Media Device Allocator API to allows multiple drivers share a media device. This API solves a very common use-case for media devices where one physical device (an USB stick) provides both audio and video. When such media device exposes a standard USB Audio class, a proprietary Video class, two or more independent drivers will share a single physical USB bridge. In such cases, it is necessary to coordinate access to the shared resource.
Using this API, drivers can allocate a media device with the shared struct device as the key. Once the media device is allocated by a driver, other drivers can get a reference to it. The media device is released when all the references are released.
Change au0828 to use Media Device Allocator API to allocate media device with the parent usb struct device as the key, so it can be shared with the snd_usb_audio driver.
Signed-off-by: Shuah Khan shuah@kernel.org --- drivers/media/usb/au0828/au0828-core.c | 12 ++++-------- drivers/media/usb/au0828/au0828.h | 1 + 2 files changed, 5 insertions(+), 8 deletions(-)
diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c index 1fdb1601dc65..4b0a395d59aa 100644 --- a/drivers/media/usb/au0828/au0828-core.c +++ b/drivers/media/usb/au0828/au0828-core.c @@ -155,9 +155,7 @@ static void au0828_unregister_media_device(struct au0828_dev *dev) dev->media_dev->disable_source = NULL; mutex_unlock(&mdev->graph_mutex);
- media_device_unregister(dev->media_dev); - media_device_cleanup(dev->media_dev); - kfree(dev->media_dev); + media_device_delete(dev->media_dev, KBUILD_MODNAME); dev->media_dev = NULL; #endif } @@ -210,14 +208,10 @@ static int au0828_media_device_init(struct au0828_dev *dev, #ifdef CONFIG_MEDIA_CONTROLLER struct media_device *mdev;
- mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); + mdev = media_device_usb_allocate(udev, KBUILD_MODNAME); if (!mdev) return -ENOMEM;
- /* check if media device is already initialized */ - if (!mdev->dev) - media_device_usb_init(mdev, udev, udev->product); - dev->media_dev = mdev; #endif return 0; @@ -480,6 +474,8 @@ static int au0828_media_device_register(struct au0828_dev *dev, /* register media device */ ret = media_device_register(dev->media_dev); if (ret) { + media_device_delete(dev->media_dev, KBUILD_MODNAME); + dev->media_dev = NULL; dev_err(&udev->dev, "Media Device Register Error: %d\n", ret); return ret; diff --git a/drivers/media/usb/au0828/au0828.h b/drivers/media/usb/au0828/au0828.h index 004eadef55c7..7dbe3db15ebe 100644 --- a/drivers/media/usb/au0828/au0828.h +++ b/drivers/media/usb/au0828/au0828.h @@ -31,6 +31,7 @@ #include <media/v4l2-ctrls.h> #include <media/v4l2-fh.h> #include <media/media-device.h> +#include <media/media-dev-allocator.h>
/* DVB */ #include <media/demux.h>