xref: /linux-6.15/include/linux/device.h (revision a115bc07)
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 	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */
130 
131 	int (*probe) (struct device *dev);
132 	int (*remove) (struct device *dev);
133 	void (*shutdown) (struct device *dev);
134 	int (*suspend) (struct device *dev, pm_message_t state);
135 	int (*resume) (struct device *dev);
136 	const struct attribute_group **groups;
137 
138 	const struct dev_pm_ops *pm;
139 
140 	struct driver_private *p;
141 };
142 
143 
144 extern int __must_check driver_register(struct device_driver *drv);
145 extern void driver_unregister(struct device_driver *drv);
146 
147 extern struct device_driver *get_driver(struct device_driver *drv);
148 extern void put_driver(struct device_driver *drv);
149 extern struct device_driver *driver_find(const char *name,
150 					 struct bus_type *bus);
151 extern int driver_probe_done(void);
152 extern void wait_for_device_probe(void);
153 
154 
155 /* sysfs interface for exporting driver attributes */
156 
157 struct driver_attribute {
158 	struct attribute attr;
159 	ssize_t (*show)(struct device_driver *driver, char *buf);
160 	ssize_t (*store)(struct device_driver *driver, const char *buf,
161 			 size_t count);
162 };
163 
164 #define DRIVER_ATTR(_name, _mode, _show, _store)	\
165 struct driver_attribute driver_attr_##_name =		\
166 	__ATTR(_name, _mode, _show, _store)
167 
168 extern int __must_check driver_create_file(struct device_driver *driver,
169 					const struct driver_attribute *attr);
170 extern void driver_remove_file(struct device_driver *driver,
171 			       const struct driver_attribute *attr);
172 
173 extern int __must_check driver_add_kobj(struct device_driver *drv,
174 					struct kobject *kobj,
175 					const char *fmt, ...);
176 
177 extern int __must_check driver_for_each_device(struct device_driver *drv,
178 					       struct device *start,
179 					       void *data,
180 					       int (*fn)(struct device *dev,
181 							 void *));
182 struct device *driver_find_device(struct device_driver *drv,
183 				  struct device *start, void *data,
184 				  int (*match)(struct device *dev, void *data));
185 
186 /*
187  * device classes
188  */
189 struct class {
190 	const char		*name;
191 	struct module		*owner;
192 
193 	struct class_attribute		*class_attrs;
194 	struct device_attribute		*dev_attrs;
195 	struct kobject			*dev_kobj;
196 
197 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
198 	char *(*devnode)(struct device *dev, mode_t *mode);
199 
200 	void (*class_release)(struct class *class);
201 	void (*dev_release)(struct device *dev);
202 
203 	int (*suspend)(struct device *dev, pm_message_t state);
204 	int (*resume)(struct device *dev);
205 
206 	const struct dev_pm_ops *pm;
207 
208 	struct class_private *p;
209 };
210 
211 struct class_dev_iter {
212 	struct klist_iter		ki;
213 	const struct device_type	*type;
214 };
215 
216 extern struct kobject *sysfs_dev_block_kobj;
217 extern struct kobject *sysfs_dev_char_kobj;
218 extern int __must_check __class_register(struct class *class,
219 					 struct lock_class_key *key);
220 extern void class_unregister(struct class *class);
221 
222 /* This is a #define to keep the compiler from merging different
223  * instances of the __key variable */
224 #define class_register(class)			\
225 ({						\
226 	static struct lock_class_key __key;	\
227 	__class_register(class, &__key);	\
228 })
229 
230 struct class_compat;
231 struct class_compat *class_compat_register(const char *name);
232 void class_compat_unregister(struct class_compat *cls);
233 int class_compat_create_link(struct class_compat *cls, struct device *dev,
234 			     struct device *device_link);
235 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
236 			      struct device *device_link);
237 
238 extern void class_dev_iter_init(struct class_dev_iter *iter,
239 				struct class *class,
240 				struct device *start,
241 				const struct device_type *type);
242 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
243 extern void class_dev_iter_exit(struct class_dev_iter *iter);
244 
245 extern int class_for_each_device(struct class *class, struct device *start,
246 				 void *data,
247 				 int (*fn)(struct device *dev, void *data));
248 extern struct device *class_find_device(struct class *class,
249 					struct device *start, void *data,
250 					int (*match)(struct device *, void *));
251 
252 struct class_attribute {
253 	struct attribute attr;
254 	ssize_t (*show)(struct class *class, char *buf);
255 	ssize_t (*store)(struct class *class, const char *buf, size_t count);
256 };
257 
258 #define CLASS_ATTR(_name, _mode, _show, _store)			\
259 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
260 
261 extern int __must_check class_create_file(struct class *class,
262 					  const struct class_attribute *attr);
263 extern void class_remove_file(struct class *class,
264 			      const struct class_attribute *attr);
265 
266 struct class_interface {
267 	struct list_head	node;
268 	struct class		*class;
269 
270 	int (*add_dev)		(struct device *, struct class_interface *);
271 	void (*remove_dev)	(struct device *, struct class_interface *);
272 };
273 
274 extern int __must_check class_interface_register(struct class_interface *);
275 extern void class_interface_unregister(struct class_interface *);
276 
277 extern struct class * __must_check __class_create(struct module *owner,
278 						  const char *name,
279 						  struct lock_class_key *key);
280 extern void class_destroy(struct class *cls);
281 
282 /* This is a #define to keep the compiler from merging different
283  * instances of the __key variable */
284 #define class_create(owner, name)		\
285 ({						\
286 	static struct lock_class_key __key;	\
287 	__class_create(owner, name, &__key);	\
288 })
289 
290 /*
291  * The type of device, "struct device" is embedded in. A class
292  * or bus can contain devices of different types
293  * like "partitions" and "disks", "mouse" and "event".
