xref: /openbmc/linux/drivers/media/usb/gspca/gspca.c (revision 8730046c)
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, buffer_len=%u, interval=%u",
205 		ep->bEndpointAddress, buffer_len, interval);
206 
207 	dev = gspca_dev->dev;
208 
209 	urb = usb_alloc_urb(0, GFP_KERNEL);
210 	if (!urb) {
211 		ret = -ENOMEM;
212 		goto error;
213 	}
214 
215 	buffer = usb_alloc_coherent(dev, buffer_len,
216 				GFP_KERNEL, &urb->transfer_dma);
217 	if (!buffer) {
218 		ret = -ENOMEM;
219 		goto error_buffer;
220 	}
221 	usb_fill_int_urb(urb, dev,
222 		usb_rcvintpipe(dev, ep->bEndpointAddress),
223 		buffer, buffer_len,
224 		int_irq, (void *)gspca_dev, interval);
225 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
226 	ret = usb_submit_urb(urb, GFP_KERNEL);
227 	if (ret < 0) {
228 		PERR("submit int URB failed with error %i", ret);
229 		goto error_submit;
230 	}
231 	gspca_dev->int_urb = urb;
232 	return ret;
233 
234 error_submit:
235 	usb_free_coherent(dev,
236 			  urb->transfer_buffer_length,
237 			  urb->transfer_buffer,
238 			  urb->transfer_dma);
239 error_buffer:
240 	usb_free_urb(urb);
241 error:
242 	return ret;
243 }
244 
245 static void gspca_input_create_urb(struct gspca_dev *gspca_dev)
246 {
247 	struct usb_interface *intf;
248 	struct usb_host_interface *intf_desc;
249 	struct usb_endpoint_descriptor *ep;
250 	int i;
251 
252 	if (gspca_dev->sd_desc->int_pkt_scan)  {
253 		intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
254 		intf_desc = intf->cur_altsetting;
255 		for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
256 			ep = &intf_desc->endpoint[i].desc;
257 			if (usb_endpoint_dir_in(ep) &&
258 			    usb_endpoint_xfer_int(ep)) {
259 
260 				alloc_and_submit_int_urb(gspca_dev, ep);
261 				break;
262 			}
263 		}
264 	}
265 }
266 
267 static void gspca_input_destroy_urb(struct gspca_dev *gspca_dev)
268 {
269 	struct urb *urb;
270 
271 	urb = gspca_dev->int_urb;
272 	if (urb) {
273 		gspca_dev->int_urb = NULL;
274 		usb_kill_urb(urb);
275 		usb_free_coherent(gspca_dev->dev,
276 				  urb->transfer_buffer_length,
277 				  urb->transfer_buffer,
278 				  urb->transfer_dma);
279 		usb_free_urb(urb);
280 	}
281 }
282 #else
283 static inline void gspca_input_destroy_urb(struct gspca_dev *gspca_dev)
284 {
285 }
286 
287 static inline void gspca_input_create_urb(struct gspca_dev *gspca_dev)
288 {
289 }
290 
291 static inline int gspca_input_connect(struct gspca_dev *dev)
292 {
293 	return 0;
294 }
295 #endif
296 
297 /*
298  * fill a video frame from an URB and resubmit
299  */
300 static void fill_frame(struct gspca_dev *gspca_dev,
301 			struct urb *urb)
302 {
303 	u8 *data;		/* address of data in the iso message */
304 	int i, len, st;
305 	cam_pkt_op pkt_scan;
306 
307 	if (urb->status != 0) {
308 		if (urb->status == -ESHUTDOWN)
309 			return;		/* disconnection */
310 #ifdef CONFIG_PM
311 		if (gspca_dev->frozen)
312 			return;
313 #endif
314 		PERR("urb status: %d", urb->status);
315 		urb->status = 0;
316 		goto resubmit;
317 	}
318 	pkt_scan = gspca_dev->sd_desc->pkt_scan;
319 	for (i = 0; i < urb->number_of_packets; i++) {
320 		len = urb->iso_frame_desc[i].actual_length;
321 
322 		/* check the packet status and length */
323 		st = urb->iso_frame_desc[i].status;
324 		if (st) {
325 			pr_err("ISOC data error: [%d] len=%d, status=%d\n",
326 			       i, len, st);
327 			gspca_dev->last_packet_type = DISCARD_PACKET;
328 			continue;
329 		}
330 		if (len == 0) {
331 			if (gspca_dev->empty_packet == 0)
332 				gspca_dev->empty_packet = 1;
333 			continue;
334 		}
335 
336 		/* let the packet be analyzed by the subdriver */
337 		PDEBUG(D_PACK, "packet [%d] o:%d l:%d",
338 			i, urb->iso_frame_desc[i].offset, len);
339 		data = (u8 *) urb->transfer_buffer
340 					+ urb->iso_frame_desc[i].offset;
341 		pkt_scan(gspca_dev, data, len);
342 	}
343 
344 resubmit:
345 	/* resubmit the URB */
346 	st = usb_submit_urb(urb, GFP_ATOMIC);
347 	if (st < 0)
348 		pr_err("usb_submit_urb() ret %d\n", st);
349 }
350 
351 /*
352  * ISOC message interrupt from the USB device
353  *
354  * Analyse each packet and call the subdriver for copy to the frame buffer.
355  */
356 static void isoc_irq(struct urb *urb)
357 {
358 	struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
359 
360 	PDEBUG(D_PACK, "isoc irq");
361 	if (!gspca_dev->streaming)
362 		return;
363 	fill_frame(gspca_dev, urb);
364 }
365 
366 /*
367  * bulk message interrupt from the USB device
368  */
369 static void bulk_irq(struct urb *urb)
370 {
371 	struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
372 	int st;
373 
374 	PDEBUG(D_PACK, "bulk irq");
375 	if (!gspca_dev->streaming)
376 		return;
377 	switch (urb->status) {
378 	case 0:
379 		break;
380 	case -ESHUTDOWN:
381 		return;		/* disconnection */
382 	default:
383 #ifdef CONFIG_PM
384 		if (gspca_dev->frozen)
385 			return;
386 #endif
387 		PERR("urb status: %d", urb->status);
388 		urb->status = 0;
389 		goto resubmit;
390 	}
391 
392 	PDEBUG(D_PACK, "packet l:%d", urb->actual_length);
393 	gspca_dev->sd_desc->pkt_scan(gspca_dev,
394 				urb->transfer_buffer,
395 				urb->actual_length);
396 
397 resubmit:
398 	/* resubmit the URB */
399 	if (gspca_dev->cam.bulk_nurbs != 0) {
400 		st = usb_submit_urb(urb, GFP_ATOMIC);
401 		if (st < 0)
402 			pr_err("usb_submit_urb() ret %d\n", st);
403 	}
404 }
405 
406 /*
407  * add data to the current frame
408  *
409  * This function is called by the subdrivers at interrupt level.
410  *
411  * To build a frame, these ones must add
412  *	- one FIRST_PACKET
413  *	- 0 or many INTER_PACKETs
414  *	- one LAST_PACKET
415  * DISCARD_PACKET invalidates the whole frame.
416  */
417 void gspca_frame_add(struct gspca_dev *gspca_dev,
418 			enum gspca_packet_type packet_type,
419 			const u8 *data,
420 			int len)
421 {
422 	struct gspca_frame *frame;
423 	int i, j;
424 
425 	PDEBUG(D_PACK, "add t:%d l:%d",	packet_type, len);
426 
427 	if (packet_type == FIRST_PACKET) {
428 		i = atomic_read(&gspca_dev->fr_i);
429 
430 		/* if there are no queued buffer, discard the whole frame */
431 		if (i == atomic_read(&gspca_dev->fr_q)) {
432 			gspca_dev->last_packet_type = DISCARD_PACKET;
433 			gspca_dev->sequence++;
434 			return;
435 		}
436 		j = gspca_dev->fr_queue[i];
437 		frame = &gspca_dev->frame[j];
438 		v4l2_get_timestamp(&frame->v4l2_buf.timestamp);
439 		frame->v4l2_buf.sequence = gspca_dev->sequence++;
440 		gspca_dev->image = frame->data;
441 		gspca_dev->image_len = 0;
442 	} else {
443 		switch (gspca_dev->last_packet_type) {
444 		case DISCARD_PACKET:
445 			if (packet_type == LAST_PACKET) {
446 				gspca_dev->last_packet_type = packet_type;
447 				gspca_dev->image = NULL;
448 				gspca_dev->image_len = 0;
449 			}
450 			return;
451 		case LAST_PACKET:
452 			return;
453 		}
454 	}
455 
456 	/* append the packet to the frame buffer */
457 	if (len > 0) {
458 		if (gspca_dev->image_len + len > gspca_dev->frsz) {
459 			PERR("frame overflow %d > %d",
460 				gspca_dev->image_len + len,
461 				gspca_dev->frsz);
462 			packet_type = DISCARD_PACKET;
463 		} else {
464 /* !! image is NULL only when last pkt is LAST or DISCARD
465 			if (gspca_dev->image == NULL) {
466 				pr_err("gspca_frame_add() image == NULL\n");
467 				return;
468 			}
469  */
470 			memcpy(gspca_dev->image + gspca_dev->image_len,
471 				data, len);
472 			gspca_dev->image_len += len;
473 		}
474 	}
475 	gspca_dev->last_packet_type = packet_type;
476 
477 	/* if last packet, invalidate packet concatenation until
478 	 * next first packet, wake up the application and advance
479 	 * in the queue */
