blob: d414331b480e72afc9ac8ac505dee449f1c795d9 [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
Alan Stern2b08c8d2005-11-23 15:43:50 -0800167/* Manually detach a device from its associated driver. */
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700168static ssize_t driver_unbind(struct device_driver *drv,
169 const char *buf, size_t count)
170{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700171 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700172 struct device *dev;
173 int err = -ENODEV;
174
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800175 dev = bus_find_device_by_name(bus, NULL, buf);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800176 if (dev && dev->driver == drv) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500177 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800178 device_lock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700179 device_release_driver(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500180 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800181 device_unlock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700182 err = count;
183 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800184 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700185 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800186 return err;
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700187}
188static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
189
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700190/*
191 * Manually attach a device to a driver.
192 * Note: the driver must want to bind to the device,
193 * it is not possible to override the driver's id table.
194 */
195static ssize_t driver_bind(struct device_driver *drv,
196 const char *buf, size_t count)
197{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700198 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700199 struct device *dev;
200 int err = -ENODEV;
201
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800202 dev = bus_find_device_by_name(bus, NULL, buf);
Ming Lei49b420a2009-01-21 23:27:47 +0800203 if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500204 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800205 device_lock(dev->parent);
206 device_lock(dev);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700207 err = driver_probe_device(drv, dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800208 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500209 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800210 device_unlock(dev->parent);
Ryan Wilson37225402006-03-22 16:26:25 -0500211
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800212 if (err > 0) {
213 /* success */
Ryan Wilson37225402006-03-22 16:26:25 -0500214 err = count;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800215 } else if (err == 0) {
216 /* driver didn't accept device */
Ryan Wilson37225402006-03-22 16:26:25 -0500217 err = -ENODEV;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800218 }
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700219 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800220 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700221 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800222 return err;
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700223}
224static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
225
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100226static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
227{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700228 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100229}
230
231static ssize_t store_drivers_autoprobe(struct bus_type *bus,
232 const char *buf, size_t count)
233{
234 if (buf[0] == '0')
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700235 bus->p->drivers_autoprobe = 0;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100236 else
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700237 bus->p->drivers_autoprobe = 1;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100238 return count;
239}
240
241static ssize_t store_drivers_probe(struct bus_type *bus,
242 const char *buf, size_t count)
243{
244 struct device *dev;
245
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800246 dev = bus_find_device_by_name(bus, NULL, buf);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100247 if (!dev)
248 return -ENODEV;
249 if (bus_rescan_devices_helper(dev, NULL) != 0)
250 return -EINVAL;
251 return count;
252}
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
Bjorn Helgaas4fa3e782013-01-29 16:44:27 -0700293 if (!bus || !bus->p)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800294 return -EINVAL;
295
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700296 klist_iter_init_node(&bus->p->klist_devices, &i,
297 (start ? &start->p->knode_bus : NULL));
298 while ((dev = next_device(&i)) && !error)
299 error = fn(dev, data);
300 klist_iter_exit(&i);
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800301 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
Bjorn Helgaas4fa3e782013-01-29 16:44:27 -0700327 if (!bus || !bus->p)
Cornelia Huck0edb5862005-06-22 16:59:51 +0200328 return NULL;
329
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700330 klist_iter_init_node(&bus->p->klist_devices, &i,
331 (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
Kay Sieversca22e562011-12-14 14:29:38 -0800364/**
365 * subsys_find_device_by_id - find a device with a specific enumeration number
366 * @subsys: subsystem
367 * @id: index 'id' in struct device
368 * @hint: device to check first
369 *
370 * Check the hint's next object and if it is a match return it directly,
371 * otherwise, fall back to a full list search. Either way a reference for
372 * the returned object is taken.
373 */
374struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id,
375 struct device *hint)
376{
377 struct klist_iter i;
378 struct device *dev;
379
380 if (!subsys)
381 return NULL;
382
383 if (hint) {
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700384 klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
Kay Sieversca22e562011-12-14 14:29:38 -0800385 dev = next_device(&i);
386 if (dev && dev->id == id && get_device(dev)) {
387 klist_iter_exit(&i);
388 return dev;
389 }
390 klist_iter_exit(&i);
391 }
392
393 klist_iter_init_node(&subsys->p->klist_devices, &i, NULL);
394 while ((dev = next_device(&i))) {
395 if (dev->id == id && get_device(dev)) {
396 klist_iter_exit(&i);
397 return dev;
398 }
399 }
400 klist_iter_exit(&i);
401 return NULL;
402}
403EXPORT_SYMBOL_GPL(subsys_find_device_by_id);
404
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800405static struct device_driver *next_driver(struct klist_iter *i)
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800406{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800407 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800408 struct driver_private *drv_priv;
409
410 if (n) {
411 drv_priv = container_of(n, struct driver_private, knode_bus);
412 return drv_priv->driver;
413 }
414 return NULL;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800415}
416
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800418 * bus_for_each_drv - driver iterator
419 * @bus: bus we're dealing with.
