/* 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_TYPE_I2C: Match will check for I2C adapter ID and address * @V4L2_ASYNC_MATCH_TYPE_FWNODE: Match will use firmware node * * This enum is used by the asynchronous connection logic to define the * algorithm that will be used to match an asynchronous device. */ enum v4l2_async_match_type { V4L2_ASYNC_MATCH_TYPE_I2C, V4L2_ASYNC_MATCH_TYPE_FWNODE, }; /** * struct v4l2_async_match_desc - async connection match information * * @type: type of match that will be used * @fwnode: pointer to &struct fwnode_handle to be matched. * Used if @match_type is %V4L2_ASYNC_MATCH_TYPE_FWNODE. * @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_TYPE_I2C. * @i2c.adapter_id: * I2C adapter ID to be matched. * Used if @match_type is %V4L2_ASYNC_MATCH_TYPE_I2C. * @i2c.address: * I2C address to be matched. * Used if @match_type is %V4L2_ASYNC_MATCH_TYPE_I2C. */ struct v4l2_async_match_desc { enum v4l2_async_match_type type; union { struct fwnode_handle *fwnode; struct { int adapter_id; unsigned short address; } i2c; }; }; /** * struct v4l2_async_connection - sub-device connection descriptor, as known to * a bridge * * @match: struct of match type and per-bus type matching data sets * @notifier: the async notifier the connection is related to * @asc_entry: used to add struct v4l2_async_connection objects to the * notifier @waiting_list or @done_list * @asc_subdev_entry: entry in struct v4l2_async_subdev.asc_list list * @sd: the related sub-device * * When this struct is used as a member in a driver specific struct, the driver * specific struct shall contain the &struct v4l2_async_connection as its first * member. */ struct v4l2_async_connection { struct v4l2_async_match_desc match; struct v4l2_async_notifier *notifier; struct list_head asc_entry; struct list_head asc_subdev_entry; struct v4l2_subdev *sd; }; /** * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations * @bound: a sub-device has been bound by the given connection * @complete: All connections have been bound successfully. The complete * callback is only executed for the root notifier. * @unbind: a subdevice is leaving * @destroy: the asc is about to be freed */ struct v4l2_async_notifier_operations { int (*bound)(struct v4l2_async_notifier *notifier, struct v4l2_subdev *subdev, struct v4l2_async_connection *asc); int (*complete)(struct v4l2_async_notifier *notifier); void (*unbind)(struct v4l2_async_notifier *notifier, struct v4l2_subdev *subdev, struct v4l2_async_connection *asc); void (*destroy)(struct v4l2_async_connection *asc); }; /** * 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 * @waiting_list: list of struct v4l2_async_connection, waiting for their * drivers * @done_list: list of struct v4l2_subdev, already probed * @notifier_entry: 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 waiting_list; struct list_head done_list; struct list_head notifier_entry; }; /** * struct v4l2_async_subdev_endpoint - Entry in sub-device's fwnode list * * @async_subdev_endpoint_entry: An entry in async_subdev_endpoint_list of * &struct v4l2_subdev * @endpoint: Endpoint fwnode agains which to match the sub-device */ struct v4l2_async_subdev_endpoint { struct list_head async_subdev_endpoint_entry; struct fwnode_handle *endpoint; }; /** * 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 * @v4l2_dev: pointer to &struct v4l2_device * * This function initializes the notifier @asc_entry. 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() or * v4l2_async_nf_add_i2c(). */ void v4l2_async_nf_init(struct v4l2_async_notifier *notifier, struct v4l2_device *v4l2_dev); /** * v4l2_async_subdev_nf_init - Initialize a sub-device notifier. * * @notifier: pointer to &struct v4l2_async_notifier * @sd: pointer to &struct v4l2_subdev * * This function initializes the notifier @asc_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() or * v4l2_async_nf_add_i2c(). */ void v4l2_async_subdev_nf_init(struct v4l2_async_notifier *notifier, struct v4l2_subdev *sd); struct v4l2_async_connection * __v4l2_async_nf_add_fwnode(struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode, unsigned int asc_struct_size); /** * v4l2_async_nf_add_fwnode - Allocate and add a fwnode async * subdev to the notifier's master asc_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 or connection struct. The * &struct v4l2_async_connection shall be the first member of the * driver's async struct, i.e. both begin at the same memory address. * * Allocate a fwnode-matched asc of size asc_struct_size, and add it to the * notifiers @asc_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_connection * __v4l2_async_nf_add_fwnode_remote(struct v4l2_async_notifier *notif, struct fwnode_handle *endpoint, unsigned int asc_struct_size); /** * v4l2_async_nf_add_fwnode_remote - Allocate and add a fwnode * remote async subdev to the * notifier's master asc_list. * * @notifier: pointer to &struct v4l2_async_notifier * @ep: local endpoint pointing to the remote connection to be matched, * pointer to &struct fwnode_handle * @type: Type of the driver's async connection struct. The &struct * v4l2_async_connection shall be the first member of the driver's async * connection 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 connection to the notifier's @asc_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_connection * __v4l2_async_nf_add_i2c(struct v4l2_async_notifier *notifier, int adapter_id, unsigned short address, unsigned int asc_struct_size); /** * v4l2_async_nf_add_i2c - Allocate and add an i2c async * subdev to the notifier's master asc_list. * * @notifier: pointer to &struct v4l2_async_notifier * @adapter: I2C adapter ID to be matched * @address: I2C address of connection to be matched * @type: Type of the driver's async connection struct. The &struct * v4l2_async_connection shall be the first member of the driver's async * connection struct, i.e. both begin at the same memory address. * * Same as v4l2_async_nf_add_fwnode() but for I2C matched * connections. */ #define v4l2_async_nf_add_i2c(notifier, adapter, address, type) \ ((type *)__v4l2_async_nf_add_i2c(notifier, adapter, address, \ sizeof(type))) /** * v4l2_async_subdev_endpoint_add - Add an endpoint fwnode to async sub-device * matching list * * @sd: the sub-device * @fwnode: the endpoint fwnode to match * * Add a fwnode to the async sub-device's matching list. This allows registering * multiple async sub-devices from a single device. * * Note that calling v4l2_subdev_cleanup() as part of the sub-device's cleanup * if endpoints have been added to the sub-device's fwnode matching list. * * Returns an error on failure, 0 on success. */ int v4l2_async_subdev_endpoint_add(struct v4l2_subdev *sd, struct fwnode_handle *fwnode); /** * v4l2_async_connection_unique - return a unique &struct v4l2_async_connection * for a sub-device * @sd: the sub-device * * Return an async connection for a sub-device, when there is a single * one only. */ struct v4l2_async_connection * v4l2_async_connection_unique(struct v4l2_subdev *sd); /** * v4l2_async_nf_register - registers a subdevice asynchronous notifier * * @notifier: pointer to &struct v4l2_async_notifier */ int v4l2_async_nf_register(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 * connections 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() or v4l2_async_nf_add_i2c(). * * 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 */ #define v4l2_async_register_subdev(sd) \ __v4l2_async_register_subdev(sd, THIS_MODULE) int __v4l2_async_register_subdev(struct v4l2_subdev *sd, struct module *module); /** * 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
