Commit | Line | Data |
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e9e31049 GL |
1 | /* |
2 | * V4L2 asynchronous subdevice registration API | |
3 | * | |
4 | * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/device.h> | |
12 | #include <linux/err.h> | |
13 | #include <linux/i2c.h> | |
14 | #include <linux/list.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/mutex.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/types.h> | |
20 | ||
21 | #include <media/v4l2-async.h> | |
22 | #include <media/v4l2-device.h> | |
23 | #include <media/v4l2-subdev.h> | |
24 | ||
25 | static bool match_i2c(struct device *dev, struct v4l2_async_subdev *asd) | |
26 | { | |
fe05e141 | 27 | #if IS_ENABLED(CONFIG_I2C) |
e9e31049 GL |
28 | struct i2c_client *client = i2c_verify_client(dev); |
29 | return client && | |
e9e31049 GL |
30 | asd->match.i2c.adapter_id == client->adapter->nr && |
31 | asd->match.i2c.address == client->addr; | |
fe05e141 GL |
32 | #else |
33 | return false; | |
34 | #endif | |
e9e31049 GL |
35 | } |
36 | ||
cfca7644 | 37 | static bool match_devname(struct device *dev, struct v4l2_async_subdev *asd) |
e9e31049 | 38 | { |
cfca7644 | 39 | return !strcmp(asd->match.device_name.name, dev_name(dev)); |
e9e31049 GL |
40 | } |
41 | ||
e7359f8e SN |
42 | static bool match_of(struct device *dev, struct v4l2_async_subdev *asd) |
43 | { | |
44 | return dev->of_node == asd->match.of.node; | |
45 | } | |
46 | ||
e9e31049 GL |
47 | static LIST_HEAD(subdev_list); |
48 | static LIST_HEAD(notifier_list); | |
49 | static DEFINE_MUTEX(list_lock); | |
50 | ||
51 | static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier, | |
52 | struct v4l2_async_subdev_list *asdl) | |
53 | { | |
54 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
55 | struct v4l2_async_subdev *asd; | |
56 | bool (*match)(struct device *, | |
57 | struct v4l2_async_subdev *); | |
58 | ||
59 | list_for_each_entry(asd, ¬ifier->waiting, list) { | |
60 | /* bus_type has been verified valid before */ | |
cfca7644 SN |
61 | switch (asd->match_type) { |
62 | case V4L2_ASYNC_MATCH_CUSTOM: | |
e9e31049 GL |
63 | match = asd->match.custom.match; |
64 | if (!match) | |
65 | /* Match always */ | |
66 | return asd; | |
67 | break; | |
cfca7644 SN |
68 | case V4L2_ASYNC_MATCH_DEVNAME: |
69 | match = match_devname; | |
e9e31049 | 70 | break; |
cfca7644 | 71 | case V4L2_ASYNC_MATCH_I2C: |
e9e31049 GL |
72 | match = match_i2c; |
73 | break; | |
e7359f8e SN |
74 | case V4L2_ASYNC_MATCH_OF: |
75 | match = match_of; | |
76 | break; | |
e9e31049 GL |
77 | default: |
78 | /* Cannot happen, unless someone breaks us */ | |
79 | WARN_ON(true); | |
80 | return NULL; | |
81 | } | |
82 | ||
83 | /* match cannot be NULL here */ | |
84 | if (match(sd->dev, asd)) | |
85 | return asd; | |
86 | } | |
87 | ||
88 | return NULL; | |
89 | } | |
90 | ||
91 | static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier, | |
92 | struct v4l2_async_subdev_list *asdl, | |
93 | struct v4l2_async_subdev *asd) | |
94 | { | |
95 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
96 | int ret; | |
97 | ||
98 | /* Remove from the waiting list */ | |
99 | list_del(&asd->list); | |
100 | asdl->asd = asd; | |
101 | asdl->notifier = notifier; | |
102 | ||
103 | if (notifier->bound) { | |
104 | ret = notifier->bound(notifier, sd, asd); | |
105 | if (ret < 0) | |
106 | return ret; | |
107 | } | |
108 | /* Move from the global subdevice list to notifier's done */ | |
109 | list_move(&asdl->list, ¬ifier->done); | |
110 | ||
111 | ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd); | |
112 | if (ret < 0) { | |
113 | if (notifier->unbind) | |
114 | notifier->unbind(notifier, sd, asd); | |
115 | return ret; | |
116 | } | |
117 | ||
118 | if (list_empty(¬ifier->waiting) && notifier->complete) | |
119 | return notifier->complete(notifier); | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | static void v4l2_async_cleanup(struct v4l2_async_subdev_list *asdl) | |
125 | { | |
126 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
127 | ||
128 | v4l2_device_unregister_subdev(sd); | |
129 | /* Subdevice driver will reprobe and put asdl back onto the list */ | |
130 | list_del_init(&asdl->list); | |
131 | asdl->asd = NULL; | |
132 | sd->dev = NULL; | |
133 | } | |
134 | ||
135 | int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, | |
136 | struct v4l2_async_notifier *notifier) | |
137 | { | |
138 | struct v4l2_async_subdev_list *asdl, *tmp; | |
139 | struct v4l2_async_subdev *asd; | |
140 | int i; | |
141 | ||
142 | if (!notifier->num_subdevs || notifier->num_subdevs > V4L2_MAX_SUBDEVS) | |
