xref: /linux-6.15/include/linux/device.h (revision cfba5de9)
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-api/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 struct iommu_param;
46 
47 struct bus_attribute {
48 	struct attribute	attr;
49 	ssize_t (*show)(struct bus_type *bus, char *buf);
50 	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
51 };
52 
53 #define BUS_ATTR_RW(_name) \
54 	struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
55 #define BUS_ATTR_RO(_name) \
56 	struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
57 #define BUS_ATTR_WO(_name) \
58 	struct bus_attribute bus_attr_##_name = __ATTR_WO(_name)
59 
60 extern int __must_check bus_create_file(struct bus_type *,
61 					struct bus_attribute *);
62 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
63 
64 /**
65  * struct bus_type - The bus type of the device
66  *
67  * @name:	The name of the bus.
68  * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
69  * @dev_root:	Default device to use as the parent.
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  * @num_vf:	Called to find out how many virtual functions a device on this
92  *		bus supports.
93  * @dma_configure:	Called to setup DMA configuration on a device on
94  *			this bus.
95  * @pm:		Power management operations of this bus, callback the specific
96  *		device driver's pm-ops.
97  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
98  *              driver implementations to a bus and allow the driver to do
99  *              bus-specific setup
100  * @p:		The private data of the driver core, only the driver core can
101  *		touch this.
102  * @lock_key:	Lock class key for use by the lock validator
103  * @need_parent_lock:	When probing or removing a device on this bus, the
104  *			device core should lock the device's parent.
105  *
106  * A bus is a channel between the processor and one or more devices. For the
107  * purposes of the device model, all devices are connected via a bus, even if
108  * it is an internal, virtual, "platform" bus. Buses can plug into each other.
109  * A USB controller is usually a PCI device, for example. The device model
110  * represents the actual connections between buses and the devices they control.
111  * A bus is represented by the bus_type structure. It contains the name, the
112  * default attributes, the bus' methods, PM operations, and the driver core's
113  * private data.
114  */
115 struct bus_type {
116 	const char		*name;
117 	const char		*dev_name;
118 	struct device		*dev_root;
119 	const struct attribute_group **bus_groups;
120 	const struct attribute_group **dev_groups;
121 	const struct attribute_group **drv_groups;
122 
123 	int (*match)(struct device *dev, struct device_driver *drv);
124 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
125 	int (*probe)(struct device *dev);
126 	int (*remove)(struct device *dev);
127 	void (*shutdown)(struct device *dev);
128 
129 	int (*online)(struct device *dev);
130 	int (*offline)(struct device *dev);
131 
132 	int (*suspend)(struct device *dev, pm_message_t state);
133 	int (*resume)(struct device *dev);
134 
135 	int (*num_vf)(struct device *dev);
136 
137 	int (*dma_configure)(struct device *dev);
138 
139 	const struct dev_pm_ops *pm;
140 
141 	const struct iommu_ops *iommu_ops;
142 
143 	struct subsys_private *p;
144 	struct lock_class_key lock_key;
145 
146 	bool need_parent_lock;
147 };
148 
149 extern int __must_check bus_register(struct bus_type *bus);
150 
151 extern void bus_unregister(struct bus_type *bus);
152 
153 extern int __must_check bus_rescan_devices(struct bus_type *bus);
154 
155 /* iterator helpers for buses */
156 struct subsys_dev_iter {
157 	struct klist_iter		ki;
158 	const struct device_type	*type;
159 };
160 void subsys_dev_iter_init(struct subsys_dev_iter *iter,
161 			 struct bus_type *subsys,
162 			 struct device *start,
163 			 const struct device_type *type);
164 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
165 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
166 
167 int device_match_name(struct device *dev, const void *name);
168 int device_match_of_node(struct device *dev, const void *np);
169 
170 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
171 		     int (*fn)(struct device *dev, void *data));
172 struct device *bus_find_device(struct bus_type *bus, struct device *start,
173 			       const void *data,
174 			       int (*match)(struct device *dev, const void *data));
175 /**
176  * bus_find_device_by_name - device iterator for locating a particular device
177  * of a specific name.
178  * @bus: bus type
179  * @start: Device to begin with
180  * @name: name of the device to match
181  */
182 static inline struct device *bus_find_device_by_name(struct bus_type *bus,
183 						     struct device *start,
184 						     const char *name)
185 {
186 	return bus_find_device(bus, start, name, device_match_name);
187 }
188 
189 /**
190  * bus_find_device_by_of_node : device iterator for locating a particular device
191  * matching the of_node.
192  * @bus: bus type
193  * @np: of_node of the device to match.
194  */
195 static inline struct device *
196 bus_find_device_by_of_node(struct bus_type *bus, const struct device_node *np)
197 {
198 	return bus_find_device(bus, NULL, np, device_match_of_node);
199 }
200 
201 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
202 					struct device *hint);
203 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
204 		     void *data, int (*fn)(struct device_driver *, void *));
205 void bus_sort_breadthfirst(struct bus_type *bus,
206 			   int (*compare)(const struct device *a,
207 					  const struct device *b));
208 /*
209  * Bus notifiers: Get notified of addition/removal of devices
210  * and binding/unbinding of drivers to devices.
211  * In the long run, it should be a replacement for the platform
212  * notify hooks.
213  */
214 struct notifier_block;
215 
216 extern int bus_register_notifier(struct bus_type *bus,
217 				 struct notifier_block *nb);
218 extern int bus_unregister_notifier(struct bus_type *bus,
219 				   struct notifier_block *nb);
220 
221 /* All 4 notifers below get called with the target struct device *
222  * as an argument. Note that those functions are likely to be called
223  * with the device lock held in the core, so be careful.
224  */
225 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
226 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device to be removed */
227 #define BUS_NOTIFY_REMOVED_DEVICE	0x00000003 /* device removed */
228 #define BUS_NOTIFY_BIND_DRIVER		0x00000004 /* driver about to be
229 						      bound */
230 #define BUS_NOTIFY_BOUND_DRIVER		0x00000005 /* driver bound to device */
231 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000006 /* driver about to be
232 						      unbound */
233 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000007 /* driver is unbound
234 						      from the device */
235 #define BUS_NOTIFY_DRIVER_NOT_BOUND	0x00000008 /* driver fails to be bound */
236 
237 extern struct kset *bus_get_kset(struct bus_type *bus);
238 extern struct klist *bus_get_device_klist(struct bus_type *bus);
239 
240 /**
241  * enum probe_type - device driver probe type to try
242  *	Device drivers may opt in for special handling of their
243  *	respective probe routines. This tells the core what to
244  *	expect and prefer.
245  *
246  * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
247  *	whether probed synchronously or asynchronously.
248  * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
249  *	probing order is not essential for booting the system may
250  *	opt into executing their probes asynchronously.
251  * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
252  *	their probe routines to run synchronously with driver and
253  *	device registration (with the exception of -EPROBE_DEFER
254  *	handling - re-probing always ends up being done asynchronously).
255  *
256  * Note that the end goal is to switch the kernel to use asynchronous
257  * probing by default, so annotating drivers with
258  * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
259  * to speed up boot process while we are validating the rest of the
260  * drivers.
261  */
262 enum probe_type {
263 	PROBE_DEFAULT_STRATEGY,
264 	PROBE_PREFER_ASYNCHRONOUS,
265 	PROBE_FORCE_SYNCHRONOUS,
266 };
267 
268 /**
269  * struct device_driver - The basic device driver structure
270  * @name:	Name of the device driver.
271  * @bus:	The bus which the device of this driver belongs to.
272  * @owner:	The module owner.
273  * @mod_name:	Used for built-in modules.
274  * @suppress_bind_attrs: Disables bind/unbind via sysfs.
275  * @probe_type:	Type of the probe (synchronous or asynchronous) to use.
