text: /*
   * 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/pinctrl/devinfo.h>
  #include <linux/pm.h>
  #include <linux/atomic.h>
  #include <linux/ratelimit.h>
  #include <linux/uidgid.h>
  #include <linux/gfp.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 fwnode_handle;
  struct iommu_ops;
  struct iommu_group;
  struct iommu_fwspec;
  
  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)
  #define BUS_ATTR_RW(_name) \
  	struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
  #define BUS_ATTR_RO(_name) \
  	struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
  
  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.
   * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
   * @dev_root:	Default device to use as the parent.
   * @bus_groups:	Default attributes of the bus.
   * @dev_groups:	Default attributes of the devices on the bus.
   * @drv_groups: 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 positive value if the
   *		given device can be handled by the given driver and zero
   *		otherwise. It may also return error code if determining that
   *		the driver supports the device is not possible. In case of
   *		-EPROBE_DEFER it will queue the device for deferred probing.
   * @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.
   *
   * @online:	Called to put the device back online (after offlining it).
   * @offline:	Called to put the device offline for hot-removal. May fail.
   *
   * @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.
   * @num_vf:	Called to find out how many virtual functions a device on this
   *		bus supports.
   * @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.
   * @lock_key:	Lock class key for use by the lock validator
   *
   * 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;
  	const char		*dev_name;
  	struct device		*dev_root;
  	const struct attribute_group **bus_groups;
  	const struct attribute_group **dev_groups;
  	const struct attribute_group **drv_groups;
  
  	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 (*online)(struct device *dev);
  	int (*offline)(struct device *dev);
  
  	int (*suspend)(struct device *dev, pm_message_t state);
  	int (*resume)(struct device *dev);
  
  	int (*num_vf)(struct device *dev);
  
  	const struct dev_pm_ops *pm;
  
  	const struct iommu_ops *iommu_ops;
  
  	struct subsys_private *p;
  	struct lock_class_key lock_key;
  };
  
  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 */
  struct subsys_dev_iter {
  	struct klist_iter		ki;
  	const struct device_type	*type;
  };
  void subsys_dev_iter_init(struct subsys_dev_iter *iter,
  			 struct bus_type *subsys,
  			 struct device *start,
  			 const struct device_type *type);
  struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
  void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
  
  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);
  struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
  					struct device *hint);
  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 to be removed */
  #define BUS_NOTIFY_REMOVED_DEVICE	0x00000003 /* device removed */
  #define BUS_NOTIFY_BIND_DRIVER		0x00000004 /* driver about to be
  						      bound */
  #define BUS_NOTIFY_BOUND_DRIVER		0x00000005 /* driver bound to device */
  #define BUS_NOTIFY_UNBIND_DRIVER	0x00000006 /* driver about to be
  						      unbound */
  #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000007 /* driver is unbound
  						      from the device */
  #define BUS_NOTIFY_DRIVER_NOT_BOUND	0x00000008 /* driver fails to be bound */
  
  extern struct kset *bus_get_kset(struct bus_type *bus);
  extern struct klist *bus_get_device_klist(struct bus_type *bus);
  
  /**
   * enum probe_type - device driver probe type to try
   *	Device drivers may opt in for special handling of their
   *	respective probe routines. This tells the core what to
   *	expect and prefer.
   *
   * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
   *	whether probed synchronously or asynchronously.
   * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
   *	probing order is not essential for booting the system may
   *	opt into executing their probes asynchronously.
   * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
   *	their probe routines to run synchronously with driver and
   *	device registration (with the exception of -EPROBE_DEFER
   *	handling - re-probing always ends up being done asynchronously).
   *
   * Note that the end goal is to switch the kernel to use asynchronous
   * probing by default, so annotating drivers with
   * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
   * to speed up boot process while we are validating the rest of the
   * drivers.
   */
  enum probe_type {
  	PROBE_DEFAULT_STRATEGY,
  	PROBE_PREFER_ASYNCHRONOUS,
  	PROBE_FORCE_SYNCHRONOUS,
  };
  
