/*
   * device.h - generic, centralized driver model
   *
   * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>

   * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
   * Copyright (c) 2008-2009 Novell Inc.

   *
   * This file is released under the GPLv2
   *
   * See Documentation/driver-model/ for more information.
   */
  
  #ifndef _DEVICE_H_
  #define _DEVICE_H_

  #include <linux/ioport.h>
  #include <linux/kobject.h>

  #include <linux/klist.h>

  #include <linux/list.h>

  #include <linux/lockdep.h>

  #include <linux/compiler.h>

  #include <linux/types.h>

  #include <linux/mutex.h>

  #include <linux/pm.h>

  #include <linux/atomic.h>

  #include <asm/device.h>

  struct device;

  struct device_private;

  struct device_driver;

  struct driver_private;

  struct module;

  struct class;

  struct subsys_private;

  struct bus_type;

  struct device_node;

  struct iommu_ops;

  
  struct bus_attribute {
  	struct attribute	attr;

  	ssize_t (*show)(struct bus_type *bus, char *buf);
  	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);

  };

  #define BUS_ATTR(_name, _mode, _show, _store)	\
  struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)

  
  extern int __must_check bus_create_file(struct bus_type *,
  					struct bus_attribute *);
  extern void bus_remove_file(struct bus_type *, struct bus_attribute *);

  /**
   * struct bus_type - The bus type of the device
   *
   * @name:	The name of the bus.
   * @bus_attrs:	Default attributes of the bus.
   * @dev_attrs:	Default attributes of the devices on the bus.
   * @drv_attrs:	Default attributes of the device drivers on the bus.
   * @match:	Called, perhaps multiple times, whenever a new device or driver
   *		is added for this bus. It should return a nonzero value if the
   *		given device can be handled by the given driver.
   * @uevent:	Called when a device is added, removed, or a few other things
   *		that generate uevents to add the environment variables.
   * @probe:	Called when a new device or driver add to this bus, and callback
   *		the specific driver's probe to initial the matched device.
   * @remove:	Called when a device removed from this bus.
   * @shutdown:	Called at shut-down time to quiesce the device.
   * @suspend:	Called when a device on this bus wants to go to sleep mode.
   * @resume:	Called to bring a device on this bus out of sleep mode.
   * @pm:		Power management operations of this bus, callback the specific
   *		device driver's pm-ops.

   * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU

   *              driver implementations to a bus and allow the driver to do
   *              bus-specific setup

   * @p:		The private data of the driver core, only the driver core can
   *		touch this.
   *
   * A bus is a channel between the processor and one or more devices. For the
   * purposes of the device model, all devices are connected via a bus, even if
   * it is an internal, virtual, "platform" bus. Buses can plug into each other.
   * A USB controller is usually a PCI device, for example. The device model
   * represents the actual connections between buses and the devices they control.
   * A bus is represented by the bus_type structure. It contains the name, the
   * default attributes, the bus' methods, PM operations, and the driver core's
   * private data.
   */

  struct bus_type {

  	const char		*name;
  	struct bus_attribute	*bus_attrs;
  	struct device_attribute	*dev_attrs;
  	struct driver_attribute	*drv_attrs;
  
  	int (*match)(struct device *dev, struct device_driver *drv);
  	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
  	int (*probe)(struct device *dev);
  	int (*remove)(struct device *dev);
  	void (*shutdown)(struct device *dev);
  
  	int (*suspend)(struct device *dev, pm_message_t state);

  	int (*resume)(struct device *dev);

  	const struct dev_pm_ops *pm;

  	struct iommu_ops *iommu_ops;

  	struct subsys_private *p;

  };

  extern int __must_check bus_register(struct bus_type *bus);
  extern void bus_unregister(struct bus_type *bus);

  extern int __must_check bus_rescan_devices(struct bus_type *bus);

  /* iterator helpers for buses */

  int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
  		     int (*fn)(struct device *dev, void *data));
  struct device *bus_find_device(struct bus_type *bus, struct device *start,
  			       void *data,
  			       int (*match)(struct device *dev, void *data));

  struct device *bus_find_device_by_name(struct bus_type *bus,
  				       struct device *start,
  				       const char *name);

  int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
  		     void *data, int (*fn)(struct device_driver *, void *));

  void bus_sort_breadthfirst(struct bus_type *bus,
  			   int (*compare)(const struct device *a,
  					  const struct device *b));

  /*
   * Bus notifiers: Get notified of addition/removal of devices
   * and binding/unbinding of drivers to devices.
   * In the long run, it should be a replacement for the platform
   * notify hooks.
   */
  struct notifier_block;
  
  extern int bus_register_notifier(struct bus_type *bus,
  				 struct notifier_block *nb);
  extern int bus_unregister_notifier(struct bus_type *bus,
  				   struct notifier_block *nb);
  
  /* All 4 notifers below get called with the target struct device *
   * as an argument. Note that those functions are likely to be called

   * with the device lock held in the core, so be careful.

