| /* |
| * 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->p->drivers_kset, 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); |