  /**
   * 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.
   * @probe_type:	Type of the probe (synchronous or asynchronous) to use.
   * @of_match_table: The open firmware table.
   * @acpi_match_table: The ACPI match 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 */
  	enum probe_type probe_type;
  
  	const struct of_device_id	*of_match_table;
  	const struct acpi_device_id	*acpi_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 *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_RW(_name) \
  	struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
  #define DRIVER_ATTR_RO(_name) \
  	struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
  #define DRIVER_ATTR_WO(_name) \
  	struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
  
  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_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 subsys_interface - interfaces to device functions
   * @name:       name of the device function
   * @subsys:     subsytem of the devices to attach to
   * @node:       the list of functions registered at the subsystem
   * @add_dev:    device hookup to device function handler
   * @remove_dev: device hookup to device function handler
   *
   * Simple interfaces attached to a subsystem. Multiple interfaces can
   * attach to a subsystem and its devices. Unlike drivers, they do not
   * exclusively claim or control devices. Interfaces usually represent
   * a specific functionality of a subsystem/class of devices.
   */
  struct subsys_interface {
  	const char *name;
  	struct bus_type *subsys;
  	struct list_head node;
  	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
  	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
  };
  
  int subsys_interface_register(struct subsys_interface *sif);
  void subsys_interface_unregister(struct subsys_interface *sif);
  
  int subsys_system_register(struct bus_type *subsys,
  			   const struct attribute_group **groups);
  int subsys_virtual_register(struct bus_type *subsys,
  			    const struct attribute_group **groups);
  
  /**
   * struct class - device classes
   * @name:	Name of the class.
   * @owner:	The module owner.
   * @class_groups: Default attributes of this class.
   * @dev_groups:	Default attributes of the devices that 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.
   * @shutdown_pre: Called at shut-down time before driver shutdown.
   * @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;
  
  	const struct attribute_group	**class_groups;
  	const struct attribute_group	**dev_groups;
  	struct kobject			*dev_kobj;
  
  	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
  	char *(*devnode)(struct device *dev, umode_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);
  	int (*shutdown_pre)(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, const void *data,
  					int (*match)(struct device *, const 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);
  };
  
  #define CLASS_ATTR_RW(_name) \
  	struct class_attribute class_attr_##_name = __ATTR_RW(_name)
  #define CLASS_ATTR_RO(_name) \
  	struct class_attribute class_attr_##_name = __ATTR_RO(_name)
  #define CLASS_ATTR_WO(_name) \
  	struct class_attribute class_attr_##_name = __ATTR_WO(_name)
  
  extern int __must_check class_create_file_ns(struct class *class,
  					     const struct class_attribute *attr,
  					     const void *ns);
  extern void class_remove_file_ns(struct class *class,
  				 const struct class_attribute *attr,
  				 const void *ns);
  
  static inline int __must_check class_create_file(struct class *class,
  					const struct class_attribute *attr)
  {
  	return class_create_file_ns(class, attr, NULL);
  }
  
  static inline void class_remove_file(struct class *class,
  				     const struct class_attribute *attr)
  {
  	return class_remove_file_ns(class, attr, NULL);
  }
  
  /* 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, umode_t *mode,
  			 kuid_t *uid, kgid_t *gid);
  	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);
  };
  
  struct dev_ext_attribute {
  	struct device_attribute attr;
  	void *var;
  };
  
  ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
  			  char *buf);
  ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
  			   const char *buf, size_t count);
  ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
  			char *buf);
  ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
  			 const char *buf, size_t count);
  ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
  			char *buf);
  ssize_t device_store_bool(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)
  #define DEVICE_ATTR_RW(_name) \
  	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
  #define DEVICE_ATTR_RO(_name) \
  	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
  #define DEVICE_ATTR_WO(_name) \
  	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
  #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
  	struct dev_ext_attribute dev_attr_##_name = \
  		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
  #define DEVICE_INT_ATTR(_name, _mode, _var) \
  	struct dev_ext_attribute dev_attr_##_name = \
  		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
  #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
  	struct dev_ext_attribute dev_attr_##_name = \
  		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
  #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
  	struct device_attribute dev_attr_##_name =		\
  		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
  
  extern int 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 bool device_remove_file_self(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);
  
