xref: /linux-6.15/include/linux/device.h (revision 27258e44)
1 /*
2  * device.h - generic, centralized driver model
3  *
4  * Copyright (c) 2001-2003 Patrick Mochel <[email protected]>
5  * Copyright (c) 2004-2009 Greg Kroah-Hartman <[email protected]>
6  * Copyright (c) 2008-2009 Novell Inc.
7  *
8  * This file is released under the GPLv2
9  *
10  * See Documentation/driver-model/ for more information.
11  */
12 
13 #ifndef _DEVICE_H_
14 #define _DEVICE_H_
15 
16 #include <linux/ioport.h>
17 #include <linux/kobject.h>
18 #include <linux/klist.h>
19 #include <linux/list.h>
20 #include <linux/lockdep.h>
21 #include <linux/compiler.h>
22 #include <linux/types.h>
23 #include <linux/module.h>
24 #include <linux/pm.h>
25 #include <linux/semaphore.h>
26 #include <asm/atomic.h>
27 #include <asm/device.h>
28 
29 struct device;
30 struct device_private;
31 struct device_driver;
32 struct driver_private;
33 struct class;
34 struct class_private;
35 struct bus_type;
36 struct bus_type_private;
37 
38 struct bus_attribute {
39 	struct attribute	attr;
40 	ssize_t (*show)(struct bus_type *bus, char *buf);
41 	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
42 };
43 
44 #define BUS_ATTR(_name, _mode, _show, _store)	\
45 struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
46 
47 extern int __must_check bus_create_file(struct bus_type *,
48 					struct bus_attribute *);
49 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
50 
51 struct bus_type {
52 	const char		*name;
53 	struct bus_attribute	*bus_attrs;
54 	struct device_attribute	*dev_attrs;
55 	struct driver_attribute	*drv_attrs;
56 
57 	int (*match)(struct device *dev, struct device_driver *drv);
58 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
59 	int (*probe)(struct device *dev);
60 	int (*remove)(struct device *dev);
61 	void (*shutdown)(struct device *dev);
62 
63 	int (*suspend)(struct device *dev, pm_message_t state);
64 	int (*resume)(struct device *dev);
65 
66 	const struct dev_pm_ops *pm;
67 
68 	struct bus_type_private *p;
69 };
70 
71 extern int __must_check bus_register(struct bus_type *bus);
72 extern void bus_unregister(struct bus_type *bus);
73 
74 extern int __must_check bus_rescan_devices(struct bus_type *bus);
75 
76 /* iterator helpers for buses */
77 
78 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
79 		     int (*fn)(struct device *dev, void *data));
80 struct device *bus_find_device(struct bus_type *bus, struct device *start,
81 			       void *data,
82 			       int (*match)(struct device *dev, void *data));
83 struct device *bus_find_device_by_name(struct bus_type *bus,
84 				       struct device *start,
85 				       const char *name);
86 
87 int __must_check bus_for_each_drv(struct bus_type *bus,
88 				  struct device_driver *start, void *data,
89 				  int (*fn)(struct device_driver *, void *));
90 
91 void bus_sort_breadthfirst(struct bus_type *bus,
92 			   int (*compare)(const struct device *a,
93 					  const struct device *b));
94 /*
95  * Bus notifiers: Get notified of addition/removal of devices
96  * and binding/unbinding of drivers to devices.
97  * In the long run, it should be a replacement for the platform
98  * notify hooks.
99  */
100 struct notifier_block;
101 
102 extern int bus_register_notifier(struct bus_type *bus,
103 				 struct notifier_block *nb);
104 extern int bus_unregister_notifier(struct bus_type *bus,
105 				   struct notifier_block *nb);
106 
107 /* All 4 notifers below get called with the target struct device *
108  * as an argument. Note that those functions are likely to be called
109  * with the device semaphore held in the core, so be careful.
