xref: /openbmc/linux/drivers/media/usb/gspca/gspca.c (revision 33ac9dba)
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  * If xfer_ep is invalid, return the first valid ep found, otherwise
609  * look for exactly the ep with address equal to xfer_ep.
610  */
611 static struct usb_host_endpoint *alt_xfer(struct usb_host_interface *alt,
612 					  int xfer, int xfer_ep)
613 {
614 	struct usb_host_endpoint *ep;
615 	int i, attr;
616 
617 	for (i = 0; i < alt->desc.bNumEndpoints; i++) {
618 		ep = &alt->endpoint[i];
619 		attr = ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
620 		if (attr == xfer
621 		    && ep->desc.wMaxPacketSize != 0
622 		    && usb_endpoint_dir_in(&ep->desc)
623 		    && (xfer_ep < 0 || ep->desc.bEndpointAddress == xfer_ep))
624 			return ep;
625 	}
626 	return NULL;
627 }
628 
629 /* compute the minimum bandwidth for the current transfer */
630 static u32 which_bandwidth(struct gspca_dev *gspca_dev)
631 {
632 	u32 bandwidth;
633 
634 	/* get the (max) image size */
635 	bandwidth = gspca_dev->pixfmt.sizeimage;
636 
637 	/* if the image is compressed, estimate its mean size */
638 	if (!gspca_dev->cam.needs_full_bandwidth &&
639 	    bandwidth < gspca_dev->pixfmt.width *
640 				gspca_dev->pixfmt.height)
641 		bandwidth = bandwidth * 3 / 8;	/* 0.375 */
642 
643 	/* estimate the frame rate */
644 	if (gspca_dev->sd_desc->get_streamparm) {
645 		struct v4l2_streamparm parm;
646 
647 		gspca_dev->sd_desc->get_streamparm(gspca_dev, &parm);
648 		bandwidth *= parm.parm.capture.timeperframe.denominator;
649 		bandwidth /= parm.parm.capture.timeperframe.numerator;
650 	} else {
651 
652 		/* don't hope more than 15 fps with USB 1.1 and
653 		 * image resolution >= 640x480 */
654 		if (gspca_dev->pixfmt.width >= 640
655 		 && gspca_dev->dev->speed == USB_SPEED_FULL)
656 			bandwidth *= 15;		/* 15 fps */
657 		else
658 			bandwidth *= 30;		/* 30 fps */
659 	}
660 
661 	PDEBUG(D_STREAM, "min bandwidth: %d", bandwidth);
662 	return bandwidth;
663 }
664 
665 /* endpoint table */
666 #define MAX_ALT 16
667 struct ep_tb_s {
668 	u32 alt;
669 	u32 bandwidth;
670 };
671 
672 /*
673  * build the table of the endpoints
674  * and compute the minimum bandwidth for the image transfer
675  */
676 static int build_isoc_ep_tb(struct gspca_dev *gspca_dev,
677 			struct usb_interface *intf,
678 			struct ep_tb_s *ep_tb)
679 {
680 	struct usb_host_endpoint *ep;
681 	int i, j, nbalt, psize, found;
682 	u32 bandwidth, last_bw;
683 
684 	nbalt = intf->num_altsetting;
685 	if (nbalt > MAX_ALT)
686 		nbalt = MAX_ALT;	/* fixme: should warn */
687 
688 	/* build the endpoint table */
689 	i = 0;
690 	last_bw = 0;
691 	for (;;) {
692 		ep_tb->bandwidth = 2000 * 2000 * 120;
693 		found = 0;
694 		for (j = 0; j < nbalt; j++) {
695 			ep = alt_xfer(&intf->altsetting[j],
696 				      USB_ENDPOINT_XFER_ISOC,
697 				      gspca_dev->xfer_ep);
698 			if (ep == NULL)
699 				continue;
700 			if (ep->desc.bInterval == 0) {
701 				pr_err("alt %d iso endp with 0 interval\n", j);
702 				continue;
703 			}
704 			psize = le16_to_cpu(ep->desc.wMaxPacketSize);
705 			psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
706 			bandwidth = psize * 1000;
707 			if (gspca_dev->dev->speed == USB_SPEED_HIGH
708 			 || gspca_dev->dev->speed == USB_SPEED_SUPER)
709 				bandwidth *= 8;
710 			bandwidth /= 1 << (ep->desc.bInterval - 1);
711 			if (bandwidth <= last_bw)
712 				continue;
713 			if (bandwidth < ep_tb->bandwidth) {
714 				ep_tb->bandwidth = bandwidth;
715 				ep_tb->alt = j;
716 				found = 1;
717 			}
718 		}
719 		if (!found)
720 			break;
721 		PDEBUG(D_STREAM, "alt %d bandwidth %d",
722 				ep_tb->alt, ep_tb->bandwidth);
723 		last_bw = ep_tb->bandwidth;
724 		i++;
725 		ep_tb++;
726 	}
727 
728 	/*
729 	 * If the camera:
730 	 * has a usb audio class interface (a built in usb mic); and
731 	 * is a usb 1 full speed device; and
732 	 * uses the max full speed iso bandwidth; and
733 	 * and has more than 1 alt setting
734 	 * then skip the highest alt setting to spare bandwidth for the mic
735 	 */
736 	if (gspca_dev->audio &&
737 			gspca_dev->dev->speed == USB_SPEED_FULL &&
738 			last_bw >= 1000000 &&
739 			i > 1) {
740 		PDEBUG(D_STREAM, "dev has usb audio, skipping highest alt");
741 		i--;
742 		ep_tb--;
743 	}
744 
745 	/* get the requested bandwidth and start at the highest atlsetting */
746 	bandwidth = which_bandwidth(gspca_dev);
747 	ep_tb--;
748 	while (i > 1) {
749 		ep_tb--;
750 		if (ep_tb->bandwidth < bandwidth)
751 			break;
752 		i--;
753 	}
754 	return i;
755 }
756 
757 /*
758  * create the URBs for image transfer
759  */
760 static int create_urbs(struct gspca_dev *gspca_dev,
761 			struct usb_host_endpoint *ep)
762 {
763 	struct urb *urb;
764 	int n, nurbs, i, psize, npkt, bsize;
765 
766 	/* calculate the packet size and the number of packets */
767 	psize = le16_to_cpu(ep->desc.wMaxPacketSize);
768 
769 	if (!gspca_dev->cam.bulk) {		/* isoc */
770 
771 		/* See paragraph 5.9 / table 5-11 of the usb 2.0 spec. */
772 		if (gspca_dev->pkt_size == 0)
773 			psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
774 		else
775 			psize = gspca_dev->pkt_size;
776 		npkt = gspca_dev->cam.npkt;
777 		if (npkt == 0)
778 			npkt = 32;		/* default value */
779 		bsize = psize * npkt;
780 		PDEBUG(D_STREAM,
781 			"isoc %d pkts size %d = bsize:%d",
782 			npkt, psize, bsize);
783 		nurbs = DEF_NURBS;
784 	} else {				/* bulk */
785 		npkt = 0;
786 		bsize = gspca_dev->cam.bulk_size;
787 		if (bsize == 0)
788 			bsize = psize;
789 		PDEBUG(D_STREAM, "bulk bsize:%d", bsize);
790 		if (gspca_dev->cam.bulk_nurbs != 0)
791 			nurbs = gspca_dev->cam.bulk_nurbs;
792 		else
793 			nurbs = 1;
794 	}
795 
796 	for (n = 0; n < nurbs; n++) {
797 		urb = usb_alloc_urb(npkt, GFP_KERNEL);
798 		if (!urb) {
799 			pr_err("usb_alloc_urb failed\n");
800 			return -ENOMEM;
801 		}
802 		gspca_dev->urb[n] = urb;
803 		urb->transfer_buffer = usb_alloc_coherent(gspca_dev->dev,
804 						bsize,
805 						GFP_KERNEL,
806 						&urb->transfer_dma);
807 
808 		if (urb->transfer_buffer == NULL) {
809 			pr_err("usb_alloc_coherent failed\n");
810 			return -ENOMEM;
811 		}
812 		urb->dev = gspca_dev->dev;
813 		urb->context = gspca_dev;
814 		urb->transfer_buffer_length = bsize;
815 		if (npkt != 0) {		/* ISOC */
816 			urb->pipe = usb_rcvisocpipe(gspca_dev->dev,
