blob: 4c289ab91357531373c25889b5911bff33ae3d64 [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>
Greg Kroah-Hartman63967682013-08-27 10:24:15 -070020#include <linux/sysfs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include "base.h"
22#include "power/power.h"
23
Kay Sieversca22e562011-12-14 14:29:38 -080024/* /sys/devices/system */
H Hartley Sweeten97ec4482012-04-16 18:14:10 -070025static struct kset *system_kset;
Kay Sieversca22e562011-12-14 14:29:38 -080026
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29/*
30 * sysfs bindings for drivers
31 */
32
33#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35
Kay Sieversb8c5cec2007-02-16 17:33:36 +010036static int __must_check bus_rescan_devices_helper(struct device *dev,
37 void *data);
38
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070039static struct bus_type *bus_get(struct bus_type *bus)
40{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070041 if (bus) {
42 kset_get(&bus->p->subsys);
43 return bus;
44 }
45 return NULL;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070046}
47
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070048static void bus_put(struct bus_type *bus)
49{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070050 if (bus)
51 kset_put(&bus->p->subsys);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070052}
53
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080054static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
55 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080057 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080058 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050059 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
61 if (drv_attr->show)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080062 ret = drv_attr->show(drv_priv->driver, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 return ret;
64}
65
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080066static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
67 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080069 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080070 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050071 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 if (drv_attr->store)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080074 ret = drv_attr->store(drv_priv->driver, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 return ret;
76}
77
Emese Revfy52cf25d2010-01-19 02:58:23 +010078static const struct sysfs_ops driver_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 .show = drv_attr_show,
80 .store = drv_attr_store,
81};
82
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080083static void driver_release(struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070084{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080085 struct driver_private *drv_priv = to_driver(kobj);
86
Harvey Harrison2b3a3022008-03-04 16:41:05 -080087 pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080088 kfree(drv_priv);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089}
90
Greg Kroah-Hartmana1148fb2007-10-11 10:47:49 -060091static struct kobj_type driver_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 .sysfs_ops = &driver_sysfs_ops,
93 .release = driver_release,
94};
95
Linus Torvalds1da177e2005-04-16 15:20:36 -070096/*
97 * sysfs bindings for buses
98 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080099static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
100 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800102 struct bus_attribute *bus_attr = to_bus_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100103 struct subsys_private *subsys_priv = to_subsys_private(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 ssize_t ret = 0;
105
106 if (bus_attr->show)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100107 ret = bus_attr->show(subsys_priv->bus, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 return ret;
109}
110
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800111static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
112 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800114 struct bus_attribute *bus_attr = to_bus_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100115 struct subsys_private *subsys_priv = to_subsys_private(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 ssize_t ret = 0;
117
118 if (bus_attr->store)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100119 ret = bus_attr->store(subsys_priv->bus, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 return ret;
121}
122
Emese Revfy52cf25d2010-01-19 02:58:23 +0100123static const struct sysfs_ops bus_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 .show = bus_attr_show,
125 .store = bus_attr_store,
126};
127
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800128int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129{
130 int error;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700131 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700132 error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700133 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 } else
135 error = -EINVAL;
136 return error;
137}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800138EXPORT_SYMBOL_GPL(bus_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800140void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700142 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700143 sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700144 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 }
146}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800147EXPORT_SYMBOL_GPL(bus_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Kay Sievers80f03e32007-05-26 11:21:36 +0200149static struct kobj_type bus_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 .sysfs_ops = &bus_sysfs_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151};
152
Kay Sievers80f03e32007-05-26 11:21:36 +0200153static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
154{
155 struct kobj_type *ktype = get_ktype(kobj);
156
157 if (ktype == &bus_ktype)
158 return 1;
159 return 0;
160}
161
Emese Revfy9cd43612009-12-31 14:52:51 +0100162static const struct kset_uevent_ops bus_uevent_ops = {
Kay Sievers80f03e32007-05-26 11:21:36 +0200163 .filter = bus_uevent_filter,
164};
165
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -0500166static struct kset *bus_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
Alan Stern2b08c8d2005-11-23 15:43:50 -0800168/* Manually detach a device from its associated driver. */
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700169static ssize_t unbind_store(struct device_driver *drv, const char *buf,
170 size_t count)
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700171{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700172 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700173 struct device *dev;
174 int err = -ENODEV;
175
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800176 dev = bus_find_device_by_name(bus, NULL, buf);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800177 if (dev && dev->driver == drv) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500178 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800179 device_lock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700180 device_release_driver(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500181 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800182 device_unlock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700183 err = count;
184 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800185 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700186 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800187 return err;
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700188}
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700189static DRIVER_ATTR_WO(unbind);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700190
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700191/*
192 * Manually attach a device to a driver.
193 * Note: the driver must want to bind to the device,
194 * it is not possible to override the driver's id table.
