aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/media/video/stk-webcam.c
blob: 9276ed99738839075615554ff384e5afd285815b (plain) (tree)
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































                                                                          
                          

                              





























                                                                               
                                                 









































































































































































































































































































































































































































































































































































































































                                                                                
                                                 




















                                                                    
                                                         









                                                         
                                                 























































































































































































































































































                                                                               



                                                      






















































                                                                 
                               































                                                                       











                                                          
                                                                   






















                                                                     













                                                     


                                                       
                          






                                                              
                                     



































































































































































                                                                             


                                           


















































































































                                                                                           
                                        












                                                         
                                          
















                                                                  
                
                                                                               









                                                        
                                                        












                                                        




                                              



                                      























                                                                             
/*
 * stk-webcam.c : Driver for Syntek 1125 USB webcam controller
 *
 * Copyright (C) 2006 Nicolas VIVIEN
 * Copyright 2007-2008 Jaime Velasco Juan <jsagarribay@gmail.com>
 *
 * Some parts are inspired from cafe_ccic.c
 * Copyright 2006-2007 Jonathan Corbet
 *
 * 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
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/kref.h>

#include <linux/usb.h>
#include <linux/vmalloc.h>
#include <linux/videodev2.h>
#include <media/v4l2-common.h>

#include "stk-webcam.h"


static int hflip = 1;
module_param(hflip, bool, 0444);
MODULE_PARM_DESC(hflip, "Horizontal image flip (mirror). Defaults to 1");

static int vflip = 1;
module_param(vflip, bool, 0444);
MODULE_PARM_DESC(vflip, "Vertical image flip. Defaults to 1");

static int debug;
module_param(debug, int, 0444);
MODULE_PARM_DESC(debug, "Debug v4l ioctls. Defaults to 0");

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jaime Velasco Juan <jsagarribay@gmail.com> and Nicolas VIVIEN");
MODULE_DESCRIPTION("Syntek DC1125 webcam driver");



/* Some cameras have audio interfaces, we aren't interested in those */
static struct usb_device_id stkwebcam_table[] = {
	{ USB_DEVICE_AND_INTERFACE_INFO(0x174f, 0xa311, 0xff, 0xff, 0xff) },
	{ USB_DEVICE_AND_INTERFACE_INFO(0x05e1, 0x0501, 0xff, 0xff, 0xff) },
	{ }
};
MODULE_DEVICE_TABLE(usb, stkwebcam_table);

static void stk_camera_cleanup(struct kref *kref)
{
	struct stk_camera *dev = to_stk_camera(kref);

	STK_INFO("Syntek USB2.0 Camera release resources"
		" video device /dev/video%d\n", dev->vdev.minor);
	video_unregister_device(&dev->vdev);
	dev->vdev.priv = NULL;

	if (dev->sio_bufs != NULL || dev->isobufs != NULL)
		STK_ERROR("We are leaking memory\n");
	usb_put_intf(dev->interface);
	kfree(dev);
}


/*
 * Basic stuff
 */
int stk_camera_write_reg(struct stk_camera *dev, u16 index, u8 value)
{
	struct usb_device *udev = dev->udev;
	int ret;

	ret =  usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			0x01,
			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			value,
			index,
			NULL,
			0,
			500);
	if (ret < 0)
		return ret;
	else
		return 0;
}

int stk_camera_read_reg(struct stk_camera *dev, u16 index, int *value)
{
	struct usb_device *udev = dev->udev;
	int ret;

	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
			0x00,
			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			0x00,
			index,
			(u8 *) value,
			sizeof(u8),
			500);
	if (ret < 0)
		return ret;
	else
		return 0;
}

static int stk_start_stream(struct stk_camera *dev)
{
	int value;
	int i, ret;
	int value_116, value_117;

	if (!is_present(dev))
		return -ENODEV;
	if (!is_memallocd(dev) || !is_initialised(dev)) {
		STK_ERROR("FIXME: Buffers are not allocated\n");
		return -EFAULT;
	}
	ret = usb_set_interface(dev->udev, 0, 5);

	if (ret < 0)
		STK_ERROR("usb_set_interface failed !\n");
	if (stk_sensor_wakeup(dev))
		STK_ERROR("error awaking the sensor\n");

	stk_camera_read_reg(dev, 0x0116, &value_116);
	stk_camera_read_reg(dev, 0x0117, &value_117);

	stk_camera_write_reg(dev, 0x0116, 0x0000);
	stk_camera_write_reg(dev, 0x0117, 0x0000);

	stk_camera_read_reg(dev, 0x0100, &value);
	stk_camera_write_reg(dev, 0x0100, value | 0x80);

	stk_camera_write_reg(dev, 0x0116, value_116);
	stk_camera_write_reg(dev, 0x0117, value_117);
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		if (dev->isobufs[i].urb) {
			ret = usb_submit_urb(dev->isobufs[i].urb, GFP_KERNEL);
			atomic_inc(&dev->urbs_used);
			if (ret)
				return ret;
		}
	}
	set_streaming(dev);
	return 0;
}

static int stk_stop_stream(struct stk_camera *dev)
{
	int value;
	int i;
	if (is_present(dev)) {
		stk_camera_read_reg(dev, 0x0100, &value);
		stk_camera_write_reg(dev, 0x0100, value & ~0x80);
		if (dev->isobufs != NULL) {
			for (i = 0; i < MAX_ISO_BUFS; i++) {
				if (dev->isobufs[i].urb)
					usb_kill_urb(dev->isobufs[i].urb);
			}
		}
		unset_streaming(dev);

		if (usb_set_interface(dev->udev, 0, 0))
			STK_ERROR("usb_set_interface failed !\n");
		if (stk_sensor_sleep(dev))
			STK_ERROR("error suspending the sensor\n");
	}
	return 0;
}

