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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * driver.c - centralized device 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/string.h>
Greg Kroah-Hartman63967682013-08-27 10:24:15 -070018#include <linux/sysfs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include "base.h"
20
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080021static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080022{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080023 struct klist_node *n = klist_next(i);
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -080024 struct device *dev = NULL;
25 struct device_private *dev_prv;
26
27 if (n) {
28 dev_prv = to_device_private_driver(n);
29 dev = dev_prv->device;
30 }
31 return dev;
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080032}
33
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080034/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080035 * driver_for_each_device - Iterator for devices bound to a driver.
36 * @drv: Driver we're iterating.
37 * @start: Device to begin with
38 * @data: Data to pass to the callback.
39 * @fn: Function to call for each device.
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080040 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080041 * Iterate over the @drv's list of devices calling @fn for each one.
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080042 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080043int driver_for_each_device(struct device_driver *drv, struct device *start,
44 void *data, int (*fn)(struct device *, void *))
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080045{
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080046 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080047 struct device *dev;
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080048 int error = 0;
49
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080050 if (!drv)
51 return -EINVAL;
52
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -070053 klist_iter_init_node(&drv->p->klist_devices, &i,
54 start ? &start->p->knode_driver : NULL);
55 while ((dev = next_device(&i)) && !error)
56 error = fn(dev, data);
57 klist_iter_exit(&i);
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080058 return error;
59}
gregkh@suse.de126eddf2005-03-22 12:17:13 -080060EXPORT_SYMBOL_GPL(driver_for_each_device);
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080061
Linus Torvalds1da177e2005-04-16 15:20:36 -070062/**
Cornelia Huck0edb5862005-06-22 16:59:51 +020063 * driver_find_device - device iterator for locating a particular device.
Randy Dunlapc41455f2005-10-23 11:59:14 -070064 * @drv: The device's driver
Cornelia Huck0edb5862005-06-22 16:59:51 +020065 * @start: Device to begin with
66 * @data: Data to pass to match function
67 * @match: Callback function to check device
68 *
69 * This is similar to the driver_for_each_device() function above, but
70 * it returns a reference to a device that is 'found' for later use, as
71 * determined by the @match callback.
72 *
73 * The callback should return 0 if the device doesn't match and non-zero
74 * if it does. If the callback returns non-zero, this function will
75 * return to the caller and not iterate over any more devices.
76 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080077struct device *driver_find_device(struct device_driver *drv,
78 struct device *start, void *data,
79 int (*match)(struct device *dev, void *data))
Cornelia Huck0edb5862005-06-22 16:59:51 +020080{
81 struct klist_iter i;
82 struct device *dev;
83
Hiroshi DOYU094e47e2012-05-11 11:03:09 +030084 if (!drv || !drv->p)
Cornelia Huck0edb5862005-06-22 16:59:51 +020085 return NULL;
86
Greg Kroah-Hartman7cd9c9b2012-04-19 19:17:30 -070087 klist_iter_init_node(&drv->p->klist_devices, &i,
88 (start ? &start->p->knode_driver : NULL));
Cornelia Huck0edb5862005-06-22 16:59:51 +020089 while ((dev = next_device(&i)))
90 if (match(dev, data) && get_device(dev))
91 break;
92 klist_iter_exit(&i);
93 return dev;
94}
95EXPORT_SYMBOL_GPL(driver_find_device);
96
97/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080098 * driver_create_file - create sysfs file for driver.
99 * @drv: driver.
100 * @attr: driver attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800102int driver_create_file(struct device_driver *drv,
Phil Carmody099c2f22009-12-18 15:34:21 +0200103 const struct driver_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
105 int error;
Lavinia Tache74642c62015-03-08 12:48:55 +0200106
Cornelia Huck0c98b192008-01-31 10:39:38 +0100107 if (drv)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800108 error = sysfs_create_file(&drv->p->kobj, &attr->attr);
Cornelia Huck0c98b192008-01-31 10:39:38 +0100109 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 error = -EINVAL;
111 return error;
112}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800113EXPORT_SYMBOL_GPL(driver_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800116 * driver_remove_file - remove sysfs file for driver.
117 * @drv: driver.
