blob: 63c143e54a5783656d9f0208acd3c9c4166ec4e2 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * bus.c - bus driver management
3 *
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -08006 * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2007 Novell Inc.
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
9 * This file is released under the GPLv2
10 *
11 */
12
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/device.h>
14#include <linux/module.h>
15#include <linux/errno.h>
16#include <linux/init.h>
17#include <linux/string.h>
18#include "base.h"
19#include "power/power.h"
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070022#define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
24/*
25 * sysfs bindings for drivers
26 */
27
28#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30
Kay Sieversb8c5cec2007-02-16 17:33:36 +010031static int __must_check bus_rescan_devices_helper(struct device *dev,
32 void *data);
33
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070034static struct bus_type *bus_get(struct bus_type *bus)
35{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070036 if (bus) {
37 kset_get(&bus->p->subsys);
38 return bus;
39 }
40 return NULL;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070041}
42
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070043static void bus_put(struct bus_type *bus)
44{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070045 if (bus)
46 kset_put(&bus->p->subsys);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070047}
48
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080049static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
50 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080052 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080053 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050054 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56 if (drv_attr->show)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080057 ret = drv_attr->show(drv_priv->driver, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 return ret;
59}
60
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080061static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
62 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080064 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080065 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050066 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68 if (drv_attr->store)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080069 ret = drv_attr->store(drv_priv->driver, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 return ret;
71}
72
73static struct sysfs_ops driver_sysfs_ops = {
74 .show = drv_attr_show,
75 .store = drv_attr_store,
76};
77
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080078static void driver_release(struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080080 struct driver_private *drv_priv = to_driver(kobj);
81
Harvey Harrison2b3a3022008-03-04 16:41:05 -080082 pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080083 kfree(drv_priv);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084}
85
Greg Kroah-Hartmana1148fb2007-10-11 10:47:49 -060086static struct kobj_type driver_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 .sysfs_ops = &driver_sysfs_ops,
88 .release = driver_release,
89};
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091/*
92 * sysfs bindings for buses
93 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080094static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
95 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080097 struct bus_attribute *bus_attr = to_bus_attr(attr);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070098 struct bus_type_private *bus_priv = to_bus(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 ssize_t ret = 0;
100
101 if (bus_attr->show)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700102 ret = bus_attr->show(bus_priv->bus, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 return ret;
104}
105
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800106static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
107 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800109 struct bus_attribute *bus_attr = to_bus_attr(attr);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700110 struct bus_type_private *bus_priv = to_bus(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 ssize_t ret = 0;
112
113 if (bus_attr->store)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700114 ret = bus_attr->store(bus_priv->bus, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 return ret;
116}
117
118static struct sysfs_ops bus_sysfs_ops = {
119 .show = bus_attr_show,
120 .store = bus_attr_store,
121};
122
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800123int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124{
125 int error;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700126 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700127 error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700128 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 } else
130 error = -EINVAL;
131 return error;
132}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800133EXPORT_SYMBOL_GPL(bus_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800135void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700137 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700138 sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700139 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 }
141}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800142EXPORT_SYMBOL_GPL(bus_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
Kay Sievers80f03e32007-05-26 11:21:36 +0200144static struct kobj_type bus_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 .sysfs_ops = &bus_sysfs_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146};
147
Kay Sievers80f03e32007-05-26 11:21:36 +0200148static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
149{
150 struct kobj_type *ktype = get_ktype(kobj);
151
152 if (ktype == &bus_ktype)
153 return 1;
154 return 0;
155}
156
157static struct kset_uevent_ops bus_uevent_ops = {
158 .filter = bus_uevent_filter,
159};
160
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -0500161static struct kset *bus_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Russell King2139bdd2006-02-07 12:58:20 -0800164#ifdef CONFIG_HOTPLUG
Alan Stern2b08c8d2005-11-23 15:43:50 -0800165/* Manually detach a device from its associated driver. */
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700166static ssize_t driver_unbind(struct device_driver *drv,
167 const char *buf, size_t count)
168{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700169 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700170 struct device *dev;
171 int err = -ENODEV;
172
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800173 dev = bus_find_device_by_name(bus, NULL, buf);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800174 if (dev && dev->driver == drv) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500175 if (dev->parent) /* Needed for USB */
176 down(&dev->parent->sem);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700177 device_release_driver(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500178 if (dev->parent)
179 up(&dev->parent->sem);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700180 err = count;
181 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800182 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700183 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800184 return err;
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700185}
186static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
187
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700188/*
189 * Manually attach a device to a driver.