/*
 * This seems to be the shortest init sequence we
 * must do in order to find the sensor
 * Bit 5 of reg. 0x0000 here is important, when reset to 0 the sensor
 * is also reset. Maybe powers down it?
 * Rest of values don't make a difference
 */

static struct regval stk1125_initvals[] = {
	/*TODO: What means this sequence? */
	{0x0000, 0x24},
	{0x0100, 0x21},
	{0x0002, 0x68},
	{0x0003, 0x80},
	{0x0005, 0x00},
	{0x0007, 0x03},
	{0x000d, 0x00},
	{0x000f, 0x02},
	{0x0300, 0x12},
	{0x0350, 0x41},
	{0x0351, 0x00},
	{0x0352, 0x00},
	{0x0353, 0x00},
	{0x0018, 0x10},
	{0x0019, 0x00},
	{0x001b, 0x0e},
	{0x001c, 0x46},
	{0x0300, 0x80},
	{0x001a, 0x04},
	{0x0110, 0x00},
	{0x0111, 0x00},
	{0x0112, 0x00},
	{0x0113, 0x00},

	{0xffff, 0xff},
};


static int stk_initialise(struct stk_camera *dev)
{
	struct regval *rv;
	int ret;
	if (!is_present(dev))
		return -ENODEV;
	if (is_initialised(dev))
		return 0;
	rv = stk1125_initvals;
	while (rv->reg != 0xffff) {
		ret = stk_camera_write_reg(dev, rv->reg, rv->val);
		if (ret)
			return ret;
		rv++;
	}
	if (stk_sensor_init(dev) == 0) {
		set_initialised(dev);
		return 0;
	} else
		return -1;
}

/* sysfs functions */
/*FIXME cleanup this */

static ssize_t show_brightness(struct device *class,
			struct device_attribute *attr, char *buf)
{
	struct video_device *vdev = to_video_device(class);
	struct stk_camera *dev = vdev_to_camera(vdev);

	return sprintf(buf, "%X\n", dev->vsettings.brightness);
}

static ssize_t store_brightness(struct device *class,
		struct device_attribute *attr, const char *buf, size_t count)
{
	char *endp;
	unsigned long value;
	int ret;

	struct video_device *vdev = to_video_device(class);
	struct stk_camera *dev = vdev_to_camera(vdev);

	value = simple_strtoul(buf, &endp, 16);

	dev->vsettings.brightness = (int) value;

	ret = stk_sensor_set_brightness(dev, value >> 8);
	if (ret)
		return ret;
	else
		return count;
}

static ssize_t show_hflip(struct device *class,
		struct device_attribute *attr, char *buf)
{
	struct video_device *vdev = to_video_device(class);
	struct stk_camera *dev = vdev_to_camera(vdev);

	return sprintf(buf, "%d\n", dev->vsettings.hflip);
}

static ssize_t store_hflip(struct device *class,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct video_device *vdev = to_video_device(class);
	struct stk_camera *dev = vdev_to_camera(vdev);

	if (strncmp(buf, "1", 1) == 0)
		dev->vsettings.hflip = 1;
	else if (strncmp(buf, "0", 1) == 0)
		dev->vsettings.hflip = 0;
	else
		return -EINVAL;

	return strlen(buf);
}

static ssize_t show_vflip(struct device *class,
		struct device_attribute *attr, char *buf)
{
	struct video_device *vdev = to_video_device(class);
	struct stk_camera *dev = vdev_to_camera(vdev);

	return sprintf(buf, "%d\n", dev->vsettings.vflip);
}

static ssize_t store_vflip(struct device *class,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct video_device *vdev = to_video_device(class);
	struct stk_camera *dev = vdev_to_camera(vdev);

	if (strncmp(buf, "1", 1) == 0)
		dev->vsettings.vflip = 1;
	else if (strncmp(buf, "0", 1) == 0)
		dev->vsettings.vflip = 0;
	else
		return -EINVAL;

	return strlen(buf);
}

static DEVICE_ATTR(brightness, S_IRUGO | S_IWUGO,
			show_brightness, store_brightness);
static DEVICE_ATTR(hflip, S_IRUGO | S_IWUGO, show_hflip, store_hflip);
static DEVICE_ATTR(vflip, S_IRUGO | S_IWUGO, show_vflip, store_vflip);

static int stk_create_sysfs_files(struct video_device *vdev)
{
	int ret;

	ret = video_device_create_file(vdev, &dev_attr_brightness);
	ret += video_device_create_file(vdev, &dev_attr_hflip);
	ret += video_device_create_file(vdev, &dev_attr_vflip);
	return ret;
}

static void stk_remove_sysfs_files(struct video_device *vdev)
{
	video_device_remove_file(vdev, &dev_attr_brightness);
	video_device_remove_file(vdev, &dev_attr_hflip);
	video_device_remove_file(vdev, &dev_attr_vflip);
}


/* *********************************************** */
/*
 * This function is called as an URB transfert is complete (Isochronous pipe).
 * So, the traitement is done in interrupt time, so it has be fast, not crash,
 * and not stall. Neat.
 */
static void stk_isoc_handler(struct urb *urb)
{
	int i;
	int ret;
	int framelen;
	unsigned long flags;

	unsigned char *fill = NULL;
	unsigned char *iso_buf = NULL;

	struct stk_camera *dev;
	struct stk_sio_buffer *fb;

	dev = (struct stk_camera *) urb->context;

	if (dev == NULL) {
		STK_ERROR("isoc_handler called with NULL device !\n");
		return;
	}

	if (urb->status == -ENOENT || urb->status == -ECONNRESET
		|| urb->status == -ESHUTDOWN) {
		atomic_dec(&dev->urbs_used);
		return;
	}

	spin_lock_irqsave(&dev->spinlock, flags);

	if (urb->status != -EINPROGRESS && urb->status != 0) {
		STK_ERROR("isoc_handler: urb->status == %d\n", urb->status);
		goto resubmit;
	}

	if (list_empty(&dev->sio_avail)) {
		/*FIXME Stop streaming after a while */
		(void) (printk_ratelimit() &&
		STK_ERROR("isoc_handler without available buffer!\n"));
		goto resubmit;
	}
	fb = list_first_entry(&dev->sio_avail,
			struct stk_sio_buffer, list);
	fill = fb->buffer + fb->v4lbuf.bytesused;

