xref: /linux-6.15/include/linux/device.h (revision cee2cfb7)
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 fwnode_handle;
42 struct iommu_ops;
43 struct iommu_group;
44 struct iommu_fwspec;
45 
46 struct bus_attribute {
47 	struct attribute	attr;
48 	ssize_t (*show)(struct bus_type *bus, char *buf);
49 	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
50 };
51 
52 #define BUS_ATTR(_name, _mode, _show, _store)	\
53 	struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
54 #define BUS_ATTR_RW(_name) \
55 	struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
56 #define BUS_ATTR_RO(_name) \
57 	struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
58 
59 extern int __must_check bus_create_file(struct bus_type *,
60 					struct bus_attribute *);
61 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
62 
63 /**
64  * struct bus_type - The bus type of the device
65  *
66  * @name:	The name of the bus.
67  * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
68  * @dev_root:	Default device to use as the parent.
69  * @dev_attrs:	Default attributes of the devices on the bus.
70  * @bus_groups:	Default attributes of the bus.
71  * @dev_groups:	Default attributes of the devices on the bus.
72  * @drv_groups: Default attributes of the device drivers on the bus.
73  * @match:	Called, perhaps multiple times, whenever a new device or driver
74  *		is added for this bus. It should return a positive value if the
75  *		given device can be handled by the given driver and zero
76  *		otherwise. It may also return error code if determining that
77  *		the driver supports the device is not possible. In case of
78  *		-EPROBE_DEFER it will queue the device for deferred probing.
79  * @uevent:	Called when a device is added, removed, or a few other things
80  *		that generate uevents to add the environment variables.
81  * @probe:	Called when a new device or driver add to this bus, and callback
82  *		the specific driver's probe to initial the matched device.
83  * @remove:	Called when a device removed from this bus.
84  * @shutdown:	Called at shut-down time to quiesce the device.
85  *
86  * @online:	Called to put the device back online (after offlining it).
87  * @offline:	Called to put the device offline for hot-removal. May fail.
88  *
89  * @suspend:	Called when a device on this bus wants to go to sleep mode.
90  * @resume:	Called to bring a device on this bus out of sleep mode.
91  * @pm:		Power management operations of this bus, callback the specific
92  *		device driver's pm-ops.
93  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
94  *              driver implementations to a bus and allow the driver to do
95  *              bus-specific setup
96  * @p:		The private data of the driver core, only the driver core can
97  *		touch this.
98  * @lock_key:	Lock class key for use by the lock validator
99  *
100  * A bus is a channel between the processor and one or more devices. For the
101  * purposes of the device model, all devices are connected via a bus, even if
102  * it is an internal, virtual, "platform" bus. Buses can plug into each other.
103  * A USB controller is usually a PCI device, for example. The device model
104  * represents the actual connections between buses and the devices they control.
105  * A bus is represented by the bus_type structure. It contains the name, the
106  * default attributes, the bus' methods, PM operations, and the driver core's
107  * private data.
108  */
109 struct bus_type {
110 	const char		*name;
111 	const char		*dev_name;
112 	struct device		*dev_root;
113 	struct device_attribute	*dev_attrs;	/* use dev_groups instead */
114 	const struct attribute_group **bus_groups;
115 	const struct attribute_group **dev_groups;
116 	const struct attribute_group **drv_groups;
117 
118 	int (*match)(struct device *dev, struct device_driver *drv);
119 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
120 	int (*probe)(struct device *dev);
121 	int (*remove)(struct device *dev);
122 	void (*shutdown)(struct device *dev);
123 
124 	int (*online)(struct device *dev);
125 	int (*offline)(struct device *dev);
126 
127 	int (*suspend)(struct device *dev, pm_message_t state);
128 	int (*resume)(struct device *dev);
129 
130 	const struct dev_pm_ops *pm;
131 
132 	const struct iommu_ops *iommu_ops;
133 
134 	struct subsys_private *p;
135 	struct lock_class_key lock_key;
136 };
137 
138 extern int __must_check bus_register(struct bus_type *bus);
139 
140 extern void bus_unregister(struct bus_type *bus);
141 
142 extern int __must_check bus_rescan_devices(struct bus_type *bus);
143 
144 /* iterator helpers for buses */
145 struct subsys_dev_iter {
146 	struct klist_iter		ki;
147 	const struct device_type	*type;
148 };
149 void subsys_dev_iter_init(struct subsys_dev_iter *iter,
150 			 struct bus_type *subsys,
151 			 struct device *start,
152 			 const struct device_type *type);
153 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
154 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
155 
156 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
157 		     int (*fn)(struct device *dev, void *data));
158 struct device *bus_find_device(struct bus_type *bus, struct device *start,
159 			       void *data,
160 			       int (*match)(struct device *dev, void *data));
161 struct device *bus_find_device_by_name(struct bus_type *bus,
162 				       struct device *start,
163 				       const char *name);
164 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
165 					struct device *hint);
166 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
167 		     void *data, int (*fn)(struct device_driver *, void *));
168 void bus_sort_breadthfirst(struct bus_type *bus,
169 			   int (*compare)(const struct device *a,
170 					  const struct device *b));
171 /*
172  * Bus notifiers: Get notified of addition/removal of devices
173  * and binding/unbinding of drivers to devices.
174  * In the long run, it should be a replacement for the platform
175  * notify hooks.
176  */
177 struct notifier_block;
178 
179 extern int bus_register_notifier(struct bus_type *bus,
180 				 struct notifier_block *nb);
181 extern int bus_unregister_notifier(struct bus_type *bus,
182 				   struct notifier_block *nb);
183 
184 /* All 4 notifers below get called with the target struct device *
185  * as an argument. Note that those functions are likely to be called
186  * with the device lock held in the core, so be careful.
187  */
188 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
189 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device to be removed */
190 #define BUS_NOTIFY_REMOVED_DEVICE	0x00000003 /* device removed */
191 #define BUS_NOTIFY_BIND_DRIVER		0x00000004 /* driver about to be
192 						      bound */
193 #define BUS_NOTIFY_BOUND_DRIVER		0x00000005 /* driver bound to device */
194 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000006 /* driver about to be
195 						      unbound */
196 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000007 /* driver is unbound
197 						      from the device */
198 #define BUS_NOTIFY_DRIVER_NOT_BOUND	0x00000008 /* driver fails to be bound */
199 
200 extern struct kset *bus_get_kset(struct bus_type *bus);
201 extern struct klist *bus_get_device_klist(struct bus_type *bus);
202 
203 /**
204  * enum probe_type - device driver probe type to try
205  *	Device drivers may opt in for special handling of their
206  *	respective probe routines. This tells the core what to
207  *	expect and prefer.
