xref: /linux/drivers/usb/gadget/function/uvc_v4l2.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *	uvc_v4l2.c  --  USB Video Class Gadget driver
4  *
5  *	Copyright (C) 2009-2010
6  *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7  */
8 
9 #include <linux/device.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/usb/g_uvc.h>
14 #include <linux/usb/uvc.h>
15 #include <linux/videodev2.h>
16 #include <linux/vmalloc.h>
17 #include <linux/wait.h>
18 
19 #include <media/v4l2-dev.h>
20 #include <media/v4l2-event.h>
21 #include <media/v4l2-ioctl.h>
22 
23 #include "f_uvc.h"
24 #include "uvc.h"
25 #include "uvc_queue.h"
26 #include "uvc_video.h"
27 #include "uvc_v4l2.h"
28 #include "uvc_configfs.h"
29 
30 static const struct uvc_format_desc *to_uvc_format(struct uvcg_format *uformat)
31 {
32 	char guid[16] = UVC_GUID_FORMAT_MJPEG;
33 	const struct uvc_format_desc *format;
34 	struct uvcg_uncompressed *unc;
35 
36 	if (uformat->type == UVCG_UNCOMPRESSED) {
37 		unc = to_uvcg_uncompressed(&uformat->group.cg_item);
38 		if (!unc)
39 			return ERR_PTR(-EINVAL);
40 
41 		memcpy(guid, unc->desc.guidFormat, sizeof(guid));
42 	}
43 
44 	format = uvc_format_by_guid(guid);
45 	if (!format)
46 		return ERR_PTR(-EINVAL);
47 
48 	return format;
49 }
50 
51 static int uvc_v4l2_get_bytesperline(struct uvcg_format *uformat,
52 			      struct uvcg_frame *uframe)
53 {
54 	struct uvcg_uncompressed *u;
55 
56 	if (uformat->type == UVCG_UNCOMPRESSED) {
57 		u = to_uvcg_uncompressed(&uformat->group.cg_item);
58 		if (!u)
59 			return 0;
60 
61 		return u->desc.bBitsPerPixel * uframe->frame.w_width / 8;
62 	}
63 
64 	return 0;
65 }
66 
67 static int uvc_get_frame_size(struct uvcg_format *uformat,
68 		       struct uvcg_frame *uframe)
69 {
70 	unsigned int bpl = uvc_v4l2_get_bytesperline(uformat, uframe);
71 
72 	return bpl ? bpl * uframe->frame.w_height :
73 		uframe->frame.dw_max_video_frame_buffer_size;
74 }
75 
76 static struct uvcg_format *find_format_by_index(struct uvc_device *uvc, int index)
77 {
78 	struct uvcg_format_ptr *format;
79 	struct uvcg_format *uformat = NULL;
80 	int i = 1;
81 
82 	list_for_each_entry(format, &uvc->header->formats, entry) {
83 		if (index == i) {
84 			uformat = format->fmt;
85 			break;
86 		}
87 		i++;
88 	}
89 
90 	return uformat;
91 }
92 
93 static struct uvcg_frame *find_frame_by_index(struct uvc_device *uvc,
94 				       struct uvcg_format *uformat,
95 				       int index)
96 {
97 	struct uvcg_format_ptr *format;
98 	struct uvcg_frame_ptr *frame;
99 	struct uvcg_frame *uframe = NULL;
100 
101 	list_for_each_entry(format, &uvc->header->formats, entry) {
102 		if (format->fmt->type != uformat->type)
103 			continue;
104 		list_for_each_entry(frame, &format->fmt->frames, entry) {
105 			if (index == frame->frm->frame.b_frame_index) {
106 				uframe = frame->frm;
107 				break;
108 			}
109 		}
110 	}
111 
112 	return uframe;
113 }
114 
115 static struct uvcg_format *find_format_by_pix(struct uvc_device *uvc,
116 					      u32 pixelformat)
117 {
118 	struct uvcg_format_ptr *format;
119 	struct uvcg_format *uformat = NULL;
120 
121 	list_for_each_entry(format, &uvc->header->formats, entry) {
122 		const struct uvc_format_desc *fmtdesc = to_uvc_format(format->fmt);
123 
124 		if (fmtdesc->fcc == pixelformat) {
125 			uformat = format->fmt;
126 			break;
127 		}
128 	}
129 
130 	return uformat;
131 }
132 
133 static struct uvcg_frame *find_closest_frame_by_size(struct uvc_device *uvc,
134 					   struct uvcg_format *uformat,
135 					   u16 rw, u16 rh)
136 {
137 	struct uvc_video *video = &uvc->video;
138 	struct uvcg_format_ptr *format;
139 	struct uvcg_frame_ptr *frame;
140 	struct uvcg_frame *uframe = NULL;
141 	unsigned int d, maxd;
142 
143 	/* Find the closest image size. The distance between image sizes is
144 	 * the size in pixels of the non-overlapping regions between the
145 	 * requested size and the frame-specified size.