817 						    ep->desc.bEndpointAddress);
818 			urb->transfer_flags = URB_ISO_ASAP
819 					| URB_NO_TRANSFER_DMA_MAP;
820 			urb->interval = 1 << (ep->desc.bInterval - 1);
821 			urb->complete = isoc_irq;
822 			urb->number_of_packets = npkt;
823 			for (i = 0; i < npkt; i++) {
824 				urb->iso_frame_desc[i].length = psize;
825 				urb->iso_frame_desc[i].offset = psize * i;
826 			}
827 		} else {		/* bulk */
828 			urb->pipe = usb_rcvbulkpipe(gspca_dev->dev,
829 						ep->desc.bEndpointAddress);
830 			urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
831 			urb->complete = bulk_irq;
832 		}
833 	}
834 	return 0;
835 }
836 
837 /*
838  * start the USB transfer
839  */
840 static int gspca_init_transfer(struct gspca_dev *gspca_dev)
841 {
842 	struct usb_interface *intf;
843 	struct usb_host_endpoint *ep;
844 	struct urb *urb;
845 	struct ep_tb_s ep_tb[MAX_ALT];
846 	int n, ret, xfer, alt, alt_idx;
847 
848 	/* reset the streaming variables */
849 	gspca_dev->image = NULL;
850 	gspca_dev->image_len = 0;
851 	gspca_dev->last_packet_type = DISCARD_PACKET;
852 	gspca_dev->sequence = 0;
853 
854 	gspca_dev->usb_err = 0;
855 
856 	/* do the specific subdriver stuff before endpoint selection */
857 	intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
858 	gspca_dev->alt = gspca_dev->cam.bulk ? intf->num_altsetting : 0;
859 	if (gspca_dev->sd_desc->isoc_init) {
860 		ret = gspca_dev->sd_desc->isoc_init(gspca_dev);
861 		if (ret < 0)
862 			return ret;
863 	}
864 	xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK
865 				   : USB_ENDPOINT_XFER_ISOC;
866 
867 	/* if bulk or the subdriver forced an altsetting, get the endpoint */
868 	if (gspca_dev->alt != 0) {
869 		gspca_dev->alt--;	/* (previous version compatibility) */
870 		ep = alt_xfer(&intf->altsetting[gspca_dev->alt], xfer,
871 			      gspca_dev->xfer_ep);
872 		if (ep == NULL) {
873 			pr_err("bad altsetting %d\n", gspca_dev->alt);
874 			return -EIO;
875 		}
876 		ep_tb[0].alt = gspca_dev->alt;
877 		alt_idx = 1;
878 	} else {
879 
880 	/* else, compute the minimum bandwidth
881 	 * and build the endpoint table */
882 		alt_idx = build_isoc_ep_tb(gspca_dev, intf, ep_tb);
883 		if (alt_idx <= 0) {
884 			pr_err("no transfer endpoint found\n");
885 			return -EIO;
886 		}
887 	}
888 
889 	/* set the highest alternate setting and
890 	 * loop until urb submit succeeds */
891 	gspca_input_destroy_urb(gspca_dev);
892 
893 	gspca_dev->alt = ep_tb[--alt_idx].alt;
894 	alt = -1;
895 	for (;;) {
896 		if (alt != gspca_dev->alt) {
897 			alt = gspca_dev->alt;
898 			if (intf->num_altsetting > 1) {
899 				ret = usb_set_interface(gspca_dev->dev,
900 							gspca_dev->iface,
901 							alt);
902 				if (ret < 0) {
903 					if (ret == -ENOSPC)
904 						goto retry; /*fixme: ugly*/
905 					pr_err("set alt %d err %d\n", alt, ret);
906 					goto out;
907 				}
908 			}
909 		}
910 		if (!gspca_dev->cam.no_urb_create) {
911 			PDEBUG(D_STREAM, "init transfer alt %d", alt);
912 			ret = create_urbs(gspca_dev,
913 				alt_xfer(&intf->altsetting[alt], xfer,
914 					 gspca_dev->xfer_ep));
915 			if (ret < 0) {
916 				destroy_urbs(gspca_dev);
917 				goto out;
918 			}
919 		}
920 
921 		/* clear the bulk endpoint */
922 		if (gspca_dev->cam.bulk)
923 			usb_clear_halt(gspca_dev->dev,
924 					gspca_dev->urb[0]->pipe);
925 
926 		/* start the cam */
927 		ret = gspca_dev->sd_desc->start(gspca_dev);
928 		if (ret < 0) {
929 			destroy_urbs(gspca_dev);
930 			goto out;
931 		}
932 		gspca_dev->streaming = 1;
933 		v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
934 
935 		/* some bulk transfers are started by the subdriver */
936 		if (gspca_dev->cam.bulk && gspca_dev->cam.bulk_nurbs == 0)
937 			break;
938 
939 		/* submit the URBs */
940 		for (n = 0; n < MAX_NURBS; n++) {
941 			urb = gspca_dev->urb[n];
942 			if (urb == NULL)
943 				break;
944 			ret = usb_submit_urb(urb, GFP_KERNEL);
945 			if (ret < 0)
946 				break;
947 		}
948 		if (ret >= 0)
949 			break;			/* transfer is started */
950 
951 		/* something when wrong
952 		 * stop the webcam and free the transfer resources */
953 		gspca_stream_off(gspca_dev);
954 		if (ret != -ENOSPC) {
955 			pr_err("usb_submit_urb alt %d err %d\n",
956 			       gspca_dev->alt, ret);
957 			goto out;
958 		}
959 
960 		/* the bandwidth is not wide enough
961 		 * negotiate or try a lower alternate setting */
962 retry:
963 		PERR("alt %d - bandwidth not wide enough, trying again", alt);
964 		msleep(20);	/* wait for kill complete */
965 		if (gspca_dev->sd_desc->isoc_nego) {
966 			ret = gspca_dev->sd_desc->isoc_nego(gspca_dev);
967 			if (ret < 0)
968 				goto out;
969 		} else {
970 			if (alt_idx <= 0) {
971 				pr_err("no transfer endpoint found\n");
972 				ret = -EIO;
973 				goto out;
974 			}
975 			gspca_dev->alt = ep_tb[--alt_idx].alt;
976 		}
977 	}
978 out:
979 	gspca_input_create_urb(gspca_dev);
980 	return ret;
981 }
982 
983 static void gspca_set_default_mode(struct gspca_dev *gspca_dev)
984 {
985 	int i;
986 
987 	i = gspca_dev->cam.nmodes - 1;	/* take the highest mode */
988 	gspca_dev->curr_mode = i;
989 	gspca_dev->pixfmt = gspca_dev->cam.cam_mode[i];
990 
991 	/* does nothing if ctrl_handler == NULL */
992 	v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
993 }
994 
995 static int wxh_to_mode(struct gspca_dev *gspca_dev,
996 			int width, int height)
997 {
998 	int i;
999 
1000 	for (i = gspca_dev->cam.nmodes; --i > 0; ) {
1001 		if (width >= gspca_dev->cam.cam_mode[i].width
1002 		    && height >= gspca_dev->cam.cam_mode[i].height)
1003 			break;
1004 	}
1005 	return i;
1006 }
1007 
1008 /*
1009  * search a mode with the right pixel format
1010  */
1011 static int gspca_get_mode(struct gspca_dev *gspca_dev,
1012 			int mode,
1013 			int pixfmt)
1014 {
1015 	int modeU, modeD;
1016 
1017 	modeU = modeD = mode;
1018 	while ((modeU < gspca_dev->cam.nmodes) || modeD >= 0) {
1019 		if (--modeD >= 0) {
1020 			if (gspca_dev->cam.cam_mode[modeD].pixelformat
1021 								== pixfmt)
1022 				return modeD;
1023 		}
1024 		if (++modeU < gspca_dev->cam.nmodes) {
1025 			if (gspca_dev->cam.cam_mode[modeU].pixelformat
1026 								== pixfmt)
1027 				return modeU;
1028 		}
1029 	}
1030 	return -EINVAL;
1031 }
1032 
1033 #ifdef CONFIG_VIDEO_ADV_DEBUG
1034 static int vidioc_g_chip_info(struct file *file, void *priv,
