xref: /openbmc/linux/drivers/media/usb/gspca/gspca.c (revision 930beb5a)
1 /*
2  * Main USB camera driver
3  *
4  * Copyright (C) 2008-2011 Jean-François Moine <http://moinejf.free.fr>
5  *
6  * Camera button input handling by Márton Németh
7  * Copyright (C) 2009-2010 Márton Németh <nm127@freemail.hu>
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License as published by the
11  * Free Software Foundation; either version 2 of the License, or (at your
12  * option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
17  * for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software Foundation,
21  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  */
23 
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 
26 #define GSPCA_VERSION	"2.14.0"
27 
28 #include <linux/init.h>
29 #include <linux/fs.h>
30 #include <linux/vmalloc.h>
31 #include <linux/sched.h>
32 #include <linux/slab.h>
33 #include <linux/mm.h>
34 #include <linux/string.h>
35 #include <linux/pagemap.h>
36 #include <linux/io.h>
37 #include <asm/page.h>
38 #include <linux/uaccess.h>
39 #include <linux/ktime.h>
40 #include <media/v4l2-ioctl.h>
41 #include <media/v4l2-ctrls.h>
42 #include <media/v4l2-fh.h>
43 #include <media/v4l2-event.h>
44 
45 #include "gspca.h"
46 
47 #if IS_ENABLED(CONFIG_INPUT)
48 #include <linux/input.h>
49 #include <linux/usb/input.h>
50 #endif
51 
52 /* global values */
53 #define DEF_NURBS 3		/* default number of URBs */
54 #if DEF_NURBS > MAX_NURBS
55 #error "DEF_NURBS too big"
56 #endif
57 
58 MODULE_AUTHOR("Jean-François Moine <http://moinejf.free.fr>");
59 MODULE_DESCRIPTION("GSPCA USB Camera Driver");
60 MODULE_LICENSE("GPL");
61 MODULE_VERSION(GSPCA_VERSION);
62 
63 int gspca_debug;
64 EXPORT_SYMBOL(gspca_debug);
65 
66 static void PDEBUG_MODE(struct gspca_dev *gspca_dev, int debug, char *txt,
67 			__u32 pixfmt, int w, int h)
68 {
69 	if ((pixfmt >> 24) >= '0' && (pixfmt >> 24) <= 'z') {
70 		PDEBUG(debug, "%s %c%c%c%c %dx%d",
71 			txt,
72 			pixfmt & 0xff,
73 			(pixfmt >> 8) & 0xff,
74 			(pixfmt >> 16) & 0xff,
75 			pixfmt >> 24,
76 			w, h);
77 	} else {
78 		PDEBUG(debug, "%s 0x%08x %dx%d",
79 			txt,
80 			pixfmt,
81 			w, h);
82 	}
83 }
84 
85 /* specific memory types - !! should be different from V4L2_MEMORY_xxx */
86 #define GSPCA_MEMORY_NO 0	/* V4L2_MEMORY_xxx starts from 1 */
87 #define GSPCA_MEMORY_READ 7
88 
89 #define BUF_ALL_FLAGS (V4L2_BUF_FLAG_QUEUED | V4L2_BUF_FLAG_DONE)
90 
91 /*
92  * VMA operations.
93  */
94 static void gspca_vm_open(struct vm_area_struct *vma)
95 {
96 	struct gspca_frame *frame = vma->vm_private_data;
97 
98 	frame->vma_use_count++;
99 	frame->v4l2_buf.flags |= V4L2_BUF_FLAG_MAPPED;
100 }
101 
102 static void gspca_vm_close(struct vm_area_struct *vma)
103 {
104 	struct gspca_frame *frame = vma->vm_private_data;
105 
106 	if (--frame->vma_use_count <= 0)
107 		frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_MAPPED;
108 }
109 
110 static const struct vm_operations_struct gspca_vm_ops = {
111 	.open		= gspca_vm_open,
112 	.close		= gspca_vm_close,
113 };
114 
115 /*
116  * Input and interrupt endpoint handling functions
117  */
118 #if IS_ENABLED(CONFIG_INPUT)
119 static void int_irq(struct urb *urb)
120 {
121 	struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
122 	int ret;
123 
124 	ret = urb->status;
125 	switch (ret) {
126 	case 0:
127 		if (gspca_dev->sd_desc->int_pkt_scan(gspca_dev,
128 		    urb->transfer_buffer, urb->actual_length) < 0) {
129 			PERR("Unknown packet received");
130 		}
131 		break;
132 
133 	case -ENOENT:
134 	case -ECONNRESET:
135 	case -ENODEV:
136 	case -ESHUTDOWN:
137 		/* Stop is requested either by software or hardware is gone,
138 		 * keep the ret value non-zero and don't resubmit later.
139 		 */
140 		break;
141 
142 	default:
143 		PERR("URB error %i, resubmitting", urb->status);
144 		urb->status = 0;
145 		ret = 0;
146 	}
147 
148 	if (ret == 0) {
149 		ret = usb_submit_urb(urb, GFP_ATOMIC);
150 		if (ret < 0)
151 			pr_err("Resubmit URB failed with error %i\n", ret);
152 	}
153 }
154 
155 static int gspca_input_connect(struct gspca_dev *dev)
156 {
157 	struct input_dev *input_dev;
158 	int err = 0;
159 
160 	dev->input_dev = NULL;
161 	if (dev->sd_desc->int_pkt_scan || dev->sd_desc->other_input)  {
162 		input_dev = input_allocate_device();
163 		if (!input_dev)
164 			return -ENOMEM;
165 
166 		usb_make_path(dev->dev, dev->phys, sizeof(dev->phys));
167 		strlcat(dev->phys, "/input0", sizeof(dev->phys));
168 
169 		input_dev->name = dev->sd_desc->name;
170 		input_dev->phys = dev->phys;
171 
172 		usb_to_input_id(dev->dev, &input_dev->id);
173 
174 		input_dev->evbit[0] = BIT_MASK(EV_KEY);
175 		input_dev->keybit[BIT_WORD(KEY_CAMERA)] = BIT_MASK(KEY_CAMERA);
176 		input_dev->dev.parent = &dev->dev->dev;
177 
178 		err = input_register_device(input_dev);
179 		if (err) {
180 			pr_err("Input device registration failed with error %i\n",
181 			       err);
182 			input_dev->dev.parent = NULL;
183 			input_free_device(input_dev);
184 		} else {
185 			dev->input_dev = input_dev;
186 		}
187 	}
188 
189 	return err;
190 }
191 
192 static int alloc_and_submit_int_urb(struct gspca_dev *gspca_dev,
193 			  struct usb_endpoint_descriptor *ep)
194 {
195 	unsigned int buffer_len;
196 	int interval;
197 	struct urb *urb;
198 	struct usb_device *dev;
199 	void *buffer = NULL;
200 	int ret = -EINVAL;
201 
202 	buffer_len = le16_to_cpu(ep->wMaxPacketSize);
203 	interval = ep->bInterval;
204 	PDEBUG(D_CONF, "found int in endpoint: 0x%x, "
205 		"buffer_len=%u, interval=%u",
206 		ep->bEndpointAddress, buffer_len, interval);
207 
208 	dev = gspca_dev->dev;
209 
210 	urb = usb_alloc_urb(0, GFP_KERNEL);
211 	if (!urb) {
212 		ret = -ENOMEM;
213 		goto error;
214 	}
215 
216 	buffer = usb_alloc_coherent(dev, buffer_len,
217 				GFP_KERNEL, &urb->transfer_dma);
218 	if (!buffer) {
219 		ret = -ENOMEM;
220 		goto error_buffer;
221 	}
222 	usb_fill_int_urb(urb, dev,
223 		usb_rcvintpipe(dev, ep->bEndpointAddress),
224 		buffer, buffer_len,
225 		int_irq, (void *)gspca_dev, interval);
226 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
227 	ret = usb_submit_urb(urb, GFP_KERNEL);
228 	if (ret < 0) {
229 		PERR("submit int URB failed with error %i", ret);
230 		goto error_submit;
231 	}
232 	gspca_dev->int_urb = urb;
233 	return ret;
234 
235 error_submit:
236 	usb_free_coherent(dev,
237 			  urb->transfer_buffer_length,
238 			  urb->transfer_buffer,
239 			  urb->transfer_dma);
240 error_buffer:
241 	usb_free_urb(urb);
242 error:
243 	return ret;
244 }
245 
246 static void gspca_input_create_urb(struct gspca_dev *gspca_dev)
247 {
248 	struct usb_interface *intf;
249 	struct usb_host_interface *intf_desc;
250 	struct usb_endpoint_descriptor *ep;
251 	int i;
252 
253 	if (gspca_dev->sd_desc->int_pkt_scan)  {
254 		intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
255 		intf_desc = intf->cur_altsetting;
256 		for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
257 			ep = &intf_desc->endpoint[i].desc;
258 			if (usb_endpoint_dir_in(ep) &&
259 			    usb_endpoint_xfer_int(ep)) {
260 
261 				alloc_and_submit_int_urb(gspca_dev, ep);
262 				break;
263 			}
264 		}
265 	}
266 }
267 
268 static void gspca_input_destroy_urb(struct gspca_dev *gspca_dev)
269 {
270 	struct urb *urb;
271 
272 	urb = gspca_dev->int_urb;
273 	if (urb) {
274 		gspca_dev->int_urb = NULL;
275 		usb_kill_urb(urb);
276 		usb_free_coherent(gspca_dev->dev,
277 				  urb->transfer_buffer_length,
278 				  urb->transfer_buffer,
279 				  urb->transfer_dma);
280 		usb_free_urb(urb);
281 	}
282 }
283 #else
284 static inline void gspca_input_destroy_urb(struct gspca_dev *gspca_dev)
285 {
286 }
287 
288 static inline void gspca_input_create_urb(struct gspca_dev *gspca_dev)
289 {
290 }
291 
292 static inline int gspca_input_connect(struct gspca_dev *dev)
293 {
294 	return 0;
295 }
296 #endif
297 
298 /*
299  * fill a video frame from an URB and resubmit
300  */
301 static void fill_frame(struct gspca_dev *gspca_dev,
302 			struct urb *urb)
303 {
304 	u8 *data;		/* address of data in the iso message */
305 	int i, len, st;
306 	cam_pkt_op pkt_scan;
307 
308 	if (urb->status != 0) {
309 		if (urb->status == -ESHUTDOWN)
310 			return;		/* disconnection */
311 #ifdef CONFIG_PM
312 		if (gspca_dev->frozen)
313 			return;
314 #endif
315 		PERR("urb status: %d", urb->status);
316 		urb->status = 0;
317 		goto resubmit;
318 	}
319 	pkt_scan = gspca_dev->sd_desc->pkt_scan;
320 	for (i = 0; i < urb->number_of_packets; i++) {
321 		len = urb->iso_frame_desc[i].actual_length;
322 
323 		/* check the packet status and length */
324 		st = urb->iso_frame_desc[i].status;
325 		if (st) {
326 			pr_err("ISOC data error: [%d] len=%d, status=%d\n",
327 			       i, len, st);
328 			gspca_dev->last_packet_type = DISCARD_PACKET;
329 			continue;
330 		}
331 		if (len == 0) {
332 			if (gspca_dev->empty_packet == 0)
333 				gspca_dev->empty_packet = 1;
334 			continue;
335 		}
336 
337 		/* let the packet be analyzed by the subdriver */
338 		PDEBUG(D_PACK, "packet [%d] o:%d l:%d",
339 			i, urb->iso_frame_desc[i].offset, len);
340 		data = (u8 *) urb->transfer_buffer
341 					+ urb->iso_frame_desc[i].offset;
342 		pkt_scan(gspca_dev, data, len);
343 	}
344 
345 resubmit:
346 	/* resubmit the URB */
347 	st = usb_submit_urb(urb, GFP_ATOMIC);
348 	if (st < 0)
349 		pr_err("usb_submit_urb() ret %d\n", st);
350 }
351 
352 /*
353  * ISOC message interrupt from the USB device
354  *
355  * Analyse each packet and call the subdriver for copy to the frame buffer.
