1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * V4L2 asynchronous subdevice registration API
5 * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
11 #include <linux/list.h>
12 #include <linux/mutex.h>
19 struct v4l2_async_notifier;
22 * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used
23 * in order to identify a match
25 * @V4L2_ASYNC_MATCH_I2C: Match will check for I2C adapter ID and address
26 * @V4L2_ASYNC_MATCH_FWNODE: Match will use firmware node
28 * This enum is used by the asynchronous sub-device logic to define the
29 * algorithm that will be used to match an asynchronous device.
31 enum v4l2_async_match_type {
33 V4L2_ASYNC_MATCH_FWNODE,
37 * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge
39 * @match_type: type of match that will be used
40 * @match: union of per-bus type matching data sets
42 * pointer to &struct fwnode_handle to be matched.
43 * Used if @match_type is %V4L2_ASYNC_MATCH_FWNODE.
44 * @match.i2c: embedded struct with I2C parameters to be matched.
45 * Both @match.i2c.adapter_id and @match.i2c.address
47 * Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
48 * @match.i2c.adapter_id:
49 * I2C adapter ID to be matched.
50 * Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
52 * I2C address to be matched.
53 * Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
54 * @asd_list: used to add struct v4l2_async_subdev objects to the
55 * master notifier @asd_list
56 * @list: used to link struct v4l2_async_subdev objects, waiting to be
57 * probed, to a notifier->waiting list
59 * When this struct is used as a member in a driver specific struct,
60 * the driver specific struct shall contain the &struct
61 * v4l2_async_subdev as its first member.
63 struct v4l2_async_subdev {
64 enum v4l2_async_match_type match_type;
66 struct fwnode_handle *fwnode;
69 unsigned short address;
73 /* v4l2-async core private: not to be used by drivers */
74 struct list_head list;
75 struct list_head asd_list;
79 * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations
80 * @bound: a subdevice driver has successfully probed one of the subdevices
81 * @complete: All subdevices have been probed successfully. The complete
82 * callback is only executed for the root notifier.
83 * @unbind: a subdevice is leaving
85 struct v4l2_async_notifier_operations {
86 int (*bound)(struct v4l2_async_notifier *notifier,
87 struct v4l2_subdev *subdev,
88 struct v4l2_async_subdev *asd);
89 int (*complete)(struct v4l2_async_notifier *notifier);
90 void (*unbind)(struct v4l2_async_notifier *notifier,
91 struct v4l2_subdev *subdev,
92 struct v4l2_async_subdev *asd);
96 * struct v4l2_async_notifier - v4l2_device notifier data
98 * @ops: notifier operations
99 * @v4l2_dev: v4l2_device of the root notifier, NULL otherwise
100 * @sd: sub-device that registered the notifier, NULL otherwise
101 * @parent: parent notifier
102 * @asd_list: master list of struct v4l2_async_subdev
103 * @waiting: list of struct v4l2_async_subdev, waiting for their drivers
104 * @done: list of struct v4l2_subdev, already probed
105 * @list: member in a global list of notifiers
107 struct v4l2_async_notifier {
108 const struct v4l2_async_notifier_operations *ops;
109 struct v4l2_device *v4l2_dev;
110 struct v4l2_subdev *sd;
111 struct v4l2_async_notifier *parent;
112 struct list_head asd_list;
113 struct list_head waiting;
114 struct list_head done;
115 struct list_head list;
119 * v4l2_async_debug_init - Initialize debugging tools.
121 * @debugfs_dir: pointer to the parent debugfs &struct dentry
123 void v4l2_async_debug_init(struct dentry *debugfs_dir);
126 * v4l2_async_nf_init - Initialize a notifier.
128 * @notifier: pointer to &struct v4l2_async_notifier
130 * This function initializes the notifier @asd_list. It must be called
131 * before adding a subdevice to a notifier, using one of:
132 * v4l2_async_nf_add_fwnode_remote(),
133 * v4l2_async_nf_add_fwnode(),
134 * v4l2_async_nf_add_i2c(),
135 * __v4l2_async_nf_add_subdev() or
136 * v4l2_async_nf_parse_fwnode_endpoints().
138 void v4l2_async_nf_init(struct v4l2_async_notifier *notifier);
141 * __v4l2_async_nf_add_subdev - Add an async subdev to the
142 * notifier's master asd list.
144 * @notifier: pointer to &struct v4l2_async_notifier
145 * @asd: pointer to &struct v4l2_async_subdev
147 * \warning: Drivers should avoid using this function and instead use one of:
148 * v4l2_async_nf_add_fwnode(),
149 * v4l2_async_nf_add_fwnode_remote() or
150 * v4l2_async_nf_add_i2c().
152 * Call this function before registering a notifier to link the provided @asd to
153 * the notifiers master @asd_list. The @asd must be allocated with k*alloc() as
154 * it will be freed by the framework when the notifier is destroyed.
156 int __v4l2_async_nf_add_subdev(struct v4l2_async_notifier *notifier,
157 struct v4l2_async_subdev *asd);
159 struct v4l2_async_subdev *
160 __v4l2_async_nf_add_fwnode(struct v4l2_async_notifier *notifier,
161 struct fwnode_handle *fwnode,
162 unsigned int asd_struct_size);
164 * v4l2_async_nf_add_fwnode - Allocate and add a fwnode async
165 * subdev to the notifier's master asd_list.
167 * @notifier: pointer to &struct v4l2_async_notifier
168 * @fwnode: fwnode handle of the sub-device to be matched, pointer to
169 * &struct fwnode_handle
170 * @type: Type of the driver's async sub-device struct. The &struct
171 * v4l2_async_subdev shall be the first member of the driver's async
172 * sub-device struct, i.e. both begin at the same memory address.
