blob: e32a74eb28a3e91c4a07658aa268598c9766ef61 [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
Dmitry Torokhov765230b2015-03-30 16:20:04 -070013#include <linux/async.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/device.h>
15#include <linux/module.h>
16#include <linux/errno.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090017#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/init.h>
19#include <linux/string.h>
Kay Sieversca22e562011-12-14 14:29:38 -080020#include <linux/mutex.h>
Greg Kroah-Hartman63967682013-08-27 10:24:15 -070021#include <linux/sysfs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "base.h"
23#include "power/power.h"
24
Kay Sieversca22e562011-12-14 14:29:38 -080025/* /sys/devices/system */
H Hartley Sweeten97ec4482012-04-16 18:14:10 -070026static struct kset *system_kset;
Kay Sieversca22e562011-12-14 14:29:38 -080027
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30/*
31 * sysfs bindings for drivers
32 */
33
34#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36
Kay Sieversb8c5cec2007-02-16 17:33:36 +010037static int __must_check bus_rescan_devices_helper(struct device *dev,
38 void *data);
39
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070040static struct bus_type *bus_get(struct bus_type *bus)
41{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070042 if (bus) {
43 kset_get(&bus->p->subsys);
44 return bus;
45 }
46 return NULL;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -070047}
48
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070049static void bus_put(struct bus_type *bus)
50{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070051 if (bus)
52 kset_put(&bus->p->subsys);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -070053}
54
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080055static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
56 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080058 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080059 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050060 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62 if (drv_attr->show)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080063 ret = drv_attr->show(drv_priv->driver, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 return ret;
65}
66
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080067static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
68 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070069{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080070 struct driver_attribute *drv_attr = to_drv_attr(attr);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080071 struct driver_private *drv_priv = to_driver(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050072 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74 if (drv_attr->store)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080075 ret = drv_attr->store(drv_priv->driver, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 return ret;
77}
78
Emese Revfy52cf25d2010-01-19 02:58:23 +010079static const struct sysfs_ops driver_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 .show = drv_attr_show,
81 .store = drv_attr_store,
82};
83
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080084static void driver_release(struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070085{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080086 struct driver_private *drv_priv = to_driver(kobj);
87
Harvey Harrison2b3a3022008-03-04 16:41:05 -080088 pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080089 kfree(drv_priv);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090}
91
Greg Kroah-Hartmana1148fb2007-10-11 10:47:49 -060092static struct kobj_type driver_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 .sysfs_ops = &driver_sysfs_ops,
94 .release = driver_release,
95};
96
Linus Torvalds1da177e2005-04-16 15:20:36 -070097/*
98 * sysfs bindings for buses
99 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800100static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
101 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800103 struct bus_attribute *bus_attr = to_bus_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100104 struct subsys_private *subsys_priv = to_subsys_private(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 ssize_t ret = 0;
106
107 if (bus_attr->show)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100108 ret = bus_attr->show(subsys_priv->bus, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 return ret;
110}
111
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800112static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
113 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800115 struct bus_attribute *bus_attr = to_bus_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100116 struct subsys_private *subsys_priv = to_subsys_private(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 ssize_t ret = 0;
118
119 if (bus_attr->store)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100120 ret = bus_attr->store(subsys_priv->bus, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 return ret;
122}
123
Emese Revfy52cf25d2010-01-19 02:58:23 +0100124static const struct sysfs_ops bus_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 .show = bus_attr_show,
126 .store = bus_attr_store,
127};
128
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800129int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130{
131 int error;
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700132 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700133 error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700134 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 } else
136 error = -EINVAL;
137 return error;
138}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800139EXPORT_SYMBOL_GPL(bus_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800141void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700143 if (bus_get(bus)) {
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700144 sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700145 bus_put(bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800148EXPORT_SYMBOL_GPL(bus_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Bart Van Assche174be702014-01-04 14:21:42 +0100150static void bus_release(struct kobject *kobj)
151{
Geliang Tang371fd7a2016-01-05 23:03:38 +0800152 struct subsys_private *priv = to_subsys_private(kobj);
Bart Van Assche174be702014-01-04 14:21:42 +0100153 struct bus_type *bus = priv->bus;
154
155 kfree(priv);
156 bus->p = NULL;
157}
158
Kay Sievers80f03e32007-05-26 11:21:36 +0200159static struct kobj_type bus_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 .sysfs_ops = &bus_sysfs_ops,
Bart Van Assche174be702014-01-04 14:21:42 +0100161 .release = bus_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162};
163
Kay Sievers80f03e32007-05-26 11:21:36 +0200164static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
165{
166 struct kobj_type *ktype = get_ktype(kobj);
167
168 if (ktype == &bus_ktype)
169 return 1;
170 return 0;
171}
172
Emese Revfy9cd43612009-12-31 14:52:51 +0100173static const struct kset_uevent_ops bus_uevent_ops = {
Kay Sievers80f03e32007-05-26 11:21:36 +0200174 .filter = bus_uevent_filter,
175};
176
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -0500177static struct kset *bus_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Alan Stern2b08c8d2005-11-23 15:43:50 -0800179/* Manually detach a device from its associated driver. */
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700180static ssize_t unbind_store(struct device_driver *drv, const char *buf,
181 size_t count)
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700182{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700183 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700184 struct device *dev;
185 int err = -ENODEV;
186
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800187 dev = bus_find_device_by_name(bus, NULL, buf);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800188 if (dev && dev->driver == drv) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500189 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800190 device_lock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700191 device_release_driver(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500192 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800193 device_unlock(dev->parent);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700194 err = count;
195 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800196 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700197 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800198 return err;
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700199}
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700200static DRIVER_ATTR_WO(unbind);
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700201
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700202/*
203 * Manually attach a device to a driver.
204 * Note: the driver must want to bind to the device,
205 * it is not possible to override the driver's id table.
