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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Pavel Machek438510f2005-04-16 15:25:24 -070023#include <linux/pm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Linus Torvalds1da177e2005-04-16 15:20:36 -070025extern 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
31static ssize_t
32sysdev_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);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050039 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040}
41
42
43static ssize_t
44sysdev_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);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050052 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053}
54
55static struct sysfs_ops sysfs_ops = {
56 .show = sysdev_show,
57 .store = sysdev_store,
58};
59
60static struct kobj_type ktype_sysdev = {
61 .sysfs_ops = &sysfs_ops,
62};
63
64
65int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
66{
67 return sysfs_create_file(&s->kobj, &a->attr);
68}
69
70
71void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
72{
73 sysfs_remove_file(&s->kobj, &a->attr);
74}
75
76EXPORT_SYMBOL_GPL(sysdev_create_file);
77EXPORT_SYMBOL_GPL(sysdev_remove_file);
78
79/*
80 * declare system_subsys
81 */
82static decl_subsys(system, &ktype_sysdev, NULL);
83
84int 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
94void 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
101EXPORT_SYMBOL_GPL(sysdev_class_register);
102EXPORT_SYMBOL_GPL(sysdev_class_unregister);
103
104
105static LIST_HEAD(sysdev_drivers);
106static 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
120int 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 */
145void 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
161EXPORT_SYMBOL_GPL(sysdev_driver_register);
162EXPORT_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 */
171int 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
218void 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
253void 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
Shaohua Liceaeade2005-08-11 10:37:39 +0800291static 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}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
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
Pavel Machek438510f2005-04-16 15:25:24 -0700326int sysdev_suspend(pm_message_t state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327{
328 struct sysdev_class * cls;
Shaohua Liceaeade2005-08-11 10:37:39 +0800329 struct sys_device *sysdev, *err_dev;
330 struct sysdev_driver *drv, *err_drv;
331 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332
333 pr_debug("Suspending System Devices\n");
334
335 list_for_each_entry_reverse(cls, &system_subsys.kset.list,
336 kset.kobj.entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
343
344 /* Call global drivers first. */
345 list_for_each_entry(drv, &sysdev_drivers, entry) {
Shaohua Liceaeade2005-08-11 10:37:39 +0800346 if (drv->suspend) {
347 ret = drv->suspend(sysdev, state);
348 if (ret)
349 goto gbl_driver;
350 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 }
352
353 /* Call auxillary drivers next. */
354 list_for_each_entry(drv, &cls->drivers, entry) {
Shaohua Liceaeade2005-08-11 10:37:39 +0800355 if (drv->suspend) {
356 ret = drv->suspend(sysdev, state);
357 if (ret)
358 goto aux_driver;
359 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 }
361
362 /* Now call the generic one */
Shaohua Liceaeade2005-08-11 10:37:39 +0800363 if (cls->suspend) {
364 ret = cls->suspend(sysdev, state);
365 if (ret)
366 goto cls_driver;
367 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 }
369 }
370 return 0;
Shaohua Liceaeade2005-08-11 10:37:39 +0800371 /* resume current sysdev */
372cls_driver:
373 drv = NULL;
374 printk(KERN_ERR "Class suspend failed for %s\n",
375 kobject_name(&sysdev->kobj));
376
377aux_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
389gbl_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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416}
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
428int 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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
442
Shaohua Liceaeade2005-08-11 10:37:39 +0800443 __sysdev_resume(sysdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 }
445 }
446 return 0;
447}
448
449
450int __init system_bus_init(void)
451{
452 system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
453 return subsystem_register(&system_subsys);
454}
455
456EXPORT_SYMBOL_GPL(sysdev_register);
457EXPORT_SYMBOL_GPL(sysdev_unregister);