[PATCH v3 21/22] media: au0828 video change to use v4l_enable_media_source()

Shuah Khan
2016-02-11T23:42:41Z

Change au0828 to check if tuner is free or not
before changing tuner configuration.

vidioc_g_tuner(), and au0828_v4l2_close() now call
v4l-core interface v4l_enable_media_source() before
changing tuner configuration.

Remove au0828_enable_analog_tuner() as it is
no longer needed because v4l2-core implements
common interfaces to check for media source
availability.

In addition, queue_setup() no longer needs the
tuner availability check since v4l2-core does it.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
drivers/media/usb/au0828/au0828-video.c | 102 ++++++++++++--------------------
1 file changed, 39 insertions(+), 63 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c
index 8c54fd2..9304f96 100644
--- a/drivers/media/usb/au0828/au0828-video.c
+++ b/drivers/media/usb/au0828/au0828-video.c
@@ -638,64 +638,6 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
return rc;
}

-static int au0828_enable_analog_tuner(struct au0828_dev *dev)
-{
-#ifdef CONFIG_MEDIA_CONTROLLER
- struct media_device *mdev = dev->media_dev;
- struct media_entity *source;
- struct media_link *link, *found_link = NULL;
- int ret, active_links = 0;
-
- if (!mdev || !dev->decoder)
- return 0;
-
- /*
- * This will find the tuner that 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, as we can't
- * do DVB streaming while the DMA engine is being used for V4L2,
- * this should be enough for the actual needs.
- */
- list_for_each_entry(link, &dev->decoder->links, list) {
- if (link->sink->entity == dev->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;
- list_for_each_entry(link, &source->links, list) {
- struct media_entity *sink;
- int flags = 0;
-
- sink = link->sink->entity;
-
- if (sink == dev->decoder)
- flags = MEDIA_LNK_FL_ENABLED;
-
- ret = media_entity_setup_link(link, flags);
- if (ret) {
- pr_err(
- "Couldn't change link %s->%s to %s. Error %d\n",
- source->name, sink->name,
- flags ? "enabled" : "disabled",
- ret);
- return ret;
- } else
- au0828_isocdbg(
- "link %s->%s was %s\n",
- source->name, sink->name,
- flags ? "ENABLED" : "disabled");
- }
-#endif
- return 0;
-}
-
static int queue_setup(struct vb2_queue *vq,
unsigned int *nbuffers, unsigned int *nplanes,
unsigned int sizes[], void *alloc_ctxs[])
@@ -707,9 +649,6 @@ static int queue_setup(struct vb2_queue *vq,
return sizes[0] < size ? -EINVAL : 0;
*nplanes = 1;
sizes[0] = size;
-
- au0828_enable_analog_tuner(dev);
-
return 0;
}

@@ -1067,8 +1006,39 @@ static int au0828_v4l2_close(struct file *filp)
goto end;

if (dev->users == 1) {
- /* Save some power by putting tuner to sleep */
- v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_power, 0);
+ /*
+ * Avoid putting tuner in sleep if DVB or ALSA are
+ * streaming.
+ *
+ * On most USB devices like au0828 the tuner can
+ * be safely put in sleep stare here if ALSA isn't
+ * streaming. Exceptions are some very old USB tuner
+ * models such as em28xx-based WinTV USB2 which have
+ * a separate audio output jack. The devices that have
+ * a separate audio output jack have analog tuners,
+ * like Philips FM1236. Those devices are always on,
+ * so the s_power callback are silently ignored.
+ * So, the current logic here does the following:
+ * Disable (put tuner to sleep) when
+ * - ALSA and DVB aren't not streaming;
+ * - the last V4L2 file handler is closed.
+ *
+ * FIXME:
+ *
+ * Additionally, this logic could be improved to
+ * disable the media source if the above conditions
+ * are met and if the device:
+ * - doesn't have a separate audio out plug (or
+ * - doesn't use a silicon tuner like xc2028/3028/4000/5000).
+ *
+ * Once this additional logic is in place, a callback
+ * is needed to enable the media source and power on
+ * the tuner, for radio to work.
+ */
+ ret = v4l_enable_media_source(vdev);
+ if (ret == 0)
+ v4l2_device_call_all(&dev->v4l2_dev, 0, core,
+ s_power, 0);
dev->std_set_in_tuner_core = 0;

/* When close the device, set the usb intf0 into alt0 to free
@@ -1469,10 +1439,16 @@ static int vidioc_s_audio(struct file *file, void *priv, const struct v4l2_audio
static int vidioc_g_tuner(struct file *file, void *priv, struct v4l2_tuner *t)
{
struct au0828_dev *dev = video_drvdata(file);
+ struct video_device *vfd = video_devdata(file);
+ int ret;

if (t->index != 0)
return -EINVAL;

+ ret = v4l_enable_media_source(vfd);
+ if (ret)
+ return ret;
+
dprintk(1, "%s called std_set %d dev_state %d\n", __func__,
dev->std_set_in_tuner_core, dev->dev_state);

--
2.5.0