blob: 6b355bd7816d8fcffea570047396eb28323f6771 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * drivers/base/core.c - core driver model code (device registration, etc)
3 *
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 *
7 * This file is released under the GPLv2
8 *
9 */
10
11#include <linux/config.h>
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/init.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/string.h>
18
19#include <asm/semaphore.h>
20
21#include "base.h"
22#include "power/power.h"
23
24int (*platform_notify)(struct device * dev) = NULL;
25int (*platform_notify_remove)(struct device * dev) = NULL;
26
27/*
28 * sysfs bindings for devices.
29 */
30
31#define to_dev(obj) container_of(obj, struct device, kobj)
32#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034static ssize_t
35dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
36{
37 struct device_attribute * dev_attr = to_dev_attr(attr);
38 struct device * dev = to_dev(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050039 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41 if (dev_attr->show)
Yani Ioannou54b6f352005-05-17 06:39:34 -040042 ret = dev_attr->show(dev, dev_attr, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 return ret;
44}
45
46static ssize_t
47dev_attr_store(struct kobject * kobj, struct attribute * attr,
48 const char * buf, size_t count)
49{
50 struct device_attribute * dev_attr = to_dev_attr(attr);
51 struct device * dev = to_dev(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050052 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54 if (dev_attr->store)
Yani Ioannou54b6f352005-05-17 06:39:34 -040055 ret = dev_attr->store(dev, dev_attr, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 return ret;
57}
58
59static struct sysfs_ops dev_sysfs_ops = {
60 .show = dev_attr_show,
61 .store = dev_attr_store,
62};
63
64
65/**
66 * device_release - free device structure.
67 * @kobj: device's kobject.
68 *
69 * This is called once the reference count for the object
70 * reaches 0. We forward the call to the device's release
71 * method, which should handle actually freeing the structure.
72 */
73static void device_release(struct kobject * kobj)
74{
75 struct device * dev = to_dev(kobj);
76
77 if (dev->release)
78 dev->release(dev);
79 else {
80 printk(KERN_ERR "Device '%s' does not have a release() function, "
81 "it is broken and must be fixed.\n",
82 dev->bus_id);
83 WARN_ON(1);
84 }
85}
86
87static struct kobj_type ktype_device = {
88 .release = device_release,
89 .sysfs_ops = &dev_sysfs_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -070090};
91
92
Kay Sievers312c0042005-11-16 09:00:00 +010093static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
95 struct kobj_type *ktype = get_ktype(kobj);
96
97 if (ktype == &ktype_device) {
98 struct device *dev = to_dev(kobj);
99 if (dev->bus)
100 return 1;
101 }
102 return 0;
103}
104
Kay Sievers312c0042005-11-16 09:00:00 +0100105static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106{
107 struct device *dev = to_dev(kobj);
108
109 return dev->bus->name;
110}
111
Kay Sievers312c0042005-11-16 09:00:00 +0100112static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 int num_envp, char *buffer, int buffer_size)
114{
115 struct device *dev = to_dev(kobj);
116 int i = 0;
117 int length = 0;
118 int retval = 0;
119
120 /* add bus name of physical device */
121 if (dev->bus)
Kay Sievers312c0042005-11-16 09:00:00 +0100122 add_uevent_var(envp, num_envp, &i,
123 buffer, buffer_size, &length,
124 "PHYSDEVBUS=%s", dev->bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
126 /* add driver name of physical device */
127 if (dev->driver)
Kay Sievers312c0042005-11-16 09:00:00 +0100128 add_uevent_var(envp, num_envp, &i,
129 buffer, buffer_size, &length,
130 "PHYSDEVDRIVER=%s", dev->driver->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132 /* terminate, set to next free slot, shrink available space */
133 envp[i] = NULL;
134 envp = &envp[i];
135 num_envp -= i;
136 buffer = &buffer[length];
137 buffer_size -= length;
138
Kay Sievers312c0042005-11-16 09:00:00 +0100139 if (dev->bus && dev->bus->uevent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 /* have the bus specific function add its stuff */
Kay Sievers312c0042005-11-16 09:00:00 +0100141 retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 if (retval) {
Kay Sievers312c0042005-11-16 09:00:00 +0100143 pr_debug ("%s - uevent() returned %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 __FUNCTION__, retval);
145 }
146 }
147
148 return retval;
149}
150
Kay Sievers312c0042005-11-16 09:00:00 +0100151static struct kset_uevent_ops device_uevent_ops = {
152 .filter = dev_uevent_filter,
153 .name = dev_uevent_name,
154 .uevent = dev_uevent,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155};
156
Kay Sieversa7fd6702005-10-01 14:49:43 +0200157static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
158 const char *buf, size_t count)
159{
Kay Sievers312c0042005-11-16 09:00:00 +0100160 kobject_uevent(&dev->kobj, KOBJ_ADD);
Kay Sieversa7fd6702005-10-01 14:49:43 +0200161 return count;
162}
163
Martin Waitz0863afb2006-01-09 20:53:55 -0800164/*
165 * devices_subsys - structure to be registered with kobject core.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 */
167
Kay Sievers312c0042005-11-16 09:00:00 +0100168decl_subsys(devices, &ktype_device, &device_uevent_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170
171/**
172 * device_create_file - create sysfs attribute file for device.