356  */
357 static void isoc_irq(struct urb *urb)
358 {
359 	struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
360 
361 	PDEBUG(D_PACK, "isoc irq");
362 	if (!gspca_dev->streaming)
363 		return;
364 	fill_frame(gspca_dev, urb);
365 }
366 
367 /*
368  * bulk message interrupt from the USB device
369  */
370 static void bulk_irq(struct urb *urb)
371 {
372 	struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
373 	int st;
374 
375 	PDEBUG(D_PACK, "bulk irq");
376 	if (!gspca_dev->streaming)
377 		return;
378 	switch (urb->status) {
379 	case 0:
380 		break;
381 	case -ESHUTDOWN:
382 		return;		/* disconnection */
383 	default:
384 #ifdef CONFIG_PM
385 		if (gspca_dev->frozen)
386 			return;
387 #endif
388 		PERR("urb status: %d", urb->status);
389 		urb->status = 0;
390 		goto resubmit;
391 	}
392 
393 	PDEBUG(D_PACK, "packet l:%d", urb->actual_length);
394 	gspca_dev->sd_desc->pkt_scan(gspca_dev,
395 				urb->transfer_buffer,
396 				urb->actual_length);
397 
398 resubmit:
399 	/* resubmit the URB */
400 	if (gspca_dev->cam.bulk_nurbs != 0) {
401 		st = usb_submit_urb(urb, GFP_ATOMIC);
402 		if (st < 0)
403 			pr_err("usb_submit_urb() ret %d\n", st);
404 	}
405 }
406 
407 /*
408  * add data to the current frame
409  *
410  * This function is called by the subdrivers at interrupt level.
411  *
412  * To build a frame, these ones must add
413  *	- one FIRST_PACKET
414  *	- 0 or many INTER_PACKETs
415  *	- one LAST_PACKET
416  * DISCARD_PACKET invalidates the whole frame.
417  */
418 void gspca_frame_add(struct gspca_dev *gspca_dev,
419 			enum gspca_packet_type packet_type,
420 			const u8 *data,
421 			int len)
422 {
423 	struct gspca_frame *frame;
424 	int i, j;
425 
426 	PDEBUG(D_PACK, "add t:%d l:%d",	packet_type, len);
427 
428 	if (packet_type == FIRST_PACKET) {
429 		i = atomic_read(&gspca_dev->fr_i);
430 
431 		/* if there are no queued buffer, discard the whole frame */
432 		if (i == atomic_read(&gspca_dev->fr_q)) {
433 			gspca_dev->last_packet_type = DISCARD_PACKET;
434 			gspca_dev->sequence++;
435 			return;
436 		}
437 		j = gspca_dev->fr_queue[i];
438 		frame = &gspca_dev->frame[j];
439 		frame->v4l2_buf.timestamp = ktime_to_timeval(ktime_get());
440 		frame->v4l2_buf.sequence = gspca_dev->sequence++;
441 		gspca_dev->image = frame->data;
442 		gspca_dev->image_len = 0;
443 	} else {
444 		switch (gspca_dev->last_packet_type) {
445 		case DISCARD_PACKET:
446 			if (packet_type == LAST_PACKET) {
447 				gspca_dev->last_packet_type = packet_type;
448 				gspca_dev->image = NULL;
449 				gspca_dev->image_len = 0;
450 			}
451 			return;
452 		case LAST_PACKET:
453 			return;
454 		}
455 	}
456 
457 	/* append the packet to the frame buffer */
458 	if (len > 0) {
459 		if (gspca_dev->image_len + len > gspca_dev->frsz) {
460 			PERR("frame overflow %d > %d",
461 				gspca_dev->image_len + len,
462 				gspca_dev->frsz);
463 			packet_type = DISCARD_PACKET;
464 		} else {
465 /* !! image is NULL only when last pkt is LAST or DISCARD
466 			if (gspca_dev->image == NULL) {
467 				pr_err("gspca_frame_add() image == NULL\n");
468 				return;
469 			}
470  */
471 			memcpy(gspca_dev->image + gspca_dev->image_len,
472 				data, len);
473 			gspca_dev->image_len += len;
474 		}
475 	}
476 	gspca_dev->last_packet_type = packet_type;
477 
478 	/* if last packet, invalidate packet concatenation until
479 	 * next first packet, wake up the application and advance
480 	 * in the queue */
481 	if (packet_type == LAST_PACKET) {
482 		i = atomic_read(&gspca_dev->fr_i);
483 		j = gspca_dev->fr_queue[i];
484 		frame = &gspca_dev->frame[j];
485 		frame->v4l2_buf.bytesused = gspca_dev->image_len;
486 		frame->v4l2_buf.flags = (frame->v4l2_buf.flags
487 					 | V4L2_BUF_FLAG_DONE)
488 					& ~V4L2_BUF_FLAG_QUEUED;
489 		i = (i + 1) % GSPCA_MAX_FRAMES;
490 		atomic_set(&gspca_dev->fr_i, i);
491 		wake_up_interruptible(&gspca_dev->wq);	/* event = new frame */
492 		PDEBUG(D_FRAM, "frame complete len:%d",
493 			frame->v4l2_buf.bytesused);
494 		gspca_dev->image = NULL;
495 		gspca_dev->image_len = 0;
496 	}
497 }
498 EXPORT_SYMBOL(gspca_frame_add);
499 
500 static int frame_alloc(struct gspca_dev *gspca_dev, struct file *file,
501 			enum v4l2_memory memory, unsigned int count)
502 {
503 	struct gspca_frame *frame;
504 	unsigned int frsz;
505 	int i;
506 
507 	frsz = gspca_dev->pixfmt.sizeimage;
508 	PDEBUG(D_STREAM, "frame alloc frsz: %d", frsz);
509 	frsz = PAGE_ALIGN(frsz);
510 	if (count >= GSPCA_MAX_FRAMES)
511 		count = GSPCA_MAX_FRAMES - 1;
512 	gspca_dev->frbuf = vmalloc_32(frsz * count);
513 	if (!gspca_dev->frbuf) {
514 		pr_err("frame alloc failed\n");
515 		return -ENOMEM;
516 	}
517 	gspca_dev->capt_file = file;
518 	gspca_dev->memory = memory;
519 	gspca_dev->frsz = frsz;
520 	gspca_dev->nframes = count;
521 	for (i = 0; i < count; i++) {
522 		frame = &gspca_dev->frame[i];
523 		frame->v4l2_buf.index = i;
524 		frame->v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
525 		frame->v4l2_buf.flags = 0;
526 		frame->v4l2_buf.field = V4L2_FIELD_NONE;
527 		frame->v4l2_buf.length = frsz;
528 		frame->v4l2_buf.memory = memory;
529 		frame->v4l2_buf.sequence = 0;
530 		frame->data = gspca_dev->frbuf + i * frsz;
531 		frame->v4l2_buf.m.offset = i * frsz;
532 	}
533 	atomic_set(&gspca_dev->fr_q, 0);
534 	atomic_set(&gspca_dev->fr_i, 0);
535 	gspca_dev->fr_o = 0;
536 	return 0;
537 }
538 
539 static void frame_free(struct gspca_dev *gspca_dev)
540 {
541 	int i;
542 
543 	PDEBUG(D_STREAM, "frame free");
544 	if (gspca_dev->frbuf != NULL) {
545 		vfree(gspca_dev->frbuf);
546 		gspca_dev->frbuf = NULL;
547 		for (i = 0; i < gspca_dev->nframes; i++)
548 			gspca_dev->frame[i].data = NULL;
549 	}
550 	gspca_dev->nframes = 0;
551 	gspca_dev->frsz = 0;
552 	gspca_dev->capt_file = NULL;
553 	gspca_dev->memory = GSPCA_MEMORY_NO;
554 }
555 
556 static void destroy_urbs(struct gspca_dev *gspca_dev)
557 {
558 	struct urb *urb;
559 	unsigned int i;
560 
561 	PDEBUG(D_STREAM, "kill transfer");
562 	for (i = 0; i < MAX_NURBS; i++) {
563 		urb = gspca_dev->urb[i];
564 		if (urb == NULL)
565 			break;
566 
567 		gspca_dev->urb[i] = NULL;
568 		usb_kill_urb(urb);
569 		usb_free_coherent(gspca_dev->dev,
570 				  urb->transfer_buffer_length,
571 				  urb->transfer_buffer,
572 				  urb->transfer_dma);
573 		usb_free_urb(urb);
574 	}
575 }
576 
577 static int gspca_set_alt0(struct gspca_dev *gspca_dev)
578 {
579 	int ret;
580 
581 	if (gspca_dev->alt == 0)
582 		return 0;
583 	ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, 0);
584 	if (ret < 0)
585 		pr_err("set alt 0 err %d\n", ret);
586 	return ret;
587 }
588 
589 /* Note: both the queue and the usb locks should be held when calling this */
590 static void gspca_stream_off(struct gspca_dev *gspca_dev)
591 {
592 	gspca_dev->streaming = 0;
593 	gspca_dev->usb_err = 0;
594 	if (gspca_dev->sd_desc->stopN)
595 		gspca_dev->sd_desc->stopN(gspca_dev);
596 	destroy_urbs(gspca_dev);
597 	gspca_input_destroy_urb(gspca_dev);
598 	gspca_set_alt0(gspca_dev);
599 	gspca_input_create_urb(gspca_dev);
600 	if (gspca_dev->sd_desc->stop0)
601 		gspca_dev->sd_desc->stop0(gspca_dev);
602 	PDEBUG(D_STREAM, "stream off OK");
603 }
604 
605 /*
606  * look for an input transfer endpoint in an alternate setting
607  */
608 static struct usb_host_endpoint *alt_xfer(struct usb_host_interface *alt,
609 					  int xfer)
610 {
611 	struct usb_host_endpoint *ep;
612 	int i, attr;
613 
614 	for (i = 0; i < alt->desc.bNumEndpoints; i++) {
615 		ep = &alt->endpoint[i];
616 		attr = ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
617 		if (attr == xfer
618 		    && ep->desc.wMaxPacketSize != 0
619 		    && usb_endpoint_dir_in(&ep->desc))
620 			return ep;
621 	}
622 	return NULL;
623 }
624 
625 /* compute the minimum bandwidth for the current transfer */
626 static u32 which_bandwidth(struct gspca_dev *gspca_dev)
627 {
628 	u32 bandwidth;
629 
630 	/* get the (max) image size */
631 	bandwidth = gspca_dev->pixfmt.sizeimage;
632 
633 	/* if the image is compressed, estimate its mean size */
634 	if (!gspca_dev->cam.needs_full_bandwidth &&
635 	    bandwidth < gspca_dev->pixfmt.width *
