xref: /linux-6.15/include/linux/device.h (revision d2b284d3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * device.h - generic, centralized driver model
4  *
5  * Copyright (c) 2001-2003 Patrick Mochel <[email protected]>
6  * Copyright (c) 2004-2009 Greg Kroah-Hartman <[email protected]>
7  * Copyright (c) 2008-2009 Novell Inc.
8  *
9  * See Documentation/driver-model/ for more information.
10  */
11 
12 #ifndef _DEVICE_H_
13 #define _DEVICE_H_
14 
15 #include <linux/ioport.h>
16 #include <linux/kobject.h>
17 #include <linux/klist.h>
18 #include <linux/list.h>
19 #include <linux/lockdep.h>
20 #include <linux/compiler.h>
21 #include <linux/types.h>
22 #include <linux/mutex.h>
23 #include <linux/pm.h>
24 #include <linux/atomic.h>
25 #include <linux/ratelimit.h>
26 #include <linux/uidgid.h>
27 #include <linux/gfp.h>
28 #include <linux/overflow.h>
29 #include <asm/device.h>
30 
31 struct device;
32 struct device_private;
33 struct device_driver;
34 struct driver_private;
35 struct module;
36 struct class;
37 struct subsys_private;
38 struct bus_type;
39 struct device_node;
40 struct fwnode_handle;
41 struct iommu_ops;
42 struct iommu_group;
43 struct iommu_fwspec;
44 struct dev_pin_info;
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 #define BUS_ATTR_WO(_name) \
59 	struct bus_attribute bus_attr_##_name = __ATTR_WO(_name)
60 
61 extern int __must_check bus_create_file(struct bus_type *,
62 					struct bus_attribute *);
63 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
64 
65 /**
66  * struct bus_type - The bus type of the device
67  *
68  * @name:	The name of the bus.
69  * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
70  * @dev_root:	Default device to use as the parent.
71  * @bus_groups:	Default attributes of the bus.
72  * @dev_groups:	Default attributes of the devices on the bus.
73  * @drv_groups: Default attributes of the device drivers on the bus.
74  * @match:	Called, perhaps multiple times, whenever a new device or driver
75  *		is added for this bus. It should return a positive value if the
76  *		given device can be handled by the given driver and zero
77  *		otherwise. It may also return error code if determining that
78  *		the driver supports the device is not possible. In case of
79  *		-EPROBE_DEFER it will queue the device for deferred probing.
80  * @uevent:	Called when a device is added, removed, or a few other things
81  *		that generate uevents to add the environment variables.
82  * @probe:	Called when a new device or driver add to this bus, and callback
83  *		the specific driver's probe to initial the matched device.
84  * @remove:	Called when a device removed from this bus.
85  * @shutdown:	Called at shut-down time to quiesce the device.
86  *
87  * @online:	Called to put the device back online (after offlining it).
88  * @offline:	Called to put the device offline for hot-removal. May fail.
89  *
90  * @suspend:	Called when a device on this bus wants to go to sleep mode.
91  * @resume:	Called to bring a device on this bus out of sleep mode.
92  * @num_vf:	Called to find out how many virtual functions a device on this
93  *		bus supports.
94  * @dma_configure:	Called to setup DMA configuration on a device on
95  *			this bus.
96  * @pm:		Power management operations of this bus, callback the specific
97  *		device driver's pm-ops.
98  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
99  *              driver implementations to a bus and allow the driver to do
100  *              bus-specific setup
101  * @p:		The private data of the driver core, only the driver core can
102  *		touch this.
103  * @lock_key:	Lock class key for use by the lock validator
104  * @need_parent_lock:	When probing or removing a device on this bus, the
105  *			device core should lock the device's parent.
106  *
107  * A bus is a channel between the processor and one or more devices. For the
108  * purposes of the device model, all devices are connected via a bus, even if
109  * it is an internal, virtual, "platform" bus. Buses can plug into each other.
110  * A USB controller is usually a PCI device, for example. The device model
111  * represents the actual connections between buses and the devices they control.
112  * A bus is represented by the bus_type structure. It contains the name, the
113  * default attributes, the bus' methods, PM operations, and the driver core's
114  * private data.
115  */
116 struct bus_type {
117 	const char		*name;
118 	const char		*dev_name;
119 	struct device		*dev_root;
120 	const struct attribute_group **bus_groups;
121 	const struct attribute_group **dev_groups;
122 	const struct attribute_group **drv_groups;
123 
124 	int (*match)(struct device *dev, struct device_driver *drv);
125 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
126 	int (*probe)(struct device *dev);
127 	int (*remove)(struct device *dev);
128 	void (*shutdown)(struct device *dev);
129 
130 	int (*online)(struct device *dev);
131 	int (*offline)(struct device *dev);
132 
133 	int (*suspend)(struct device *dev, pm_message_t state);
134 	int (*resume)(struct device *dev);
135 
136 	int (*num_vf)(struct device *dev);
137 
138 	int (*dma_configure)(struct device *dev);
139 
140 	const struct dev_pm_ops *pm;
141 
142 	const struct iommu_ops *iommu_ops;
143 
144 	struct subsys_private *p;
145 	struct lock_class_key lock_key;
146 
147 	bool need_parent_lock;
148 };
149 
150 extern int __must_check bus_register(struct bus_type *bus);
151 
152 extern void bus_unregister(struct bus_type *bus);
153 
154 extern int __must_check bus_rescan_devices(struct bus_type *bus);
155 
156 /* iterator helpers for buses */
157 struct subsys_dev_iter {
158 	struct klist_iter		ki;
159 	const struct device_type	*type;
160 };
161 void subsys_dev_iter_init(struct subsys_dev_iter *iter,
162 			 struct bus_type *subsys,
163 			 struct device *start,
164 			 const struct device_type *type);
165 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
166 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
167 
168 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
169 		     int (*fn)(struct device *dev, void *data));
170 struct device *bus_find_device(struct bus_type *bus, struct device *start,
171 			       void *data,
172 			       int (*match)(struct device *dev, void *data));
173 struct device *bus_find_device_by_name(struct bus_type *bus,
174 				       struct device *start,
175 				       const char *name);
176 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
177 					struct device *hint);
178 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
179 		     void *data, int (*fn)(struct device_driver *, void *));
180 void bus_sort_breadthfirst(struct bus_type *bus,
181 			   int (*compare)(const struct device *a,
182 					  const struct device *b));
183 /*
184  * Bus notifiers: Get notified of addition/removal of devices
185  * and binding/unbinding of drivers to devices.
186  * In the long run, it should be a replacement for the platform
187  * notify hooks.
188  */
189 struct notifier_block;
190 
191 extern int bus_register_notifier(struct bus_type *bus,
192 				 struct notifier_block *nb);
193 extern int bus_unregister_notifier(struct bus_type *bus,
194 				   struct notifier_block *nb);
195 
196 /* All 4 notifers below get called with the target struct device *
197  * as an argument. Note that those functions are likely to be called
198  * with the device lock held in the core, so be careful.
199  */
200 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
201 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device to be removed */
202 #define BUS_NOTIFY_REMOVED_DEVICE	0x00000003 /* device removed */
203 #define BUS_NOTIFY_BIND_DRIVER		0x00000004 /* driver about to be
204 						      bound */
205 #define BUS_NOTIFY_BOUND_DRIVER		0x00000005 /* driver bound to device */
206 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000006 /* driver about to be
207 						      unbound */
208 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000007 /* driver is unbound
209 						      from the device */
210 #define BUS_NOTIFY_DRIVER_NOT_BOUND	0x00000008 /* driver fails to be bound */
211 
212 extern struct kset *bus_get_kset(struct bus_type *bus);
213 extern struct klist *bus_get_device_klist(struct bus_type *bus);
214 
215 /**
216  * enum probe_type - device driver probe type to try
217  *	Device drivers may opt in for special handling of their
218  *	respective probe routines. This tells the core what to
219  *	expect and prefer.