480 	if (packet_type == LAST_PACKET) {
481 		i = atomic_read(&gspca_dev->fr_i);
482 		j = gspca_dev->fr_queue[i];
483 		frame = &gspca_dev->frame[j];
484 		frame->v4l2_buf.bytesused = gspca_dev->image_len;
485 		frame->v4l2_buf.flags = (frame->v4l2_buf.flags
486 					 | V4L2_BUF_FLAG_DONE)
487 					& ~V4L2_BUF_FLAG_QUEUED;
488 		i = (i + 1) % GSPCA_MAX_FRAMES;
489 		atomic_set(&gspca_dev->fr_i, i);
490 		wake_up_interruptible(&gspca_dev->wq);	/* event = new frame */
491 		PDEBUG(D_FRAM, "frame complete len:%d",
492 			frame->v4l2_buf.bytesused);
493 		gspca_dev->image = NULL;
494 		gspca_dev->image_len = 0;
495 	}
496 }
497 EXPORT_SYMBOL(gspca_frame_add);
498 
499 static int frame_alloc(struct gspca_dev *gspca_dev, struct file *file,
500 			enum v4l2_memory memory, unsigned int count)
501 {
502 	struct gspca_frame *frame;
503 	unsigned int frsz;
504 	int i;
505 
506 	frsz = gspca_dev->pixfmt.sizeimage;
507 	PDEBUG(D_STREAM, "frame alloc frsz: %d", frsz);
508 	frsz = PAGE_ALIGN(frsz);
509 	if (count >= GSPCA_MAX_FRAMES)
510 		count = GSPCA_MAX_FRAMES - 1;
511 	gspca_dev->frbuf = vmalloc_32(frsz * count);
512 	if (!gspca_dev->frbuf) {
513 		pr_err("frame alloc failed\n");
514 		return -ENOMEM;
515 	}
516 	gspca_dev->capt_file = file;
517 	gspca_dev->memory = memory;
518 	gspca_dev->frsz = frsz;
519 	gspca_dev->nframes = count;
520 	for (i = 0; i < count; i++) {
521 		frame = &gspca_dev->frame[i];
522 		frame->v4l2_buf.index = i;
523 		frame->v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
524 		frame->v4l2_buf.flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
525 		frame->v4l2_buf.field = V4L2_FIELD_NONE;
526 		frame->v4l2_buf.length = frsz;
527 		frame->v4l2_buf.memory = memory;
528 		frame->v4l2_buf.sequence = 0;
529 		frame->data = gspca_dev->frbuf + i * frsz;
530 		frame->v4l2_buf.m.offset = i * frsz;
531 	}
532 	atomic_set(&gspca_dev->fr_q, 0);
533 	atomic_set(&gspca_dev->fr_i, 0);
534 	gspca_dev->fr_o = 0;
535 	return 0;
536 }
537 
538 static void frame_free(struct gspca_dev *gspca_dev)
539 {
540 	int i;
541 
542 	PDEBUG(D_STREAM, "frame free");
543 	if (gspca_dev->frbuf != NULL) {
544 		vfree(gspca_dev->frbuf);
545 		gspca_dev->frbuf = NULL;
546 		for (i = 0; i < gspca_dev->nframes; i++)
547 			gspca_dev->frame[i].data = NULL;
548 	}
549 	gspca_dev->nframes = 0;
550 	gspca_dev->frsz = 0;
551 	gspca_dev->capt_file = NULL;
552 	gspca_dev->memory = GSPCA_MEMORY_NO;
553 }
554 
555 static void destroy_urbs(struct gspca_dev *gspca_dev)
556 {
557 	struct urb *urb;
558 	unsigned int i;
559 
560 	PDEBUG(D_STREAM, "kill transfer");
561 	for (i = 0; i < MAX_NURBS; i++) {
562 		urb = gspca_dev->urb[i];
563 		if (urb == NULL)
564 			break;
565 
566 		gspca_dev->urb[i] = NULL;
567 		usb_kill_urb(urb);
568 		usb_free_coherent(gspca_dev->dev,
569 				  urb->transfer_buffer_length,
570 				  urb->transfer_buffer,
571 				  urb->transfer_dma);
572 		usb_free_urb(urb);
573 	}
574 }
575 
576 static int gspca_set_alt0(struct gspca_dev *gspca_dev)
577 {
578 	int ret;
579 
580 	if (gspca_dev->alt == 0)
581 		return 0;
582 	ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, 0);
583 	if (ret < 0)
584 		pr_err("set alt 0 err %d\n", ret);
585 	return ret;
586 }
587 
588 /* Note: both the queue and the usb locks should be held when calling this */
589 static void gspca_stream_off(struct gspca_dev *gspca_dev)
590 {
591 	gspca_dev->streaming = 0;
592 	gspca_dev->usb_err = 0;
593 	if (gspca_dev->sd_desc->stopN)
594 		gspca_dev->sd_desc->stopN(gspca_dev);
595 	destroy_urbs(gspca_dev);
596 	gspca_input_destroy_urb(gspca_dev);
597 	gspca_set_alt0(gspca_dev);
598 	gspca_input_create_urb(gspca_dev);
599 	if (gspca_dev->sd_desc->stop0)
600 		gspca_dev->sd_desc->stop0(gspca_dev);
601 	PDEBUG(D_STREAM, "stream off OK");
602 }
603 
604 /*
605  * look for an input transfer endpoint in an alternate setting.
606  *
607  * If xfer_ep is invalid, return the first valid ep found, otherwise
608  * look for exactly the ep with address equal to xfer_ep.
609  */
610 static struct usb_host_endpoint *alt_xfer(struct usb_host_interface *alt,
611 					  int xfer, int xfer_ep)
612 {
613 	struct usb_host_endpoint *ep;
614 	int i, attr;
615 
616 	for (i = 0; i < alt->desc.bNumEndpoints; i++) {
617 		ep = &alt->endpoint[i];
618 		attr = ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
619 		if (attr == xfer
620 		    && ep->desc.wMaxPacketSize != 0
621 		    && usb_endpoint_dir_in(&ep->desc)
622 		    && (xfer_ep < 0 || ep->desc.bEndpointAddress == xfer_ep))
623 			return ep;
624 	}
625 	return NULL;
626 }
627 
628 /* compute the minimum bandwidth for the current transfer */
629 static u32 which_bandwidth(struct gspca_dev *gspca_dev)
630 {
631 	u32 bandwidth;
632 
633 	/* get the (max) image size */
634 	bandwidth = gspca_dev->pixfmt.sizeimage;
635 
636 	/* if the image is compressed, estimate its mean size */
637 	if (!gspca_dev->cam.needs_full_bandwidth &&
638 	    bandwidth < gspca_dev->pixfmt.width *
639 				gspca_dev->pixfmt.height)
640 		bandwidth = bandwidth * 3 / 8;	/* 0.375 */
641 
642 	/* estimate the frame rate */
643 	if (gspca_dev->sd_desc->get_streamparm) {
644 		struct v4l2_streamparm parm;
645 
646 		gspca_dev->sd_desc->get_streamparm(gspca_dev, &parm);
647 		bandwidth *= parm.parm.capture.timeperframe.denominator;
648 		bandwidth /= parm.parm.capture.timeperframe.numerator;
649 	} else {
650 
651 		/* don't hope more than 15 fps with USB 1.1 and
652 		 * image resolution >= 640x480 */
653 		if (gspca_dev->pixfmt.width >= 640
654 		 && gspca_dev->dev->speed == USB_SPEED_FULL)
655 			bandwidth *= 15;		/* 15 fps */
656 		else
657 			bandwidth *= 30;		/* 30 fps */
658 	}
659 
660 	PDEBUG(D_STREAM, "min bandwidth: %d", bandwidth);
661 	return bandwidth;
662 }
663 
664 /* endpoint table */
665 #define MAX_ALT 16
666 struct ep_tb_s {
667 	u32 alt;
668 	u32 bandwidth;
669 };
670 
671 /*
672  * build the table of the endpoints
673  * and compute the minimum bandwidth for the image transfer
674  */
675 static int build_isoc_ep_tb(struct gspca_dev *gspca_dev,
676 			struct usb_interface *intf,
677 			struct ep_tb_s *ep_tb)
678 {
679 	struct usb_host_endpoint *ep;
680 	int i, j, nbalt, psize, found;
681 	u32 bandwidth, last_bw;
682 
683 	nbalt = intf->num_altsetting;
684 	if (nbalt > MAX_ALT)
685 		nbalt = MAX_ALT;	/* fixme: should warn */
686 
687 	/* build the endpoint table */
688 	i = 0;
689 	last_bw = 0;
690 	for (;;) {
691 		ep_tb->bandwidth = 2000 * 2000 * 120;
692 		found = 0;
693 		for (j = 0; j < nbalt; j++) {
694 			ep = alt_xfer(&intf->altsetting[j],
695 				      USB_ENDPOINT_XFER_ISOC,
696 				      gspca_dev->xfer_ep);
697 			if (ep == NULL)
698 				continue;
699 			if (ep->desc.bInterval == 0) {
700 				pr_err("alt %d iso endp with 0 interval\n", j);
701 				continue;
702 			}
703 			psize = le16_to_cpu(ep->desc.wMaxPacketSize);
704 			psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
705 			bandwidth = psize * 1000;
706 			if (gspca_dev->dev->speed == USB_SPEED_HIGH
707 			 || gspca_dev->dev->speed >= USB_SPEED_SUPER)
708 				bandwidth *= 8;
709 			bandwidth /= 1 << (ep->desc.bInterval - 1);
710 			if (bandwidth <= last_bw)
711 				continue;
712 			if (bandwidth < ep_tb->bandwidth) {
713 				ep_tb->bandwidth = bandwidth;
714 				ep_tb->alt = j;
715 				found = 1;
716 			}
717 		}
718 		if (!found)
719 			break;
720 		PDEBUG(D_STREAM, "alt %d bandwidth %d",
721 				ep_tb->alt, ep_tb->bandwidth);
722 		last_bw = ep_tb->bandwidth;
723 		i++;
724 		ep_tb++;
725 	}
726 
727 	/*
728 	 * If the camera:
729 	 * has a usb audio class interface (a built in usb mic); and
730 	 * is a usb 1 full speed device; and