   */
  #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
  #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device removed */

  #define BUS_NOTIFY_BIND_DRIVER		0x00000003 /* driver about to be
  						      bound */
  #define BUS_NOTIFY_BOUND_DRIVER		0x00000004 /* driver bound to device */
  #define BUS_NOTIFY_UNBIND_DRIVER	0x00000005 /* driver about to be

  						      unbound */

  #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000006 /* driver is unbound

  						      from the device */

  extern struct kset *bus_get_kset(struct bus_type *bus);

  extern struct klist *bus_get_device_klist(struct bus_type *bus);

  /**
   * struct device_driver - The basic device driver structure
   * @name:	Name of the device driver.
   * @bus:	The bus which the device of this driver belongs to.
   * @owner:	The module owner.
   * @mod_name:	Used for built-in modules.
   * @suppress_bind_attrs: Disables bind/unbind via sysfs.
   * @of_match_table: The open firmware table.
   * @probe:	Called to query the existence of a specific device,
   *		whether this driver can work with it, and bind the driver
   *		to a specific device.
   * @remove:	Called when the device is removed from the system to
   *		unbind a device from this driver.
   * @shutdown:	Called at shut-down time to quiesce the device.
   * @suspend:	Called to put the device to sleep mode. Usually to a
   *		low power state.
   * @resume:	Called to bring a device from sleep mode.
   * @groups:	Default attributes that get created by the driver core
   *		automatically.
   * @pm:		Power management operations of the device which matched
   *		this driver.
   * @p:		Driver core's private data, no one other than the driver
   *		core can touch this.
   *
   * The device driver-model tracks all of the drivers known to the system.
   * The main reason for this tracking is to enable the driver core to match
   * up drivers with new devices. Once drivers are known objects within the
   * system, however, a number of other things become possible. Device drivers
   * can export information and configuration variables that are independent
   * of any specific device.
   */

  struct device_driver {

  	const char		*name;
  	struct bus_type		*bus;

  	struct module		*owner;

  	const char		*mod_name;	/* used for built-in modules */
  
  	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */

  	const struct of_device_id	*of_match_table;

  	int (*probe) (struct device *dev);
  	int (*remove) (struct device *dev);
  	void (*shutdown) (struct device *dev);
  	int (*suspend) (struct device *dev, pm_message_t state);
  	int (*resume) (struct device *dev);

  	const struct attribute_group **groups;

  	const struct dev_pm_ops *pm;

  	struct driver_private *p;

  };

  extern int __must_check driver_register(struct device_driver *drv);
  extern void driver_unregister(struct device_driver *drv);

  extern struct device_driver *get_driver(struct device_driver *drv);
  extern void put_driver(struct device_driver *drv);
  extern struct device_driver *driver_find(const char *name,
  					 struct bus_type *bus);

  extern int driver_probe_done(void);

  extern void wait_for_device_probe(void);

  /* sysfs interface for exporting driver attributes */

  
  struct driver_attribute {

  	struct attribute attr;
  	ssize_t (*show)(struct device_driver *driver, char *buf);
  	ssize_t (*store)(struct device_driver *driver, const char *buf,
  			 size_t count);

  };

  #define DRIVER_ATTR(_name, _mode, _show, _store)	\
  struct driver_attribute driver_attr_##_name =		\
  	__ATTR(_name, _mode, _show, _store)

  extern int __must_check driver_create_file(struct device_driver *driver,

  					const struct driver_attribute *attr);

  extern void driver_remove_file(struct device_driver *driver,

  			       const struct driver_attribute *attr);

  extern int __must_check driver_add_kobj(struct device_driver *drv,
  					struct kobject *kobj,
  					const char *fmt, ...);

  extern int __must_check driver_for_each_device(struct device_driver *drv,
  					       struct device *start,
  					       void *data,
  					       int (*fn)(struct device *dev,
  							 void *));
  struct device *driver_find_device(struct device_driver *drv,
  				  struct device *start, void *data,
  				  int (*match)(struct device *dev, void *data));

