/* * 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->drivers, 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);