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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> |
f67d115f | 24 | #include <linux/device.h> |
4e57b681 | 25 | #include <asm/semaphore.h> |
1da177e4 | 26 | |
f67d115f AB |
27 | #include "base.h" |
28 | ||
1da177e4 LT |
29 | extern struct subsystem devices_subsys; |
30 | ||
31 | #define to_sysdev(k) container_of(k, struct sys_device, kobj) | |
32 | #define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr) | |
33 | ||
34 | ||
35 | static ssize_t | |
36 | sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer) | |
37 | { | |
38 | struct sys_device * sysdev = to_sysdev(kobj); | |
39 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
40 | ||
41 | if (sysdev_attr->show) | |
42 | return sysdev_attr->show(sysdev, buffer); | |
4a0c20bf | 43 | return -EIO; |
1da177e4 LT |
44 | } |
45 | ||
46 | ||
47 | static ssize_t | |
48 | sysdev_store(struct kobject * kobj, struct attribute * attr, | |
49 | const char * buffer, size_t count) | |
50 | { | |
51 | struct sys_device * sysdev = to_sysdev(kobj); | |
52 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
53 | ||
54 | if (sysdev_attr->store) | |
55 | return sysdev_attr->store(sysdev, buffer, count); | |
4a0c20bf | 56 | return -EIO; |
1da177e4 LT |
57 | } |
58 | ||
59 | static struct sysfs_ops sysfs_ops = { | |
60 | .show = sysdev_show, | |
61 | .store = sysdev_store, | |
62 | }; | |
63 | ||
64 | static struct kobj_type ktype_sysdev = { | |
65 | .sysfs_ops = &sysfs_ops, | |
66 | }; | |
67 | ||
68 | ||
69 | int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a) | |
70 | { | |
71 | return sysfs_create_file(&s->kobj, &a->attr); | |
72 | } | |
73 | ||
74 | ||
75 | void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a) | |
76 | { | |
77 | sysfs_remove_file(&s->kobj, &a->attr); | |
78 | } | |
79 | ||
80 | EXPORT_SYMBOL_GPL(sysdev_create_file); | |
81 | EXPORT_SYMBOL_GPL(sysdev_remove_file); | |
82 | ||
83 | /* | |
84 | * declare system_subsys | |
85 | */ | |
86 | static decl_subsys(system, &ktype_sysdev, NULL); | |
87 | ||
88 | int sysdev_class_register(struct sysdev_class * cls) | |
89 | { | |
90 | pr_debug("Registering sysdev class '%s'\n", | |
91 | kobject_name(&cls->kset.kobj)); | |
92 | INIT_LIST_HEAD(&cls->drivers); | |
93 | cls->kset.subsys = &system_subsys; | |
94 | kset_set_kset_s(cls, system_subsys); | |
95 | return kset_register(&cls->kset); | |
96 | } | |
97 | ||
98 | void sysdev_class_unregister(struct sysdev_class * cls) | |
99 | { | |
100 | pr_debug("Unregistering sysdev class '%s'\n", | |
101 | kobject_name(&cls->kset.kobj)); | |
102 | kset_unregister(&cls->kset); | |
103 | } | |
104 | ||
105 | EXPORT_SYMBOL_GPL(sysdev_class_register); | |
106 | EXPORT_SYMBOL_GPL(sysdev_class_unregister); | |
107 | ||
108 | ||
109 | static LIST_HEAD(sysdev_drivers); | |
110 | static DECLARE_MUTEX(sysdev_drivers_lock); | |
111 | ||
112 | /** | |
113 | * sysdev_driver_register - Register auxillary driver | |
114 | * @cls: Device class driver belongs to. | |
115 | * @drv: Driver. | |
116 | * | |
117 | * If @cls is valid, then @drv is inserted into @cls->drivers to be | |
118 | * called on each operation on devices of that class. The refcount | |
119 | * of @cls is incremented. | |
120 | * Otherwise, @drv is inserted into sysdev_drivers, and called for | |
121 | * each device. | |
122 | */ | |
123 | ||
124 | int sysdev_driver_register(struct sysdev_class * cls, | |
125 | struct sysdev_driver * drv) | |
126 | { | |
127 | down(&sysdev_drivers_lock); | |
128 | if (cls && kset_get(&cls->kset)) { | |