  /**
   * struct class - device classes
   * @name:	Name of the class.
   * @owner:	The module owner.
   * @class_attrs: Default attributes of this class.
   * @dev_attrs:	Default attributes of the devices belong to the class.
   * @dev_bin_attrs: Default binary attributes of the devices belong to the class.
   * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
   * @dev_uevent:	Called when a device is added, removed from this class, or a
   *		few other things that generate uevents to add the environment
   *		variables.
   * @devnode:	Callback to provide the devtmpfs.
   * @class_release: Called to release this class.
   * @dev_release: Called to release the device.
   * @suspend:	Used to put the device to sleep mode, usually to a low power
   *		state.
   * @resume:	Used to bring the device from the sleep mode.
   * @ns_type:	Callbacks so sysfs can detemine namespaces.
   * @namespace:	Namespace of the device belongs to this class.
   * @pm:		The default device power management operations of this class.
   * @p:		The private data of the driver core, no one other than the
   *		driver core can touch this.
   *
   * A class is a higher-level view of a device that abstracts out low-level
   * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
   * at the class level, they are all simply disks. Classes allow user space
   * to work with devices based on what they do, rather than how they are
   * connected or how they work.

   */
  struct class {

  	const char		*name;
  	struct module		*owner;

  	struct class_attribute		*class_attrs;

  	struct device_attribute		*dev_attrs;

  	struct bin_attribute		*dev_bin_attrs;

  	struct kobject			*dev_kobj;

  	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);

  	char *(*devnode)(struct device *dev, mode_t *mode);

  	void (*class_release)(struct class *class);
  	void (*dev_release)(struct device *dev);

  	int (*suspend)(struct device *dev, pm_message_t state);
  	int (*resume)(struct device *dev);

  	const struct kobj_ns_type_operations *ns_type;
  	const void *(*namespace)(struct device *dev);

  	const struct dev_pm_ops *pm;

  	struct subsys_private *p;

  };

  struct class_dev_iter {
  	struct klist_iter		ki;
  	const struct device_type	*type;
  };

  extern struct kobject *sysfs_dev_block_kobj;
  extern struct kobject *sysfs_dev_char_kobj;

  extern int __must_check __class_register(struct class *class,
  					 struct lock_class_key *key);

  extern void class_unregister(struct class *class);

  
  /* This is a #define to keep the compiler from merging different
   * instances of the __key variable */
  #define class_register(class)			\
  ({						\
  	static struct lock_class_key __key;	\
  	__class_register(class, &__key);	\
  })

  struct class_compat;
  struct class_compat *class_compat_register(const char *name);
  void class_compat_unregister(struct class_compat *cls);
  int class_compat_create_link(struct class_compat *cls, struct device *dev,
  			     struct device *device_link);
  void class_compat_remove_link(struct class_compat *cls, struct device *dev,
  			      struct device *device_link);

  extern void class_dev_iter_init(struct class_dev_iter *iter,
  				struct class *class,
  				struct device *start,
  				const struct device_type *type);
  extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
  extern void class_dev_iter_exit(struct class_dev_iter *iter);

  extern int class_for_each_device(struct class *class, struct device *start,
  				 void *data,

  				 int (*fn)(struct device *dev, void *data));

  extern struct device *class_find_device(struct class *class,
  					struct device *start, void *data,

  					int (*match)(struct device *, void *));

  
  struct class_attribute {

  	struct attribute attr;

  	ssize_t (*show)(struct class *class, struct class_attribute *attr,
  			char *buf);
  	ssize_t (*store)(struct class *class, struct class_attribute *attr,
  			const char *buf, size_t count);

  	const void *(*namespace)(struct class *class,
  				 const struct class_attribute *attr);

  };

  #define CLASS_ATTR(_name, _mode, _show, _store)			\
  struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)

  extern int __must_check class_create_file(struct class *class,
  					  const struct class_attribute *attr);
  extern void class_remove_file(struct class *class,
  			      const struct class_attribute *attr);

  /* Simple class attribute that is just a static string */
  
  struct class_attribute_string {
  	struct class_attribute attr;
  	char *str;
  };
  