220  *
221  * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
222  *	whether probed synchronously or asynchronously.
223  * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
224  *	probing order is not essential for booting the system may
225  *	opt into executing their probes asynchronously.
226  * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
227  *	their probe routines to run synchronously with driver and
228  *	device registration (with the exception of -EPROBE_DEFER
229  *	handling - re-probing always ends up being done asynchronously).
230  *
231  * Note that the end goal is to switch the kernel to use asynchronous
232  * probing by default, so annotating drivers with
233  * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
234  * to speed up boot process while we are validating the rest of the
235  * drivers.
236  */
237 enum probe_type {
238 	PROBE_DEFAULT_STRATEGY,
239 	PROBE_PREFER_ASYNCHRONOUS,
240 	PROBE_FORCE_SYNCHRONOUS,
241 };
242 
243 /**
244  * struct device_driver - The basic device driver structure
245  * @name:	Name of the device driver.
246  * @bus:	The bus which the device of this driver belongs to.
247  * @owner:	The module owner.
248  * @mod_name:	Used for built-in modules.
249  * @suppress_bind_attrs: Disables bind/unbind via sysfs.
250  * @probe_type:	Type of the probe (synchronous or asynchronous) to use.
251  * @of_match_table: The open firmware table.
252  * @acpi_match_table: The ACPI match table.
253  * @probe:	Called to query the existence of a specific device,
254  *		whether this driver can work with it, and bind the driver
255  *		to a specific device.
256  * @remove:	Called when the device is removed from the system to
257  *		unbind a device from this driver.
258  * @shutdown:	Called at shut-down time to quiesce the device.
259  * @suspend:	Called to put the device to sleep mode. Usually to a
260  *		low power state.
261  * @resume:	Called to bring a device from sleep mode.
262  * @groups:	Default attributes that get created by the driver core
263  *		automatically.
264  * @pm:		Power management operations of the device which matched
265  *		this driver.
266  * @coredump:	Called when sysfs entry is written to. The device driver
267  *		is expected to call the dev_coredump API resulting in a
268  *		uevent.
269  * @p:		Driver core's private data, no one other than the driver
270  *		core can touch this.
271  *
272  * The device driver-model tracks all of the drivers known to the system.
273  * The main reason for this tracking is to enable the driver core to match
274  * up drivers with new devices. Once drivers are known objects within the
275  * system, however, a number of other things become possible. Device drivers
276  * can export information and configuration variables that are independent
277  * of any specific device.
278  */
279 struct device_driver {
280 	const char		*name;
281 	struct bus_type		*bus;
282 
283 	struct module		*owner;
284 	const char		*mod_name;	/* used for built-in modules */
285 
286 	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */
287 	enum probe_type probe_type;
288 
289 	const struct of_device_id	*of_match_table;
290 	const struct acpi_device_id	*acpi_match_table;
291 
292 	int (*probe) (struct device *dev);
293 	int (*remove) (struct device *dev);
294 	void (*shutdown) (struct device *dev);
295 	int (*suspend) (struct device *dev, pm_message_t state);
296 	int (*resume) (struct device *dev);
297 	const struct attribute_group **groups;
298 
299 	const struct dev_pm_ops *pm;
300 	void (*coredump) (struct device *dev);
301 
302 	struct driver_private *p;
303 };
304 
305 
306 extern int __must_check driver_register(struct device_driver *drv);
307 extern void driver_unregister(struct device_driver *drv);
308 
309 extern struct device_driver *driver_find(const char *name,
310 					 struct bus_type *bus);
311 extern int driver_probe_done(void);
312 extern void wait_for_device_probe(void);
313 
314 /* sysfs interface for exporting driver attributes */
315 
316 struct driver_attribute {
317 	struct attribute attr;
318 	ssize_t (*show)(struct device_driver *driver, char *buf);
319 	ssize_t (*store)(struct device_driver *driver, const char *buf,
320 			 size_t count);
321 };
322 
323 #define DRIVER_ATTR_RW(_name) \
324 	struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
325 #define DRIVER_ATTR_RO(_name) \
326 	struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
327 #define DRIVER_ATTR_WO(_name) \
328 	struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
329 
330 extern int __must_check driver_create_file(struct device_driver *driver,
331 					const struct driver_attribute *attr);
332 extern void driver_remove_file(struct device_driver *driver,
333 			       const struct driver_attribute *attr);
334 
335 extern int __must_check driver_for_each_device(struct device_driver *drv,
336 					       struct device *start,
337 					       void *data,
338 					       int (*fn)(struct device *dev,
339 							 void *));
340 struct device *driver_find_device(struct device_driver *drv,
341 				  struct device *start, void *data,
342 				  int (*match)(struct device *dev, void *data));
343 
344 void driver_deferred_probe_add(struct device *dev);
345 int driver_deferred_probe_check_state(struct device *dev);
346 
347 /**
348  * struct subsys_interface - interfaces to device functions
349  * @name:       name of the device function
350  * @subsys:     subsytem of the devices to attach to
351  * @node:       the list of functions registered at the subsystem
352  * @add_dev:    device hookup to device function handler
353  * @remove_dev: device hookup to device function handler
354  *
355  * Simple interfaces attached to a subsystem. Multiple interfaces can
356  * attach to a subsystem and its devices. Unlike drivers, they do not
357  * exclusively claim or control devices. Interfaces usually represent
358  * a specific functionality of a subsystem/class of devices.
359  */
360 struct subsys_interface {
361 	const char *name;
362 	struct bus_type *subsys;
363 	struct list_head node;
364 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
365 	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
366 };
367 
368 int subsys_interface_register(struct subsys_interface *sif);
369 void subsys_interface_unregister(struct subsys_interface *sif);
370 
371 int subsys_system_register(struct bus_type *subsys,
372 			   const struct attribute_group **groups);
373 int subsys_virtual_register(struct bus_type *subsys,
374 			    const struct attribute_group **groups);
375 
376 /**
377  * struct class - device classes
378  * @name:	Name of the class.
379  * @owner:	The module owner.
380  * @class_groups: Default attributes of this class.
381  * @dev_groups:	Default attributes of the devices that belong to the class.
382  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
383  * @dev_uevent:	Called when a device is added, removed from this class, or a
384  *		few other things that generate uevents to add the environment
385  *		variables.
386  * @devnode:	Callback to provide the devtmpfs.
387  * @class_release: Called to release this class.
388  * @dev_release: Called to release the device.
389  * @shutdown_pre: Called at shut-down time before driver shutdown.
390  * @ns_type:	Callbacks so sysfs can detemine namespaces.
391  * @namespace:	Namespace of the device belongs to this class.
392  * @get_ownership: Allows class to specify uid/gid of the sysfs directories
393  *		for the devices belonging to the class. Usually tied to
394  *		device's namespace.
395  * @pm:		The default device power management operations of this class.
396  * @p:		The private data of the driver core, no one other than the
397  *		driver core can touch this.
398  *
399  * A class is a higher-level view of a device that abstracts out low-level
400  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
401  * at the class level, they are all simply disks. Classes allow user space
402  * to work with devices based on what they do, rather than how they are
403  * connected or how they work.