731 	 * uses the max full speed iso bandwidth; and
732 	 * and has more than 1 alt setting
733 	 * then skip the highest alt setting to spare bandwidth for the mic
734 	 */
735 	if (gspca_dev->audio &&
736 			gspca_dev->dev->speed == USB_SPEED_FULL &&
737 			last_bw >= 1000000 &&
738 			i > 1) {
739 		PDEBUG(D_STREAM, "dev has usb audio, skipping highest alt");
740 		i--;
741 		ep_tb--;
742 	}
743 
744 	/* get the requested bandwidth and start at the highest atlsetting */
745 	bandwidth = which_bandwidth(gspca_dev);
746 	ep_tb--;
747 	while (i > 1) {
748 		ep_tb--;
749 		if (ep_tb->bandwidth < bandwidth)
750 			break;
751 		i--;
752 	}
753 	return i;
754 }
755 
756 /*
757  * create the URBs for image transfer
758  */
759 static int create_urbs(struct gspca_dev *gspca_dev,
760 			struct usb_host_endpoint *ep)
761 {
762 	struct urb *urb;
763 	int n, nurbs, i, psize, npkt, bsize;
764 
765 	/* calculate the packet size and the number of packets */
766 	psize = le16_to_cpu(ep->desc.wMaxPacketSize);
767 
768 	if (!gspca_dev->cam.bulk) {		/* isoc */
769 
770 		/* See paragraph 5.9 / table 5-11 of the usb 2.0 spec. */
771 		if (gspca_dev->pkt_size == 0)
772 			psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
773 		else
774 			psize = gspca_dev->pkt_size;
775 		npkt = gspca_dev->cam.npkt;
776 		if (npkt == 0)
777 			npkt = 32;		/* default value */
778 		bsize = psize * npkt;
779 		PDEBUG(D_STREAM,
780 			"isoc %d pkts size %d = bsize:%d",
781 			npkt, psize, bsize);
782 		nurbs = DEF_NURBS;
783 	} else {				/* bulk */
784 		npkt = 0;
785 		bsize = gspca_dev->cam.bulk_size;
786 		if (bsize == 0)
787 			bsize = psize;
788 		PDEBUG(D_STREAM, "bulk bsize:%d", bsize);
789 		if (gspca_dev->cam.bulk_nurbs != 0)
790 			nurbs = gspca_dev->cam.bulk_nurbs;
791 		else
792 			nurbs = 1;
793 	}
794 
795 	for (n = 0; n < nurbs; n++) {
796 		urb = usb_alloc_urb(npkt, GFP_KERNEL);
797 		if (!urb)
798 			return -ENOMEM;
799 		gspca_dev->urb[n] = urb;
800 		urb->transfer_buffer = usb_alloc_coherent(gspca_dev->dev,
801 						bsize,
802 						GFP_KERNEL,
803 						&urb->transfer_dma);
804 
805 		if (urb->transfer_buffer == NULL) {
806 			pr_err("usb_alloc_coherent failed\n");
807 			return -ENOMEM;
808 		}
809 		urb->dev = gspca_dev->dev;
810 		urb->context = gspca_dev;
811 		urb->transfer_buffer_length = bsize;
812 		if (npkt != 0) {		/* ISOC */
813 			urb->pipe = usb_rcvisocpipe(gspca_dev->dev,
814 						    ep->desc.bEndpointAddress);
815 			urb->transfer_flags = URB_ISO_ASAP
816 					| URB_NO_TRANSFER_DMA_MAP;
817 			urb->interval = 1 << (ep->desc.bInterval - 1);
818 			urb->complete = isoc_irq;
819 			urb->number_of_packets = npkt;
820 			for (i = 0; i < npkt; i++) {
821 				urb->iso_frame_desc[i].length = psize;
822 				urb->iso_frame_desc[i].offset = psize * i;
823 			}
824 		} else {		/* bulk */
825 			urb->pipe = usb_rcvbulkpipe(gspca_dev->dev,
826 						ep->desc.bEndpointAddress);
827 			urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
828 			urb->complete = bulk_irq;
829 		}
830 	}
831 	return 0;
832 }
833 
834 /*
835  * start the USB transfer
836  */
837 static int gspca_init_transfer(struct gspca_dev *gspca_dev)
838 {
839 	struct usb_interface *intf;
840 	struct usb_host_endpoint *ep;
841 	struct urb *urb;
842 	struct ep_tb_s ep_tb[MAX_ALT];
843 	int n, ret, xfer, alt, alt_idx;
844 
845 	/* reset the streaming variables */
846 	gspca_dev->image = NULL;
847 	gspca_dev->image_len = 0;
848 	gspca_dev->last_packet_type = DISCARD_PACKET;
849 	gspca_dev->sequence = 0;
850 
851 	gspca_dev->usb_err = 0;
852 
853 	/* do the specific subdriver stuff before endpoint selection */
854 	intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
855 	gspca_dev->alt = gspca_dev->cam.bulk ? intf->num_altsetting : 0;
856 	if (gspca_dev->sd_desc->isoc_init) {
857 		ret = gspca_dev->sd_desc->isoc_init(gspca_dev);
858 		if (ret < 0)
859 			return ret;
860 	}
861 	xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK
862 				   : USB_ENDPOINT_XFER_ISOC;
863 
864 	/* if bulk or the subdriver forced an altsetting, get the endpoint */
865 	if (gspca_dev->alt != 0) {
866 		gspca_dev->alt--;	/* (previous version compatibility) */
867 		ep = alt_xfer(&intf->altsetting[gspca_dev->alt], xfer,
868 			      gspca_dev->xfer_ep);
869 		if (ep == NULL) {
870 			pr_err("bad altsetting %d\n", gspca_dev->alt);
871 			return -EIO;
872 		}
873 		ep_tb[0].alt = gspca_dev->alt;
874 		alt_idx = 1;
875 	} else {
876 		/* else, compute the minimum bandwidth
877 		 * and build the endpoint table */
878 		alt_idx = build_isoc_ep_tb(gspca_dev, intf, ep_tb);
879 		if (alt_idx <= 0) {
880 			pr_err("no transfer endpoint found\n");
881 			return -EIO;
882 		}
883 	}
884 
885 	/* set the highest alternate setting and
886 	 * loop until urb submit succeeds */
887 	gspca_input_destroy_urb(gspca_dev);
888 
889 	gspca_dev->alt = ep_tb[--alt_idx].alt;
890 	alt = -1;
891 	for (;;) {
892 		if (alt != gspca_dev->alt) {
893 			alt = gspca_dev->alt;
894 			if (intf->num_altsetting > 1) {
895 				ret = usb_set_interface(gspca_dev->dev,
896 							gspca_dev->iface,
897 							alt);
898 				if (ret < 0) {
899 					if (ret == -ENOSPC)
900 						goto retry; /*fixme: ugly*/
901 					pr_err("set alt %d err %d\n", alt, ret);
902 					goto out;
903 				}
904 			}
905 		}
906 		if (!gspca_dev->cam.no_urb_create) {
907 			PDEBUG(D_STREAM, "init transfer alt %d", alt);
908 			ret = create_urbs(gspca_dev,
909 				alt_xfer(&intf->altsetting[alt], xfer,
910 					 gspca_dev->xfer_ep));
911 			if (ret < 0) {
912 				destroy_urbs(gspca_dev);
913 				goto out;
914 			}
915 		}
916 
917 		/* clear the bulk endpoint */
918 		if (gspca_dev->cam.bulk)
919 			usb_clear_halt(gspca_dev->dev,
920 					gspca_dev->urb[0]->pipe);
921 
922 		/* start the cam */
923 		ret = gspca_dev->sd_desc->start(gspca_dev);
924 		if (ret < 0) {
925 			destroy_urbs(gspca_dev);
926 			goto out;
927 		}
928 		gspca_dev->streaming = 1;
929 		v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
930 
931 		/* some bulk transfers are started by the subdriver */
932 		if (gspca_dev->cam.bulk && gspca_dev->cam.bulk_nurbs == 0)
933 			break;
934 
935 		/* submit the URBs */
936 		for (n = 0; n < MAX_NURBS; n++) {
937 			urb = gspca_dev->urb[n];
938 			if (urb == NULL)
939 				break;
940 			ret = usb_submit_urb(urb, GFP_KERNEL);
941 			if (ret < 0)
942 				break;
943 		}
944 		if (ret >= 0)
945 			break;			/* transfer is started */
946 
947 		/* something when wrong
948 		 * stop the webcam and free the transfer resources */
949 		gspca_stream_off(gspca_dev);
950 		if (ret != -ENOSPC) {
951 			pr_err("usb_submit_urb alt %d err %d\n",
952 			       gspca_dev->alt, ret);
953 			goto out;
954 		}
955 
956 		/* the bandwidth is not wide enough
957 		 * negotiate or try a lower alternate setting */
958 retry:
959 		PERR("alt %d - bandwidth not wide enough, trying again", alt);
960 		msleep(20);	/* wait for kill complete */
961 		if (gspca_dev->sd_desc->isoc_nego) {
962 			ret = gspca_dev->sd_desc->isoc_nego(gspca_dev);
963 			if (ret < 0)
964 				goto out;
965 		} else {
966 			if (alt_idx <= 0) {
967 				pr_err("no transfer endpoint found\n");
968 				ret = -EIO;
969 				goto out;
970 			}
971 			gspca_dev->alt = ep_tb[--alt_idx].alt;
972 		}
973 	}
974 out:
975 	gspca_input_create_urb(gspca_dev);
976 	return ret;
977 }
978 
979 static void gspca_set_default_mode(struct gspca_dev *gspca_dev)
980 {
981 	int i;
982 
983 	i = gspca_dev->cam.nmodes - 1;	/* take the highest mode */
984 	gspca_dev->curr_mode = i;
985 	gspca_dev->pixfmt = gspca_dev->cam.cam_mode[i];
986 
