diff options
Diffstat (limited to 'include/media/v4l2-async.h')
| -rw-r--r-- | include/media/v4l2-async.h | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h new file mode 100644 index 000000000..25eb1d138 --- /dev/null +++ b/include/media/v4l2-async.h @@ -0,0 +1,316 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * V4L2 asynchronous subdevice registration API + * + * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de> + */ + +#ifndef V4L2_ASYNC_H +#define V4L2_ASYNC_H + +#include <linux/list.h> +#include <linux/mutex.h> + +struct dentry; +struct device; +struct device_node; +struct v4l2_device; +struct v4l2_subdev; +struct v4l2_async_notifier; + +/** + * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used + * in order to identify a match + * + * @V4L2_ASYNC_MATCH_I2C: Match will check for I2C adapter ID and address + * @V4L2_ASYNC_MATCH_FWNODE: Match will use firmware node + * + * This enum is used by the asynchronous sub-device logic to define the + * algorithm that will be used to match an asynchronous device. + */ +enum v4l2_async_match_type { + V4L2_ASYNC_MATCH_I2C, + V4L2_ASYNC_MATCH_FWNODE, +}; + +/** + * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge + * + * @match_type: type of match that will be used + * @match: union of per-bus type matching data sets + * @match.fwnode: + * pointer to &struct fwnode_handle to be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_FWNODE. + * @match.i2c: embedded struct with I2C parameters to be matched. + * Both @match.i2c.adapter_id and @match.i2c.address + * should be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. + * @match.i2c.adapter_id: + * I2C adapter ID to be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. + * @match.i2c.address: + * I2C address to be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. + * @asd_list: used to add struct v4l2_async_subdev objects to the + * master notifier @asd_list + * @list: used to link struct v4l2_async_subdev objects, waiting to be + * probed, to a notifier->waiting list + * + * When this struct is used as a member in a driver specific struct, + * the driver specific struct shall contain the &struct + * v4l2_async_subdev as its first member. + */ +struct v4l2_async_subdev { + enum v4l2_async_match_type match_type; + union { + struct fwnode_handle *fwnode; + struct { + int adapter_id; + unsigned short address; + } i2c; + } match; + + /* v4l2-async core private: not to be used by drivers */ + struct list_head list; + struct list_head asd_list; +}; + +/** + * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations + * @bound: a subdevice driver has successfully probed one of the subdevices + * @complete: All subdevices have been probed successfully. The complete + * callback is only executed for the root notifier. + * @unbind: a subdevice is leaving + * @destroy: the asd is about to be freed + */ +struct v4l2_async_notifier_operations { + int (*bound)(struct v4l2_async_notifier *notifier, + struct v4l2_subdev *subdev, + struct v4l2_async_subdev *asd); + int (*complete)(struct v4l2_async_notifier *notifier); + void (*unbind)(struct v4l2_async_notifier *notifier, + struct v4l2_subdev *subdev, + struct v4l2_async_subdev *asd); + void (*destroy)(struct v4l2_async_subdev *asd); +}; + +/** + * struct v4l2_async_notifier - v4l2_device notifier data + * + * @ops: notifier operations + * @v4l2_dev: v4l2_device of the root notifier, NULL otherwise + * @sd: sub-device that registered the notifier, NULL otherwise + * @parent: parent notifier + * @asd_list: master list of struct v4l2_async_subdev + * @waiting: list of struct v4l2_async_subdev, waiting for their drivers + * @done: list of struct v4l2_subdev, already probed + * @list: member in a global list of notifiers + */ +struct v4l2_async_notifier { + const struct v4l2_async_notifier_operations *ops; + struct v4l2_device *v4l2_dev; + struct v4l2_subdev *sd; + struct v4l2_async_notifier *parent; + struct list_head asd_list; + struct list_head waiting; + struct list_head done; + struct list_head list; +}; + +/** + * v4l2_async_debug_init - Initialize debugging tools. + * + * @debugfs_dir: pointer to the parent debugfs &struct dentry + */ +void v4l2_async_debug_init(struct dentry *debugfs_dir); + +/** + * v4l2_async_nf_init - Initialize a notifier. + * + * @notifier: pointer to &struct v4l2_async_notifier + * + * This function initializes the notifier @asd_list. It must be called + * before adding a subdevice to a notifier, using one of: + * v4l2_async_nf_add_fwnode_remote(), + * v4l2_async_nf_add_fwnode(), + * v4l2_async_nf_add_i2c(), + * __v4l2_async_nf_add_subdev() or + * v4l2_async_nf_parse_fwnode_endpoints(). + */ +void v4l2_async_nf_init(struct v4l2_async_notifier *notifier); + +/** + * __v4l2_async_nf_add_subdev - Add an async subdev to the + * notifier's master asd list. + * + * @notifier: pointer to &struct v4l2_async_notifier + * @asd: pointer to &struct v4l2_async_subdev + * + * \warning: Drivers should avoid using this function and instead use one of: + * v4l2_async_nf_add_fwnode(), + * v4l2_async_nf_add_fwnode_remote() or + * v4l2_async_nf_add_i2c(). + * + * Call this function before registering a notifier to link the provided @asd to + * the notifiers master @asd_list. The @asd must be allocated with k*alloc() as + * it will be freed by the framework when the notifier is destroyed. + */ +int __v4l2_async_nf_add_subdev(struct v4l2_async_notifier *notifier, + struct v4l2_async_subdev *asd); + +struct v4l2_async_subdev * +__v4l2_async_nf_add_fwnode(struct v4l2_async_notifier *notifier, + struct fwnode_handle *fwnode, + unsigned int asd_struct_size); +/** + * v4l2_async_nf_add_fwnode - Allocate and add a