404  */
405 struct class {
406 	const char		*name;
407 	struct module		*owner;
408 
409 	const struct attribute_group	**class_groups;
410 	const struct attribute_group	**dev_groups;
411 	struct kobject			*dev_kobj;
412 
413 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
414 	char *(*devnode)(struct device *dev, umode_t *mode);
415 
416 	void (*class_release)(struct class *class);
417 	void (*dev_release)(struct device *dev);
418 
419 	int (*shutdown_pre)(struct device *dev);
420 
421 	const struct kobj_ns_type_operations *ns_type;
422 	const void *(*namespace)(struct device *dev);
423 
424 	void (*get_ownership)(struct device *dev, kuid_t *uid, kgid_t *gid);
425 
426 	const struct dev_pm_ops *pm;
427 
428 	struct subsys_private *p;
429 };
430 
431 struct class_dev_iter {
432 	struct klist_iter		ki;
433 	const struct device_type	*type;
434 };
435 
436 extern struct kobject *sysfs_dev_block_kobj;
437 extern struct kobject *sysfs_dev_char_kobj;
438 extern int __must_check __class_register(struct class *class,
439 					 struct lock_class_key *key);
440 extern void class_unregister(struct class *class);
441 
442 /* This is a #define to keep the compiler from merging different
443  * instances of the __key variable */
444 #define class_register(class)			\
445 ({						\
446 	static struct lock_class_key __key;	\
447 	__class_register(class, &__key);	\
448 })
449 
450 struct class_compat;
451 struct class_compat *class_compat_register(const char *name);
452 void class_compat_unregister(struct class_compat *cls);
453 int class_compat_create_link(struct class_compat *cls, struct device *dev,
454 			     struct device *device_link);
455 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
456 			      struct device *device_link);
457 
458 extern void class_dev_iter_init(struct class_dev_iter *iter,
459 				struct class *class,
460 				struct device *start,
461 				const struct device_type *type);
462 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
463 extern void class_dev_iter_exit(struct class_dev_iter *iter);
464 
465 extern int class_for_each_device(struct class *class, struct device *start,
466 				 void *data,
467 				 int (*fn)(struct device *dev, void *data));
468 extern struct device *class_find_device(struct class *class,
469 					struct device *start, const void *data,
470 					int (*match)(struct device *, const void *));
471 
472 struct class_attribute {
473 	struct attribute attr;
474 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
475 			char *buf);
476 	ssize_t (*store)(struct class *class, struct class_attribute *attr,
477 			const char *buf, size_t count);
478 };
479 
480 #define CLASS_ATTR_RW(_name) \
481 	struct class_attribute class_attr_##_name = __ATTR_RW(_name)
482 #define CLASS_ATTR_RO(_name) \
483 	struct class_attribute class_attr_##_name = __ATTR_RO(_name)
484 #define CLASS_ATTR_WO(_name) \
485 	struct class_attribute class_attr_##_name = __ATTR_WO(_name)
486 
487 extern int __must_check class_create_file_ns(struct class *class,
488 					     const struct class_attribute *attr,
489 					     const void *ns);
490 extern void class_remove_file_ns(struct class *class,
491 				 const struct class_attribute *attr,
492 				 const void *ns);
493 
494 static inline int __must_check class_create_file(struct class *class,
495 					const struct class_attribute *attr)
496 {
497 	return class_create_file_ns(class, attr, NULL);
498 }
499 
500 static inline void class_remove_file(struct class *class,
501 				     const struct class_attribute *attr)
502 {
503 	return class_remove_file_ns(class, attr, NULL);
504 }
505 
506 /* Simple class attribute that is just a static string */
507 struct class_attribute_string {
508 	struct class_attribute attr;
509 	char *str;
510 };
511 
512 /* Currently read-only only */
513 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
514 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
515 #define CLASS_ATTR_STRING(_name, _mode, _str) \
516 	struct class_attribute_string class_attr_##_name = \
517 		_CLASS_ATTR_STRING(_name, _mode, _str)
518 
519 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
520                         char *buf);
521 
522 struct class_interface {
523 	struct list_head	node;
524 	struct class		*class;
525 
526 	int (*add_dev)		(struct device *, struct class_interface *);
527 	void (*remove_dev)	(struct device *, struct class_interface *);
528 };
529 
530 extern int __must_check class_interface_register(struct class_interface *);
531 extern void class_interface_unregister(struct class_interface *);
532 
533 extern struct class * __must_check __class_create(struct module *owner,
534 						  const char *name,
535 						  struct lock_class_key *key);
536 extern void class_destroy(struct class *cls);
537 
538 /* This is a #define to keep the compiler from merging different
539  * instances of the __key variable */
540 #define class_create(owner, name)		\
541 ({						\
542 	static struct lock_class_key __key;	\
543 	__class_create(owner, name, &__key);	\
544 })
545 
546 /*
547  * The type of device, "struct device" is embedded in. A class
548  * or bus can contain devices of different types
549  * like "partitions" and "disks", "mouse" and "event".
550  * This identifies the device type and carries type-specific
551  * information, equivalent to the kobj_type of a kobject.
552  * If "name" is specified, the uevent will contain it in
553  * the DEVTYPE variable.
554  */
555 struct device_type {
556 	const char *name;
557 	const struct attribute_group **groups;
558 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
559 	char *(*devnode)(struct device *dev, umode_t *mode,
560 			 kuid_t *uid, kgid_t *gid);
561 	void (*release)(struct device *dev);
562 
563 	const struct dev_pm_ops *pm;
564 };
565 
566 /* interface for exporting device attributes */
567 struct device_attribute {
568 	struct attribute	attr;
569 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
570 			char *buf);
571 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
572 			 const char *buf, size_t count);
573 };
574 
575 struct dev_ext_attribute {
576 	struct device_attribute attr;
577 	void *var;
578 };
579 
580 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
581 			  char *buf);
582 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
583 			   const char *buf, size_t count);
584 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
585 			char *buf);
586 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
587 			 const char *buf, size_t count);
588 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
589 			char *buf);
590 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
591 			 const char *buf, size_t count);
592 
593 #define DEVICE_ATTR(_name, _mode, _show, _store) \
594 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
595 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
596 	struct device_attribute dev_attr_##_name = \
597 		__ATTR_PREALLOC(_name, _mode, _show, _store)
598 #define DEVICE_ATTR_RW(_name) \
599 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
600 #define DEVICE_ATTR_RO(_name) \
601 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
602 #define DEVICE_ATTR_WO(_name) \
603 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
604 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
605 	struct dev_ext_attribute dev_attr_##_name = \
606 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
607 #define DEVICE_INT_ATTR(_name, _mode, _var) \
608 	struct dev_ext_attribute dev_attr_##_name = \
609 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
610 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
611 	struct dev_ext_attribute dev_attr_##_name = \
612 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
613 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
614 	struct device_attribute dev_attr_##_name =		\
615 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
616 
617 extern int device_create_file(struct device *device,
618 			      const struct device_attribute *entry);
619 extern void device_remove_file(struct device *dev,
620 			       const struct device_attribute *attr);
621 extern bool device_remove_file_self(struct device *dev,
622 				    const struct device_attribute *attr);
623 extern int __must_check device_create_bin_file(struct device *dev,
624 					const struct bin_attribute *attr);
625 extern void device_remove_bin_file(struct device *dev,
626 				   const struct bin_attribute *attr);
627 
628 /* device resource management */
629 typedef void (*dr_release_t)(struct device *dev, void *res);
630 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
631 
632 #ifdef CONFIG_DEBUG_DEVRES
