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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 | ||
37 | static bool match_platform(struct device *dev, struct v4l2_async_subdev *asd) | |
38 | { | |
3c2ade01 | 39 | return !strcmp(asd->match.platform.name, dev_name(dev)); |
e9e31049 GL |
40 | } |
41 | ||
42 | static LIST_HEAD(subdev_list); | |
43 | static LIST_HEAD(notifier_list); | |
44 | static DEFINE_MUTEX(list_lock); | |
45 | ||
46 | static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier, | |
47 | struct v4l2_async_subdev_list *asdl) | |
48 | { | |
49 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
50 | struct v4l2_async_subdev *asd; | |
51 | bool (*match)(struct device *, | |
52 | struct v4l2_async_subdev *); | |
53 | ||
54 | list_for_each_entry(asd, ¬ifier->waiting, list) { | |
55 | /* bus_type has been verified valid before */ | |
56 | switch (asd->bus_type) { | |
57 | case V4L2_ASYNC_BUS_CUSTOM: | |
58 | match = asd->match.custom.match; | |
59 | if (!match) | |
60 | /* Match always */ | |
61 | return asd; | |
62 | break; | |
63 | case V4L2_ASYNC_BUS_PLATFORM: | |
64 | match = match_platform; | |
65 | break; | |
66 | case V4L2_ASYNC_BUS_I2C: | |
67 | match = match_i2c; | |
68 | break; | |
69 | default: | |
70 | /* Cannot happen, unless someone breaks us */ | |
71 | WARN_ON(true); | |
72 | return NULL; | |
73 | } | |
74 | ||
75 | /* match cannot be NULL here */ | |
76 | if (match(sd->dev, asd)) | |
77 | return asd; | |
78 | } | |
79 | ||
80 | return NULL; | |
81 | } | |
82 | ||
83 | static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier, | |
84 | struct v4l2_async_subdev_list *asdl, | |
85 | struct v4l2_async_subdev *asd) | |
86 | { | |
87 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
88 | int ret; | |
89 | ||
90 | /* Remove from the waiting list */ | |
91 | list_del(&asd->list); | |
92 | asdl->asd = asd; | |
93 | asdl->notifier = notifier; | |
94 | ||
95 | if (notifier->bound) { | |
96 | ret = notifier->bound(notifier, sd, asd); | |
97 | if (ret < 0) | |
98 | return ret; | |
99 | } | |
100 | /* Move from the global subdevice list to notifier's done */ | |
101 | list_move(&asdl->list, ¬ifier->done); | |
102 | ||
103 | ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd); | |
104 | if (ret < 0) { | |
105 | if (notifier->unbind) | |
106 | notifier->unbind(notifier, sd, asd); | |
107 | return ret; | |
108 | } | |
109 | ||
110 | if (list_empty(¬ifier->waiting) && notifier->complete) | |
111 | return notifier->complete(notifier); | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | static void v4l2_async_cleanup(struct v4l2_async_subdev_list *asdl) | |
117 | { | |
118 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
119 | ||
120 | v4l2_device_unregister_subdev(sd); | |
121 | /* Subdevice driver will reprobe and put asdl back onto the list */ | |
122 | list_del_init(&asdl->list); | |
123 | asdl->asd = NULL; | |
124 | sd->dev = NULL; | |
125 | } | |
126 | ||
127 | int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, | |
128 | struct v4l2_async_notifier *notifier) | |
129 | { | |
130 | struct v4l2_async_subdev_list *asdl, *tmp; | |
131 | struct v4l2_async_subdev *asd; | |
132 | int i; | |
133 | ||
134 | if (!notifier->num_subdevs || notifier->num_subdevs > V4L2_MAX_SUBDEVS) | |
135 | return -EINVAL; | |
136 | ||
137 | notifier->v4l2_dev = v4l2_dev; | |
138 | INIT_LIST_HEAD(¬ifier->waiting); | |
139 | INIT_LIST_HEAD(¬ifier->done); | |
140 | ||
141 | for (i = 0; i < notifier->num_subdevs; i++) { | |
142 | asd = notifier->subdev[i]; | |
143 | ||
144 | switch (asd->bus_type) { | |
145 | case V4L2_ASYNC_BUS_CUSTOM: | |
146 | case V4L2_ASYNC_BUS_PLATFORM: | |
147 | case V4L2_ASYNC_BUS_I2C: | |
148 | break; | |
149 | default: | |
150 | dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL, | |
151 | "Invalid bus-type %u on %p\n", | |
152 | asd->bus_type, asd); | |
153 | return -EINVAL; | |