636 				gspca_dev->pixfmt.height)
637 		bandwidth = bandwidth * 3 / 8;	/* 0.375 */
638 
639 	/* estimate the frame rate */
640 	if (gspca_dev->sd_desc->get_streamparm) {
641 		struct v4l2_streamparm parm;
642 
643 		gspca_dev->sd_desc->get_streamparm(gspca_dev, &parm);
644 		bandwidth *= parm.parm.capture.timeperframe.denominator;
645 		bandwidth /= parm.parm.capture.timeperframe.numerator;
646 	} else {
647 
648 		/* don't hope more than 15 fps with USB 1.1 and
649 		 * image resolution >= 640x480 */
650 		if (gspca_dev->pixfmt.width >= 640
651 		 && gspca_dev->dev->speed == USB_SPEED_FULL)
652 			bandwidth *= 15;		/* 15 fps */
653 		else
654 			bandwidth *= 30;		/* 30 fps */
655 	}
656 
657 	PDEBUG(D_STREAM, "min bandwidth: %d", bandwidth);
658 	return bandwidth;
659 }
660 
661 /* endpoint table */
662 #define MAX_ALT 16
663 struct ep_tb_s {
664 	u32 alt;
665 	u32 bandwidth;
666 };
667 
668 /*
669  * build the table of the endpoints
670  * and compute the minimum bandwidth for the image transfer
671  */
672 static int build_isoc_ep_tb(struct gspca_dev *gspca_dev,
673 			struct usb_interface *intf,
674 			struct ep_tb_s *ep_tb)
675 {
676 	struct usb_host_endpoint *ep;
677 	int i, j, nbalt, psize, found;
678 	u32 bandwidth, last_bw;
679 
680 	nbalt = intf->num_altsetting;
681 	if (nbalt > MAX_ALT)
682 		nbalt = MAX_ALT;	/* fixme: should warn */
683 
684 	/* build the endpoint table */
685 	i = 0;
686 	last_bw = 0;
687 	for (;;) {
688 		ep_tb->bandwidth = 2000 * 2000 * 120;
689 		found = 0;
690 		for (j = 0; j < nbalt; j++) {
691 			ep = alt_xfer(&intf->altsetting[j],
692 				      USB_ENDPOINT_XFER_ISOC);
693 			if (ep == NULL)
694 				continue;
695 			if (ep->desc.bInterval == 0) {
696 				pr_err("alt %d iso endp with 0 interval\n", j);
697 				continue;
698 			}
699 			psize = le16_to_cpu(ep->desc.wMaxPacketSize);
700 			psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
701 			bandwidth = psize * 1000;
702 			if (gspca_dev->dev->speed == USB_SPEED_HIGH
703 			 || gspca_dev->dev->speed == USB_SPEED_SUPER)
704 				bandwidth *= 8;
705 			bandwidth /= 1 << (ep->desc.bInterval - 1);
706 			if (bandwidth <= last_bw)
707 				continue;
708 			if (bandwidth < ep_tb->bandwidth) {
709 				ep_tb->bandwidth = bandwidth;
710 				ep_tb->alt = j;
711 				found = 1;
712 			}
713 		}
714 		if (!found)
715 			break;
716 		PDEBUG(D_STREAM, "alt %d bandwidth %d",
717 				ep_tb->alt, ep_tb->bandwidth);
718 		last_bw = ep_tb->bandwidth;
719 		i++;
720 		ep_tb++;
721 	}
722 
723 	/*
724 	 * If the camera:
725 	 * has a usb audio class interface (a built in usb mic); and
726 	 * is a usb 1 full speed device; and
727 	 * uses the max full speed iso bandwidth; and
728 	 * and has more than 1 alt setting
729 	 * then skip the highest alt setting to spare bandwidth for the mic
730 	 */
731 	if (gspca_dev->audio &&
732 			gspca_dev->dev->speed == USB_SPEED_FULL &&
733 			last_bw >= 1000000 &&
734 			i > 1) {
735 		PDEBUG(D_STREAM, "dev has usb audio, skipping highest alt");
736 		i--;
737 		ep_tb--;
738 	}
739 
740 	/* get the requested bandwidth and start at the highest atlsetting */
741 	bandwidth = which_bandwidth(gspca_dev);
742 	ep_tb--;
743 	while (i > 1) {
744 		ep_tb--;
745 		if (ep_tb->bandwidth < bandwidth)
746 			break;
747 		i--;
748 	}
749 	return i;
750 }
751 
752 /*
753  * create the URBs for image transfer
754  */
755 static int create_urbs(struct gspca_dev *gspca_dev,
756 			struct usb_host_endpoint *ep)
757 {
758 	struct urb *urb;
759 	int n, nurbs, i, psize, npkt, bsize;
760 
761 	/* calculate the packet size and the number of packets */
762 	psize = le16_to_cpu(ep->desc.wMaxPacketSize);
763 
764 	if (!gspca_dev->cam.bulk) {		/* isoc */
765 
766 		/* See paragraph 5.9 / table 5-11 of the usb 2.0 spec. */
767 		if (gspca_dev->pkt_size == 0)
768 			psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
769 		else
770 			psize = gspca_dev->pkt_size;
771 		npkt = gspca_dev->cam.npkt;
772 		if (npkt == 0)
773 			npkt = 32;		/* default value */
774 		bsize = psize * npkt;
775 		PDEBUG(D_STREAM,
776 			"isoc %d pkts size %d = bsize:%d",
777 			npkt, psize, bsize);
778 		nurbs = DEF_NURBS;
779 	} else {				/* bulk */
780 		npkt = 0;
781 		bsize = gspca_dev->cam.bulk_size;
782 		if (bsize == 0)
783 			bsize = psize;
784 		PDEBUG(D_STREAM, "bulk bsize:%d", bsize);
785 		if (gspca_dev->cam.bulk_nurbs != 0)
786 			nurbs = gspca_dev->cam.bulk_nurbs;
787 		else
788 			nurbs = 1;
789 	}
790 
791 	for (n = 0; n < nurbs; n++) {
792 		urb = usb_alloc_urb(npkt, GFP_KERNEL);
793 		if (!urb) {
794 			pr_err("usb_alloc_urb failed\n");
795 			return -ENOMEM;
796 		}
797 		gspca_dev->urb[n] = urb;
798 		urb->transfer_buffer = usb_alloc_coherent(gspca_dev->dev,
799 						bsize,
800 						GFP_KERNEL,
801 						&urb->transfer_dma);
802 
803 		if (urb->transfer_buffer == NULL) {
804 			pr_err("usb_alloc_coherent failed\n");
805 			return -ENOMEM;
806 		}
807 		urb->dev = gspca_dev->dev;
808 		urb->context = gspca_dev;
809 		urb->transfer_buffer_length = bsize;
810 		if (npkt != 0) {		/* ISOC */
811 			urb->pipe = usb_rcvisocpipe(gspca_dev->dev,
812 						    ep->desc.bEndpointAddress);
813 			urb->transfer_flags = URB_ISO_ASAP
814 					| URB_NO_TRANSFER_DMA_MAP;
815 			urb->interval = 1 << (ep->desc.bInterval - 1);
816 			urb->complete = isoc_irq;
817 			urb->number_of_packets = npkt;
818 			for (i = 0; i < npkt; i++) {
819 				urb->iso_frame_desc[i].length = psize;
820 				urb->iso_frame_desc[i].offset = psize * i;
821 			}
822 		} else {		/* bulk */
823 			urb->pipe = usb_rcvbulkpipe(gspca_dev->dev,
824 						ep->desc.bEndpointAddress);
825 			urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
826 			urb->complete = bulk_irq;
827 		}
828 	}
829 	return 0;
830 }
831 
832 /*
833  * start the USB transfer
834  */
835 static int gspca_init_transfer(struct gspca_dev *gspca_dev)
836 {
837 	struct usb_interface *intf;
838 	struct usb_host_endpoint *ep;
839 	struct urb *urb;
840 	struct ep_tb_s ep_tb[MAX_ALT];
841 	int n, ret, xfer, alt, alt_idx;
842 
843 	/* reset the streaming variables */
844 	gspca_dev->image = NULL;
845 	gspca_dev->image_len = 0;
846 	gspca_dev->last_packet_type = DISCARD_PACKET;
847 	gspca_dev->sequence = 0;
848 
849 	gspca_dev->usb_err = 0;
850 
851 	/* do the specific subdriver stuff before endpoint selection */
852 	intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
853 	gspca_dev->alt = gspca_dev->cam.bulk ? intf->num_altsetting : 0;
854 	if (gspca_dev->sd_desc->isoc_init) {
855 		ret = gspca_dev->sd_desc->isoc_init(gspca_dev);
856 		if (ret < 0)
857 			return ret;
858 	}
859 	xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK
860 				   : USB_ENDPOINT_XFER_ISOC;
861 
862 	/* if bulk or the subdriver forced an altsetting, get the endpoint */
863 	if (gspca_dev->alt != 0) {
864 		gspca_dev->alt--;	/* (previous version compatibility) */
865 		ep = alt_xfer(&intf->altsetting[gspca_dev->alt], xfer);
866 		if (ep == NULL) {
867 			pr_err("bad altsetting %d\n", gspca_dev->alt);
868 			return -EIO;
869 		}
870 		ep_tb[0].alt = gspca_dev->alt;
871 		alt_idx = 1;
872 	} else {
873 
874 	/* else, compute the minimum bandwidth
875 	 * and build the endpoint table */
876 		alt_idx = build_isoc_ep_tb(gspca_dev, intf, ep_tb);
877 		if (alt_idx <= 0) {
878 			pr_err("no transfer endpoint found\n");
879 			return -EIO;
880 		}
881 	}
882 
883 	/* set the highest alternate setting and
884 	 * loop until urb submit succeeds */
885 	gspca_input_destroy_urb(gspca_dev);
886 
887 	gspca_dev->alt = ep_tb[--alt_idx].alt;
888 	alt = -1;
889 	for (;;) {
890 		if (alt != gspca_dev->alt) {
891 			alt = gspca_dev->alt;
892 			if (intf->num_altsetting > 1) {
893 				ret = usb_set_interface(gspca_dev->dev,
894 							gspca_dev->iface,
895 							alt);
896 				if (ret < 0) {
897 					if (ret == -ENOSPC)
898 						goto retry; /*fixme: ugly*/
899 					pr_err("set alt %d err %d\n", alt, ret);
900 					goto out;
901 				}
902 			}
903 		}
904 		if (!gspca_dev->cam.no_urb_create) {
905 			PDEBUG(D_STREAM, "init transfer alt %d", alt);
906 			ret = create_urbs(gspca_dev,
907 				alt_xfer(&intf->altsetting[alt], xfer));
908 			if (ret < 0) {
