[PATCH] CLASS: move a "simple" class logic into the class core.
[linux-2.6.git] / drivers / base / class.c
1 /*
2  * class.c - basic device class management
3  *
4  * Copyright (c) 2002-3 Patrick Mochel
5  * Copyright (c) 2002-3 Open Source Development Labs
6  * Copyright (c) 2003-2004 Greg Kroah-Hartman
7  * Copyright (c) 2003-2004 IBM Corp.
8  *
9  * This file is released under the GPLv2
10  *
11  */
12
13 #include <linux/config.h>
14 #include <linux/device.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/string.h>
18 #include <linux/kdev_t.h>
19 #include <linux/err.h>
20 #include "base.h"
21
22 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
23 #define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
24
25 static ssize_t
26 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
27 {
28         struct class_attribute * class_attr = to_class_attr(attr);
29         struct class * dc = to_class(kobj);
30         ssize_t ret = -EIO;
31
32         if (class_attr->show)
33                 ret = class_attr->show(dc, buf);
34         return ret;
35 }
36
37 static ssize_t
38 class_attr_store(struct kobject * kobj, struct attribute * attr,
39                  const char * buf, size_t count)
40 {
41         struct class_attribute * class_attr = to_class_attr(attr);
42         struct class * dc = to_class(kobj);
43         ssize_t ret = -EIO;
44
45         if (class_attr->store)
46                 ret = class_attr->store(dc, buf, count);
47         return ret;
48 }
49
50 static void class_release(struct kobject * kobj)
51 {
52         struct class *class = to_class(kobj);
53
54         pr_debug("class '%s': release.\n", class->name);
55
56         if (class->class_release)
57                 class->class_release(class);
58         else
59                 pr_debug("class '%s' does not have a release() function, "
60                          "be careful\n", class->name);
61 }
62
63 static struct sysfs_ops class_sysfs_ops = {
64         .show   = class_attr_show,
65         .store  = class_attr_store,
66 };
67
68 static struct kobj_type ktype_class = {
69         .sysfs_ops      = &class_sysfs_ops,
70         .release        = class_release,
71 };
72
73 /* Hotplug events for classes go to the class_obj subsys */
74 static decl_subsys(class, &ktype_class, NULL);
75
76
77 int class_create_file(struct class * cls, const struct class_attribute * attr)
78 {
79         int error;
80         if (cls) {
81                 error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
82         } else
83                 error = -EINVAL;
84         return error;
85 }
86
87 void class_remove_file(struct class * cls, const struct class_attribute * attr)
88 {
89         if (cls)
90                 sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
91 }
92
93 struct class * class_get(struct class * cls)
94 {
95         if (cls)
96                 return container_of(subsys_get(&cls->subsys), struct class, subsys);
97         return NULL;
98 }
99
100 void class_put(struct class * cls)
101 {
102         subsys_put(&cls->subsys);
103 }
104
105
106 static int add_class_attrs(struct class * cls)
107 {
108         int i;
109         int error = 0;
110
111         if (cls->class_attrs) {
112                 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
113                         error = class_create_file(cls,&cls->class_attrs[i]);
114                         if (error)
115                                 goto Err;
116                 }
117         }
118  Done:
119         return error;
120  Err:
121         while (--i >= 0)
122                 class_remove_file(cls,&cls->class_attrs[i]);
123         goto Done;
124 }
125
126 static void remove_class_attrs(struct class * cls)
127 {
128         int i;
129
130         if (cls->class_attrs) {
131                 for (i = 0; attr_name(cls->class_attrs[i]); i++)
132                         class_remove_file(cls,&cls->class_attrs[i]);
133         }
134 }
135
136 int class_register(struct class * cls)
137 {
138         int error;
139
140         pr_debug("device class '%s': registering\n", cls->name);
141
142         INIT_LIST_HEAD(&cls->children);
143         INIT_LIST_HEAD(&cls->interfaces);
144         init_MUTEX(&cls->sem);
145         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
146         if (error)
147                 return error;
148
149         subsys_set_kset(cls, class_subsys);
150
151         error = subsystem_register(&cls->subsys);
152         if (!error) {
153                 error = add_class_attrs(class_get(cls));
154                 class_put(cls);
155         }
156         return error;
157 }
158
159 void class_unregister(struct class * cls)