276  * @of_match_table: The open firmware table.
277  * @acpi_match_table: The ACPI match table.
278  * @probe:	Called to query the existence of a specific device,
279  *		whether this driver can work with it, and bind the driver
280  *		to a specific device.
281  * @remove:	Called when the device is removed from the system to
282  *		unbind a device from this driver.
283  * @shutdown:	Called at shut-down time to quiesce the device.
284  * @suspend:	Called to put the device to sleep mode. Usually to a
285  *		low power state.
286  * @resume:	Called to bring a device from sleep mode.
287  * @groups:	Default attributes that get created by the driver core
288  *		automatically.
289  * @pm:		Power management operations of the device which matched
290  *		this driver.
291  * @coredump:	Called when sysfs entry is written to. The device driver
292  *		is expected to call the dev_coredump API resulting in a
293  *		uevent.
294  * @p:		Driver core's private data, no one other than the driver
295  *		core can touch this.
296  *
297  * The device driver-model tracks all of the drivers known to the system.
298  * The main reason for this tracking is to enable the driver core to match
299  * up drivers with new devices. Once drivers are known objects within the
300  * system, however, a number of other things become possible. Device drivers
301  * can export information and configuration variables that are independent
302  * of any specific device.
303  */
304 struct device_driver {
305 	const char		*name;
306 	struct bus_type		*bus;
307 
308 	struct module		*owner;
309 	const char		*mod_name;	/* used for built-in modules */
310 
311 	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */
312 	enum probe_type probe_type;
313 
314 	const struct of_device_id	*of_match_table;
315 	const struct acpi_device_id	*acpi_match_table;
316 
317 	int (*probe) (struct device *dev);
318 	int (*remove) (struct device *dev);
319 	void (*shutdown) (struct device *dev);
320 	int (*suspend) (struct device *dev, pm_message_t state);
321 	int (*resume) (struct device *dev);
322 	const struct attribute_group **groups;
323 
324 	const struct dev_pm_ops *pm;
325 	void (*coredump) (struct device *dev);
326 
327 	struct driver_private *p;
328 };
329 
330 
331 extern int __must_check driver_register(struct device_driver *drv);
332 extern void driver_unregister(struct device_driver *drv);
333 
334 extern struct device_driver *driver_find(const char *name,
335 					 struct bus_type *bus);
336 extern int driver_probe_done(void);
337 extern void wait_for_device_probe(void);
338 
339 /* sysfs interface for exporting driver attributes */
340 
341 struct driver_attribute {
342 	struct attribute attr;
343 	ssize_t (*show)(struct device_driver *driver, char *buf);
344 	ssize_t (*store)(struct device_driver *driver, const char *buf,
345 			 size_t count);
346 };
347 
348 #define DRIVER_ATTR_RW(_name) \
349 	struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
350 #define DRIVER_ATTR_RO(_name) \
351 	struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
352 #define DRIVER_ATTR_WO(_name) \
353 	struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
354 
355 extern int __must_check driver_create_file(struct device_driver *driver,
356 					const struct driver_attribute *attr);
357 extern void driver_remove_file(struct device_driver *driver,
358 			       const struct driver_attribute *attr);
359 
360 extern int __must_check driver_for_each_device(struct device_driver *drv,
361 					       struct device *start,
362 					       void *data,
363 					       int (*fn)(struct device *dev,
364 							 void *));
365 struct device *driver_find_device(struct device_driver *drv,
366 				  struct device *start, const void *data,
367 				  int (*match)(struct device *dev, const void *data));
368 
369 /**
370  * driver_find_device_by_name - device iterator for locating a particular device
371  * of a specific name.
372  * @driver: the driver we're iterating
373  * @name: name of the device to match
374  */
375 static inline struct device *driver_find_device_by_name(struct device_driver *drv,
376 							const char *name)
377 {
378 	return driver_find_device(drv, NULL, name, device_match_name);
379 }
380 
381 /**
382  * driver_find_device_by_of_node- device iterator for locating a particular device
383  * by of_node pointer.
384  * @driver: the driver we're iterating
385  * @np: of_node pointer to match.
386  */
387 static inline struct device *
388 driver_find_device_by_of_node(struct device_driver *drv,
389 			      const struct device_node *np)
390 {
391 	return driver_find_device(drv, NULL, np, device_match_of_node);
392 }
393 
394 void driver_deferred_probe_add(struct device *dev);
395 int driver_deferred_probe_check_state(struct device *dev);
396 int driver_deferred_probe_check_state_continue(struct device *dev);
397 
398 /**
399  * struct subsys_interface - interfaces to device functions
400  * @name:       name of the device function
401  * @subsys:     subsytem of the devices to attach to
402  * @node:       the list of functions registered at the subsystem
403  * @add_dev:    device hookup to device function handler
404  * @remove_dev: device hookup to device function handler
405  *
406  * Simple interfaces attached to a subsystem. Multiple interfaces can
407  * attach to a subsystem and its devices. Unlike drivers, they do not
408  * exclusively claim or control devices. Interfaces usually represent
409  * a specific functionality of a subsystem/class of devices.
410  */
411 struct subsys_interface {
412 	const char *name;
413 	struct bus_type *subsys;
414 	struct list_head node;
415 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
416 	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
417 };
418 
419 int subsys_interface_register(struct subsys_interface *sif);
420 void subsys_interface_unregister(struct subsys_interface *sif);
421 
422 int subsys_system_register(struct bus_type *subsys,
423 			   const struct attribute_group **groups);
424 int subsys_virtual_register(struct bus_type *subsys,
425 			    const struct attribute_group **groups);
426 
427 /**
428  * struct class - device classes
429  * @name:	Name of the class.
430  * @owner:	The module owner.
431  * @class_groups: Default attributes of this class.
432  * @dev_groups:	Default attributes of the devices that belong to the class.
433  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
434  * @dev_uevent:	Called when a device is added, removed from this class, or a
435  *		few other things that generate uevents to add the environment
436  *		variables.
437  * @devnode:	Callback to provide the devtmpfs.
438  * @class_release: Called to release this class.
439  * @dev_release: Called to release the device.
440  * @shutdown_pre: Called at shut-down time before driver shutdown.
441  * @ns_type:	Callbacks so sysfs can detemine namespaces.
442  * @namespace:	Namespace of the device belongs to this class.
443  * @get_ownership: Allows class to specify uid/gid of the sysfs directories
444  *		for the devices belonging to the class. Usually tied to
445  *		device's namespace.
446  * @pm:		The default device power management operations of this class.
447  * @p:		The private data of the driver core, no one other than the
448  *		driver core can touch this.
449  *
450  * A class is a higher-level view of a device that abstracts out low-level
451  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
452  * at the class level, they are all simply disks. Classes allow user space
453  * to work with devices based on what they do, rather than how they are
454  * connected or how they work.