173 * @dev: device.
174 * @attr: device attribute descriptor.
175 */
176
177int device_create_file(struct device * dev, struct device_attribute * attr)
178{
179 int error = 0;
180 if (get_device(dev)) {
181 error = sysfs_create_file(&dev->kobj, &attr->attr);
182 put_device(dev);
183 }
184 return error;
185}
186
187/**
188 * device_remove_file - remove sysfs attribute file.
189 * @dev: device.
190 * @attr: device attribute descriptor.
191 */
192
193void device_remove_file(struct device * dev, struct device_attribute * attr)
194{
195 if (get_device(dev)) {
196 sysfs_remove_file(&dev->kobj, &attr->attr);
197 put_device(dev);
198 }
199}
200
James Bottomley34bb61f2005-09-06 16:56:51 -0700201static void klist_children_get(struct klist_node *n)
202{
203 struct device *dev = container_of(n, struct device, knode_parent);
204
205 get_device(dev);
206}
207
208static void klist_children_put(struct klist_node *n)
209{
210 struct device *dev = container_of(n, struct device, knode_parent);
211
212 put_device(dev);
213}
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216/**
217 * device_initialize - init device structure.
218 * @dev: device.
219 *
220 * This prepares the device for use by other layers,
221 * including adding it to the device hierarchy.
222 * It is the first half of device_register(), if called by
223 * that, though it can also be called separately, so one
224 * may use @dev's fields (e.g. the refcount).
225 */
226
227void device_initialize(struct device *dev)
228{
229 kobj_set_kset_s(dev, devices_subsys);
230 kobject_init(&dev->kobj);
James Bottomley34bb61f2005-09-06 16:56:51 -0700231 klist_init(&dev->klist_children, klist_children_get,
232 klist_children_put);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 INIT_LIST_HEAD(&dev->dma_pools);
mochel@digitalimplant.orgaf703162005-03-21 10:41:04 -0800234 init_MUTEX(&dev->sem);
David Brownell0ac85242005-09-12 19:39:34 -0700235 device_init_wakeup(dev, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236}
237
238/**
239 * device_add - add device to device hierarchy.
240 * @dev: device.
241 *
242 * This is part 2 of device_register(), though may be called
243 * separately _iff_ device_initialize() has been called separately.
244 *
245 * This adds it to the kobject hierarchy via kobject_add(), adds it
246 * to the global and sibling lists for the device, then
247 * adds it to the other relevant subsystems of the driver model.
248 */
249int device_add(struct device *dev)
250{
251 struct device *parent = NULL;
252 int error = -EINVAL;
253
254 dev = get_device(dev);
255 if (!dev || !strlen(dev->bus_id))
256 goto Error;
257
258 parent = get_device(dev->parent);
259
260 pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
261
262 /* first, register with generic layer. */
263 kobject_set_name(&dev->kobj, "%s", dev->bus_id);
264 if (parent)
265 dev->kobj.parent = &parent->kobj;
266
267 if ((error = kobject_add(&dev->kobj)))
268 goto Error;
Kay Sieversa7fd6702005-10-01 14:49:43 +0200269
270 dev->uevent_attr.attr.name = "uevent";
271 dev->uevent_attr.attr.mode = S_IWUSR;
272 if (dev->driver)
273 dev->uevent_attr.attr.owner = dev->driver->owner;
274 dev->uevent_attr.store = store_uevent;
275 device_create_file(dev, &dev->uevent_attr);
276
Kay Sievers312c0042005-11-16 09:00:00 +0100277 kobject_uevent(&dev->kobj, KOBJ_ADD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 if ((error = device_pm_add(dev)))
279 goto PMError;
280 if ((error = bus_add_device(dev)))
281 goto BusError;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 if (parent)
James Bottomleyd856f1e2005-08-19 09:14:01 -0400283 klist_add_tail(&dev->knode_parent, &parent->klist_children);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
285 /* notify platform of device entry */
286 if (platform_notify)
287 platform_notify(dev);
288 Done:
289 put_device(dev);
290 return error;
291 BusError:
292 device_pm_remove(dev);
293 PMError:
Kay Sievers312c0042005-11-16 09:00:00 +0100294 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 kobject_del(&dev->kobj);
296 Error:
297 if (parent)
298 put_device(parent);
299 goto Done;
300}
301
302
303/**
304 * device_register - register a device with the system.
