blob: 12eec3f633b13f0b6e6544a6ce895ff298d4cd84 [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>
19#include "base.h"
20#include "power/power.h"
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070023#define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25/*
26 * sysfs bindings for drivers
27 */
28
29#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31
Kay Sieversb8c5cec2007-02-16 17:33:36 +010032static int __must_check bus_rescan_devices_helper(struct device *dev,
33 void *data);
34
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070035static struct bus_type *bus_get(struct bus_type *bus)
36{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070037 if (bus) {
38 kset_get(&bus->p->subsys);
39 return bus;
40 }
41 return NULL;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070042}
43
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070044static void bus_put(struct bus_type *bus)
45{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070046 if (bus)
47 kset_put(&bus->p->subsys);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070048}
49
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080050static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
51 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080053 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080054 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050055 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57 if (drv_attr->show)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080058 ret = drv_attr->show(drv_priv->driver, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 return ret;
60}
61
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080062static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
63 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070064{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080065 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080066 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050067 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69 if (drv_attr->store)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080070 ret = drv_attr->store(drv_priv->driver, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return ret;
72}
73
Emese Revfy52cf25d2010-01-19 02:58:23 +010074static const struct sysfs_ops driver_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 .show = drv_attr_show,
76 .store = drv_attr_store,
77};
78
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080079static void driver_release(struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080081 struct driver_private *drv_priv = to_driver(kobj);
82
Harvey Harrison2b3a3022008-03-04 16:41:05 -080083 pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080084 kfree(drv_priv);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085}
86
Greg Kroah-Hartmana1148fb2007-10-11 10:47:49 -060087static struct kobj_type driver_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 .sysfs_ops = &driver_sysfs_ops,
89 .release = driver_release,
90};
91
Linus Torvalds1da177e2005-04-16 15:20:36 -070092/*
93 * sysfs bindings for buses
94 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080095static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
96 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080098 struct bus_attribute *bus_attr = to_bus_attr(attr);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070099 struct bus_type_private *bus_priv = to_bus(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 ssize_t ret = 0;
101
102 if (bus_attr->show)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700103 ret = bus_attr->show(bus_priv->bus, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 return ret;
105}
106
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800107static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
108 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800110 struct bus_attribute *bus_attr = to_bus_attr(attr);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700111 struct bus_type_private *bus_priv = to_bus(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 ssize_t ret = 0;
113
114 if (bus_attr->store)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700115 ret = bus_attr->store(bus_priv->bus, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 return ret;
117}
118
Emese Revfy52cf25d2010-01-19 02:58:23 +0100119static const struct sysfs_ops bus_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 .show = bus_attr_show,
121 .store = bus_attr_store,
122};
123
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800124int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125{
126 int error;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700127 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700128 error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700129 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 } else
131 error = -EINVAL;
132 return error;
133}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800134EXPORT_SYMBOL_GPL(bus_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800136void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700138 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700139 sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700140 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 }
142}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800143EXPORT_SYMBOL_GPL(bus_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Kay Sievers80f03e32007-05-26 11:21:36 +0200145static struct kobj_type bus_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 .sysfs_ops = &bus_sysfs_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147};
148
Kay Sievers80f03e32007-05-26 11:21:36 +0200149static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
150{
151 struct kobj_type *ktype = get_ktype(kobj);
152
153 if (ktype == &bus_ktype)
154 return 1;
155 return 0;
156}
157
Emese Revfy9cd43612009-12-31 14:52:51 +0100158static const struct kset_uevent_ops bus_uevent_ops = {
Kay Sievers80f03e32007-05-26 11:21:36 +0200159 .filter = bus_uevent_filter,
160};
161
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -0500162static struct kset *bus_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
Russell King2139bdd2006-02-07 12:58:20 -0800165#ifdef CONFIG_HOTPLUG
Alan Stern2b08c8d2005-11-23 15:43:50 -0800166/* Manually detach a device from its associated driver. */
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700167static ssize_t driver_unbind(struct device_driver *drv,
168 const char *buf, size_t count)
169{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700170 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700171 struct device *dev;
172 int err = -ENODEV;
173
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800174 dev = bus_find_device_by_name(bus, NULL, buf);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800175 if (dev && dev->driver == drv) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500176 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800177 device_lock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700178 device_release_driver(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500179 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800180 device_unlock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700181 err = count;
182 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800183 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700184 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800185 return err;
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700186}
187static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
188
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700189/*
190 * Manually attach a device to a driver.