1035 				struct v4l2_dbg_chip_info *chip)
1036 {
1037 	struct gspca_dev *gspca_dev = video_drvdata(file);
1038 
1039 	gspca_dev->usb_err = 0;
1040 	if (gspca_dev->sd_desc->get_chip_info)
1041 		return gspca_dev->sd_desc->get_chip_info(gspca_dev, chip);
1042 	return chip->match.addr ? -EINVAL : 0;
1043 }
1044 
1045 static int vidioc_g_register(struct file *file, void *priv,
1046 		struct v4l2_dbg_register *reg)
1047 {
1048 	struct gspca_dev *gspca_dev = video_drvdata(file);
1049 
1050 	gspca_dev->usb_err = 0;
1051 	return gspca_dev->sd_desc->get_register(gspca_dev, reg);
1052 }
1053 
1054 static int vidioc_s_register(struct file *file, void *priv,
1055 		const 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->set_register(gspca_dev, reg);
1061 }
1062 #endif
1063 
1064 static int vidioc_enum_fmt_vid_cap(struct file *file, void  *priv,
1065 				struct v4l2_fmtdesc *fmtdesc)
1066 {
1067 	struct gspca_dev *gspca_dev = video_drvdata(file);
1068 	int i, j, index;
1069 	__u32 fmt_tb[8];
1070 
1071 	/* give an index to each format */
1072 	index = 0;
1073 	j = 0;
1074 	for (i = gspca_dev->cam.nmodes; --i >= 0; ) {
1075 		fmt_tb[index] = gspca_dev->cam.cam_mode[i].pixelformat;
1076 		j = 0;
1077 		for (;;) {
1078 			if (fmt_tb[j] == fmt_tb[index])
1079 				break;
1080 			j++;
1081 		}
1082 		if (j == index) {
1083 			if (fmtdesc->index == index)
1084 				break;		/* new format */
1085 			index++;
1086 			if (index >= ARRAY_SIZE(fmt_tb))
1087 				return -EINVAL;
1088 		}
1089 	}
1090 	if (i < 0)
1091 		return -EINVAL;		/* no more format */
1092 
1093 	fmtdesc->pixelformat = fmt_tb[index];
1094 	if (gspca_dev->cam.cam_mode[i].sizeimage <
1095 			gspca_dev->cam.cam_mode[i].width *
1096 				gspca_dev->cam.cam_mode[i].height)
1097 		fmtdesc->flags = V4L2_FMT_FLAG_COMPRESSED;
1098 	fmtdesc->description[0] = fmtdesc->pixelformat & 0xff;
1099 	fmtdesc->description[1] = (fmtdesc->pixelformat >> 8) & 0xff;
1100 	fmtdesc->description[2] = (fmtdesc->pixelformat >> 16) & 0xff;
1101 	fmtdesc->description[3] = fmtdesc->pixelformat >> 24;
1102 	fmtdesc->description[4] = '\0';
1103 	return 0;
1104 }
1105 
1106 static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
1107 			    struct v4l2_format *fmt)
1108 {
1109 	struct gspca_dev *gspca_dev = video_drvdata(file);
1110 
1111 	fmt->fmt.pix = gspca_dev->pixfmt;
1112 	/* some drivers use priv internally, zero it before giving it back to
1113 	   the core */
1114 	fmt->fmt.pix.priv = 0;
1115 	return 0;
1116 }
1117 
1118 static int try_fmt_vid_cap(struct gspca_dev *gspca_dev,
1119 			struct v4l2_format *fmt)
1120 {
1121 	int w, h, mode, mode2;
1122 
1123 	w = fmt->fmt.pix.width;
1124 	h = fmt->fmt.pix.height;
1125 
1126 	PDEBUG_MODE(gspca_dev, D_CONF, "try fmt cap",
1127 		    fmt->fmt.pix.pixelformat, w, h);
1128 
1129 	/* search the closest mode for width and height */
1130 	mode = wxh_to_mode(gspca_dev, w, h);
1131 
1132 	/* OK if right palette */
1133 	if (gspca_dev->cam.cam_mode[mode].pixelformat
1134 						!= fmt->fmt.pix.pixelformat) {
1135 
1136 		/* else, search the closest mode with the same pixel format */
1137 		mode2 = gspca_get_mode(gspca_dev, mode,
1138 					fmt->fmt.pix.pixelformat);
1139 		if (mode2 >= 0)
1140 			mode = mode2;
1141 	}
1142 	fmt->fmt.pix = gspca_dev->cam.cam_mode[mode];
1143 	if (gspca_dev->sd_desc->try_fmt) {
1144 		/* pass original resolution to subdriver try_fmt */
1145 		fmt->fmt.pix.width = w;
1146 		fmt->fmt.pix.height = h;
1147 		gspca_dev->sd_desc->try_fmt(gspca_dev, fmt);
1148 	}
1149 	/* some drivers use priv internally, zero it before giving it back to
1150 	   the core */
1151 	fmt->fmt.pix.priv = 0;
1152 	return mode;			/* used when s_fmt */
1153 }
1154 
1155 static int vidioc_try_fmt_vid_cap(struct file *file,
1156 			      void *priv,
1157 			      struct v4l2_format *fmt)
1158 {
1159 	struct gspca_dev *gspca_dev = video_drvdata(file);
1160 	int ret;
1161 
1162 	ret = try_fmt_vid_cap(gspca_dev, fmt);
1163 	if (ret < 0)
1164 		return ret;
1165 	return 0;
1166 }
1167 
1168 static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
1169 			    struct v4l2_format *fmt)
1170 {
1171 	struct gspca_dev *gspca_dev = video_drvdata(file);
1172 	int ret;
1173 
1174 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1175 		return -ERESTARTSYS;
1176 
1177 	ret = try_fmt_vid_cap(gspca_dev, fmt);
1178 	if (ret < 0)
1179 		goto out;
1180 
1181 	if (gspca_dev->nframes != 0
1182 	    && fmt->fmt.pix.sizeimage > gspca_dev->frsz) {
1183 		ret = -EINVAL;
1184 		goto out;
1185 	}
1186 
1187 	if (gspca_dev->streaming) {
1188 		ret = -EBUSY;
1189 		goto out;
1190 	}
1191 	gspca_dev->curr_mode = ret;
1192 	if (gspca_dev->sd_desc->try_fmt)
1193 		/* subdriver try_fmt can modify format parameters */
1194 		gspca_dev->pixfmt = fmt->fmt.pix;
1195 	else
1196 		gspca_dev->pixfmt = gspca_dev->cam.cam_mode[ret];
1197 
1198 	ret = 0;
1199 out:
1200 	mutex_unlock(&gspca_dev->queue_lock);
1201 	return ret;
1202 }
1203 
1204 static int vidioc_enum_framesizes(struct file *file, void *priv,
1205 				  struct v4l2_frmsizeenum *fsize)
1206 {
1207 	struct gspca_dev *gspca_dev = video_drvdata(file);
1208 	int i;
1209 	__u32 index = 0;
1210 
1211 	if (gspca_dev->sd_desc->enum_framesizes)
1212 		return gspca_dev->sd_desc->enum_framesizes(gspca_dev, fsize);
1213 
1214 	for (i = 0; i < gspca_dev->cam.nmodes; i++) {
1215 		if (fsize->pixel_format !=
1216 				gspca_dev->cam.cam_mode[i].pixelformat)
1217 			continue;
1218 
1219 		if (fsize->index == index) {
1220 			fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1221 			fsize->discrete.width =
1222 				gspca_dev->cam.cam_mode[i].width;
1223 			fsize->discrete.height =
1224 				gspca_dev->cam.cam_mode[i].height;
1225 			return 0;
1226 		}
1227 		index++;
1228 	}
1229 
1230 	return -EINVAL;
1231 }
1232 
1233 static int vidioc_enum_frameintervals(struct file *filp, void *priv,
1234 				      struct v4l2_frmivalenum *fival)
1235 {
1236 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1237 	int mode = wxh_to_mode(gspca_dev, fival->width, fival->height);
1238 	__u32 i;
1239 
1240 	if (gspca_dev->cam.mode_framerates == NULL ||
1241 			gspca_dev->cam.mode_framerates[mode].nrates == 0)
1242 		return -EINVAL;
1243 
1244 	if (fival->pixel_format !=
1245 			gspca_dev->cam.cam_mode[mode].pixelformat)
1246 		return -EINVAL;
1247 
