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1da177e4 LT |
1 | /* |
2 | * sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc) | |
3 | * | |
4 | * Copyright (c) 2002-3 Patrick Mochel | |
5 | * 2002-3 Open Source Development Lab | |
6 | * | |
7 | * This file is released under the GPLv2 | |
8 | * | |
9 | * This exports a 'system' bus type. | |
10 | * By default, a 'sys' bus gets added to the root of the system. There will | |
11 | * always be core system devices. Devices can use sysdev_register() to | |
12 | * add themselves as children of the system bus. | |
13 | */ | |
14 | ||
15 | #include <linux/config.h> | |
16 | #include <linux/sysdev.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/string.h> | |
438510f6 | 23 | #include <linux/pm.h> |
1da177e4 | 24 | |
1da177e4 LT |
25 | extern struct subsystem devices_subsys; |
26 | ||
27 | #define to_sysdev(k) container_of(k, struct sys_device, kobj) | |
28 | #define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr) | |
29 | ||
30 | ||
31 | static ssize_t | |
32 | sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer) | |
33 | { | |
34 | struct sys_device * sysdev = to_sysdev(kobj); | |
35 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
36 | ||
37 | if (sysdev_attr->show) | |
38 | return sysdev_attr->show(sysdev, buffer); | |
4a0c20bf | 39 | return -EIO; |
1da177e4 LT |
40 | } |
41 | ||
42 | ||
43 | static ssize_t | |
44 | sysdev_store(struct kobject * kobj, struct attribute * attr, | |
45 | const char * buffer, size_t count) | |
46 | { | |
47 | struct sys_device * sysdev = to_sysdev(kobj); | |
48 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
49 | ||
50 | if (sysdev_attr->store) | |
51 | return sysdev_attr->store(sysdev, buffer, count); | |
4a0c20bf | 52 | return -EIO; |
1da177e4 LT |
53 | } |
54 | ||
55 | static struct sysfs_ops sysfs_ops = { | |
56 | .show = sysdev_show, | |
57 | .store = sysdev_store, | |
58 | }; | |
59 | ||
60 | static struct kobj_type ktype_sysdev = { | |
61 | .sysfs_ops = &sysfs_ops, | |
62 | }; | |
63 | ||
64 | ||
65 | int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a) | |
66 | { | |
67 | return sysfs_create_file(&s->kobj, &a->attr); | |
68 | } | |
69 | ||
70 | ||
71 | void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a) | |
72 | { | |
73 | sysfs_remove_file(&s->kobj, &a->attr); | |
74 | } | |
75 | ||
76 | EXPORT_SYMBOL_GPL(sysdev_create_file); | |
77 | EXPORT_SYMBOL_GPL(sysdev_remove_file); | |
78 | ||
79 | /* | |
80 | * declare system_subsys | |
81 | */ | |
82 | static decl_subsys(system, &ktype_sysdev, NULL); | |
83 | ||
84 | int sysdev_class_register(struct sysdev_class * cls) | |
85 | { | |
86 | pr_debug("Registering sysdev class '%s'\n", | |
87 | kobject_name(&cls->kset.kobj)); | |
88 | INIT_LIST_HEAD(&cls->drivers); | |
89 | cls->kset.subsys = &system_subsys; | |
90 | kset_set_kset_s(cls, system_subsys); | |
91 | return kset_register(&cls->kset); | |
92 | } | |
93 | ||
94 | void sysdev_class_unregister(struct sysdev_class * cls) | |
95 | { | |
96 | pr_debug("Unregistering sysdev class '%s'\n", | |
97 | kobject_name(&cls->kset.kobj)); | |
98 | kset_unregister(&cls->kset); | |
99 | } | |
100 | ||
101 | EXPORT_SYMBOL_GPL(sysdev_class_register); | |
102 | EXPORT_SYMBOL_GPL(sysdev_class_unregister); | |
103 | ||
104 | ||
105 | static LIST_HEAD(sysdev_drivers); | |
106 | static DECLARE_MUTEX(sysdev_drivers_lock); | |
107 | ||
108 | /** | |
109 | * sysdev_driver_register - Register auxillary driver | |
110 | * @cls: Device class driver belongs to. | |
111 | * @drv: Driver. | |
112 | * | |
113 | * If @cls is valid, then @drv is inserted into @cls->drivers to be | |
114 | * called on each operation on devices of that class. The refcount | |