909 				destroy_urbs(gspca_dev);
910 				goto out;
911 			}
912 		}
913 
914 		/* clear the bulk endpoint */
915 		if (gspca_dev->cam.bulk)
916 			usb_clear_halt(gspca_dev->dev,
917 					gspca_dev->urb[0]->pipe);
918 
919 		/* start the cam */
920 		ret = gspca_dev->sd_desc->start(gspca_dev);
921 		if (ret < 0) {
922 			destroy_urbs(gspca_dev);
923 			goto out;
924 		}
925 		gspca_dev->streaming = 1;
926 		v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
927 
928 		/* some bulk transfers are started by the subdriver */
929 		if (gspca_dev->cam.bulk && gspca_dev->cam.bulk_nurbs == 0)
930 			break;
931 
932 		/* submit the URBs */
933 		for (n = 0; n < MAX_NURBS; n++) {
934 			urb = gspca_dev->urb[n];
935 			if (urb == NULL)
936 				break;
937 			ret = usb_submit_urb(urb, GFP_KERNEL);
938 			if (ret < 0)
939 				break;
940 		}
941 		if (ret >= 0)
942 			break;			/* transfer is started */
943 
944 		/* something when wrong
945 		 * stop the webcam and free the transfer resources */
946 		gspca_stream_off(gspca_dev);
947 		if (ret != -ENOSPC) {
948 			pr_err("usb_submit_urb alt %d err %d\n",
949 			       gspca_dev->alt, ret);
950 			goto out;
951 		}
952 
953 		/* the bandwidth is not wide enough
954 		 * negotiate or try a lower alternate setting */
955 retry:
956 		PERR("alt %d - bandwidth not wide enough, trying again", alt);
957 		msleep(20);	/* wait for kill complete */
958 		if (gspca_dev->sd_desc->isoc_nego) {
959 			ret = gspca_dev->sd_desc->isoc_nego(gspca_dev);
960 			if (ret < 0)
961 				goto out;
962 		} else {
963 			if (alt_idx <= 0) {
964 				pr_err("no transfer endpoint found\n");
965 				ret = -EIO;
966 				goto out;
967 			}
968 			gspca_dev->alt = ep_tb[--alt_idx].alt;
969 		}
970 	}
971 out:
972 	gspca_input_create_urb(gspca_dev);
973 	return ret;
974 }
975 
976 static void gspca_set_default_mode(struct gspca_dev *gspca_dev)
977 {
978 	int i;
979 
980 	i = gspca_dev->cam.nmodes - 1;	/* take the highest mode */
981 	gspca_dev->curr_mode = i;
982 	gspca_dev->pixfmt = gspca_dev->cam.cam_mode[i];
983 
984 	/* does nothing if ctrl_handler == NULL */
985 	v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
986 }
987 
988 static int wxh_to_mode(struct gspca_dev *gspca_dev,
989 			int width, int height)
990 {
991 	int i;
992 
993 	for (i = gspca_dev->cam.nmodes; --i > 0; ) {
994 		if (width >= gspca_dev->cam.cam_mode[i].width
995 		    && height >= gspca_dev->cam.cam_mode[i].height)
996 			break;
997 	}
998 	return i;
999 }
1000 
1001 /*
1002  * search a mode with the right pixel format
1003  */
1004 static int gspca_get_mode(struct gspca_dev *gspca_dev,
1005 			int mode,
1006 			int pixfmt)
1007 {
1008 	int modeU, modeD;
1009 
1010 	modeU = modeD = mode;
1011 	while ((modeU < gspca_dev->cam.nmodes) || modeD >= 0) {
1012 		if (--modeD >= 0) {
1013 			if (gspca_dev->cam.cam_mode[modeD].pixelformat
1014 								== pixfmt)
1015 				return modeD;
1016 		}
1017 		if (++modeU < gspca_dev->cam.nmodes) {
1018 			if (gspca_dev->cam.cam_mode[modeU].pixelformat
1019 								== pixfmt)
1020 				return modeU;
1021 		}
1022 	}
1023 	return -EINVAL;
1024 }
1025 
1026 #ifdef CONFIG_VIDEO_ADV_DEBUG
1027 static int vidioc_g_chip_info(struct file *file, void *priv,
1028 				struct v4l2_dbg_chip_info *chip)
1029 {
1030 	struct gspca_dev *gspca_dev = video_drvdata(file);
1031 
1032 	gspca_dev->usb_err = 0;
1033 	if (gspca_dev->sd_desc->get_chip_info)
1034 		return gspca_dev->sd_desc->get_chip_info(gspca_dev, chip);
1035 	return chip->match.addr ? -EINVAL : 0;
1036 }
1037 
1038 static int vidioc_g_register(struct file *file, void *priv,
1039 		struct v4l2_dbg_register *reg)
1040 {
1041 	struct gspca_dev *gspca_dev = video_drvdata(file);
1042 
1043 	gspca_dev->usb_err = 0;
1044 	return gspca_dev->sd_desc->get_register(gspca_dev, reg);
1045 }
1046 
1047 static int vidioc_s_register(struct file *file, void *priv,
1048 		const struct v4l2_dbg_register *reg)
1049 {
1050 	struct gspca_dev *gspca_dev = video_drvdata(file);
1051 
1052 	gspca_dev->usb_err = 0;
1053 	return gspca_dev->sd_desc->set_register(gspca_dev, reg);
1054 }
1055 #endif
1056 
1057 static int vidioc_enum_fmt_vid_cap(struct file *file, void  *priv,
1058 				struct v4l2_fmtdesc *fmtdesc)
1059 {
1060 	struct gspca_dev *gspca_dev = video_drvdata(file);
1061 	int i, j, index;
1062 	__u32 fmt_tb[8];
1063 
1064 	/* give an index to each format */
1065 	index = 0;
1066 	j = 0;
1067 	for (i = gspca_dev->cam.nmodes; --i >= 0; ) {
1068 		fmt_tb[index] = gspca_dev->cam.cam_mode[i].pixelformat;
1069 		j = 0;
1070 		for (;;) {
1071 			if (fmt_tb[j] == fmt_tb[index])
1072 				break;
1073 			j++;
1074 		}
1075 		if (j == index) {
1076 			if (fmtdesc->index == index)
1077 				break;		/* new format */
1078 			index++;
1079 			if (index >= ARRAY_SIZE(fmt_tb))
1080 				return -EINVAL;
1081 		}
1082 	}
1083 	if (i < 0)
1084 		return -EINVAL;		/* no more format */
1085 
1086 	fmtdesc->pixelformat = fmt_tb[index];
1087 	if (gspca_dev->cam.cam_mode[i].sizeimage <
1088 			gspca_dev->cam.cam_mode[i].width *
1089 				gspca_dev->cam.cam_mode[i].height)
1090 		fmtdesc->flags = V4L2_FMT_FLAG_COMPRESSED;
1091 	fmtdesc->description[0] = fmtdesc->pixelformat & 0xff;
1092 	fmtdesc->description[1] = (fmtdesc->pixelformat >> 8) & 0xff;
1093 	fmtdesc->description[2] = (fmtdesc->pixelformat >> 16) & 0xff;
1094 	fmtdesc->description[3] = fmtdesc->pixelformat >> 24;
1095 	fmtdesc->description[4] = '\0';
1096 	return 0;
1097 }
1098 
1099 static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
1100 			    struct v4l2_format *fmt)
1101 {
1102 	struct gspca_dev *gspca_dev = video_drvdata(file);
1103 
1104 	fmt->fmt.pix = gspca_dev->pixfmt;
1105 	/* some drivers use priv internally, zero it before giving it to
1106 	   userspace */
1107 	fmt->fmt.pix.priv = 0;
1108 	return 0;
1109 }
1110 
1111 static int try_fmt_vid_cap(struct gspca_dev *gspca_dev,
1112 			struct v4l2_format *fmt)
1113 {
1114 	int w, h, mode, mode2;
1115 
1116 	w = fmt->fmt.pix.width;
1117 	h = fmt->fmt.pix.height;
1118 
1119 	PDEBUG_MODE(gspca_dev, D_CONF, "try fmt cap",
1120 		    fmt->fmt.pix.pixelformat, w, h);
1121 
1122 	/* search the closest mode for width and height */
1123 	mode = wxh_to_mode(gspca_dev, w, h);
1124 
1125 	/* OK if right palette */
1126 	if (gspca_dev->cam.cam_mode[mode].pixelformat
1127 						!= fmt->fmt.pix.pixelformat) {
1128 
1129 		/* else, search the closest mode with the same pixel format */
1130 		mode2 = gspca_get_mode(gspca_dev, mode,
1131 					fmt->fmt.pix.pixelformat);
1132 		if (mode2 >= 0)
1133 			mode = mode2;
1134 	}
1135 	fmt->fmt.pix = gspca_dev->cam.cam_mode[mode];
1136 	if (gspca_dev->sd_desc->try_fmt) {
1137 		/* pass original resolution to subdriver try_fmt */
1138 		fmt->fmt.pix.width = w;
1139 		fmt->fmt.pix.height = h;
1140 		gspca_dev->sd_desc->try_fmt(gspca_dev, fmt);
1141 	}
1142 	/* some drivers use priv internally, zero it before giving it to
1143 	   userspace */
1144 	fmt->fmt.pix.priv = 0;
1145 	return mode;			/* used when s_fmt */
1146 }
1147 
1148 static int vidioc_try_fmt_vid_cap(struct file *file,
1149 			      void *priv,
1150 			      struct v4l2_format *fmt)
1151 {
1152 	struct gspca_dev *gspca_dev = video_drvdata(file);
1153 	int ret;
1154 
1155 	ret = try_fmt_vid_cap(gspca_dev, fmt);
1156 	if (ret < 0)
1157 		return ret;
1158 	return 0;
1159 }
1160 
1161 static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
1162 			    struct v4l2_format *fmt)
1163 {
1164 	struct gspca_dev *gspca_dev = video_drvdata(file);
1165 	int ret;
1166 
1167 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1168 		return -ERESTARTSYS;
1169 
1170 	ret = try_fmt_vid_cap(gspca_dev, fmt);
1171 	if (ret < 0)
1172 		goto out;
1173 
1174 	if (gspca_dev->nframes != 0
1175 	    && fmt->fmt.pix.sizeimage > gspca_dev->frsz) {
1176 		ret = -EINVAL;
1177 		goto out;
1178 	}
1179 
1180 	if (gspca_dev->streaming) {
1181 		ret = -EBUSY;
1182 		goto out;
1183 	}
1184 	gspca_dev->curr_mode = ret;
1185 	if (gspca_dev->sd_desc->try_fmt)
1186 		/* subdriver try_fmt can modify format parameters */
1187 		gspca_dev->pixfmt = fmt->fmt.pix;
1188 	else
1189 		gspca_dev->pixfmt = gspca_dev->cam.cam_mode[ret];