  /* Currently read-only only */
  #define _CLASS_ATTR_STRING(_name, _mode, _str) \
  	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
  #define CLASS_ATTR_STRING(_name, _mode, _str) \
  	struct class_attribute_string class_attr_##_name = \
  		_CLASS_ATTR_STRING(_name, _mode, _str)
  
  extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
                          char *buf);

  struct class_interface {
  	struct list_head	node;
  	struct class		*class;

  	int (*add_dev)		(struct device *, struct class_interface *);
  	void (*remove_dev)	(struct device *, struct class_interface *);

  };

  extern int __must_check class_interface_register(struct class_interface *);

  extern void class_interface_unregister(struct class_interface *);

  extern struct class * __must_check __class_create(struct module *owner,
  						  const char *name,
  						  struct lock_class_key *key);

  extern void class_destroy(struct class *cls);

  /* This is a #define to keep the compiler from merging different
   * instances of the __key variable */
  #define class_create(owner, name)		\
  ({						\
  	static struct lock_class_key __key;	\
  	__class_create(owner, name, &__key);	\
  })

  /*
   * The type of device, "struct device" is embedded in. A class
   * or bus can contain devices of different types
   * like "partitions" and "disks", "mouse" and "event".
   * This identifies the device type and carries type-specific
   * information, equivalent to the kobj_type of a kobject.
   * If "name" is specified, the uevent will contain it in
   * the DEVTYPE variable.
   */

  struct device_type {

  	const char *name;

  	const struct attribute_group **groups;

  	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);

  	char *(*devnode)(struct device *dev, mode_t *mode);

  	void (*release)(struct device *dev);

  	const struct dev_pm_ops *pm;

  };

  /* interface for exporting device attributes */
  struct device_attribute {
  	struct attribute	attr;
  	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
  			char *buf);
  	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
  			 const char *buf, size_t count);
  };

  #define DEVICE_ATTR(_name, _mode, _show, _store) \
  struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)

  extern int __must_check device_create_file(struct device *device,

  					const struct device_attribute *entry);

  extern void device_remove_file(struct device *dev,

  			       const struct device_attribute *attr);

  extern int __must_check device_create_bin_file(struct device *dev,

  					const struct bin_attribute *attr);

  extern void device_remove_bin_file(struct device *dev,

  				   const struct bin_attribute *attr);

  extern int device_schedule_callback_owner(struct device *dev,

  		void (*func)(struct device *dev), struct module *owner);

  
  /* This is a macro to avoid include problems with THIS_MODULE */
  #define device_schedule_callback(dev, func)			\
  	device_schedule_callback_owner(dev, func, THIS_MODULE)

  
  /* device resource management */
  typedef void (*dr_release_t)(struct device *dev, void *res);
  typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
  
  #ifdef CONFIG_DEBUG_DEVRES

  extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,

  			     const char *name);
  #define devres_alloc(release, size, gfp) \
  	__devres_alloc(release, size, gfp, #release)
  #else

  extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);

  #endif
  extern void devres_free(void *res);
  extern void devres_add(struct device *dev, void *res);

  extern void *devres_find(struct device *dev, dr_release_t release,

  			 dr_match_t match, void *match_data);

  extern void *devres_get(struct device *dev, void *new_res,
  			dr_match_t match, void *match_data);
  extern void *devres_remove(struct device *dev, dr_release_t release,
  			   dr_match_t match, void *match_data);

  extern int devres_destroy(struct device *dev, dr_release_t release,
  			  dr_match_t match, void *match_data);
  
  /* devres group */
  extern void * __must_check devres_open_group(struct device *dev, void *id,
  					     gfp_t gfp);
  extern void devres_close_group(struct device *dev, void *id);
  extern void devres_remove_group(struct device *dev, void *id);
  extern int devres_release_group(struct device *dev, void *id);
  
  /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
  extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
  extern void devm_kfree(struct device *dev, void *p);

  struct device_dma_parameters {
  	/*
  	 * a low level driver may set these to teach IOMMU code about
  	 * sg limitations.
  	 */
  	unsigned int max_segment_size;
  	unsigned long segment_boundary_mask;
  };

