xref: /linux-6.15/include/linux/device.h (revision 7eb6e340)
1 /*
2  * device.h - generic, centralized driver model
3  *
4  * Copyright (c) 2001-2003 Patrick Mochel <[email protected]>
5  * Copyright (c) 2004-2009 Greg Kroah-Hartman <[email protected]>
6  * Copyright (c) 2008-2009 Novell Inc.
7  *
8  * This file is released under the GPLv2
9  *
10  * See Documentation/driver-model/ for more information.
11  */
12 
13 #ifndef _DEVICE_H_
14 #define _DEVICE_H_
15 
16 #include <linux/ioport.h>
17 #include <linux/kobject.h>
18 #include <linux/klist.h>
19 #include <linux/list.h>
20 #include <linux/lockdep.h>
21 #include <linux/compiler.h>
22 #include <linux/types.h>
23 #include <linux/mutex.h>
24 #include <linux/pinctrl/devinfo.h>
25 #include <linux/pm.h>
26 #include <linux/atomic.h>
27 #include <linux/ratelimit.h>
28 #include <linux/uidgid.h>
29 #include <linux/gfp.h>
30 #include <asm/device.h>
31 
32 struct device;
33 struct device_private;
34 struct device_driver;
35 struct driver_private;
36 struct module;
37 struct class;
38 struct subsys_private;
39 struct bus_type;
40 struct device_node;
41 struct iommu_ops;
42 struct iommu_group;
43 
44 struct bus_attribute {
45 	struct attribute	attr;
46 	ssize_t (*show)(struct bus_type *bus, char *buf);
47 	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
48 };
49 
50 #define BUS_ATTR(_name, _mode, _show, _store)	\
51 	struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
52 #define BUS_ATTR_RW(_name) \
53 	struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
54 #define BUS_ATTR_RO(_name) \
55 	struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
56 
57 extern int __must_check bus_create_file(struct bus_type *,
58 					struct bus_attribute *);
59 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
60 
61 /**
62  * struct bus_type - The bus type of the device
63  *
64  * @name:	The name of the bus.
65  * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
66  * @dev_root:	Default device to use as the parent.
67  * @dev_attrs:	Default attributes of the devices on the bus.
68  * @bus_groups:	Default attributes of the bus.
69  * @dev_groups:	Default attributes of the devices on the bus.
70  * @drv_groups: Default attributes of the device drivers on the bus.
71  * @match:	Called, perhaps multiple times, whenever a new device or driver
72  *		is added for this bus. It should return a nonzero value if the
73  *		given device can be handled by the given driver.
74  * @uevent:	Called when a device is added, removed, or a few other things
75  *		that generate uevents to add the environment variables.
76  * @probe:	Called when a new device or driver add to this bus, and callback
77  *		the specific driver's probe to initial the matched device.
78  * @remove:	Called when a device removed from this bus.
79  * @shutdown:	Called at shut-down time to quiesce the device.
80  *
81  * @online:	Called to put the device back online (after offlining it).
82  * @offline:	Called to put the device offline for hot-removal. May fail.
83  *
84  * @suspend:	Called when a device on this bus wants to go to sleep mode.
85  * @resume:	Called to bring a device on this bus out of sleep mode.
86  * @pm:		Power management operations of this bus, callback the specific
87  *		device driver's pm-ops.
88  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
89  *              driver implementations to a bus and allow the driver to do
90  *              bus-specific setup
91  * @p:		The private data of the driver core, only the driver core can
92  *		touch this.
93  * @lock_key:	Lock class key for use by the lock validator
94  *
95  * A bus is a channel between the processor and one or more devices. For the
96  * purposes of the device model, all devices are connected via a bus, even if
97  * it is an internal, virtual, "platform" bus. Buses can plug into each other.
98  * A USB controller is usually a PCI device, for example. The device model
99  * represents the actual connections between buses and the devices they control.
100  * A bus is represented by the bus_type structure. It contains the name, the
101  * default attributes, the bus' methods, PM operations, and the driver core's
102  * private data.
103  */
104 struct bus_type {
105 	const char		*name;
106 	const char		*dev_name;
107 	struct device		*dev_root;
108 	struct device_attribute	*dev_attrs;	/* use dev_groups instead */
109 	const struct attribute_group **bus_groups;
110 	const struct attribute_group **dev_groups;
111 	const struct attribute_group **drv_groups;
112 
113 	int (*match)(struct device *dev, struct device_driver *drv);
114 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
115 	int (*probe)(struct device *dev);
116 	int (*remove)(struct device *dev);
117 	void (*shutdown)(struct device *dev);
118 
119 	int (*online)(struct device *dev);
120 	int (*offline)(struct device *dev);
121 
122 	int (*suspend)(struct device *dev, pm_message_t state);
123 	int (*resume)(struct device *dev);
124 
125 	const struct dev_pm_ops *pm;
126 
127 	struct iommu_ops *iommu_ops;
128 
129 	struct subsys_private *p;
130 	struct lock_class_key lock_key;
131 };
132 
133 extern int __must_check bus_register(struct bus_type *bus);
134 
135 extern void bus_unregister(struct bus_type *bus);
136 
137 extern int __must_check bus_rescan_devices(struct bus_type *bus);
138 
139 /* iterator helpers for buses */
140 struct subsys_dev_iter {
141 	struct klist_iter		ki;
142 	const struct device_type	*type;
143 };
144 void subsys_dev_iter_init(struct subsys_dev_iter *iter,
145 			 struct bus_type *subsys,
146 			 struct device *start,
147 			 const struct device_type *type);
148 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
149 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
150 
151 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
152 		     int (*fn)(struct device *dev, void *data));
153 struct device *bus_find_device(struct bus_type *bus, struct device *start,
154 			       void *data,
155 			       int (*match)(struct device *dev, void *data));
156 struct device *bus_find_device_by_name(struct bus_type *bus,
157 				       struct device *start,
158 				       const char *name);
159 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
160 					struct device *hint);
161 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
162 		     void *data, int (*fn)(struct device_driver *, void *));
163 void bus_sort_breadthfirst(struct bus_type *bus,
164 			   int (*compare)(const struct device *a,
165 					  const struct device *b));
166 /*
167  * Bus notifiers: Get notified of addition/removal of devices
168  * and binding/unbinding of drivers to devices.
