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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> |
4e57b681 | 24 | #include <asm/semaphore.h> |
1da177e4 | 25 | |
1da177e4 LT |
26 | extern struct subsystem devices_subsys; |
27 | ||
28 | #define to_sysdev(k) container_of(k, struct sys_device, kobj) | |
29 | #define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr) | |
30 | ||
31 | ||
32 | static ssize_t | |
33 | sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer) | |
34 | { | |
35 | struct sys_device * sysdev = to_sysdev(kobj); | |
36 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
37 | ||
38 | if (sysdev_attr->show) | |
39 | return sysdev_attr->show(sysdev, buffer); | |
4a0c20bf | 40 | return -EIO; |
1da177e4 LT |
41 | } |
42 | ||
43 | ||
44 | static ssize_t | |
45 | sysdev_store(struct kobject * kobj, struct attribute * attr, | |
46 | const char * buffer, size_t count) | |
47 | { | |
48 | struct sys_device * sysdev = to_sysdev(kobj); | |
49 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
50 | ||
51 | if (sysdev_attr->store) | |
52 | return sysdev_attr->store(sysdev, buffer, count); | |
4a0c20bf | 53 | return -EIO; |
1da177e4 LT |
54 | } |
55 | ||
56 | static struct sysfs_ops sysfs_ops = { | |
57 | .show = sysdev_show, | |
58 | .store = sysdev_store, | |
59 | }; | |
60 | ||
61 | static struct kobj_type ktype_sysdev = { | |
62 | .sysfs_ops = &sysfs_ops, | |
63 | }; | |
64 | ||
65 | ||
66 | int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a) | |
67 | { | |
68 | return sysfs_create_file(&s->kobj, &a->attr); | |
69 | } | |
70 | ||
71 | ||
72 | void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a) | |
73 | { | |
74 | sysfs_remove_file(&s->kobj, &a->attr); | |
75 | } | |
76 | ||
77 | EXPORT_SYMBOL_GPL(sysdev_create_file); | |
78 | EXPORT_SYMBOL_GPL(sysdev_remove_file); | |
79 | ||
80 | /* | |
81 | * declare system_subsys | |
82 | */ | |
83 | static decl_subsys(system, &ktype_sysdev, NULL); | |
84 | ||
85 | int sysdev_class_register(struct sysdev_class * cls) | |
86 | { | |
87 | pr_debug("Registering sysdev class '%s'\n", | |
88 | kobject_name(&cls->kset.kobj)); | |
89 | INIT_LIST_HEAD(&cls->drivers); | |
90 | cls->kset.subsys = &system_subsys; | |
91 | kset_set_kset_s(cls, system_subsys); | |
92 | return kset_register(&cls->kset); | |
93 | } | |
94 | ||
95 | void sysdev_class_unregister(struct sysdev_class * cls) | |
96 | { | |
97 | pr_debug("Unregistering sysdev class '%s'\n", | |
98 | kobject_name(&cls->kset.kobj)); | |
99 | kset_unregister(&cls->kset); | |
100 | } | |
101 | ||
102 | EXPORT_SYMBOL_GPL(sysdev_class_register); | |
103 | EXPORT_SYMBOL_GPL(sysdev_class_unregister); | |
104 | ||
105 | ||
106 | static LIST_HEAD(sysdev_drivers); | |
107 | static DECLARE_MUTEX(sysdev_drivers_lock); | |
108 | ||
109 | /** | |
110 | * sysdev_driver_register - Register auxillary driver | |
111 | * @cls: Device class driver belongs to. | |
112 | * @drv: Driver. | |
113 | * | |
114 | * If @cls is valid, then @drv is inserted into @cls->drivers to be | |
115 | * called on each operation on devices of that class. The refcount | |
116 | * of @cls is incremented. | |
117 | * Otherwise, @drv is inserted into sysdev_drivers, and called for | |
118 | * each device. | |
119 | */ | |
120 | ||
121 | int sysdev_driver_register(struct sysdev_class * cls, | |
122 | struct sysdev_driver * drv) | |
123 | { | |
124 | down(&sysdev_drivers_lock); | |
125 | if (cls && kset_get(&cls->kset)) { | |
126 | list_add_tail(&drv->entry, &cls->drivers); | |
127 | ||
