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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 | ||
1da177e4 LT |
15 | #include <linux/sysdev.h> |
16 | #include <linux/err.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/string.h> | |
438510f6 | 22 | #include <linux/pm.h> |
f67d115f | 23 | #include <linux/device.h> |
9f3f776b | 24 | #include <linux/mutex.h> |
1da177e4 | 25 | |
f67d115f AB |
26 | #include "base.h" |
27 | ||
823bccfc | 28 | extern struct kset devices_subsys; |
1da177e4 LT |
29 | |
30 | #define to_sysdev(k) container_of(k, struct sys_device, kobj) | |
31 | #define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr) | |
32 | ||
33 | ||
34 | static ssize_t | |
35 | sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer) | |
36 | { | |
37 | struct sys_device * sysdev = to_sysdev(kobj); | |
38 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
39 | ||
40 | if (sysdev_attr->show) | |
41 | return sysdev_attr->show(sysdev, buffer); | |
4a0c20bf | 42 | return -EIO; |
1da177e4 LT |
43 | } |
44 | ||
45 | ||
46 | static ssize_t | |
47 | sysdev_store(struct kobject * kobj, struct attribute * attr, | |
48 | const char * buffer, size_t count) | |
49 | { | |
50 | struct sys_device * sysdev = to_sysdev(kobj); | |
51 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); | |
52 | ||
53 | if (sysdev_attr->store) | |
54 | return sysdev_attr->store(sysdev, buffer, count); | |
4a0c20bf | 55 | return -EIO; |
1da177e4 LT |
56 | } |
57 | ||
58 | static struct sysfs_ops sysfs_ops = { | |
59 | .show = sysdev_show, | |
60 | .store = sysdev_store, | |
61 | }; | |
62 | ||
63 | static struct kobj_type ktype_sysdev = { | |
64 | .sysfs_ops = &sysfs_ops, | |
65 | }; | |
66 | ||
67 | ||
68 | int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a) | |
69 | { | |
70 | return sysfs_create_file(&s->kobj, &a->attr); | |
71 | } | |
72 | ||
73 | ||
74 | void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a) | |
75 | { | |
76 | sysfs_remove_file(&s->kobj, &a->attr); | |
77 | } | |
78 | ||
79 | EXPORT_SYMBOL_GPL(sysdev_create_file); | |
80 | EXPORT_SYMBOL_GPL(sysdev_remove_file); | |
81 | ||
670dd90d SL |
82 | #define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj) |
83 | #define to_sysdev_class_attr(a) container_of(a, \ | |
84 | struct sysdev_class_attribute, attr) | |
85 | ||
86 | static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr, | |
87 | char *buffer) | |
88 | { | |
89 | struct sysdev_class * class = to_sysdev_class(kobj); | |
90 | struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr); | |
91 | ||
92 | if (class_attr->show) | |
93 | return class_attr->show(class, buffer); | |
94 | return -EIO; | |
95 | } | |
96 | ||
97 | static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr, | |
98 | const char *buffer, size_t count) | |
99 | { | |
100 | struct sysdev_class * class = to_sysdev_class(kobj); | |
101 | struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr); | |
102 | ||
103 | if (class_attr->store) | |
104 | return class_attr->store(class, buffer, count); | |
105 | return -EIO; | |
106 | } | |
107 | ||
108 | static struct sysfs_ops sysfs_class_ops = { | |
109 | .show = sysdev_class_show, | |
110 | .store = sysdev_class_store, | |
111 | }; | |
112 | ||
113 | static struct kobj_type ktype_sysdev_class = { | |
114 | .sysfs_ops = &sysfs_class_ops, | |
115 | }; | |
116 | ||
117 | int sysdev_class_create_file(struct sysdev_class *c, | |
118 | struct sysdev_class_attribute *a) | |
119 | { | |
120 | return sysfs_create_file(&c->kset.kobj, &a->attr); | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(sysdev_class_create_file); | |
123 | ||
124 | void sysdev_class_remove_file(struct sysdev_class *c, | |
125 | struct sysdev_class_attribute *a) | |
126 | { | |
127 | sysfs_remove_file(&c->kset.kobj, &a->attr); | |
128 | } | |
129 | EXPORT_SYMBOL_GPL(sysdev_class_remove_file); | |
130 | ||