455  */
456 struct class {
457 	const char		*name;
458 	struct module		*owner;
459 
460 	const struct attribute_group	**class_groups;
461 	const struct attribute_group	**dev_groups;
462 	struct kobject			*dev_kobj;
463 
464 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
465 	char *(*devnode)(struct device *dev, umode_t *mode);
466 
467 	void (*class_release)(struct class *class);
468 	void (*dev_release)(struct device *dev);
469 
470 	int (*shutdown_pre)(struct device *dev);
471 
472 	const struct kobj_ns_type_operations *ns_type;
473 	const void *(*namespace)(struct device *dev);
474 
475 	void (*get_ownership)(struct device *dev, kuid_t *uid, kgid_t *gid);
476 
477 	const struct dev_pm_ops *pm;
478 
479 	struct subsys_private *p;
480 };
481 
482 struct class_dev_iter {
483 	struct klist_iter		ki;
484 	const struct device_type	*type;
485 };
486 
487 extern struct kobject *sysfs_dev_block_kobj;
488 extern struct kobject *sysfs_dev_char_kobj;
489 extern int __must_check __class_register(struct class *class,
490 					 struct lock_class_key *key);
491 extern void class_unregister(struct class *class);
492 
493 /* This is a #define to keep the compiler from merging different
494  * instances of the __key variable */
495 #define class_register(class)			\
496 ({						\
497 	static struct lock_class_key __key;	\
498 	__class_register(class, &__key);	\
499 })
500 
501 struct class_compat;
502 struct class_compat *class_compat_register(const char *name);
503 void class_compat_unregister(struct class_compat *cls);
504 int class_compat_create_link(struct class_compat *cls, struct device *dev,
505 			     struct device *device_link);
506 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
507 			      struct device *device_link);
508 
509 extern void class_dev_iter_init(struct class_dev_iter *iter,
510 				struct class *class,
511 				struct device *start,
512 				const struct device_type *type);
513 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
514 extern void class_dev_iter_exit(struct class_dev_iter *iter);
515 
516 extern int class_for_each_device(struct class *class, struct device *start,
517 				 void *data,
518 				 int (*fn)(struct device *dev, void *data));
519 extern struct device *class_find_device(struct class *class,
520 					struct device *start, const void *data,
521 					int (*match)(struct device *, const void *));
522 
523 /**
524  * class_find_device_by_name - device iterator for locating a particular device
525  * of a specific name.
526  * @class: class type
527  * @name: name of the device to match
528  */
529 static inline struct device *class_find_device_by_name(struct class *class,
530 						       const char *name)
531 {
532 	return class_find_device(class, NULL, name, device_match_name);
533 }
534 
535 /**
536  * class_find_device_by_of_node : device iterator for locating a particular device
537  * matching the of_node.
538  * @class: class type
539  * @np: of_node of the device to match.
540  */
541 static inline struct device *
542 class_find_device_by_of_node(struct class *class, const struct device_node *np)
543 {
544 	return class_find_device(class, NULL, np, device_match_of_node);
545 }
546 
547 struct class_attribute {
548 	struct attribute attr;
549 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
550 			char *buf);
551 	ssize_t (*store)(struct class *class, struct class_attribute *attr,
552 			const char *buf, size_t count);
553 };
554 
555 #define CLASS_ATTR_RW(_name) \
556 	struct class_attribute class_attr_##_name = __ATTR_RW(_name)
557 #define CLASS_ATTR_RO(_name) \
558 	struct class_attribute class_attr_##_name = __ATTR_RO(_name)
559 #define CLASS_ATTR_WO(_name) \
560 	struct class_attribute class_attr_##_name = __ATTR_WO(_name)
561 
562 extern int __must_check class_create_file_ns(struct class *class,
563 					     const struct class_attribute *attr,
564 					     const void *ns);
565 extern void class_remove_file_ns(struct class *class,
566 				 const struct class_attribute *attr,
567 				 const void *ns);
568 
569 static inline int __must_check class_create_file(struct class *class,
570 					const struct class_attribute *attr)
571 {
572 	return class_create_file_ns(class, attr, NULL);
573 }
574 
575 static inline void class_remove_file(struct class *class,
576 				     const struct class_attribute *attr)
577 {
578 	return class_remove_file_ns(class, attr, NULL);
579 }
580 
581 /* Simple class attribute that is just a static string */
582 struct class_attribute_string {
583 	struct class_attribute attr;
584 	char *str;
585 };
586 
587 /* Currently read-only only */
588 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
589 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
590 #define CLASS_ATTR_STRING(_name, _mode, _str) \
591 	struct class_attribute_string class_attr_##_name = \
592 		_CLASS_ATTR_STRING(_name, _mode, _str)
593 
594 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
595                         char *buf);
596 
597 struct class_interface {
598 	struct list_head	node;
599 	struct class		*class;
600 
601 	int (*add_dev)		(struct device *, struct class_interface *);
602 	void (*remove_dev)	(struct device *, struct class_interface *);
603 };
604 
605 extern int __must_check class_interface_register(struct class_interface *);
606 extern void class_interface_unregister(struct class_interface *);
607 
608 extern struct class * __must_check __class_create(struct module *owner,
609 						  const char *name,
610 						  struct lock_class_key *key);
611 extern void class_destroy(struct class *cls);
612 
613 /* This is a #define to keep the compiler from merging different
614  * instances of the __key variable */
615 #define class_create(owner, name)		\
616 ({						\
617 	static struct lock_class_key __key;	\
618 	__class_create(owner, name, &__key);	\
619 })
620 
621 /*
622  * The type of device, "struct device" is embedded in. A class
623  * or bus can contain devices of different types
624  * like "partitions" and "disks", "mouse" and "event".
625  * This identifies the device type and carries type-specific
626  * information, equivalent to the kobj_type of a kobject.
627  * If "name" is specified, the uevent will contain it in
628  * the DEVTYPE variable.
629  */
630 struct device_type {
631 	const char *name;
632 	const struct attribute_group **groups;
633 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
634 	char *(*devnode)(struct device *dev, umode_t *mode,
635 			 kuid_t *uid, kgid_t *gid);
636 	void (*release)(struct device *dev);
637 
638 	const struct dev_pm_ops *pm;
639 };
640 
641 /* interface for exporting device attributes */
642 struct device_attribute {
643 	struct attribute	attr;
644 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
645 			char *buf);
646 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
647 			 const char *buf, size_t count);
648 };
649 
650 struct dev_ext_attribute {
651 	struct device_attribute attr;
652 	void *var;
653 };
654 
655 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
656 			  char *buf);
657 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
658 			   const char *buf, size_t count);
659 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
660 			char *buf);
661 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
662 			 const char *buf, size_t count);
663 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
664 			char *buf);
665 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
666 			 const char *buf, size_t count);
667 
668 #define DEVICE_ATTR(_name, _mode, _show, _store) \
669 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
670 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
671 	struct device_attribute dev_attr_##_name = \
672 		__ATTR_PREALLOC(_name, _mode, _show, _store)
673 #define DEVICE_ATTR_RW(_name) \
674 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
675 #define DEVICE_ATTR_RO(_name) \
676 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
677 #define DEVICE_ATTR_WO(_name) \
678 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
679 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
680 	struct dev_ext_attribute dev_attr_##_name = \
681 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
682 #define DEVICE_INT_ATTR(_name, _mode, _var) \
683 	struct dev_ext_attribute dev_attr_##_name = \
684 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
685 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
686 	struct dev_ext_attribute dev_attr_##_name = \
687 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
688 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
689 	struct device_attribute dev_attr_##_name =		\
690 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
691 
692 extern int device_create_file(struct device *device,
693 			      const struct device_attribute *entry);
694 extern void device_remove_file(struct device *dev,
695 			       const struct device_attribute *attr);
696 extern bool device_remove_file_self(struct device *dev,
697 				    const struct device_attribute *attr);
698 extern int __must_check device_create_bin_file(struct device *dev,
699 					const struct bin_attribute *attr);
700 extern void device_remove_bin_file(struct device *dev,
701 				   const struct bin_attribute *attr);
702 
703 /* device resource management */
704 typedef void (*dr_release_t)(struct device *dev, void *res);
