/* 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
*/
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);
};
/**
* 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_notifier_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_notifier_add_fwnode_remote_subdev,
* @v4l2_async_notifier_add_fwnode_subdev,
* @v4l2_async_notifier_add_i2c_subdev,
* @__v4l2_async_notifier_add_subdev or
* @v4l2_async_notifier_parse_fwnode_endpoints.
*/
void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
/**
* __v4l2_async_notifier_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_notifier_add_fwnode_subdev,
* @v4l2_async_notifier_add_fwnode_remote_subdev or
* @v4l2_async_notifier_add_i2c_subdev.
*
* 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_notifier_add_subdev(struct v4l2_async_notifier *notifier,
struct v4l2_async_subdev *asd);
struct v4l2_async_subdev *
__v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
struct fwnode_handle *fwnode,
unsigned int asd_struct_size);
/**
* v4l2_async_notifier_add_fwnode_subdev - 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_notifier_add_fwnode_subdev(notifier, fwnode, type) \
((type *)__v4l2_async_notifier_add_fwnode_subdev(notifier, fwnode, \
sizeof(type)))
struct v4l2_async_subdev *
__v4l2_async_notifier_add_fwnode_remote_subdev(struct v4l2_async_notifier *notif,
struct fwnode_handle *endpoint,
unsigned int asd_struct_size);
/**
* v4l2_async_notifier_add_fwnode_remote_subdev - 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_notifier_add_fwnode_subdev, but with the
* exception that the fwnode refers to a local endpoint, not the remote one.
*/
#define v4l2_async_notifier_add_fwnode_remote_subdev(notifier, ep, type) \
((type *) \
__v4l2_async_notifier_add_fwnode_remote_subdev(notifier, ep, \
sizeof(type)))
struct v4l2_async_subdev *
__v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
int adapter_id, unsigned short address,
unsigned int asd_struct_size);
/**
* v4l2_async_notifier_add_i2c_subdev - 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_notifier_add_fwnode_subdev() but for I2C matched
* sub-devices.
*/
#define v4l2_async_notifier_add_i2c_subdev(notifier, adapter, address, type) \
((type *)__v4l2_async_notifier_add_i2c_subdev(notifier, adapter, \
address, sizeof(type)))
/**
* v4l2_async_notifier_register - registers a subdevice asynchronous notifier
*
* @v4l2_dev: pointer to &struct v4l2_device
* @notifier: pointer to &struct v4l2_async_notifier
*/
int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
struct v4l2_async_notifier *notifier);
/**
* v4l2_async_subdev_notifier_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_notifier_register(struct v4l2_subdev *sd,
struct v4l2_async_notifier *notifier);
/**
* v4l2_async_notifier_unregister - unregisters a subdevice
* asynchronous notifier
*
* @notifier: pointer to &struct v4l2_async_notifier
*/
void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
/**
* v4l2_async_notifier_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_notifier_add_fwnode_remote_subdev,
* @v4l2_async_notifier_add_fwnode_subdev,
* @v4l2_async_notifier_add_i2c_subdev,
* @__v4l2_async_notifier_add_subdev or
* @v4l2_async_notifier_parse_fwnode_endpoints.
*
* There is no harm from calling v4l2_async_notifier_cleanup in other
* cases as long as its memory has been zeroed after it has been
* allocated.
*/
void v4l2_async_notifier_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_notifier_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