1da177e4 LT |
131 | /* |
132 | * declare system_subsys | |
133 | */ | |
3514faca | 134 | static decl_subsys(system, NULL); |
1da177e4 LT |
135 | |
136 | int sysdev_class_register(struct sysdev_class * cls) | |
137 | { | |
138 | pr_debug("Registering sysdev class '%s'\n", | |
139 | kobject_name(&cls->kset.kobj)); | |
140 | INIT_LIST_HEAD(&cls->drivers); | |
823bccfc | 141 | cls->kset.kobj.parent = &system_subsys.kobj; |
3514faca | 142 | cls->kset.kobj.ktype = &ktype_sysdev_class; |
27f20e5e | 143 | cls->kset.kobj.kset = &system_subsys; |
1da177e4 LT |
144 | return kset_register(&cls->kset); |
145 | } | |
146 | ||
147 | void sysdev_class_unregister(struct sysdev_class * cls) | |
148 | { | |
149 | pr_debug("Unregistering sysdev class '%s'\n", | |
150 | kobject_name(&cls->kset.kobj)); | |
151 | kset_unregister(&cls->kset); | |
152 | } | |
153 | ||
154 | EXPORT_SYMBOL_GPL(sysdev_class_register); | |
155 | EXPORT_SYMBOL_GPL(sysdev_class_unregister); | |
156 | ||
9f3f776b | 157 | static DEFINE_MUTEX(sysdev_drivers_lock); |
1da177e4 LT |
158 | |
159 | /** | |
160 | * sysdev_driver_register - Register auxillary driver | |
44b760a8 | 161 | * @cls: Device class driver belongs to. |
1da177e4 LT |
162 | * @drv: Driver. |
163 | * | |
44b760a8 | 164 | * @drv is inserted into @cls->drivers to be |
1da177e4 LT |
165 | * called on each operation on devices of that class. The refcount |
166 | * of @cls is incremented. | |
1da177e4 LT |
167 | */ |
168 | ||
44b760a8 | 169 | int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv) |
1da177e4 | 170 | { |
44b760a8 AM |
171 | int err = 0; |
172 | ||
9f3f776b | 173 | mutex_lock(&sysdev_drivers_lock); |
1da177e4 LT |
174 | if (cls && kset_get(&cls->kset)) { |
175 | list_add_tail(&drv->entry, &cls->drivers); | |
176 | ||
177 | /* If devices of this class already exist, tell the driver */ | |
178 | if (drv->add) { | |
179 | struct sys_device *dev; | |
180 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
181 | drv->add(dev); | |
182 | } | |
44b760a8 AM |
183 | } else { |
184 | err = -EINVAL; | |
185 | printk(KERN_ERR "%s: invalid device class\n", __FUNCTION__); | |
186 | WARN_ON(1); | |
187 | } | |
9f3f776b | 188 | mutex_unlock(&sysdev_drivers_lock); |
44b760a8 | 189 | return err; |
1da177e4 LT |
190 | } |
191 | ||
192 | ||
193 | /** | |
194 | * sysdev_driver_unregister - Remove an auxillary driver. | |
195 | * @cls: Class driver belongs to. | |
196 | * @drv: Driver. | |
197 | */ | |
198 | void sysdev_driver_unregister(struct sysdev_class * cls, | |
199 | struct sysdev_driver * drv) | |
200 | { | |
9f3f776b | 201 | mutex_lock(&sysdev_drivers_lock); |
1da177e4 LT |
202 | list_del_init(&drv->entry); |
203 | if (cls) { | |
204 | if (drv->remove) { | |
205 | struct sys_device *dev; | |
206 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) | |
207 | drv->remove(dev); | |
208 | } | |
209 | kset_put(&cls->kset); | |
210 | } | |
9f3f776b | 211 | mutex_unlock(&sysdev_drivers_lock); |
1da177e4 LT |
212 | } |
213 | ||
214 | EXPORT_SYMBOL_GPL(sysdev_driver_register); | |
215 | EXPORT_SYMBOL_GPL(sysdev_driver_unregister); | |
216 | ||
217 | ||
218 | ||
219 | /** | |
220 | * sysdev_register - add a system device to the tree | |
221 | * @sysdev: device in question | |
222 | * | |
223 | */ | |
224 | int sysdev_register(struct sys_device * sysdev) | |
225 | { | |
226 | int error; | |
227 | struct sysdev_class * cls = sysdev->cls; | |
228 | ||
229 | if (!cls) | |
230 | return -EINVAL; | |
231 | ||
232 | /* Make sure the kset is set */ | |
233 | sysdev->kobj.kset = &cls->kset; | |
234 | ||
235 | /* But make sure we point to the right type for sysfs translation */ | |
236 | sysdev->kobj.ktype = &ktype_sysdev; | |
237 | error = kobject_set_name(&sysdev->kobj, "%s%d", | |
238 | kobject_name(&cls->kset.kobj), sysdev->id); | |
239 | if (error) | |
240 | return error; | |
241 | ||