206 */
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700207static ssize_t bind_store(struct device_driver *drv, const char *buf,
208 size_t count)
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700209{
Greg Kroah-Hartman5901d012007-09-13 02:53:13 -0700210 struct bus_type *bus = bus_get(drv->bus);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700211 struct device *dev;
212 int err = -ENODEV;
213
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800214 dev = bus_find_device_by_name(bus, NULL, buf);
Ming Lei49b420a2009-01-21 23:27:47 +0800215 if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
Alan Sternbf74ad52005-11-17 16:54:12 -0500216 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800217 device_lock(dev->parent);
218 device_lock(dev);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700219 err = driver_probe_device(drv, dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800220 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500221 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800222 device_unlock(dev->parent);
Ryan Wilson37225402006-03-22 16:26:25 -0500223
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800224 if (err > 0) {
225 /* success */
Ryan Wilson37225402006-03-22 16:26:25 -0500226 err = count;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800227 } else if (err == 0) {
228 /* driver didn't accept device */
Ryan Wilson37225402006-03-22 16:26:25 -0500229 err = -ENODEV;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800230 }
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700231 }
Alan Stern2b08c8d2005-11-23 15:43:50 -0800232 put_device(dev);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700233 bus_put(bus);
Alan Stern2b08c8d2005-11-23 15:43:50 -0800234 return err;
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700235}
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700236static DRIVER_ATTR_WO(bind);
Greg Kroah-Hartmanafdce752005-06-22 16:09:05 -0700237
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100238static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
239{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700240 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100241}
242
243static ssize_t store_drivers_autoprobe(struct bus_type *bus,
244 const char *buf, size_t count)
245{
246 if (buf[0] == '0')
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700247 bus->p->drivers_autoprobe = 0;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100248 else
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700249 bus->p->drivers_autoprobe = 1;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100250 return count;
251}
252
253static ssize_t store_drivers_probe(struct bus_type *bus,
254 const char *buf, size_t count)
255{
256 struct device *dev;
Alex Williamson0372ffb2014-10-31 11:13:07 -0600257 int err = -EINVAL;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100258
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800259 dev = bus_find_device_by_name(bus, NULL, buf);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100260 if (!dev)
261 return -ENODEV;
Alex Williamson0372ffb2014-10-31 11:13:07 -0600262 if (bus_rescan_devices_helper(dev, NULL) == 0)
263 err = count;
264 put_device(dev);
265 return err;
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100266}
Greg Kroah-Hartman151ef382005-06-22 16:09:05 -0700267
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800268static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800269{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800270 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800271 struct device *dev = NULL;
272 struct device_private *dev_prv;
273
274 if (n) {
275 dev_prv = to_device_private_bus(n);
276 dev = dev_prv->device;
277 }
278 return dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800279}
280
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800282 * bus_for_each_dev - device iterator.
283 * @bus: bus type.
284 * @start: device to start iterating from.
285 * @data: data for the callback.
286 * @fn: function to be called for each device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800288 * Iterate over @bus's list of devices, and call @fn for each,
289 * passing it @data. If @start is not NULL, we use that device to
290 * begin iterating from.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800292 * We check the return of @fn each time. If it returns anything
293 * other than 0, we break out and return that value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800295 * NOTE: The device that returns a non-zero value is not retained
296 * in any way, nor is its refcount incremented. If the caller needs
Alex Chiang0fa1b0a2009-05-14 23:15:22 +0200297 * to retain this data, it should do so, and increment the reference
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800298 * count in the supplied callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800300int bus_for_each_dev(struct bus_type *bus, struct device *start,
301 void *data, int (*fn)(struct device *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302{
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800303 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800304 struct device *dev;
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800305 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
Bjorn Helgaas4fa3e782013-01-29 16:44:27 -0700307 if (!bus || !bus->p)
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800308 return -EINVAL;
309
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700310 klist_iter_init_node(&bus->p->klist_devices, &i,
311 (start ? &start->p->knode_bus : NULL));
312 while ((dev = next_device(&i)) && !error)
313 error = fn(dev, data);
314 klist_iter_exit(&i);
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800315 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800317EXPORT_SYMBOL_GPL(bus_for_each_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
Cornelia Huck0edb5862005-06-22 16:59:51 +0200319/**
320 * bus_find_device - device iterator for locating a particular device.
321 * @bus: bus type
322 * @start: Device to begin with
323 * @data: Data to pass to match function
324 * @match: Callback function to check device
325 *
326 * This is similar to the bus_for_each_dev() function above, but it
327 * returns a reference to a device that is 'found' for later use, as
328 * determined by the @match callback.
329 *
330 * The callback should return 0 if the device doesn't match and non-zero
331 * if it does. If the callback returns non-zero, this function will
332 * return to the caller and not iterate over any more devices.
333 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800334struct device *bus_find_device(struct bus_type *bus,
335 struct device *start, void *data,
336 int (*match)(struct device *dev, void *data))
Cornelia Huck0edb5862005-06-22 16:59:51 +0200337{
338 struct klist_iter i;
339 struct device *dev;
340
Bjorn Helgaas4fa3e782013-01-29 16:44:27 -0700341 if (!bus || !bus->p)
Cornelia Huck0edb5862005-06-22 16:59:51 +0200342 return NULL;
343
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700344 klist_iter_init_node(&bus->p->klist_devices, &i,
345 (start ? &start->p->knode_bus : NULL));
Cornelia Huck0edb5862005-06-22 16:59:51 +0200346 while ((dev = next_device(&i)))
347 if (match(dev, data) && get_device(dev))
348 break;
349 klist_iter_exit(&i);
350 return dev;
351}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800352EXPORT_SYMBOL_GPL(bus_find_device);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800353
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800354static int match_name(struct device *dev, void *data)
355{
356 const char *name = data;
357
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100358 return sysfs_streq(name, dev_name(dev));
Greg Kroah-Hartman1f9ffc02008-01-27 10:29:20 -0800359}
360
361/**
362 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
363 * @bus: bus type
364 * @start: Device to begin with
365 * @name: name of the device to match
366 *
367 * This is similar to the bus_find_device() function above, but it handles
368 * searching by a name automatically, no need to write another strcmp matching
369 * function.