305 * @dev: pointer to the device structure
306 *
307 * This happens in two clean steps - initialize the device
308 * and add it to the system. The two steps can be called
309 * separately, but this is the easiest and most common.
310 * I.e. you should only call the two helpers separately if
311 * have a clearly defined need to use and refcount the device
312 * before it is added to the hierarchy.
313 */
314
315int device_register(struct device *dev)
316{
317 device_initialize(dev);
318 return device_add(dev);
319}
320
321
322/**
323 * get_device - increment reference count for device.
324 * @dev: device.
325 *
326 * This simply forwards the call to kobject_get(), though
327 * we do take care to provide for the case that we get a NULL
328 * pointer passed in.
329 */
330
331struct device * get_device(struct device * dev)
332{
333 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
334}
335
336
337/**
338 * put_device - decrement reference count.
339 * @dev: device in question.
340 */
341void put_device(struct device * dev)
342{
343 if (dev)
344 kobject_put(&dev->kobj);
345}
346
347
348/**
349 * device_del - delete device from system.
350 * @dev: device.
351 *
352 * This is the first part of the device unregistration
353 * sequence. This removes the device from the lists we control
354 * from here, has it removed from the other driver model
355 * subsystems it was added to in device_add(), and removes it
356 * from the kobject hierarchy.
357 *
358 * NOTE: this should be called manually _iff_ device_add() was
359 * also called manually.
360 */
361
362void device_del(struct device * dev)
363{
364 struct device * parent = dev->parent;
365
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 if (parent)
Patrick Mocheld62c0f92005-06-24 08:39:33 -0700367 klist_del(&dev->knode_parent);
Kay Sieversa7fd6702005-10-01 14:49:43 +0200368 device_remove_file(dev, &dev->uevent_attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
370 /* Notify the platform of the removal, in case they
371 * need to do anything...
372 */
373 if (platform_notify_remove)
374 platform_notify_remove(dev);
375 bus_remove_device(dev);
376 device_pm_remove(dev);
Kay Sievers312c0042005-11-16 09:00:00 +0100377 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 kobject_del(&dev->kobj);
379 if (parent)
380 put_device(parent);
381}
382
383/**
384 * device_unregister - unregister device from system.
385 * @dev: device going away.
386 *
387 * We do this in two parts, like we do device_register(). First,
388 * we remove it from all the subsystems with device_del(), then
389 * we decrement the reference count via put_device(). If that
390 * is the final reference count, the device will be cleaned up
391 * via device_release() above. Otherwise, the structure will
392 * stick around until the final reference to the device is dropped.
393 */
394void device_unregister(struct device * dev)
395{
396 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
397 device_del(dev);
398 put_device(dev);
399}
400
401
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800402static struct device * next_device(struct klist_iter * i)
403{
404 struct klist_node * n = klist_next(i);
405 return n ? container_of(n, struct device, knode_parent) : NULL;
406}
407
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408/**
409 * device_for_each_child - device child iterator.
Randy Dunlapc41455f2005-10-23 11:59:14 -0700410 * @parent: parent struct device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 * @data: data for the callback.
412 * @fn: function to be called for each device.
413 *
Randy Dunlapc41455f2005-10-23 11:59:14 -0700414 * Iterate over @parent's child devices, and call @fn for each,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 * passing it @data.
416 *
417 * We check the return of @fn each time. If it returns anything
418 * other than 0, we break out and return that value.
419 */
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800420int device_for_each_child(struct device * parent, void * data,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 int (*fn)(struct device *, void *))
422{
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800423 struct klist_iter i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 struct device * child;
425 int error = 0;
426
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800427 klist_iter_init(&parent->klist_children, &i);
428 while ((child = next_device(&i)) && !error)
429 error = fn(child, data);
430 klist_iter_exit(&i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 return error;
432}
433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434int __init devices_init(void)
435{
436 return subsystem_register(&devices_subsys);
437}
438
439EXPORT_SYMBOL_GPL(device_for_each_child);
440
441EXPORT_SYMBOL_GPL(device_initialize);
442EXPORT_SYMBOL_GPL(device_add);
443EXPORT_SYMBOL_GPL(device_register);
444
445EXPORT_SYMBOL_GPL(device_del);
446EXPORT_SYMBOL_GPL(device_unregister);
447EXPORT_SYMBOL_GPL(get_device);
448EXPORT_SYMBOL_GPL(put_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
450EXPORT_SYMBOL_GPL(device_create_file);
451EXPORT_SYMBOL_GPL(device_remove_file);