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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> | |
758d90e1 | 15 | #include <linux/mm.h> |
e9e31049 GL |
16 | #include <linux/module.h> |
17 | #include <linux/mutex.h> | |
ecdf0cfe | 18 | #include <linux/of.h> |
e9e31049 GL |
19 | #include <linux/platform_device.h> |
20 | #include <linux/slab.h> | |
21 | #include <linux/types.h> | |
22 | ||
23 | #include <media/v4l2-async.h> | |
24 | #include <media/v4l2-device.h> | |
25 | #include <media/v4l2-subdev.h> | |
26 | ||
86217651 | 27 | static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd) |
e9e31049 | 28 | { |
fe05e141 | 29 | #if IS_ENABLED(CONFIG_I2C) |
86217651 | 30 | struct i2c_client *client = i2c_verify_client(sd->dev); |
e9e31049 | 31 | return client && |
e9e31049 GL |
32 | asd->match.i2c.adapter_id == client->adapter->nr && |
33 | asd->match.i2c.address == client->addr; | |
fe05e141 GL |
34 | #else |
35 | return false; | |
36 | #endif | |
e9e31049 GL |
37 | } |
38 | ||
86217651 SA |
39 | static bool match_devname(struct v4l2_subdev *sd, |
40 | struct v4l2_async_subdev *asd) | |
e9e31049 | 41 | { |
86217651 | 42 | return !strcmp(asd->match.device_name.name, dev_name(sd->dev)); |
e9e31049 GL |
43 | } |
44 | ||
ecdf0cfe SA |
45 | static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd) |
46 | { | |
47 | if (!is_of_node(sd->fwnode) || !is_of_node(asd->match.fwnode.fwnode)) | |
48 | return sd->fwnode == asd->match.fwnode.fwnode; | |
49 | ||
50 | return !of_node_cmp(of_node_full_name(to_of_node(sd->fwnode)), | |
51 | of_node_full_name( | |
52 | to_of_node(asd->match.fwnode.fwnode))); | |
53 | } | |
54 | ||
86217651 SA |
55 | static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd) |
56 | { | |
57 | if (!asd->match.custom.match) | |
58 | /* Match always */ | |
59 | return true; | |
60 | ||
61 | return asd->match.custom.match(sd->dev, asd); | |
e7359f8e SN |
62 | } |
63 | ||
e9e31049 GL |
64 | static LIST_HEAD(subdev_list); |
65 | static LIST_HEAD(notifier_list); | |
66 | static DEFINE_MUTEX(list_lock); | |
67 | ||
68 | static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier, | |
b426b3a6 | 69 | struct v4l2_subdev *sd) |
e9e31049 | 70 | { |
86217651 | 71 | bool (*match)(struct v4l2_subdev *, struct v4l2_async_subdev *); |
e9e31049 | 72 | struct v4l2_async_subdev *asd; |
e9e31049 GL |
73 | |
74 | list_for_each_entry(asd, ¬ifier->waiting, list) { | |
75 | /* bus_type has been verified valid before */ | |
cfca7644 SN |
76 | switch (asd->match_type) { |
77 | case V4L2_ASYNC_MATCH_CUSTOM: | |
86217651 | 78 | match = match_custom; |
e9e31049 | 79 | break; |
cfca7644 SN |
80 | case V4L2_ASYNC_MATCH_DEVNAME: |
81 | match = match_devname; | |
e9e31049 | 82 | break; |
cfca7644 | 83 | case V4L2_ASYNC_MATCH_I2C: |
e9e31049 GL |
84 | match = match_i2c; |
85 | break; | |
ecdf0cfe SA |
86 | case V4L2_ASYNC_MATCH_FWNODE: |
87 | match = match_fwnode; | |
88 | break; | |
e9e31049 GL |
89 | default: |
90 | /* Cannot happen, unless someone breaks us */ | |
91 | WARN_ON(true); | |
92 | return NULL; | |
93 | } | |
94 | ||
95 | /* match cannot be NULL here */ | |
86217651 | 96 | if (match(sd, asd)) |
e9e31049 GL |
97 | return asd; |
98 | } | |
99 | ||
100 | return NULL; | |
101 | } | |
102 | ||
103 | static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier, | |
b426b3a6 | 104 | struct v4l2_subdev *sd, |
e9e31049 GL |
105 | struct v4l2_async_subdev *asd) |
106 | { | |
e9e31049 GL |
107 | int ret; |
108 | ||
e9e31049 GL |
109 | if (notifier->bound) { |
110 | ret = notifier->bound(notifier, sd, asd); | |
111 | if (ret < 0) | |
112 | return ret; | |
113 | } | |
e9e31049 GL |
114 | |
115 | ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd); | |
116 | if (ret < 0) { | |
