[media] v4l: Add a media_device pointer to the v4l2_device structure

The pointer will later be used to register/unregister media entities
when registering/unregistering a v4l2_subdev or a video_device.

With the introduction of media devices, device drivers need to store a
pointer to a driver-specific structure in the device's drvdata.
v4l2_device can't claim ownership of the drvdata anymore.

To maintain compatibility with drivers that rely on v4l2_device storing
a pointer to itself in the device's drvdata, v4l2_device_register() will
keep doing so if the drvdata is NULL.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index eb8479565dc416ef9ac857e18f66444b2796d5cd..7de55cfae04e27f40d1f1153814812b918fa7870 100644 (file)
--- 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 8c0ad8b372d864645b88d3decb9a0e2047c2f15c..cfbd8a38991dbe1425ea7381f45fe32a9d854c97 100644 (file)
--- a/drivers/media/video/v4l2-device.c
+++ b/drivers/media/video/v4l2-device.c
@@ -47,9 +47,8 @@ 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;
 }
 EXPORT_SYMBOL_GPL(v4l2_device_register);
@@ -72,10 +71,12 @@ 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;
 }
 EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
 

diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index 78b11e5a6db7d86f8e5ddbf86b2d610c2400dfd6..0c2bd30750386eda1274112d5b68bb0638b95da7 100644 (file)
--- 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;
+#if defined(CONFIG_MEDIA_CONTROLLER)
+       struct media_device *mdev;
+#endif
        /* 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