705 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
706 
707 #ifdef CONFIG_DEBUG_DEVRES
708 extern void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
709 				 int nid, const char *name) __malloc;
710 #define devres_alloc(release, size, gfp) \
711 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
712 #define devres_alloc_node(release, size, gfp, nid) \
713 	__devres_alloc_node(release, size, gfp, nid, #release)
714 #else
715 extern void *devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
716 			       int nid) __malloc;
717 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
718 {
719 	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
720 }
721 #endif
722 
723 extern void devres_for_each_res(struct device *dev, dr_release_t release,
724 				dr_match_t match, void *match_data,
725 				void (*fn)(struct device *, void *, void *),
726 				void *data);
727 extern void devres_free(void *res);
728 extern void devres_add(struct device *dev, void *res);
729 extern void *devres_find(struct device *dev, dr_release_t release,
730 			 dr_match_t match, void *match_data);
731 extern void *devres_get(struct device *dev, void *new_res,
732 			dr_match_t match, void *match_data);
733 extern void *devres_remove(struct device *dev, dr_release_t release,
734 			   dr_match_t match, void *match_data);
735 extern int devres_destroy(struct device *dev, dr_release_t release,
736 			  dr_match_t match, void *match_data);
737 extern int devres_release(struct device *dev, dr_release_t release,
738 			  dr_match_t match, void *match_data);
739 
740 /* devres group */
741 extern void * __must_check devres_open_group(struct device *dev, void *id,
742 					     gfp_t gfp);
743 extern void devres_close_group(struct device *dev, void *id);
744 extern void devres_remove_group(struct device *dev, void *id);
745 extern int devres_release_group(struct device *dev, void *id);
746 
747 /* managed devm_k.alloc/kfree for device drivers */
748 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
749 extern __printf(3, 0)
750 char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
751 		      va_list ap) __malloc;
752 extern __printf(3, 4)
753 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...) __malloc;
754 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
755 {
756 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
757 }
758 static inline void *devm_kmalloc_array(struct device *dev,
759 				       size_t n, size_t size, gfp_t flags)
760 {
761 	size_t bytes;
762 
763 	if (unlikely(check_mul_overflow(n, size, &bytes)))
764 		return NULL;
765 
766 	return devm_kmalloc(dev, bytes, flags);
767 }
768 static inline void *devm_kcalloc(struct device *dev,
769 				 size_t n, size_t size, gfp_t flags)
770 {
771 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
772 }
773 extern void devm_kfree(struct device *dev, const void *p);
774 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
775 extern const char *devm_kstrdup_const(struct device *dev,
776 				      const char *s, gfp_t gfp);
777 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
778 			  gfp_t gfp);
779 
780 extern unsigned long devm_get_free_pages(struct device *dev,
781 					 gfp_t gfp_mask, unsigned int order);
782 extern void devm_free_pages(struct device *dev, unsigned long addr);
783 
784 void __iomem *devm_ioremap_resource(struct device *dev,
785 				    const struct resource *res);
786 
787 void __iomem *devm_of_iomap(struct device *dev,
788 			    struct device_node *node, int index,
789 			    resource_size_t *size);
790 
791 /* allows to add/remove a custom action to devres stack */
792 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
793 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
794 void devm_release_action(struct device *dev, void (*action)(void *), void *data);
795 
796 static inline int devm_add_action_or_reset(struct device *dev,
797 					   void (*action)(void *), void *data)
798 {
799 	int ret;
800 
801 	ret = devm_add_action(dev, action, data);
802 	if (ret)
803 		action(data);
804 
805 	return ret;
806 }
807 
808 /**
809  * devm_alloc_percpu - Resource-managed alloc_percpu
810  * @dev: Device to allocate per-cpu memory for
811  * @type: Type to allocate per-cpu memory for
812  *
813  * Managed alloc_percpu. Per-cpu memory allocated with this function is
814  * automatically freed on driver detach.
815  *
816  * RETURNS:
817  * Pointer to allocated memory on success, NULL on failure.
818  */
819 #define devm_alloc_percpu(dev, type)      \
820 	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
821 						      __alignof__(type)))
822 
823 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
824 				   size_t align);
825 void devm_free_percpu(struct device *dev, void __percpu *pdata);
826 
827 struct device_dma_parameters {
828 	/*
829 	 * a low level driver may set these to teach IOMMU code about
830 	 * sg limitations.
831 	 */
832 	unsigned int max_segment_size;
833 	unsigned long segment_boundary_mask;
834 };
835 
836 /**
837  * struct device_connection - Device Connection Descriptor
838  * @fwnode: The device node of the connected device
839  * @endpoint: The names of the two devices connected together
840  * @id: Unique identifier for the connection
841  * @list: List head, private, for internal use only
842  *
843  * NOTE: @fwnode is not used together with @endpoint. @fwnode is used when
844  * platform firmware defines the connection. When the connection is registered
845  * with device_connection_add() @endpoint is used instead.
846  */
847 struct device_connection {
848 	struct fwnode_handle	*fwnode;
849 	const char		*endpoint[2];
850 	const char		*id;
851 	struct list_head	list;
852 };
853 
854 void *device_connection_find_match(struct device *dev, const char *con_id,
855 				void *data,
856 				void *(*match)(struct device_connection *con,
857 					       int ep, void *data));
858 
859 struct device *device_connection_find(struct device *dev, const char *con_id);
860 
861 void device_connection_add(struct device_connection *con);
862 void device_connection_remove(struct device_connection *con);
863 
864 /**
865  * device_connections_add - Add multiple device connections at once
866  * @cons: Zero terminated array of device connection descriptors
867  */
868 static inline void device_connections_add(struct device_connection *cons)
869 {
870 	struct device_connection *c;
871 
872 	for (c = cons; c->endpoint[0]; c++)
873 		device_connection_add(c);
874 }
875 
876 /**
877  * device_connections_remove - Remove multiple device connections at once
878  * @cons: Zero terminated array of device connection descriptors
879  */
880 static inline void device_connections_remove(struct device_connection *cons)
881 {
882 	struct device_connection *c;
883 
884 	for (c = cons; c->endpoint[0]; c++)
885 		device_connection_remove(c);
886 }
887 
888 /**
889  * enum device_link_state - Device link states.
890  * @DL_STATE_NONE: The presence of the drivers is not being tracked.
891  * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
892  * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
893  * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
894  * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
895  * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
896  */
897 enum device_link_state {
898 	DL_STATE_NONE = -1,
899 	DL_STATE_DORMANT = 0,
900 	DL_STATE_AVAILABLE,
901 	DL_STATE_CONSUMER_PROBE,
902 	DL_STATE_ACTIVE,
903 	DL_STATE_SUPPLIER_UNBIND,
904 };
905 
906 /*
907  * Device link flags.
908  *
909  * STATELESS: The core won't track the presence of supplier/consumer drivers.
910  * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
911  * PM_RUNTIME: If set, the runtime PM framework will use this link.
912  * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
913  * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
914  * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
915  */
916 #define DL_FLAG_STATELESS		BIT(0)
917 #define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)
918 #define DL_FLAG_PM_RUNTIME		BIT(2)
919 #define DL_FLAG_RPM_ACTIVE		BIT(3)
920 #define DL_FLAG_AUTOREMOVE_SUPPLIER	BIT(4)
921 #define DL_FLAG_AUTOPROBE_CONSUMER	BIT(5)
922 
923 /**
924  * struct device_link - Device link representation.
925  * @supplier: The device on the supplier end of the link.
926  * @s_node: Hook to the supplier device's list of links to consumers.
927  * @consumer: The device on the consumer end of the link.
928  * @c_node: Hook to the consumer device's list of links to suppliers.
929  * @status: The state of the link (with respect to the presence of drivers).
930  * @flags: Link flags.
931  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
932  * @kref: Count repeated addition of the same link.
933  * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
934  * @supplier_preactivated: Supplier has been made active before consumer probe.
935  */
936 struct device_link {
937 	struct device *supplier;
938 	struct list_head s_node;
939 	struct device *consumer;
940 	struct list_head c_node;
941 	enum device_link_state status;
942 	u32 flags;
943 	refcount_t rpm_active;
944 	struct kref kref;
945 #ifdef CONFIG_SRCU
946 	struct rcu_head rcu_head;
947 #endif
948 	bool supplier_preactivated; /* Owned by consumer probe. */
949 };
950 
951 /**
952  * enum dl_dev_state - Device driver presence tracking information.
