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Commit 3e0ec41c authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Mauro Carvalho Chehab
Browse files

[media] V4L: dynamically allocate video_device nodes in subdevices 



Currently only very few drivers actually use video_device nodes, embedded
in struct v4l2_subdev. Allocate these nodes dynamically for those drivers
to save memory for the rest.

Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Tested-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 2fbdc9bd

drivers/media/video/v4l2-device.c

+31 −5
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/types.h>

#include <linux/ioctl.h>

#include <linux/i2c.h>

#include <linux/slab.h>

#if defined(CONFIG_SPI)

#include <linux/spi/spi.h>

#endif
@@ -193,6 +194,13 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 
}

EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);



static void v4l2_device_release_subdev_node(struct video_device *vdev)

{

	struct v4l2_subdev *sd = video_get_drvdata(vdev);

	sd->devnode = NULL;

	kfree(vdev);

}



int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)

{

	struct video_device *vdev;
@@ -206,22 +214,40 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) 
		if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))

			continue;



		vdev = &sd->devnode;

		vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);

		if (!vdev) {

			err = -ENOMEM;

			goto clean_up;

		}



		video_set_drvdata(vdev, sd);

		strlcpy(vdev->name, sd->name, sizeof(vdev->name));

		vdev->v4l2_dev = v4l2_dev;

		vdev->fops = &v4l2_subdev_fops;

		vdev->release = video_device_release_empty;

		vdev->release = v4l2_device_release_subdev_node;

		vdev->ctrl_handler = sd->ctrl_handler;

		err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,

					      sd->owner);

		if (err < 0)

			return err;

		if (err < 0) {

			kfree(vdev);

			goto clean_up;

		}

#if defined(CONFIG_MEDIA_CONTROLLER)

		sd->entity.v4l.major = VIDEO_MAJOR;

		sd->entity.v4l.minor = vdev->minor;

#endif

		sd->devnode = vdev;

	}

	return 0;



clean_up:

	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {

		if (!sd->devnode)

			break;

		video_unregister_device(sd->devnode);

	}



	return err;

}

EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
@@ -247,7 +273,7 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) 
	if (v4l2_dev->mdev)

		media_device_unregister_entity(&sd->entity);

#endif

	video_unregister_device(&sd->devnode);

	video_unregister_device(sd->devnode);

	module_put(sd->owner);

}

EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);

include/media/v4l2-subdev.h

+2 −2
Original line number Diff line number Diff line
@@ -534,13 +534,13 @@ struct v4l2_subdev { 
	void *dev_priv;

	void *host_priv;

	/* subdev device node */

	struct video_device devnode;

	struct video_device *devnode;

};



#define media_entity_to_v4l2_subdev(ent) \

	container_of(ent, struct v4l2_subdev, entity)

#define vdev_to_v4l2_subdev(vdev) \

	container_of(vdev, struct v4l2_subdev, devnode)

	video_get_drvdata(vdev)



/*

 * Used for storing subdev information per file handle