169  * In the long run, it should be a replacement for the platform
170  * notify hooks.
171  */
172 struct notifier_block;
173 
174 extern int bus_register_notifier(struct bus_type *bus,
175 				 struct notifier_block *nb);
176 extern int bus_unregister_notifier(struct bus_type *bus,
177 				   struct notifier_block *nb);
178 
179 /* All 4 notifers below get called with the target struct device *
180  * as an argument. Note that those functions are likely to be called
181  * with the device lock held in the core, so be careful.
182  */
183 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
184 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device removed */
185 #define BUS_NOTIFY_BIND_DRIVER		0x00000003 /* driver about to be
186 						      bound */
187 #define BUS_NOTIFY_BOUND_DRIVER		0x00000004 /* driver bound to device */
188 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000005 /* driver about to be
189 						      unbound */
190 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000006 /* driver is unbound
191 						      from the device */
192 
193 extern struct kset *bus_get_kset(struct bus_type *bus);
194 extern struct klist *bus_get_device_klist(struct bus_type *bus);
195 
196 /**
197  * struct device_driver - The basic device driver structure
198  * @name:	Name of the device driver.
199  * @bus:	The bus which the device of this driver belongs to.
200  * @owner:	The module owner.
201  * @mod_name:	Used for built-in modules.
202  * @suppress_bind_attrs: Disables bind/unbind via sysfs.
203  * @of_match_table: The open firmware table.
204  * @acpi_match_table: The ACPI match table.
205  * @probe:	Called to query the existence of a specific device,
206  *		whether this driver can work with it, and bind the driver
207  *		to a specific device.
208  * @remove:	Called when the device is removed from the system to
209  *		unbind a device from this driver.
210  * @shutdown:	Called at shut-down time to quiesce the device.
211  * @suspend:	Called to put the device to sleep mode. Usually to a
212  *		low power state.
213  * @resume:	Called to bring a device from sleep mode.
214  * @groups:	Default attributes that get created by the driver core
215  *		automatically.
216  * @pm:		Power management operations of the device which matched
217  *		this driver.
218  * @p:		Driver core's private data, no one other than the driver
219  *		core can touch this.
220  *
221  * The device driver-model tracks all of the drivers known to the system.
222  * The main reason for this tracking is to enable the driver core to match
223  * up drivers with new devices. Once drivers are known objects within the
224  * system, however, a number of other things become possible. Device drivers
225  * can export information and configuration variables that are independent
226  * of any specific device.
227  */
228 struct device_driver {
229 	const char		*name;
230 	struct bus_type		*bus;
231 
232 	struct module		*owner;
233 	const char		*mod_name;	/* used for built-in modules */
234 
235 	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */
236 
237 	const struct of_device_id	*of_match_table;
238 	const struct acpi_device_id	*acpi_match_table;
239 
240 	int (*probe) (struct device *dev);
241 	int (*remove) (struct device *dev);
242 	void (*shutdown) (struct device *dev);
243 	int (*suspend) (struct device *dev, pm_message_t state);
244 	int (*resume) (struct device *dev);
245 	const struct attribute_group **groups;
246 
247 	const struct dev_pm_ops *pm;
248 
249 	struct driver_private *p;
250 };
251 
252 
253 extern int __must_check driver_register(struct device_driver *drv);
254 extern void driver_unregister(struct device_driver *drv);
255 
256 extern struct device_driver *driver_find(const char *name,
257 					 struct bus_type *bus);
258 extern int driver_probe_done(void);
259 extern void wait_for_device_probe(void);
260 
261 
262 /* sysfs interface for exporting driver attributes */
263 
264 struct driver_attribute {
265 	struct attribute attr;
266 	ssize_t (*show)(struct device_driver *driver, char *buf);
267 	ssize_t (*store)(struct device_driver *driver, const char *buf,
268 			 size_t count);
269 };
270 
271 #define DRIVER_ATTR(_name, _mode, _show, _store) \
272 	struct driver_attribute driver_attr_##_name = __ATTR(_name, _mode, _show, _store)
273 #define DRIVER_ATTR_RW(_name) \
274 	struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
275 #define DRIVER_ATTR_RO(_name) \
276 	struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
277 #define DRIVER_ATTR_WO(_name) \
278 	struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
279 
280 extern int __must_check driver_create_file(struct device_driver *driver,
281 					const struct driver_attribute *attr);
282 extern void driver_remove_file(struct device_driver *driver,
283 			       const struct driver_attribute *attr);
284 
285 extern int __must_check driver_for_each_device(struct device_driver *drv,
286 					       struct device *start,
287 					       void *data,
288 					       int (*fn)(struct device *dev,
289 							 void *));
290 struct device *driver_find_device(struct device_driver *drv,
291 				  struct device *start, void *data,
292 				  int (*match)(struct device *dev, void *data));
293 
294 /**
295  * struct subsys_interface - interfaces to device functions
296  * @name:       name of the device function
297  * @subsys:     subsytem of the devices to attach to
298  * @node:       the list of functions registered at the subsystem
299  * @add_dev:    device hookup to device function handler
300  * @remove_dev: device hookup to device function handler
301  *
302  * Simple interfaces attached to a subsystem. Multiple interfaces can
303  * attach to a subsystem and its devices. Unlike drivers, they do not
304  * exclusively claim or control devices. Interfaces usually represent
305  * a specific functionality of a subsystem/class of devices.