420 * @start: driver to start iterating on.
421 * @data: data to pass to the callback.
422 * @fn: function to call for each driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800424 * This is nearly identical to the device iterator above.
425 * We iterate over each driver that belongs to @bus, and call
426 * @fn for each. If @fn returns anything but 0, we break out
427 * and return it. If @start is not NULL, we use it as the head
428 * of the list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800430 * NOTE: we don't return the driver that returns a non-zero
431 * value, nor do we leave the reference count incremented for that
432 * driver. If the caller needs to know that info, it must set it
433 * in the callback. It must also be sure to increment the refcount
434 * so it doesn't disappear before returning to the caller.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800436int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
437 void *data, int (*fn)(struct device_driver *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438{
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800439 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800440 struct device_driver *drv;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800441 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800443 if (!bus)
444 return -EINVAL;
445
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700446 klist_iter_init_node(&bus->p->klist_drivers, &i,
447 start ? &start->p->knode_bus : NULL);
448 while ((drv = next_driver(&i)) && !error)
449 error = fn(drv, data);
450 klist_iter_exit(&i);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800451 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800453EXPORT_SYMBOL_GPL(bus_for_each_drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
Andrew Morton4aca67e2007-02-13 22:39:26 -0800455static int device_add_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456{
457 int error = 0;
458 int i;
459
Andrew Morton4aca67e2007-02-13 22:39:26 -0800460 if (!bus->dev_attrs)
461 return 0;
462
463 for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800464 error = device_create_file(dev, &bus->dev_attrs[i]);
Andrew Morton4aca67e2007-02-13 22:39:26 -0800465 if (error) {
466 while (--i >= 0)
467 device_remove_file(dev, &bus->dev_attrs[i]);
468 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 }
470 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472}
473
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800474static void device_remove_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475{
476 int i;
477
478 if (bus->dev_attrs) {
479 for (i = 0; attr_name(bus->dev_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800480 device_remove_file(dev, &bus->dev_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 }
482}
483
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800485 * bus_add_device - add device to bus
486 * @dev: device being added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 *
Alan Stern2023c612009-07-30 15:27:18 -0400488 * - Add device's bus attributes.
489 * - Create links to device's bus.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800490 * - Add the device to its bus's list of devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800492int bus_add_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800494 struct bus_type *bus = bus_get(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 int error = 0;
496
497 if (bus) {
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100498 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
Greg Kroah-Hartmand377e852005-06-22 16:09:05 -0700499 error = device_add_attrs(bus, dev);
Andrew Mortonf86db392006-08-14 22:43:20 -0700500 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200501 goto out_put;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700502 error = sysfs_create_link(&bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100503 &dev->kobj, dev_name(dev));
Andrew Mortonf86db392006-08-14 22:43:20 -0700504 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200505 goto out_id;
Andrew Mortonf86db392006-08-14 22:43:20 -0700506 error = sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700507 &dev->bus->p->subsys.kobj, "subsystem");
Andrew Mortonf86db392006-08-14 22:43:20 -0700508 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200509 goto out_subsys;
Alan Stern2023c612009-07-30 15:27:18 -0400510 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 }
Cornelia Huck513e7332006-09-22 11:37:08 +0200512 return 0;
513
Cornelia Huck513e7332006-09-22 11:37:08 +0200514out_subsys:
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100515 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
Cornelia Huck513e7332006-09-22 11:37:08 +0200516out_id:
517 device_remove_attrs(bus, dev);
518out_put:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700519 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 return error;
521}
522
523/**
Alan Stern2023c612009-07-30 15:27:18 -0400524 * bus_probe_device - probe drivers for a new device
525 * @dev: device to probe
Kay Sievers53877d02006-04-04 20:42:26 +0200526 *
Alan Stern2023c612009-07-30 15:27:18 -0400527 * - Automatically probe for a driver if the bus allows it.