190 * Note: the driver must want to bind to the device,
191 * it is not possible to override the driver's id table.
192 */
193static ssize_t driver_bind(struct device_driver *drv,
194 const char *buf, size_t count)
195{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700196 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700197 struct device *dev;
198 int err = -ENODEV;
199
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800200 dev = bus_find_device_by_name(bus, NULL, buf);
Ming Lei49b420a2009-01-21 23:27:47 +0800201 if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500202 if (dev->parent) /* Needed for USB */
203 down(&dev->parent->sem);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700204 down(&dev->sem);
205 err = driver_probe_device(drv, dev);
206 up(&dev->sem);
Alan Sternbf74ad52005-11-17 16:54:12 -0500207 if (dev->parent)
208 up(&dev->parent->sem);
Ryan Wilson37225402006-03-22 16:26:25 -0500209
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800210 if (err > 0) {
211 /* success */
Ryan Wilson37225402006-03-22 16:26:25 -0500212 err = count;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800213 } else if (err == 0) {
214 /* driver didn't accept device */
Ryan Wilson37225402006-03-22 16:26:25 -0500215 err = -ENODEV;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800216 }
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700217 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800218 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700219 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800220 return err;
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700221}
222static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
223
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100224static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
225{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700226 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100227}
228
229static ssize_t store_drivers_autoprobe(struct bus_type *bus,
230 const char *buf, size_t count)
231{
232 if (buf[0] == '0')
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700233 bus->p->drivers_autoprobe = 0;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100234 else
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700235 bus->p->drivers_autoprobe = 1;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100236 return count;
237}
238
239static ssize_t store_drivers_probe(struct bus_type *bus,
240 const char *buf, size_t count)
241{
242 struct device *dev;
243
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800244 dev = bus_find_device_by_name(bus, NULL, buf);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100245 if (!dev)
246 return -ENODEV;
247 if (bus_rescan_devices_helper(dev, NULL) != 0)
248 return -EINVAL;
249 return count;
250}
Russell King2139bdd2006-02-07 12:58:20 -0800251#endif
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700252
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800253static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800254{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800255 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800256 struct device *dev = NULL;
257 struct device_private *dev_prv;
258
259 if (n) {
260 dev_prv = to_device_private_bus(n);
261 dev = dev_prv->device;
262 }
263 return dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800264}
265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800267 * bus_for_each_dev - device iterator.
268 * @bus: bus type.
269 * @start: device to start iterating from.
270 * @data: data for the callback.
271 * @fn: function to be called for each device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800273 * Iterate over @bus's list of devices, and call @fn for each,
274 * passing it @data. If @start is not NULL, we use that device to
275 * begin iterating from.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800277 * We check the return of @fn each time. If it returns anything
278 * other than 0, we break out and return that value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800280 * NOTE: The device that returns a non-zero value is not retained
281 * in any way, nor is its refcount incremented. If the caller needs
Alex Chiang0fa1b0a2009-05-14 23:15:22 +0200282 * to retain this data, it should do so, and increment the reference
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800283 * count in the supplied callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800285int bus_for_each_dev(struct bus_type *bus, struct device *start,
286 void *data, int (*fn)(struct device *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287{
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800288 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800289 struct device *dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800290 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800292 if (!bus)
293 return -EINVAL;
294
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700295 klist_iter_init_node(&bus->p->klist_devices, &i,
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800296 (start ? &start->p->knode_bus : NULL));
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800297 while ((dev = next_device(&i)) && !error)
298 error = fn(dev, data);
299 klist_iter_exit(&i);
300 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800302EXPORT_SYMBOL_GPL(bus_for_each_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303
Cornelia Huck0edb5862005-06-22 16:59:51 +0200304/**
305 * bus_find_device - device iterator for locating a particular device.
