   const char *buf, size_t count)
1456{
1457	struct fb_info *fb_info = dev_get_drvdata(fbdev);
1458	struct dlfb_data *dev = fb_info->par;
1459
1460	atomic_set(&dev->bytes_rendered, 0);
1461	atomic_set(&dev->bytes_identical, 0);
1462	atomic_set(&dev->bytes_sent, 0);
1463	atomic_set(&dev->cpu_kcycles_used, 0);
1464
1465	return count;
1466}
1467
1468static struct bin_attribute edid_attr = {
1469	.attr.name = "edid",
1470	.attr.mode = 0666,
1471	.size = EDID_LENGTH,
1472	.read = edid_show,
1473	.write = edid_store
1474};
1475
1476static struct device_attribute fb_device_attrs[] = {
1477	__ATTR_RO(metrics_bytes_rendered),
1478	__ATTR_RO(metrics_bytes_identical),
1479	__ATTR_RO(metrics_bytes_sent),
1480	__ATTR_RO(metrics_cpu_kcycles_used),
1481	__ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1482};
1483
1484/*
1485 * This is necessary before we can communicate with the display controller.
1486 */
1487static int dlfb_select_std_channel(struct dlfb_data *dev)
1488{
1489	int ret;
1490	u8 set_def_chn[] = {	   0x57, 0xCD, 0xDC, 0xA7,
1491				0x1C, 0x88, 0x5E, 0x15,
1492				0x60, 0xFE, 0xC6, 0x97,
1493				0x16, 0x3D, 0x47, 0xF2  };
1494
1495	ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1496			NR_USB_REQUEST_CHANNEL,
1497			(USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1498			set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1499	return ret;
1500}
1501
1502static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1503					struct usb_interface *interface)
1504{
1505	char *desc;
1506	char *buf;
1507	char *desc_end;
1508	int total_len;
1509
1510	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1511	if (!buf)
1512		return false;
1513	desc = buf;
1514
1515	total_len = usb_get_descriptor(interface_to_usbdev(interface),
1516					0x5f, /* vendor specific */
1517					0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1518
1519	/* if not found, look in configuration descriptor */
1520	if (total_len < 0) {
1521		if (0 == usb_get_extra_descriptor(interface->cur_altsetting,
1522			0x5f, &desc))
1523			total_len = (int) desc[0];
1524	}
1525
1526	if (total_len > 5) {
1527		pr_info("vendor descriptor length:%x data:%11ph\n", total_len,
1528			desc);
1529
1530		if ((desc[0] != total_len) || /* descriptor length */
1531		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
1532		    (desc[2] != 0x01) ||   /* version (2 bytes) */
1533		    (desc[3] != 0x00) ||
1534		    (desc[4] != total_len - 2)) /* length after type */
1535			goto unrecognized;
1536
1537		desc_end = desc + total_len;
1538		desc += 5; /* the fixed header we've already parsed */
1539
1540		while (desc < desc_end) {
1541			u8 length;
1542			u16 key;
1543
1544			key = le16_to_cpu(*((u16 *) desc));
1545			desc += sizeof(u16);
1546			length = *desc;
1547			desc++;
1548
1549			switch (key) {
1550			case 0x0200: { /* max_area */
1551				u32 max_area;
1552				max_area = le32_to_cpu(*((u32 *)desc));
1553				pr_warn("DL chip limited to %d pixel modes\n",
1554					max_area);
1555				dev->sku_pixel_limit = max_area;
1556				break;
1557			}
1558			default:
1559				break;
1560			}
1561			desc += length;
1562		}
1563	} else {
1564		pr_info("vendor descriptor not available (%d)\n", total_len);
1565	}
1566
1567	goto success;
1568
1569unrecognized:
1570	/* allow udlfb to load for now even if firmware unrecognized */
1571	pr_err("Unrecognized vendor firmware descriptor\n");
1572
1573success:
1574	kfree(buf);
1575	return true;
1576}
1577
1578static void dlfb_init_framebuffer_work(struct work_struct *work);
1579
1580static int dlfb_usb_probe(struct usb_interface *interface,
1581			const struct usb_device_id *id)
1582{
1583	struct usb_device *usbdev;
1584	struct dlfb_data *dev;
1585	int retval = -ENOMEM;
1586
1587	/* usb initialization */
1588
1589	usbdev = interface_to_usbdev(interface);
1590
1591	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1592	if (dev == NULL) {