143 | return -EINVAL; | |
144 | ||
145 | notifier->v4l2_dev = v4l2_dev; | |
146 | INIT_LIST_HEAD(¬ifier->waiting); | |
147 | INIT_LIST_HEAD(¬ifier->done); | |
148 | ||
149 | for (i = 0; i < notifier->num_subdevs; i++) { | |
e8419d08 | 150 | asd = notifier->subdevs[i]; |
e9e31049 | 151 | |
cfca7644 SN |
152 | switch (asd->match_type) { |
153 | case V4L2_ASYNC_MATCH_CUSTOM: | |
154 | case V4L2_ASYNC_MATCH_DEVNAME: | |
155 | case V4L2_ASYNC_MATCH_I2C: | |
e7359f8e | 156 | case V4L2_ASYNC_MATCH_OF: |
e9e31049 GL |
157 | break; |
158 | default: | |
159 | dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL, | |
cfca7644 SN |
160 | "Invalid match type %u on %p\n", |
161 | asd->match_type, asd); | |
e9e31049 GL |
162 | return -EINVAL; |
163 | } | |
164 | list_add_tail(&asd->list, ¬ifier->waiting); | |
165 | } | |
166 | ||
167 | mutex_lock(&list_lock); | |
168 | ||
169 | /* Keep also completed notifiers on the list */ | |
170 | list_add(¬ifier->list, ¬ifier_list); | |
171 | ||
172 | list_for_each_entry_safe(asdl, tmp, &subdev_list, list) { | |
173 | int ret; | |
174 | ||
175 | asd = v4l2_async_belongs(notifier, asdl); | |
176 | if (!asd) | |
177 | continue; | |
178 | ||
179 | ret = v4l2_async_test_notify(notifier, asdl, asd); | |
180 | if (ret < 0) { | |
181 | mutex_unlock(&list_lock); | |
182 | return ret; | |
183 | } | |
184 | } | |
185 | ||
186 | mutex_unlock(&list_lock); | |
187 | ||
188 | return 0; | |
189 | } | |
190 | EXPORT_SYMBOL(v4l2_async_notifier_register); | |
191 | ||
192 | void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier) | |
193 | { | |
194 | struct v4l2_async_subdev_list *asdl, *tmp; | |
195 | unsigned int notif_n_subdev = notifier->num_subdevs; | |
196 | unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS); | |
197 | struct device *dev[n_subdev]; | |
198 | int i = 0; | |
199 | ||
200 | mutex_lock(&list_lock); | |
201 | ||
202 | list_del(¬ifier->list); | |
203 | ||
204 | list_for_each_entry_safe(asdl, tmp, ¬ifier->done, list) { | |
205 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
206 | ||
207 | dev[i] = get_device(sd->dev); | |
208 | ||
209 | v4l2_async_cleanup(asdl); | |
210 | ||
211 | /* If we handled USB devices, we'd have to lock the parent too */ | |
212 | device_release_driver(dev[i++]); | |
213 | ||
214 | if (notifier->unbind) | |
215 | notifier->unbind(notifier, sd, sd->asdl.asd); | |
216 | } | |
217 | ||
218 | mutex_unlock(&list_lock); | |
219 | ||
220 | while (i--) { | |
221 | struct device *d = dev[i]; | |
222 | ||
223 | if (d && device_attach(d) < 0) { | |
224 | const char *name = "(none)"; | |
225 | int lock = device_trylock(d); | |
226 | ||
227 | if (lock && d->driver) | |
228 | name = d->driver->name; | |
229 | dev_err(d, "Failed to re-probe to %s\n", name); | |
230 | if (lock) | |
231 | device_unlock(d); | |
232 | } | |
233 | put_device(d); | |
234 | } | |
235 | /* | |
236 | * Don't care about the waiting list, it is initialised and populated | |
237 | * upon notifier registration. | |
238 | */ | |
239 | } | |
240 | EXPORT_SYMBOL(v4l2_async_notifier_unregister); | |
241 | ||
242 | int v4l2_async_register_subdev(struct v4l2_subdev *sd) | |
243 | { | |
244 | struct v4l2_async_subdev_list *asdl = &sd->asdl; | |
245 | struct v4l2_async_notifier *notifier; | |
246 | ||
247 | mutex_lock(&list_lock); | |
248 | ||
249 | INIT_LIST_HEAD(&asdl->list); | |
250 | ||
251 | list_for_each_entry(notifier, ¬ifier_list, list) { | |
252 | struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, asdl); | |
253 | if (asd) { | |
254 | int ret = v4l2_async_test_notify(notifier, asdl, asd); | |
255 | mutex_unlock(&list_lock); | |
256 | return ret; | |
257 | } | |
258 | } | |
259 | ||
260 | /* None matched, wait for hot-plugging */ | |
261 | list_add(&asdl->list, &subdev_list); | |
262 | ||
263 | mutex_unlock(&list_lock); | |
264 | ||
265 | return 0; | |
266 | } | |
267 | EXPORT_SYMBOL(v4l2_async_register_subdev); | |
268 | ||
269 | void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) | |
270 | { | |
271 | struct v4l2_async_subdev_list *asdl = &sd->asdl; | |
272 | struct v4l2_async_notifier *notifier = asdl->notifier; | |
273 | ||
274 | if (!asdl->asd) { | |
275 | if (!list_empty(&asdl->list)) | |
276 | v4l2_async_cleanup(asdl); | |
277 | return; | |
278 | } | |
279 | ||
280 | mutex_lock(&list_lock); | |
281 | ||
282 | list_add(&asdl->asd->list, ¬ifier->waiting); | |
283 | ||
284 | v4l2_async_cleanup(asdl); | |
285 | ||
286 | if (notifier->unbind) | |
287 | notifier->unbind(notifier, sd, sd->asdl.asd); | |
288 | ||
289 | mutex_unlock(&list_lock); | |
290 | } | |
291 | EXPORT_SYMBOL(v4l2_async_unregister_subdev); |