1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * V4L2 asynchronous subdevice registration API
4 *
5 * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
6 */
7
8#ifndef V4L2_ASYNC_H
9#define V4L2_ASYNC_H
10
11#include <linux/list.h>
12#include <linux/mutex.h>
13
14struct device;
15struct device_node;
16struct v4l2_device;
17struct v4l2_subdev;
18struct v4l2_async_notifier;
19
20/**
21 * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used
22 *	in order to identify a match
23 *
24 * @V4L2_ASYNC_MATCH_CUSTOM: Match will use the logic provided by &struct
25 *	v4l2_async_subdev.match ops
26 * @V4L2_ASYNC_MATCH_DEVNAME: Match will use the device name
27 * @V4L2_ASYNC_MATCH_I2C: Match will check for I2C adapter ID and address
28 * @V4L2_ASYNC_MATCH_FWNODE: Match will use firmware node
29 *
30 * This enum is used by the asyncrhronous sub-device logic to define the
31 * algorithm that will be used to match an asynchronous device.
32 */
33enum v4l2_async_match_type {
34	V4L2_ASYNC_MATCH_CUSTOM,
35	V4L2_ASYNC_MATCH_DEVNAME,
36	V4L2_ASYNC_MATCH_I2C,
37	V4L2_ASYNC_MATCH_FWNODE,
38};
39
40/**
41 * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge
42 *
43 * @match_type:	type of match that will be used
44 * @match:	union of per-bus type matching data sets
45 * @match.fwnode:
46 *		pointer to &struct fwnode_handle to be matched.
47 *		Used if @match_type is %V4L2_ASYNC_MATCH_FWNODE.
48 * @match.device_name:
49 *		string containing the device name to be matched.
50 *		Used if @match_type is %V4L2_ASYNC_MATCH_DEVNAME.
51 * @match.i2c:	embedded struct with I2C parameters to be matched.
52 *		Both @match.i2c.adapter_id and @match.i2c.address
53 *		should be matched.
54 *		Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
55 * @match.i2c.adapter_id:
56 *		I2C adapter ID to be matched.
57 *		Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
58 * @match.i2c.address:
59 *		I2C address to be matched.
60 *		Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
61 * @match.custom:
62 *		Driver-specific match criteria.
63 *		Used if @match_type is %V4L2_ASYNC_MATCH_CUSTOM.
64 * @match.custom.match:
65 *		Driver-specific match function to be used if
66 *		%V4L2_ASYNC_MATCH_CUSTOM.
67 * @match.custom.priv:
68 *		Driver-specific private struct with match parameters
69 *		to be used if %V4L2_ASYNC_MATCH_CUSTOM.
70 * @asd_list:	used to add struct v4l2_async_subdev objects to the
71 *		master notifier @asd_list
72 * @list:	used to link struct v4l2_async_subdev objects, waiting to be
73 *		probed, to a notifier->waiting list
74 *
75 * When this struct is used as a member in a driver specific struct,
76 * the driver specific struct shall contain the &struct
77 * v4l2_async_subdev as its first member.
78 */
79struct v4l2_async_subdev {
80	enum v4l2_async_match_type match_type;
81	union {
82		struct fwnode_handle *fwnode;
83		const char *device_name;
84		struct {
85			int adapter_id;
86			unsigned short address;
87		} i2c;
88		struct {
89			bool (*match)(struct device *dev,
90				      struct v4l2_async_subdev *sd);
91			void *priv;
92		} custom;
93	} match;
94
95	/* v4l2-async core private: not to be used by drivers */
96	struct list_head list;
97	struct list_head asd_list;
98};
99
100/**
101 * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations
102 * @bound:	a subdevice driver has successfully probed one of the subdevices
103 * @complete:	All subdevices have been probed successfully. The complete
104 *		callback is only executed for the root notifier.