Kay Sievers53877d02006-04-04 20:42:26 +0200528 */
Alan Stern2023c612009-07-30 15:27:18 -0400529void bus_probe_device(struct device *dev)
Kay Sievers53877d02006-04-04 20:42:26 +0200530{
Andrew Mortonf86db392006-08-14 22:43:20 -0700531 struct bus_type *bus = dev->bus;
Kay Sieversca22e562011-12-14 14:29:38 -0800532 struct subsys_interface *sif;
Alan Stern2023c612009-07-30 15:27:18 -0400533 int ret;
Kay Sievers53877d02006-04-04 20:42:26 +0200534
Kay Sieversca22e562011-12-14 14:29:38 -0800535 if (!bus)
536 return;
537
538 if (bus->p->drivers_autoprobe) {
Alan Stern2023c612009-07-30 15:27:18 -0400539 ret = device_attach(dev);
Cornelia Huckc6a46692007-02-05 16:15:26 -0800540 WARN_ON(ret < 0);
Kay Sievers53877d02006-04-04 20:42:26 +0200541 }
Kay Sieversca22e562011-12-14 14:29:38 -0800542
543 mutex_lock(&bus->p->mutex);
544 list_for_each_entry(sif, &bus->p->interfaces, node)
545 if (sif->add_dev)
546 sif->add_dev(dev, sif);
547 mutex_unlock(&bus->p->mutex);
Kay Sievers53877d02006-04-04 20:42:26 +0200548}
549
550/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800551 * bus_remove_device - remove device from bus
552 * @dev: device to be removed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 *
Kay Sieversca22e562011-12-14 14:29:38 -0800554 * - Remove device from all interfaces.
555 * - Remove symlink from bus' directory.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800556 * - Delete device from bus's list.
557 * - Detach from its driver.
558 * - Drop reference taken in bus_add_device().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800560void bus_remove_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561{
Kay Sieversca22e562011-12-14 14:29:38 -0800562 struct bus_type *bus = dev->bus;
563 struct subsys_interface *sif;
Greg Kroah-Hartman3f62e572008-03-13 17:07:03 -0400564
Kay Sieversca22e562011-12-14 14:29:38 -0800565 if (!bus)
566 return;
567
568 mutex_lock(&bus->p->mutex);
569 list_for_each_entry(sif, &bus->p->interfaces, node)
570 if (sif->remove_dev)
571 sif->remove_dev(dev, sif);
572 mutex_unlock(&bus->p->mutex);
573
574 sysfs_remove_link(&dev->kobj, "subsystem");
575 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
576 dev_name(dev));
577 device_remove_attrs(dev->bus, dev);
578 if (klist_node_attached(&dev->p->knode_bus))
579 klist_del(&dev->p->knode_bus);
580
581 pr_debug("bus: '%s': remove device %s\n",
582 dev->bus->name, dev_name(dev));
583 device_release_driver(dev);
584 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585}
586
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800587static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588{
589 int error = 0;
590 int i;
591
592 if (bus->drv_attrs) {
593 for (i = 0; attr_name(bus->drv_attrs[i]); i++) {
594 error = driver_create_file(drv, &bus->drv_attrs[i]);
595 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800596 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 }
598 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800599done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800601err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 while (--i >= 0)
603 driver_remove_file(drv, &bus->drv_attrs[i]);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800604 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605}
606
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800607static void driver_remove_attrs(struct bus_type *bus,
608 struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609{
610 int i;
611
612 if (bus->drv_attrs) {
613 for (i = 0; attr_name(bus->drv_attrs[i]); i++)
614 driver_remove_file(drv, &bus->drv_attrs[i]);
615 }
616}
617
Andrew Mortonf86db392006-08-14 22:43:20 -0700618static int __must_check add_bind_files(struct device_driver *drv)
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800619{
Andrew Mortonf86db392006-08-14 22:43:20 -0700620 int ret;
621
622 ret = driver_create_file(drv, &driver_attr_unbind);
623 if (ret == 0) {
624 ret = driver_create_file(drv, &driver_attr_bind);
625 if (ret)
626 driver_remove_file(drv, &driver_attr_unbind);
627 }
628 return ret;
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800629}
630
631static void remove_bind_files(struct device_driver *drv)
632{
633 driver_remove_file(drv, &driver_attr_bind);
634 driver_remove_file(drv, &driver_attr_unbind);
635}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100636
Kay Sievers83807702007-07-30 02:28:56 +0200637static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
638static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
639 show_drivers_autoprobe, store_drivers_autoprobe);
640
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100641static int add_probe_files(struct bus_type *bus)
642{
643 int retval;
644
Kay Sievers83807702007-07-30 02:28:56 +0200645 retval = bus_create_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100646 if (retval)
647 goto out;
648
Kay Sievers83807702007-07-30 02:28:56 +0200649 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100650 if (retval)
Kay Sievers83807702007-07-30 02:28:56 +0200651 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100652out:
653 return retval;
654}
655
656static void remove_probe_files(struct bus_type *bus)
657{
Kay Sievers83807702007-07-30 02:28:56 +0200658 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
659 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100660}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200662static ssize_t driver_uevent_store(struct device_driver *drv,
663 const char *buf, size_t count)
664{
665 enum kobject_action action;
666
667 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800668 kobject_uevent(&drv->p->kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200669 return count;
670}
671static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
672
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800674 * bus_add_driver - Add a driver to the bus.