987 	/* does nothing if ctrl_handler == NULL */
988 	v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
989 }
990 
991 static int wxh_to_mode(struct gspca_dev *gspca_dev,
992 			int width, int height)
993 {
994 	int i;
995 
996 	for (i = 0; i < gspca_dev->cam.nmodes; i++) {
997 		if (width == gspca_dev->cam.cam_mode[i].width
998 		    && height == gspca_dev->cam.cam_mode[i].height)
999 			return i;
1000 	}
1001 	return -EINVAL;
1002 }
1003 
1004 static int wxh_to_nearest_mode(struct gspca_dev *gspca_dev,
1005 			int width, int height)
1006 {
1007 	int i;
1008 
1009 	for (i = gspca_dev->cam.nmodes; --i > 0; ) {
1010 		if (width >= gspca_dev->cam.cam_mode[i].width
1011 		    && height >= gspca_dev->cam.cam_mode[i].height)
1012 			break;
1013 	}
1014 	return i;
1015 }
1016 
1017 /*
1018  * search a mode with the right pixel format
1019  */
1020 static int gspca_get_mode(struct gspca_dev *gspca_dev,
1021 			int mode,
1022 			int pixfmt)
1023 {
1024 	int modeU, modeD;
1025 
1026 	modeU = modeD = mode;
1027 	while ((modeU < gspca_dev->cam.nmodes) || modeD >= 0) {
1028 		if (--modeD >= 0) {
1029 			if (gspca_dev->cam.cam_mode[modeD].pixelformat
1030 								== pixfmt)
1031 				return modeD;
1032 		}
1033 		if (++modeU < gspca_dev->cam.nmodes) {
1034 			if (gspca_dev->cam.cam_mode[modeU].pixelformat
1035 								== pixfmt)
1036 				return modeU;
1037 		}
1038 	}
1039 	return -EINVAL;
1040 }
1041 
1042 #ifdef CONFIG_VIDEO_ADV_DEBUG
1043 static int vidioc_g_chip_info(struct file *file, void *priv,
1044 				struct v4l2_dbg_chip_info *chip)
1045 {
1046 	struct gspca_dev *gspca_dev = video_drvdata(file);
1047 
1048 	gspca_dev->usb_err = 0;
1049 	if (gspca_dev->sd_desc->get_chip_info)
1050 		return gspca_dev->sd_desc->get_chip_info(gspca_dev, chip);
1051 	return chip->match.addr ? -EINVAL : 0;
1052 }
1053 
1054 static int vidioc_g_register(struct file *file, void *priv,
1055 		struct v4l2_dbg_register *reg)
1056 {
1057 	struct gspca_dev *gspca_dev = video_drvdata(file);
1058 
1059 	gspca_dev->usb_err = 0;
1060 	return gspca_dev->sd_desc->get_register(gspca_dev, reg);
1061 }
1062 
1063 static int vidioc_s_register(struct file *file, void *priv,
1064 		const struct v4l2_dbg_register *reg)
1065 {
1066 	struct gspca_dev *gspca_dev = video_drvdata(file);
1067 
1068 	gspca_dev->usb_err = 0;
1069 	return gspca_dev->sd_desc->set_register(gspca_dev, reg);
1070 }
1071 #endif
1072 
1073 static int vidioc_enum_fmt_vid_cap(struct file *file, void  *priv,
1074 				struct v4l2_fmtdesc *fmtdesc)
1075 {
1076 	struct gspca_dev *gspca_dev = video_drvdata(file);
1077 	int i, j, index;
1078 	__u32 fmt_tb[8];
1079 
1080 	/* give an index to each format */
1081 	index = 0;
1082 	j = 0;
1083 	for (i = gspca_dev->cam.nmodes; --i >= 0; ) {
1084 		fmt_tb[index] = gspca_dev->cam.cam_mode[i].pixelformat;
1085 		j = 0;
1086 		for (;;) {
1087 			if (fmt_tb[j] == fmt_tb[index])
1088 				break;
1089 			j++;
1090 		}
1091 		if (j == index) {
1092 			if (fmtdesc->index == index)
1093 				break;		/* new format */
1094 			index++;
1095 			if (index >= ARRAY_SIZE(fmt_tb))
1096 				return -EINVAL;
1097 		}
1098 	}
1099 	if (i < 0)
1100 		return -EINVAL;		/* no more format */
1101 
1102 	fmtdesc->pixelformat = fmt_tb[index];
1103 	if (gspca_dev->cam.cam_mode[i].sizeimage <
1104 			gspca_dev->cam.cam_mode[i].width *
1105 				gspca_dev->cam.cam_mode[i].height)
1106 		fmtdesc->flags = V4L2_FMT_FLAG_COMPRESSED;
1107 	fmtdesc->description[0] = fmtdesc->pixelformat & 0xff;
1108 	fmtdesc->description[1] = (fmtdesc->pixelformat >> 8) & 0xff;
1109 	fmtdesc->description[2] = (fmtdesc->pixelformat >> 16) & 0xff;
1110 	fmtdesc->description[3] = fmtdesc->pixelformat >> 24;
1111 	fmtdesc->description[4] = '\0';
1112 	return 0;
1113 }
1114 
1115 static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
1116 			    struct v4l2_format *fmt)
1117 {
1118 	struct gspca_dev *gspca_dev = video_drvdata(file);
1119 
1120 	fmt->fmt.pix = gspca_dev->pixfmt;
1121 	/* some drivers use priv internally, zero it before giving it back to
1122 	   the core */
1123 	fmt->fmt.pix.priv = 0;
1124 	return 0;
1125 }
1126 
1127 static int try_fmt_vid_cap(struct gspca_dev *gspca_dev,
1128 			struct v4l2_format *fmt)
1129 {
1130 	int w, h, mode, mode2;
1131 
1132 	w = fmt->fmt.pix.width;
1133 	h = fmt->fmt.pix.height;
1134 
1135 	PDEBUG_MODE(gspca_dev, D_CONF, "try fmt cap",
1136 		    fmt->fmt.pix.pixelformat, w, h);
1137 
1138 	/* search the nearest mode for width and height */
1139 	mode = wxh_to_nearest_mode(gspca_dev, w, h);
1140 
1141 	/* OK if right palette */
1142 	if (gspca_dev->cam.cam_mode[mode].pixelformat
1143 						!= fmt->fmt.pix.pixelformat) {
1144 
1145 		/* else, search the closest mode with the same pixel format */
1146 		mode2 = gspca_get_mode(gspca_dev, mode,
1147 					fmt->fmt.pix.pixelformat);
1148 		if (mode2 >= 0)
1149 			mode = mode2;
1150 	}
1151 	fmt->fmt.pix = gspca_dev->cam.cam_mode[mode];
1152 	if (gspca_dev->sd_desc->try_fmt) {
1153 		/* pass original resolution to subdriver try_fmt */
1154 		fmt->fmt.pix.width = w;
1155 		fmt->fmt.pix.height = h;
1156 		gspca_dev->sd_desc->try_fmt(gspca_dev, fmt);
1157 	}
1158 	/* some drivers use priv internally, zero it before giving it back to
1159 	   the core */
1160 	fmt->fmt.pix.priv = 0;
1161 	return mode;			/* used when s_fmt */
1162 }
1163 
1164 static int vidioc_try_fmt_vid_cap(struct file *file,
1165 			      void *priv,
1166 			      struct v4l2_format *fmt)
1167 {
1168 	struct gspca_dev *gspca_dev = video_drvdata(file);
1169 	int ret;
1170 
1171 	ret = try_fmt_vid_cap(gspca_dev, fmt);
1172 	if (ret < 0)
1173 		return ret;
1174 	return 0;
1175 }
1176 
1177 static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
1178 			    struct v4l2_format *fmt)
1179 {
1180 	struct gspca_dev *gspca_dev = video_drvdata(file);
1181 	int ret;
1182 
1183 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1184 		return -ERESTARTSYS;
1185 
1186 	ret = try_fmt_vid_cap(gspca_dev, fmt);
1187 	if (ret < 0)
1188 		goto out;
1189 
1190 	if (gspca_dev->nframes != 0
1191 	    && fmt->fmt.pix.sizeimage > gspca_dev->frsz) {
1192 		ret = -EINVAL;
1193 		goto out;
1194 	}
1195 
1196 	if (gspca_dev->streaming) {
1197 		ret = -EBUSY;
1198 		goto out;
1199 	}
1200 	gspca_dev->curr_mode = ret;
1201 	if (gspca_dev->sd_desc->try_fmt)
1202 		/* subdriver try_fmt can modify format parameters */
1203 		gspca_dev->pixfmt = fmt->fmt.pix;
1204 	else
1205 		gspca_dev->pixfmt = gspca_dev->cam.cam_mode[ret];
1206 
1207 	ret = 0;
1208 out:
1209 	mutex_unlock(&gspca_dev->queue_lock);
1210 	return ret;
1211 }
1212 
1213 static int vidioc_enum_framesizes(struct file *file, void *priv,
1214 				  struct v4l2_frmsizeenum *fsize)
1215 {
1216 	struct gspca_dev *gspca_dev = video_drvdata(file);
1217 	int i;
1218 	__u32 index = 0;
1219 
1220 	if (gspca_dev->sd_desc->enum_framesizes)
1221 		return gspca_dev->sd_desc->enum_framesizes(gspca_dev, fsize);
1222 
1223 	for (i = 0; i < gspca_dev->cam.nmodes; i++) {
1224 		if (fsize->pixel_format !=
1225 				gspca_dev->cam.cam_mode[i].pixelformat)
1226 			continue;
1227 
1228 		if (fsize->index == index) {
1229 			fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1230 			fsize->discrete.width =
1231 				gspca_dev->cam.cam_mode[i].width;
1232 			fsize->discrete.height =
1233 				gspca_dev->cam.cam_mode[i].height;
1234 			return 0;
1235 		}
1236 		index++;
1237 	}
1238 
1239 	return -EINVAL;
1240 }
1241 
1242 static int vidioc_enum_frameintervals(struct file *filp, void *priv,
1243 				      struct v4l2_frmivalenum *fival)
1244 {
1245 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1246 	int mode;
