xref: /linux-6.15/include/linux/device.h (revision be576734)
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  * @sync_state:	Called to sync device state to software state after all the
84  *		state tracking consumers linked to this device (present at
85  *		the time of late_initcall) have successfully bound to a
86  *		driver. If the device has no consumers, this function will
87  *		be called at late_initcall_sync level. If the device has
88  *		consumers that are never bound to a driver, this function
89  *		will never get called until they do.
90  * @remove:	Called when a device removed from this bus.
91  * @shutdown:	Called at shut-down time to quiesce the device.
92  *
93  * @online:	Called to put the device back online (after offlining it).
94  * @offline:	Called to put the device offline for hot-removal. May fail.
95  *
96  * @suspend:	Called when a device on this bus wants to go to sleep mode.
97  * @resume:	Called to bring a device on this bus out of sleep mode.
98  * @num_vf:	Called to find out how many virtual functions a device on this
99  *		bus supports.
100  * @dma_configure:	Called to setup DMA configuration on a device on
101  *			this bus.
102  * @pm:		Power management operations of this bus, callback the specific
103  *		device driver's pm-ops.
104  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
105  *              driver implementations to a bus and allow the driver to do
106  *              bus-specific setup
107  * @p:		The private data of the driver core, only the driver core can
108  *		touch this.
109  * @lock_key:	Lock class key for use by the lock validator
110  * @need_parent_lock:	When probing or removing a device on this bus, the
111  *			device core should lock the device's parent.
112  *
113  * A bus is a channel between the processor and one or more devices. For the
114  * purposes of the device model, all devices are connected via a bus, even if
115  * it is an internal, virtual, "platform" bus. Buses can plug into each other.
116  * A USB controller is usually a PCI device, for example. The device model
117  * represents the actual connections between buses and the devices they control.
118  * A bus is represented by the bus_type structure. It contains the name, the
119  * default attributes, the bus' methods, PM operations, and the driver core's
120  * private data.
121  */
122 struct bus_type {
123 	const char		*name;
124 	const char		*dev_name;
125 	struct device		*dev_root;
126 	const struct attribute_group **bus_groups;
127 	const struct attribute_group **dev_groups;
128 	const struct attribute_group **drv_groups;
129 
130 	int (*match)(struct device *dev, struct device_driver *drv);
131 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
132 	int (*probe)(struct device *dev);
133 	void (*sync_state)(struct device *dev);
134 	int (*remove)(struct device *dev);
135 	void (*shutdown)(struct device *dev);
136 
137 	int (*online)(struct device *dev);
138 	int (*offline)(struct device *dev);
139 
140 	int (*suspend)(struct device *dev, pm_message_t state);
141 	int (*resume)(struct device *dev);
142 
143 	int (*num_vf)(struct device *dev);
144 
145 	int (*dma_configure)(struct device *dev);
146 
147 	const struct dev_pm_ops *pm;
148 
149 	const struct iommu_ops *iommu_ops;
150 
151 	struct subsys_private *p;
152 	struct lock_class_key lock_key;
153 
154 	bool need_parent_lock;
155 };
156 
157 extern int __must_check bus_register(struct bus_type *bus);
158 
159 extern void bus_unregister(struct bus_type *bus);
160 
161 extern int __must_check bus_rescan_devices(struct bus_type *bus);
162 
163 /* iterator helpers for buses */
164 struct subsys_dev_iter {
165 	struct klist_iter		ki;
166 	const struct device_type	*type;
167 };
168 void subsys_dev_iter_init(struct subsys_dev_iter *iter,
169 			 struct bus_type *subsys,
170 			 struct device *start,
171 			 const struct device_type *type);
172 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
173 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
174 
175 int device_match_name(struct device *dev, const void *name);
176 int device_match_of_node(struct device *dev, const void *np);
177 int device_match_fwnode(struct device *dev, const void *fwnode);
178 int device_match_devt(struct device *dev, const void *pdevt);
179 int device_match_acpi_dev(struct device *dev, const void *adev);
180 int device_match_any(struct device *dev, const void *unused);
181 
182 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
183 		     int (*fn)(struct device *dev, void *data));
184 struct device *bus_find_device(struct bus_type *bus, struct device *start,
185 			       const void *data,
186 			       int (*match)(struct device *dev, const void *data));
187 /**
188  * bus_find_device_by_name - device iterator for locating a particular device
189  * of a specific name.
190  * @bus: bus type
191  * @start: Device to begin with
192  * @name: name of the device to match
193  */
194 static inline struct device *bus_find_device_by_name(struct bus_type *bus,
195 						     struct device *start,
196 						     const char *name)
197 {
198 	return bus_find_device(bus, start, name, device_match_name);
199 }
200 
201 /**
202  * bus_find_device_by_of_node : device iterator for locating a particular device
203  * matching the of_node.
204  * @bus: bus type
205  * @np: of_node of the device to match.
206  */
207 static inline struct device *
208 bus_find_device_by_of_node(struct bus_type *bus, const struct device_node *np)
209 {
210 	return bus_find_device(bus, NULL, np, device_match_of_node);
211 }
212 
213 /**
214  * bus_find_device_by_fwnode : device iterator for locating a particular device
215  * matching the fwnode.
216  * @bus: bus type
217  * @fwnode: fwnode of the device to match.
218  */
219 static inline struct device *
220 bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwnode)
221 {
222 	return bus_find_device(bus, NULL, fwnode, device_match_fwnode);
223 }
224 
225 /**
226  * bus_find_device_by_devt : device iterator for locating a particular device
227  * matching the device type.
228  * @bus: bus type
229  * @devt: device type of the device to match.
230  */
231 static inline struct device *bus_find_device_by_devt(struct bus_type *bus,
232 						     dev_t devt)
233 {
234 	return bus_find_device(bus, NULL, &devt, device_match_devt);
235 }
236 
237 /**
238  * bus_find_next_device - Find the next device after a given device in a
239  * given bus.
240  * @bus: bus type
241  * @cur: device to begin the search with.
242  */
243 static inline struct device *
244 bus_find_next_device(struct bus_type *bus,struct device *cur)
245 {
246 	return bus_find_device(bus, cur, NULL, device_match_any);
247 }
248 
249 #ifdef CONFIG_ACPI
250 struct acpi_device;
251 
252 /**
253  * bus_find_device_by_acpi_dev : device iterator for locating a particular device
254  * matching the ACPI COMPANION device.
255  * @bus: bus type
256  * @adev: ACPI COMPANION device to match.
257  */
258 static inline struct device *
259 bus_find_device_by_acpi_dev(struct bus_type *bus, const struct acpi_device *adev)
260 {
261 	return bus_find_device(bus, NULL, adev, device_match_acpi_dev);
262 }
263 #else
264 static inline struct device *
265 bus_find_device_by_acpi_dev(struct bus_type *bus, const void *adev)
266 {
267 	return NULL;
268 }
269 #endif
270 
271 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
272 					struct device *hint);
273 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
274 		     void *data, int (*fn)(struct device_driver *, void *));
275 void bus_sort_breadthfirst(struct bus_type *bus,
276 			   int (*compare)(const struct device *a,
277 					  const struct device *b));
278 /*
279  * Bus notifiers: Get notified of addition/removal of devices
280  * and binding/unbinding of drivers to devices.
281  * In the long run, it should be a replacement for the platform
282  * notify hooks.
283  */
284 struct notifier_block;
285 
286 extern int bus_register_notifier(struct bus_type *bus,
287 				 struct notifier_block *nb);
288 extern int bus_unregister_notifier(struct bus_type *bus,
289 				   struct notifier_block *nb);
290 
291 /* All 4 notifers below get called with the target struct device *
292  * as an argument. Note that those functions are likely to be called
293  * with the device lock held in the core, so be careful.
294  */
295 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
296 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device to be removed */
297 #define BUS_NOTIFY_REMOVED_DEVICE	0x00000003 /* device removed */
298 #define BUS_NOTIFY_BIND_DRIVER		0x00000004 /* driver about to be
299 						      bound */
300 #define BUS_NOTIFY_BOUND_DRIVER		0x00000005 /* driver bound to device */
301 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000006 /* driver about to be
302 						      unbound */
303 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000007 /* driver is unbound
304 						      from the device */
305 #define BUS_NOTIFY_DRIVER_NOT_BOUND	0x00000008 /* driver fails to be bound */
306 
307 extern struct kset *bus_get_kset(struct bus_type *bus);
308 extern struct klist *bus_get_device_klist(struct bus_type *bus);
309 
310 /**
311  * enum probe_type - device driver probe type to try
312  *	Device drivers may opt in for special handling of their
313  *	respective probe routines. This tells the core what to
314  *	expect and prefer.