191 * Note: the driver must want to bind to the device,
192 * it is not possible to override the driver's id table.
193 */
194static ssize_t driver_bind(struct device_driver *drv,
195 const char *buf, size_t count)
196{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700197 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700198 struct device *dev;
199 int err = -ENODEV;
200
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800201 dev = bus_find_device_by_name(bus, NULL, buf);
Ming Lei49b420a2009-01-21 23:27:47 +0800202 if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500203 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800204 device_lock(dev->parent);
205 device_lock(dev);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700206 err = driver_probe_device(drv, dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800207 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500208 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800209 device_unlock(dev->parent);
Ryan Wilson37225402006-03-22 16:26:25 -0500210
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800211 if (err > 0) {
212 /* success */
Ryan Wilson37225402006-03-22 16:26:25 -0500213 err = count;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800214 } else if (err == 0) {
215 /* driver didn't accept device */
Ryan Wilson37225402006-03-22 16:26:25 -0500216 err = -ENODEV;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800217 }
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700218 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800219 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700220 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800221 return err;
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700222}
223static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
224
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100225static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
226{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700227 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100228}
229
230static ssize_t store_drivers_autoprobe(struct bus_type *bus,
231 const char *buf, size_t count)
232{
233 if (buf[0] == '0')
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700234 bus->p->drivers_autoprobe = 0;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100235 else
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700236 bus->p->drivers_autoprobe = 1;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100237 return count;
238}
239
240static ssize_t store_drivers_probe(struct bus_type *bus,
241 const char *buf, size_t count)
242{
243 struct device *dev;
244
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800245 dev = bus_find_device_by_name(bus, NULL, buf);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100246 if (!dev)
247 return -ENODEV;
248 if (bus_rescan_devices_helper(dev, NULL) != 0)
249 return -EINVAL;
250 return count;
251}
Russell King2139bdd2006-02-07 12:58:20 -0800252#endif
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700253
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800254static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800255{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800256 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800257 struct device *dev = NULL;
258 struct device_private *dev_prv;
259
260 if (n) {
261 dev_prv = to_device_private_bus(n);
262 dev = dev_prv->device;
263 }
264 return dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800265}
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800268 * bus_for_each_dev - device iterator.
269 * @bus: bus type.
270 * @start: device to start iterating from.
271 * @data: data for the callback.
272 * @fn: function to be called for each device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800274 * Iterate over @bus's list of devices, and call @fn for each,
275 * passing it @data. If @start is not NULL, we use that device to
276 * begin iterating from.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800278 * We check the return of @fn each time. If it returns anything
279 * other than 0, we break out and return that value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800281 * NOTE: The device that returns a non-zero value is not retained
282 * in any way, nor is its refcount incremented. If the caller needs
Alex Chiang0fa1b0a2009-05-14 23:15:22 +0200283 * to retain this data, it should do so, and increment the reference
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800284 * count in the supplied callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800286int bus_for_each_dev(struct bus_type *bus, struct device *start,
287 void *data, int (*fn)(struct device *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288{
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800289 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800290 struct device *dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800291 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800293 if (!bus)
294 return -EINVAL;
295
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700296 klist_iter_init_node(&bus->p->klist_devices, &i,
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800297 (start ? &start->p->knode_bus : NULL));
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800298 while ((dev = next_device(&i)) && !error)
299 error = fn(dev, data);
300 klist_iter_exit(&i);
301 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800303EXPORT_SYMBOL_GPL(bus_for_each_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
Cornelia Huck0edb5862005-06-22 16:59:51 +0200305/**
306 * bus_find_device - device iterator for locating a particular device.
