[alsa-devel] [PATCH 23/31] media: au0828 implement enable_source and disable_source handlers
Shuah Khan
shuahkh at osg.samsung.com
Thu Jan 28 21:14:25 CET 2016
On 01/28/2016 09:43 AM, Mauro Carvalho Chehab wrote:
> Em Wed, 6 Jan 2016 13:27:12 -0700
> Shuah Khan <shuahkh at osg.samsung.com> escreveu:
>
>> Implements enable_source and disable_source handlers for other
>> drivers (v4l2-core, dvb-core, and ALSA) to use to check for
>> tuner connected to the decoder and activate the link if tuner
>> is free, and deactivate and free the tuner when it is no longer
>> needed.
>>
>> Signed-off-by: Shuah Khan <shuahkh at osg.samsung.com>
>> ---
>> drivers/media/usb/au0828/au0828-core.c | 148 +++++++++++++++++++++++++++++++++
>> drivers/media/usb/au0828/au0828.h | 2 +
>> 2 files changed, 150 insertions(+)
>>
>> diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
>> index a15a61a..f8d2db3 100644
>> --- a/drivers/media/usb/au0828/au0828-core.c
>> +++ b/drivers/media/usb/au0828/au0828-core.c
>> @@ -370,6 +370,150 @@ static int au0828_create_media_graph(struct au0828_dev *dev)
>> return 0;
>> }
>>
>> +static int au0828_enable_source(struct media_entity *entity,
>> + struct media_pipeline *pipe)
>> +{
>
> The best would be to put those enable source stuff at the core, in a way
> that other drivers could share it.
Hans and I discussed this at the Media Summit in Finland.
It will be very difficult to make this work in a generic
way. Besides, bridge driver knows the hardware it has and
it would make sense for it to implement enable and disable
source handlers.
>
> Not sure about the implementation, as this requires testing ;)
> Did you consider the cases where the source connector is S-Video
> or Composite?
I think you asked this question on another patch and Devin
responded to that thread. Let's discuss it there.
thanks,
-- Shuah
>
>> +#ifdef CONFIG_MEDIA_CONTROLLER
>> + struct media_entity *source;
>> + struct media_entity *sink;
>> + struct media_link *link, *found_link = NULL;
>> + int ret = 0;
>> + struct media_device *mdev = entity->graph_obj.mdev;
>> + struct au0828_dev *dev;
>> +
>> + if (!mdev)
>> + return -ENODEV;
>> +
>> + /* for Audio and Video entities, source is the decoder */
>> + mutex_lock(&mdev->graph_mutex);
>> +
>> + dev = mdev->source_priv;
>> + if (!dev->tuner || !dev->decoder) {
>> + ret = -ENODEV;
>> + goto end;
>> + }
>> +
>> + /*
>> + * For Audio and V4L2 entity, find the link to which decoder
>> + * is the sink. Look for an active link between decoder and
>> + * tuner, if one exists, nothing to do. If not, look for any
>> + * active links between tuner and any other entity. If one
>> + * exists, tuner is busy. If tuner is free, setup link and
>> + * start pipeline from source (tuner).
>> + * For DVB FE entity, the source for the link is the tuner.
>> + * Check if tuner is available and setup link and start
>> + * pipeline.
