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
14 struct device;
15 struct device_node;
16 struct v4l2_device;
17 struct v4l2_subdev;
18 struct 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 */
33 enum 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 */
79 struct 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 */
107 struct 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 */
129 struct 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 */
148 void 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
158 * provided asd to the notifiers master @asd_list.
159 */
160 int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
161 struct v4l2_async_subdev *asd);
162
163 /**
164 * v4l2_async_notifier_add_fwnode_subdev - Allocate and add a fwnode async
165 * subdev to the notifier's master asd_list.
166 *
167 * @notifier: pointer to &struct v4l2_async_notifier
168 * @fwnode: fwnode handle of the sub-device to be matched
169 * @asd_struct_size: size of the driver's async sub-device struct, including
170 * sizeof(struct v4l2_async_subdev). The &struct
171 * v4l2_async_subdev shall be the first member of
172 * the driver's async sub-device struct, i.e. both
173 * begin at the same memory address.
174 *
175 * Allocate a fwnode-matched asd of size asd_struct_size, and add it to the
176 * notifiers @asd_list. The function also gets a reference of the fwnode which
177 * is released later at notifier cleanup time.
178 */
179 struct v4l2_async_subdev *
180 v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
181 struct fwnode_handle *fwnode,
182 unsigned int asd_struct_size);
183
184 /**
185 * v4l2_async_notifier_add_fwnode_remote_subdev - Allocate and add a fwnode
186 * remote async subdev to the
187 * notifier's master asd_list.
188 *
189 * @notif: pointer to &struct v4l2_async_notifier
190 * @endpoint: local endpoint pointing to the remote sub-device to be matched
191 * @asd: Async sub-device struct allocated by the caller. The &struct
192 * v4l2_async_subdev shall be the first member of the driver's async
193 * sub-device struct, i.e. both begin at the same memory address.
194 *
195 * Gets the remote endpoint of a given local endpoint, set it up for fwnode
196 * matching and adds the async sub-device to the notifier's @asd_list. The
197 * function also gets a reference of the fwnode which is released later at
198 * notifier cleanup time.
199 *
200 * This is just like @v4l2_async_notifier_add_fwnode_subdev, but with the
201 * exception that the fwnode refers to a local endpoint, not the remote one, and
202 * the function relies on the caller to allocate the async sub-device struct.
203 */
204 int
205 v4l2_async_notifier_add_fwnode_remote_subdev(struct v4l2_async_notifier *notif,
206 struct fwnode_handle *endpoint,
207 struct v4l2_async_subdev *asd);
208
209 /**
210 * v4l2_async_notifier_add_i2c_subdev - Allocate and add an i2c async
211 * subdev to the notifier's master asd_list.
212 *
213 * @notifier: pointer to &struct v4l2_async_notifier
214 * @adapter_id: I2C adapter ID to be matched
215 * @address: I2C address of sub-device to be matched
216 * @asd_struct_size: size of the driver's async sub-device struct, including
217 * sizeof(struct v4l2_async_subdev). The &struct
218 * v4l2_async_subdev shall be the first member of
219 * the driver's async sub-device struct, i.e. both
220 * begin at the same memory address.
221 *
222 * Same as above but for I2C matched sub-devices.
223 */
224 struct v4l2_async_subdev *
225 v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
226 int adapter_id, unsigned short address,
227 unsigned int asd_struct_size);
228
229 /**
230 * v4l2_async_notifier_add_devname_subdev - Allocate and add a device-name
231 * async subdev to the notifier's master asd_list.
232 *
233 * @notifier: pointer to &struct v4l2_async_notifier
234 * @device_name: device name string to be matched
235 * @asd_struct_size: size of the driver's async sub-device struct, including
236 * sizeof(struct v4l2_async_subdev). The &struct
237 * v4l2_async_subdev shall be the first member of
238 * the driver's async sub-device struct, i.e. both
239 * begin at the same memory address.
240 *
241 * Same as above but for device-name matched sub-devices.
242 */
243 struct v4l2_async_subdev *
244 v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
245 const char *device_name,
246 unsigned int asd_struct_size);
247
248 /**
249 * v4l2_async_notifier_register - registers a subdevice asynchronous notifier
250 *
251 * @v4l2_dev: pointer to &struct v4l2_device
252 * @notifier: pointer to &struct v4l2_async_notifier
253 */
254 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
255 struct v4l2_async_notifier *notifier);
256
257 /**
258 * v4l2_async_subdev_notifier_register - registers a subdevice asynchronous
259 * notifier for a sub-device
260 *
261 * @sd: pointer to &struct v4l2_subdev
262 * @notifier: pointer to &struct v4l2_async_notifier
263 */
264 int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
265 struct v4l2_async_notifier *notifier);
266
267 /**
268 * v4l2_async_notifier_unregister - unregisters a subdevice
269 * asynchronous notifier
270 *
271 * @notifier: pointer to &struct v4l2_async_notifier
272 */
273 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
274
275 /**
276 * v4l2_async_notifier_cleanup - clean up notifier resources
277 * @notifier: the notifier the resources of which are to be cleaned up
278 *
279 * Release memory resources related to a notifier, including the async
280 * sub-devices allocated for the purposes of the notifier but not the notifier
281 * itself. The user is responsible for calling this function to clean up the
282 * notifier after calling
283 * @v4l2_async_notifier_add_subdev,
284 * @v4l2_async_notifier_parse_fwnode_endpoints or
285 * @v4l2_fwnode_reference_parse_sensor_common.
286 *
287 * There is no harm from calling v4l2_async_notifier_cleanup in other
288 * cases as long as its memory has been zeroed after it has been
289 * allocated.
290 */
291 void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier);
292
293 /**
294 * v4l2_async_register_subdev - registers a sub-device to the asynchronous
295 * subdevice framework
296 *
297 * @sd: pointer to &struct v4l2_subdev
298 */
299 int v4l2_async_register_subdev(struct v4l2_subdev *sd);
300
301 /**
302 * v4l2_async_register_subdev_sensor_common - registers a sensor sub-device to
303 * the asynchronous sub-device
304 * framework and parse set up common
305 * sensor related devices
306 *
307 * @sd: pointer to struct &v4l2_subdev
308 *
309 * This function is just like v4l2_async_register_subdev() with the exception
310 * that calling it will also parse firmware interfaces for remote references
311 * using v4l2_async_notifier_parse_fwnode_sensor_common() and registers the
312 * async sub-devices. The sub-device is similarly unregistered by calling
313 * v4l2_async_unregister_subdev().
314 *
315 * While registered, the subdev module is marked as in-use.
316 *
317 * An error is returned if the module is no longer loaded on any attempts
318 * to register it.
319 */
320 int __must_check
321 v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd);
322
323 /**
324 * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous
325 * subdevice framework
326 *
327 * @sd: pointer to &struct v4l2_subdev
328 */
329 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
330 #endif