128 | /* If devices of this class already exist, tell the driver */ | |
129 | if (drv->add) { | |
130 | struct sys_device *dev; | |
131 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
132 | drv->add(dev); | |
133 | } | |
134 | } else | |
135 | list_add_tail(&drv->entry, &sysdev_drivers); | |
136 | up(&sysdev_drivers_lock); | |
137 | return 0; | |
138 | } | |
139 | ||
140 | ||
141 | /** | |
142 | * sysdev_driver_unregister - Remove an auxillary driver. | |
143 | * @cls: Class driver belongs to. | |
144 | * @drv: Driver. | |
145 | */ | |
146 | void sysdev_driver_unregister(struct sysdev_class * cls, | |
147 | struct sysdev_driver * drv) | |
148 | { | |
149 | down(&sysdev_drivers_lock); | |
150 | list_del_init(&drv->entry); | |
151 | if (cls) { | |
152 | if (drv->remove) { | |
153 | struct sys_device *dev; | |
154 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
155 | drv->remove(dev); | |
156 | } | |
157 | kset_put(&cls->kset); | |
158 | } | |
159 | up(&sysdev_drivers_lock); | |
160 | } | |
161 | ||
162 | EXPORT_SYMBOL_GPL(sysdev_driver_register); | |
163 | EXPORT_SYMBOL_GPL(sysdev_driver_unregister); | |
164 | ||
165 | ||
166 | ||
167 | /** | |
168 | * sysdev_register - add a system device to the tree | |
169 | * @sysdev: device in question | |
170 | * | |
171 | */ | |
172 | int sysdev_register(struct sys_device * sysdev) | |
173 | { | |
174 | int error; | |
175 | struct sysdev_class * cls = sysdev->cls; | |
176 | ||
177 | if (!cls) | |
178 | return -EINVAL; | |
179 | ||
180 | /* Make sure the kset is set */ | |
181 | sysdev->kobj.kset = &cls->kset; | |
182 | ||
183 | /* But make sure we point to the right type for sysfs translation */ | |
184 | sysdev->kobj.ktype = &ktype_sysdev; | |
185 | error = kobject_set_name(&sysdev->kobj, "%s%d", | |
186 | kobject_name(&cls->kset.kobj), sysdev->id); | |
187 | if (error) | |
188 | return error; | |
189 | ||
190 | pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj)); | |
191 | ||
192 | /* Register the object */ | |
193 | error = kobject_register(&sysdev->kobj); | |
194 | ||
195 | if (!error) { | |
196 | struct sysdev_driver * drv; | |
197 | ||
198 | down(&sysdev_drivers_lock); | |
199 | /* Generic notification is implicit, because it's that | |
200 | * code that should have called us. | |
201 | */ | |
202 | ||
203 | /* Notify global drivers */ | |
204 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
205 | if (drv->add) | |
206 | drv->add(sysdev); | |
207 | } | |
208 | ||
209 | /* Notify class auxillary drivers */ | |
210 | list_for_each_entry(drv, &cls->drivers, entry) { | |
211 | if (drv->add) | |
212 | drv->add(sysdev); | |
213 | } | |
214 | up(&sysdev_drivers_lock); | |
215 | } | |
216 | return error; | |
217 | } | |
218 | ||
219 | void sysdev_unregister(struct sys_device * sysdev) | |
220 | { | |
221 | struct sysdev_driver * drv; | |
222 | ||
223 | down(&sysdev_drivers_lock); | |
224 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
225 | if (drv->remove) | |
226 | drv->remove(sysdev); | |
227 | } | |
228 | ||
229 | list_for_each_entry(drv, &sysdev->cls->drivers, entry) { | |
230 | if (drv->remove) | |
231 | drv->remove(sysdev); | |
232 | } | |
233 | up(&sysdev_drivers_lock); | |
234 | ||
235 | kobject_unregister(&sysdev->kobj); | |
236 | } | |
237 | ||
238 | ||
239 | ||
240 | /** | |
241 | * sysdev_shutdown - Shut down all system devices. | |
242 | * | |
243 | * Loop over each class of system devices, and the devices in each | |
244 | * of those classes. For each device, we call the shutdown method for | |