1248 	for (i = 0; i < gspca_dev->cam.mode_framerates[mode].nrates; i++) {
1249 		if (fival->index == i) {
1250 			fival->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1251 			fival->discrete.numerator = 1;
1252 			fival->discrete.denominator =
1253 				gspca_dev->cam.mode_framerates[mode].rates[i];
1254 			return 0;
1255 		}
1256 	}
1257 
1258 	return -EINVAL;
1259 }
1260 
1261 static void gspca_release(struct v4l2_device *v4l2_device)
1262 {
1263 	struct gspca_dev *gspca_dev =
1264 		container_of(v4l2_device, struct gspca_dev, v4l2_dev);
1265 
1266 	v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
1267 	v4l2_device_unregister(&gspca_dev->v4l2_dev);
1268 	kfree(gspca_dev->usb_buf);
1269 	kfree(gspca_dev);
1270 }
1271 
1272 static int dev_open(struct file *file)
1273 {
1274 	struct gspca_dev *gspca_dev = video_drvdata(file);
1275 	int ret;
1276 
1277 	PDEBUG(D_STREAM, "[%s] open", current->comm);
1278 
1279 	/* protect the subdriver against rmmod */
1280 	if (!try_module_get(gspca_dev->module))
1281 		return -ENODEV;
1282 
1283 	ret = v4l2_fh_open(file);
1284 	if (ret)
1285 		module_put(gspca_dev->module);
1286 	return ret;
1287 }
1288 
1289 static int dev_close(struct file *file)
1290 {
1291 	struct gspca_dev *gspca_dev = video_drvdata(file);
1292 
1293 	PDEBUG(D_STREAM, "[%s] close", current->comm);
1294 
1295 	/* Needed for gspca_stream_off, always lock before queue_lock! */
1296 	if (mutex_lock_interruptible(&gspca_dev->usb_lock))
1297 		return -ERESTARTSYS;
1298 
1299 	if (mutex_lock_interruptible(&gspca_dev->queue_lock)) {
1300 		mutex_unlock(&gspca_dev->usb_lock);
1301 		return -ERESTARTSYS;
1302 	}
1303 
1304 	/* if the file did the capture, free the streaming resources */
1305 	if (gspca_dev->capt_file == file) {
1306 		if (gspca_dev->streaming)
1307 			gspca_stream_off(gspca_dev);
1308 		frame_free(gspca_dev);
1309 	}
1310 	module_put(gspca_dev->module);
1311 	mutex_unlock(&gspca_dev->queue_lock);
1312 	mutex_unlock(&gspca_dev->usb_lock);
1313 
1314 	PDEBUG(D_STREAM, "close done");
1315 
1316 	return v4l2_fh_release(file);
1317 }
1318 
1319 static int vidioc_querycap(struct file *file, void  *priv,
1320 			   struct v4l2_capability *cap)
1321 {
1322 	struct gspca_dev *gspca_dev = video_drvdata(file);
1323 
1324 	strlcpy((char *) cap->driver, gspca_dev->sd_desc->name,
1325 			sizeof cap->driver);
1326 	if (gspca_dev->dev->product != NULL) {
1327 		strlcpy((char *) cap->card, gspca_dev->dev->product,
1328 			sizeof cap->card);
1329 	} else {
1330 		snprintf((char *) cap->card, sizeof cap->card,
1331 			"USB Camera (%04x:%04x)",
1332 			le16_to_cpu(gspca_dev->dev->descriptor.idVendor),
1333 			le16_to_cpu(gspca_dev->dev->descriptor.idProduct));
1334 	}
1335 	usb_make_path(gspca_dev->dev, (char *) cap->bus_info,
1336 			sizeof(cap->bus_info));
1337 	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE
1338 			  | V4L2_CAP_STREAMING
1339 			  | V4L2_CAP_READWRITE;
1340 	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
1341 	return 0;
1342 }
1343 
1344 static int vidioc_enum_input(struct file *file, void *priv,
1345 				struct v4l2_input *input)
1346 {
1347 	struct gspca_dev *gspca_dev = video_drvdata(file);
1348 
1349 	if (input->index != 0)
1350 		return -EINVAL;
1351 	input->type = V4L2_INPUT_TYPE_CAMERA;
1352 	input->status = gspca_dev->cam.input_flags;
1353 	strlcpy(input->name, gspca_dev->sd_desc->name,
1354 		sizeof input->name);
1355 	return 0;
1356 }
1357 
1358 static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
1359 {
1360 	*i = 0;
1361 	return 0;
1362 }
1363 
1364 static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
1365 {
1366 	if (i > 0)
1367 		return -EINVAL;
1368 	return (0);
1369 }
1370 
1371 static int vidioc_reqbufs(struct file *file, void *priv,
1372 			  struct v4l2_requestbuffers *rb)
1373 {
1374 	struct gspca_dev *gspca_dev = video_drvdata(file);
1375 	int i, ret = 0, streaming;
1376 
1377 	i = rb->memory;			/* (avoid compilation warning) */
1378 	switch (i) {
1379 	case GSPCA_MEMORY_READ:			/* (internal call) */
1380 	case V4L2_MEMORY_MMAP:
1381 	case V4L2_MEMORY_USERPTR:
1382 		break;
1383 	default:
1384 		return -EINVAL;
1385 	}
1386 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1387 		return -ERESTARTSYS;
1388 
1389 	if (gspca_dev->memory != GSPCA_MEMORY_NO
1390 	    && gspca_dev->memory != GSPCA_MEMORY_READ
1391 	    && gspca_dev->memory != rb->memory) {
1392 		ret = -EBUSY;
1393 		goto out;
1394 	}
1395 
1396 	/* only one file may do the capture */
1397 	if (gspca_dev->capt_file != NULL
1398 	    && gspca_dev->capt_file != file) {
1399 		ret = -EBUSY;
1400 		goto out;
1401 	}
1402 
1403 	/* if allocated, the buffers must not be mapped */
1404 	for (i = 0; i < gspca_dev->nframes; i++) {
1405 		if (gspca_dev->frame[i].vma_use_count) {
1406 			ret = -EBUSY;
1407 			goto out;
1408 		}
1409 	}
1410 
1411 	/* stop streaming */
1412 	streaming = gspca_dev->streaming;
1413 	if (streaming) {
1414 		gspca_stream_off(gspca_dev);
1415 
1416 		/* Don't restart the stream when switching from read
1417 		 * to mmap mode */
1418 		if (gspca_dev->memory == GSPCA_MEMORY_READ)
1419 			streaming = 0;
1420 	}
1421 
1422 	/* free the previous allocated buffers, if any */
1423 	if (gspca_dev->nframes != 0)
1424 		frame_free(gspca_dev);
1425 	if (rb->count == 0)			/* unrequest */
1426 		goto out;
1427 	ret = frame_alloc(gspca_dev, file, rb->memory, rb->count);
1428 	if (ret == 0) {
1429 		rb->count = gspca_dev->nframes;
1430 		if (streaming)
1431 			ret = gspca_init_transfer(gspca_dev);
1432 	}
1433 out:
1434 	mutex_unlock(&gspca_dev->queue_lock);
1435 	PDEBUG(D_STREAM, "reqbufs st:%d c:%d", ret, rb->count);
1436 	return ret;
1437 }
1438 
1439 static int vidioc_querybuf(struct file *file, void *priv,
1440 			   struct v4l2_buffer *v4l2_buf)
1441 {
1442 	struct gspca_dev *gspca_dev = video_drvdata(file);
1443 	struct gspca_frame *frame;
1444 
1445 	if (v4l2_buf->index >= gspca_dev->nframes)
1446 		return -EINVAL;
1447 
1448 	frame = &gspca_dev->frame[v4l2_buf->index];
1449 	memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
1450 	return 0;
1451 }
1452 
1453 static int vidioc_streamon(struct file *file, void *priv,
1454 			   enum v4l2_buf_type buf_type)
1455 {
1456 	struct gspca_dev *gspca_dev = video_drvdata(file);
1457 	int ret;
1458 
1459 	if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1460 		return -EINVAL;