675 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700677int bus_add_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800679 struct bus_type *bus;
680 struct driver_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 int error = 0;
682
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800683 bus = bus_get(drv->bus);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400684 if (!bus)
Greg Kroah-Hartman4f6e1942007-04-20 11:29:52 -0700685 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800687 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800688
689 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
Cornelia Huck07634462008-02-18 17:04:25 +0100690 if (!priv) {
691 error = -ENOMEM;
692 goto out_put_bus;
693 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800694 klist_init(&priv->klist_devices, NULL, NULL);
695 priv->driver = drv;
696 drv->p = priv;
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400697 priv->kobj.kset = bus->p->drivers_kset;
698 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
699 "%s", drv->name);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700700 if (error)
Cornelia Huck07634462008-02-18 17:04:25 +0100701 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702
Ming Lei190888a2012-11-19 23:35:17 +0800703 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700704 if (drv->bus->p->drivers_autoprobe) {
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100705 error = driver_attach(drv);
706 if (error)
707 goto out_unregister;
708 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400709 module_add_driver(drv->owner, drv);
710
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200711 error = driver_create_file(drv, &driver_attr_uevent);
712 if (error) {
713 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800714 __func__, drv->name);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200715 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400716 error = driver_add_attrs(bus, drv);
717 if (error) {
718 /* How the hell do we get out of this pickle? Give up */
719 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800720 __func__, drv->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 }
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700722
723 if (!drv->suppress_bind_attrs) {
724 error = add_bind_files(drv);
725 if (error) {
726 /* Ditto */
727 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
728 __func__, drv->name);
729 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400730 }
731
Kay Sievers5c8563d2009-05-28 14:24:07 -0700732 return 0;
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700733
Andrew Mortonf86db392006-08-14 22:43:20 -0700734out_unregister:
Phil Carmody99b28f12009-12-14 20:28:12 +0200735 kobject_put(&priv->kobj);
Kay Sievers5c8563d2009-05-28 14:24:07 -0700736 kfree(drv->p);
737 drv->p = NULL;
Andrew Mortonf86db392006-08-14 22:43:20 -0700738out_put_bus:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700739 bus_put(bus);
Andrew Mortonf86db392006-08-14 22:43:20 -0700740 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741}
742
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800744 * bus_remove_driver - delete driver from bus's knowledge.
745 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800747 * Detach the driver from the devices it controls, and remove
748 * it from its bus's list of drivers. Finally, we drop the reference
749 * to the bus we took in bus_add_driver().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800751void bus_remove_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752{
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400753 if (!drv->bus)
754 return;
755
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700756 if (!drv->suppress_bind_attrs)
757 remove_bind_files(drv);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400758 driver_remove_attrs(drv->bus, drv);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200759 driver_remove_file(drv, &driver_attr_uevent);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800760 klist_remove(&drv->p->knode_bus);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800761 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400762 driver_detach(drv);
763 module_remove_driver(drv);
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800764 kobject_put(&drv->p->kobj);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700765 bus_put(drv->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766}
767
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768/* Helper for bus_rescan_devices's iter */
Andrew Mortonf86db392006-08-14 22:43:20 -0700769static int __must_check bus_rescan_devices_helper(struct device *dev,
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800770 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771{
Andrew Mortonf86db392006-08-14 22:43:20 -0700772 int ret = 0;
773
Alan Sternbf74ad52005-11-17 16:54:12 -0500774 if (!dev->driver) {
775 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800776 device_lock(dev->parent);
Andrew Mortonf86db392006-08-14 22:43:20 -0700777 ret = device_attach(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500778 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800779 device_unlock(dev->parent);
Alan Sternbf74ad52005-11-17 16:54:12 -0500780 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700781 return ret < 0 ? ret : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782}
783
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784/**
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700785 * bus_rescan_devices - rescan devices on the bus for possible drivers
786 * @bus: the bus to scan.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 *
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700788 * This function will look for devices on the bus with no driver
789 * attached and rescan it against existing drivers to see if it matches
790 * any by calling device_attach() for the unbound devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800792int bus_rescan_devices(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793{
Andrew Mortonf86db392006-08-14 22:43:20 -0700794 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800796EXPORT_SYMBOL_GPL(bus_rescan_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
Moore, Erice935d5d2006-03-14 09:18:18 -0700798/**
799 * device_reprobe - remove driver for a device and probe for a new driver
800 * @dev: the device to reprobe
801 *
802 * This function detaches the attached driver (if any) for the given
803 * device and restarts the driver probing process. It is intended
804 * to use if probing criteria changed during a devices lifetime and
805 * driver attachment should change accordingly.