146 	 */
147 	maxd = (unsigned int)-1;
148 
149 	list_for_each_entry(format, &uvc->header->formats, entry) {
150 		if (format->fmt->type != uformat->type)
151 			continue;
152 
153 		list_for_each_entry(frame, &format->fmt->frames, entry) {
154 			u16 w, h;
155 
156 			w = frame->frm->frame.w_width;
157 			h = frame->frm->frame.w_height;
158 
159 			d = min(w, rw) * min(h, rh);
160 			d = w*h + rw*rh - 2*d;
161 			if (d < maxd) {
162 				maxd = d;
163 				uframe = frame->frm;
164 			}
165 
166 			if (maxd == 0)
167 				break;
168 		}
169 	}
170 
171 	if (!uframe)
172 		uvcg_dbg(&video->uvc->func, "Unsupported size %ux%u\n", rw, rh);
173 
174 	return uframe;
175 }
176 
177 /* --------------------------------------------------------------------------
178  * Requests handling
179  */
180 
181 static int
182 uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
183 {
184 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
185 	struct usb_request *req = uvc->control_req;
186 
187 	if (data->length < 0)
188 		return usb_ep_set_halt(cdev->gadget->ep0);
189 
190 	req->length = min_t(unsigned int, uvc->event_length, data->length);
191 	req->zero = data->length < uvc->event_length;
192 
193 	memcpy(req->buf, data->data, req->length);
194 
195 	return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
196 }
197 
198 /* --------------------------------------------------------------------------
199  * V4L2 ioctls
200  */
201 
202 static int
203 uvc_v4l2_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
204 {
205 	struct video_device *vdev = video_devdata(file);
206 	struct uvc_device *uvc = video_get_drvdata(vdev);
207 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
208 
209 	strscpy(cap->driver, "g_uvc", sizeof(cap->driver));
210 	strscpy(cap->card, cdev->gadget->name, sizeof(cap->card));
211 	strscpy(cap->bus_info, dev_name(&cdev->gadget->dev),
212 		sizeof(cap->bus_info));
213 	return 0;
214 }
215 
216 static int
217 uvc_v4l2_get_format(struct file *file, void *fh, struct v4l2_format *fmt)
218 {
219 	struct video_device *vdev = video_devdata(file);
220 	struct uvc_device *uvc = video_get_drvdata(vdev);
221 	struct uvc_video *video = &uvc->video;
222 
223 	fmt->fmt.pix.pixelformat = video->fcc;
224 	fmt->fmt.pix.width = video->width;
225 	fmt->fmt.pix.height = video->height;
226 	fmt->fmt.pix.field = V4L2_FIELD_NONE;
227 	fmt->fmt.pix.bytesperline = video->bpp * video->width / 8;
228 	fmt->fmt.pix.sizeimage = video->imagesize;
229 	fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
230 	fmt->fmt.pix.priv = 0;
231 
232 	return 0;
233 }
234 
235 static int
236 uvc_v4l2_try_format(struct file *file, void *fh, struct v4l2_format *fmt)
237 {
238 	struct video_device *vdev = video_devdata(file);
239 	struct uvc_device *uvc = video_get_drvdata(vdev);
240 	struct uvc_video *video = &uvc->video;
241 	struct uvcg_format *uformat;
242 	struct uvcg_frame *uframe;
243 	u8 *fcc;
244 
245 	if (fmt->type != video->queue.queue.type)
246 		return -EINVAL;
247 
248 	fcc = (u8 *)&fmt->fmt.pix.pixelformat;