208  *
209  * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
210  *	whether probed synchronously or asynchronously.
211  * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
212  *	probing order is not essential for booting the system may
213  *	opt into executing their probes asynchronously.
214  * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
215  *	their probe routines to run synchronously with driver and
216  *	device registration (with the exception of -EPROBE_DEFER
217  *	handling - re-probing always ends up being done asynchronously).
218  *
219  * Note that the end goal is to switch the kernel to use asynchronous
220  * probing by default, so annotating drivers with
221  * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
222  * to speed up boot process while we are validating the rest of the
223  * drivers.
224  */
225 enum probe_type {
226 	PROBE_DEFAULT_STRATEGY,
227 	PROBE_PREFER_ASYNCHRONOUS,
228 	PROBE_FORCE_SYNCHRONOUS,
229 };
230 
231 /**
232  * struct device_driver - The basic device driver structure
233  * @name:	Name of the device driver.
234  * @bus:	The bus which the device of this driver belongs to.
235  * @owner:	The module owner.
236  * @mod_name:	Used for built-in modules.
237  * @suppress_bind_attrs: Disables bind/unbind via sysfs.
238  * @probe_type:	Type of the probe (synchronous or asynchronous) to use.
239  * @of_match_table: The open firmware table.
240  * @acpi_match_table: The ACPI match table.
241  * @probe:	Called to query the existence of a specific device,
242  *		whether this driver can work with it, and bind the driver
243  *		to a specific device.
244  * @remove:	Called when the device is removed from the system to
245  *		unbind a device from this driver.
246  * @shutdown:	Called at shut-down time to quiesce the device.
247  * @suspend:	Called to put the device to sleep mode. Usually to a
248  *		low power state.
249  * @resume:	Called to bring a device from sleep mode.
250  * @groups:	Default attributes that get created by the driver core
251  *		automatically.
252  * @pm:		Power management operations of the device which matched
253  *		this driver.
254  * @p:		Driver core's private data, no one other than the driver
255  *		core can touch this.
256  *
257  * The device driver-model tracks all of the drivers known to the system.
258  * The main reason for this tracking is to enable the driver core to match
259  * up drivers with new devices. Once drivers are known objects within the
260  * system, however, a number of other things become possible. Device drivers
261  * can export information and configuration variables that are independent
262  * of any specific device.
263  */
264 struct device_driver {
265 	const char		*name;
266 	struct bus_type		*bus;
267 
268 	struct module		*owner;
269 	const char		*mod_name;	/* used for built-in modules */
270 
271 	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */
272 	enum probe_type probe_type;
273 
274 	const struct of_device_id	*of_match_table;
275 	const struct acpi_device_id	*acpi_match_table;
276 
277 	int (*probe) (struct device *dev);
278 	int (*remove) (struct device *dev);
279 	void (*shutdown) (struct device *dev);
280 	int (*suspend) (struct device *dev, pm_message_t state);
281 	int (*resume) (struct device *dev);
282 	const struct attribute_group **groups;
283 
284 	const struct dev_pm_ops *pm;
285 
286 	struct driver_private *p;
287 };
288 
289 
290 extern int __must_check driver_register(struct device_driver *drv);
291 extern void driver_unregister(struct device_driver *drv);
292 
293 extern struct device_driver *driver_find(const char *name,
294 					 struct bus_type *bus);
295 extern int driver_probe_done(void);
296 extern void wait_for_device_probe(void);
297 
298 
299 /* sysfs interface for exporting driver attributes */
300 
301 struct driver_attribute {
302 	struct attribute attr;
303 	ssize_t (*show)(struct device_driver *driver, char *buf);
304 	ssize_t (*store)(struct device_driver *driver, const char *buf,
305 			 size_t count);
306 };
307 
308 #define DRIVER_ATTR(_name, _mode, _show, _store) \
309 	struct driver_attribute driver_attr_##_name = __ATTR(_name, _mode, _show, _store)
310 #define DRIVER_ATTR_RW(_name) \
311 	struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
312 #define DRIVER_ATTR_RO(_name) \
313 	struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
314 #define DRIVER_ATTR_WO(_name) \
315 	struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
316 
317 extern int __must_check driver_create_file(struct device_driver *driver,
318 					const struct driver_attribute *attr);
319 extern void driver_remove_file(struct device_driver *driver,
320 			       const struct driver_attribute *attr);
321 
322 extern int __must_check driver_for_each_device(struct device_driver *drv,
323 					       struct device *start,
324 					       void *data,
325 					       int (*fn)(struct device *dev,
326 							 void *));
327 struct device *driver_find_device(struct device_driver *drv,
328 				  struct device *start, void *data,
329 				  int (*match)(struct device *dev, void *data));
330 
331 /**
332  * struct subsys_interface - interfaces to device functions
333  * @name:       name of the device function
334  * @subsys:     subsytem of the devices to attach to
335  * @node:       the list of functions registered at the subsystem
336  * @add_dev:    device hookup to device function handler
337  * @remove_dev: device hookup to device function handler
338  *
339  * Simple interfaces attached to a subsystem. Multiple interfaces can
340  * attach to a subsystem and its devices. Unlike drivers, they do not
341  * exclusively claim or control devices. Interfaces usually represent
342  * a specific functionality of a subsystem/class of devices.
343  */
344 struct subsys_interface {
345 	const char *name;
346 	struct bus_type *subsys;
347 	struct list_head node;
348 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
349 	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
350 };
351 
352 int subsys_interface_register(struct subsys_interface *sif);
353 void subsys_interface_unregister(struct subsys_interface *sif);
354 
355 int subsys_system_register(struct bus_type *subsys,
356 			   const struct attribute_group **groups);
357 int subsys_virtual_register(struct bus_type *subsys,
358 			    const struct attribute_group **groups);
359 
360 /**
361  * struct class - device classes
362  * @name:	Name of the class.
363  * @owner:	The module owner.
364  * @class_attrs: Default attributes of this class.
365  * @class_groups: Default attributes of this class.
366  * @dev_groups:	Default attributes of the devices that belong to the class.
367  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
368  * @dev_uevent:	Called when a device is added, removed from this class, or a
369  *		few other things that generate uevents to add the environment
370  *		variables.
371  * @devnode:	Callback to provide the devtmpfs.
372  * @class_release: Called to release this class.
373  * @dev_release: Called to release the device.
374  * @suspend:	Used to put the device to sleep mode, usually to a low power
375  *		state.
376  * @resume:	Used to bring the device from the sleep mode.
377  * @ns_type:	Callbacks so sysfs can detemine namespaces.
378  * @namespace:	Namespace of the device belongs to this class.
379  * @pm:		The default device power management operations of this class.
