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 * driver_add_kobj - add a kobject below the specified driver
129 * You really don't want to do this, this is only here due to one looney
130 * iseries driver, go poke those developers if you are annoyed about
133 int driver_add_kobj(struct device_driver *drv, struct kobject *kobj,
134 const char *fmt, ...)
140 name = kvasprintf(GFP_KERNEL, fmt, args);
146 return kobject_add_ng(kobj, &drv->kobj, "%s", name);
148 EXPORT_SYMBOL_GPL(driver_add_kobj);
151 * get_driver - increment driver reference count.
154 struct device_driver * get_driver(struct device_driver * drv)
156 return drv ? to_drv(kobject_get(&drv->kobj)) : NULL;
161 * put_driver - decrement driver's refcount.
164 void put_driver(struct device_driver * drv)
166 kobject_put(&drv->kobj);
169 static int driver_add_groups(struct device_driver *drv,
170 struct attribute_group **groups)
176 for (i = 0; groups[i]; i++) {
177 error = sysfs_create_group(&drv->kobj, groups[i]);
180 sysfs_remove_group(&drv->kobj,
189 static void driver_remove_groups(struct device_driver *drv,
190 struct attribute_group **groups)
195 for (i = 0; groups[i]; i++)
196 sysfs_remove_group(&drv->kobj, groups[i]);
201 * driver_register - register driver with bus
202 * @drv: driver to register
204 * We pass off most of the work to the bus_add_driver() call,
205 * since most of the things we have to do deal with the bus
208 int driver_register(struct device_driver * drv)
212 if ((drv->bus->probe && drv->probe) ||
213 (drv->bus->remove && drv->remove) ||
214 (drv->bus->shutdown && drv->shutdown)) {
215 printk(KERN_WARNING "Driver '%s' needs updating - please use bus_type methods\n", drv->name);
217 klist_init(&drv->klist_devices, NULL, NULL);
218 ret = bus_add_driver(drv);
221 ret = driver_add_groups(drv, drv->groups);
223 bus_remove_driver(drv);
228 * driver_unregister - remove driver from system.
231 * Again, we pass off most of the work to the bus-level call.
234 void driver_unregister(struct device_driver * drv)
236 driver_remove_groups(drv, drv->groups);
237 bus_remove_driver(drv);
241 * driver_find - locate driver on a bus by its name.
242 * @name: name of the driver.
243 * @bus: bus to scan for the driver.
245 * Call kset_find_obj() to iterate over list of drivers on
246 * a bus to find driver by name. Return driver if found.
248 * Note that kset_find_obj increments driver's reference count.
250 struct device_driver *driver_find(const char *name, struct bus_type *bus)
252 struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
258 EXPORT_SYMBOL_GPL(driver_register);
259 EXPORT_SYMBOL_GPL(driver_unregister);
260 EXPORT_SYMBOL_GPL(get_driver);
261 EXPORT_SYMBOL_GPL(put_driver);
262 EXPORT_SYMBOL_GPL(driver_find);
264 EXPORT_SYMBOL_GPL(driver_create_file);
265 EXPORT_SYMBOL_GPL(driver_remove_file);