blob: 181ed2660b33b7f4e96e18250b493edd90539def [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090016#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/init.h>
18#include <linux/string.h>
Kay Sieversca22e562011-12-14 14:29:38 -080019#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include "base.h"
21#include "power/power.h"
22
Kay Sieversca22e562011-12-14 14:29:38 -080023/* /sys/devices/system */
H Hartley Sweeten97ec4482012-04-16 18:14:10 -070024static struct kset *system_kset;
Kay Sieversca22e562011-12-14 14:29:38 -080025
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28/*
29 * sysfs bindings for drivers
30 */
31
32#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34
Kay Sieversb8c5cec2007-02-16 17:33:36 +010035static int __must_check bus_rescan_devices_helper(struct device *dev,
36 void *data);
37
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070038static struct bus_type *bus_get(struct bus_type *bus)
39{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070040 if (bus) {
41 kset_get(&bus->p->subsys);
42 return bus;
43 }
44 return NULL;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070045}
46
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070047static void bus_put(struct bus_type *bus)
48{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070049 if (bus)
50 kset_put(&bus->p->subsys);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070051}
52
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080053static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
54 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070055{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080056 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080057 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050058 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60 if (drv_attr->show)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080061 ret = drv_attr->show(drv_priv->driver, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 return ret;
63}
64
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080065static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
66 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080068 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080069 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050070 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72 if (drv_attr->store)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080073 ret = drv_attr->store(drv_priv->driver, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 return ret;
75}
76
Emese Revfy52cf25d2010-01-19 02:58:23 +010077static const struct sysfs_ops driver_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 .show = drv_attr_show,
79 .store = drv_attr_store,
80};
81
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080082static void driver_release(struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080084 struct driver_private *drv_priv = to_driver(kobj);
85
Harvey Harrison2b3a3022008-03-04 16:41:05 -080086 pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080087 kfree(drv_priv);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088}
89
Greg Kroah-Hartmana1148fb2007-10-11 10:47:49 -060090static struct kobj_type driver_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 .sysfs_ops = &driver_sysfs_ops,
92 .release = driver_release,
93};
94
Linus Torvalds1da177e2005-04-16 15:20:36 -070095/*
96 * sysfs bindings for buses
97 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080098static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
99 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800101 struct bus_attribute *bus_attr = to_bus_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100102 struct subsys_private *subsys_priv = to_subsys_private(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 ssize_t ret = 0;
104
105 if (bus_attr->show)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100106 ret = bus_attr->show(subsys_priv->bus, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 return ret;
108}
109
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800110static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
111 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800113 struct bus_attribute *bus_attr = to_bus_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100114 struct subsys_private *subsys_priv = to_subsys_private(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 ssize_t ret = 0;
116
117 if (bus_attr->store)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100118 ret = bus_attr->store(subsys_priv->bus, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 return ret;
120}
121
Emese Revfy52cf25d2010-01-19 02:58:23 +0100122static const struct sysfs_ops bus_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 .show = bus_attr_show,
124 .store = bus_attr_store,
125};
126
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800127int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
129 int error;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700130 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700131 error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700132 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 } else
134 error = -EINVAL;
135 return error;
136}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800137EXPORT_SYMBOL_GPL(bus_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800139void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700141 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700142 sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700143 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 }
145}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800146EXPORT_SYMBOL_GPL(bus_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Kay Sievers80f03e32007-05-26 11:21:36 +0200148static struct kobj_type bus_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 .sysfs_ops = &bus_sysfs_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150};
151
Kay Sievers80f03e32007-05-26 11:21:36 +0200152static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
153{
154 struct kobj_type *ktype = get_ktype(kobj);
155
156 if (ktype == &bus_ktype)
157 return 1;
158 return 0;
159}
160
Emese Revfy9cd43612009-12-31 14:52:51 +0100161static const struct kset_uevent_ops bus_uevent_ops = {
Kay Sievers80f03e32007-05-26 11:21:36 +0200162 .filter = bus_uevent_filter,
163};
164
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -0500165static struct kset *bus_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
Russell King2139bdd2006-02-07 12:58:20 -0800168#ifdef CONFIG_HOTPLUG
Alan Stern2b08c8d2005-11-23 15:43:50 -0800169/* Manually detach a device from its associated driver. */
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700170static ssize_t driver_unbind(struct device_driver *drv,
171 const char *buf, size_t count)
172{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700173 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700174 struct device *dev;
175 int err = -ENODEV;
176
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800177 dev = bus_find_device_by_name(bus, NULL, buf);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800178 if (dev && dev->driver == drv) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500179 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800180 device_lock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700181 device_release_driver(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500182 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800183 device_unlock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700184 err = count;
185 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800186 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700187 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800188 return err;
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700189}
190static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
191
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700192/*
193 * Manually attach a device to a driver.
194 * Note: the driver must want to bind to the device,
195 * it is not possible to override the driver's id table.
