1	// SPDX-License-Identifier: GPL-2.0-only
2	/*
3	* udlfb.c -- Framebuffer driver for DisplayLink USB controller
4	*
5	* Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
6	* Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
7	* Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
8	*
9	* Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
10	* usb-skeleton by GregKH.
11	*
12	* Device-specific portions based on information from Displaylink, with work
13	* from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
14	*/
15
16	#include <linux/module.h>
17	#include <linux/kernel.h>
18	#include <linux/init.h>
19	#include <linux/usb.h>
20	#include <linux/uaccess.h>
21	#include <linux/mm.h>
22	#include <linux/fb.h>
23	#include <linux/vmalloc.h>
24	#include <linux/slab.h>
25	#include <linux/delay.h>
26	#include <asm/unaligned.h>
27	#include <video/udlfb.h>
28	#include "edid.h"
29
30	#define OUT_EP_NUM 1 /* The endpoint number we will use */
31
32	static const struct fb_fix_screeninfo dlfb_fix = {
33	.id = "udlfb",
34	.type = FB_TYPE_PACKED_PIXELS,
35	.visual = FB_VISUAL_TRUECOLOR,
36	.xpanstep = 0,
37	.ypanstep = 0,
38	.ywrapstep = 0,
39	.accel = FB_ACCEL_NONE,
40	};
41
42	static const u32 udlfb_info_flags = FBINFO_READS_FAST |
43	FBINFO_VIRTFB |
44	FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
45	FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
46
47	/*
48	* There are many DisplayLink-based graphics products, all with unique PIDs.
49	* So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
50	* We also require a match on SubClass (0x00) and Protocol (0x00),
51	* which is compatible with all known USB 2.0 era graphics chips and firmware,
52	* but allows DisplayLink to increment those for any future incompatible chips
53	*/
54	static const struct usb_device_id id_table[] = {
55	{.idVendor = 0x17e9,
56	.bInterfaceClass = 0xff,
57	.bInterfaceSubClass = 0x00,
58	.bInterfaceProtocol = 0x00,
59	.match_flags = USB_DEVICE_ID_MATCH_VENDOR |
60	USB_DEVICE_ID_MATCH_INT_CLASS |
61	USB_DEVICE_ID_MATCH_INT_SUBCLASS |
62	USB_DEVICE_ID_MATCH_INT_PROTOCOL,
63	},
64	{},
65	};
66	MODULE_DEVICE_TABLE(usb, id_table);
67
68	/* module options */
69	static bool console = true; /* Allow fbcon to open framebuffer */
70	static bool fb_defio = true; /* Detect mmap writes using page faults */
71	static bool shadow = true; /* Optionally disable shadow framebuffer */
72	static int pixel_limit; /* Optionally force a pixel resolution limit */
73
74	struct dlfb_deferred_free {
75	struct list_head list;
76	void *mem;
77	};
78
79	static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len);
80
81	/* dlfb keeps a list of urbs for efficient bulk transfers */
82	static void dlfb_urb_completion(struct urb *urb);
83	static struct urb *dlfb_get_urb(struct dlfb_data *dlfb);
84	static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb * urb, size_t len);
85	static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size);
86	static void dlfb_free_urb_list(struct dlfb_data *dlfb);
87
88	/*
89	* All DisplayLink bulk operations start with 0xAF, followed by specific code
90	* All operations are written to buffers which then later get sent to device
91	*/
92	static char *dlfb_set_register(char *buf, u8 reg, u8 val)
93	{
94	*buf++ = 0xAF;
95	*buf++ = 0x20;
96	*buf++ = reg;
97	*buf++ = val;
98	return buf;
99	}
100
101	static char *dlfb_vidreg_lock(char *buf)
102	{
103	return dlfb_set_register(buf, reg: 0xFF, val: 0x00);
104	}
105
106	static char *dlfb_vidreg_unlock(char *buf)
107	{
108	return dlfb_set_register(buf, reg: 0xFF, val: 0xFF);
109	}
110
111	/*
112	* Map FB_BLANK_* to DisplayLink register
113	* DLReg FB_BLANK_*
114	* ----- -----------------------------
115	* 0x00 FB_BLANK_UNBLANK (0)
116	* 0x01 FB_BLANK (1)
117	* 0x03 FB_BLANK_VSYNC_SUSPEND (2)
118	* 0x05 FB_BLANK_HSYNC_SUSPEND (3)
119	* 0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
120	*/
121	static char *dlfb_blanking(char *buf, int fb_blank)
122	{
123	u8 reg;
124
125	switch (fb_blank) {
126	case FB_BLANK_POWERDOWN:
127	reg = 0x07;
128	break;
129	case FB_BLANK_HSYNC_SUSPEND:
130	reg = 0x05;
131	break;
132	case FB_BLANK_VSYNC_SUSPEND:
133	reg = 0x03;
134	break;
135	case FB_BLANK_NORMAL:
136	reg = 0x01;
137	break;
138	default:
139	reg = 0x00;
140	}
141
142	buf = dlfb_set_register(buf, reg: 0x1F, val: reg);
143
144	return buf;
145	}
146
147	static char *dlfb_set_color_depth(char *buf, u8 selection)
148	{
149	return dlfb_set_register(buf, reg: 0x00, val: selection);
150	}
151
152	static char *dlfb_set_base16bpp(char *wrptr, u32 base)
153	{
154	/* the base pointer is 16 bits wide, 0x20 is hi byte. */
155	wrptr = dlfb_set_register(buf: wrptr, reg: 0x20, val: base >> 16);
156	wrptr = dlfb_set_register(buf: wrptr, reg: 0x21, val: base >> 8);
157	return dlfb_set_register(buf: wrptr, reg: 0x22, val: base);
158	}
159
160	/*
161	* DisplayLink HW has separate 16bpp and 8bpp framebuffers.
162	* In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
163	*/
164	static char *dlfb_set_base8bpp(char *wrptr, u32 base)
165	{
166	wrptr = dlfb_set_register(buf: wrptr, reg: 0x26, val: base >> 16);
167	wrptr = dlfb_set_register(buf: wrptr, reg: 0x27, val: base >> 8);
168	return dlfb_set_register(buf: wrptr, reg: 0x28, val: base);
169	}
170
171	static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
172	{
173	wrptr = dlfb_set_register(buf: wrptr, reg, val: value >> 8);
174	return dlfb_set_register(buf: wrptr, reg: reg+1, val: value);
175	}
176
177	/*
178	* This is kind of weird because the controller takes some
179	* register values in a different byte order than other registers.
180	*/
181	static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
182	{
183	wrptr = dlfb_set_register(buf: wrptr, reg, val: value);
184	return dlfb_set_register(buf: wrptr, reg: reg+1, val: value >> 8);
185	}
186
187	/*
188	* LFSR is linear feedback shift register. The reason we have this is
189	* because the display controller needs to minimize the clock depth of
190	* various counters used in the display path. So this code reverses the
191	* provided value into the lfsr16 value by counting backwards to get
192	* the value that needs to be set in the hardware comparator to get the
193	* same actual count. This makes sense once you read above a couple of
194	* times and think about it from a hardware perspective.
195	*/
196	static u16 dlfb_lfsr16(u16 actual_count)
197	{
198	u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
199
200	while (actual_count--) {
201	lv = ((lv << 1) |
202	(((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
203	& 0xFFFF;
204	}
205
206	return (u16) lv;
207	}
208
209	/*
210	* This does LFSR conversion on the value that is to be written.
211	* See LFSR explanation above for more detail.
212	*/
213	static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
214	{
215	return dlfb_set_register_16(wrptr, reg, value: dlfb_lfsr16(actual_count: value));
216	}
217
218	/*
219	* This takes a standard fbdev screeninfo struct and all of its monitor mode
220	* details and converts them into the DisplayLink equivalent register commands.
221	*/
222	static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
223	{
224	u16 xds, yds;
225	u16 xde, yde;
226	u16 yec;
227
228	/* x display start */
229	xds = var->left_margin + var->hsync_len;
230	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x01, value: xds);
231	/* x display end */
232	xde = xds + var->xres;
233	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x03, value: xde);
234
235	/* y display start */
236	yds = var->upper_margin + var->vsync_len;
237	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x05, value: yds);
238	/* y display end */
239	yde = yds + var->yres;
240	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x07, value: yde);
241
242	/* x end count is active + blanking - 1 */
243	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x09,
244	value: xde + var->right_margin - 1);
245
246	/* libdlo hardcodes hsync start to 1 */
247	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x0B, value: 1);
248
249	/* hsync end is width of sync pulse + 1 */
250	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x0D, value: var->hsync_len + 1);
251
252	/* hpixels is active pixels */
253	wrptr = dlfb_set_register_16(wrptr, reg: 0x0F, value: var->xres);
254
255	/* yendcount is vertical active + vertical blanking */
256	yec = var->yres + var->upper_margin + var->lower_margin +
257	var->vsync_len;
258	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x11, value: yec);
259
260	/* libdlo hardcodes vsync start to 0 */
261	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x13, value: 0);
262
263	/* vsync end is width of vsync pulse */
264	wrptr = dlfb_set_register_lfsr16(wrptr, reg: 0x15, value: var->vsync_len);
265
266	/* vpixels is active pixels */
267	wrptr = dlfb_set_register_16(wrptr, reg: 0x17, value: var->yres);
268
269	/* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
270	wrptr = dlfb_set_register_16be(wrptr, reg: 0x1B,
271	value: 200*1000*1000/var->pixclock);
272
273	return wrptr;
274	}
275
276	/*
277	* This takes a standard fbdev screeninfo struct that was fetched or prepared
278	* and then generates the appropriate command sequence that then drives the
279	* display controller.