129 | list_add_tail(&drv->entry, &cls->drivers); | |
130 | ||
131 | /* If devices of this class already exist, tell the driver */ | |
132 | if (drv->add) { | |
133 | struct sys_device *dev; | |
134 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
135 | drv->add(dev); | |
136 | } | |
137 | } else | |
138 | list_add_tail(&drv->entry, &sysdev_drivers); | |
139 | up(&sysdev_drivers_lock); | |
140 | return 0; | |
141 | } | |
142 | ||
143 | ||
144 | /** | |
145 | * sysdev_driver_unregister - Remove an auxillary driver. | |
146 | * @cls: Class driver belongs to. | |
147 | * @drv: Driver. | |
148 | */ | |
149 | void sysdev_driver_unregister(struct sysdev_class * cls, | |
150 | struct sysdev_driver * drv) | |
151 | { | |
152 | down(&sysdev_drivers_lock); | |
153 | list_del_init(&drv->entry); | |
154 | if (cls) { | |
155 | if (drv->remove) { | |
156 | struct sys_device *dev; | |
157 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
158 | drv->remove(dev); | |
159 | } | |
160 | kset_put(&cls->kset); | |
161 | } | |
162 | up(&sysdev_drivers_lock); | |
163 | } | |
164 | ||
165 | EXPORT_SYMBOL_GPL(sysdev_driver_register); | |
166 | EXPORT_SYMBOL_GPL(sysdev_driver_unregister); | |
167 | ||
168 | ||
169 | ||
170 | /** | |
171 | * sysdev_register - add a system device to the tree | |
172 | * @sysdev: device in question | |
173 | * | |
174 | */ | |
175 | int sysdev_register(struct sys_device * sysdev) | |
176 | { | |
177 | int error; | |
178 | struct sysdev_class * cls = sysdev->cls; | |
179 | ||
180 | if (!cls) | |
181 | return -EINVAL; | |
182 | ||
183 | /* Make sure the kset is set */ | |
184 | sysdev->kobj.kset = &cls->kset; | |
185 | ||
186 | /* But make sure we point to the right type for sysfs translation */ | |
187 | sysdev->kobj.ktype = &ktype_sysdev; | |
188 | error = kobject_set_name(&sysdev->kobj, "%s%d", | |
189 | kobject_name(&cls->kset.kobj), sysdev->id); | |
190 | if (error) | |
191 | return error; | |
192 | ||
193 | pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj)); | |
194 | ||
195 | /* Register the object */ | |
196 | error = kobject_register(&sysdev->kobj); | |
197 | ||
198 | if (!error) { | |
199 | struct sysdev_driver * drv; | |
200 | ||
201 | down(&sysdev_drivers_lock); | |
202 | /* Generic notification is implicit, because it's that | |
203 | * code that should have called us. | |
204 | */ | |
205 | ||
206 | /* Notify global drivers */ | |
207 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
208 | if (drv->add) | |
209 | drv->add(sysdev); | |
210 | } | |
211 | ||
212 | /* Notify class auxillary drivers */ | |
213 | list_for_each_entry(drv, &cls->drivers, entry) { | |
214 | if (drv->add) | |
215 | drv->add(sysdev); | |
216 | } | |
217 | up(&sysdev_drivers_lock); | |
218 | } | |
219 | return error; | |
220 | } | |
221 | ||
222 | void sysdev_unregister(struct sys_device * sysdev) | |
223 | { | |
224 | struct sysdev_driver * drv; | |
225 | ||
226 | down(&sysdev_drivers_lock); | |
227 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
228 | if (drv->remove) | |
229 | drv->remove(sysdev); | |
230 | } | |
231 | ||
232 | list_for_each_entry(drv, &sysdev->cls->drivers, entry) { | |
233 | if (drv->remove) | |
234 | drv->remove(sysdev); | |
235 | } | |
236 | up(&sysdev_drivers_lock); | |
237 | ||
238 | kobject_unregister(&sysdev->kobj); | |
239 | } | |
240 | ||
241 | ||
242 | ||
243 | /** | |
244 | * sysdev_shutdown - Shut down all system devices. | |
245 | * | |
246 | * Loop over each class of system devices, and the devices in each | |
