V4L/DVB (6717): ivtv: Initial merge of video48 yuv handling into the IVTV_IOC_DMA_FRAME framework

Previously, all yuv data written to /dev/video48 had only basic support with
no double buffering to avoid display tearing.

With this patch, yuv frames written to video48 are now handled by the existing
IVTV_IOC_DMA_FRAME framework. As such, the frames are hardware buffered to
avoid tearing, and honour scaling mode & field order options. Unlike the
proprietary IVTV_IOC_DMA_FRAME ioctl, all parameters are controlled by the
V4L2 API.

Due to mpeg & yuv output restrictions being different, their V4L2 output
controls have been separated. To control the yuv output, the V4L2 calls must
be done via video48.

If the ivtvfb module is loaded, there will be one side effect to this merge.
The yuv output window will be constrained to the visible framebuffer area. In
the event that a virtual framebuffer size is being used, the limit to the
output size will be the virtual dimensions, but only the portion that falls
within the currently visible area of the framebuffer will be shown.

Like the IVTV_IOC_DMA_FRAME ioctl, the supplied frames must be padded to 720
pixels wide. However the height must only be padded up the nearest multiple
of 32. This would mean an image of 102 lines must be padded to 128. As long
as the true source image size is given, the padding will not be visible in
the final output.

Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 51 insertions, 7 deletions

diff --git a/drivers/media/video/ivtv/ivtv-yuv.c b/drivers/media/video/ivtv/ivtv-yuv.c
index cd42db9b5a15..711ce5b5a20f 100644
--- a/drivers/media/video/ivtv/ivtv-yuv.c
+++ b/drivers/media/video/ivtv/ivtv-yuv.c
@@ -1035,17 +1035,11 @@ void ivtv_yuv_frame_complete(struct ivtv *itv)
                         (itv->yuv_info.draw_frame + 1) % IVTV_YUV_BUFFERS);
 }
 
-int ivtv_yuv_prep_frame(struct ivtv *itv, struct ivtv_dma_frame *args)
+int ivtv_yuv_udma_frame(struct ivtv *itv, struct ivtv_dma_frame *args)
 {
         DEFINE_WAIT(wait);
         int rc = 0;
         int got_sig = 0;
-
-        IVTV_DEBUG_INFO("yuv_prep_frame\n");
-
-        ivtv_yuv_next_free(itv);
-        ivtv_yuv_setup_frame(itv, args);
-
         /* DMA the frame */
         mutex_lock(&itv->udma.lock);
 
@@ -1084,6 +1078,56 @@ int ivtv_yuv_prep_frame(struct ivtv *itv, struct ivtv_dma_frame *args)
         return rc;
 }
 
+/* Setup frame according to V4L2 parameters */
+void ivtv_yuv_setup_stream_frame(struct ivtv *itv)
+{
+        struct yuv_playback_info *yi = &itv->yuv_info;
+        struct ivtv_dma_frame dma_args;
+
+        ivtv_yuv_next_free(itv);
+
+        /* Copy V4L2 parameters to an ivtv_dma_frame struct... */
+        dma_args.y_source = 0L;
+        dma_args.uv_source = 0L;
+        dma_args.src.left = 0;
+        dma_args.src.top = 0;
+        dma_args.src.width = yi->v4l2_src_w;
+        dma_args.src.height = yi->v4l2_src_h;
+        dma_args.dst = yi->main_rect;
+        dma_args.src_width = yi->v4l2_src_w;
+        dma_args.src_height = yi->v4l2_src_h;
+
+        /* ... and use the same setup routine as ivtv_yuv_prep_frame */
+        ivtv_yuv_setup_frame(itv, &dma_args);
+
+        if (!itv->dma_data_req_offset)
+                itv->dma_data_req_offset = yuv_offset[yi->draw_frame];
+}
+
+/* Attempt to dma a frame from a user buffer */
+int ivtv_yuv_udma_stream_frame(struct ivtv *itv, void *src)
+{
+        struct yuv_playback_info *yi = &itv->yuv_info;
+        struct ivtv_dma_frame dma_args;
+
+        ivtv_yuv_setup_stream_frame(itv);
+
+        /* We only need to supply source addresses for this */
+        dma_args.y_source = src;
+        dma_args.uv_source = src + 720 * ((yi->v4l2_src_h + 31) & ~31);
+        return ivtv_yuv_udma_frame(itv, &dma_args);
+}
+
+/* IVTV_IOC_DMA_FRAME ioctl handler */
+int ivtv_yuv_prep_frame(struct ivtv *itv, struct ivtv_dma_frame *args)
+{
+        IVTV_DEBUG_INFO("yuv_prep_frame\n");
+
+        ivtv_yuv_next_free(itv);
+        ivtv_yuv_setup_frame(itv, args);
+        return ivtv_yuv_udma_frame(itv, args);
+}
+
 void ivtv_yuv_close(struct ivtv *itv)
 {
         int h_filter, v_filter_1, v_filter_2;