249 	uvcg_dbg(&uvc->func, "Trying format 0x%08x (%c%c%c%c): %ux%u\n",
250 		fmt->fmt.pix.pixelformat,
251 		fcc[0], fcc[1], fcc[2], fcc[3],
252 		fmt->fmt.pix.width, fmt->fmt.pix.height);
253 
254 	uformat = find_format_by_pix(uvc, fmt->fmt.pix.pixelformat);
255 	if (!uformat)
256 		return -EINVAL;
257 
258 	uframe = find_closest_frame_by_size(uvc, uformat,
259 				fmt->fmt.pix.width, fmt->fmt.pix.height);
260 	if (!uframe)
261 		return -EINVAL;
262 
263 	fmt->fmt.pix.width = uframe->frame.w_width;
264 	fmt->fmt.pix.height = uframe->frame.w_height;
265 	fmt->fmt.pix.field = V4L2_FIELD_NONE;
266 	fmt->fmt.pix.bytesperline = uvc_v4l2_get_bytesperline(uformat, uframe);
267 	fmt->fmt.pix.sizeimage = uvc_get_frame_size(uformat, uframe);
268 	fmt->fmt.pix.pixelformat = to_uvc_format(uformat)->fcc;
269 	fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
270 	fmt->fmt.pix.priv = 0;
271 
272 	return 0;
273 }
274 
275 static int
276 uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt)
277 {
278 	struct video_device *vdev = video_devdata(file);
279 	struct uvc_device *uvc = video_get_drvdata(vdev);
280 	struct uvc_video *video = &uvc->video;
281 	int ret;
282 
283 	ret = uvc_v4l2_try_format(file, fh, fmt);
284 	if (ret)
285 		return ret;
286 
287 	video->fcc = fmt->fmt.pix.pixelformat;
288 	video->bpp = fmt->fmt.pix.bytesperline * 8 / video->width;
289 	video->width = fmt->fmt.pix.width;
290 	video->height = fmt->fmt.pix.height;
291 	video->imagesize = fmt->fmt.pix.sizeimage;
292 
293 	return ret;
294 }
295 
296 static int
297 uvc_v4l2_enum_frameintervals(struct file *file, void *fh,
298 		struct v4l2_frmivalenum *fival)
299 {
300 	struct video_device *vdev = video_devdata(file);
301 	struct uvc_device *uvc = video_get_drvdata(vdev);
302 	struct uvcg_format *uformat = NULL;
303 	struct uvcg_frame *uframe = NULL;
304 	struct uvcg_frame_ptr *frame;
305 
306 	uformat = find_format_by_pix(uvc, fival->pixel_format);
307 	if (!uformat)
308 		return -EINVAL;
309 
310 	list_for_each_entry(frame, &uformat->frames, entry) {
311 		if (frame->frm->frame.w_width == fival->width &&
312 		    frame->frm->frame.w_height == fival->height) {
313 			uframe = frame->frm;
314 			break;
315 		}
316 	}
317 	if (!uframe)
318 		return -EINVAL;
319 
320 	if (fival->index >= uframe->frame.b_frame_interval_type)
321 		return -EINVAL;
322 
323 	fival->discrete.numerator =
324 		uframe->dw_frame_interval[fival->index];
325 
326 	/* TODO: handle V4L2_FRMIVAL_TYPE_STEPWISE */
327 	fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
328 	fival->discrete.denominator = 10000000;
329 	v4l2_simplify_fraction(&fival->discrete.numerator,
330 		&fival->discrete.denominator, 8, 333);
331 
332 	return 0;
333 }
334 
335 static int
336 uvc_v4l2_enum_framesizes(struct file *file, void *fh,
337 		struct v4l2_frmsizeenum *fsize)
338 {
339 	struct video_device *vdev = video_devdata(file);
340 	struct uvc_device *uvc = video_get_drvdata(vdev);
341 	struct uvcg_format *uformat = NULL;
342 	struct uvcg_frame *uframe = NULL;
343 
344 	uformat = find_format_by_pix(uvc, fsize->pixel_format);