	for (i = 0; i < urb->number_of_packets; i++) {
		if (urb->iso_frame_desc[i].status != 0) {
			if (urb->iso_frame_desc[i].status != -EXDEV)
				STK_ERROR("Frame %d has error %d\n", i,
					urb->iso_frame_desc[i].status);
			continue;
		}
		framelen = urb->iso_frame_desc[i].actual_length;
		iso_buf = urb->transfer_buffer + urb->iso_frame_desc[i].offset;

		if (framelen <= 4)
			continue; /* no data */

		/*
		 * we found something informational from there
		 * the isoc frames have to type of headers
		 * type1: 00 xx 00 00 or 20 xx 00 00
		 * type2: 80 xx 00 00 00 00 00 00 or a0 xx 00 00 00 00 00 00
		 * xx is a sequencer which has never been seen over 0x3f
		 * imho data written down looks like bayer, i see similarities
		 * after every 640 bytes
		 */
		if (*iso_buf & 0x80) {
			framelen -= 8;
			iso_buf += 8;
			/* This marks a new frame */
			if (fb->v4lbuf.bytesused != 0
				&& fb->v4lbuf.bytesused != dev->frame_size) {
				(void) (printk_ratelimit() &&
				STK_ERROR("frame %d, "
					"bytesused=%d, skipping\n",
					i, fb->v4lbuf.bytesused));
				fb->v4lbuf.bytesused = 0;
				fill = fb->buffer;
			} else if (fb->v4lbuf.bytesused == dev->frame_size) {
				list_move_tail(dev->sio_avail.next,
					&dev->sio_full);
				wake_up(&dev->wait_frame);
				if (list_empty(&dev->sio_avail)) {
					(void) (printk_ratelimit() &&
					STK_ERROR("No buffer available\n"));
					goto resubmit;
				}
				fb = list_first_entry(&dev->sio_avail,
					struct stk_sio_buffer, list);
				fb->v4lbuf.bytesused = 0;
				fill = fb->buffer;
			}
		} else {
			framelen -= 4;
			iso_buf += 4;
		}

		/* Our buffer is full !!! */
		if (framelen + fb->v4lbuf.bytesused > dev->frame_size) {
			(void) (printk_ratelimit() &&
			STK_ERROR("Frame buffer overflow, lost sync\n"));
			/*FIXME Do something here? */
			continue;
		}
		spin_unlock_irqrestore(&dev->spinlock, flags);
		memcpy(fill, iso_buf, framelen);
		spin_lock_irqsave(&dev->spinlock, flags);
		fill += framelen;

		/* New size of our buffer */
		fb->v4lbuf.bytesused += framelen;
	}

resubmit:
	spin_unlock_irqrestore(&dev->spinlock, flags);
	urb->dev = dev->udev;
	ret = usb_submit_urb(urb, GFP_ATOMIC);
	if (ret != 0) {
		STK_ERROR("Error (%d) re-submitting urb in stk_isoc_handler.\n",
			ret);
	}
}

/* -------------------------------------------- */

static int stk_prepare_iso(struct stk_camera *dev)
{
	void *kbuf;
	int i, j;
	struct urb *urb;
	struct usb_device *udev;

	if (dev == NULL)
		return -ENXIO;
	udev = dev->udev;

	if (dev->isobufs)
		STK_ERROR("isobufs already allocated. Bad\n");
	else
		dev->isobufs = kzalloc(MAX_ISO_BUFS * sizeof(*dev->isobufs),
					GFP_KERNEL);
	if (dev->isobufs == NULL) {
		STK_ERROR("Unable to allocate iso buffers\n");
		return -ENOMEM;
	}
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		if (dev->isobufs[i].data == NULL) {
			kbuf = kzalloc(ISO_BUFFER_SIZE, GFP_KERNEL);
			if (kbuf == NULL) {
				STK_ERROR("Failed to allocate iso buffer %d\n",
					i);
				goto isobufs_out;
			}
			dev->isobufs[i].data = kbuf;
		} else
			STK_ERROR("isobuf data already allocated\n");
		if (dev->isobufs[i].urb == NULL) {
			urb = usb_alloc_urb(ISO_FRAMES_PER_DESC, GFP_KERNEL);
			if (urb == NULL) {
				STK_ERROR("Failed to allocate URB %d\n", i);
				goto isobufs_out;
			}
			dev->isobufs[i].urb = urb;
		} else {
			STK_ERROR("Killing URB\n");
			usb_kill_urb(dev->isobufs[i].urb);
			urb = dev->isobufs[i].urb;
		}
		urb->interval = 1;
		urb->dev = udev;
		urb->pipe = usb_rcvisocpipe(udev, dev->isoc_ep);
		urb->transfer_flags = URB_ISO_ASAP;
		urb->transfer_buffer = dev->isobufs[i].data;
		urb->transfer_buffer_length = ISO_BUFFER_SIZE;
		urb->complete = stk_isoc_handler;
		urb->context = dev;
		urb->start_frame = 0;
		urb->number_of_packets = ISO_FRAMES_PER_DESC;

		for (j = 0; j < ISO_FRAMES_PER_DESC; j++) {
			urb->iso_frame_desc[j].offset = j * ISO_MAX_FRAME_SIZE;
			urb->iso_frame_desc[j].length = ISO_MAX_FRAME_SIZE;
		}
	}
	set_memallocd(dev);
	return 0;

isobufs_out:
	for (i = 0; i < MAX_ISO_BUFS && dev->isobufs[i].data; i++)
		kfree(dev->isobufs[i].data);
	for (i = 0; i < MAX_ISO_BUFS && dev->isobufs[i].urb; i++)
		usb_free_urb(dev->isobufs[i].urb);
	kfree(dev->isobufs);
	dev->isobufs = NULL;
	return -ENOMEM;
}

static void stk_clean_iso(struct stk_camera *dev)
{
	int i;

	if (dev == NULL || dev->isobufs == NULL)
		return;

	for (i = 0; i < MAX_ISO_BUFS; i++) {
		struct urb *urb;