195 */
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700196static ssize_t bind_store(struct device_driver *drv, const char *buf,
197 size_t count)
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700198{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700199 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700200 struct device *dev;
201 int err = -ENODEV;
202
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800203 dev = bus_find_device_by_name(bus, NULL, buf);
Ming Lei49b420a2009-01-21 23:27:47 +0800204 if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500205 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800206 device_lock(dev->parent);
207 device_lock(dev);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700208 err = driver_probe_device(drv, dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800209 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500210 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800211 device_unlock(dev->parent);
Ryan Wilson37225402006-03-22 16:26:25 -0500212
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800213 if (err > 0) {
214 /* success */
Ryan Wilson37225402006-03-22 16:26:25 -0500215 err = count;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800216 } else if (err == 0) {
217 /* driver didn't accept device */
Ryan Wilson37225402006-03-22 16:26:25 -0500218 err = -ENODEV;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800219 }
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700220 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800221 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700222 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800223 return err;
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700224}
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700225static DRIVER_ATTR_WO(bind);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700226
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100227static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
228{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700229 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100230}
231
232static ssize_t store_drivers_autoprobe(struct bus_type *bus,
233 const char *buf, size_t count)
234{
235 if (buf[0] == '0')
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700236 bus->p->drivers_autoprobe = 0;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100237 else
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700238 bus->p->drivers_autoprobe = 1;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100239 return count;
240}
241
242static ssize_t store_drivers_probe(struct bus_type *bus,
243 const char *buf, size_t count)
244{
245 struct device *dev;
246
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800247 dev = bus_find_device_by_name(bus, NULL, buf);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100248 if (!dev)
249 return -ENODEV;
250 if (bus_rescan_devices_helper(dev, NULL) != 0)
251 return -EINVAL;
252 return count;
253}
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700254
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800255static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800256{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800257 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800258 struct device *dev = NULL;
259 struct device_private *dev_prv;
260
261 if (n) {
262 dev_prv = to_device_private_bus(n);
263 dev = dev_prv->device;
264 }
265 return dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800266}
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800269 * bus_for_each_dev - device iterator.
270 * @bus: bus type.
271 * @start: device to start iterating from.
272 * @data: data for the callback.
273 * @fn: function to be called for each device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800275 * Iterate over @bus's list of devices, and call @fn for each,
276 * passing it @data. If @start is not NULL, we use that device to
277 * begin iterating from.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800279 * We check the return of @fn each time. If it returns anything
280 * other than 0, we break out and return that value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800282 * NOTE: The device that returns a non-zero value is not retained
283 * in any way, nor is its refcount incremented. If the caller needs
Alex Chiang0fa1b0a2009-05-14 23:15:22 +0200284 * to retain this data, it should do so, and increment the reference
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800285 * count in the supplied callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800287int bus_for_each_dev(struct bus_type *bus, struct device *start,
288 void *data, int (*fn)(struct device *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800290 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800291 struct device *dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800292 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
Bjorn Helgaas4fa3e782013-01-29 16:44:27 -0700294 if (!bus || !bus->p)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800295 return -EINVAL;
296
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700297 klist_iter_init_node(&bus->p->klist_devices, &i,
298 (start ? &start->p->knode_bus : NULL));
299 while ((dev = next_device(&i)) && !error)
300 error = fn(dev, data);
301 klist_iter_exit(&i);
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800302 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800304EXPORT_SYMBOL_GPL(bus_for_each_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
Cornelia Huck0edb5862005-06-22 16:59:51 +0200306/**
307 * bus_find_device - device iterator for locating a particular device.
308 * @bus: bus type
309 * @start: Device to begin with
310 * @data: Data to pass to match function
311 * @match: Callback function to check device
312 *
313 * This is similar to the bus_for_each_dev() function above, but it
314 * returns a reference to a device that is 'found' for later use, as
315 * determined by the @match callback.
316 *
317 * The callback should return 0 if the device doesn't match and non-zero
318 * if it does. If the callback returns non-zero, this function will
319 * return to the caller and not iterate over any more devices.
320 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800321struct device *bus_find_device(struct bus_type *bus,
322 struct device *start, void *data,
323 int (*match)(struct device *dev, void *data))
Cornelia Huck0edb5862005-06-22 16:59:51 +0200324{
325 struct klist_iter i;
326 struct device *dev;
327
Bjorn Helgaas4fa3e782013-01-29 16:44:27 -0700328 if (!bus || !bus->p)
Cornelia Huck0edb5862005-06-22 16:59:51 +0200329 return NULL;
330
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700331 klist_iter_init_node(&bus->p->klist_devices, &i,
332 (start ? &start->p->knode_bus : NULL));
Cornelia Huck0edb5862005-06-22 16:59:51 +0200333 while ((dev = next_device(&i)))
334 if (match(dev, data) && get_device(dev))
335 break;
336 klist_iter_exit(&i);
337 return dev;
338}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800339EXPORT_SYMBOL_GPL(bus_find_device);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800340
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800341static int match_name(struct device *dev, void *data)
342{
343 const char *name = data;
344
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100345 return sysfs_streq(name, dev_name(dev));
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800346}
347
348/**
349 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
350 * @bus: bus type
351 * @start: Device to begin with
352 * @name: name of the device to match
353 *
354 * This is similar to the bus_find_device() function above, but it handles
355 * searching by a name automatically, no need to write another strcmp matching
356 * function.
357 */
358struct device *bus_find_device_by_name(struct bus_type *bus,
359 struct device *start, const char *name)
360{
361 return bus_find_device(bus, start, (void *)name, match_name);
362}
363EXPORT_SYMBOL_GPL(bus_find_device_by_name);
364
Kay Sieversca22e562011-12-14 14:29:38 -0800365/**
366 * subsys_find_device_by_id - find a device with a specific enumeration number
367 * @subsys: subsystem
368 * @id: index 'id' in struct device
369 * @hint: device to check first
370 *
371 * Check the hint's next object and if it is a match return it directly,
372 * otherwise, fall back to a full list search. Either way a reference for
373 * the returned object is taken.
