usb/uvc/uvc_metadata.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  *      uvc_metadata.c  --  USB Video Class driver - Metadata handling
0004  *
0005  *      Copyright (C) 2016
0006  *          Guennadi Liakhovetski (guennadi.liakhovetski@intel.com)
0007  */
0008
0009 #include <linux/kernel.h>
0010 #include <linux/list.h>
0011 #include <linux/module.h>
0012 #include <linux/usb.h>
0013 #include <linux/videodev2.h>
0014
0015 #include <media/v4l2-ioctl.h>
0016 #include <media/videobuf2-v4l2.h>
0017 #include <media/videobuf2-vmalloc.h>
0018
0019 #include "uvcvideo.h"
0020
0021 /* -----------------------------------------------------------------------------
0022  * V4L2 ioctls
0023  */
0024
0025 static int uvc_meta_v4l2_querycap(struct file *file, void *fh,
0026                   struct v4l2_capability *cap)
0027 {
0028     struct v4l2_fh *vfh = file->private_data;
0029     struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
0030     struct uvc_video_chain *chain = stream->chain;
0031
0032     strscpy(cap->driver, "uvcvideo", sizeof(cap->driver));
0033     strscpy(cap->card, stream->dev->name, sizeof(cap->card));
0034     usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
0035     cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
0036               | chain->caps;
0037
0038     return 0;
0039 }
0040
0041 static int uvc_meta_v4l2_get_format(struct file *file, void *fh,
0042                     struct v4l2_format *format)
0043 {
0044     struct v4l2_fh *vfh = file->private_data;
0045     struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
0046     struct v4l2_meta_format *fmt = &format->fmt.meta;
0047
0048     if (format->type != vfh->vdev->queue->type)
0049         return -EINVAL;
0050
0051     memset(fmt, 0, sizeof(*fmt));
0052
0053     fmt->dataformat = stream->meta.format;
0054     fmt->buffersize = UVC_METADATA_BUF_SIZE;
0055
0056     return 0;
0057 }
0058
0059 static int uvc_meta_v4l2_try_format(struct file *file, void *fh,
0060                     struct v4l2_format *format)
0061 {
0062     struct v4l2_fh *vfh = file->private_data;
0063     struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
0064     struct uvc_device *dev = stream->dev;
0065     struct v4l2_meta_format *fmt = &format->fmt.meta;
0066     u32 fmeta = fmt->dataformat;
0067
0068     if (format->type != vfh->vdev->queue->type)
0069         return -EINVAL;
0070
0071     memset(fmt, 0, sizeof(*fmt));
0072
0073     fmt->dataformat = fmeta == dev->info->meta_format
0074             ? fmeta : V4L2_META_FMT_UVC;
0075     fmt->buffersize = UVC_METADATA_BUF_SIZE;
0076
0077     return 0;
0078 }
0079
0080 static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
0081                     struct v4l2_format *format)
0082 {
0083     struct v4l2_fh *vfh = file->private_data;
0084     struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
0085     struct v4l2_meta_format *fmt = &format->fmt.meta;
0086     int ret;
0087
0088     ret = uvc_meta_v4l2_try_format(file, fh, format);
0089     if (ret < 0)
0090         return ret;
0091
0092     /*
0093      * We could in principle switch at any time, also during streaming.
0094      * Metadata buffers would still be perfectly parseable, but it's more
0095      * consistent and cleaner to disallow that.
0096      */
0097     mutex_lock(&stream->mutex);
0098
0099     if (uvc_queue_allocated(&stream->queue))
0100         ret = -EBUSY;
0101     else
0102         stream->meta.format = fmt->dataformat;
0103
0104     mutex_unlock(&stream->mutex);
0105
0106     return ret;
0107 }
0108
0109 static int uvc_meta_v4l2_enum_formats(struct file *file, void *fh,
0110                       struct v4l2_fmtdesc *fdesc)
0111 {
0112     struct v4l2_fh *vfh = file->private_data;
0113     struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
0114     struct uvc_device *dev = stream->dev;
0115     u32 index = fdesc->index;
0116
0117     if (fdesc->type != vfh->vdev->queue->type ||
0118         index > 1U || (index && !dev->info->meta_format))
0119         return -EINVAL;
0120
0121     memset(fdesc, 0, sizeof(*fdesc));
0122
0123     fdesc->type = vfh->vdev->queue->type;
0124     fdesc->index = index;
0125     fdesc->pixelformat = index ? dev->info->meta_format : V4L2_META_FMT_UVC;
0126
0127     return 0;
0128 }
0129
0130 static const struct v4l2_ioctl_ops uvc_meta_ioctl_ops = {
0131     .vidioc_querycap        = uvc_meta_v4l2_querycap,
0132     .vidioc_g_fmt_meta_cap      = uvc_meta_v4l2_get_format,
0133     .vidioc_s_fmt_meta_cap      = uvc_meta_v4l2_set_format,
0134     .vidioc_try_fmt_meta_cap    = uvc_meta_v4l2_try_format,
0135     .vidioc_enum_fmt_meta_cap   = uvc_meta_v4l2_enum_formats,
0136     .vidioc_reqbufs         = vb2_ioctl_reqbufs,
0137     .vidioc_querybuf        = vb2_ioctl_querybuf,
0138     .vidioc_qbuf            = vb2_ioctl_qbuf,
0139     .vidioc_dqbuf           = vb2_ioctl_dqbuf,
0140     .vidioc_create_bufs     = vb2_ioctl_create_bufs,
0141     .vidioc_prepare_buf     = vb2_ioctl_prepare_buf,
0142     .vidioc_streamon        = vb2_ioctl_streamon,
0143     .vidioc_streamoff       = vb2_ioctl_streamoff,
0144 };
0145
0146 /* -----------------------------------------------------------------------------
0147  * V4L2 File Operations
0148  */
0149
0150 static const struct v4l2_file_operations uvc_meta_fops = {
0151     .owner = THIS_MODULE,
0152     .unlocked_ioctl = video_ioctl2,
0153     .open = v4l2_fh_open,
0154     .release = vb2_fop_release,
0155     .poll = vb2_fop_poll,
0156     .mmap = vb2_fop_mmap,
0157 };
0158
0159 int uvc_meta_register(struct uvc_streaming *stream)
0160 {
0161     struct uvc_device *dev = stream->dev;
0162     struct video_device *vdev = &stream->meta.vdev;
0163     struct uvc_video_queue *queue = &stream->meta.queue;
0164
0165     stream->meta.format = V4L2_META_FMT_UVC;
0166
0167     /*
0168      * The video interface queue uses manual locking and thus does not set
0169      * the queue pointer. Set it manually here.
0170      */
0171     vdev->queue = &queue->queue;
0172
0173     return uvc_register_video_device(dev, stream, vdev, queue,
0174                      V4L2_BUF_TYPE_META_CAPTURE,
0175                      &uvc_meta_fops, &uvc_meta_ioctl_ops);
0176 }