806 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700807int device_reprobe(struct device *dev)
Moore, Erice935d5d2006-03-14 09:18:18 -0700808{
809 if (dev->driver) {
810 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800811 device_lock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700812 device_release_driver(dev);
813 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800814 device_unlock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700815 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700816 return bus_rescan_devices_helper(dev, NULL);
Moore, Erice935d5d2006-03-14 09:18:18 -0700817}
818EXPORT_SYMBOL_GPL(device_reprobe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800821 * find_bus - locate bus by name.
822 * @name: name of bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800824 * Call kset_find_obj() to iterate over list of buses to
825 * find a bus by name. Return bus if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800827 * Note that kset_find_obj increments bus' reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 */
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200829#if 0
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800830struct bus_type *find_bus(char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800832 struct kobject *k = kset_find_obj(bus_kset, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 return k ? to_bus(k) : NULL;
834}
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200835#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
837
838/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800839 * bus_add_attrs - Add default attributes for this bus.
840 * @bus: Bus that has just been registered.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 */
842
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800843static int bus_add_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844{
845 int error = 0;
846 int i;
847
848 if (bus->bus_attrs) {
849 for (i = 0; attr_name(bus->bus_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800850 error = bus_create_file(bus, &bus->bus_attrs[i]);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700851 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800852 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 }
854 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800855done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800857err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 while (--i >= 0)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800859 bus_remove_file(bus, &bus->bus_attrs[i]);
860 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861}
862
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800863static void bus_remove_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864{
865 int i;
866
867 if (bus->bus_attrs) {
868 for (i = 0; attr_name(bus->bus_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800869 bus_remove_file(bus, &bus->bus_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 }
871}
872
James Bottomley34bb61f2005-09-06 16:56:51 -0700873static void klist_devices_get(struct klist_node *n)
874{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800875 struct device_private *dev_prv = to_device_private_bus(n);
876 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700877
878 get_device(dev);
879}
880
881static void klist_devices_put(struct klist_node *n)
882{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800883 struct device_private *dev_prv = to_device_private_bus(n);
884 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700885
886 put_device(dev);
887}
888
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200889static ssize_t bus_uevent_store(struct bus_type *bus,
890 const char *buf, size_t count)
891{
892 enum kobject_action action;
893
894 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700895 kobject_uevent(&bus->p->subsys.kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200896 return count;
897}
898static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
899
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900/**
Michal Hockobe871b72013-03-12 17:21:19 +0100901 * bus_register - register a driver-core subsystem
Randy Dunlap78d79552012-01-21 11:02:28 -0800902 * @bus: bus to register
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 *
Randy Dunlap78d79552012-01-21 11:02:28 -0800904 * Once we have that, we register the bus with the kobject
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800905 * infrastructure, then register the children subsystems it has:
Kay Sieversca22e562011-12-14 14:29:38 -0800906 * the devices and drivers that belong to the subsystem.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 */
Michal Hockobe871b72013-03-12 17:21:19 +0100908int bus_register(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909{
910 int retval;
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100911 struct subsys_private *priv;
Michal Hockobe871b72013-03-12 17:21:19 +0100912 struct lock_class_key *key = &bus->lock_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100914 priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700915 if (!priv)
916 return -ENOMEM;
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000917
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700918 priv->bus = bus;
919 bus->p = priv;
920
921 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
922
923 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 if (retval)
925 goto out;
926
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700927 priv->subsys.kobj.kset = bus_kset;
928 priv->subsys.kobj.ktype = &bus_ktype;
929 priv->drivers_autoprobe = 1;
Greg Kroah-Hartmand6b05b82007-09-12 15:06:57 -0700930
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700931 retval = kset_register(&priv->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 if (retval)
933 goto out;
934
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200935 retval = bus_create_file(bus, &bus_attr_uevent);
936 if (retval)
937 goto bus_uevent_fail;
938
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700939 priv->devices_kset = kset_create_and_add("devices", NULL,
940 &priv->subsys.kobj);
941 if (!priv->devices_kset) {
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700942 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 goto bus_devices_fail;
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700944 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700946 priv->drivers_kset = kset_create_and_add("drivers", NULL,
947 &priv->subsys.kobj);
948 if (!priv->drivers_kset) {
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700949 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 goto bus_drivers_fail;
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700951 }
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800952
Kay Sieversca22e562011-12-14 14:29:38 -0800953 INIT_LIST_HEAD(&priv->interfaces);
