drivers/base/driver.c - kernel/msm - Gitiles

 /*
  * 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);
 	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)
 		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);

 /**
  * 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,
 			     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) {
 		put_driver(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.
  *
  * 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);
	/*
	* 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);
	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)
	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);

	/**
	* 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,
	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) {
	put_driver(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.
	*
	* 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);