1190 
1191 	ret = 0;
1192 out:
1193 	mutex_unlock(&gspca_dev->queue_lock);
1194 	return ret;
1195 }
1196 
1197 static int vidioc_enum_framesizes(struct file *file, void *priv,
1198 				  struct v4l2_frmsizeenum *fsize)
1199 {
1200 	struct gspca_dev *gspca_dev = video_drvdata(file);
1201 	int i;
1202 	__u32 index = 0;
1203 
1204 	if (gspca_dev->sd_desc->enum_framesizes)
1205 		return gspca_dev->sd_desc->enum_framesizes(gspca_dev, fsize);
1206 
1207 	for (i = 0; i < gspca_dev->cam.nmodes; i++) {
1208 		if (fsize->pixel_format !=
1209 				gspca_dev->cam.cam_mode[i].pixelformat)
1210 			continue;
1211 
1212 		if (fsize->index == index) {
1213 			fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1214 			fsize->discrete.width =
1215 				gspca_dev->cam.cam_mode[i].width;
1216 			fsize->discrete.height =
1217 				gspca_dev->cam.cam_mode[i].height;
1218 			return 0;
1219 		}
1220 		index++;
1221 	}
1222 
1223 	return -EINVAL;
1224 }
1225 
1226 static int vidioc_enum_frameintervals(struct file *filp, void *priv,
1227 				      struct v4l2_frmivalenum *fival)
1228 {
1229 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1230 	int mode = wxh_to_mode(gspca_dev, fival->width, fival->height);
1231 	__u32 i;
1232 
1233 	if (gspca_dev->cam.mode_framerates == NULL ||
1234 			gspca_dev->cam.mode_framerates[mode].nrates == 0)
1235 		return -EINVAL;
1236 
1237 	if (fival->pixel_format !=
1238 			gspca_dev->cam.cam_mode[mode].pixelformat)
1239 		return -EINVAL;
1240 
1241 	for (i = 0; i < gspca_dev->cam.mode_framerates[mode].nrates; i++) {
1242 		if (fival->index == i) {
1243 			fival->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1244 			fival->discrete.numerator = 1;
1245 			fival->discrete.denominator =
1246 				gspca_dev->cam.mode_framerates[mode].rates[i];
1247 			return 0;
1248 		}
1249 	}
1250 
1251 	return -EINVAL;
1252 }
1253 
1254 static void gspca_release(struct v4l2_device *v4l2_device)
1255 {
1256 	struct gspca_dev *gspca_dev =
1257 		container_of(v4l2_device, struct gspca_dev, v4l2_dev);
1258 
1259 	v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
1260 	v4l2_device_unregister(&gspca_dev->v4l2_dev);
1261 	kfree(gspca_dev->usb_buf);
1262 	kfree(gspca_dev);
1263 }
1264 
1265 static int dev_open(struct file *file)
1266 {
1267 	struct gspca_dev *gspca_dev = video_drvdata(file);
1268 	int ret;
1269 
1270 	PDEBUG(D_STREAM, "[%s] open", current->comm);
1271 
1272 	/* protect the subdriver against rmmod */
1273 	if (!try_module_get(gspca_dev->module))
1274 		return -ENODEV;
1275 
1276 	ret = v4l2_fh_open(file);
1277 	if (ret)
1278 		module_put(gspca_dev->module);
1279 	return ret;
1280 }
1281 
1282 static int dev_close(struct file *file)
1283 {
1284 	struct gspca_dev *gspca_dev = video_drvdata(file);
1285 
1286 	PDEBUG(D_STREAM, "[%s] close", current->comm);
1287 
1288 	/* Needed for gspca_stream_off, always lock before queue_lock! */
1289 	if (mutex_lock_interruptible(&gspca_dev->usb_lock))
1290 		return -ERESTARTSYS;
1291 
1292 	if (mutex_lock_interruptible(&gspca_dev->queue_lock)) {
1293 		mutex_unlock(&gspca_dev->usb_lock);
1294 		return -ERESTARTSYS;
1295 	}
1296 
1297 	/* if the file did the capture, free the streaming resources */
1298 	if (gspca_dev->capt_file == file) {
1299 		if (gspca_dev->streaming)
1300 			gspca_stream_off(gspca_dev);
1301 		frame_free(gspca_dev);
1302 	}
1303 	module_put(gspca_dev->module);
1304 	mutex_unlock(&gspca_dev->queue_lock);
1305 	mutex_unlock(&gspca_dev->usb_lock);
1306 
1307 	PDEBUG(D_STREAM, "close done");
1308 
1309 	return v4l2_fh_release(file);
1310 }
1311 
1312 static int vidioc_querycap(struct file *file, void  *priv,
1313 			   struct v4l2_capability *cap)
1314 {
1315 	struct gspca_dev *gspca_dev = video_drvdata(file);
1316 
1317 	strlcpy((char *) cap->driver, gspca_dev->sd_desc->name,
1318 			sizeof cap->driver);
1319 	if (gspca_dev->dev->product != NULL) {
1320 		strlcpy((char *) cap->card, gspca_dev->dev->product,
1321 			sizeof cap->card);
1322 	} else {
1323 		snprintf((char *) cap->card, sizeof cap->card,
1324 			"USB Camera (%04x:%04x)",
1325 			le16_to_cpu(gspca_dev->dev->descriptor.idVendor),
1326 			le16_to_cpu(gspca_dev->dev->descriptor.idProduct));
1327 	}
1328 	usb_make_path(gspca_dev->dev, (char *) cap->bus_info,
1329 			sizeof(cap->bus_info));
1330 	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE
1331 			  | V4L2_CAP_STREAMING
1332 			  | V4L2_CAP_READWRITE;
1333 	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
1334 	return 0;
1335 }
1336 
1337 static int vidioc_enum_input(struct file *file, void *priv,
1338 				struct v4l2_input *input)
1339 {
1340 	struct gspca_dev *gspca_dev = video_drvdata(file);
1341 
1342 	if (input->index != 0)
1343 		return -EINVAL;
1344 	input->type = V4L2_INPUT_TYPE_CAMERA;
1345 	input->status = gspca_dev->cam.input_flags;
1346 	strlcpy(input->name, gspca_dev->sd_desc->name,
1347 		sizeof input->name);
1348 	return 0;
1349 }
1350 
1351 static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
1352 {
1353 	*i = 0;
1354 	return 0;
1355 }
1356 
1357 static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
1358 {
1359 	if (i > 0)
1360 		return -EINVAL;
1361 	return (0);
1362 }
1363 
1364 static int vidioc_reqbufs(struct file *file, void *priv,
1365 			  struct v4l2_requestbuffers *rb)
1366 {
1367 	struct gspca_dev *gspca_dev = video_drvdata(file);
1368 	int i, ret = 0, streaming;
1369 
1370 	i = rb->memory;			/* (avoid compilation warning) */
1371 	switch (i) {
1372 	case GSPCA_MEMORY_READ:			/* (internal call) */
1373 	case V4L2_MEMORY_MMAP:
1374 	case V4L2_MEMORY_USERPTR:
1375 		break;
1376 	default:
1377 		return -EINVAL;
1378 	}
1379 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1380 		return -ERESTARTSYS;
1381 
1382 	if (gspca_dev->memory != GSPCA_MEMORY_NO
1383 	    && gspca_dev->memory != GSPCA_MEMORY_READ
1384 	    && gspca_dev->memory != rb->memory) {
1385 		ret = -EBUSY;
1386 		goto out;
1387 	}
1388 
1389 	/* only one file may do the capture */
1390 	if (gspca_dev->capt_file != NULL
1391 	    && gspca_dev->capt_file != file) {
1392 		ret = -EBUSY;
1393 		goto out;
1394 	}
1395 
1396 	/* if allocated, the buffers must not be mapped */
1397 	for (i = 0; i < gspca_dev->nframes; i++) {
1398 		if (gspca_dev->frame[i].vma_use_count) {
1399 			ret = -EBUSY;
1400 			goto out;
1401 		}
1402 	}
1403 
1404 	/* stop streaming */
1405 	streaming = gspca_dev->streaming;
1406 	if (streaming) {
1407 		gspca_stream_off(gspca_dev);
1408 
1409 		/* Don't restart the stream when switching from read
1410 		 * to mmap mode */
1411 		if (gspca_dev->memory == GSPCA_MEMORY_READ)
1412 			streaming = 0;
1413 	}
1414 
1415 	/* free the previous allocated buffers, if any */
1416 	if (gspca_dev->nframes != 0)
1417 		frame_free(gspca_dev);
1418 	if (rb->count == 0)			/* unrequest */
1419 		goto out;
1420 	ret = frame_alloc(gspca_dev, file, rb->memory, rb->count);
1421 	if (ret == 0) {
1422 		rb->count = gspca_dev->nframes;
1423 		if (streaming)
1424 			ret = gspca_init_transfer(gspca_dev);
1425 	}
1426 out:
1427 	mutex_unlock(&gspca_dev->queue_lock);
1428 	PDEBUG(D_STREAM, "reqbufs st:%d c:%d", ret, rb->count);
1429 	return ret;
1430 }
1431 
1432 static int vidioc_querybuf(struct file *file, void *priv,
1433 			   struct v4l2_buffer *v4l2_buf)
1434 {
1435 	struct gspca_dev *gspca_dev = video_drvdata(file);
1436 	struct gspca_frame *frame;
1437 
1438 	if (v4l2_buf->index >= gspca_dev->nframes)
1439 		return -EINVAL;
1440 
1441 	frame = &gspca_dev->frame[v4l2_buf->index];
1442 	memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
1443 	return 0;
1444 }
1445 
1446 static int vidioc_streamon(struct file *file, void *priv,
1447 			   enum v4l2_buf_type buf_type)
1448 {
1449 	struct gspca_dev *gspca_dev = video_drvdata(file);
1450 	int ret;
1451 
1452 	if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1453 		return -EINVAL;
1454 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1455 		return -ERESTARTSYS;
1456 
1457 	/* check the capture file */
1458 	if (gspca_dev->capt_file != file) {
1459 		ret = -EBUSY;
1460 		goto out;
1461 	}
1462 
1463 	if (gspca_dev->nframes == 0
1464 	    || !(gspca_dev->frame[0].v4l2_buf.flags & V4L2_BUF_FLAG_QUEUED)) {