fwnode async + * subdev to the notifier's master asd_list. + * + * @notifier: pointer to &struct v4l2_async_notifier + * @fwnode: fwnode handle of the sub-device to be matched, pointer to + * &struct fwnode_handle + * @type: Type of the driver's async sub-device struct. The &struct + * v4l2_async_subdev shall be the first member of the driver's async + * sub-device struct, i.e. both begin at the same memory address. + * + * Allocate a fwnode-matched asd of size asd_struct_size, and add it to the + * notifiers @asd_list. The function also gets a reference of the fwnode which + * is released later at notifier cleanup time. + */ +#define v4l2_async_nf_add_fwnode(notifier, fwnode, type) \ + ((type *)__v4l2_async_nf_add_fwnode(notifier, fwnode, sizeof(type))) + +struct v4l2_async_subdev * +__v4l2_async_nf_add_fwnode_remote(struct v4l2_async_notifier *notif, + struct fwnode_handle *endpoint, + unsigned int asd_struct_size); +/** + * v4l2_async_nf_add_fwnode_remote - Allocate and add a fwnode + * remote async subdev to the + * notifier's master asd_list. + * + * @notifier: pointer to &struct v4l2_async_notifier + * @ep: local endpoint pointing to the remote sub-device to be matched, + * pointer to &struct fwnode_handle + * @type: Type of the driver's async sub-device struct. The &struct + * v4l2_async_subdev shall be the first member of the driver's async + * sub-device struct, i.e. both begin at the same memory address. + * + * Gets the remote endpoint of a given local endpoint, set it up for fwnode + * matching and adds the async sub-device to the notifier's @asd_list. The + * function also gets a reference of the fwnode which is released later at + * notifier cleanup time. + * + * This is just like v4l2_async_nf_add_fwnode(), but with the + * exception that the fwnode refers to a local endpoint, not the remote one. + */ +#define v4l2_async_nf_add_fwnode_remote(notifier, ep, type) \ + ((type *)__v4l2_async_nf_add_fwnode_remote(notifier, ep, sizeof(type))) + +struct v4l2_async_subdev * +__v4l2_async_nf_add_i2c(struct v4l2_async_notifier *notifier, + int adapter_id, unsigned short address, + unsigned int asd_struct_size); +/** + * v4l2_async_nf_add_i2c - Allocate and add an i2c async + * subdev to the notifier's master asd_list. + * + * @notifier: pointer to &struct v4l2_async_notifier + * @adapter: I2C adapter ID to be matched + * @address: I2C address of sub-device to be matched + * @type: Type of the driver's async sub-device struct. The &struct + * v4l2_async_subdev shall be the first member of the driver's async + * sub-device struct, i.e. both begin at the same memory address. + * + * Same as v4l2_async_nf_add_fwnode() but for I2C matched + * sub-devices. + */ +#define v4l2_async_nf_add_i2c(notifier, adapter, address, type) \ + ((type *)__v4l2_async_nf_add_i2c(notifier, adapter, address, \ + sizeof(type))) + +/** + * v4l2_async_nf_register - registers a subdevice asynchronous notifier + * + * @v4l2_dev: pointer to &struct v4l2_device + * @notifier: pointer to &struct v4l2_async_notifier + */ +int v4l2_async_nf_register(struct v4l2_device *v4l2_dev, + struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_subdev_nf_register - registers a subdevice asynchronous + * notifier for a sub-device + * + * @sd: pointer to &struct v4l2_subdev + * @notifier: pointer to &struct v4l2_async_notifier + */ +int v4l2_async_subdev_nf_register(struct v4l2_subdev *sd, + struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_nf_unregister - unregisters a subdevice + * asynchronous notifier + * + * @notifier: pointer to &struct v4l2_async_notifier + */ +void v4l2_async_nf_unregister(struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_nf_cleanup - clean up notifier resources + * @notifier: the notifier the resources of which are to be cleaned up + * + * Release memory resources related to a notifier, including the async + * sub-devices allocated for the purposes of the notifier but not the notifier + * itself. The user is responsible for calling this function to clean up the + * notifier after calling + * v4l2_async_nf_add_fwnode_remote(), + * v4l2_async_nf_add_fwnode(), + * v4l2_async_nf_add_i2c(), + * __v4l2_async_nf_add_subdev() or + * v4l2_async_nf_parse_fwnode_endpoints(). + * + * There is no harm from calling v4l2_async_nf_cleanup() in other + * cases as long as its memory has been zeroed after it has been + * allocated. + */ +void v4l2_async_nf_cleanup(struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_register_subdev - registers a sub-device to the asynchronous + * subdevice framework + * + * @sd: pointer to &struct v4l2_subdev + */ +int v4l2_async_register_subdev(struct v4l2_subdev *sd); + +/** + * v4l2_async_register_subdev_sensor - registers a sensor sub-device to the + * asynchronous sub-device framework and + * parse set up common sensor related + * devices + * + * @sd: pointer to struct &v4l2_subdev + * + * This function is just like v4l2_async_register_subdev() with the exception + * that calling it will also parse firmware interfaces for remote references + * using v4l2_async_nf_parse_fwnode_sensor() and registers the + * async sub-devices. The sub-device is similarly unregistered by calling + * v4l2_async_unregister_subdev(). + * + * While registered, the subdev module is marked as in-use. + * + * An error is returned if the module is no longer loaded on any attempts + * to register it. + */ +int __must_check +v4l2_async_register_subdev_sensor(struct v4l2_subdev *sd); + +/** + * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous + * subdevice framework + * + * @sd: pointer to &struct v4l2_subdev + */ +void v4l2_async_unregister_subdev(struct v4l2_subdev *sd); +#endif |