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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>
18#include "base.h"
19
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080020static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080021{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080022 struct klist_node *n = klist_next(i);
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -080023 struct device *dev = NULL;
24 struct device_private *dev_prv;
25
26 if (n) {
27 dev_prv = to_device_private_driver(n);
28 dev = dev_prv->device;
29 }
30 return dev;
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080031}
32
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080033/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080034 * driver_for_each_device - Iterator for devices bound to a driver.
35 * @drv: Driver we're iterating.
36 * @start: Device to begin with
37 * @data: Data to pass to the callback.
38 * @fn: Function to call for each device.
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080039 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080040 * Iterate over the @drv's list of devices calling @fn for each one.
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080041 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080042int driver_for_each_device(struct device_driver *drv, struct device *start,
43 void *data, int (*fn)(struct device *, void *))
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080044{
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080045 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080046 struct device *dev;
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080047 int error = 0;
48
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080049 if (!drv)
50 return -EINVAL;
51
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080052 klist_iter_init_node(&drv->p->klist_devices, &i,
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -080053 start ? &start->p->knode_driver : NULL);
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080054 while ((dev = next_device(&i)) && !error)
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080055 error = fn(dev, data);
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -080056 klist_iter_exit(&i);
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080057 return error;
58}
gregkh@suse.de126eddf2005-03-22 12:17:13 -080059EXPORT_SYMBOL_GPL(driver_for_each_device);
mochel@digitalimplant.orgfae3cd02005-03-21 10:59:56 -080060
Linus Torvalds1da177e2005-04-16 15:20:36 -070061/**
Cornelia Huck0edb5862005-06-22 16:59:51 +020062 * driver_find_device - device iterator for locating a particular device.
Randy Dunlapc41455f2005-10-23 11:59:14 -070063 * @drv: The device's driver
Cornelia Huck0edb5862005-06-22 16:59:51 +020064 * @start: Device to begin with
65 * @data: Data to pass to match function
66 * @match: Callback function to check device
67 *
68 * This is similar to the driver_for_each_device() function above, but
69 * it returns a reference to a device that is 'found' for later use, as
70 * determined by the @match callback.
71 *
72 * The callback should return 0 if the device doesn't match and non-zero
73 * if it does. If the callback returns non-zero, this function will
74 * return to the caller and not iterate over any more devices.
75 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080076struct device *driver_find_device(struct device_driver *drv,
77 struct device *start, void *data,
78 int (*match)(struct device *dev, void *data))
Cornelia Huck0edb5862005-06-22 16:59:51 +020079{
80 struct klist_iter i;
81 struct device *dev;
82
83 if (!drv)
84 return NULL;
85
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080086 klist_iter_init_node(&drv->p->klist_devices, &i,
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -080087 (start ? &start->p->knode_driver : NULL));
Cornelia Huck0edb5862005-06-22 16:59:51 +020088 while ((dev = next_device(&i)))
89 if (match(dev, data) && get_device(dev))
90 break;
91 klist_iter_exit(&i);
92 return dev;
93}
94EXPORT_SYMBOL_GPL(driver_find_device);
95
96/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080097 * driver_create_file - create sysfs file for driver.
98 * @drv: driver.
99 * @attr: driver attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800101int driver_create_file(struct device_driver *drv,
Phil Carmody099c2f22009-12-18 15:34:21 +0200102 const struct driver_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103{
104 int error;
Cornelia Huck0c98b192008-01-31 10:39:38 +0100105 if (drv)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800106 error = sysfs_create_file(&drv->p->kobj, &attr->attr);
Cornelia Huck0c98b192008-01-31 10:39:38 +0100107 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 error = -EINVAL;
109 return error;
110}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800111EXPORT_SYMBOL_GPL(driver_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800114 * driver_remove_file - remove sysfs file for driver.
115 * @drv: driver.