307 * @bus: bus type
308 * @start: Device to begin with
309 * @data: Data to pass to match function
310 * @match: Callback function to check device
311 *
312 * This is similar to the bus_for_each_dev() function above, but it
313 * returns a reference to a device that is 'found' for later use, as
314 * determined by the @match callback.
315 *
316 * The callback should return 0 if the device doesn't match and non-zero
317 * if it does. If the callback returns non-zero, this function will
318 * return to the caller and not iterate over any more devices.
319 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800320struct device *bus_find_device(struct bus_type *bus,
321 struct device *start, void *data,
322 int (*match)(struct device *dev, void *data))
Cornelia Huck0edb5862005-06-22 16:59:51 +0200323{
324 struct klist_iter i;
325 struct device *dev;
326
327 if (!bus)
328 return NULL;
329
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700330 klist_iter_init_node(&bus->p->klist_devices, &i,
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800331 (start ? &start->p->knode_bus : NULL));
Cornelia Huck0edb5862005-06-22 16:59:51 +0200332 while ((dev = next_device(&i)))
333 if (match(dev, data) && get_device(dev))
334 break;
335 klist_iter_exit(&i);
336 return dev;
337}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800338EXPORT_SYMBOL_GPL(bus_find_device);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800339
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800340static int match_name(struct device *dev, void *data)
341{
342 const char *name = data;
343
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100344 return sysfs_streq(name, dev_name(dev));
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800345}
346
347/**
348 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
349 * @bus: bus type
350 * @start: Device to begin with
351 * @name: name of the device to match
352 *
353 * This is similar to the bus_find_device() function above, but it handles
354 * searching by a name automatically, no need to write another strcmp matching
355 * function.
356 */
357struct device *bus_find_device_by_name(struct bus_type *bus,
358 struct device *start, const char *name)
359{
360 return bus_find_device(bus, start, (void *)name, match_name);
361}
362EXPORT_SYMBOL_GPL(bus_find_device_by_name);
363
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800364static struct device_driver *next_driver(struct klist_iter *i)
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800365{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800366 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800367 struct driver_private *drv_priv;
368
369 if (n) {
370 drv_priv = container_of(n, struct driver_private, knode_bus);
371 return drv_priv->driver;
372 }
373 return NULL;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800374}
375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800377 * bus_for_each_drv - driver iterator
378 * @bus: bus we're dealing with.
379 * @start: driver to start iterating on.
380 * @data: data to pass to the callback.
381 * @fn: function to call for each driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800383 * This is nearly identical to the device iterator above.
384 * We iterate over each driver that belongs to @bus, and call
385 * @fn for each. If @fn returns anything but 0, we break out
386 * and return it. If @start is not NULL, we use it as the head
387 * of the list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800389 * NOTE: we don't return the driver that returns a non-zero
390 * value, nor do we leave the reference count incremented for that
391 * driver. If the caller needs to know that info, it must set it
392 * in the callback. It must also be sure to increment the refcount
393 * so it doesn't disappear before returning to the caller.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800395int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
396 void *data, int (*fn)(struct device_driver *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397{
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800398 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800399 struct device_driver *drv;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800400 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800402 if (!bus)
403 return -EINVAL;
404
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700405 klist_iter_init_node(&bus->p->klist_drivers, &i,
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800406 start ? &start->p->knode_bus : NULL);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800407 while ((drv = next_driver(&i)) && !error)
408 error = fn(drv, data);
409 klist_iter_exit(&i);
410 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800412EXPORT_SYMBOL_GPL(bus_for_each_drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
Andrew Morton4aca67e2007-02-13 22:39:26 -0800414static int device_add_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415{
416 int error = 0;
417 int i;
418
Andrew Morton4aca67e2007-02-13 22:39:26 -0800419 if (!bus->dev_attrs)
420 return 0;
421
422 for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800423 error = device_create_file(dev, &bus->dev_attrs[i]);
Andrew Morton4aca67e2007-02-13 22:39:26 -0800424 if (error) {
425 while (--i >= 0)
426 device_remove_file(dev, &bus->dev_attrs[i]);
427 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 }
429 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431}
432
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800433static void device_remove_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434{
435 int i;
436
437 if (bus->dev_attrs) {
438 for (i = 0; attr_name(bus->dev_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800439 device_remove_file(dev, &bus->dev_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 }
441}
442
Kay Sieversb9cafc72006-09-14 11:23:28 +0200443#ifdef CONFIG_SYSFS_DEPRECATED
444static int make_deprecated_bus_links(struct device *dev)
445{
446 return sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700447 &dev->bus->p->subsys.kobj, "bus");
Kay Sieversb9cafc72006-09-14 11:23:28 +0200448}
449
450static void remove_deprecated_bus_links(struct device *dev)
451{
452 sysfs_remove_link(&dev->kobj, "bus");
453}
454#else
455static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
456static inline void remove_deprecated_bus_links(struct device *dev) { }
457#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458
459/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800460 * bus_add_device - add device to bus
461 * @dev: device being added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 *
Alan Stern2023c612009-07-30 15:27:18 -0400463 * - Add device's bus attributes.
