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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
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#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>
Pavel Machek438510f2005-04-16 15:25:24 -070022#include <linux/pm.h>
Adrian Bunkf67d1152006-01-19 17:30:17 +010023#include <linux/device.h>
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -070024#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Adrian Bunkf67d1152006-01-19 17:30:17 +010026#include "base.h"
27
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#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
32static ssize_t
33sysdev_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);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050040 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041}
42
43
44static ssize_t
45sysdev_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);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050053 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054}
55
56static struct sysfs_ops sysfs_ops = {
57 .show = sysdev_show,
58 .store = sysdev_store,
59};
60
61static struct kobj_type ktype_sysdev = {
62 .sysfs_ops = &sysfs_ops,
63};
64
65
66int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
67{
68 return sysfs_create_file(&s->kobj, &a->attr);
69}
70
71
72void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
73{
74 sysfs_remove_file(&s->kobj, &a->attr);
75}
76
77EXPORT_SYMBOL_GPL(sysdev_create_file);
78EXPORT_SYMBOL_GPL(sysdev_remove_file);
79
Shaohua Li670dd902006-05-08 13:45:57 +080080#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
81#define to_sysdev_class_attr(a) container_of(a, \
82 struct sysdev_class_attribute, attr)
83
84static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
85 char *buffer)
86{
87 struct sysdev_class * class = to_sysdev_class(kobj);
88 struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
89
90 if (class_attr->show)
91 return class_attr->show(class, buffer);
92 return -EIO;
93}
94
95static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
96 const char *buffer, size_t count)
97{
98 struct sysdev_class * class = to_sysdev_class(kobj);
99 struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr);
100
101 if (class_attr->store)
102 return class_attr->store(class, buffer, count);
103 return -EIO;
104}
105
106static struct sysfs_ops sysfs_class_ops = {
107 .show = sysdev_class_show,
108 .store = sysdev_class_store,
109};
110
111static struct kobj_type ktype_sysdev_class = {
112 .sysfs_ops = &sysfs_class_ops,
113};
114
115int sysdev_class_create_file(struct sysdev_class *c,
116 struct sysdev_class_attribute *a)
117{
118 return sysfs_create_file(&c->kset.kobj, &a->attr);
119}
120EXPORT_SYMBOL_GPL(sysdev_class_create_file);
121
122void sysdev_class_remove_file(struct sysdev_class *c,
123 struct sysdev_class_attribute *a)
124{
125 sysfs_remove_file(&c->kset.kobj, &a->attr);
126}
127EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
128
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600129static struct kset *system_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131int sysdev_class_register(struct sysdev_class * cls)
132{
133 pr_debug("Registering sysdev class '%s'\n",
134 kobject_name(&cls->kset.kobj));
135 INIT_LIST_HEAD(&cls->drivers);
Greg Kroah-Hartmanef79df22008-03-09 03:37:16 +0530136 memset(&cls->kset.kobj, 0x00, sizeof(struct kobject));
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600137 cls->kset.kobj.parent = &system_kset->kobj;
Greg Kroah-Hartman3514fac2007-10-16 10:11:44 -0600138 cls->kset.kobj.ktype = &ktype_sysdev_class;
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600139 cls->kset.kobj.kset = system_kset;
Kay Sieversaf5ca3f2007-12-20 02:09:39 +0100140 kobject_set_name(&cls->kset.kobj, cls->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 return kset_register(&cls->kset);
142}
143
144void sysdev_class_unregister(struct sysdev_class * cls)
145{
146 pr_debug("Unregistering sysdev class '%s'\n",
147 kobject_name(&cls->kset.kobj));
148 kset_unregister(&cls->kset);
149}
150
151EXPORT_SYMBOL_GPL(sysdev_class_register);
152EXPORT_SYMBOL_GPL(sysdev_class_unregister);
153
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700154static DEFINE_MUTEX(sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156/**
157 * sysdev_driver_register - Register auxillary driver
Akinobu Mita44b760a2007-08-19 16:51:14 +0900158 * @cls: Device class driver belongs to.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 * @drv: Driver.