  /* 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_node(dr_release_t release, size_t size, gfp_t gfp,
  				 int nid, const char *name) __malloc;
  #define devres_alloc(release, size, gfp) \
  	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
  #define devres_alloc_node(release, size, gfp, nid) \
  	__devres_alloc_node(release, size, gfp, nid, #release)
  #else
  extern void *devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
  			       int nid) __malloc;
  static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
  {
  	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
  }
  #endif
  
  extern void devres_for_each_res(struct device *dev, dr_release_t release,
  				dr_match_t match, void *match_data,
  				void (*fn)(struct device *, void *, void *),
  				void *data);
  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);
  extern int devres_release(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 devm_k.alloc/kfree for device drivers */
  extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
  extern __printf(3, 0)
  char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
  		      va_list ap) __malloc;
  extern __printf(3, 4)
  char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...) __malloc;
  static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
  {
  	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
  }
  static inline void *devm_kmalloc_array(struct device *dev,
  				       size_t n, size_t size, gfp_t flags)
  {
  	if (size != 0 && n > SIZE_MAX / size)
  		return NULL;
  	return devm_kmalloc(dev, n * size, flags);
  }
  static inline void *devm_kcalloc(struct device *dev,
  				 size_t n, size_t size, gfp_t flags)
  {
  	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
  }
  extern void devm_kfree(struct device *dev, void *p);
  extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
  extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
  			  gfp_t gfp);
  
  extern unsigned long devm_get_free_pages(struct device *dev,
  					 gfp_t gfp_mask, unsigned int order);
  extern void devm_free_pages(struct device *dev, unsigned long addr);
  
  void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
  
  /* allows to add/remove a custom action to devres stack */
  int devm_add_action(struct device *dev, void (*action)(void *), void *data);
  void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
  
  static inline int devm_add_action_or_reset(struct device *dev,
  					   void (*action)(void *), void *data)
  {
  	int ret;
  
  	ret = devm_add_action(dev, action, data);
  	if (ret)
  		action(data);
  
  	return ret;
  }
  
  /**
   * devm_alloc_percpu - Resource-managed alloc_percpu
   * @dev: Device to allocate per-cpu memory for
   * @type: Type to allocate per-cpu memory for
   *
   * Managed alloc_percpu. Per-cpu memory allocated with this function is
   * automatically freed on driver detach.
   *
   * RETURNS:
   * Pointer to allocated memory on success, NULL on failure.
   */
  #define devm_alloc_percpu(dev, type)      \
  	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
  						      __alignof__(type)))
  
  void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
  				   size_t align);
  void devm_free_percpu(struct device *dev, void __percpu *pdata);
  
  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;
  };
  
  /**
   * enum device_link_state - Device link states.
   * @DL_STATE_NONE: The presence of the drivers is not being tracked.
   * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
   * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
   * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
   * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
   * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
   */
  enum device_link_state {
  	DL_STATE_NONE = -1,
  	DL_STATE_DORMANT = 0,
  	DL_STATE_AVAILABLE,
  	DL_STATE_CONSUMER_PROBE,
  	DL_STATE_ACTIVE,
  	DL_STATE_SUPPLIER_UNBIND,
  };
  
  /*
   * Device link flags.
   *
   * STATELESS: The core won't track the presence of supplier/consumer drivers.
   * AUTOREMOVE: Remove this link automatically on consumer driver unbind.
   * PM_RUNTIME: If set, the runtime PM framework will use this link.
   * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
   */
  #define DL_FLAG_STATELESS	BIT(0)
  #define DL_FLAG_AUTOREMOVE	BIT(1)
  #define DL_FLAG_PM_RUNTIME	BIT(2)
  #define DL_FLAG_RPM_ACTIVE	BIT(3)
  
  /**
   * struct device_link - Device link representation.
   * @supplier: The device on the supplier end of the link.
   * @s_node: Hook to the supplier device's list of links to consumers.
   * @consumer: The device on the consumer end of the link.
   * @c_node: Hook to the consumer device's list of links to suppliers.
   * @status: The state of the link (with respect to the presence of drivers).
   * @flags: Link flags.
   * @rpm_active: Whether or not the consumer device is runtime-PM-active.
   * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
   */
  struct device_link {
  	struct device *supplier;
  	struct list_head s_node;
  	struct device *consumer;
  	struct list_head c_node;
  	enum device_link_state status;
  	u32 flags;
  	bool rpm_active;
  #ifdef CONFIG_SRCU
  	struct rcu_head rcu_head;
  #endif
  };
  