115 | * of @cls is incremented. | |
116 | * Otherwise, @drv is inserted into sysdev_drivers, and called for | |
117 | * each device. | |
118 | */ | |
119 | ||
120 | int sysdev_driver_register(struct sysdev_class * cls, | |
121 | struct sysdev_driver * drv) | |
122 | { | |
123 | down(&sysdev_drivers_lock); | |
124 | if (cls && kset_get(&cls->kset)) { | |
125 | list_add_tail(&drv->entry, &cls->drivers); | |
126 | ||
127 | /* If devices of this class already exist, tell the driver */ | |
128 | if (drv->add) { | |
129 | struct sys_device *dev; | |
130 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
131 | drv->add(dev); | |
132 | } | |
133 | } else | |
134 | list_add_tail(&drv->entry, &sysdev_drivers); | |
135 | up(&sysdev_drivers_lock); | |
136 | return 0; | |
137 | } | |
138 | ||
139 | ||
140 | /** | |
141 | * sysdev_driver_unregister - Remove an auxillary driver. | |
142 | * @cls: Class driver belongs to. | |
143 | * @drv: Driver. | |
144 | */ | |
145 | void sysdev_driver_unregister(struct sysdev_class * cls, | |
146 | struct sysdev_driver * drv) | |
147 | { | |
148 | down(&sysdev_drivers_lock); | |
149 | list_del_init(&drv->entry); | |
150 | if (cls) { | |
151 | if (drv->remove) { | |
152 | struct sys_device *dev; | |
153 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
154 | drv->remove(dev); | |
155 | } | |
156 | kset_put(&cls->kset); | |
157 | } | |
158 | up(&sysdev_drivers_lock); | |
159 | } | |
160 | ||
161 | EXPORT_SYMBOL_GPL(sysdev_driver_register); | |
162 | EXPORT_SYMBOL_GPL(sysdev_driver_unregister); | |
163 | ||
164 | ||
165 | ||
166 | /** | |
167 | * sysdev_register - add a system device to the tree | |
168 | * @sysdev: device in question | |
169 | * | |
170 | */ | |
171 | int sysdev_register(struct sys_device * sysdev) | |
172 | { | |
173 | int error; | |
174 | struct sysdev_class * cls = sysdev->cls; | |
175 | ||
176 | if (!cls) | |
177 | return -EINVAL; | |
178 | ||
179 | /* Make sure the kset is set */ | |
180 | sysdev->kobj.kset = &cls->kset; | |
181 | ||
182 | /* But make sure we point to the right type for sysfs translation */ | |
183 | sysdev->kobj.ktype = &ktype_sysdev; | |
184 | error = kobject_set_name(&sysdev->kobj, "%s%d", | |
185 | kobject_name(&cls->kset.kobj), sysdev->id); | |
186 | if (error) | |
187 | return error; | |
188 | ||
189 | pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj)); | |
190 | ||
191 | /* Register the object */ | |
192 | error = kobject_register(&sysdev->kobj); | |
193 | ||
194 | if (!error) { | |
195 | struct sysdev_driver * drv; | |
196 | ||
197 | down(&sysdev_drivers_lock); | |
198 | /* Generic notification is implicit, because it's that | |
199 | * code that should have called us. | |
200 | */ | |
201 | ||
202 | /* Notify global drivers */ | |
203 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
204 | if (drv->add) | |
205 | drv->add(sysdev); | |
206 | } | |
207 | ||
208 | /* Notify class auxillary drivers */ | |
209 | list_for_each_entry(drv, &cls->drivers, entry) { | |
210 | if (drv->add) | |
211 | drv->add(sysdev); | |
212 | } | |
213 | up(&sysdev_drivers_lock); | |
214 | } | |
215 | return error; | |
216 | } | |
217 | ||
218 | void sysdev_unregister(struct sys_device * sysdev) | |
219 | { | |
220 | struct sysdev_driver * drv; | |
221 | ||
222 | down(&sysdev_drivers_lock); | |
223 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
224 | if (drv->remove) | |
225 | drv->remove(sysdev); | |
226 | } | |
227 | ||
228 | list_for_each_entry(drv, &sysdev->cls->drivers, entry) { | |
229 | if (drv->remove) | |
230 | drv->remove(sysdev); | |
231 | } | |
232 | up(&sysdev_drivers_lock); | |
233 | ||
234 | kobject_unregister(&sysdev->kobj); | |
