aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/video/usbvideo/vicam.c
blob: 1ffcc393fcbb810f4e9437a8933b1409d809d905 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
/*
 * USB ViCam WebCam driver
 * Copyright (c) 2002 Joe Burks (jburks@wavicle.org),
 *                    Christopher L Cheney (ccheney@cheney.cx),
 *                    Pavel Machek (pavel@suse.cz),
 *                    John Tyner (jtyner@cs.ucr.edu),
 *                    Monroe Williams (monroe@pobox.com)
 *
 * Supports 3COM HomeConnect PC Digital WebCam
 * Supports Compro PS39U WebCam
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * This source code is based heavily on the CPiA webcam driver which was
 * written by Peter Pregler, Scott J. Bertin and Johannes Erdfelt
 *
 * Portions of this code were also copied from usbvideo.c
 *
 * Special thanks to the whole team at Sourceforge for help making
 * this driver become a reality.  Notably:
 * Andy Armstrong who reverse engineered the color encoding and
 * Pavel Machek and Chris Cheney who worked on reverse engineering the
 *    camera controls and wrote the first generation driver.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/videodev.h>
#include <linux/usb.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/firmware.h>
#include <linux/ihex.h>
#include "usbvideo.h"

// #define VICAM_DEBUG

#ifdef VICAM_DEBUG
#define ADBG(lineno,fmt,args...) printk(fmt, jiffies, __func__, lineno, ##args)
#define DBG(fmt,args...) ADBG((__LINE__),KERN_DEBUG __FILE__"(%ld):%s (%d):"fmt,##args)
#else
#define DBG(fmn,args...) do {} while(0)
#endif

#define DRIVER_AUTHOR           "Joe Burks, jburks@wavicle.org"
#define DRIVER_DESC             "ViCam WebCam Driver"

/* Define these values to match your device */
#define USB_VICAM_VENDOR_ID	0x04c1
#define USB_VICAM_PRODUCT_ID	0x009d
#define USB_COMPRO_VENDOR_ID	0x0602
#define USB_COMPRO_PRODUCT_ID	0x1001

#define VICAM_BYTES_PER_PIXEL   3
#define VICAM_MAX_READ_SIZE     (512*242+128)
#define VICAM_MAX_FRAME_SIZE    (VICAM_BYTES_PER_PIXEL*320*240)
#define VICAM_FRAMES            2

#define VICAM_HEADER_SIZE       64

/* rvmalloc / rvfree copied from usbvideo.c
 *
 * Not sure why these are not yet non-statics which I can reference through
 * usbvideo.h the same as it is in 2.4.20.  I bet this will get fixed sometime
 * in the future.
 *
*/
static void *rvmalloc(unsigned long size)
{
	void *mem;
	unsigned long adr;

	size = PAGE_ALIGN(size);
	mem = vmalloc_32(size);
	if (!mem)
		return NULL;

	memset(mem, 0, size); /* Clear the ram out, no junk to the user */
	adr = (unsigned long) mem;
	while (size > 0) {
		SetPageReserved(vmalloc_to_page((void *)adr));
		adr += PAGE_SIZE;
		size -= PAGE_SIZE;
	}

	return mem;
}

static void rvfree(void *mem, unsigned long size)
{
	unsigned long adr;

	if (!mem)
		return;

	adr = (unsigned long) mem;
	while ((long) size > 0) {
		ClearPageReserved(vmalloc_to_page((void *)adr));
		adr += PAGE_SIZE;
		size -= PAGE_SIZE;
	}
	vfree(mem);
}

struct vicam_camera {
	u16 shutter_speed;	// capture shutter speed
	u16 gain;		// capture gain

	u8 *raw_image;		// raw data captured from the camera
	u8 *framebuf;		// processed data in RGB24 format
	u8 *cntrlbuf;		// area used to send control msgs

	struct video_device vdev;	// v4l video device
	struct usb_device *udev;	// usb device

	/* guard against simultaneous accesses to the camera */
	struct mutex cam_lock;

	int is_initialized;
	u8 open_count;
	u8 bulkEndpoint;
	int needsDummyRead;
};

static int vicam_probe( struct usb_interface *intf, const struct usb_device_id *id);
static void vicam_disconnect(struct usb_interface *intf);
static void read_frame(struct vicam_camera *cam, int framenum);
static void vicam_decode_color(const u8 *, u8 *);

static int __send_control_msg(struct vicam_camera *cam,
			      u8 request,
			      u16 value,
			      u16 index,
			      unsigned char *cp,
			      u16 size)
{
	int status;