374 */
375struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id,
376 struct device *hint)
377{
378 struct klist_iter i;
379 struct device *dev;
380
381 if (!subsys)
382 return NULL;
383
384 if (hint) {
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700385 klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
Kay Sieversca22e562011-12-14 14:29:38 -0800386 dev = next_device(&i);
387 if (dev && dev->id == id && get_device(dev)) {
388 klist_iter_exit(&i);
389 return dev;
390 }
391 klist_iter_exit(&i);
392 }
393
394 klist_iter_init_node(&subsys->p->klist_devices, &i, NULL);
395 while ((dev = next_device(&i))) {
396 if (dev->id == id && get_device(dev)) {
397 klist_iter_exit(&i);
398 return dev;
399 }
400 }
401 klist_iter_exit(&i);
402 return NULL;
403}
404EXPORT_SYMBOL_GPL(subsys_find_device_by_id);
405
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800406static struct device_driver *next_driver(struct klist_iter *i)
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800407{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800408 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800409 struct driver_private *drv_priv;
410
411 if (n) {
412 drv_priv = container_of(n, struct driver_private, knode_bus);
413 return drv_priv->driver;
414 }
415 return NULL;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800416}
417
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800419 * bus_for_each_drv - driver iterator
420 * @bus: bus we're dealing with.
421 * @start: driver to start iterating on.
422 * @data: data to pass to the callback.
423 * @fn: function to call for each driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800425 * This is nearly identical to the device iterator above.
426 * We iterate over each driver that belongs to @bus, and call
427 * @fn for each. If @fn returns anything but 0, we break out
428 * and return it. If @start is not NULL, we use it as the head
429 * of the list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800431 * NOTE: we don't return the driver that returns a non-zero
432 * value, nor do we leave the reference count incremented for that
433 * driver. If the caller needs to know that info, it must set it
434 * in the callback. It must also be sure to increment the refcount
435 * so it doesn't disappear before returning to the caller.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800437int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
438 void *data, int (*fn)(struct device_driver *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439{
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800440 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800441 struct device_driver *drv;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800442 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800444 if (!bus)
445 return -EINVAL;
446
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700447 klist_iter_init_node(&bus->p->klist_drivers, &i,
448 start ? &start->p->knode_bus : NULL);
449 while ((drv = next_driver(&i)) && !error)
450 error = fn(drv, data);
451 klist_iter_exit(&i);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800452 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800454EXPORT_SYMBOL_GPL(bus_for_each_drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
Andrew Morton4aca67e2007-02-13 22:39:26 -0800456static int device_add_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457{
458 int error = 0;
459 int i;
460
Andrew Morton4aca67e2007-02-13 22:39:26 -0800461 if (!bus->dev_attrs)
462 return 0;
463
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700464 for (i = 0; bus->dev_attrs[i].attr.name; i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800465 error = device_create_file(dev, &bus->dev_attrs[i]);
Andrew Morton4aca67e2007-02-13 22:39:26 -0800466 if (error) {
467 while (--i >= 0)
468 device_remove_file(dev, &bus->dev_attrs[i]);
469 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 }
471 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473}
474
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800475static void device_remove_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476{
477 int i;
478
479 if (bus->dev_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700480 for (i = 0; bus->dev_attrs[i].attr.name; i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800481 device_remove_file(dev, &bus->dev_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 }
483}
484
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800486 * bus_add_device - add device to bus
487 * @dev: device being added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 *
Alan Stern2023c612009-07-30 15:27:18 -0400489 * - Add device's bus attributes.
490 * - Create links to device's bus.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800491 * - Add the device to its bus's list of devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800493int bus_add_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800495 struct bus_type *bus = bus_get(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 int error = 0;
497
498 if (bus) {
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100499 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
Greg Kroah-Hartmand377e852005-06-22 16:09:05 -0700500 error = device_add_attrs(bus, dev);
Andrew Mortonf86db392006-08-14 22:43:20 -0700501 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200502 goto out_put;
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -0700503 error = device_add_groups(dev, bus->dev_groups);
504 if (error)
505 goto out_groups;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700506 error = sysfs_create_link(&bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100507 &dev->kobj, dev_name(dev));
Andrew Mortonf86db392006-08-14 22:43:20 -0700508 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200509 goto out_id;
Andrew Mortonf86db392006-08-14 22:43:20 -0700510 error = sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700511 &dev->bus->p->subsys.kobj, "subsystem");
Andrew Mortonf86db392006-08-14 22:43:20 -0700512 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200513 goto out_subsys;
Alan Stern2023c612009-07-30 15:27:18 -0400514 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 }
Cornelia Huck513e7332006-09-22 11:37:08 +0200516 return 0;
517
Cornelia Huck513e7332006-09-22 11:37:08 +0200518out_subsys:
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100519 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -0700520out_groups:
521 device_remove_groups(dev, bus->dev_groups);
Cornelia Huck513e7332006-09-22 11:37:08 +0200522out_id:
523 device_remove_attrs(bus, dev);
524out_put:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700525 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 return error;
527}
528
529/**
Alan Stern2023c612009-07-30 15:27:18 -0400530 * bus_probe_device - probe drivers for a new device
531 * @dev: device to probe
Kay Sievers53877d02006-04-04 20:42:26 +0200532 *
Alan Stern2023c612009-07-30 15:27:18 -0400533 * - Automatically probe for a driver if the bus allows it.