196 */
197static ssize_t driver_bind(struct device_driver *drv,
198 const char *buf, size_t count)
199{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700200 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700201 struct device *dev;
202 int err = -ENODEV;
203
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800204 dev = bus_find_device_by_name(bus, NULL, buf);
Ming Lei49b420a2009-01-21 23:27:47 +0800205 if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500206 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800207 device_lock(dev->parent);
208 device_lock(dev);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700209 err = driver_probe_device(drv, dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800210 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500211 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800212 device_unlock(dev->parent);
Ryan Wilson37225402006-03-22 16:26:25 -0500213
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800214 if (err > 0) {
215 /* success */
Ryan Wilson37225402006-03-22 16:26:25 -0500216 err = count;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800217 } else if (err == 0) {
218 /* driver didn't accept device */
Ryan Wilson37225402006-03-22 16:26:25 -0500219 err = -ENODEV;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800220 }
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700221 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800222 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700223 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800224 return err;
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700225}
226static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
227
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100228static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
229{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700230 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100231}
232
233static ssize_t store_drivers_autoprobe(struct bus_type *bus,
234 const char *buf, size_t count)
235{
236 if (buf[0] == '0')
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700237 bus->p->drivers_autoprobe = 0;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100238 else
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700239 bus->p->drivers_autoprobe = 1;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100240 return count;
241}
242
243static ssize_t store_drivers_probe(struct bus_type *bus,
244 const char *buf, size_t count)
245{
246 struct device *dev;
247
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800248 dev = bus_find_device_by_name(bus, NULL, buf);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100249 if (!dev)
250 return -ENODEV;
251 if (bus_rescan_devices_helper(dev, NULL) != 0)
252 return -EINVAL;
253 return count;
254}
Russell King2139bdd2006-02-07 12:58:20 -0800255#endif
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700256
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800257static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800258{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800259 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800260 struct device *dev = NULL;
261 struct device_private *dev_prv;
262
263 if (n) {
264 dev_prv = to_device_private_bus(n);
265 dev = dev_prv->device;
266 }
267 return dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800268}
269
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800271 * bus_for_each_dev - device iterator.
272 * @bus: bus type.
273 * @start: device to start iterating from.
274 * @data: data for the callback.
275 * @fn: function to be called for each device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800277 * Iterate over @bus's list of devices, and call @fn for each,
278 * passing it @data. If @start is not NULL, we use that device to
279 * begin iterating from.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800281 * We check the return of @fn each time. If it returns anything
282 * other than 0, we break out and return that value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800284 * NOTE: The device that returns a non-zero value is not retained
285 * in any way, nor is its refcount incremented. If the caller needs
Alex Chiang0fa1b0a2009-05-14 23:15:22 +0200286 * to retain this data, it should do so, and increment the reference
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800287 * count in the supplied callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800289int bus_for_each_dev(struct bus_type *bus, struct device *start,
290 void *data, int (*fn)(struct device *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291{
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800292 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800293 struct device *dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800294 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800296 if (!bus)
297 return -EINVAL;
298
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700299 klist_iter_init_node(&bus->p->klist_devices, &i,
300 (start ? &start->p->knode_bus : NULL));
301 while ((dev = next_device(&i)) && !error)
302 error = fn(dev, data);
303 klist_iter_exit(&i);
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800304 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800306EXPORT_SYMBOL_GPL(bus_for_each_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Cornelia Huck0edb5862005-06-22 16:59:51 +0200308/**
309 * bus_find_device - device iterator for locating a particular device.
310 * @bus: bus type
311 * @start: Device to begin with
312 * @data: Data to pass to match function
313 * @match: Callback function to check device
314 *
315 * This is similar to the bus_for_each_dev() function above, but it
316 * returns a reference to a device that is 'found' for later use, as
317 * determined by the @match callback.
318 *
319 * The callback should return 0 if the device doesn't match and non-zero
320 * if it does. If the callback returns non-zero, this function will
321 * return to the caller and not iterate over any more devices.
322 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800323struct device *bus_find_device(struct bus_type *bus,
324 struct device *start, void *data,
325 int (*match)(struct device *dev, void *data))
Cornelia Huck0edb5862005-06-22 16:59:51 +0200326{
327 struct klist_iter i;
328 struct device *dev;
329
330 if (!bus)
331 return NULL;
332
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700333 klist_iter_init_node(&bus->p->klist_devices, &i,
334 (start ? &start->p->knode_bus : NULL));
Cornelia Huck0edb5862005-06-22 16:59:51 +0200335 while ((dev = next_device(&i)))
336 if (match(dev, data) && get_device(dev))
337 break;
338 klist_iter_exit(&i);
339 return dev;
340}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800341EXPORT_SYMBOL_GPL(bus_find_device);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800342
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800343static int match_name(struct device *dev, void *data)
344{
345 const char *name = data;
346
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100347 return sysfs_streq(name, dev_name(dev));
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800348}
349
350/**
351 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
352 * @bus: bus type
353 * @start: Device to begin with
354 * @name: name of the device to match
355 *
356 * This is similar to the bus_find_device() function above, but it handles
357 * searching by a name automatically, no need to write another strcmp matching
358 * function.
359 */
360struct device *bus_find_device_by_name(struct bus_type *bus,
361 struct device *start, const char *name)
362{
363 return bus_find_device(bus, start, (void *)name, match_name);
364}
365EXPORT_SYMBOL_GPL(bus_find_device_by_name);
366
Kay Sieversca22e562011-12-14 14:29:38 -0800367/**
368 * subsys_find_device_by_id - find a device with a specific enumeration number
369 * @subsys: subsystem
370 * @id: index 'id' in struct device
371 * @hint: device to check first
372 *
373 * Check the hint's next object and if it is a match return it directly,
374 * otherwise, fall back to a full list search. Either way a reference for
375 * the returned object is taken.