633 extern void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
634 				 int nid, const char *name) __malloc;
635 #define devres_alloc(release, size, gfp) \
636 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
637 #define devres_alloc_node(release, size, gfp, nid) \
638 	__devres_alloc_node(release, size, gfp, nid, #release)
639 #else
640 extern void *devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
641 			       int nid) __malloc;
642 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
643 {
644 	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
645 }
646 #endif
647 
648 extern void devres_for_each_res(struct device *dev, dr_release_t release,
649 				dr_match_t match, void *match_data,
650 				void (*fn)(struct device *, void *, void *),
651 				void *data);
652 extern void devres_free(void *res);
653 extern void devres_add(struct device *dev, void *res);
654 extern void *devres_find(struct device *dev, dr_release_t release,
655 			 dr_match_t match, void *match_data);
656 extern void *devres_get(struct device *dev, void *new_res,
657 			dr_match_t match, void *match_data);
658 extern void *devres_remove(struct device *dev, dr_release_t release,
659 			   dr_match_t match, void *match_data);
660 extern int devres_destroy(struct device *dev, dr_release_t release,
661 			  dr_match_t match, void *match_data);
662 extern int devres_release(struct device *dev, dr_release_t release,
663 			  dr_match_t match, void *match_data);
664 
665 /* devres group */
666 extern void * __must_check devres_open_group(struct device *dev, void *id,
667 					     gfp_t gfp);
668 extern void devres_close_group(struct device *dev, void *id);
669 extern void devres_remove_group(struct device *dev, void *id);
670 extern int devres_release_group(struct device *dev, void *id);
671 
672 /* managed devm_k.alloc/kfree for device drivers */
673 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
674 extern __printf(3, 0)
675 char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
676 		      va_list ap) __malloc;
677 extern __printf(3, 4)
678 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...) __malloc;
679 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
680 {
681 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
682 }
683 static inline void *devm_kmalloc_array(struct device *dev,
684 				       size_t n, size_t size, gfp_t flags)
685 {
686 	size_t bytes;
687 
688 	if (unlikely(check_mul_overflow(n, size, &bytes)))
689 		return NULL;
690 
691 	return devm_kmalloc(dev, bytes, flags);
692 }
693 static inline void *devm_kcalloc(struct device *dev,
694 				 size_t n, size_t size, gfp_t flags)
695 {
696 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
697 }
698 extern void devm_kfree(struct device *dev, const void *p);
699 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
700 extern const char *devm_kstrdup_const(struct device *dev,
701 				      const char *s, gfp_t gfp);
702 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
703 			  gfp_t gfp);
704 
705 extern unsigned long devm_get_free_pages(struct device *dev,
706 					 gfp_t gfp_mask, unsigned int order);
707 extern void devm_free_pages(struct device *dev, unsigned long addr);
708 
709 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
710 
711 void __iomem *devm_of_iomap(struct device *dev,
712 			    struct device_node *node, int index,
713 			    resource_size_t *size);
714 
715 /* allows to add/remove a custom action to devres stack */
716 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
717 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
718 
719 static inline int devm_add_action_or_reset(struct device *dev,
720 					   void (*action)(void *), void *data)
721 {
722 	int ret;
723 
724 	ret = devm_add_action(dev, action, data);
725 	if (ret)
726 		action(data);
727 
728 	return ret;
729 }
730 
731 /**
732  * devm_alloc_percpu - Resource-managed alloc_percpu
733  * @dev: Device to allocate per-cpu memory for
734  * @type: Type to allocate per-cpu memory for
735  *
736  * Managed alloc_percpu. Per-cpu memory allocated with this function is
737  * automatically freed on driver detach.
738  *
739  * RETURNS:
740  * Pointer to allocated memory on success, NULL on failure.
741  */
742 #define devm_alloc_percpu(dev, type)      \
743 	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
744 						      __alignof__(type)))
745 
746 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
747 				   size_t align);
748 void devm_free_percpu(struct device *dev, void __percpu *pdata);
749 
750 struct device_dma_parameters {
751 	/*
752 	 * a low level driver may set these to teach IOMMU code about
753 	 * sg limitations.
754 	 */
755 	unsigned int max_segment_size;
756 	unsigned long segment_boundary_mask;
757 };
758 
759 /**
760  * struct device_connection - Device Connection Descriptor
761  * @endpoint: The names of the two devices connected together
762  * @id: Unique identifier for the connection
763  * @list: List head, private, for internal use only
764  */
765 struct device_connection {
766 	const char		*endpoint[2];
767 	const char		*id;
768 	struct list_head	list;
769 };
770 
771 void *device_connection_find_match(struct device *dev, const char *con_id,
772 				void *data,
773 				void *(*match)(struct device_connection *con,
774 					       int ep, void *data));
775 
776 struct device *device_connection_find(struct device *dev, const char *con_id);
777 
778 void device_connection_add(struct device_connection *con);
779 void device_connection_remove(struct device_connection *con);
780 
781 /**
782  * device_connections_add - Add multiple device connections at once
783  * @cons: Zero terminated array of device connection descriptors
784  */
785 static inline void device_connections_add(struct device_connection *cons)
786 {
787 	struct device_connection *c;
788 
789 	for (c = cons; c->endpoint[0]; c++)
790 		device_connection_add(c);
791 }
792 
793 /**
794  * device_connections_remove - Remove multiple device connections at once
795  * @cons: Zero terminated array of device connection descriptors
796  */
797 static inline void device_connections_remove(struct device_connection *cons)
798 {
799 	struct device_connection *c;
800 
801 	for (c = cons; c->endpoint[0]; c++)
802 		device_connection_remove(c);
803 }
804 
805 /**
806  * enum device_link_state - Device link states.
807  * @DL_STATE_NONE: The presence of the drivers is not being tracked.
808  * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
809  * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
810  * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
811  * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
812  * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
813  */
814 enum device_link_state {
815 	DL_STATE_NONE = -1,
816 	DL_STATE_DORMANT = 0,
817 	DL_STATE_AVAILABLE,
818 	DL_STATE_CONSUMER_PROBE,
819 	DL_STATE_ACTIVE,
820 	DL_STATE_SUPPLIER_UNBIND,
821 };
822 
823 /*
824  * Device link flags.
825  *
826  * STATELESS: The core won't track the presence of supplier/consumer drivers.
827  * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
828  * PM_RUNTIME: If set, the runtime PM framework will use this link.
829  * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
830  * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
831  * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
832  */
833 #define DL_FLAG_STATELESS		BIT(0)
834 #define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)
835 #define DL_FLAG_PM_RUNTIME		BIT(2)
836 #define DL_FLAG_RPM_ACTIVE		BIT(3)
837 #define DL_FLAG_AUTOREMOVE_SUPPLIER	BIT(4)
838 #define DL_FLAG_AUTOPROBE_CONSUMER	BIT(5)
839 
840 /**
841  * struct device_link - Device link representation.
842  * @supplier: The device on the supplier end of the link.
843  * @s_node: Hook to the supplier device's list of links to consumers.
844  * @consumer: The device on the consumer end of the link.
845  * @c_node: Hook to the consumer device's list of links to suppliers.
846  * @status: The state of the link (with respect to the presence of drivers).
847  * @flags: Link flags.
848  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
849  * @kref: Count repeated addition of the same link.
850  * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
851  */
852 struct device_link {
853 	struct device *supplier;
854 	struct list_head s_node;
855 	struct device *consumer;
856 	struct list_head c_node;
857 	enum device_link_state status;
858 	u32 flags;
859 	refcount_t rpm_active;
860 	struct kref kref;
861 #ifdef CONFIG_SRCU
862 	struct rcu_head rcu_head;
863 #endif
864 };
865 
866 /**
867  * enum dl_dev_state - Device driver presence tracking information.