370 */
371struct device *bus_find_device_by_name(struct bus_type *bus,
372 struct device *start, const char *name)
373{
374 return bus_find_device(bus, start, (void *)name, match_name);
375}
376EXPORT_SYMBOL_GPL(bus_find_device_by_name);
377
Kay Sieversca22e562011-12-14 14:29:38 -0800378/**
379 * subsys_find_device_by_id - find a device with a specific enumeration number
380 * @subsys: subsystem
381 * @id: index 'id' in struct device
382 * @hint: device to check first
383 *
384 * Check the hint's next object and if it is a match return it directly,
385 * otherwise, fall back to a full list search. Either way a reference for
386 * the returned object is taken.
387 */
388struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id,
389 struct device *hint)
390{
391 struct klist_iter i;
392 struct device *dev;
393
394 if (!subsys)
395 return NULL;
396
397 if (hint) {
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700398 klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
Kay Sieversca22e562011-12-14 14:29:38 -0800399 dev = next_device(&i);
400 if (dev && dev->id == id && get_device(dev)) {
401 klist_iter_exit(&i);
402 return dev;
403 }
404 klist_iter_exit(&i);
405 }
406
407 klist_iter_init_node(&subsys->p->klist_devices, &i, NULL);
408 while ((dev = next_device(&i))) {
409 if (dev->id == id && get_device(dev)) {
410 klist_iter_exit(&i);
411 return dev;
412 }
413 }
414 klist_iter_exit(&i);
415 return NULL;
416}
417EXPORT_SYMBOL_GPL(subsys_find_device_by_id);
418
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800419static struct device_driver *next_driver(struct klist_iter *i)
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800420{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800421 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800422 struct driver_private *drv_priv;
423
424 if (n) {
425 drv_priv = container_of(n, struct driver_private, knode_bus);
426 return drv_priv->driver;
427 }
428 return NULL;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800429}
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800432 * bus_for_each_drv - driver iterator
433 * @bus: bus we're dealing with.
434 * @start: driver to start iterating on.
435 * @data: data to pass to the callback.
436 * @fn: function to call for each driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800438 * This is nearly identical to the device iterator above.
439 * We iterate over each driver that belongs to @bus, and call
440 * @fn for each. If @fn returns anything but 0, we break out
441 * and return it. If @start is not NULL, we use it as the head
442 * of the list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800444 * NOTE: we don't return the driver that returns a non-zero
445 * value, nor do we leave the reference count incremented for that
446 * driver. If the caller needs to know that info, it must set it
447 * in the callback. It must also be sure to increment the refcount
448 * so it doesn't disappear before returning to the caller.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800450int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
451 void *data, int (*fn)(struct device_driver *, void *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452{
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800453 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800454 struct device_driver *drv;
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800455 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800457 if (!bus)
458 return -EINVAL;
459
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -0700460 klist_iter_init_node(&bus->p->klist_drivers, &i,
461 start ? &start->p->knode_bus : NULL);
462 while ((drv = next_driver(&i)) && !error)
463 error = fn(drv, data);
464 klist_iter_exit(&i);
mochel@digitalimplant.org38fdac32005-03-21 12:00:18 -0800465 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800467EXPORT_SYMBOL_GPL(bus_for_each_drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468
Andrew Morton4aca67e2007-02-13 22:39:26 -0800469static int device_add_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470{
471 int error = 0;
472 int i;
473
Andrew Morton4aca67e2007-02-13 22:39:26 -0800474 if (!bus->dev_attrs)
475 return 0;
476
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700477 for (i = 0; bus->dev_attrs[i].attr.name; i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800478 error = device_create_file(dev, &bus->dev_attrs[i]);
Andrew Morton4aca67e2007-02-13 22:39:26 -0800479 if (error) {
480 while (--i >= 0)
481 device_remove_file(dev, &bus->dev_attrs[i]);
482 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 }
484 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486}
487
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800488static void device_remove_attrs(struct bus_type *bus, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489{
490 int i;
491
492 if (bus->dev_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700493 for (i = 0; bus->dev_attrs[i].attr.name; i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800494 device_remove_file(dev, &bus->dev_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 }
496}
497
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800499 * bus_add_device - add device to bus
500 * @dev: device being added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 *
Alan Stern2023c612009-07-30 15:27:18 -0400502 * - Add device's bus attributes.
503 * - Create links to device's bus.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800504 * - Add the device to its bus's list of devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800506int bus_add_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800508 struct bus_type *bus = bus_get(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 int error = 0;
510
511 if (bus) {
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100512 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
Greg Kroah-Hartmand377e852005-06-22 16:09:05 -0700513 error = device_add_attrs(bus, dev);
Andrew Mortonf86db392006-08-14 22:43:20 -0700514 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200515 goto out_put;
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -0700516 error = device_add_groups(dev, bus->dev_groups);
517 if (error)
Junjie Mao1c342032015-01-28 10:02:44 +0800518 goto out_id;
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700519 error = sysfs_create_link(&bus->p->devices_kset->kobj,
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100520 &dev->kobj, dev_name(dev));
Andrew Mortonf86db392006-08-14 22:43:20 -0700521 if (error)
Junjie Mao1c342032015-01-28 10:02:44 +0800522 goto out_groups;
Andrew Mortonf86db392006-08-14 22:43:20 -0700523 error = sysfs_create_link(&dev->kobj,
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700524 &dev->bus->p->subsys.kobj, "subsystem");
Andrew Mortonf86db392006-08-14 22:43:20 -0700525 if (error)
Cornelia Huck513e7332006-09-22 11:37:08 +0200526 goto out_subsys;
Alan Stern2023c612009-07-30 15:27:18 -0400527 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 }
Cornelia Huck513e7332006-09-22 11:37:08 +0200529 return 0;
530
Cornelia Huck513e7332006-09-22 11:37:08 +0200531out_subsys:
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100532 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -0700533out_groups:
534 device_remove_groups(dev, bus->dev_groups);
Cornelia Huck513e7332006-09-22 11:37:08 +0200535out_id:
536 device_remove_attrs(bus, dev);
537out_put:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700538 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 return error;
540}
541
542/**
Alan Stern2023c612009-07-30 15:27:18 -0400543 * bus_probe_device - probe drivers for a new device
544 * @dev: device to probe
Kay Sievers53877d02006-04-04 20:42:26 +0200545 *
Alan Stern2023c612009-07-30 15:27:18 -0400546 * - Automatically probe for a driver if the bus allows it.