154 | } | |
155 | list_add_tail(&asd->list, ¬ifier->waiting); | |
156 | } | |
157 | ||
158 | mutex_lock(&list_lock); | |
159 | ||
160 | /* Keep also completed notifiers on the list */ | |
161 | list_add(¬ifier->list, ¬ifier_list); | |
162 | ||
163 | list_for_each_entry_safe(asdl, tmp, &subdev_list, list) { | |
164 | int ret; | |
165 | ||
166 | asd = v4l2_async_belongs(notifier, asdl); | |
167 | if (!asd) | |
168 | continue; | |
169 | ||
170 | ret = v4l2_async_test_notify(notifier, asdl, asd); | |
171 | if (ret < 0) { | |
172 | mutex_unlock(&list_lock); | |
173 | return ret; | |
174 | } | |
175 | } | |
176 | ||
177 | mutex_unlock(&list_lock); | |
178 | ||
179 | return 0; | |
180 | } | |
181 | EXPORT_SYMBOL(v4l2_async_notifier_register); | |
182 | ||
183 | void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier) | |
184 | { | |
185 | struct v4l2_async_subdev_list *asdl, *tmp; | |
186 | unsigned int notif_n_subdev = notifier->num_subdevs; | |
187 | unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS); | |
188 | struct device *dev[n_subdev]; | |
189 | int i = 0; | |
190 | ||
191 | mutex_lock(&list_lock); | |
192 | ||
193 | list_del(¬ifier->list); | |
194 | ||
195 | list_for_each_entry_safe(asdl, tmp, ¬ifier->done, list) { | |
196 | struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl); | |
197 | ||
198 | dev[i] = get_device(sd->dev); | |
199 | ||
200 | v4l2_async_cleanup(asdl); | |
201 | ||
202 | /* If we handled USB devices, we'd have to lock the parent too */ | |
203 | device_release_driver(dev[i++]); | |
204 | ||
205 | if (notifier->unbind) | |
206 | notifier->unbind(notifier, sd, sd->asdl.asd); | |
207 | } | |
208 | ||
209 | mutex_unlock(&list_lock); | |
210 | ||
211 | while (i--) { | |
212 | struct device *d = dev[i]; | |
213 | ||
214 | if (d && device_attach(d) < 0) { | |
215 | const char *name = "(none)"; | |
216 | int lock = device_trylock(d); | |
217 | ||
218 | if (lock && d->driver) | |
219 | name = d->driver->name; | |
220 | dev_err(d, "Failed to re-probe to %s\n", name); | |
221 | if (lock) | |
222 | device_unlock(d); | |
223 | } | |
224 | put_device(d); | |
225 | } | |
226 | /* | |
227 | * Don't care about the waiting list, it is initialised and populated | |
228 | * upon notifier registration. | |
229 | */ | |
230 | } | |
231 | EXPORT_SYMBOL(v4l2_async_notifier_unregister); | |
232 | ||
233 | int v4l2_async_register_subdev(struct v4l2_subdev *sd) | |
234 | { | |
235 | struct v4l2_async_subdev_list *asdl = &sd->asdl; | |
236 | struct v4l2_async_notifier *notifier; | |
237 | ||
238 | mutex_lock(&list_lock); | |
239 | ||
240 | INIT_LIST_HEAD(&asdl->list); | |
241 | ||
242 | list_for_each_entry(notifier, ¬ifier_list, list) { | |
243 | struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, asdl); | |
244 | if (asd) { | |
245 | int ret = v4l2_async_test_notify(notifier, asdl, asd); | |
246 | mutex_unlock(&list_lock); | |
247 | return ret; | |
248 | } | |
249 | } | |
250 | ||
251 | /* None matched, wait for hot-plugging */ | |
252 | list_add(&asdl->list, &subdev_list); | |
253 | ||
254 | mutex_unlock(&list_lock); | |
255 | ||
256 | return 0; | |
257 | } | |
258 | EXPORT_SYMBOL(v4l2_async_register_subdev); | |
259 | ||
260 | void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) | |
261 | { | |
262 | struct v4l2_async_subdev_list *asdl = &sd->asdl; | |
263 | struct v4l2_async_notifier *notifier = asdl->notifier; | |
264 | ||
265 | if (!asdl->asd) { | |
266 | if (!list_empty(&asdl->list)) | |
267 | v4l2_async_cleanup(asdl); | |
268 | return; | |
269 | } | |
270 | ||
271 | mutex_lock(&list_lock); | |
272 | ||
273 | list_add(&asdl->asd->list, ¬ifier->waiting); | |
274 | ||
275 | v4l2_async_cleanup(asdl); | |
276 | ||
277 | if (notifier->unbind) | |
278 | notifier->unbind(notifier, sd, sd->asdl.asd); | |
279 | ||
280 | mutex_unlock(&list_lock); | |
281 | } | |
282 | EXPORT_SYMBOL(v4l2_async_unregister_subdev); |