380  * @p:		The private data of the driver core, no one other than the
381  *		driver core can touch this.
382  *
383  * A class is a higher-level view of a device that abstracts out low-level
384  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
385  * at the class level, they are all simply disks. Classes allow user space
386  * to work with devices based on what they do, rather than how they are
387  * connected or how they work.
388  */
389 struct class {
390 	const char		*name;
391 	struct module		*owner;
392 
393 	struct class_attribute		*class_attrs;
394 	const struct attribute_group	**class_groups;
395 	const struct attribute_group	**dev_groups;
396 	struct kobject			*dev_kobj;
397 
398 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
399 	char *(*devnode)(struct device *dev, umode_t *mode);
400 
401 	void (*class_release)(struct class *class);
402 	void (*dev_release)(struct device *dev);
403 
404 	int (*suspend)(struct device *dev, pm_message_t state);
405 	int (*resume)(struct device *dev);
406 
407 	const struct kobj_ns_type_operations *ns_type;
408 	const void *(*namespace)(struct device *dev);
409 
410 	const struct dev_pm_ops *pm;
411 
412 	struct subsys_private *p;
413 };
414 
415 struct class_dev_iter {
416 	struct klist_iter		ki;
417 	const struct device_type	*type;
418 };
419 
420 extern struct kobject *sysfs_dev_block_kobj;
421 extern struct kobject *sysfs_dev_char_kobj;
422 extern int __must_check __class_register(struct class *class,
423 					 struct lock_class_key *key);
424 extern void class_unregister(struct class *class);
425 
426 /* This is a #define to keep the compiler from merging different
427  * instances of the __key variable */
428 #define class_register(class)			\
429 ({						\
430 	static struct lock_class_key __key;	\
431 	__class_register(class, &__key);	\
432 })
433 
434 struct class_compat;
435 struct class_compat *class_compat_register(const char *name);
436 void class_compat_unregister(struct class_compat *cls);
437 int class_compat_create_link(struct class_compat *cls, struct device *dev,
438 			     struct device *device_link);
439 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
440 			      struct device *device_link);
441 
442 extern void class_dev_iter_init(struct class_dev_iter *iter,
443 				struct class *class,
444 				struct device *start,
445 				const struct device_type *type);
446 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
447 extern void class_dev_iter_exit(struct class_dev_iter *iter);
448 
449 extern int class_for_each_device(struct class *class, struct device *start,
450 				 void *data,
451 				 int (*fn)(struct device *dev, void *data));
452 extern struct device *class_find_device(struct class *class,
453 					struct device *start, const void *data,
454 					int (*match)(struct device *, const void *));
455 
456 struct class_attribute {
457 	struct attribute attr;
458 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
459 			char *buf);
460 	ssize_t (*store)(struct class *class, struct class_attribute *attr,
461 			const char *buf, size_t count);
462 };
463 
464 #define CLASS_ATTR(_name, _mode, _show, _store) \
465 	struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
466 #define CLASS_ATTR_RW(_name) \
467 	struct class_attribute class_attr_##_name = __ATTR_RW(_name)
468 #define CLASS_ATTR_RO(_name) \
469 	struct class_attribute class_attr_##_name = __ATTR_RO(_name)
470 #define CLASS_ATTR_WO(_name) \
471 	struct class_attribute class_attr_##_name = __ATTR_WO(_name)
472 
473 extern int __must_check class_create_file_ns(struct class *class,
474 					     const struct class_attribute *attr,
475 					     const void *ns);
476 extern void class_remove_file_ns(struct class *class,
477 				 const struct class_attribute *attr,
478 				 const void *ns);
479 
480 static inline int __must_check class_create_file(struct class *class,
481 					const struct class_attribute *attr)
482 {
483 	return class_create_file_ns(class, attr, NULL);
484 }
485 
486 static inline void class_remove_file(struct class *class,
487 				     const struct class_attribute *attr)
488 {
489 	return class_remove_file_ns(class, attr, NULL);
490 }
491 
492 /* Simple class attribute that is just a static string */
493 struct class_attribute_string {
494 	struct class_attribute attr;
495 	char *str;
496 };
497 
498 /* Currently read-only only */
499 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
500 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
501 #define CLASS_ATTR_STRING(_name, _mode, _str) \
502 	struct class_attribute_string class_attr_##_name = \
503 		_CLASS_ATTR_STRING(_name, _mode, _str)
504 
505 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
506                         char *buf);
507 
508 struct class_interface {
509 	struct list_head	node;
510 	struct class		*class;
511 
512 	int (*add_dev)		(struct device *, struct class_interface *);
513 	void (*remove_dev)	(struct device *, struct class_interface *);
514 };
515 
516 extern int __must_check class_interface_register(struct class_interface *);
517 extern void class_interface_unregister(struct class_interface *);
518 
519 extern struct class * __must_check __class_create(struct module *owner,
520 						  const char *name,
521 						  struct lock_class_key *key);
522 extern void class_destroy(struct class *cls);
523 
524 /* This is a #define to keep the compiler from merging different
525  * instances of the __key variable */
526 #define class_create(owner, name)		\
527 ({						\
528 	static struct lock_class_key __key;	\
529 	__class_create(owner, name, &__key);	\
530 })
531 
532 /*
533  * The type of device, "struct device" is embedded in. A class
534  * or bus can contain devices of different types
535  * like "partitions" and "disks", "mouse" and "event".
536  * This identifies the device type and carries type-specific
537  * information, equivalent to the kobj_type of a kobject.
538  * If "name" is specified, the uevent will contain it in
539  * the DEVTYPE variable.