954 __mutex_init(&priv->mutex, "subsys mutex", key);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700955 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
956 klist_init(&priv->klist_drivers, NULL, NULL);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100957
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100958 retval = add_probe_files(bus);
959 if (retval)
960 goto bus_probe_files_fail;
961
Cornelia Huck1bb68812006-09-22 11:37:04 +0200962 retval = bus_add_attrs(bus);
963 if (retval)
964 goto bus_attrs_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800966 pr_debug("bus: '%s': registered\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 return 0;
968
Cornelia Huck1bb68812006-09-22 11:37:04 +0200969bus_attrs_fail:
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100970 remove_probe_files(bus);
971bus_probe_files_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700972 kset_unregister(bus->p->drivers_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973bus_drivers_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700974 kset_unregister(bus->p->devices_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975bus_devices_fail:
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200976 bus_remove_file(bus, &bus_attr_uevent);
977bus_uevent_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700978 kset_unregister(&bus->p->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979out:
Jike Song600c20f2010-07-15 17:43:54 +0800980 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +0800981 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 return retval;
983}
Michal Hockobe871b72013-03-12 17:21:19 +0100984EXPORT_SYMBOL_GPL(bus_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800987 * bus_unregister - remove a bus from the system
988 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800990 * Unregister the child subsystems and the bus itself.
991 * Finally, we call bus_put() to release the refcount
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800993void bus_unregister(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994{
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800995 pr_debug("bus: '%s': unregistering\n", bus->name);
Kay Sieversca22e562011-12-14 14:29:38 -0800996 if (bus->dev_root)
997 device_unregister(bus->dev_root);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 bus_remove_attrs(bus);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100999 remove_probe_files(bus);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001000 kset_unregister(bus->p->drivers_kset);
1001 kset_unregister(bus->p->devices_kset);
Kay Sievers7ac1cf42007-08-12 20:43:55 +02001002 bus_remove_file(bus, &bus_attr_uevent);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001003 kset_unregister(&bus->p->subsys);
1004 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +08001005 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001007EXPORT_SYMBOL_GPL(bus_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001009int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
1010{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001011 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001012}
1013EXPORT_SYMBOL_GPL(bus_register_notifier);
1014
1015int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
1016{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001017 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001018}
1019EXPORT_SYMBOL_GPL(bus_unregister_notifier);
1020
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -07001021struct kset *bus_get_kset(struct bus_type *bus)
1022{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001023 return &bus->p->subsys;
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -07001024}
1025EXPORT_SYMBOL_GPL(bus_get_kset);
1026
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001027struct klist *bus_get_device_klist(struct bus_type *bus)
1028{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001029 return &bus->p->klist_devices;
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001030}
1031EXPORT_SYMBOL_GPL(bus_get_device_klist);
1032
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001033/*
Robert P. J. Daydca25eb2010-11-21 08:15:01 -05001034 * Yes, this forcibly breaks the klist abstraction temporarily. It
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001035 * just wants to sort the klist, not change reference counts and
1036 * take/drop locks rapidly in the process. It does all this while
1037 * holding the lock for the list, so objects can't otherwise be
1038 * added/removed while we're swizzling.
1039 */
1040static void device_insertion_sort_klist(struct device *a, struct list_head *list,
1041 int (*compare)(const struct device *a,
1042 const struct device *b))
1043{
1044 struct list_head *pos;
1045 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001046 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001047 struct device *b;
1048
1049 list_for_each(pos, list) {
1050 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001051 dev_prv = to_device_private_bus(n);
1052 b = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001053 if (compare(a, b) <= 0) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001054 list_move_tail(&a->p->knode_bus.n_node,
1055 &b->p->knode_bus.n_node);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001056 return;
1057 }
1058 }
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001059 list_move_tail(&a->p->knode_bus.n_node, list);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001060}
1061
1062void bus_sort_breadthfirst(struct bus_type *bus,
1063 int (*compare)(const struct device *a,
1064 const struct device *b))
1065{
1066 LIST_HEAD(sorted_devices);
1067 struct list_head *pos, *tmp;
1068 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001069 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001070 struct device *dev;
1071 struct klist *device_klist;
1072
1073 device_klist = bus_get_device_klist(bus);
1074
1075 spin_lock(&device_klist->k_lock);
1076 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1077 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001078 dev_prv = to_device_private_bus(n);
1079 dev = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001080 device_insertion_sort_klist(dev, &sorted_devices, compare);
1081 }
1082 list_splice(&sorted_devices, &device_klist->k_list);
1083 spin_unlock(&device_klist->k_lock);
1084}
1085EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1086
Kay Sieversca22e562011-12-14 14:29:38 -08001087/**
1088 * subsys_dev_iter_init - initialize subsys device iterator
1089 * @iter: subsys iterator to initialize
1090 * @subsys: the subsys we wanna iterate over
1091 * @start: the device to start iterating from, if any
1092 * @type: device_type of the devices to iterate over, NULL for all
1093 *
1094 * Initialize subsys iterator @iter such that it iterates over devices
1095 * of @subsys. If @start is set, the list iteration will start there,
1096 * otherwise if it is NULL, the iteration starts at the beginning of
1097 * the list.