160 *
Akinobu Mita44b760a2007-08-19 16:51:14 +0900161 * @drv is inserted into @cls->drivers to be
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 * called on each operation on devices of that class. The refcount
163 * of @cls is incremented.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 */
165
Akinobu Mita44b760a2007-08-19 16:51:14 +0900166int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167{
Akinobu Mita44b760a2007-08-19 16:51:14 +0900168 int err = 0;
169
Ben Dooksda009f32008-03-04 15:09:06 -0800170 if (!cls) {
171 printk(KERN_WARNING "sysdev: invalid class passed to "
172 "sysdev_driver_register!\n");
173 WARN_ON(1);
174 return -EINVAL;
175 }
176
177 /* Check whether this driver has already been added to a class. */
178 if ((drv->entry.next != drv->entry.prev) ||
179 (drv->entry.next != NULL)) {
180 printk(KERN_WARNING "sysdev: class %s: driver (%p) has already"
181 " been registered to a class, something is wrong, but "
182 "will forge on!\n", cls->name, drv);
183 WARN_ON(1);
184 }
185
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700186 mutex_lock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 if (cls && kset_get(&cls->kset)) {
188 list_add_tail(&drv->entry, &cls->drivers);
189
190 /* If devices of this class already exist, tell the driver */
191 if (drv->add) {
192 struct sys_device *dev;
193 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
194 drv->add(dev);
195 }
Akinobu Mita44b760a2007-08-19 16:51:14 +0900196 } else {
197 err = -EINVAL;
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800198 printk(KERN_ERR "%s: invalid device class\n", __func__);
Akinobu Mita44b760a2007-08-19 16:51:14 +0900199 WARN_ON(1);
200 }
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700201 mutex_unlock(&sysdev_drivers_lock);
Akinobu Mita44b760a2007-08-19 16:51:14 +0900202 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203}
204
205
206/**
207 * sysdev_driver_unregister - Remove an auxillary driver.
208 * @cls: Class driver belongs to.
209 * @drv: Driver.
210 */
211void sysdev_driver_unregister(struct sysdev_class * cls,
212 struct sysdev_driver * drv)
213{
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700214 mutex_lock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 list_del_init(&drv->entry);
216 if (cls) {
217 if (drv->remove) {
218 struct sys_device *dev;
219 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
220 drv->remove(dev);
221 }
222 kset_put(&cls->kset);
223 }
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700224 mutex_unlock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225}
226
227EXPORT_SYMBOL_GPL(sysdev_driver_register);
228EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
229
230
231
232/**
233 * sysdev_register - add a system device to the tree
234 * @sysdev: device in question
235 *
236 */
237int sysdev_register(struct sys_device * sysdev)
238{
239 int error;
240 struct sysdev_class * cls = sysdev->cls;
241
242 if (!cls)
243 return -EINVAL;
244
Greg Kroah-Hartman61030bf2007-12-17 15:54:39 -0400245 pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
246
Greg Kroah-Hartmanef79df22008-03-09 03:37:16 +0530247 /* initialize the kobject to 0, in case it had previously been used */
248 memset(&sysdev->kobj, 0x00, sizeof(struct kobject));
249
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 /* Make sure the kset is set */
251 sysdev->kobj.kset = &cls->kset;
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 /* Register the object */
Greg Kroah-Hartman61030bf2007-12-17 15:54:39 -0400254 error = kobject_init_and_add(&sysdev->kobj, &ktype_sysdev, NULL,
255 "%s%d", kobject_name(&cls->kset.kobj),
256 sysdev->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 if (!error) {
259 struct sysdev_driver * drv;
260
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700261 mutex_lock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 /* Generic notification is implicit, because it's that
263 * code that should have called us.
264 */
265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 /* Notify class auxillary drivers */
267 list_for_each_entry(drv, &cls->drivers, entry) {
268 if (drv->add)
269 drv->add(sysdev);
270 }
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700271 mutex_unlock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 }
Greg Kroah-Hartman61030bf2007-12-17 15:54:39 -0400273 kobject_uevent(&sysdev->kobj, KOBJ_ADD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 return error;
275}
276
277void sysdev_unregister(struct sys_device * sysdev)
278{
279 struct sysdev_driver * drv;
280
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700281 mutex_lock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
283 if (drv->remove)
284 drv->remove(sysdev);
285 }
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700286 mutex_unlock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800288 kobject_put(&sysdev->kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289}
290
291
292
293/**
294 * sysdev_shutdown - Shut down all system devices.
295 *
296 * Loop over each class of system devices, and the devices in each
297 * of those classes. For each device, we call the shutdown method for
Akinobu Mita44b760a2007-08-19 16:51:14 +0900298 * each driver registered for the device - the auxillaries,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 * and the class driver.
300 *
301 * Note: The list is iterated in reverse order, so that we shut down
302 * child devices before we shut down thier parents. The list ordering
303 * is guaranteed by virtue of the fact that child devices are registered
304 * after their parents.
305 */
306
307void sysdev_shutdown(void)
308{
309 struct sysdev_class * cls;
310
311 pr_debug("Shutting Down System Devices\n");
312
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700313 mutex_lock(&sysdev_drivers_lock);
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600314 list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 struct sys_device * sysdev;
316
317 pr_debug("Shutting down type '%s':\n",
318 kobject_name(&cls->kset.kobj));
319
320 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
321 struct sysdev_driver * drv;
322 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
323
Akinobu Mita44b760a2007-08-19 16:51:14 +0900324 /* Call auxillary drivers first */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 list_for_each_entry(drv, &cls->drivers, entry) {
326 if (drv->shutdown)
327 drv->shutdown(sysdev);
328 }
329
330 /* Now call the generic one */
331 if (cls->shutdown)
332 cls->shutdown(sysdev);
333 }
334 }
Matthias Kaehlcke9f3f7762007-05-23 14:19:42 -0700335 mutex_unlock(&sysdev_drivers_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336}
337
Shaohua Liceaeade2005-08-11 10:37:39 +0800338static void __sysdev_resume(struct sys_device *dev)
339{
340 struct sysdev_class *cls = dev->cls;
341 struct sysdev_driver *drv;
342
343 /* First, call the class-specific one */
344 if (cls->resume)
345 cls->resume(dev);
346
347 /* Call auxillary drivers next. */
348 list_for_each_entry(drv, &cls->drivers, entry) {
349 if (drv->resume)
350 drv->resume(dev);
351 }
Shaohua Liceaeade2005-08-11 10:37:39 +0800352}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
354/**
355 * sysdev_suspend - Suspend all system devices.