540  */
541 struct device_type {
542 	const char *name;
543 	const struct attribute_group **groups;
544 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
545 	char *(*devnode)(struct device *dev, umode_t *mode,
546 			 kuid_t *uid, kgid_t *gid);
547 	void (*release)(struct device *dev);
548 
549 	const struct dev_pm_ops *pm;
550 };
551 
552 /* interface for exporting device attributes */
553 struct device_attribute {
554 	struct attribute	attr;
555 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
556 			char *buf);
557 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
558 			 const char *buf, size_t count);
559 };
560 
561 struct dev_ext_attribute {
562 	struct device_attribute attr;
563 	void *var;
564 };
565 
566 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
567 			  char *buf);
568 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
569 			   const char *buf, size_t count);
570 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
571 			char *buf);
572 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
573 			 const char *buf, size_t count);
574 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
575 			char *buf);
576 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
577 			 const char *buf, size_t count);
578 
579 #define DEVICE_ATTR(_name, _mode, _show, _store) \
580 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
581 #define DEVICE_ATTR_RW(_name) \
582 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
583 #define DEVICE_ATTR_RO(_name) \
584 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
585 #define DEVICE_ATTR_WO(_name) \
586 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
587 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
588 	struct dev_ext_attribute dev_attr_##_name = \
589 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
590 #define DEVICE_INT_ATTR(_name, _mode, _var) \
591 	struct dev_ext_attribute dev_attr_##_name = \
592 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
593 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
594 	struct dev_ext_attribute dev_attr_##_name = \
595 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
596 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
597 	struct device_attribute dev_attr_##_name =		\
598 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
599 
600 extern int device_create_file(struct device *device,
601 			      const struct device_attribute *entry);
602 extern void device_remove_file(struct device *dev,
603 			       const struct device_attribute *attr);
604 extern bool device_remove_file_self(struct device *dev,
605 				    const struct device_attribute *attr);
606 extern int __must_check device_create_bin_file(struct device *dev,
607 					const struct bin_attribute *attr);
608 extern void device_remove_bin_file(struct device *dev,
609 				   const struct bin_attribute *attr);
610 
611 /* device resource management */
612 typedef void (*dr_release_t)(struct device *dev, void *res);
613 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
614 
615 #ifdef CONFIG_DEBUG_DEVRES
616 extern void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
617 				 int nid, const char *name) __malloc;
618 #define devres_alloc(release, size, gfp) \
619 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
620 #define devres_alloc_node(release, size, gfp, nid) \
621 	__devres_alloc_node(release, size, gfp, nid, #release)
622 #else
623 extern void *devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
624 			       int nid) __malloc;
625 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
626 {
627 	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
628 }
629 #endif
630 
631 extern void devres_for_each_res(struct device *dev, dr_release_t release,
632 				dr_match_t match, void *match_data,
633 				void (*fn)(struct device *, void *, void *),
634 				void *data);
635 extern void devres_free(void *res);
636 extern void devres_add(struct device *dev, void *res);
637 extern void *devres_find(struct device *dev, dr_release_t release,
638 			 dr_match_t match, void *match_data);
639 extern void *devres_get(struct device *dev, void *new_res,
640 			dr_match_t match, void *match_data);
641 extern void *devres_remove(struct device *dev, dr_release_t release,
642 			   dr_match_t match, void *match_data);
643 extern int devres_destroy(struct device *dev, dr_release_t release,
644 			  dr_match_t match, void *match_data);
645 extern int devres_release(struct device *dev, dr_release_t release,
646 			  dr_match_t match, void *match_data);
647 
648 /* devres group */
649 extern void * __must_check devres_open_group(struct device *dev, void *id,
650 					     gfp_t gfp);
651 extern void devres_close_group(struct device *dev, void *id);
652 extern void devres_remove_group(struct device *dev, void *id);
653 extern int devres_release_group(struct device *dev, void *id);
654 
655 /* managed devm_k.alloc/kfree for device drivers */
656 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
657 extern __printf(3, 0)
658 char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
659 		      va_list ap) __malloc;
660 extern __printf(3, 4)
661 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...) __malloc;
662 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
663 {
664 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
665 }
666 static inline void *devm_kmalloc_array(struct device *dev,
667 				       size_t n, size_t size, gfp_t flags)
668 {
669 	if (size != 0 && n > SIZE_MAX / size)
670 		return NULL;
671 	return devm_kmalloc(dev, n * size, flags);
672 }
673 static inline void *devm_kcalloc(struct device *dev,
674 				 size_t n, size_t size, gfp_t flags)
675 {
676 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
677 }
678 extern void devm_kfree(struct device *dev, void *p);
679 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
680 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
681 			  gfp_t gfp);
682 
683 extern unsigned long devm_get_free_pages(struct device *dev,
684 					 gfp_t gfp_mask, unsigned int order);
685 extern void devm_free_pages(struct device *dev, unsigned long addr);
686 
687 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
688 
689 /* allows to add/remove a custom action to devres stack */
690 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
691 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
692 
693 static inline int devm_add_action_or_reset(struct device *dev,
694 					   void (*action)(void *), void *data)
695 {
696 	int ret;
697 
698 	ret = devm_add_action(dev, action, data);
699 	if (ret)
700 		action(data);
701 
702 	return ret;
703 }
704 
705 /**
706  * devm_alloc_percpu - Resource-managed alloc_percpu
707  * @dev: Device to allocate per-cpu memory for
708  * @type: Type to allocate per-cpu memory for
709  *
710  * Managed alloc_percpu. Per-cpu memory allocated with this function is
711  * automatically freed on driver detach.
712  *
713  * RETURNS:
714  * Pointer to allocated memory on success, NULL on failure.
715  */
716 #define devm_alloc_percpu(dev, type)      \
717 	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
718 						      __alignof__(type)))
719 
720 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
721 				   size_t align);
722 void devm_free_percpu(struct device *dev, void __percpu *pdata);
723 
724 struct device_dma_parameters {
725 	/*
726 	 * a low level driver may set these to teach IOMMU code about
727 	 * sg limitations.
728 	 */
729 	unsigned int max_segment_size;
730 	unsigned long segment_boundary_mask;
731 };
732 
733 /**
734  * enum device_link_state - Device link states.
735  * @DL_STATE_NONE: The presence of the drivers is not being tracked.
736  * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
737  * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
738  * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
739  * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
740  * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
741  */
742 enum device_link_state {
743 	DL_STATE_NONE = -1,
744 	DL_STATE_DORMANT = 0,
745 	DL_STATE_AVAILABLE,
746 	DL_STATE_CONSUMER_PROBE,
747 	DL_STATE_ACTIVE,
748 	DL_STATE_SUPPLIER_UNBIND,
749 };
750 
751 /*
752  * Device link flags.
753  *
754  * STATELESS: The core won't track the presence of supplier/consumer drivers.
755  * AUTOREMOVE: Remove this link automatically on consumer driver unbind.
756  * PM_RUNTIME: If set, the runtime PM framework will use this link.
757  * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
758  */
759 #define DL_FLAG_STATELESS	BIT(0)
760 #define DL_FLAG_AUTOREMOVE	BIT(1)
761 #define DL_FLAG_PM_RUNTIME	BIT(2)
762 #define DL_FLAG_RPM_ACTIVE	BIT(3)
763 
764 /**
765  * struct device_link - Device link representation.
766  * @supplier: The device on the supplier end of the link.
767  * @s_node: Hook to the supplier device's list of links to consumers.
768  * @consumer: The device on the consumer end of the link.
769  * @c_node: Hook to the consumer device's list of links to suppliers.
770  * @status: The state of the link (with respect to the presence of drivers).
771  * @flags: Link flags.