306  */
307 struct subsys_interface {
308 	const char *name;
309 	struct bus_type *subsys;
310 	struct list_head node;
311 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
312 	int (*remove_dev)(struct device *dev, struct subsys_interface *sif);
313 };
314 
315 int subsys_interface_register(struct subsys_interface *sif);
316 void subsys_interface_unregister(struct subsys_interface *sif);
317 
318 int subsys_system_register(struct bus_type *subsys,
319 			   const struct attribute_group **groups);
320 int subsys_virtual_register(struct bus_type *subsys,
321 			    const struct attribute_group **groups);
322 
323 /**
324  * struct class - device classes
325  * @name:	Name of the class.
326  * @owner:	The module owner.
327  * @class_attrs: Default attributes of this class.
328  * @dev_groups:	Default attributes of the devices that belong to the class.
329  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
330  * @dev_uevent:	Called when a device is added, removed from this class, or a
331  *		few other things that generate uevents to add the environment
332  *		variables.
333  * @devnode:	Callback to provide the devtmpfs.
334  * @class_release: Called to release this class.
335  * @dev_release: Called to release the device.
336  * @suspend:	Used to put the device to sleep mode, usually to a low power
337  *		state.
338  * @resume:	Used to bring the device from the sleep mode.
339  * @ns_type:	Callbacks so sysfs can detemine namespaces.
340  * @namespace:	Namespace of the device belongs to this class.
341  * @pm:		The default device power management operations of this class.
342  * @p:		The private data of the driver core, no one other than the
343  *		driver core can touch this.
344  *
345  * A class is a higher-level view of a device that abstracts out low-level
346  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
347  * at the class level, they are all simply disks. Classes allow user space
348  * to work with devices based on what they do, rather than how they are
349  * connected or how they work.
350  */
351 struct class {
352 	const char		*name;
353 	struct module		*owner;
354 
355 	struct class_attribute		*class_attrs;
356 	const struct attribute_group	**dev_groups;
357 	struct kobject			*dev_kobj;
358 
359 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
360 	char *(*devnode)(struct device *dev, umode_t *mode);
361 
362 	void (*class_release)(struct class *class);
363 	void (*dev_release)(struct device *dev);
364 
365 	int (*suspend)(struct device *dev, pm_message_t state);
366 	int (*resume)(struct device *dev);
367 
368 	const struct kobj_ns_type_operations *ns_type;
369 	const void *(*namespace)(struct device *dev);
370 
371 	const struct dev_pm_ops *pm;
372 
373 	struct subsys_private *p;
374 };
375 
376 struct class_dev_iter {
377 	struct klist_iter		ki;
378 	const struct device_type	*type;
379 };
380 
381 extern struct kobject *sysfs_dev_block_kobj;
382 extern struct kobject *sysfs_dev_char_kobj;
383 extern int __must_check __class_register(struct class *class,
384 					 struct lock_class_key *key);
385 extern void class_unregister(struct class *class);
386 
387 /* This is a #define to keep the compiler from merging different
388  * instances of the __key variable */
389 #define class_register(class)			\
390 ({						\
391 	static struct lock_class_key __key;	\
392 	__class_register(class, &__key);	\
393 })
394 
395 struct class_compat;
396 struct class_compat *class_compat_register(const char *name);
397 void class_compat_unregister(struct class_compat *cls);
398 int class_compat_create_link(struct class_compat *cls, struct device *dev,
399 			     struct device *device_link);
400 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
401 			      struct device *device_link);
402 
403 extern void class_dev_iter_init(struct class_dev_iter *iter,
404 				struct class *class,
405 				struct device *start,
406 				const struct device_type *type);
407 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
408 extern void class_dev_iter_exit(struct class_dev_iter *iter);
409 
410 extern int class_for_each_device(struct class *class, struct device *start,
411 				 void *data,
412 				 int (*fn)(struct device *dev, void *data));
413 extern struct device *class_find_device(struct class *class,
414 					struct device *start, const void *data,
415 					int (*match)(struct device *, const void *));
416 
417 struct class_attribute {
418 	struct attribute attr;
419 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
420 			char *buf);
421 	ssize_t (*store)(struct class *class, struct class_attribute *attr,
422 			const char *buf, size_t count);
423 };
424 
425 #define CLASS_ATTR(_name, _mode, _show, _store) \
426 	struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
427 #define CLASS_ATTR_RW(_name) \
428 	struct class_attribute class_attr_##_name = __ATTR_RW(_name)
429 #define CLASS_ATTR_RO(_name) \
430 	struct class_attribute class_attr_##_name = __ATTR_RO(_name)
431 
432 extern int __must_check class_create_file_ns(struct class *class,
433 					     const struct class_attribute *attr,
434 					     const void *ns);
435 extern void class_remove_file_ns(struct class *class,
436 				 const struct class_attribute *attr,
437 				 const void *ns);
438 
439 static inline int __must_check class_create_file(struct class *class,
440 					const struct class_attribute *attr)
441 {
442 	return class_create_file_ns(class, attr, NULL);
443 }
444 
445 static inline void class_remove_file(struct class *class,
446 				     const struct class_attribute *attr)
447 {
448 	return class_remove_file_ns(class, attr, NULL);
449 }
450 
451 /* Simple class attribute that is just a static string */
452 struct class_attribute_string {
453 	struct class_attribute attr;
454 	char *str;
455 };
456 
457 /* Currently read-only only */
458 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
459 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
460 #define CLASS_ATTR_STRING(_name, _mode, _str) \
461 	struct class_attribute_string class_attr_##_name = \
462 		_CLASS_ATTR_STRING(_name, _mode, _str)
463 
464 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
465                         char *buf);
466 
467 struct class_interface {
468 	struct list_head	node;
469 	struct class		*class;
470 
471 	int (*add_dev)		(struct device *, struct class_interface *);
472 	void (*remove_dev)	(struct device *, struct class_interface *);
473 };
474 
475 extern int __must_check class_interface_register(struct class_interface *);
476 extern void class_interface_unregister(struct class_interface *);
477 
478 extern struct class * __must_check __class_create(struct module *owner,
479 						  const char *name,
480 						  struct lock_class_key *key);
481 extern void class_destroy(struct class *cls);