1593		dev_err(&interface->dev, "dlfb_usb_probe: failed alloc of dev struct\n");
1594		goto error;
1595	}
1596
1597	kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1598
1599	dev->udev = usbdev;
1600	dev->gdev = &usbdev->dev; /* our generic struct device * */
1601	usb_set_intfdata(interface, dev);
1602
1603	pr_info("%s %s - serial #%s\n",
1604		usbdev->manufacturer, usbdev->product, usbdev->serial);
1605	pr_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1606		usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1607		usbdev->descriptor.bcdDevice, dev);
1608	pr_info("console enable=%d\n", console);
1609	pr_info("fb_defio enable=%d\n", fb_defio);
1610	pr_info("shadow enable=%d\n", shadow);
1611
1612	dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1613
1614	if (!dlfb_parse_vendor_descriptor(dev, interface)) {
1615		pr_err("firmware not recognized. Assume incompatible device\n");
1616		goto error;
1617	}
1618
1619	if (pixel_limit) {
1620		pr_warn("DL chip limit of %d overridden"
1621			" by module param to %d\n",
1622			dev->sku_pixel_limit, pixel_limit);
1623		dev->sku_pixel_limit = pixel_limit;
1624	}
1625
1626
1627	if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1628		retval = -ENOMEM;
1629		pr_err("dlfb_alloc_urb_list failed\n");
1630		goto error;
1631	}
1632
1633	kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1634
1635	/* We don't register a new USB class. Our client interface is fbdev */
1636
1637	/* Workitem keep things fast & simple during USB enumeration */
1638	INIT_DELAYED_WORK(&dev->init_framebuffer_work,
1639			  dlfb_init_framebuffer_work);
1640	schedule_delayed_work(&dev->init_framebuffer_work, 0);
1641
1642	return 0;
1643
1644error:
1645	if (dev) {
1646
1647		kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1648		kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1649
1650		/* dev has been deallocated. Do not dereference */
1651	}
1652
1653	return retval;
1654}
1655
1656static void dlfb_init_framebuffer_work(struct work_struct *work)
1657{
1658	struct dlfb_data *dev = container_of(work, struct dlfb_data,
1659					     init_framebuffer_work.work);
1660	struct fb_info *info;
1661	int retval;
1662	int i;
1663
1664	/* allocates framebuffer driver structure, not framebuffer memory */
1665	info = framebuffer_alloc(0, dev->gdev);
1666	if (!info) {
1667		pr_err("framebuffer_alloc failed\n");
1668		goto error;
1669	}
1670
1671	dev->info = info;
1672	info->par = dev;
1673	info->pseudo_palette = dev->pseudo_palette;
1674	info->fbops = &dlfb_ops;
1675
1676	retval = fb_alloc_cmap(&info->cmap, 256, 0);
1677	if (retval < 0) {
1678		pr_err("fb_alloc_cmap failed %x\n", retval);
1679		goto error;
1680	}
1681
1682	INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1683			  dlfb_free_framebuffer_work);
1684
1685	INIT_LIST_HEAD(&info->modelist);
1686
1687	retval = dlfb_setup_modes(dev, info, NULL, 0);
1688	if (retval != 0) {
1689		pr_err("unable to find common mode for display and adapter\n");
1690		goto error;
1691	}
1692
1693	/* ready to begin using device */
1694
1695	atomic_set(&dev->usb_active, 1);
1696	dlfb_select_std_channel(dev);
1697
1698	dlfb_ops_check_var(&info->var, info);
1699	dlfb_ops_set_par(info);
1700
1701	retval = register_framebuffer(info);
1702	if (retval < 0) {
1703		pr_err("register_framebuffer failed %d\n", retval);
1704		goto error;
1705	}
1706
1707	for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
1708		retval = device_create_file(info->dev, &fb_device_attrs[i]);
1709		if (retval) {
1710			pr_warn("device_create_file failed %d\n", retval);
1711		}
1712	}
1713
1714	retval = device_create_bin_file(info->dev, &edid_attr);
1715	if (retval) {
1716		pr_warn("device_create_bin_file failed %d\n", retval);
1717	}
1718
1719	pr_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1720			" Using %dK framebuffer memory\n", info->node,
1721			info->var.xres, info->var.yres,
1722			((dev->backing_buffer) ?