280	*/
281	static int dlfb_set_video_mode(struct dlfb_data *dlfb,
282	struct fb_var_screeninfo *var)
283	{
284	char *buf;
285	char *wrptr;
286	int retval;
287	int writesize;
288	struct urb *urb;
289
290	if (!atomic_read(v: &dlfb->usb_active))
291	return -EPERM;
292
293	urb = dlfb_get_urb(dlfb);
294	if (!urb)
295	return -ENOMEM;
296
297	buf = (char *) urb->transfer_buffer;
298
299	/*
300	* This first section has to do with setting the base address on the
301	* controller * associated with the display. There are 2 base
302	* pointers, currently, we only * use the 16 bpp segment.
303	*/
304	wrptr = dlfb_vidreg_lock(buf);
305	wrptr = dlfb_set_color_depth(buf: wrptr, selection: 0x00);
306	/* set base for 16bpp segment to 0 */
307	wrptr = dlfb_set_base16bpp(wrptr, base: 0);
308	/* set base for 8bpp segment to end of fb */
309	wrptr = dlfb_set_base8bpp(wrptr, base: dlfb->info->fix.smem_len);
310
311	wrptr = dlfb_set_vid_cmds(wrptr, var);
312	wrptr = dlfb_blanking(buf: wrptr, fb_blank: FB_BLANK_UNBLANK);
313	wrptr = dlfb_vidreg_unlock(buf: wrptr);
314
315	writesize = wrptr - buf;
316
317	retval = dlfb_submit_urb(dlfb, urb, len: writesize);
318
319	dlfb->blank_mode = FB_BLANK_UNBLANK;
320
321	return retval;
322	}
323
324	static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
325	{
326	unsigned long start = vma->vm_start;
327	unsigned long size = vma->vm_end - vma->vm_start;
328	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
329	unsigned long page, pos;
330
331	if (info->fbdefio)
332	return fb_deferred_io_mmap(info, vma);
333
334	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
335	return -EINVAL;
336	if (size > info->fix.smem_len)
337	return -EINVAL;
338	if (offset > info->fix.smem_len - size)
339	return -EINVAL;
340
341	pos = (unsigned long)info->fix.smem_start + offset;
342
343	dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n",
344	pos, size);
345
346	while (size > 0) {
347	page = vmalloc_to_pfn(addr: (void *)pos);
348	if (remap_pfn_range(vma, addr: start, pfn: page, PAGE_SIZE, PAGE_SHARED))
349	return -EAGAIN;
350
351	start += PAGE_SIZE;
352	pos += PAGE_SIZE;
353	if (size > PAGE_SIZE)
354	size -= PAGE_SIZE;
355	else
356	size = 0;
357	}
358
359	return 0;
360	}
361
362	/*
363	* Trims identical data from front and back of line
364	* Sets new front buffer address and width
365	* And returns byte count of identical pixels
366	* Assumes CPU natural alignment (unsigned long)
367	* for back and front buffer ptrs and width
368	*/
369	static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
370	{
371	int j, k;
372	const unsigned long *back = (const unsigned long *) bback;
373	const unsigned long *front = (const unsigned long *) *bfront;
374	const int width = *width_bytes / sizeof(unsigned long);
375	int identical;
376	int start = width;
377	int end = width;
378
379	for (j = 0; j < width; j++) {
380	if (back[j] != front[j]) {
381	start = j;
382	break;
383	}
384	}
385
386	for (k = width - 1; k > j; k--) {
387	if (back[k] != front[k]) {
388	end = k+1;
389	break;
390	}
391	}
392
393	identical = start + (width - end);
394	*bfront = (u8 *) &front[start];
395	*width_bytes = (end - start) * sizeof(unsigned long);
396
397	return identical * sizeof(unsigned long);
398	}
399
400	/*
401	* Render a command stream for an encoded horizontal line segment of pixels.
402	*
403	* A command buffer holds several commands.
404	* It always begins with a fresh command header
405	* (the protocol doesn't require this, but we enforce it to allow
406	* multiple buffers to be potentially encoded and sent in parallel).
407	* A single command encodes one contiguous horizontal line of pixels
408	*
409	* The function relies on the client to do all allocation, so that
410	* rendering can be done directly to output buffers (e.g. USB URBs).
411	* The function fills the supplied command buffer, providing information
412	* on where it left off, so the client may call in again with additional
413	* buffers if the line will take several buffers to complete.
414	*
415	* A single command can transmit a maximum of 256 pixels,
416	* regardless of the compression ratio (protocol design limit).
417	* To the hardware, 0 for a size byte means 256
418	*
419	* Rather than 256 pixel commands which are either rl or raw encoded,
420	* the rlx command simply assumes alternating raw and rl spans within one cmd.
421	* This has a slightly larger header overhead, but produces more even results.
422	* It also processes all data (read and write) in a single pass.
423	* Performance benchmarks of common cases show it having just slightly better
424	* compression than 256 pixel raw or rle commands, with similar CPU consumpion.
425	* But for very rl friendly data, will compress not quite as well.
426	*/
427	static void dlfb_compress_hline(
428	const uint16_t **pixel_start_ptr,
429	const uint16_t *const pixel_end,
430	uint32_t *device_address_ptr,
431	uint8_t **command_buffer_ptr,
432	const uint8_t *const cmd_buffer_end,
433	unsigned long back_buffer_offset,
434	int *ident_ptr)
435	{
436	const uint16_t *pixel = *pixel_start_ptr;
437	uint32_t dev_addr = *device_address_ptr;
438	uint8_t *cmd = *command_buffer_ptr;
439
440	while ((pixel_end > pixel) &&
441	(cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
442	uint8_t *raw_pixels_count_byte = NULL;
443	uint8_t *cmd_pixels_count_byte = NULL;
444	const uint16_t *raw_pixel_start = NULL;
445	const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL;
446
447	if (back_buffer_offset &&
448	*pixel == *(u16 *)((u8 *)pixel + back_buffer_offset)) {
449	pixel++;
450	dev_addr += BPP;
451	(*ident_ptr)++;
452	continue;
453	}
454
455	*cmd++ = 0xAF;
456	*cmd++ = 0x6B;
457	*cmd++ = dev_addr >> 16;
458	*cmd++ = dev_addr >> 8;
459	*cmd++ = dev_addr;
460
461	cmd_pixels_count_byte = cmd++; /* we'll know this later */
462	cmd_pixel_start = pixel;
463
464	raw_pixels_count_byte = cmd++; /* we'll know this later */
465	raw_pixel_start = pixel;
466
467	cmd_pixel_end = pixel + min3(MAX_CMD_PIXELS + 1UL,
468	(unsigned long)(pixel_end - pixel),
469	(unsigned long)(cmd_buffer_end - 1 - cmd) / BPP);
470
471	if (back_buffer_offset) {
472	/* note: the framebuffer may change under us, so we must test for underflow */
473	while (cmd_pixel_end - 1 > pixel &&
474	*(cmd_pixel_end - 1) == *(u16 *)((u8 *)(cmd_pixel_end - 1) + back_buffer_offset))
475	cmd_pixel_end--;
476	}
477
478	while (pixel < cmd_pixel_end) {
479	const uint16_t * const repeating_pixel = pixel;
480	u16 pixel_value = *pixel;
481
482	put_unaligned_be16(val: pixel_value, p: cmd);
483	if (back_buffer_offset)
484	*(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value;
485	cmd += 2;
486	pixel++;
487
488	if (unlikely((pixel < cmd_pixel_end) &&
489	(*pixel == pixel_value))) {
490	/* go back and fill in raw pixel count */
491	*raw_pixels_count_byte = ((repeating_pixel -
492	raw_pixel_start) + 1) & 0xFF;
493
494	do {
495	if (back_buffer_offset)
496	*(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value;
497	pixel++;
498	} while ((pixel < cmd_pixel_end) &&
499	(*pixel == pixel_value));
500
501	/* immediately after raw data is repeat byte */
502	*cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
503
504	/* Then start another raw pixel span */
505	raw_pixel_start = pixel;
506	raw_pixels_count_byte = cmd++;
507	}
508	}
509
510	if (pixel > raw_pixel_start) {
511	/* finalize last RAW span */
512	*raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
513	} else {
514	/* undo unused byte */
515	cmd--;
516	}
517
518	*cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
519	dev_addr += (u8 *)pixel - (u8 *)cmd_pixel_start;
520	}
521
522	if (cmd_buffer_end - MIN_RLX_CMD_BYTES <= cmd) {
523	/* Fill leftover bytes with no-ops */
524	if (cmd_buffer_end > cmd)
525	memset(cmd, 0xAF, cmd_buffer_end - cmd);
526	cmd = (uint8_t *) cmd_buffer_end;
527	}
528
529	*command_buffer_ptr = cmd;
530	*pixel_start_ptr = pixel;
531	*device_address_ptr = dev_addr;
532	}
533
534	/*
535	* There are 3 copies of every pixel: The front buffer that the fbdev
536	* client renders to, the actual framebuffer across the USB bus in hardware
537	* (that we can only write to, slowly, and can never read), and (optionally)
538	* our shadow copy that tracks what's been sent to that hardware buffer.