376 */
377struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id,
378 struct device *hint)
379{
380 struct klist_iter i;
381 struct device *dev;
382
383 if (!subsys)
384 return NULL;
385
386 if (hint) {
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700387 klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
Kay Sieversca22e562011-12-14 14:29:38 -0800388 dev = next_device(&i);
389 if (dev && dev->id == id && get_device(dev)) {
390 klist_iter_exit(&i);
391 return dev;
392 }
393 klist_iter_exit(&i);
394 }
395
396 klist_iter_init_node(&subsys->p->klist_devices, &i, NULL);
397 while ((dev = next_device(&i))) {
398 if (dev->id == id && get_device(dev)) {
399 klist_iter_exit(&i);
400 return dev;
401 }
402 }
403 klist_iter_exit(&i);
404 return NULL;
405}
406EXPORT_SYMBOL_GPL(subsys_find_device_by_id);
407
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800408static struct device_driver *next_driver(struct klist_iter *i)
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800409{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800410 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800411 struct driver_private *drv_priv;
412
413 if (n) {
414 drv_priv = container_of(n, struct driver_private, knode_bus);
415 return drv_priv->driver;
416 }
417 return NULL;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800418}
419
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800421 * bus_for_each_drv - driver iterator
422 * @bus: bus we're dealing with.
423 * @start: driver to start iterating on.
424 * @data: data to pass to the callback.
425 * @fn: function to call for each driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800427 * This is nearly identical to the device iterator above.
428 * We iterate over each driver that belongs to @bus, and call
429 * @fn for each. If @fn returns anything but 0, we break out
430 * and return it. If @start is not NULL, we use it as the head
431 * of the list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800433 * NOTE: we don't return the driver that returns a non-zero
434 * value, nor do we leave the reference count incremented for that
435 * driver. If the caller needs to know that info, it must set it
436 * in the callback. It must also be sure to increment the refcount
437 * so it doesn't disappear before returning to the caller.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800439int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
440 void *data, int (*fn)(struct device_driver *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441{
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800442 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800443 struct device_driver *drv;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800444 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800446 if (!bus)
447 return -EINVAL;
448
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700449 klist_iter_init_node(&bus->p->klist_drivers, &i,
450 start ? &start->p->knode_bus : NULL);
451 while ((drv = next_driver(&i)) && !error)
452 error = fn(drv, data);
453 klist_iter_exit(&i);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800454 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800456EXPORT_SYMBOL_GPL(bus_for_each_drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
Andrew Morton4aca67e2007-02-13 22:39:26 -0800458static int device_add_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459{
460 int error = 0;
461 int i;
462
Andrew Morton4aca67e2007-02-13 22:39:26 -0800463 if (!bus->dev_attrs)
464 return 0;
465
466 for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800467 error = device_create_file(dev, &bus->dev_attrs[i]);
Andrew Morton4aca67e2007-02-13 22:39:26 -0800468 if (error) {
469 while (--i >= 0)
470 device_remove_file(dev, &bus->dev_attrs[i]);
471 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 }
473 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475}
476
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800477static void device_remove_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478{
479 int i;
480
481 if (bus->dev_attrs) {
482 for (i = 0; attr_name(bus->dev_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800483 device_remove_file(dev, &bus->dev_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 }
485}
486
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800488 * bus_add_device - add device to bus
489 * @dev: device being added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 *
Alan Stern2023c612009-07-30 15:27:18 -0400491 * - Add device's bus attributes.
492 * - Create links to device's bus.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800493 * - Add the device to its bus's list of devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800495int bus_add_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800497 struct bus_type *bus = bus_get(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 int error = 0;
499
500 if (bus) {
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100501 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
Greg Kroah-Hartmand377e852005-06-22 16:09:05 -0700502 error = device_add_attrs(bus, dev);
Andrew Mortonf86db392006-08-14 22:43:20 -0700503 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200504 goto out_put;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700505 error = sysfs_create_link(&bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100506 &dev->kobj, dev_name(dev));
Andrew Mortonf86db392006-08-14 22:43:20 -0700507 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200508 goto out_id;
Andrew Mortonf86db392006-08-14 22:43:20 -0700509 error = sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700510 &dev->bus->p->subsys.kobj, "subsystem");
Andrew Mortonf86db392006-08-14 22:43:20 -0700511 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200512 goto out_subsys;
Alan Stern2023c612009-07-30 15:27:18 -0400513 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 }
Cornelia Huck513e7332006-09-22 11:37:08 +0200515 return 0;
516
Cornelia Huck513e7332006-09-22 11:37:08 +0200517out_subsys:
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100518 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
Cornelia Huck513e7332006-09-22 11:37:08 +0200519out_id:
520 device_remove_attrs(bus, dev);
521out_put:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700522 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 return error;
524}
525
526/**
Alan Stern2023c612009-07-30 15:27:18 -0400527 * bus_probe_device - probe drivers for a new device
528 * @dev: device to probe
Kay Sievers53877d02006-04-04 20:42:26 +0200529 *
Alan Stern2023c612009-07-30 15:27:18 -0400530 * - Automatically probe for a driver if the bus allows it.