  /**
   * struct device - The basic device structure
   * @parent:	The device's "parent" device, the device to which it is attached.
   * 		In most cases, a parent device is some sort of bus or host
   * 		controller. If parent is NULL, the device, is a top-level device,
   * 		which is not usually what you want.
   * @p:		Holds the private data of the driver core portions of the device.
   * 		See the comment of the struct device_private for detail.
   * @kobj:	A top-level, abstract class from which other classes are derived.
   * @init_name:	Initial name of the device.
   * @type:	The type of device.
   * 		This identifies the device type and carries type-specific
   * 		information.
   * @mutex:	Mutex to synchronize calls to its driver.
   * @bus:	Type of bus device is on.
   * @driver:	Which driver has allocated this
   * @platform_data: Platform data specific to the device.
   * 		Example: For devices on custom boards, as typical of embedded
   * 		and SOC based hardware, Linux often uses platform_data to point
   * 		to board-specific structures describing devices and how they
   * 		are wired.  That can include what ports are available, chip
   * 		variants, which GPIO pins act in what additional roles, and so
   * 		on.  This shrinks the "Board Support Packages" (BSPs) and
   * 		minimizes board-specific #ifdefs in drivers.
   * @power:	For device power management.
   * 		See Documentation/power/devices.txt for details.

   * @pm_domain:	Provide callbacks that are executed during system suspend,

   * 		hibernation, system resume and during runtime PM transitions
   * 		along with subsystem-level and driver-level callbacks.
   * @numa_node:	NUMA node this device is close to.
   * @dma_mask:	Dma mask (if dma'ble device).
   * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
   * 		hardware supports 64-bit addresses for consistent allocations
   * 		such descriptors.
   * @dma_parms:	A low level driver may set these to teach IOMMU code about
   * 		segment limitations.
   * @dma_pools:	Dma pools (if dma'ble device).
   * @dma_mem:	Internal for coherent mem override.
   * @archdata:	For arch-specific additions.
   * @of_node:	Associated device tree node.

   * @devt:	For creating the sysfs "dev".
   * @devres_lock: Spinlock to protect the resource of the device.
   * @devres_head: The resources list of the device.
   * @knode_class: The node used to add the device to the class list.
   * @class:	The class of the device.
   * @groups:	Optional attribute groups.
   * @release:	Callback to free the device after all references have
   * 		gone away. This should be set by the allocator of the
   * 		device (i.e. the bus driver that discovered the device).
   *
   * At the lowest level, every device in a Linux system is represented by an
   * instance of struct device. The device structure contains the information
   * that the device model core needs to model the system. Most subsystems,
   * however, track additional information about the devices they host. As a
   * result, it is rare for devices to be represented by bare device structures;
   * instead, that structure, like kobject structures, is usually embedded within
   * a higher-level representation of the device.
   */

  struct device {

  	struct device		*parent;

  	struct device_private	*p;

  	struct kobject kobj;

  	const char		*init_name; /* initial name of the device */

  	const struct device_type *type;

  	struct mutex		mutex;	/* mutex to synchronize calls to

  					 * its driver.
  					 */

  	struct bus_type	*bus;		/* type of bus device is on */

  	struct device_driver *driver;	/* which driver has allocated this
  					   device */

  	void		*platform_data;	/* Platform specific data, device
  					   core doesn't touch it */

  	struct dev_pm_info	power;

  	struct dev_pm_domain	*pm_domain;

  #ifdef CONFIG_NUMA
  	int		numa_node;	/* NUMA node this device is close to */
  #endif

  	u64		*dma_mask;	/* dma mask (if dma'able device) */
  	u64		coherent_dma_mask;/* Like dma_mask, but for
  					     alloc_coherent mappings as
  					     not all hardware supports
  					     64 bit addresses for consistent
  					     allocations such descriptors. */

  	struct device_dma_parameters *dma_parms;

  	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
  
  	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
  					     override */

  	/* arch specific additions */
  	struct dev_archdata	archdata;

  
  	struct device_node	*of_node; /* associated device tree node */

  	dev_t			devt;	/* dev_t, creates the sysfs "dev" */

  	spinlock_t		devres_lock;
  	struct list_head	devres_head;

  	struct klist_node	knode_class;

  	struct class		*class;

  	const struct attribute_group **groups;	/* optional groups */

  	void	(*release)(struct device *dev);

  };

  /* Get the wakeup routines, which depend on struct device */
  #include <linux/pm_wakeup.h>

  static inline const char *dev_name(const struct device *dev)

  {

  	/* Use the init name until the kobject becomes available */
  	if (dev->init_name)
  		return dev->init_name;

  	return kobject_name(&dev->kobj);

