/*
* driver.c - centralized device driver management
*
* Copyright (c) 2002-3 Patrick Mochel
* Copyright (c) 2002-3 Open Source Development Labs
* Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
* Copyright (c) 2007 Novell Inc.
*
* 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"
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->p->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 *dev, void *data))
{
struct klist_iter i;
struct device *dev;
if (!drv)
return NULL;
klist_iter_init_node(&drv->p->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 (drv)
error = sysfs_create_file(&drv->p->kobj, &attr->attr);
else
error = -EINVAL;
return error;
}
EXPORT_SYMBOL_GPL(driver_create_file);
/**
* 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 (drv)
sysfs_remove_file(&drv->p->kobj, &attr->attr);
}
EXPORT_SYMBOL_GPL(driver_remove_file);
/**
* driver_add_kobj - add a kobject below the specified driver
* @drv: requesting device driver
* @kobj: kobject to add below this driver
* @fmt: format string that names the kobject
*
* You really don't want to do this, this is only here due to one looney
* iseries driver, go poke those developers if you are annoyed about
* this...
*/
int driver_add_kobj(struct device_driver *drv, struct kobject *kobj,
const char *fmt, ...)
{
va_list args;
char *name;
int ret;
va_start(args, fmt);
name = kvasprintf(GFP_KERNEL, fmt, args);
va_end(args);
if (!name)
return -ENOMEM;
ret = kobject_add(kobj, &drv->p->kobj, "%s", name);
kfree(name);
return ret;
}
EXPORT_SYMBOL_GPL(driver_add_kobj);
/**
* get_driver - increment driver reference count.
* @drv: driver.
*/
struct device_driver *get_driver(struct device_driver *drv)
{
if (drv) {
struct driver_private *priv;
struct kobject *kobj;
kobj = kobject_get(&drv->p->kobj);
priv = to_driver(kobj);
return priv->driver;
}
return NULL;
}
EXPORT_SYMBOL_GPL(get_driver);
/**
* put_driver - decrement driver's refcount.
* @drv: driver.
*/
void put_driver(struct device_driver *drv)
{
kobject_put(&drv->p->kobj);
}
EXPORT_SYMBOL_GPL(put_driver);
static int driver_add_groups(struct device_driver *drv,
struct attribute_group **groups)
{
int error = 0;
int i;
if (groups) {
for (i = 0; groups[i]; i++) {
error = sysfs_create_group(&drv->p->kobj, groups[i]);
if (error) {
while (--i >= 0)
sysfs_remove_group(&drv->p->kobj,
groups[i]);
break;
}
}
}
return error;
}
static void driver_remove_groups(struct device_driver *drv,
struct attribute_group **groups)
{
int i;
if (groups)
for (i = 0; groups[i]; i++)
sysfs_remove_group(&drv->p->kobj, groups[i]);
}
/**
* 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)
{
int ret;
struct device_driver *other;
BUG_ON(!drv->bus->p);
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);
other = driver_find(drv->name, drv->bus);
if (other) {
put_driver(other);
printk(KERN_ERR "Error: Driver '%s' is already registered, "
"aborting...\n", drv->name);
return -EEXIST;
}
ret = bus_add_driver(drv);
if (ret)
return ret;
ret = driver_add_groups(drv, drv->groups);
if (ret)
bus_remove_driver(drv);
return ret;
}
EXPORT_SYMBOL_GPL(driver_register);
/**
* 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)
{
driver_remove_groups(drv, drv->groups);
bus_remove_driver(drv);
}
EXPORT_SYMBOL_GPL(driver_unregister);
/**
* 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);
struct driver_private *priv;
if (k) {
priv = to_driver(k);
return priv->driver;
}
return NULL;
}
EXPORT_SYMBOL_GPL(driver_find);