118 * @attr: driver attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800120void driver_remove_file(struct device_driver *drv,
Phil Carmody099c2f22009-12-18 15:34:21 +0200121 const struct driver_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122{
Cornelia Huck0c98b192008-01-31 10:39:38 +0100123 if (drv)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800124 sysfs_remove_file(&drv->p->kobj, &attr->attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800126EXPORT_SYMBOL_GPL(driver_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
Greg Kroah-Hartmaned0617b2013-08-08 15:22:56 -0700128int driver_add_groups(struct device_driver *drv,
129 const struct attribute_group **groups)
Cornelia Huck57c74532007-12-05 12:50:23 +0100130{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700131 return sysfs_create_groups(&drv->p->kobj, groups);
Cornelia Huck57c74532007-12-05 12:50:23 +0100132}
133
Greg Kroah-Hartmaned0617b2013-08-08 15:22:56 -0700134void driver_remove_groups(struct device_driver *drv,
135 const struct attribute_group **groups)
Cornelia Huck57c74532007-12-05 12:50:23 +0100136{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700137 sysfs_remove_groups(&drv->p->kobj, groups);
Cornelia Huck57c74532007-12-05 12:50:23 +0100138}
139
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800141 * driver_register - register driver with bus
142 * @drv: driver to register
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800144 * We pass off most of the work to the bus_add_driver() call,
145 * since most of the things we have to do deal with the bus
146 * structures.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800148int driver_register(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149{
Cornelia Huck57c74532007-12-05 12:50:23 +0100150 int ret;
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400151 struct device_driver *other;
Cornelia Huck57c74532007-12-05 12:50:23 +0100152
Dave Youngf48f3fe2009-02-14 21:23:22 +0800153 BUG_ON(!drv->bus->p);
154
Russell King594c8282006-01-05 14:29:51 +0000155 if ((drv->bus->probe && drv->probe) ||
156 (drv->bus->remove && drv->remove) ||
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800157 (drv->bus->shutdown && drv->shutdown))
158 printk(KERN_WARNING "Driver '%s' needs updating - please use "
159 "bus_type methods\n", drv->name);
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400160
161 other = driver_find(drv->name, drv->bus);
162 if (other) {
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400163 printk(KERN_ERR "Error: Driver '%s' is already registered, "
164 "aborting...\n", drv->name);
Stas Sergeev39acbc12009-10-18 00:31:38 +0400165 return -EBUSY;
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400166 }
167
Cornelia Huck57c74532007-12-05 12:50:23 +0100168 ret = bus_add_driver(drv);
169 if (ret)
170 return ret;
171 ret = driver_add_groups(drv, drv->groups);
Sebastian Otta14af322012-07-17 10:39:10 +0200172 if (ret) {
Cornelia Huck57c74532007-12-05 12:50:23 +0100173 bus_remove_driver(drv);
Sebastian Otta14af322012-07-17 10:39:10 +0200174 return ret;
175 }
Sebastian Ott5a7689f2012-07-02 19:08:15 +0200176 kobject_uevent(&drv->p->kobj, KOBJ_ADD);
177
Cornelia Huck57c74532007-12-05 12:50:23 +0100178 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800180EXPORT_SYMBOL_GPL(driver_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800183 * driver_unregister - remove driver from system.
184 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800186 * Again, we pass off most of the work to the bus-level call.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800188void driver_unregister(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189{
Kay Sievers5c8563d2009-05-28 14:24:07 -0700190 if (!drv || !drv->p) {
191 WARN(1, "Unexpected driver unregister!\n");
192 return;
193 }
Cornelia Huck57c74532007-12-05 12:50:23 +0100194 driver_remove_groups(drv, drv->groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 bus_remove_driver(drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800197EXPORT_SYMBOL_GPL(driver_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800200 * driver_find - locate driver on a bus by its name.
201 * @name: name of the driver.
202 * @bus: bus to scan for the driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800204 * Call kset_find_obj() to iterate over list of drivers on
205 * a bus to find driver by name. Return driver if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 *
Alan Sternfde25a92012-01-24 13:34:24 -0500207 * This routine provides no locking to prevent the driver it returns
208 * from being unregistered or unloaded while the caller is using it.
209 * The caller is responsible for preventing this.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 */
211struct device_driver *driver_find(const char *name, struct bus_type *bus)
212{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700213 struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800214 struct driver_private *priv;
215
216 if (k) {
Alan Sternfde25a92012-01-24 13:34:24 -0500217 /* Drop reference added by kset_find_obj() */
218 kobject_put(k);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800219 priv = to_driver(k);
220 return priv->driver;
221 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 return NULL;
223}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224EXPORT_SYMBOL_GPL(driver_find);