482 
483 /* This is a #define to keep the compiler from merging different
484  * instances of the __key variable */
485 #define class_create(owner, name)		\
486 ({						\
487 	static struct lock_class_key __key;	\
488 	__class_create(owner, name, &__key);	\
489 })
490 
491 /*
492  * The type of device, "struct device" is embedded in. A class
493  * or bus can contain devices of different types
494  * like "partitions" and "disks", "mouse" and "event".
495  * This identifies the device type and carries type-specific
496  * information, equivalent to the kobj_type of a kobject.
497  * If "name" is specified, the uevent will contain it in
498  * the DEVTYPE variable.
499  */
500 struct device_type {
501 	const char *name;
502 	const struct attribute_group **groups;
503 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
504 	char *(*devnode)(struct device *dev, umode_t *mode,
505 			 kuid_t *uid, kgid_t *gid);
506 	void (*release)(struct device *dev);
507 
508 	const struct dev_pm_ops *pm;
509 };
510 
511 /* interface for exporting device attributes */
512 struct device_attribute {
513 	struct attribute	attr;
514 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
515 			char *buf);
516 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
517 			 const char *buf, size_t count);
518 };
519 
520 struct dev_ext_attribute {
521 	struct device_attribute attr;
522 	void *var;
523 };
524 
525 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
526 			  char *buf);
527 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
528 			   const char *buf, size_t count);
529 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
530 			char *buf);
531 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
532 			 const char *buf, size_t count);
533 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
534 			char *buf);
535 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
536 			 const char *buf, size_t count);
537 
538 #define DEVICE_ATTR(_name, _mode, _show, _store) \
539 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
540 #define DEVICE_ATTR_RW(_name) \
541 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
542 #define DEVICE_ATTR_RO(_name) \
543 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
544 #define DEVICE_ATTR_WO(_name) \
545 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
546 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
547 	struct dev_ext_attribute dev_attr_##_name = \
548 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
549 #define DEVICE_INT_ATTR(_name, _mode, _var) \
550 	struct dev_ext_attribute dev_attr_##_name = \
551 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
552 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
553 	struct dev_ext_attribute dev_attr_##_name = \
554 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
555 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
556 	struct device_attribute dev_attr_##_name =		\
557 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
558 
559 extern int device_create_file(struct device *device,
560 			      const struct device_attribute *entry);
561 extern void device_remove_file(struct device *dev,
562 			       const struct device_attribute *attr);
563 extern bool device_remove_file_self(struct device *dev,
564 				    const struct device_attribute *attr);
565 extern int __must_check device_create_bin_file(struct device *dev,
566 					const struct bin_attribute *attr);
567 extern void device_remove_bin_file(struct device *dev,
568 				   const struct bin_attribute *attr);
569 extern int device_schedule_callback_owner(struct device *dev,
570 		void (*func)(struct device *dev), struct module *owner);
571 
572 /* This is a macro to avoid include problems with THIS_MODULE */
573 #define device_schedule_callback(dev, func)			\
574 	device_schedule_callback_owner(dev, func, THIS_MODULE)
575 
576 /* device resource management */
577 typedef void (*dr_release_t)(struct device *dev, void *res);
578 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
579 
580 #ifdef CONFIG_DEBUG_DEVRES
581 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
582 			     const char *name);
583 #define devres_alloc(release, size, gfp) \
584 	__devres_alloc(release, size, gfp, #release)
585 #else
586 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
587 #endif
588 extern void devres_for_each_res(struct device *dev, dr_release_t release,
589 				dr_match_t match, void *match_data,
590 				void (*fn)(struct device *, void *, void *),
591 				void *data);
592 extern void devres_free(void *res);
593 extern void devres_add(struct device *dev, void *res);
594 extern void *devres_find(struct device *dev, dr_release_t release,
595 			 dr_match_t match, void *match_data);
596 extern void *devres_get(struct device *dev, void *new_res,
597 			dr_match_t match, void *match_data);
598 extern void *devres_remove(struct device *dev, dr_release_t release,
599 			   dr_match_t match, void *match_data);
600 extern int devres_destroy(struct device *dev, dr_release_t release,
601 			  dr_match_t match, void *match_data);
602 extern int devres_release(struct device *dev, dr_release_t release,
603 			  dr_match_t match, void *match_data);
604 
605 /* devres group */
606 extern void * __must_check devres_open_group(struct device *dev, void *id,
607 					     gfp_t gfp);
608 extern void devres_close_group(struct device *dev, void *id);
609 extern void devres_remove_group(struct device *dev, void *id);
610 extern int devres_release_group(struct device *dev, void *id);
611 
612 /* managed devm_k.alloc/kfree for device drivers */
613 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp);
614 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
615 {
616 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
617 }
618 static inline void *devm_kmalloc_array(struct device *dev,
619 				       size_t n, size_t size, gfp_t flags)
620 {
621 	if (size != 0 && n > SIZE_MAX / size)
622 		return NULL;
623 	return devm_kmalloc(dev, n * size, flags);
624 }
625 static inline void *devm_kcalloc(struct device *dev,
626 				 size_t n, size_t size, gfp_t flags)
627 {
628 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
629 }
630 extern void devm_kfree(struct device *dev, void *p);
631 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp);
632 
633 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
634 void __iomem *devm_request_and_ioremap(struct device *dev,
635 			struct resource *res);
636 
637 /* allows to add/remove a custom action to devres stack */
638 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
639 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
640 
641 struct device_dma_parameters {
642 	/*
643 	 * a low level driver may set these to teach IOMMU code about
644 	 * sg limitations.