464 * - Create links to device's bus.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800465 * - Add the device to its bus's list of devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800467int bus_add_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800469 struct bus_type *bus = bus_get(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 int error = 0;
471
472 if (bus) {
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100473 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
Greg Kroah-Hartmand377e852005-06-22 16:09:05 -0700474 error = device_add_attrs(bus, dev);
Andrew Mortonf86db392006-08-14 22:43:20 -0700475 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200476 goto out_put;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700477 error = sysfs_create_link(&bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100478 &dev->kobj, dev_name(dev));
Andrew Mortonf86db392006-08-14 22:43:20 -0700479 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200480 goto out_id;
Andrew Mortonf86db392006-08-14 22:43:20 -0700481 error = sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700482 &dev->bus->p->subsys.kobj, "subsystem");
Andrew Mortonf86db392006-08-14 22:43:20 -0700483 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200484 goto out_subsys;
Kay Sieversb9cafc72006-09-14 11:23:28 +0200485 error = make_deprecated_bus_links(dev);
Cornelia Huck513e7332006-09-22 11:37:08 +0200486 if (error)
487 goto out_deprecated;
Alan Stern2023c612009-07-30 15:27:18 -0400488 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 }
Cornelia Huck513e7332006-09-22 11:37:08 +0200490 return 0;
491
492out_deprecated:
493 sysfs_remove_link(&dev->kobj, "subsystem");
494out_subsys:
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100495 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
Cornelia Huck513e7332006-09-22 11:37:08 +0200496out_id:
497 device_remove_attrs(bus, dev);
498out_put:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700499 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 return error;
501}
502
503/**
Alan Stern2023c612009-07-30 15:27:18 -0400504 * bus_probe_device - probe drivers for a new device
505 * @dev: device to probe
Kay Sievers53877d02006-04-04 20:42:26 +0200506 *
Alan Stern2023c612009-07-30 15:27:18 -0400507 * - Automatically probe for a driver if the bus allows it.
Kay Sievers53877d02006-04-04 20:42:26 +0200508 */
Alan Stern2023c612009-07-30 15:27:18 -0400509void bus_probe_device(struct device *dev)
Kay Sievers53877d02006-04-04 20:42:26 +0200510{
Andrew Mortonf86db392006-08-14 22:43:20 -0700511 struct bus_type *bus = dev->bus;
Alan Stern2023c612009-07-30 15:27:18 -0400512 int ret;
Kay Sievers53877d02006-04-04 20:42:26 +0200513
Alan Stern2023c612009-07-30 15:27:18 -0400514 if (bus && bus->p->drivers_autoprobe) {
515 ret = device_attach(dev);
Cornelia Huckc6a46692007-02-05 16:15:26 -0800516 WARN_ON(ret < 0);
Kay Sievers53877d02006-04-04 20:42:26 +0200517 }
518}
519
520/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800521 * bus_remove_device - remove device from bus
522 * @dev: device to be removed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800524 * - Remove symlink from bus's directory.
525 * - Delete device from bus's list.
526 * - Detach from its driver.