539	*/
540	static int dlfb_render_hline(struct dlfb_data *dlfb, struct urb **urb_ptr,
541	const char *front, char **urb_buf_ptr,
542	u32 byte_offset, u32 byte_width,
543	int *ident_ptr, int *sent_ptr)
544	{
545	const u8 *line_start, *line_end, *next_pixel;
546	u32 dev_addr = dlfb->base16 + byte_offset;
547	struct urb *urb = *urb_ptr;
548	u8 *cmd = *urb_buf_ptr;
549	u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
550	unsigned long back_buffer_offset = 0;
551
552	line_start = (u8 *) (front + byte_offset);
553	next_pixel = line_start;
554	line_end = next_pixel + byte_width;
555
556	if (dlfb->backing_buffer) {
557	int offset;
558	const u8 *back_start = (u8 *) (dlfb->backing_buffer
559	+ byte_offset);
560
561	back_buffer_offset = (unsigned long)back_start - (unsigned long)line_start;
562
563	*ident_ptr += dlfb_trim_hline(bback: back_start, bfront: &next_pixel,
564	width_bytes: &byte_width);
565
566	offset = next_pixel - line_start;
567	line_end = next_pixel + byte_width;
568	dev_addr += offset;
569	back_start += offset;
570	line_start += offset;
571	}
572
573	while (next_pixel < line_end) {
574
575	dlfb_compress_hline(pixel_start_ptr: (const uint16_t **) &next_pixel,
576	pixel_end: (const uint16_t *) line_end, device_address_ptr: &dev_addr,
577	command_buffer_ptr: (u8 **) &cmd, cmd_buffer_end: (u8 *) cmd_end, back_buffer_offset,
578	ident_ptr);
579
580	if (cmd >= cmd_end) {
581	int len = cmd - (u8 *) urb->transfer_buffer;
582	if (dlfb_submit_urb(dlfb, urb, len))
583	return 1; /* lost pixels is set */
584	*sent_ptr += len;
585	urb = dlfb_get_urb(dlfb);
586	if (!urb)
587	return 1; /* lost_pixels is set */
588	*urb_ptr = urb;
589	cmd = urb->transfer_buffer;
590	cmd_end = &cmd[urb->transfer_buffer_length];
591	}
592	}
593
594	*urb_buf_ptr = cmd;
595
596	return 0;
597	}
598
599	static int dlfb_handle_damage(struct dlfb_data *dlfb, int x, int y, int width, int height)
600	{
601	int i, ret;
602	char *cmd;
603	cycles_t start_cycles, end_cycles;
604	int bytes_sent = 0;
605	int bytes_identical = 0;
606	struct urb *urb;
607	int aligned_x;
608
609	start_cycles = get_cycles();
610
611	mutex_lock(&dlfb->render_mutex);
612
613	aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
614	width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
615	x = aligned_x;
616
617	if ((width <= 0) ||
618	(x + width > dlfb->info->var.xres) ||
619	(y + height > dlfb->info->var.yres)) {
620	ret = -EINVAL;
621	goto unlock_ret;
622	}
623
624	if (!atomic_read(v: &dlfb->usb_active)) {
625	ret = 0;
626	goto unlock_ret;
627	}
628
629	urb = dlfb_get_urb(dlfb);
630	if (!urb) {
631	ret = 0;
632	goto unlock_ret;
633	}
634	cmd = urb->transfer_buffer;
635
636	for (i = y; i < y + height ; i++) {
637	const int line_offset = dlfb->info->fix.line_length * i;
638	const int byte_offset = line_offset + (x * BPP);
639
640	if (dlfb_render_hline(dlfb, urb_ptr: &urb,
641	front: (char *) dlfb->info->fix.smem_start,
642	urb_buf_ptr: &cmd, byte_offset, byte_width: width * BPP,
643	ident_ptr: &bytes_identical, sent_ptr: &bytes_sent))
644	goto error;
645	}
646
647	if (cmd > (char *) urb->transfer_buffer) {
648	int len;
649	if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length)
650	*cmd++ = 0xAF;
651	/* Send partial buffer remaining before exiting */
652	len = cmd - (char *) urb->transfer_buffer;
653	dlfb_submit_urb(dlfb, urb, len);
654	bytes_sent += len;
655	} else
656	dlfb_urb_completion(urb);
657
658	error:
659	atomic_add(i: bytes_sent, v: &dlfb->bytes_sent);
660	atomic_add(i: bytes_identical, v: &dlfb->bytes_identical);
661	atomic_add(i: width*height*2, v: &dlfb->bytes_rendered);
662	end_cycles = get_cycles();
663	atomic_add(i: ((unsigned int) ((end_cycles - start_cycles)
664	>> 10)), /* Kcycles */
665	v: &dlfb->cpu_kcycles_used);
666
667	ret = 0;
668
669	unlock_ret:
670	mutex_unlock(lock: &dlfb->render_mutex);
671	return ret;
672	}
673
674	static void dlfb_init_damage(struct dlfb_data *dlfb)
675	{
676	dlfb->damage_x = INT_MAX;
677	dlfb->damage_x2 = 0;
678	dlfb->damage_y = INT_MAX;
679	dlfb->damage_y2 = 0;
680	}
681
682	static void dlfb_damage_work(struct work_struct *w)
683	{
684	struct dlfb_data *dlfb = container_of(w, struct dlfb_data, damage_work);
685	int x, x2, y, y2;
686
687	spin_lock_irq(lock: &dlfb->damage_lock);
688	x = dlfb->damage_x;
689	x2 = dlfb->damage_x2;
690	y = dlfb->damage_y;
691	y2 = dlfb->damage_y2;
692	dlfb_init_damage(dlfb);
693	spin_unlock_irq(lock: &dlfb->damage_lock);
694
695	if (x < x2 && y < y2)
696	dlfb_handle_damage(dlfb, x, y, width: x2 - x, height: y2 - y);
697	}
698
699	static void dlfb_offload_damage(struct dlfb_data *dlfb, int x, int y, int width, int height)
700	{
701	unsigned long flags;
702	int x2 = x + width;
703	int y2 = y + height;
704
705	if (x >= x2 || y >= y2)
706	return;
707
708	spin_lock_irqsave(&dlfb->damage_lock, flags);
709	dlfb->damage_x = min(x, dlfb->damage_x);
710	dlfb->damage_x2 = max(x2, dlfb->damage_x2);
711	dlfb->damage_y = min(y, dlfb->damage_y);
712	dlfb->damage_y2 = max(y2, dlfb->damage_y2);
713	spin_unlock_irqrestore(lock: &dlfb->damage_lock, flags);
714
715	schedule_work(work: &dlfb->damage_work);
716	}
717
718	/*
719	* NOTE: fb_defio.c is holding info->fbdefio.mutex
720	* Touching ANY framebuffer memory that triggers a page fault
721	* in fb_defio will cause a deadlock, when it also tries to
722	* grab the same mutex.