868  * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
869  * @DL_DEV_PROBING: A driver is probing.
870  * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
871  * @DL_DEV_UNBINDING: The driver is unbinding from the device.
872  */
873 enum dl_dev_state {
874 	DL_DEV_NO_DRIVER = 0,
875 	DL_DEV_PROBING,
876 	DL_DEV_DRIVER_BOUND,
877 	DL_DEV_UNBINDING,
878 };
879 
880 /**
881  * struct dev_links_info - Device data related to device links.
882  * @suppliers: List of links to supplier devices.
883  * @consumers: List of links to consumer devices.
884  * @status: Driver status information.
885  */
886 struct dev_links_info {
887 	struct list_head suppliers;
888 	struct list_head consumers;
889 	enum dl_dev_state status;
890 };
891 
892 /**
893  * struct device - The basic device structure
894  * @parent:	The device's "parent" device, the device to which it is attached.
895  * 		In most cases, a parent device is some sort of bus or host
896  * 		controller. If parent is NULL, the device, is a top-level device,
897  * 		which is not usually what you want.
898  * @p:		Holds the private data of the driver core portions of the device.
899  * 		See the comment of the struct device_private for detail.
900  * @kobj:	A top-level, abstract class from which other classes are derived.
901  * @init_name:	Initial name of the device.
902  * @type:	The type of device.
903  * 		This identifies the device type and carries type-specific
904  * 		information.
905  * @mutex:	Mutex to synchronize calls to its driver.
906  * @bus:	Type of bus device is on.
907  * @driver:	Which driver has allocated this
908  * @platform_data: Platform data specific to the device.
909  * 		Example: For devices on custom boards, as typical of embedded
910  * 		and SOC based hardware, Linux often uses platform_data to point
911  * 		to board-specific structures describing devices and how they
912  * 		are wired.  That can include what ports are available, chip
913  * 		variants, which GPIO pins act in what additional roles, and so
914  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
915  * 		minimizes board-specific #ifdefs in drivers.
916  * @driver_data: Private pointer for driver specific info.
917  * @links:	Links to suppliers and consumers of this device.
918  * @power:	For device power management.
919  *		See Documentation/driver-api/pm/devices.rst for details.
920  * @pm_domain:	Provide callbacks that are executed during system suspend,
921  * 		hibernation, system resume and during runtime PM transitions
922  * 		along with subsystem-level and driver-level callbacks.
923  * @pins:	For device pin management.
924  *		See Documentation/driver-api/pinctl.rst for details.
925  * @msi_list:	Hosts MSI descriptors
926  * @msi_domain: The generic MSI domain this device is using.
927  * @numa_node:	NUMA node this device is close to.
928  * @dma_ops:    DMA mapping operations for this device.
929  * @dma_mask:	Dma mask (if dma'ble device).
930  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
931  * 		hardware supports 64-bit addresses for consistent allocations
932  * 		such descriptors.
933  * @bus_dma_mask: Mask of an upstream bridge or bus which imposes a smaller DMA
934  *		limit than the device itself supports.
935  * @dma_pfn_offset: offset of DMA memory range relatively of RAM
936  * @dma_parms:	A low level driver may set these to teach IOMMU code about
937  * 		segment limitations.
938  * @dma_pools:	Dma pools (if dma'ble device).
939  * @dma_mem:	Internal for coherent mem override.
940  * @cma_area:	Contiguous memory area for dma allocations
941  * @archdata:	For arch-specific additions.
942  * @of_node:	Associated device tree node.
943  * @fwnode:	Associated device node supplied by platform firmware.
944  * @devt:	For creating the sysfs "dev".
945  * @id:		device instance
946  * @devres_lock: Spinlock to protect the resource of the device.
947  * @devres_head: The resources list of the device.
948  * @knode_class: The node used to add the device to the class list.
949  * @class:	The class of the device.
950  * @groups:	Optional attribute groups.
951  * @release:	Callback to free the device after all references have
952  * 		gone away. This should be set by the allocator of the
953  * 		device (i.e. the bus driver that discovered the device).
954  * @iommu_group: IOMMU group the device belongs to.
955  * @iommu_fwspec: IOMMU-specific properties supplied by firmware.
956  *
957  * @offline_disabled: If set, the device is permanently online.
958  * @offline:	Set after successful invocation of bus type's .offline().
959  * @of_node_reused: Set if the device-tree node is shared with an ancestor
960  *              device.
961  * @dma_coherent: this particular device is dma coherent, even if the
962  *		architecture supports non-coherent devices.
963  *
964  * At the lowest level, every device in a Linux system is represented by an
965  * instance of struct device. The device structure contains the information
966  * that the device model core needs to model the system. Most subsystems,
967  * however, track additional information about the devices they host. As a
968  * result, it is rare for devices to be represented by bare device structures;
969  * instead, that structure, like kobject structures, is usually embedded within
970  * a higher-level representation of the device.
971  */
972 struct device {
973 	struct device		*parent;
974 
975 	struct device_private	*p;
976 
977 	struct kobject kobj;
978 	const char		*init_name; /* initial name of the device */
979 	const struct device_type *type;
980 
981 	struct mutex		mutex;	/* mutex to synchronize calls to
982 					 * its driver.
