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 --- Documentation/video4linux/v4l2-framework.txt | 17 ++++++++++++----- drivers/media/video/v4l2-device.c | 13 +++++++------ include/media/v4l2-device.h | 4 ++++ 3 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index eb84795..7de55cf 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 f0c77dd..0af46e4 100644 --- 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 78b11e5..0c2bd30 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; +#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