1247 	__u32 i;
1248 
1249 	mode = wxh_to_mode(gspca_dev, fival->width, fival->height);
1250 	if (mode < 0)
1251 		return -EINVAL;
1252 
1253 	if (gspca_dev->cam.mode_framerates == NULL ||
1254 			gspca_dev->cam.mode_framerates[mode].nrates == 0)
1255 		return -EINVAL;
1256 
1257 	if (fival->pixel_format !=
1258 			gspca_dev->cam.cam_mode[mode].pixelformat)
1259 		return -EINVAL;
1260 
1261 	for (i = 0; i < gspca_dev->cam.mode_framerates[mode].nrates; i++) {
1262 		if (fival->index == i) {
1263 			fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
1264 			fival->discrete.numerator = 1;
1265 			fival->discrete.denominator =
1266 				gspca_dev->cam.mode_framerates[mode].rates[i];
1267 			return 0;
1268 		}
1269 	}
1270 
1271 	return -EINVAL;
1272 }
1273 
1274 static void gspca_release(struct v4l2_device *v4l2_device)
1275 {
1276 	struct gspca_dev *gspca_dev =
1277 		container_of(v4l2_device, struct gspca_dev, v4l2_dev);
1278 
1279 	v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
1280 	v4l2_device_unregister(&gspca_dev->v4l2_dev);
1281 	kfree(gspca_dev->usb_buf);
1282 	kfree(gspca_dev);
1283 }
1284 
1285 static int dev_open(struct file *file)
1286 {
1287 	struct gspca_dev *gspca_dev = video_drvdata(file);
1288 	int ret;
1289 
1290 	PDEBUG(D_STREAM, "[%s] open", current->comm);
1291 
1292 	/* protect the subdriver against rmmod */
1293 	if (!try_module_get(gspca_dev->module))
1294 		return -ENODEV;
1295 
1296 	ret = v4l2_fh_open(file);
1297 	if (ret)
1298 		module_put(gspca_dev->module);
1299 	return ret;
1300 }
1301 
1302 static int dev_close(struct file *file)
1303 {
1304 	struct gspca_dev *gspca_dev = video_drvdata(file);
1305 
1306 	PDEBUG(D_STREAM, "[%s] close", current->comm);
1307 
1308 	/* Needed for gspca_stream_off, always lock before queue_lock! */
1309 	if (mutex_lock_interruptible(&gspca_dev->usb_lock))
1310 		return -ERESTARTSYS;
1311 
1312 	if (mutex_lock_interruptible(&gspca_dev->queue_lock)) {
1313 		mutex_unlock(&gspca_dev->usb_lock);
1314 		return -ERESTARTSYS;
1315 	}
1316 
1317 	/* if the file did the capture, free the streaming resources */
1318 	if (gspca_dev->capt_file == file) {
1319 		if (gspca_dev->streaming)
1320 			gspca_stream_off(gspca_dev);
1321 		frame_free(gspca_dev);
1322 	}
1323 	module_put(gspca_dev->module);
1324 	mutex_unlock(&gspca_dev->queue_lock);
1325 	mutex_unlock(&gspca_dev->usb_lock);
1326 
1327 	PDEBUG(D_STREAM, "close done");
1328 
1329 	return v4l2_fh_release(file);
1330 }
1331 
1332 static int vidioc_querycap(struct file *file, void  *priv,
1333 			   struct v4l2_capability *cap)
1334 {
1335 	struct gspca_dev *gspca_dev = video_drvdata(file);
1336 
1337 	strlcpy((char *) cap->driver, gspca_dev->sd_desc->name,
1338 			sizeof cap->driver);
1339 	if (gspca_dev->dev->product != NULL) {
1340 		strlcpy((char *) cap->card, gspca_dev->dev->product,
1341 			sizeof cap->card);
1342 	} else {
1343 		snprintf((char *) cap->card, sizeof cap->card,
1344 			"USB Camera (%04x:%04x)",
1345 			le16_to_cpu(gspca_dev->dev->descriptor.idVendor),
1346 			le16_to_cpu(gspca_dev->dev->descriptor.idProduct));
1347 	}
1348 	usb_make_path(gspca_dev->dev, (char *) cap->bus_info,
1349 			sizeof(cap->bus_info));
1350 	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE
1351 			  | V4L2_CAP_STREAMING
1352 			  | V4L2_CAP_READWRITE;
1353 	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
1354 	return 0;
1355 }
1356 
1357 static int vidioc_enum_input(struct file *file, void *priv,
1358 				struct v4l2_input *input)
1359 {
1360 	struct gspca_dev *gspca_dev = video_drvdata(file);
1361 
1362 	if (input->index != 0)
1363 		return -EINVAL;
1364 	input->type = V4L2_INPUT_TYPE_CAMERA;
1365 	input->status = gspca_dev->cam.input_flags;
1366 	strlcpy(input->name, gspca_dev->sd_desc->name,
1367 		sizeof input->name);
1368 	return 0;
1369 }
1370 
1371 static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
1372 {
1373 	*i = 0;
1374 	return 0;
1375 }
1376 
1377 static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
1378 {
1379 	if (i > 0)
1380 		return -EINVAL;
1381 	return (0);
1382 }
1383 
1384 static int vidioc_reqbufs(struct file *file, void *priv,
1385 			  struct v4l2_requestbuffers *rb)
1386 {
1387 	struct gspca_dev *gspca_dev = video_drvdata(file);
1388 	int i, ret = 0, streaming;
1389 
1390 	i = rb->memory;			/* (avoid compilation warning) */
1391 	switch (i) {
1392 	case GSPCA_MEMORY_READ:			/* (internal call) */
1393 	case V4L2_MEMORY_MMAP:
1394 	case V4L2_MEMORY_USERPTR:
1395 		break;
1396 	default:
1397 		return -EINVAL;
1398 	}
1399 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1400 		return -ERESTARTSYS;
1401 
1402 	if (gspca_dev->memory != GSPCA_MEMORY_NO
1403 	    && gspca_dev->memory != GSPCA_MEMORY_READ
1404 	    && gspca_dev->memory != rb->memory) {
1405 		ret = -EBUSY;
1406 		goto out;
1407 	}
1408 
1409 	/* only one file may do the capture */
1410 	if (gspca_dev->capt_file != NULL
1411 	    && gspca_dev->capt_file != file) {
1412 		ret = -EBUSY;
1413 		goto out;
1414 	}
1415 
1416 	/* if allocated, the buffers must not be mapped */
1417 	for (i = 0; i < gspca_dev->nframes; i++) {
1418 		if (gspca_dev->frame[i].vma_use_count) {
1419 			ret = -EBUSY;
1420 			goto out;
1421 		}
1422 	}
1423 
1424 	/* stop streaming */
1425 	streaming = gspca_dev->streaming;
1426 	if (streaming) {
1427 		gspca_stream_off(gspca_dev);
1428 
1429 		/* Don't restart the stream when switching from read
1430 		 * to mmap mode */
1431 		if (gspca_dev->memory == GSPCA_MEMORY_READ)
1432 			streaming = 0;
1433 	}
1434 
1435 	/* free the previous allocated buffers, if any */
1436 	if (gspca_dev->nframes != 0)
1437 		frame_free(gspca_dev);
1438 	if (rb->count == 0)			/* unrequest */
1439 		goto out;
1440 	ret = frame_alloc(gspca_dev, file, rb->memory, rb->count);
1441 	if (ret == 0) {
1442 		rb->count = gspca_dev->nframes;
1443 		if (streaming)
1444 			ret = gspca_init_transfer(gspca_dev);
1445 	}
1446 out:
1447 	mutex_unlock(&gspca_dev->queue_lock);
1448 	PDEBUG(D_STREAM, "reqbufs st:%d c:%d", ret, rb->count);
1449 	return ret;
1450 }
1451 
1452 static int vidioc_querybuf(struct file *file, void *priv,
1453 			   struct v4l2_buffer *v4l2_buf)
1454 {
1455 	struct gspca_dev *gspca_dev = video_drvdata(file);
1456 	struct gspca_frame *frame;
1457 
1458 	if (v4l2_buf->index >= gspca_dev->nframes)
1459 		return -EINVAL;
1460 
1461 	frame = &gspca_dev->frame[v4l2_buf->index];
1462 	memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
1463 	return 0;
1464 }
1465 
1466 static int vidioc_streamon(struct file *file, void *priv,
1467 			   enum v4l2_buf_type buf_type)
1468 {
1469 	struct gspca_dev *gspca_dev = video_drvdata(file);
1470 	int ret;
1471 
1472 	if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1473 		return -EINVAL;
1474 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1475 		return -ERESTARTSYS;
1476 
1477 	/* check the capture file */
1478 	if (gspca_dev->capt_file != file) {
1479 		ret = -EBUSY;
1480 		goto out;
1481 	}
1482 
1483 	if (gspca_dev->nframes == 0
1484 	    || !(gspca_dev->frame[0].v4l2_buf.flags & V4L2_BUF_FLAG_QUEUED)) {
1485 		ret = -EINVAL;
1486 		goto out;
1487 	}
1488 	if (!gspca_dev->streaming) {
1489 		ret = gspca_init_transfer(gspca_dev);
1490 		if (ret < 0)
1491 			goto out;
1492 	}
1493 	PDEBUG_MODE(gspca_dev, D_STREAM, "stream on OK",
1494 		    gspca_dev->pixfmt.pixelformat,
1495 		    gspca_dev->pixfmt.width, gspca_dev->pixfmt.height);
1496 	ret = 0;
1497 out:
1498 	mutex_unlock(&gspca_dev->queue_lock);
1499 	return ret;
1500 }
1501 
1502 static int vidioc_streamoff(struct file *file, void *priv,
1503 				enum v4l2_buf_type buf_type)