Kay Sievers53877d02006-04-04 20:42:26 +0200547 */
Alan Stern2023c612009-07-30 15:27:18 -0400548void bus_probe_device(struct device *dev)
Kay Sievers53877d02006-04-04 20:42:26 +0200549{
Andrew Mortonf86db392006-08-14 22:43:20 -0700550 struct bus_type *bus = dev->bus;
Kay Sieversca22e562011-12-14 14:29:38 -0800551 struct subsys_interface *sif;
Kay Sievers53877d02006-04-04 20:42:26 +0200552
Kay Sieversca22e562011-12-14 14:29:38 -0800553 if (!bus)
554 return;
555
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700556 if (bus->p->drivers_autoprobe)
557 device_initial_probe(dev);
Kay Sieversca22e562011-12-14 14:29:38 -0800558
559 mutex_lock(&bus->p->mutex);
560 list_for_each_entry(sif, &bus->p->interfaces, node)
561 if (sif->add_dev)
562 sif->add_dev(dev, sif);
563 mutex_unlock(&bus->p->mutex);
Kay Sievers53877d02006-04-04 20:42:26 +0200564}
565
566/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800567 * bus_remove_device - remove device from bus
568 * @dev: device to be removed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 *
Kay Sieversca22e562011-12-14 14:29:38 -0800570 * - Remove device from all interfaces.
571 * - Remove symlink from bus' directory.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800572 * - Delete device from bus's list.
573 * - Detach from its driver.
574 * - Drop reference taken in bus_add_device().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800576void bus_remove_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577{
Kay Sieversca22e562011-12-14 14:29:38 -0800578 struct bus_type *bus = dev->bus;
579 struct subsys_interface *sif;
Greg Kroah-Hartman3f62e572008-03-13 17:07:03 -0400580
Kay Sieversca22e562011-12-14 14:29:38 -0800581 if (!bus)
582 return;
583
584 mutex_lock(&bus->p->mutex);
585 list_for_each_entry(sif, &bus->p->interfaces, node)
586 if (sif->remove_dev)
587 sif->remove_dev(dev, sif);
588 mutex_unlock(&bus->p->mutex);
589
590 sysfs_remove_link(&dev->kobj, "subsystem");
591 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
592 dev_name(dev));
593 device_remove_attrs(dev->bus, dev);
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -0700594 device_remove_groups(dev, dev->bus->dev_groups);
Kay Sieversca22e562011-12-14 14:29:38 -0800595 if (klist_node_attached(&dev->p->knode_bus))
596 klist_del(&dev->p->knode_bus);
597
598 pr_debug("bus: '%s': remove device %s\n",
599 dev->bus->name, dev_name(dev));
600 device_release_driver(dev);
601 bus_put(dev->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602}
603
Andrew Mortonf86db392006-08-14 22:43:20 -0700604static int __must_check add_bind_files(struct device_driver *drv)
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800605{
Andrew Mortonf86db392006-08-14 22:43:20 -0700606 int ret;
607
608 ret = driver_create_file(drv, &driver_attr_unbind);
609 if (ret == 0) {
610 ret = driver_create_file(drv, &driver_attr_bind);
611 if (ret)
612 driver_remove_file(drv, &driver_attr_unbind);
613 }
614 return ret;
Greg Kroah-Hartman874c6242005-12-13 15:17:34 -0800615}
616
617static void remove_bind_files(struct device_driver *drv)
618{
619 driver_remove_file(drv, &driver_attr_bind);
620 driver_remove_file(drv, &driver_attr_unbind);
621}
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100622
Kay Sievers83807702007-07-30 02:28:56 +0200623static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
624static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
625 show_drivers_autoprobe, store_drivers_autoprobe);
626
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100627static int add_probe_files(struct bus_type *bus)
628{
629 int retval;
630
Kay Sievers83807702007-07-30 02:28:56 +0200631 retval = bus_create_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100632 if (retval)
633 goto out;
634
Kay Sievers83807702007-07-30 02:28:56 +0200635 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100636 if (retval)
Kay Sievers83807702007-07-30 02:28:56 +0200637 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100638out:
639 return retval;
640}
641
642static void remove_probe_files(struct bus_type *bus)
643{
Kay Sievers83807702007-07-30 02:28:56 +0200644 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
645 bus_remove_file(bus, &bus_attr_drivers_probe);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100646}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700648static ssize_t uevent_store(struct device_driver *drv, const char *buf,
649 size_t count)
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200650{
651 enum kobject_action action;
652
653 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800654 kobject_uevent(&drv->p->kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200655 return count;
656}
Greg Kroah-Hartman2581c9c2013-08-23 15:04:42 -0700657static DRIVER_ATTR_WO(uevent);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200658
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700659static void driver_attach_async(void *_drv, async_cookie_t cookie)
660{
661 struct device_driver *drv = _drv;
662 int ret;
663
664 ret = driver_attach(drv);
665
666 pr_debug("bus: '%s': driver %s async attach completed: %d\n",
667 drv->bus->name, drv->name, ret);
668}
669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800671 * bus_add_driver - Add a driver to the bus.