345 	if (!uformat)
346 		return -EINVAL;
347 
348 	if (fsize->index >= uformat->num_frames)
349 		return -EINVAL;
350 
351 	uframe = find_frame_by_index(uvc, uformat, fsize->index + 1);
352 	if (!uframe)
353 		return -EINVAL;
354 
355 	fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
356 	fsize->discrete.width = uframe->frame.w_width;
357 	fsize->discrete.height = uframe->frame.w_height;
358 
359 	return 0;
360 }
361 
362 static int
363 uvc_v4l2_enum_format(struct file *file, void *fh, struct v4l2_fmtdesc *f)
364 {
365 	struct video_device *vdev = video_devdata(file);
366 	struct uvc_device *uvc = video_get_drvdata(vdev);
367 	const struct uvc_format_desc *fmtdesc;
368 	struct uvcg_format *uformat;
369 
370 	if (f->index >= uvc->header->num_fmt)
371 		return -EINVAL;
372 
373 	uformat = find_format_by_index(uvc, f->index + 1);
374 	if (!uformat)
375 		return -EINVAL;
376 
377 	fmtdesc = to_uvc_format(uformat);
378 	f->pixelformat = fmtdesc->fcc;
379 
380 	return 0;
381 }
382 
383 static int
384 uvc_v4l2_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *b)
385 {
386 	struct video_device *vdev = video_devdata(file);
387 	struct uvc_device *uvc = video_get_drvdata(vdev);
388 	struct uvc_video *video = &uvc->video;
389 
390 	if (b->type != video->queue.queue.type)
391 		return -EINVAL;
392 
393 	return uvcg_alloc_buffers(&video->queue, b);
394 }
395 
396 static int
397 uvc_v4l2_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
398 {
399 	struct video_device *vdev = video_devdata(file);
400 	struct uvc_device *uvc = video_get_drvdata(vdev);
401 	struct uvc_video *video = &uvc->video;
402 
403 	return uvcg_query_buffer(&video->queue, b);
404 }
405 
406 static int
407 uvc_v4l2_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
408 {
409 	struct video_device *vdev = video_devdata(file);
410 	struct uvc_device *uvc = video_get_drvdata(vdev);
411 	struct uvc_video *video = &uvc->video;
412 	int ret;
413 
414 	ret = uvcg_queue_buffer(&video->queue, b);
415 	if (ret < 0)
416 		return ret;
417 
418 	if (uvc->state == UVC_STATE_STREAMING)
419 		queue_work(video->async_wq, &video->pump);
420 
421 	return ret;
422 }
423 
424 static int
425 uvc_v4l2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *b)
426 {
427 	struct video_device *vdev = video_devdata(file);
428 	struct uvc_device *uvc = video_get_drvdata(vdev);
429 	struct uvc_video *video = &uvc->video;
430 
431 	return uvcg_dequeue_buffer(&video->queue, b, file->f_flags & O_NONBLOCK);
432 }
433 
434 static int
435 uvc_v4l2_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
436 {
437 	struct video_device *vdev = video_devdata(file);
438 	struct uvc_device *uvc = video_get_drvdata(vdev);
439 	struct uvc_video *video = &uvc->video;
440 	int ret;
441 
442 	if (type != video->queue.queue.type)
443 		return -EINVAL;
444 
445 	/* Enable UVC video. */
446 	ret = uvcg_video_enable(video);
447 	if (ret < 0)
448 		return ret;
449 
450 	/*
451 	 * Complete the alternate setting selection setup phase now that
452 	 * userspace is ready to provide video frames.