1465 		ret = -EINVAL;
1466 		goto out;
1467 	}
1468 	if (!gspca_dev->streaming) {
1469 		ret = gspca_init_transfer(gspca_dev);
1470 		if (ret < 0)
1471 			goto out;
1472 	}
1473 	PDEBUG_MODE(gspca_dev, D_STREAM, "stream on OK",
1474 		    gspca_dev->pixfmt.pixelformat,
1475 		    gspca_dev->pixfmt.width, gspca_dev->pixfmt.height);
1476 	ret = 0;
1477 out:
1478 	mutex_unlock(&gspca_dev->queue_lock);
1479 	return ret;
1480 }
1481 
1482 static int vidioc_streamoff(struct file *file, void *priv,
1483 				enum v4l2_buf_type buf_type)
1484 {
1485 	struct gspca_dev *gspca_dev = video_drvdata(file);
1486 	int i, ret;
1487 
1488 	if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1489 		return -EINVAL;
1490 
1491 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1492 		return -ERESTARTSYS;
1493 
1494 	if (!gspca_dev->streaming) {
1495 		ret = 0;
1496 		goto out;
1497 	}
1498 
1499 	/* check the capture file */
1500 	if (gspca_dev->capt_file != file) {
1501 		ret = -EBUSY;
1502 		goto out;
1503 	}
1504 
1505 	/* stop streaming */
1506 	gspca_stream_off(gspca_dev);
1507 	/* In case another thread is waiting in dqbuf */
1508 	wake_up_interruptible(&gspca_dev->wq);
1509 
1510 	/* empty the transfer queues */
1511 	for (i = 0; i < gspca_dev->nframes; i++)
1512 		gspca_dev->frame[i].v4l2_buf.flags &= ~BUF_ALL_FLAGS;
1513 	atomic_set(&gspca_dev->fr_q, 0);
1514 	atomic_set(&gspca_dev->fr_i, 0);
1515 	gspca_dev->fr_o = 0;
1516 	ret = 0;
1517 out:
1518 	mutex_unlock(&gspca_dev->queue_lock);
1519 	return ret;
1520 }
1521 
1522 static int vidioc_g_jpegcomp(struct file *file, void *priv,
1523 			struct v4l2_jpegcompression *jpegcomp)
1524 {
1525 	struct gspca_dev *gspca_dev = video_drvdata(file);
1526 
1527 	gspca_dev->usb_err = 0;
1528 	return gspca_dev->sd_desc->get_jcomp(gspca_dev, jpegcomp);
1529 }
1530 
1531 static int vidioc_s_jpegcomp(struct file *file, void *priv,
1532 			const struct v4l2_jpegcompression *jpegcomp)
1533 {
1534 	struct gspca_dev *gspca_dev = video_drvdata(file);
1535 
1536 	gspca_dev->usb_err = 0;
1537 	return gspca_dev->sd_desc->set_jcomp(gspca_dev, jpegcomp);
1538 }
1539 
1540 static int vidioc_g_parm(struct file *filp, void *priv,
1541 			struct v4l2_streamparm *parm)
1542 {
1543 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1544 
1545 	parm->parm.capture.readbuffers = gspca_dev->nbufread;
1546 
1547 	if (gspca_dev->sd_desc->get_streamparm) {
1548 		gspca_dev->usb_err = 0;
1549 		gspca_dev->sd_desc->get_streamparm(gspca_dev, parm);
1550 		return gspca_dev->usb_err;
1551 	}
1552 	return 0;
1553 }
1554 
1555 static int vidioc_s_parm(struct file *filp, void *priv,
1556 			struct v4l2_streamparm *parm)
1557 {
1558 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1559 	int n;
1560 
1561 	n = parm->parm.capture.readbuffers;
1562 	if (n == 0 || n >= GSPCA_MAX_FRAMES)
1563 		parm->parm.capture.readbuffers = gspca_dev->nbufread;
1564 	else
1565 		gspca_dev->nbufread = n;
1566 
1567 	if (gspca_dev->sd_desc->set_streamparm) {
1568 		gspca_dev->usb_err = 0;
1569 		gspca_dev->sd_desc->set_streamparm(gspca_dev, parm);
1570 		return gspca_dev->usb_err;
1571 	}
1572 
1573 	return 0;
1574 }
1575 
1576 static int dev_mmap(struct file *file, struct vm_area_struct *vma)
1577 {
1578 	struct gspca_dev *gspca_dev = video_drvdata(file);
1579 	struct gspca_frame *frame;
1580 	struct page *page;
1581 	unsigned long addr, start, size;
1582 	int i, ret;
1583 
1584 	start = vma->vm_start;
1585 	size = vma->vm_end - vma->vm_start;
1586 	PDEBUG(D_STREAM, "mmap start:%08x size:%d", (int) start, (int) size);
1587 
1588 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1589 		return -ERESTARTSYS;
1590 	if (gspca_dev->capt_file != file) {
1591 		ret = -EINVAL;
1592 		goto out;
1593 	}
1594 
1595 	frame = NULL;
1596 	for (i = 0; i < gspca_dev->nframes; ++i) {
1597 		if (gspca_dev->frame[i].v4l2_buf.memory != V4L2_MEMORY_MMAP) {
1598 			PDEBUG(D_STREAM, "mmap bad memory type");
1599 			break;
1600 		}
1601 		if ((gspca_dev->frame[i].v4l2_buf.m.offset >> PAGE_SHIFT)
1602 						== vma->vm_pgoff) {
1603 			frame = &gspca_dev->frame[i];
1604 			break;
1605 		}
1606 	}
1607 	if (frame == NULL) {
1608 		PDEBUG(D_STREAM, "mmap no frame buffer found");
1609 		ret = -EINVAL;
1610 		goto out;
1611 	}
1612 	if (size != frame->v4l2_buf.length) {
1613 		PDEBUG(D_STREAM, "mmap bad size");
1614 		ret = -EINVAL;
1615 		goto out;
1616 	}
1617 
1618 	/*
1619 	 * - VM_IO marks the area as being a mmaped region for I/O to a
1620 	 *   device. It also prevents the region from being core dumped.
1621 	 */
1622 	vma->vm_flags |= VM_IO;
1623 
1624 	addr = (unsigned long) frame->data;
1625 	while (size > 0) {
1626 		page = vmalloc_to_page((void *) addr);
1627 		ret = vm_insert_page(vma, start, page);
1628 		if (ret < 0)
1629 			goto out;
1630 		start += PAGE_SIZE;
1631 		addr += PAGE_SIZE;
1632 		size -= PAGE_SIZE;
1633 	}
1634 
1635 	vma->vm_ops = &gspca_vm_ops;
1636 	vma->vm_private_data = frame;
1637 	gspca_vm_open(vma);
1638 	ret = 0;
1639 out:
1640 	mutex_unlock(&gspca_dev->queue_lock);
1641 	return ret;
1642 }
1643 
1644 static int frame_ready_nolock(struct gspca_dev *gspca_dev, struct file *file,
1645 				enum v4l2_memory memory)
1646 {
1647 	if (!gspca_dev->present)
1648 		return -ENODEV;
1649 	if (gspca_dev->capt_file != file || gspca_dev->memory != memory ||
1650 			!gspca_dev->streaming)
1651 		return -EINVAL;
1652 
1653 	/* check if a frame is ready */
1654 	return gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i);
1655 }
1656 
1657 static int frame_ready(struct gspca_dev *gspca_dev, struct file *file,
1658 			enum v4l2_memory memory)
1659 {
1660 	int ret;
1661 
1662 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1663 		return -ERESTARTSYS;
1664 	ret = frame_ready_nolock(gspca_dev, file, memory);
1665 	mutex_unlock(&gspca_dev->queue_lock);
1666 	return ret;
1667 }
1668 
1669 /*
1670  * dequeue a video buffer
1671  *
1672  * If nonblock_ing is false, block until a buffer is available.
1673  */
1674 static int vidioc_dqbuf(struct file *file, void *priv,
1675 			struct v4l2_buffer *v4l2_buf)
1676 {
1677 	struct gspca_dev *gspca_dev = video_drvdata(file);
1678 	struct gspca_frame *frame;
1679 	int i, j, ret;
1680 
1681 	PDEBUG(D_FRAM, "dqbuf");
1682 
1683 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1684 		return -ERESTARTSYS;
1685 
1686 	for (;;) {
1687 		ret = frame_ready_nolock(gspca_dev, file, v4l2_buf->memory);
1688 		if (ret < 0)
1689 			goto out;
1690 		if (ret > 0)
1691 			break;
1692 
1693 		mutex_unlock(&gspca_dev->queue_lock);
1694 
1695 		if (file->f_flags & O_NONBLOCK)
1696 			return -EAGAIN;
1697 
1698 		/* wait till a frame is ready */
1699 		ret = wait_event_interruptible_timeout(gspca_dev->wq,
1700 			frame_ready(gspca_dev, file, v4l2_buf->memory),
1701 			msecs_to_jiffies(3000));
1702 		if (ret < 0)
1703 			return ret;
1704 		if (ret == 0)
1705 			return -EIO;
1706 
1707 		if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1708 			return -ERESTARTSYS;
1709 	}
1710 
1711 	i = gspca_dev->fr_o;
1712 	j = gspca_dev->fr_queue[i];
1713 	frame = &gspca_dev->frame[j];
1714 
1715 	gspca_dev->fr_o = (i + 1) % GSPCA_MAX_FRAMES;
1716 
1717 	frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_DONE;
1718 	memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
1719 	PDEBUG(D_FRAM, "dqbuf %d", j);
1720 	ret = 0;
1721 
1722 	if (gspca_dev->memory == V4L2_MEMORY_USERPTR) {
1723 		if (copy_to_user((__u8 __user *) frame->v4l2_buf.m.userptr,
1724 				 frame->data,
1725 				 frame->v4l2_buf.bytesused)) {
1726 			PERR("dqbuf cp to user failed");
1727 			ret = -EFAULT;
1728 		}
1729 	}
1730 out:
1731 	mutex_unlock(&gspca_dev->queue_lock);
1732 
1733 	if (ret == 0 && gspca_dev->sd_desc->dq_callback) {
1734 		mutex_lock(&gspca_dev->usb_lock);
1735 		gspca_dev->usb_err = 0;
1736 		if (gspca_dev->present)
1737 			gspca_dev->sd_desc->dq_callback(gspca_dev);
1738 		mutex_unlock(&gspca_dev->usb_lock);
1739 	}
1740 
1741 	return ret;
1742 }
1743 
1744 /*
1745  * queue a video buffer
1746  *
1747  * Attempting to queue a buffer that has already been
1748  * queued will return -EINVAL.
