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[RFC/PATCH,v6,10/12] v4l: Add a media_device pointer to the v4l2_device structure

Message ID 1290652099-15102-11-git-send-email-laurent.pinchart@ideasonboard.com (mailing list archive)
State RFC, archived
Headers show

Commit Message

Laurent Pinchart Nov. 25, 2010, 2:28 a.m. UTC
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diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index 4db1def..aeb2a22 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -83,11 +83,17 @@  You must register the device instance:
 	v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
-Registration will initialize the v4l2_device struct and link dev->driver_data
-to v4l2_dev. If v4l2_dev->name is empty then it will be set to a value derived
-from dev (driver name followed by the bus_id, to be precise). If you set it
-up before calling v4l2_device_register then it will be untouched. If dev is
-NULL, then you *must* setup v4l2_dev->name before calling v4l2_device_register.
+Registration will initialize the v4l2_device struct. If the dev->driver_data
+field is NULL, it will be linked to v4l2_dev. Drivers that use the media
+device framework in addition to the V4L2 framework need to set
+dev->driver_data manually to point to the driver-specific device structure
+that embed the struct v4l2_device instance. This is achieved by a
+dev_set_drvdata() call before registering the V4L2 device instance.
+If v4l2_dev->name is empty then it will be set to a value derived from dev
+(driver name followed by the bus_id, to be precise). If you set it up before
+calling v4l2_device_register then it will be untouched. If dev is NULL, then
+you *must* setup v4l2_dev->name before calling v4l2_device_register.
 You can use v4l2_device_set_name() to set the name based on a driver name and
 a driver-global atomic_t instance. This will generate names like ivtv0, ivtv1,
@@ -108,6 +114,7 @@  You unregister with:
 	v4l2_device_unregister(struct v4l2_device *v4l2_dev);
+If the dev->driver_data field points to v4l2_dev, it will be reset to NULL.
 Unregistering will also automatically unregister all subdevs from the device.
 If you have a hotpluggable device (e.g. a USB device), then when a disconnect
diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
index 318e911..8447466 100644
--- a/drivers/media/video/v4l2-device.c
+++ b/drivers/media/video/v4l2-device.c
@@ -46,9 +46,8 @@  int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
 	if (!v4l2_dev->name[0])
 		snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
 			dev->driver->name, dev_name(dev));
-	if (dev_get_drvdata(dev))
-		v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
-	dev_set_drvdata(dev, v4l2_dev);
+	if (!dev_get_drvdata(dev))
+		dev_set_drvdata(dev, v4l2_dev);
 	return 0;
@@ -71,10 +70,12 @@  EXPORT_SYMBOL_GPL(v4l2_device_set_name);
 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
-	if (v4l2_dev->dev) {
+	if (v4l2_dev->dev == NULL)
+		return;
+	if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
 		dev_set_drvdata(v4l2_dev->dev, NULL);
-		v4l2_dev->dev = NULL;
-	}
+	v4l2_dev->dev = NULL;
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index 6648036..b649c74 100644
--- a/include/media/v4l2-device.h
+++ b/include/media/v4l2-device.h
@@ -21,6 +21,7 @@ 
 #ifndef _V4L2_DEVICE_H
 #define _V4L2_DEVICE_H
+#include <media/media-device.h>
 #include <media/v4l2-subdev.h>
 /* Each instance of a V4L2 device should create the v4l2_device struct,
@@ -39,6 +40,9 @@  struct v4l2_device {
 	   Note: dev might be NULL if there is no parent device
 	   as is the case with e.g. ISA devices. */
 	struct device *dev;
+	struct media_device *mdev;
 	/* used to keep track of the registered subdevs */
 	struct list_head subdevs;
 	/* lock this struct; can be used by the driver as well if this