527 * - Drop reference taken in bus_add_device().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800529void bus_remove_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530{
531 if (dev->bus) {
Kay Sieversb9d9c822006-06-15 15:31:56 +0200532 sysfs_remove_link(&dev->kobj, "subsystem");
Kay Sieversb9cafc72006-09-14 11:23:28 +0200533 remove_deprecated_bus_links(dev);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800534 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100535 dev_name(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 device_remove_attrs(dev->bus, dev);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800537 if (klist_node_attached(&dev->p->knode_bus))
538 klist_del(&dev->p->knode_bus);
Greg Kroah-Hartman3f62e572008-03-13 17:07:03 -0400539
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800540 pr_debug("bus: '%s': remove device %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100541 dev->bus->name, dev_name(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 device_release_driver(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700543 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 }
545}
546
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800547static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548{
549 int error = 0;
550 int i;
551
552 if (bus->drv_attrs) {
553 for (i = 0; attr_name(bus->drv_attrs[i]); i++) {
554 error = driver_create_file(drv, &bus->drv_attrs[i]);
555 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800556 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 }
558 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800559done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800561err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 while (--i >= 0)
563 driver_remove_file(drv, &bus->drv_attrs[i]);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800564 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565}
566
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800567static void driver_remove_attrs(struct bus_type *bus,
568 struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569{
570 int i;
571
572 if (bus->drv_attrs) {
573 for (i = 0; attr_name(bus->drv_attrs[i]); i++)
574 driver_remove_file(drv, &bus->drv_attrs[i]);
575 }
576}
577
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800578#ifdef CONFIG_HOTPLUG
579/*
580 * Thanks to drivers making their tables __devinit, we can't allow manual
581 * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
582 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700583static int __must_check add_bind_files(struct device_driver *drv)
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800584{
Andrew Mortonf86db392006-08-14 22:43:20 -0700585 int ret;
586
587 ret = driver_create_file(drv, &driver_attr_unbind);
588 if (ret == 0) {
589 ret = driver_create_file(drv, &driver_attr_bind);
590 if (ret)
591 driver_remove_file(drv, &driver_attr_unbind);
592 }
593 return ret;
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800594}
595
596static void remove_bind_files(struct device_driver *drv)
597{
598 driver_remove_file(drv, &driver_attr_bind);
599 driver_remove_file(drv, &driver_attr_unbind);
600}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100601
Kay Sievers83807702007-07-30 02:28:56 +0200602static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
603static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
604 show_drivers_autoprobe, store_drivers_autoprobe);
605
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100606static int add_probe_files(struct bus_type *bus)
607{
608 int retval;
609
Kay Sievers83807702007-07-30 02:28:56 +0200610 retval = bus_create_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100611 if (retval)
612 goto out;
613
Kay Sievers83807702007-07-30 02:28:56 +0200614 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100615 if (retval)
Kay Sievers83807702007-07-30 02:28:56 +0200616 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100617out:
618 return retval;
619}
620
621static void remove_probe_files(struct bus_type *bus)
622{
Kay Sievers83807702007-07-30 02:28:56 +0200623 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
624 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100625}
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800626#else
Yoichi Yuasa35acfdd2006-07-15 01:30:11 +0900627static inline int add_bind_files(struct device_driver *drv) { return 0; }
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800628static inline void remove_bind_files(struct device_driver *drv) {}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100629static inline int add_probe_files(struct bus_type *bus) { return 0; }
630static inline void remove_probe_files(struct bus_type *bus) {}
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800631#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200633static ssize_t driver_uevent_store(struct device_driver *drv,
634 const char *buf, size_t count)
635{
636 enum kobject_action action;
637
638 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800639 kobject_uevent(&drv->p->kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200640 return count;
641}
642static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800645 * bus_add_driver - Add a driver to the bus.