645 	 */
646 	unsigned int max_segment_size;
647 	unsigned long segment_boundary_mask;
648 };
649 
650 struct acpi_device;
651 
652 struct acpi_dev_node {
653 #ifdef CONFIG_ACPI
654 	struct acpi_device *companion;
655 #endif
656 };
657 
658 /**
659  * struct device - The basic device structure
660  * @parent:	The device's "parent" device, the device to which it is attached.
661  * 		In most cases, a parent device is some sort of bus or host
662  * 		controller. If parent is NULL, the device, is a top-level device,
663  * 		which is not usually what you want.
664  * @p:		Holds the private data of the driver core portions of the device.
665  * 		See the comment of the struct device_private for detail.
666  * @kobj:	A top-level, abstract class from which other classes are derived.
667  * @init_name:	Initial name of the device.
668  * @type:	The type of device.
669  * 		This identifies the device type and carries type-specific
670  * 		information.
671  * @mutex:	Mutex to synchronize calls to its driver.
672  * @bus:	Type of bus device is on.
673  * @driver:	Which driver has allocated this
674  * @platform_data: Platform data specific to the device.
675  * 		Example: For devices on custom boards, as typical of embedded
676  * 		and SOC based hardware, Linux often uses platform_data to point
677  * 		to board-specific structures describing devices and how they
678  * 		are wired.  That can include what ports are available, chip
679  * 		variants, which GPIO pins act in what additional roles, and so
680  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
681  * 		minimizes board-specific #ifdefs in drivers.
682  * @power:	For device power management.
683  * 		See Documentation/power/devices.txt for details.
684  * @pm_domain:	Provide callbacks that are executed during system suspend,
685  * 		hibernation, system resume and during runtime PM transitions
686  * 		along with subsystem-level and driver-level callbacks.
687  * @pins:	For device pin management.
688  *		See Documentation/pinctrl.txt for details.
689  * @numa_node:	NUMA node this device is close to.
690  * @dma_mask:	Dma mask (if dma'ble device).
691  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
692  * 		hardware supports 64-bit addresses for consistent allocations
693  * 		such descriptors.
694  * @dma_parms:	A low level driver may set these to teach IOMMU code about
695  * 		segment limitations.
696  * @dma_pools:	Dma pools (if dma'ble device).
697  * @dma_mem:	Internal for coherent mem override.
698  * @cma_area:	Contiguous memory area for dma allocations
699  * @archdata:	For arch-specific additions.
700  * @of_node:	Associated device tree node.
701  * @acpi_node:	Associated ACPI device node.
702  * @devt:	For creating the sysfs "dev".
703  * @id:		device instance
704  * @devres_lock: Spinlock to protect the resource of the device.
705  * @devres_head: The resources list of the device.
706  * @knode_class: The node used to add the device to the class list.
707  * @class:	The class of the device.
708  * @groups:	Optional attribute groups.
709  * @release:	Callback to free the device after all references have
710  * 		gone away. This should be set by the allocator of the
711  * 		device (i.e. the bus driver that discovered the device).
712  * @iommu_group: IOMMU group the device belongs to.
713  *
714  * @offline_disabled: If set, the device is permanently online.
715  * @offline:	Set after successful invocation of bus type's .offline().
716  *
717  * At the lowest level, every device in a Linux system is represented by an
718  * instance of struct device. The device structure contains the information
719  * that the device model core needs to model the system. Most subsystems,
720  * however, track additional information about the devices they host. As a
721  * result, it is rare for devices to be represented by bare device structures;
722  * instead, that structure, like kobject structures, is usually embedded within
723  * a higher-level representation of the device.
724  */
725 struct device {
726 	struct device		*parent;
727 
728 	struct device_private	*p;
729 
730 	struct kobject kobj;
731 	const char		*init_name; /* initial name of the device */
732 	const struct device_type *type;
733 
734 	struct mutex		mutex;	/* mutex to synchronize calls to
735 					 * its driver.