235 | } | |
236 | ||
237 | ||
238 | ||
239 | /** | |
240 | * sysdev_shutdown - Shut down all system devices. | |
241 | * | |
242 | * Loop over each class of system devices, and the devices in each | |
243 | * of those classes. For each device, we call the shutdown method for | |
244 | * each driver registered for the device - the globals, the auxillaries, | |
245 | * and the class driver. | |
246 | * | |
247 | * Note: The list is iterated in reverse order, so that we shut down | |
248 | * child devices before we shut down thier parents. The list ordering | |
249 | * is guaranteed by virtue of the fact that child devices are registered | |
250 | * after their parents. | |
251 | */ | |
252 | ||
253 | void sysdev_shutdown(void) | |
254 | { | |
255 | struct sysdev_class * cls; | |
256 | ||
257 | pr_debug("Shutting Down System Devices\n"); | |
258 | ||
259 | down(&sysdev_drivers_lock); | |
260 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, | |
261 | kset.kobj.entry) { | |
262 | struct sys_device * sysdev; | |
263 | ||
264 | pr_debug("Shutting down type '%s':\n", | |
265 | kobject_name(&cls->kset.kobj)); | |
266 | ||
267 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
268 | struct sysdev_driver * drv; | |
269 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); | |
270 | ||
271 | /* Call global drivers first. */ | |
272 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
273 | if (drv->shutdown) | |
274 | drv->shutdown(sysdev); | |
275 | } | |
276 | ||
277 | /* Call auxillary drivers next. */ | |
278 | list_for_each_entry(drv, &cls->drivers, entry) { | |
279 | if (drv->shutdown) | |
280 | drv->shutdown(sysdev); | |
281 | } | |
282 | ||
283 | /* Now call the generic one */ | |
284 | if (cls->shutdown) | |
285 | cls->shutdown(sysdev); | |
286 | } | |
287 | } | |
288 | up(&sysdev_drivers_lock); | |
289 | } | |
290 | ||
ceaeade1 SL |
291 | static void __sysdev_resume(struct sys_device *dev) |
292 | { | |
293 | struct sysdev_class *cls = dev->cls; | |
294 | struct sysdev_driver *drv; | |
295 | ||
296 | /* First, call the class-specific one */ | |
297 | if (cls->resume) | |
298 | cls->resume(dev); | |
299 | ||
300 | /* Call auxillary drivers next. */ | |
301 | list_for_each_entry(drv, &cls->drivers, entry) { | |
302 | if (drv->resume) | |
303 | drv->resume(dev); | |
304 | } | |
305 | ||
306 | /* Call global drivers. */ | |
307 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
308 | if (drv->resume) | |
309 | drv->resume(dev); | |
310 | } | |
311 | } | |
1da177e4 LT |
312 | |
313 | /** | |
314 | * sysdev_suspend - Suspend all system devices. | |
315 | * @state: Power state to enter. | |
316 | * | |
317 | * We perform an almost identical operation as sys_device_shutdown() | |
318 | * above, though calling ->suspend() instead. Interrupts are disabled | |
319 | * when this called. Devices are responsible for both saving state and | |
320 | * quiescing or powering down the device. | |
321 | * | |
322 | * This is only called by the device PM core, so we let them handle | |
323 | * all synchronization. | |
324 | */ | |
325 | ||
438510f6 | 326 | int sysdev_suspend(pm_message_t state) |
1da177e4 LT |
327 | { |
328 | struct sysdev_class * cls; | |
ceaeade1 SL |
329 | struct sys_device *sysdev, *err_dev; |
330 | struct sysdev_driver *drv, *err_drv; | |
331 | int ret; | |
1da177e4 LT |
332 | |
333 | pr_debug("Suspending System Devices\n"); | |
334 | ||
335 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, | |
336 | kset.kobj.entry) { | |
1da177e4 LT |
337 | |
338 | pr_debug("Suspending type '%s':\n", | |
339 | kobject_name(&cls->kset.kobj)); | |
340 | ||
341 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