672 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700674int bus_add_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800676 struct bus_type *bus;
677 struct driver_private *priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 int error = 0;
679
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800680 bus = bus_get(drv->bus);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400681 if (!bus)
Greg Kroah-Hartman4f6e1942007-04-20 11:29:52 -0700682 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800684 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800685
686 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
Cornelia Huck07634462008-02-18 17:04:25 +0100687 if (!priv) {
688 error = -ENOMEM;
689 goto out_put_bus;
690 }
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800691 klist_init(&priv->klist_devices, NULL, NULL);
692 priv->driver = drv;
693 drv->p = priv;
Greg Kroah-Hartmanc8e90d82007-12-17 15:54:39 -0400694 priv->kobj.kset = bus->p->drivers_kset;
695 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
696 "%s", drv->name);
Cornelia Huckdc0afa82007-07-09 11:39:18 -0700697 if (error)
Cornelia Huck07634462008-02-18 17:04:25 +0100698 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699
Ming Lei190888a2012-11-19 23:35:17 +0800700 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700701 if (drv->bus->p->drivers_autoprobe) {
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700702 if (driver_allows_async_probing(drv)) {
703 pr_debug("bus: '%s': probing driver %s asynchronously\n",
704 drv->bus->name, drv->name);
705 async_schedule(driver_attach_async, drv);
706 } else {
707 error = driver_attach(drv);
708 if (error)
709 goto out_unregister;
710 }
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100711 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400712 module_add_driver(drv->owner, drv);
713
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200714 error = driver_create_file(drv, &driver_attr_uevent);
715 if (error) {
716 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800717 __func__, drv->name);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200718 }
Greg Kroah-Hartmane18945b2013-09-27 21:47:21 -0700719 error = driver_add_groups(drv, bus->drv_groups);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400720 if (error) {
721 /* How the hell do we get out of this pickle? Give up */
Greg Kroah-Hartmaned0617b2013-08-08 15:22:56 -0700722 printk(KERN_ERR "%s: driver_create_groups(%s) failed\n",
723 __func__, drv->name);
Greg Kroah-Hartmane18945b2013-09-27 21:47:21 -0700724 }
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700725
726 if (!drv->suppress_bind_attrs) {
727 error = add_bind_files(drv);
728 if (error) {
729 /* Ditto */
730 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
731 __func__, drv->name);
732 }
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400733 }
734
Kay Sievers5c8563d2009-05-28 14:24:07 -0700735 return 0;
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700736
Andrew Mortonf86db392006-08-14 22:43:20 -0700737out_unregister:
Phil Carmody99b28f12009-12-14 20:28:12 +0200738 kobject_put(&priv->kobj);
Christophe JAILLET5555eb92017-08-29 21:23:49 +0200739 /* drv->p is freed in driver_release() */
Kay Sievers5c8563d2009-05-28 14:24:07 -0700740 drv->p = NULL;
Andrew Mortonf86db392006-08-14 22:43:20 -0700741out_put_bus:
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700742 bus_put(bus);
Andrew Mortonf86db392006-08-14 22:43:20 -0700743 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744}
745
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800747 * bus_remove_driver - delete driver from bus's knowledge.
748 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800750 * Detach the driver from the devices it controls, and remove
751 * it from its bus's list of drivers. Finally, we drop the reference
752 * to the bus we took in bus_add_driver().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800754void bus_remove_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755{
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400756 if (!drv->bus)
757 return;
758
Dmitry Torokhov1a6f2a72009-10-12 20:17:41 -0700759 if (!drv->suppress_bind_attrs)
760 remove_bind_files(drv);
Greg Kroah-Hartmaned0617b2013-08-08 15:22:56 -0700761 driver_remove_groups(drv, drv->bus->drv_groups);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200762 driver_remove_file(drv, &driver_attr_uevent);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800763 klist_remove(&drv->p->knode_bus);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800764 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
Jeff Garzikd9fd4d3b32006-10-04 07:48:03 -0400765 driver_detach(drv);
766 module_remove_driver(drv);
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800767 kobject_put(&drv->p->kobj);
Greg Kroah-Hartmanfc1ede52007-09-13 02:53:13 -0700768 bus_put(drv->bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769}
770
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771/* Helper for bus_rescan_devices's iter */
Andrew Mortonf86db392006-08-14 22:43:20 -0700772static int __must_check bus_rescan_devices_helper(struct device *dev,
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800773 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774{
Andrew Mortonf86db392006-08-14 22:43:20 -0700775 int ret = 0;
776
Alan Sternbf74ad52005-11-17 16:54:12 -0500777 if (!dev->driver) {
778 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800779 device_lock(dev->parent);
Andrew Mortonf86db392006-08-14 22:43:20 -0700780 ret = device_attach(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500781 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800782 device_unlock(dev->parent);
Alan Sternbf74ad52005-11-17 16:54:12 -0500783 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700784 return ret < 0 ? ret : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785}
786
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787/**
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700788 * bus_rescan_devices - rescan devices on the bus for possible drivers
789 * @bus: the bus to scan.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 *
Greg Kroah-Hartman23d3d602005-06-22 16:09:05 -0700791 * This function will look for devices on the bus with no driver
792 * attached and rescan it against existing drivers to see if it matches
793 * any by calling device_attach() for the unbound devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800795int bus_rescan_devices(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796{
Andrew Mortonf86db392006-08-14 22:43:20 -0700797 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800799EXPORT_SYMBOL_GPL(bus_rescan_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
Moore, Erice935d5d2006-03-14 09:18:18 -0700801/**
802 * device_reprobe - remove driver for a device and probe for a new driver
803 * @dev: the device to reprobe
804 *
805 * This function detaches the attached driver (if any) for the given
806 * device and restarts the driver probing process. It is intended
807 * to use if probing criteria changed during a devices lifetime and
808 * driver attachment should change accordingly.
809 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700810int device_reprobe(struct device *dev)
Moore, Erice935d5d2006-03-14 09:18:18 -0700811{
812 if (dev->driver) {
813 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800814 device_lock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700815 device_release_driver(dev);
816 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800817 device_unlock(dev->parent);
Moore, Erice935d5d2006-03-14 09:18:18 -0700818 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700819 return bus_rescan_devices_helper(dev, NULL);
Moore, Erice935d5d2006-03-14 09:18:18 -0700820}
821EXPORT_SYMBOL_GPL(device_reprobe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800824 * find_bus - locate bus by name.