1504 {
1505 	struct gspca_dev *gspca_dev = video_drvdata(file);
1506 	int i, ret;
1507 
1508 	if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1509 		return -EINVAL;
1510 
1511 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1512 		return -ERESTARTSYS;
1513 
1514 	if (!gspca_dev->streaming) {
1515 		ret = 0;
1516 		goto out;
1517 	}
1518 
1519 	/* check the capture file */
1520 	if (gspca_dev->capt_file != file) {
1521 		ret = -EBUSY;
1522 		goto out;
1523 	}
1524 
1525 	/* stop streaming */
1526 	gspca_stream_off(gspca_dev);
1527 	/* In case another thread is waiting in dqbuf */
1528 	wake_up_interruptible(&gspca_dev->wq);
1529 
1530 	/* empty the transfer queues */
1531 	for (i = 0; i < gspca_dev->nframes; i++)
1532 		gspca_dev->frame[i].v4l2_buf.flags &= ~BUF_ALL_FLAGS;
1533 	atomic_set(&gspca_dev->fr_q, 0);
1534 	atomic_set(&gspca_dev->fr_i, 0);
1535 	gspca_dev->fr_o = 0;
1536 	ret = 0;
1537 out:
1538 	mutex_unlock(&gspca_dev->queue_lock);
1539 	return ret;
1540 }
1541 
1542 static int vidioc_g_jpegcomp(struct file *file, void *priv,
1543 			struct v4l2_jpegcompression *jpegcomp)
1544 {
1545 	struct gspca_dev *gspca_dev = video_drvdata(file);
1546 
1547 	gspca_dev->usb_err = 0;
1548 	return gspca_dev->sd_desc->get_jcomp(gspca_dev, jpegcomp);
1549 }
1550 
1551 static int vidioc_s_jpegcomp(struct file *file, void *priv,
1552 			const struct v4l2_jpegcompression *jpegcomp)
1553 {
1554 	struct gspca_dev *gspca_dev = video_drvdata(file);
1555 
1556 	gspca_dev->usb_err = 0;
1557 	return gspca_dev->sd_desc->set_jcomp(gspca_dev, jpegcomp);
1558 }
1559 
1560 static int vidioc_g_parm(struct file *filp, void *priv,
1561 			struct v4l2_streamparm *parm)
1562 {
1563 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1564 
1565 	parm->parm.capture.readbuffers = gspca_dev->nbufread;
1566 
1567 	if (gspca_dev->sd_desc->get_streamparm) {
1568 		gspca_dev->usb_err = 0;
1569 		gspca_dev->sd_desc->get_streamparm(gspca_dev, parm);
1570 		return gspca_dev->usb_err;
1571 	}
1572 	return 0;
1573 }
1574 
1575 static int vidioc_s_parm(struct file *filp, void *priv,
1576 			struct v4l2_streamparm *parm)
1577 {
1578 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1579 	unsigned int n;
1580 
1581 	n = parm->parm.capture.readbuffers;
1582 	if (n == 0 || n >= GSPCA_MAX_FRAMES)
1583 		parm->parm.capture.readbuffers = gspca_dev->nbufread;
1584 	else
1585 		gspca_dev->nbufread = n;
1586 
1587 	if (gspca_dev->sd_desc->set_streamparm) {
1588 		gspca_dev->usb_err = 0;
1589 		gspca_dev->sd_desc->set_streamparm(gspca_dev, parm);
1590 		return gspca_dev->usb_err;
1591 	}
1592 
1593 	return 0;
1594 }
1595 
1596 static int dev_mmap(struct file *file, struct vm_area_struct *vma)
1597 {
1598 	struct gspca_dev *gspca_dev = video_drvdata(file);
1599 	struct gspca_frame *frame;
1600 	struct page *page;
1601 	unsigned long addr, start, size;
1602 	int i, ret;
1603 
1604 	start = vma->vm_start;
1605 	size = vma->vm_end - vma->vm_start;
1606 	PDEBUG(D_STREAM, "mmap start:%08x size:%d", (int) start, (int) size);
1607 
1608 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1609 		return -ERESTARTSYS;
1610 	if (gspca_dev->capt_file != file) {
1611 		ret = -EINVAL;
1612 		goto out;
1613 	}
1614 
1615 	frame = NULL;
1616 	for (i = 0; i < gspca_dev->nframes; ++i) {
1617 		if (gspca_dev->frame[i].v4l2_buf.memory != V4L2_MEMORY_MMAP) {
1618 			PDEBUG(D_STREAM, "mmap bad memory type");
1619 			break;
1620 		}
1621 		if ((gspca_dev->frame[i].v4l2_buf.m.offset >> PAGE_SHIFT)
1622 						== vma->vm_pgoff) {
1623 			frame = &gspca_dev->frame[i];
1624 			break;
1625 		}
1626 	}
1627 	if (frame == NULL) {
1628 		PDEBUG(D_STREAM, "mmap no frame buffer found");
1629 		ret = -EINVAL;
1630 		goto out;
1631 	}
1632 	if (size != frame->v4l2_buf.length) {
1633 		PDEBUG(D_STREAM, "mmap bad size");
1634 		ret = -EINVAL;
1635 		goto out;
1636 	}
1637 
1638 	/*
1639 	 * - VM_IO marks the area as being a mmaped region for I/O to a
1640 	 *   device. It also prevents the region from being core dumped.
1641 	 */
1642 	vma->vm_flags |= VM_IO;
1643 
1644 	addr = (unsigned long) frame->data;
1645 	while (size > 0) {
1646 		page = vmalloc_to_page((void *) addr);
1647 		ret = vm_insert_page(vma, start, page);
1648 		if (ret < 0)
1649 			goto out;
1650 		start += PAGE_SIZE;
1651 		addr += PAGE_SIZE;
1652 		size -= PAGE_SIZE;
1653 	}
1654 
1655 	vma->vm_ops = &gspca_vm_ops;
1656 	vma->vm_private_data = frame;
1657 	gspca_vm_open(vma);
1658 	ret = 0;
1659 out:
1660 	mutex_unlock(&gspca_dev->queue_lock);
1661 	return ret;
1662 }
1663 
1664 static int frame_ready_nolock(struct gspca_dev *gspca_dev, struct file *file,
1665 				enum v4l2_memory memory)
1666 {
1667 	if (!gspca_dev->present)
1668 		return -ENODEV;
1669 	if (gspca_dev->capt_file != file || gspca_dev->memory != memory ||
1670 			!gspca_dev->streaming)
1671 		return -EINVAL;
1672 
1673 	/* check if a frame is ready */
1674 	return gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i);
1675 }
1676 
1677 static int frame_ready(struct gspca_dev *gspca_dev, struct file *file,
1678 			enum v4l2_memory memory)
1679 {
1680 	int ret;
1681 
1682 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1683 		return -ERESTARTSYS;
1684 	ret = frame_ready_nolock(gspca_dev, file, memory);
1685 	mutex_unlock(&gspca_dev->queue_lock);
1686 	return ret;
1687 }
1688 
1689 /*
1690  * dequeue a video buffer
1691  *
1692  * If nonblock_ing is false, block until a buffer is available.
1693  */
1694 static int vidioc_dqbuf(struct file *file, void *priv,
1695 			struct v4l2_buffer *v4l2_buf)
1696 {
1697 	struct gspca_dev *gspca_dev = video_drvdata(file);
1698 	struct gspca_frame *frame;
1699 	int i, j, ret;
1700 
1701 	PDEBUG(D_FRAM, "dqbuf");
1702 
1703 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1704 		return -ERESTARTSYS;
1705 
1706 	for (;;) {
1707 		ret = frame_ready_nolock(gspca_dev, file, v4l2_buf->memory);
1708 		if (ret < 0)
1709 			goto out;
1710 		if (ret > 0)
1711 			break;
1712 
1713 		mutex_unlock(&gspca_dev->queue_lock);
1714 
1715 		if (file->f_flags & O_NONBLOCK)
1716 			return -EAGAIN;
1717 
1718 		/* wait till a frame is ready */
1719 		ret = wait_event_interruptible_timeout(gspca_dev->wq,
1720 			frame_ready(gspca_dev, file, v4l2_buf->memory),
1721 			msecs_to_jiffies(3000));
1722 		if (ret < 0)
1723 			return ret;
1724 		if (ret == 0)
1725 			return -EIO;
1726 
1727 		if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1728 			return -ERESTARTSYS;
1729 	}
1730 
1731 	i = gspca_dev->fr_o;
1732 	j = gspca_dev->fr_queue[i];
1733 	frame = &gspca_dev->frame[j];
1734 
1735 	gspca_dev->fr_o = (i + 1) % GSPCA_MAX_FRAMES;
1736 
1737 	frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_DONE;
1738 	memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
1739 	PDEBUG(D_FRAM, "dqbuf %d", j);
1740 	ret = 0;
1741 
1742 	if (gspca_dev->memory == V4L2_MEMORY_USERPTR) {
1743 		if (copy_to_user((__u8 __user *) frame->v4l2_buf.m.userptr,
1744 				 frame->data,
1745 				 frame->v4l2_buf.bytesused)) {
1746 			PERR("dqbuf cp to user failed");
1747 			ret = -EFAULT;
1748 		}
1749 	}
1750 out:
1751 	mutex_unlock(&gspca_dev->queue_lock);
1752 
1753 	if (ret == 0 && gspca_dev->sd_desc->dq_callback) {
1754 		mutex_lock(&gspca_dev->usb_lock);
1755 		gspca_dev->usb_err = 0;
1756 		if (gspca_dev->present)
1757 			gspca_dev->sd_desc->dq_callback(gspca_dev);
1758 		mutex_unlock(&gspca_dev->usb_lock);
1759 	}
1760 
1761 	return ret;
1762 }
1763 
1764 /*
1765  * queue a video buffer
1766  *
1767  * Attempting to queue a buffer that has already been
1768  * queued will return -EINVAL.