117 | if (notifier->unbind) | |
118 | notifier->unbind(notifier, sd, asd); | |
119 | return ret; | |
120 | } | |
121 | ||
47b037a0 TT |
122 | /* Remove from the waiting list */ |
123 | list_del(&asd->list); | |
124 | sd->asd = asd; | |
125 | sd->notifier = notifier; | |
126 | ||
127 | /* Move from the global subdevice list to notifier's done */ | |
128 | list_move(&sd->async_list, ¬ifier->done); | |
129 | ||
e9e31049 GL |
130 | if (list_empty(¬ifier->waiting) && notifier->complete) |
131 | return notifier->complete(notifier); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
b426b3a6 | 136 | static void v4l2_async_cleanup(struct v4l2_subdev *sd) |
e9e31049 | 137 | { |
e9e31049 | 138 | v4l2_device_unregister_subdev(sd); |
b426b3a6 SN |
139 | /* Subdevice driver will reprobe and put the subdev back onto the list */ |
140 | list_del_init(&sd->async_list); | |
141 | sd->asd = NULL; | |
e9e31049 GL |
142 | sd->dev = NULL; |
143 | } | |
144 | ||
145 | int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, | |
146 | struct v4l2_async_notifier *notifier) | |
147 | { | |
b426b3a6 | 148 | struct v4l2_subdev *sd, *tmp; |
e9e31049 GL |
149 | struct v4l2_async_subdev *asd; |
150 | int i; | |
151 | ||
fbf1e94f NS |
152 | if (!v4l2_dev || !notifier->num_subdevs || |
153 | notifier->num_subdevs > V4L2_MAX_SUBDEVS) | |
e9e31049 GL |
154 | return -EINVAL; |
155 | ||
156 | notifier->v4l2_dev = v4l2_dev; | |
157 | INIT_LIST_HEAD(¬ifier->waiting); | |
158 | INIT_LIST_HEAD(¬ifier->done); | |
159 | ||
160 | for (i = 0; i < notifier->num_subdevs; i++) { | |
e8419d08 | 161 | asd = notifier->subdevs[i]; |
e9e31049 | 162 | |
cfca7644 SN |
163 | switch (asd->match_type) { |
164 | case V4L2_ASYNC_MATCH_CUSTOM: | |
165 | case V4L2_ASYNC_MATCH_DEVNAME: | |
166 | case V4L2_ASYNC_MATCH_I2C: | |
ecdf0cfe | 167 | case V4L2_ASYNC_MATCH_FWNODE: |
e9e31049 GL |
168 | break; |
169 | default: | |
170 | dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL, | |
cfca7644 SN |
171 | "Invalid match type %u on %p\n", |
172 | asd->match_type, asd); | |
e9e31049 GL |
173 | return -EINVAL; |
174 | } | |
175 | list_add_tail(&asd->list, ¬ifier->waiting); | |
176 | } | |
177 | ||
178 | mutex_lock(&list_lock); | |
179 | ||
b426b3a6 | 180 | list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) { |
e9e31049 GL |
181 | int ret; |
182 | ||
b426b3a6 | 183 | asd = v4l2_async_belongs(notifier, sd); |
e9e31049 GL |
184 | if (!asd) |
185 | continue; | |
186 | ||
b426b3a6 | 187 | ret = v4l2_async_test_notify(notifier, sd, asd); |
e9e31049 GL |
188 | if (ret < 0) { |
189 | mutex_unlock(&list_lock); | |
190 | return ret; | |
191 | } | |
192 | } | |
193 | ||
47b037a0 TT |
194 | /* Keep also completed notifiers on the list */ |
195 | list_add(¬ifier->list, ¬ifier_list); | |
196 | ||
e9e31049 GL |
197 | mutex_unlock(&list_lock); |
198 | ||
199 | return 0; | |
200 | } | |
201 | EXPORT_SYMBOL(v4l2_async_notifier_register); | |
202 | ||
203 | void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier) | |
204 | { | |
b426b3a6 | 205 | struct v4l2_subdev *sd, *tmp; |
e9e31049 GL |
206 | unsigned int notif_n_subdev = notifier->num_subdevs; |
207 | unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS); | |
24e9a47e | 208 | struct device **dev; |
e9e31049 GL |
209 | int i = 0; |
210 | ||
8e3fbfee LP |
211 | if (!notifier->v4l2_dev) |
212 | return; | |
213 | ||
758d90e1 | 214 | dev = kvmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL); |
24e9a47e MCC |
215 | if (!dev) { |
216 | dev_err(notifier->v4l2_dev->dev, | |
217 | "Failed to allocate device cache!\n"); | |
218 | } | |
219 | ||
e9e31049 GL |
220 | mutex_lock(&list_lock); |
221 | ||
222 | list_del(¬ifier->list); | |
223 | ||
