[alsa-devel] [PATCH MC Next Gen 16/20] media: au0828 change to use Managed Media Controller API

[Shuah Khan]

Change au0828 to use Managed Media Controller API to coordinate
creating/deleting media device on parent usb device it shares
with the snd-usb-audio driver. With this change, au0828 uses
media_device_get_devres() to allocate a new media device devres
or return an existing one, if it finds one.

Signed-off-by: Shuah Khan <shuahkh at osg.samsung.com>
---
 drivers/media/usb/au0828/au0828-core.c | 45 +++++++++++++++++-----------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index 4fd7db8..544d304 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c
@@ -135,9 +135,9 @@ static void au0828_unregister_media_device(struct au0828_dev *dev)
 {
 
 #ifdef CONFIG_MEDIA_CONTROLLER
-	if (dev->media_dev) {
+	if (dev->media_dev &&
+	    media_devnode_is_registered(&dev->media_dev->devnode)) {
 		media_device_unregister(dev->media_dev);
-		kfree(dev->media_dev);
 		dev->media_dev = NULL;
 	}
 #endif
@@ -222,31 +222,30 @@ static void au0828_media_device_register(struct au0828_dev *dev,
 	struct media_device *mdev;
 	int ret;
 
-	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	mdev = media_device_get_devres(&udev->dev);
 	if (!mdev)
 		return;
 
-	mdev->dev = &udev->dev;
-
-	if (!dev->board.name)
-		strlcpy(mdev->model, "unknown au0828", sizeof(mdev->model));
-	else
-		strlcpy(mdev->model, dev->board.name, sizeof(mdev->model));
-	if (udev->serial)
-		strlcpy(mdev->serial, udev->serial, sizeof(mdev->serial));
-	strcpy(mdev->bus_info, udev->devpath);
-	mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
-	mdev->driver_version = LINUX_VERSION_CODE;
-
-	ret = media_device_register(mdev);
-	if (ret) {
-		pr_err(
-			"Couldn't create a media device. Error: %d\n",
-			ret);
-		kfree(mdev);
-		return;
+	if (!media_devnode_is_registered(&mdev->devnode)) {
+		/* register media device */
+		mdev->dev = &udev->dev;
+
+		if (udev->product)
+			strlcpy(mdev->model, udev->product,
+				sizeof(mdev->model));
+		if (udev->serial)
+			strlcpy(mdev->serial, udev->serial,
+				sizeof(mdev->serial));
+		strcpy(mdev->bus_info, udev->devpath);
+		mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
+		ret = media_device_register(mdev);
+		if (ret) {
+			dev_err(&udev->dev,
+				"Couldn't create a media device. Error: %d\n",
+				ret);
+			return;
+		}
 	}
-
 	dev->media_dev = mdev;
 #endif
 }
-- 
2.1.4