723	*/
724	static void dlfb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
725	{
726	struct fb_deferred_io_pageref *pageref;
727	struct dlfb_data *dlfb = info->par;
728	struct urb *urb;
729	char *cmd;
730	cycles_t start_cycles, end_cycles;
731	int bytes_sent = 0;
732	int bytes_identical = 0;
733	int bytes_rendered = 0;
734
735	mutex_lock(&dlfb->render_mutex);
736
737	if (!fb_defio)
738	goto unlock_ret;
739
740	if (!atomic_read(v: &dlfb->usb_active))
741	goto unlock_ret;
742
743	start_cycles = get_cycles();
744
745	urb = dlfb_get_urb(dlfb);
746	if (!urb)
747	goto unlock_ret;
748
749	cmd = urb->transfer_buffer;
750
751	/* walk the written page list and render each to device */
752	list_for_each_entry(pageref, pagereflist, list) {
753	if (dlfb_render_hline(dlfb, urb_ptr: &urb, front: (char *) info->fix.smem_start,
754	urb_buf_ptr: &cmd, byte_offset: pageref->offset, PAGE_SIZE,
755	ident_ptr: &bytes_identical, sent_ptr: &bytes_sent))
756	goto error;
757	bytes_rendered += PAGE_SIZE;
758	}
759
760	if (cmd > (char *) urb->transfer_buffer) {
761	int len;
762	if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length)
763	*cmd++ = 0xAF;
764	/* Send partial buffer remaining before exiting */
765	len = cmd - (char *) urb->transfer_buffer;
766	dlfb_submit_urb(dlfb, urb, len);
767	bytes_sent += len;
768	} else
769	dlfb_urb_completion(urb);
770
771	error:
772	atomic_add(i: bytes_sent, v: &dlfb->bytes_sent);
773	atomic_add(i: bytes_identical, v: &dlfb->bytes_identical);
774	atomic_add(i: bytes_rendered, v: &dlfb->bytes_rendered);
775	end_cycles = get_cycles();
776	atomic_add(i: ((unsigned int) ((end_cycles - start_cycles)
777	>> 10)), /* Kcycles */
778	v: &dlfb->cpu_kcycles_used);
779	unlock_ret:
780	mutex_unlock(lock: &dlfb->render_mutex);
781	}
782
783	static int dlfb_get_edid(struct dlfb_data *dlfb, char *edid, int len)
784	{
785	int i, ret;
786	char *rbuf;
787
788	rbuf = kmalloc(size: 2, GFP_KERNEL);
789	if (!rbuf)
790	return 0;
791
792	for (i = 0; i < len; i++) {
793	ret = usb_control_msg(dev: dlfb->udev,
794	usb_rcvctrlpipe(dlfb->udev, 0), request: 0x02,
795	requesttype: (0x80 | (0x02 << 5)), value: i << 8, index: 0xA1,
796	data: rbuf, size: 2, USB_CTRL_GET_TIMEOUT);
797	if (ret < 2) {
798	dev_err(&dlfb->udev->dev,
799	"Read EDID byte %d failed: %d\n", i, ret);
800	i--;
801	break;
802	}
803	edid[i] = rbuf[1];
804	}
805
806	kfree(objp: rbuf);
807
808	return i;
809	}
810
811	static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
812	unsigned long arg)
813	{
814
815	struct dlfb_data *dlfb = info->par;
816
817	if (!atomic_read(v: &dlfb->usb_active))
818	return 0;
819
820	/* TODO: Update X server to get this from sysfs instead */
821	if (cmd == DLFB_IOCTL_RETURN_EDID) {
822	void __user *edid = (void __user *)arg;
823	if (copy_to_user(to: edid, from: dlfb->edid, n: dlfb->edid_size))
824	return -EFAULT;
825	return 0;
826	}
827
828	/* TODO: Help propose a standard fb.h ioctl to report mmap damage */
829	if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
830	struct dloarea area;
831
832	if (copy_from_user(to: &area, from: (void __user *)arg,
833	n: sizeof(struct dloarea)))
834	return -EFAULT;
835
836	/*
837	* If we have a damage-aware client, turn fb_defio "off"
838	* To avoid perf imact of unnecessary page fault handling.
839	* Done by resetting the delay for this fb_info to a very
840	* long period. Pages will become writable and stay that way.
841	* Reset to normal value when all clients have closed this fb.
842	*/
843	if (info->fbdefio)
844	info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
845
846	if (area.x < 0)
847	area.x = 0;
848
849	if (area.x > info->var.xres)
850	area.x = info->var.xres;
851
852	if (area.y < 0)
853	area.y = 0;
854
855	if (area.y > info->var.yres)
856	area.y = info->var.yres;
857
858	dlfb_handle_damage(dlfb, x: area.x, y: area.y, width: area.w, height: area.h);
859	}
860
861	return 0;
862	}
863
864	/* taken from vesafb */
865	static int
866	dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
867	unsigned blue, unsigned transp, struct fb_info *info)
868	{
869	int err = 0;
870
871	if (regno >= info->cmap.len)
872	return 1;
873
874	if (regno < 16) {
875	if (info->var.red.offset == 10) {
876	/* 1:5:5:5 */
877	((u32 *) (info->pseudo_palette))[regno] =
878	((red & 0xf800) >> 1) |
879	((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
880	} else {
881	/* 0:5:6:5 */
882	((u32 *) (info->pseudo_palette))[regno] =
883	((red & 0xf800)) |
884	((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
885	}
886	}
887
888	return err;
889	}
890
891	/*
892	* It's common for several clients to have framebuffer open simultaneously.
893	* e.g. both fbcon and X. Makes things interesting.
894	* Assumes caller is holding info->lock (for open and release at least)
895	*/
896	static int dlfb_ops_open(struct fb_info *info, int user)
897	{
898	struct dlfb_data *dlfb = info->par;
899
900	/*
901	* fbcon aggressively connects to first framebuffer it finds,
902	* preventing other clients (X) from working properly. Usually
903	* not what the user wants. Fail by default with option to enable.
904	*/
905	if ((user == 0) && (!console))
906	return -EBUSY;
907
908	/* If the USB device is gone, we don't accept new opens */
909	if (dlfb->virtualized)
910	return -ENODEV;
911
912	dlfb->fb_count++;
913
914	if (fb_defio && (info->fbdefio == NULL)) {
915	/* enable defio at last moment if not disabled by client */
916
917	struct fb_deferred_io *fbdefio;
918
919	fbdefio = kzalloc(size: sizeof(struct fb_deferred_io), GFP_KERNEL);
920
921	if (fbdefio) {
922	fbdefio->delay = DL_DEFIO_WRITE_DELAY;
923	fbdefio->sort_pagereflist = true;
924	fbdefio->deferred_io = dlfb_dpy_deferred_io;
925	}
926
927	info->fbdefio = fbdefio;
928	fb_deferred_io_init(info);
929	}
930
931	dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n",
932	user, info, dlfb->fb_count);
933
934	return 0;
935	}
936
937	static void dlfb_ops_destroy(struct fb_info *info)
938	{
939	struct dlfb_data *dlfb = info->par;
940
941	cancel_work_sync(work: &dlfb->damage_work);
942
943	mutex_destroy(lock: &dlfb->render_mutex);
944
945	if (info->cmap.len != 0)
946	fb_dealloc_cmap(cmap: &info->cmap);
947	if (info->monspecs.modedb)
948	fb_destroy_modedb(modedb: info->monspecs.modedb);
949	vfree(addr: info->screen_buffer);
950
951	fb_destroy_modelist(head: &info->modelist);
952
953	while (!list_empty(head: &dlfb->deferred_free)) {
954	struct dlfb_deferred_free *d = list_entry(dlfb->deferred_free.next, struct dlfb_deferred_free, list);
955	list_del(entry: &d->list);
956	vfree(addr: d->mem);
957	kfree(objp: d);
958	}
959	vfree(addr: dlfb->backing_buffer);
960	kfree(objp: dlfb->edid);
961	dlfb_free_urb_list(dlfb);
962	usb_put_dev(dev: dlfb->udev);
963	kfree(objp: dlfb);
964
965	/* Assume info structure is freed after this point */
966	framebuffer_release(info);
967	}
968
969	/*
970	* Assumes caller is holding info->lock mutex (for open and release at least)