Kay Sievers53877d02006-04-04 20:42:26 +0200534 */
Alan Stern2023c612009-07-30 15:27:18 -0400535void bus_probe_device(struct device *dev)
Kay Sievers53877d02006-04-04 20:42:26 +0200536{
Andrew Mortonf86db392006-08-14 22:43:20 -0700537 struct bus_type *bus = dev->bus;
Kay Sieversca22e562011-12-14 14:29:38 -0800538 struct subsys_interface *sif;
Alan Stern2023c612009-07-30 15:27:18 -0400539 int ret;
Kay Sievers53877d02006-04-04 20:42:26 +0200540
Kay Sieversca22e562011-12-14 14:29:38 -0800541 if (!bus)
542 return;
543
544 if (bus->p->drivers_autoprobe) {
Alan Stern2023c612009-07-30 15:27:18 -0400545 ret = device_attach(dev);
Cornelia Huckc6a46692007-02-05 16:15:26 -0800546 WARN_ON(ret < 0);
Kay Sievers53877d02006-04-04 20:42:26 +0200547 }
Kay Sieversca22e562011-12-14 14:29:38 -0800548
549 mutex_lock(&bus->p->mutex);
550 list_for_each_entry(sif, &bus->p->interfaces, node)
551 if (sif->add_dev)
552 sif->add_dev(dev, sif);
553 mutex_unlock(&bus->p->mutex);
Kay Sievers53877d02006-04-04 20:42:26 +0200554}
555
556/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800557 * bus_remove_device - remove device from bus
558 * @dev: device to be removed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 *
Kay Sieversca22e562011-12-14 14:29:38 -0800560 * - Remove device from all interfaces.
561 * - Remove symlink from bus' directory.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800562 * - Delete device from bus's list.
563 * - Detach from its driver.
564 * - Drop reference taken in bus_add_device().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800566void bus_remove_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567{
Kay Sieversca22e562011-12-14 14:29:38 -0800568 struct bus_type *bus = dev->bus;
569 struct subsys_interface *sif;
Greg Kroah-Hartman3f62e572008-03-13 17:07:03 -0400570
Kay Sieversca22e562011-12-14 14:29:38 -0800571 if (!bus)
572 return;
573
574 mutex_lock(&bus->p->mutex);
575 list_for_each_entry(sif, &bus->p->interfaces, node)
576 if (sif->remove_dev)
577 sif->remove_dev(dev, sif);
578 mutex_unlock(&bus->p->mutex);
579
580 sysfs_remove_link(&dev->kobj, "subsystem");
581 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
582 dev_name(dev));
583 device_remove_attrs(dev->bus, dev);
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -0700584 device_remove_groups(dev, dev->bus->dev_groups);
Kay Sieversca22e562011-12-14 14:29:38 -0800585 if (klist_node_attached(&dev->p->knode_bus))
586 klist_del(&dev->p->knode_bus);
587
588 pr_debug("bus: '%s': remove device %s\n",
589 dev->bus->name, dev_name(dev));
590 device_release_driver(dev);
591 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592}
593
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800594static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595{
596 int error = 0;
597 int i;
598
599 if (bus->drv_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700600 for (i = 0; bus->drv_attrs[i].attr.name; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 error = driver_create_file(drv, &bus->drv_attrs[i]);
602 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800603 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 }
605 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800606done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800608err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 while (--i >= 0)
610 driver_remove_file(drv, &bus->drv_attrs[i]);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800611 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612}
613
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800614static void driver_remove_attrs(struct bus_type *bus,
615 struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616{
617 int i;
618
619 if (bus->drv_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700620 for (i = 0; bus->drv_attrs[i].attr.name; i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 driver_remove_file(drv, &bus->drv_attrs[i]);
622 }
623}
624
Andrew Mortonf86db392006-08-14 22:43:20 -0700625static int __must_check add_bind_files(struct device_driver *drv)
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800626{
Andrew Mortonf86db392006-08-14 22:43:20 -0700627 int ret;
628
629 ret = driver_create_file(drv, &driver_attr_unbind);
630 if (ret == 0) {
631 ret = driver_create_file(drv, &driver_attr_bind);
632 if (ret)
633 driver_remove_file(drv, &driver_attr_unbind);
634 }
635 return ret;
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800636}
637
638static void remove_bind_files(struct device_driver *drv)
639{
640 driver_remove_file(drv, &driver_attr_bind);
641 driver_remove_file(drv, &driver_attr_unbind);
642}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100643
Kay Sievers83807702007-07-30 02:28:56 +0200644static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
645static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
646 show_drivers_autoprobe, store_drivers_autoprobe);
647
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100648static int add_probe_files(struct bus_type *bus)
649{
650 int retval;
651
Kay Sievers83807702007-07-30 02:28:56 +0200652 retval = bus_create_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100653 if (retval)
654 goto out;
655
Kay Sievers83807702007-07-30 02:28:56 +0200656 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100657 if (retval)
Kay Sievers83807702007-07-30 02:28:56 +0200658 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100659out:
660 return retval;
661}
662
663static void remove_probe_files(struct bus_type *bus)
664{
Kay Sievers83807702007-07-30 02:28:56 +0200665 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
666 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100667}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700669static ssize_t uevent_store(struct device_driver *drv, const char *buf,
670 size_t count)
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200671{
672 enum kobject_action action;
673
674 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800675 kobject_uevent(&drv->p->kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200676 return count;
677}
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700678static DRIVER_ATTR_WO(uevent);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200679
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800681 * bus_add_driver - Add a driver to the bus.