247 | * of those classes. For each device, we call the shutdown method for | |
248 | * each driver registered for the device - the globals, the auxillaries, | |
249 | * and the class driver. | |
250 | * | |
251 | * Note: The list is iterated in reverse order, so that we shut down | |
252 | * child devices before we shut down thier parents. The list ordering | |
253 | * is guaranteed by virtue of the fact that child devices are registered | |
254 | * after their parents. | |
255 | */ | |
256 | ||
257 | void sysdev_shutdown(void) | |
258 | { | |
259 | struct sysdev_class * cls; | |
260 | ||
261 | pr_debug("Shutting Down System Devices\n"); | |
262 | ||
263 | down(&sysdev_drivers_lock); | |
264 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, | |
265 | kset.kobj.entry) { | |
266 | struct sys_device * sysdev; | |
267 | ||
268 | pr_debug("Shutting down type '%s':\n", | |
269 | kobject_name(&cls->kset.kobj)); | |
270 | ||
271 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
272 | struct sysdev_driver * drv; | |
273 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); | |
274 | ||
275 | /* Call global drivers first. */ | |
276 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
277 | if (drv->shutdown) | |
278 | drv->shutdown(sysdev); | |
279 | } | |
280 | ||
281 | /* Call auxillary drivers next. */ | |
282 | list_for_each_entry(drv, &cls->drivers, entry) { | |
283 | if (drv->shutdown) | |
284 | drv->shutdown(sysdev); | |
285 | } | |
286 | ||
287 | /* Now call the generic one */ | |
288 | if (cls->shutdown) | |
289 | cls->shutdown(sysdev); | |
290 | } | |
291 | } | |
292 | up(&sysdev_drivers_lock); | |
293 | } | |
294 | ||
ceaeade1 SL |
295 | static void __sysdev_resume(struct sys_device *dev) |
296 | { | |
297 | struct sysdev_class *cls = dev->cls; | |
298 | struct sysdev_driver *drv; | |
299 | ||
300 | /* First, call the class-specific one */ | |
301 | if (cls->resume) | |
302 | cls->resume(dev); | |
303 | ||
304 | /* Call auxillary drivers next. */ | |
305 | list_for_each_entry(drv, &cls->drivers, entry) { | |
306 | if (drv->resume) | |
307 | drv->resume(dev); | |
308 | } | |
309 | ||
310 | /* Call global drivers. */ | |
311 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
312 | if (drv->resume) | |
313 | drv->resume(dev); | |
314 | } | |
315 | } | |
1da177e4 LT |
316 | |
317 | /** | |
318 | * sysdev_suspend - Suspend all system devices. | |
319 | * @state: Power state to enter. | |
320 | * | |
321 | * We perform an almost identical operation as sys_device_shutdown() | |
322 | * above, though calling ->suspend() instead. Interrupts are disabled | |
323 | * when this called. Devices are responsible for both saving state and | |
324 | * quiescing or powering down the device. | |
325 | * | |
326 | * This is only called by the device PM core, so we let them handle | |
327 | * all synchronization. | |
328 | */ | |
329 | ||
438510f6 | 330 | int sysdev_suspend(pm_message_t state) |
1da177e4 LT |
331 | { |
332 | struct sysdev_class * cls; | |
ceaeade1 SL |
333 | struct sys_device *sysdev, *err_dev; |
334 | struct sysdev_driver *drv, *err_drv; | |
335 | int ret; | |
1da177e4 LT |
336 | |
337 | pr_debug("Suspending System Devices\n"); | |
338 | ||
339 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, | |
340 | kset.kobj.entry) { | |
1da177e4 LT |
341 | |
342 | pr_debug("Suspending type '%s':\n", | |
343 | kobject_name(&cls->kset.kobj)); | |
344 | ||
345 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
346 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
347 | ||
348 | /* Call global drivers first. */ | |