Kay Sievers53877d02006-04-04 20:42:26 +0200531 */
Alan Stern2023c612009-07-30 15:27:18 -0400532void bus_probe_device(struct device *dev)
Kay Sievers53877d02006-04-04 20:42:26 +0200533{
Andrew Mortonf86db392006-08-14 22:43:20 -0700534 struct bus_type *bus = dev->bus;
Kay Sieversca22e562011-12-14 14:29:38 -0800535 struct subsys_interface *sif;
Alan Stern2023c612009-07-30 15:27:18 -0400536 int ret;
Kay Sievers53877d02006-04-04 20:42:26 +0200537
Kay Sieversca22e562011-12-14 14:29:38 -0800538 if (!bus)
539 return;
540
541 if (bus->p->drivers_autoprobe) {
Alan Stern2023c612009-07-30 15:27:18 -0400542 ret = device_attach(dev);
Cornelia Huckc6a46692007-02-05 16:15:26 -0800543 WARN_ON(ret < 0);
Kay Sievers53877d02006-04-04 20:42:26 +0200544 }
Kay Sieversca22e562011-12-14 14:29:38 -0800545
546 mutex_lock(&bus->p->mutex);
547 list_for_each_entry(sif, &bus->p->interfaces, node)
548 if (sif->add_dev)
549 sif->add_dev(dev, sif);
550 mutex_unlock(&bus->p->mutex);
Kay Sievers53877d02006-04-04 20:42:26 +0200551}
552
553/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800554 * bus_remove_device - remove device from bus
555 * @dev: device to be removed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 *
Kay Sieversca22e562011-12-14 14:29:38 -0800557 * - Remove device from all interfaces.
558 * - Remove symlink from bus' directory.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800559 * - Delete device from bus's list.
560 * - Detach from its driver.
561 * - Drop reference taken in bus_add_device().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800563void bus_remove_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564{
Kay Sieversca22e562011-12-14 14:29:38 -0800565 struct bus_type *bus = dev->bus;
566 struct subsys_interface *sif;
Greg Kroah-Hartman3f62e572008-03-13 17:07:03 -0400567
Kay Sieversca22e562011-12-14 14:29:38 -0800568 if (!bus)
569 return;
570
571 mutex_lock(&bus->p->mutex);
572 list_for_each_entry(sif, &bus->p->interfaces, node)
573 if (sif->remove_dev)
574 sif->remove_dev(dev, sif);
575 mutex_unlock(&bus->p->mutex);
576
577 sysfs_remove_link(&dev->kobj, "subsystem");
578 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
579 dev_name(dev));
580 device_remove_attrs(dev->bus, dev);
581 if (klist_node_attached(&dev->p->knode_bus))
582 klist_del(&dev->p->knode_bus);
583
584 pr_debug("bus: '%s': remove device %s\n",
585 dev->bus->name, dev_name(dev));
586 device_release_driver(dev);
587 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588}
589
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800590static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591{
592 int error = 0;
593 int i;
594
595 if (bus->drv_attrs) {
596 for (i = 0; attr_name(bus->drv_attrs[i]); i++) {
597 error = driver_create_file(drv, &bus->drv_attrs[i]);
598 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800599 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 }
601 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800602done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800604err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 while (--i >= 0)
606 driver_remove_file(drv, &bus->drv_attrs[i]);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800607 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608}
609
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800610static void driver_remove_attrs(struct bus_type *bus,
611 struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612{
613 int i;
614
615 if (bus->drv_attrs) {
616 for (i = 0; attr_name(bus->drv_attrs[i]); i++)
617 driver_remove_file(drv, &bus->drv_attrs[i]);
618 }
619}
620
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800621#ifdef CONFIG_HOTPLUG
622/*
623 * Thanks to drivers making their tables __devinit, we can't allow manual
624 * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
625 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700626static int __must_check add_bind_files(struct device_driver *drv)
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800627{
Andrew Mortonf86db392006-08-14 22:43:20 -0700628 int ret;
629
630 ret = driver_create_file(drv, &driver_attr_unbind);
631 if (ret == 0) {
632 ret = driver_create_file(drv, &driver_attr_bind);
633 if (ret)
634 driver_remove_file(drv, &driver_attr_unbind);
635 }
636 return ret;
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800637}
638
639static void remove_bind_files(struct device_driver *drv)
640{
641 driver_remove_file(drv, &driver_attr_bind);
642 driver_remove_file(drv, &driver_attr_unbind);
643}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100644
Kay Sievers83807702007-07-30 02:28:56 +0200645static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
646static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
647 show_drivers_autoprobe, store_drivers_autoprobe);
648
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100649static int add_probe_files(struct bus_type *bus)
650{
651 int retval;
652
Kay Sievers83807702007-07-30 02:28:56 +0200653 retval = bus_create_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100654 if (retval)
655 goto out;
656
Kay Sievers83807702007-07-30 02:28:56 +0200657 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100658 if (retval)
Kay Sievers83807702007-07-30 02:28:56 +0200659 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100660out:
661 return retval;
662}
663
664static void remove_probe_files(struct bus_type *bus)
665{
Kay Sievers83807702007-07-30 02:28:56 +0200666 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
667 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100668}
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800669#else
Yoichi Yuasa35acfdd2006-07-15 01:30:11 +0900670static inline int add_bind_files(struct device_driver *drv) { return 0; }
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800671static inline void remove_bind_files(struct device_driver *drv) {}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100672static inline int add_probe_files(struct bus_type *bus) { return 0; }
673static inline void remove_probe_files(struct bus_type *bus) {}
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800674#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200676static ssize_t driver_uevent_store(struct device_driver *drv,
677 const char *buf, size_t count)
678{
679 enum kobject_action action;
680
681 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800682 kobject_uevent(&drv->p->kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200683 return count;
684}
685static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
686
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800688 * bus_add_driver - Add a driver to the bus.
