V4L/DVB (10104): uvcvideo: Add support for video output devices

Extend the range of supported UVC devices by allowing video output devices
matching the following structure:

TT_STREAMING -> VC_PROCESSING_UNIT -> VC_EXTENSION_UNIT{0,n} -> OTT_*

Video output devices are reported with the V4L2_CAP_VIDEO_OUTPUT capability
flag and are subject to the same restrictions as video input devices.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 95 insertions, 7 deletions

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 6d0ac3be8191..e7c31995527f 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -453,6 +453,34 @@ static void uvc_video_decode_end(struct uvc_video_device *video,
         }
 }
 
+static int uvc_video_encode_header(struct uvc_video_device *video,
+                struct uvc_buffer *buf, __u8 *data, int len)
+{
+        data[0] = 2;    /* Header length */
+        data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
+                | (video->last_fid & UVC_STREAM_FID);
+        return 2;
+}
+
+static int uvc_video_encode_data(struct uvc_video_device *video,
+                struct uvc_buffer *buf, __u8 *data, int len)
+{
+        struct uvc_video_queue *queue = &video->queue;
+        unsigned int nbytes;
+        void *mem;
+
+        /* Copy video data to the URB buffer. */
+        mem = queue->mem + buf->buf.m.offset + queue->buf_used;
+        nbytes = min((unsigned int)len, buf->buf.bytesused - queue->buf_used);
+        nbytes = min(video->bulk.max_payload_size - video->bulk.payload_size,
+                        nbytes);
+        memcpy(data, mem, nbytes);
+
+        queue->buf_used += nbytes;
+
+        return nbytes;
+}
+
 /* ------------------------------------------------------------------------
  * URB handling
  */
@@ -559,6 +587,48 @@ static void uvc_video_decode_bulk(struct urb *urb,
         }
 }
 
+static void uvc_video_encode_bulk(struct urb *urb,
+        struct uvc_video_device *video, struct uvc_buffer *buf)
+{
+        u8 *mem = urb->transfer_buffer;
+        int len = video->urb_size, ret;
+
+        if (buf == NULL) {
+                urb->transfer_buffer_length = 0;
+                return;
+        }
+
+        /* If the URB is the first of its payload, add the header. */
+        if (video->bulk.header_size == 0) {
+                ret = uvc_video_encode_header(video, buf, mem, len);
+                video->bulk.header_size = ret;
+                video->bulk.payload_size += ret;
+                mem += ret;
+                len -= ret;
+        }
+
+        /* Process video data. */
+        ret = uvc_video_encode_data(video, buf, mem, len);
+
+        video->bulk.payload_size += ret;
+        len -= ret;
+
+        if (buf->buf.bytesused == video->queue.buf_used ||
+            video->bulk.payload_size == video->bulk.max_payload_size) {
+                if (buf->buf.bytesused == video->queue.buf_used) {
+                        video->queue.buf_used = 0;
+                        buf->state = UVC_BUF_STATE_DONE;
+                        uvc_queue_next_buffer(&video->queue, buf);
+                        video->last_fid ^= UVC_STREAM_FID;
+                }
+
+                video->bulk.header_size = 0;
+                video->bulk.payload_size = 0;
+        }
+
+        urb->transfer_buffer_length = video->urb_size - len;
+}
+
 static void uvc_video_complete(struct urb *urb)
 {
         struct uvc_video_device *video = urb->context;
@@ -756,7 +826,15 @@ static int uvc_init_video_bulk(struct uvc_video_device *video,
         if (uvc_alloc_urb_buffers(video, size) < 0)
                 return -ENOMEM;
 
-        pipe = usb_rcvbulkpipe(video->dev->udev, ep->desc.bEndpointAddress);
+        if (usb_endpoint_dir_in(&ep->desc))
+                pipe = usb_rcvbulkpipe(video->dev->udev,
+                                       ep->desc.bEndpointAddress);
+        else
+                pipe = usb_sndbulkpipe(video->dev->udev,
+                                       ep->desc.bEndpointAddress);
+
+        if (video->streaming->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
+                size = 0;
 
         for (i = 0; i < UVC_URBS; ++i) {
                 urb = usb_alloc_urb(0, gfp_flags);
@@ -977,12 +1055,22 @@ int uvc_video_init(struct uvc_video_device *video)
         atomic_set(&video->active, 0);
 
         /* Select the video decoding function */
-        if (video->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
-                video->decode = uvc_video_decode_isight;
-        else if (video->streaming->intf->num_altsetting > 1)
-                video->decode = uvc_video_decode_isoc;
-        else
-                video->decode = uvc_video_decode_bulk;
+        if (video->streaming->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
+                if (video->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
+                        video->decode = uvc_video_decode_isight;
+                else if (video->streaming->intf->num_altsetting > 1)
+                        video->decode = uvc_video_decode_isoc;
+                else
+                        video->decode = uvc_video_decode_bulk;
+        } else {
+                if (video->streaming->intf->num_altsetting == 1)
+                        video->decode = uvc_video_encode_bulk;
+                else {
+                        uvc_printk(KERN_INFO, "Isochronous endpoints are not "
+                                "supported for video output devices.\n");
+                        return -EINVAL;
+                }
+        }
 
         return 0;
 }