		urb = dev->isobufs[i].urb;
		if (urb) {
			if (atomic_read(&dev->urbs_used))
				usb_kill_urb(urb);
			usb_free_urb(urb);
		}
		kfree(dev->isobufs[i].data);
	}
	kfree(dev->isobufs);
	dev->isobufs = NULL;
	unset_memallocd(dev);
}

static int stk_setup_siobuf(struct stk_camera *dev, int index)
{
	struct stk_sio_buffer *buf = dev->sio_bufs + index;
	INIT_LIST_HEAD(&buf->list);
	buf->v4lbuf.length = PAGE_ALIGN(dev->frame_size);
	buf->buffer = vmalloc_user(buf->v4lbuf.length);
	if (buf->buffer == NULL)
		return -ENOMEM;
	buf->mapcount = 0;
	buf->dev = dev;
	buf->v4lbuf.index = index;
	buf->v4lbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	buf->v4lbuf.field = V4L2_FIELD_NONE;
	buf->v4lbuf.memory = V4L2_MEMORY_MMAP;
	buf->v4lbuf.m.offset = 2*index*buf->v4lbuf.length;
	return 0;
}

static int stk_free_sio_buffers(struct stk_camera *dev)
{
	int i;
	int nbufs;
	unsigned long flags;
	if (dev->n_sbufs == 0 || dev->sio_bufs == NULL)
		return 0;
	/*
	* If any buffers are mapped, we cannot free them at all.
	*/
	for (i = 0; i < dev->n_sbufs; i++) {
		if (dev->sio_bufs[i].mapcount > 0)
			return -EBUSY;
	}
	/*
	* OK, let's do it.
	*/
	spin_lock_irqsave(&dev->spinlock, flags);
	INIT_LIST_HEAD(&dev->sio_avail);
	INIT_LIST_HEAD(&dev->sio_full);
	nbufs = dev->n_sbufs;
	dev->n_sbufs = 0;
	spin_unlock_irqrestore(&dev->spinlock, flags);
	for (i = 0; i < nbufs; i++) {
		if (dev->sio_bufs[i].buffer != NULL)
			vfree(dev->sio_bufs[i].buffer);
	}
	kfree(dev->sio_bufs);
	dev->sio_bufs = NULL;
	return 0;
}

static int stk_prepare_sio_buffers(struct stk_camera *dev, unsigned n_sbufs)
{
	int i;
	if (dev->sio_bufs != NULL)
		STK_ERROR("sio_bufs already allocated\n");
	else {
		dev->sio_bufs = kzalloc(n_sbufs * sizeof(struct stk_sio_buffer),
				GFP_KERNEL);
		if (dev->sio_bufs == NULL)
			return -ENOMEM;
		for (i = 0; i < n_sbufs; i++) {
			if (stk_setup_siobuf(dev, i))
				return (dev->n_sbufs > 1)? 0 : -ENOMEM;
			dev->n_sbufs = i+1;
		}
	}
	return 0;
}

static int stk_allocate_buffers(struct stk_camera *dev, unsigned n_sbufs)
{
	int err;
	err = stk_prepare_iso(dev);
	if (err) {
		stk_clean_iso(dev);
		return err;
	}
	err = stk_prepare_sio_buffers(dev, n_sbufs);
	if (err) {
		stk_free_sio_buffers(dev);
		return err;
	}
	return 0;
}

static void stk_free_buffers(struct stk_camera *dev)
{
	stk_clean_iso(dev);
	stk_free_sio_buffers(dev);
}
/* -------------------------------------------- */

/* v4l file operations */

static int v4l_stk_open(struct inode *inode, struct file *fp)
{
	struct stk_camera *dev;
	struct video_device *vdev;

	vdev = video_devdata(fp);
	dev = vdev_to_camera(vdev);

	if (dev == NULL || !is_present(dev))
		return -ENXIO;
	fp->private_data = vdev;
	kref_get(&dev->kref);
	usb_autopm_get_interface(dev->interface);

	return 0;
}

static int v4l_stk_release(struct inode *inode, struct file *fp)
{
	struct stk_camera *dev;
	struct video_device *vdev;

	vdev = video_devdata(fp);
	if (vdev == NULL) {
		STK_ERROR("v4l_release called w/o video devdata\n");
		return -EFAULT;
	}
	dev = vdev_to_camera(vdev);
	if (dev == NULL) {
		STK_ERROR("v4l_release called on removed device\n");
		return -ENODEV;
	}

	if (dev->owner != fp) {
		usb_autopm_put_interface(dev->interface);
		kref_put(&dev->kref, stk_camera_cleanup);
		return 0;
	}

	stk_stop_stream(dev);

	stk_free_buffers(dev);

	dev->owner = NULL;

	usb_autopm_put_interface(dev->interface);
	kref_put(&dev->kref, stk_camera_cleanup);

	return 0;
}

static ssize_t v4l_stk_read(struct file *fp, char __user *buf,
		size_t count, loff_t *f_pos)
{
	int i;
	int ret;
	unsigned long flags;
	struct stk_camera *dev;
	struct video_device *vdev;
	struct stk_sio_buffer *sbuf;

	vdev = video_devdata(fp);
	if (vdev == NULL)
		return -EFAULT;
	dev = vdev_to_camera(vdev);

	if (dev == NULL)
		return -EIO;

	if (!is_present(dev))
		return -EIO;
	if (dev->owner && dev->owner != fp)
		return -EBUSY;
	dev->owner = fp;
	if (!is_streaming(dev)) {
		if (stk_initialise(dev)
			|| stk_allocate_buffers(dev, 3)
			|| stk_start_stream(dev))
			return -ENOMEM;
		spin_lock_irqsave(&dev->spinlock, flags);
		for (i = 0; i < dev->n_sbufs; i++) {
			list_add_tail(&dev->sio_bufs[i].list, &dev->sio_avail);
			dev->sio_bufs[i].v4lbuf.flags = V4L2_BUF_FLAG_QUEUED;
		}
		spin_unlock_irqrestore(&dev->spinlock, flags);
	}
	if (*f_pos == 0) {
		if (fp->f_flags & O_NONBLOCK && list_empty(&dev->sio_full))
			return -EWOULDBLOCK;
		ret = wait_event_interruptible(dev->wait_frame,
			!list_empty(&dev->sio_full) || !is_present(dev));
		if (ret)
			return ret;
		if (!is_present(dev))
			return -EIO;
	}
	if (count + *f_pos > dev->frame_size)
		count = dev->frame_size - *f_pos;
	spin_lock_irqsave(&dev->spinlock, flags);
	if (list_empty(&dev->sio_full)) {
		spin_unlock_irqrestore(&dev->spinlock, flags);
		STK_ERROR("BUG: No siobufs ready\n");
		return 0;
	}
	sbuf = list_first_entry(&dev->sio_full, struct stk_sio_buffer, list);
	spin_unlock_irqrestore(&dev->spinlock, flags);

	if (copy_to_user(buf, sbuf->buffer + *f_pos, count))
		return -EFAULT;