	/* cp must be memory that has been allocated by kmalloc */

	status = usb_control_msg(cam->udev,
				 usb_sndctrlpipe(cam->udev, 0),
				 request,
				 USB_DIR_OUT | USB_TYPE_VENDOR |
				 USB_RECIP_DEVICE, value, index,
				 cp, size, 1000);

	status = min(status, 0);

	if (status < 0) {
		printk(KERN_INFO "Failed sending control message, error %d.\n",
		       status);
	}

	return status;
}

static int send_control_msg(struct vicam_camera *cam,
			    u8 request,
			    u16 value,
			    u16 index,
			    unsigned char *cp,
			    u16 size)
{
	int status = -ENODEV;
	mutex_lock(&cam->cam_lock);
	if (cam->udev) {
		status = __send_control_msg(cam, request, value,
					    index, cp, size);
	}
	mutex_unlock(&cam->cam_lock);
	return status;
}
static int
initialize_camera(struct vicam_camera *cam)
{
	int err;
	const struct ihex_binrec *rec;
	const struct firmware *fw;

	err = request_ihex_firmware(&fw, "vicam/firmware.fw", &cam->udev->dev);
	if (err) {
		printk(KERN_ERR "Failed to load \"vicam/firmware.fw\": %d\n",
		       err);
		return err;
	}

	for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
		memcpy(cam->cntrlbuf, rec->data, be16_to_cpu(rec->len));

		err = send_control_msg(cam, 0xff, 0, 0,
				       cam->cntrlbuf, be16_to_cpu(rec->len));
		if (err)
			break;
	}

	release_firmware(fw);

	return err;
}

static int
set_camera_power(struct vicam_camera *cam, int state)
{
	int status;

	if ((status = send_control_msg(cam, 0x50, state, 0, NULL, 0)) < 0)
		return status;

	if (state) {
		send_control_msg(cam, 0x55, 1, 0, NULL, 0);
	}

	return 0;
}

static int
vicam_ioctl(struct inode *inode, struct file *file, unsigned int ioctlnr, unsigned long arg)
{
	void __user *user_arg = (void __user *)arg;
	struct vicam_camera *cam = file->private_data;
	int retval = 0;

	if (!cam)
		return -ENODEV;

	switch (ioctlnr) {
		/* query capabilities */
	case VIDIOCGCAP:
		{
			struct video_capability b;

			DBG("VIDIOCGCAP\n");
			memset(&b, 0, sizeof(b));
			strcpy(b.name, "ViCam-based Camera");
			b.type = VID_TYPE_CAPTURE;
			b.channels = 1;
			b.audios = 0;
			b.maxwidth = 320;	/* VIDEOSIZE_CIF */
			b.maxheight = 240;
			b.minwidth = 320;	/* VIDEOSIZE_48_48 */
			b.minheight = 240;

			if (copy_to_user(user_arg, &b, sizeof(b)))
				retval = -EFAULT;

			break;
		}
		/* get/set video source - we are a camera and nothing else */
	case VIDIOCGCHAN:
		{
			struct video_channel v;

			DBG("VIDIOCGCHAN\n");
			if (copy_from_user(&v, user_arg, sizeof(v))) {
				retval = -EFAULT;
				break;
			}
			if (v.channel != 0) {
				retval = -EINVAL;
				break;
			}

			v.channel = 0;
			strcpy(v.name, "Camera");
			v.tuners = 0;
			v.flags = 0;
			v.type = VIDEO_TYPE_CAMERA;
			v.norm = 0;

			if (copy_to_user(user_arg, &v, sizeof(v)))
				retval = -EFAULT;
			break;
		}

	case VIDIOCSCHAN:
		{
			int v;

			if (copy_from_user(&v, user_arg, sizeof(v)))
				retval = -EFAULT;
			DBG("VIDIOCSCHAN %d\n", v);

			if (retval == 0 && v != 0)
				retval = -EINVAL;

			break;
		}

		/* image properties */
	case VIDIOCGPICT:
		{
			struct video_picture vp;
			DBG("VIDIOCGPICT\n");
			memset(&vp, 0, sizeof (struct video_picture));
			vp.brightness = cam->gain << 8;
			vp.depth = 24;
			vp.palette = VIDEO_PALETTE_RGB24;
			if (copy_to_user(user_arg, &vp, sizeof (struct video_picture)))
				retval = -EFAULT;
			break;
		}

	case VIDIOCSPICT:
		{
			struct video_picture vp;

			if (copy_from_user(&vp, user_arg, sizeof(vp))) {
				retval = -EFAULT;
				break;
			}