174 * Allocate a fwnode-matched asd of size asd_struct_size, and add it to the
175 * notifiers @asd_list. The function also gets a reference of the fwnode which
176 * is released later at notifier cleanup time.
178 #define v4l2_async_nf_add_fwnode(notifier, fwnode, type) \
179 ((type *)__v4l2_async_nf_add_fwnode(notifier, fwnode, sizeof(type)))
181 struct v4l2_async_subdev *
182 __v4l2_async_nf_add_fwnode_remote(struct v4l2_async_notifier *notif,
183 struct fwnode_handle *endpoint,
184 unsigned int asd_struct_size);
186 * v4l2_async_nf_add_fwnode_remote - Allocate and add a fwnode
187 * remote async subdev to the
188 * notifier's master asd_list.
190 * @notifier: pointer to &struct v4l2_async_notifier
191 * @ep: local endpoint pointing to the remote sub-device to be matched,
192 * pointer to &struct fwnode_handle
193 * @type: Type of the driver's async sub-device struct. The &struct
194 * v4l2_async_subdev shall be the first member of the driver's async
195 * sub-device struct, i.e. both begin at the same memory address.
197 * Gets the remote endpoint of a given local endpoint, set it up for fwnode
198 * matching and adds the async sub-device to the notifier's @asd_list. The
199 * function also gets a reference of the fwnode which is released later at
200 * notifier cleanup time.
202 * This is just like v4l2_async_nf_add_fwnode(), but with the
203 * exception that the fwnode refers to a local endpoint, not the remote one.
205 #define v4l2_async_nf_add_fwnode_remote(notifier, ep, type) \
206 ((type *)__v4l2_async_nf_add_fwnode_remote(notifier, ep, sizeof(type)))
208 struct v4l2_async_subdev *
209 __v4l2_async_nf_add_i2c(struct v4l2_async_notifier *notifier,
210 int adapter_id, unsigned short address,
211 unsigned int asd_struct_size);
213 * v4l2_async_nf_add_i2c - Allocate and add an i2c async
214 * subdev to the notifier's master asd_list.
216 * @notifier: pointer to &struct v4l2_async_notifier
217 * @adapter: I2C adapter ID to be matched
218 * @address: I2C address of sub-device to be matched
219 * @type: Type of the driver's async sub-device struct. The &struct
220 * v4l2_async_subdev shall be the first member of the driver's async
221 * sub-device struct, i.e. both begin at the same memory address.
223 * Same as v4l2_async_nf_add_fwnode() but for I2C matched
226 #define v4l2_async_nf_add_i2c(notifier, adapter, address, type) \
227 ((type *)__v4l2_async_nf_add_i2c(notifier, adapter, address, \
231 * v4l2_async_nf_register - registers a subdevice asynchronous notifier
233 * @v4l2_dev: pointer to &struct v4l2_device
234 * @notifier: pointer to &struct v4l2_async_notifier
236 int v4l2_async_nf_register(struct v4l2_device *v4l2_dev,
237 struct v4l2_async_notifier *notifier);
240 * v4l2_async_subdev_nf_register - registers a subdevice asynchronous
241 * notifier for a sub-device
243 * @sd: pointer to &struct v4l2_subdev
244 * @notifier: pointer to &struct v4l2_async_notifier
246 int v4l2_async_subdev_nf_register(struct v4l2_subdev *sd,
247 struct v4l2_async_notifier *notifier);
250 * v4l2_async_nf_unregister - unregisters a subdevice
251 * asynchronous notifier
253 * @notifier: pointer to &struct v4l2_async_notifier
255 void v4l2_async_nf_unregister(struct v4l2_async_notifier *notifier);
258 * v4l2_async_nf_cleanup - clean up notifier resources
259 * @notifier: the notifier the resources of which are to be cleaned up
261 * Release memory resources related to a notifier, including the async
262 * sub-devices allocated for the purposes of the notifier but not the notifier
263 * itself. The user is responsible for calling this function to clean up the
264 * notifier after calling
265 * v4l2_async_nf_add_fwnode_remote(),
266 * v4l2_async_nf_add_fwnode(),
267 * v4l2_async_nf_add_i2c(),
268 * __v4l2_async_nf_add_subdev() or
269 * v4l2_async_nf_parse_fwnode_endpoints().
271 * There is no harm from calling v4l2_async_nf_cleanup() in other
272 * cases as long as its memory has been zeroed after it has been
275 void v4l2_async_nf_cleanup(struct v4l2_async_notifier *notifier);
278 * v4l2_async_register_subdev - registers a sub-device to the asynchronous
279 * subdevice framework
281 * @sd: pointer to &struct v4l2_subdev
283 int v4l2_async_register_subdev(struct v4l2_subdev *sd);
286 * v4l2_async_register_subdev_sensor - registers a sensor sub-device to the
287 * asynchronous sub-device framework and
288 * parse set up common sensor related
291 * @sd: pointer to struct &v4l2_subdev
293 * This function is just like v4l2_async_register_subdev() with the exception
294 * that calling it will also parse firmware interfaces for remote references
295 * using v4l2_async_nf_parse_fwnode_sensor() and registers the
296 * async sub-devices. The sub-device is similarly unregistered by calling
297 * v4l2_async_unregister_subdev().
299 * While registered, the subdev module is marked as in-use.
301 * An error is returned if the module is no longer loaded on any attempts
305 v4l2_async_register_subdev_sensor(struct v4l2_subdev *sd);
308 * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous
309 * subdevice framework
311 * @sd: pointer to &struct v4l2_subdev
313 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);