2 * driver.c - centralized device driver management
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2007 Novell Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/module.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
20 static struct device *next_device(struct klist_iter *i)
22 struct klist_node *n = klist_next(i);
23 struct device *dev = NULL;
24 struct device_private *dev_prv;
27 dev_prv = to_device_private_driver(n);
28 dev = dev_prv->device;
34 * 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.
40 * Iterate over the @drv's list of devices calling @fn for each one.
42 int driver_for_each_device(struct device_driver *drv, struct device *start,
43 void *data, int (*fn)(struct device *, void *))
52 klist_iter_init_node(&drv->p->klist_devices, &i,
53 start ? &start->p->knode_driver : NULL);
54 while ((dev = next_device(&i)) && !error)
55 error = fn(dev, data);
59 EXPORT_SYMBOL_GPL(driver_for_each_device);
62 * driver_find_device - device iterator for locating a particular device.
63 * @drv: The device's driver
64 * @start: Device to begin with
65 * @data: Data to pass to match function
66 * @match: Callback function to check device
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.
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.
76 struct device *driver_find_device(struct device_driver *drv,
77 struct device *start, void *data,
78 int (*match)(struct device *dev, void *data))
86 klist_iter_init_node(&drv->p->klist_devices, &i,
87 (start ? &start->p->knode_driver : NULL));
88 while ((dev = next_device(&i)))
89 if (match(dev, data) && get_device(dev))
94 EXPORT_SYMBOL_GPL(driver_find_device);
97 * driver_create_file - create sysfs file for driver.
99 * @attr: driver attribute descriptor.
101 int driver_create_file(struct device_driver *drv,
102 const struct driver_attribute *attr)
106 error = sysfs_create_file(&drv->p->kobj, &attr->attr);
111 EXPORT_SYMBOL_GPL(driver_create_file);
114 * driver_remove_file - remove sysfs file for driver.
116 * @attr: driver attribute descriptor.
118 void driver_remove_file(struct device_driver *drv,
119 const struct driver_attribute *attr)
122 sysfs_remove_file(&drv->p->kobj, &attr->attr);
124 EXPORT_SYMBOL_GPL(driver_remove_file);
127 * driver_add_kobj - add a kobject below the specified driver
128 * @drv: requesting device driver
129 * @kobj: kobject to add below this driver
130 * @fmt: format string that names the kobject
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
136 int driver_add_kobj(struct device_driver *drv, struct kobject *kobj,
137 const char *fmt, ...)
144 name = kvasprintf(GFP_KERNEL, fmt, args);
150 ret = kobject_add(kobj, &drv->p->kobj, "%s", name);
154 EXPORT_SYMBOL_GPL(driver_add_kobj);
156 static int driver_add_groups(struct device_driver *drv,
157 const struct attribute_group **groups)
163 for (i = 0; groups[i]; i++) {
164 error = sysfs_create_group(&drv->p->kobj, groups[i]);
167 sysfs_remove_group(&drv->p->kobj,
176 static void driver_remove_groups(struct device_driver *drv,
177 const struct attribute_group **groups)
182 for (i = 0; groups[i]; i++)
183 sysfs_remove_group(&drv->p->kobj, groups[i]);
187 * driver_register - register driver with bus
188 * @drv: driver to register
190 * We pass off most of the work to the bus_add_driver() call,
191 * since most of the things we have to do deal with the bus
194 int driver_register(struct device_driver *drv)
197 struct device_driver *other;
199 BUG_ON(!drv->bus->p);
201 if ((drv->bus->probe && drv->probe) ||
202 (drv->bus->remove && drv->remove) ||
203 (drv->bus->shutdown && drv->shutdown))
204 printk(KERN_WARNING "Driver '%s' needs updating - please use "
205 "bus_type methods\n", drv->name);
207 other = driver_find(drv->name, drv->bus);
209 printk(KERN_ERR "Error: Driver '%s' is already registered, "
210 "aborting...\n", drv->name);
214 ret = bus_add_driver(drv);
217 ret = driver_add_groups(drv, drv->groups);
219 bus_remove_driver(drv);
222 EXPORT_SYMBOL_GPL(driver_register);
225 * driver_unregister - remove driver from system.
228 * Again, we pass off most of the work to the bus-level call.
230 void driver_unregister(struct device_driver *drv)
232 if (!drv || !drv->p) {
233 WARN(1, "Unexpected driver unregister!\n");
236 driver_remove_groups(drv, drv->groups);
237 bus_remove_driver(drv);
239 EXPORT_SYMBOL_GPL(driver_unregister);
242 * driver_find - locate driver on a bus by its name.
243 * @name: name of the driver.
244 * @bus: bus to scan for the driver.
246 * Call kset_find_obj() to iterate over list of drivers on
247 * a bus to find driver by name. Return driver if found.
249 * This routine provides no locking to prevent the driver it returns
250 * from being unregistered or unloaded while the caller is using it.
251 * The caller is responsible for preventing this.
253 struct device_driver *driver_find(const char *name, struct bus_type *bus)
255 struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
256 struct driver_private *priv;
259 /* Drop reference added by kset_find_obj() */
266 EXPORT_SYMBOL_GPL(driver_find);