2 * class.c - basic device class management
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.
9 * This file is released under the GPLv2
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>
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)
26 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
28 struct class_attribute * class_attr = to_class_attr(attr);
29 struct class * dc = to_class(kobj);
33 ret = class_attr->show(dc, buf);
38 class_attr_store(struct kobject * kobj, struct attribute * attr,
39 const char * buf, size_t count)
41 struct class_attribute * class_attr = to_class_attr(attr);
42 struct class * dc = to_class(kobj);
45 if (class_attr->store)
46 ret = class_attr->store(dc, buf, count);
50 static void class_release(struct kobject * kobj)
52 struct class *class = to_class(kobj);
54 pr_debug("class '%s': release.\n", class->name);
56 if (class->class_release)
57 class->class_release(class);
59 pr_debug("class '%s' does not have a release() function, "
60 "be careful\n", class->name);
63 static struct sysfs_ops class_sysfs_ops = {
64 .show = class_attr_show,
65 .store = class_attr_store,
68 static struct kobj_type ktype_class = {
69 .sysfs_ops = &class_sysfs_ops,
70 .release = class_release,
73 /* Hotplug events for classes go to the class_obj subsys */
74 static decl_subsys(class, &ktype_class, NULL);
77 int class_create_file(struct class * cls, const struct class_attribute * attr)
81 error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
87 void class_remove_file(struct class * cls, const struct class_attribute * attr)
90 sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
93 struct class * class_get(struct class * cls)
96 return container_of(subsys_get(&cls->subsys), struct class, subsys);
100 void class_put(struct class * cls)
102 subsys_put(&cls->subsys);
106 static int add_class_attrs(struct class * cls)
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]);
122 class_remove_file(cls,&cls->class_attrs[i]);
126 static void remove_class_attrs(struct class * cls)
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]);
136 int class_register(struct class * cls)
140 pr_debug("device class '%s': registering\n", cls->name);
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);
149 subsys_set_kset(cls, class_subsys);
151 error = subsystem_register(&cls->subsys);
153 error = add_class_attrs(class_get(cls));
159 void class_unregister(struct class * cls)
161 pr_debug("device class '%s': unregistering\n", cls->name);
162 remove_class_attrs(cls);
163 subsystem_unregister(&cls->subsys);
166 static void class_create_release(struct class *cls)
171 static void class_device_create_release(struct class_device *class_dev)
176 struct class *class_create(struct module *owner, char *name)
181 cls = kmalloc(sizeof(struct class), GFP_KERNEL);
186 memset(cls, 0x00, sizeof(struct class));
190 cls->class_release = class_create_release;
191 cls->release = class_device_create_release;
193 retval = class_register(cls);
201 return ERR_PTR(retval);
204 void class_destroy(struct class *cls)
206 if ((cls == NULL) || (IS_ERR(cls)))
209 class_unregister(cls);
212 /* Class Device Stuff */
214 int class_device_create_file(struct class_device * class_dev,
215 const struct class_device_attribute * attr)
219 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
223 void class_device_remove_file(struct class_device * class_dev,
224 const struct class_device_attribute * attr)
227 sysfs_remove_file(&class_dev->kobj, &attr->attr);
230 int class_device_create_bin_file(struct class_device *class_dev,
231 struct bin_attribute *attr)
235 error = sysfs_create_bin_file(&class_dev->kobj, attr);
239 void class_device_remove_bin_file(struct class_device *class_dev,
240 struct bin_attribute *attr)
243 sysfs_remove_bin_file(&class_dev->kobj, attr);
247 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
250 struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
251 struct class_device * cd = to_class_dev(kobj);
254 if (class_dev_attr->show)
255 ret = class_dev_attr->show(cd, buf);
260 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
261 const char * buf, size_t count)
263 struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
264 struct class_device * cd = to_class_dev(kobj);
267 if (class_dev_attr->store)
268 ret = class_dev_attr->store(cd, buf, count);
272 static struct sysfs_ops class_dev_sysfs_ops = {
273 .show = class_device_attr_show,
274 .store = class_device_attr_store,
277 static void class_dev_release(struct kobject * kobj)
279 struct class_device *cd = to_class_dev(kobj);
280 struct class * cls = cd->class;
282 pr_debug("device class '%s': release.\n", cd->class_id);
287 printk(KERN_ERR "Device class '%s' does not have a release() function, "
288 "it is broken and must be fixed.\n",
294 static struct kobj_type ktype_class_device = {
295 .sysfs_ops = &class_dev_sysfs_ops,
296 .release = class_dev_release,
299 static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
301 struct kobj_type *ktype = get_ktype(kobj);
303 if (ktype == &ktype_class_device) {
304 struct class_device *class_dev = to_class_dev(kobj);
305 if (class_dev->class)
311 static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
313 struct class_device *class_dev = to_class_dev(kobj);
315 return class_dev->class->name;
318 static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
319 int num_envp, char *buffer, int buffer_size)
321 struct class_device *class_dev = to_class_dev(kobj);
326 pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
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);
333 add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
334 &length, "PHYSDEVPATH=%s", path);
338 add_hotplug_env_var(envp, num_envp, &i,
339 buffer, buffer_size, &length,