689 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700691int bus_add_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800693 struct bus_type *bus;
694 struct driver_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 int error = 0;
696
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800697 bus = bus_get(drv->bus);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400698 if (!bus)
Greg Kroah-Hartman4f6e1942007-04-20 11:29:52 -0700699 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800701 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800702
703 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
Cornelia Huck07634462008-02-18 17:04:25 +0100704 if (!priv) {
705 error = -ENOMEM;
706 goto out_put_bus;
707 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800708 klist_init(&priv->klist_devices, NULL, NULL);
709 priv->driver = drv;
710 drv->p = priv;
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400711 priv->kobj.kset = bus->p->drivers_kset;
712 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
713 "%s", drv->name);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700714 if (error)
Cornelia Huck07634462008-02-18 17:04:25 +0100715 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700717 if (drv->bus->p->drivers_autoprobe) {
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100718 error = driver_attach(drv);
719 if (error)
720 goto out_unregister;
721 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800722 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400723 module_add_driver(drv->owner, drv);
724
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200725 error = driver_create_file(drv, &driver_attr_uevent);
726 if (error) {
727 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800728 __func__, drv->name);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200729 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400730 error = driver_add_attrs(bus, drv);
731 if (error) {
732 /* How the hell do we get out of this pickle? Give up */
733 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800734 __func__, drv->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 }
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700736
737 if (!drv->suppress_bind_attrs) {
738 error = add_bind_files(drv);
739 if (error) {
740 /* Ditto */
741 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
742 __func__, drv->name);
743 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400744 }
745
Kay Sievers5c8563d2009-05-28 14:24:07 -0700746 return 0;
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700747
Andrew Mortonf86db392006-08-14 22:43:20 -0700748out_unregister:
Phil Carmody99b28f12009-12-14 20:28:12 +0200749 kobject_put(&priv->kobj);
Kay Sievers5c8563d2009-05-28 14:24:07 -0700750 kfree(drv->p);
751 drv->p = NULL;
Andrew Mortonf86db392006-08-14 22:43:20 -0700752out_put_bus:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700753 bus_put(bus);
Andrew Mortonf86db392006-08-14 22:43:20 -0700754 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755}
756
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800758 * bus_remove_driver - delete driver from bus's knowledge.
759 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800761 * Detach the driver from the devices it controls, and remove
762 * it from its bus's list of drivers. Finally, we drop the reference
763 * to the bus we took in bus_add_driver().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800765void bus_remove_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766{
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400767 if (!drv->bus)
768 return;
769
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700770 if (!drv->suppress_bind_attrs)
771 remove_bind_files(drv);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400772 driver_remove_attrs(drv->bus, drv);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200773 driver_remove_file(drv, &driver_attr_uevent);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800774 klist_remove(&drv->p->knode_bus);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800775 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400776 driver_detach(drv);
777 module_remove_driver(drv);
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800778 kobject_put(&drv->p->kobj);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700779 bus_put(drv->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780}
781
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782/* Helper for bus_rescan_devices's iter */
Andrew Mortonf86db392006-08-14 22:43:20 -0700783static int __must_check bus_rescan_devices_helper(struct device *dev,
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800784 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785{
Andrew Mortonf86db392006-08-14 22:43:20 -0700786 int ret = 0;
787
Alan Sternbf74ad52005-11-17 16:54:12 -0500788 if (!dev->driver) {
789 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800790 device_lock(dev->parent);
Andrew Mortonf86db392006-08-14 22:43:20 -0700791 ret = device_attach(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500792 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800793 device_unlock(dev->parent);
Alan Sternbf74ad52005-11-17 16:54:12 -0500794 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700795 return ret < 0 ? ret : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796}
797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798/**
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700799 * bus_rescan_devices - rescan devices on the bus for possible drivers
800 * @bus: the bus to scan.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 *
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700802 * This function will look for devices on the bus with no driver
803 * attached and rescan it against existing drivers to see if it matches
804 * any by calling device_attach() for the unbound devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800806int bus_rescan_devices(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807{
Andrew Mortonf86db392006-08-14 22:43:20 -0700808 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800810EXPORT_SYMBOL_GPL(bus_rescan_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811
Moore, Erice935d5d2006-03-14 09:18:18 -0700812/**
813 * device_reprobe - remove driver for a device and probe for a new driver
814 * @dev: the device to reprobe
815 *
816 * This function detaches the attached driver (if any) for the given
817 * device and restarts the driver probing process. It is intended
818 * to use if probing criteria changed during a devices lifetime and
819 * driver attachment should change accordingly.
820 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700821int device_reprobe(struct device *dev)
Moore, Erice935d5d2006-03-14 09:18:18 -0700822{
823 if (dev->driver) {
824 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800825 device_lock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700826 device_release_driver(dev);
827 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800828 device_unlock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700829 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700830 return bus_rescan_devices_helper(dev, NULL);
Moore, Erice935d5d2006-03-14 09:18:18 -0700831}
832EXPORT_SYMBOL_GPL(device_reprobe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800835 * find_bus - locate bus by name.