1723			info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1724	return;
1725
1726error:
1727	dlfb_free_framebuffer(dev);
1728}
1729
1730static void dlfb_usb_disconnect(struct usb_interface *interface)
1731{
1732	struct dlfb_data *dev;
1733	struct fb_info *info;
1734	int i;
1735
1736	dev = usb_get_intfdata(interface);
1737	info = dev->info;
1738
1739	pr_info("USB disconnect starting\n");
1740
1741	/* we virtualize until all fb clients release. Then we free */
1742	dev->virtualized = true;
1743
1744	/* When non-active we'll update virtual framebuffer, but no new urbs */
1745	atomic_set(&dev->usb_active, 0);
1746
1747	/* this function will wait for all in-flight urbs to complete */
1748	dlfb_free_urb_list(dev);
1749
1750	if (info) {
1751		/* remove udlfb's sysfs interfaces */
1752		for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1753			device_remove_file(info->dev, &fb_device_attrs[i]);
1754		device_remove_bin_file(info->dev, &edid_attr);
1755		unlink_framebuffer(info);
1756	}
1757
1758	usb_set_intfdata(interface, NULL);
1759	dev->udev = NULL;
1760	dev->gdev = NULL;
1761
1762	/* if clients still have us open, will be freed on last close */
1763	if (dev->fb_count == 0)
1764		schedule_delayed_work(&dev->free_framebuffer_work, 0);
1765
1766	/* release reference taken by kref_init in probe() */
1767	kref_put(&dev->kref, dlfb_free);
1768
1769	/* consider dlfb_data freed */
1770
1771	return;
1772}
1773
1774static struct usb_driver dlfb_driver = {
1775	.name = "udlfb",
1776	.probe = dlfb_usb_probe,
1777	.disconnect = dlfb_usb_disconnect,
1778	.id_table = id_table,
1779};
1780
1781module_usb_driver(dlfb_driver);
1782
1783static void dlfb_urb_completion(struct urb *urb)
1784{
1785	struct urb_node *unode = urb->context;
1786	struct dlfb_data *dev = unode->dev;
1787	unsigned long flags;
1788
1789	/* sync/async unlink faults aren't errors */
1790	if (urb->status) {
1791		if (!(urb->status == -ENOENT ||
1792		    urb->status == -ECONNRESET ||
1793		    urb->status == -ESHUTDOWN)) {
1794			pr_err("%s - nonzero write bulk status received: %d\n",
1795				__func__, urb->status);
1796			atomic_set(&dev->lost_pixels, 1);
1797		}
1798	}
1799
1800	urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1801
1802	spin_lock_irqsave(&dev->urbs.lock, flags);
1803	list_add_tail(&unode->entry, &dev->urbs.list);
1804	dev->urbs.available++;
1805	spin_unlock_irqrestore(&dev->urbs.lock, flags);
1806
1807	/*
1808	 * When using fb_defio, we deadlock if up() is called
1809	 * while another is waiting. So queue to another process.
