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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.org94e7b1c2005-03-21 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.org94e7b1c2005-03-21 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.org94e7b1c2005-03-21 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.org94e7b1c2005-03-21 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.org94e7b1c2005-03-21 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.org94e7b1c2005-03-21 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
126/**
Greg Kroah-Hartmancbe9c592007-12-19 15:54:39 -0400127 * driver_add_kobj - add a kobject below the specified driver
Randy Dunlap71996772008-02-18 13:09:03 -0800128 * @drv: requesting device driver
129 * @kobj: kobject to add below this driver
130 * @fmt: format string that names the kobject
Greg Kroah-Hartmancbe9c592007-12-19 15:54:39 -0400131 *
132 * You really don't want to do this, this is only here due to one looney
133 * iseries driver, go poke those developers if you are annoyed about
134 * this...
135 */
136int driver_add_kobj(struct device_driver *drv, struct kobject *kobj,
137 const char *fmt, ...)
138{
139 va_list args;
140 char *name;
Jesper Juhld4783762008-03-28 14:16:12 -0700141 int ret;
Greg Kroah-Hartmancbe9c592007-12-19 15:54:39 -0400142
143 va_start(args, fmt);
144 name = kvasprintf(GFP_KERNEL, fmt, args);
145 va_end(args);
146
147 if (!name)
148 return -ENOMEM;
149
Jesper Juhld4783762008-03-28 14:16:12 -0700150 ret = kobject_add(kobj, &drv->p->kobj, "%s", name);
151 kfree(name);
152 return ret;
Greg Kroah-Hartmancbe9c592007-12-19 15:54:39 -0400153}
154EXPORT_SYMBOL_GPL(driver_add_kobj);
155
156/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800157 * get_driver - increment driver reference count.
158 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800160struct device_driver *get_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800162 if (drv) {
163 struct driver_private *priv;
164 struct kobject *kobj;
165
166 kobj = kobject_get(&drv->p->kobj);
167 priv = to_driver(kobj);
168 return priv->driver;
169 }
170 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800172EXPORT_SYMBOL_GPL(get_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
174/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800175 * put_driver - decrement driver's refcount.
176 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800178void put_driver(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800180 kobject_put(&drv->p->kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800182EXPORT_SYMBOL_GPL(put_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Cornelia Huck57c74532007-12-05 12:50:23 +0100184static int driver_add_groups(struct device_driver *drv,
David Brownella4dbd672009-06-24 10:06:31 -0700185 const struct attribute_group **groups)
Cornelia Huck57c74532007-12-05 12:50:23 +0100186{
187 int error = 0;
188 int i;
189
190 if (groups) {
191 for (i = 0; groups[i]; i++) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800192 error = sysfs_create_group(&drv->p->kobj, groups[i]);
Cornelia Huck57c74532007-12-05 12:50:23 +0100193 if (error) {
194 while (--i >= 0)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800195 sysfs_remove_group(&drv->p->kobj,
Cornelia Huck57c74532007-12-05 12:50:23 +0100196 groups[i]);
197 break;
198 }
199 }
200 }
201 return error;
202}
203
204static void driver_remove_groups(struct device_driver *drv,
David Brownella4dbd672009-06-24 10:06:31 -0700205 const struct attribute_group **groups)
Cornelia Huck57c74532007-12-05 12:50:23 +0100206{
207 int i;
208
209 if (groups)
210 for (i = 0; groups[i]; i++)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800211 sysfs_remove_group(&drv->p->kobj, groups[i]);
Cornelia Huck57c74532007-12-05 12:50:23 +0100212}
213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800215 * driver_register - register driver with bus
216 * @drv: driver to register
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800218 * We pass off most of the work to the bus_add_driver() call,
219 * since most of the things we have to do deal with the bus
220 * structures.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800222int driver_register(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223{
Cornelia Huck57c74532007-12-05 12:50:23 +0100224 int ret;
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400225 struct device_driver *other;
Cornelia Huck57c74532007-12-05 12:50:23 +0100226
Dave Youngf48f3fe2009-02-14 21:23:22 +0800227 BUG_ON(!drv->bus->p);
228
Russell King594c8282006-01-05 14:29:51 +0000229 if ((drv->bus->probe && drv->probe) ||
230 (drv->bus->remove && drv->remove) ||
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800231 (drv->bus->shutdown && drv->shutdown))
232 printk(KERN_WARNING "Driver '%s' needs updating - please use "
233 "bus_type methods\n", drv->name);
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400234
235 other = driver_find(drv->name, drv->bus);
236 if (other) {
237 put_driver(other);
238 printk(KERN_ERR "Error: Driver '%s' is already registered, "
239 "aborting...\n", drv->name);
Stas Sergeev39acbc12009-10-18 00:31:38 +0400240 return -EBUSY;
Stas Sergeev16dc42e2008-04-26 19:52:35 +0400241 }
242
Cornelia Huck57c74532007-12-05 12:50:23 +0100243 ret = bus_add_driver(drv);
244 if (ret)
245 return ret;
246 ret = driver_add_groups(drv, drv->groups);
247 if (ret)
248 bus_remove_driver(drv);
249 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800251EXPORT_SYMBOL_GPL(driver_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800254 * driver_unregister - remove driver from system.
255 * @drv: driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800257 * Again, we pass off most of the work to the bus-level call.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800259void driver_unregister(struct device_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260{
Kay Sievers5c8563d2009-05-28 14:24:07 -0700261 if (!drv || !drv->p) {
262 WARN(1, "Unexpected driver unregister!\n");
263 return;
264 }
Cornelia Huck57c74532007-12-05 12:50:23 +0100265 driver_remove_groups(drv, drv->groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 bus_remove_driver(drv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800268EXPORT_SYMBOL_GPL(driver_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
270/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800271 * driver_find - locate driver on a bus by its name.
272 * @name: name of the driver.
273 * @bus: bus to scan for the driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800275 * Call kset_find_obj() to iterate over list of drivers on
276 * a bus to find driver by name. Return driver if found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800278 * Note that kset_find_obj increments driver's reference count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 */
280struct device_driver *driver_find(const char *name, struct bus_type *bus)
281{
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700282 struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800283 struct driver_private *priv;
284
285 if (k) {
286 priv = to_driver(k);
287 return priv->driver;
288 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 return NULL;
290}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291EXPORT_SYMBOL_GPL(driver_find);