646 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700648int bus_add_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800650 struct bus_type *bus;
651 struct driver_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 int error = 0;
653
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800654 bus = bus_get(drv->bus);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400655 if (!bus)
Greg Kroah-Hartman4f6e1942007-04-20 11:29:52 -0700656 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800658 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800659
660 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
Cornelia Huck07634462008-02-18 17:04:25 +0100661 if (!priv) {
662 error = -ENOMEM;
663 goto out_put_bus;
664 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800665 klist_init(&priv->klist_devices, NULL, NULL);
666 priv->driver = drv;
667 drv->p = priv;
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400668 priv->kobj.kset = bus->p->drivers_kset;
669 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
670 "%s", drv->name);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700671 if (error)
Cornelia Huck07634462008-02-18 17:04:25 +0100672 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700674 if (drv->bus->p->drivers_autoprobe) {
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100675 error = driver_attach(drv);
676 if (error)
677 goto out_unregister;
678 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800679 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400680 module_add_driver(drv->owner, drv);
681
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200682 error = driver_create_file(drv, &driver_attr_uevent);
683 if (error) {
684 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800685 __func__, drv->name);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200686 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400687 error = driver_add_attrs(bus, drv);
688 if (error) {
689 /* How the hell do we get out of this pickle? Give up */
690 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800691 __func__, drv->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 }
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700693
694 if (!drv->suppress_bind_attrs) {
695 error = add_bind_files(drv);
696 if (error) {
697 /* Ditto */
698 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
699 __func__, drv->name);
700 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400701 }
702
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400703 kobject_uevent(&priv->kobj, KOBJ_ADD);
Kay Sievers5c8563d2009-05-28 14:24:07 -0700704 return 0;
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700705
Andrew Mortonf86db392006-08-14 22:43:20 -0700706out_unregister:
Phil Carmody99b28f12009-12-14 20:28:12 +0200707 kobject_put(&priv->kobj);
Kay Sievers5c8563d2009-05-28 14:24:07 -0700708 kfree(drv->p);
709 drv->p = NULL;
Andrew Mortonf86db392006-08-14 22:43:20 -0700710out_put_bus:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700711 bus_put(bus);
Andrew Mortonf86db392006-08-14 22:43:20 -0700712 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713}
714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800716 * bus_remove_driver - delete driver from bus's knowledge.
717 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800719 * Detach the driver from the devices it controls, and remove
720 * it from its bus's list of drivers. Finally, we drop the reference
721 * to the bus we took in bus_add_driver().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800723void bus_remove_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724{
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400725 if (!drv->bus)
726 return;
727
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700728 if (!drv->suppress_bind_attrs)
729 remove_bind_files(drv);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400730 driver_remove_attrs(drv->bus, drv);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200731 driver_remove_file(drv, &driver_attr_uevent);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800732 klist_remove(&drv->p->knode_bus);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800733 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400734 driver_detach(drv);
735 module_remove_driver(drv);
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800736 kobject_put(&drv->p->kobj);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700737 bus_put(drv->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738}
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740/* Helper for bus_rescan_devices's iter */
Andrew Mortonf86db392006-08-14 22:43:20 -0700741static int __must_check bus_rescan_devices_helper(struct device *dev,
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800742 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743{
Andrew Mortonf86db392006-08-14 22:43:20 -0700744 int ret = 0;
745
Alan Sternbf74ad52005-11-17 16:54:12 -0500746 if (!dev->driver) {
747 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800748 device_lock(dev->parent);
Andrew Mortonf86db392006-08-14 22:43:20 -0700749 ret = device_attach(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500750 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800751 device_unlock(dev->parent);
Alan Sternbf74ad52005-11-17 16:54:12 -0500752 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700753 return ret < 0 ? ret : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754}
755
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756/**
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700757 * bus_rescan_devices - rescan devices on the bus for possible drivers
758 * @bus: the bus to scan.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 *
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700760 * This function will look for devices on the bus with no driver
761 * attached and rescan it against existing drivers to see if it matches
762 * any by calling device_attach() for the unbound devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800764int bus_rescan_devices(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765{
Andrew Mortonf86db392006-08-14 22:43:20 -0700766 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800768EXPORT_SYMBOL_GPL(bus_rescan_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769
Moore, Erice935d5d2006-03-14 09:18:18 -0700770/**
771 * device_reprobe - remove driver for a device and probe for a new driver
772 * @dev: the device to reprobe
773 *
774 * This function detaches the attached driver (if any) for the given
775 * device and restarts the driver probing process. It is intended
776 * to use if probing criteria changed during a devices lifetime and
777 * driver attachment should change accordingly.