953  * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
954  * @DL_DEV_PROBING: A driver is probing.
955  * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
956  * @DL_DEV_UNBINDING: The driver is unbinding from the device.
957  */
958 enum dl_dev_state {
959 	DL_DEV_NO_DRIVER = 0,
960 	DL_DEV_PROBING,
961 	DL_DEV_DRIVER_BOUND,
962 	DL_DEV_UNBINDING,
963 };
964 
965 /**
966  * struct dev_links_info - Device data related to device links.
967  * @suppliers: List of links to supplier devices.
968  * @consumers: List of links to consumer devices.
969  * @status: Driver status information.
970  */
971 struct dev_links_info {
972 	struct list_head suppliers;
973 	struct list_head consumers;
974 	enum dl_dev_state status;
975 };
976 
977 /**
978  * struct device - The basic device structure
979  * @parent:	The device's "parent" device, the device to which it is attached.
980  * 		In most cases, a parent device is some sort of bus or host
981  * 		controller. If parent is NULL, the device, is a top-level device,
982  * 		which is not usually what you want.
983  * @p:		Holds the private data of the driver core portions of the device.
984  * 		See the comment of the struct device_private for detail.
985  * @kobj:	A top-level, abstract class from which other classes are derived.
986  * @init_name:	Initial name of the device.
987  * @type:	The type of device.
988  * 		This identifies the device type and carries type-specific
989  * 		information.
990  * @mutex:	Mutex to synchronize calls to its driver.
991  * @bus:	Type of bus device is on.
992  * @driver:	Which driver has allocated this
993  * @platform_data: Platform data specific to the device.
994  * 		Example: For devices on custom boards, as typical of embedded
995  * 		and SOC based hardware, Linux often uses platform_data to point
996  * 		to board-specific structures describing devices and how they
997  * 		are wired.  That can include what ports are available, chip
998  * 		variants, which GPIO pins act in what additional roles, and so
999  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
1000  * 		minimizes board-specific #ifdefs in drivers.
1001  * @driver_data: Private pointer for driver specific info.
1002  * @links:	Links to suppliers and consumers of this device.
1003  * @power:	For device power management.
1004  *		See Documentation/driver-api/pm/devices.rst for details.
1005  * @pm_domain:	Provide callbacks that are executed during system suspend,
1006  * 		hibernation, system resume and during runtime PM transitions
1007  * 		along with subsystem-level and driver-level callbacks.
1008  * @pins:	For device pin management.
1009  *		See Documentation/driver-api/pinctl.rst for details.
1010  * @msi_list:	Hosts MSI descriptors
1011  * @msi_domain: The generic MSI domain this device is using.
1012  * @numa_node:	NUMA node this device is close to.
1013  * @dma_ops:    DMA mapping operations for this device.
1014  * @dma_mask:	Dma mask (if dma'ble device).
1015  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
1016  * 		hardware supports 64-bit addresses for consistent allocations
1017  * 		such descriptors.
1018  * @bus_dma_mask: Mask of an upstream bridge or bus which imposes a smaller DMA
1019  *		limit than the device itself supports.
1020  * @dma_pfn_offset: offset of DMA memory range relatively of RAM
1021  * @dma_parms:	A low level driver may set these to teach IOMMU code about
1022  * 		segment limitations.
1023  * @dma_pools:	Dma pools (if dma'ble device).
1024  * @dma_mem:	Internal for coherent mem override.
1025  * @cma_area:	Contiguous memory area for dma allocations
1026  * @archdata:	For arch-specific additions.
1027  * @of_node:	Associated device tree node.
1028  * @fwnode:	Associated device node supplied by platform firmware.
1029  * @devt:	For creating the sysfs "dev".
1030  * @id:		device instance
1031  * @devres_lock: Spinlock to protect the resource of the device.
1032  * @devres_head: The resources list of the device.
1033  * @knode_class: The node used to add the device to the class list.
1034  * @class:	The class of the device.
1035  * @groups:	Optional attribute groups.
1036  * @release:	Callback to free the device after all references have
1037  * 		gone away. This should be set by the allocator of the
1038  * 		device (i.e. the bus driver that discovered the device).
1039  * @iommu_group: IOMMU group the device belongs to.
1040  * @iommu_fwspec: IOMMU-specific properties supplied by firmware.
1041  * @iommu_param: Per device generic IOMMU runtime data
1042  *
1043  * @offline_disabled: If set, the device is permanently online.
1044  * @offline:	Set after successful invocation of bus type's .offline().
1045  * @of_node_reused: Set if the device-tree node is shared with an ancestor
1046  *              device.
1047  * @dma_coherent: this particular device is dma coherent, even if the
1048  *		architecture supports non-coherent devices.
1049  *
1050  * At the lowest level, every device in a Linux system is represented by an
1051  * instance of struct device. The device structure contains the information
1052  * that the device model core needs to model the system. Most subsystems,
1053  * however, track additional information about the devices they host. As a
1054  * result, it is rare for devices to be represented by bare device structures;
1055  * instead, that structure, like kobject structures, is usually embedded within
1056  * a higher-level representation of the device.
1057  */
1058 struct device {
1059 	struct kobject kobj;
1060 	struct device		*parent;
1061 
1062 	struct device_private	*p;
1063 
1064 	const char		*init_name; /* initial name of the device */
1065 	const struct device_type *type;
1066 
1067 	struct bus_type	*bus;		/* type of bus device is on */
1068 	struct device_driver *driver;	/* which driver has allocated this
1069 					   device */
1070 	void		*platform_data;	/* Platform specific data, device
1071 					   core doesn't touch it */
1072 	void		*driver_data;	/* Driver data, set and get with
1073 					   dev_set_drvdata/dev_get_drvdata */
1074 	struct mutex		mutex;	/* mutex to synchronize calls to
1075 					 * its driver.