983 					 */
984 
985 	struct bus_type	*bus;		/* type of bus device is on */
986 	struct device_driver *driver;	/* which driver has allocated this
987 					   device */
988 	void		*platform_data;	/* Platform specific data, device
989 					   core doesn't touch it */
990 	void		*driver_data;	/* Driver data, set and get with
991 					   dev_set_drvdata/dev_get_drvdata */
992 	struct dev_links_info	links;
993 	struct dev_pm_info	power;
994 	struct dev_pm_domain	*pm_domain;
995 
996 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
997 	struct irq_domain	*msi_domain;
998 #endif
999 #ifdef CONFIG_PINCTRL
1000 	struct dev_pin_info	*pins;
1001 #endif
1002 #ifdef CONFIG_GENERIC_MSI_IRQ
1003 	struct list_head	msi_list;
1004 #endif
1005 
1006 #ifdef CONFIG_NUMA
1007 	int		numa_node;	/* NUMA node this device is close to */
1008 #endif
1009 	const struct dma_map_ops *dma_ops;
1010 	u64		*dma_mask;	/* dma mask (if dma'able device) */
1011 	u64		coherent_dma_mask;/* Like dma_mask, but for
1012 					     alloc_coherent mappings as
1013 					     not all hardware supports
1014 					     64 bit addresses for consistent
1015 					     allocations such descriptors. */
1016 	u64		bus_dma_mask;	/* upstream dma_mask constraint */
1017 	unsigned long	dma_pfn_offset;
1018 
1019 	struct device_dma_parameters *dma_parms;
1020 
1021 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
1022 
1023 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
1024 					     override */
1025 #ifdef CONFIG_DMA_CMA
1026 	struct cma *cma_area;		/* contiguous memory area for dma
1027 					   allocations */
1028 #endif
1029 	/* arch specific additions */
1030 	struct dev_archdata	archdata;
1031 
1032 	struct device_node	*of_node; /* associated device tree node */
1033 	struct fwnode_handle	*fwnode; /* firmware device node */
1034 
1035 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
1036 	u32			id;	/* device instance */
1037 
1038 	spinlock_t		devres_lock;
1039 	struct list_head	devres_head;
1040 
1041 	struct class		*class;
1042 	const struct attribute_group **groups;	/* optional groups */
1043 
1044 	void	(*release)(struct device *dev);
1045 	struct iommu_group	*iommu_group;
1046 	struct iommu_fwspec	*iommu_fwspec;
1047 
1048 	bool			offline_disabled:1;
1049 	bool			offline:1;
1050 	bool			of_node_reused:1;
1051 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
1052     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
1053     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
1054 	bool			dma_coherent:1;
1055 #endif
1056 };
1057 
1058 static inline struct device *kobj_to_dev(struct kobject *kobj)
1059 {
1060 	return container_of(kobj, struct device, kobj);
1061 }
1062 
1063 /**
1064  * device_iommu_mapped - Returns true when the device DMA is translated
1065  *			 by an IOMMU
1066  * @dev: Device to perform the check on
1067  */
1068 static inline bool device_iommu_mapped(struct device *dev)
1069 {
1070 	return (dev->iommu_group != NULL);
1071 }
1072 
1073 /* Get the wakeup routines, which depend on struct device */
1074 #include <linux/pm_wakeup.h>
1075 
1076 static inline const char *dev_name(const struct device *dev)
1077 {
1078 	/* Use the init name until the kobject becomes available */
1079 	if (dev->init_name)
1080 		return dev->init_name;
1081 
1082 	return kobject_name(&dev->kobj);
1083 }
1084 
1085 extern __printf(2, 3)
1086 int dev_set_name(struct device *dev, const char *name, ...);
1087 
1088 #ifdef CONFIG_NUMA
1089 static inline int dev_to_node(struct device *dev)
1090 {
1091 	return dev->numa_node;
1092 }
1093 static inline void set_dev_node(struct device *dev, int node)
1094 {
1095 	dev->numa_node = node;
1096 }
1097 #else
1098 static inline int dev_to_node(struct device *dev)
1099 {
1100 	return -1;
1101 }
1102 static inline void set_dev_node(struct device *dev, int node)
1103 {
1104 }
1105 #endif
1106 
1107 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
1108 {
1109 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1110 	return dev->msi_domain;
1111 #else
1112 	return NULL;
1113 #endif
1114 }
1115 
1116 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
1117 {
1118 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1119 	dev->msi_domain = d;
1120 #endif
1121 }
1122 
1123 static inline void *dev_get_drvdata(const struct device *dev)
1124 {
1125 	return dev->driver_data;
1126 }
1127 
1128 static inline void dev_set_drvdata(struct device *dev, void *data)
1129 {
1130 	dev->driver_data = data;
1131 }
1132 
1133 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
1134 {
1135 	return dev ? dev->power.subsys_data : NULL;
1136 }
1137 
1138 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
1139 {
1140 	return dev->kobj.uevent_suppress;
1141 }
1142 
1143 static inline void dev_set_uevent_suppress(struct device *dev, int val)
1144 {
1145 	dev->kobj.uevent_suppress = val;
1146 }
1147 
1148 static inline int device_is_registered(struct device *dev)
1149 {
1150 	return dev->kobj.state_in_sysfs;
1151 }
1152 
1153 static inline void device_enable_async_suspend(struct device *dev)
1154 {
1155 	if (!dev->power.is_prepared)
1156 		dev->power.async_suspend = true;
1157 }
1158 
1159 static inline void device_disable_async_suspend(struct device *dev)
1160 {
1161 	if (!dev->power.is_prepared)
1162 		dev->power.async_suspend = false;
1163 }
1164 
1165 static inline bool device_async_suspend_enabled(struct device *dev)
1166 {
1167 	return !!dev->power.async_suspend;
1168 }
1169 
1170 static inline void dev_pm_syscore_device(struct device *dev, bool val)
1171 {
1172 #ifdef CONFIG_PM_SLEEP
1173 	dev->power.syscore = val;
1174 #endif
1175 }
1176 
1177 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
1178 {
1179 	dev->power.driver_flags = flags;
1180 }
1181 
1182 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
1183 {
1184 	return !!(dev->power.driver_flags & flags);
1185 }
1186 
1187 static inline void device_lock(struct device *dev)
1188 {
1189 	mutex_lock(&dev->mutex);
1190 }
1191 
1192 static inline int device_lock_interruptible(struct device *dev)
1193 {
1194 	return mutex_lock_interruptible(&dev->mutex);
1195 }
1196 
1197 static inline int device_trylock(struct device *dev)
1198 {
1199 	return mutex_trylock(&dev->mutex);
1200 }
1201 
1202 static inline void device_unlock(struct device *dev)
1203 {
1204 	mutex_unlock(&dev->mutex);
1205 }
1206 
1207 static inline void device_lock_assert(struct device *dev)
1208 {
1209 	lockdep_assert_held(&dev->mutex);
1210 }
1211 
1212 static inline struct device_node *dev_of_node(struct device *dev)
1213 {
1214 	if (!IS_ENABLED(CONFIG_OF))
1215 		return NULL;
1216 	return dev->of_node;
1217 }
1218 
1219 void driver_init(void);
1220 
1221 /*
1222  * High level routines for use by the bus drivers
1223  */
1224 extern int __must_check device_register(struct device *dev);
1225 extern void device_unregister(struct device *dev);
1226 extern void device_initialize(struct device *dev);
1227 extern int __must_check device_add(struct device *dev);
1228 extern void device_del(struct device *dev);
1229 extern int device_for_each_child(struct device *dev, void *data,
1230 		     int (*fn)(struct device *dev, void *data));
1231 extern int device_for_each_child_reverse(struct device *dev, void *data,
1232 		     int (*fn)(struct device *dev, void *data));
1233 extern struct device *device_find_child(struct device *dev, void *data,
1234 				int (*match)(struct device *dev, void *data));
1235 extern int device_rename(struct device *dev, const char *new_name);
1236 extern int device_move(struct device *dev, struct device *new_parent,
1237 		       enum dpm_order dpm_order);
1238 extern const char *device_get_devnode(struct device *dev,
1239 				      umode_t *mode, kuid_t *uid, kgid_t *gid,
1240 				      const char **tmp);
1241 
1242 static inline bool device_supports_offline(struct device *dev)
1243 {
1244 	return dev->bus && dev->bus->offline && dev->bus->online;
1245 }
1246 
1247 extern void lock_device_hotplug(void);
1248 extern void unlock_device_hotplug(void);
1249 extern int lock_device_hotplug_sysfs(void);
1250 extern int device_offline(struct device *dev);
1251 extern int device_online(struct device *dev);
1252 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1253 extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1254 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
1255 
1256 static inline int dev_num_vf(struct device *dev)
1257 {
1258 	if (dev->bus && dev->bus->num_vf)
1259 		return dev->bus->num_vf(dev);
1260 	return 0;
1261 }
1262 
1263 /*
1264  * Root device objects for grouping under /sys/devices
1265  */
1266 extern struct device *__root_device_register(const char *name,
1267 					     struct module *owner);
1268 
1269 /* This is a macro to avoid include problems with THIS_MODULE */
1270 #define root_device_register(name) \
1271 	__root_device_register(name, THIS_MODULE)
1272 
1273 extern void root_device_unregister(struct device *root);
1274 
1275 static inline void *dev_get_platdata(const struct device *dev)
1276 {
1277 	return dev->platform_data;
1278 }
1279 
1280 /*
1281  * Manual binding of a device to driver. See drivers/base/bus.c
1282  * for information on use.