	*f_pos += count;

	if (*f_pos >= dev->frame_size) {
		*f_pos = 0;
		spin_lock_irqsave(&dev->spinlock, flags);
		list_move_tail(&sbuf->list, &dev->sio_avail);
		spin_unlock_irqrestore(&dev->spinlock, flags);
	}
	return count;
}

static unsigned int v4l_stk_poll(struct file *fp, poll_table *wait)
{
	struct stk_camera *dev;
	struct video_device *vdev;

	vdev = video_devdata(fp);

	if (vdev == NULL)
		return -EFAULT;

	dev = vdev_to_camera(vdev);
	if (dev == NULL)
		return -ENODEV;

	poll_wait(fp, &dev->wait_frame, wait);

	if (!is_present(dev))
		return POLLERR;

	if (!list_empty(&dev->sio_full))
		return (POLLIN | POLLRDNORM);

	return 0;
}


static void stk_v4l_vm_open(struct vm_area_struct *vma)
{
	struct stk_sio_buffer *sbuf = vma->vm_private_data;
	sbuf->mapcount++;
}
static void stk_v4l_vm_close(struct vm_area_struct *vma)
{
	struct stk_sio_buffer *sbuf = vma->vm_private_data;
	sbuf->mapcount--;
	if (sbuf->mapcount == 0)
		sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_MAPPED;
}
static struct vm_operations_struct stk_v4l_vm_ops = {
	.open = stk_v4l_vm_open,
	.close = stk_v4l_vm_close
};

static int v4l_stk_mmap(struct file *fp, struct vm_area_struct *vma)
{
	unsigned int i;
	int ret;
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
	struct stk_camera *dev;
	struct video_device *vdev;
	struct stk_sio_buffer *sbuf = NULL;

	if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
		return -EINVAL;

	vdev = video_devdata(fp);
	dev = vdev_to_camera(vdev);

	for (i = 0; i < dev->n_sbufs; i++) {
		if (dev->sio_bufs[i].v4lbuf.m.offset == offset) {
			sbuf = dev->sio_bufs + i;
			break;
		}
	}
	if (sbuf == NULL)
		return -EINVAL;
	ret = remap_vmalloc_range(vma, sbuf->buffer, 0);
	if (ret)
		return ret;
	vma->vm_flags |= VM_DONTEXPAND;
	vma->vm_private_data = sbuf;
	vma->vm_ops = &stk_v4l_vm_ops;
	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_MAPPED;
	stk_v4l_vm_open(vma);
	return 0;
}

/* v4l ioctl handlers */

static int stk_vidioc_querycap(struct file *filp,
		void *priv, struct v4l2_capability *cap)
{
	strcpy(cap->driver, "stk");
	strcpy(cap->card, "stk");
	cap->version = DRIVER_VERSION_NUM;

	cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
		| V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
	return 0;
}

static int stk_vidioc_enum_input(struct file *filp,
		void *priv, struct v4l2_input *input)
{
	if (input->index != 0)
		return -EINVAL;

	strcpy(input->name, "Syntek USB Camera");
	input->type = V4L2_INPUT_TYPE_CAMERA;
	return 0;
}


static int stk_vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
{
	*i = 0;
	return 0;
}

static int stk_vidioc_s_input(struct file *filp, void *priv, unsigned int i)
{
	if (i != 0)
		return -EINVAL;
	else
		return 0;
}

/* from vivi.c */
static int stk_vidioc_s_std(struct file *filp, void *priv, v4l2_std_id *a)
{
	return 0;
}

/* List of all V4Lv2 controls supported by the driver */
static struct v4l2_queryctrl stk_controls[] = {
	{
		.id      = V4L2_CID_BRIGHTNESS,
		.type    = V4L2_CTRL_TYPE_INTEGER,
		.name    = "Brightness",
		.minimum = 0,
		.maximum = 0xffff,
		.step    = 0x0100,
		.default_value = 0x6000,
	},
	/*TODO: get more controls to work */
};

static int stk_vidioc_queryctrl(struct file *filp,
		void *priv, struct v4l2_queryctrl *c)
{
	int i;
	int nbr;
	nbr = ARRAY_SIZE(stk_controls);

	for (i = 0; i < nbr; i++) {
		if (stk_controls[i].id == c->id) {
			memcpy(c, &stk_controls[i],
				sizeof(struct v4l2_queryctrl));
			return 0;
		}
	}
	return -EINVAL;
}

static int stk_vidioc_g_ctrl(struct file *filp,
		void *priv, struct v4l2_control *c)
{
	struct stk_camera *dev = priv;
	switch (c->id) {
	case V4L2_CID_BRIGHTNESS:
		c->value = dev->vsettings.brightness;
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static int stk_vidioc_s_ctrl(struct file *filp,
		void *priv, struct v4l2_control *c)
{
	struct stk_camera *dev = priv;
	switch (c->id) {
	case V4L2_CID_BRIGHTNESS:
		dev->vsettings.brightness = c->value;
		return stk_sensor_set_brightness(dev, c->value >> 8);
	default:
		return -EINVAL;
	}
	return 0;
}


static int stk_vidioc_enum_fmt_cap(struct file *filp,
		void *priv, struct v4l2_fmtdesc *fmtd)
{
	fmtd->flags = 0;