1461 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1462 		return -ERESTARTSYS;
1463 
1464 	/* check the capture file */
1465 	if (gspca_dev->capt_file != file) {
1466 		ret = -EBUSY;
1467 		goto out;
1468 	}
1469 
1470 	if (gspca_dev->nframes == 0
1471 	    || !(gspca_dev->frame[0].v4l2_buf.flags & V4L2_BUF_FLAG_QUEUED)) {
1472 		ret = -EINVAL;
1473 		goto out;
1474 	}
1475 	if (!gspca_dev->streaming) {
1476 		ret = gspca_init_transfer(gspca_dev);
1477 		if (ret < 0)
1478 			goto out;
1479 	}
1480 	PDEBUG_MODE(gspca_dev, D_STREAM, "stream on OK",
1481 		    gspca_dev->pixfmt.pixelformat,
1482 		    gspca_dev->pixfmt.width, gspca_dev->pixfmt.height);
1483 	ret = 0;
1484 out:
1485 	mutex_unlock(&gspca_dev->queue_lock);
1486 	return ret;
1487 }
1488 
1489 static int vidioc_streamoff(struct file *file, void *priv,
1490 				enum v4l2_buf_type buf_type)
1491 {
1492 	struct gspca_dev *gspca_dev = video_drvdata(file);
1493 	int i, ret;
1494 
1495 	if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1496 		return -EINVAL;
1497 
1498 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1499 		return -ERESTARTSYS;
1500 
1501 	if (!gspca_dev->streaming) {
1502 		ret = 0;
1503 		goto out;
1504 	}
1505 
1506 	/* check the capture file */
1507 	if (gspca_dev->capt_file != file) {
1508 		ret = -EBUSY;
1509 		goto out;
1510 	}
1511 
1512 	/* stop streaming */
1513 	gspca_stream_off(gspca_dev);
1514 	/* In case another thread is waiting in dqbuf */
1515 	wake_up_interruptible(&gspca_dev->wq);
1516 
1517 	/* empty the transfer queues */
1518 	for (i = 0; i < gspca_dev->nframes; i++)
1519 		gspca_dev->frame[i].v4l2_buf.flags &= ~BUF_ALL_FLAGS;
1520 	atomic_set(&gspca_dev->fr_q, 0);
1521 	atomic_set(&gspca_dev->fr_i, 0);
1522 	gspca_dev->fr_o = 0;
1523 	ret = 0;
1524 out:
1525 	mutex_unlock(&gspca_dev->queue_lock);
1526 	return ret;
1527 }
1528 
1529 static int vidioc_g_jpegcomp(struct file *file, void *priv,
1530 			struct v4l2_jpegcompression *jpegcomp)
1531 {
1532 	struct gspca_dev *gspca_dev = video_drvdata(file);
1533 
1534 	gspca_dev->usb_err = 0;
1535 	return gspca_dev->sd_desc->get_jcomp(gspca_dev, jpegcomp);
1536 }
1537 
1538 static int vidioc_s_jpegcomp(struct file *file, void *priv,
1539 			const struct v4l2_jpegcompression *jpegcomp)
1540 {
1541 	struct gspca_dev *gspca_dev = video_drvdata(file);
1542 
1543 	gspca_dev->usb_err = 0;
1544 	return gspca_dev->sd_desc->set_jcomp(gspca_dev, jpegcomp);
1545 }
1546 
1547 static int vidioc_g_parm(struct file *filp, void *priv,
1548 			struct v4l2_streamparm *parm)
1549 {
1550 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1551 
1552 	parm->parm.capture.readbuffers = gspca_dev->nbufread;
1553 
1554 	if (gspca_dev->sd_desc->get_streamparm) {
1555 		gspca_dev->usb_err = 0;
1556 		gspca_dev->sd_desc->get_streamparm(gspca_dev, parm);
1557 		return gspca_dev->usb_err;
1558 	}
1559 	return 0;
1560 }
1561 
1562 static int vidioc_s_parm(struct file *filp, void *priv,
1563 			struct v4l2_streamparm *parm)
1564 {
1565 	struct gspca_dev *gspca_dev = video_drvdata(filp);
1566 	int n;
1567 
1568 	n = parm->parm.capture.readbuffers;
1569 	if (n == 0 || n >= GSPCA_MAX_FRAMES)
1570 		parm->parm.capture.readbuffers = gspca_dev->nbufread;
1571 	else
1572 		gspca_dev->nbufread = n;
1573 
1574 	if (gspca_dev->sd_desc->set_streamparm) {
1575 		gspca_dev->usb_err = 0;
1576 		gspca_dev->sd_desc->set_streamparm(gspca_dev, parm);
1577 		return gspca_dev->usb_err;
1578 	}
1579 
1580 	return 0;
1581 }
1582 
1583 static int dev_mmap(struct file *file, struct vm_area_struct *vma)
1584 {
1585 	struct gspca_dev *gspca_dev = video_drvdata(file);
1586 	struct gspca_frame *frame;
1587 	struct page *page;
1588 	unsigned long addr, start, size;
1589 	int i, ret;
1590 
1591 	start = vma->vm_start;
1592 	size = vma->vm_end - vma->vm_start;
1593 	PDEBUG(D_STREAM, "mmap start:%08x size:%d", (int) start, (int) size);
1594 
1595 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1596 		return -ERESTARTSYS;
1597 	if (gspca_dev->capt_file != file) {
1598 		ret = -EINVAL;
1599 		goto out;
1600 	}
1601 
1602 	frame = NULL;
1603 	for (i = 0; i < gspca_dev->nframes; ++i) {
1604 		if (gspca_dev->frame[i].v4l2_buf.memory != V4L2_MEMORY_MMAP) {
1605 			PDEBUG(D_STREAM, "mmap bad memory type");
1606 			break;
1607 		}
1608 		if ((gspca_dev->frame[i].v4l2_buf.m.offset >> PAGE_SHIFT)
1609 						== vma->vm_pgoff) {
1610 			frame = &gspca_dev->frame[i];
1611 			break;
1612 		}
1613 	}
1614 	if (frame == NULL) {
1615 		PDEBUG(D_STREAM, "mmap no frame buffer found");
1616 		ret = -EINVAL;
1617 		goto out;
1618 	}
1619 	if (size != frame->v4l2_buf.length) {
1620 		PDEBUG(D_STREAM, "mmap bad size");
1621 		ret = -EINVAL;
1622 		goto out;
1623 	}
1624 
1625 	/*
1626 	 * - VM_IO marks the area as being a mmaped region for I/O to a
1627 	 *   device. It also prevents the region from being core dumped.
1628 	 */
1629 	vma->vm_flags |= VM_IO;
1630 
1631 	addr = (unsigned long) frame->data;
1632 	while (size > 0) {
1633 		page = vmalloc_to_page((void *) addr);
1634 		ret = vm_insert_page(vma, start, page);
1635 		if (ret < 0)
1636 			goto out;
1637 		start += PAGE_SIZE;
1638 		addr += PAGE_SIZE;
1639 		size -= PAGE_SIZE;
1640 	}
1641 
1642 	vma->vm_ops = &gspca_vm_ops;
1643 	vma->vm_private_data = frame;
1644 	gspca_vm_open(vma);
1645 	ret = 0;
1646 out:
1647 	mutex_unlock(&gspca_dev->queue_lock);
1648 	return ret;
1649 }
1650 
1651 static int frame_ready_nolock(struct gspca_dev *gspca_dev, struct file *file,
1652 				enum v4l2_memory memory)
1653 {
1654 	if (!gspca_dev->present)
1655 		return -ENODEV;
1656 	if (gspca_dev->capt_file != file || gspca_dev->memory != memory ||
1657 			!gspca_dev->streaming)
1658 		return -EINVAL;
1659 
1660 	/* check if a frame is ready */
1661 	return gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i);
1662 }
1663 
1664 static int frame_ready(struct gspca_dev *gspca_dev, struct file *file,
1665 			enum v4l2_memory memory)
1666 {
1667 	int ret;
1668 
1669 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1670 		return -ERESTARTSYS;
1671 	ret = frame_ready_nolock(gspca_dev, file, memory);
1672 	mutex_unlock(&gspca_dev->queue_lock);
1673 	return ret;
1674 }
1675 
1676 /*
1677  * dequeue a video buffer
1678  *
1679  * If nonblock_ing is false, block until a buffer is available.