160 {
161         pr_debug("device class '%s': unregistering\n", cls->name);
162         remove_class_attrs(cls);
163         subsystem_unregister(&cls->subsys);
164 }
165
166 static void class_create_release(struct class *cls)
167 {
168         kfree(cls);
169 }
170
171 static void class_device_create_release(struct class_device *class_dev)
172 {
173         kfree(class_dev);
174 }
175
176 struct class *class_create(struct module *owner, char *name)
177 {
178         struct class *cls;
179         int retval;
180
181         cls = kmalloc(sizeof(struct class), GFP_KERNEL);
182         if (!cls) {
183                 retval = -ENOMEM;
184                 goto error;
185         }
186         memset(cls, 0x00, sizeof(struct class));
187
188         cls->name = name;
189         cls->owner = owner;
190         cls->class_release = class_create_release;
191         cls->release = class_device_create_release;
192
193         retval = class_register(cls);
194         if (retval)
195                 goto error;
196
197         return cls;
198
199 error:
200         kfree(cls);
201         return ERR_PTR(retval);
202 }
203
204 void class_destroy(struct class *cls)
205 {
206         if ((cls == NULL) || (IS_ERR(cls)))
207                 return;
208
209         class_unregister(cls);
210 }
211
212 /* Class Device Stuff */
213
214 int class_device_create_file(struct class_device * class_dev,
215                              const struct class_device_attribute * attr)
216 {
217         int error = -EINVAL;
218         if (class_dev)
219                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
220         return error;
221 }
222
223 void class_device_remove_file(struct class_device * class_dev,
224                               const struct class_device_attribute * attr)
225 {
226         if (class_dev)
227                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
228 }
229
230 int class_device_create_bin_file(struct class_device *class_dev,
231                                  struct bin_attribute *attr)
232 {
233         int error = -EINVAL;
234         if (class_dev)
235                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
236         return error;
237 }
238
239 void class_device_remove_bin_file(struct class_device *class_dev,
240                                   struct bin_attribute *attr)
241 {
242         if (class_dev)
243                 sysfs_remove_bin_file(&class_dev->kobj, attr);
244 }
245
246 static ssize_t
247 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
248                        char * buf)
249 {
250         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
251         struct class_device * cd = to_class_dev(kobj);
252         ssize_t ret = 0;
253
254         if (class_dev_attr->show)
255                 ret = class_dev_attr->show(cd, buf);
256         return ret;
257 }
258
259 static ssize_t
260 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
261                         const char * buf, size_t count)
262 {
263         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
264         struct class_device * cd = to_class_dev(kobj);
265         ssize_t ret = 0;
266
267         if (class_dev_attr->store)
268                 ret = class_dev_attr->store(cd, buf, count);
269         return ret;
270 }
271
272 static struct sysfs_ops class_dev_sysfs_ops = {
273         .show   = class_device_attr_show,
274         .store  = class_device_attr_store,
275 };
276
277 static void class_dev_release(struct kobject * kobj)
278 {
279         struct class_device *cd = to_class_dev(kobj);
280         struct class * cls = cd->class;
281
282         pr_debug("device class '%s': release.\n", cd->class_id);
283
284         if (cls->release)
285                 cls->release(cd);
286         else {
287                 printk(KERN_ERR "Device class '%s' does not have a release() function, "
288                         "it is broken and must be fixed.\n",
289                         cd->class_id);
290                 WARN_ON(1);
291         }
292 }
293
294 static struct kobj_type ktype_class_device = {
295         .sysfs_ops      = &class_dev_sysfs_ops,
296         .release        = class_dev_release,
297 };
298
299 static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
300 {
301         struct kobj_type *ktype = get_ktype(kobj);
302
303         if (ktype == &ktype_class_device) {
304                 struct class_device *class_dev = to_class_dev(kobj);
305                 if (class_dev->class)
306                         return 1;
307         }
308         return 0;
309 }
310
311 static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
312 {
