]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - drivers/base/driver.c
2 * driver.c - centralized device driver management
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
7 * This file is released under the GPLv2
11 #include <linux/device.h>
12 #include <linux/module.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
17 #define to_dev(node) container_of(node, struct device, driver_list)
18 #define to_drv(obj) container_of(obj, struct device_driver, kobj)
21 static struct device
* next_device(struct klist_iter
* i
)
23 struct klist_node
* n
= klist_next(i
);
24 return n
? container_of(n
, struct device
, knode_driver
) : NULL
;
28 * driver_for_each_device - Iterator for devices bound to a driver.
29 * @drv: Driver we're iterating.
30 * @start: Device to begin with
31 * @data: Data to pass to the callback.
32 * @fn: Function to call for each device.
34 * Iterate over the @drv's list of devices calling @fn for each one.
37 int driver_for_each_device(struct device_driver
* drv
, struct device
* start
,
38 void * data
, int (*fn
)(struct device
*, void *))
47 klist_iter_init_node(&drv
->klist_devices
, &i
,
48 start
? &start
->knode_driver
: NULL
);
49 while ((dev
= next_device(&i
)) && !error
)
50 error
= fn(dev
, data
);
55 EXPORT_SYMBOL_GPL(driver_for_each_device
);
59 * driver_find_device - device iterator for locating a particular device.
60 * @drv: The device's driver
61 * @start: Device to begin with
62 * @data: Data to pass to match function
63 * @match: Callback function to check device
65 * This is similar to the driver_for_each_device() function above, but
66 * it returns a reference to a device that is 'found' for later use, as
67 * determined by the @match callback.
69 * The callback should return 0 if the device doesn't match and non-zero
70 * if it does. If the callback returns non-zero, this function will
71 * return to the caller and not iterate over any more devices.
73 struct device
* driver_find_device(struct device_driver
*drv
,
74 struct device
* start
, void * data
,
75 int (*match
)(struct device
*, void *))
83 klist_iter_init_node(&drv
->klist_devices
, &i
,
84 (start
? &start
->knode_driver
: NULL
));
85 while ((dev
= next_device(&i
)))
86 if (match(dev
, data
) && get_device(dev
))
91 EXPORT_SYMBOL_GPL(driver_find_device
);
94 * driver_create_file - create sysfs file for driver.
96 * @attr: driver attribute descriptor.
99 int driver_create_file(struct device_driver
* drv
, struct driver_attribute
* attr
)
102 if (get_driver(drv
)) {
103 error
= sysfs_create_file(&drv
->kobj
, &attr
->attr
);
112 * driver_remove_file - remove sysfs file for driver.
114 * @attr: driver attribute descriptor.
117 void driver_remove_file(struct device_driver
* drv
, struct driver_attribute
* attr
)
119 if (get_driver(drv
)) {
120 sysfs_remove_file(&drv
->kobj
, &attr
->attr
);
127 * get_driver - increment driver reference count.
130 struct device_driver
* get_driver(struct device_driver
* drv
)
132 return drv
? to_drv(kobject_get(&drv
->kobj
)) : NULL
;
137 * put_driver - decrement driver's refcount.
140 void put_driver(struct device_driver
* drv
)
142 kobject_put(&drv
->kobj
);
146 * driver_register - register driver with bus
147 * @drv: driver to register
149 * We pass off most of the work to the bus_add_driver() call,
150 * since most of the things we have to do deal with the bus
153 * The one interesting aspect is that we setup @drv->unloaded
154 * as a completion that gets complete when the driver reference
157 int driver_register(struct device_driver
* drv
)
159 if ((drv
->bus
->probe
&& drv
->probe
) ||
160 (drv
->bus
->remove
&& drv
->remove
) ||
161 (drv
->bus
->shutdown
&& drv
->shutdown
)) {
162 printk(KERN_WARNING
"Driver '%s' needs updating - please use bus_type methods\n", drv
->name
);
164 klist_init(&drv
->klist_devices
, NULL
, NULL
);
165 init_completion(&drv
->unloaded
);
166 return bus_add_driver(drv
);
171 * driver_unregister - remove driver from system.
174 * Again, we pass off most of the work to the bus-level call.
176 * Though, once that is done, we wait until @drv->unloaded is completed.
177 * This will block until the driver refcount reaches 0, and it is
178 * released. Only modular drivers will call this function, and we
179 * have to guarantee that it won't complete, letting the driver
180 * unload until all references are gone.
183 void driver_unregister(struct device_driver
* drv
)
185 bus_remove_driver(drv
);
186 wait_for_completion(&drv
->unloaded
);
190 * driver_find - locate driver on a bus by its name.
191 * @name: name of the driver.
192 * @bus: bus to scan for the driver.
194 * Call kset_find_obj() to iterate over list of drivers on
195 * a bus to find driver by name. Return driver if found.
197 * Note that kset_find_obj increments driver's reference count.
199 struct device_driver
*driver_find(const char *name
, struct bus_type
*bus
)
201 struct kobject
*k
= kset_find_obj(&bus
->drivers
, name
);
207 EXPORT_SYMBOL_GPL(driver_register
);
208 EXPORT_SYMBOL_GPL(driver_unregister
);
209 EXPORT_SYMBOL_GPL(get_driver
);
210 EXPORT_SYMBOL_GPL(put_driver
);
211 EXPORT_SYMBOL_GPL(driver_find
);
213 EXPORT_SYMBOL_GPL(driver_create_file
);
214 EXPORT_SYMBOL_GPL(driver_remove_file
);