825 * @name: name of bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800827 * Call kset_find_obj() to iterate over list of buses to
828 * find a bus by name. Return bus if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800830 * Note that kset_find_obj increments bus' reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831 */
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200832#if 0
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800833struct bus_type *find_bus(char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800835 struct kobject *k = kset_find_obj(bus_kset, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 return k ? to_bus(k) : NULL;
837}
Adrian Bunk7e4ef082006-06-26 22:26:56 +0200838#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700840static int bus_add_groups(struct bus_type *bus,
841 const struct attribute_group **groups)
842{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700843 return sysfs_create_groups(&bus->p->subsys.kobj, groups);
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700844}
845
846static void bus_remove_groups(struct bus_type *bus,
847 const struct attribute_group **groups)
848{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700849 sysfs_remove_groups(&bus->p->subsys.kobj, groups);
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700850}
851
James Bottomley34bb61f2005-09-06 16:56:51 -0700852static void klist_devices_get(struct klist_node *n)
853{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800854 struct device_private *dev_prv = to_device_private_bus(n);
855 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700856
857 get_device(dev);
858}
859
860static void klist_devices_put(struct klist_node *n)
861{
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -0800862 struct device_private *dev_prv = to_device_private_bus(n);
863 struct device *dev = dev_prv->device;
James Bottomley34bb61f2005-09-06 16:56:51 -0700864
865 put_device(dev);
866}
867
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200868static ssize_t bus_uevent_store(struct bus_type *bus,
869 const char *buf, size_t count)
870{
871 enum kobject_action action;
872
873 if (kobject_action_type(buf, count, &action) == 0)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700874 kobject_uevent(&bus->p->subsys.kobj, action);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200875 return count;
876}
877static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
878
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879/**
Michal Hockobe871b72013-03-12 17:21:19 +0100880 * bus_register - register a driver-core subsystem
Randy Dunlap78d79552012-01-21 11:02:28 -0800881 * @bus: bus to register
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 *
Randy Dunlap78d79552012-01-21 11:02:28 -0800883 * Once we have that, we register the bus with the kobject
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800884 * infrastructure, then register the children subsystems it has:
Kay Sieversca22e562011-12-14 14:29:38 -0800885 * the devices and drivers that belong to the subsystem.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 */
Michal Hockobe871b72013-03-12 17:21:19 +0100887int bus_register(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888{
889 int retval;
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100890 struct subsys_private *priv;
Michal Hockobe871b72013-03-12 17:21:19 +0100891 struct lock_class_key *key = &bus->lock_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100893 priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700894 if (!priv)
895 return -ENOMEM;
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000896
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700897 priv->bus = bus;
898 bus->p = priv;
899
900 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
901
902 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 if (retval)
904 goto out;
905
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700906 priv->subsys.kobj.kset = bus_kset;
907 priv->subsys.kobj.ktype = &bus_ktype;
908 priv->drivers_autoprobe = 1;
Greg Kroah-Hartmand6b05b82007-09-12 15:06:57 -0700909
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700910 retval = kset_register(&priv->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 if (retval)
912 goto out;
913
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200914 retval = bus_create_file(bus, &bus_attr_uevent);
915 if (retval)
916 goto bus_uevent_fail;
917
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700918 priv->devices_kset = kset_create_and_add("devices", NULL,
919 &priv->subsys.kobj);
920 if (!priv->devices_kset) {
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700921 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 goto bus_devices_fail;
Greg Kroah-Hartman3d899592007-11-01 13:31:26 -0700923 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700925 priv->drivers_kset = kset_create_and_add("drivers", NULL,
926 &priv->subsys.kobj);
927 if (!priv->drivers_kset) {
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700928 retval = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 goto bus_drivers_fail;
Greg Kroah-Hartman6dcec252007-11-01 13:31:26 -0700930 }
mochel@digitalimplant.org465c7a32005-03-21 11:49:14 -0800931
Kay Sieversca22e562011-12-14 14:29:38 -0800932 INIT_LIST_HEAD(&priv->interfaces);
933 __mutex_init(&priv->mutex, "subsys mutex", key);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700934 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
935 klist_init(&priv->klist_drivers, NULL, NULL);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100936
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100937 retval = add_probe_files(bus);
938 if (retval)
939 goto bus_probe_files_fail;
940
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700941 retval = bus_add_groups(bus, bus->bus_groups);
942 if (retval)
943 goto bus_groups_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800945 pr_debug("bus: '%s': registered\n", bus->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 return 0;
947
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700948bus_groups_fail:
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100949 remove_probe_files(bus);
950bus_probe_files_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700951 kset_unregister(bus->p->drivers_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952bus_drivers_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700953 kset_unregister(bus->p->devices_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954bus_devices_fail:
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200955 bus_remove_file(bus, &bus_attr_uevent);
956bus_uevent_fail:
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700957 kset_unregister(&bus->p->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958out:
Jike Song600c20f2010-07-15 17:43:54 +0800959 kfree(bus->p);
Dave Youngf48f3fe2009-02-14 21:23:22 +0800960 bus->p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 return retval;
962}
Michal Hockobe871b72013-03-12 17:21:19 +0100963EXPORT_SYMBOL_GPL(bus_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800966 * bus_unregister - remove a bus from the system
967 * @bus: bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800969 * Unregister the child subsystems and the bus itself.