1769  */
1770 static int vidioc_qbuf(struct file *file, void *priv,
1771 			struct v4l2_buffer *v4l2_buf)
1772 {
1773 	struct gspca_dev *gspca_dev = video_drvdata(file);
1774 	struct gspca_frame *frame;
1775 	int i, index, ret;
1776 
1777 	PDEBUG(D_FRAM, "qbuf %d", v4l2_buf->index);
1778 
1779 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1780 		return -ERESTARTSYS;
1781 
1782 	index = v4l2_buf->index;
1783 	if ((unsigned) index >= gspca_dev->nframes) {
1784 		PDEBUG(D_FRAM,
1785 			"qbuf idx %d >= %d", index, gspca_dev->nframes);
1786 		ret = -EINVAL;
1787 		goto out;
1788 	}
1789 	if (v4l2_buf->memory != gspca_dev->memory) {
1790 		PDEBUG(D_FRAM, "qbuf bad memory type");
1791 		ret = -EINVAL;
1792 		goto out;
1793 	}
1794 
1795 	frame = &gspca_dev->frame[index];
1796 	if (frame->v4l2_buf.flags & BUF_ALL_FLAGS) {
1797 		PDEBUG(D_FRAM, "qbuf bad state");
1798 		ret = -EINVAL;
1799 		goto out;
1800 	}
1801 
1802 	frame->v4l2_buf.flags |= V4L2_BUF_FLAG_QUEUED;
1803 
1804 	if (frame->v4l2_buf.memory == V4L2_MEMORY_USERPTR) {
1805 		frame->v4l2_buf.m.userptr = v4l2_buf->m.userptr;
1806 		frame->v4l2_buf.length = v4l2_buf->length;
1807 	}
1808 
1809 	/* put the buffer in the 'queued' queue */
1810 	i = atomic_read(&gspca_dev->fr_q);
1811 	gspca_dev->fr_queue[i] = index;
1812 	atomic_set(&gspca_dev->fr_q, (i + 1) % GSPCA_MAX_FRAMES);
1813 
1814 	v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
1815 	v4l2_buf->flags &= ~V4L2_BUF_FLAG_DONE;
1816 	ret = 0;
1817 out:
1818 	mutex_unlock(&gspca_dev->queue_lock);
1819 	return ret;
1820 }
1821 
1822 /*
1823  * allocate the resources for read()
1824  */
1825 static int read_alloc(struct gspca_dev *gspca_dev,
1826 			struct file *file)
1827 {
1828 	struct v4l2_buffer v4l2_buf;
1829 	int i, ret;
1830 
1831 	PDEBUG(D_STREAM, "read alloc");
1832 
1833 	if (mutex_lock_interruptible(&gspca_dev->usb_lock))
1834 		return -ERESTARTSYS;
1835 
1836 	if (gspca_dev->nframes == 0) {
1837 		struct v4l2_requestbuffers rb;
1838 
1839 		memset(&rb, 0, sizeof rb);
1840 		rb.count = gspca_dev->nbufread;
1841 		rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1842 		rb.memory = GSPCA_MEMORY_READ;
1843 		ret = vidioc_reqbufs(file, gspca_dev, &rb);
1844 		if (ret != 0) {
1845 			PDEBUG(D_STREAM, "read reqbuf err %d", ret);
1846 			goto out;
1847 		}
1848 		memset(&v4l2_buf, 0, sizeof v4l2_buf);
1849 		v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1850 		v4l2_buf.memory = GSPCA_MEMORY_READ;
1851 		for (i = 0; i < gspca_dev->nbufread; i++) {
1852 			v4l2_buf.index = i;
1853 			ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1854 			if (ret != 0) {
1855 				PDEBUG(D_STREAM, "read qbuf err: %d", ret);
1856 				goto out;
1857 			}
1858 		}
1859 	}
1860 
1861 	/* start streaming */
1862 	ret = vidioc_streamon(file, gspca_dev, V4L2_BUF_TYPE_VIDEO_CAPTURE);
1863 	if (ret != 0)
1864 		PDEBUG(D_STREAM, "read streamon err %d", ret);
1865 out:
1866 	mutex_unlock(&gspca_dev->usb_lock);
1867 	return ret;
1868 }
1869 
1870 static unsigned int dev_poll(struct file *file, poll_table *wait)
1871 {
1872 	struct gspca_dev *gspca_dev = video_drvdata(file);
1873 	unsigned long req_events = poll_requested_events(wait);
1874 	int ret = 0;
1875 
1876 	PDEBUG(D_FRAM, "poll");
1877 
1878 	if (req_events & POLLPRI)
1879 		ret |= v4l2_ctrl_poll(file, wait);
1880 
1881 	if (req_events & (POLLIN | POLLRDNORM)) {
1882 		/* if reqbufs is not done, the user would use read() */
1883 		if (gspca_dev->memory == GSPCA_MEMORY_NO) {
1884 			if (read_alloc(gspca_dev, file) != 0) {
1885 				ret |= POLLERR;
1886 				goto out;
1887 			}
1888 		}
1889 
1890 		poll_wait(file, &gspca_dev->wq, wait);
1891 
1892 		/* check if an image has been received */
1893 		if (mutex_lock_interruptible(&gspca_dev->queue_lock) != 0) {
1894 			ret |= POLLERR;
1895 			goto out;
1896 		}
1897 		if (gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i))
1898 			ret |= POLLIN | POLLRDNORM;
1899 		mutex_unlock(&gspca_dev->queue_lock);
1900 	}
1901 
1902 out:
1903 	if (!gspca_dev->present)
1904 		ret |= POLLHUP;
1905 
1906 	return ret;
1907 }
1908 
1909 static ssize_t dev_read(struct file *file, char __user *data,
1910 		    size_t count, loff_t *ppos)
1911 {
1912 	struct gspca_dev *gspca_dev = video_drvdata(file);
1913 	struct gspca_frame *frame;
1914 	struct v4l2_buffer v4l2_buf;
1915 	struct timeval timestamp;
1916 	int n, ret, ret2;
1917 
1918 	PDEBUG(D_FRAM, "read (%zd)", count);
1919 	if (gspca_dev->memory == GSPCA_MEMORY_NO) { /* first time ? */
1920 		ret = read_alloc(gspca_dev, file);
1921 		if (ret != 0)
1922 			return ret;
1923 	}
1924 
1925 	/* get a frame */
1926 	v4l2_get_timestamp(&timestamp);
1927 	timestamp.tv_sec--;
1928 	n = 2;
1929 	for (;;) {
1930 		memset(&v4l2_buf, 0, sizeof v4l2_buf);
1931 		v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1932 		v4l2_buf.memory = GSPCA_MEMORY_READ;
1933 		ret = vidioc_dqbuf(file, gspca_dev, &v4l2_buf);
1934 		if (ret != 0) {
1935 			PDEBUG(D_STREAM, "read dqbuf err %d", ret);
1936 			return ret;
1937 		}
1938 
1939 		/* if the process slept for more than 1 second,
1940 		 * get a newer frame */
1941 		frame = &gspca_dev->frame[v4l2_buf.index];
1942 		if (--n < 0)
1943 			break;			/* avoid infinite loop */
1944 		if (frame->v4l2_buf.timestamp.tv_sec >= timestamp.tv_sec)
1945 			break;
1946 		ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1947 		if (ret != 0) {
1948 			PDEBUG(D_STREAM, "read qbuf err %d", ret);
1949 			return ret;
1950 		}
1951 	}
1952 
1953 	/* copy the frame */
1954 	if (count > frame->v4l2_buf.bytesused)
1955 		count = frame->v4l2_buf.bytesused;
1956 	ret = copy_to_user(data, frame->data, count);
1957 	if (ret != 0) {
1958 		PERR("read cp to user lack %d / %zd", ret, count);
1959 		ret = -EFAULT;
1960 		goto out;
1961 	}
1962 	ret = count;
1963 out:
1964 	/* in each case, requeue the buffer */
1965 	ret2 = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1966 	if (ret2 != 0)
1967 		return ret2;
1968 	return ret;
1969 }
1970 
1971 static struct v4l2_file_operations dev_fops = {
1972 	.owner = THIS_MODULE,
1973 	.open = dev_open,
1974 	.release = dev_close,
1975 	.read = dev_read,
1976 	.mmap = dev_mmap,
1977 	.unlocked_ioctl = video_ioctl2,
1978 	.poll	= dev_poll,
1979 };
1980 
1981 static const struct v4l2_ioctl_ops dev_ioctl_ops = {
1982 	.vidioc_querycap	= vidioc_querycap,
1983 	.vidioc_dqbuf		= vidioc_dqbuf,
1984 	.vidioc_qbuf		= vidioc_qbuf,
1985 	.vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
1986 	.vidioc_try_fmt_vid_cap	= vidioc_try_fmt_vid_cap,
1987 	.vidioc_g_fmt_vid_cap	= vidioc_g_fmt_vid_cap,
1988 	.vidioc_s_fmt_vid_cap	= vidioc_s_fmt_vid_cap,
1989 	.vidioc_streamon	= vidioc_streamon,
1990 	.vidioc_enum_input	= vidioc_enum_input,
1991 	.vidioc_g_input		= vidioc_g_input,
1992 	.vidioc_s_input		= vidioc_s_input,
1993 	.vidioc_reqbufs		= vidioc_reqbufs,
1994 	.vidioc_querybuf	= vidioc_querybuf,
1995 	.vidioc_streamoff	= vidioc_streamoff,
1996 	.vidioc_g_jpegcomp	= vidioc_g_jpegcomp,
1997 	.vidioc_s_jpegcomp	= vidioc_s_jpegcomp,
1998 	.vidioc_g_parm		= vidioc_g_parm,
1999 	.vidioc_s_parm		= vidioc_s_parm,
2000 	.vidioc_enum_framesizes = vidioc_enum_framesizes,
2001 	.vidioc_enum_frameintervals = vidioc_enum_frameintervals,
2002 #ifdef CONFIG_VIDEO_ADV_DEBUG
2003 	.vidioc_g_chip_info	= vidioc_g_chip_info,
2004 	.vidioc_g_register	= vidioc_g_register,
2005 	.vidioc_s_register	= vidioc_s_register,
2006 #endif
2007 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
2008 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
2009 };
2010 
2011 static const struct video_device gspca_template = {
2012 	.name = "gspca main driver",
2013 	.fops = &dev_fops,
2014 	.ioctl_ops = &dev_ioctl_ops,
2015 	.release = video_device_release_empty, /* We use v4l2_dev.release */
2016 };
2017 
2018 /*
2019  * probe and create a new gspca device
2020  *
2021  * This function must be called by the sub-driver when it is
2022  * called for probing a new device.