	switch (fmtd->index) {
	case 0:
		fmtd->pixelformat = V4L2_PIX_FMT_RGB565;
		strcpy(fmtd->description, "r5g6b5");
		break;
	case 1:
		fmtd->pixelformat = V4L2_PIX_FMT_RGB565X;
		strcpy(fmtd->description, "r5g6b5BE");
		break;
	case 2:
		fmtd->pixelformat = V4L2_PIX_FMT_UYVY;
		strcpy(fmtd->description, "yuv4:2:2");
		break;
	case 3:
		fmtd->pixelformat = V4L2_PIX_FMT_SBGGR8;
		strcpy(fmtd->description, "Raw bayer");
		break;
	case 4:
		fmtd->pixelformat = V4L2_PIX_FMT_YUYV;
		strcpy(fmtd->description, "yuv4:2:2");
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static struct stk_size {
	unsigned w;
	unsigned h;
	enum stk_mode m;
} stk_sizes[] = {
	{ .w = 1280, .h = 1024, .m = MODE_SXGA, },
	{ .w = 640,  .h = 480,  .m = MODE_VGA,  },
	{ .w = 352,  .h = 288,  .m = MODE_CIF,  },
	{ .w = 320,  .h = 240,  .m = MODE_QVGA, },
	{ .w = 176,  .h = 144,  .m = MODE_QCIF, },
};

static int stk_vidioc_g_fmt_cap(struct file *filp,
		void *priv, struct v4l2_format *f)
{
	struct v4l2_pix_format *pix_format = &f->fmt.pix;
	struct stk_camera *dev = priv;
	int i;

	for (i = 0; i < ARRAY_SIZE(stk_sizes)
			&& stk_sizes[i].m != dev->vsettings.mode;
		i++);
	if (i == ARRAY_SIZE(stk_sizes)) {
		STK_ERROR("ERROR: mode invalid\n");
		return -EINVAL;
	}
	pix_format->width = stk_sizes[i].w;
	pix_format->height = stk_sizes[i].h;
	pix_format->field = V4L2_FIELD_NONE;
	pix_format->colorspace = V4L2_COLORSPACE_SRGB;
	pix_format->priv = 0;
	pix_format->pixelformat = dev->vsettings.palette;
	if (dev->vsettings.palette == V4L2_PIX_FMT_SBGGR8)
		pix_format->bytesperline = pix_format->width;
	else
		pix_format->bytesperline = 2 * pix_format->width;
	pix_format->sizeimage = pix_format->bytesperline
				* pix_format->height;
	return 0;
}

static int stk_vidioc_try_fmt_cap(struct file *filp,
		void *priv, struct v4l2_format *fmtd)
{
	int i;
	switch (fmtd->fmt.pix.pixelformat) {
	case V4L2_PIX_FMT_RGB565:
	case V4L2_PIX_FMT_RGB565X:
	case V4L2_PIX_FMT_UYVY:
	case V4L2_PIX_FMT_YUYV:
	case V4L2_PIX_FMT_SBGGR8:
		break;
	default:
		return -EINVAL;
	}
	for (i = 1; i < ARRAY_SIZE(stk_sizes); i++) {
		if (fmtd->fmt.pix.width > stk_sizes[i].w)
			break;
	}
	if (i == ARRAY_SIZE(stk_sizes)
		|| (abs(fmtd->fmt.pix.width - stk_sizes[i-1].w)
			< abs(fmtd->fmt.pix.width - stk_sizes[i].w))) {
		fmtd->fmt.pix.height = stk_sizes[i-1].h;
		fmtd->fmt.pix.width = stk_sizes[i-1].w;
		fmtd->fmt.pix.priv = i - 1;
	} else {
		fmtd->fmt.pix.height = stk_sizes[i].h;
		fmtd->fmt.pix.width = stk_sizes[i].w;
		fmtd->fmt.pix.priv = i;
	}

	fmtd->fmt.pix.field = V4L2_FIELD_NONE;
	fmtd->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
	if (fmtd->fmt.pix.pixelformat == V4L2_PIX_FMT_SBGGR8)
		fmtd->fmt.pix.bytesperline = fmtd->fmt.pix.width;
	else
		fmtd->fmt.pix.bytesperline = 2 * fmtd->fmt.pix.width;
	fmtd->fmt.pix.sizeimage = fmtd->fmt.pix.bytesperline
		* fmtd->fmt.pix.height;
	return 0;
}

static int stk_setup_format(struct stk_camera *dev)
{
	int i = 0;
	int depth;
	if (dev->vsettings.palette == V4L2_PIX_FMT_SBGGR8)
		depth = 1;
	else
		depth = 2;
	while (stk_sizes[i].m != dev->vsettings.mode
			&& i < ARRAY_SIZE(stk_sizes))
		i++;
	if (i == ARRAY_SIZE(stk_sizes)) {
		STK_ERROR("Something is broken in %s\n", __func__);
		return -EFAULT;
	}
	/* This registers controls some timings, not sure of what. */
	stk_camera_write_reg(dev, 0x001b, 0x0e);
	if (dev->vsettings.mode == MODE_SXGA)
		stk_camera_write_reg(dev, 0x001c, 0x0e);
	else
		stk_camera_write_reg(dev, 0x001c, 0x46);
	/*
	 * Registers 0x0115 0x0114 are the size of each line (bytes),
	 * regs 0x0117 0x0116 are the heigth of the image.
	 */
	stk_camera_write_reg(dev, 0x0115,
		((stk_sizes[i].w * depth) >> 8) & 0xff);
	stk_camera_write_reg(dev, 0x0114,
		(stk_sizes[i].w * depth) & 0xff);
	stk_camera_write_reg(dev, 0x0117,
		(stk_sizes[i].h >> 8) & 0xff);
	stk_camera_write_reg(dev, 0x0116,
		stk_sizes[i].h & 0xff);
	return stk_sensor_configure(dev);
}

static int stk_vidioc_s_fmt_cap(struct file *filp,
		void *priv, struct v4l2_format *fmtd)
{
	int ret;
	struct stk_camera *dev = priv;