1283  */
1284 extern int __must_check device_bind_driver(struct device *dev);
1285 extern void device_release_driver(struct device *dev);
1286 extern int  __must_check device_attach(struct device *dev);
1287 extern int __must_check driver_attach(struct device_driver *drv);
1288 extern void device_initial_probe(struct device *dev);
1289 extern int __must_check device_reprobe(struct device *dev);
1290 
1291 extern bool device_is_bound(struct device *dev);
1292 
1293 /*
1294  * Easy functions for dynamically creating devices on the fly
1295  */
1296 extern __printf(5, 0)
1297 struct device *device_create_vargs(struct class *cls, struct device *parent,
1298 				   dev_t devt, void *drvdata,
1299 				   const char *fmt, va_list vargs);
1300 extern __printf(5, 6)
1301 struct device *device_create(struct class *cls, struct device *parent,
1302 			     dev_t devt, void *drvdata,
1303 			     const char *fmt, ...);
1304 extern __printf(6, 7)
1305 struct device *device_create_with_groups(struct class *cls,
1306 			     struct device *parent, dev_t devt, void *drvdata,
1307 			     const struct attribute_group **groups,
1308 			     const char *fmt, ...);
1309 extern void device_destroy(struct class *cls, dev_t devt);
1310 
1311 extern int __must_check device_add_groups(struct device *dev,
1312 					const struct attribute_group **groups);
1313 extern void device_remove_groups(struct device *dev,
1314 				 const struct attribute_group **groups);
1315 
1316 static inline int __must_check device_add_group(struct device *dev,
1317 					const struct attribute_group *grp)
1318 {
1319 	const struct attribute_group *groups[] = { grp, NULL };
1320 
1321 	return device_add_groups(dev, groups);
1322 }
1323 
1324 static inline void device_remove_group(struct device *dev,
1325 				       const struct attribute_group *grp)
1326 {
1327 	const struct attribute_group *groups[] = { grp, NULL };
1328 
1329 	return device_remove_groups(dev, groups);
1330 }
1331 
1332 extern int __must_check devm_device_add_groups(struct device *dev,
1333 					const struct attribute_group **groups);
1334 extern void devm_device_remove_groups(struct device *dev,
1335 				      const struct attribute_group **groups);
1336 extern int __must_check devm_device_add_group(struct device *dev,
1337 					const struct attribute_group *grp);
1338 extern void devm_device_remove_group(struct device *dev,
1339 				     const struct attribute_group *grp);
1340 
1341 /*
1342  * Platform "fixup" functions - allow the platform to have their say
1343  * about devices and actions that the general device layer doesn't
1344  * know about.
1345  */
1346 /* Notify platform of device discovery */
1347 extern int (*platform_notify)(struct device *dev);
1348 
1349 extern int (*platform_notify_remove)(struct device *dev);
1350 
1351 
1352 /*
1353  * get_device - atomically increment the reference count for the device.
1354  *
1355  */
1356 extern struct device *get_device(struct device *dev);
1357 extern void put_device(struct device *dev);
1358 
1359 #ifdef CONFIG_DEVTMPFS
1360 extern int devtmpfs_create_node(struct device *dev);
1361 extern int devtmpfs_delete_node(struct device *dev);
1362 extern int devtmpfs_mount(const char *mntdir);
1363 #else
1364 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
1365 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
1366 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
1367 #endif
1368 
1369 /* drivers/base/power/shutdown.c */
1370 extern void device_shutdown(void);
1371 
1372 /* debugging and troubleshooting/diagnostic helpers. */
1373 extern const char *dev_driver_string(const struct device *dev);
1374 
1375 /* Device links interface. */
1376 struct device_link *device_link_add(struct device *consumer,
1377 				    struct device *supplier, u32 flags);
1378 void device_link_del(struct device_link *link);
1379 void device_link_remove(void *consumer, struct device *supplier);
1380 
1381 #ifndef dev_fmt
1382 #define dev_fmt(fmt) fmt
1383 #endif
1384 
1385 #ifdef CONFIG_PRINTK
1386 
1387 __printf(3, 0) __cold
1388 int dev_vprintk_emit(int level, const struct device *dev,
1389 		     const char *fmt, va_list args);
1390 __printf(3, 4) __cold
1391 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
1392 
1393 __printf(3, 4) __cold
1394 void dev_printk(const char *level, const struct device *dev,
1395 		const char *fmt, ...);
1396 __printf(2, 3) __cold
1397 void _dev_emerg(const struct device *dev, const char *fmt, ...);
1398 __printf(2, 3) __cold
1399 void _dev_alert(const struct device *dev, const char *fmt, ...);
1400 __printf(2, 3) __cold
1401 void _dev_crit(const struct device *dev, const char *fmt, ...);
1402 __printf(2, 3) __cold
1403 void _dev_err(const struct device *dev, const char *fmt, ...);
1404 __printf(2, 3) __cold
1405 void _dev_warn(const struct device *dev, const char *fmt, ...);
1406 __printf(2, 3) __cold
1407 void _dev_notice(const struct device *dev, const char *fmt, ...);
1408 __printf(2, 3) __cold
1409 void _dev_info(const struct device *dev, const char *fmt, ...);
1410 
1411 #else
1412 
1413 static inline __printf(3, 0)
1414 int dev_vprintk_emit(int level, const struct device *dev,
1415 		     const char *fmt, va_list args)
1416 { return 0; }
1417 static inline __printf(3, 4)
1418 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1419 { return 0; }
1420 
1421 static inline void __dev_printk(const char *level, const struct device *dev,
1422 				struct va_format *vaf)
1423 {}
1424 static inline __printf(3, 4)
1425 void dev_printk(const char *level, const struct device *dev,
1426 		 const char *fmt, ...)
1427 {}
1428 
1429 static inline __printf(2, 3)
1430 void _dev_emerg(const struct device *dev, const char *fmt, ...)
1431 {}
1432 static inline __printf(2, 3)
1433 void _dev_crit(const struct device *dev, const char *fmt, ...)
1434 {}
1435 static inline __printf(2, 3)
1436 void _dev_alert(const struct device *dev, const char *fmt, ...)
1437 {}
1438 static inline __printf(2, 3)
1439 void _dev_err(const struct device *dev, const char *fmt, ...)
1440 {}
1441 static inline __printf(2, 3)
1442 void _dev_warn(const struct device *dev, const char *fmt, ...)
1443 {}
1444 static inline __printf(2, 3)
1445 void _dev_notice(const struct device *dev, const char *fmt, ...)
1446 {}
1447 static inline __printf(2, 3)
1448 void _dev_info(const struct device *dev, const char *fmt, ...)
1449 {}
1450 
1451 #endif
1452 
1453 /*
1454  * #defines for all the dev_<level> macros to prefix with whatever
1455  * possible use of #define dev_fmt(fmt) ...