313         struct class_device *class_dev = to_class_dev(kobj);
314
315         return class_dev->class->name;
316 }
317
318 static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
319                          int num_envp, char *buffer, int buffer_size)
320 {
321         struct class_device *class_dev = to_class_dev(kobj);
322         int i = 0;
323         int length = 0;
324         int retval = 0;
325
326         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
327
328         if (class_dev->dev) {
329                 /* add physical device, backing this device  */
330                 struct device *dev = class_dev->dev;
331                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
332
333                 add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
334                                     &length, "PHYSDEVPATH=%s", path);
335                 kfree(path);
336
337                 if (dev->bus)
338                         add_hotplug_env_var(envp, num_envp, &i,
339                                             buffer, buffer_size, &length,
340                                             "PHYSDEVBUS=%s", dev->bus->name);
341
342                 if (dev->driver)
343                         add_hotplug_env_var(envp, num_envp, &i,
344                                             buffer, buffer_size, &length,
345                                             "PHYSDEVDRIVER=%s", dev->driver->name);
346         }
347
348         if (MAJOR(class_dev->devt)) {
349                 add_hotplug_env_var(envp, num_envp, &i,
350                                     buffer, buffer_size, &length,
351                                     "MAJOR=%u", MAJOR(class_dev->devt));
352
353                 add_hotplug_env_var(envp, num_envp, &i,
354                                     buffer, buffer_size, &length,
355                                     "MINOR=%u", MINOR(class_dev->devt));
356         }
357
358         /* terminate, set to next free slot, shrink available space */
359         envp[i] = NULL;
360         envp = &envp[i];
361         num_envp -= i;
362         buffer = &buffer[length];
363         buffer_size -= length;
364
365         if (class_dev->class->hotplug) {
366                 /* have the bus specific function add its stuff */
367                 retval = class_dev->class->hotplug (class_dev, envp, num_envp,
368                                                     buffer, buffer_size);
369                         if (retval) {
370                         pr_debug ("%s - hotplug() returned %d\n",
371                                   __FUNCTION__, retval);
372                 }
373         }
374
375         return retval;
376 }
377
378 static struct kset_hotplug_ops class_hotplug_ops = {
379         .filter =       class_hotplug_filter,
380         .name =         class_hotplug_name,
381         .hotplug =      class_hotplug,
382 };
383
384 static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
385
386
387 static int class_device_add_attrs(struct class_device * cd)
388 {
389         int i;
390         int error = 0;
391         struct class * cls = cd->class;
392
393         if (cls->class_dev_attrs) {
394                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
395                         error = class_device_create_file(cd,
396                                                          &cls->class_dev_attrs[i]);
397                         if (error)
398                                 goto Err;
399                 }
400         }
401  Done:
402         return error;
403  Err:
404         while (--i >= 0)
405                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
406         goto Done;
407 }
408
409 static void class_device_remove_attrs(struct class_device * cd)
410 {
411         int i;
412         struct class * cls = cd->class;
413
414         if (cls->class_dev_attrs) {
415                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
416                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
417         }
418 }
419
420 static ssize_t show_dev(struct class_device *class_dev, char *buf)
421 {
422         return print_dev_t(buf, class_dev->devt);
423 }
424
425 void class_device_initialize(struct class_device *class_dev)
426 {
427         kobj_set_kset_s(class_dev, class_obj_subsys);
428         kobject_init(&class_dev->kobj);
429         INIT_LIST_HEAD(&class_dev->node);
430 }
431
432 int class_device_add(struct class_device *class_dev)
433 {
434         struct class * parent = NULL;
435         struct class_interface * class_intf;
436         int error;
437
438         class_dev = class_device_get(class_dev);
439         if (!class_dev)