110  */
111 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
112 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device removed */
113 #define BUS_NOTIFY_BOUND_DRIVER		0x00000003 /* driver bound to device */
114 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000004 /* driver about to be
115 						      unbound */
116 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000005 /* driver is unbound
117 						      from the device */
118 
119 extern struct kset *bus_get_kset(struct bus_type *bus);
120 extern struct klist *bus_get_device_klist(struct bus_type *bus);
121 
122 struct device_driver {
123 	const char		*name;
124 	struct bus_type		*bus;
125 
126 	struct module		*owner;
127 	const char 		*mod_name;	/* used for built-in modules */
128 
129 	int (*probe) (struct device *dev);
130 	int (*remove) (struct device *dev);
131 	void (*shutdown) (struct device *dev);
132 	int (*suspend) (struct device *dev, pm_message_t state);
133 	int (*resume) (struct device *dev);
134 	const struct attribute_group **groups;
135 
136 	const struct dev_pm_ops *pm;
137 
138 	struct driver_private *p;
139 };
140 
141 
142 extern int __must_check driver_register(struct device_driver *drv);
143 extern void driver_unregister(struct device_driver *drv);
144 
145 extern struct device_driver *get_driver(struct device_driver *drv);
146 extern void put_driver(struct device_driver *drv);
147 extern struct device_driver *driver_find(const char *name,
148 					 struct bus_type *bus);
149 extern int driver_probe_done(void);
150 extern void wait_for_device_probe(void);
151 
152 
153 /* sysfs interface for exporting driver attributes */
154 
155 struct driver_attribute {
156 	struct attribute attr;
157 	ssize_t (*show)(struct device_driver *driver, char *buf);
158 	ssize_t (*store)(struct device_driver *driver, const char *buf,
159 			 size_t count);
160 };
161 
162 #define DRIVER_ATTR(_name, _mode, _show, _store)	\
163 struct driver_attribute driver_attr_##_name =		\
164 	__ATTR(_name, _mode, _show, _store)
165 
166 extern int __must_check driver_create_file(struct device_driver *driver,
167 					   struct driver_attribute *attr);
168 extern void driver_remove_file(struct device_driver *driver,
169 			       struct driver_attribute *attr);
170 
171 extern int __must_check driver_add_kobj(struct device_driver *drv,
172 					struct kobject *kobj,
173 					const char *fmt, ...);
174 
175 extern int __must_check driver_for_each_device(struct device_driver *drv,
176 					       struct device *start,
177 					       void *data,
178 					       int (*fn)(struct device *dev,
179 							 void *));
180 struct device *driver_find_device(struct device_driver *drv,
181 				  struct device *start, void *data,
182 				  int (*match)(struct device *dev, void *data));
183 
184 /*
185  * device classes
186  */
187 struct class {
188 	const char		*name;
189 	struct module		*owner;
190 
191 	struct class_attribute		*class_attrs;
192 	struct device_attribute		*dev_attrs;
193 	struct kobject			*dev_kobj;
194 
195 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
196 	char *(*devnode)(struct device *dev, mode_t *mode);
197 
198 	void (*class_release)(struct class *class);
199 	void (*dev_release)(struct device *dev);
200 
201 	int (*suspend)(struct device *dev, pm_message_t state);
202 	int (*resume)(struct device *dev);
203 
204 	const struct dev_pm_ops *pm;
205 
206 	struct class_private *p;
207 };
208 
209 struct class_dev_iter {
210 	struct klist_iter		ki;
211 	const struct device_type	*type;
212 };
213 
214 extern struct kobject *sysfs_dev_block_kobj;
215 extern struct kobject *sysfs_dev_char_kobj;
216 extern int __must_check __class_register(struct class *class,
217 					 struct lock_class_key *key);
218 extern void class_unregister(struct class *class);
219 
220 /* This is a #define to keep the compiler from merging different
221  * instances of the __key variable */
222 #define class_register(class)			\
223 ({						\
224 	static struct lock_class_key __key;	\
225 	__class_register(class, &__key);	\
226 })
227 
228 struct class_compat;
229 struct class_compat *class_compat_register(const char *name);
230 void class_compat_unregister(struct class_compat *cls);
231 int class_compat_create_link(struct class_compat *cls, struct device *dev,
232 			     struct device *device_link);
233 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
234 			      struct device *device_link);
235 
236 extern void class_dev_iter_init(struct class_dev_iter *iter,
237 				struct class *class,
238 				struct device *start,
239 				const struct device_type *type);
240 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
241 extern void class_dev_iter_exit(struct class_dev_iter *iter);
242 
243 extern int class_for_each_device(struct class *class, struct device *start,
244 				 void *data,
245 				 int (*fn)(struct device *dev, void *data));
246 extern struct device *class_find_device(struct class *class,
247 					struct device *start, void *data,