772  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
773  * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
774  */
775 struct device_link {
776 	struct device *supplier;
777 	struct list_head s_node;
778 	struct device *consumer;
779 	struct list_head c_node;
780 	enum device_link_state status;
781 	u32 flags;
782 	bool rpm_active;
783 #ifdef CONFIG_SRCU
784 	struct rcu_head rcu_head;
785 #endif
786 };
787 
788 /**
789  * enum dl_dev_state - Device driver presence tracking information.
790  * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
791  * @DL_DEV_PROBING: A driver is probing.
792  * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
793  * @DL_DEV_UNBINDING: The driver is unbinding from the device.
794  */
795 enum dl_dev_state {
796 	DL_DEV_NO_DRIVER = 0,
797 	DL_DEV_PROBING,
798 	DL_DEV_DRIVER_BOUND,
799 	DL_DEV_UNBINDING,
800 };
801 
802 /**
803  * struct dev_links_info - Device data related to device links.
804  * @suppliers: List of links to supplier devices.
805  * @consumers: List of links to consumer devices.
806  * @status: Driver status information.
807  */
808 struct dev_links_info {
809 	struct list_head suppliers;
810 	struct list_head consumers;
811 	enum dl_dev_state status;
812 };
813 
814 /**
815  * struct device - The basic device structure
816  * @parent:	The device's "parent" device, the device to which it is attached.
817  * 		In most cases, a parent device is some sort of bus or host
818  * 		controller. If parent is NULL, the device, is a top-level device,
819  * 		which is not usually what you want.
820  * @p:		Holds the private data of the driver core portions of the device.
821  * 		See the comment of the struct device_private for detail.
822  * @kobj:	A top-level, abstract class from which other classes are derived.
823  * @init_name:	Initial name of the device.
824  * @type:	The type of device.
825  * 		This identifies the device type and carries type-specific
826  * 		information.
827  * @mutex:	Mutex to synchronize calls to its driver.
828  * @bus:	Type of bus device is on.
829  * @driver:	Which driver has allocated this
830  * @platform_data: Platform data specific to the device.
831  * 		Example: For devices on custom boards, as typical of embedded
832  * 		and SOC based hardware, Linux often uses platform_data to point
833  * 		to board-specific structures describing devices and how they
834  * 		are wired.  That can include what ports are available, chip
835  * 		variants, which GPIO pins act in what additional roles, and so
836  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
837  * 		minimizes board-specific #ifdefs in drivers.
838  * @driver_data: Private pointer for driver specific info.
839  * @links:	Links to suppliers and consumers of this device.
840  * @power:	For device power management.
841  * 		See Documentation/power/admin-guide/devices.rst for details.
842  * @pm_domain:	Provide callbacks that are executed during system suspend,
843  * 		hibernation, system resume and during runtime PM transitions
844  * 		along with subsystem-level and driver-level callbacks.
845  * @pins:	For device pin management.
846  *		See Documentation/pinctrl.txt for details.
847  * @msi_list:	Hosts MSI descriptors
848  * @msi_domain: The generic MSI domain this device is using.
849  * @numa_node:	NUMA node this device is close to.
850  * @dma_mask:	Dma mask (if dma'ble device).
851  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
852  * 		hardware supports 64-bit addresses for consistent allocations
853  * 		such descriptors.
854  * @dma_pfn_offset: offset of DMA memory range relatively of RAM
855  * @dma_parms:	A low level driver may set these to teach IOMMU code about
856  * 		segment limitations.
857  * @dma_pools:	Dma pools (if dma'ble device).
858  * @dma_mem:	Internal for coherent mem override.
859  * @cma_area:	Contiguous memory area for dma allocations
860  * @archdata:	For arch-specific additions.
861  * @of_node:	Associated device tree node.
862  * @fwnode:	Associated device node supplied by platform firmware.
863  * @devt:	For creating the sysfs "dev".
864  * @id:		device instance
865  * @devres_lock: Spinlock to protect the resource of the device.
866  * @devres_head: The resources list of the device.
867  * @knode_class: The node used to add the device to the class list.
868  * @class:	The class of the device.
869  * @groups:	Optional attribute groups.
870  * @release:	Callback to free the device after all references have
871  * 		gone away. This should be set by the allocator of the
872  * 		device (i.e. the bus driver that discovered the device).
873  * @iommu_group: IOMMU group the device belongs to.
874  * @iommu_fwspec: IOMMU-specific properties supplied by firmware.
875  *
876  * @offline_disabled: If set, the device is permanently online.
877  * @offline:	Set after successful invocation of bus type's .offline().
878  *
879  * At the lowest level, every device in a Linux system is represented by an
880  * instance of struct device. The device structure contains the information
881  * that the device model core needs to model the system. Most subsystems,
882  * however, track additional information about the devices they host. As a
883  * result, it is rare for devices to be represented by bare device structures;
884  * instead, that structure, like kobject structures, is usually embedded within
885  * a higher-level representation of the device.
886  */
887 struct device {
888 	struct device		*parent;
889 
890 	struct device_private	*p;
891 
892 	struct kobject kobj;
893 	const char		*init_name; /* initial name of the device */
894 	const struct device_type *type;
895 
896 	struct mutex		mutex;	/* mutex to synchronize calls to
897 					 * its driver.