971	*/
972	static int dlfb_ops_release(struct fb_info *info, int user)
973	{
974	struct dlfb_data *dlfb = info->par;
975
976	dlfb->fb_count--;
977
978	if ((dlfb->fb_count == 0) && (info->fbdefio)) {
979	fb_deferred_io_cleanup(info);
980	kfree(objp: info->fbdefio);
981	info->fbdefio = NULL;
982	}
983
984	dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count);
985
986	return 0;
987	}
988
989	/*
990	* Check whether a video mode is supported by the DisplayLink chip
991	* We start from monitor's modes, so don't need to filter that here
992	*/
993	static int dlfb_is_valid_mode(struct fb_videomode *mode, struct dlfb_data *dlfb)
994	{
995	if (mode->xres * mode->yres > dlfb->sku_pixel_limit)
996	return 0;
997
998	return 1;
999	}
1000
1001	static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1002	{
1003	const struct fb_bitfield red = { 11, 5, 0 };
1004	const struct fb_bitfield green = { 5, 6, 0 };
1005	const struct fb_bitfield blue = { 0, 5, 0 };
1006
1007	var->bits_per_pixel = 16;
1008	var->red = red;
1009	var->green = green;
1010	var->blue = blue;
1011	}
1012
1013	static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1014	struct fb_info *info)
1015	{
1016	struct fb_videomode mode;
1017	struct dlfb_data *dlfb = info->par;
1018
1019	/* set device-specific elements of var unrelated to mode */
1020	dlfb_var_color_format(var);
1021
1022	fb_var_to_videomode(mode: &mode, var);
1023
1024	if (!dlfb_is_valid_mode(mode: &mode, dlfb))
1025	return -EINVAL;
1026
1027	return 0;
1028	}
1029
1030	static int dlfb_ops_set_par(struct fb_info *info)
1031	{
1032	struct dlfb_data *dlfb = info->par;
1033	int result;
1034	u16 *pix_framebuffer;
1035	int i;
1036	struct fb_var_screeninfo fvs;
1037	u32 line_length = info->var.xres * (info->var.bits_per_pixel / 8);
1038
1039	/* clear the activate field because it causes spurious miscompares */
1040	fvs = info->var;
1041	fvs.activate = 0;
1042	fvs.vmode &= ~FB_VMODE_SMOOTH_XPAN;
1043
1044	if (!memcmp(p: &dlfb->current_mode, q: &fvs, size: sizeof(struct fb_var_screeninfo)))
1045	return 0;
1046
1047	result = dlfb_realloc_framebuffer(dlfb, info, new_len: info->var.yres * line_length);
1048	if (result)
1049	return result;
1050
1051	result = dlfb_set_video_mode(dlfb, var: &info->var);
1052
1053	if (result)
1054	return result;
1055
1056	dlfb->current_mode = fvs;
1057	info->fix.line_length = line_length;
1058
1059	if (dlfb->fb_count == 0) {
1060
1061	/* paint greenscreen */
1062
1063	pix_framebuffer = (u16 *)info->screen_buffer;
1064	for (i = 0; i < info->fix.smem_len / 2; i++)
1065	pix_framebuffer[i] = 0x37e6;
1066	}
1067
1068	dlfb_handle_damage(dlfb, x: 0, y: 0, width: info->var.xres, height: info->var.yres);
1069
1070	return 0;
1071	}
1072
1073	/* To fonzi the jukebox (e.g. make blanking changes take effect) */
1074	static char *dlfb_dummy_render(char *buf)
1075	{
1076	*buf++ = 0xAF;
1077	*buf++ = 0x6A; /* copy */
1078	*buf++ = 0x00; /* from address*/
1079	*buf++ = 0x00;
1080	*buf++ = 0x00;
1081	*buf++ = 0x01; /* one pixel */
1082	*buf++ = 0x00; /* to address */
1083	*buf++ = 0x00;
1084	*buf++ = 0x00;
1085	return buf;
1086	}
1087
1088	/*
1089	* In order to come back from full DPMS off, we need to set the mode again
1090	*/
1091	static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1092	{
1093	struct dlfb_data *dlfb = info->par;
1094	char *bufptr;
1095	struct urb *urb;
1096
1097	dev_dbg(info->dev, "blank, mode %d --> %d\n",
1098	dlfb->blank_mode, blank_mode);
1099
1100	if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) &&
1101	(blank_mode != FB_BLANK_POWERDOWN)) {
1102
1103	/* returning from powerdown requires a fresh modeset */
1104	dlfb_set_video_mode(dlfb, var: &info->var);
1105	}
1106
1107	urb = dlfb_get_urb(dlfb);
1108	if (!urb)
1109	return 0;
1110
1111	bufptr = (char *) urb->transfer_buffer;
1112	bufptr = dlfb_vidreg_lock(buf: bufptr);
1113	bufptr = dlfb_blanking(buf: bufptr, fb_blank: blank_mode);
1114	bufptr = dlfb_vidreg_unlock(buf: bufptr);
1115
1116	/* seems like a render op is needed to have blank change take effect */
1117	bufptr = dlfb_dummy_render(buf: bufptr);
1118
1119	dlfb_submit_urb(dlfb, urb, len: bufptr -
1120	(char *) urb->transfer_buffer);
1121
1122	dlfb->blank_mode = blank_mode;
1123
1124	return 0;
1125	}
1126
1127	static void dlfb_ops_damage_range(struct fb_info *info, off_t off, size_t len)
1128	{
1129	struct dlfb_data *dlfb = info->par;
1130	int start = max((int)(off / info->fix.line_length), 0);
1131	int lines = min((u32)((len / info->fix.line_length) + 1), (u32)info->var.yres);
1132
1133	dlfb_handle_damage(dlfb, x: 0, y: start, width: info->var.xres, height: lines);
1134	}
1135
1136	static void dlfb_ops_damage_area(struct fb_info *info, u32 x, u32 y, u32 width, u32 height)
1137	{
1138	struct dlfb_data *dlfb = info->par;
1139
1140	dlfb_offload_damage(dlfb, x, y, width, height);
1141	}
1142
1143	FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(dlfb_ops,
1144	dlfb_ops_damage_range,
1145	dlfb_ops_damage_area)
1146
1147	static const struct fb_ops dlfb_ops = {
1148	.owner = THIS_MODULE,
1149	__FB_DEFAULT_DEFERRED_OPS_RDWR(dlfb_ops),
1150	.fb_setcolreg = dlfb_ops_setcolreg,
1151	__FB_DEFAULT_DEFERRED_OPS_DRAW(dlfb_ops),
1152	.fb_mmap = dlfb_ops_mmap,
1153	.fb_ioctl = dlfb_ops_ioctl,
1154	.fb_open = dlfb_ops_open,
1155	.fb_release = dlfb_ops_release,
1156	.fb_blank = dlfb_ops_blank,
1157	.fb_check_var = dlfb_ops_check_var,
1158	.fb_set_par = dlfb_ops_set_par,
1159	.fb_destroy = dlfb_ops_destroy,
1160	};
1161
1162
1163	static void dlfb_deferred_vfree(struct dlfb_data *dlfb, void *mem)
1164	{
1165	struct dlfb_deferred_free *d = kmalloc(size: sizeof(struct dlfb_deferred_free), GFP_KERNEL);
1166	if (!d)
1167	return;
1168	d->mem = mem;
1169	list_add(new: &d->list, head: &dlfb->deferred_free);
1170	}
1171
1172	/*
1173	* Assumes &info->lock held by caller
1174	* Assumes no active clients have framebuffer open
1175	*/
1176	static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len)
1177	{
1178	u32 old_len = info->fix.smem_len;
1179	const void *old_fb = info->screen_buffer;
1180	unsigned char *new_fb;
1181	unsigned char *new_back = NULL;
1182
1183	new_len = PAGE_ALIGN(new_len);
1184
1185	if (new_len > old_len) {
1186	/*
1187	* Alloc system memory for virtual framebuffer
1188	*/
1189	new_fb = vmalloc(size: new_len);
1190	if (!new_fb) {
1191	dev_err(info->dev, "Virtual framebuffer alloc failed\n");
1192	return -ENOMEM;
1193	}
1194	memset(new_fb, 0xff, new_len);
1195
1196	if (info->screen_buffer) {
1197	memcpy(new_fb, old_fb, old_len);
1198	dlfb_deferred_vfree(dlfb, mem: info->screen_buffer);
1199	}
1200
1201	info->screen_buffer = new_fb;
1202	info->fix.smem_len = new_len;
1203	info->fix.smem_start = (unsigned long) new_fb;
1204	info->flags = udlfb_info_flags;
1205
1206	/*
1207	* Second framebuffer copy to mirror the framebuffer state
1208	* on the physical USB device. We can function without this.