	if (dev == NULL)
		return -ENODEV;
	if (!is_present(dev))
		return -ENODEV;
	if (is_streaming(dev))
		return -EBUSY;
	if (dev->owner && dev->owner != filp)
		return -EBUSY;
	ret = stk_vidioc_try_fmt_cap(filp, priv, fmtd);
	if (ret)
		return ret;
	dev->owner = filp;

	dev->vsettings.palette = fmtd->fmt.pix.pixelformat;
	stk_free_buffers(dev);
	dev->frame_size = fmtd->fmt.pix.sizeimage;
	dev->vsettings.mode = stk_sizes[fmtd->fmt.pix.priv].m;

	stk_initialise(dev);
	return stk_setup_format(dev);
}

static int stk_vidioc_reqbufs(struct file *filp,
		void *priv, struct v4l2_requestbuffers *rb)
{
	struct stk_camera *dev = priv;

	if (dev == NULL)
		return -ENODEV;
	if (rb->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
		return -EINVAL;
	if (rb->memory != V4L2_MEMORY_MMAP)
		return -EINVAL;
	if (is_streaming(dev)
		|| (dev->owner && dev->owner != filp))
		return -EBUSY;
	dev->owner = filp;

	/*FIXME If they ask for zero, we must stop streaming and free */
	if (rb->count < 3)
		rb->count = 3;
	/* Arbitrary limit */
	else if (rb->count > 5)
		rb->count = 5;

	stk_allocate_buffers(dev, rb->count);
	rb->count = dev->n_sbufs;
	return 0;
}

static int stk_vidioc_querybuf(struct file *filp,
		void *priv, struct v4l2_buffer *buf)
{
	int index;
	struct stk_camera *dev = priv;
	struct stk_sio_buffer *sbuf;

	if (buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
		return -EINVAL;

	index = buf->index;

	if (index < 0 || index >= dev->n_sbufs)
		return -EINVAL;
	sbuf = dev->sio_bufs + buf->index;
	*buf = sbuf->v4lbuf;
	return 0;
}

static int stk_vidioc_qbuf(struct file *filp,
		void *priv, struct v4l2_buffer *buf)
{
	struct stk_camera *dev = priv;
	struct stk_sio_buffer *sbuf;
	unsigned long flags;
	if (buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
		return -EINVAL;

	if (buf->memory != V4L2_MEMORY_MMAP)
		return -EINVAL;

	if (buf->index < 0 || buf->index >= dev->n_sbufs)
		return -EINVAL;
	sbuf = dev->sio_bufs + buf->index;
	if (sbuf->v4lbuf.flags & V4L2_BUF_FLAG_QUEUED)
		return 0;
	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_QUEUED;
	sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_DONE;
	spin_lock_irqsave(&dev->spinlock, flags);
	list_add_tail(&sbuf->list, &dev->sio_avail);
	*buf = sbuf->v4lbuf;
	spin_unlock_irqrestore(&dev->spinlock, flags);
	return 0;
}

static int stk_vidioc_dqbuf(struct file *filp,
		void *priv, struct v4l2_buffer *buf)
{
	struct stk_camera *dev = priv;
	struct stk_sio_buffer *sbuf;
	unsigned long flags;
	int ret;

	if (buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE
		|| !is_streaming(dev))
		return -EINVAL;

	if (filp->f_flags & O_NONBLOCK && list_empty(&dev->sio_full))
		return -EWOULDBLOCK;
	ret = wait_event_interruptible(dev->wait_frame,
		!list_empty(&dev->sio_full) || !is_present(dev));
	if (ret)
		return ret;
	if (!is_present(dev))
		return -EIO;

	spin_lock_irqsave(&dev->spinlock, flags);
	sbuf = list_first_entry(&dev->sio_full, struct stk_sio_buffer, list);
	list_del_init(&sbuf->list);
	spin_unlock_irqrestore(&dev->spinlock, flags);
	sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_QUEUED;
	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_DONE;
	sbuf->v4lbuf.sequence = ++dev->sequence;
	do_gettimeofday(&sbuf->v4lbuf.timestamp);

	*buf = sbuf->v4lbuf;
	return 0;
}

static int stk_vidioc_streamon(struct file *filp,
		void *priv, enum v4l2_buf_type type)
{
	struct stk_camera *dev = priv;
	if (is_streaming(dev))
		return 0;
	if (dev->sio_bufs == NULL)
		return -EINVAL;
	dev->sequence = 0;
	return stk_start_stream(dev);
}

static int stk_vidioc_streamoff(struct file *filp,
		void *priv, enum v4l2_buf_type type)
{
	struct stk_camera *dev = priv;
	unsigned long flags;
	int i;
	stk_stop_stream(dev);
	spin_lock_irqsave(&dev->spinlock, flags);
	INIT_LIST_HEAD(&dev->sio_avail);
	INIT_LIST_HEAD(&dev->sio_full);
	for (i = 0; i < dev->n_sbufs; i++) {
		INIT_LIST_HEAD(&dev->sio_bufs[i].list);
		dev->sio_bufs[i].v4lbuf.flags = 0;
	}
	spin_unlock_irqrestore(&dev->spinlock, flags);
	return 0;
}


static int stk_vidioc_g_parm(struct file *filp,
		void *priv, struct v4l2_streamparm *sp)
{
	if (sp->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
		return -EINVAL;

	sp->parm.capture.capability = 0;
	sp->parm.capture.capturemode = 0;
	/*FIXME This is not correct */
	sp->parm.capture.timeperframe.numerator = 1;
	sp->parm.capture.timeperframe.denominator = 30;
	sp->parm.capture.readbuffers = 2;
	sp->parm.capture.extendedmode = 0;
	return 0;
}

static struct file_operations v4l_stk_fops = {
	.owner = THIS_MODULE,
	.open = v4l_stk_open,
	.release = v4l_stk_release,
	.read = v4l_stk_read,
	.poll = v4l_stk_poll,
	.mmap = v4l_stk_mmap,
	.ioctl = video_ioctl2,
#ifdef CONFIG_COMPAT
	.compat_ioctl = v4l_compat_ioctl32,
#endif
	.llseek = no_llseek
};

static void stk_v4l_dev_release(struct video_device *vd)
{
}

static struct video_device stk_v4l_data = {
	.name = "stkwebcam",
	.type = VFL_TYPE_GRABBER,
	.type2 = VID_TYPE_CAPTURE,
	.minor = -1,
	.tvnorms = V4L2_STD_UNKNOWN,
	.current_norm = V4L2_STD_UNKNOWN,
	.fops = &v4l_stk_fops,
	.release = stk_v4l_dev_release,

