1 // SPDX-License-Identifier: GPL-2.0
3  * driver.c - centralized device driver management
5  * Copyright (c) 2002-3 Patrick Mochel
6  * Copyright (c) 2002-3 Open Source Development Labs
7  * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
28 		dev = dev_prv->device;  in next_device()
34  * driver_set_override() - Helper to set or clear driver override.
36  * @override: Address of string to change (e.g. &device->driver_override);
38  * @s: NUL-terminated string, new driver name to force a match, pass empty
46  * Returns: 0 on success or a negative error code on failure.
55 		return -EINVAL;  in driver_set_override()
63 	if (len >= (PAGE_SIZE - 1))  in driver_set_override()
64 		return -EINVAL;  in driver_set_override()
68 	 * bunch of \0 characters like python likes to do.  in driver_set_override()
73 		/* Empty string passed - clear override */  in driver_set_override()
80 		return 0;  in driver_set_override()
85 		len = cp - s;  in driver_set_override()
89 		return -ENOMEM;  in driver_set_override()
96 		/* "\n" passed - clear override */  in driver_set_override()
104 	return 0;  in driver_set_override()
109  * driver_for_each_device - Iterator for devices bound to a driver.
110  * @drv: Driver we're iterating.
115  * Iterate over the @drv's list of devices calling @fn for each one.
117 int driver_for_each_device(struct device_driver *drv, struct device *start,  in driver_for_each_device()  argument
122 	int error = 0;  in driver_for_each_device()
124 	if (!drv)  in driver_for_each_device()
125 		return -EINVAL;  in driver_for_each_device()
127 	klist_iter_init_node(&drv->p->klist_devices, &i,  in driver_for_each_device()
128 			     start ? &start->p->knode_driver : NULL);  in driver_for_each_device()
137  * driver_find_device - device iterator for locating a particular device.
138  * @drv: The device's driver
147  * The callback should return 0 if the device doesn't match and non-zero
148  * if it does.  If the callback returns non-zero, this function will
151 struct device *driver_find_device(struct device_driver *drv,  in driver_find_device()  argument
158 	if (!drv || !drv->p)  in driver_find_device()
161 	klist_iter_init_node(&drv->p->klist_devices, &i,  in driver_find_device()
162 			     (start ? &start->p->knode_driver : NULL));  in driver_find_device()
172  * driver_create_file - create sysfs file for driver.
173  * @drv: driver.
176 int driver_create_file(struct device_driver *drv,  in driver_create_file()  argument
181 	if (drv)  in driver_create_file()
182 		error = sysfs_create_file(&drv->p->kobj, &attr->attr);  in driver_create_file()
184 		error = -EINVAL;  in driver_create_file()
190  * driver_remove_file - remove sysfs file for driver.
191  * @drv: driver.
194 void driver_remove_file(struct device_driver *drv,  in driver_remove_file()  argument
197 	if (drv)  in driver_remove_file()
198 		sysfs_remove_file(&drv->p->kobj, &attr->attr);  in driver_remove_file()
202 int driver_add_groups(struct device_driver *drv,  in driver_add_groups()  argument
205 	return sysfs_create_groups(&drv->p->kobj, groups);  in driver_add_groups()
208 void driver_remove_groups(struct device_driver *drv,  in driver_remove_groups()  argument
211 	sysfs_remove_groups(&drv->p->kobj, groups);  in driver_remove_groups()
215  * driver_register - register driver with bus
216  * @drv: driver to register
222 int driver_register(struct device_driver *drv)  in driver_register()  argument
227 	if (!bus_is_registered(drv->bus)) {  in driver_register()
229 			   drv->name, drv->bus->name);  in driver_register()
230 		return -EINVAL;  in driver_register()
233 	if ((drv->bus->probe && drv->probe) ||  in driver_register()
234 	    (drv->bus->remove && drv->remove) ||  in driver_register()
235 	    (drv->bus->shutdown && drv->shutdown))  in driver_register()
236 		pr_warn("Driver '%s' needs updating - please use "  in driver_register()
237 			"bus_type methods\n", drv->name);  in driver_register()
239 	other = driver_find(drv->name, drv->bus);  in driver_register()
242 			"aborting...\n", drv->name);  in driver_register()
243 		return -EBUSY;  in driver_register()
246 	ret = bus_add_driver(drv);  in driver_register()
249 	ret = driver_add_groups(drv, drv->groups);  in driver_register()
251 		bus_remove_driver(drv);  in driver_register()
254 	kobject_uevent(&drv->p->kobj, KOBJ_ADD);  in driver_register()
262  * driver_unregister - remove driver from system.
263  * @drv: driver.
265  * Again, we pass off most of the work to the bus-level call.
267 void driver_unregister(struct device_driver *drv)  in driver_unregister()  argument
269 	if (!drv || !drv->p) {  in driver_unregister()
273 	driver_remove_groups(drv, drv->groups);  in driver_unregister()
274 	bus_remove_driver(drv);  in driver_unregister()