682 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700684int bus_add_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800686 struct bus_type *bus;
687 struct driver_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 int error = 0;
689
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800690 bus = bus_get(drv->bus);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400691 if (!bus)
Greg Kroah-Hartman4f6e1942007-04-20 11:29:52 -0700692 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800694 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800695
696 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
Cornelia Huck07634462008-02-18 17:04:25 +0100697 if (!priv) {
698 error = -ENOMEM;
699 goto out_put_bus;
700 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800701 klist_init(&priv->klist_devices, NULL, NULL);
702 priv->driver = drv;
703 drv->p = priv;
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400704 priv->kobj.kset = bus->p->drivers_kset;
705 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
706 "%s", drv->name);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700707 if (error)
Cornelia Huck07634462008-02-18 17:04:25 +0100708 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Ming Lei190888a2012-11-19 23:35:17 +0800710 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700711 if (drv->bus->p->drivers_autoprobe) {
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100712 error = driver_attach(drv);
713 if (error)
714 goto out_unregister;
715 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400716 module_add_driver(drv->owner, drv);
717
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200718 error = driver_create_file(drv, &driver_attr_uevent);
719 if (error) {
720 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800721 __func__, drv->name);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200722 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400723 error = driver_add_attrs(bus, drv);
724 if (error) {
725 /* How the hell do we get out of this pickle? Give up */
726 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800727 __func__, drv->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 }
Greg Kroah-Hartmaned0617b2013-08-08 15:22:56 -0700729 error = driver_add_groups(drv, bus->drv_groups);
730 if (error)
731 printk(KERN_ERR "%s: driver_create_groups(%s) failed\n",
732 __func__, drv->name);
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700733
734 if (!drv->suppress_bind_attrs) {
735 error = add_bind_files(drv);
736 if (error) {
737 /* Ditto */
738 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
739 __func__, drv->name);
740 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400741 }
742
Kay Sievers5c8563d2009-05-28 14:24:07 -0700743 return 0;
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700744
Andrew Mortonf86db392006-08-14 22:43:20 -0700745out_unregister:
Phil Carmody99b28f12009-12-14 20:28:12 +0200746 kobject_put(&priv->kobj);
Kay Sievers5c8563d2009-05-28 14:24:07 -0700747 kfree(drv->p);
748 drv->p = NULL;
Andrew Mortonf86db392006-08-14 22:43:20 -0700749out_put_bus:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700750 bus_put(bus);
Andrew Mortonf86db392006-08-14 22:43:20 -0700751 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752}
753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800755 * bus_remove_driver - delete driver from bus's knowledge.
756 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800758 * Detach the driver from the devices it controls, and remove
759 * it from its bus's list of drivers. Finally, we drop the reference
760 * to the bus we took in bus_add_driver().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800762void bus_remove_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763{
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400764 if (!drv->bus)
765 return;
766
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700767 if (!drv->suppress_bind_attrs)
768 remove_bind_files(drv);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400769 driver_remove_attrs(drv->bus, drv);
Greg Kroah-Hartmaned0617b2013-08-08 15:22:56 -0700770 driver_remove_groups(drv, drv->bus->drv_groups);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200771 driver_remove_file(drv, &driver_attr_uevent);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800772 klist_remove(&drv->p->knode_bus);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800773 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400774 driver_detach(drv);
775 module_remove_driver(drv);
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800776 kobject_put(&drv->p->kobj);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700777 bus_put(drv->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778}
779
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780/* Helper for bus_rescan_devices's iter */
Andrew Mortonf86db392006-08-14 22:43:20 -0700781static int __must_check bus_rescan_devices_helper(struct device *dev,
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800782 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783{
Andrew Mortonf86db392006-08-14 22:43:20 -0700784 int ret = 0;
785
Alan Sternbf74ad52005-11-17 16:54:12 -0500786 if (!dev->driver) {
787 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800788 device_lock(dev->parent);
Andrew Mortonf86db392006-08-14 22:43:20 -0700789 ret = device_attach(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500790 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800791 device_unlock(dev->parent);
Alan Sternbf74ad52005-11-17 16:54:12 -0500792 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700793 return ret < 0 ? ret : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794}
795
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796/**
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700797 * bus_rescan_devices - rescan devices on the bus for possible drivers
798 * @bus: the bus to scan.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 *
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700800 * This function will look for devices on the bus with no driver
801 * attached and rescan it against existing drivers to see if it matches
802 * any by calling device_attach() for the unbound devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800804int bus_rescan_devices(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805{
Andrew Mortonf86db392006-08-14 22:43:20 -0700806 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800808EXPORT_SYMBOL_GPL(bus_rescan_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809
Moore, Erice935d5d2006-03-14 09:18:18 -0700810/**
811 * device_reprobe - remove driver for a device and probe for a new driver
812 * @dev: the device to reprobe
813 *
814 * This function detaches the attached driver (if any) for the given
815 * device and restarts the driver probing process. It is intended
816 * to use if probing criteria changed during a devices lifetime and
817 * driver attachment should change accordingly.
818 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700819int device_reprobe(struct device *dev)
Moore, Erice935d5d2006-03-14 09:18:18 -0700820{
821 if (dev->driver) {
822 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800823 device_lock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700824 device_release_driver(dev);
825 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800826 device_unlock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700827 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700828 return bus_rescan_devices_helper(dev, NULL);
Moore, Erice935d5d2006-03-14 09:18:18 -0700829}
830EXPORT_SYMBOL_GPL(device_reprobe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800833 * find_bus - locate bus by name.
834 * @name: name of bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800836 * Call kset_find_obj() to iterate over list of buses to
837 * find a bus by name. Return bus if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800839 * Note that kset_find_obj increments bus' reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 */
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200841#if 0
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800842struct bus_type *find_bus(char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800844 struct kobject *k = kset_find_obj(bus_kset, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 return k ? to_bus(k) : NULL;
846}
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200847#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848
849
850/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800851 * bus_add_attrs - Add default attributes for this bus.