  }

  extern __printf(2, 3)
  int dev_set_name(struct device *dev, const char *name, ...);

  #ifdef CONFIG_NUMA
  static inline int dev_to_node(struct device *dev)
  {
  	return dev->numa_node;
  }
  static inline void set_dev_node(struct device *dev, int node)
  {
  	dev->numa_node = node;
  }
  #else
  static inline int dev_to_node(struct device *dev)
  {
  	return -1;
  }
  static inline void set_dev_node(struct device *dev, int node)
  {
  }
  #endif

  static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
  {
  	return dev ? dev->power.subsys_data : NULL;
  }

  static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
  {
  	return dev->kobj.uevent_suppress;
  }
  
  static inline void dev_set_uevent_suppress(struct device *dev, int val)
  {
  	dev->kobj.uevent_suppress = val;
  }

  static inline int device_is_registered(struct device *dev)
  {

  	return dev->kobj.state_in_sysfs;

  }

  static inline void device_enable_async_suspend(struct device *dev)
  {

  	if (!dev->power.is_prepared)

  		dev->power.async_suspend = true;
  }

  static inline void device_disable_async_suspend(struct device *dev)
  {

  	if (!dev->power.is_prepared)

  		dev->power.async_suspend = false;
  }
  
  static inline bool device_async_suspend_enabled(struct device *dev)
  {
  	return !!dev->power.async_suspend;
  }

  static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
  {
  	dev->power.ignore_children = enable;
  }

  static inline void device_lock(struct device *dev)
  {

  	mutex_lock(&dev->mutex);

  }
  
  static inline int device_trylock(struct device *dev)
  {

  	return mutex_trylock(&dev->mutex);

  }
  
  static inline void device_unlock(struct device *dev)
  {

  	mutex_unlock(&dev->mutex);

  }

  void driver_init(void);

  /*
   * High level routines for use by the bus drivers
   */

  extern int __must_check device_register(struct device *dev);
  extern void device_unregister(struct device *dev);
  extern void device_initialize(struct device *dev);
  extern int __must_check device_add(struct device *dev);
  extern void device_del(struct device *dev);
  extern int device_for_each_child(struct device *dev, void *data,
  		     int (*fn)(struct device *dev, void *data));
  extern struct device *device_find_child(struct device *dev, void *data,
  				int (*match)(struct device *dev, void *data));

  extern int device_rename(struct device *dev, const char *new_name);

  extern int device_move(struct device *dev, struct device *new_parent,
  		       enum dpm_order dpm_order);

  extern const char *device_get_devnode(struct device *dev,
  				      mode_t *mode, const char **tmp);

  extern void *dev_get_drvdata(const struct device *dev);

  extern int dev_set_drvdata(struct device *dev, void *data);

  
  /*

   * Root device objects for grouping under /sys/devices
   */
  extern struct device *__root_device_register(const char *name,
  					     struct module *owner);

  
  /*
   * This is a macro to avoid include problems with THIS_MODULE,
   * just as per what is done for device_schedule_callback() above.
   */
  #define root_device_register(name) \
  	__root_device_register(name, THIS_MODULE)

  extern void root_device_unregister(struct device *root);

  static inline void *dev_get_platdata(const struct device *dev)
  {
  	return dev->platform_data;
  }

  /*

   * Manual binding of a device to driver. See drivers/base/bus.c
   * for information on use.
   */

  extern int __must_check device_bind_driver(struct device *dev);

  extern void device_release_driver(struct device *dev);
  extern int  __must_check device_attach(struct device *dev);

  extern int __must_check driver_attach(struct device_driver *drv);
  extern int __must_check device_reprobe(struct device *dev);

  /*
   * Easy functions for dynamically creating devices on the fly
   */

  extern struct device *device_create_vargs(struct class *cls,
  					  struct device *parent,
  					  dev_t devt,
  					  void *drvdata,
  					  const char *fmt,
  					  va_list vargs);

  extern __printf(5, 6)
  struct device *device_create(struct class *cls, struct device *parent,
  			     dev_t devt, void *drvdata,
  			     const char *fmt, ...);

  extern void device_destroy(struct class *cls, dev_t devt);

  /*
   * Platform "fixup" functions - allow the platform to have their say
   * about devices and actions that the general device layer doesn't
   * know about.
   */
  /* Notify platform of device discovery */

  extern int (*platform_notify)(struct device *dev);

  extern int (*platform_notify_remove)(struct device *dev);

