Commit | Line | Data |
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989d42e8 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * driver.c - centralized device driver management | |
4 | * | |
5 | * Copyright (c) 2002-3 Patrick Mochel | |
6 | * Copyright (c) 2002-3 Open Source Development Labs | |
e5dd1278 GKH |
7 | * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de> |
8 | * Copyright (c) 2007 Novell Inc. | |
1da177e4 LT |
9 | */ |
10 | ||
1da177e4 LT |
11 | #include <linux/device.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/errno.h> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
1da177e4 | 15 | #include <linux/string.h> |
63967685 | 16 | #include <linux/sysfs.h> |
1da177e4 LT |
17 | #include "base.h" |
18 | ||
4a3ad20c | 19 | static struct device *next_device(struct klist_iter *i) |
94e7b1c5 | 20 | { |
4a3ad20c | 21 | struct klist_node *n = klist_next(i); |
8940b4f3 GKH |
22 | struct device *dev = NULL; |
23 | struct device_private *dev_prv; | |
24 | ||
25 | if (n) { | |
26 | dev_prv = to_device_private_driver(n); | |
27 | dev = dev_prv->device; | |
28 | } | |
29 | return dev; | |
94e7b1c5 | 30 | } |
31 | ||
fae3cd00 | 32 | /** |
4a3ad20c GKH |
33 | * driver_for_each_device - Iterator for devices bound to a driver. |
34 | * @drv: Driver we're iterating. | |
35 | * @start: Device to begin with | |
36 | * @data: Data to pass to the callback. | |
37 | * @fn: Function to call for each device. | |
fae3cd00 | 38 | * |
4a3ad20c | 39 | * Iterate over the @drv's list of devices calling @fn for each one. |
fae3cd00 | 40 | */ |
4a3ad20c GKH |
41 | int driver_for_each_device(struct device_driver *drv, struct device *start, |
42 | void *data, int (*fn)(struct device *, void *)) | |
fae3cd00 | 43 | { |
94e7b1c5 | 44 | struct klist_iter i; |
4a3ad20c | 45 | struct device *dev; |
fae3cd00 | 46 | int error = 0; |
47 | ||
94e7b1c5 | 48 | if (!drv) |
49 | return -EINVAL; | |
50 | ||
7cd9c9bb GKH |
51 | klist_iter_init_node(&drv->p->klist_devices, &i, |
52 | start ? &start->p->knode_driver : NULL); | |
93ead7c9 | 53 | while (!error && (dev = next_device(&i))) |
7cd9c9bb GKH |
54 | error = fn(dev, data); |
55 | klist_iter_exit(&i); | |
fae3cd00 | 56 | return error; |
57 | } | |
126eddfb | 58 | EXPORT_SYMBOL_GPL(driver_for_each_device); |
fae3cd00 | 59 | |
0edb5860 CH |
60 | /** |
61 | * driver_find_device - device iterator for locating a particular device. | |
c41455fb | 62 | * @drv: The device's driver |
0edb5860 CH |
63 | * @start: Device to begin with |
64 | * @data: Data to pass to match function | |
65 | * @match: Callback function to check device | |
66 | * | |
67 | * This is similar to the driver_for_each_device() function above, but | |
68 | * it returns a reference to a device that is 'found' for later use, as | |
69 | * determined by the @match callback. | |
70 | * | |
71 | * The callback should return 0 if the device doesn't match and non-zero | |
72 | * if it does. If the callback returns non-zero, this function will | |
73 | * return to the caller and not iterate over any more devices. | |
74 | */ | |
4a3ad20c | 75 | struct device *driver_find_device(struct device_driver *drv, |
92ce7e83 SP |
76 | struct device *start, const void *data, |
77 | int (*match)(struct device *dev, const void *data)) | |
0edb5860 CH |
78 | { |
79 | struct klist_iter i; | |
80 | struct device *dev; | |
81 | ||
094e47e9 | 82 | if (!drv || !drv->p) |
0edb5860 CH |
83 | return NULL; |
84 | ||
7cd9c9bb GKH |
85 | klist_iter_init_node(&drv->p->klist_devices, &i, |
86 | (start ? &start->p->knode_driver : NULL)); | |
0edb5860 CH |
87 | while ((dev = next_device(&i))) |
88 | if (match(dev, data) && get_device(dev)) | |
89 | break; | |
90 | klist_iter_exit(&i); | |
91 | return dev; | |
92 | } | |
93 | EXPORT_SYMBOL_GPL(driver_find_device); | |
94 | ||
1da177e4 | 95 | /** |
4a3ad20c GKH |
96 | * driver_create_file - create sysfs file for driver. |
97 | * @drv: driver. | |
98 | * @attr: driver attribute descriptor. | |
1da177e4 | 99 | */ |
4a3ad20c | 100 | int driver_create_file(struct device_driver *drv, |
099c2f21 | 101 | const struct driver_attribute *attr) |
1da177e4 LT |
102 | { |
103 | int error; | |
74642c6c | 104 | |
0c98b19f | 105 | if (drv) |
e5dd1278 | 106 | error = sysfs_create_file(&drv->p->kobj, &attr->attr); |
0c98b19f | 107 | else |
1da177e4 LT |
108 | error = -EINVAL; |
109 | return error; | |
110 | } | |
4a3ad20c | 111 | EXPORT_SYMBOL_GPL(driver_create_file); |
1da177e4 LT |
112 | |
113 | /** | |
4a3ad20c GKH |
114 | * driver_remove_file - remove sysfs file for driver. |