1749  */
1750 static int vidioc_qbuf(struct file *file, void *priv,
1751 			struct v4l2_buffer *v4l2_buf)
1752 {
1753 	struct gspca_dev *gspca_dev = video_drvdata(file);
1754 	struct gspca_frame *frame;
1755 	int i, index, ret;
1756 
1757 	PDEBUG(D_FRAM, "qbuf %d", v4l2_buf->index);
1758 
1759 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1760 		return -ERESTARTSYS;
1761 
1762 	index = v4l2_buf->index;
1763 	if ((unsigned) index >= gspca_dev->nframes) {
1764 		PDEBUG(D_FRAM,
1765 			"qbuf idx %d >= %d", index, gspca_dev->nframes);
1766 		ret = -EINVAL;
1767 		goto out;
1768 	}
1769 	if (v4l2_buf->memory != gspca_dev->memory) {
1770 		PDEBUG(D_FRAM, "qbuf bad memory type");
1771 		ret = -EINVAL;
1772 		goto out;
1773 	}
1774 
1775 	frame = &gspca_dev->frame[index];
1776 	if (frame->v4l2_buf.flags & BUF_ALL_FLAGS) {
1777 		PDEBUG(D_FRAM, "qbuf bad state");
1778 		ret = -EINVAL;
1779 		goto out;
1780 	}
1781 
1782 	frame->v4l2_buf.flags |= V4L2_BUF_FLAG_QUEUED;
1783 
1784 	if (frame->v4l2_buf.memory == V4L2_MEMORY_USERPTR) {
1785 		frame->v4l2_buf.m.userptr = v4l2_buf->m.userptr;
1786 		frame->v4l2_buf.length = v4l2_buf->length;
1787 	}
1788 
1789 	/* put the buffer in the 'queued' queue */
1790 	i = atomic_read(&gspca_dev->fr_q);
1791 	gspca_dev->fr_queue[i] = index;
1792 	atomic_set(&gspca_dev->fr_q, (i + 1) % GSPCA_MAX_FRAMES);
1793 
1794 	v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
1795 	v4l2_buf->flags &= ~V4L2_BUF_FLAG_DONE;
1796 	ret = 0;
1797 out:
1798 	mutex_unlock(&gspca_dev->queue_lock);
1799 	return ret;
1800 }
1801 
1802 /*
1803  * allocate the resources for read()
1804  */
1805 static int read_alloc(struct gspca_dev *gspca_dev,
1806 			struct file *file)
1807 {
1808 	struct v4l2_buffer v4l2_buf;
1809 	int i, ret;
1810 
1811 	PDEBUG(D_STREAM, "read alloc");
1812 
1813 	if (mutex_lock_interruptible(&gspca_dev->usb_lock))
1814 		return -ERESTARTSYS;
1815 
1816 	if (gspca_dev->nframes == 0) {
1817 		struct v4l2_requestbuffers rb;
1818 
1819 		memset(&rb, 0, sizeof rb);
1820 		rb.count = gspca_dev->nbufread;
1821 		rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1822 		rb.memory = GSPCA_MEMORY_READ;
1823 		ret = vidioc_reqbufs(file, gspca_dev, &rb);
1824 		if (ret != 0) {
1825 			PDEBUG(D_STREAM, "read reqbuf err %d", ret);
1826 			goto out;
1827 		}
1828 		memset(&v4l2_buf, 0, sizeof v4l2_buf);
1829 		v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1830 		v4l2_buf.memory = GSPCA_MEMORY_READ;
1831 		for (i = 0; i < gspca_dev->nbufread; i++) {
1832 			v4l2_buf.index = i;
1833 			ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1834 			if (ret != 0) {
1835 				PDEBUG(D_STREAM, "read qbuf err: %d", ret);
1836 				goto out;
1837 			}
1838 		}
1839 	}
1840 
1841 	/* start streaming */
1842 	ret = vidioc_streamon(file, gspca_dev, V4L2_BUF_TYPE_VIDEO_CAPTURE);
1843 	if (ret != 0)
1844 		PDEBUG(D_STREAM, "read streamon err %d", ret);
1845 out:
1846 	mutex_unlock(&gspca_dev->usb_lock);
1847 	return ret;
1848 }
1849 
1850 static unsigned int dev_poll(struct file *file, poll_table *wait)
1851 {
1852 	struct gspca_dev *gspca_dev = video_drvdata(file);
1853 	unsigned long req_events = poll_requested_events(wait);
1854 	int ret = 0;
1855 
1856 	PDEBUG(D_FRAM, "poll");
1857 
1858 	if (req_events & POLLPRI)
1859 		ret |= v4l2_ctrl_poll(file, wait);
1860 
1861 	if (req_events & (POLLIN | POLLRDNORM)) {
1862 		/* if reqbufs is not done, the user would use read() */
1863 		if (gspca_dev->memory == GSPCA_MEMORY_NO) {
1864 			if (read_alloc(gspca_dev, file) != 0) {
1865 				ret |= POLLERR;
1866 				goto out;
1867 			}
1868 		}
1869 
1870 		poll_wait(file, &gspca_dev->wq, wait);
1871 
1872 		/* check if an image has been received */
1873 		if (mutex_lock_interruptible(&gspca_dev->queue_lock) != 0) {
1874 			ret |= POLLERR;
1875 			goto out;
1876 		}
1877 		if (gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i))
1878 			ret |= POLLIN | POLLRDNORM;
1879 		mutex_unlock(&gspca_dev->queue_lock);
1880 	}
1881 
1882 out:
1883 	if (!gspca_dev->present)
1884 		ret |= POLLHUP;
1885 
1886 	return ret;
1887 }
1888 
1889 static ssize_t dev_read(struct file *file, char __user *data,
1890 		    size_t count, loff_t *ppos)
1891 {
1892 	struct gspca_dev *gspca_dev = video_drvdata(file);
1893 	struct gspca_frame *frame;
1894 	struct v4l2_buffer v4l2_buf;
1895 	struct timeval timestamp;
1896 	int n, ret, ret2;
1897 
1898 	PDEBUG(D_FRAM, "read (%zd)", count);
1899 	if (gspca_dev->memory == GSPCA_MEMORY_NO) { /* first time ? */
1900 		ret = read_alloc(gspca_dev, file);
1901 		if (ret != 0)
1902 			return ret;
1903 	}
1904 
1905 	/* get a frame */
1906 	timestamp = ktime_to_timeval(ktime_get());
1907 	timestamp.tv_sec--;
1908 	n = 2;
1909 	for (;;) {
1910 		memset(&v4l2_buf, 0, sizeof v4l2_buf);
1911 		v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1912 		v4l2_buf.memory = GSPCA_MEMORY_READ;
1913 		ret = vidioc_dqbuf(file, gspca_dev, &v4l2_buf);
1914 		if (ret != 0) {
1915 			PDEBUG(D_STREAM, "read dqbuf err %d", ret);
1916 			return ret;
1917 		}
1918 
1919 		/* if the process slept for more than 1 second,
1920 		 * get a newer frame */
1921 		frame = &gspca_dev->frame[v4l2_buf.index];
1922 		if (--n < 0)
1923 			break;			/* avoid infinite loop */
1924 		if (frame->v4l2_buf.timestamp.tv_sec >= timestamp.tv_sec)
1925 			break;
1926 		ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1927 		if (ret != 0) {
1928 			PDEBUG(D_STREAM, "read qbuf err %d", ret);
1929 			return ret;
1930 		}
1931 	}
1932 
1933 	/* copy the frame */
1934 	if (count > frame->v4l2_buf.bytesused)
1935 		count = frame->v4l2_buf.bytesused;
1936 	ret = copy_to_user(data, frame->data, count);
1937 	if (ret != 0) {
1938 		PERR("read cp to user lack %d / %zd", ret, count);
1939 		ret = -EFAULT;
1940 		goto out;
1941 	}
1942 	ret = count;
1943 out:
1944 	/* in each case, requeue the buffer */
1945 	ret2 = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1946 	if (ret2 != 0)
1947 		return ret2;
1948 	return ret;
1949 }
1950 
1951 static struct v4l2_file_operations dev_fops = {
1952 	.owner = THIS_MODULE,
1953 	.open = dev_open,
1954 	.release = dev_close,
1955 	.read = dev_read,
1956 	.mmap = dev_mmap,
1957 	.unlocked_ioctl = video_ioctl2,
1958 	.poll	= dev_poll,
1959 };
1960 
1961 static const struct v4l2_ioctl_ops dev_ioctl_ops = {
1962 	.vidioc_querycap	= vidioc_querycap,
1963 	.vidioc_dqbuf		= vidioc_dqbuf,
1964 	.vidioc_qbuf		= vidioc_qbuf,
1965 	.vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
1966 	.vidioc_try_fmt_vid_cap	= vidioc_try_fmt_vid_cap,
1967 	.vidioc_g_fmt_vid_cap	= vidioc_g_fmt_vid_cap,
1968 	.vidioc_s_fmt_vid_cap	= vidioc_s_fmt_vid_cap,
1969 	.vidioc_streamon	= vidioc_streamon,
1970 	.vidioc_enum_input	= vidioc_enum_input,
1971 	.vidioc_g_input		= vidioc_g_input,
1972 	.vidioc_s_input		= vidioc_s_input,
1973 	.vidioc_reqbufs		= vidioc_reqbufs,
1974 	.vidioc_querybuf	= vidioc_querybuf,
1975 	.vidioc_streamoff	= vidioc_streamoff,
1976 	.vidioc_g_jpegcomp	= vidioc_g_jpegcomp,
1977 	.vidioc_s_jpegcomp	= vidioc_s_jpegcomp,
1978 	.vidioc_g_parm		= vidioc_g_parm,
1979 	.vidioc_s_parm		= vidioc_s_parm,
1980 	.vidioc_enum_framesizes = vidioc_enum_framesizes,
1981 	.vidioc_enum_frameintervals = vidioc_enum_frameintervals,
1982 #ifdef CONFIG_VIDEO_ADV_DEBUG
1983 	.vidioc_g_chip_info	= vidioc_g_chip_info,
1984 	.vidioc_g_register	= vidioc_g_register,
1985 	.vidioc_s_register	= vidioc_s_register,
1986 #endif
1987 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
1988 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
1989 };
1990 
1991 static const struct video_device gspca_template = {
1992 	.name = "gspca main driver",
1993 	.fops = &dev_fops,
1994 	.ioctl_ops = &dev_ioctl_ops,
1995 	.release = video_device_release_empty, /* We use v4l2_dev.release */
1996 };
1997 
1998 /*
1999  * probe and create a new gspca device
2000  *
2001  * This function must be called by the sub-driver when it is
2002  * called for probing a new device.