1209	* But with imperfect damage info we may send pixels over USB
1210	* that were, in fact, unchanged - wasting limited USB bandwidth
1211	*/
1212	if (shadow)
1213	new_back = vzalloc(size: new_len);
1214	if (!new_back)
1215	dev_info(info->dev,
1216	"No shadow/backing buffer allocated\n");
1217	else {
1218	dlfb_deferred_vfree(dlfb, mem: dlfb->backing_buffer);
1219	dlfb->backing_buffer = new_back;
1220	}
1221	}
1222	return 0;
1223	}
1224
1225	/*
1226	* 1) Get EDID from hw, or use sw default
1227	* 2) Parse into various fb_info structs
1228	* 3) Allocate virtual framebuffer memory to back highest res mode
1229	*
1230	* Parses EDID into three places used by various parts of fbdev:
1231	* fb_var_screeninfo contains the timing of the monitor's preferred mode
1232	* fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1233	* fb_info.modelist is a linked list of all monitor & VESA modes which work
1234	*
1235	* If EDID is not readable/valid, then modelist is all VESA modes,
1236	* monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1237	* Returns 0 if successful
1238	*/
1239	static int dlfb_setup_modes(struct dlfb_data *dlfb,
1240	struct fb_info *info,
1241	char *default_edid, size_t default_edid_size)
1242	{
1243	char *edid;
1244	int i, result = 0, tries = 3;
1245	struct device *dev = info->device;
1246	struct fb_videomode *mode;
1247	const struct fb_videomode *default_vmode = NULL;
1248
1249	if (info->dev) {
1250	/* only use mutex if info has been registered */
1251	mutex_lock(&info->lock);
1252	/* parent device is used otherwise */
1253	dev = info->dev;
1254	}
1255
1256	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1257	if (!edid) {
1258	result = -ENOMEM;
1259	goto error;
1260	}
1261
1262	fb_destroy_modelist(head: &info->modelist);
1263	memset(&info->monspecs, 0, sizeof(info->monspecs));
1264
1265	/*
1266	* Try to (re)read EDID from hardware first
1267	* EDID data may return, but not parse as valid
1268	* Try again a few times, in case of e.g. analog cable noise
1269	*/
1270	while (tries--) {
1271
1272	i = dlfb_get_edid(dlfb, edid, EDID_LENGTH);
1273
1274	if (i >= EDID_LENGTH)
1275	fb_edid_to_monspecs(edid, specs: &info->monspecs);
1276
1277	if (info->monspecs.modedb_len > 0) {
1278	dlfb->edid = edid;
1279	dlfb->edid_size = i;
1280	break;
1281	}
1282	}
1283
1284	/* If that fails, use a previously returned EDID if available */
1285	if (info->monspecs.modedb_len == 0) {
1286	dev_err(dev, "Unable to get valid EDID from device/display\n");
1287
1288	if (dlfb->edid) {
1289	fb_edid_to_monspecs(edid: dlfb->edid, specs: &info->monspecs);
1290	if (info->monspecs.modedb_len > 0)
1291	dev_err(dev, "Using previously queried EDID\n");
1292	}
1293	}
1294
1295	/* If that fails, use the default EDID we were handed */
1296	if (info->monspecs.modedb_len == 0) {
1297	if (default_edid_size >= EDID_LENGTH) {
1298	fb_edid_to_monspecs(edid: default_edid, specs: &info->monspecs);
1299	if (info->monspecs.modedb_len > 0) {
1300	memcpy(edid, default_edid, default_edid_size);
1301	dlfb->edid = edid;
1302	dlfb->edid_size = default_edid_size;
1303	dev_err(dev, "Using default/backup EDID\n");
1304	}
1305	}
1306	}
1307
1308	/* If we've got modes, let's pick a best default mode */
1309	if (info->monspecs.modedb_len > 0) {
1310
1311	for (i = 0; i < info->monspecs.modedb_len; i++) {
1312	mode = &info->monspecs.modedb[i];
1313	if (dlfb_is_valid_mode(mode, dlfb)) {
1314	fb_add_videomode(mode, head: &info->modelist);
1315	} else {
1316	dev_dbg(dev, "Specified mode %dx%d too big\n",
1317	mode->xres, mode->yres);
1318	if (i == 0)
1319	/* if we've removed top/best mode */
1320	info->monspecs.misc
1321	&= ~FB_MISC_1ST_DETAIL;
1322	}
1323	}
1324
1325	default_vmode = fb_find_best_display(specs: &info->monspecs,
1326	head: &info->modelist);
1327	}
1328
1329	/* If everything else has failed, fall back to safe default mode */
1330	if (default_vmode == NULL) {
1331
1332	struct fb_videomode fb_vmode = {0};
1333
1334	/*
1335	* Add the standard VESA modes to our modelist
1336	* Since we don't have EDID, there may be modes that
1337	* overspec monitor and/or are incorrect aspect ratio, etc.
1338	* But at least the user has a chance to choose
1339	*/
1340	for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1341	mode = (struct fb_videomode *)&vesa_modes[i];
1342	if (dlfb_is_valid_mode(mode, dlfb))
1343	fb_add_videomode(mode, head: &info->modelist);
1344	else
1345	dev_dbg(dev, "VESA mode %dx%d too big\n",
1346	mode->xres, mode->yres);
1347	}
1348
1349	/*
1350	* default to resolution safe for projectors
1351	* (since they are most common case without EDID)
1352	*/
1353	fb_vmode.xres = 800;
1354	fb_vmode.yres = 600;
1355	fb_vmode.refresh = 60;
1356	default_vmode = fb_find_nearest_mode(mode: &fb_vmode,
1357	head: &info->modelist);
1358	}
1359
1360	/* If we have good mode and no active clients*/
1361	if ((default_vmode != NULL) && (dlfb->fb_count == 0)) {
1362
1363	fb_videomode_to_var(var: &info->var, mode: default_vmode);
1364	dlfb_var_color_format(var: &info->var);
1365
1366	/*
1367	* with mode size info, we can now alloc our framebuffer.
1368	*/
1369	memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1370	} else
1371	result = -EINVAL;
1372
1373	error:
1374	if (edid && (dlfb->edid != edid))
1375	kfree(objp: edid);
1376
1377	if (info->dev)
1378	mutex_unlock(lock: &info->lock);
1379
1380	return result;
1381	}
1382
1383	static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1384	struct device_attribute *a, char *buf) {
1385	struct fb_info *fb_info = dev_get_drvdata(dev: fbdev);
1386	struct dlfb_data *dlfb = fb_info->par;
1387	return sysfs_emit(buf, fmt: "%u\n",
1388	atomic_read(v: &dlfb->bytes_rendered));
1389	}
1390
1391	static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1392	struct device_attribute *a, char *buf) {
1393	struct fb_info *fb_info = dev_get_drvdata(dev: fbdev);
1394	struct dlfb_data *dlfb = fb_info->par;
1395	return sysfs_emit(buf, fmt: "%u\n",
1396	atomic_read(v: &dlfb->bytes_identical));
1397	}
1398
1399	static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1400	struct device_attribute *a, char *buf) {
1401	struct fb_info *fb_info = dev_get_drvdata(dev: fbdev);
1402	struct dlfb_data *dlfb = fb_info->par;
1403	return sysfs_emit(buf, fmt: "%u\n",
1404	atomic_read(v: &dlfb->bytes_sent));
1405	}
1406
1407	static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1408	struct device_attribute *a, char *buf) {
1409	struct fb_info *fb_info = dev_get_drvdata(dev: fbdev);
1410	struct dlfb_data *dlfb = fb_info->par;
1411	return sysfs_emit(buf, fmt: "%u\n",
1412	atomic_read(v: &dlfb->cpu_kcycles_used));
1413	}
1414
1415	static ssize_t edid_show(
1416	struct file *filp,
1417	struct kobject *kobj, struct bin_attribute *a,
1418	char *buf, loff_t off, size_t count) {
1419	struct device *fbdev = kobj_to_dev(kobj);
1420	struct fb_info *fb_info = dev_get_drvdata(dev: fbdev);
1421	struct dlfb_data *dlfb = fb_info->par;
1422
1423	if (dlfb->edid == NULL)
1424	return 0;
1425
1426	if ((off >= dlfb->edid_size) || (count > dlfb->edid_size))
1427	return 0;
1428
1429	if (off + count > dlfb->edid_size)
1430	count = dlfb->edid_size - off;
1431
1432	memcpy(buf, dlfb->edid, count);
1433
1434	return count;
1435	}
1436
1437	static ssize_t edid_store(
1438	struct file *filp,
1439	struct kobject *kobj, struct bin_attribute *a,
1440	char *src, loff_t src_off, size_t src_size) {
1441	struct device *fbdev = kobj_to_dev(kobj);
1442	struct fb_info *fb_info = dev_get_drvdata(dev: fbdev);
1443	struct dlfb_data *dlfb = fb_info->par;
1444	int ret;
1445
1446	/* We only support write of entire EDID at once, no offset*/
1447	if ((src_size != EDID_LENGTH) || (src_off != 0))
1448	return -EINVAL;
1449
1450	ret = dlfb_setup_modes(dlfb, info: fb_info, default_edid: src, default_edid_size: src_size);
1451	if (ret)
1452	return ret;
1453
1454	if (!dlfb->edid || memcmp(p: src, q: dlfb->edid, size: src_size))
1455	return -EINVAL;
1456
1457	ret = dlfb_ops_set_par(info: fb_info);
1458	if (ret)
1459	return ret;
1460
1461	return src_size;
1462	}
1463
1464	static ssize_t metrics_reset_store(struct device *fbdev,
1465	struct device_attribute *attr,
1466	const char *buf, size_t count)
1467	{
1468	struct fb_info *fb_info = dev_get_drvdata(dev: fbdev);
1469	struct dlfb_data *dlfb = fb_info->par;
1470
1471	atomic_set(v: &dlfb->bytes_rendered, i: 0);
1472	atomic_set(v: &dlfb->bytes_identical, i: 0);
1473	atomic_set(v: &dlfb->bytes_sent, i: 0);
1474	atomic_set(v: &dlfb->cpu_kcycles_used, i: 0);
1475
1476	return count;
1477	}
1478
1479	static const struct bin_attribute edid_attr = {
1480	.attr.name = "edid",
1481	.attr.mode = 0666,
1482	.size = EDID_LENGTH,
1483	.read = edid_show,
1484	.write = edid_store
1485	};
1486
1487	static const struct device_attribute fb_device_attrs[] = {
1488	__ATTR_RO(metrics_bytes_rendered),
1489	__ATTR_RO(metrics_bytes_identical),
1490	__ATTR_RO(metrics_bytes_sent),
1491	__ATTR_RO(metrics_cpu_kcycles_used),
1492	__ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1493	};
1494
1495	/*
1496	* This is necessary before we can communicate with the display controller.