836 * @name: name of bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800838 * Call kset_find_obj() to iterate over list of buses to
839 * find a bus by name. Return bus if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800841 * Note that kset_find_obj increments bus' reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 */
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200843#if 0
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800844struct bus_type *find_bus(char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800846 struct kobject *k = kset_find_obj(bus_kset, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 return k ? to_bus(k) : NULL;
848}
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200849#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850
851
852/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800853 * bus_add_attrs - Add default attributes for this bus.
854 * @bus: Bus that has just been registered.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 */
856
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800857static int bus_add_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858{
859 int error = 0;
860 int i;
861
862 if (bus->bus_attrs) {
863 for (i = 0; attr_name(bus->bus_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800864 error = bus_create_file(bus, &bus->bus_attrs[i]);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700865 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800866 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 }
868 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800869done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800871err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 while (--i >= 0)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800873 bus_remove_file(bus, &bus->bus_attrs[i]);
874 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875}
876
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800877static void bus_remove_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878{
879 int i;
880
881 if (bus->bus_attrs) {
882 for (i = 0; attr_name(bus->bus_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800883 bus_remove_file(bus, &bus->bus_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 }
885}
886
James Bottomley34bb61f2005-09-06 16:56:51 -0700887static void klist_devices_get(struct klist_node *n)
888{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800889 struct device_private *dev_prv = to_device_private_bus(n);
890 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700891
892 get_device(dev);
893}
894
895static void klist_devices_put(struct klist_node *n)
896{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800897 struct device_private *dev_prv = to_device_private_bus(n);
898 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700899
900 put_device(dev);
901}
902
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200903static ssize_t bus_uevent_store(struct bus_type *bus,
904 const char *buf, size_t count)
905{
906 enum kobject_action action;
907
908 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700909 kobject_uevent(&bus->p->subsys.kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200910 return count;
911}
912static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914/**
Kay Sieversca22e562011-12-14 14:29:38 -0800915 * __bus_register - register a driver-core subsystem
Randy Dunlap78d79552012-01-21 11:02:28 -0800916 * @bus: bus to register
917 * @key: lockdep class key
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 *
Randy Dunlap78d79552012-01-21 11:02:28 -0800919 * Once we have that, we register the bus with the kobject
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800920 * infrastructure, then register the children subsystems it has:
Kay Sieversca22e562011-12-14 14:29:38 -0800921 * the devices and drivers that belong to the subsystem.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 */
Kay Sieversca22e562011-12-14 14:29:38 -0800923int __bus_register(struct bus_type *bus, struct lock_class_key *key)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924{
925 int retval;
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100926 struct subsys_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100928 priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700929 if (!priv)
930 return -ENOMEM;
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000931
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700932 priv->bus = bus;
933 bus->p = priv;
934
935 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
936
937 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 if (retval)
939 goto out;
940
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700941 priv->subsys.kobj.kset = bus_kset;
942 priv->subsys.kobj.ktype = &bus_ktype;
943 priv->drivers_autoprobe = 1;
Greg Kroah-Hartmand6b05b82007-09-12 15:06:57 -0700944
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700945 retval = kset_register(&priv->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 if (retval)
947 goto out;
948
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200949 retval = bus_create_file(bus, &bus_attr_uevent);
950 if (retval)
951 goto bus_uevent_fail;
952
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700953 priv->devices_kset = kset_create_and_add("devices", NULL,
954 &priv->subsys.kobj);
955 if (!priv->devices_kset) {
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700956 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 goto bus_devices_fail;
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700958 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700960 priv->drivers_kset = kset_create_and_add("drivers", NULL,
961 &priv->subsys.kobj);
962 if (!priv->drivers_kset) {
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700963 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 goto bus_drivers_fail;
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700965 }
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800966
Kay Sieversca22e562011-12-14 14:29:38 -0800967 INIT_LIST_HEAD(&priv->interfaces);
968 __mutex_init(&priv->mutex, "subsys mutex", key);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700969 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
970 klist_init(&priv->klist_drivers, NULL, NULL);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100971
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100972 retval = add_probe_files(bus);
973 if (retval)
974 goto bus_probe_files_fail;
975
Cornelia Huck1bb68812006-09-22 11:37:04 +0200976 retval = bus_add_attrs(bus);
977 if (retval)
978 goto bus_attrs_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800980 pr_debug("bus: '%s': registered\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 return 0;
982
Cornelia Huck1bb68812006-09-22 11:37:04 +0200983bus_attrs_fail:
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100984 remove_probe_files(bus);
985bus_probe_files_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700986 kset_unregister(bus->p->drivers_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987bus_drivers_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700988 kset_unregister(bus->p->devices_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989bus_devices_fail:
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200990 bus_remove_file(bus, &bus_attr_uevent);
991bus_uevent_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700992 kset_unregister(&bus->p->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993out:
Jike Song600c20f2010-07-15 17:43:54 +0800994 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +0800995 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 return retval;
997}
Kay Sieversca22e562011-12-14 14:29:38 -0800998EXPORT_SYMBOL_GPL(__bus_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001001 * bus_unregister - remove a bus from the system
1002 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001004 * Unregister the child subsystems and the bus itself.