898 					 */
899 
900 	struct bus_type	*bus;		/* type of bus device is on */
901 	struct device_driver *driver;	/* which driver has allocated this
902 					   device */
903 	void		*platform_data;	/* Platform specific data, device
904 					   core doesn't touch it */
905 	void		*driver_data;	/* Driver data, set and get with
906 					   dev_set/get_drvdata */
907 	struct dev_links_info	links;
908 	struct dev_pm_info	power;
909 	struct dev_pm_domain	*pm_domain;
910 
911 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
912 	struct irq_domain	*msi_domain;
913 #endif
914 #ifdef CONFIG_PINCTRL
915 	struct dev_pin_info	*pins;
916 #endif
917 #ifdef CONFIG_GENERIC_MSI_IRQ
918 	struct list_head	msi_list;
919 #endif
920 
921 #ifdef CONFIG_NUMA
922 	int		numa_node;	/* NUMA node this device is close to */
923 #endif
924 	u64		*dma_mask;	/* dma mask (if dma'able device) */
925 	u64		coherent_dma_mask;/* Like dma_mask, but for
926 					     alloc_coherent mappings as
927 					     not all hardware supports
928 					     64 bit addresses for consistent
929 					     allocations such descriptors. */
930 	unsigned long	dma_pfn_offset;
931 
932 	struct device_dma_parameters *dma_parms;
933 
934 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
935 
936 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
937 					     override */
938 #ifdef CONFIG_DMA_CMA
939 	struct cma *cma_area;		/* contiguous memory area for dma
940 					   allocations */
941 #endif
942 	/* arch specific additions */
943 	struct dev_archdata	archdata;
944 
945 	struct device_node	*of_node; /* associated device tree node */
946 	struct fwnode_handle	*fwnode; /* firmware device node */
947 
948 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
949 	u32			id;	/* device instance */
950 
951 	spinlock_t		devres_lock;
952 	struct list_head	devres_head;
953 
954 	struct klist_node	knode_class;
955 	struct class		*class;
956 	const struct attribute_group **groups;	/* optional groups */
957 
958 	void	(*release)(struct device *dev);
959 	struct iommu_group	*iommu_group;
960 	struct iommu_fwspec	*iommu_fwspec;
961 
962 	bool			offline_disabled:1;
963 	bool			offline:1;
964 };
965 
966 static inline struct device *kobj_to_dev(struct kobject *kobj)
967 {
968 	return container_of(kobj, struct device, kobj);
969 }
970 
971 /* Get the wakeup routines, which depend on struct device */
972 #include <linux/pm_wakeup.h>
973 
974 static inline const char *dev_name(const struct device *dev)
975 {
976 	/* Use the init name until the kobject becomes available */
977 	if (dev->init_name)
978 		return dev->init_name;
979 
980 	return kobject_name(&dev->kobj);
981 }
982 
983 extern __printf(2, 3)
984 int dev_set_name(struct device *dev, const char *name, ...);
985 
986 #ifdef CONFIG_NUMA
987 static inline int dev_to_node(struct device *dev)
988 {
989 	return dev->numa_node;
990 }
991 static inline void set_dev_node(struct device *dev, int node)
992 {
993 	dev->numa_node = node;
994 }
995 #else
996 static inline int dev_to_node(struct device *dev)
997 {
998 	return -1;
999 }
1000 static inline void set_dev_node(struct device *dev, int node)
1001 {
1002 }
1003 #endif
1004 
1005 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
1006 {
1007 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1008 	return dev->msi_domain;
1009 #else
1010 	return NULL;
1011 #endif
1012 }
1013 
1014 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
1015 {
1016 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1017 	dev->msi_domain = d;
1018 #endif
1019 }
1020 
1021 static inline void *dev_get_drvdata(const struct device *dev)
1022 {
1023 	return dev->driver_data;
1024 }
1025 
1026 static inline void dev_set_drvdata(struct device *dev, void *data)
1027 {
1028 	dev->driver_data = data;
1029 }
1030 
1031 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
1032 {
1033 	return dev ? dev->power.subsys_data : NULL;
1034 }
1035 
1036 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
1037 {
1038 	return dev->kobj.uevent_suppress;
1039 }
1040 
1041 static inline void dev_set_uevent_suppress(struct device *dev, int val)
1042 {
1043 	dev->kobj.uevent_suppress = val;
1044 }
1045 
1046 static inline int device_is_registered(struct device *dev)
1047 {
1048 	return dev->kobj.state_in_sysfs;
1049 }
1050 
1051 static inline void device_enable_async_suspend(struct device *dev)
1052 {
1053 	if (!dev->power.is_prepared)
1054 		dev->power.async_suspend = true;
1055 }
1056 
1057 static inline void device_disable_async_suspend(struct device *dev)
1058 {
1059 	if (!dev->power.is_prepared)
1060 		dev->power.async_suspend = false;
1061 }
1062 
1063 static inline bool device_async_suspend_enabled(struct device *dev)
1064 {
1065 	return !!dev->power.async_suspend;
1066 }
1067 
1068 static inline void dev_pm_syscore_device(struct device *dev, bool val)
1069 {
1070 #ifdef CONFIG_PM_SLEEP
1071 	dev->power.syscore = val;
1072 #endif
1073 }
1074 
1075 static inline void device_lock(struct device *dev)
1076 {
1077 	mutex_lock(&dev->mutex);
1078 }
1079 
1080 static inline int device_lock_interruptible(struct device *dev)
1081 {
1082 	return mutex_lock_interruptible(&dev->mutex);
1083 }
1084 
1085 static inline int device_trylock(struct device *dev)
1086 {
1087 	return mutex_trylock(&dev->mutex);
1088 }
1089 
1090 static inline void device_unlock(struct device *dev)
1091 {
1092 	mutex_unlock(&dev->mutex);
1093 }
1094 
1095 static inline void device_lock_assert(struct device *dev)
1096 {
1097 	lockdep_assert_held(&dev->mutex);
1098 }
1099 
1100 static inline struct device_node *dev_of_node(struct device *dev)
1101 {
1102 	if (!IS_ENABLED(CONFIG_OF))
1103 		return NULL;
1104 	return dev->of_node;
1105 }
1106 
1107 void driver_init(void);
1108 
1109 /*
1110  * High level routines for use by the bus drivers
1111  */
1112 extern int __must_check device_register(struct device *dev);
1113 extern void device_unregister(struct device *dev);
1114 extern void device_initialize(struct device *dev);
1115 extern int __must_check device_add(struct device *dev);
1116 extern void device_del(struct device *dev);
1117 extern int device_for_each_child(struct device *dev, void *data,
1118 		     int (*fn)(struct device *dev, void *data));
1119 extern int device_for_each_child_reverse(struct device *dev, void *data,
1120 		     int (*fn)(struct device *dev, void *data));
1121 extern struct device *device_find_child(struct device *dev, void *data,
1122 				int (*match)(struct device *dev, void *data));
1123 extern int device_rename(struct device *dev, const char *new_name);
1124 extern int device_move(struct device *dev, struct device *new_parent,
1125 		       enum dpm_order dpm_order);
1126 extern const char *device_get_devnode(struct device *dev,
1127 				      umode_t *mode, kuid_t *uid, kgid_t *gid,
1128 				      const char **tmp);
1129 
1130 static inline bool device_supports_offline(struct device *dev)
1131 {
1132 	return dev->bus && dev->bus->offline && dev->bus->online;
1133 }
1134 
1135 extern void lock_device_hotplug(void);
1136 extern void unlock_device_hotplug(void);
1137 extern int lock_device_hotplug_sysfs(void);
1138 extern int device_offline(struct device *dev);
1139 extern int device_online(struct device *dev);
1140 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1141 extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1142 
1143 /*
1144  * Root device objects for grouping under /sys/devices
1145  */
1146 extern struct device *__root_device_register(const char *name,
1147 					     struct module *owner);
1148 
1149 /* This is a macro to avoid include problems with THIS_MODULE */
1150 #define root_device_register(name) \
1151 	__root_device_register(name, THIS_MODULE)
1152 
1153 extern void root_device_unregister(struct device *root);
1154 
1155 static inline void *dev_get_platdata(const struct device *dev)
1156 {
1157 	return dev->platform_data;
1158 }
1159 
1160 /*
1161  * Manual binding of a device to driver. See drivers/base/bus.c
1162  * for information on use.
