Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[linux-2.6] / drivers / base / sys.c
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>
23 #include <linux/pm.h>
24 #include <linux/device.h>
25 #include <asm/semaphore.h>
26
27 #include "base.h"
28
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);
43         return -EIO;
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);
56         return -EIO;
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
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 }
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
330 int sysdev_suspend(pm_message_t state)
331 {
332         struct sysdev_class * cls;
333         struct sys_device *sysdev, *err_dev;
334         struct sysdev_driver *drv, *err_drv;
335         int ret;
336
337         pr_debug("Suspending System Devices\n");
338
339         list_for_each_entry_reverse(cls, &system_subsys.kset.list,
340                                     kset.kobj.entry) {
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) {
346                         pr_debug(" %s\n", kobject_name(&sysdev->kobj));
347
348                         /* Call global drivers first. */
349                         list_for_each_entry(drv, &sysdev_drivers, entry) {
350                                 if (drv->suspend) {
351                                         ret = drv->suspend(sysdev, state);
352                                         if (ret)
353                                                 goto gbl_driver;
354                                 }
355                         }
356
357                         /* Call auxillary drivers next. */
358                         list_for_each_entry(drv, &cls->drivers, entry) {
359                                 if (drv->suspend) {
360                                         ret = drv->suspend(sysdev, state);
361                                         if (ret)
362                                                 goto aux_driver;
363                                 }
364                         }
365
366                         /* Now call the generic one */
367                         if (cls->suspend) {
368                                 ret = cls->suspend(sysdev, state);
369                                 if (ret)
370                                         goto cls_driver;
371                         }
372                 }
373         }
374         return 0;
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;
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) {
445                         pr_debug(" %s\n", kobject_name(&sysdev->kobj));
446
447                         __sysdev_resume(sysdev);
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);