736 					 */
737 
738 	struct bus_type	*bus;		/* type of bus device is on */
739 	struct device_driver *driver;	/* which driver has allocated this
740 					   device */
741 	void		*platform_data;	/* Platform specific data, device
742 					   core doesn't touch it */
743 	struct dev_pm_info	power;
744 	struct dev_pm_domain	*pm_domain;
745 
746 #ifdef CONFIG_PINCTRL
747 	struct dev_pin_info	*pins;
748 #endif
749 
750 #ifdef CONFIG_NUMA
751 	int		numa_node;	/* NUMA node this device is close to */
752 #endif
753 	u64		*dma_mask;	/* dma mask (if dma'able device) */
754 	u64		coherent_dma_mask;/* Like dma_mask, but for
755 					     alloc_coherent mappings as
756 					     not all hardware supports
757 					     64 bit addresses for consistent
758 					     allocations such descriptors. */
759 
760 	struct device_dma_parameters *dma_parms;
761 
762 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
763 
764 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
765 					     override */
766 #ifdef CONFIG_DMA_CMA
767 	struct cma *cma_area;		/* contiguous memory area for dma
768 					   allocations */
769 #endif
770 	/* arch specific additions */
771 	struct dev_archdata	archdata;
772 
773 	struct device_node	*of_node; /* associated device tree node */
774 	struct acpi_dev_node	acpi_node; /* associated ACPI device node */
775 
776 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
777 	u32			id;	/* device instance */
778 
779 	spinlock_t		devres_lock;
780 	struct list_head	devres_head;
781 
782 	struct klist_node	knode_class;
783 	struct class		*class;
784 	const struct attribute_group **groups;	/* optional groups */
785 
786 	void	(*release)(struct device *dev);
787 	struct iommu_group	*iommu_group;
788 
789 	bool			offline_disabled:1;
790 	bool			offline:1;
791 };
792 
793 static inline struct device *kobj_to_dev(struct kobject *kobj)
794 {
795 	return container_of(kobj, struct device, kobj);
796 }
797 
798 /* Get the wakeup routines, which depend on struct device */
799 #include <linux/pm_wakeup.h>
800 
801 static inline const char *dev_name(const struct device *dev)
802 {
803 	/* Use the init name until the kobject becomes available */
804 	if (dev->init_name)
805 		return dev->init_name;
806 
807 	return kobject_name(&dev->kobj);
808 }
809 
810 extern __printf(2, 3)
811 int dev_set_name(struct device *dev, const char *name, ...);
812 
813 #ifdef CONFIG_NUMA
814 static inline int dev_to_node(struct device *dev)
815 {
816 	return dev->numa_node;
817 }
818 static inline void set_dev_node(struct device *dev, int node)
819 {
820 	dev->numa_node = node;
821 }
822 #else
823 static inline int dev_to_node(struct device *dev)
824 {
825 	return -1;
826 }
827 static inline void set_dev_node(struct device *dev, int node)
828 {
829 }
830 #endif
831 
832 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
833 {
834 	return dev ? dev->power.subsys_data : NULL;
835 }
836 
837 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
838 {
839 	return dev->kobj.uevent_suppress;
840 }
841 
842 static inline void dev_set_uevent_suppress(struct device *dev, int val)
843 {
844 	dev->kobj.uevent_suppress = val;
845 }
846 
847 static inline int device_is_registered(struct device *dev)
848 {
849 	return dev->kobj.state_in_sysfs;
850 }
851 
852 static inline void device_enable_async_suspend(struct device *dev)
853 {
854 	if (!dev->power.is_prepared)
855 		dev->power.async_suspend = true;
856 }
857 
858 static inline void device_disable_async_suspend(struct device *dev)
859 {
860 	if (!dev->power.is_prepared)
861 		dev->power.async_suspend = false;
862 }
863 
864 static inline bool device_async_suspend_enabled(struct device *dev)
865 {
866 	return !!dev->power.async_suspend;
867 }
868 
869 static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
870 {
871 	dev->power.ignore_children = enable;
872 }
873 
874 static inline void dev_pm_syscore_device(struct device *dev, bool val)
875 {
876 #ifdef CONFIG_PM_SLEEP
877 	dev->power.syscore = val;
878 #endif
879 }
880 
881 static inline void device_lock(struct device *dev)
882 {
883 	mutex_lock(&dev->mutex);
884 }
885 
886 static inline int device_trylock(struct device *dev)
887 {
888 	return mutex_trylock(&dev->mutex);
889 }
890 
891 static inline void device_unlock(struct device *dev)
892 {
893 	mutex_unlock(&dev->mutex);
894 }
895 
896 void driver_init(void);
897 
898 /*
899  * High level routines for use by the bus drivers
900  */
901 extern int __must_check device_register(struct device *dev);
902 extern void device_unregister(struct device *dev);
903 extern void device_initialize(struct device *dev);
904 extern int __must_check device_add(struct device *dev);
905 extern void device_del(struct device *dev);
906 extern int device_for_each_child(struct device *dev, void *data,
907 		     int (*fn)(struct device *dev, void *data));
908 extern struct device *device_find_child(struct device *dev, void *data,
909 				int (*match)(struct device *dev, void *data));
910 extern int device_rename(struct device *dev, const char *new_name);
911 extern int device_move(struct device *dev, struct device *new_parent,
912 		       enum dpm_order dpm_order);
913 extern const char *device_get_devnode(struct device *dev,
914 				      umode_t *mode, kuid_t *uid, kgid_t *gid,
915 				      const char **tmp);
916 extern void *dev_get_drvdata(const struct device *dev);
917 extern int dev_set_drvdata(struct device *dev, void *data);
918 
919 static inline bool device_supports_offline(struct device *dev)
920 {
921 	return dev->bus && dev->bus->offline && dev->bus->online;
922 }
923 
924 extern void lock_device_hotplug(void);
925 extern void unlock_device_hotplug(void);
926 extern int lock_device_hotplug_sysfs(void);
927 extern int device_offline(struct device *dev);
928 extern int device_online(struct device *dev);
929 /*
930  * Root device objects for grouping under /sys/devices
931  */
932 extern struct device *__root_device_register(const char *name,
933 					     struct module *owner);
934 
935 /*
936  * This is a macro to avoid include problems with THIS_MODULE,
937  * just as per what is done for device_schedule_callback() above.