342 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
343 | ||
344 | /* Call global drivers first. */ | |
345 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
ceaeade1 SL |
346 | if (drv->suspend) { |
347 | ret = drv->suspend(sysdev, state); | |
348 | if (ret) | |
349 | goto gbl_driver; | |
350 | } | |
1da177e4 LT |
351 | } |
352 | ||
353 | /* Call auxillary drivers next. */ | |
354 | list_for_each_entry(drv, &cls->drivers, entry) { | |
ceaeade1 SL |
355 | if (drv->suspend) { |
356 | ret = drv->suspend(sysdev, state); | |
357 | if (ret) | |
358 | goto aux_driver; | |
359 | } | |
1da177e4 LT |
360 | } |
361 | ||
362 | /* Now call the generic one */ | |
ceaeade1 SL |
363 | if (cls->suspend) { |
364 | ret = cls->suspend(sysdev, state); | |
365 | if (ret) | |
366 | goto cls_driver; | |
367 | } | |
1da177e4 LT |
368 | } |
369 | } | |
370 | return 0; | |
ceaeade1 SL |
371 | /* resume current sysdev */ |
372 | cls_driver: | |
373 | drv = NULL; | |
374 | printk(KERN_ERR "Class suspend failed for %s\n", | |
375 | kobject_name(&sysdev->kobj)); | |
376 | ||
377 | aux_driver: | |
378 | if (drv) | |
379 | printk(KERN_ERR "Class driver suspend failed for %s\n", | |
380 | kobject_name(&sysdev->kobj)); | |
381 | list_for_each_entry(err_drv, &cls->drivers, entry) { | |
382 | if (err_drv == drv) | |
383 | break; | |
384 | if (err_drv->resume) | |
385 | err_drv->resume(sysdev); | |
386 | } | |
387 | drv = NULL; | |
388 | ||
389 | gbl_driver: | |
390 | if (drv) | |
391 | printk(KERN_ERR "sysdev driver suspend failed for %s\n", | |
392 | kobject_name(&sysdev->kobj)); | |
393 | list_for_each_entry(err_drv, &sysdev_drivers, entry) { | |
394 | if (err_drv == drv) | |
395 | break; | |
396 | if (err_drv->resume) | |
397 | err_drv->resume(sysdev); | |
398 | } | |
399 | /* resume other sysdevs in current class */ | |
400 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
401 | if (err_dev == sysdev) | |
402 | break; | |
403 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
404 | __sysdev_resume(err_dev); | |
405 | } | |
406 | ||
407 | /* resume other classes */ | |
408 | list_for_each_entry_continue(cls, &system_subsys.kset.list, | |
409 | kset.kobj.entry) { | |
410 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
411 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
412 | __sysdev_resume(err_dev); | |
413 | } | |
414 | } | |
415 | return ret; | |
1da177e4 LT |
416 | } |
417 | ||
418 | ||
419 | /** | |
420 | * sysdev_resume - Bring system devices back to life. | |
421 | * | |
422 | * Similar to sys_device_suspend(), but we iterate the list forwards | |
423 | * to guarantee that parent devices are resumed before their children. | |
424 | * | |
425 | * Note: Interrupts are disabled when called. | |
426 | */ | |
427 | ||
428 | int sysdev_resume(void) | |
429 | { | |
430 | struct sysdev_class * cls; | |
431 | ||
432 | pr_debug("Resuming System Devices\n"); | |
433 | ||
434 | list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) { | |
435 | struct sys_device * sysdev; | |
436 | ||
437 | pr_debug("Resuming type '%s':\n", | |
438 | kobject_name(&cls->kset.kobj)); | |
439 | ||
440 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
441 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
442 | ||
ceaeade1 | 443 | __sysdev_resume(sysdev); |
1da177e4 LT |
444 | } |
445 | } | |
446 | return 0; | |
447 | } | |
448 | ||
449 | ||
450 | int __init system_bus_init(void) | |
451 | { | |
452 | system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj; | |
453 | return subsystem_register(&system_subsys); | |
454 | } | |
455 | ||
456 | EXPORT_SYMBOL_GPL(sysdev_register); | |
457 | EXPORT_SYMBOL_GPL(sysdev_unregister); |