linux/drivers/media/usb/uvc/uvc_metadata.c
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   1/*
   2 *      uvc_metadata.c  --  USB Video Class driver - Metadata handling
   3 *
   4 *      Copyright (C) 2016
   5 *          Guennadi Liakhovetski (guennadi.liakhovetski@intel.com)
   6 *
   7 *      This program is free software; you can redistribute it and/or modify
   8 *      it under the terms of the GNU General Public License as published by
   9 *      the Free Software Foundation; either version 2 of the License, or
  10 *      (at your option) any later version.
  11 */
  12
  13#include <linux/kernel.h>
  14#include <linux/list.h>
  15#include <linux/module.h>
  16#include <linux/usb.h>
  17#include <linux/videodev2.h>
  18
  19#include <media/v4l2-ioctl.h>
  20#include <media/videobuf2-v4l2.h>
  21#include <media/videobuf2-vmalloc.h>
  22
  23#include "uvcvideo.h"
  24
  25/* -----------------------------------------------------------------------------
  26 * V4L2 ioctls
  27 */
  28
  29static int uvc_meta_v4l2_querycap(struct file *file, void *fh,
  30                                  struct v4l2_capability *cap)
  31{
  32        struct v4l2_fh *vfh = file->private_data;
  33        struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
  34        struct uvc_video_chain *chain = stream->chain;
  35
  36        strlcpy(cap->driver, "uvcvideo", sizeof(cap->driver));
  37        strlcpy(cap->card, vfh->vdev->name, sizeof(cap->card));
  38        usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
  39        cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
  40                          | chain->caps;
  41
  42        return 0;
  43}
  44
  45static int uvc_meta_v4l2_get_format(struct file *file, void *fh,
  46                                    struct v4l2_format *format)
  47{
  48        struct v4l2_fh *vfh = file->private_data;
  49        struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
  50        struct v4l2_meta_format *fmt = &format->fmt.meta;
  51
  52        if (format->type != vfh->vdev->queue->type)
  53                return -EINVAL;
  54
  55        memset(fmt, 0, sizeof(*fmt));
  56
  57        fmt->dataformat = stream->meta.format;
  58        fmt->buffersize = UVC_METATADA_BUF_SIZE;
  59
  60        return 0;
  61}
  62
  63static int uvc_meta_v4l2_try_format(struct file *file, void *fh,
  64                                    struct v4l2_format *format)
  65{
  66        struct v4l2_fh *vfh = file->private_data;
  67        struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
  68        struct uvc_device *dev = stream->dev;
  69        struct v4l2_meta_format *fmt = &format->fmt.meta;
  70        u32 fmeta = fmt->dataformat;
  71
  72        if (format->type != vfh->vdev->queue->type)
  73                return -EINVAL;
  74
  75        memset(fmt, 0, sizeof(*fmt));
  76
  77        fmt->dataformat = fmeta == dev->meta_format ? fmeta : V4L2_META_FMT_UVC;
  78        fmt->buffersize = UVC_METATADA_BUF_SIZE;
  79
  80        return 0;
  81}
  82
  83static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
  84                                    struct v4l2_format *format)
  85{
  86        struct v4l2_fh *vfh = file->private_data;
  87        struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
  88        struct v4l2_meta_format *fmt = &format->fmt.meta;
  89        int ret;
  90
  91        ret = uvc_meta_v4l2_try_format(file, fh, format);
  92        if (ret < 0)
  93                return ret;
  94
  95        /*
  96         * We could in principle switch at any time, also during streaming.
  97         * Metadata buffers would still be perfectly parseable, but it's more
  98         * consistent and cleaner to disallow that.
  99         */
 100        mutex_lock(&stream->mutex);
 101
 102        if (uvc_queue_allocated(&stream->queue))
 103                ret = -EBUSY;
 104        else
 105                stream->meta.format = fmt->dataformat;
 106
 107        mutex_unlock(&stream->mutex);
 108
 109        return ret;
 110}
 111
 112static int uvc_meta_v4l2_enum_formats(struct file *file, void *fh,
 113                                      struct v4l2_fmtdesc *fdesc)
 114{
 115        struct v4l2_fh *vfh = file->private_data;
 116        struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
 117        struct uvc_device *dev = stream->dev;
 118        u32 index = fdesc->index;
 119
 120        if (fdesc->type != vfh->vdev->queue->type ||
 121            index > 1U || (index && !dev->meta_format))
 122                return -EINVAL;
 123
 124        memset(fdesc, 0, sizeof(*fdesc));
 125
 126        fdesc->type = vfh->vdev->queue->type;
 127        fdesc->index = index;
 128        fdesc->pixelformat = index ? dev->meta_format : V4L2_META_FMT_UVC;
 129
 130        return 0;
 131}
 132
 133static const struct v4l2_ioctl_ops uvc_meta_ioctl_ops = {
 134        .vidioc_querycap                = uvc_meta_v4l2_querycap,
 135        .vidioc_g_fmt_meta_cap          = uvc_meta_v4l2_get_format,
 136        .vidioc_s_fmt_meta_cap          = uvc_meta_v4l2_set_format,
 137        .vidioc_try_fmt_meta_cap        = uvc_meta_v4l2_try_format,
 138        .vidioc_enum_fmt_meta_cap       = uvc_meta_v4l2_enum_formats,
 139        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
 140        .vidioc_querybuf                = vb2_ioctl_querybuf,
 141        .vidioc_qbuf                    = vb2_ioctl_qbuf,
 142        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
 143        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
 144        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
 145        .vidioc_streamon                = vb2_ioctl_streamon,
 146        .vidioc_streamoff               = vb2_ioctl_streamoff,
 147};
 148
 149/* -----------------------------------------------------------------------------
 150 * V4L2 File Operations
 151 */
 152
 153static const struct v4l2_file_operations uvc_meta_fops = {
 154        .owner = THIS_MODULE,
 155        .unlocked_ioctl = video_ioctl2,
 156        .open = v4l2_fh_open,
 157        .release = vb2_fop_release,
 158        .poll = vb2_fop_poll,
 159        .mmap = vb2_fop_mmap,
 160};
 161
 162int uvc_meta_register(struct uvc_streaming *stream)
 163{
 164        struct uvc_device *dev = stream->dev;
 165        struct video_device *vdev = &stream->meta.vdev;
 166        struct uvc_video_queue *queue = &stream->meta.queue;
 167
 168        stream->meta.format = V4L2_META_FMT_UVC;
 169
 170        /*
 171         * The video interface queue uses manual locking and thus does not set
 172         * the queue pointer. Set it manually here.
 173         */
 174        vdev->queue = &queue->queue;
 175
 176        return uvc_register_video_device(dev, stream, vdev, queue,
 177                                         V4L2_BUF_TYPE_META_CAPTURE,
 178                                         &uvc_meta_fops, &uvc_meta_ioctl_ops);
 179}
 180