245 | * each driver registered for the device - the globals, the auxillaries, | |
246 | * and the class driver. | |
247 | * | |
248 | * Note: The list is iterated in reverse order, so that we shut down | |
249 | * child devices before we shut down thier parents. The list ordering | |
250 | * is guaranteed by virtue of the fact that child devices are registered | |
251 | * after their parents. | |
252 | */ | |
253 | ||
254 | void sysdev_shutdown(void) | |
255 | { | |
256 | struct sysdev_class * cls; | |
257 | ||
258 | pr_debug("Shutting Down System Devices\n"); | |
259 | ||
260 | down(&sysdev_drivers_lock); | |
261 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, | |
262 | kset.kobj.entry) { | |
263 | struct sys_device * sysdev; | |
264 | ||
265 | pr_debug("Shutting down type '%s':\n", | |
266 | kobject_name(&cls->kset.kobj)); | |
267 | ||
268 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
269 | struct sysdev_driver * drv; | |
270 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); | |
271 | ||
272 | /* Call global drivers first. */ | |
273 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
274 | if (drv->shutdown) | |
275 | drv->shutdown(sysdev); | |
276 | } | |
277 | ||
278 | /* Call auxillary drivers next. */ | |
279 | list_for_each_entry(drv, &cls->drivers, entry) { | |
280 | if (drv->shutdown) | |
281 | drv->shutdown(sysdev); | |
282 | } | |
283 | ||
284 | /* Now call the generic one */ | |
285 | if (cls->shutdown) | |
286 | cls->shutdown(sysdev); | |
287 | } | |
288 | } | |
289 | up(&sysdev_drivers_lock); | |
290 | } | |
291 | ||
ceaeade1 SL |
292 | static void __sysdev_resume(struct sys_device *dev) |
293 | { | |
294 | struct sysdev_class *cls = dev->cls; | |
295 | struct sysdev_driver *drv; | |
296 | ||
297 | /* First, call the class-specific one */ | |
298 | if (cls->resume) | |
299 | cls->resume(dev); | |
300 | ||
301 | /* Call auxillary drivers next. */ | |
302 | list_for_each_entry(drv, &cls->drivers, entry) { | |
303 | if (drv->resume) | |
304 | drv->resume(dev); | |
305 | } | |
306 | ||
307 | /* Call global drivers. */ | |
308 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
309 | if (drv->resume) | |
310 | drv->resume(dev); | |
311 | } | |
312 | } | |
1da177e4 LT |
313 | |
314 | /** | |
315 | * sysdev_suspend - Suspend all system devices. | |
316 | * @state: Power state to enter. | |
317 | * | |
318 | * We perform an almost identical operation as sys_device_shutdown() | |
319 | * above, though calling ->suspend() instead. Interrupts are disabled | |
320 | * when this called. Devices are responsible for both saving state and | |
321 | * quiescing or powering down the device. | |
322 | * | |
323 | * This is only called by the device PM core, so we let them handle | |
324 | * all synchronization. | |
325 | */ | |
326 | ||
438510f6 | 327 | int sysdev_suspend(pm_message_t state) |
1da177e4 LT |
328 | { |
329 | struct sysdev_class * cls; | |
ceaeade1 SL |
330 | struct sys_device *sysdev, *err_dev; |
331 | struct sysdev_driver *drv, *err_drv; | |
332 | int ret; | |
1da177e4 LT |
333 | |
334 | pr_debug("Suspending System Devices\n"); | |
335 | ||
336 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, | |
337 | kset.kobj.entry) { | |
1da177e4 LT |
338 | |
339 | pr_debug("Suspending type '%s':\n", | |
340 | kobject_name(&cls->kset.kobj)); | |
341 | ||
342 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
343 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
344 | ||
345 | /* Call global drivers first. */ | |