970 * Finally, we call bus_put() to release the refcount
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800972void bus_unregister(struct bus_type *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973{
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800974 pr_debug("bus: '%s': unregistering\n", bus->name);
Kay Sieversca22e562011-12-14 14:29:38 -0800975 if (bus->dev_root)
976 device_unregister(bus->dev_root);
Greg Kroah-Hartman12478ba2013-08-08 15:22:57 -0700977 bus_remove_groups(bus, bus->bus_groups);
Kay Sieversb8c5cec2007-02-16 17:33:36 +0100978 remove_probe_files(bus);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700979 kset_unregister(bus->p->drivers_kset);
980 kset_unregister(bus->p->devices_kset);
Kay Sievers7ac1cf42007-08-12 20:43:55 +0200981 bus_remove_file(bus, &bus_attr_uevent);
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700982 kset_unregister(&bus->p->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800984EXPORT_SYMBOL_GPL(bus_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000986int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
987{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700988 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000989}
990EXPORT_SYMBOL_GPL(bus_register_notifier);
991
992int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
993{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700994 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000995}
996EXPORT_SYMBOL_GPL(bus_unregister_notifier);
997
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -0700998struct kset *bus_get_kset(struct bus_type *bus)
999{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001000 return &bus->p->subsys;
Greg Kroah-Hartman0fed80f2007-11-01 19:41:16 -07001001}
1002EXPORT_SYMBOL_GPL(bus_get_kset);
1003
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001004struct klist *bus_get_device_klist(struct bus_type *bus)
1005{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -07001006 return &bus->p->klist_devices;
Greg Kroah-Hartmanb2490722007-11-01 19:41:16 -07001007}
1008EXPORT_SYMBOL_GPL(bus_get_device_klist);
1009
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001010/*
Robert P. J. Daydca25eb2010-11-21 08:15:01 -05001011 * Yes, this forcibly breaks the klist abstraction temporarily. It
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001012 * just wants to sort the klist, not change reference counts and
1013 * take/drop locks rapidly in the process. It does all this while
1014 * holding the lock for the list, so objects can't otherwise be
1015 * added/removed while we're swizzling.
1016 */
1017static void device_insertion_sort_klist(struct device *a, struct list_head *list,
1018 int (*compare)(const struct device *a,
1019 const struct device *b))
1020{
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001021 struct klist_node *n;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001022 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001023 struct device *b;
1024
Geliang Tang4c627852016-01-05 23:03:37 +08001025 list_for_each_entry(n, list, n_node) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001026 dev_prv = to_device_private_bus(n);
1027 b = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001028 if (compare(a, b) <= 0) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001029 list_move_tail(&a->p->knode_bus.n_node,
1030 &b->p->knode_bus.n_node);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001031 return;
1032 }
1033 }
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001034 list_move_tail(&a->p->knode_bus.n_node, list);
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001035}
1036
1037void bus_sort_breadthfirst(struct bus_type *bus,
1038 int (*compare)(const struct device *a,
1039 const struct device *b))
1040{
1041 LIST_HEAD(sorted_devices);
Geliang Tang4c627852016-01-05 23:03:37 +08001042 struct klist_node *n, *tmp;
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001043 struct device_private *dev_prv;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001044 struct device *dev;
1045 struct klist *device_klist;
1046
1047 device_klist = bus_get_device_klist(bus);
1048
1049 spin_lock(&device_klist->k_lock);
Geliang Tang4c627852016-01-05 23:03:37 +08001050 list_for_each_entry_safe(n, tmp, &device_klist->k_list, n_node) {
Greg Kroah-Hartmanae1b4172008-12-16 12:26:21 -08001051 dev_prv = to_device_private_bus(n);
1052 dev = dev_prv->device;
Greg Kroah-Hartman99178b02008-08-26 11:00:57 -05001053 device_insertion_sort_klist(dev, &sorted_devices, compare);
1054 }
1055 list_splice(&sorted_devices, &device_klist->k_list);
1056 spin_unlock(&device_klist->k_lock);
1057}
1058EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1059
Kay Sieversca22e562011-12-14 14:29:38 -08001060/**
1061 * subsys_dev_iter_init - initialize subsys device iterator
1062 * @iter: subsys iterator to initialize
1063 * @subsys: the subsys we wanna iterate over
1064 * @start: the device to start iterating from, if any
1065 * @type: device_type of the devices to iterate over, NULL for all
1066 *
1067 * Initialize subsys iterator @iter such that it iterates over devices
1068 * of @subsys. If @start is set, the list iteration will start there,
1069 * otherwise if it is NULL, the iteration starts at the beginning of
1070 * the list.
1071 */
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001072void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
1073 struct device *start, const struct device_type *type)
Kay Sieversca22e562011-12-14 14:29:38 -08001074{
1075 struct klist_node *start_knode = NULL;
1076
1077 if (start)
1078 start_knode = &start->p->knode_bus;
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -07001079 klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
1080 iter->type = type;
Kay Sieversca22e562011-12-14 14:29:38 -08001081}
1082EXPORT_SYMBOL_GPL(subsys_dev_iter_init);
1083
1084/**
1085 * subsys_dev_iter_next - iterate to the next device
1086 * @iter: subsys iterator to proceed
1087 *
1088 * Proceed @iter to the next device and return it. Returns NULL if
1089 * iteration is complete.
1090 *
1091 * The returned device is referenced and won't be released till
1092 * iterator is proceed to the next device or exited. The caller is
1093 * free to do whatever it wants to do with the device including
1094 * calling back into subsys code.
1095 */
1096struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
1097{
1098 struct klist_node *knode;
1099 struct device *dev;
1100
1101 for (;;) {
1102 knode = klist_next(&iter->ki);
1103 if (!knode)
1104 return NULL;
Geliang Tang371fd7a2016-01-05 23:03:38 +08001105 dev = to_device_private_bus(knode)->device;
Kay Sieversca22e562011-12-14 14:29:38 -08001106 if (!iter->type || iter->type == dev->type)
1107 return dev;
1108 }
1109}
1110EXPORT_SYMBOL_GPL(subsys_dev_iter_next);
1111
1112/**
1113 * subsys_dev_iter_exit - finish iteration
1114 * @iter: subsys iterator to finish
1115 *
1116 * Finish an iteration. Always call this function after iteration is
1117 * complete whether the iteration ran till the end or not.