			DBG("VIDIOCSPICT depth = %d, pal = %d\n", vp.depth,
			    vp.palette);

			cam->gain = vp.brightness >> 8;

			if (vp.depth != 24
			    || vp.palette != VIDEO_PALETTE_RGB24)
				retval = -EINVAL;

			break;
		}

		/* get/set capture window */
	case VIDIOCGWIN:
		{
			struct video_window vw;
			vw.x = 0;
			vw.y = 0;
			vw.width = 320;
			vw.height = 240;
			vw.chromakey = 0;
			vw.flags = 0;
			vw.clips = NULL;
			vw.clipcount = 0;

			DBG("VIDIOCGWIN\n");

			if (copy_to_user(user_arg, (void *)&vw, sizeof(vw)))
				retval = -EFAULT;

			// I'm not sure what the deal with a capture window is, it is very poorly described
			// in the doc.  So I won't support it now.
			break;
		}

	case VIDIOCSWIN:
		{

			struct video_window vw;

			if (copy_from_user(&vw, user_arg, sizeof(vw))) {
				retval = -EFAULT;
				break;
			}

			DBG("VIDIOCSWIN %d x %d\n", vw.width, vw.height);

			if ( vw.width != 320 || vw.height != 240 )
				retval = -EFAULT;

			break;
		}

		/* mmap interface */
	case VIDIOCGMBUF:
		{
			struct video_mbuf vm;
			int i;

			DBG("VIDIOCGMBUF\n");
			memset(&vm, 0, sizeof (vm));
			vm.size =
			    VICAM_MAX_FRAME_SIZE * VICAM_FRAMES;
			vm.frames = VICAM_FRAMES;
			for (i = 0; i < VICAM_FRAMES; i++)
				vm.offsets[i] = VICAM_MAX_FRAME_SIZE * i;

			if (copy_to_user(user_arg, (void *)&vm, sizeof(vm)))
				retval = -EFAULT;

			break;
		}

	case VIDIOCMCAPTURE:
		{
			struct video_mmap vm;
			// int video_size;

			if (copy_from_user((void *)&vm, user_arg, sizeof(vm))) {
				retval = -EFAULT;
				break;
			}

			DBG("VIDIOCMCAPTURE frame=%d, height=%d, width=%d, format=%d.\n",vm.frame,vm.width,vm.height,vm.format);

			if ( vm.frame >= VICAM_FRAMES || vm.format != VIDEO_PALETTE_RGB24 )
				retval = -EINVAL;

			// in theory right here we'd start the image capturing
			// (fill in a bulk urb and submit it asynchronously)
			//
			// Instead we're going to do a total hack job for now and
			// retrieve the frame in VIDIOCSYNC

			break;
		}

	case VIDIOCSYNC:
		{
			int frame;

			if (copy_from_user((void *)&frame, user_arg, sizeof(int))) {
				retval = -EFAULT;
				break;
			}
			DBG("VIDIOCSYNC: %d\n", frame);

			read_frame(cam, frame);
			vicam_decode_color(cam->raw_image,
					   cam->framebuf +
					   frame * VICAM_MAX_FRAME_SIZE );

			break;
		}

		/* pointless to implement overlay with this camera */
	case VIDIOCCAPTURE:
	case VIDIOCGFBUF:
	case VIDIOCSFBUF:
	case VIDIOCKEY:
		retval = -EINVAL;
		break;

		/* tuner interface - we have none */
	case VIDIOCGTUNER:
	case VIDIOCSTUNER:
	case VIDIOCGFREQ:
	case VIDIOCSFREQ:
		retval = -EINVAL;
		break;

		/* audio interface - we have none */
	case VIDIOCGAUDIO:
	case VIDIOCSAUDIO:
		retval = -EINVAL;
		break;
	default:
		retval = -ENOIOCTLCMD;
		break;
	}

	return retval;
}

static int
vicam_open(struct inode *inode, struct file *file)
{
	struct video_device *dev = video_devdata(file);
	struct vicam_camera *cam = video_get_drvdata(dev);