  /**
   * enum dl_dev_state - Device driver presence tracking information.
   * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
   * @DL_DEV_PROBING: A driver is probing.
   * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
   * @DL_DEV_UNBINDING: The driver is unbinding from the device.
   */
  enum dl_dev_state {
  	DL_DEV_NO_DRIVER = 0,
  	DL_DEV_PROBING,
  	DL_DEV_DRIVER_BOUND,
  	DL_DEV_UNBINDING,
  };
  
  /**
   * struct dev_links_info - Device data related to device links.
   * @suppliers: List of links to supplier devices.
   * @consumers: List of links to consumer devices.
   * @status: Driver status information.
   */
  struct dev_links_info {
  	struct list_head suppliers;
  	struct list_head consumers;
  	enum dl_dev_state status;
  };
  
  /**
   * 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.
   * @driver_data: Private pointer for driver specific info.
   * @links:	Links to suppliers and consumers of this device.
   * @power:	For device power management.
   *		See Documentation/driver-api/pm/devices.rst 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.
   * @pins:	For device pin management.
   *		See Documentation/driver-api/pinctl.rst for details.
   * @msi_list:	Hosts MSI descriptors
   * @msi_domain: The generic MSI domain this device is using.
   * @numa_node:	NUMA node this device is close to.
   * @dma_ops:    DMA mapping operations for this device.
   * @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_pfn_offset: offset of DMA memory range relatively of RAM
   * @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.
   * @cma_area:	Contiguous memory area for dma allocations
   * @archdata:	For arch-specific additions.
   * @of_node:	Associated device tree node.
   * @fwnode:	Associated device node supplied by platform firmware.
   * @devt:	For creating the sysfs "dev".
   * @id:		device instance
   * @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).
   * @iommu_group: IOMMU group the device belongs to.
   * @iommu_fwspec: IOMMU-specific properties supplied by firmware.
   *
   * @offline_disabled: If set, the device is permanently online.
   * @offline:	Set after successful invocation of bus type's .offline().
   * @of_node_reused: Set if the device-tree node is shared with an ancestor
   *              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 */
  	void		*driver_data;	/* Driver data, set and get with
  					   dev_set/get_drvdata */
  	struct dev_links_info	links;
  	struct dev_pm_info	power;
  	struct dev_pm_domain	*pm_domain;
  
  #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
  	struct irq_domain	*msi_domain;
  #endif
  #ifdef CONFIG_PINCTRL
  	struct dev_pin_info	*pins;
  #endif
  #ifdef CONFIG_GENERIC_MSI_IRQ
  	struct list_head	msi_list;
  #endif
  
  #ifdef CONFIG_NUMA
  	int		numa_node;	/* NUMA node this device is close to */
  #endif
  	const struct dma_map_ops *dma_ops;
  	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. */
  	unsigned long	dma_pfn_offset;
  
  	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 */
  #ifdef CONFIG_DMA_CMA
  	struct cma *cma_area;		/* contiguous memory area for dma
  					   allocations */
  #endif
  	/* arch specific additions */
  	struct dev_archdata	archdata;
  
  	struct device_node	*of_node; /* associated device tree node */
  	struct fwnode_handle	*fwnode; /* firmware device node */
  
  	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
  	u32			id;	/* device instance */
  
  	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);
  	struct iommu_group	*iommu_group;
  	struct iommu_fwspec	*iommu_fwspec;
  
  	bool			offline_disabled:1;
  	bool			offline:1;
  	bool			of_node_reused:1;
  };
  
  static inline struct device *kobj_to_dev(struct kobject *kobj)
  {
  	return container_of(kobj, struct device, kobj);
  }
  