105 * @unbind:	a subdevice is leaving
106 */
107struct v4l2_async_notifier_operations {
108	int (*bound)(struct v4l2_async_notifier *notifier,
109		     struct v4l2_subdev *subdev,
110		     struct v4l2_async_subdev *asd);
111	int (*complete)(struct v4l2_async_notifier *notifier);
112	void (*unbind)(struct v4l2_async_notifier *notifier,
113		       struct v4l2_subdev *subdev,
114		       struct v4l2_async_subdev *asd);
115};
116
117/**
118 * struct v4l2_async_notifier - v4l2_device notifier data
119 *
120 * @ops:	notifier operations
121 * @v4l2_dev:	v4l2_device of the root notifier, NULL otherwise
122 * @sd:		sub-device that registered the notifier, NULL otherwise
123 * @parent:	parent notifier
124 * @asd_list:	master list of struct v4l2_async_subdev
125 * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
126 * @done:	list of struct v4l2_subdev, already probed
127 * @list:	member in a global list of notifiers
128 */
129struct v4l2_async_notifier {
130	const struct v4l2_async_notifier_operations *ops;
131	struct v4l2_device *v4l2_dev;
132	struct v4l2_subdev *sd;
133	struct v4l2_async_notifier *parent;
134	struct list_head asd_list;
135	struct list_head waiting;
136	struct list_head done;
137	struct list_head list;
138};
139
140/**
141 * v4l2_async_notifier_init - Initialize a notifier.
142 *
143 * @notifier: pointer to &struct v4l2_async_notifier
144 *
145 * This function initializes the notifier @asd_list. It must be called
146 * before the first call to @v4l2_async_notifier_add_subdev.
147 */
148void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
149
150/**
151 * v4l2_async_notifier_add_subdev - Add an async subdev to the
152 *				notifier's master asd list.
153 *
154 * @notifier: pointer to &struct v4l2_async_notifier
155 * @asd: pointer to &struct v4l2_async_subdev
156 *
157 * Call this function before registering a notifier to link the provided @asd to
158 * the notifiers master @asd_list. The @asd must be allocated with k*alloc() as
159 * it will be freed by the framework when the notifier is destroyed.
160 */
161int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
162				   struct v4l2_async_subdev *asd);
163
164/**
165 * v4l2_async_notifier_add_fwnode_subdev - Allocate and add a fwnode async
166 *				subdev to the notifier's master asd_list.
167 *
168 * @notifier: pointer to &struct v4l2_async_notifier
169 * @fwnode: fwnode handle of the sub-device to be matched
170 * @asd_struct_size: size of the driver's async sub-device struct, including
171 *		     sizeof(struct v4l2_async_subdev). The &struct
172 *		     v4l2_async_subdev shall be the first member of
173 *		     the driver's async sub-device struct, i.e. both
174 *		     begin at the same memory address.
175 *
176 * Allocate a fwnode-matched asd of size asd_struct_size, and add it to the
177 * notifiers @asd_list. The function also gets a reference of the fwnode which
178 * is released later at notifier cleanup time.
179 */
180struct v4l2_async_subdev *
181v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
182				      struct fwnode_handle *fwnode,
183				      unsigned int asd_struct_size);
184
185/**
186 * v4l2_async_notifier_add_fwnode_remote_subdev - Allocate and add a fwnode
187 *						  remote async subdev to the
188 *						  notifier's master asd_list.
189 *
190 * @notif: pointer to &struct v4l2_async_notifier
191 * @endpoint: local endpoint pointing to the remote sub-device to be matched
192 * @asd_struct_size: size of the driver's async sub-device struct, including
193 *		     sizeof(struct v4l2_async_subdev). The &struct
194 *		     v4l2_async_subdev shall be the first member of
195 *		     the driver's async sub-device struct, i.e. both
196 *		     begin at the same memory address.
197 *
198 * Gets the remote endpoint of a given local endpoint, set it up for fwnode
199 * matching and adds the async sub-device to the notifier's @asd_list. The
200 * function also gets a reference of the fwnode which is released later at
201 * notifier cleanup time.
202 *
203 * This is just like @v4l2_async_notifier_add_fwnode_subdev, but with the
204 * exception that the fwnode refers to a local endpoint, not the remote one.
205 */
206struct v4l2_async_subdev *
207v4l2_async_notifier_add_fwnode_remote_subdev(struct v4l2_async_notifier *notif,
208					     struct fwnode_handle *endpoint,
209					     unsigned int asd_struct_size);
210
211/**
212 * v4l2_async_notifier_add_i2c_subdev - Allocate and add an i2c async
213 *				subdev to the notifier's master asd_list.