  /*

   * get_device - atomically increment the reference count for the device.
   *
   */

  extern struct device *get_device(struct device *dev);
  extern void put_device(struct device *dev);

  extern void wait_for_device_probe(void);

  #ifdef CONFIG_DEVTMPFS
  extern int devtmpfs_create_node(struct device *dev);
  extern int devtmpfs_delete_node(struct device *dev);

  extern int devtmpfs_mount(const char *mntdir);

  #else
  static inline int devtmpfs_create_node(struct device *dev) { return 0; }
  static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
  static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
  #endif

  /* drivers/base/power/shutdown.c */

  extern void device_shutdown(void);

  /* debugging and troubleshooting/diagnostic helpers. */

  extern const char *dev_driver_string(const struct device *dev);

  
  
  #ifdef CONFIG_PRINTK

  extern int __dev_printk(const char *level, const struct device *dev,
  			struct va_format *vaf);

  extern __printf(3, 4)
  int dev_printk(const char *level, const struct device *dev,
  	       const char *fmt, ...)
  	;
  extern __printf(2, 3)
  int dev_emerg(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  int dev_alert(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  int dev_crit(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  int dev_err(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  int dev_warn(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  int dev_notice(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  int _dev_info(const struct device *dev, const char *fmt, ...);

  
  #else

  static inline int __dev_printk(const char *level, const struct device *dev,
  			       struct va_format *vaf)

  { return 0; }
  static inline __printf(3, 4)
  int dev_printk(const char *level, const struct device *dev,
  	       const char *fmt, ...)
  { return 0; }
  
  static inline __printf(2, 3)
  int dev_emerg(const struct device *dev, const char *fmt, ...)
  { return 0; }
  static inline __printf(2, 3)
  int dev_crit(const struct device *dev, const char *fmt, ...)
  { return 0; }
  static inline __printf(2, 3)
  int dev_alert(const struct device *dev, const char *fmt, ...)
  { return 0; }
  static inline __printf(2, 3)
  int dev_err(const struct device *dev, const char *fmt, ...)
  { return 0; }
  static inline __printf(2, 3)
  int dev_warn(const struct device *dev, const char *fmt, ...)
  { return 0; }
  static inline __printf(2, 3)
  int dev_notice(const struct device *dev, const char *fmt, ...)
  { return 0; }
  static inline __printf(2, 3)
  int _dev_info(const struct device *dev, const char *fmt, ...)
  { return 0; }

  
  #endif
  
  /*
   * Stupid hackaround for existing uses of non-printk uses dev_info
   *
   * Note that the definition of dev_info below is actually _dev_info
   * and a macro is used to avoid redefining dev_info
   */
  
  #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg)

  #if defined(DEBUG)
  #define dev_dbg(dev, format, arg...)		\

  	dev_printk(KERN_DEBUG, dev, format, ##arg)

  #elif defined(CONFIG_DYNAMIC_DEBUG)

  #define dev_dbg(dev, format, ...)		     \
  do {						     \

  	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \

  } while (0)

  #else

  #define dev_dbg(dev, format, arg...)				\
  ({								\
  	if (0)							\
  		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
  	0;							\
  })

  #endif

  #ifdef VERBOSE_DEBUG
  #define dev_vdbg	dev_dbg
  #else

  #define dev_vdbg(dev, format, arg...)				\
  ({								\
  	if (0)							\
  		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
  	0;							\
  })

  #endif

  /*

   * dev_WARN*() acts like dev_printk(), but with the key difference

   * of using a WARN/WARN_ON to get the message out, including the
   * file/line information and a backtrace.
   */
  #define dev_WARN(dev, format, arg...) \
  	WARN(1, "Device: %s
  " format, dev_driver_string(dev), ## arg);

  #define dev_WARN_ONCE(dev, condition, format, arg...) \
  	WARN_ONCE(condition, "Device %s
  " format, \
  			dev_driver_string(dev), ## arg)

  /* Create alias, so I can be autoloaded. */
  #define MODULE_ALIAS_CHARDEV(major,minor) \
  	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
  #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
  	MODULE_ALIAS("char-major-" __stringify(major) "-*")

  
  #ifdef CONFIG_SYSFS_DEPRECATED
  extern long sysfs_deprecated;
  #else
  #define sysfs_deprecated 0
  #endif

  #endif /* _DEVICE_H_ */