	DBG("open\n");

	if (!cam) {
		printk(KERN_ERR
		       "vicam video_device improperly initialized");
		return -EINVAL;
	}

	/* the videodev_lock held above us protects us from
	 * simultaneous opens...for now. we probably shouldn't
	 * rely on this fact forever.
	 */

	lock_kernel();
	if (cam->open_count > 0) {
		printk(KERN_INFO
		       "vicam_open called on already opened camera");
		unlock_kernel();
		return -EBUSY;
	}

	cam->raw_image = kmalloc(VICAM_MAX_READ_SIZE, GFP_KERNEL);
	if (!cam->raw_image) {
		unlock_kernel();
		return -ENOMEM;
	}

	cam->framebuf = rvmalloc(VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
	if (!cam->framebuf) {
		kfree(cam->raw_image);
		unlock_kernel();
		return -ENOMEM;
	}

	cam->cntrlbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!cam->cntrlbuf) {
		kfree(cam->raw_image);
		rvfree(cam->framebuf, VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
		unlock_kernel();
		return -ENOMEM;
	}

	// First upload firmware, then turn the camera on

	if (!cam->is_initialized) {
		initialize_camera(cam);

		cam->is_initialized = 1;
	}

	set_camera_power(cam, 1);

	cam->needsDummyRead = 1;
	cam->open_count++;

	file->private_data = cam;
	unlock_kernel();

	return 0;
}

static int
vicam_close(struct inode *inode, struct file *file)
{
	struct vicam_camera *cam = file->private_data;
	int open_count;
	struct usb_device *udev;

	DBG("close\n");

	/* it's not the end of the world if
	 * we fail to turn the camera off.
	 */

	set_camera_power(cam, 0);

	kfree(cam->raw_image);
	rvfree(cam->framebuf, VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
	kfree(cam->cntrlbuf);

	mutex_lock(&cam->cam_lock);

	cam->open_count--;
	open_count = cam->open_count;
	udev = cam->udev;

	mutex_unlock(&cam->cam_lock);

	if (!open_count && !udev) {
		kfree(cam);
	}

	return 0;
}

static void vicam_decode_color(const u8 *data, u8 *rgb)
{
	/* vicam_decode_color - Convert from Vicam Y-Cr-Cb to RGB
	 * Copyright (C) 2002 Monroe Williams (monroe@pobox.com)
	 */

	int i, prevY, nextY;

	prevY = 512;
	nextY = 512;

	data += VICAM_HEADER_SIZE;

	for( i = 0; i < 240; i++, data += 512 ) {
		const int y = ( i * 242 ) / 240;

		int j, prevX, nextX;
		int Y, Cr, Cb;

		if ( y == 242 - 1 ) {
			nextY = -512;
		}

		prevX = 1;
		nextX = 1;

		for ( j = 0; j < 320; j++, rgb += 3 ) {
			const int x = ( j * 512 ) / 320;
			const u8 * const src = &data[x];

			if ( x == 512 - 1 ) {
				nextX = -1;
			}

			Cr = ( src[prevX] - src[0] ) +
				( src[nextX] - src[0] );
			Cr /= 2;

			Cb = ( src[prevY] - src[prevX + prevY] ) +
				( src[prevY] - src[nextX + prevY] ) +
				( src[nextY] - src[prevX + nextY] ) +
				( src[nextY] - src[nextX + nextY] );
			Cb /= 4;

			Y = 1160 * ( src[0] + ( Cr / 2 ) - 16 );

			if ( i & 1 ) {
				int Ct = Cr;
				Cr = Cb;
				Cb = Ct;
			}

			if ( ( x ^ i ) & 1 ) {
				Cr = -Cr;
				Cb = -Cb;
			}

			rgb[0] = clamp( ( ( Y + ( 2017 * Cb ) ) +
					500 ) / 900, 0, 255 );
			rgb[1] = clamp( ( ( Y - ( 392 * Cb ) -
					  ( 813 * Cr ) ) +
					  500 ) / 1000, 0, 255 );
			rgb[2] = clamp( ( ( Y + ( 1594 * Cr ) ) +
					500 ) / 1300, 0, 255 );

			prevX = -1;
		}

		prevY = -512;
	}
}

static void
read_frame(struct vicam_camera *cam, int framenum)
{
	unsigned char *request = cam->cntrlbuf;
	int realShutter;
	int n;
	int actual_length;