938  */
939 #define root_device_register(name) \
940 	__root_device_register(name, THIS_MODULE)
941 
942 extern void root_device_unregister(struct device *root);
943 
944 static inline void *dev_get_platdata(const struct device *dev)
945 {
946 	return dev->platform_data;
947 }
948 
949 /*
950  * Manual binding of a device to driver. See drivers/base/bus.c
951  * for information on use.
952  */
953 extern int __must_check device_bind_driver(struct device *dev);
954 extern void device_release_driver(struct device *dev);
955 extern int  __must_check device_attach(struct device *dev);
956 extern int __must_check driver_attach(struct device_driver *drv);
957 extern int __must_check device_reprobe(struct device *dev);
958 
959 /*
960  * Easy functions for dynamically creating devices on the fly
961  */
962 extern struct device *device_create_vargs(struct class *cls,
963 					  struct device *parent,
964 					  dev_t devt,
965 					  void *drvdata,
966 					  const char *fmt,
967 					  va_list vargs);
968 extern __printf(5, 6)
969 struct device *device_create(struct class *cls, struct device *parent,
970 			     dev_t devt, void *drvdata,
971 			     const char *fmt, ...);
972 extern __printf(6, 7)
973 struct device *device_create_with_groups(struct class *cls,
974 			     struct device *parent, dev_t devt, void *drvdata,
975 			     const struct attribute_group **groups,
976 			     const char *fmt, ...);
977 extern void device_destroy(struct class *cls, dev_t devt);
978 
979 /*
980  * Platform "fixup" functions - allow the platform to have their say
981  * about devices and actions that the general device layer doesn't
982  * know about.
983  */
984 /* Notify platform of device discovery */
985 extern int (*platform_notify)(struct device *dev);
986 
987 extern int (*platform_notify_remove)(struct device *dev);
988 
989 
990 /*
991  * get_device - atomically increment the reference count for the device.
992  *
993  */
994 extern struct device *get_device(struct device *dev);
995 extern void put_device(struct device *dev);
996 
997 #ifdef CONFIG_DEVTMPFS
998 extern int devtmpfs_create_node(struct device *dev);
999 extern int devtmpfs_delete_node(struct device *dev);
1000 extern int devtmpfs_mount(const char *mntdir);
1001 #else
1002 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
1003 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
1004 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
1005 #endif
1006 
1007 /* drivers/base/power/shutdown.c */
1008 extern void device_shutdown(void);
1009 
1010 /* debugging and troubleshooting/diagnostic helpers. */
1011 extern const char *dev_driver_string(const struct device *dev);
1012 
1013 
1014 #ifdef CONFIG_PRINTK
1015 
1016 extern __printf(3, 0)
1017 int dev_vprintk_emit(int level, const struct device *dev,
1018 		     const char *fmt, va_list args);
1019 extern __printf(3, 4)
1020 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
1021 
1022 extern __printf(3, 4)
1023 int dev_printk(const char *level, const struct device *dev,
1024 	       const char *fmt, ...);
1025 extern __printf(2, 3)
1026 int dev_emerg(const struct device *dev, const char *fmt, ...);
1027 extern __printf(2, 3)
1028 int dev_alert(const struct device *dev, const char *fmt, ...);
1029 extern __printf(2, 3)
1030 int dev_crit(const struct device *dev, const char *fmt, ...);
1031 extern __printf(2, 3)
1032 int dev_err(const struct device *dev, const char *fmt, ...);
1033 extern __printf(2, 3)
1034 int dev_warn(const struct device *dev, const char *fmt, ...);
1035 extern __printf(2, 3)
1036 int dev_notice(const struct device *dev, const char *fmt, ...);
1037 extern __printf(2, 3)
1038 int _dev_info(const struct device *dev, const char *fmt, ...);
1039 
1040 #else
1041 
1042 static inline __printf(3, 0)
1043 int dev_vprintk_emit(int level, const struct device *dev,
1044 		     const char *fmt, va_list args)
1045 { return 0; }
1046 static inline __printf(3, 4)
1047 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1048 { return 0; }
1049 
1050 static inline int __dev_printk(const char *level, const struct device *dev,
1051 			       struct va_format *vaf)
1052 { return 0; }
1053 static inline __printf(3, 4)
1054 int dev_printk(const char *level, const struct device *dev,
1055 	       const char *fmt, ...)
1056 { return 0; }
1057 
1058 static inline __printf(2, 3)
1059 int dev_emerg(const struct device *dev, const char *fmt, ...)
1060 { return 0; }
1061 static inline __printf(2, 3)
1062 int dev_crit(const struct device *dev, const char *fmt, ...)
1063 { return 0; }
1064 static inline __printf(2, 3)
1065 int dev_alert(const struct device *dev, const char *fmt, ...)
1066 { return 0; }
1067 static inline __printf(2, 3)
1068 int dev_err(const struct device *dev, const char *fmt, ...)
1069 { return 0; }
1070 static inline __printf(2, 3)
1071 int dev_warn(const struct device *dev, const char *fmt, ...)