453 	 */
454 	uvc_function_setup_continue(uvc, 0);
455 	uvc->state = UVC_STATE_STREAMING;
456 
457 	return 0;
458 }
459 
460 static int
461 uvc_v4l2_streamoff(struct file *file, void *fh, enum v4l2_buf_type type)
462 {
463 	struct video_device *vdev = video_devdata(file);
464 	struct uvc_device *uvc = video_get_drvdata(vdev);
465 	struct uvc_video *video = &uvc->video;
466 	int ret = 0;
467 
468 	if (type != video->queue.queue.type)
469 		return -EINVAL;
470 
471 	ret = uvcg_video_disable(video);
472 	if (ret < 0)
473 		return ret;
474 
475 	uvc->state = UVC_STATE_CONNECTED;
476 	uvc_function_setup_continue(uvc, 1);
477 	return 0;
478 }
479 
480 static int
481 uvc_v4l2_subscribe_event(struct v4l2_fh *fh,
482 			 const struct v4l2_event_subscription *sub)
483 {
484 	struct uvc_device *uvc = video_get_drvdata(fh->vdev);
485 	struct uvc_file_handle *handle = to_uvc_file_handle(fh);
486 	int ret;
487 
488 	if (sub->type < UVC_EVENT_FIRST || sub->type > UVC_EVENT_LAST)
489 		return -EINVAL;
490 
491 	if (sub->type == UVC_EVENT_SETUP && uvc->func_connected)
492 		return -EBUSY;
493 
494 	ret = v4l2_event_subscribe(fh, sub, 2, NULL);
495 	if (ret < 0)
496 		return ret;
497 
498 	if (sub->type == UVC_EVENT_SETUP) {
499 		uvc->func_connected = true;
500 		handle->is_uvc_app_handle = true;
501 		uvc_function_connect(uvc);
502 	}
503 
504 	return 0;
505 }
506 
507 static void uvc_v4l2_disable(struct uvc_device *uvc)
508 {
509 	uvc_function_disconnect(uvc);
510 	uvcg_video_disable(&uvc->video);
511 	uvcg_free_buffers(&uvc->video.queue);
512 	uvc->func_connected = false;
513 	wake_up_interruptible(&uvc->func_connected_queue);
514 }
515 
516 static int
517 uvc_v4l2_unsubscribe_event(struct v4l2_fh *fh,
518 			   const struct v4l2_event_subscription *sub)
519 {
520 	struct uvc_device *uvc = video_get_drvdata(fh->vdev);
521 	struct uvc_file_handle *handle = to_uvc_file_handle(fh);
522 	int ret;
523 
524 	ret = v4l2_event_unsubscribe(fh, sub);
525 	if (ret < 0)
526 		return ret;
527 
528 	if (sub->type == UVC_EVENT_SETUP && handle->is_uvc_app_handle) {
529 		uvc_v4l2_disable(uvc);
530 		handle->is_uvc_app_handle = false;
531 	}
532 
533 	return 0;
534 }
535 
536 static long
537 uvc_v4l2_ioctl_default(struct file *file, void *fh, bool valid_prio,
538 		       unsigned int cmd, void *arg)
539 {
540 	struct video_device *vdev = video_devdata(file);
541 	struct uvc_device *uvc = video_get_drvdata(vdev);
542 
543 	switch (cmd) {
544 	case UVCIOC_SEND_RESPONSE:
545 		return uvc_send_response(uvc, arg);
546 
547 	default:
548 		return -ENOIOCTLCMD;
549 	}
550 }
551 
552 const struct v4l2_ioctl_ops uvc_v4l2_ioctl_ops = {
553 	.vidioc_querycap = uvc_v4l2_querycap,
554 	.vidioc_try_fmt_vid_out = uvc_v4l2_try_format,
555 	.vidioc_g_fmt_vid_out = uvc_v4l2_get_format,
556 	.vidioc_s_fmt_vid_out = uvc_v4l2_set_format,
557 	.vidioc_enum_frameintervals = uvc_v4l2_enum_frameintervals,
558 	.vidioc_enum_framesizes = uvc_v4l2_enum_framesizes,