315  *
316  * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
317  *	whether probed synchronously or asynchronously.
318  * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
319  *	probing order is not essential for booting the system may
320  *	opt into executing their probes asynchronously.
321  * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
322  *	their probe routines to run synchronously with driver and
323  *	device registration (with the exception of -EPROBE_DEFER
324  *	handling - re-probing always ends up being done asynchronously).
325  *
326  * Note that the end goal is to switch the kernel to use asynchronous
327  * probing by default, so annotating drivers with
328  * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
329  * to speed up boot process while we are validating the rest of the
330  * drivers.
331  */
332 enum probe_type {
333 	PROBE_DEFAULT_STRATEGY,
334 	PROBE_PREFER_ASYNCHRONOUS,
335 	PROBE_FORCE_SYNCHRONOUS,
336 };
337 
338 /**
339  * struct device_driver - The basic device driver structure
340  * @name:	Name of the device driver.
341  * @bus:	The bus which the device of this driver belongs to.
342  * @owner:	The module owner.
343  * @mod_name:	Used for built-in modules.
344  * @suppress_bind_attrs: Disables bind/unbind via sysfs.
345  * @probe_type:	Type of the probe (synchronous or asynchronous) to use.
346  * @of_match_table: The open firmware table.
347  * @acpi_match_table: The ACPI match table.
348  * @probe:	Called to query the existence of a specific device,
349  *		whether this driver can work with it, and bind the driver
350  *		to a specific device.
351  * @sync_state:	Called to sync device state to software state after all the
352  *		state tracking consumers linked to this device (present at
353  *		the time of late_initcall) have successfully bound to a
354  *		driver. If the device has no consumers, this function will
355  *		be called at late_initcall_sync level. If the device has
356  *		consumers that are never bound to a driver, this function
357  *		will never get called until they do.
358  * @remove:	Called when the device is removed from the system to
359  *		unbind a device from this driver.
360  * @shutdown:	Called at shut-down time to quiesce the device.
361  * @suspend:	Called to put the device to sleep mode. Usually to a
362  *		low power state.
363  * @resume:	Called to bring a device from sleep mode.
364  * @groups:	Default attributes that get created by the driver core
365  *		automatically.
366  * @dev_groups:	Additional attributes attached to device instance once the
367  *		it is bound to the driver.
368  * @pm:		Power management operations of the device which matched
369  *		this driver.
370  * @coredump:	Called when sysfs entry is written to. The device driver
371  *		is expected to call the dev_coredump API resulting in a
372  *		uevent.
373  * @p:		Driver core's private data, no one other than the driver
374  *		core can touch this.
375  *
376  * The device driver-model tracks all of the drivers known to the system.
377  * The main reason for this tracking is to enable the driver core to match
378  * up drivers with new devices. Once drivers are known objects within the
379  * system, however, a number of other things become possible. Device drivers
380  * can export information and configuration variables that are independent
381  * of any specific device.
382  */
383 struct device_driver {
384 	const char		*name;
385 	struct bus_type		*bus;
386 
387 	struct module		*owner;
388 	const char		*mod_name;	/* used for built-in modules */
389 
390 	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */
391 	enum probe_type probe_type;
392 
393 	const struct of_device_id	*of_match_table;
394 	const struct acpi_device_id	*acpi_match_table;
395 
396 	int (*probe) (struct device *dev);
397 	void (*sync_state)(struct device *dev);
398 	int (*remove) (struct device *dev);
399 	void (*shutdown) (struct device *dev);
400 	int (*suspend) (struct device *dev, pm_message_t state);
401 	int (*resume) (struct device *dev);
402 	const struct attribute_group **groups;
403 	const struct attribute_group **dev_groups;
404 
405 	const struct dev_pm_ops *pm;
406 	void (*coredump) (struct device *dev);
407 
408 	struct driver_private *p;
409 };
410 
411 
412 extern int __must_check driver_register(struct device_driver *drv);
413 extern void driver_unregister(struct device_driver *drv);
414 
415 extern struct device_driver *driver_find(const char *name,
416 					 struct bus_type *bus);
417 extern int driver_probe_done(void);
418 extern void wait_for_device_probe(void);
419 
420 /* sysfs interface for exporting driver attributes */
421 
422 struct driver_attribute {
423 	struct attribute attr;
424 	ssize_t (*show)(struct device_driver *driver, char *buf);
425 	ssize_t (*store)(struct device_driver *driver, const char *buf,
426 			 size_t count);
427 };
428 
429 #define DRIVER_ATTR_RW(_name) \
430 	struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
431 #define DRIVER_ATTR_RO(_name) \
432 	struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
433 #define DRIVER_ATTR_WO(_name) \
434 	struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
435 
436 extern int __must_check driver_create_file(struct device_driver *driver,
437 					const struct driver_attribute *attr);
438 extern void driver_remove_file(struct device_driver *driver,
439 			       const struct driver_attribute *attr);
440 
441 extern int __must_check driver_for_each_device(struct device_driver *drv,
442 					       struct device *start,
443 					       void *data,
444 					       int (*fn)(struct device *dev,
445 							 void *));
446 struct device *driver_find_device(struct device_driver *drv,
447 				  struct device *start, const void *data,
448 				  int (*match)(struct device *dev, const void *data));
449 
450 /**
451  * driver_find_device_by_name - device iterator for locating a particular device
452  * of a specific name.
453  * @drv: the driver we're iterating
454  * @name: name of the device to match
455  */
456 static inline struct device *driver_find_device_by_name(struct device_driver *drv,
457 							const char *name)
458 {
459 	return driver_find_device(drv, NULL, name, device_match_name);
460 }
461 
462 /**
463  * driver_find_device_by_of_node- device iterator for locating a particular device
464  * by of_node pointer.
465  * @drv: the driver we're iterating
466  * @np: of_node pointer to match.
467  */
468 static inline struct device *
469 driver_find_device_by_of_node(struct device_driver *drv,
470 			      const struct device_node *np)
471 {
472 	return driver_find_device(drv, NULL, np, device_match_of_node);
473 }
474 
475 /**
476  * driver_find_device_by_fwnode- device iterator for locating a particular device
477  * by fwnode pointer.
478  * @drv: the driver we're iterating
479  * @fwnode: fwnode pointer to match.
480  */
481 static inline struct device *
482 driver_find_device_by_fwnode(struct device_driver *drv,
483 			     const struct fwnode_handle *fwnode)
484 {
485 	return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
486 }
487 
488 /**
489  * driver_find_device_by_devt- device iterator for locating a particular device
490  * by devt.
491  * @drv: the driver we're iterating
492  * @devt: devt pointer to match.
493  */
494 static inline struct device *driver_find_device_by_devt(struct device_driver *drv,
495 							dev_t devt)
496 {
497 	return driver_find_device(drv, NULL, &devt, device_match_devt);
498 }
499 
500 static inline struct device *driver_find_next_device(struct device_driver *drv,
501 						     struct device *start)
502 {
503 	return driver_find_device(drv, start, NULL, device_match_any);
504 }
505 
506 #ifdef CONFIG_ACPI
507 /**
508  * driver_find_device_by_acpi_dev : device iterator for locating a particular
509  * device matching the ACPI_COMPANION device.
510  * @drv: the driver we're iterating
511  * @adev: ACPI_COMPANION device to match.
512  */
513 static inline struct device *
514 driver_find_device_by_acpi_dev(struct device_driver *drv,
515 			       const struct acpi_device *adev)
516 {
517 	return driver_find_device(drv, NULL, adev, device_match_acpi_dev);
518 }
519 #else
520 static inline struct device *
521 driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
522 {
523 	return NULL;
524 }
525 #endif
526 
527 void driver_deferred_probe_add(struct device *dev);
528 int driver_deferred_probe_check_state(struct device *dev);
529 int driver_deferred_probe_check_state_continue(struct device *dev);
530 
531 /**
532  * struct subsys_interface - interfaces to device functions
533  * @name:       name of the device function
534  * @subsys:     subsytem of the devices to attach to
535  * @node:       the list of functions registered at the subsystem
536  * @add_dev:    device hookup to device function handler
537  * @remove_dev: device hookup to device function handler
538  *
539  * Simple interfaces attached to a subsystem. Multiple interfaces can
540  * attach to a subsystem and its devices. Unlike drivers, they do not
541  * exclusively claim or control devices. Interfaces usually represent
542  * a specific functionality of a subsystem/class of devices.