2003  */
2004 int gspca_dev_probe2(struct usb_interface *intf,
2005 		const struct usb_device_id *id,
2006 		const struct sd_desc *sd_desc,
2007 		int dev_size,
2008 		struct module *module)
2009 {
2010 	struct gspca_dev *gspca_dev;
2011 	struct usb_device *dev = interface_to_usbdev(intf);
2012 	int ret;
2013 
2014 	pr_info("%s-" GSPCA_VERSION " probing %04x:%04x\n",
2015 		sd_desc->name, id->idVendor, id->idProduct);
2016 
2017 	/* create the device */
2018 	if (dev_size < sizeof *gspca_dev)
2019 		dev_size = sizeof *gspca_dev;
2020 	gspca_dev = kzalloc(dev_size, GFP_KERNEL);
2021 	if (!gspca_dev) {
2022 		pr_err("couldn't kzalloc gspca struct\n");
2023 		return -ENOMEM;
2024 	}
2025 	gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
2026 	if (!gspca_dev->usb_buf) {
2027 		pr_err("out of memory\n");
2028 		ret = -ENOMEM;
2029 		goto out;
2030 	}
2031 	gspca_dev->dev = dev;
2032 	gspca_dev->iface = intf->cur_altsetting->desc.bInterfaceNumber;
2033 
2034 	/* check if any audio device */
2035 	if (dev->actconfig->desc.bNumInterfaces != 1) {
2036 		int i;
2037 		struct usb_interface *intf2;
2038 
2039 		for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
2040 			intf2 = dev->actconfig->interface[i];
2041 			if (intf2 != NULL
2042 			 && intf2->altsetting != NULL
2043 			 && intf2->altsetting->desc.bInterfaceClass ==
2044 					 USB_CLASS_AUDIO) {
2045 				gspca_dev->audio = 1;
2046 				break;
2047 			}
2048 		}
2049 	}
2050 
2051 	gspca_dev->v4l2_dev.release = gspca_release;
2052 	ret = v4l2_device_register(&intf->dev, &gspca_dev->v4l2_dev);
2053 	if (ret)
2054 		goto out;
2055 	gspca_dev->sd_desc = sd_desc;
2056 	gspca_dev->nbufread = 2;
2057 	gspca_dev->empty_packet = -1;	/* don't check the empty packets */
2058 	gspca_dev->vdev = gspca_template;
2059 	gspca_dev->vdev.v4l2_dev = &gspca_dev->v4l2_dev;
2060 	video_set_drvdata(&gspca_dev->vdev, gspca_dev);
2061 	set_bit(V4L2_FL_USE_FH_PRIO, &gspca_dev->vdev.flags);
2062 	gspca_dev->module = module;
2063 	gspca_dev->present = 1;
2064 
2065 	mutex_init(&gspca_dev->usb_lock);
2066 	gspca_dev->vdev.lock = &gspca_dev->usb_lock;
2067 	mutex_init(&gspca_dev->queue_lock);
2068 	init_waitqueue_head(&gspca_dev->wq);
2069 
2070 	/* configure the subdriver and initialize the USB device */
2071 	ret = sd_desc->config(gspca_dev, id);
2072 	if (ret < 0)
2073 		goto out;
2074 	ret = sd_desc->init(gspca_dev);
2075 	if (ret < 0)
2076 		goto out;
2077 	if (sd_desc->init_controls)
2078 		ret = sd_desc->init_controls(gspca_dev);
2079 	if (ret < 0)
2080 		goto out;
2081 	gspca_set_default_mode(gspca_dev);
2082 
2083 	ret = gspca_input_connect(gspca_dev);
2084 	if (ret)
2085 		goto out;
2086 
2087 	/*
2088 	 * Don't take usb_lock for these ioctls. This improves latency if
2089 	 * usb_lock is taken for a long time, e.g. when changing a control
2090 	 * value, and a new frame is ready to be dequeued.
2091 	 */
2092 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_DQBUF);
2093 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QBUF);
2094 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QUERYBUF);
2095 #ifdef CONFIG_VIDEO_ADV_DEBUG
2096 	if (!gspca_dev->sd_desc->get_register)
2097 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_G_REGISTER);
2098 	if (!gspca_dev->sd_desc->set_register)
2099 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_S_REGISTER);
2100 #endif
2101 	if (!gspca_dev->sd_desc->get_jcomp)
2102 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_G_JPEGCOMP);
2103 	if (!gspca_dev->sd_desc->set_jcomp)
2104 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_S_JPEGCOMP);
2105 
2106 	/* init video stuff */
2107 	ret = video_register_device(&gspca_dev->vdev,
2108 				  VFL_TYPE_GRABBER,
2109 				  -1);
2110 	if (ret < 0) {
2111 		pr_err("video_register_device err %d\n", ret);
2112 		goto out;
2113 	}
2114 
2115 	usb_set_intfdata(intf, gspca_dev);
2116 	PDEBUG(D_PROBE, "%s created", video_device_node_name(&gspca_dev->vdev));
2117 
2118 	gspca_input_create_urb(gspca_dev);
2119 
2120 	return 0;
2121 out:
2122 #if IS_ENABLED(CONFIG_INPUT)
2123 	if (gspca_dev->input_dev)
2124 		input_unregister_device(gspca_dev->input_dev);
2125 #endif
2126 	v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
2127 	kfree(gspca_dev->usb_buf);
2128 	kfree(gspca_dev);
2129 	return ret;
2130 }
2131 EXPORT_SYMBOL(gspca_dev_probe2);
2132 
2133 /* same function as the previous one, but check the interface */
2134 int gspca_dev_probe(struct usb_interface *intf,
2135 		const struct usb_device_id *id,
2136 		const struct sd_desc *sd_desc,
2137 		int dev_size,
2138 		struct module *module)
2139 {
2140 	struct usb_device *dev = interface_to_usbdev(intf);
2141 
2142 	/* we don't handle multi-config cameras */
2143 	if (dev->descriptor.bNumConfigurations != 1) {
2144 		pr_err("%04x:%04x too many config\n",
2145 		       id->idVendor, id->idProduct);
2146 		return -ENODEV;
2147 	}
2148 
2149 	/* the USB video interface must be the first one */
2150 	if (dev->actconfig->desc.bNumInterfaces != 1
2151 	 && intf->cur_altsetting->desc.bInterfaceNumber != 0)
2152 		return -ENODEV;
2153 
2154 	return gspca_dev_probe2(intf, id, sd_desc, dev_size, module);
2155 }
2156 EXPORT_SYMBOL(gspca_dev_probe);
2157 
2158 /*
2159  * USB disconnection
2160  *
2161  * This function must be called by the sub-driver
2162  * when the device disconnects, after the specific resources are freed.
2163  */
2164 void gspca_disconnect(struct usb_interface *intf)
2165 {
2166 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2167 #if IS_ENABLED(CONFIG_INPUT)
2168 	struct input_dev *input_dev;
2169 #endif
2170 
2171 	PDEBUG(D_PROBE, "%s disconnect",
2172 		video_device_node_name(&gspca_dev->vdev));
2173 
2174 	mutex_lock(&gspca_dev->usb_lock);
2175 
2176 	gspca_dev->present = 0;
2177 	destroy_urbs(gspca_dev);
2178 
2179 #if IS_ENABLED(CONFIG_INPUT)
2180 	gspca_input_destroy_urb(gspca_dev);
2181 	input_dev = gspca_dev->input_dev;
2182 	if (input_dev) {
2183 		gspca_dev->input_dev = NULL;
2184 		input_unregister_device(input_dev);
2185 	}
2186 #endif
2187 	/* Free subdriver's streaming resources / stop sd workqueue(s) */
2188 	if (gspca_dev->sd_desc->stop0 && gspca_dev->streaming)
2189 		gspca_dev->sd_desc->stop0(gspca_dev);
2190 	gspca_dev->streaming = 0;
2191 	gspca_dev->dev = NULL;
2192 	wake_up_interruptible(&gspca_dev->wq);
2193 
2194 	v4l2_device_disconnect(&gspca_dev->v4l2_dev);
2195 	video_unregister_device(&gspca_dev->vdev);
2196 
2197 	mutex_unlock(&gspca_dev->usb_lock);
2198 
2199 	/* (this will call gspca_release() immediately or on last close) */
2200 	v4l2_device_put(&gspca_dev->v4l2_dev);
2201 }
2202 EXPORT_SYMBOL(gspca_disconnect);
2203 
2204 #ifdef CONFIG_PM
2205 int gspca_suspend(struct usb_interface *intf, pm_message_t message)
2206 {
2207 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2208 
2209 	gspca_input_destroy_urb(gspca_dev);
2210 
2211 	if (!gspca_dev->streaming)
2212 		return 0;
2213 
2214 	mutex_lock(&gspca_dev->usb_lock);
2215 	gspca_dev->frozen = 1;		/* avoid urb error messages */
2216 	gspca_dev->usb_err = 0;
2217 	if (gspca_dev->sd_desc->stopN)
2218 		gspca_dev->sd_desc->stopN(gspca_dev);
2219 	destroy_urbs(gspca_dev);
2220 	gspca_set_alt0(gspca_dev);
2221 	if (gspca_dev->sd_desc->stop0)
2222 		gspca_dev->sd_desc->stop0(gspca_dev);
2223 	mutex_unlock(&gspca_dev->usb_lock);
2224 
2225 	return 0;
2226 }
2227 EXPORT_SYMBOL(gspca_suspend);
2228 
2229 int gspca_resume(struct usb_interface *intf)
2230 {
2231 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2232 	int streaming, ret = 0;
2233 
2234 	mutex_lock(&gspca_dev->usb_lock);
2235 	gspca_dev->frozen = 0;
2236 	gspca_dev->usb_err = 0;
2237 	gspca_dev->sd_desc->init(gspca_dev);
2238 	/*
2239 	 * Most subdrivers send all ctrl values on sd_start and thus
2240 	 * only write to the device registers on s_ctrl when streaming ->
2241 	 * Clear streaming to avoid setting all ctrls twice.
2242 	 */
2243 	streaming = gspca_dev->streaming;
2244 	gspca_dev->streaming = 0;
2245 	if (streaming)
2246 		ret = gspca_init_transfer(gspca_dev);
2247 	else
2248 		gspca_input_create_urb(gspca_dev);
2249 	mutex_unlock(&gspca_dev->usb_lock);
2250 
2251 	return ret;
2252 }
2253 EXPORT_SYMBOL(gspca_resume);
2254 #endif
2255 
2256 /* -- module insert / remove -- */
2257 static int __init gspca_init(void)
2258 {
2259 	pr_info("v" GSPCA_VERSION " registered\n");
2260 	return 0;
2261 }
2262 static void __exit gspca_exit(void)
2263 {
2264 }
2265 
2266 module_init(gspca_init);
2267 module_exit(gspca_exit);
2268 
2269 module_param_named(debug, gspca_debug, int, 0644);
2270 MODULE_PARM_DESC(debug,
2271 		"1:probe 2:config 3:stream 4:frame 5:packet 6:usbi 7:usbo");
2272