306 * @bus: bus type
307 * @start: Device to begin with
308 * @data: Data to pass to match function
309 * @match: Callback function to check device
310 *
311 * This is similar to the bus_for_each_dev() function above, but it
312 * returns a reference to a device that is 'found' for later use, as
313 * determined by the @match callback.
314 *
315 * The callback should return 0 if the device doesn't match and non-zero
316 * if it does. If the callback returns non-zero, this function will
317 * return to the caller and not iterate over any more devices.
318 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800319struct device *bus_find_device(struct bus_type *bus,
320 struct device *start, void *data,
321 int (*match)(struct device *dev, void *data))
Cornelia Huck0edb5862005-06-22 16:59:51 +0200322{
323 struct klist_iter i;
324 struct device *dev;
325
326 if (!bus)
327 return NULL;
328
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700329 klist_iter_init_node(&bus->p->klist_devices, &i,
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800330 (start ? &start->p->knode_bus : NULL));
Cornelia Huck0edb5862005-06-22 16:59:51 +0200331 while ((dev = next_device(&i)))
332 if (match(dev, data) && get_device(dev))
333 break;
334 klist_iter_exit(&i);
335 return dev;
336}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800337EXPORT_SYMBOL_GPL(bus_find_device);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800338
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800339static int match_name(struct device *dev, void *data)
340{
341 const char *name = data;
342
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100343 return sysfs_streq(name, dev_name(dev));
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800344}
345
346/**
347 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
348 * @bus: bus type
349 * @start: Device to begin with
350 * @name: name of the device to match
351 *
352 * This is similar to the bus_find_device() function above, but it handles
353 * searching by a name automatically, no need to write another strcmp matching
354 * function.
355 */
356struct device *bus_find_device_by_name(struct bus_type *bus,
357 struct device *start, const char *name)
358{
359 return bus_find_device(bus, start, (void *)name, match_name);
360}
361EXPORT_SYMBOL_GPL(bus_find_device_by_name);
362
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800363static struct device_driver *next_driver(struct klist_iter *i)
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800364{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800365 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800366 struct driver_private *drv_priv;
367
368 if (n) {
369 drv_priv = container_of(n, struct driver_private, knode_bus);
370 return drv_priv->driver;
371 }
372 return NULL;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800373}
374
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800376 * bus_for_each_drv - driver iterator
377 * @bus: bus we're dealing with.
378 * @start: driver to start iterating on.
379 * @data: data to pass to the callback.
380 * @fn: function to call for each driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800382 * This is nearly identical to the device iterator above.
383 * We iterate over each driver that belongs to @bus, and call
384 * @fn for each. If @fn returns anything but 0, we break out
385 * and return it. If @start is not NULL, we use it as the head
386 * of the list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800388 * NOTE: we don't return the driver that returns a non-zero
389 * value, nor do we leave the reference count incremented for that
390 * driver. If the caller needs to know that info, it must set it
391 * in the callback. It must also be sure to increment the refcount
392 * so it doesn't disappear before returning to the caller.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800394int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
395 void *data, int (*fn)(struct device_driver *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396{
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800397 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800398 struct device_driver *drv;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800399 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800401 if (!bus)
402 return -EINVAL;
403
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700404 klist_iter_init_node(&bus->p->klist_drivers, &i,
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800405 start ? &start->p->knode_bus : NULL);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800406 while ((drv = next_driver(&i)) && !error)
407 error = fn(drv, data);
408 klist_iter_exit(&i);
409 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800411EXPORT_SYMBOL_GPL(bus_for_each_drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
Andrew Morton4aca67e2007-02-13 22:39:26 -0800413static int device_add_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414{
415 int error = 0;
416 int i;
417
Andrew Morton4aca67e2007-02-13 22:39:26 -0800418 if (!bus->dev_attrs)
419 return 0;
420
421 for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800422 error = device_create_file(dev, &bus->dev_attrs[i]);
Andrew Morton4aca67e2007-02-13 22:39:26 -0800423 if (error) {
424 while (--i >= 0)
425 device_remove_file(dev, &bus->dev_attrs[i]);
426 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 }
428 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430}
431
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800432static void device_remove_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433{
434 int i;
435
436 if (bus->dev_attrs) {
437 for (i = 0; attr_name(bus->dev_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800438 device_remove_file(dev, &bus->dev_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 }
440}
441
Kay Sieversb9cafc72006-09-14 11:23:28 +0200442#ifdef CONFIG_SYSFS_DEPRECATED
443static int make_deprecated_bus_links(struct device *dev)
444{
445 return sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700446 &dev->bus->p->subsys.kobj, "bus");
Kay Sieversb9cafc72006-09-14 11:23:28 +0200447}
448
449static void remove_deprecated_bus_links(struct device *dev)
450{
451 sysfs_remove_link(&dev->kobj, "bus");
452}
453#else
454static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
455static inline void remove_deprecated_bus_links(struct device *dev) { }
456#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
458/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800459 * bus_add_device - add device to bus
460 * @dev: device being added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 *
Alan Stern2023c612009-07-30 15:27:18 -0400462 * - Add device's bus attributes.