214 *
215 * @notifier: pointer to &struct v4l2_async_notifier
216 * @adapter_id: I2C adapter ID to be matched
217 * @address: I2C address of sub-device to be matched
218 * @asd_struct_size: size of the driver's async sub-device struct, including
219 *		     sizeof(struct v4l2_async_subdev). The &struct
220 *		     v4l2_async_subdev shall be the first member of
221 *		     the driver's async sub-device struct, i.e. both
222 *		     begin at the same memory address.
223 *
224 * Same as above but for I2C matched sub-devices.
225 */
226struct v4l2_async_subdev *
227v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
228				   int adapter_id, unsigned short address,
229				   unsigned int asd_struct_size);
230
231/**
232 * v4l2_async_notifier_add_devname_subdev - Allocate and add a device-name
233 *				async subdev to the notifier's master asd_list.
234 *
235 * @notifier: pointer to &struct v4l2_async_notifier
236 * @device_name: device name string to be matched
237 * @asd_struct_size: size of the driver's async sub-device struct, including
238 *		     sizeof(struct v4l2_async_subdev). The &struct
239 *		     v4l2_async_subdev shall be the first member of
240 *		     the driver's async sub-device struct, i.e. both
241 *		     begin at the same memory address.
242 *
243 * Same as above but for device-name matched sub-devices.
244 */
245struct v4l2_async_subdev *
246v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
247				       const char *device_name,
248				       unsigned int asd_struct_size);
249
250/**
251 * v4l2_async_notifier_register - registers a subdevice asynchronous notifier
252 *
253 * @v4l2_dev: pointer to &struct v4l2_device
254 * @notifier: pointer to &struct v4l2_async_notifier
255 */
256int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
257				 struct v4l2_async_notifier *notifier);
258
259/**
260 * v4l2_async_subdev_notifier_register - registers a subdevice asynchronous
261 *					 notifier for a sub-device
262 *
263 * @sd: pointer to &struct v4l2_subdev
264 * @notifier: pointer to &struct v4l2_async_notifier
265 */
266int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
267					struct v4l2_async_notifier *notifier);
268
269/**
270 * v4l2_async_notifier_unregister - unregisters a subdevice
271 *	asynchronous notifier
272 *
273 * @notifier: pointer to &struct v4l2_async_notifier
274 */
275void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
276
277/**
278 * v4l2_async_notifier_cleanup - clean up notifier resources
279 * @notifier: the notifier the resources of which are to be cleaned up
280 *
281 * Release memory resources related to a notifier, including the async
282 * sub-devices allocated for the purposes of the notifier but not the notifier
283 * itself. The user is responsible for calling this function to clean up the
284 * notifier after calling
285 * @v4l2_async_notifier_add_subdev,
286 * @v4l2_async_notifier_parse_fwnode_endpoints or
287 * @v4l2_fwnode_reference_parse_sensor_common.
288 *
289 * There is no harm from calling v4l2_async_notifier_cleanup in other
290 * cases as long as its memory has been zeroed after it has been
291 * allocated.
292 */
293void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier);
294
295/**
296 * v4l2_async_register_subdev - registers a sub-device to the asynchronous
297 *	subdevice framework
298 *
299 * @sd: pointer to &struct v4l2_subdev
300 */
301int v4l2_async_register_subdev(struct v4l2_subdev *sd);
302
303/**
304 * v4l2_async_register_subdev_sensor_common - registers a sensor sub-device to
305 *					      the asynchronous sub-device
306 *					      framework and parse set up common
307 *					      sensor related devices
308 *
309 * @sd: pointer to struct &v4l2_subdev
310 *
311 * This function is just like v4l2_async_register_subdev() with the exception
312 * that calling it will also parse firmware interfaces for remote references
313 * using v4l2_async_notifier_parse_fwnode_sensor_common() and registers the
314 * async sub-devices. The sub-device is similarly unregistered by calling
315 * v4l2_async_unregister_subdev().
316 *
317 * While registered, the subdev module is marked as in-use.
318 *
319 * An error is returned if the module is no longer loaded on any attempts
320 * to register it.
321 */
322int __must_check
323v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd);
324
325/**
326 * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous
327 *	subdevice framework
328 *
329 * @sd: pointer to &struct v4l2_subdev
330 */
331void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
332#endif
333