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Diffstat (limited to 'drivers/media/v4l2-core/v4l2-device.c')
-rw-r--r--drivers/media/v4l2-core/v4l2-device.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
new file mode 100644
index 000000000..d2e58ae91
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ V4L2 device support.
+
+ Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
+
+ */
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#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 (sd->flags & V4L2_SUBDEV_FL_IS_I2C)
+ v4l2_i2c_subdev_unregister(sd);
+ else if (sd->flags & V4L2_SUBDEV_FL_IS_SPI)
+ v4l2_spi_subdev_unregister(sd);
+ }
+ /* 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)
+{
+ 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, true);
+ 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, &sd->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(&sd->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_subdev_release(struct v4l2_subdev *sd)
+{
+ struct module *owner = !sd->owner_v4l2_dev ? sd->owner : NULL;
+
+ if (sd->internal_ops && sd->internal_ops->release)
+ sd->internal_ops->release(sd);
+ sd->devnode = NULL;
+ module_put(owner);
+}
+
+static void v4l2_device_release_subdev_node(struct video_device *vdev)
+{
+ v4l2_subdev_release(video_get_drvdata(vdev));
+ kfree(vdev);
+}
+
+int __v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev,
+ bool read_only)
+{
+ 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);
+ strscpy(vdev->name, sd->name, sizeof(vdev->name));
+ vdev->dev_parent = sd->dev;
+ vdev->v4l2_dev = v4l2_dev;
+ vdev->fops = &v4l2_subdev_fops;
+ vdev->release = v4l2_device_release_subdev_node;
+ vdev->ctrl_handler = sd->ctrl_handler;
+ if (read_only)
+ set_bit(V4L2_FL_SUBDEV_RO_DEVNODE, &vdev->flags);
+ sd->devnode = vdev;
+ err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
+ sd->owner);
+ if (err < 0) {
+ sd->devnode = NULL;
+ kfree(vdev);
+ goto clean_up;
+ }
+#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 |
+ MEDIA_LNK_FL_IMMUTABLE);
+ 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
+ if (sd->devnode)
+ video_unregister_device(sd->devnode);
+ else
+ v4l2_subdev_release(sd);
+}
+EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);