	if (cam->needsDummyRead) {
		cam->needsDummyRead = 0;
		read_frame(cam, framenum);
	}

	memset(request, 0, 16);
	request[0] = cam->gain;	// 0 = 0% gain, FF = 100% gain

	request[1] = 0;	// 512x242 capture

	request[2] = 0x90;	// the function of these two bytes
	request[3] = 0x07;	// is not yet understood

	if (cam->shutter_speed > 60) {
		// Short exposure
		realShutter =
		    ((-15631900 / cam->shutter_speed) + 260533) / 1000;
		request[4] = realShutter & 0xFF;
		request[5] = (realShutter >> 8) & 0xFF;
		request[6] = 0x03;
		request[7] = 0x01;
	} else {
		// Long exposure
		realShutter = 15600 / cam->shutter_speed - 1;
		request[4] = 0;
		request[5] = 0;
		request[6] = realShutter & 0xFF;
		request[7] = realShutter >> 8;
	}

	// Per John Markus Bjørndalen, byte at index 8 causes problems if it isn't 0
	request[8] = 0;
	// bytes 9-15 do not seem to affect exposure or image quality

	mutex_lock(&cam->cam_lock);

	if (!cam->udev) {
		goto done;
	}

	n = __send_control_msg(cam, 0x51, 0x80, 0, request, 16);

	if (n < 0) {
		printk(KERN_ERR
		       " Problem sending frame capture control message");
		goto done;
	}

	n = usb_bulk_msg(cam->udev,
			 usb_rcvbulkpipe(cam->udev, cam->bulkEndpoint),
			 cam->raw_image,
			 512 * 242 + 128, &actual_length, 10000);

	if (n < 0) {
		printk(KERN_ERR "Problem during bulk read of frame data: %d\n",
		       n);
	}

 done:
	mutex_unlock(&cam->cam_lock);
}

static ssize_t
vicam_read( struct file *file, char __user *buf, size_t count, loff_t *ppos )
{
	struct vicam_camera *cam = file->private_data;

	DBG("read %d bytes.\n", (int) count);

	if (*ppos >= VICAM_MAX_FRAME_SIZE) {
		*ppos = 0;
		return 0;
	}

	if (*ppos == 0) {
		read_frame(cam, 0);
		vicam_decode_color(cam->raw_image,
				   cam->framebuf +
				   0 * VICAM_MAX_FRAME_SIZE);
	}

	count = min_t(size_t, count, VICAM_MAX_FRAME_SIZE - *ppos);

	if (copy_to_user(buf, &cam->framebuf[*ppos], count)) {
		count = -EFAULT;
	} else {
		*ppos += count;
	}

	if (count == VICAM_MAX_FRAME_SIZE) {
		*ppos = 0;
	}

	return count;
}


static int
vicam_mmap(struct file *file, struct vm_area_struct *vma)
{
	// TODO: allocate the raw frame buffer if necessary
	unsigned long page, pos;
	unsigned long start = vma->vm_start;
	unsigned long size  = vma->vm_end-vma->vm_start;
	struct vicam_camera *cam = file->private_data;

	if (!cam)
		return -ENODEV;

	DBG("vicam_mmap: %ld\n", size);

	/* We let mmap allocate as much as it wants because Linux was adding 2048 bytes
	 * to the size the application requested for mmap and it was screwing apps up.
	 if (size > VICAM_FRAMES*VICAM_MAX_FRAME_SIZE)
	 return -EINVAL;
	 */

	pos = (unsigned long)cam->framebuf;
	while (size > 0) {
		page = vmalloc_to_pfn((void *)pos);
		if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
			return -EAGAIN;

		start += PAGE_SIZE;
		pos += PAGE_SIZE;
		if (size > PAGE_SIZE)
			size -= PAGE_SIZE;
		else
			size = 0;
	}

	return 0;
}

static const struct file_operations vicam_fops = {
	.owner		= THIS_MODULE,
	.open		= vicam_open,
	.release	= vicam_close,
	.read		= vicam_read,
	.mmap		= vicam_mmap,
	.ioctl		= vicam_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= v4l_compat_ioctl32,
#endif
	.llseek		= no_llseek,
};

static struct video_device vicam_template = {
	.name 		= "ViCam-based USB Camera",
	.fops 		= &vicam_fops,
	.minor 		= -1,
	.release 	= video_device_release_empty,
};