248 					int (*match)(struct device *, void *));
249 
250 struct class_attribute {
251 	struct attribute attr;
252 	ssize_t (*show)(struct class *class, char *buf);
253 	ssize_t (*store)(struct class *class, const char *buf, size_t count);
254 };
255 
256 #define CLASS_ATTR(_name, _mode, _show, _store)			\
257 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
258 
259 extern int __must_check class_create_file(struct class *class,
260 					  const struct class_attribute *attr);
261 extern void class_remove_file(struct class *class,
262 			      const struct class_attribute *attr);
263 
264 struct class_interface {
265 	struct list_head	node;
266 	struct class		*class;
267 
268 	int (*add_dev)		(struct device *, struct class_interface *);
269 	void (*remove_dev)	(struct device *, struct class_interface *);
270 };
271 
272 extern int __must_check class_interface_register(struct class_interface *);
273 extern void class_interface_unregister(struct class_interface *);
274 
275 extern struct class * __must_check __class_create(struct module *owner,
276 						  const char *name,
277 						  struct lock_class_key *key);
278 extern void class_destroy(struct class *cls);
279 
280 /* This is a #define to keep the compiler from merging different
281  * instances of the __key variable */
282 #define class_create(owner, name)		\
283 ({						\
284 	static struct lock_class_key __key;	\
285 	__class_create(owner, name, &__key);	\
286 })
287 
288 /*
289  * The type of device, "struct device" is embedded in. A class
290  * or bus can contain devices of different types
291  * like "partitions" and "disks", "mouse" and "event".
292  * This identifies the device type and carries type-specific
293  * information, equivalent to the kobj_type of a kobject.
294  * If "name" is specified, the uevent will contain it in
295  * the DEVTYPE variable.
296  */
297 struct device_type {
298 	const char *name;
299 	const struct attribute_group **groups;
300 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
301 	char *(*devnode)(struct device *dev, mode_t *mode);
302 	void (*release)(struct device *dev);
303 
304 	const struct dev_pm_ops *pm;
305 };
306 
307 /* interface for exporting device attributes */
308 struct device_attribute {
309 	struct attribute	attr;
310 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
311 			char *buf);
312 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
313 			 const char *buf, size_t count);
314 };
315 
316 #define DEVICE_ATTR(_name, _mode, _show, _store) \
317 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
318 
319 extern int __must_check device_create_file(struct device *device,
320 					   struct device_attribute *entry);
321 extern void device_remove_file(struct device *dev,
322 			       struct device_attribute *attr);
323 extern int __must_check device_create_bin_file(struct device *dev,
324 					       struct bin_attribute *attr);
325 extern void device_remove_bin_file(struct device *dev,
326 				   struct bin_attribute *attr);
327 extern int device_schedule_callback_owner(struct device *dev,
328 		void (*func)(struct device *dev), struct module *owner);
329 
330 /* This is a macro to avoid include problems with THIS_MODULE */
331 #define device_schedule_callback(dev, func)			\
332 	device_schedule_callback_owner(dev, func, THIS_MODULE)
333 
334 /* device resource management */
335 typedef void (*dr_release_t)(struct device *dev, void *res);
336 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
337 
338 #ifdef CONFIG_DEBUG_DEVRES
339 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
340 			     const char *name);
341 #define devres_alloc(release, size, gfp) \
342 	__devres_alloc(release, size, gfp, #release)
343 #else
344 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
345 #endif
346 extern void devres_free(void *res);
347 extern void devres_add(struct device *dev, void *res);
348 extern void *devres_find(struct device *dev, dr_release_t release,
349 			 dr_match_t match, void *match_data);
350 extern void *devres_get(struct device *dev, void *new_res,
351 			dr_match_t match, void *match_data);
352 extern void *devres_remove(struct device *dev, dr_release_t release,
353 			   dr_match_t match, void *match_data);
354 extern int devres_destroy(struct device *dev, dr_release_t release,
355 			  dr_match_t match, void *match_data);
356 
357 /* devres group */
358 extern void * __must_check devres_open_group(struct device *dev, void *id,
359 					     gfp_t gfp);
360 extern void devres_close_group(struct device *dev, void *id);
361 extern void devres_remove_group(struct device *dev, void *id);
362 extern int devres_release_group(struct device *dev, void *id);
363 
364 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
365 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
366 extern void devm_kfree(struct device *dev, void *p);
367 
368 struct device_dma_parameters {
369 	/*
370 	 * a low level driver may set these to teach IOMMU code about
371 	 * sg limitations.