852 * @bus: Bus that has just been registered.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 */
854
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800855static int bus_add_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856{
857 int error = 0;
858 int i;
859
860 if (bus->bus_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700861 for (i = 0; bus->bus_attrs[i].attr.name; i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800862 error = bus_create_file(bus, &bus->bus_attrs[i]);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700863 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800864 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 }
866 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800867done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800869err:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 while (--i >= 0)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800871 bus_remove_file(bus, &bus->bus_attrs[i]);
872 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873}
874
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800875static void bus_remove_attrs(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876{
877 int i;
878
879 if (bus->bus_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700880 for (i = 0; bus->bus_attrs[i].attr.name; i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800881 bus_remove_file(bus, &bus->bus_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 }
883}
884
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700885static int bus_add_groups(struct bus_type *bus,
886 const struct attribute_group **groups)
887{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700888 return sysfs_create_groups(&bus->p->subsys.kobj, groups);
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700889}
890
891static void bus_remove_groups(struct bus_type *bus,
892 const struct attribute_group **groups)
893{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700894 sysfs_remove_groups(&bus->p->subsys.kobj, groups);
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700895}
896
James Bottomley34bb61f2005-09-06 16:56:51 -0700897static void klist_devices_get(struct klist_node *n)
898{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800899 struct device_private *dev_prv = to_device_private_bus(n);
900 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700901
902 get_device(dev);
903}
904
905static void klist_devices_put(struct klist_node *n)
906{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800907 struct device_private *dev_prv = to_device_private_bus(n);
908 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700909
910 put_device(dev);
911}
912
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200913static ssize_t bus_uevent_store(struct bus_type *bus,
914 const char *buf, size_t count)
915{
916 enum kobject_action action;
917
918 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700919 kobject_uevent(&bus->p->subsys.kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200920 return count;
921}
922static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
923
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924/**
Michal Hockobe871b72013-03-12 17:21:19 +0100925 * bus_register - register a driver-core subsystem
Randy Dunlap78d79552012-01-21 11:02:28 -0800926 * @bus: bus to register
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 *
Randy Dunlap78d79552012-01-21 11:02:28 -0800928 * Once we have that, we register the bus with the kobject
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800929 * infrastructure, then register the children subsystems it has:
Kay Sieversca22e562011-12-14 14:29:38 -0800930 * the devices and drivers that belong to the subsystem.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 */
Michal Hockobe871b72013-03-12 17:21:19 +0100932int bus_register(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933{
934 int retval;
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100935 struct subsys_private *priv;
Michal Hockobe871b72013-03-12 17:21:19 +0100936 struct lock_class_key *key = &bus->lock_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100938 priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700939 if (!priv)
940 return -ENOMEM;
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000941
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700942 priv->bus = bus;
943 bus->p = priv;
944
945 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
946
947 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 if (retval)
949 goto out;
950
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700951 priv->subsys.kobj.kset = bus_kset;
952 priv->subsys.kobj.ktype = &bus_ktype;
953 priv->drivers_autoprobe = 1;
Greg Kroah-Hartmand6b05b82007-09-12 15:06:57 -0700954
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700955 retval = kset_register(&priv->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 if (retval)
957 goto out;
958
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200959 retval = bus_create_file(bus, &bus_attr_uevent);
960 if (retval)
961 goto bus_uevent_fail;
962
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700963 priv->devices_kset = kset_create_and_add("devices", NULL,
964 &priv->subsys.kobj);
965 if (!priv->devices_kset) {
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700966 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 goto bus_devices_fail;
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700968 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700970 priv->drivers_kset = kset_create_and_add("drivers", NULL,
971 &priv->subsys.kobj);
972 if (!priv->drivers_kset) {
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700973 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 goto bus_drivers_fail;
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700975 }
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800976
Kay Sieversca22e562011-12-14 14:29:38 -0800977 INIT_LIST_HEAD(&priv->interfaces);
978 __mutex_init(&priv->mutex, "subsys mutex", key);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700979 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
980 klist_init(&priv->klist_drivers, NULL, NULL);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100981
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100982 retval = add_probe_files(bus);
983 if (retval)
984 goto bus_probe_files_fail;
985
Cornelia Huck1bb68812006-09-22 11:37:04 +0200986 retval = bus_add_attrs(bus);
987 if (retval)
988 goto bus_attrs_fail;
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700989 retval = bus_add_groups(bus, bus->bus_groups);
990 if (retval)
991 goto bus_groups_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800993 pr_debug("bus: '%s': registered\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 return 0;
995
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700996bus_groups_fail:
997 bus_remove_attrs(bus);
Cornelia Huck1bb68812006-09-22 11:37:04 +0200998bus_attrs_fail:
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100999 remove_probe_files(bus);
1000bus_probe_files_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001001 kset_unregister(bus->p->drivers_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002bus_drivers_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001003 kset_unregister(bus->p->devices_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004bus_devices_fail:
Kay Sievers7ac1cf42007-08-12 20:43:55 +02001005 bus_remove_file(bus, &bus_attr_uevent);
1006bus_uevent_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001007 kset_unregister(&bus->p->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008out:
Jike Song600c20f2010-07-15 17:43:54 +08001009 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +08001010 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 return retval;
1012}
Michal Hockobe871b72013-03-12 17:21:19 +01001013EXPORT_SYMBOL_GPL(bus_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001016 * bus_unregister - remove a bus from the system
1017 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001019 * Unregister the child subsystems and the bus itself.