1076 					 */
1077 
1078 	struct dev_links_info	links;
1079 	struct dev_pm_info	power;
1080 	struct dev_pm_domain	*pm_domain;
1081 
1082 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1083 	struct irq_domain	*msi_domain;
1084 #endif
1085 #ifdef CONFIG_PINCTRL
1086 	struct dev_pin_info	*pins;
1087 #endif
1088 #ifdef CONFIG_GENERIC_MSI_IRQ
1089 	struct list_head	msi_list;
1090 #endif
1091 
1092 	const struct dma_map_ops *dma_ops;
1093 	u64		*dma_mask;	/* dma mask (if dma'able device) */
1094 	u64		coherent_dma_mask;/* Like dma_mask, but for
1095 					     alloc_coherent mappings as
1096 					     not all hardware supports
1097 					     64 bit addresses for consistent
1098 					     allocations such descriptors. */
1099 	u64		bus_dma_mask;	/* upstream dma_mask constraint */
1100 	unsigned long	dma_pfn_offset;
1101 
1102 	struct device_dma_parameters *dma_parms;
1103 
1104 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
1105 
1106 #ifdef CONFIG_DMA_DECLARE_COHERENT
1107 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
1108 					     override */
1109 #endif
1110 #ifdef CONFIG_DMA_CMA
1111 	struct cma *cma_area;		/* contiguous memory area for dma
1112 					   allocations */
1113 #endif
1114 	/* arch specific additions */
1115 	struct dev_archdata	archdata;
1116 
1117 	struct device_node	*of_node; /* associated device tree node */
1118 	struct fwnode_handle	*fwnode; /* firmware device node */
1119 
1120 #ifdef CONFIG_NUMA
1121 	int		numa_node;	/* NUMA node this device is close to */
1122 #endif
1123 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
1124 	u32			id;	/* device instance */
1125 
1126 	spinlock_t		devres_lock;
1127 	struct list_head	devres_head;
1128 
1129 	struct class		*class;
1130 	const struct attribute_group **groups;	/* optional groups */
1131 
1132 	void	(*release)(struct device *dev);
1133 	struct iommu_group	*iommu_group;
1134 	struct iommu_fwspec	*iommu_fwspec;
1135 	struct iommu_param	*iommu_param;
1136 
1137 	bool			offline_disabled:1;
1138 	bool			offline:1;
1139 	bool			of_node_reused:1;
1140 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
1141     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
1142     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
1143 	bool			dma_coherent:1;
1144 #endif
1145 };
1146 
1147 static inline struct device *kobj_to_dev(struct kobject *kobj)
1148 {
1149 	return container_of(kobj, struct device, kobj);
1150 }
1151 
1152 /**
1153  * device_iommu_mapped - Returns true when the device DMA is translated
1154  *			 by an IOMMU
1155  * @dev: Device to perform the check on
1156  */
1157 static inline bool device_iommu_mapped(struct device *dev)
1158 {
1159 	return (dev->iommu_group != NULL);
1160 }
1161 
1162 /* Get the wakeup routines, which depend on struct device */
1163 #include <linux/pm_wakeup.h>
1164 
1165 static inline const char *dev_name(const struct device *dev)
1166 {
1167 	/* Use the init name until the kobject becomes available */
1168 	if (dev->init_name)
1169 		return dev->init_name;
1170 
1171 	return kobject_name(&dev->kobj);
1172 }
1173 
1174 extern __printf(2, 3)
1175 int dev_set_name(struct device *dev, const char *name, ...);
1176 
1177 #ifdef CONFIG_NUMA
1178 static inline int dev_to_node(struct device *dev)
1179 {
1180 	return dev->numa_node;
1181 }
1182 static inline void set_dev_node(struct device *dev, int node)
1183 {
1184 	dev->numa_node = node;
1185 }
1186 #else
1187 static inline int dev_to_node(struct device *dev)
1188 {
1189 	return NUMA_NO_NODE;
1190 }
1191 static inline void set_dev_node(struct device *dev, int node)
1192 {
1193 }
1194 #endif
1195 
1196 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
1197 {
1198 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1199 	return dev->msi_domain;
1200 #else
1201 	return NULL;
1202 #endif
1203 }
1204 
1205 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
1206 {
1207 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1208 	dev->msi_domain = d;
1209 #endif
1210 }
1211 
1212 static inline void *dev_get_drvdata(const struct device *dev)
1213 {
1214 	return dev->driver_data;
1215 }
1216 
1217 static inline void dev_set_drvdata(struct device *dev, void *data)
1218 {
1219 	dev->driver_data = data;
1220 }
1221 
1222 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
1223 {
1224 	return dev ? dev->power.subsys_data : NULL;
1225 }
1226 
1227 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
1228 {
1229 	return dev->kobj.uevent_suppress;
1230 }
1231 
1232 static inline void dev_set_uevent_suppress(struct device *dev, int val)
1233 {
1234 	dev->kobj.uevent_suppress = val;
1235 }
1236 
1237 static inline int device_is_registered(struct device *dev)
1238 {
1239 	return dev->kobj.state_in_sysfs;
1240 }
1241 
1242 static inline void device_enable_async_suspend(struct device *dev)
1243 {
1244 	if (!dev->power.is_prepared)
1245 		dev->power.async_suspend = true;
1246 }
1247 
1248 static inline void device_disable_async_suspend(struct device *dev)
1249 {
1250 	if (!dev->power.is_prepared)
1251 		dev->power.async_suspend = false;
1252 }
1253 
1254 static inline bool device_async_suspend_enabled(struct device *dev)
1255 {
1256 	return !!dev->power.async_suspend;
1257 }
1258 
1259 static inline bool device_pm_not_required(struct device *dev)
1260 {
1261 	return dev->power.no_pm;
1262 }
1263 
1264 static inline void device_set_pm_not_required(struct device *dev)
1265 {
1266 	dev->power.no_pm = true;
1267 }
1268 
1269 static inline void dev_pm_syscore_device(struct device *dev, bool val)
1270 {
1271 #ifdef CONFIG_PM_SLEEP
1272 	dev->power.syscore = val;
1273 #endif
1274 }
1275 
1276 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
1277 {
1278 	dev->power.driver_flags = flags;
1279 }
1280 
1281 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
1282 {
1283 	return !!(dev->power.driver_flags & flags);
1284 }
1285 
1286 static inline void device_lock(struct device *dev)
1287 {
1288 	mutex_lock(&dev->mutex);
1289 }
1290 
1291 static inline int device_lock_interruptible(struct device *dev)
1292 {
1293 	return mutex_lock_interruptible(&dev->mutex);
1294 }
1295 
1296 static inline int device_trylock(struct device *dev)
1297 {
1298 	return mutex_trylock(&dev->mutex);
1299 }
1300 
1301 static inline void device_unlock(struct device *dev)
1302 {
1303 	mutex_unlock(&dev->mutex);
1304 }
1305 
1306 static inline void device_lock_assert(struct device *dev)
1307 {
1308 	lockdep_assert_held(&dev->mutex);
1309 }
1310 
1311 static inline struct device_node *dev_of_node(struct device *dev)
1312 {
1313 	if (!IS_ENABLED(CONFIG_OF) || !dev)
1314 		return NULL;
1315 	return dev->of_node;
1316 }
1317 
1318 void driver_init(void);
1319 
1320 /*
1321  * High level routines for use by the bus drivers
1322  */
1323 extern int __must_check device_register(struct device *dev);
1324 extern void device_unregister(struct device *dev);
1325 extern void device_initialize(struct device *dev);
1326 extern int __must_check device_add(struct device *dev);
1327 extern void device_del(struct device *dev);
1328 extern int device_for_each_child(struct device *dev, void *data,
1329 		     int (*fn)(struct device *dev, void *data));
1330 extern int device_for_each_child_reverse(struct device *dev, void *data,
1331 		     int (*fn)(struct device *dev, void *data));
1332 extern struct device *device_find_child(struct device *dev, void *data,
1333 				int (*match)(struct device *dev, void *data));
1334 extern struct device *device_find_child_by_name(struct device *parent,
1335 						const char *name);
1336 extern int device_rename(struct device *dev, const char *new_name);
1337 extern int device_move(struct device *dev, struct device *new_parent,
1338 		       enum dpm_order dpm_order);
1339 extern const char *device_get_devnode(struct device *dev,
1340 				      umode_t *mode, kuid_t *uid, kgid_t *gid,
1341 				      const char **tmp);
1342 
1343 static inline bool device_supports_offline(struct device *dev)
1344 {
1345 	return dev->bus && dev->bus->offline && dev->bus->online;
1346 }
1347 
1348 extern void lock_device_hotplug(void);
1349 extern void unlock_device_hotplug(void);
1350 extern int lock_device_hotplug_sysfs(void);
1351 extern int device_offline(struct device *dev);
1352 extern int device_online(struct device *dev);
1353 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1354 extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1355 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
1356 
1357 static inline int dev_num_vf(struct device *dev)
1358 {
1359 	if (dev->bus && dev->bus->num_vf)
1360 		return dev->bus->num_vf(dev);
1361 	return 0;
1362 }
1363 
1364 /*
1365  * Root device objects for grouping under /sys/devices
1366  */
1367 extern struct device *__root_device_register(const char *name,
1368 					     struct module *owner);
1369 
1370 /* This is a macro to avoid include problems with THIS_MODULE */
1371 #define root_device_register(name) \
1372 	__root_device_register(name, THIS_MODULE)
1373 
1374 extern void root_device_unregister(struct device *root);
1375 
1376 static inline void *dev_get_platdata(const struct device *dev)
1377 {
1378 	return dev->platform_data;
1379 }
1380 
1381 /*
1382  * Manual binding of a device to driver. See drivers/base/bus.c
1383  * for information on use.