294  * This identifies the device type and carries type-specific
295  * information, equivalent to the kobj_type of a kobject.
296  * If "name" is specified, the uevent will contain it in
297  * the DEVTYPE variable.
298  */
299 struct device_type {
300 	const char *name;
301 	const struct attribute_group **groups;
302 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
303 	char *(*devnode)(struct device *dev, mode_t *mode);
304 	void (*release)(struct device *dev);
305 
306 	const struct dev_pm_ops *pm;
307 };
308 
309 /* interface for exporting device attributes */
310 struct device_attribute {
311 	struct attribute	attr;
312 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
313 			char *buf);
314 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
315 			 const char *buf, size_t count);
316 };
317 
318 #define DEVICE_ATTR(_name, _mode, _show, _store) \
319 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
320 
321 extern int __must_check device_create_file(struct device *device,
322 					const struct device_attribute *entry);
323 extern void device_remove_file(struct device *dev,
324 			       const struct device_attribute *attr);
325 extern int __must_check device_create_bin_file(struct device *dev,
326 					const struct bin_attribute *attr);
327 extern void device_remove_bin_file(struct device *dev,
328 				   const struct bin_attribute *attr);
329 extern int device_schedule_callback_owner(struct device *dev,
330 		void (*func)(struct device *dev), struct module *owner);
331 
332 /* This is a macro to avoid include problems with THIS_MODULE */
333 #define device_schedule_callback(dev, func)			\
334 	device_schedule_callback_owner(dev, func, THIS_MODULE)
335 
336 /* device resource management */
337 typedef void (*dr_release_t)(struct device *dev, void *res);
338 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
339 
340 #ifdef CONFIG_DEBUG_DEVRES
341 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
342 			     const char *name);
343 #define devres_alloc(release, size, gfp) \
344 	__devres_alloc(release, size, gfp, #release)
345 #else
346 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
347 #endif
348 extern void devres_free(void *res);
349 extern void devres_add(struct device *dev, void *res);
350 extern void *devres_find(struct device *dev, dr_release_t release,
351 			 dr_match_t match, void *match_data);
352 extern void *devres_get(struct device *dev, void *new_res,
353 			dr_match_t match, void *match_data);
354 extern void *devres_remove(struct device *dev, dr_release_t release,
355 			   dr_match_t match, void *match_data);
356 extern int devres_destroy(struct device *dev, dr_release_t release,
357 			  dr_match_t match, void *match_data);
358 
359 /* devres group */
360 extern void * __must_check devres_open_group(struct device *dev, void *id,
361 					     gfp_t gfp);
362 extern void devres_close_group(struct device *dev, void *id);
363 extern void devres_remove_group(struct device *dev, void *id);
364 extern int devres_release_group(struct device *dev, void *id);
365 
366 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
367 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
368 extern void devm_kfree(struct device *dev, void *p);
369 
370 struct device_dma_parameters {
371 	/*
372 	 * a low level driver may set these to teach IOMMU code about
373 	 * sg limitations.
374 	 */
375 	unsigned int max_segment_size;
376 	unsigned long segment_boundary_mask;
377 };
378 
379 struct device {
380 	struct device		*parent;
381 
382 	struct device_private	*p;
383 
384 	struct kobject kobj;
385 	const char		*init_name; /* initial name of the device */
386 	struct device_type	*type;
387 
388 	struct semaphore	sem;	/* semaphore to synchronize calls to
389 					 * its driver.