346 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
ceaeade1 SL |
347 | if (drv->suspend) { |
348 | ret = drv->suspend(sysdev, state); | |
349 | if (ret) | |
350 | goto gbl_driver; | |
351 | } | |
1da177e4 LT |
352 | } |
353 | ||
354 | /* Call auxillary drivers next. */ | |
355 | list_for_each_entry(drv, &cls->drivers, entry) { | |
ceaeade1 SL |
356 | if (drv->suspend) { |
357 | ret = drv->suspend(sysdev, state); | |
358 | if (ret) | |
359 | goto aux_driver; | |
360 | } | |
1da177e4 LT |
361 | } |
362 | ||
363 | /* Now call the generic one */ | |
ceaeade1 SL |
364 | if (cls->suspend) { |
365 | ret = cls->suspend(sysdev, state); | |
366 | if (ret) | |
367 | goto cls_driver; | |
368 | } | |
1da177e4 LT |
369 | } |
370 | } | |
371 | return 0; | |
ceaeade1 SL |
372 | /* resume current sysdev */ |
373 | cls_driver: | |
374 | drv = NULL; | |
375 | printk(KERN_ERR "Class suspend failed for %s\n", | |
376 | kobject_name(&sysdev->kobj)); | |
377 | ||
378 | aux_driver: | |
379 | if (drv) | |
380 | printk(KERN_ERR "Class driver suspend failed for %s\n", | |
381 | kobject_name(&sysdev->kobj)); | |
382 | list_for_each_entry(err_drv, &cls->drivers, entry) { | |
383 | if (err_drv == drv) | |
384 | break; | |
385 | if (err_drv->resume) | |
386 | err_drv->resume(sysdev); | |
387 | } | |
388 | drv = NULL; | |
389 | ||
390 | gbl_driver: | |
391 | if (drv) | |
392 | printk(KERN_ERR "sysdev driver suspend failed for %s\n", | |
393 | kobject_name(&sysdev->kobj)); | |
394 | list_for_each_entry(err_drv, &sysdev_drivers, entry) { | |
395 | if (err_drv == drv) | |
396 | break; | |
397 | if (err_drv->resume) | |
398 | err_drv->resume(sysdev); | |
399 | } | |
400 | /* resume other sysdevs in current class */ | |
401 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
402 | if (err_dev == sysdev) | |
403 | break; | |
404 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
405 | __sysdev_resume(err_dev); | |
406 | } | |
407 | ||
408 | /* resume other classes */ | |
409 | list_for_each_entry_continue(cls, &system_subsys.kset.list, | |
410 | kset.kobj.entry) { | |
411 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
412 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
413 | __sysdev_resume(err_dev); | |
414 | } | |
415 | } | |
416 | return ret; | |
1da177e4 LT |
417 | } |
418 | ||
419 | ||
420 | /** | |
421 | * sysdev_resume - Bring system devices back to life. | |
422 | * | |
423 | * Similar to sys_device_suspend(), but we iterate the list forwards | |
424 | * to guarantee that parent devices are resumed before their children. | |
425 | * | |
426 | * Note: Interrupts are disabled when called. | |
427 | */ | |
428 | ||
429 | int sysdev_resume(void) | |
430 | { | |
431 | struct sysdev_class * cls; | |
432 | ||
433 | pr_debug("Resuming System Devices\n"); | |
434 | ||
435 | list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) { | |
436 | struct sys_device * sysdev; | |
437 | ||
438 | pr_debug("Resuming type '%s':\n", | |
439 | kobject_name(&cls->kset.kobj)); | |
440 | ||
441 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
442 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
443 | ||
ceaeade1 | 444 | __sysdev_resume(sysdev); |
1da177e4 LT |
445 | } |
446 | } | |
447 | return 0; | |
448 | } | |
449 | ||
450 | ||
451 | int __init system_bus_init(void) | |
452 | { | |
453 | system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj; | |
454 | return subsystem_register(&system_subsys); | |
455 | } | |
456 | ||
457 | EXPORT_SYMBOL_GPL(sysdev_register); | |
458 | EXPORT_SYMBOL_GPL(sysdev_unregister); |