1005 * Finally, we call bus_put() to release the refcount
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001007void bus_unregister(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008{
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -08001009 pr_debug("bus: '%s': unregistering\n", bus->name);
Kay Sieversca22e562011-12-14 14:29:38 -08001010 if (bus->dev_root)
1011 device_unregister(bus->dev_root);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 bus_remove_attrs(bus);
Kay Sieversb8c5cec2007-02-16 17:33:36 +01001013 remove_probe_files(bus);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001014 kset_unregister(bus->p->drivers_kset);
1015 kset_unregister(bus->p->devices_kset);
Kay Sievers7ac1cf42007-08-12 20:43:55 +02001016 bus_remove_file(bus, &bus_attr_uevent);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001017 kset_unregister(&bus->p->subsys);
1018 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +08001019 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001021EXPORT_SYMBOL_GPL(bus_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001023int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
1024{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001025 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001026}
1027EXPORT_SYMBOL_GPL(bus_register_notifier);
1028
1029int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
1030{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001031 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001032}
1033EXPORT_SYMBOL_GPL(bus_unregister_notifier);
1034
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -07001035struct kset *bus_get_kset(struct bus_type *bus)
1036{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001037 return &bus->p->subsys;
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -07001038}
1039EXPORT_SYMBOL_GPL(bus_get_kset);
1040
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001041struct klist *bus_get_device_klist(struct bus_type *bus)
1042{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001043 return &bus->p->klist_devices;
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001044}
1045EXPORT_SYMBOL_GPL(bus_get_device_klist);
1046
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001047/*
Robert P. J. Daydca25eb2010-11-21 08:15:01 -05001048 * Yes, this forcibly breaks the klist abstraction temporarily. It
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001049 * just wants to sort the klist, not change reference counts and
1050 * take/drop locks rapidly in the process. It does all this while
1051 * holding the lock for the list, so objects can't otherwise be
1052 * added/removed while we're swizzling.
1053 */
1054static void device_insertion_sort_klist(struct device *a, struct list_head *list,
1055 int (*compare)(const struct device *a,
1056 const struct device *b))
1057{
1058 struct list_head *pos;
1059 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001060 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001061 struct device *b;
1062
1063 list_for_each(pos, list) {
1064 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001065 dev_prv = to_device_private_bus(n);
1066 b = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001067 if (compare(a, b) <= 0) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001068 list_move_tail(&a->p->knode_bus.n_node,
1069 &b->p->knode_bus.n_node);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001070 return;
1071 }
1072 }
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001073 list_move_tail(&a->p->knode_bus.n_node, list);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001074}
1075
1076void bus_sort_breadthfirst(struct bus_type *bus,
1077 int (*compare)(const struct device *a,
1078 const struct device *b))
1079{
1080 LIST_HEAD(sorted_devices);
1081 struct list_head *pos, *tmp;
1082 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001083 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001084 struct device *dev;
1085 struct klist *device_klist;
1086
1087 device_klist = bus_get_device_klist(bus);
1088
1089 spin_lock(&device_klist->k_lock);
1090 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1091 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001092 dev_prv = to_device_private_bus(n);
1093 dev = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001094 device_insertion_sort_klist(dev, &sorted_devices, compare);
1095 }
1096 list_splice(&sorted_devices, &device_klist->k_list);
1097 spin_unlock(&device_klist->k_lock);
1098}
1099EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1100
Kay Sieversca22e562011-12-14 14:29:38 -08001101/**
1102 * subsys_dev_iter_init - initialize subsys device iterator
1103 * @iter: subsys iterator to initialize
1104 * @subsys: the subsys we wanna iterate over
1105 * @start: the device to start iterating from, if any
1106 * @type: device_type of the devices to iterate over, NULL for all
1107 *
1108 * Initialize subsys iterator @iter such that it iterates over devices
1109 * of @subsys. If @start is set, the list iteration will start there,
1110 * otherwise if it is NULL, the iteration starts at the beginning of
1111 * the list.
1112 */
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001113void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
1114 struct device *start, const struct device_type *type)
Kay Sieversca22e562011-12-14 14:29:38 -08001115{
1116 struct klist_node *start_knode = NULL;
1117
1118 if (start)
1119 start_knode = &start->p->knode_bus;
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001120 klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
1121 iter->type = type;
Kay Sieversca22e562011-12-14 14:29:38 -08001122}
1123EXPORT_SYMBOL_GPL(subsys_dev_iter_init);
1124
1125/**
1126 * subsys_dev_iter_next - iterate to the next device
1127 * @iter: subsys iterator to proceed
1128 *
1129 * Proceed @iter to the next device and return it. Returns NULL if
1130 * iteration is complete.
1131 *
1132 * The returned device is referenced and won't be released till
1133 * iterator is proceed to the next device or exited. The caller is
1134 * free to do whatever it wants to do with the device including
1135 * calling back into subsys code.