543  */
544 struct subsys_interface {
545 	const char *name;
546 	struct bus_type *subsys;
547 	struct list_head node;
548 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
549 	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
550 };
551 
552 int subsys_interface_register(struct subsys_interface *sif);
553 void subsys_interface_unregister(struct subsys_interface *sif);
554 
555 int subsys_system_register(struct bus_type *subsys,
556 			   const struct attribute_group **groups);
557 int subsys_virtual_register(struct bus_type *subsys,
558 			    const struct attribute_group **groups);
559 
560 /**
561  * struct class - device classes
562  * @name:	Name of the class.
563  * @owner:	The module owner.
564  * @class_groups: Default attributes of this class.
565  * @dev_groups:	Default attributes of the devices that belong to the class.
566  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
567  * @dev_uevent:	Called when a device is added, removed from this class, or a
568  *		few other things that generate uevents to add the environment
569  *		variables.
570  * @devnode:	Callback to provide the devtmpfs.
571  * @class_release: Called to release this class.
572  * @dev_release: Called to release the device.
573  * @shutdown_pre: Called at shut-down time before driver shutdown.
574  * @ns_type:	Callbacks so sysfs can detemine namespaces.
575  * @namespace:	Namespace of the device belongs to this class.
576  * @get_ownership: Allows class to specify uid/gid of the sysfs directories
577  *		for the devices belonging to the class. Usually tied to
578  *		device's namespace.
579  * @pm:		The default device power management operations of this class.
580  * @p:		The private data of the driver core, no one other than the
581  *		driver core can touch this.
582  *
583  * A class is a higher-level view of a device that abstracts out low-level
584  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
585  * at the class level, they are all simply disks. Classes allow user space
586  * to work with devices based on what they do, rather than how they are
587  * connected or how they work.
588  */
589 struct class {
590 	const char		*name;
591 	struct module		*owner;
592 
593 	const struct attribute_group	**class_groups;
594 	const struct attribute_group	**dev_groups;
595 	struct kobject			*dev_kobj;
596 
597 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
598 	char *(*devnode)(struct device *dev, umode_t *mode);
599 
600 	void (*class_release)(struct class *class);
601 	void (*dev_release)(struct device *dev);
602 
603 	int (*shutdown_pre)(struct device *dev);
604 
605 	const struct kobj_ns_type_operations *ns_type;
606 	const void *(*namespace)(struct device *dev);
607 
608 	void (*get_ownership)(struct device *dev, kuid_t *uid, kgid_t *gid);
609 
610 	const struct dev_pm_ops *pm;
611 
612 	struct subsys_private *p;
613 };
614 
615 struct class_dev_iter {
616 	struct klist_iter		ki;
617 	const struct device_type	*type;
618 };
619 
620 extern struct kobject *sysfs_dev_block_kobj;
621 extern struct kobject *sysfs_dev_char_kobj;
622 extern int __must_check __class_register(struct class *class,
623 					 struct lock_class_key *key);
624 extern void class_unregister(struct class *class);
625 
626 /* This is a #define to keep the compiler from merging different
627  * instances of the __key variable */
628 #define class_register(class)			\
629 ({						\
630 	static struct lock_class_key __key;	\
631 	__class_register(class, &__key);	\
632 })
633 
634 struct class_compat;
635 struct class_compat *class_compat_register(const char *name);
636 void class_compat_unregister(struct class_compat *cls);
637 int class_compat_create_link(struct class_compat *cls, struct device *dev,
638 			     struct device *device_link);
639 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
640 			      struct device *device_link);
641 
642 extern void class_dev_iter_init(struct class_dev_iter *iter,
643 				struct class *class,
644 				struct device *start,
645 				const struct device_type *type);
646 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
647 extern void class_dev_iter_exit(struct class_dev_iter *iter);
648 
649 extern int class_for_each_device(struct class *class, struct device *start,
650 				 void *data,
651 				 int (*fn)(struct device *dev, void *data));
652 extern struct device *class_find_device(struct class *class,
653 					struct device *start, const void *data,
654 					int (*match)(struct device *, const void *));
655 
656 /**
657  * class_find_device_by_name - device iterator for locating a particular device
658  * of a specific name.
659  * @class: class type
660  * @name: name of the device to match
661  */
662 static inline struct device *class_find_device_by_name(struct class *class,
663 						       const char *name)
664 {
665 	return class_find_device(class, NULL, name, device_match_name);
666 }
667 
668 /**
669  * class_find_device_by_of_node : device iterator for locating a particular device
670  * matching the of_node.
671  * @class: class type
672  * @np: of_node of the device to match.
673  */
674 static inline struct device *
675 class_find_device_by_of_node(struct class *class, const struct device_node *np)
676 {
677 	return class_find_device(class, NULL, np, device_match_of_node);
678 }
679 
680 /**
681  * class_find_device_by_fwnode : device iterator for locating a particular device
682  * matching the fwnode.
683  * @class: class type
684  * @fwnode: fwnode of the device to match.
685  */
686 static inline struct device *
687 class_find_device_by_fwnode(struct class *class,
688 			    const struct fwnode_handle *fwnode)
689 {
690 	return class_find_device(class, NULL, fwnode, device_match_fwnode);
691 }
692 
693 /**
694  * class_find_device_by_devt : device iterator for locating a particular device
695  * matching the device type.
696  * @class: class type
697  * @devt: device type of the device to match.
698  */
699 static inline struct device *class_find_device_by_devt(struct class *class,
700 						       dev_t devt)
701 {
702 	return class_find_device(class, NULL, &devt, device_match_devt);
703 }
704 
705 #ifdef CONFIG_ACPI
706 struct acpi_device;
707 /**
708  * class_find_device_by_acpi_dev : device iterator for locating a particular
709  * device matching the ACPI_COMPANION device.
710  * @class: class type
711  * @adev: ACPI_COMPANION device to match.
712  */
713 static inline struct device *
714 class_find_device_by_acpi_dev(struct class *class, const struct acpi_device *adev)
715 {
716 	return class_find_device(class, NULL, adev, device_match_acpi_dev);
717 }
718 #else
719 static inline struct device *
720 class_find_device_by_acpi_dev(struct class *class, const void *adev)
721 {
722 	return NULL;
723 }
724 #endif
725 
726 struct class_attribute {
727 	struct attribute attr;
728 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
729 			char *buf);
730 	ssize_t (*store)(struct class *class, struct class_attribute *attr,
731 			const char *buf, size_t count);
732 };
733 
734 #define CLASS_ATTR_RW(_name) \
735 	struct class_attribute class_attr_##_name = __ATTR_RW(_name)
736 #define CLASS_ATTR_RO(_name) \
737 	struct class_attribute class_attr_##_name = __ATTR_RO(_name)
738 #define CLASS_ATTR_WO(_name) \
739 	struct class_attribute class_attr_##_name = __ATTR_WO(_name)
740 
741 extern int __must_check class_create_file_ns(struct class *class,
742 					     const struct class_attribute *attr,
743 					     const void *ns);
744 extern void class_remove_file_ns(struct class *class,
745 				 const struct class_attribute *attr,
746 				 const void *ns);
747 
748 static inline int __must_check class_create_file(struct class *class,
749 					const struct class_attribute *attr)
750 {
751 	return class_create_file_ns(class, attr, NULL);
752 }
753 
754 static inline void class_remove_file(struct class *class,
755 				     const struct class_attribute *attr)
756 {
757 	return class_remove_file_ns(class, attr, NULL);
758 }
759 
760 /* Simple class attribute that is just a static string */
761 struct class_attribute_string {
762 	struct class_attribute attr;
763 	char *str;
764 };
765 
766 /* Currently read-only only */
767 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
768 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
769 #define CLASS_ATTR_STRING(_name, _mode, _str) \
770 	struct class_attribute_string class_attr_##_name = \
771 		_CLASS_ATTR_STRING(_name, _mode, _str)
772 
773 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
774                         char *buf);
775 
776 struct class_interface {
777 	struct list_head	node;
778 	struct class		*class;
779 
780 	int (*add_dev)		(struct device *, struct class_interface *);
781 	void (*remove_dev)	(struct device *, struct class_interface *);
782 };
783 
784 extern int __must_check class_interface_register(struct class_interface *);
785 extern void class_interface_unregister(struct class_interface *);
786 
787 extern struct class * __must_check __class_create(struct module *owner,
788 						  const char *name,
789 						  struct lock_class_key *key);
790 extern void class_destroy(struct class *cls);
791 
792 /* This is a #define to keep the compiler from merging different
793  * instances of the __key variable */
794 #define class_create(owner, name)		\
795 ({						\
796 	static struct lock_class_key __key;	\
797 	__class_create(owner, name, &__key);	\
798 })
799 
800 /*
801  * The type of device, "struct device" is embedded in. A class
802  * or bus can contain devices of different types
803  * like "partitions" and "disks", "mouse" and "event".
804  * This identifies the device type and carries type-specific
805  * information, equivalent to the kobj_type of a kobject.