1384  */
1385 extern int __must_check device_bind_driver(struct device *dev);
1386 extern void device_release_driver(struct device *dev);
1387 extern int  __must_check device_attach(struct device *dev);
1388 extern int __must_check driver_attach(struct device_driver *drv);
1389 extern void device_initial_probe(struct device *dev);
1390 extern int __must_check device_reprobe(struct device *dev);
1391 
1392 extern bool device_is_bound(struct device *dev);
1393 
1394 /*
1395  * Easy functions for dynamically creating devices on the fly
1396  */
1397 extern __printf(5, 0)
1398 struct device *device_create_vargs(struct class *cls, struct device *parent,
1399 				   dev_t devt, void *drvdata,
1400 				   const char *fmt, va_list vargs);
1401 extern __printf(5, 6)
1402 struct device *device_create(struct class *cls, struct device *parent,
1403 			     dev_t devt, void *drvdata,
1404 			     const char *fmt, ...);
1405 extern __printf(6, 7)
1406 struct device *device_create_with_groups(struct class *cls,
1407 			     struct device *parent, dev_t devt, void *drvdata,
1408 			     const struct attribute_group **groups,
1409 			     const char *fmt, ...);
1410 extern void device_destroy(struct class *cls, dev_t devt);
1411 
1412 extern int __must_check device_add_groups(struct device *dev,
1413 					const struct attribute_group **groups);
1414 extern void device_remove_groups(struct device *dev,
1415 				 const struct attribute_group **groups);
1416 
1417 static inline int __must_check device_add_group(struct device *dev,
1418 					const struct attribute_group *grp)
1419 {
1420 	const struct attribute_group *groups[] = { grp, NULL };
1421 
1422 	return device_add_groups(dev, groups);
1423 }
1424 
1425 static inline void device_remove_group(struct device *dev,
1426 				       const struct attribute_group *grp)
1427 {
1428 	const struct attribute_group *groups[] = { grp, NULL };
1429 
1430 	return device_remove_groups(dev, groups);
1431 }
1432 
1433 extern int __must_check devm_device_add_groups(struct device *dev,
1434 					const struct attribute_group **groups);
1435 extern void devm_device_remove_groups(struct device *dev,
1436 				      const struct attribute_group **groups);
1437 extern int __must_check devm_device_add_group(struct device *dev,
1438 					const struct attribute_group *grp);
1439 extern void devm_device_remove_group(struct device *dev,
1440 				     const struct attribute_group *grp);
1441 
1442 /*
1443  * Platform "fixup" functions - allow the platform to have their say
1444  * about devices and actions that the general device layer doesn't
1445  * know about.
1446  */
1447 /* Notify platform of device discovery */
1448 extern int (*platform_notify)(struct device *dev);
1449 
1450 extern int (*platform_notify_remove)(struct device *dev);
1451 
1452 
1453 /*
1454  * get_device - atomically increment the reference count for the device.
1455  *
1456  */
1457 extern struct device *get_device(struct device *dev);
1458 extern void put_device(struct device *dev);
1459 
1460 #ifdef CONFIG_DEVTMPFS
1461 extern int devtmpfs_create_node(struct device *dev);
1462 extern int devtmpfs_delete_node(struct device *dev);
1463 extern int devtmpfs_mount(const char *mntdir);
1464 #else
1465 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
1466 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
1467 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
1468 #endif
1469 
1470 /* drivers/base/power/shutdown.c */
1471 extern void device_shutdown(void);
1472 
1473 /* debugging and troubleshooting/diagnostic helpers. */
1474 extern const char *dev_driver_string(const struct device *dev);
1475 
1476 /* Device links interface. */
1477 struct device_link *device_link_add(struct device *consumer,
1478 				    struct device *supplier, u32 flags);
1479 void device_link_del(struct device_link *link);
1480 void device_link_remove(void *consumer, struct device *supplier);
1481 
1482 #ifndef dev_fmt
1483 #define dev_fmt(fmt) fmt
1484 #endif
1485 
1486 #ifdef CONFIG_PRINTK
1487 
1488 __printf(3, 0) __cold
1489 int dev_vprintk_emit(int level, const struct device *dev,
1490 		     const char *fmt, va_list args);
1491 __printf(3, 4) __cold
1492 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
1493 
1494 __printf(3, 4) __cold
1495 void dev_printk(const char *level, const struct device *dev,
1496 		const char *fmt, ...);
1497 __printf(2, 3) __cold
1498 void _dev_emerg(const struct device *dev, const char *fmt, ...);
1499 __printf(2, 3) __cold
1500 void _dev_alert(const struct device *dev, const char *fmt, ...);
1501 __printf(2, 3) __cold
1502 void _dev_crit(const struct device *dev, const char *fmt, ...);
1503 __printf(2, 3) __cold
1504 void _dev_err(const struct device *dev, const char *fmt, ...);
1505 __printf(2, 3) __cold
1506 void _dev_warn(const struct device *dev, const char *fmt, ...);
1507 __printf(2, 3) __cold
1508 void _dev_notice(const struct device *dev, const char *fmt, ...);
1509 __printf(2, 3) __cold
1510 void _dev_info(const struct device *dev, const char *fmt, ...);
1511 
1512 #else
1513 
1514 static inline __printf(3, 0)
1515 int dev_vprintk_emit(int level, const struct device *dev,
1516 		     const char *fmt, va_list args)
1517 { return 0; }
1518 static inline __printf(3, 4)
1519 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1520 { return 0; }
1521 
1522 static inline void __dev_printk(const char *level, const struct device *dev,
1523 				struct va_format *vaf)
1524 {}
1525 static inline __printf(3, 4)
1526 void dev_printk(const char *level, const struct device *dev,
1527 		 const char *fmt, ...)
1528 {}
1529 
1530 static inline __printf(2, 3)
1531 void _dev_emerg(const struct device *dev, const char *fmt, ...)
1532 {}
1533 static inline __printf(2, 3)
1534 void _dev_crit(const struct device *dev, const char *fmt, ...)
1535 {}
1536 static inline __printf(2, 3)
1537 void _dev_alert(const struct device *dev, const char *fmt, ...)
1538 {}
1539 static inline __printf(2, 3)
1540 void _dev_err(const struct device *dev, const char *fmt, ...)
1541 {}
1542 static inline __printf(2, 3)
1543 void _dev_warn(const struct device *dev, const char *fmt, ...)
1544 {}
1545 static inline __printf(2, 3)
1546 void _dev_notice(const struct device *dev, const char *fmt, ...)
1547 {}
1548 static inline __printf(2, 3)
1549 void _dev_info(const struct device *dev, const char *fmt, ...)
1550 {}
1551 
1552 #endif
1553 
1554 /*
1555  * #defines for all the dev_<level> macros to prefix with whatever
1556  * possible use of #define dev_fmt(fmt) ...