1680  */
1681 static int vidioc_dqbuf(struct file *file, void *priv,
1682 			struct v4l2_buffer *v4l2_buf)
1683 {
1684 	struct gspca_dev *gspca_dev = video_drvdata(file);
1685 	struct gspca_frame *frame;
1686 	int i, j, ret;
1687 
1688 	PDEBUG(D_FRAM, "dqbuf");
1689 
1690 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1691 		return -ERESTARTSYS;
1692 
1693 	for (;;) {
1694 		ret = frame_ready_nolock(gspca_dev, file, v4l2_buf->memory);
1695 		if (ret < 0)
1696 			goto out;
1697 		if (ret > 0)
1698 			break;
1699 
1700 		mutex_unlock(&gspca_dev->queue_lock);
1701 
1702 		if (file->f_flags & O_NONBLOCK)
1703 			return -EAGAIN;
1704 
1705 		/* wait till a frame is ready */
1706 		ret = wait_event_interruptible_timeout(gspca_dev->wq,
1707 			frame_ready(gspca_dev, file, v4l2_buf->memory),
1708 			msecs_to_jiffies(3000));
1709 		if (ret < 0)
1710 			return ret;
1711 		if (ret == 0)
1712 			return -EIO;
1713 
1714 		if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1715 			return -ERESTARTSYS;
1716 	}
1717 
1718 	i = gspca_dev->fr_o;
1719 	j = gspca_dev->fr_queue[i];
1720 	frame = &gspca_dev->frame[j];
1721 
1722 	gspca_dev->fr_o = (i + 1) % GSPCA_MAX_FRAMES;
1723 
1724 	frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_DONE;
1725 	memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
1726 	PDEBUG(D_FRAM, "dqbuf %d", j);
1727 	ret = 0;
1728 
1729 	if (gspca_dev->memory == V4L2_MEMORY_USERPTR) {
1730 		if (copy_to_user((__u8 __user *) frame->v4l2_buf.m.userptr,
1731 				 frame->data,
1732 				 frame->v4l2_buf.bytesused)) {
1733 			PERR("dqbuf cp to user failed");
1734 			ret = -EFAULT;
1735 		}
1736 	}
1737 out:
1738 	mutex_unlock(&gspca_dev->queue_lock);
1739 
1740 	if (ret == 0 && gspca_dev->sd_desc->dq_callback) {
1741 		mutex_lock(&gspca_dev->usb_lock);
1742 		gspca_dev->usb_err = 0;
1743 		if (gspca_dev->present)
1744 			gspca_dev->sd_desc->dq_callback(gspca_dev);
1745 		mutex_unlock(&gspca_dev->usb_lock);
1746 	}
1747 
1748 	return ret;
1749 }
1750 
1751 /*
1752  * queue a video buffer
1753  *
1754  * Attempting to queue a buffer that has already been
1755  * queued will return -EINVAL.
1756  */
1757 static int vidioc_qbuf(struct file *file, void *priv,
1758 			struct v4l2_buffer *v4l2_buf)
1759 {
1760 	struct gspca_dev *gspca_dev = video_drvdata(file);
1761 	struct gspca_frame *frame;
1762 	int i, index, ret;
1763 
1764 	PDEBUG(D_FRAM, "qbuf %d", v4l2_buf->index);
1765 
1766 	if (mutex_lock_interruptible(&gspca_dev->queue_lock))
1767 		return -ERESTARTSYS;
1768 
1769 	index = v4l2_buf->index;
1770 	if ((unsigned) index >= gspca_dev->nframes) {
1771 		PDEBUG(D_FRAM,
1772 			"qbuf idx %d >= %d", index, gspca_dev->nframes);
1773 		ret = -EINVAL;
1774 		goto out;
1775 	}
1776 	if (v4l2_buf->memory != gspca_dev->memory) {
1777 		PDEBUG(D_FRAM, "qbuf bad memory type");
1778 		ret = -EINVAL;
1779 		goto out;
1780 	}
1781 
1782 	frame = &gspca_dev->frame[index];
1783 	if (frame->v4l2_buf.flags & BUF_ALL_FLAGS) {
1784 		PDEBUG(D_FRAM, "qbuf bad state");
1785 		ret = -EINVAL;
1786 		goto out;
1787 	}
1788 
1789 	frame->v4l2_buf.flags |= V4L2_BUF_FLAG_QUEUED;
1790 
1791 	if (frame->v4l2_buf.memory == V4L2_MEMORY_USERPTR) {
1792 		frame->v4l2_buf.m.userptr = v4l2_buf->m.userptr;
1793 		frame->v4l2_buf.length = v4l2_buf->length;
1794 	}
1795 
1796 	/* put the buffer in the 'queued' queue */
1797 	i = atomic_read(&gspca_dev->fr_q);
1798 	gspca_dev->fr_queue[i] = index;
1799 	atomic_set(&gspca_dev->fr_q, (i + 1) % GSPCA_MAX_FRAMES);
1800 
1801 	v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
1802 	v4l2_buf->flags &= ~V4L2_BUF_FLAG_DONE;
1803 	ret = 0;
1804 out:
1805 	mutex_unlock(&gspca_dev->queue_lock);
1806 	return ret;
1807 }
1808 
1809 /*
1810  * allocate the resources for read()
1811  */
1812 static int read_alloc(struct gspca_dev *gspca_dev,
1813 			struct file *file)
1814 {
1815 	struct v4l2_buffer v4l2_buf;
1816 	int i, ret;
1817 
1818 	PDEBUG(D_STREAM, "read alloc");
1819 
1820 	if (mutex_lock_interruptible(&gspca_dev->usb_lock))
1821 		return -ERESTARTSYS;
1822 
1823 	if (gspca_dev->nframes == 0) {
1824 		struct v4l2_requestbuffers rb;
1825 
1826 		memset(&rb, 0, sizeof rb);
1827 		rb.count = gspca_dev->nbufread;
1828 		rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1829 		rb.memory = GSPCA_MEMORY_READ;
1830 		ret = vidioc_reqbufs(file, gspca_dev, &rb);
1831 		if (ret != 0) {
1832 			PDEBUG(D_STREAM, "read reqbuf err %d", ret);
1833 			goto out;
1834 		}
1835 		memset(&v4l2_buf, 0, sizeof v4l2_buf);
1836 		v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1837 		v4l2_buf.memory = GSPCA_MEMORY_READ;
1838 		for (i = 0; i < gspca_dev->nbufread; i++) {
1839 			v4l2_buf.index = i;
1840 			ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1841 			if (ret != 0) {
1842 				PDEBUG(D_STREAM, "read qbuf err: %d", ret);
1843 				goto out;
1844 			}
1845 		}
1846 	}
1847 
1848 	/* start streaming */
1849 	ret = vidioc_streamon(file, gspca_dev, V4L2_BUF_TYPE_VIDEO_CAPTURE);
1850 	if (ret != 0)
1851 		PDEBUG(D_STREAM, "read streamon err %d", ret);
1852 out:
1853 	mutex_unlock(&gspca_dev->usb_lock);
1854 	return ret;
1855 }
1856 
1857 static unsigned int dev_poll(struct file *file, poll_table *wait)
1858 {
1859 	struct gspca_dev *gspca_dev = video_drvdata(file);
1860 	unsigned long req_events = poll_requested_events(wait);
1861 	int ret = 0;
1862 
1863 	PDEBUG(D_FRAM, "poll");
1864 
1865 	if (req_events & POLLPRI)
1866 		ret |= v4l2_ctrl_poll(file, wait);
1867 
1868 	if (req_events & (POLLIN | POLLRDNORM)) {
1869 		/* if reqbufs is not done, the user would use read() */
1870 		if (gspca_dev->memory == GSPCA_MEMORY_NO) {
1871 			if (read_alloc(gspca_dev, file) != 0) {
1872 				ret |= POLLERR;
1873 				goto out;
1874 			}
1875 		}
1876 
1877 		poll_wait(file, &gspca_dev->wq, wait);
1878 
1879 		/* check if an image has been received */
1880 		if (mutex_lock_interruptible(&gspca_dev->queue_lock) != 0) {
1881 			ret |= POLLERR;
1882 			goto out;
1883 		}
1884 		if (gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i))
1885 			ret |= POLLIN | POLLRDNORM;
1886 		mutex_unlock(&gspca_dev->queue_lock);
1887 	}
1888 
1889 out:
1890 	if (!gspca_dev->present)
1891 		ret |= POLLHUP;
1892 
1893 	return ret;
1894 }
1895 
1896 static ssize_t dev_read(struct file *file, char __user *data,
1897 		    size_t count, loff_t *ppos)
1898 {
1899 	struct gspca_dev *gspca_dev = video_drvdata(file);
1900 	struct gspca_frame *frame;
1901 	struct v4l2_buffer v4l2_buf;