806  * If "name" is specified, the uevent will contain it in
807  * the DEVTYPE variable.
808  */
809 struct device_type {
810 	const char *name;
811 	const struct attribute_group **groups;
812 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
813 	char *(*devnode)(struct device *dev, umode_t *mode,
814 			 kuid_t *uid, kgid_t *gid);
815 	void (*release)(struct device *dev);
816 
817 	const struct dev_pm_ops *pm;
818 };
819 
820 /* interface for exporting device attributes */
821 struct device_attribute {
822 	struct attribute	attr;
823 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
824 			char *buf);
825 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
826 			 const char *buf, size_t count);
827 };
828 
829 struct dev_ext_attribute {
830 	struct device_attribute attr;
831 	void *var;
832 };
833 
834 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
835 			  char *buf);
836 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
837 			   const char *buf, size_t count);
838 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
839 			char *buf);
840 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
841 			 const char *buf, size_t count);
842 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
843 			char *buf);
844 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
845 			 const char *buf, size_t count);
846 
847 #define DEVICE_ATTR(_name, _mode, _show, _store) \
848 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
849 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
850 	struct device_attribute dev_attr_##_name = \
851 		__ATTR_PREALLOC(_name, _mode, _show, _store)
852 #define DEVICE_ATTR_RW(_name) \
853 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
854 #define DEVICE_ATTR_RO(_name) \
855 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
856 #define DEVICE_ATTR_WO(_name) \
857 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
858 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
859 	struct dev_ext_attribute dev_attr_##_name = \
860 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
861 #define DEVICE_INT_ATTR(_name, _mode, _var) \
862 	struct dev_ext_attribute dev_attr_##_name = \
863 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
864 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
865 	struct dev_ext_attribute dev_attr_##_name = \
866 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
867 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
868 	struct device_attribute dev_attr_##_name =		\
869 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
870 
871 extern int device_create_file(struct device *device,
872 			      const struct device_attribute *entry);
873 extern void device_remove_file(struct device *dev,
874 			       const struct device_attribute *attr);
875 extern bool device_remove_file_self(struct device *dev,
876 				    const struct device_attribute *attr);
877 extern int __must_check device_create_bin_file(struct device *dev,
878 					const struct bin_attribute *attr);
879 extern void device_remove_bin_file(struct device *dev,
880 				   const struct bin_attribute *attr);
881 
882 /* device resource management */
883 typedef void (*dr_release_t)(struct device *dev, void *res);
884 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
885 
886 #ifdef CONFIG_DEBUG_DEVRES
887 extern void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
888 				 int nid, const char *name) __malloc;
889 #define devres_alloc(release, size, gfp) \
890 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
891 #define devres_alloc_node(release, size, gfp, nid) \
892 	__devres_alloc_node(release, size, gfp, nid, #release)
893 #else
894 extern void *devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
895 			       int nid) __malloc;
896 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
897 {
898 	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
899 }
900 #endif
901 
902 extern void devres_for_each_res(struct device *dev, dr_release_t release,
903 				dr_match_t match, void *match_data,
904 				void (*fn)(struct device *, void *, void *),
905 				void *data);
906 extern void devres_free(void *res);
907 extern void devres_add(struct device *dev, void *res);
908 extern void *devres_find(struct device *dev, dr_release_t release,
909 			 dr_match_t match, void *match_data);
910 extern void *devres_get(struct device *dev, void *new_res,
911 			dr_match_t match, void *match_data);
912 extern void *devres_remove(struct device *dev, dr_release_t release,
913 			   dr_match_t match, void *match_data);
914 extern int devres_destroy(struct device *dev, dr_release_t release,
915 			  dr_match_t match, void *match_data);
916 extern int devres_release(struct device *dev, dr_release_t release,
917 			  dr_match_t match, void *match_data);
918 
919 /* devres group */
920 extern void * __must_check devres_open_group(struct device *dev, void *id,
921 					     gfp_t gfp);
922 extern void devres_close_group(struct device *dev, void *id);
923 extern void devres_remove_group(struct device *dev, void *id);
924 extern int devres_release_group(struct device *dev, void *id);
925 
926 /* managed devm_k.alloc/kfree for device drivers */
927 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
928 extern __printf(3, 0)
929 char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
930 		      va_list ap) __malloc;
931 extern __printf(3, 4)
932 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...) __malloc;
933 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
934 {
935 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
936 }
937 static inline void *devm_kmalloc_array(struct device *dev,
938 				       size_t n, size_t size, gfp_t flags)
939 {
940 	size_t bytes;
941 
942 	if (unlikely(check_mul_overflow(n, size, &bytes)))
943 		return NULL;
944 
945 	return devm_kmalloc(dev, bytes, flags);
946 }
947 static inline void *devm_kcalloc(struct device *dev,
948 				 size_t n, size_t size, gfp_t flags)
949 {
950 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
951 }
952 extern void devm_kfree(struct device *dev, const void *p);
953 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
954 extern const char *devm_kstrdup_const(struct device *dev,
955 				      const char *s, gfp_t gfp);
956 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
957 			  gfp_t gfp);
958 
959 extern unsigned long devm_get_free_pages(struct device *dev,
960 					 gfp_t gfp_mask, unsigned int order);
961 extern void devm_free_pages(struct device *dev, unsigned long addr);
962 
963 void __iomem *devm_ioremap_resource(struct device *dev,
964 				    const struct resource *res);
965 
966 void __iomem *devm_of_iomap(struct device *dev,
967 			    struct device_node *node, int index,
968 			    resource_size_t *size);
969 
970 /* allows to add/remove a custom action to devres stack */
971 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
972 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
973 void devm_release_action(struct device *dev, void (*action)(void *), void *data);
974 
975 static inline int devm_add_action_or_reset(struct device *dev,
976 					   void (*action)(void *), void *data)
977 {
978 	int ret;
979 
980 	ret = devm_add_action(dev, action, data);
981 	if (ret)
982 		action(data);
983 
984 	return ret;
985 }
986 
987 /**
988  * devm_alloc_percpu - Resource-managed alloc_percpu
989  * @dev: Device to allocate per-cpu memory for
990  * @type: Type to allocate per-cpu memory for
991  *
992  * Managed alloc_percpu. Per-cpu memory allocated with this function is
993  * automatically freed on driver detach.
994  *
995  * RETURNS:
996  * Pointer to allocated memory on success, NULL on failure.
997  */
998 #define devm_alloc_percpu(dev, type)      \
999 	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
1000 						      __alignof__(type)))
1001 
1002 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1003 				   size_t align);
1004 void devm_free_percpu(struct device *dev, void __percpu *pdata);
1005 
1006 struct device_dma_parameters {
1007 	/*
1008 	 * a low level driver may set these to teach IOMMU code about
1009 	 * sg limitations.
1010 	 */
1011 	unsigned int max_segment_size;
1012 	unsigned long segment_boundary_mask;
1013 };
1014 
1015 /**
1016  * struct device_connection - Device Connection Descriptor
1017  * @fwnode: The device node of the connected device
1018  * @endpoint: The names of the two devices connected together
1019  * @id: Unique identifier for the connection
1020  * @list: List head, private, for internal use only
1021  *
1022  * NOTE: @fwnode is not used together with @endpoint. @fwnode is used when
1023  * platform firmware defines the connection. When the connection is registered
1024  * with device_connection_add() @endpoint is used instead.
1025  */
1026 struct device_connection {
1027 	struct fwnode_handle	*fwnode;
1028 	const char		*endpoint[2];
1029 	const char		*id;
1030 	struct list_head	list;
1031 };
1032 
1033 typedef void *(*devcon_match_fn_t)(struct device_connection *con, int ep,
1034 				   void *data);
1035 
1036 void *fwnode_connection_find_match(struct fwnode_handle *fwnode,
1037 				   const char *con_id, void *data,
1038 				   devcon_match_fn_t match);
1039 void *device_connection_find_match(struct device *dev, const char *con_id,
1040 				   void *data, devcon_match_fn_t match);
1041 
1042 struct device *device_connection_find(struct device *dev, const char *con_id);
1043 
1044 void device_connection_add(struct device_connection *con);
1045 void device_connection_remove(struct device_connection *con);
1046 
1047 /**
1048  * device_connections_add - Add multiple device connections at once
1049  * @cons: Zero terminated array of device connection descriptors
1050  */
1051 static inline void device_connections_add(struct device_connection *cons)
1052 {
1053 	struct device_connection *c;
1054 
1055 	for (c = cons; c->endpoint[0]; c++)
1056 		device_connection_add(c);
1057 }
1058 
1059 /**
1060  * device_connections_remove - Remove multiple device connections at once
1061  * @cons: Zero terminated array of device connection descriptors
1062  */
1063 static inline void device_connections_remove(struct device_connection *cons)
1064 {
1065 	struct device_connection *c;
1066 
1067 	for (c = cons; c->endpoint[0]; c++)
1068 		device_connection_remove(c);
1069 }
1070 
1071 /**
1072  * enum device_link_state - Device link states.