1118 */
1119void subsys_dev_iter_exit(struct subsys_dev_iter *iter)
1120{
1121 klist_iter_exit(&iter->ki);
1122}
1123EXPORT_SYMBOL_GPL(subsys_dev_iter_exit);
1124
1125int subsys_interface_register(struct subsys_interface *sif)
1126{
1127 struct bus_type *subsys;
1128 struct subsys_dev_iter iter;
1129 struct device *dev;
1130
1131 if (!sif || !sif->subsys)
1132 return -ENODEV;
1133
1134 subsys = bus_get(sif->subsys);
1135 if (!subsys)
1136 return -EINVAL;
1137
1138 mutex_lock(&subsys->p->mutex);
1139 list_add_tail(&sif->node, &subsys->p->interfaces);
1140 if (sif->add_dev) {
1141 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1142 while ((dev = subsys_dev_iter_next(&iter)))
1143 sif->add_dev(dev, sif);
1144 subsys_dev_iter_exit(&iter);
1145 }
1146 mutex_unlock(&subsys->p->mutex);
1147
1148 return 0;
1149}
1150EXPORT_SYMBOL_GPL(subsys_interface_register);
1151
1152void subsys_interface_unregister(struct subsys_interface *sif)
1153{
Jonghwan Choi2b315942012-01-14 11:06:03 +09001154 struct bus_type *subsys;
Kay Sieversca22e562011-12-14 14:29:38 -08001155 struct subsys_dev_iter iter;
1156 struct device *dev;
1157
Jonghwan Choi2b315942012-01-14 11:06:03 +09001158 if (!sif || !sif->subsys)
Kay Sieversca22e562011-12-14 14:29:38 -08001159 return;
1160
Jonghwan Choi2b315942012-01-14 11:06:03 +09001161 subsys = sif->subsys;
1162
Kay Sieversca22e562011-12-14 14:29:38 -08001163 mutex_lock(&subsys->p->mutex);
1164 list_del_init(&sif->node);
1165 if (sif->remove_dev) {
1166 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1167 while ((dev = subsys_dev_iter_next(&iter)))
1168 sif->remove_dev(dev, sif);
1169 subsys_dev_iter_exit(&iter);
1170 }
1171 mutex_unlock(&subsys->p->mutex);
1172
1173 bus_put(subsys);
1174}
1175EXPORT_SYMBOL_GPL(subsys_interface_unregister);
1176
1177static void system_root_device_release(struct device *dev)
1178{
1179 kfree(dev);
1180}
Tejun Heod73ce002013-03-12 11:30:05 -07001181
1182static int subsys_register(struct bus_type *subsys,
1183 const struct attribute_group **groups,
1184 struct kobject *parent_of_root)
1185{
1186 struct device *dev;
1187 int err;
1188
1189 err = bus_register(subsys);
1190 if (err < 0)
1191 return err;
1192
1193 dev = kzalloc(sizeof(struct device), GFP_KERNEL);
1194 if (!dev) {
1195 err = -ENOMEM;
1196 goto err_dev;
1197 }
1198
1199 err = dev_set_name(dev, "%s", subsys->name);
1200 if (err < 0)
1201 goto err_name;
1202
1203 dev->kobj.parent = parent_of_root;
1204 dev->groups = groups;
1205 dev->release = system_root_device_release;
1206
1207 err = device_register(dev);
1208 if (err < 0)
1209 goto err_dev_reg;
1210
1211 subsys->dev_root = dev;
1212 return 0;
1213
1214err_dev_reg:
1215 put_device(dev);
1216 dev = NULL;
1217err_name:
1218 kfree(dev);
1219err_dev:
1220 bus_unregister(subsys);
1221 return err;
1222}
1223
Kay Sieversca22e562011-12-14 14:29:38 -08001224/**
1225 * subsys_system_register - register a subsystem at /sys/devices/system/
Randy Dunlap78d79552012-01-21 11:02:28 -08001226 * @subsys: system subsystem
1227 * @groups: default attributes for the root device
Kay Sieversca22e562011-12-14 14:29:38 -08001228 *
1229 * All 'system' subsystems have a /sys/devices/system/<name> root device
1230 * with the name of the subsystem. The root device can carry subsystem-
1231 * wide attributes. All registered devices are below this single root
1232 * device and are named after the subsystem with a simple enumeration
Masanari Iidae2278672014-02-18 22:54:36 +09001233 * number appended. The registered devices are not explicitly named;
Kay Sieversca22e562011-12-14 14:29:38 -08001234 * only 'id' in the device needs to be set.
1235 *
1236 * Do not use this interface for anything new, it exists for compatibility
1237 * with bad ideas only. New subsystems should use plain subsystems; and
1238 * add the subsystem-wide attributes should be added to the subsystem
1239 * directory itself and not some create fake root-device placed in
1240 * /sys/devices/system/<name>.
1241 */
1242int subsys_system_register(struct bus_type *subsys,
1243 const struct attribute_group **groups)
1244{
Tejun Heod73ce002013-03-12 11:30:05 -07001245 return subsys_register(subsys, groups, &system_kset->kobj);
Kay Sieversca22e562011-12-14 14:29:38 -08001246}
1247EXPORT_SYMBOL_GPL(subsys_system_register);
1248
Tejun Heod73ce002013-03-12 11:30:05 -07001249/**
1250 * subsys_virtual_register - register a subsystem at /sys/devices/virtual/
1251 * @subsys: virtual subsystem
1252 * @groups: default attributes for the root device
1253 *
1254 * All 'virtual' subsystems have a /sys/devices/system/<name> root device
1255 * with the name of the subystem. The root device can carry subsystem-wide
1256 * attributes. All registered devices are below this single root device.
1257 * There's no restriction on device naming. This is for kernel software
1258 * constructs which need sysfs interface.
1259 */
1260int subsys_virtual_register(struct bus_type *subsys,
1261 const struct attribute_group **groups)
1262{
1263 struct kobject *virtual_dir;
1264
1265 virtual_dir = virtual_device_parent(NULL);
1266 if (!virtual_dir)
1267 return -ENOMEM;
1268
1269 return subsys_register(subsys, groups, virtual_dir);
1270}
Greg Kroah-Hartman1c04fc32013-05-10 09:14:04 -07001271EXPORT_SYMBOL_GPL(subsys_virtual_register);
Tejun Heod73ce002013-03-12 11:30:05 -07001272
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273int __init buses_init(void)
1274{
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001275 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
1276 if (!bus_kset)
1277 return -ENOMEM;
Kay Sieversca22e562011-12-14 14:29:38 -08001278
1279 system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
1280 if (!system_kset)
1281 return -ENOMEM;
1282
Greg Kroah-Hartman59a54832007-10-29 23:22:26 -05001283 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284}