  /* 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 irq_domain *dev_get_msi_domain(const struct device *dev)
  {
  #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
  	return dev->msi_domain;
  #else
  	return NULL;
  #endif
  }
  
  static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
  {
  #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
  	dev->msi_domain = d;
  #endif
  }
  
  static inline void *dev_get_drvdata(const struct device *dev)
  {
  	return dev->driver_data;
  }
  
  static inline void dev_set_drvdata(struct device *dev, void *data)
  {
  	dev->driver_data = data;
  }
  
  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 dev_pm_syscore_device(struct device *dev, bool val)
  {
  #ifdef CONFIG_PM_SLEEP
  	dev->power.syscore = val;
  #endif
  }
  
  static inline void device_lock(struct device *dev)
  {
  	mutex_lock(&dev->mutex);
  }
  
  static inline int device_lock_interruptible(struct device *dev)
  {
  	return mutex_lock_interruptible(&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);
  }
  
  static inline void device_lock_assert(struct device *dev)
  {
  	lockdep_assert_held(&dev->mutex);
  }
  
  static inline struct device_node *dev_of_node(struct device *dev)
  {
  	if (!IS_ENABLED(CONFIG_OF))
  		return NULL;
  	return dev->of_node;
  }
  
  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 int device_for_each_child_reverse(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,
  				      umode_t *mode, kuid_t *uid, kgid_t *gid,
  				      const char **tmp);
  
  static inline bool device_supports_offline(struct device *dev)
  {
  	return dev->bus && dev->bus->offline && dev->bus->online;
  }
  
  extern void lock_device_hotplug(void);
  extern void unlock_device_hotplug(void);
  extern int lock_device_hotplug_sysfs(void);
  extern int device_offline(struct device *dev);
  extern int device_online(struct device *dev);
  extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
  extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
  void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
  
  static inline int dev_num_vf(struct device *dev)
  {
  	if (dev->bus && dev->bus->num_vf)
  		return dev->bus->num_vf(dev);
  	return 0;
  }
  
  /*
   * 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 */
  #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 void device_initial_probe(struct device *dev);
  extern int __must_check device_reprobe(struct device *dev);
  
  extern bool device_is_bound(struct device *dev);
  
  /*
   * Easy functions for dynamically creating devices on the fly
   */
  extern __printf(5, 0)
  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 __printf(6, 7)
  struct device *device_create_with_groups(struct class *cls,
  			     struct device *parent, dev_t devt, void *drvdata,
  			     const struct attribute_group **groups,
  			     const char *fmt, ...);
  extern void device_destroy(struct class *cls, dev_t devt);
  
  extern int __must_check device_add_groups(struct device *dev,
  					const struct attribute_group **groups);
  extern void device_remove_groups(struct device *dev,
  				 const struct attribute_group **groups);
  
  static inline int __must_check device_add_group(struct device *dev,
  					const struct attribute_group *grp)
  {
  	const struct attribute_group *groups[] = { grp, NULL };
  
  	return device_add_groups(dev, groups);
  }
  
  static inline void device_remove_group(struct device *dev,
  				       const struct attribute_group *grp)
  {
  	const struct attribute_group *groups[] = { grp, NULL };
  
  	return device_remove_groups(dev, groups);
  }
  
  extern int __must_check devm_device_add_groups(struct device *dev,
  					const struct attribute_group **groups);
  extern void devm_device_remove_groups(struct device *dev,
  				      const struct attribute_group **groups);
  extern int __must_check devm_device_add_group(struct device *dev,
  					const struct attribute_group *grp);
  extern void devm_device_remove_group(struct device *dev,
  				     const struct attribute_group *grp);
  
  /*
   * 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);
  
  #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);
  
  /* Device links interface. */
  struct device_link *device_link_add(struct device *consumer,
  				    struct device *supplier, u32 flags);
  void device_link_del(struct device_link *link);
  
  #ifdef CONFIG_PRINTK
  
  extern __printf(3, 0)
  int dev_vprintk_emit(int level, const struct device *dev,
  		     const char *fmt, va_list args);
  extern __printf(3, 4)
  int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
  
  extern __printf(3, 4)
  void dev_printk(const char *level, const struct device *dev,
  		const char *fmt, ...);
  extern __printf(2, 3)
  void dev_emerg(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  void dev_alert(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  void dev_crit(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  void dev_err(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  void dev_warn(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  void dev_notice(const struct device *dev, const char *fmt, ...);
  extern __printf(2, 3)
  void _dev_info(const struct device *dev, const char *fmt, ...);
  