1073  * @DL_STATE_NONE: The presence of the drivers is not being tracked.
1074  * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
1075  * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
1076  * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
1077  * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
1078  * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
1079  */
1080 enum device_link_state {
1081 	DL_STATE_NONE = -1,
1082 	DL_STATE_DORMANT = 0,
1083 	DL_STATE_AVAILABLE,
1084 	DL_STATE_CONSUMER_PROBE,
1085 	DL_STATE_ACTIVE,
1086 	DL_STATE_SUPPLIER_UNBIND,
1087 };
1088 
1089 /*
1090  * Device link flags.
1091  *
1092  * STATELESS: The core will not remove this link automatically.
1093  * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
1094  * PM_RUNTIME: If set, the runtime PM framework will use this link.
1095  * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
1096  * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
1097  * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
1098  * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
1099  */
1100 #define DL_FLAG_STATELESS		BIT(0)
1101 #define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)
1102 #define DL_FLAG_PM_RUNTIME		BIT(2)
1103 #define DL_FLAG_RPM_ACTIVE		BIT(3)
1104 #define DL_FLAG_AUTOREMOVE_SUPPLIER	BIT(4)
1105 #define DL_FLAG_AUTOPROBE_CONSUMER	BIT(5)
1106 #define DL_FLAG_MANAGED			BIT(6)
1107 
1108 /**
1109  * struct device_link - Device link representation.
1110  * @supplier: The device on the supplier end of the link.
1111  * @s_node: Hook to the supplier device's list of links to consumers.
1112  * @consumer: The device on the consumer end of the link.
1113  * @c_node: Hook to the consumer device's list of links to suppliers.
1114  * @status: The state of the link (with respect to the presence of drivers).
1115  * @flags: Link flags.
1116  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
1117  * @kref: Count repeated addition of the same link.
1118  * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
1119  * @supplier_preactivated: Supplier has been made active before consumer probe.
1120  */
1121 struct device_link {
1122 	struct device *supplier;
1123 	struct list_head s_node;
1124 	struct device *consumer;
1125 	struct list_head c_node;
1126 	enum device_link_state status;
1127 	u32 flags;
1128 	refcount_t rpm_active;
1129 	struct kref kref;
1130 #ifdef CONFIG_SRCU
1131 	struct rcu_head rcu_head;
1132 #endif
1133 	bool supplier_preactivated; /* Owned by consumer probe. */
1134 };
1135 
1136 /**
1137  * enum dl_dev_state - Device driver presence tracking information.
1138  * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
1139  * @DL_DEV_PROBING: A driver is probing.
1140  * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
1141  * @DL_DEV_UNBINDING: The driver is unbinding from the device.
1142  */
1143 enum dl_dev_state {
1144 	DL_DEV_NO_DRIVER = 0,
1145 	DL_DEV_PROBING,
1146 	DL_DEV_DRIVER_BOUND,
1147 	DL_DEV_UNBINDING,
1148 };
1149 
1150 /**
1151  * struct dev_links_info - Device data related to device links.
1152  * @suppliers: List of links to supplier devices.
1153  * @consumers: List of links to consumer devices.
1154  * @needs_suppliers: Hook to global list of devices waiting for suppliers.
1155  * @defer_sync: Hook to global list of devices that have deferred sync_state.
1156  * @status: Driver status information.
1157  */
1158 struct dev_links_info {
1159 	struct list_head suppliers;
1160 	struct list_head consumers;
1161 	struct list_head needs_suppliers;
1162 	struct list_head defer_sync;
1163 	enum dl_dev_state status;
1164 };
1165 
1166 /**
1167  * struct device - The basic device structure
1168  * @parent:	The device's "parent" device, the device to which it is attached.
1169  * 		In most cases, a parent device is some sort of bus or host
1170  * 		controller. If parent is NULL, the device, is a top-level device,
1171  * 		which is not usually what you want.
1172  * @p:		Holds the private data of the driver core portions of the device.
1173  * 		See the comment of the struct device_private for detail.
1174  * @kobj:	A top-level, abstract class from which other classes are derived.
1175  * @init_name:	Initial name of the device.
1176  * @type:	The type of device.
1177  * 		This identifies the device type and carries type-specific
1178  * 		information.
1179  * @mutex:	Mutex to synchronize calls to its driver.
1180  * @lockdep_mutex: An optional debug lock that a subsystem can use as a
1181  * 		peer lock to gain localized lockdep coverage of the device_lock.
1182  * @bus:	Type of bus device is on.
1183  * @driver:	Which driver has allocated this
1184  * @platform_data: Platform data specific to the device.
1185  * 		Example: For devices on custom boards, as typical of embedded
1186  * 		and SOC based hardware, Linux often uses platform_data to point
1187  * 		to board-specific structures describing devices and how they
1188  * 		are wired.  That can include what ports are available, chip
1189  * 		variants, which GPIO pins act in what additional roles, and so
1190  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
1191  * 		minimizes board-specific #ifdefs in drivers.
1192  * @driver_data: Private pointer for driver specific info.
1193  * @links:	Links to suppliers and consumers of this device.
1194  * @power:	For device power management.
1195  *		See Documentation/driver-api/pm/devices.rst for details.
1196  * @pm_domain:	Provide callbacks that are executed during system suspend,
1197  * 		hibernation, system resume and during runtime PM transitions
1198  * 		along with subsystem-level and driver-level callbacks.
1199  * @pins:	For device pin management.
1200  *		See Documentation/driver-api/pinctl.rst for details.
1201  * @msi_list:	Hosts MSI descriptors
1202  * @msi_domain: The generic MSI domain this device is using.
1203  * @numa_node:	NUMA node this device is close to.
1204  * @dma_ops:    DMA mapping operations for this device.
1205  * @dma_mask:	Dma mask (if dma'ble device).
1206  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
1207  * 		hardware supports 64-bit addresses for consistent allocations
1208  * 		such descriptors.
1209  * @bus_dma_mask: Mask of an upstream bridge or bus which imposes a smaller DMA
1210  *		limit than the device itself supports.
1211  * @dma_pfn_offset: offset of DMA memory range relatively of RAM
1212  * @dma_parms:	A low level driver may set these to teach IOMMU code about
1213  * 		segment limitations.
1214  * @dma_pools:	Dma pools (if dma'ble device).
1215  * @dma_mem:	Internal for coherent mem override.
1216  * @cma_area:	Contiguous memory area for dma allocations
1217  * @archdata:	For arch-specific additions.
1218  * @of_node:	Associated device tree node.
1219  * @fwnode:	Associated device node supplied by platform firmware.
1220  * @devt:	For creating the sysfs "dev".
1221  * @id:		device instance
1222  * @devres_lock: Spinlock to protect the resource of the device.
1223  * @devres_head: The resources list of the device.
1224  * @knode_class: The node used to add the device to the class list.
1225  * @class:	The class of the device.
1226  * @groups:	Optional attribute groups.
1227  * @release:	Callback to free the device after all references have
1228  * 		gone away. This should be set by the allocator of the
1229  * 		device (i.e. the bus driver that discovered the device).
1230  * @iommu_group: IOMMU group the device belongs to.
1231  * @iommu_fwspec: IOMMU-specific properties supplied by firmware.
1232  * @iommu_param: Per device generic IOMMU runtime data
1233  *
1234  * @offline_disabled: If set, the device is permanently online.
1235  * @offline:	Set after successful invocation of bus type's .offline().
1236  * @of_node_reused: Set if the device-tree node is shared with an ancestor
1237  *              device.
1238  * @state_synced: The hardware state of this device has been synced to match
1239  *		  the software state of this device by calling the driver/bus
1240  *		  sync_state() callback.
1241  * @dma_coherent: this particular device is dma coherent, even if the
1242  *		architecture supports non-coherent devices.
1243  *
1244  * At the lowest level, every device in a Linux system is represented by an
1245  * instance of struct device. The device structure contains the information
1246  * that the device model core needs to model the system. Most subsystems,
1247  * however, track additional information about the devices they host. As a
1248  * result, it is rare for devices to be represented by bare device structures;
1249  * instead, that structure, like kobject structures, is usually embedded within
1250  * a higher-level representation of the device.