463 * - Create links to device's bus.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800464 * - Add the device to its bus's list of devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800466int bus_add_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800468 struct bus_type *bus = bus_get(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 int error = 0;
470
471 if (bus) {
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100472 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
Greg Kroah-Hartmand377e852005-06-22 16:09:05 -0700473 error = device_add_attrs(bus, dev);
Andrew Mortonf86db392006-08-14 22:43:20 -0700474 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200475 goto out_put;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700476 error = sysfs_create_link(&bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100477 &dev->kobj, dev_name(dev));
Andrew Mortonf86db392006-08-14 22:43:20 -0700478 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200479 goto out_id;
Andrew Mortonf86db392006-08-14 22:43:20 -0700480 error = sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700481 &dev->bus->p->subsys.kobj, "subsystem");
Andrew Mortonf86db392006-08-14 22:43:20 -0700482 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200483 goto out_subsys;
Kay Sieversb9cafc72006-09-14 11:23:28 +0200484 error = make_deprecated_bus_links(dev);
Cornelia Huck513e7332006-09-22 11:37:08 +0200485 if (error)
486 goto out_deprecated;
Alan Stern2023c612009-07-30 15:27:18 -0400487 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 }
Cornelia Huck513e7332006-09-22 11:37:08 +0200489 return 0;
490
491out_deprecated:
492 sysfs_remove_link(&dev->kobj, "subsystem");
493out_subsys:
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100494 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
Cornelia Huck513e7332006-09-22 11:37:08 +0200495out_id:
496 device_remove_attrs(bus, dev);
497out_put:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700498 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 return error;
500}
501
502/**
Alan Stern2023c612009-07-30 15:27:18 -0400503 * bus_probe_device - probe drivers for a new device
504 * @dev: device to probe
Kay Sievers53877d02006-04-04 20:42:26 +0200505 *
Alan Stern2023c612009-07-30 15:27:18 -0400506 * - Automatically probe for a driver if the bus allows it.
Kay Sievers53877d02006-04-04 20:42:26 +0200507 */
Alan Stern2023c612009-07-30 15:27:18 -0400508void bus_probe_device(struct device *dev)
Kay Sievers53877d02006-04-04 20:42:26 +0200509{
Andrew Mortonf86db392006-08-14 22:43:20 -0700510 struct bus_type *bus = dev->bus;
Alan Stern2023c612009-07-30 15:27:18 -0400511 int ret;
Kay Sievers53877d02006-04-04 20:42:26 +0200512
Alan Stern2023c612009-07-30 15:27:18 -0400513 if (bus && bus->p->drivers_autoprobe) {
514 ret = device_attach(dev);
Cornelia Huckc6a46692007-02-05 16:15:26 -0800515 WARN_ON(ret < 0);
Kay Sievers53877d02006-04-04 20:42:26 +0200516 }
517}
518
519/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800520 * bus_remove_device - remove device from bus
521 * @dev: device to be removed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800523 * - Remove symlink from bus's directory.
524 * - Delete device from bus's list.
525 * - Detach from its driver.
526 * - Drop reference taken in bus_add_device().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800528void bus_remove_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529{
530 if (dev->bus) {
Kay Sieversb9d9c822006-06-15 15:31:56 +0200531 sysfs_remove_link(&dev->kobj, "subsystem");
Kay Sieversb9cafc72006-09-14 11:23:28 +0200532 remove_deprecated_bus_links(dev);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800533 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100534 dev_name(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 device_remove_attrs(dev->bus, dev);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800536 if (klist_node_attached(&dev->p->knode_bus))
537 klist_del(&dev->p->knode_bus);
Greg Kroah-Hartman3f62e572008-03-13 17:07:03 -0400538
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800539 pr_debug("bus: '%s': remove device %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100540 dev->bus->name, dev_name(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 device_release_driver(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700542 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 }
544}
545
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800546static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547{
548 int error = 0;
549 int i;
550
551 if (bus->drv_attrs) {
552 for (i = 0; attr_name(bus->drv_attrs[i]); i++) {
553 error = driver_create_file(drv, &bus->drv_attrs[i]);
554 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800555 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 }
557 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800558done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800560err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 while (--i >= 0)
562 driver_remove_file(drv, &bus->drv_attrs[i]);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800563 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564}
565
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800566static void driver_remove_attrs(struct bus_type *bus,
567 struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568{
569 int i;
570
571 if (bus->drv_attrs) {
572 for (i = 0; attr_name(bus->drv_attrs[i]); i++)
573 driver_remove_file(drv, &bus->drv_attrs[i]);
574 }
575}
576
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800577#ifdef CONFIG_HOTPLUG
578/*
579 * Thanks to drivers making their tables __devinit, we can't allow manual
580 * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
581 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700582static int __must_check add_bind_files(struct device_driver *drv)
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800583{
Andrew Mortonf86db392006-08-14 22:43:20 -0700584 int ret;
585
586 ret = driver_create_file(drv, &driver_attr_unbind);
587 if (ret == 0) {
588 ret = driver_create_file(drv, &driver_attr_bind);
589 if (ret)
590 driver_remove_file(drv, &driver_attr_unbind);
591 }
592 return ret;
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800593}
594
595static void remove_bind_files(struct device_driver *drv)
596{
597 driver_remove_file(drv, &driver_attr_bind);
598 driver_remove_file(drv, &driver_attr_unbind);
599}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100600
Kay Sievers83807702007-07-30 02:28:56 +0200601static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
602static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
603 show_drivers_autoprobe, store_drivers_autoprobe);
604
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100605static int add_probe_files(struct bus_type *bus)
606{
607 int retval;
608
Kay Sievers83807702007-07-30 02:28:56 +0200609 retval = bus_create_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100610 if (retval)
611 goto out;
612
Kay Sievers83807702007-07-30 02:28:56 +0200613 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100614 if (retval)
Kay Sievers83807702007-07-30 02:28:56 +0200615 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100616out:
617 return retval;
618}
619
620static void remove_probe_files(struct bus_type *bus)
621{
Kay Sievers83807702007-07-30 02:28:56 +0200622 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
623 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100624}
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800625#else
Yoichi Yuasa35acfdd2006-07-15 01:30:11 +0900626static inline int add_bind_files(struct device_driver *drv) { return 0; }
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800627static inline void remove_bind_files(struct device_driver *drv) {}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100628static inline int add_probe_files(struct bus_type *bus) { return 0; }
629static inline void remove_probe_files(struct bus_type *bus) {}
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800630#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200632static ssize_t driver_uevent_store(struct device_driver *drv,
633 const char *buf, size_t count)
634{
635 enum kobject_action action;
636
637 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800638 kobject_uevent(&drv->p->kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200639 return count;
640}
641static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
642
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800644 * bus_add_driver - Add a driver to the bus.
645 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700647int bus_add_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800649 struct bus_type *bus;
650 struct driver_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 int error = 0;
652
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800653 bus = bus_get(drv->bus);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400654 if (!bus)
Greg Kroah-Hartman4f6e1942007-04-20 11:29:52 -0700655 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800657 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800658
659 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
Cornelia Huck07634462008-02-18 17:04:25 +0100660 if (!priv) {
661 error = -ENOMEM;
662 goto out_put_bus;
663 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800664 klist_init(&priv->klist_devices, NULL, NULL);
665 priv->driver = drv;
666 drv->p = priv;
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400667 priv->kobj.kset = bus->p->drivers_kset;
668 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
669 "%s", drv->name);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700670 if (error)
Cornelia Huck07634462008-02-18 17:04:25 +0100671 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700673 if (drv->bus->p->drivers_autoprobe) {
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100674 error = driver_attach(drv);
675 if (error)
676 goto out_unregister;
677 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800678 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400679 module_add_driver(drv->owner, drv);
680
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200681 error = driver_create_file(drv, &driver_attr_uevent);
682 if (error) {
683 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800684 __func__, drv->name);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200685 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400686 error = driver_add_attrs(bus, drv);
687 if (error) {
688 /* How the hell do we get out of this pickle? Give up */
689 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800690 __func__, drv->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 }
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700692
693 if (!drv->suppress_bind_attrs) {
694 error = add_bind_files(drv);
695 if (error) {
696 /* Ditto */
697 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
698 __func__, drv->name);
699 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400700 }
701
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400702 kobject_uevent(&priv->kobj, KOBJ_ADD);
Kay Sievers5c8563d2009-05-28 14:24:07 -0700703 return 0;
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700704
Andrew Mortonf86db392006-08-14 22:43:20 -0700705out_unregister:
Kay Sievers5c8563d2009-05-28 14:24:07 -0700706 kfree(drv->p);
707 drv->p = NULL;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800708 kobject_put(&priv->kobj);
Andrew Mortonf86db392006-08-14 22:43:20 -0700709out_put_bus:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700710 bus_put(bus);
Andrew Mortonf86db392006-08-14 22:43:20 -0700711 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712}
713
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800715 * bus_remove_driver - delete driver from bus's knowledge.
716 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800718 * Detach the driver from the devices it controls, and remove
719 * it from its bus's list of drivers. Finally, we drop the reference
720 * to the bus we took in bus_add_driver().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800722void bus_remove_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723{
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400724 if (!drv->bus)
725 return;
726
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700727 if (!drv->suppress_bind_attrs)
728 remove_bind_files(drv);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400729 driver_remove_attrs(drv->bus, drv);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200730 driver_remove_file(drv, &driver_attr_uevent);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800731 klist_remove(&drv->p->knode_bus);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800732 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400733 driver_detach(drv);
734 module_remove_driver(drv);
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800735 kobject_put(&drv->p->kobj);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700736 bus_put(drv->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737}
738
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739/* Helper for bus_rescan_devices's iter */
Andrew Mortonf86db392006-08-14 22:43:20 -0700740static int __must_check bus_rescan_devices_helper(struct device *dev,
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800741 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742{
Andrew Mortonf86db392006-08-14 22:43:20 -0700743 int ret = 0;
744
Alan Sternbf74ad52005-11-17 16:54:12 -0500745 if (!dev->driver) {
746 if (dev->parent) /* Needed for USB */
747 down(&dev->parent->sem);
Andrew Mortonf86db392006-08-14 22:43:20 -0700748 ret = device_attach(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500749 if (dev->parent)
750 up(&dev->parent->sem);
751 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700752 return ret < 0 ? ret : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753}
754
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755/**
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700756 * bus_rescan_devices - rescan devices on the bus for possible drivers
757 * @bus: the bus to scan.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 *
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700759 * This function will look for devices on the bus with no driver
760 * attached and rescan it against existing drivers to see if it matches
761 * any by calling device_attach() for the unbound devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800763int bus_rescan_devices(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764{
Andrew Mortonf86db392006-08-14 22:43:20 -0700765 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800767EXPORT_SYMBOL_GPL(bus_rescan_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
Moore, Erice935d5d2006-03-14 09:18:18 -0700769/**
770 * device_reprobe - remove driver for a device and probe for a new driver
771 * @dev: the device to reprobe
772 *
773 * This function detaches the attached driver (if any) for the given
774 * device and restarts the driver probing process. It is intended
775 * to use if probing criteria changed during a devices lifetime and
776 * driver attachment should change accordingly.
777 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700778int device_reprobe(struct device *dev)
Moore, Erice935d5d2006-03-14 09:18:18 -0700779{
780 if (dev->driver) {
781 if (dev->parent) /* Needed for USB */
782 down(&dev->parent->sem);
783 device_release_driver(dev);
784 if (dev->parent)
785 up(&dev->parent->sem);
786 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700787 return bus_rescan_devices_helper(dev, NULL);
Moore, Erice935d5d2006-03-14 09:18:18 -0700788}
789EXPORT_SYMBOL_GPL(device_reprobe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800792 * find_bus - locate bus by name.
793 * @name: name of bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800795 * Call kset_find_obj() to iterate over list of buses to
796 * find a bus by name. Return bus if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800798 * Note that kset_find_obj increments bus' reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 */
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200800#if 0
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800801struct bus_type *find_bus(char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800803 struct kobject *k = kset_find_obj(bus_kset, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 return k ? to_bus(k) : NULL;
805}
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200806#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807
808
809/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800810 * bus_add_attrs - Add default attributes for this bus.
811 * @bus: Bus that has just been registered.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 */
813
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800814static int bus_add_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815{
816 int error = 0;
817 int i;
818
819 if (bus->bus_attrs) {
820 for (i = 0; attr_name(bus->bus_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800821 error = bus_create_file(bus, &bus->bus_attrs[i]);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700822 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800823 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824 }
825 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800826done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800828err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 while (--i >= 0)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800830 bus_remove_file(bus, &bus->bus_attrs[i]);
831 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832}
833
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800834static void bus_remove_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835{
836 int i;
837
838 if (bus->bus_attrs) {
839 for (i = 0; attr_name(bus->bus_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800840 bus_remove_file(bus, &bus->bus_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 }
842}
843
James Bottomley34bb61f2005-09-06 16:56:51 -0700844static void klist_devices_get(struct klist_node *n)
845{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800846 struct device_private *dev_prv = to_device_private_bus(n);
847 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700848
849 get_device(dev);
850}
851
852static void klist_devices_put(struct klist_node *n)
853{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800854 struct device_private *dev_prv = to_device_private_bus(n);
855 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700856
857 put_device(dev);
858}
859
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200860static ssize_t bus_uevent_store(struct bus_type *bus,
861 const char *buf, size_t count)
862{
863 enum kobject_action action;
864
865 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700866 kobject_uevent(&bus->p->subsys.kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200867 return count;
868}
869static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
870
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800872 * bus_register - register a bus with the system.
873 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800875 * Once we have that, we registered the bus with the kobject
876 * infrastructure, then register the children subsystems it has:
877 * the devices and drivers that belong to the bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800879int bus_register(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880{
881 int retval;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700882 struct bus_type_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700884 priv = kzalloc(sizeof(struct bus_type_private), GFP_KERNEL);
885 if (!priv)
886 return -ENOMEM;
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000887
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700888 priv->bus = bus;
889 bus->p = priv;
890
891 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
892
893 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 if (retval)
895 goto out;
896
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700897 priv->subsys.kobj.kset = bus_kset;
898 priv->subsys.kobj.ktype = &bus_ktype;
899 priv->drivers_autoprobe = 1;
Greg Kroah-Hartmand6b05b82007-09-12 15:06:57 -0700900
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700901 retval = kset_register(&priv->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 if (retval)
903 goto out;
904
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200905 retval = bus_create_file(bus, &bus_attr_uevent);
906 if (retval)
907 goto bus_uevent_fail;
908
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700909 priv->devices_kset = kset_create_and_add("devices", NULL,
910 &priv->subsys.kobj);
911 if (!priv->devices_kset) {
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700912 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 goto bus_devices_fail;
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700914 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700916 priv->drivers_kset = kset_create_and_add("drivers", NULL,
917 &priv->subsys.kobj);
918 if (!priv->drivers_kset) {
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700919 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 goto bus_drivers_fail;
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700921 }
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800922
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700923 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
924 klist_init(&priv->klist_drivers, NULL, NULL);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100925
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100926 retval = add_probe_files(bus);
927 if (retval)
928 goto bus_probe_files_fail;
929
Cornelia Huck1bb68812006-09-22 11:37:04 +0200930 retval = bus_add_attrs(bus);
931 if (retval)
932 goto bus_attrs_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800934 pr_debug("bus: '%s': registered\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 return 0;
936
Cornelia Huck1bb68812006-09-22 11:37:04 +0200937bus_attrs_fail:
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100938 remove_probe_files(bus);
939bus_probe_files_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700940 kset_unregister(bus->p->drivers_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941bus_drivers_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700942 kset_unregister(bus->p->devices_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943bus_devices_fail:
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200944 bus_remove_file(bus, &bus_attr_uevent);
945bus_uevent_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700946 kset_unregister(&bus->p->subsys);
947 kfree(bus->p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948out:
Dave Youngf48f3fe2009-02-14 21:23:22 +0800949 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 return retval;
951}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800952EXPORT_SYMBOL_GPL(bus_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800955 * bus_unregister - remove a bus from the system
956 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800958 * Unregister the child subsystems and the bus itself.
959 * Finally, we call bus_put() to release the refcount
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800961void bus_unregister(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962{
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800963 pr_debug("bus: '%s': unregistering\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 bus_remove_attrs(bus);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100965 remove_probe_files(bus);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700966 kset_unregister(bus->p->drivers_kset);
967 kset_unregister(bus->p->devices_kset);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200968 bus_remove_file(bus, &bus_attr_uevent);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700969 kset_unregister(&bus->p->subsys);
970 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +0800971 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800973EXPORT_SYMBOL_GPL(bus_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000975int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
976{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700977 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000978}
979EXPORT_SYMBOL_GPL(bus_register_notifier);
980
981int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
982{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700983 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000984}
985EXPORT_SYMBOL_GPL(bus_unregister_notifier);
986
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -0700987struct kset *bus_get_kset(struct bus_type *bus)
988{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700989 return &bus->p->subsys;
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -0700990}
991EXPORT_SYMBOL_GPL(bus_get_kset);
992
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -0700993struct klist *bus_get_device_klist(struct bus_type *bus)
994{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700995 return &bus->p->klist_devices;
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -0700996}
997EXPORT_SYMBOL_GPL(bus_get_device_klist);
998
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -0500999/*
1000 * Yes, this forcably breaks the klist abstraction temporarily. It
1001 * just wants to sort the klist, not change reference counts and
1002 * take/drop locks rapidly in the process. It does all this while
1003 * holding the lock for the list, so objects can't otherwise be
1004 * added/removed while we're swizzling.
1005 */
1006static void device_insertion_sort_klist(struct device *a, struct list_head *list,
1007 int (*compare)(const struct device *a,
1008 const struct device *b))
1009{
1010 struct list_head *pos;
1011 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001012 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001013 struct device *b;
1014
1015 list_for_each(pos, list) {
1016 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001017 dev_prv = to_device_private_bus(n);
1018 b = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001019 if (compare(a, b) <= 0) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001020 list_move_tail(&a->p->knode_bus.n_node,
1021 &b->p->knode_bus.n_node);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001022 return;
1023 }
1024 }
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001025 list_move_tail(&a->p->knode_bus.n_node, list);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001026}
1027
1028void bus_sort_breadthfirst(struct bus_type *bus,
1029 int (*compare)(const struct device *a,
1030 const struct device *b))
1031{
1032 LIST_HEAD(sorted_devices);
1033 struct list_head *pos, *tmp;
1034 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001035 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001036 struct device *dev;
1037 struct klist *device_klist;
1038
1039 device_klist = bus_get_device_klist(bus);
1040
1041 spin_lock(&device_klist->k_lock);
1042 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1043 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001044 dev_prv = to_device_private_bus(n);
1045 dev = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001046 device_insertion_sort_klist(dev, &sorted_devices, compare);
1047 }
1048 list_splice(&sorted_devices, &device_klist->k_list);
1049 spin_unlock(&device_klist->k_lock);
1050}
1051EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1052
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053int __init buses_init(void)
1054{
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001055 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
1056 if (!bus_kset)
1057 return -ENOMEM;
1058 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059}