1136 */
1137struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
1138{
1139 struct klist_node *knode;
1140 struct device *dev;
1141
1142 for (;;) {
1143 knode = klist_next(&iter->ki);
1144 if (!knode)
1145 return NULL;
1146 dev = container_of(knode, struct device_private, knode_bus)->device;
1147 if (!iter->type || iter->type == dev->type)
1148 return dev;
1149 }
1150}
1151EXPORT_SYMBOL_GPL(subsys_dev_iter_next);
1152
1153/**
1154 * subsys_dev_iter_exit - finish iteration
1155 * @iter: subsys iterator to finish
1156 *
1157 * Finish an iteration. Always call this function after iteration is
1158 * complete whether the iteration ran till the end or not.
1159 */
1160void subsys_dev_iter_exit(struct subsys_dev_iter *iter)
1161{
1162 klist_iter_exit(&iter->ki);
1163}
1164EXPORT_SYMBOL_GPL(subsys_dev_iter_exit);
1165
1166int subsys_interface_register(struct subsys_interface *sif)
1167{
1168 struct bus_type *subsys;
1169 struct subsys_dev_iter iter;
1170 struct device *dev;
1171
1172 if (!sif || !sif->subsys)
1173 return -ENODEV;
1174
1175 subsys = bus_get(sif->subsys);
1176 if (!subsys)
1177 return -EINVAL;
1178
1179 mutex_lock(&subsys->p->mutex);
1180 list_add_tail(&sif->node, &subsys->p->interfaces);
1181 if (sif->add_dev) {
1182 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1183 while ((dev = subsys_dev_iter_next(&iter)))
1184 sif->add_dev(dev, sif);
1185 subsys_dev_iter_exit(&iter);
1186 }
1187 mutex_unlock(&subsys->p->mutex);
1188
1189 return 0;
1190}
1191EXPORT_SYMBOL_GPL(subsys_interface_register);
1192
1193void subsys_interface_unregister(struct subsys_interface *sif)
1194{
Jonghwan Choi2b315942012-01-14 11:06:03 +09001195 struct bus_type *subsys;
Kay Sieversca22e562011-12-14 14:29:38 -08001196 struct subsys_dev_iter iter;
1197 struct device *dev;
1198
Jonghwan Choi2b315942012-01-14 11:06:03 +09001199 if (!sif || !sif->subsys)
Kay Sieversca22e562011-12-14 14:29:38 -08001200 return;
1201
Jonghwan Choi2b315942012-01-14 11:06:03 +09001202 subsys = sif->subsys;
1203
Kay Sieversca22e562011-12-14 14:29:38 -08001204 mutex_lock(&subsys->p->mutex);
1205 list_del_init(&sif->node);
1206 if (sif->remove_dev) {
1207 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1208 while ((dev = subsys_dev_iter_next(&iter)))
1209 sif->remove_dev(dev, sif);
1210 subsys_dev_iter_exit(&iter);
1211 }
1212 mutex_unlock(&subsys->p->mutex);
1213
1214 bus_put(subsys);
1215}
1216EXPORT_SYMBOL_GPL(subsys_interface_unregister);
1217
1218static void system_root_device_release(struct device *dev)
1219{
1220 kfree(dev);
1221}
1222/**
1223 * subsys_system_register - register a subsystem at /sys/devices/system/
Randy Dunlap78d79552012-01-21 11:02:28 -08001224 * @subsys: system subsystem
1225 * @groups: default attributes for the root device
Kay Sieversca22e562011-12-14 14:29:38 -08001226 *
1227 * All 'system' subsystems have a /sys/devices/system/<name> root device
1228 * with the name of the subsystem. The root device can carry subsystem-
1229 * wide attributes. All registered devices are below this single root
1230 * device and are named after the subsystem with a simple enumeration
1231 * number appended. The registered devices are not explicitely named;
1232 * only 'id' in the device needs to be set.
1233 *
1234 * Do not use this interface for anything new, it exists for compatibility
1235 * with bad ideas only. New subsystems should use plain subsystems; and
1236 * add the subsystem-wide attributes should be added to the subsystem
1237 * directory itself and not some create fake root-device placed in
1238 * /sys/devices/system/<name>.
1239 */
1240int subsys_system_register(struct bus_type *subsys,
1241 const struct attribute_group **groups)
1242{
1243 struct device *dev;
1244 int err;
1245
1246 err = bus_register(subsys);
1247 if (err < 0)
1248 return err;
1249
1250 dev = kzalloc(sizeof(struct device), GFP_KERNEL);
1251 if (!dev) {
1252 err = -ENOMEM;
1253 goto err_dev;
1254 }
1255
1256 err = dev_set_name(dev, "%s", subsys->name);
1257 if (err < 0)
1258 goto err_name;
1259
1260 dev->kobj.parent = &system_kset->kobj;
1261 dev->groups = groups;
1262 dev->release = system_root_device_release;
1263
1264 err = device_register(dev);
1265 if (err < 0)
1266 goto err_dev_reg;
1267
1268 subsys->dev_root = dev;
1269 return 0;
1270
1271err_dev_reg:
1272 put_device(dev);
1273 dev = NULL;
1274err_name:
1275 kfree(dev);
1276err_dev:
1277 bus_unregister(subsys);
1278 return err;
1279}
1280EXPORT_SYMBOL_GPL(subsys_system_register);
1281
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282int __init buses_init(void)
1283{
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001284 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
1285 if (!bus_kset)
1286 return -ENOMEM;
Kay Sieversca22e562011-12-14 14:29:38 -08001287
1288 system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
1289 if (!system_kset)
1290 return -ENOMEM;
1291
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001292 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293}