356 * @state: Power state to enter.
357 *
358 * We perform an almost identical operation as sys_device_shutdown()
359 * above, though calling ->suspend() instead. Interrupts are disabled
360 * when this called. Devices are responsible for both saving state and
361 * quiescing or powering down the device.
362 *
363 * This is only called by the device PM core, so we let them handle
364 * all synchronization.
365 */
366
Pavel Machek438510f2005-04-16 15:25:24 -0700367int sysdev_suspend(pm_message_t state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368{
369 struct sysdev_class * cls;
Shaohua Liceaeade2005-08-11 10:37:39 +0800370 struct sys_device *sysdev, *err_dev;
371 struct sysdev_driver *drv, *err_drv;
372 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
374 pr_debug("Suspending System Devices\n");
375
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600376 list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 pr_debug("Suspending type '%s':\n",
378 kobject_name(&cls->kset.kobj));
379
380 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
382
Akinobu Mita44b760a2007-08-19 16:51:14 +0900383 /* Call auxillary drivers first */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 list_for_each_entry(drv, &cls->drivers, entry) {
Shaohua Liceaeade2005-08-11 10:37:39 +0800385 if (drv->suspend) {
386 ret = drv->suspend(sysdev, state);
387 if (ret)
388 goto aux_driver;
389 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 }
391
392 /* Now call the generic one */
Shaohua Liceaeade2005-08-11 10:37:39 +0800393 if (cls->suspend) {
394 ret = cls->suspend(sysdev, state);
395 if (ret)
396 goto cls_driver;
397 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 }
399 }
400 return 0;
Shaohua Liceaeade2005-08-11 10:37:39 +0800401 /* resume current sysdev */
402cls_driver:
403 drv = NULL;
404 printk(KERN_ERR "Class suspend failed for %s\n",
405 kobject_name(&sysdev->kobj));
406
407aux_driver:
408 if (drv)
409 printk(KERN_ERR "Class driver suspend failed for %s\n",
410 kobject_name(&sysdev->kobj));
411 list_for_each_entry(err_drv, &cls->drivers, entry) {
412 if (err_drv == drv)
413 break;
414 if (err_drv->resume)
415 err_drv->resume(sysdev);
416 }
Shaohua Liceaeade2005-08-11 10:37:39 +0800417
Shaohua Liceaeade2005-08-11 10:37:39 +0800418 /* resume other sysdevs in current class */
419 list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
420 if (err_dev == sysdev)
421 break;
422 pr_debug(" %s\n", kobject_name(&err_dev->kobj));
423 __sysdev_resume(err_dev);
424 }
425
426 /* resume other classes */
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600427 list_for_each_entry_continue(cls, &system_kset->list, kset.kobj.entry) {
Shaohua Liceaeade2005-08-11 10:37:39 +0800428 list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
429 pr_debug(" %s\n", kobject_name(&err_dev->kobj));
430 __sysdev_resume(err_dev);
431 }
432 }
433 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434}
435
436
437/**
438 * sysdev_resume - Bring system devices back to life.
439 *
440 * Similar to sys_device_suspend(), but we iterate the list forwards
441 * to guarantee that parent devices are resumed before their children.
442 *
443 * Note: Interrupts are disabled when called.
444 */
445
446int sysdev_resume(void)
447{
448 struct sysdev_class * cls;
449
450 pr_debug("Resuming System Devices\n");
451
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600452 list_for_each_entry(cls, &system_kset->list, kset.kobj.entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 struct sys_device * sysdev;
454
455 pr_debug("Resuming type '%s':\n",
456 kobject_name(&cls->kset.kobj));
457
458 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
460
Shaohua Liceaeade2005-08-11 10:37:39 +0800461 __sysdev_resume(sysdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 }
463 }
464 return 0;
465}
466
467
468int __init system_bus_init(void)
469{
Greg Kroah-Hartmanaade4042007-11-01 09:29:06 -0600470 system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
471 if (!system_kset)
472 return -ENOMEM;
473 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474}
475
476EXPORT_SYMBOL_GPL(sysdev_register);
477EXPORT_SYMBOL_GPL(sysdev_unregister);