[media] cx231xx: enable tuner->decoder link at videobuf start

The tuner->decoder needs to be enabled when we're about to
start streaming.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

1 files changed, 71 insertions, 0 deletions

diff --git a/drivers/media/usb/cx231xx/cx231xx-video.c b/drivers/media/usb/cx231xx/cx231xx-video.c
index f3d1a488dfa7..634763535d60 100644
--- a/drivers/media/usb/cx231xx/cx231xx-video.c
+++ b/drivers/media/usb/cx231xx/cx231xx-video.c
@@ -703,6 +703,74 @@ static void free_buffer(struct videobuf_queue *vq, struct cx231xx_buffer *buf)
         buf->vb.state = VIDEOBUF_NEEDS_INIT;
 }
 
+static int cx231xx_enable_analog_tuner(struct cx231xx *dev)
+{
+#ifdef CONFIG_MEDIA_CONTROLLER
+        struct media_device *mdev = dev->media_dev;
+        struct media_entity  *entity, *decoder = NULL, *source;
+        struct media_link *link, *found_link = NULL;
+        int i, ret, active_links = 0;
+
+        if (!mdev)
+                return 0;
+
+/*
+ * This will find the tuner that it is connected into the decoder.
+ * Technically, this is not 100% correct, as the device may be using an
+ * analog input instead of the tuner. However, we can't use the DVB for dvb
+ * while the DMA engine is being used for V4L2.
+ */
+        media_device_for_each_entity(entity, mdev) {
+                if (entity->type == MEDIA_ENT_T_V4L2_SUBDEV_DECODER) {
+                        decoder = entity;
+                        break;
+                }
+        }
+        if (!decoder)
+                return 0;
+
+        for (i = 0; i < decoder->num_links; i++) {
+                link = &decoder->links[i];
+                if (link->sink->entity == decoder) {
+                        found_link = link;
+                        if (link->flags & MEDIA_LNK_FL_ENABLED)
+                                active_links++;
+                        break;
+                }
+        }
+
+        if (active_links == 1 || !found_link)
+                return 0;
+
+        source = found_link->source->entity;
+        for (i = 0; i < source->num_links; i++) {
+                struct media_entity *sink;
+                int flags = 0;
+
+                link = &source->links[i];
+                sink = link->sink->entity;
+
+                if (sink == entity)
+                        flags = MEDIA_LNK_FL_ENABLED;
+
+                ret = media_entity_setup_link(link, flags);
+                if (ret) {
+                        dev_err(dev->dev,
+                                "Couldn't change link %s->%s to %s. Error %d\n",
+                                source->name, sink->name,
+                                flags ? "enabled" : "disabled",
+                                ret);
+                        return ret;
+                } else
+                        dev_dbg(dev->dev,
+                                "link %s->%s was %s\n",
+                                source->name, sink->name,
+                                flags ? "ENABLED" : "disabled");
+        }
+#endif
+        return 0;
+}
+
 static int
 buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
                enum v4l2_field field)
@@ -756,6 +824,9 @@ buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
         }
 
         buf->vb.state = VIDEOBUF_PREPARED;
+
+        cx231xx_enable_analog_tuner(dev);
+
         return 0;
 
 fail: