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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>
Adrian Bunkf67d1152006-01-19 17:30:17 +010024#include <linux/device.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080025#include <asm/semaphore.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Adrian Bunkf67d1152006-01-19 17:30:17 +010027#include "base.h"
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029extern 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
35static ssize_t
36sysdev_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);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050043 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044}
45
46
47static ssize_t
48sysdev_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);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050056 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
59static struct sysfs_ops sysfs_ops = {
60 .show = sysdev_show,
61 .store = sysdev_store,
62};
63
64static struct kobj_type ktype_sysdev = {
65 .sysfs_ops = &sysfs_ops,
66};
67
68
69int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
70{
71 return sysfs_create_file(&s->kobj, &a->attr);
72}
73
74
75void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
76{
77 sysfs_remove_file(&s->kobj, &a->attr);
78}
79
80EXPORT_SYMBOL_GPL(sysdev_create_file);
81EXPORT_SYMBOL_GPL(sysdev_remove_file);
82
83/*
84 * declare system_subsys
85 */
86static decl_subsys(system, &ktype_sysdev, NULL);
87
88int 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
98void 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
105EXPORT_SYMBOL_GPL(sysdev_class_register);
106EXPORT_SYMBOL_GPL(sysdev_class_unregister);
107
108
109static LIST_HEAD(sysdev_drivers);
110static 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
124int 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 */
149void 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
165EXPORT_SYMBOL_GPL(sysdev_driver_register);
166EXPORT_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 */
175int 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
222void 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
257void 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
Shaohua Liceaeade2005-08-11 10:37:39 +0800295static 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}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
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
Pavel Machek438510f2005-04-16 15:25:24 -0700330int sysdev_suspend(pm_message_t state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331{
332 struct sysdev_class * cls;
Shaohua Liceaeade2005-08-11 10:37:39 +0800333 struct sys_device *sysdev, *err_dev;
334 struct sysdev_driver *drv, *err_drv;
335 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
337 pr_debug("Suspending System Devices\n");
338
339 list_for_each_entry_reverse(cls, &system_subsys.kset.list,
340 kset.kobj.entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
347
348 /* Call global drivers first. */
349 list_for_each_entry(drv, &sysdev_drivers, entry) {
Shaohua Liceaeade2005-08-11 10:37:39 +0800350 if (drv->suspend) {
351 ret = drv->suspend(sysdev, state);
352 if (ret)
353 goto gbl_driver;
354 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 }
356
357 /* Call auxillary drivers next. */
358 list_for_each_entry(drv, &cls->drivers, entry) {
Shaohua Liceaeade2005-08-11 10:37:39 +0800359 if (drv->suspend) {
360 ret = drv->suspend(sysdev, state);
361 if (ret)
362 goto aux_driver;
363 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 }
365
366 /* Now call the generic one */
Shaohua Liceaeade2005-08-11 10:37:39 +0800367 if (cls->suspend) {
368 ret = cls->suspend(sysdev, state);
369 if (ret)
370 goto cls_driver;
371 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 }
373 }
374 return 0;
Shaohua Liceaeade2005-08-11 10:37:39 +0800375 /* resume current sysdev */
376cls_driver:
377 drv = NULL;
378 printk(KERN_ERR "Class suspend failed for %s\n",
379 kobject_name(&sysdev->kobj));
380
381aux_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
393gbl_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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420}
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
432int 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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
446
Shaohua Liceaeade2005-08-11 10:37:39 +0800447 __sysdev_resume(sysdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 }
449 }
450 return 0;
451}
452
453
454int __init system_bus_init(void)
455{
456 system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
457 return subsystem_register(&system_subsys);
458}
459
460EXPORT_SYMBOL_GPL(sysdev_register);
461EXPORT_SYMBOL_GPL(sysdev_unregister);