340 "PHYSDEVBUS=%s", dev->bus->name);
343 add_hotplug_env_var(envp, num_envp, &i,
344 buffer, buffer_size, &length,
345 "PHYSDEVDRIVER=%s", dev->driver->name);
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));
353 add_hotplug_env_var(envp, num_envp, &i,
354 buffer, buffer_size, &length,
355 "MINOR=%u", MINOR(class_dev->devt));
358 /* terminate, set to next free slot, shrink available space */
362 buffer = &buffer[length];
363 buffer_size -= length;
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);
370 pr_debug ("%s - hotplug() returned %d\n",
371 __FUNCTION__, retval);
378 static struct kset_hotplug_ops class_hotplug_ops = {
379 .filter = class_hotplug_filter,
380 .name = class_hotplug_name,
381 .hotplug = class_hotplug,
384 static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
387 static int class_device_add_attrs(struct class_device * cd)
391 struct class * cls = cd->class;
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]);
405 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
409 static void class_device_remove_attrs(struct class_device * cd)
412 struct class * cls = cd->class;
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]);
420 static ssize_t show_dev(struct class_device *class_dev, char *buf)
422 return print_dev_t(buf, class_dev->devt);
425 void class_device_initialize(struct class_device *class_dev)
427 kobj_set_kset_s(class_dev, class_obj_subsys);
428 kobject_init(&class_dev->kobj);
429 INIT_LIST_HEAD(&class_dev->node);
432 int class_device_add(struct class_device *class_dev)
434 struct class * parent = NULL;
435 struct class_interface * class_intf;
438 class_dev = class_device_get(class_dev);
442 if (!strlen(class_dev->class_id)) {
447 parent = class_get(class_dev->class);
449 pr_debug("CLASS: registering class device: ID = '%s'\n",
450 class_dev->class_id);
452 /* first, register with generic layer. */
453 kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
455 class_dev->kobj.parent = &parent->subsys.kset.kobj;
457 if ((error = kobject_add(&class_dev->kobj)))
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);
466 kobject_del(&class_dev->kobj);
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;
475 class_device_create_file(class_dev, attr);
476 class_dev->devt_attr = attr;
479 class_device_add_attrs(class_dev);
481 sysfs_create_link(&class_dev->kobj,
482 &class_dev->dev->kobj, "device");
484 /* notify any interfaces this device is now here */
487 list_add_tail(&class_dev->node, &parent->children);
488 list_for_each_entry(class_intf, &parent->interfaces, node)
490 class_intf->add(class_dev);
493 kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
498 class_device_put(class_dev);
502 int class_device_register(struct class_device *class_dev)
504 class_device_initialize(class_dev);
505 return class_device_add(class_dev);
508 struct class_device *class_device_create(struct class *cls, dev_t devt,
509 struct device *device, char *fmt, ...)
512 struct class_device *class_dev = NULL;
513 int retval = -ENODEV;
515 if (cls == NULL || IS_ERR(cls))
518 class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
523 memset(class_dev, 0x00, sizeof(struct class_device));
525 class_dev->devt = devt;
526 class_dev->dev = device;
527 class_dev->class = cls;
530 vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
532 retval = class_device_register(class_dev);
540 return ERR_PTR(retval);
543 void class_device_del(struct class_device *class_dev)
545 struct class * parent = class_dev->class;
546 struct class_interface * class_intf;
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);
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;
564 class_device_remove_attrs(class_dev);
566 kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
567 kobject_del(&class_dev->kobj);
573 void class_device_unregister(struct class_device *class_dev)
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);
581 void class_device_destroy(struct class *cls, dev_t devt)
583 struct class_device *class_dev = NULL;
584 struct class_device *class_dev_tmp;
587 list_for_each_entry(class_dev_tmp, &cls->children, node) {
588 if (class_dev_tmp->devt == devt) {
589 class_dev = class_dev_tmp;
596 class_device_unregister(class_dev);
599 int class_device_rename(struct class_device *class_dev, char *new_name)
603 class_dev = class_device_get(class_dev);
607 pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
610 strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
612 error = kobject_rename(&class_dev->kobj, new_name);
614 class_device_put(class_dev);
619 struct class_device * class_device_get(struct class_device *class_dev)
622 return to_class_dev(kobject_get(&class_dev->kobj));
626 void class_device_put(struct class_device *class_dev)
628 kobject_put(&class_dev->kobj);
632 int class_interface_register(struct class_interface *class_intf)
634 struct class *parent;
635 struct class_device *class_dev;
637 if (!class_intf || !class_intf->class)
640 parent = class_get(class_intf->class);
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);
655 void class_interface_unregister(struct class_interface *class_intf)
657 struct class * parent = class_intf->class;
658 struct class_device *class_dev;
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);
676 int __init classes_init(void)
680 retval = subsystem_register(&class_subsys);
684 /* ick, this is ugly, the things we go through to keep from showing up
686 subsystem_init(&class_obj_subsys);
687 if (!class_obj_subsys.kset.subsys)
688 class_obj_subsys.kset.subsys = &class_obj_subsys;
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);
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);
715 EXPORT_SYMBOL_GPL(class_interface_register);
716 EXPORT_SYMBOL_GPL(class_interface_unregister);