1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
139 lines
3.2 KiB
C
139 lines
3.2 KiB
C
/*
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* driver.c - centralized device driver management
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*
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* Copyright (c) 2002-3 Patrick Mochel
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* Copyright (c) 2002-3 Open Source Development Labs
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*
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* This file is released under the GPLv2
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*
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*/
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#include <linux/config.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include "base.h"
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#define to_dev(node) container_of(node, struct device, driver_list)
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#define to_drv(obj) container_of(obj, struct device_driver, kobj)
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/**
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* driver_create_file - create sysfs file for driver.
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* @drv: driver.
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* @attr: driver attribute descriptor.
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*/
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int driver_create_file(struct device_driver * drv, struct driver_attribute * attr)
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{
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int error;
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if (get_driver(drv)) {
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error = sysfs_create_file(&drv->kobj, &attr->attr);
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put_driver(drv);
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} else
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error = -EINVAL;
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return error;
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}
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/**
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* driver_remove_file - remove sysfs file for driver.
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* @drv: driver.
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* @attr: driver attribute descriptor.
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*/
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void driver_remove_file(struct device_driver * drv, struct driver_attribute * attr)
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{
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if (get_driver(drv)) {
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sysfs_remove_file(&drv->kobj, &attr->attr);
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put_driver(drv);
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}
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}
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/**
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* get_driver - increment driver reference count.
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* @drv: driver.
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*/
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struct device_driver * get_driver(struct device_driver * drv)
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{
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return drv ? to_drv(kobject_get(&drv->kobj)) : NULL;
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}
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/**
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* put_driver - decrement driver's refcount.
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* @drv: driver.
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*/
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void put_driver(struct device_driver * drv)
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{
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kobject_put(&drv->kobj);
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}
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/**
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* driver_register - register driver with bus
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* @drv: driver to register
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*
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* We pass off most of the work to the bus_add_driver() call,
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* since most of the things we have to do deal with the bus
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* structures.
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*
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* The one interesting aspect is that we setup @drv->unloaded
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* as a completion that gets complete when the driver reference
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* count reaches 0.
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*/
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int driver_register(struct device_driver * drv)
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{
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INIT_LIST_HEAD(&drv->devices);
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init_completion(&drv->unloaded);
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return bus_add_driver(drv);
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}
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/**
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* driver_unregister - remove driver from system.
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* @drv: driver.
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*
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* Again, we pass off most of the work to the bus-level call.
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*
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* Though, once that is done, we wait until @drv->unloaded is completed.
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* This will block until the driver refcount reaches 0, and it is
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* released. Only modular drivers will call this function, and we
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* have to guarantee that it won't complete, letting the driver
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* unload until all references are gone.
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*/
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void driver_unregister(struct device_driver * drv)
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{
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bus_remove_driver(drv);
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wait_for_completion(&drv->unloaded);
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}
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/**
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* driver_find - locate driver on a bus by its name.
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* @name: name of the driver.
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* @bus: bus to scan for the driver.
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*
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* Call kset_find_obj() to iterate over list of drivers on
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* a bus to find driver by name. Return driver if found.
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*
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* Note that kset_find_obj increments driver's reference count.
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*/
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struct device_driver *driver_find(const char *name, struct bus_type *bus)
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{
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struct kobject *k = kset_find_obj(&bus->drivers, name);
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if (k)
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return to_drv(k);
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return NULL;
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}
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EXPORT_SYMBOL_GPL(driver_register);
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EXPORT_SYMBOL_GPL(driver_unregister);
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EXPORT_SYMBOL_GPL(get_driver);
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EXPORT_SYMBOL_GPL(put_driver);
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EXPORT_SYMBOL_GPL(driver_find);
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EXPORT_SYMBOL_GPL(driver_create_file);
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EXPORT_SYMBOL_GPL(driver_remove_file);
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