2023  */
2024 int gspca_dev_probe2(struct usb_interface *intf,
2025 		const struct usb_device_id *id,
2026 		const struct sd_desc *sd_desc,
2027 		int dev_size,
2028 		struct module *module)
2029 {
2030 	struct gspca_dev *gspca_dev;
2031 	struct usb_device *dev = interface_to_usbdev(intf);
2032 	int ret;
2033 
2034 	pr_info("%s-" GSPCA_VERSION " probing %04x:%04x\n",
2035 		sd_desc->name, id->idVendor, id->idProduct);
2036 
2037 	/* create the device */
2038 	if (dev_size < sizeof *gspca_dev)
2039 		dev_size = sizeof *gspca_dev;
2040 	gspca_dev = kzalloc(dev_size, GFP_KERNEL);
2041 	if (!gspca_dev) {
2042 		pr_err("couldn't kzalloc gspca struct\n");
2043 		return -ENOMEM;
2044 	}
2045 	gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
2046 	if (!gspca_dev->usb_buf) {
2047 		pr_err("out of memory\n");
2048 		ret = -ENOMEM;
2049 		goto out;
2050 	}
2051 	gspca_dev->dev = dev;
2052 	gspca_dev->iface = intf->cur_altsetting->desc.bInterfaceNumber;
2053 	gspca_dev->xfer_ep = -1;
2054 
2055 	/* check if any audio device */
2056 	if (dev->actconfig->desc.bNumInterfaces != 1) {
2057 		int i;
2058 		struct usb_interface *intf2;
2059 
2060 		for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
2061 			intf2 = dev->actconfig->interface[i];
2062 			if (intf2 != NULL
2063 			 && intf2->altsetting != NULL
2064 			 && intf2->altsetting->desc.bInterfaceClass ==
2065 					 USB_CLASS_AUDIO) {
2066 				gspca_dev->audio = 1;
2067 				break;
2068 			}
2069 		}
2070 	}
2071 
2072 	gspca_dev->v4l2_dev.release = gspca_release;
2073 	ret = v4l2_device_register(&intf->dev, &gspca_dev->v4l2_dev);
2074 	if (ret)
2075 		goto out;
2076 	gspca_dev->sd_desc = sd_desc;
2077 	gspca_dev->nbufread = 2;
2078 	gspca_dev->empty_packet = -1;	/* don't check the empty packets */
2079 	gspca_dev->vdev = gspca_template;
2080 	gspca_dev->vdev.v4l2_dev = &gspca_dev->v4l2_dev;
2081 	video_set_drvdata(&gspca_dev->vdev, gspca_dev);
2082 	gspca_dev->module = module;
2083 	gspca_dev->present = 1;
2084 
2085 	mutex_init(&gspca_dev->usb_lock);
2086 	gspca_dev->vdev.lock = &gspca_dev->usb_lock;
2087 	mutex_init(&gspca_dev->queue_lock);
2088 	init_waitqueue_head(&gspca_dev->wq);
2089 
2090 	/* configure the subdriver and initialize the USB device */
2091 	ret = sd_desc->config(gspca_dev, id);
2092 	if (ret < 0)
2093 		goto out;
2094 	ret = sd_desc->init(gspca_dev);
2095 	if (ret < 0)
2096 		goto out;
2097 	if (sd_desc->init_controls)
2098 		ret = sd_desc->init_controls(gspca_dev);
2099 	if (ret < 0)
2100 		goto out;
2101 	gspca_set_default_mode(gspca_dev);
2102 
2103 	ret = gspca_input_connect(gspca_dev);
2104 	if (ret)
2105 		goto out;
2106 
2107 	/*
2108 	 * Don't take usb_lock for these ioctls. This improves latency if
2109 	 * usb_lock is taken for a long time, e.g. when changing a control
2110 	 * value, and a new frame is ready to be dequeued.
2111 	 */
2112 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_DQBUF);
2113 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QBUF);
2114 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QUERYBUF);
2115 #ifdef CONFIG_VIDEO_ADV_DEBUG
2116 	if (!gspca_dev->sd_desc->get_register)
2117 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_G_REGISTER);
2118 	if (!gspca_dev->sd_desc->set_register)
2119 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_S_REGISTER);
2120 #endif
2121 	if (!gspca_dev->sd_desc->get_jcomp)
2122 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_G_JPEGCOMP);
2123 	if (!gspca_dev->sd_desc->set_jcomp)
2124 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_S_JPEGCOMP);
2125 
2126 	/* init video stuff */
2127 	ret = video_register_device(&gspca_dev->vdev,
2128 				  VFL_TYPE_GRABBER,
2129 				  -1);
2130 	if (ret < 0) {
2131 		pr_err("video_register_device err %d\n", ret);
2132 		goto out;
2133 	}
2134 
2135 	usb_set_intfdata(intf, gspca_dev);
2136 	PDEBUG(D_PROBE, "%s created", video_device_node_name(&gspca_dev->vdev));
2137 
2138 	gspca_input_create_urb(gspca_dev);
2139 
2140 	return 0;
2141 out:
2142 #if IS_ENABLED(CONFIG_INPUT)
2143 	if (gspca_dev->input_dev)
2144 		input_unregister_device(gspca_dev->input_dev);
2145 #endif
2146 	v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
2147 	kfree(gspca_dev->usb_buf);
2148 	kfree(gspca_dev);
2149 	return ret;
2150 }
2151 EXPORT_SYMBOL(gspca_dev_probe2);
2152 
2153 /* same function as the previous one, but check the interface */
2154 int gspca_dev_probe(struct usb_interface *intf,
2155 		const struct usb_device_id *id,
2156 		const struct sd_desc *sd_desc,
2157 		int dev_size,
2158 		struct module *module)
2159 {
2160 	struct usb_device *dev = interface_to_usbdev(intf);
2161 
2162 	/* we don't handle multi-config cameras */
2163 	if (dev->descriptor.bNumConfigurations != 1) {
2164 		pr_err("%04x:%04x too many config\n",
2165 		       id->idVendor, id->idProduct);
2166 		return -ENODEV;
2167 	}
2168 
2169 	/* the USB video interface must be the first one */
2170 	if (dev->actconfig->desc.bNumInterfaces != 1
2171 	 && intf->cur_altsetting->desc.bInterfaceNumber != 0)
2172 		return -ENODEV;
2173 
2174 	return gspca_dev_probe2(intf, id, sd_desc, dev_size, module);
2175 }
2176 EXPORT_SYMBOL(gspca_dev_probe);
2177 
2178 /*
2179  * USB disconnection
2180  *
2181  * This function must be called by the sub-driver
2182  * when the device disconnects, after the specific resources are freed.
2183  */
2184 void gspca_disconnect(struct usb_interface *intf)
2185 {
2186 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2187 #if IS_ENABLED(CONFIG_INPUT)
2188 	struct input_dev *input_dev;
2189 #endif
2190 
2191 	PDEBUG(D_PROBE, "%s disconnect",
2192 		video_device_node_name(&gspca_dev->vdev));
2193 
2194 	mutex_lock(&gspca_dev->usb_lock);
2195 
2196 	gspca_dev->present = 0;
2197 	destroy_urbs(gspca_dev);
2198 
2199 #if IS_ENABLED(CONFIG_INPUT)
2200 	gspca_input_destroy_urb(gspca_dev);
2201 	input_dev = gspca_dev->input_dev;
2202 	if (input_dev) {
2203 		gspca_dev->input_dev = NULL;
2204 		input_unregister_device(input_dev);
2205 	}
2206 #endif
2207 	/* Free subdriver's streaming resources / stop sd workqueue(s) */
2208 	if (gspca_dev->sd_desc->stop0 && gspca_dev->streaming)
2209 		gspca_dev->sd_desc->stop0(gspca_dev);
2210 	gspca_dev->streaming = 0;
2211 	gspca_dev->dev = NULL;
2212 	wake_up_interruptible(&gspca_dev->wq);
2213 
2214 	v4l2_device_disconnect(&gspca_dev->v4l2_dev);
2215 	video_unregister_device(&gspca_dev->vdev);
2216 
2217 	mutex_unlock(&gspca_dev->usb_lock);
2218 
2219 	/* (this will call gspca_release() immediately or on last close) */
2220 	v4l2_device_put(&gspca_dev->v4l2_dev);
2221 }
2222 EXPORT_SYMBOL(gspca_disconnect);
2223 
2224 #ifdef CONFIG_PM
2225 int gspca_suspend(struct usb_interface *intf, pm_message_t message)
2226 {
2227 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2228 
2229 	gspca_input_destroy_urb(gspca_dev);
2230 
2231 	if (!gspca_dev->streaming)
2232 		return 0;
2233 
2234 	mutex_lock(&gspca_dev->usb_lock);
2235 	gspca_dev->frozen = 1;		/* avoid urb error messages */
2236 	gspca_dev->usb_err = 0;
2237 	if (gspca_dev->sd_desc->stopN)
2238 		gspca_dev->sd_desc->stopN(gspca_dev);
2239 	destroy_urbs(gspca_dev);
2240 	gspca_set_alt0(gspca_dev);
2241 	if (gspca_dev->sd_desc->stop0)
2242 		gspca_dev->sd_desc->stop0(gspca_dev);
2243 	mutex_unlock(&gspca_dev->usb_lock);
2244 
2245 	return 0;
2246 }
2247 EXPORT_SYMBOL(gspca_suspend);
2248 
2249 int gspca_resume(struct usb_interface *intf)
2250 {
2251 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2252 	int streaming, ret = 0;
2253 
2254 	mutex_lock(&gspca_dev->usb_lock);
2255 	gspca_dev->frozen = 0;
2256 	gspca_dev->usb_err = 0;
2257 	gspca_dev->sd_desc->init(gspca_dev);
2258 	/*
2259 	 * Most subdrivers send all ctrl values on sd_start and thus
2260 	 * only write to the device registers on s_ctrl when streaming ->
2261 	 * Clear streaming to avoid setting all ctrls twice.
2262 	 */
2263 	streaming = gspca_dev->streaming;
2264 	gspca_dev->streaming = 0;
2265 	if (streaming)
2266 		ret = gspca_init_transfer(gspca_dev);
2267 	else
2268 		gspca_input_create_urb(gspca_dev);
2269 	mutex_unlock(&gspca_dev->usb_lock);
2270 
2271 	return ret;
2272 }
2273 EXPORT_SYMBOL(gspca_resume);
2274 #endif
2275 
2276 /* -- module insert / remove -- */
2277 static int __init gspca_init(void)
2278 {
2279 	pr_info("v" GSPCA_VERSION " registered\n");
2280 	return 0;
2281 }
2282 static void __exit gspca_exit(void)
2283 {
2284 }
2285 
2286 module_init(gspca_init);
2287 module_exit(gspca_exit);
2288 
2289 module_param_named(debug, gspca_debug, int, 0644);
2290 MODULE_PARM_DESC(debug,
2291 		"1:probe 2:config 3:stream 4:frame 5:packet 6:usbi 7:usbo");
2292