390 					 */
391 
392 	struct bus_type	*bus;		/* type of bus device is on */
393 	struct device_driver *driver;	/* which driver has allocated this
394 					   device */
395 	void		*platform_data;	/* Platform specific data, device
396 					   core doesn't touch it */
397 	struct dev_pm_info	power;
398 
399 #ifdef CONFIG_NUMA
400 	int		numa_node;	/* NUMA node this device is close to */
401 #endif
402 	u64		*dma_mask;	/* dma mask (if dma'able device) */
403 	u64		coherent_dma_mask;/* Like dma_mask, but for
404 					     alloc_coherent mappings as
405 					     not all hardware supports
406 					     64 bit addresses for consistent
407 					     allocations such descriptors. */
408 
409 	struct device_dma_parameters *dma_parms;
410 
411 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
412 
413 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
414 					     override */
415 	/* arch specific additions */
416 	struct dev_archdata	archdata;
417 
418 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
419 
420 	spinlock_t		devres_lock;
421 	struct list_head	devres_head;
422 
423 	struct klist_node	knode_class;
424 	struct class		*class;
425 	const struct attribute_group **groups;	/* optional groups */
426 
427 	void	(*release)(struct device *dev);
428 };
429 
430 /* Get the wakeup routines, which depend on struct device */
431 #include <linux/pm_wakeup.h>
432 
433 static inline const char *dev_name(const struct device *dev)
434 {
435 	return kobject_name(&dev->kobj);
436 }
437 
438 extern int dev_set_name(struct device *dev, const char *name, ...)
439 			__attribute__((format(printf, 2, 3)));
440 
441 #ifdef CONFIG_NUMA
442 static inline int dev_to_node(struct device *dev)
443 {
444 	return dev->numa_node;
445 }
446 static inline void set_dev_node(struct device *dev, int node)
447 {
448 	dev->numa_node = node;
449 }
450 #else
451 static inline int dev_to_node(struct device *dev)
452 {
453 	return -1;
454 }
455 static inline void set_dev_node(struct device *dev, int node)
456 {
457 }
458 #endif
459 
460 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
461 {
462 	return dev->kobj.uevent_suppress;
463 }
464 
465 static inline void dev_set_uevent_suppress(struct device *dev, int val)
466 {
467 	dev->kobj.uevent_suppress = val;
468 }
469 
470 static inline int device_is_registered(struct device *dev)
471 {
472 	return dev->kobj.state_in_sysfs;
473 }
474 
475 static inline void device_enable_async_suspend(struct device *dev)
476 {
477 	if (dev->power.status == DPM_ON)
478 		dev->power.async_suspend = true;
479 }
480 
481 static inline void device_disable_async_suspend(struct device *dev)
482 {
483 	if (dev->power.status == DPM_ON)
484 		dev->power.async_suspend = false;
485 }
486 
487 static inline bool device_async_suspend_enabled(struct device *dev)
488 {
489 	return !!dev->power.async_suspend;
490 }
491 
492 void driver_init(void);
493 
494 /*
495  * High level routines for use by the bus drivers
496  */
497 extern int __must_check device_register(struct device *dev);
498 extern void device_unregister(struct device *dev);
499 extern void device_initialize(struct device *dev);
500 extern int __must_check device_add(struct device *dev);
501 extern void device_del(struct device *dev);
502 extern int device_for_each_child(struct device *dev, void *data,
503 		     int (*fn)(struct device *dev, void *data));
504 extern struct device *device_find_child(struct device *dev, void *data,
505 				int (*match)(struct device *dev, void *data));
506 extern int device_rename(struct device *dev, char *new_name);
507 extern int device_move(struct device *dev, struct device *new_parent,
508 		       enum dpm_order dpm_order);
509 extern const char *device_get_devnode(struct device *dev,
510 				      mode_t *mode, const char **tmp);
511 extern void *dev_get_drvdata(const struct device *dev);
512 extern void dev_set_drvdata(struct device *dev, void *data);
513 
514 /*
515  * Root device objects for grouping under /sys/devices
516  */
517 extern struct device *__root_device_register(const char *name,
518 					     struct module *owner);
519 static inline struct device *root_device_register(const char *name)
520 {
521 	return __root_device_register(name, THIS_MODULE);
522 }
523 extern void root_device_unregister(struct device *root);
524 
525 static inline void *dev_get_platdata(const struct device *dev)
526 {
527 	return dev->platform_data;
528 }
529 
530 /*
531  * Manual binding of a device to driver. See drivers/base/bus.c
532  * for information on use.