/* table of devices that work with this driver */
static struct usb_device_id vicam_table[] = {
	{USB_DEVICE(USB_VICAM_VENDOR_ID, USB_VICAM_PRODUCT_ID)},
	{USB_DEVICE(USB_COMPRO_VENDOR_ID, USB_COMPRO_PRODUCT_ID)},
	{}			/* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, vicam_table);

static struct usb_driver vicam_driver = {
	.name		= "vicam",
	.probe		= vicam_probe,
	.disconnect	= vicam_disconnect,
	.id_table	= vicam_table
};

/**
 *	vicam_probe
 *	@intf: the interface
 *	@id: the device id
 *
 *	Called by the usb core when a new device is connected that it thinks
 *	this driver might be interested in.
 */
static int
vicam_probe( struct usb_interface *intf, const struct usb_device_id *id)
{
	struct usb_device *dev = interface_to_usbdev(intf);
	int bulkEndpoint = 0;
	const struct usb_host_interface *interface;
	const struct usb_endpoint_descriptor *endpoint;
	struct vicam_camera *cam;

	printk(KERN_INFO "ViCam based webcam connected\n");

	interface = intf->cur_altsetting;

	DBG(KERN_DEBUG "Interface %d. has %u. endpoints!\n",
	       interface->desc.bInterfaceNumber, (unsigned) (interface->desc.bNumEndpoints));
	endpoint = &interface->endpoint[0].desc;

	if ((endpoint->bEndpointAddress & 0x80) &&
	    ((endpoint->bmAttributes & 3) == 0x02)) {
		/* we found a bulk in endpoint */
		bulkEndpoint = endpoint->bEndpointAddress;
	} else {
		printk(KERN_ERR
		       "No bulk in endpoint was found ?! (this is bad)\n");
	}

	if ((cam =
	     kzalloc(sizeof (struct vicam_camera), GFP_KERNEL)) == NULL) {
		printk(KERN_WARNING
		       "could not allocate kernel memory for vicam_camera struct\n");
		return -ENOMEM;
	}


	cam->shutter_speed = 15;

	mutex_init(&cam->cam_lock);

	memcpy(&cam->vdev, &vicam_template, sizeof(vicam_template));
	video_set_drvdata(&cam->vdev, cam);

	cam->udev = dev;
	cam->bulkEndpoint = bulkEndpoint;

	if (video_register_device(&cam->vdev, VFL_TYPE_GRABBER, -1) < 0) {
		kfree(cam);
		printk(KERN_WARNING "video_register_device failed\n");
		return -EIO;
	}

	printk(KERN_INFO "ViCam webcam driver now controlling video device %d\n",cam->vdev.minor);

	usb_set_intfdata (intf, cam);

	return 0;
}

static void
vicam_disconnect(struct usb_interface *intf)
{
	int open_count;
	struct vicam_camera *cam = usb_get_intfdata (intf);
	usb_set_intfdata (intf, NULL);

	/* we must unregister the device before taking its
	 * cam_lock. This is because the video open call
	 * holds the same lock as video unregister. if we
	 * unregister inside of the cam_lock and open also
	 * uses the cam_lock, we get deadlock.
	 */

	video_unregister_device(&cam->vdev);

	/* stop the camera from being used */

	mutex_lock(&cam->cam_lock);

	/* mark the camera as gone */

	cam->udev = NULL;

	/* the only thing left to do is synchronize with
	 * our close/release function on who should release
	 * the camera memory. if there are any users using the
	 * camera, it's their job. if there are no users,
	 * it's ours.
	 */

	open_count = cam->open_count;

	mutex_unlock(&cam->cam_lock);

	if (!open_count) {
		kfree(cam);
	}

	printk(KERN_DEBUG "ViCam-based WebCam disconnected\n");
}

/*
 */
static int __init
usb_vicam_init(void)
{
	int retval;
	DBG(KERN_INFO "ViCam-based WebCam driver startup\n");
	retval = usb_register(&vicam_driver);
	if (retval)
		printk(KERN_WARNING "usb_register failed!\n");
	return retval;
}

static void __exit
usb_vicam_exit(void)
{
	DBG(KERN_INFO
	       "ViCam-based WebCam driver shutdown\n");

	usb_deregister(&vicam_driver);
}

module_init(usb_vicam_init);
module_exit(usb_vicam_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_FIRMWARE("vicam/firmware.fw");