1163  */
1164 extern int __must_check device_bind_driver(struct device *dev);
1165 extern void device_release_driver(struct device *dev);
1166 extern int  __must_check device_attach(struct device *dev);
1167 extern int __must_check driver_attach(struct device_driver *drv);
1168 extern void device_initial_probe(struct device *dev);
1169 extern int __must_check device_reprobe(struct device *dev);
1170 
1171 extern bool device_is_bound(struct device *dev);
1172 
1173 /*
1174  * Easy functions for dynamically creating devices on the fly
1175  */
1176 extern __printf(5, 0)
1177 struct device *device_create_vargs(struct class *cls, struct device *parent,
1178 				   dev_t devt, void *drvdata,
1179 				   const char *fmt, va_list vargs);
1180 extern __printf(5, 6)
1181 struct device *device_create(struct class *cls, struct device *parent,
1182 			     dev_t devt, void *drvdata,
1183 			     const char *fmt, ...);
1184 extern __printf(6, 7)
1185 struct device *device_create_with_groups(struct class *cls,
1186 			     struct device *parent, dev_t devt, void *drvdata,
1187 			     const struct attribute_group **groups,
1188 			     const char *fmt, ...);
1189 extern void device_destroy(struct class *cls, dev_t devt);
1190 
1191 /*
1192  * Platform "fixup" functions - allow the platform to have their say
1193  * about devices and actions that the general device layer doesn't
1194  * know about.
1195  */
1196 /* Notify platform of device discovery */
1197 extern int (*platform_notify)(struct device *dev);
1198 
1199 extern int (*platform_notify_remove)(struct device *dev);
1200 
1201 
1202 /*
1203  * get_device - atomically increment the reference count for the device.
1204  *
1205  */
1206 extern struct device *get_device(struct device *dev);
1207 extern void put_device(struct device *dev);
1208 
1209 #ifdef CONFIG_DEVTMPFS
1210 extern int devtmpfs_create_node(struct device *dev);
1211 extern int devtmpfs_delete_node(struct device *dev);
1212 extern int devtmpfs_mount(const char *mntdir);
1213 #else
1214 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
1215 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
1216 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
1217 #endif
1218 
1219 /* drivers/base/power/shutdown.c */
1220 extern void device_shutdown(void);
1221 
1222 /* debugging and troubleshooting/diagnostic helpers. */
1223 extern const char *dev_driver_string(const struct device *dev);
1224 
1225 /* Device links interface. */
1226 struct device_link *device_link_add(struct device *consumer,
1227 				    struct device *supplier, u32 flags);
1228 void device_link_del(struct device_link *link);
1229 
1230 #ifdef CONFIG_PRINTK
1231 
1232 extern __printf(3, 0)
1233 int dev_vprintk_emit(int level, const struct device *dev,
1234 		     const char *fmt, va_list args);
1235 extern __printf(3, 4)
1236 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
1237 
1238 extern __printf(3, 4)
1239 void dev_printk(const char *level, const struct device *dev,
1240 		const char *fmt, ...);
1241 extern __printf(2, 3)
1242 void dev_emerg(const struct device *dev, const char *fmt, ...);
1243 extern __printf(2, 3)
1244 void dev_alert(const struct device *dev, const char *fmt, ...);
1245 extern __printf(2, 3)
1246 void dev_crit(const struct device *dev, const char *fmt, ...);
1247 extern __printf(2, 3)
1248 void dev_err(const struct device *dev, const char *fmt, ...);
1249 extern __printf(2, 3)
1250 void dev_warn(const struct device *dev, const char *fmt, ...);
1251 extern __printf(2, 3)
1252 void dev_notice(const struct device *dev, const char *fmt, ...);
1253 extern __printf(2, 3)
1254 void _dev_info(const struct device *dev, const char *fmt, ...);
1255 
1256 #else
1257 
1258 static inline __printf(3, 0)
1259 int dev_vprintk_emit(int level, const struct device *dev,
1260 		     const char *fmt, va_list args)
1261 { return 0; }
1262 static inline __printf(3, 4)
1263 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1264 { return 0; }
1265 
1266 static inline void __dev_printk(const char *level, const struct device *dev,
1267 				struct va_format *vaf)
1268 {}
1269 static inline __printf(3, 4)
1270 void dev_printk(const char *level, const struct device *dev,
1271 		const char *fmt, ...)
1272 {}
1273 
1274 static inline __printf(2, 3)
1275 void dev_emerg(const struct device *dev, const char *fmt, ...)
1276 {}
1277 static inline __printf(2, 3)
1278 void dev_crit(const struct device *dev, const char *fmt, ...)
1279 {}
1280 static inline __printf(2, 3)
1281 void dev_alert(const struct device *dev, const char *fmt, ...)
1282 {}
1283 static inline __printf(2, 3)
1284 void dev_err(const struct device *dev, const char *fmt, ...)
1285 {}
1286 static inline __printf(2, 3)
1287 void dev_warn(const struct device *dev, const char *fmt, ...)
1288 {}
1289 static inline __printf(2, 3)
1290 void dev_notice(const struct device *dev, const char *fmt, ...)
1291 {}
1292 static inline __printf(2, 3)
1293 void _dev_info(const struct device *dev, const char *fmt, ...)