533  */
534 extern int __must_check device_bind_driver(struct device *dev);
535 extern void device_release_driver(struct device *dev);
536 extern int  __must_check device_attach(struct device *dev);
537 extern int __must_check driver_attach(struct device_driver *drv);
538 extern int __must_check device_reprobe(struct device *dev);
539 
540 /*
541  * Easy functions for dynamically creating devices on the fly
542  */
543 extern struct device *device_create_vargs(struct class *cls,
544 					  struct device *parent,
545 					  dev_t devt,
546 					  void *drvdata,
547 					  const char *fmt,
548 					  va_list vargs);
549 extern struct device *device_create(struct class *cls, struct device *parent,
550 				    dev_t devt, void *drvdata,
551 				    const char *fmt, ...)
552 				    __attribute__((format(printf, 5, 6)));
553 extern void device_destroy(struct class *cls, dev_t devt);
554 
555 /*
556  * Platform "fixup" functions - allow the platform to have their say
557  * about devices and actions that the general device layer doesn't
558  * know about.
559  */
560 /* Notify platform of device discovery */
561 extern int (*platform_notify)(struct device *dev);
562 
563 extern int (*platform_notify_remove)(struct device *dev);
564 
565 
566 /**
567  * get_device - atomically increment the reference count for the device.
568  *
569  */
570 extern struct device *get_device(struct device *dev);
571 extern void put_device(struct device *dev);
572 
573 extern void wait_for_device_probe(void);
574 
575 #ifdef CONFIG_DEVTMPFS
576 extern int devtmpfs_create_node(struct device *dev);
577 extern int devtmpfs_delete_node(struct device *dev);
578 extern int devtmpfs_mount(const char *mntdir);
579 #else
580 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
581 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
582 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
583 #endif
584 
585 /* drivers/base/power/shutdown.c */
586 extern void device_shutdown(void);
587 
588 /* drivers/base/sys.c */
589 extern void sysdev_shutdown(void);
590 
591 /* debugging and troubleshooting/diagnostic helpers. */
592 extern const char *dev_driver_string(const struct device *dev);
593 #define dev_printk(level, dev, format, arg...)	\
594 	printk(level "%s %s: " format , dev_driver_string(dev) , \
595 	       dev_name(dev) , ## arg)
596 
597 #define dev_emerg(dev, format, arg...)		\
598 	dev_printk(KERN_EMERG , dev , format , ## arg)
599 #define dev_alert(dev, format, arg...)		\
600 	dev_printk(KERN_ALERT , dev , format , ## arg)
601 #define dev_crit(dev, format, arg...)		\
602 	dev_printk(KERN_CRIT , dev , format , ## arg)
603 #define dev_err(dev, format, arg...)		\
604 	dev_printk(KERN_ERR , dev , format , ## arg)
605 #define dev_warn(dev, format, arg...)		\
606 	dev_printk(KERN_WARNING , dev , format , ## arg)
607 #define dev_notice(dev, format, arg...)		\
608 	dev_printk(KERN_NOTICE , dev , format , ## arg)
609 #define dev_info(dev, format, arg...)		\
610 	dev_printk(KERN_INFO , dev , format , ## arg)
611 
612 #if defined(DEBUG)
613 #define dev_dbg(dev, format, arg...)		\
614 	dev_printk(KERN_DEBUG , dev , format , ## arg)
615 #elif defined(CONFIG_DYNAMIC_DEBUG)
616 #define dev_dbg(dev, format, ...) do { \
617 	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
618 	} while (0)
619 #else
620 #define dev_dbg(dev, format, arg...)		\
621 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
622 #endif
623 
624 #ifdef VERBOSE_DEBUG
625 #define dev_vdbg	dev_dbg
626 #else
627 
628 #define dev_vdbg(dev, format, arg...)		\
629 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
630 #endif
631 
632 /*
633  * dev_WARN() acts like dev_printk(), but with the key difference
634  * of using a WARN/WARN_ON to get the message out, including the
635  * file/line information and a backtrace.
636  */
637 #define dev_WARN(dev, format, arg...) \
638 	WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg);
639 
640 /* Create alias, so I can be autoloaded. */
641 #define MODULE_ALIAS_CHARDEV(major,minor) \
642 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
643 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
644 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
645 #endif /* _DEVICE_H_ */
646