1020 * Finally, we call bus_put() to release the refcount
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001022void bus_unregister(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023{
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -08001024 pr_debug("bus: '%s': unregistering\n", bus->name);
Kay Sieversca22e562011-12-14 14:29:38 -08001025 if (bus->dev_root)
1026 device_unregister(bus->dev_root);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 bus_remove_attrs(bus);
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -07001028 bus_remove_groups(bus, bus->bus_groups);
Kay Sieversb8c5cec2007-02-16 17:33:36 +01001029 remove_probe_files(bus);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001030 kset_unregister(bus->p->drivers_kset);
1031 kset_unregister(bus->p->devices_kset);
Kay Sievers7ac1cf42007-08-12 20:43:55 +02001032 bus_remove_file(bus, &bus_attr_uevent);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001033 kset_unregister(&bus->p->subsys);
1034 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +08001035 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001037EXPORT_SYMBOL_GPL(bus_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001039int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
1040{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001041 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001042}
1043EXPORT_SYMBOL_GPL(bus_register_notifier);
1044
1045int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
1046{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001047 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +10001048}
1049EXPORT_SYMBOL_GPL(bus_unregister_notifier);
1050
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -07001051struct kset *bus_get_kset(struct bus_type *bus)
1052{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001053 return &bus->p->subsys;
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -07001054}
1055EXPORT_SYMBOL_GPL(bus_get_kset);
1056
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001057struct klist *bus_get_device_klist(struct bus_type *bus)
1058{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001059 return &bus->p->klist_devices;
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001060}
1061EXPORT_SYMBOL_GPL(bus_get_device_klist);
1062
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001063/*
Robert P. J. Daydca25eb2010-11-21 08:15:01 -05001064 * Yes, this forcibly breaks the klist abstraction temporarily. It
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001065 * just wants to sort the klist, not change reference counts and
1066 * take/drop locks rapidly in the process. It does all this while
1067 * holding the lock for the list, so objects can't otherwise be
1068 * added/removed while we're swizzling.
1069 */
1070static void device_insertion_sort_klist(struct device *a, struct list_head *list,
1071 int (*compare)(const struct device *a,
1072 const struct device *b))
1073{
1074 struct list_head *pos;
1075 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001076 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001077 struct device *b;
1078
1079 list_for_each(pos, list) {
1080 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001081 dev_prv = to_device_private_bus(n);
1082 b = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001083 if (compare(a, b) <= 0) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001084 list_move_tail(&a->p->knode_bus.n_node,
1085 &b->p->knode_bus.n_node);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001086 return;
1087 }
1088 }
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001089 list_move_tail(&a->p->knode_bus.n_node, list);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001090}
1091
1092void bus_sort_breadthfirst(struct bus_type *bus,
1093 int (*compare)(const struct device *a,
1094 const struct device *b))
1095{
1096 LIST_HEAD(sorted_devices);
1097 struct list_head *pos, *tmp;
1098 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001099 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001100 struct device *dev;
1101 struct klist *device_klist;
1102
1103 device_klist = bus_get_device_klist(bus);
1104
1105 spin_lock(&device_klist->k_lock);
1106 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1107 n = container_of(pos, struct klist_node, n_node);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001108 dev_prv = to_device_private_bus(n);
1109 dev = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001110 device_insertion_sort_klist(dev, &sorted_devices, compare);
1111 }
1112 list_splice(&sorted_devices, &device_klist->k_list);
1113 spin_unlock(&device_klist->k_lock);
1114}
1115EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1116
Kay Sieversca22e562011-12-14 14:29:38 -08001117/**
1118 * subsys_dev_iter_init - initialize subsys device iterator
1119 * @iter: subsys iterator to initialize
1120 * @subsys: the subsys we wanna iterate over
1121 * @start: the device to start iterating from, if any
1122 * @type: device_type of the devices to iterate over, NULL for all
1123 *
1124 * Initialize subsys iterator @iter such that it iterates over devices
1125 * of @subsys. If @start is set, the list iteration will start there,
1126 * otherwise if it is NULL, the iteration starts at the beginning of
1127 * the list.
1128 */
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001129void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
1130 struct device *start, const struct device_type *type)
Kay Sieversca22e562011-12-14 14:29:38 -08001131{
1132 struct klist_node *start_knode = NULL;
1133
1134 if (start)
1135 start_knode = &start->p->knode_bus;
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001136 klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
1137 iter->type = type;
Kay Sieversca22e562011-12-14 14:29:38 -08001138}
1139EXPORT_SYMBOL_GPL(subsys_dev_iter_init);
1140
1141/**
1142 * subsys_dev_iter_next - iterate to the next device
1143 * @iter: subsys iterator to proceed
1144 *
1145 * Proceed @iter to the next device and return it. Returns NULL if
1146 * iteration is complete.
1147 *
1148 * The returned device is referenced and won't be released till
1149 * iterator is proceed to the next device or exited. The caller is
1150 * free to do whatever it wants to do with the device including
1151 * calling back into subsys code.
1152 */
1153struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
1154{
1155 struct klist_node *knode;
1156 struct device *dev;
1157
1158 for (;;) {
1159 knode = klist_next(&iter->ki);
1160 if (!knode)
1161 return NULL;
1162 dev = container_of(knode, struct device_private, knode_bus)->device;
1163 if (!iter->type || iter->type == dev->type)
1164 return dev;
1165 }
1166}
1167EXPORT_SYMBOL_GPL(subsys_dev_iter_next);
1168
1169/**
1170 * subsys_dev_iter_exit - finish iteration
1171 * @iter: subsys iterator to finish
1172 *
1173 * Finish an iteration. Always call this function after iteration is
1174 * complete whether the iteration ran till the end or not.
