/* * 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/slab.h>#include <linux/string.h>#include "base.h" static struct device *next_device(struct klist_iter *i){	struct klist_node *n = klist_next(i);	struct device *dev = NULL;	struct device_private *dev_prv; 	if (n) {		dev_prv = to_device_private_driver(n);		dev = dev_prv->device;	}	return dev;} /** * 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->p->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 || !drv->p)		return NULL; 	klist_iter_init_node(&drv->p->klist_devices, &i,			     (start ? &start->p->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,		       const 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,			const struct driver_attribute *attr){	if (drv)		sysfs_remove_file(&drv->p->kobj, &attr->attr);}EXPORT_SYMBOL_GPL(driver_remove_file); static int driver_add_groups(struct device_driver *drv,			     const 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,				 const 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) {		printk(KERN_ERR "Error: Driver '%s' is already registered, "			"aborting...\n", drv->name);		return -EBUSY;	} 	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){	if (!drv || !drv->p) {		WARN(1, "Unexpected driver unregister!\n");		return;	}	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. * * This routine provides no locking to prevent the driver it returns * from being unregistered or unloaded while the caller is using it. * The caller is responsible for preventing this. */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) {		/* Drop reference added by kset_find_obj() */		kobject_put(k);		priv = to_driver(k);		return priv->driver;	}	return NULL;}EXPORT_SYMBOL_GPL(driver_find);