1456  */
1457 
1458 #define dev_emerg(dev, fmt, ...)					\
1459 	_dev_emerg(dev, dev_fmt(fmt), ##__VA_ARGS__)
1460 #define dev_crit(dev, fmt, ...)						\
1461 	_dev_crit(dev, dev_fmt(fmt), ##__VA_ARGS__)
1462 #define dev_alert(dev, fmt, ...)					\
1463 	_dev_alert(dev, dev_fmt(fmt), ##__VA_ARGS__)
1464 #define dev_err(dev, fmt, ...)						\
1465 	_dev_err(dev, dev_fmt(fmt), ##__VA_ARGS__)
1466 #define dev_warn(dev, fmt, ...)						\
1467 	_dev_warn(dev, dev_fmt(fmt), ##__VA_ARGS__)
1468 #define dev_notice(dev, fmt, ...)					\
1469 	_dev_notice(dev, dev_fmt(fmt), ##__VA_ARGS__)
1470 #define dev_info(dev, fmt, ...)						\
1471 	_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
1472 
1473 #if defined(CONFIG_DYNAMIC_DEBUG)
1474 #define dev_dbg(dev, fmt, ...)						\
1475 	dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
1476 #elif defined(DEBUG)
1477 #define dev_dbg(dev, fmt, ...)						\
1478 	dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__)
1479 #else
1480 #define dev_dbg(dev, fmt, ...)						\
1481 ({									\
1482 	if (0)								\
1483 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1484 })
1485 #endif
1486 
1487 #ifdef CONFIG_PRINTK
1488 #define dev_level_once(dev_level, dev, fmt, ...)			\
1489 do {									\
1490 	static bool __print_once __read_mostly;				\
1491 									\
1492 	if (!__print_once) {						\
1493 		__print_once = true;					\
1494 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1495 	}								\
1496 } while (0)
1497 #else
1498 #define dev_level_once(dev_level, dev, fmt, ...)			\
1499 do {									\
1500 	if (0)								\
1501 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1502 } while (0)
1503 #endif
1504 
1505 #define dev_emerg_once(dev, fmt, ...)					\
1506 	dev_level_once(dev_emerg, dev, fmt, ##__VA_ARGS__)
1507 #define dev_alert_once(dev, fmt, ...)					\
1508 	dev_level_once(dev_alert, dev, fmt, ##__VA_ARGS__)
1509 #define dev_crit_once(dev, fmt, ...)					\
1510 	dev_level_once(dev_crit, dev, fmt, ##__VA_ARGS__)
1511 #define dev_err_once(dev, fmt, ...)					\
1512 	dev_level_once(dev_err, dev, fmt, ##__VA_ARGS__)
1513 #define dev_warn_once(dev, fmt, ...)					\
1514 	dev_level_once(dev_warn, dev, fmt, ##__VA_ARGS__)
1515 #define dev_notice_once(dev, fmt, ...)					\
1516 	dev_level_once(dev_notice, dev, fmt, ##__VA_ARGS__)
1517 #define dev_info_once(dev, fmt, ...)					\
1518 	dev_level_once(dev_info, dev, fmt, ##__VA_ARGS__)
1519 #define dev_dbg_once(dev, fmt, ...)					\
1520 	dev_level_once(dev_dbg, dev, fmt, ##__VA_ARGS__)
1521 
1522 #define dev_level_ratelimited(dev_level, dev, fmt, ...)			\
1523 do {									\
1524 	static DEFINE_RATELIMIT_STATE(_rs,				\
1525 				      DEFAULT_RATELIMIT_INTERVAL,	\
1526 				      DEFAULT_RATELIMIT_BURST);		\
1527 	if (__ratelimit(&_rs))						\
1528 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1529 } while (0)
1530 
1531 #define dev_emerg_ratelimited(dev, fmt, ...)				\
1532 	dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
1533 #define dev_alert_ratelimited(dev, fmt, ...)				\
1534 	dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
1535 #define dev_crit_ratelimited(dev, fmt, ...)				\
1536 	dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
1537 #define dev_err_ratelimited(dev, fmt, ...)				\
1538 	dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
1539 #define dev_warn_ratelimited(dev, fmt, ...)				\
1540 	dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
1541 #define dev_notice_ratelimited(dev, fmt, ...)				\
1542 	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
1543 #define dev_info_ratelimited(dev, fmt, ...)				\
1544 	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
1545 #if defined(CONFIG_DYNAMIC_DEBUG)
1546 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
1547 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1548 do {									\
1549 	static DEFINE_RATELIMIT_STATE(_rs,				\
1550 				      DEFAULT_RATELIMIT_INTERVAL,	\
1551 				      DEFAULT_RATELIMIT_BURST);		\
1552 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
1553 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
1554 	    __ratelimit(&_rs))						\
1555 		__dynamic_dev_dbg(&descriptor, dev, dev_fmt(fmt),	\
1556 				  ##__VA_ARGS__);			\
1557 } while (0)
1558 #elif defined(DEBUG)
1559 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1560 do {									\
1561 	static DEFINE_RATELIMIT_STATE(_rs,				\
1562 				      DEFAULT_RATELIMIT_INTERVAL,	\
1563 				      DEFAULT_RATELIMIT_BURST);		\
1564 	if (__ratelimit(&_rs))						\
1565 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1566 } while (0)
1567 #else
1568 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1569 do {									\
1570 	if (0)								\
1571 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1572 } while (0)
1573 #endif
1574 
1575 #ifdef VERBOSE_DEBUG
1576 #define dev_vdbg	dev_dbg
1577 #else
1578 #define dev_vdbg(dev, fmt, ...)						\
1579 ({									\
1580 	if (0)								\
1581 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1582 })
1583 #endif
1584 
1585 /*
1586  * dev_WARN*() acts like dev_printk(), but with the key difference of
1587  * using WARN/WARN_ONCE to include file/line information and a backtrace.
1588  */
1589 #define dev_WARN(dev, format, arg...) \
1590 	WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
1591 
1592 #define dev_WARN_ONCE(dev, condition, format, arg...) \
1593 	WARN_ONCE(condition, "%s %s: " format, \
1594 			dev_driver_string(dev), dev_name(dev), ## arg)
1595 
1596 /* Create alias, so I can be autoloaded. */
1597 #define MODULE_ALIAS_CHARDEV(major,minor) \
1598 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1599 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1600 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
1601 
1602 #ifdef CONFIG_SYSFS_DEPRECATED
1603 extern long sysfs_deprecated;
1604 #else
1605 #define sysfs_deprecated 0
1606 #endif
1607 
1608 /**
1609  * module_driver() - Helper macro for drivers that don't do anything
1610  * special in module init/exit. This eliminates a lot of boilerplate.
1611  * Each module may only use this macro once, and calling it replaces
1612  * module_init() and module_exit().
1613  *
1614  * @__driver: driver name
1615  * @__register: register function for this driver type
1616  * @__unregister: unregister function for this driver type
1617  * @...: Additional arguments to be passed to __register and __unregister.
1618  *
1619  * Use this macro to construct bus specific macros for registering
1620  * drivers, and do not use it on its own.
1621  */
1622 #define module_driver(__driver, __register, __unregister, ...) \
1623 static int __init __driver##_init(void) \
1624 { \
1625 	return __register(&(__driver) , ##__VA_ARGS__); \
1626 } \
1627 module_init(__driver##_init); \
1628 static void __exit __driver##_exit(void) \
1629 { \
1630 	__unregister(&(__driver) , ##__VA_ARGS__); \
1631 } \
1632 module_exit(__driver##_exit);
1633 
1634 /**
1635  * builtin_driver() - Helper macro for drivers that don't do anything
1636  * special in init and have no exit. This eliminates some boilerplate.
1637  * Each driver may only use this macro once, and calling it replaces
1638  * device_initcall (or in some cases, the legacy __initcall).  This is
1639  * meant to be a direct parallel of module_driver() above but without
1640  * the __exit stuff that is not used for builtin cases.
1641  *
1642  * @__driver: driver name
1643  * @__register: register function for this driver type
1644  * @...: Additional arguments to be passed to __register
1645  *
1646  * Use this macro to construct bus specific macros for registering
1647  * drivers, and do not use it on its own.
1648  */
1649 #define builtin_driver(__driver, __register, ...) \
1650 static int __init __driver##_init(void) \
1651 { \
1652 	return __register(&(__driver) , ##__VA_ARGS__); \
1653 } \
1654 device_initcall(__driver##_init);
1655 
1656 #endif /* _DEVICE_H_ */
1657