1072 { return 0; }
1073 static inline __printf(2, 3)
1074 int dev_notice(const struct device *dev, const char *fmt, ...)
1075 { return 0; }
1076 static inline __printf(2, 3)
1077 int _dev_info(const struct device *dev, const char *fmt, ...)
1078 { return 0; }
1079 
1080 #endif
1081 
1082 /*
1083  * Stupid hackaround for existing uses of non-printk uses dev_info
1084  *
1085  * Note that the definition of dev_info below is actually _dev_info
1086  * and a macro is used to avoid redefining dev_info
1087  */
1088 
1089 #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg)
1090 
1091 #if defined(CONFIG_DYNAMIC_DEBUG)
1092 #define dev_dbg(dev, format, ...)		     \
1093 do {						     \
1094 	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
1095 } while (0)
1096 #elif defined(DEBUG)
1097 #define dev_dbg(dev, format, arg...)		\
1098 	dev_printk(KERN_DEBUG, dev, format, ##arg)
1099 #else
1100 #define dev_dbg(dev, format, arg...)				\
1101 ({								\
1102 	if (0)							\
1103 		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
1104 	0;							\
1105 })
1106 #endif
1107 
1108 #define dev_level_ratelimited(dev_level, dev, fmt, ...)			\
1109 do {									\
1110 	static DEFINE_RATELIMIT_STATE(_rs,				\
1111 				      DEFAULT_RATELIMIT_INTERVAL,	\
1112 				      DEFAULT_RATELIMIT_BURST);		\
1113 	if (__ratelimit(&_rs))						\
1114 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1115 } while (0)
1116 
1117 #define dev_emerg_ratelimited(dev, fmt, ...)				\
1118 	dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
1119 #define dev_alert_ratelimited(dev, fmt, ...)				\
1120 	dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
1121 #define dev_crit_ratelimited(dev, fmt, ...)				\
1122 	dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
1123 #define dev_err_ratelimited(dev, fmt, ...)				\
1124 	dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
1125 #define dev_warn_ratelimited(dev, fmt, ...)				\
1126 	dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
1127 #define dev_notice_ratelimited(dev, fmt, ...)				\
1128 	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
1129 #define dev_info_ratelimited(dev, fmt, ...)				\
1130 	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
1131 #if defined(CONFIG_DYNAMIC_DEBUG)
1132 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
1133 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1134 do {									\
1135 	static DEFINE_RATELIMIT_STATE(_rs,				\
1136 				      DEFAULT_RATELIMIT_INTERVAL,	\
1137 				      DEFAULT_RATELIMIT_BURST);		\
1138 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
1139 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
1140 	    __ratelimit(&_rs))						\
1141 		__dynamic_dev_dbg(&descriptor, dev, fmt,		\
1142 				  ##__VA_ARGS__);			\
1143 } while (0)
1144 #elif defined(DEBUG)
1145 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1146 do {									\
1147 	static DEFINE_RATELIMIT_STATE(_rs,				\
1148 				      DEFAULT_RATELIMIT_INTERVAL,	\
1149 				      DEFAULT_RATELIMIT_BURST);		\
1150 	if (__ratelimit(&_rs))						\
1151 		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
1152 } while (0)
1153 #else
1154 #define dev_dbg_ratelimited(dev, fmt, ...)			\
1155 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
1156 #endif
1157 
1158 #ifdef VERBOSE_DEBUG
1159 #define dev_vdbg	dev_dbg
1160 #else
1161 #define dev_vdbg(dev, format, arg...)				\
1162 ({								\
1163 	if (0)							\
1164 		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
1165 	0;							\
1166 })
1167 #endif
1168 
1169 /*
1170  * dev_WARN*() acts like dev_printk(), but with the key difference of
1171  * using WARN/WARN_ONCE to include file/line information and a backtrace.
1172  */
1173 #define dev_WARN(dev, format, arg...) \
1174 	WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
1175 
1176 #define dev_WARN_ONCE(dev, condition, format, arg...) \
1177 	WARN_ONCE(condition, "%s %s: " format, \
1178 			dev_driver_string(dev), dev_name(dev), ## arg)
1179 
1180 /* Create alias, so I can be autoloaded. */
1181 #define MODULE_ALIAS_CHARDEV(major,minor) \
1182 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1183 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1184 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
1185 
1186 #ifdef CONFIG_SYSFS_DEPRECATED
1187 extern long sysfs_deprecated;
1188 #else
1189 #define sysfs_deprecated 0
1190 #endif
1191 
1192 /**
1193  * module_driver() - Helper macro for drivers that don't do anything
1194  * special in module init/exit. This eliminates a lot of boilerplate.
1195  * Each module may only use this macro once, and calling it replaces
1196  * module_init() and module_exit().
1197  *
1198  * @__driver: driver name
1199  * @__register: register function for this driver type
1200  * @__unregister: unregister function for this driver type
1201  * @...: Additional arguments to be passed to __register and __unregister.
1202  *
1203  * Use this macro to construct bus specific macros for registering
1204  * drivers, and do not use it on its own.
1205  */
1206 #define module_driver(__driver, __register, __unregister, ...) \
1207 static int __init __driver##_init(void) \
1208 { \
1209 	return __register(&(__driver) , ##__VA_ARGS__); \
1210 } \
1211 module_init(__driver##_init); \
1212 static void __exit __driver##_exit(void) \
1213 { \
1214 	__unregister(&(__driver) , ##__VA_ARGS__); \
1215 } \
1216 module_exit(__driver##_exit);
1217 
1218 #endif /* _DEVICE_H_ */
1219