/*
V4L2 device support.
Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/types.h>
#include <linux/ioctl.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#if defined(CONFIG_SPI)
#include <linux/spi/spi.h>
#endif
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>
int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
{
if (v4l2_dev == NULL)
return -EINVAL;
INIT_LIST_HEAD(&v4l2_dev->subdevs);
spin_lock_init(&v4l2_dev->lock);
v4l2_prio_init(&v4l2_dev->prio);
kref_init(&v4l2_dev->ref);
get_device(dev);
v4l2_dev->dev = dev;
if (dev == NULL) {
/* If dev == NULL, then name must be filled in by the caller */
if (WARN_ON(!v4l2_dev->name[0]))
return -EINVAL;
return 0;
}
/* Set name to driver name + device name if it is empty. */
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))
dev_set_drvdata(dev, v4l2_dev);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_device_register);
static void v4l2_device_release(struct kref *ref)
{
struct v4l2_device *v4l2_dev =
container_of(ref, struct v4l2_device, ref);
if (v4l2_dev->release)
v4l2_dev->release(v4l2_dev);
}
int v4l2_device_put(struct v4l2_device *v4l2_dev)
{
return kref_put(&v4l2_dev->ref, v4l2_device_release);
}
EXPORT_SYMBOL_GPL(v4l2_device_put);
int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
atomic_t *instance)
{
int num = atomic_inc_return(instance) - 1;
int len = strlen(basename);
if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
"%s-%d", basename, num);
else
snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
"%s%d", basename, num);
return num;
}
EXPORT_SYMBOL_GPL(v4l2_device_set_name);
void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
{
if (v4l2_dev->dev == NULL)
return;
if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
dev_set_drvdata(v4l2_dev->dev, NULL);
put_device(v4l2_dev->dev);
v4l2_dev->dev = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
{
struct v4l2_subdev *sd, *next;
/* Just return if v4l2_dev is NULL or if it was already
* unregistered before. */
if (v4l2_dev == NULL || !v4l2_dev->name[0])
return;
v4l2_device_disconnect(v4l2_dev);
/* Unregister subdevs */
list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
v4l2_device_unregister_subdev(sd);
#if IS_ENABLED(CONFIG_I2C)
if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
struct i2c_client *client = v4l2_get_subdevdata(sd);
/*
* We need to unregister the i2c client
* explicitly. We cannot rely on
* i2c_del_adapter to always unregister
* clients for us, since if the i2c bus is a
* platform bus, then it is never deleted.
*
* Device tree or ACPI based devices must not
* be unregistered as they have not been
* registered by us, and would not be
* re-created by just probing the V4L2 driver.
*/
if (client &&
!client->dev.of_node && !client->dev.fwnode)
i2c_unregister_device(client);
continue;
}
#endif
#if defined(CONFIG_SPI)
if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
struct spi_device *spi = v4l2_get_subdevdata(sd);
if (spi && !spi->dev.of_node && !spi->dev.fwnode)
spi_unregister_device(spi);
continue;
}
#endif
}
/* Mark as unregistered, thus preventing duplicate unregistrations */
v4l2_dev->name[0] = '\0';
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister);
int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
struct v4l2_subdev *sd)
{
#if defined(CONFIG_MEDIA_CONTROLLER)
struct media_entity *entity = &sd->entity;
#endif
int err;
/* Check for valid input */
if (!v4l2_dev || !sd || sd->v4l2_dev || !sd->name[0])
return -EINVAL;
/*
* The reason to acquire the module here is to avoid unloading
* a module of sub-device which is registered to a media
* device. To make it possible to unload modules for media
* devices that also register sub-devices, do not
* try_module_get() such sub-device owners.
*/
sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
sd->owner == v4l2_dev->dev->driver->owner;
if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
return -ENODEV;
sd->v4l2_dev = v4l2_dev;
/* This just returns 0 if either of the two args is NULL */
err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
if (err)
goto error_module;
#if defined(CONFIG_MEDIA_CONTROLLER)
/* Register the entity. */
if (v4l2_dev->mdev) {
err = media_device_register_entity(v4l2_dev->mdev, entity);
if (err < 0)
goto error_module;
}
#endif
if (sd->internal_ops && sd->internal_ops->registered) {
err = sd->internal_ops->registered(sd);
if (err)
goto error_unregister;
}
spin_lock(&v4l2_dev->lock);
list_add_tail(&sd->list, &v4l2_dev->subdevs);
spin_unlock(&v4l2_dev->lock);
return 0;
error_unregister:
#if defined(CONFIG_MEDIA_CONTROLLER)
media_device_unregister_entity(entity);
#endif
error_module:
if (!sd->owner_v4l2_dev)
module_put(sd->owner);
sd->v4l2_dev = NULL;
return err;
}
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;
struct v4l2_subdev *sd;
int err;
/* Register a device node for every subdev marked with the
* V4L2_SUBDEV_FL_HAS_DEVNODE flag.
*/
list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
continue;
if (sd->devnode)
continue;
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 = 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) {
kfree(vdev);
goto clean_up;
}
sd->devnode = vdev;
#if defined(CONFIG_MEDIA_CONTROLLER)
sd->entity.info.dev.major = VIDEO_MAJOR;
sd->entity.info.dev.minor = vdev->minor;
/* Interface is created by __video_register_device() */
if (vdev->v4l2_dev->mdev) {
struct media_link *link;
link = media_create_intf_link(&sd->entity,
&vdev->intf_devnode->intf,
MEDIA_LNK_FL_ENABLED);
if (!link) {
err = -ENOMEM;
goto clean_up;
}
}
#endif
}
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);
void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
{
struct v4l2_device *v4l2_dev;
/* return if it isn't registered */
if (sd == NULL || sd->v4l2_dev == NULL)
return;
v4l2_dev = sd->v4l2_dev;
spin_lock(&v4l2_dev->lock);
list_del(&sd->list);
spin_unlock(&v4l2_dev->lock);
if (sd->internal_ops && sd->internal_ops->unregistered)
sd->internal_ops->unregistered(sd);
sd->v4l2_dev = NULL;
#if defined(CONFIG_MEDIA_CONTROLLER)
if (v4l2_dev->mdev) {
/*
* No need to explicitly remove links, as both pads and
* links are removed by the function below, in the right order
*/
media_device_unregister_entity(&sd->entity);
}
#endif
video_unregister_device(sd->devnode);
if (!sd->owner_v4l2_dev)
module_put(sd->owner);
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