778 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700779int device_reprobe(struct device *dev)
Moore, Erice935d5d2006-03-14 09:18:18 -0700780{
781 if (dev->driver) {
782 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800783 device_lock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700784 device_release_driver(dev);
785 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800786 device_unlock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700787 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700788 return bus_rescan_devices_helper(dev, NULL);
Moore, Erice935d5d2006-03-14 09:18:18 -0700789}
790EXPORT_SYMBOL_GPL(device_reprobe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800793 * find_bus - locate bus by name.
794 * @name: name of bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800796 * Call kset_find_obj() to iterate over list of buses to
797 * find a bus by name. Return bus if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800799 * Note that kset_find_obj increments bus' reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 */
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200801#if 0
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800802struct bus_type *find_bus(char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800804 struct kobject *k = kset_find_obj(bus_kset, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 return k ? to_bus(k) : NULL;
806}
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200807#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808
809
810/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800811 * bus_add_attrs - Add default attributes for this bus.
812 * @bus: Bus that has just been registered.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 */
814
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800815static int bus_add_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816{
817 int error = 0;
818 int i;
819
820 if (bus->bus_attrs) {
821 for (i = 0; attr_name(bus->bus_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800822 error = bus_create_file(bus, &bus->bus_attrs[i]);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700823 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800824 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 }
826 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800827done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800829err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 while (--i >= 0)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800831 bus_remove_file(bus, &bus->bus_attrs[i]);
832 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833}
834
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800835static void bus_remove_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836{
837 int i;
838
839 if (bus->bus_attrs) {
840 for (i = 0; attr_name(bus->bus_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800841 bus_remove_file(bus, &bus->bus_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 }
843}
844
James Bottomley34bb61f2005-09-06 16:56:51 -0700845static void klist_devices_get(struct klist_node *n)
846{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800847 struct device_private *dev_prv = to_device_private_bus(n);
848 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700849
850 get_device(dev);
851}
852
853static void klist_devices_put(struct klist_node *n)
854{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800855 struct device_private *dev_prv = to_device_private_bus(n);
856 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700857
858 put_device(dev);
859}
860
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200861static ssize_t bus_uevent_store(struct bus_type *bus,
862 const char *buf, size_t count)
863{
864 enum kobject_action action;
865
866 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700867 kobject_uevent(&bus->p->subsys.kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200868 return count;
869}
870static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
871
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800873 * bus_register - register a bus with the system.
874 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800876 * Once we have that, we registered the bus with the kobject
877 * infrastructure, then register the children subsystems it has:
878 * the devices and drivers that belong to the bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800880int bus_register(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881{
882 int retval;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700883 struct bus_type_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700885 priv = kzalloc(sizeof(struct bus_type_private), GFP_KERNEL);
886 if (!priv)
887 return -ENOMEM;
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000888
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700889 priv->bus = bus;
890 bus->p = priv;
891
892 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
893
894 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 if (retval)
896 goto out;
897
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700898 priv->subsys.kobj.kset = bus_kset;
899 priv->subsys.kobj.ktype = &bus_ktype;
900 priv->drivers_autoprobe = 1;
Greg Kroah-Hartmand6b05b82007-09-12 15:06:57 -0700901
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700902 retval = kset_register(&priv->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 if (retval)
904 goto out;
905
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200906 retval = bus_create_file(bus, &bus_attr_uevent);
907 if (retval)
908 goto bus_uevent_fail;
909
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700910 priv->devices_kset = kset_create_and_add("devices", NULL,
911 &priv->subsys.kobj);
912 if (!priv->devices_kset) {
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700913 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 goto bus_devices_fail;
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700915 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700917 priv->drivers_kset = kset_create_and_add("drivers", NULL,
918 &priv->subsys.kobj);
919 if (!priv->drivers_kset) {
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700920 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 goto bus_drivers_fail;
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700922 }
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800923
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700924 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
925 klist_init(&priv->klist_drivers, NULL, NULL);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100926
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100927 retval = add_probe_files(bus);
928 if (retval)
929 goto bus_probe_files_fail;
930
Cornelia Huck1bb68812006-09-22 11:37:04 +0200931 retval = bus_add_attrs(bus);
932 if (retval)
933 goto bus_attrs_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800935 pr_debug("bus: '%s': registered\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 return 0;
937
Cornelia Huck1bb68812006-09-22 11:37:04 +0200938bus_attrs_fail:
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100939 remove_probe_files(bus);
940bus_probe_files_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700941 kset_unregister(bus->p->drivers_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942bus_drivers_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700943 kset_unregister(bus->p->devices_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944bus_devices_fail:
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200945 bus_remove_file(bus, &bus_attr_uevent);
946bus_uevent_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700947 kset_unregister(&bus->p->subsys);
948 kfree(bus->p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949out:
Dave Youngf48f3fe2009-02-14 21:23:22 +0800950 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 return retval;
952}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800953EXPORT_SYMBOL_GPL(bus_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800956 * bus_unregister - remove a bus from the system
957 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800959 * Unregister the child subsystems and the bus itself.