242 | pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj)); | |
243 | ||
244 | /* Register the object */ | |
245 | error = kobject_register(&sysdev->kobj); | |
246 | ||
247 | if (!error) { | |
248 | struct sysdev_driver * drv; | |
249 | ||
9f3f776b | 250 | mutex_lock(&sysdev_drivers_lock); |
1da177e4 LT |
251 | /* Generic notification is implicit, because it's that |
252 | * code that should have called us. | |
253 | */ | |
254 | ||
1da177e4 LT |
255 | /* Notify class auxillary drivers */ |
256 | list_for_each_entry(drv, &cls->drivers, entry) { | |
257 | if (drv->add) | |
258 | drv->add(sysdev); | |
259 | } | |
9f3f776b | 260 | mutex_unlock(&sysdev_drivers_lock); |
1da177e4 LT |
261 | } |
262 | return error; | |
263 | } | |
264 | ||
265 | void sysdev_unregister(struct sys_device * sysdev) | |
266 | { | |
267 | struct sysdev_driver * drv; | |
268 | ||
9f3f776b | 269 | mutex_lock(&sysdev_drivers_lock); |
1da177e4 LT |
270 | list_for_each_entry(drv, &sysdev->cls->drivers, entry) { |
271 | if (drv->remove) | |
272 | drv->remove(sysdev); | |
273 | } | |
9f3f776b | 274 | mutex_unlock(&sysdev_drivers_lock); |
1da177e4 LT |
275 | |
276 | kobject_unregister(&sysdev->kobj); | |
277 | } | |
278 | ||
279 | ||
280 | ||
281 | /** | |
282 | * sysdev_shutdown - Shut down all system devices. | |
283 | * | |
284 | * Loop over each class of system devices, and the devices in each | |
285 | * of those classes. For each device, we call the shutdown method for | |
44b760a8 | 286 | * each driver registered for the device - the auxillaries, |
1da177e4 LT |
287 | * and the class driver. |
288 | * | |
289 | * Note: The list is iterated in reverse order, so that we shut down | |
290 | * child devices before we shut down thier parents. The list ordering | |
291 | * is guaranteed by virtue of the fact that child devices are registered | |
292 | * after their parents. | |
293 | */ | |
294 | ||
295 | void sysdev_shutdown(void) | |
296 | { | |
297 | struct sysdev_class * cls; | |
298 | ||
299 | pr_debug("Shutting Down System Devices\n"); | |
300 | ||
9f3f776b | 301 | mutex_lock(&sysdev_drivers_lock); |
823bccfc | 302 | list_for_each_entry_reverse(cls, &system_subsys.list, |
1da177e4 LT |
303 | kset.kobj.entry) { |
304 | struct sys_device * sysdev; | |
305 | ||
306 | pr_debug("Shutting down type '%s':\n", | |
307 | kobject_name(&cls->kset.kobj)); | |
308 | ||
309 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
310 | struct sysdev_driver * drv; | |
311 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); | |
312 | ||
44b760a8 | 313 | /* Call auxillary drivers first */ |
1da177e4 LT |
314 | list_for_each_entry(drv, &cls->drivers, entry) { |
315 | if (drv->shutdown) | |
316 | drv->shutdown(sysdev); | |
317 | } | |
318 | ||
319 | /* Now call the generic one */ | |
320 | if (cls->shutdown) | |
321 | cls->shutdown(sysdev); | |
322 | } | |
323 | } | |
9f3f776b | 324 | mutex_unlock(&sysdev_drivers_lock); |
1da177e4 LT |
325 | } |
326 | ||
ceaeade1 SL |
327 | static void __sysdev_resume(struct sys_device *dev) |
328 | { | |
329 | struct sysdev_class *cls = dev->cls; | |
330 | struct sysdev_driver *drv; | |
331 | ||
332 | /* First, call the class-specific one */ | |
333 | if (cls->resume) | |
334 | cls->resume(dev); | |
335 | ||
336 | /* Call auxillary drivers next. */ | |
337 | list_for_each_entry(drv, &cls->drivers, entry) { | |
338 | if (drv->resume) | |
339 | drv->resume(dev); | |
340 | } | |
ceaeade1 | 341 | } |
1da177e4 LT |
342 | |
343 | /** | |
344 | * sysdev_suspend - Suspend all system devices. | |
345 | * @state: Power state to enter. | |
346 | * | |
347 | * We perform an almost identical operation as sys_device_shutdown() | |
348 | * above, though calling ->suspend() instead. Interrupts are disabled | |
349 | * when this called. Devices are responsible for both saving state and | |
350 | * quiescing or powering down the device. | |
351 | * | |