  #else
  
  static inline __printf(3, 0)
  int dev_vprintk_emit(int level, const struct device *dev,
  		     const char *fmt, va_list args)
  { return 0; }
  static inline __printf(3, 4)
  int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
  { return 0; }
  
  static inline void __dev_printk(const char *level, const struct device *dev,
  				struct va_format *vaf)
  {}
  static inline __printf(3, 4)
  void dev_printk(const char *level, const struct device *dev,
  		const char *fmt, ...)
  {}
  
  static inline __printf(2, 3)
  void dev_emerg(const struct device *dev, const char *fmt, ...)
  {}
  static inline __printf(2, 3)
  void dev_crit(const struct device *dev, const char *fmt, ...)
  {}
  static inline __printf(2, 3)
  void dev_alert(const struct device *dev, const char *fmt, ...)
  {}
  static inline __printf(2, 3)
  void dev_err(const struct device *dev, const char *fmt, ...)
  {}
  static inline __printf(2, 3)
  void dev_warn(const struct device *dev, const char *fmt, ...)
  {}
  static inline __printf(2, 3)
  void dev_notice(const struct device *dev, const char *fmt, ...)
  {}
  static inline __printf(2, 3)
  void _dev_info(const struct device *dev, const char *fmt, ...)
  {}
  
  #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(CONFIG_DYNAMIC_DEBUG)
  #define dev_dbg(dev, format, ...)		     \
  do {						     \
  	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
  } while (0)
  #elif defined(DEBUG)
  #define dev_dbg(dev, format, arg...)		\
  	dev_printk(KERN_DEBUG, dev, format, ##arg)
  #else
  #define dev_dbg(dev, format, arg...)				\
  ({								\
  	if (0)							\
  		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
  })
  #endif
  
  #ifdef CONFIG_PRINTK
  #define dev_level_once(dev_level, dev, fmt, ...)			\
  do {									\
  	static bool __print_once __read_mostly;				\
  									\
  	if (!__print_once) {						\
  		__print_once = true;					\
  		dev_level(dev, fmt, ##__VA_ARGS__);			\
  	}								\
  } while (0)
  #else
  #define dev_level_once(dev_level, dev, fmt, ...)			\
  do {									\
  	if (0)								\
  		dev_level(dev, fmt, ##__VA_ARGS__);			\
  } while (0)
  #endif
  
  #define dev_emerg_once(dev, fmt, ...)					\
  	dev_level_once(dev_emerg, dev, fmt, ##__VA_ARGS__)
  #define dev_alert_once(dev, fmt, ...)					\
  	dev_level_once(dev_alert, dev, fmt, ##__VA_ARGS__)
  #define dev_crit_once(dev, fmt, ...)					\
  	dev_level_once(dev_crit, dev, fmt, ##__VA_ARGS__)
  #define dev_err_once(dev, fmt, ...)					\
  	dev_level_once(dev_err, dev, fmt, ##__VA_ARGS__)
  #define dev_warn_once(dev, fmt, ...)					\
  	dev_level_once(dev_warn, dev, fmt, ##__VA_ARGS__)
  #define dev_notice_once(dev, fmt, ...)					\
  	dev_level_once(dev_notice, dev, fmt, ##__VA_ARGS__)
  #define dev_info_once(dev, fmt, ...)					\
  	dev_level_once(dev_info, dev, fmt, ##__VA_ARGS__)
  #define dev_dbg_once(dev, fmt, ...)					\
  	dev_level_once(dev_dbg, dev, fmt, ##__VA_ARGS__)
  
  #define dev_level_ratelimited(dev_level, dev, fmt, ...)			\
  do {									\
  	static DEFINE_RATELIMIT_STATE(_rs,				\
  				      DEFAULT_RATELIMIT_INTERVAL,	\
  				      DEFAULT_RATELIMIT_BURST);		\
  	if (__ratelimit(&_rs))						\
  		dev_level(dev, fmt, ##__VA_ARGS__);			\
  } while (0)
  