1294 {}
1295 
1296 #endif
1297 
1298 /*
1299  * Stupid hackaround for existing uses of non-printk uses dev_info
1300  *
1301  * Note that the definition of dev_info below is actually _dev_info
1302  * and a macro is used to avoid redefining dev_info
1303  */
1304 
1305 #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg)
1306 
1307 #if defined(CONFIG_DYNAMIC_DEBUG)
1308 #define dev_dbg(dev, format, ...)		     \
1309 do {						     \
1310 	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
1311 } while (0)
1312 #elif defined(DEBUG)
1313 #define dev_dbg(dev, format, arg...)		\
1314 	dev_printk(KERN_DEBUG, dev, format, ##arg)
1315 #else
1316 #define dev_dbg(dev, format, arg...)				\
1317 ({								\
1318 	if (0)							\
1319 		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
1320 })
1321 #endif
1322 
1323 #ifdef CONFIG_PRINTK
1324 #define dev_level_once(dev_level, dev, fmt, ...)			\
1325 do {									\
1326 	static bool __print_once __read_mostly;				\
1327 									\
1328 	if (!__print_once) {						\
1329 		__print_once = true;					\
1330 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1331 	}								\
1332 } while (0)
1333 #else
1334 #define dev_level_once(dev_level, dev, fmt, ...)			\
1335 do {									\
1336 	if (0)								\
1337 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1338 } while (0)
1339 #endif
1340 
1341 #define dev_emerg_once(dev, fmt, ...)					\
1342 	dev_level_once(dev_emerg, dev, fmt, ##__VA_ARGS__)
1343 #define dev_alert_once(dev, fmt, ...)					\
1344 	dev_level_once(dev_alert, dev, fmt, ##__VA_ARGS__)
1345 #define dev_crit_once(dev, fmt, ...)					\
1346 	dev_level_once(dev_crit, dev, fmt, ##__VA_ARGS__)
1347 #define dev_err_once(dev, fmt, ...)					\
1348 	dev_level_once(dev_err, dev, fmt, ##__VA_ARGS__)
1349 #define dev_warn_once(dev, fmt, ...)					\
1350 	dev_level_once(dev_warn, dev, fmt, ##__VA_ARGS__)
1351 #define dev_notice_once(dev, fmt, ...)					\
1352 	dev_level_once(dev_notice, dev, fmt, ##__VA_ARGS__)
1353 #define dev_info_once(dev, fmt, ...)					\
1354 	dev_level_once(dev_info, dev, fmt, ##__VA_ARGS__)
1355 #define dev_dbg_once(dev, fmt, ...)					\
1356 	dev_level_once(dev_dbg, dev, fmt, ##__VA_ARGS__)
1357 
1358 #define dev_level_ratelimited(dev_level, dev, fmt, ...)			\
1359 do {									\
1360 	static DEFINE_RATELIMIT_STATE(_rs,				\
1361 				      DEFAULT_RATELIMIT_INTERVAL,	\
1362 				      DEFAULT_RATELIMIT_BURST);		\
1363 	if (__ratelimit(&_rs))						\
1364 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1365 } while (0)
1366 
1367 #define dev_emerg_ratelimited(dev, fmt, ...)				\
1368 	dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
1369 #define dev_alert_ratelimited(dev, fmt, ...)				\
1370 	dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
1371 #define dev_crit_ratelimited(dev, fmt, ...)				\
1372 	dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
1373 #define dev_err_ratelimited(dev, fmt, ...)				\
1374 	dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
1375 #define dev_warn_ratelimited(dev, fmt, ...)				\
1376 	dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
1377 #define dev_notice_ratelimited(dev, fmt, ...)				\
1378 	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
1379 #define dev_info_ratelimited(dev, fmt, ...)				\
1380 	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
1381 #if defined(CONFIG_DYNAMIC_DEBUG)
1382 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
1383 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1384 do {									\
1385 	static DEFINE_RATELIMIT_STATE(_rs,				\
1386 				      DEFAULT_RATELIMIT_INTERVAL,	\
1387 				      DEFAULT_RATELIMIT_BURST);		\
1388 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
1389 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
1390 	    __ratelimit(&_rs))						\
1391 		__dynamic_dev_dbg(&descriptor, dev, fmt,		\
1392 				  ##__VA_ARGS__);			\
1393 } while (0)
1394 #elif defined(DEBUG)
1395 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1396 do {									\
1397 	static DEFINE_RATELIMIT_STATE(_rs,				\
1398 				      DEFAULT_RATELIMIT_INTERVAL,	\
1399 				      DEFAULT_RATELIMIT_BURST);		\
1400 	if (__ratelimit(&_rs))						\
1401 		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
1402 } while (0)
1403 #else
1404 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1405 do {									\
1406 	if (0)								\
1407 		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
1408 } while (0)
1409 #endif
1410 
1411 #ifdef VERBOSE_DEBUG
1412 #define dev_vdbg	dev_dbg
1413 #else
1414 #define dev_vdbg(dev, format, arg...)				\
1415 ({								\
1416 	if (0)							\
1417 		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
1418 })
1419 #endif
1420 
1421 /*
1422  * dev_WARN*() acts like dev_printk(), but with the key difference of
1423  * using WARN/WARN_ONCE to include file/line information and a backtrace.
1424  */
1425 #define dev_WARN(dev, format, arg...) \
1426 	WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
1427 
1428 #define dev_WARN_ONCE(dev, condition, format, arg...) \
1429 	WARN_ONCE(condition, "%s %s: " format, \
1430 			dev_driver_string(dev), dev_name(dev), ## arg)
1431 
1432 /* Create alias, so I can be autoloaded. */
1433 #define MODULE_ALIAS_CHARDEV(major,minor) \
1434 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1435 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1436 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
1437 
1438 #ifdef CONFIG_SYSFS_DEPRECATED
1439 extern long sysfs_deprecated;
1440 #else
1441 #define sysfs_deprecated 0
1442 #endif
1443 
1444 /**
1445  * module_driver() - Helper macro for drivers that don't do anything
1446  * special in module init/exit. This eliminates a lot of boilerplate.
1447  * Each module may only use this macro once, and calling it replaces
1448  * module_init() and module_exit().
1449  *
1450  * @__driver: driver name
1451  * @__register: register function for this driver type
1452  * @__unregister: unregister function for this driver type
1453  * @...: Additional arguments to be passed to __register and __unregister.
1454  *
1455  * Use this macro to construct bus specific macros for registering
1456  * drivers, and do not use it on its own.
1457  */
1458 #define module_driver(__driver, __register, __unregister, ...) \
1459 static int __init __driver##_init(void) \
1460 { \
1461 	return __register(&(__driver) , ##__VA_ARGS__); \
1462 } \
1463 module_init(__driver##_init); \
1464 static void __exit __driver##_exit(void) \
1465 { \
1466 	__unregister(&(__driver) , ##__VA_ARGS__); \
1467 } \
1468 module_exit(__driver##_exit);
1469 
1470 /**
1471  * builtin_driver() - Helper macro for drivers that don't do anything
1472  * special in init and have no exit. This eliminates some boilerplate.
1473  * Each driver may only use this macro once, and calling it replaces
1474  * device_initcall (or in some cases, the legacy __initcall).  This is
1475  * meant to be a direct parallel of module_driver() above but without
1476  * the __exit stuff that is not used for builtin cases.
1477  *
1478  * @__driver: driver name
1479  * @__register: register function for this driver type
1480  * @...: Additional arguments to be passed to __register
1481  *
1482  * Use this macro to construct bus specific macros for registering
1483  * drivers, and do not use it on its own.
1484  */
1485 #define builtin_driver(__driver, __register, ...) \
1486 static int __init __driver##_init(void) \
1487 { \
1488 	return __register(&(__driver) , ##__VA_ARGS__); \
1489 } \
1490 device_initcall(__driver##_init);
1491 
1492 #endif /* _DEVICE_H_ */
1493