ceedcc4e | 224 | list_for_each_entry_safe(sd, tmp, ¬ifier->done, async_list) { |
24e9a47e MCC |
225 | struct device *d; |
226 | ||
227 | d = get_device(sd->dev); | |
e9e31049 | 228 | |
b426b3a6 | 229 | v4l2_async_cleanup(sd); |
e9e31049 GL |
230 | |
231 | /* If we handled USB devices, we'd have to lock the parent too */ | |
24e9a47e | 232 | device_release_driver(d); |
e9e31049 GL |
233 | |
234 | if (notifier->unbind) | |
b426b3a6 | 235 | notifier->unbind(notifier, sd, sd->asd); |
24e9a47e MCC |
236 | |
237 | /* | |
238 | * Store device at the device cache, in order to call | |
239 | * put_device() on the final step | |
240 | */ | |
241 | if (dev) | |
242 | dev[i++] = d; | |
243 | else | |
244 | put_device(d); | |
e9e31049 GL |
245 | } |
246 | ||
247 | mutex_unlock(&list_lock); | |
248 | ||
24e9a47e MCC |
249 | /* |
250 | * Call device_attach() to reprobe devices | |
251 | * | |
252 | * NOTE: If dev allocation fails, i is 0, and the whole loop won't be | |
253 | * executed. | |
254 | */ | |
e9e31049 GL |
255 | while (i--) { |
256 | struct device *d = dev[i]; | |
257 | ||
258 | if (d && device_attach(d) < 0) { | |
259 | const char *name = "(none)"; | |
260 | int lock = device_trylock(d); | |
261 | ||
262 | if (lock && d->driver) | |
263 | name = d->driver->name; | |
264 | dev_err(d, "Failed to re-probe to %s\n", name); | |
265 | if (lock) | |
266 | device_unlock(d); | |
267 | } | |
268 | put_device(d); | |
269 | } | |
758d90e1 | 270 | kvfree(dev); |
8e3fbfee LP |
271 | |
272 | notifier->v4l2_dev = NULL; | |
273 | ||
e9e31049 GL |
274 | /* |
275 | * Don't care about the waiting list, it is initialised and populated | |
276 | * upon notifier registration. | |
277 | */ | |
278 | } | |
279 | EXPORT_SYMBOL(v4l2_async_notifier_unregister); | |
280 | ||
281 | int v4l2_async_register_subdev(struct v4l2_subdev *sd) | |
282 | { | |
e9e31049 GL |
283 | struct v4l2_async_notifier *notifier; |
284 | ||
86217651 SA |
285 | /* |
286 | * No reference taken. The reference is held by the device | |
287 | * (struct v4l2_subdev.dev), and async sub-device does not | |
288 | * exist independently of the device at any point of time. | |
289 | */ | |
859969b3 SA |
290 | if (!sd->fwnode && sd->dev) |
291 | sd->fwnode = dev_fwnode(sd->dev); | |
86217651 | 292 | |
e9e31049 GL |
293 | mutex_lock(&list_lock); |
294 | ||
b426b3a6 | 295 | INIT_LIST_HEAD(&sd->async_list); |
e9e31049 GL |
296 | |
297 | list_for_each_entry(notifier, ¬ifier_list, list) { | |
b426b3a6 | 298 | struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd); |
e9e31049 | 299 | if (asd) { |
b426b3a6 | 300 | int ret = v4l2_async_test_notify(notifier, sd, asd); |
e9e31049 GL |
301 | mutex_unlock(&list_lock); |
302 | return ret; | |
303 | } | |
304 | } | |
305 | ||
306 | /* None matched, wait for hot-plugging */ | |
b426b3a6 | 307 | list_add(&sd->async_list, &subdev_list); |
e9e31049 GL |
308 | |
309 | mutex_unlock(&list_lock); | |
310 | ||
311 | return 0; | |
312 | } | |
313 | EXPORT_SYMBOL(v4l2_async_register_subdev); | |
314 | ||
315 | void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) | |
316 | { | |
b426b3a6 | 317 | struct v4l2_async_notifier *notifier = sd->notifier; |
e9e31049 | 318 | |
b426b3a6 SN |
319 | if (!sd->asd) { |
320 | if (!list_empty(&sd->async_list)) | |
321 | v4l2_async_cleanup(sd); | |
e9e31049 GL |
322 | return; |
323 | } | |
324 | ||
325 | mutex_lock(&list_lock); | |
326 | ||
b426b3a6 | 327 | list_add(&sd->asd->list, ¬ifier->waiting); |
e9e31049 | 328 | |
b426b3a6 | 329 | v4l2_async_cleanup(sd); |
e9e31049 GL |
330 | |
331 | if (notifier->unbind) | |
b426b3a6 | 332 | notifier->unbind(notifier, sd, sd->asd); |
e9e31049 GL |
333 | |
334 | mutex_unlock(&list_lock); | |
335 | } | |
336 | EXPORT_SYMBOL(v4l2_async_unregister_subdev); |