  #define dev_emerg_ratelimited(dev, fmt, ...)				\
  	dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
  #define dev_alert_ratelimited(dev, fmt, ...)				\
  	dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
  #define dev_crit_ratelimited(dev, fmt, ...)				\
  	dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
  #define dev_err_ratelimited(dev, fmt, ...)				\
  	dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
  #define dev_warn_ratelimited(dev, fmt, ...)				\
  	dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
  #define dev_notice_ratelimited(dev, fmt, ...)				\
  	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
  #define dev_info_ratelimited(dev, fmt, ...)				\
  	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
  #if defined(CONFIG_DYNAMIC_DEBUG)
  /* descriptor check is first to prevent flooding with "callbacks suppressed" */
  #define dev_dbg_ratelimited(dev, fmt, ...)				\
  do {									\
  	static DEFINE_RATELIMIT_STATE(_rs,				\
  				      DEFAULT_RATELIMIT_INTERVAL,	\
  				      DEFAULT_RATELIMIT_BURST);		\
  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
  	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
  	    __ratelimit(&_rs))						\
  		__dynamic_dev_dbg(&descriptor, dev, fmt,		\
  				  ##__VA_ARGS__);			\
  } while (0)
  #elif defined(DEBUG)
  #define dev_dbg_ratelimited(dev, fmt, ...)				\
  do {									\
  	static DEFINE_RATELIMIT_STATE(_rs,				\
  				      DEFAULT_RATELIMIT_INTERVAL,	\
  				      DEFAULT_RATELIMIT_BURST);		\
  	if (__ratelimit(&_rs))						\
  		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
  } while (0)
  #else
  #define dev_dbg_ratelimited(dev, fmt, ...)				\
  do {									\
  	if (0)								\
  		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
  } while (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);	\
  })
  #endif
  
  /*
   * dev_WARN*() acts like dev_printk(), but with the key difference of
   * using WARN/WARN_ONCE to include file/line information and a backtrace.
   */
  #define dev_WARN(dev, format, arg...) \
  	WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
  
  #define dev_WARN_ONCE(dev, condition, format, arg...) \
  	WARN_ONCE(condition, "%s %s: " format, \
  			dev_driver_string(dev), dev_name(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
  
  /**
   * module_driver() - Helper macro for drivers that don't do anything
   * special in module init/exit. This eliminates a lot of boilerplate.
   * Each module may only use this macro once, and calling it replaces
   * module_init() and module_exit().
   *
   * @__driver: driver name
   * @__register: register function for this driver type
   * @__unregister: unregister function for this driver type
   * @...: Additional arguments to be passed to __register and __unregister.
   *
   * Use this macro to construct bus specific macros for registering
   * drivers, and do not use it on its own.
   */
  #define module_driver(__driver, __register, __unregister, ...) \
  static int __init __driver##_init(void) \
  { \
  	return __register(&(__driver) , ##__VA_ARGS__); \
  } \
  module_init(__driver##_init); \
  static void __exit __driver##_exit(void) \
  { \
  	__unregister(&(__driver) , ##__VA_ARGS__); \
  } \
  module_exit(__driver##_exit);
  
  /**
   * builtin_driver() - Helper macro for drivers that don't do anything
   * special in init and have no exit. This eliminates some boilerplate.
   * Each driver may only use this macro once, and calling it replaces
   * device_initcall (or in some cases, the legacy __initcall).  This is
   * meant to be a direct parallel of module_driver() above but without
   * the __exit stuff that is not used for builtin cases.
   *
   * @__driver: driver name
   * @__register: register function for this driver type
   * @...: Additional arguments to be passed to __register
   *
   * Use this macro to construct bus specific macros for registering
   * drivers, and do not use it on its own.
   */
  #define builtin_driver(__driver, __register, ...) \
  static int __init __driver##_init(void) \
  { \
  	return __register(&(__driver) , ##__VA_ARGS__); \
  } \
  device_initcall(__driver##_init);
  
  #endif /* _DEVICE_H_ */
  