1175 */
1176void subsys_dev_iter_exit(struct subsys_dev_iter *iter)
1177{
1178 klist_iter_exit(&iter->ki);
1179}
1180EXPORT_SYMBOL_GPL(subsys_dev_iter_exit);
1181
1182int subsys_interface_register(struct subsys_interface *sif)
1183{
1184 struct bus_type *subsys;
1185 struct subsys_dev_iter iter;
1186 struct device *dev;
1187
1188 if (!sif || !sif->subsys)
1189 return -ENODEV;
1190
1191 subsys = bus_get(sif->subsys);
1192 if (!subsys)
1193 return -EINVAL;
1194
1195 mutex_lock(&subsys->p->mutex);
1196 list_add_tail(&sif->node, &subsys->p->interfaces);
1197 if (sif->add_dev) {
1198 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1199 while ((dev = subsys_dev_iter_next(&iter)))
1200 sif->add_dev(dev, sif);
1201 subsys_dev_iter_exit(&iter);
1202 }
1203 mutex_unlock(&subsys->p->mutex);
1204
1205 return 0;
1206}
1207EXPORT_SYMBOL_GPL(subsys_interface_register);
1208
1209void subsys_interface_unregister(struct subsys_interface *sif)
1210{
Jonghwan Choi2b315942012-01-14 11:06:03 +09001211 struct bus_type *subsys;
Kay Sieversca22e562011-12-14 14:29:38 -08001212 struct subsys_dev_iter iter;
1213 struct device *dev;
1214
Jonghwan Choi2b315942012-01-14 11:06:03 +09001215 if (!sif || !sif->subsys)
Kay Sieversca22e562011-12-14 14:29:38 -08001216 return;
1217
Jonghwan Choi2b315942012-01-14 11:06:03 +09001218 subsys = sif->subsys;
1219
Kay Sieversca22e562011-12-14 14:29:38 -08001220 mutex_lock(&subsys->p->mutex);
1221 list_del_init(&sif->node);
1222 if (sif->remove_dev) {
1223 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1224 while ((dev = subsys_dev_iter_next(&iter)))
1225 sif->remove_dev(dev, sif);
1226 subsys_dev_iter_exit(&iter);
1227 }
1228 mutex_unlock(&subsys->p->mutex);
1229
1230 bus_put(subsys);
1231}
1232EXPORT_SYMBOL_GPL(subsys_interface_unregister);
1233
1234static void system_root_device_release(struct device *dev)
1235{
1236 kfree(dev);
1237}
Tejun Heod73ce002013-03-12 11:30:05 -07001238
1239static int subsys_register(struct bus_type *subsys,
1240 const struct attribute_group **groups,
1241 struct kobject *parent_of_root)
1242{
1243 struct device *dev;
1244 int err;
1245
1246 err = bus_register(subsys);
1247 if (err < 0)
1248 return err;
1249
1250 dev = kzalloc(sizeof(struct device), GFP_KERNEL);
1251 if (!dev) {
1252 err = -ENOMEM;
1253 goto err_dev;
1254 }
1255
1256 err = dev_set_name(dev, "%s", subsys->name);
1257 if (err < 0)
1258 goto err_name;
1259
1260 dev->kobj.parent = parent_of_root;
1261 dev->groups = groups;
1262 dev->release = system_root_device_release;
1263
1264 err = device_register(dev);
1265 if (err < 0)
1266 goto err_dev_reg;
1267
1268 subsys->dev_root = dev;
1269 return 0;
1270
1271err_dev_reg:
1272 put_device(dev);
1273 dev = NULL;
1274err_name:
1275 kfree(dev);
1276err_dev:
1277 bus_unregister(subsys);
1278 return err;
1279}
1280
Kay Sieversca22e562011-12-14 14:29:38 -08001281/**
1282 * subsys_system_register - register a subsystem at /sys/devices/system/
Randy Dunlap78d79552012-01-21 11:02:28 -08001283 * @subsys: system subsystem
1284 * @groups: default attributes for the root device
Kay Sieversca22e562011-12-14 14:29:38 -08001285 *
1286 * All 'system' subsystems have a /sys/devices/system/<name> root device
1287 * with the name of the subsystem. The root device can carry subsystem-
1288 * wide attributes. All registered devices are below this single root
1289 * device and are named after the subsystem with a simple enumeration
1290 * number appended. The registered devices are not explicitely named;
1291 * only 'id' in the device needs to be set.
1292 *
1293 * Do not use this interface for anything new, it exists for compatibility
1294 * with bad ideas only. New subsystems should use plain subsystems; and
1295 * add the subsystem-wide attributes should be added to the subsystem
1296 * directory itself and not some create fake root-device placed in
1297 * /sys/devices/system/<name>.
1298 */
1299int subsys_system_register(struct bus_type *subsys,
1300 const struct attribute_group **groups)
1301{
Tejun Heod73ce002013-03-12 11:30:05 -07001302 return subsys_register(subsys, groups, &system_kset->kobj);
Kay Sieversca22e562011-12-14 14:29:38 -08001303}
1304EXPORT_SYMBOL_GPL(subsys_system_register);
1305
Tejun Heod73ce002013-03-12 11:30:05 -07001306/**
1307 * subsys_virtual_register - register a subsystem at /sys/devices/virtual/
1308 * @subsys: virtual subsystem
1309 * @groups: default attributes for the root device
1310 *
1311 * All 'virtual' subsystems have a /sys/devices/system/<name> root device
1312 * with the name of the subystem. The root device can carry subsystem-wide
1313 * attributes. All registered devices are below this single root device.
1314 * There's no restriction on device naming. This is for kernel software
1315 * constructs which need sysfs interface.
1316 */
1317int subsys_virtual_register(struct bus_type *subsys,
1318 const struct attribute_group **groups)
1319{
1320 struct kobject *virtual_dir;
1321
1322 virtual_dir = virtual_device_parent(NULL);
1323 if (!virtual_dir)
1324 return -ENOMEM;
1325
1326 return subsys_register(subsys, groups, virtual_dir);
1327}
Greg Kroah-Hartman1c04fc32013-05-10 09:14:04 -07001328EXPORT_SYMBOL_GPL(subsys_virtual_register);
Tejun Heod73ce002013-03-12 11:30:05 -07001329
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330int __init buses_init(void)
1331{
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001332 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
1333 if (!bus_kset)
1334 return -ENOMEM;
Kay Sieversca22e562011-12-14 14:29:38 -08001335
1336 system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
1337 if (!system_kset)
1338 return -ENOMEM;
1339
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001340 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341}