1557  */
1558 
1559 #define dev_emerg(dev, fmt, ...)					\
1560 	_dev_emerg(dev, dev_fmt(fmt), ##__VA_ARGS__)
1561 #define dev_crit(dev, fmt, ...)						\
1562 	_dev_crit(dev, dev_fmt(fmt), ##__VA_ARGS__)
1563 #define dev_alert(dev, fmt, ...)					\
1564 	_dev_alert(dev, dev_fmt(fmt), ##__VA_ARGS__)
1565 #define dev_err(dev, fmt, ...)						\
1566 	_dev_err(dev, dev_fmt(fmt), ##__VA_ARGS__)
1567 #define dev_warn(dev, fmt, ...)						\
1568 	_dev_warn(dev, dev_fmt(fmt), ##__VA_ARGS__)
1569 #define dev_notice(dev, fmt, ...)					\
1570 	_dev_notice(dev, dev_fmt(fmt), ##__VA_ARGS__)
1571 #define dev_info(dev, fmt, ...)						\
1572 	_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
1573 
1574 #if defined(CONFIG_DYNAMIC_DEBUG)
1575 #define dev_dbg(dev, fmt, ...)						\
1576 	dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
1577 #elif defined(DEBUG)
1578 #define dev_dbg(dev, fmt, ...)						\
1579 	dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__)
1580 #else
1581 #define dev_dbg(dev, fmt, ...)						\
1582 ({									\
1583 	if (0)								\
1584 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1585 })
1586 #endif
1587 
1588 #ifdef CONFIG_PRINTK
1589 #define dev_level_once(dev_level, dev, fmt, ...)			\
1590 do {									\
1591 	static bool __print_once __read_mostly;				\
1592 									\
1593 	if (!__print_once) {						\
1594 		__print_once = true;					\
1595 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1596 	}								\
1597 } while (0)
1598 #else
1599 #define dev_level_once(dev_level, dev, fmt, ...)			\
1600 do {									\
1601 	if (0)								\
1602 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1603 } while (0)
1604 #endif
1605 
1606 #define dev_emerg_once(dev, fmt, ...)					\
1607 	dev_level_once(dev_emerg, dev, fmt, ##__VA_ARGS__)
1608 #define dev_alert_once(dev, fmt, ...)					\
1609 	dev_level_once(dev_alert, dev, fmt, ##__VA_ARGS__)
1610 #define dev_crit_once(dev, fmt, ...)					\
1611 	dev_level_once(dev_crit, dev, fmt, ##__VA_ARGS__)
1612 #define dev_err_once(dev, fmt, ...)					\
1613 	dev_level_once(dev_err, dev, fmt, ##__VA_ARGS__)
1614 #define dev_warn_once(dev, fmt, ...)					\
1615 	dev_level_once(dev_warn, dev, fmt, ##__VA_ARGS__)
1616 #define dev_notice_once(dev, fmt, ...)					\
1617 	dev_level_once(dev_notice, dev, fmt, ##__VA_ARGS__)
1618 #define dev_info_once(dev, fmt, ...)					\
1619 	dev_level_once(dev_info, dev, fmt, ##__VA_ARGS__)
1620 #define dev_dbg_once(dev, fmt, ...)					\
1621 	dev_level_once(dev_dbg, dev, fmt, ##__VA_ARGS__)
1622 
1623 #define dev_level_ratelimited(dev_level, dev, fmt, ...)			\
1624 do {									\
1625 	static DEFINE_RATELIMIT_STATE(_rs,				\
1626 				      DEFAULT_RATELIMIT_INTERVAL,	\
1627 				      DEFAULT_RATELIMIT_BURST);		\
1628 	if (__ratelimit(&_rs))						\
1629 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1630 } while (0)
1631 
1632 #define dev_emerg_ratelimited(dev, fmt, ...)				\
1633 	dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
1634 #define dev_alert_ratelimited(dev, fmt, ...)				\
1635 	dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
1636 #define dev_crit_ratelimited(dev, fmt, ...)				\
1637 	dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
1638 #define dev_err_ratelimited(dev, fmt, ...)				\
1639 	dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
1640 #define dev_warn_ratelimited(dev, fmt, ...)				\
1641 	dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
1642 #define dev_notice_ratelimited(dev, fmt, ...)				\
1643 	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
1644 #define dev_info_ratelimited(dev, fmt, ...)				\
1645 	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
1646 #if defined(CONFIG_DYNAMIC_DEBUG)
1647 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
1648 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1649 do {									\
1650 	static DEFINE_RATELIMIT_STATE(_rs,				\
1651 				      DEFAULT_RATELIMIT_INTERVAL,	\
1652 				      DEFAULT_RATELIMIT_BURST);		\
1653 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
1654 	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
1655 	    __ratelimit(&_rs))						\
1656 		__dynamic_dev_dbg(&descriptor, dev, dev_fmt(fmt),	\
1657 				  ##__VA_ARGS__);			\
1658 } while (0)
1659 #elif defined(DEBUG)
1660 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1661 do {									\
1662 	static DEFINE_RATELIMIT_STATE(_rs,				\
1663 				      DEFAULT_RATELIMIT_INTERVAL,	\
1664 				      DEFAULT_RATELIMIT_BURST);		\
1665 	if (__ratelimit(&_rs))						\
1666 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1667 } while (0)
1668 #else
1669 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1670 do {									\
1671 	if (0)								\
1672 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1673 } while (0)
1674 #endif
1675 
1676 #ifdef VERBOSE_DEBUG
1677 #define dev_vdbg	dev_dbg
1678 #else
1679 #define dev_vdbg(dev, fmt, ...)						\
1680 ({									\
1681 	if (0)								\
1682 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1683 })
1684 #endif
1685 
1686 /*
1687  * dev_WARN*() acts like dev_printk(), but with the key difference of
1688  * using WARN/WARN_ONCE to include file/line information and a backtrace.
1689  */
1690 #define dev_WARN(dev, format, arg...) \
1691 	WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
1692 
1693 #define dev_WARN_ONCE(dev, condition, format, arg...) \
1694 	WARN_ONCE(condition, "%s %s: " format, \
1695 			dev_driver_string(dev), dev_name(dev), ## arg)
1696 
1697 /* Create alias, so I can be autoloaded. */
1698 #define MODULE_ALIAS_CHARDEV(major,minor) \
1699 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1700 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1701 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
1702 
1703 #ifdef CONFIG_SYSFS_DEPRECATED
1704 extern long sysfs_deprecated;
1705 #else
1706 #define sysfs_deprecated 0
1707 #endif
1708 
1709 /**
1710  * module_driver() - Helper macro for drivers that don't do anything
1711  * special in module init/exit. This eliminates a lot of boilerplate.
1712  * Each module may only use this macro once, and calling it replaces
1713  * module_init() and module_exit().
1714  *
1715  * @__driver: driver name
1716  * @__register: register function for this driver type
1717  * @__unregister: unregister function for this driver type
1718  * @...: Additional arguments to be passed to __register and __unregister.
1719  *
1720  * Use this macro to construct bus specific macros for registering
1721  * drivers, and do not use it on its own.
1722  */
1723 #define module_driver(__driver, __register, __unregister, ...) \
1724 static int __init __driver##_init(void) \
1725 { \
1726 	return __register(&(__driver) , ##__VA_ARGS__); \
1727 } \
1728 module_init(__driver##_init); \
1729 static void __exit __driver##_exit(void) \
1730 { \
1731 	__unregister(&(__driver) , ##__VA_ARGS__); \
1732 } \
1733 module_exit(__driver##_exit);
1734 
1735 /**
1736  * builtin_driver() - Helper macro for drivers that don't do anything
1737  * special in init and have no exit. This eliminates some boilerplate.
1738  * Each driver may only use this macro once, and calling it replaces
1739  * device_initcall (or in some cases, the legacy __initcall).  This is
1740  * meant to be a direct parallel of module_driver() above but without
1741  * the __exit stuff that is not used for builtin cases.
1742  *
1743  * @__driver: driver name
1744  * @__register: register function for this driver type
1745  * @...: Additional arguments to be passed to __register
1746  *
1747  * Use this macro to construct bus specific macros for registering
1748  * drivers, and do not use it on its own.
1749  */
1750 #define builtin_driver(__driver, __register, ...) \
1751 static int __init __driver##_init(void) \
1752 { \
1753 	return __register(&(__driver) , ##__VA_ARGS__); \
1754 } \
1755 device_initcall(__driver##_init);
1756 
1757 #endif /* _DEVICE_H_ */
1758