1902 	struct timeval timestamp;
1903 	int n, ret, ret2;
1904 
1905 	PDEBUG(D_FRAM, "read (%zd)", count);
1906 	if (gspca_dev->memory == GSPCA_MEMORY_NO) { /* first time ? */
1907 		ret = read_alloc(gspca_dev, file);
1908 		if (ret != 0)
1909 			return ret;
1910 	}
1911 
1912 	/* get a frame */
1913 	timestamp = ktime_to_timeval(ktime_get());
1914 	timestamp.tv_sec--;
1915 	n = 2;
1916 	for (;;) {
1917 		memset(&v4l2_buf, 0, sizeof v4l2_buf);
1918 		v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
1919 		v4l2_buf.memory = GSPCA_MEMORY_READ;
1920 		ret = vidioc_dqbuf(file, gspca_dev, &v4l2_buf);
1921 		if (ret != 0) {
1922 			PDEBUG(D_STREAM, "read dqbuf err %d", ret);
1923 			return ret;
1924 		}
1925 
1926 		/* if the process slept for more than 1 second,
1927 		 * get a newer frame */
1928 		frame = &gspca_dev->frame[v4l2_buf.index];
1929 		if (--n < 0)
1930 			break;			/* avoid infinite loop */
1931 		if (frame->v4l2_buf.timestamp.tv_sec >= timestamp.tv_sec)
1932 			break;
1933 		ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1934 		if (ret != 0) {
1935 			PDEBUG(D_STREAM, "read qbuf err %d", ret);
1936 			return ret;
1937 		}
1938 	}
1939 
1940 	/* copy the frame */
1941 	if (count > frame->v4l2_buf.bytesused)
1942 		count = frame->v4l2_buf.bytesused;
1943 	ret = copy_to_user(data, frame->data, count);
1944 	if (ret != 0) {
1945 		PERR("read cp to user lack %d / %zd", ret, count);
1946 		ret = -EFAULT;
1947 		goto out;
1948 	}
1949 	ret = count;
1950 out:
1951 	/* in each case, requeue the buffer */
1952 	ret2 = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
1953 	if (ret2 != 0)
1954 		return ret2;
1955 	return ret;
1956 }
1957 
1958 static struct v4l2_file_operations dev_fops = {
1959 	.owner = THIS_MODULE,
1960 	.open = dev_open,
1961 	.release = dev_close,
1962 	.read = dev_read,
1963 	.mmap = dev_mmap,
1964 	.unlocked_ioctl = video_ioctl2,
1965 	.poll	= dev_poll,
1966 };
1967 
1968 static const struct v4l2_ioctl_ops dev_ioctl_ops = {
1969 	.vidioc_querycap	= vidioc_querycap,
1970 	.vidioc_dqbuf		= vidioc_dqbuf,
1971 	.vidioc_qbuf		= vidioc_qbuf,
1972 	.vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
1973 	.vidioc_try_fmt_vid_cap	= vidioc_try_fmt_vid_cap,
1974 	.vidioc_g_fmt_vid_cap	= vidioc_g_fmt_vid_cap,
1975 	.vidioc_s_fmt_vid_cap	= vidioc_s_fmt_vid_cap,
1976 	.vidioc_streamon	= vidioc_streamon,
1977 	.vidioc_enum_input	= vidioc_enum_input,
1978 	.vidioc_g_input		= vidioc_g_input,
1979 	.vidioc_s_input		= vidioc_s_input,
1980 	.vidioc_reqbufs		= vidioc_reqbufs,
1981 	.vidioc_querybuf	= vidioc_querybuf,
1982 	.vidioc_streamoff	= vidioc_streamoff,
1983 	.vidioc_g_jpegcomp	= vidioc_g_jpegcomp,
1984 	.vidioc_s_jpegcomp	= vidioc_s_jpegcomp,
1985 	.vidioc_g_parm		= vidioc_g_parm,
1986 	.vidioc_s_parm		= vidioc_s_parm,
1987 	.vidioc_enum_framesizes = vidioc_enum_framesizes,
1988 	.vidioc_enum_frameintervals = vidioc_enum_frameintervals,
1989 #ifdef CONFIG_VIDEO_ADV_DEBUG
1990 	.vidioc_g_chip_info	= vidioc_g_chip_info,
1991 	.vidioc_g_register	= vidioc_g_register,
1992 	.vidioc_s_register	= vidioc_s_register,
1993 #endif
1994 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
1995 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
1996 };
1997 
1998 static const struct video_device gspca_template = {
1999 	.name = "gspca main driver",
2000 	.fops = &dev_fops,
2001 	.ioctl_ops = &dev_ioctl_ops,
2002 	.release = video_device_release_empty, /* We use v4l2_dev.release */
2003 };
2004 
2005 /*
2006  * probe and create a new gspca device
2007  *
2008  * This function must be called by the sub-driver when it is
2009  * called for probing a new device.
2010  */
2011 int gspca_dev_probe2(struct usb_interface *intf,
2012 		const struct usb_device_id *id,
2013 		const struct sd_desc *sd_desc,
2014 		int dev_size,
2015 		struct module *module)
2016 {
2017 	struct gspca_dev *gspca_dev;
2018 	struct usb_device *dev = interface_to_usbdev(intf);
2019 	int ret;
2020 
2021 	pr_info("%s-" GSPCA_VERSION " probing %04x:%04x\n",
2022 		sd_desc->name, id->idVendor, id->idProduct);
2023 
2024 	/* create the device */
2025 	if (dev_size < sizeof *gspca_dev)
2026 		dev_size = sizeof *gspca_dev;
2027 	gspca_dev = kzalloc(dev_size, GFP_KERNEL);
2028 	if (!gspca_dev) {
2029 		pr_err("couldn't kzalloc gspca struct\n");
2030 		return -ENOMEM;
2031 	}
2032 	gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
2033 	if (!gspca_dev->usb_buf) {
2034 		pr_err("out of memory\n");
2035 		ret = -ENOMEM;
2036 		goto out;
2037 	}
2038 	gspca_dev->dev = dev;
2039 	gspca_dev->iface = intf->cur_altsetting->desc.bInterfaceNumber;
2040 	gspca_dev->xfer_ep = -1;
2041 
2042 	/* check if any audio device */
2043 	if (dev->actconfig->desc.bNumInterfaces != 1) {
2044 		int i;
2045 		struct usb_interface *intf2;
2046 
2047 		for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
2048 			intf2 = dev->actconfig->interface[i];
2049 			if (intf2 != NULL
2050 			 && intf2->altsetting != NULL
2051 			 && intf2->altsetting->desc.bInterfaceClass ==
2052 					 USB_CLASS_AUDIO) {
2053 				gspca_dev->audio = 1;
2054 				break;
2055 			}
2056 		}
2057 	}
2058 
2059 	gspca_dev->v4l2_dev.release = gspca_release;
2060 	ret = v4l2_device_register(&intf->dev, &gspca_dev->v4l2_dev);
2061 	if (ret)
2062 		goto out;
2063 	gspca_dev->sd_desc = sd_desc;
2064 	gspca_dev->nbufread = 2;
2065 	gspca_dev->empty_packet = -1;	/* don't check the empty packets */
2066 	gspca_dev->vdev = gspca_template;
2067 	gspca_dev->vdev.v4l2_dev = &gspca_dev->v4l2_dev;
2068 	video_set_drvdata(&gspca_dev->vdev, gspca_dev);
2069 	gspca_dev->module = module;
2070 	gspca_dev->present = 1;
2071 
2072 	mutex_init(&gspca_dev->usb_lock);
2073 	gspca_dev->vdev.lock = &gspca_dev->usb_lock;
2074 	mutex_init(&gspca_dev->queue_lock);
2075 	init_waitqueue_head(&gspca_dev->wq);
2076 
2077 	/* configure the subdriver and initialize the USB device */
2078 	ret = sd_desc->config(gspca_dev, id);
2079 	if (ret < 0)
2080 		goto out;
2081 	ret = sd_desc->init(gspca_dev);
2082 	if (ret < 0)
2083 		goto out;
2084 	if (sd_desc->init_controls)
2085 		ret = sd_desc->init_controls(gspca_dev);
2086 	if (ret < 0)
2087 		goto out;
2088 	gspca_set_default_mode(gspca_dev);
2089 
2090 	ret = gspca_input_connect(gspca_dev);
2091 	if (ret)
2092 		goto out;
2093 
2094 	/*
2095 	 * Don't take usb_lock for these ioctls. This improves latency if
2096 	 * usb_lock is taken for a long time, e.g. when changing a control
2097 	 * value, and a new frame is ready to be dequeued.
