blob: efe03a024a5bc39bf958881143d740312c3b09bc [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
93static int dev_hotplug_filter(struct kset *kset, struct kobject *kobj)
94{
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
Dmitry Torokhov419cab32005-04-26 02:32:54 -0500105static const char *dev_hotplug_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
112static int dev_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
113 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)
122 add_hotplug_env_var(envp, num_envp, &i,
123 buffer, buffer_size, &length,
124 "PHYSDEVBUS=%s", dev->bus->name);
125
126 /* add driver name of physical device */
127 if (dev->driver)
128 add_hotplug_env_var(envp, num_envp, &i,
129 buffer, buffer_size, &length,
130 "PHYSDEVDRIVER=%s", dev->driver->name);
131
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
Alexander Nyberg177a4322005-02-26 13:38:51 +0100139 if (dev->bus && dev->bus->hotplug) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 /* have the bus specific function add its stuff */
141 retval = dev->bus->hotplug (dev, envp, num_envp, buffer, buffer_size);
142 if (retval) {
143 pr_debug ("%s - hotplug() returned %d\n",
144 __FUNCTION__, retval);
145 }
146 }
147
148 return retval;
149}
150
151static struct kset_hotplug_ops device_hotplug_ops = {
152 .filter = dev_hotplug_filter,
153 .name = dev_hotplug_name,
154 .hotplug = dev_hotplug,
155};
156
157/**
158 * device_subsys - structure to be registered with kobject core.
159 */
160
161decl_subsys(devices, &ktype_device, &device_hotplug_ops);
162
163
164/**
165 * device_create_file - create sysfs attribute file for device.
166 * @dev: device.
167 * @attr: device attribute descriptor.
168 */
169
170int device_create_file(struct device * dev, struct device_attribute * attr)
171{
172 int error = 0;
173 if (get_device(dev)) {
174 error = sysfs_create_file(&dev->kobj, &attr->attr);
175 put_device(dev);
176 }
177 return error;
178}
179
180/**
181 * device_remove_file - remove sysfs attribute file.
182 * @dev: device.
183 * @attr: device attribute descriptor.
184 */
185
186void device_remove_file(struct device * dev, struct device_attribute * attr)
187{
188 if (get_device(dev)) {
189 sysfs_remove_file(&dev->kobj, &attr->attr);
190 put_device(dev);
191 }
192}
193
194
195/**
196 * device_initialize - init device structure.
197 * @dev: device.
198 *
199 * This prepares the device for use by other layers,
200 * including adding it to the device hierarchy.
201 * It is the first half of device_register(), if called by
202 * that, though it can also be called separately, so one
203 * may use @dev's fields (e.g. the refcount).
204 */
205
206void device_initialize(struct device *dev)
207{
208 kobj_set_kset_s(dev, devices_subsys);
209 kobject_init(&dev->kobj);
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800210 klist_init(&dev->klist_children);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 INIT_LIST_HEAD(&dev->dma_pools);
mochel@digitalimplant.orgaf703162005-03-21 10:41:04 -0800212 init_MUTEX(&dev->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213}
214
215/**
216 * device_add - add device to device hierarchy.
217 * @dev: device.
218 *
219 * This is part 2 of device_register(), though may be called
220 * separately _iff_ device_initialize() has been called separately.
221 *
222 * This adds it to the kobject hierarchy via kobject_add(), adds it
223 * to the global and sibling lists for the device, then
224 * adds it to the other relevant subsystems of the driver model.
225 */
226int device_add(struct device *dev)
227{
228 struct device *parent = NULL;
229 int error = -EINVAL;
230
231 dev = get_device(dev);
232 if (!dev || !strlen(dev->bus_id))
233 goto Error;
234
235 parent = get_device(dev->parent);
236
237 pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
238
239 /* first, register with generic layer. */
240 kobject_set_name(&dev->kobj, "%s", dev->bus_id);
241 if (parent)
242 dev->kobj.parent = &parent->kobj;
243
244 if ((error = kobject_add(&dev->kobj)))
245 goto Error;
Kay Sievers187a1a92005-05-23 15:50:26 -0700246 kobject_hotplug(&dev->kobj, KOBJ_ADD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 if ((error = device_pm_add(dev)))
248 goto PMError;
249 if ((error = bus_add_device(dev)))
250 goto BusError;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 if (parent)
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800252 klist_add_tail(&parent->klist_children, &dev->knode_parent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
254 /* notify platform of device entry */
255 if (platform_notify)
256 platform_notify(dev);
257 Done:
258 put_device(dev);
259 return error;
260 BusError:
261 device_pm_remove(dev);
262 PMError:
Kay Sievers187a1a92005-05-23 15:50:26 -0700263 kobject_hotplug(&dev->kobj, KOBJ_REMOVE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 kobject_del(&dev->kobj);
265 Error:
266 if (parent)
267 put_device(parent);
268 goto Done;
269}
270
271
272/**
273 * device_register - register a device with the system.