559 	.vidioc_enum_fmt_vid_out = uvc_v4l2_enum_format,
560 	.vidioc_reqbufs = uvc_v4l2_reqbufs,
561 	.vidioc_querybuf = uvc_v4l2_querybuf,
562 	.vidioc_qbuf = uvc_v4l2_qbuf,
563 	.vidioc_dqbuf = uvc_v4l2_dqbuf,
564 	.vidioc_streamon = uvc_v4l2_streamon,
565 	.vidioc_streamoff = uvc_v4l2_streamoff,
566 	.vidioc_subscribe_event = uvc_v4l2_subscribe_event,
567 	.vidioc_unsubscribe_event = uvc_v4l2_unsubscribe_event,
568 	.vidioc_default = uvc_v4l2_ioctl_default,
569 };
570 
571 /* --------------------------------------------------------------------------
572  * V4L2
573  */
574 
575 static int
576 uvc_v4l2_open(struct file *file)
577 {
578 	struct video_device *vdev = video_devdata(file);
579 	struct uvc_device *uvc = video_get_drvdata(vdev);
580 	struct uvc_file_handle *handle;
581 
582 	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
583 	if (handle == NULL)
584 		return -ENOMEM;
585 
586 	v4l2_fh_init(&handle->vfh, vdev);
587 	v4l2_fh_add(&handle->vfh);
588 
589 	handle->device = &uvc->video;
590 	file->private_data = &handle->vfh;
591 
592 	return 0;
593 }
594 
595 static int
596 uvc_v4l2_release(struct file *file)
597 {
598 	struct video_device *vdev = video_devdata(file);
599 	struct uvc_device *uvc = video_get_drvdata(vdev);
600 	struct uvc_file_handle *handle = to_uvc_file_handle(file->private_data);
601 	struct uvc_video *video = handle->device;
602 
603 	mutex_lock(&video->mutex);
604 	if (handle->is_uvc_app_handle)
605 		uvc_v4l2_disable(uvc);
606 	mutex_unlock(&video->mutex);
607 
608 	file->private_data = NULL;
609 	v4l2_fh_del(&handle->vfh);
610 	v4l2_fh_exit(&handle->vfh);
611 	kfree(handle);
612 
613 	return 0;
614 }
615 
616 static int
617 uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
618 {
619 	struct video_device *vdev = video_devdata(file);
620 	struct uvc_device *uvc = video_get_drvdata(vdev);
621 
622 	return uvcg_queue_mmap(&uvc->video.queue, vma);
623 }
624 
625 static __poll_t
626 uvc_v4l2_poll(struct file *file, poll_table *wait)
627 {
628 	struct video_device *vdev = video_devdata(file);
629 	struct uvc_device *uvc = video_get_drvdata(vdev);
630 
631 	return uvcg_queue_poll(&uvc->video.queue, file, wait);
632 }
633 
634 #ifndef CONFIG_MMU
635 static unsigned long uvcg_v4l2_get_unmapped_area(struct file *file,
636 		unsigned long addr, unsigned long len, unsigned long pgoff,
637 		unsigned long flags)
638 {
639 	struct video_device *vdev = video_devdata(file);
640 	struct uvc_device *uvc = video_get_drvdata(vdev);
641 
642 	return uvcg_queue_get_unmapped_area(&uvc->video.queue, pgoff);
643 }
644 #endif
645 
646 const struct v4l2_file_operations uvc_v4l2_fops = {
647 	.owner		= THIS_MODULE,
648 	.open		= uvc_v4l2_open,
649 	.release	= uvc_v4l2_release,
650 	.unlocked_ioctl	= video_ioctl2,
651 	.mmap		= uvc_v4l2_mmap,
652 	.poll		= uvc_v4l2_poll,
653 #ifndef CONFIG_MMU
654 	.get_unmapped_area = uvcg_v4l2_get_unmapped_area,
655 #endif
656 };
657