352 | * This is only called by the device PM core, so we let them handle | |
353 | * all synchronization. | |
354 | */ | |
355 | ||
438510f6 | 356 | int sysdev_suspend(pm_message_t state) |
1da177e4 LT |
357 | { |
358 | struct sysdev_class * cls; | |
ceaeade1 SL |
359 | struct sys_device *sysdev, *err_dev; |
360 | struct sysdev_driver *drv, *err_drv; | |
361 | int ret; | |
1da177e4 LT |
362 | |
363 | pr_debug("Suspending System Devices\n"); | |
364 | ||
823bccfc | 365 | list_for_each_entry_reverse(cls, &system_subsys.list, |
1da177e4 | 366 | kset.kobj.entry) { |
1da177e4 LT |
367 | |
368 | pr_debug("Suspending type '%s':\n", | |
369 | kobject_name(&cls->kset.kobj)); | |
370 | ||
371 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
372 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
373 | ||
44b760a8 | 374 | /* Call auxillary drivers first */ |
1da177e4 | 375 | list_for_each_entry(drv, &cls->drivers, entry) { |
ceaeade1 SL |
376 | if (drv->suspend) { |
377 | ret = drv->suspend(sysdev, state); | |
378 | if (ret) | |
379 | goto aux_driver; | |
380 | } | |
1da177e4 LT |
381 | } |
382 | ||
383 | /* Now call the generic one */ | |
ceaeade1 SL |
384 | if (cls->suspend) { |
385 | ret = cls->suspend(sysdev, state); | |
386 | if (ret) | |
387 | goto cls_driver; | |
388 | } | |
1da177e4 LT |
389 | } |
390 | } | |
391 | return 0; | |
ceaeade1 SL |
392 | /* resume current sysdev */ |
393 | cls_driver: | |
394 | drv = NULL; | |
395 | printk(KERN_ERR "Class suspend failed for %s\n", | |
396 | kobject_name(&sysdev->kobj)); | |
397 | ||
398 | aux_driver: | |
399 | if (drv) | |
400 | printk(KERN_ERR "Class driver suspend failed for %s\n", | |
401 | kobject_name(&sysdev->kobj)); | |
402 | list_for_each_entry(err_drv, &cls->drivers, entry) { | |
403 | if (err_drv == drv) | |
404 | break; | |
405 | if (err_drv->resume) | |
406 | err_drv->resume(sysdev); | |
407 | } | |
ceaeade1 | 408 | |
ceaeade1 SL |
409 | /* resume other sysdevs in current class */ |
410 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
411 | if (err_dev == sysdev) | |
412 | break; | |
413 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
414 | __sysdev_resume(err_dev); | |
415 | } | |
416 | ||
417 | /* resume other classes */ | |
823bccfc | 418 | list_for_each_entry_continue(cls, &system_subsys.list, |
ceaeade1 SL |
419 | kset.kobj.entry) { |
420 | list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { | |
421 | pr_debug(" %s\n", kobject_name(&err_dev->kobj)); | |
422 | __sysdev_resume(err_dev); | |
423 | } | |
424 | } | |
425 | return ret; | |
1da177e4 LT |
426 | } |
427 | ||
428 | ||
429 | /** | |
430 | * sysdev_resume - Bring system devices back to life. | |
431 | * | |
432 | * Similar to sys_device_suspend(), but we iterate the list forwards | |
433 | * to guarantee that parent devices are resumed before their children. | |
434 | * | |
435 | * Note: Interrupts are disabled when called. | |
436 | */ | |
437 | ||
438 | int sysdev_resume(void) | |
439 | { | |
440 | struct sysdev_class * cls; | |
441 | ||
442 | pr_debug("Resuming System Devices\n"); | |
443 | ||
823bccfc | 444 | list_for_each_entry(cls, &system_subsys.list, kset.kobj.entry) { |
1da177e4 LT |
445 | struct sys_device * sysdev; |
446 | ||
447 | pr_debug("Resuming type '%s':\n", | |
448 | kobject_name(&cls->kset.kobj)); | |
449 | ||
450 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { | |
1da177e4 LT |
451 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
452 | ||
ceaeade1 | 453 | __sysdev_resume(sysdev); |
1da177e4 LT |
454 | } |
455 | } | |
456 | return 0; | |
457 | } | |
458 | ||
459 | ||
460 | int __init system_bus_init(void) | |
461 | { | |
823bccfc | 462 | system_subsys.kobj.parent = &devices_subsys.kobj; |
1da177e4 LT |
463 | return subsystem_register(&system_subsys); |
464 | } | |
465 | ||
466 | EXPORT_SYMBOL_GPL(sysdev_register); | |
467 | EXPORT_SYMBOL_GPL(sysdev_unregister); |