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
30static 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(item: &uformat->group.cg_item);
38 if (!unc)
39 return ERR_PTR(error: -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(error: -EINVAL);
47
48 return format;
49}
50
51static 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(item: &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
67static 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
76static 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
93static 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
115static 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(uformat: format->fmt);
123
124 if (fmtdesc->fcc == pixelformat) {
125 uformat = format->fmt;
126 break;
127 }
128 }
129
130 return uformat;
131}
132
133static 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
181static int
182uvc_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(ep: 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(ep: cdev->gadget->ep0, req, GFP_KERNEL);
196}
197
198/* --------------------------------------------------------------------------
199 * V4L2 ioctls
200 */
201
202static int
203uvc_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
216static int
217uvc_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
235static int
236uvc_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, pixelformat: fmt->fmt.pix.pixelformat);
255 if (!uformat)
256 return -EINVAL;
257
258 uframe = find_closest_frame_by_size(uvc, uformat,
259 rw: fmt->fmt.pix.width, rh: 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
275static int
276uvc_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
296static int
297uvc_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, pixelformat: 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(numerator: &fival->discrete.numerator,
330 denominator: &fival->discrete.denominator, n_terms: 8, threshold: 333);
331
332 return 0;
333}
334
335static int
336uvc_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, pixelformat: 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, index: 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
362static int
363uvc_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, index: 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
383static int
384uvc_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(queue: &video->queue, rb: b);
394}
395
396static int
397uvc_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(queue: &video->queue, buf: b);
404}
405
406static int
407uvc_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(queue: &video->queue, buf: b);
415 if (ret < 0)
416 return ret;
417
418 if (uvc->state == UVC_STATE_STREAMING)
419 queue_work(wq: video->async_wq, work: &video->pump);
420
421 return ret;
422}
423
424static int
425uvc_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(queue: &video->queue, buf: b, nonblocking: file->f_flags & O_NONBLOCK);
432}
433
434static int
435uvc_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, disable_ep: 0);
455 uvc->state = UVC_STATE_STREAMING;
456
457 return 0;
458}
459
460static int
461uvc_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, disable_ep: 1);
477 return 0;
478}
479
480static int
481uvc_v4l2_subscribe_event(struct v4l2_fh *fh,
482 const struct v4l2_event_subscription *sub)
483{
484 struct uvc_device *uvc = video_get_drvdata(vdev: 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, elems: 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
507static void uvc_v4l2_disable(struct uvc_device *uvc)
508{
509 uvc_function_disconnect(uvc);
510 uvcg_video_disable(video: &uvc->video);
511 uvcg_free_buffers(queue: &uvc->video.queue);
512 uvc->func_connected = false;
513 wake_up_interruptible(&uvc->func_connected_queue);
514}
515
516static int
517uvc_v4l2_unsubscribe_event(struct v4l2_fh *fh,
518 const struct v4l2_event_subscription *sub)
519{
520 struct uvc_device *uvc = video_get_drvdata(vdev: 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
536static long
537uvc_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, data: arg);
546
547 default:
548 return -ENOIOCTLCMD;
549 }
550}
551
552const 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
575static int
576uvc_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(size: sizeof(*handle), GFP_KERNEL);
583 if (handle == NULL)
584 return -ENOMEM;
585
586 v4l2_fh_init(fh: &handle->vfh, vdev);
587 v4l2_fh_add(fh: &handle->vfh);
588
589 handle->device = &uvc->video;
590 file->private_data = &handle->vfh;
591
592 return 0;
593}
594
595static int
596uvc_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(lock: &video->mutex);
607
608 file->private_data = NULL;
609 v4l2_fh_del(fh: &handle->vfh);
610 v4l2_fh_exit(fh: &handle->vfh);
611 kfree(objp: handle);
612
613 return 0;
614}
615
616static int
617uvc_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(queue: &uvc->video.queue, vma);
623}
624
625static __poll_t
626uvc_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(queue: &uvc->video.queue, file, wait);
632}
633
634#ifndef CONFIG_MMU
635static 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
646const 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

source code of linux/drivers/usb/gadget/function/uvc_v4l2.c