1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
/*
* driver.c - centralized device driver management
*
* Copyright (c) 2002-3 Patrick Mochel
* Copyright (c) 2002-3 Open Source Development Labs
*
* This file is released under the GPLv2
*
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/string.h>
#include "base.h"
#define to_dev(node) container_of(node, struct device, driver_list)
#define to_drv(obj) container_of(obj, struct device_driver, kobj)
static struct device * next_device(struct klist_iter * i)
{
struct klist_node * n = klist_next(i);
return n ? container_of(n, struct device, knode_driver) : NULL;
}
/**
* driver_for_each_device - Iterator for devices bound to a driver.
* @drv: Driver we're iterating.
* @start: Device to begin with
* @data: Data to pass to the callback.
* @fn: Function to call for each device.
*
* Iterate over the @drv's list of devices calling @fn for each one.
*/
int driver_for_each_device(struct device_driver * drv, struct device * start,
void * data, int (*fn)(struct device *, void *))
{
struct klist_iter i;
struct device * dev;
int error = 0;
if (!drv)
return -EINVAL;
klist_iter_init_node(&drv->klist_devices, &i,
start ? &start->knode_driver : NULL);
while ((dev = next_device(&i)) && !error)
error = fn(dev, data);
klist_iter_exit(&i);
return error;
}
EXPORT_SYMBOL_GPL(driver_for_each_device);
/**
* driver_find_device - device iterator for locating a particular device.
* @drv: The device's driver
* @start: Device to begin with
* @data: Data to pass to match function
* @match: Callback function to check device
*
* This is similar to the driver_for_each_device() function above, but
* it returns a reference to a device that is 'found' for later use, as
* determined by the @match callback.
*
* The callback should return 0 if the device doesn't match and non-zero
* if it does. If the callback returns non-zero, this function will
* return to the caller and not iterate over any more devices.
*/
struct device * driver_find_device(struct device_driver *drv,
struct device * start, void * data,
int (*match)(struct device *, void *))
{
struct klist_iter i;
struct device *dev;
if (!drv)
return NULL;
klist_iter_init_node(&drv->klist_devices, &i,
(start ? &start->knode_driver : NULL));
while ((dev = next_device(&i)))
if (match(dev, data) && get_device(dev))
break;
klist_iter_exit(&i);
return dev;
}
EXPORT_SYMBOL_GPL(driver_find_device);
/**
* driver_create_file - create sysfs file for driver.
* @drv: driver.
* @attr: driver attribute descriptor.
*/
int driver_create_file(struct device_driver * drv, struct driver_attribute * attr)
{
int error;
if (get_driver(drv)) {
error = sysfs_create_file(&drv->kobj, &attr->attr);
put_driver(drv);
} else
error = -EINVAL;
return error;
}
/**
* driver_remove_file - remove sysfs file for driver.
* @drv: driver.
* @attr: driver attribute descriptor.
*/
void driver_remove_file(struct device_driver * drv, struct driver_attribute * attr)
{
if (get_driver(drv)) {
sysfs_remove_file(&drv->kobj, &attr->attr);
put_driver(drv);
}
}
/**
* get_driver - increment driver reference count.
* @drv: driver.
*/
struct device_driver * get_driver(struct device_driver * drv)
{
return drv ? to_drv(kobject_get(&drv->kobj)) : NULL;
}
/**
* put_driver - decrement driver's refcount.
* @drv: driver.
*/
void put_driver(struct device_driver * drv)
{
kobject_put(&drv->kobj);
}
/**
* driver_register - register driver with bus
* @drv: driver to register
*
* We pass off most of the work to the bus_add_driver() call,
* since most of the things we have to do deal with the bus
* structures.
*/
int driver_register(struct device_driver * drv)
{
if ((drv->bus->probe && drv->probe) ||
(drv->bus->remove && drv->remove) ||
(drv->bus->shutdown && drv->shutdown)) {
printk(KERN_WARNING "Driver '%s' needs updating - please use bus_type methods\n", drv->name);
}
klist_init(&drv->klist_devices, NULL, NULL);
return bus_add_driver(drv);
}
/**
* driver_unregister - remove driver from system.
* @drv: driver.
*
* Again, we pass off most of the work to the bus-level call.
*/
void driver_unregister(struct device_driver * drv)
{
bus_remove_driver(drv);
}
/**
* driver_find - locate driver on a bus by its name.
* @name: name of the driver.
* @bus: bus to scan for the driver.
*
* Call kset_find_obj() to iterate over list of drivers on
* a bus to find driver by name. Return driver if found.
*
* Note that kset_find_obj increments driver's reference count.
*/
struct device_driver *driver_find(const char *name, struct bus_type *bus)
{
struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
if (k)
return to_drv(k);
return NULL;
}
EXPORT_SYMBOL_GPL(driver_register);
EXPORT_SYMBOL_GPL(driver_unregister);
EXPORT_SYMBOL_GPL(get_driver);
EXPORT_SYMBOL_GPL(put_driver);
EXPORT_SYMBOL_GPL(driver_find);
EXPORT_SYMBOL_GPL(driver_create_file);
EXPORT_SYMBOL_GPL(driver_remove_file);
|