440                 return -EINVAL;
441
442         if (!strlen(class_dev->class_id)) {
443                 error = -EINVAL;
444                 goto register_done;
445         }
446
447         parent = class_get(class_dev->class);
448
449         pr_debug("CLASS: registering class device: ID = '%s'\n",
450                  class_dev->class_id);
451
452         /* first, register with generic layer. */
453         kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
454         if (parent)
455                 class_dev->kobj.parent = &parent->subsys.kset.kobj;
456
457         if ((error = kobject_add(&class_dev->kobj)))
458                 goto register_done;
459
460         /* add the needed attributes to this device */
461         if (MAJOR(class_dev->devt)) {
462                 struct class_device_attribute *attr;
463                 attr = kmalloc(sizeof(*attr), GFP_KERNEL);
464                 if (!attr) {
465                         error = -ENOMEM;
466                         kobject_del(&class_dev->kobj);
467                         goto register_done;
468                 }
469                 memset(attr, sizeof(*attr), 0x00);
470                 attr->attr.name = "dev";
471                 attr->attr.mode = S_IRUGO;
472                 attr->attr.owner = parent->owner;
473                 attr->show = show_dev;
474                 attr->store = NULL;
475                 class_device_create_file(class_dev, attr);
476                 class_dev->devt_attr = attr;
477         }
478
479         class_device_add_attrs(class_dev);
480         if (class_dev->dev)
481                 sysfs_create_link(&class_dev->kobj,
482                                   &class_dev->dev->kobj, "device");
483
484         /* notify any interfaces this device is now here */
485         if (parent) {
486                 down(&parent->sem);
487                 list_add_tail(&class_dev->node, &parent->children);
488                 list_for_each_entry(class_intf, &parent->interfaces, node)
489                         if (class_intf->add)
490                                 class_intf->add(class_dev);
491                 up(&parent->sem);
492         }
493         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
494
495  register_done:
496         if (error && parent)
497                 class_put(parent);
498         class_device_put(class_dev);
499         return error;
500 }
501
502 int class_device_register(struct class_device *class_dev)
503 {
504         class_device_initialize(class_dev);
505         return class_device_add(class_dev);
506 }
507
508 struct class_device *class_device_create(struct class *cls, dev_t devt,
509                                          struct device *device, char *fmt, ...)
510 {
511         va_list args;
512         struct class_device *class_dev = NULL;
513         int retval = -ENODEV;
514
515         if (cls == NULL || IS_ERR(cls))
516                 goto error;
517
518         class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
519         if (!class_dev) {
520                 retval = -ENOMEM;
521                 goto error;
522         }
523         memset(class_dev, 0x00, sizeof(struct class_device));
524
525         class_dev->devt = devt;
526         class_dev->dev = device;
527         class_dev->class = cls;
528
529         va_start(args, fmt);
530         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
531         va_end(args);
532         retval = class_device_register(class_dev);
533         if (retval)
534                 goto error;
535
536         return class_dev;
537
538 error:
539         kfree(class_dev);
540         return ERR_PTR(retval);
541 }
542
543 void class_device_del(struct class_device *class_dev)
544 {
545         struct class * parent = class_dev->class;
546         struct class_interface * class_intf;
547
548         if (parent) {
549                 down(&parent->sem);
550                 list_del_init(&class_dev->node);
551                 list_for_each_entry(class_intf, &parent->interfaces, node)
552                         if (class_intf->remove)
553                                 class_intf->remove(class_dev);
554                 up(&parent->sem);
555         }
556
557         if (class_dev->dev)
558                 sysfs_remove_link(&class_dev->kobj, "device");
559         if (class_dev->devt_attr) {
560                 class_device_remove_file(class_dev, class_dev->devt_attr);
561                 kfree(class_dev->devt_attr);
562                 class_dev->devt_attr = NULL;
563         }
564         class_device_remove_attrs(class_dev);
565
566         kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
