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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* V4L2 asynchronous subdevice registration API
*
* Copyright (C) 2012-2013, Guennadi Liakhovetski <[email protected]>
*/
#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
*/
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
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