960 * Finally, we call bus_put() to release the refcount
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800962void bus_unregister(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963{
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800964 pr_debug("bus: '%s': unregistering\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 bus_remove_attrs(bus);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100966 remove_probe_files(bus);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700967 kset_unregister(bus->p->drivers_kset);
968 kset_unregister(bus->p->devices_kset);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200969 bus_remove_file(bus, &bus_attr_uevent);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700970 kset_unregister(&bus->p->subsys);
971 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +0800972 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800974EXPORT_SYMBOL_GPL(bus_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000976int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
977{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700978 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000979}
980EXPORT_SYMBOL_GPL(bus_register_notifier);
981
982int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
983{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700984 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000985}
986EXPORT_SYMBOL_GPL(bus_unregister_notifier);
987
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -0700988struct kset *bus_get_kset(struct bus_type *bus)
989{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700990 return &bus->p->subsys;
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -0700991}
992EXPORT_SYMBOL_GPL(bus_get_kset);
993
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -0700994struct klist *bus_get_device_klist(struct bus_type *bus)
995{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700996 return &bus->p->klist_devices;
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -0700997}
998EXPORT_SYMBOL_GPL(bus_get_device_klist);
999
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001000/*
1001 * Yes, this forcably breaks the klist abstraction temporarily. It
1002 * just wants to sort the klist, not change reference counts and
1003 * take/drop locks rapidly in the process. It does all this while
1004 * holding the lock for the list, so objects can't otherwise be
1005 * added/removed while we're swizzling.
1006 */
1007static void device_insertion_sort_klist(struct device *a, struct list_head *list,
1008 int (*compare)(const struct device *a,
1009 const struct device *b))
1010{
1011 struct list_head *pos;
1012 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001013 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001014 struct device *b;
1015
1016 list_for_each(pos, list) {
1017 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001018 dev_prv = to_device_private_bus(n);
1019 b = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001020 if (compare(a, b) <= 0) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001021 list_move_tail(&a->p->knode_bus.n_node,
1022 &b->p->knode_bus.n_node);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001023 return;
1024 }
1025 }
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001026 list_move_tail(&a->p->knode_bus.n_node, list);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001027}
1028
1029void bus_sort_breadthfirst(struct bus_type *bus,
1030 int (*compare)(const struct device *a,
1031 const struct device *b))
1032{
1033 LIST_HEAD(sorted_devices);
1034 struct list_head *pos, *tmp;
1035 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001036 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001037 struct device *dev;
1038 struct klist *device_klist;
1039
1040 device_klist = bus_get_device_klist(bus);
1041
1042 spin_lock(&device_klist->k_lock);
1043 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1044 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001045 dev_prv = to_device_private_bus(n);
1046 dev = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001047 device_insertion_sort_klist(dev, &sorted_devices, compare);
1048 }
1049 list_splice(&sorted_devices, &device_klist->k_list);
1050 spin_unlock(&device_klist->k_lock);
1051}
1052EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1053
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054int __init buses_init(void)
1055{
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001056 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
1057 if (!bus_kset)
1058 return -ENOMEM;
1059 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060}