	.vidioc_querycap = stk_vidioc_querycap,
	.vidioc_enum_fmt_cap = stk_vidioc_enum_fmt_cap,
	.vidioc_try_fmt_cap = stk_vidioc_try_fmt_cap,
	.vidioc_s_fmt_cap = stk_vidioc_s_fmt_cap,
	.vidioc_g_fmt_cap = stk_vidioc_g_fmt_cap,
	.vidioc_enum_input = stk_vidioc_enum_input,
	.vidioc_s_input = stk_vidioc_s_input,
	.vidioc_g_input = stk_vidioc_g_input,
	.vidioc_s_std = stk_vidioc_s_std,
	.vidioc_reqbufs = stk_vidioc_reqbufs,
	.vidioc_querybuf = stk_vidioc_querybuf,
	.vidioc_qbuf = stk_vidioc_qbuf,
	.vidioc_dqbuf = stk_vidioc_dqbuf,
	.vidioc_streamon = stk_vidioc_streamon,
	.vidioc_streamoff = stk_vidioc_streamoff,
	.vidioc_queryctrl = stk_vidioc_queryctrl,
	.vidioc_g_ctrl = stk_vidioc_g_ctrl,
	.vidioc_s_ctrl = stk_vidioc_s_ctrl,
	.vidioc_g_parm = stk_vidioc_g_parm,
};


static int stk_register_video_device(struct stk_camera *dev)
{
	int err;

	dev->vdev = stk_v4l_data;
	dev->vdev.debug = debug;
	dev->vdev.dev = &dev->interface->dev;
	dev->vdev.priv = dev;
	err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.minor);
	return err;
}


/* USB Stuff */

static int stk_camera_probe(struct usb_interface *interface,
		const struct usb_device_id *id)
{
	int i;
	int err;

	struct stk_camera *dev = NULL;
	struct usb_device *udev = interface_to_usbdev(interface);
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;

	dev = kzalloc(sizeof(struct stk_camera), GFP_KERNEL);
	if (dev == NULL) {
		STK_ERROR("Out of memory !\n");
		return -ENOMEM;
	}

	kref_init(&dev->kref);
	spin_lock_init(&dev->spinlock);
	init_waitqueue_head(&dev->wait_frame);

	dev->udev = udev;
	dev->interface = interface;
	usb_get_intf(interface);

	dev->vsettings.vflip = vflip;
	dev->vsettings.hflip = hflip;
	dev->n_sbufs = 0;
	set_present(dev);

	/* Set up the endpoint information
	 * use only the first isoc-in endpoint
	 * for the current alternate setting */
	iface_desc = interface->cur_altsetting;

	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
		endpoint = &iface_desc->endpoint[i].desc;

		if (!dev->isoc_ep
			&& ((endpoint->bEndpointAddress
				& USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
			&& ((endpoint->bmAttributes
				& USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_ISOC)) {
			/* we found an isoc in endpoint */
			dev->isoc_ep = (endpoint->bEndpointAddress & 0xF);
			break;
		}
	}
	if (!dev->isoc_ep) {
		STK_ERROR("Could not find isoc-in endpoint");
		kref_put(&dev->kref, stk_camera_cleanup);
		return -ENODEV;
	}
	dev->vsettings.brightness = 0x7fff;
	dev->vsettings.palette = V4L2_PIX_FMT_RGB565;
	dev->vsettings.mode = MODE_VGA;
	dev->frame_size = 640 * 480 * 2;

	INIT_LIST_HEAD(&dev->sio_avail);
	INIT_LIST_HEAD(&dev->sio_full);

	usb_set_intfdata(interface, dev);

	err = stk_register_video_device(dev);
	if (err) {
		kref_put(&dev->kref, stk_camera_cleanup);
		return err;
	}

	stk_create_sysfs_files(&dev->vdev);
	usb_autopm_enable(dev->interface);

	return 0;
}

static void stk_camera_disconnect(struct usb_interface *interface)
{
	struct stk_camera *dev = usb_get_intfdata(interface);

	usb_set_intfdata(interface, NULL);
	unset_present(dev);

	wake_up_interruptible(&dev->wait_frame);
	stk_remove_sysfs_files(&dev->vdev);

	kref_put(&dev->kref, stk_camera_cleanup);
}

#ifdef CONFIG_PM
static int stk_camera_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct stk_camera *dev = usb_get_intfdata(intf);
	if (is_streaming(dev)) {
		stk_stop_stream(dev);
		/* yes, this is ugly */
		set_streaming(dev);
	}
	return 0;
}

static int stk_camera_resume(struct usb_interface *intf)
{
	struct stk_camera *dev = usb_get_intfdata(intf);
	if (!is_initialised(dev))
		return 0;
	unset_initialised(dev);
	stk_initialise(dev);
	stk_setup_format(dev);
	if (is_streaming(dev))
		stk_start_stream(dev);
	return 0;
}
#endif

static struct usb_driver stk_camera_driver = {
	.name = "stkwebcam",
	.probe = stk_camera_probe,
	.disconnect = stk_camera_disconnect,
	.id_table = stkwebcam_table,
#ifdef CONFIG_PM
	.suspend = stk_camera_suspend,
	.resume = stk_camera_resume,
#endif
};


static int __init stk_camera_init(void)
{
	int result;

	result = usb_register(&stk_camera_driver);
	if (result)
		STK_ERROR("usb_register failed ! Error number %d\n", result);


	return result;
}

static void __exit stk_camera_exit(void)
{
	usb_deregister(&stk_camera_driver);
}

module_init(stk_camera_init);
module_exit(stk_camera_exit);