>> + */
>> + if (entity->function != MEDIA_ENT_F_DTV_DEMOD)
>> + sink = dev->decoder;
>> + else
>> + sink = entity;
>> +
>> + /* Is an active link between sink and tuner */
>> + if (dev->active_link) {
>> + if (dev->active_link->sink->entity == sink &&
>> + dev->active_link->source->entity == dev->tuner) {
>> + ret = 0;
>> + goto end;
>> + } else {
>> + ret = -EBUSY;
>> + goto end;
>> + }
>> + }
>> +
>> + list_for_each_entry(link, &sink->links, list) {
>> + /* Check sink, and source */
>> + if (link->sink->entity == sink &&
>> + link->source->entity == dev->tuner) {
>> + found_link = link;
>> + break;
>> + }
>> + }
>> +
>> + if (!found_link) {
>> + ret = -ENODEV;
>> + goto end;
>> + }
>> +
>> + /* activate link between source and sink and start pipeline */
>> + source = found_link->source->entity;
>> + ret = __media_entity_setup_link(found_link, MEDIA_LNK_FL_ENABLED);
>> + if (ret) {
>> + pr_err(
>> + "Activate tuner link %s->%s. Error %d\n",
>> + source->name, sink->name, ret);
>> + goto end;
>> + }
>> +
>> + ret = __media_entity_pipeline_start(entity, pipe);
>> + if (ret) {
>> + pr_err("Start Pipeline: %s->%s Error %d\n",
>> + source->name, entity->name, ret);
>> + ret = __media_entity_setup_link(found_link, 0);
>> + pr_err("Deactive link Error %d\n", ret);
>> + goto end;
>> + }
>> + /*
>> + * save active link and active link owner to avoid audio
>> + * deactivating video owned link from disable_source and
>> + * vice versa
>> + */
>> + dev->active_link = found_link;
>> + dev->active_link_owner = entity;
>> +end:
>> + mutex_unlock(&mdev->graph_mutex);
>> + pr_debug("au0828_enable_source() end %s %d %d\n",
>> + entity->name, entity->function, ret);
>> + return ret;
>> +#endif
>> + return 0;
>> +}
>> +
>> +static void au0828_disable_source(struct media_entity *entity)
>> +{
>> +#ifdef CONFIG_MEDIA_CONTROLLER
>> + struct media_entity *sink;
>> + int ret = 0;
>> + struct media_device *mdev = entity->graph_obj.mdev;
>> + struct au0828_dev *dev;
>> +
>> + if (!mdev)
>> + return;
>> +
>> + mutex_lock(&mdev->graph_mutex);
>> + dev = mdev->source_priv;
>> + if (!dev->tuner || !dev->decoder || !dev->active_link) {
>> + ret = -ENODEV;
>> + goto end;
>> + }
>> +
>> + if (entity->function != MEDIA_ENT_F_DTV_DEMOD)
>> + sink = dev->decoder;
>> + else
>> + sink = entity;
>> +
>> + /* link is active - stop pipeline from source (tuner) */
>> + if (dev->active_link && dev->active_link->sink->entity == sink &&
>> + dev->active_link->source->entity == dev->tuner) {
>> + /*
>> + * prevent video from deactivating link when audio
>> + * has active pipeline
>> + */
>> + if (dev->active_link_owner != entity)
>> + goto end;
>> + __media_entity_pipeline_stop(entity);
>> + ret = __media_entity_setup_link(dev->active_link, 0);
>> + if (ret)
>> + pr_err("Deactive link Error %d\n", ret);
>> + dev->active_link = NULL;
>> + dev->active_link_owner = NULL;
>> + }
>> +
>> +end:
>> + mutex_unlock(&mdev->graph_mutex);
>> +#endif
>> +}
>> +
>> static int au0828_media_device_register(struct au0828_dev *dev,
>> struct usb_device *udev)
>> {
>> @@ -400,6 +544,10 @@ static int au0828_media_device_register(struct au0828_dev *dev,
>> ret);
>> return ret;
>> }
>> + /* set enable_source */
>> + dev->media_dev->source_priv = (void *) dev;
>> + dev->media_dev->enable_source = au0828_enable_source;
>> + dev->media_dev->disable_source = au0828_disable_source;
>> #endif
>> return 0;
>> }
>> diff --git a/drivers/media/usb/au0828/au0828.h b/drivers/media/usb/au0828/au0828.h
>> index cfb6d58..3707664 100644
>> --- a/drivers/media/usb/au0828/au0828.h
>> +++ b/drivers/media/usb/au0828/au0828.h
>> @@ -289,6 +289,8 @@ struct au0828_dev {
>> bool vdev_linked;
>> bool vbi_linked;
>> bool audio_capture_linked;
>> + struct media_link *active_link;
>> + struct media_entity *active_link_owner;
>> #endif
>> };
>>
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh at osg.samsung.com | (970) 217-8978
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