115 | * @drv: driver. | |
116 | * @attr: driver attribute descriptor. | |
1da177e4 | 117 | */ |
4a3ad20c | 118 | void driver_remove_file(struct device_driver *drv, |
099c2f21 | 119 | const struct driver_attribute *attr) |
1da177e4 | 120 | { |
0c98b19f | 121 | if (drv) |
e5dd1278 | 122 | sysfs_remove_file(&drv->p->kobj, &attr->attr); |
1da177e4 | 123 | } |
4a3ad20c | 124 | EXPORT_SYMBOL_GPL(driver_remove_file); |
1da177e4 | 125 | |
ed0617b5 GKH |
126 | int driver_add_groups(struct device_driver *drv, |
127 | const struct attribute_group **groups) | |
57c74534 | 128 | { |
3e9b2bae | 129 | return sysfs_create_groups(&drv->p->kobj, groups); |
57c74534 CH |
130 | } |
131 | ||
ed0617b5 GKH |
132 | void driver_remove_groups(struct device_driver *drv, |
133 | const struct attribute_group **groups) | |
57c74534 | 134 | { |
3e9b2bae | 135 | sysfs_remove_groups(&drv->p->kobj, groups); |
57c74534 CH |
136 | } |
137 | ||
1da177e4 | 138 | /** |
4a3ad20c GKH |
139 | * driver_register - register driver with bus |
140 | * @drv: driver to register | |
1da177e4 | 141 | * |
4a3ad20c GKH |
142 | * We pass off most of the work to the bus_add_driver() call, |
143 | * since most of the things we have to do deal with the bus | |
144 | * structures. | |
1da177e4 | 145 | */ |
4a3ad20c | 146 | int driver_register(struct device_driver *drv) |
1da177e4 | 147 | { |
57c74534 | 148 | int ret; |
16dc42e0 | 149 | struct device_driver *other; |
57c74534 | 150 | |
0dda2bb6 FS |
151 | if (!drv->bus->p) { |
152 | pr_err("Driver '%s' was unable to register with bus_type '%s' because the bus was not initialized.\n", | |
153 | drv->name, drv->bus->name); | |
154 | return -EINVAL; | |
155 | } | |
f48f3feb | 156 | |
594c8281 RK |
157 | if ((drv->bus->probe && drv->probe) || |
158 | (drv->bus->remove && drv->remove) || | |
4a3ad20c GKH |
159 | (drv->bus->shutdown && drv->shutdown)) |
160 | printk(KERN_WARNING "Driver '%s' needs updating - please use " | |
161 | "bus_type methods\n", drv->name); | |
16dc42e0 SS |
162 | |
163 | other = driver_find(drv->name, drv->bus); | |
164 | if (other) { | |
16dc42e0 SS |
165 | printk(KERN_ERR "Error: Driver '%s' is already registered, " |
166 | "aborting...\n", drv->name); | |
39acbc12 | 167 | return -EBUSY; |
16dc42e0 SS |
168 | } |
169 | ||
57c74534 CH |
170 | ret = bus_add_driver(drv); |
171 | if (ret) | |
172 | return ret; | |
173 | ret = driver_add_groups(drv, drv->groups); | |
a14af325 | 174 | if (ret) { |
57c74534 | 175 | bus_remove_driver(drv); |
a14af325 SO |
176 | return ret; |
177 | } | |
5a7689fd SO |
178 | kobject_uevent(&drv->p->kobj, KOBJ_ADD); |
179 | ||
57c74534 | 180 | return ret; |
1da177e4 | 181 | } |
4a3ad20c | 182 | EXPORT_SYMBOL_GPL(driver_register); |
1da177e4 | 183 | |
1da177e4 | 184 | /** |
4a3ad20c GKH |
185 | * driver_unregister - remove driver from system. |
186 | * @drv: driver. | |
1da177e4 | 187 | * |
4a3ad20c | 188 | * Again, we pass off most of the work to the bus-level call. |
1da177e4 | 189 | */ |
4a3ad20c | 190 | void driver_unregister(struct device_driver *drv) |
1da177e4 | 191 | { |
5c8563d7 KS |
192 | if (!drv || !drv->p) { |
193 | WARN(1, "Unexpected driver unregister!\n"); | |
194 | return; | |
195 | } | |
57c74534 | 196 | driver_remove_groups(drv, drv->groups); |
1da177e4 | 197 | bus_remove_driver(drv); |
1da177e4 | 198 | } |
4a3ad20c | 199 | EXPORT_SYMBOL_GPL(driver_unregister); |
1da177e4 LT |
200 | |
201 | /** | |
4a3ad20c GKH |
202 | * driver_find - locate driver on a bus by its name. |
203 | * @name: name of the driver. | |
204 | * @bus: bus to scan for the driver. | |
1da177e4 | 205 | * |
4a3ad20c GKH |
206 | * Call kset_find_obj() to iterate over list of drivers on |
207 | * a bus to find driver by name. Return driver if found. | |
1da177e4 | 208 | * |
fde25a9b AS |
209 | * This routine provides no locking to prevent the driver it returns |
210 | * from being unregistered or unloaded while the caller is using it. | |
211 | * The caller is responsible for preventing this. | |
1da177e4 LT |
212 | */ |
213 | struct device_driver *driver_find(const char *name, struct bus_type *bus) | |
214 | { | |
c6f7e72a | 215 | struct kobject *k = kset_find_obj(bus->p->drivers_kset, name); |
e5dd1278 GKH |
216 | struct driver_private *priv; |
217 | ||
218 | if (k) { | |
fde25a9b AS |
219 | /* Drop reference added by kset_find_obj() */ |
220 | kobject_put(k); | |
e5dd1278 GKH |
221 | priv = to_driver(k); |
222 | return priv->driver; | |
223 | } | |
1da177e4 LT |
224 | return NULL; |
225 | } | |
1da177e4 | 226 | EXPORT_SYMBOL_GPL(driver_find); |