xref: /linux/drivers/media/usb/uvc/uvc_metadata.c (revision 03ab8e6297acd1bc0eedaa050e2a1635c576fd11)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      uvc_metadata.c  --  USB Video Class driver - Metadata handling
4  *
5  *      Copyright (C) 2016
6  *          Guennadi Liakhovetski (guennadi.liakhovetski@intel.com)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/list.h>
11 #include <linux/module.h>
12 #include <linux/usb.h>
13 #include <linux/videodev2.h>
14 
15 #include <media/v4l2-ioctl.h>
16 #include <media/videobuf2-v4l2.h>
17 #include <media/videobuf2-vmalloc.h>
18 
19 #include "uvcvideo.h"
20 
21 /* -----------------------------------------------------------------------------
22  * V4L2 ioctls
23  */
24 
uvc_meta_v4l2_querycap(struct file * file,void * fh,struct v4l2_capability * cap)25 static int uvc_meta_v4l2_querycap(struct file *file, void *fh,
26 				  struct v4l2_capability *cap)
27 {
28 	struct v4l2_fh *vfh = file->private_data;
29 	struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
30 	struct uvc_video_chain *chain = stream->chain;
31 
32 	strscpy(cap->driver, "uvcvideo", sizeof(cap->driver));
33 	strscpy(cap->card, stream->dev->name, sizeof(cap->card));
34 	usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
35 	cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
36 			  | chain->caps;
37 
38 	return 0;
39 }
40 
uvc_meta_v4l2_get_format(struct file * file,void * fh,struct v4l2_format * format)41 static int uvc_meta_v4l2_get_format(struct file *file, void *fh,
42 				    struct v4l2_format *format)
43 {
44 	struct v4l2_fh *vfh = file->private_data;
45 	struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
46 	struct v4l2_meta_format *fmt = &format->fmt.meta;
47 
48 	if (format->type != vfh->vdev->queue->type)
49 		return -EINVAL;
50 
51 	memset(fmt, 0, sizeof(*fmt));
52 
53 	fmt->dataformat = stream->meta.format;
54 	fmt->buffersize = UVC_METADATA_BUF_SIZE;
55 
56 	return 0;
57 }
58 
uvc_meta_v4l2_try_format(struct file * file,void * fh,struct v4l2_format * format)59 static int uvc_meta_v4l2_try_format(struct file *file, void *fh,
60 				    struct v4l2_format *format)
61 {
62 	struct v4l2_fh *vfh = file->private_data;
63 	struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
64 	struct uvc_device *dev = stream->dev;
65 	struct v4l2_meta_format *fmt = &format->fmt.meta;
66 	u32 fmeta = fmt->dataformat;
67 
68 	if (format->type != vfh->vdev->queue->type)
69 		return -EINVAL;
70 
71 	memset(fmt, 0, sizeof(*fmt));
72 
73 	fmt->dataformat = fmeta == dev->info->meta_format
74 			? fmeta : V4L2_META_FMT_UVC;
75 	fmt->buffersize = UVC_METADATA_BUF_SIZE;
76 
77 	return 0;
78 }
79 
uvc_meta_v4l2_set_format(struct file * file,void * fh,struct v4l2_format * format)80 static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
81 				    struct v4l2_format *format)
82 {
83 	struct v4l2_fh *vfh = file->private_data;
84 	struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
85 	struct v4l2_meta_format *fmt = &format->fmt.meta;
86 	int ret;
87 
88 	ret = uvc_meta_v4l2_try_format(file, fh, format);
89 	if (ret < 0)
90 		return ret;
91 
92 	/*
93 	 * We could in principle switch at any time, also during streaming.
94 	 * Metadata buffers would still be perfectly parseable, but it's more
95 	 * consistent and cleaner to disallow that.
96 	 */
97 	mutex_lock(&stream->mutex);
98 
99 	if (uvc_queue_allocated(&stream->queue))
100 		ret = -EBUSY;
101 	else
102 		stream->meta.format = fmt->dataformat;
103 
104 	mutex_unlock(&stream->mutex);
105 
106 	return ret;
107 }
108 
uvc_meta_v4l2_enum_formats(struct file * file,void * fh,struct v4l2_fmtdesc * fdesc)109 static int uvc_meta_v4l2_enum_formats(struct file *file, void *fh,
110 				      struct v4l2_fmtdesc *fdesc)
111 {
112 	struct v4l2_fh *vfh = file->private_data;
113 	struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
114 	struct uvc_device *dev = stream->dev;
115 	u32 index = fdesc->index;
116 
117 	if (fdesc->type != vfh->vdev->queue->type ||
118 	    index > 1U || (index && !dev->info->meta_format))
119 		return -EINVAL;
120 
121 	memset(fdesc, 0, sizeof(*fdesc));
122 
123 	fdesc->type = vfh->vdev->queue->type;
124 	fdesc->index = index;
125 	fdesc->pixelformat = index ? dev->info->meta_format : V4L2_META_FMT_UVC;
126 
127 	return 0;
128 }
129 
130 static const struct v4l2_ioctl_ops uvc_meta_ioctl_ops = {
131 	.vidioc_querycap		= uvc_meta_v4l2_querycap,
132 	.vidioc_g_fmt_meta_cap		= uvc_meta_v4l2_get_format,
133 	.vidioc_s_fmt_meta_cap		= uvc_meta_v4l2_set_format,
134 	.vidioc_try_fmt_meta_cap	= uvc_meta_v4l2_try_format,
135 	.vidioc_enum_fmt_meta_cap	= uvc_meta_v4l2_enum_formats,
136 	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
137 	.vidioc_querybuf		= vb2_ioctl_querybuf,
138 	.vidioc_qbuf			= vb2_ioctl_qbuf,
139 	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
140 	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
141 	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
142 	.vidioc_streamon		= vb2_ioctl_streamon,
143 	.vidioc_streamoff		= vb2_ioctl_streamoff,
144 };
145 
146 /* -----------------------------------------------------------------------------
147  * V4L2 File Operations
148  */
149 
150 static const struct v4l2_file_operations uvc_meta_fops = {
151 	.owner = THIS_MODULE,
152 	.unlocked_ioctl = video_ioctl2,
153 	.open = v4l2_fh_open,
154 	.release = vb2_fop_release,
155 	.poll = vb2_fop_poll,
156 	.mmap = vb2_fop_mmap,
157 };
158 
uvc_meta_register(struct uvc_streaming * stream)159 int uvc_meta_register(struct uvc_streaming *stream)
160 {
161 	struct uvc_device *dev = stream->dev;
162 	struct video_device *vdev = &stream->meta.vdev;
163 	struct uvc_video_queue *queue = &stream->meta.queue;
164 
165 	stream->meta.format = V4L2_META_FMT_UVC;
166 
167 	/*
168 	 * The video interface queue uses manual locking and thus does not set
169 	 * the queue pointer. Set it manually here.
170 	 */
171 	vdev->queue = &queue->queue;
172 
173 	return uvc_register_video_device(dev, stream, vdev, queue,
174 					 V4L2_BUF_TYPE_META_CAPTURE,
175 					 &uvc_meta_fops, &uvc_meta_ioctl_ops);
176 }
177