372 	 */
373 	unsigned int max_segment_size;
374 	unsigned long segment_boundary_mask;
375 };
376 
377 struct device {
378 	struct device		*parent;
379 
380 	struct device_private	*p;
381 
382 	struct kobject kobj;
383 	const char		*init_name; /* initial name of the device */
384 	struct device_type	*type;
385 
386 	struct semaphore	sem;	/* semaphore to synchronize calls to
387 					 * its driver.
388 					 */
389 
390 	struct bus_type	*bus;		/* type of bus device is on */
391 	struct device_driver *driver;	/* which driver has allocated this
392 					   device */
393 	void		*platform_data;	/* Platform specific data, device
394 					   core doesn't touch it */
395 	struct dev_pm_info	power;
396 
397 #ifdef CONFIG_NUMA
398 	int		numa_node;	/* NUMA node this device is close to */
399 #endif
400 	u64		*dma_mask;	/* dma mask (if dma'able device) */
401 	u64		coherent_dma_mask;/* Like dma_mask, but for
402 					     alloc_coherent mappings as
403 					     not all hardware supports
404 					     64 bit addresses for consistent
405 					     allocations such descriptors. */
406 
407 	struct device_dma_parameters *dma_parms;
408 
409 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
410 
411 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
412 					     override */
413 	/* arch specific additions */
414 	struct dev_archdata	archdata;
415 
416 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
417 
418 	spinlock_t		devres_lock;
419 	struct list_head	devres_head;
420 
421 	struct klist_node	knode_class;
422 	struct class		*class;
423 	const struct attribute_group **groups;	/* optional groups */
424 
425 	void	(*release)(struct device *dev);
426 };
427 
428 /* Get the wakeup routines, which depend on struct device */
429 #include <linux/pm_wakeup.h>
430 
431 static inline const char *dev_name(const struct device *dev)
432 {
433 	return kobject_name(&dev->kobj);
434 }
435 
436 extern int dev_set_name(struct device *dev, const char *name, ...)
437 			__attribute__((format(printf, 2, 3)));
438 
439 #ifdef CONFIG_NUMA
440 static inline int dev_to_node(struct device *dev)
441 {
442 	return dev->numa_node;
443 }
444 static inline void set_dev_node(struct device *dev, int node)
445 {
446 	dev->numa_node = node;
447 }
448 #else
449 static inline int dev_to_node(struct device *dev)
450 {
451 	return -1;
452 }
453 static inline void set_dev_node(struct device *dev, int node)
454 {
455 }
456 #endif
457 
458 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
459 {
460 	return dev->kobj.uevent_suppress;
461 }
462 
463 static inline void dev_set_uevent_suppress(struct device *dev, int val)
464 {
465 	dev->kobj.uevent_suppress = val;
466 }
467 
468 static inline int device_is_registered(struct device *dev)
469 {
470 	return dev->kobj.state_in_sysfs;
471 }
472 
473 void driver_init(void);
474 
475 /*
476  * High level routines for use by the bus drivers
477  */
478 extern int __must_check device_register(struct device *dev);
479 extern void device_unregister(struct device *dev);
480 extern void device_initialize(struct device *dev);
481 extern int __must_check device_add(struct device *dev);
482 extern void device_del(struct device *dev);
483 extern int device_for_each_child(struct device *dev, void *data,
484 		     int (*fn)(struct device *dev, void *data));
485 extern struct device *device_find_child(struct device *dev, void *data,
486 				int (*match)(struct device *dev, void *data));
487 extern int device_rename(struct device *dev, char *new_name);
488 extern int device_move(struct device *dev, struct device *new_parent,
489 		       enum dpm_order dpm_order);
490 extern const char *device_get_devnode(struct device *dev,
491 				      mode_t *mode, const char **tmp);
492 extern void *dev_get_drvdata(const struct device *dev);
493 extern void dev_set_drvdata(struct device *dev, void *data);
494 
495 /*
496  * Root device objects for grouping under /sys/devices
497  */
498 extern struct device *__root_device_register(const char *name,
499 					     struct module *owner);
500 static inline struct device *root_device_register(const char *name)
501 {
502 	return __root_device_register(name, THIS_MODULE);
503 }
504 extern void root_device_unregister(struct device *root);
505 
506 static inline void *dev_get_platdata(const struct device *dev)
507 {
508 	return dev->platform_data;
509 }
510 
511 /*
512  * Manual binding of a device to driver. See drivers/base/bus.c
513  * for information on use.