1251  */
1252 struct device {
1253 	struct kobject kobj;
1254 	struct device		*parent;
1255 
1256 	struct device_private	*p;
1257 
1258 	const char		*init_name; /* initial name of the device */
1259 	const struct device_type *type;
1260 
1261 	struct bus_type	*bus;		/* type of bus device is on */
1262 	struct device_driver *driver;	/* which driver has allocated this
1263 					   device */
1264 	void		*platform_data;	/* Platform specific data, device
1265 					   core doesn't touch it */
1266 	void		*driver_data;	/* Driver data, set and get with
1267 					   dev_set_drvdata/dev_get_drvdata */
1268 #ifdef CONFIG_PROVE_LOCKING
1269 	struct mutex		lockdep_mutex;
1270 #endif
1271 	struct mutex		mutex;	/* mutex to synchronize calls to
1272 					 * its driver.
1273 					 */
1274 
1275 	struct dev_links_info	links;
1276 	struct dev_pm_info	power;
1277 	struct dev_pm_domain	*pm_domain;
1278 
1279 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1280 	struct irq_domain	*msi_domain;
1281 #endif
1282 #ifdef CONFIG_PINCTRL
1283 	struct dev_pin_info	*pins;
1284 #endif
1285 #ifdef CONFIG_GENERIC_MSI_IRQ
1286 	struct list_head	msi_list;
1287 #endif
1288 
1289 	const struct dma_map_ops *dma_ops;
1290 	u64		*dma_mask;	/* dma mask (if dma'able device) */
1291 	u64		coherent_dma_mask;/* Like dma_mask, but for
1292 					     alloc_coherent mappings as
1293 					     not all hardware supports
1294 					     64 bit addresses for consistent
1295 					     allocations such descriptors. */
1296 	u64		bus_dma_mask;	/* upstream dma_mask constraint */
1297 	unsigned long	dma_pfn_offset;
1298 
1299 	struct device_dma_parameters *dma_parms;
1300 
1301 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
1302 
1303 #ifdef CONFIG_DMA_DECLARE_COHERENT
1304 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
1305 					     override */
1306 #endif
1307 #ifdef CONFIG_DMA_CMA
1308 	struct cma *cma_area;		/* contiguous memory area for dma
1309 					   allocations */
1310 #endif
1311 	/* arch specific additions */
1312 	struct dev_archdata	archdata;
1313 
1314 	struct device_node	*of_node; /* associated device tree node */
1315 	struct fwnode_handle	*fwnode; /* firmware device node */
1316 
1317 #ifdef CONFIG_NUMA
1318 	int		numa_node;	/* NUMA node this device is close to */
1319 #endif
1320 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
1321 	u32			id;	/* device instance */
1322 
1323 	spinlock_t		devres_lock;
1324 	struct list_head	devres_head;
1325 
1326 	struct class		*class;
1327 	const struct attribute_group **groups;	/* optional groups */
1328 
1329 	void	(*release)(struct device *dev);
1330 	struct iommu_group	*iommu_group;
1331 	struct iommu_fwspec	*iommu_fwspec;
1332 	struct iommu_param	*iommu_param;
1333 
1334 	bool			offline_disabled:1;
1335 	bool			offline:1;
1336 	bool			of_node_reused:1;
1337 	bool			state_synced:1;
1338 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
1339     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
1340     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
1341 	bool			dma_coherent:1;
1342 #endif
1343 };
1344 
1345 static inline struct device *kobj_to_dev(struct kobject *kobj)
1346 {
1347 	return container_of(kobj, struct device, kobj);
1348 }
1349 
1350 /**
1351  * device_iommu_mapped - Returns true when the device DMA is translated
1352  *			 by an IOMMU
1353  * @dev: Device to perform the check on
1354  */
1355 static inline bool device_iommu_mapped(struct device *dev)
1356 {
1357 	return (dev->iommu_group != NULL);
1358 }
1359 
1360 /* Get the wakeup routines, which depend on struct device */
1361 #include <linux/pm_wakeup.h>
1362 
1363 static inline const char *dev_name(const struct device *dev)
1364 {
1365 	/* Use the init name until the kobject becomes available */
1366 	if (dev->init_name)
1367 		return dev->init_name;
1368 
1369 	return kobject_name(&dev->kobj);
1370 }
1371 
1372 extern __printf(2, 3)
1373 int dev_set_name(struct device *dev, const char *name, ...);
1374 
1375 #ifdef CONFIG_NUMA
1376 static inline int dev_to_node(struct device *dev)
1377 {
1378 	return dev->numa_node;
1379 }
1380 static inline void set_dev_node(struct device *dev, int node)
1381 {
1382 	dev->numa_node = node;
1383 }
1384 #else
1385 static inline int dev_to_node(struct device *dev)
1386 {
1387 	return NUMA_NO_NODE;
1388 }
1389 static inline void set_dev_node(struct device *dev, int node)
1390 {
1391 }
1392 #endif
1393 
1394 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
1395 {
1396 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1397 	return dev->msi_domain;
1398 #else
1399 	return NULL;
1400 #endif
1401 }
1402 
1403 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
1404 {
1405 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
1406 	dev->msi_domain = d;
1407 #endif
1408 }
1409 
1410 static inline void *dev_get_drvdata(const struct device *dev)
1411 {
1412 	return dev->driver_data;
1413 }
1414 
1415 static inline void dev_set_drvdata(struct device *dev, void *data)
1416 {
1417 	dev->driver_data = data;
1418 }
1419 
1420 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
1421 {
1422 	return dev ? dev->power.subsys_data : NULL;
1423 }
1424 
1425 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
1426 {
1427 	return dev->kobj.uevent_suppress;
1428 }
1429 
1430 static inline void dev_set_uevent_suppress(struct device *dev, int val)
1431 {
1432 	dev->kobj.uevent_suppress = val;
1433 }
1434 
1435 static inline int device_is_registered(struct device *dev)
1436 {
1437 	return dev->kobj.state_in_sysfs;
1438 }
1439 
1440 static inline void device_enable_async_suspend(struct device *dev)
1441 {
1442 	if (!dev->power.is_prepared)
1443 		dev->power.async_suspend = true;
1444 }
1445 
1446 static inline void device_disable_async_suspend(struct device *dev)
1447 {
1448 	if (!dev->power.is_prepared)
1449 		dev->power.async_suspend = false;
1450 }
1451 
1452 static inline bool device_async_suspend_enabled(struct device *dev)
1453 {
1454 	return !!dev->power.async_suspend;
1455 }
1456 
1457 static inline bool device_pm_not_required(struct device *dev)
1458 {
1459 	return dev->power.no_pm;
1460 }
1461 
1462 static inline void device_set_pm_not_required(struct device *dev)
1463 {
1464 	dev->power.no_pm = true;
1465 }
1466 
1467 static inline void dev_pm_syscore_device(struct device *dev, bool val)
1468 {
1469 #ifdef CONFIG_PM_SLEEP
1470 	dev->power.syscore = val;
1471 #endif
1472 }
1473 
1474 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
1475 {
1476 	dev->power.driver_flags = flags;
1477 }
1478 
1479 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
1480 {
1481 	return !!(dev->power.driver_flags & flags);
1482 }
1483 
1484 static inline void device_lock(struct device *dev)
1485 {
1486 	mutex_lock(&dev->mutex);
1487 }
1488 
1489 static inline int device_lock_interruptible(struct device *dev)
1490 {
1491 	return mutex_lock_interruptible(&dev->mutex);
1492 }
1493 
1494 static inline int device_trylock(struct device *dev)
1495 {
1496 	return mutex_trylock(&dev->mutex);
1497 }
1498 
1499 static inline void device_unlock(struct device *dev)
1500 {
1501 	mutex_unlock(&dev->mutex);
1502 }
1503 
1504 static inline void device_lock_assert(struct device *dev)
1505 {
1506 	lockdep_assert_held(&dev->mutex);
1507 }
1508 
1509 static inline struct device_node *dev_of_node(struct device *dev)
1510 {
1511 	if (!IS_ENABLED(CONFIG_OF) || !dev)
1512 		return NULL;
1513 	return dev->of_node;
1514 }
1515 
1516 void driver_init(void);
1517 
1518 /*
1519  * High level routines for use by the bus drivers
1520  */
1521 extern int __must_check device_register(struct device *dev);
1522 extern void device_unregister(struct device *dev);
1523 extern void device_initialize(struct device *dev);
1524 extern int __must_check device_add(struct device *dev);
1525 extern void device_del(struct device *dev);
1526 extern int device_for_each_child(struct device *dev, void *data,
1527 		     int (*fn)(struct device *dev, void *data));
1528 extern int device_for_each_child_reverse(struct device *dev, void *data,
1529 		     int (*fn)(struct device *dev, void *data));
1530 extern struct device *device_find_child(struct device *dev, void *data,
1531 				int (*match)(struct device *dev, void *data));
1532 extern struct device *device_find_child_by_name(struct device *parent,
1533 						const char *name);
1534 extern int device_rename(struct device *dev, const char *new_name);
1535 extern int device_move(struct device *dev, struct device *new_parent,
1536 		       enum dpm_order dpm_order);
1537 extern const char *device_get_devnode(struct device *dev,
1538 				      umode_t *mode, kuid_t *uid, kgid_t *gid,
1539 				      const char **tmp);
1540 
1541 static inline bool device_supports_offline(struct device *dev)
1542 {
1543 	return dev->bus && dev->bus->offline && dev->bus->online;
1544 }
1545 
1546 extern void lock_device_hotplug(void);
1547 extern void unlock_device_hotplug(void);
1548 extern int lock_device_hotplug_sysfs(void);
1549 extern int device_offline(struct device *dev);
1550 extern int device_online(struct device *dev);
1551 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1552 extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1553 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
1554 
1555 static inline int dev_num_vf(struct device *dev)
1556 {
1557 	if (dev->bus && dev->bus->num_vf)
1558 		return dev->bus->num_vf(dev);
1559 	return 0;
1560 }
1561 
1562 /*
1563  * Root device objects for grouping under /sys/devices
1564  */
1565 extern struct device *__root_device_register(const char *name,
1566 					     struct module *owner);
1567 
1568 /* This is a macro to avoid include problems with THIS_MODULE */
1569 #define root_device_register(name) \
1570 	__root_device_register(name, THIS_MODULE)
1571 
1572 extern void root_device_unregister(struct device *root);
1573 
1574 static inline void *dev_get_platdata(const struct device *dev)
1575 {
1576 	return dev->platform_data;
1577 }
1578 
1579 /*
1580  * Manual binding of a device to driver. See drivers/base/bus.c
1581  * for information on use.