1098 */
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001099void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
1100 struct device *start, const struct device_type *type)
Kay Sieversca22e562011-12-14 14:29:38 -08001101{
1102 struct klist_node *start_knode = NULL;
1103
1104 if (start)
1105 start_knode = &start->p->knode_bus;
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001106 klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
1107 iter->type = type;
Kay Sieversca22e562011-12-14 14:29:38 -08001108}
1109EXPORT_SYMBOL_GPL(subsys_dev_iter_init);
1110
1111/**
1112 * subsys_dev_iter_next - iterate to the next device
1113 * @iter: subsys iterator to proceed
1114 *
1115 * Proceed @iter to the next device and return it. Returns NULL if
1116 * iteration is complete.
1117 *
1118 * The returned device is referenced and won't be released till
1119 * iterator is proceed to the next device or exited. The caller is
1120 * free to do whatever it wants to do with the device including
1121 * calling back into subsys code.
1122 */
1123struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
1124{
1125 struct klist_node *knode;
1126 struct device *dev;
1127
1128 for (;;) {
1129 knode = klist_next(&iter->ki);
1130 if (!knode)
1131 return NULL;
1132 dev = container_of(knode, struct device_private, knode_bus)->device;
1133 if (!iter->type || iter->type == dev->type)
1134 return dev;
1135 }
1136}
1137EXPORT_SYMBOL_GPL(subsys_dev_iter_next);
1138
1139/**
1140 * subsys_dev_iter_exit - finish iteration
1141 * @iter: subsys iterator to finish
1142 *
1143 * Finish an iteration. Always call this function after iteration is
1144 * complete whether the iteration ran till the end or not.
1145 */
1146void subsys_dev_iter_exit(struct subsys_dev_iter *iter)
1147{
1148 klist_iter_exit(&iter->ki);
1149}
1150EXPORT_SYMBOL_GPL(subsys_dev_iter_exit);
1151
1152int subsys_interface_register(struct subsys_interface *sif)
1153{
1154 struct bus_type *subsys;
1155 struct subsys_dev_iter iter;
1156 struct device *dev;
1157
1158 if (!sif || !sif->subsys)
1159 return -ENODEV;
1160
1161 subsys = bus_get(sif->subsys);
1162 if (!subsys)
1163 return -EINVAL;
1164
1165 mutex_lock(&subsys->p->mutex);
1166 list_add_tail(&sif->node, &subsys->p->interfaces);
1167 if (sif->add_dev) {
1168 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1169 while ((dev = subsys_dev_iter_next(&iter)))
1170 sif->add_dev(dev, sif);
1171 subsys_dev_iter_exit(&iter);
1172 }
1173 mutex_unlock(&subsys->p->mutex);
1174
1175 return 0;
1176}
1177EXPORT_SYMBOL_GPL(subsys_interface_register);
1178
1179void subsys_interface_unregister(struct subsys_interface *sif)
1180{
Jonghwan Choi2b315942012-01-14 11:06:03 +09001181 struct bus_type *subsys;
Kay Sieversca22e562011-12-14 14:29:38 -08001182 struct subsys_dev_iter iter;
1183 struct device *dev;
1184
Jonghwan Choi2b315942012-01-14 11:06:03 +09001185 if (!sif || !sif->subsys)
Kay Sieversca22e562011-12-14 14:29:38 -08001186 return;
1187
Jonghwan Choi2b315942012-01-14 11:06:03 +09001188 subsys = sif->subsys;
1189
Kay Sieversca22e562011-12-14 14:29:38 -08001190 mutex_lock(&subsys->p->mutex);
1191 list_del_init(&sif->node);
1192 if (sif->remove_dev) {
1193 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1194 while ((dev = subsys_dev_iter_next(&iter)))
1195 sif->remove_dev(dev, sif);
1196 subsys_dev_iter_exit(&iter);
1197 }
1198 mutex_unlock(&subsys->p->mutex);
1199
1200 bus_put(subsys);
1201}
1202EXPORT_SYMBOL_GPL(subsys_interface_unregister);
1203
1204static void system_root_device_release(struct device *dev)
1205{
1206 kfree(dev);
1207}
Tejun Heod73ce002013-03-12 11:30:05 -07001208
1209static int subsys_register(struct bus_type *subsys,
1210 const struct attribute_group **groups,