1497	*/
1498	static int dlfb_select_std_channel(struct dlfb_data *dlfb)
1499	{
1500	int ret;
1501	static const u8 set_def_chn[] = {
1502	0x57, 0xCD, 0xDC, 0xA7,
1503	0x1C, 0x88, 0x5E, 0x15,
1504	0x60, 0xFE, 0xC6, 0x97,
1505	0x16, 0x3D, 0x47, 0xF2 };
1506
1507	ret = usb_control_msg_send(dev: dlfb->udev, endpoint: 0, NR_USB_REQUEST_CHANNEL,
1508	requesttype: (USB_DIR_OUT | USB_TYPE_VENDOR), value: 0, index: 0,
1509	data: &set_def_chn, size: sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT,
1510	GFP_KERNEL);
1511
1512	return ret;
1513	}
1514
1515	static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb,
1516	struct usb_interface *intf)
1517	{
1518	char *desc;
1519	char *buf;
1520	char *desc_end;
1521	int total_len;
1522
1523	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1524	if (!buf)
1525	return false;
1526	desc = buf;
1527
1528	total_len = usb_get_descriptor(interface_to_usbdev(intf),
1529	desctype: 0x5f, /* vendor specific */
1530	descindex: 0, buf: desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1531
1532	/* if not found, look in configuration descriptor */
1533	if (total_len < 0) {
1534	if (0 == usb_get_extra_descriptor(intf->cur_altsetting,
1535	0x5f, &desc))
1536	total_len = (int) desc[0];
1537	}
1538
1539	if (total_len > 5) {
1540	dev_info(&intf->dev,
1541	"vendor descriptor length: %d data: %11ph\n",
1542	total_len, desc);
1543
1544	if ((desc[0] != total_len) || /* descriptor length */
1545	(desc[1] != 0x5f) || /* vendor descriptor type */
1546	(desc[2] != 0x01) || /* version (2 bytes) */
1547	(desc[3] != 0x00) ||
1548	(desc[4] != total_len - 2)) /* length after type */
1549	goto unrecognized;
1550
1551	desc_end = desc + total_len;
1552	desc += 5; /* the fixed header we've already parsed */
1553
1554	while (desc < desc_end) {
1555	u8 length;
1556	u16 key;
1557
1558	key = *desc++;
1559	key |= (u16)*desc++ << 8;
1560	length = *desc++;
1561
1562	switch (key) {
1563	case 0x0200: { /* max_area */
1564	u32 max_area = *desc++;
1565	max_area |= (u32)*desc++ << 8;
1566	max_area |= (u32)*desc++ << 16;
1567	max_area |= (u32)*desc++ << 24;
1568	dev_warn(&intf->dev,
1569	"DL chip limited to %d pixel modes\n",
1570	max_area);
1571	dlfb->sku_pixel_limit = max_area;
1572	break;
1573	}
1574	default:
1575	break;
1576	}
1577	desc += length;
1578	}
1579	} else {
1580	dev_info(&intf->dev, "vendor descriptor not available (%d)\n",
1581	total_len);
1582	}
1583
1584	goto success;
1585
1586	unrecognized:
1587	/* allow udlfb to load for now even if firmware unrecognized */
1588	dev_err(&intf->dev, "Unrecognized vendor firmware descriptor\n");
1589
1590	success:
1591	kfree(objp: buf);
1592	return true;
1593	}
1594
1595	static int dlfb_usb_probe(struct usb_interface *intf,
1596	const struct usb_device_id *id)
1597	{
1598	int i;
1599	const struct device_attribute *attr;
1600	struct dlfb_data *dlfb;
1601	struct fb_info *info;
1602	int retval;
1603	struct usb_device *usbdev = interface_to_usbdev(intf);
1604	static u8 out_ep[] = {OUT_EP_NUM + USB_DIR_OUT, 0};
1605
1606	/* usb initialization */
1607	dlfb = kzalloc(size: sizeof(*dlfb), GFP_KERNEL);
1608	if (!dlfb) {
1609	dev_err(&intf->dev, "%s: failed to allocate dlfb\n", __func__);
1610	return -ENOMEM;
1611	}
1612
1613	INIT_LIST_HEAD(list: &dlfb->deferred_free);
1614
1615	dlfb->udev = usb_get_dev(dev: usbdev);
1616	usb_set_intfdata(intf, data: dlfb);
1617
1618	if (!usb_check_bulk_endpoints(intf, ep_addrs: out_ep)) {
1619	dev_err(&intf->dev, "Invalid DisplayLink device!\n");
1620	retval = -EINVAL;
1621	goto error;
1622	}
1623
1624	dev_dbg(&intf->dev, "console enable=%d\n", console);
1625	dev_dbg(&intf->dev, "fb_defio enable=%d\n", fb_defio);
1626	dev_dbg(&intf->dev, "shadow enable=%d\n", shadow);
1627
1628	dlfb->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1629
1630	if (!dlfb_parse_vendor_descriptor(dlfb, intf)) {
1631	dev_err(&intf->dev,
1632	"firmware not recognized, incompatible device?\n");
1633	retval = -ENODEV;
1634	goto error;
1635	}
1636
1637	if (pixel_limit) {
1638	dev_warn(&intf->dev,
1639	"DL chip limit of %d overridden to %d\n",
1640	dlfb->sku_pixel_limit, pixel_limit);
1641	dlfb->sku_pixel_limit = pixel_limit;
1642	}
1643
1644
1645	/* allocates framebuffer driver structure, not framebuffer memory */
1646	info = framebuffer_alloc(size: 0, dev: &dlfb->udev->dev);
1647	if (!info) {
1648	retval = -ENOMEM;
1649	goto error;
1650	}
1651
1652	dlfb->info = info;
1653	info->par = dlfb;
1654	info->pseudo_palette = dlfb->pseudo_palette;
1655	dlfb->ops = dlfb_ops;
1656	info->fbops = &dlfb->ops;
1657
1658	mutex_init(&dlfb->render_mutex);
1659	dlfb_init_damage(dlfb);
1660	spin_lock_init(&dlfb->damage_lock);
1661	INIT_WORK(&dlfb->damage_work, dlfb_damage_work);
1662
1663	INIT_LIST_HEAD(list: &info->modelist);
1664
1665	if (!dlfb_alloc_urb_list(dlfb, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1666	retval = -ENOMEM;
1667	dev_err(&intf->dev, "unable to allocate urb list\n");
1668	goto error;
1669	}
1670
1671	/* We don't register a new USB class. Our client interface is dlfbev */
1672
1673	retval = fb_alloc_cmap(cmap: &info->cmap, len: 256, transp: 0);
1674	if (retval < 0) {
1675	dev_err(info->device, "cmap allocation failed: %d\n", retval);
1676	goto error;
1677	}
1678
1679	retval = dlfb_setup_modes(dlfb, info, NULL, default_edid_size: 0);
1680	if (retval != 0) {
1681	dev_err(info->device,
1682	"unable to find common mode for display and adapter\n");
1683	goto error;
1684	}
1685
1686	/* ready to begin using device */
1687
1688	atomic_set(v: &dlfb->usb_active, i: 1);
1689	dlfb_select_std_channel(dlfb);
1690
1691	dlfb_ops_check_var(var: &info->var, info);
1692	retval = dlfb_ops_set_par(info);
1693	if (retval)
1694	goto error;
1695
1696	retval = register_framebuffer(fb_info: info);
1697	if (retval < 0) {
1698	dev_err(info->device, "unable to register framebuffer: %d\n",
1699	retval);
1700	goto error;
1701	}
1702
1703	for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
1704	attr = &fb_device_attrs[i];
1705	retval = device_create_file(device: info->dev, entry: attr);
1706	if (retval)
1707	dev_warn(info->device,
1708	"failed to create '%s' attribute: %d\n",
1709	attr->attr.name, retval);
1710	}
1711
1712	retval = device_create_bin_file(dev: info->dev, attr: &edid_attr);
1713	if (retval)
1714	dev_warn(info->device, "failed to create '%s' attribute: %d\n",
1715	edid_attr.attr.name, retval);
1716
1717	dev_info(info->device,
1718	"%s is DisplayLink USB device (%dx%d, %dK framebuffer memory)\n",
1719	dev_name(info->dev), info->var.xres, info->var.yres,
1720	((dlfb->backing_buffer) ?