1810	 */
1811	if (fb_defio)
1812		schedule_delayed_work(&unode->release_urb_work, 0);
1813	else
1814		up(&dev->urbs.limit_sem);
1815}
1816
1817static void dlfb_free_urb_list(struct dlfb_data *dev)
1818{
1819	int count = dev->urbs.count;
1820	struct list_head *node;
1821	struct urb_node *unode;
1822	struct urb *urb;
1823	int ret;
1824	unsigned long flags;
1825
1826	pr_notice("Freeing all render urbs\n");
1827
1828	/* keep waiting and freeing, until we've got 'em all */
1829	while (count--) {
1830
1831		/* Getting interrupted means a leak, but ok at disconnect */
1832		ret = down_interruptible(&dev->urbs.limit_sem);
1833		if (ret)
1834			break;
1835
1836		spin_lock_irqsave(&dev->urbs.lock, flags);
1837
1838		node = dev->urbs.list.next; /* have reserved one with sem */
1839		list_del_init(node);
1840
1841		spin_unlock_irqrestore(&dev->urbs.lock, flags);
1842
1843		unode = list_entry(node, struct urb_node, entry);
1844		urb = unode->urb;
1845
1846		/* Free each separately allocated piece */
1847		usb_free_coherent(urb->dev, dev->urbs.size,
1848				  urb->transfer_buffer, urb->transfer_dma);
1849		usb_free_urb(urb);
1850		kfree(node);
1851	}
1852
1853	dev->urbs.count = 0;
1854}
1855
1856static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1857{
1858	int i = 0;
1859	struct urb *urb;
1860	struct urb_node *unode;
1861	char *buf;
1862
1863	spin_lock_init(&dev->urbs.lock);
1864
1865	dev->urbs.size = size;
1866	INIT_LIST_HEAD(&dev->urbs.list);
1867
1868	while (i < count) {
1869		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1870		if (!unode)
1871			break;
1872		unode->dev = dev;
1873
1874		INIT_DELAYED_WORK(&unode->release_urb_work,
1875			  dlfb_release_urb_work);
1876
1877		urb = usb_alloc_urb(0, GFP_KERNEL);
1878		if (!urb) {
1879			kfree(unode);
1880			break;
1881		}
1882		unode->urb = urb;
1883
1884		buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1885					 &urb->transfer_dma);
1886		if (!buf) {
1887			kfree(unode);
1888			usb_free_urb(urb);
1889			break;
1890		}
1891
1892		/* urb->transfer_buffer_length set to actual before submit */
1893		usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1894			buf, size, dlfb_urb_completion, unode);
1895		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1896
1897		list_add_tail(&unode->entry, &dev->urbs.list);
1898
1899		i++;
1900	}
1901
1902	sema_init(&dev->urbs.limit_sem, i);
1903	dev->urbs.count = i;
1904	dev->urbs.available = i;
1905
1906	pr_notice("allocated %d %d byte urbs\n", i, (int) size);
1907
1908	return i;
1909}
1910
1911static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1912{
1913	int ret;
1914	struct list_head *entry;
1915	struct urb_node *unode;
1916	struct urb *urb = NULL;
1917	unsigned long flags;
1918
1919	/* Wait for an in-flight buffer to complete and get re-queued */
1920	ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1921	if (ret) {
1922		atomic_set(&dev->lost_pixels, 1);
1923		pr_warn("wait for urb interrupted: %x available: %d\n",
1924		       ret, dev->urbs.available);
1925		goto error;
1926	}
1927
1928	spin_lock_irqsave(&dev->urbs.lock, flags);
1929
1930	BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1931	entry = dev->urbs.list.next;
1932	list_del_init(entry);
1933	dev->urbs.available--;
1934
1935	spin_unlock_irqrestore(&dev->urbs.lock, flags);
1936
1937	unode = list_entry(entry, struct urb_node, entry);
1938	urb = unode->urb;
1939
1940error:
1941	return urb;
1942}
1943
1944static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1945{
1946	int ret;
1947
1948	BUG_ON(len > dev->urbs.size);
1949
1950	urb->transfer_buffer_length = len; /* set to actual payload len */
1951	ret = usb_submit_urb(urb, GFP_KERNEL);
1952	if (ret) {
1953		dlfb_urb_completion(urb); /* because no one else will */
1954		atomic_set(&dev->lost_pixels, 1);
1955		pr_err("usb_submit_urb error %x\n", ret);
1956	}
1957	return ret;
1958}
1959
1960module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1961MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
1962
1963module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1964MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
1965
1966module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1967MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
1968
1969module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1970MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)");
1971
1972MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1973	      "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1974	      "Bernie Thompson <bernie@plugable.com>");
1975MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1976MODULE_LICENSE("GPL");
1977
1978