349 | list_for_each_entry(drv, &sysdev_drivers, entry) { | |
ceaeade1 SL |
350 | if (drv->suspend) { |
351 | ret = drv->suspend(sysdev, state); | |
352 | if (ret) | |
353 | goto gbl_driver; | |
354 | } | |
1da177e4 LT |
355 | } |
356 | ||
357 | /* Call auxillary drivers next. */ | |
358 | list_for_each_entry(drv, &cls->drivers, entry) { | |
ceaeade1 SL |
359 | if (drv->suspend) { |
360 | ret = drv->suspend(sysdev, state); | |
361 | if (ret) | |
362 | goto aux_driver; | |
363 | } | |
1da177e4 LT |
364 | } |
365 | ||
366 | /* Now call the generic one */ | |
ceaeade1 SL |
367 | if (cls->suspend) { |
368 | ret = cls->suspend(sysdev, state); | |
369 | if (ret) | |
370 | goto cls_driver; | |
371 | } | |
1da177e4 LT |
372 | } |
373 | } | |
374 | return 0; | |
ceaeade1 SL |
375 | /* resume current sysdev */ |
376 | cls_driver: | |
377 | drv = NULL; | |
378 | printk(KERN_ERR "Class suspend failed for %s\n", | |
379 | kobject_name(&sysdev->kobj)); | |
380 | ||
381 | aux_driver: | |
382 | if (drv) | |
383 | printk(KERN_ERR "Class driver suspend failed for %s\n", | |
384 | kobject_name(&sysdev->kobj)); | |
385 | list_for_each_entry(err_drv, &cls->drivers, entry) { | |
386 | if (err_drv == drv) | |
387 | break; | |
388 | if (err_drv->resume) | |
389 | err_drv->resume(sysdev); | |
390 | } | |
391 | drv = NULL; | |
392 | ||
393 | gbl_driver: | |
394 | if (drv) | |
395 | printk(KERN_ERR "sysdev driver suspend failed for %s\n", | |
396 | kobject_name(&sysdev->kobj)); | |
397 | list_for_each_entry(err_drv, &sysdev_drivers, entry) { | |
398 | if (err_drv == drv) | |
399 | break; | |
400 | if (err_drv->resume) | |
401 | err_drv->resume(sysdev); | |
402 | } | |
403 | /* resume other sysdevs in current class */ | |
404 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
405 | if (err_dev == sysdev) | |
406 | break; | |
407 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
408 | __sysdev_resume(err_dev); | |
409 | } | |
410 | ||
411 | /* resume other classes */ | |
412 | list_for_each_entry_continue(cls, &system_subsys.kset.list, | |
413 | kset.kobj.entry) { | |
414 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
415 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
416 | __sysdev_resume(err_dev); | |
417 | } | |
418 | } | |
419 | return ret; | |
1da177e4 LT |
420 | } |
421 | ||
422 | ||
423 | /** | |
424 | * sysdev_resume - Bring system devices back to life. | |
425 | * | |
426 | * Similar to sys_device_suspend(), but we iterate the list forwards | |
427 | * to guarantee that parent devices are resumed before their children. | |
428 | * | |
429 | * Note: Interrupts are disabled when called. | |
430 | */ | |
431 | ||
432 | int sysdev_resume(void) | |
433 | { | |
434 | struct sysdev_class * cls; | |
435 | ||
436 | pr_debug("Resuming System Devices\n"); | |
437 | ||
438 | list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) { | |
439 | struct sys_device * sysdev; | |
440 | ||
441 | pr_debug("Resuming type '%s':\n", | |
442 | kobject_name(&cls->kset.kobj)); | |
443 | ||
444 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
445 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
446 | ||
ceaeade1 | 447 | __sysdev_resume(sysdev); |
1da177e4 LT |
448 | } |
449 | } | |
450 | return 0; | |
451 | } | |
452 | ||
453 | ||
454 | int __init system_bus_init(void) | |
455 | { | |
456 | system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj; | |
457 | return subsystem_register(&system_subsys); | |
458 | } | |
459 | ||
460 | EXPORT_SYMBOL_GPL(sysdev_register); | |
461 | EXPORT_SYMBOL_GPL(sysdev_unregister); |