1721	info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1722	return 0;
1723
1724	error:
1725	if (dlfb->info) {
1726	dlfb_ops_destroy(info: dlfb->info);
1727	} else {
1728	usb_put_dev(dev: dlfb->udev);
1729	kfree(objp: dlfb);
1730	}
1731	return retval;
1732	}
1733
1734	static void dlfb_usb_disconnect(struct usb_interface *intf)
1735	{
1736	struct dlfb_data *dlfb;
1737	struct fb_info *info;
1738	int i;
1739
1740	dlfb = usb_get_intfdata(intf);
1741	info = dlfb->info;
1742
1743	dev_dbg(&intf->dev, "USB disconnect starting\n");
1744
1745	/* we virtualize until all fb clients release. Then we free */
1746	dlfb->virtualized = true;
1747
1748	/* When non-active we'll update virtual framebuffer, but no new urbs */
1749	atomic_set(v: &dlfb->usb_active, i: 0);
1750
1751	/* this function will wait for all in-flight urbs to complete */
1752	dlfb_free_urb_list(dlfb);
1753
1754	/* remove udlfb's sysfs interfaces */
1755	for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1756	device_remove_file(dev: info->dev, attr: &fb_device_attrs[i]);
1757	device_remove_bin_file(dev: info->dev, attr: &edid_attr);
1758
1759	unregister_framebuffer(fb_info: info);
1760	}
1761
1762	static struct usb_driver dlfb_driver = {
1763	.name = "udlfb",
1764	.probe = dlfb_usb_probe,
1765	.disconnect = dlfb_usb_disconnect,
1766	.id_table = id_table,
1767	};
1768
1769	module_usb_driver(dlfb_driver);
1770
1771	static void dlfb_urb_completion(struct urb *urb)
1772	{
1773	struct urb_node *unode = urb->context;
1774	struct dlfb_data *dlfb = unode->dlfb;
1775	unsigned long flags;
1776
1777	switch (urb->status) {
1778	case 0:
1779	/* success */
1780	break;
1781	case -ECONNRESET:
1782	case -ENOENT:
1783	case -ESHUTDOWN:
1784	/* sync/async unlink faults aren't errors */
1785	break;
1786	default:
1787	dev_err(&dlfb->udev->dev,
1788	"%s - nonzero write bulk status received: %d\n",
1789	__func__, urb->status);
1790	atomic_set(v: &dlfb->lost_pixels, i: 1);
1791	break;
1792	}
1793
1794	urb->transfer_buffer_length = dlfb->urbs.size; /* reset to actual */
1795
1796	spin_lock_irqsave(&dlfb->urbs.lock, flags);
1797	list_add_tail(new: &unode->entry, head: &dlfb->urbs.list);
1798	dlfb->urbs.available++;
1799	spin_unlock_irqrestore(lock: &dlfb->urbs.lock, flags);
1800
1801	up(sem: &dlfb->urbs.limit_sem);
1802	}
1803
1804	static void dlfb_free_urb_list(struct dlfb_data *dlfb)
1805	{
1806	int count = dlfb->urbs.count;
1807	struct list_head *node;
1808	struct urb_node *unode;
1809	struct urb *urb;
1810
1811	/* keep waiting and freeing, until we've got 'em all */
1812	while (count--) {
1813	down(sem: &dlfb->urbs.limit_sem);
1814
1815	spin_lock_irq(lock: &dlfb->urbs.lock);
1816
1817	node = dlfb->urbs.list.next; /* have reserved one with sem */
1818	list_del_init(entry: node);
1819
1820	spin_unlock_irq(lock: &dlfb->urbs.lock);
1821
1822	unode = list_entry(node, struct urb_node, entry);
1823	urb = unode->urb;
1824
1825	/* Free each separately allocated piece */
1826	usb_free_coherent(dev: urb->dev, size: dlfb->urbs.size,
1827	addr: urb->transfer_buffer, dma: urb->transfer_dma);
1828	usb_free_urb(urb);
1829	kfree(objp: node);
1830	}
1831
1832	dlfb->urbs.count = 0;
1833	}
1834
1835	static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size)
1836	{
1837	struct urb *urb;
1838	struct urb_node *unode;
1839	char *buf;
1840	size_t wanted_size = count * size;
1841
1842	spin_lock_init(&dlfb->urbs.lock);
1843
1844	retry:
1845	dlfb->urbs.size = size;
1846	INIT_LIST_HEAD(list: &dlfb->urbs.list);
1847
1848	sema_init(sem: &dlfb->urbs.limit_sem, val: 0);
1849	dlfb->urbs.count = 0;
1850	dlfb->urbs.available = 0;
1851
1852	while (dlfb->urbs.count * size < wanted_size) {
1853	unode = kzalloc(size: sizeof(*unode), GFP_KERNEL);
1854	if (!unode)
1855	break;
1856	unode->dlfb = dlfb;
1857
1858	urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
1859	if (!urb) {
1860	kfree(objp: unode);
1861	break;
1862	}
1863	unode->urb = urb;
1864
1865	buf = usb_alloc_coherent(dev: dlfb->udev, size, GFP_KERNEL,
1866	dma: &urb->transfer_dma);
1867	if (!buf) {
1868	kfree(objp: unode);
1869	usb_free_urb(urb);
1870	if (size > PAGE_SIZE) {
1871	size /= 2;
1872	dlfb_free_urb_list(dlfb);
1873	goto retry;
1874	}
1875	break;
1876	}
1877
1878	/* urb->transfer_buffer_length set to actual before submit */
1879	usb_fill_bulk_urb(urb, dev: dlfb->udev,
1880	usb_sndbulkpipe(dlfb->udev, OUT_EP_NUM),
1881	transfer_buffer: buf, buffer_length: size, complete_fn: dlfb_urb_completion, context: unode);
1882	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1883
1884	list_add_tail(new: &unode->entry, head: &dlfb->urbs.list);
1885
1886	up(sem: &dlfb->urbs.limit_sem);
1887	dlfb->urbs.count++;
1888	dlfb->urbs.available++;
1889	}
1890
1891	return dlfb->urbs.count;
1892	}
1893
1894	static struct urb *dlfb_get_urb(struct dlfb_data *dlfb)
1895	{
1896	int ret;
1897	struct list_head *entry;
1898	struct urb_node *unode;
1899
1900	/* Wait for an in-flight buffer to complete and get re-queued */
1901	ret = down_timeout(sem: &dlfb->urbs.limit_sem, GET_URB_TIMEOUT);
1902	if (ret) {
1903	atomic_set(v: &dlfb->lost_pixels, i: 1);
1904	dev_warn(&dlfb->udev->dev,
1905	"wait for urb interrupted: %d available: %d\n",
1906	ret, dlfb->urbs.available);
1907	return NULL;
1908	}
1909
1910	spin_lock_irq(lock: &dlfb->urbs.lock);
1911
1912	BUG_ON(list_empty(&dlfb->urbs.list)); /* reserved one with limit_sem */
1913	entry = dlfb->urbs.list.next;
1914	list_del_init(entry);
1915	dlfb->urbs.available--;
1916
1917	spin_unlock_irq(lock: &dlfb->urbs.lock);
1918
1919	unode = list_entry(entry, struct urb_node, entry);
1920	return unode->urb;
1921	}
1922
1923	static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb *urb, size_t len)
1924	{
1925	int ret;
1926
1927	BUG_ON(len > dlfb->urbs.size);
1928
1929	urb->transfer_buffer_length = len; /* set to actual payload len */
1930	ret = usb_submit_urb(urb, GFP_KERNEL);
1931	if (ret) {
1932	dlfb_urb_completion(urb); /* because no one else will */
1933	atomic_set(v: &dlfb->lost_pixels, i: 1);
1934	dev_err(&dlfb->udev->dev, "submit urb error: %d\n", ret);
1935	}
1936	return ret;
1937	}
1938
1939	module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1940	MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
1941
1942	module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1943	MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
1944
1945	module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1946	MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
1947
1948	module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1949	MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)");
1950
1951	MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1952	"Jaya Kumar <jayakumar.lkml@gmail.com>, "
1953	"Bernie Thompson <bernie@plugable.com>");
1954	MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1955	MODULE_LICENSE("GPL");
1956
1957