2098 	 */
2099 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_DQBUF);
2100 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QBUF);
2101 	v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QUERYBUF);
2102 #ifdef CONFIG_VIDEO_ADV_DEBUG
2103 	if (!gspca_dev->sd_desc->get_register)
2104 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_G_REGISTER);
2105 	if (!gspca_dev->sd_desc->set_register)
2106 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_S_REGISTER);
2107 #endif
2108 	if (!gspca_dev->sd_desc->get_jcomp)
2109 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_G_JPEGCOMP);
2110 	if (!gspca_dev->sd_desc->set_jcomp)
2111 		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_S_JPEGCOMP);
2112 
2113 	/* init video stuff */
2114 	ret = video_register_device(&gspca_dev->vdev,
2115 				  VFL_TYPE_GRABBER,
2116 				  -1);
2117 	if (ret < 0) {
2118 		pr_err("video_register_device err %d\n", ret);
2119 		goto out;
2120 	}
2121 
2122 	usb_set_intfdata(intf, gspca_dev);
2123 	PDEBUG(D_PROBE, "%s created", video_device_node_name(&gspca_dev->vdev));
2124 
2125 	gspca_input_create_urb(gspca_dev);
2126 
2127 	return 0;
2128 out:
2129 #if IS_ENABLED(CONFIG_INPUT)
2130 	if (gspca_dev->input_dev)
2131 		input_unregister_device(gspca_dev->input_dev);
2132 #endif
2133 	v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
2134 	kfree(gspca_dev->usb_buf);
2135 	kfree(gspca_dev);
2136 	return ret;
2137 }
2138 EXPORT_SYMBOL(gspca_dev_probe2);
2139 
2140 /* same function as the previous one, but check the interface */
2141 int gspca_dev_probe(struct usb_interface *intf,
2142 		const struct usb_device_id *id,
2143 		const struct sd_desc *sd_desc,
2144 		int dev_size,
2145 		struct module *module)
2146 {
2147 	struct usb_device *dev = interface_to_usbdev(intf);
2148 
2149 	/* we don't handle multi-config cameras */
2150 	if (dev->descriptor.bNumConfigurations != 1) {
2151 		pr_err("%04x:%04x too many config\n",
2152 		       id->idVendor, id->idProduct);
2153 		return -ENODEV;
2154 	}
2155 
2156 	/* the USB video interface must be the first one */
2157 	if (dev->actconfig->desc.bNumInterfaces != 1
2158 	 && intf->cur_altsetting->desc.bInterfaceNumber != 0)
2159 		return -ENODEV;
2160 
2161 	return gspca_dev_probe2(intf, id, sd_desc, dev_size, module);
2162 }
2163 EXPORT_SYMBOL(gspca_dev_probe);
2164 
2165 /*
2166  * USB disconnection
2167  *
2168  * This function must be called by the sub-driver
2169  * when the device disconnects, after the specific resources are freed.
2170  */
2171 void gspca_disconnect(struct usb_interface *intf)
2172 {
2173 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2174 #if IS_ENABLED(CONFIG_INPUT)
2175 	struct input_dev *input_dev;
2176 #endif
2177 
2178 	PDEBUG(D_PROBE, "%s disconnect",
2179 		video_device_node_name(&gspca_dev->vdev));
2180 
2181 	mutex_lock(&gspca_dev->usb_lock);
2182 
2183 	gspca_dev->present = 0;
2184 	destroy_urbs(gspca_dev);
2185 
2186 #if IS_ENABLED(CONFIG_INPUT)
2187 	gspca_input_destroy_urb(gspca_dev);
2188 	input_dev = gspca_dev->input_dev;
2189 	if (input_dev) {
2190 		gspca_dev->input_dev = NULL;
2191 		input_unregister_device(input_dev);
2192 	}
2193 #endif
2194 	/* Free subdriver's streaming resources / stop sd workqueue(s) */
2195 	if (gspca_dev->sd_desc->stop0 && gspca_dev->streaming)
2196 		gspca_dev->sd_desc->stop0(gspca_dev);
2197 	gspca_dev->streaming = 0;
2198 	gspca_dev->dev = NULL;
2199 	wake_up_interruptible(&gspca_dev->wq);
2200 
2201 	v4l2_device_disconnect(&gspca_dev->v4l2_dev);
2202 	video_unregister_device(&gspca_dev->vdev);
2203 
2204 	mutex_unlock(&gspca_dev->usb_lock);
2205 
2206 	/* (this will call gspca_release() immediately or on last close) */
2207 	v4l2_device_put(&gspca_dev->v4l2_dev);
2208 }
2209 EXPORT_SYMBOL(gspca_disconnect);
2210 
2211 #ifdef CONFIG_PM
2212 int gspca_suspend(struct usb_interface *intf, pm_message_t message)
2213 {
2214 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2215 
2216 	gspca_input_destroy_urb(gspca_dev);
2217 
2218 	if (!gspca_dev->streaming)
2219 		return 0;
2220 
2221 	mutex_lock(&gspca_dev->usb_lock);
2222 	gspca_dev->frozen = 1;		/* avoid urb error messages */
2223 	gspca_dev->usb_err = 0;
2224 	if (gspca_dev->sd_desc->stopN)
2225 		gspca_dev->sd_desc->stopN(gspca_dev);
2226 	destroy_urbs(gspca_dev);
2227 	gspca_set_alt0(gspca_dev);
2228 	if (gspca_dev->sd_desc->stop0)
2229 		gspca_dev->sd_desc->stop0(gspca_dev);
2230 	mutex_unlock(&gspca_dev->usb_lock);
2231 
2232 	return 0;
2233 }
2234 EXPORT_SYMBOL(gspca_suspend);
2235 
2236 int gspca_resume(struct usb_interface *intf)
2237 {
2238 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
2239 	int streaming, ret = 0;
2240 
2241 	mutex_lock(&gspca_dev->usb_lock);
2242 	gspca_dev->frozen = 0;
2243 	gspca_dev->usb_err = 0;
2244 	gspca_dev->sd_desc->init(gspca_dev);
2245 	/*
2246 	 * Most subdrivers send all ctrl values on sd_start and thus
2247 	 * only write to the device registers on s_ctrl when streaming ->
2248 	 * Clear streaming to avoid setting all ctrls twice.
2249 	 */
2250 	streaming = gspca_dev->streaming;
2251 	gspca_dev->streaming = 0;
2252 	if (streaming)
2253 		ret = gspca_init_transfer(gspca_dev);
2254 	else
2255 		gspca_input_create_urb(gspca_dev);
2256 	mutex_unlock(&gspca_dev->usb_lock);
2257 
2258 	return ret;
2259 }
2260 EXPORT_SYMBOL(gspca_resume);
2261 #endif
2262 
2263 /* -- module insert / remove -- */
2264 static int __init gspca_init(void)
2265 {
2266 	pr_info("v" GSPCA_VERSION " registered\n");
2267 	return 0;
2268 }
2269 static void __exit gspca_exit(void)
2270 {
2271 }
2272 
2273 module_init(gspca_init);
2274 module_exit(gspca_exit);
2275 
2276 module_param_named(debug, gspca_debug, int, 0644);
2277 MODULE_PARM_DESC(debug,
2278 		"1:probe 2:config 3:stream 4:frame 5:packet 6:usbi 7:usbo");
2279