On 06/03/2015 11:42 AM, Mauro Carvalho Chehab wrote:
Em Wed, 03 Jun 2015 09:12:53 -0600 Shuah Khan shuahkh@osg.samsung.com escreveu:
Add new media controller API to allocate media device as a device resource. When a media device is created on the main struct device which is the parent device for the interface device, it will be available to all drivers associated with that interface. For example, if a usb media device driver creates the media device on the main struct device which is common for all the drivers that control the media device, including the non-media ALSA driver, media controller API can be used to share access to the resources on the media device. This new interface provides the above described feature. A second interface that finds and returns the media device is added to allow drivers to find the media device created by any of the drivers associated with the device.
Signed-off-by: Shuah Khan shuahkh@osg.samsung.com
drivers/media/media-device.c | 33 +++++++++++++++++++++++++++++++++ include/media/media-device.h | 2 ++ 2 files changed, 35 insertions(+)
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c index 7b39440..a4d5b24 100644 --- a/drivers/media/media-device.c +++ b/drivers/media/media-device.c @@ -462,3 +462,36 @@ void media_device_unregister_entity(struct media_entity *entity) entity->parent = NULL; } EXPORT_SYMBOL_GPL(media_device_unregister_entity);
+static void media_device_release_devres(struct device *dev, void *res) +{ +}
+/*
- media_device_get_devres() - get media device as device resource
creates if one doesn't exist+*/ +struct media_device *media_device_get_devres(struct device *dev) +{
- struct media_device *mdev;
- mdev = devres_find(dev, media_device_release_devres, NULL, NULL);
- if (mdev)
return mdev;- mdev = devres_alloc(media_device_release_devres,
sizeof(struct media_device), GFP_KERNEL);- if (!mdev)
return NULL;- return devres_get(dev, mdev, NULL, NULL);
+} +EXPORT_SYMBOL_GPL(media_device_get_devres);
+/*
- media_device_find_devres() - find media device as device resource
+*/ +struct media_device *media_device_find_devres(struct device *dev) +{
- return devres_find(dev, media_device_release_devres, NULL, NULL);
+} +EXPORT_SYMBOL_GPL(media_device_find_devres); diff --git a/include/media/media-device.h b/include/media/media-device.h index 6e6db78..22792cd 100644 --- a/include/media/media-device.h +++ b/include/media/media-device.h @@ -95,6 +95,8 @@ void media_device_unregister(struct media_device *mdev); int __must_check media_device_register_entity(struct media_device *mdev, struct media_entity *entity); void media_device_unregister_entity(struct media_entity *entity); +struct media_device *media_device_get_devres(struct device *dev); +struct media_device *media_device_find_devres(struct device *dev);
Hmm... what happens if the Kernel is compiled without MC controller support?
Yeah. I noticed media controller api users have the code in ifdef CONFIG_MEDIA_CONTROLLER.
I think that the best would be to add a #ifdef at the header file and provide an alternate dummy method to avoid the need of testing for it everywhere.
I agree with you that a better way to do it would be defining media controller api in ifdef CONFIG_MEDIA_CONTROLLER and provide stubs for else case, similar to what I did in sound/usb/media.c
I followed the existing code to add new interfaces. Do you want to see all media controller interfaces in ifdef clause with stubs or just the two new interfaces I added? Or is this something that should be done as a separate change to catch all media controller interfaces?
thanks, -- Shuah