1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * uvc_metadata.c -- USB Video Class driver - Metadata handling
6 * Guennadi Liakhovetski (guennadi.liakhovetski@intel.com)
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>
15 #include <media/v4l2-ioctl.h>
16 #include <media/videobuf2-v4l2.h>
17 #include <media/videobuf2-vmalloc.h>
21 /* -----------------------------------------------------------------------------
25 static int uvc_meta_v4l2_querycap(struct file *file, void *fh,
26 struct v4l2_capability *cap)
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;
32 strscpy(cap->driver, "uvcvideo", sizeof(cap->driver));
33 strscpy(cap->card, vfh->vdev->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
41 static int uvc_meta_v4l2_get_format(struct file *file, void *fh,
42 struct v4l2_format *format)
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;
48 if (format->type != vfh->vdev->queue->type)
51 memset(fmt, 0, sizeof(*fmt));
53 fmt->dataformat = stream->meta.format;
54 fmt->buffersize = UVC_METADATA_BUF_SIZE;
59 static int uvc_meta_v4l2_try_format(struct file *file, void *fh,
60 struct v4l2_format *format)
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;
68 if (format->type != vfh->vdev->queue->type)
71 memset(fmt, 0, sizeof(*fmt));
73 fmt->dataformat = fmeta == dev->info->meta_format
74 ? fmeta : V4L2_META_FMT_UVC;
75 fmt->buffersize = UVC_METADATA_BUF_SIZE;
80 static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
81 struct v4l2_format *format)
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;
88 ret = uvc_meta_v4l2_try_format(file, fh, format);
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.
97 mutex_lock(&stream->mutex);
99 if (uvc_queue_allocated(&stream->queue))
102 stream->meta.format = fmt->dataformat;
104 mutex_unlock(&stream->mutex);
109 static int uvc_meta_v4l2_enum_formats(struct file *file, void *fh,
110 struct v4l2_fmtdesc *fdesc)
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;
117 if (fdesc->type != vfh->vdev->queue->type ||
118 index > 1U || (index && !dev->info->meta_format))
121 memset(fdesc, 0, sizeof(*fdesc));
123 fdesc->type = vfh->vdev->queue->type;
124 fdesc->index = index;
125 fdesc->pixelformat = index ? dev->info->meta_format : V4L2_META_FMT_UVC;
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,
146 /* -----------------------------------------------------------------------------
147 * V4L2 File Operations
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,
159 int uvc_meta_register(struct uvc_streaming *stream)
161 struct uvc_device *dev = stream->dev;
162 struct video_device *vdev = &stream->meta.vdev;
163 struct uvc_video_queue *queue = &stream->meta.queue;
165 stream->meta.format = V4L2_META_FMT_UVC;
168 * The video interface queue uses manual locking and thus does not set
169 * the queue pointer. Set it manually here.
171 vdev->queue = &queue->queue;
173 return uvc_register_video_device(dev, stream, vdev, queue,
174 V4L2_BUF_TYPE_META_CAPTURE,
175 &uvc_meta_fops, &uvc_meta_ioctl_ops);