274 * @dev: pointer to the device structure
275 *
276 * This happens in two clean steps - initialize the device
277 * and add it to the system. The two steps can be called
278 * separately, but this is the easiest and most common.
279 * I.e. you should only call the two helpers separately if
280 * have a clearly defined need to use and refcount the device
281 * before it is added to the hierarchy.
282 */
283
284int device_register(struct device *dev)
285{
286 device_initialize(dev);
287 return device_add(dev);
288}
289
290
291/**
292 * get_device - increment reference count for device.
293 * @dev: device.
294 *
295 * This simply forwards the call to kobject_get(), though
296 * we do take care to provide for the case that we get a NULL
297 * pointer passed in.
298 */
299
300struct device * get_device(struct device * dev)
301{
302 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
303}
304
305
306/**
307 * put_device - decrement reference count.
308 * @dev: device in question.
309 */
310void put_device(struct device * dev)
311{
312 if (dev)
313 kobject_put(&dev->kobj);
314}
315
316
317/**
318 * device_del - delete device from system.
319 * @dev: device.
320 *
321 * This is the first part of the device unregistration
322 * sequence. This removes the device from the lists we control
323 * from here, has it removed from the other driver model
324 * subsystems it was added to in device_add(), and removes it
325 * from the kobject hierarchy.
326 *
327 * NOTE: this should be called manually _iff_ device_add() was
328 * also called manually.
329 */
330
331void device_del(struct device * dev)
332{
333 struct device * parent = dev->parent;
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 if (parent)
Patrick Mocheld62c0f92005-06-24 08:39:33 -0700336 klist_del(&dev->knode_parent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
338 /* Notify the platform of the removal, in case they
339 * need to do anything...
340 */
341 if (platform_notify_remove)
342 platform_notify_remove(dev);
343 bus_remove_device(dev);
344 device_pm_remove(dev);
kay.sievers@vrfy.orge57cd732005-04-18 21:57:36 -0700345 kobject_hotplug(&dev->kobj, KOBJ_REMOVE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 kobject_del(&dev->kobj);
347 if (parent)
348 put_device(parent);
349}
350
351/**
352 * device_unregister - unregister device from system.
353 * @dev: device going away.
354 *
355 * We do this in two parts, like we do device_register(). First,
356 * we remove it from all the subsystems with device_del(), then
357 * we decrement the reference count via put_device(). If that
358 * is the final reference count, the device will be cleaned up
359 * via device_release() above. Otherwise, the structure will
360 * stick around until the final reference to the device is dropped.
361 */
362void device_unregister(struct device * dev)
363{
364 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
365 device_del(dev);
366 put_device(dev);
367}
368
369
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800370static struct device * next_device(struct klist_iter * i)
371{
372 struct klist_node * n = klist_next(i);
373 return n ? container_of(n, struct device, knode_parent) : NULL;
374}
375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376/**
377 * device_for_each_child - device child iterator.
378 * @dev: parent struct device.
379 * @data: data for the callback.
380 * @fn: function to be called for each device.
381 *
382 * Iterate over @dev's child devices, and call @fn for each,
383 * passing it @data.
384 *
385 * We check the return of @fn each time. If it returns anything
386 * other than 0, we break out and return that value.
387 */
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800388int device_for_each_child(struct device * parent, void * data,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 int (*fn)(struct device *, void *))
390{
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800391 struct klist_iter i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 struct device * child;
393 int error = 0;
394
mochel@digitalimplant.org36239572005-03-24 19:08:30 -0800395 klist_iter_init(&parent->klist_children, &i);
396 while ((child = next_device(&i)) && !error)
397 error = fn(child, data);
398 klist_iter_exit(&i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 return error;
400}
401
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402int __init devices_init(void)
403{
404 return subsystem_register(&devices_subsys);
405}
406
407EXPORT_SYMBOL_GPL(device_for_each_child);
408
409EXPORT_SYMBOL_GPL(device_initialize);
410EXPORT_SYMBOL_GPL(device_add);
411EXPORT_SYMBOL_GPL(device_register);
412
413EXPORT_SYMBOL_GPL(device_del);
414EXPORT_SYMBOL_GPL(device_unregister);
415EXPORT_SYMBOL_GPL(get_device);
416EXPORT_SYMBOL_GPL(put_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418EXPORT_SYMBOL_GPL(device_create_file);
419EXPORT_SYMBOL_GPL(device_remove_file);