1582  */
1583 extern int __must_check device_bind_driver(struct device *dev);
1584 extern void device_release_driver(struct device *dev);
1585 extern int  __must_check device_attach(struct device *dev);
1586 extern int __must_check driver_attach(struct device_driver *drv);
1587 extern void device_initial_probe(struct device *dev);
1588 extern int __must_check device_reprobe(struct device *dev);
1589 
1590 extern bool device_is_bound(struct device *dev);
1591 
1592 /*
1593  * Easy functions for dynamically creating devices on the fly
1594  */
1595 extern __printf(5, 0)
1596 struct device *device_create_vargs(struct class *cls, struct device *parent,
1597 				   dev_t devt, void *drvdata,
1598 				   const char *fmt, va_list vargs);
1599 extern __printf(5, 6)
1600 struct device *device_create(struct class *cls, struct device *parent,
1601 			     dev_t devt, void *drvdata,
1602 			     const char *fmt, ...);
1603 extern __printf(6, 7)
1604 struct device *device_create_with_groups(struct class *cls,
1605 			     struct device *parent, dev_t devt, void *drvdata,
1606 			     const struct attribute_group **groups,
1607 			     const char *fmt, ...);
1608 extern void device_destroy(struct class *cls, dev_t devt);
1609 
1610 extern int __must_check device_add_groups(struct device *dev,
1611 					const struct attribute_group **groups);
1612 extern void device_remove_groups(struct device *dev,
1613 				 const struct attribute_group **groups);
1614 
1615 static inline int __must_check device_add_group(struct device *dev,
1616 					const struct attribute_group *grp)
1617 {
1618 	const struct attribute_group *groups[] = { grp, NULL };
1619 
1620 	return device_add_groups(dev, groups);
1621 }
1622 
1623 static inline void device_remove_group(struct device *dev,
1624 				       const struct attribute_group *grp)
1625 {
1626 	const struct attribute_group *groups[] = { grp, NULL };
1627 
1628 	return device_remove_groups(dev, groups);
1629 }
1630 
1631 extern int __must_check devm_device_add_groups(struct device *dev,
1632 					const struct attribute_group **groups);
1633 extern void devm_device_remove_groups(struct device *dev,
1634 				      const struct attribute_group **groups);
1635 extern int __must_check devm_device_add_group(struct device *dev,
1636 					const struct attribute_group *grp);
1637 extern void devm_device_remove_group(struct device *dev,
1638 				     const struct attribute_group *grp);
1639 
1640 /*
1641  * Platform "fixup" functions - allow the platform to have their say
1642  * about devices and actions that the general device layer doesn't
1643  * know about.
1644  */
1645 /* Notify platform of device discovery */
1646 extern int (*platform_notify)(struct device *dev);
1647 
1648 extern int (*platform_notify_remove)(struct device *dev);
1649 
1650 
1651 /*
1652  * get_device - atomically increment the reference count for the device.
1653  *
1654  */
1655 extern struct device *get_device(struct device *dev);
1656 extern void put_device(struct device *dev);
1657 extern bool kill_device(struct device *dev);
1658 
1659 #ifdef CONFIG_DEVTMPFS
1660 extern int devtmpfs_create_node(struct device *dev);
1661 extern int devtmpfs_delete_node(struct device *dev);
1662 extern int devtmpfs_mount(const char *mntdir);
1663 #else
1664 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
1665 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
1666 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
1667 #endif
1668 
1669 /* drivers/base/power/shutdown.c */
1670 extern void device_shutdown(void);
1671 
1672 /* debugging and troubleshooting/diagnostic helpers. */
1673 extern const char *dev_driver_string(const struct device *dev);
1674 
1675 /* Device links interface. */
1676 struct device_link *device_link_add(struct device *consumer,
1677 				    struct device *supplier, u32 flags);
1678 void device_link_del(struct device_link *link);
1679 void device_link_remove(void *consumer, struct device *supplier);
1680 void device_links_supplier_sync_state_pause(void);
1681 void device_links_supplier_sync_state_resume(void);
1682 
1683 #ifndef dev_fmt
1684 #define dev_fmt(fmt) fmt
1685 #endif
1686 
1687 #ifdef CONFIG_PRINTK
1688 
1689 __printf(3, 0) __cold
1690 int dev_vprintk_emit(int level, const struct device *dev,
1691 		     const char *fmt, va_list args);
1692 __printf(3, 4) __cold
1693 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
1694 
1695 __printf(3, 4) __cold
1696 void dev_printk(const char *level, const struct device *dev,
1697 		const char *fmt, ...);
1698 __printf(2, 3) __cold
1699 void _dev_emerg(const struct device *dev, const char *fmt, ...);
1700 __printf(2, 3) __cold
1701 void _dev_alert(const struct device *dev, const char *fmt, ...);
1702 __printf(2, 3) __cold
1703 void _dev_crit(const struct device *dev, const char *fmt, ...);
1704 __printf(2, 3) __cold
1705 void _dev_err(const struct device *dev, const char *fmt, ...);
1706 __printf(2, 3) __cold
1707 void _dev_warn(const struct device *dev, const char *fmt, ...);
1708 __printf(2, 3) __cold
1709 void _dev_notice(const struct device *dev, const char *fmt, ...);
1710 __printf(2, 3) __cold
1711 void _dev_info(const struct device *dev, const char *fmt, ...);
1712 
1713 #else
1714 
1715 static inline __printf(3, 0)
1716 int dev_vprintk_emit(int level, const struct device *dev,
1717 		     const char *fmt, va_list args)
1718 { return 0; }
1719 static inline __printf(3, 4)
1720 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1721 { return 0; }
1722 
1723 static inline void __dev_printk(const char *level, const struct device *dev,
1724 				struct va_format *vaf)
1725 {}
1726 static inline __printf(3, 4)
1727 void dev_printk(const char *level, const struct device *dev,
1728 		 const char *fmt, ...)
1729 {}
1730 
1731 static inline __printf(2, 3)
1732 void _dev_emerg(const struct device *dev, const char *fmt, ...)
1733 {}
1734 static inline __printf(2, 3)
1735 void _dev_crit(const struct device *dev, const char *fmt, ...)
1736 {}
1737 static inline __printf(2, 3)
1738 void _dev_alert(const struct device *dev, const char *fmt, ...)
1739 {}
1740 static inline __printf(2, 3)
1741 void _dev_err(const struct device *dev, const char *fmt, ...)
1742 {}
1743 static inline __printf(2, 3)
1744 void _dev_warn(const struct device *dev, const char *fmt, ...)
1745 {}
1746 static inline __printf(2, 3)
1747 void _dev_notice(const struct device *dev, const char *fmt, ...)
1748 {}
1749 static inline __printf(2, 3)
1750 void _dev_info(const struct device *dev, const char *fmt, ...)
1751 {}
1752 
1753 #endif
1754 
1755 /*
1756  * #defines for all the dev_<level> macros to prefix with whatever
1757  * possible use of #define dev_fmt(fmt) ...