514  */
515 extern int __must_check device_bind_driver(struct device *dev);
516 extern void device_release_driver(struct device *dev);
517 extern int  __must_check device_attach(struct device *dev);
518 extern int __must_check driver_attach(struct device_driver *drv);
519 extern int __must_check device_reprobe(struct device *dev);
520 
521 /*
522  * Easy functions for dynamically creating devices on the fly
523  */
524 extern struct device *device_create_vargs(struct class *cls,
525 					  struct device *parent,
526 					  dev_t devt,
527 					  void *drvdata,
528 					  const char *fmt,
529 					  va_list vargs);
530 extern struct device *device_create(struct class *cls, struct device *parent,
531 				    dev_t devt, void *drvdata,
532 				    const char *fmt, ...)
533 				    __attribute__((format(printf, 5, 6)));
534 extern void device_destroy(struct class *cls, dev_t devt);
535 
536 /*
537  * Platform "fixup" functions - allow the platform to have their say
538  * about devices and actions that the general device layer doesn't
539  * know about.
540  */
541 /* Notify platform of device discovery */
542 extern int (*platform_notify)(struct device *dev);
543 
544 extern int (*platform_notify_remove)(struct device *dev);
545 
546 
547 /**
548  * get_device - atomically increment the reference count for the device.
549  *
550  */
551 extern struct device *get_device(struct device *dev);
552 extern void put_device(struct device *dev);
553 
554 extern void wait_for_device_probe(void);
555 
556 #ifdef CONFIG_DEVTMPFS
557 extern int devtmpfs_create_node(struct device *dev);
558 extern int devtmpfs_delete_node(struct device *dev);
559 extern int devtmpfs_mount(const char *mountpoint);
560 #else
561 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
562 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
563 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
564 #endif
565 
566 /* drivers/base/power/shutdown.c */
567 extern void device_shutdown(void);
568 
569 /* drivers/base/sys.c */
570 extern void sysdev_shutdown(void);
571 
572 /* debugging and troubleshooting/diagnostic helpers. */
573 extern const char *dev_driver_string(const struct device *dev);
574 #define dev_printk(level, dev, format, arg...)	\
575 	printk(level "%s %s: " format , dev_driver_string(dev) , \
576 	       dev_name(dev) , ## arg)
577 
578 #define dev_emerg(dev, format, arg...)		\
579 	dev_printk(KERN_EMERG , dev , format , ## arg)
580 #define dev_alert(dev, format, arg...)		\
581 	dev_printk(KERN_ALERT , dev , format , ## arg)
582 #define dev_crit(dev, format, arg...)		\
583 	dev_printk(KERN_CRIT , dev , format , ## arg)
584 #define dev_err(dev, format, arg...)		\
585 	dev_printk(KERN_ERR , dev , format , ## arg)
586 #define dev_warn(dev, format, arg...)		\
587 	dev_printk(KERN_WARNING , dev , format , ## arg)
588 #define dev_notice(dev, format, arg...)		\
589 	dev_printk(KERN_NOTICE , dev , format , ## arg)
590 #define dev_info(dev, format, arg...)		\
591 	dev_printk(KERN_INFO , dev , format , ## arg)
592 
593 #if defined(DEBUG)
594 #define dev_dbg(dev, format, arg...)		\
595 	dev_printk(KERN_DEBUG , dev , format , ## arg)
596 #elif defined(CONFIG_DYNAMIC_DEBUG)
597 #define dev_dbg(dev, format, ...) do { \
598 	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
599 	} while (0)
600 #else
601 #define dev_dbg(dev, format, arg...)		\
602 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
603 #endif
604 
605 #ifdef VERBOSE_DEBUG
606 #define dev_vdbg	dev_dbg
607 #else
608 
609 #define dev_vdbg(dev, format, arg...)		\
610 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
611 #endif
612 
613 /*
614  * dev_WARN() acts like dev_printk(), but with the key difference
615  * of using a WARN/WARN_ON to get the message out, including the
616  * file/line information and a backtrace.
617  */
618 #define dev_WARN(dev, format, arg...) \
619 	WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg);
620 
621 /* Create alias, so I can be autoloaded. */
622 #define MODULE_ALIAS_CHARDEV(major,minor) \
623 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
624 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
625 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
626 #endif /* _DEVICE_H_ */
627