1211 struct kobject *parent_of_root)
1212{
1213 struct device *dev;
1214 int err;
1215
1216 err = bus_register(subsys);
1217 if (err < 0)
1218 return err;
1219
1220 dev = kzalloc(sizeof(struct device), GFP_KERNEL);
1221 if (!dev) {
1222 err = -ENOMEM;
1223 goto err_dev;
1224 }
1225
1226 err = dev_set_name(dev, "%s", subsys->name);
1227 if (err < 0)
1228 goto err_name;
1229
1230 dev->kobj.parent = parent_of_root;
1231 dev->groups = groups;
1232 dev->release = system_root_device_release;
1233
1234 err = device_register(dev);
1235 if (err < 0)
1236 goto err_dev_reg;
1237
1238 subsys->dev_root = dev;
1239 return 0;
1240
1241err_dev_reg:
1242 put_device(dev);
1243 dev = NULL;
1244err_name:
1245 kfree(dev);
1246err_dev:
1247 bus_unregister(subsys);
1248 return err;
1249}
1250
Kay Sieversca22e562011-12-14 14:29:38 -08001251/**
1252 * subsys_system_register - register a subsystem at /sys/devices/system/
Randy Dunlap78d79552012-01-21 11:02:28 -08001253 * @subsys: system subsystem
1254 * @groups: default attributes for the root device
Kay Sieversca22e562011-12-14 14:29:38 -08001255 *
1256 * All 'system' subsystems have a /sys/devices/system/<name> root device
1257 * with the name of the subsystem. The root device can carry subsystem-
1258 * wide attributes. All registered devices are below this single root
1259 * device and are named after the subsystem with a simple enumeration
1260 * number appended. The registered devices are not explicitely named;
1261 * only 'id' in the device needs to be set.
1262 *
1263 * Do not use this interface for anything new, it exists for compatibility
1264 * with bad ideas only. New subsystems should use plain subsystems; and
1265 * add the subsystem-wide attributes should be added to the subsystem
1266 * directory itself and not some create fake root-device placed in
1267 * /sys/devices/system/<name>.
1268 */
1269int subsys_system_register(struct bus_type *subsys,
1270 const struct attribute_group **groups)
1271{
Tejun Heod73ce002013-03-12 11:30:05 -07001272 return subsys_register(subsys, groups, &system_kset->kobj);
Kay Sieversca22e562011-12-14 14:29:38 -08001273}
1274EXPORT_SYMBOL_GPL(subsys_system_register);
1275
Tejun Heod73ce002013-03-12 11:30:05 -07001276/**
1277 * subsys_virtual_register - register a subsystem at /sys/devices/virtual/
1278 * @subsys: virtual subsystem
1279 * @groups: default attributes for the root device
1280 *
1281 * All 'virtual' subsystems have a /sys/devices/system/<name> root device
1282 * with the name of the subystem. The root device can carry subsystem-wide
1283 * attributes. All registered devices are below this single root device.
1284 * There's no restriction on device naming. This is for kernel software
1285 * constructs which need sysfs interface.
1286 */
1287int subsys_virtual_register(struct bus_type *subsys,
1288 const struct attribute_group **groups)
1289{
1290 struct kobject *virtual_dir;
1291
1292 virtual_dir = virtual_device_parent(NULL);
1293 if (!virtual_dir)
1294 return -ENOMEM;
1295
1296 return subsys_register(subsys, groups, virtual_dir);
1297}
Greg Kroah-Hartman1c04fc32013-05-10 09:14:04 -07001298EXPORT_SYMBOL_GPL(subsys_virtual_register);
Tejun Heod73ce002013-03-12 11:30:05 -07001299
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300int __init buses_init(void)
1301{
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001302 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
1303 if (!bus_kset)
1304 return -ENOMEM;
Kay Sieversca22e562011-12-14 14:29:38 -08001305
1306 system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
1307 if (!system_kset)
1308 return -ENOMEM;
1309
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001310 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311}