1758  */
1759 
1760 #define dev_emerg(dev, fmt, ...)					\
1761 	_dev_emerg(dev, dev_fmt(fmt), ##__VA_ARGS__)
1762 #define dev_crit(dev, fmt, ...)						\
1763 	_dev_crit(dev, dev_fmt(fmt), ##__VA_ARGS__)
1764 #define dev_alert(dev, fmt, ...)					\
1765 	_dev_alert(dev, dev_fmt(fmt), ##__VA_ARGS__)
1766 #define dev_err(dev, fmt, ...)						\
1767 	_dev_err(dev, dev_fmt(fmt), ##__VA_ARGS__)
1768 #define dev_warn(dev, fmt, ...)						\
1769 	_dev_warn(dev, dev_fmt(fmt), ##__VA_ARGS__)
1770 #define dev_notice(dev, fmt, ...)					\
1771 	_dev_notice(dev, dev_fmt(fmt), ##__VA_ARGS__)
1772 #define dev_info(dev, fmt, ...)						\
1773 	_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
1774 
1775 #if defined(CONFIG_DYNAMIC_DEBUG)
1776 #define dev_dbg(dev, fmt, ...)						\
1777 	dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
1778 #elif defined(DEBUG)
1779 #define dev_dbg(dev, fmt, ...)						\
1780 	dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__)
1781 #else
1782 #define dev_dbg(dev, fmt, ...)						\
1783 ({									\
1784 	if (0)								\
1785 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1786 })
1787 #endif
1788 
1789 #ifdef CONFIG_PRINTK
1790 #define dev_level_once(dev_level, dev, fmt, ...)			\
1791 do {									\
1792 	static bool __print_once __read_mostly;				\
1793 									\
1794 	if (!__print_once) {						\
1795 		__print_once = true;					\
1796 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1797 	}								\
1798 } while (0)
1799 #else
1800 #define dev_level_once(dev_level, dev, fmt, ...)			\
1801 do {									\
1802 	if (0)								\
1803 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1804 } while (0)
1805 #endif
1806 
1807 #define dev_emerg_once(dev, fmt, ...)					\
1808 	dev_level_once(dev_emerg, dev, fmt, ##__VA_ARGS__)
1809 #define dev_alert_once(dev, fmt, ...)					\
1810 	dev_level_once(dev_alert, dev, fmt, ##__VA_ARGS__)
1811 #define dev_crit_once(dev, fmt, ...)					\
1812 	dev_level_once(dev_crit, dev, fmt, ##__VA_ARGS__)
1813 #define dev_err_once(dev, fmt, ...)					\
1814 	dev_level_once(dev_err, dev, fmt, ##__VA_ARGS__)
1815 #define dev_warn_once(dev, fmt, ...)					\
1816 	dev_level_once(dev_warn, dev, fmt, ##__VA_ARGS__)
1817 #define dev_notice_once(dev, fmt, ...)					\
1818 	dev_level_once(dev_notice, dev, fmt, ##__VA_ARGS__)
1819 #define dev_info_once(dev, fmt, ...)					\
1820 	dev_level_once(dev_info, dev, fmt, ##__VA_ARGS__)
1821 #define dev_dbg_once(dev, fmt, ...)					\
1822 	dev_level_once(dev_dbg, dev, fmt, ##__VA_ARGS__)
1823 
1824 #define dev_level_ratelimited(dev_level, dev, fmt, ...)			\
1825 do {									\
1826 	static DEFINE_RATELIMIT_STATE(_rs,				\
1827 				      DEFAULT_RATELIMIT_INTERVAL,	\
1828 				      DEFAULT_RATELIMIT_BURST);		\
1829 	if (__ratelimit(&_rs))						\
1830 		dev_level(dev, fmt, ##__VA_ARGS__);			\
1831 } while (0)
1832 
1833 #define dev_emerg_ratelimited(dev, fmt, ...)				\
1834 	dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
1835 #define dev_alert_ratelimited(dev, fmt, ...)				\
1836 	dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
1837 #define dev_crit_ratelimited(dev, fmt, ...)				\
1838 	dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
1839 #define dev_err_ratelimited(dev, fmt, ...)				\
1840 	dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
1841 #define dev_warn_ratelimited(dev, fmt, ...)				\
1842 	dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
1843 #define dev_notice_ratelimited(dev, fmt, ...)				\
1844 	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
1845 #define dev_info_ratelimited(dev, fmt, ...)				\
1846 	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
1847 #if defined(CONFIG_DYNAMIC_DEBUG)
1848 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
1849 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1850 do {									\
1851 	static DEFINE_RATELIMIT_STATE(_rs,				\
1852 				      DEFAULT_RATELIMIT_INTERVAL,	\
1853 				      DEFAULT_RATELIMIT_BURST);		\
1854 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
1855 	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
1856 	    __ratelimit(&_rs))						\
1857 		__dynamic_dev_dbg(&descriptor, dev, dev_fmt(fmt),	\
1858 				  ##__VA_ARGS__);			\
1859 } while (0)
1860 #elif defined(DEBUG)
1861 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1862 do {									\
1863 	static DEFINE_RATELIMIT_STATE(_rs,				\
1864 				      DEFAULT_RATELIMIT_INTERVAL,	\
1865 				      DEFAULT_RATELIMIT_BURST);		\
1866 	if (__ratelimit(&_rs))						\
1867 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1868 } while (0)
1869 #else
1870 #define dev_dbg_ratelimited(dev, fmt, ...)				\
1871 do {									\
1872 	if (0)								\
1873 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1874 } while (0)
1875 #endif
1876 
1877 #ifdef VERBOSE_DEBUG
1878 #define dev_vdbg	dev_dbg
1879 #else
1880 #define dev_vdbg(dev, fmt, ...)						\
1881 ({									\
1882 	if (0)								\
1883 		dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
1884 })
1885 #endif
1886 
1887 /*
1888  * dev_WARN*() acts like dev_printk(), but with the key difference of
1889  * using WARN/WARN_ONCE to include file/line information and a backtrace.
1890  */
1891 #define dev_WARN(dev, format, arg...) \
1892 	WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
1893 
1894 #define dev_WARN_ONCE(dev, condition, format, arg...) \
1895 	WARN_ONCE(condition, "%s %s: " format, \
1896 			dev_driver_string(dev), dev_name(dev), ## arg)
1897 
1898 /* Create alias, so I can be autoloaded. */
1899 #define MODULE_ALIAS_CHARDEV(major,minor) \
1900 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1901 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1902 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
1903 
1904 #ifdef CONFIG_SYSFS_DEPRECATED
1905 extern long sysfs_deprecated;
1906 #else
1907 #define sysfs_deprecated 0
1908 #endif
1909 
1910 /**
1911  * module_driver() - Helper macro for drivers that don't do anything
1912  * special in module init/exit. This eliminates a lot of boilerplate.
1913  * Each module may only use this macro once, and calling it replaces
1914  * module_init() and module_exit().
1915  *
1916  * @__driver: driver name
1917  * @__register: register function for this driver type
1918  * @__unregister: unregister function for this driver type
1919  * @...: Additional arguments to be passed to __register and __unregister.
1920  *
1921  * Use this macro to construct bus specific macros for registering
1922  * drivers, and do not use it on its own.
1923  */
1924 #define module_driver(__driver, __register, __unregister, ...) \
1925 static int __init __driver##_init(void) \
1926 { \
1927 	return __register(&(__driver) , ##__VA_ARGS__); \
1928 } \
1929 module_init(__driver##_init); \
1930 static void __exit __driver##_exit(void) \
1931 { \
1932 	__unregister(&(__driver) , ##__VA_ARGS__); \
1933 } \
1934 module_exit(__driver##_exit);
1935 
1936 /**
1937  * builtin_driver() - Helper macro for drivers that don't do anything
1938  * special in init and have no exit. This eliminates some boilerplate.
1939  * Each driver may only use this macro once, and calling it replaces
1940  * device_initcall (or in some cases, the legacy __initcall).  This is
1941  * meant to be a direct parallel of module_driver() above but without
1942  * the __exit stuff that is not used for builtin cases.
1943  *
1944  * @__driver: driver name
1945  * @__register: register function for this driver type
1946  * @...: Additional arguments to be passed to __register
1947  *
1948  * Use this macro to construct bus specific macros for registering
1949  * drivers, and do not use it on its own.
1950  */
1951 #define builtin_driver(__driver, __register, ...) \
1952 static int __init __driver##_init(void) \
1953 { \
1954 	return __register(&(__driver) , ##__VA_ARGS__); \
1955 } \
1956 device_initcall(__driver##_init);
1957 
1958 #endif /* _DEVICE_H_ */
1959