567         kobject_del(&class_dev->kobj);
568
569         if (parent)
570                 class_put(parent);
571 }
572
573 void class_device_unregister(struct class_device *class_dev)
574 {
575         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
576                  class_dev->class_id);
577         class_device_del(class_dev);
578         class_device_put(class_dev);
579 }
580
581 void class_device_destroy(struct class *cls, dev_t devt)
582 {
583         struct class_device *class_dev = NULL;
584         struct class_device *class_dev_tmp;
585
586         down(&cls->sem);
587         list_for_each_entry(class_dev_tmp, &cls->children, node) {
588                 if (class_dev_tmp->devt == devt) {
589                         class_dev = class_dev_tmp;
590                         break;
591                 }
592         }
593         up(&cls->sem);
594
595         if (class_dev)
596                 class_device_unregister(class_dev);
597 }
598
599 int class_device_rename(struct class_device *class_dev, char *new_name)
600 {
601         int error = 0;
602
603         class_dev = class_device_get(class_dev);
604         if (!class_dev)
605                 return -EINVAL;
606
607         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
608                  new_name);
609
610         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
611
612         error = kobject_rename(&class_dev->kobj, new_name);
613
614         class_device_put(class_dev);
615
616         return error;
617 }
618
619 struct class_device * class_device_get(struct class_device *class_dev)
620 {
621         if (class_dev)
622                 return to_class_dev(kobject_get(&class_dev->kobj));
623         return NULL;
624 }
625
626 void class_device_put(struct class_device *class_dev)
627 {
628         kobject_put(&class_dev->kobj);
629 }
630
631
632 int class_interface_register(struct class_interface *class_intf)
633 {
634         struct class *parent;
635         struct class_device *class_dev;
636
637         if (!class_intf || !class_intf->class)
638                 return -ENODEV;
639
640         parent = class_get(class_intf->class);
641         if (!parent)
642                 return -EINVAL;
643
644         down(&parent->sem);
645         list_add_tail(&class_intf->node, &parent->interfaces);
646         if (class_intf->add) {
647                 list_for_each_entry(class_dev, &parent->children, node)
648                         class_intf->add(class_dev);
649         }
650         up(&parent->sem);
651
652         return 0;
653 }
654
655 void class_interface_unregister(struct class_interface *class_intf)
656 {
657         struct class * parent = class_intf->class;
658         struct class_device *class_dev;
659
660         if (!parent)
661                 return;
662
663         down(&parent->sem);
664         list_del_init(&class_intf->node);
665         if (class_intf->remove) {
666                 list_for_each_entry(class_dev, &parent->children, node)
667                         class_intf->remove(class_dev);
668         }
669         up(&parent->sem);
670
671         class_put(parent);
672 }
673
674
675
676 int __init classes_init(void)
677 {
678         int retval;
679
680         retval = subsystem_register(&class_subsys);
681         if (retval)
682                 return retval;
683
684         /* ick, this is ugly, the things we go through to keep from showing up
685          * in sysfs... */
686         subsystem_init(&class_obj_subsys);
687         if (!class_obj_subsys.kset.subsys)
688                         class_obj_subsys.kset.subsys = &class_obj_subsys;
689         return 0;
690 }
691
692 EXPORT_SYMBOL_GPL(class_create_file);
693 EXPORT_SYMBOL_GPL(class_remove_file);
694 EXPORT_SYMBOL_GPL(class_register);
695 EXPORT_SYMBOL_GPL(class_unregister);
696 EXPORT_SYMBOL_GPL(class_get);
697 EXPORT_SYMBOL_GPL(class_put);
698 EXPORT_SYMBOL_GPL(class_create);
699 EXPORT_SYMBOL_GPL(class_destroy);
700
701 EXPORT_SYMBOL_GPL(class_device_register);
702 EXPORT_SYMBOL_GPL(class_device_unregister);
703 EXPORT_SYMBOL_GPL(class_device_initialize);
704 EXPORT_SYMBOL_GPL(class_device_add);
705 EXPORT_SYMBOL_GPL(class_device_del);
706 EXPORT_SYMBOL_GPL(class_device_get);
707 EXPORT_SYMBOL_GPL(class_device_put);
708 EXPORT_SYMBOL_GPL(class_device_create);
709 EXPORT_SYMBOL_GPL(class_device_destroy);
710 EXPORT_SYMBOL_GPL(class_device_create_file);
711 EXPORT_SYMBOL_GPL(class_device_remove_file);
712 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
713 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
714
715 EXPORT_SYMBOL_GPL(class_interface_register);
716 EXPORT_SYMBOL_GPL(class_interface_unregister);