116 * @attr: driver attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800118void driver_remove_file(struct device_driver *drv,
Phil Carmody099c2f22009-12-18 15:34:21 +0200119 const struct driver_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120{
Cornelia Huck0c98b192008-01-31 10:39:38 +0100121 if (drv)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800122 sysfs_remove_file(&drv->p->kobj, &attr->attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800124EXPORT_SYMBOL_GPL(driver_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Cornelia Huck57c74532007-12-05 12:50:23 +0100126static int driver_add_groups(struct device_driver *drv,
David Brownella4dbd672009-06-24 10:06:31 -0700127 const struct attribute_group **groups)
Cornelia Huck57c74532007-12-05 12:50:23 +0100128{
129 int error = 0;
130 int i;
131
132 if (groups) {
133 for (i = 0; groups[i]; i++) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800134 error = sysfs_create_group(&drv->p->kobj, groups[i]);
Cornelia Huck57c74532007-12-05 12:50:23 +0100135 if (error) {
136 while (--i >= 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800137 sysfs_remove_group(&drv->p->kobj,
Cornelia Huck57c74532007-12-05 12:50:23 +0100138 groups[i]);
139 break;
140 }
141 }
142 }
143 return error;
144}
145
146static void driver_remove_groups(struct device_driver *drv,
David Brownella4dbd672009-06-24 10:06:31 -0700147 const struct attribute_group **groups)
Cornelia Huck57c74532007-12-05 12:50:23 +0100148{
149 int i;
150
151 if (groups)
152 for (i = 0; groups[i]; i++)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800153 sysfs_remove_group(&drv->p->kobj, groups[i]);
Cornelia Huck57c74532007-12-05 12:50:23 +0100154}
155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800157 * driver_register - register driver with bus
158 * @drv: driver to register
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800160 * We pass off most of the work to the bus_add_driver() call,
161 * since most of the things we have to do deal with the bus
162 * structures.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800164int driver_register(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
Cornelia Huck57c74532007-12-05 12:50:23 +0100166 int ret;
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400167 struct device_driver *other;
Cornelia Huck57c74532007-12-05 12:50:23 +0100168
Dave Youngf48f3fe2009-02-14 21:23:22 +0800169 BUG_ON(!drv->bus->p);
170
Russell King594c8282006-01-05 14:29:51 +0000171 if ((drv->bus->probe && drv->probe) ||
172 (drv->bus->remove && drv->remove) ||
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800173 (drv->bus->shutdown && drv->shutdown))
174 printk(KERN_WARNING "Driver '%s' needs updating - please use "
175 "bus_type methods\n", drv->name);
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400176
177 other = driver_find(drv->name, drv->bus);
178 if (other) {
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400179 printk(KERN_ERR "Error: Driver '%s' is already registered, "
180 "aborting...\n", drv->name);
Stas Sergeev39acbc12009-10-18 00:31:38 +0400181 return -EBUSY;
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400182 }
183
Cornelia Huck57c74532007-12-05 12:50:23 +0100184 ret = bus_add_driver(drv);
185 if (ret)
186 return ret;
187 ret = driver_add_groups(drv, drv->groups);
188 if (ret)
189 bus_remove_driver(drv);
190 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800192EXPORT_SYMBOL_GPL(driver_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800195 * driver_unregister - remove driver from system.
196 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800198 * Again, we pass off most of the work to the bus-level call.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800200void driver_unregister(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201{
Kay Sievers5c8563d2009-05-28 14:24:07 -0700202 if (!drv || !drv->p) {
203 WARN(1, "Unexpected driver unregister!\n");
204 return;
205 }
Cornelia Huck57c74532007-12-05 12:50:23 +0100206 driver_remove_groups(drv, drv->groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 bus_remove_driver(drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800209EXPORT_SYMBOL_GPL(driver_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800212 * driver_find - locate driver on a bus by its name.
213 * @name: name of the driver.
214 * @bus: bus to scan for the driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800216 * Call kset_find_obj() to iterate over list of drivers on
217 * a bus to find driver by name. Return driver if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 *
Alan Sternfde25a92012-01-24 13:34:24 -0500219 * This routine provides no locking to prevent the driver it returns
220 * from being unregistered or unloaded while the caller is using it.
221 * The caller is responsible for preventing this.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 */
223struct device_driver *driver_find(const char *name, struct bus_type *bus)
224{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700225 struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800226 struct driver_private *priv;
227
228 if (k) {
Alan Sternfde25a92012-01-24 13:34:24 -0500229 /* Drop reference added by kset_find_obj() */
230 kobject_put(k);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800231 priv = to_driver(k);
232 return priv->driver;
233 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 return NULL;
235}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236EXPORT_SYMBOL_GPL(driver_find);