xref: /linux-6.15/include/linux/device.h (revision 2e4c77be)
1 /*
2  * device.h - generic, centralized driver model
3  *
4  * Copyright (c) 2001-2003 Patrick Mochel <[email protected]>
5  * Copyright (c) 2004-2007 Greg Kroah-Hartman <[email protected]>
6  *
7  * This file is released under the GPLv2
8  *
9  * See Documentation/driver-model/ for more information.
10  */
11 
12 #ifndef _DEVICE_H_
13 #define _DEVICE_H_
14 
15 #include <linux/ioport.h>
16 #include <linux/kobject.h>
17 #include <linux/klist.h>
18 #include <linux/list.h>
19 #include <linux/lockdep.h>
20 #include <linux/compiler.h>
21 #include <linux/types.h>
22 #include <linux/module.h>
23 #include <linux/pm.h>
24 #include <linux/semaphore.h>
25 #include <asm/atomic.h>
26 #include <asm/device.h>
27 
28 #define BUS_ID_SIZE		20
29 
30 struct device;
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 (*suspend_late)(struct device *dev, pm_message_t state);
65 	int (*resume_early)(struct device *dev);
66 	int (*resume)(struct device *dev);
67 
68 	struct dev_pm_ops *pm;
69 
70 	struct bus_type_private *p;
71 };
72 
73 extern int __must_check bus_register(struct bus_type *bus);
74 extern void bus_unregister(struct bus_type *bus);
75 
76 extern int __must_check bus_rescan_devices(struct bus_type *bus);
77 
78 /* iterator helpers for buses */
79 
80 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
81 		     int (*fn)(struct device *dev, void *data));
82 struct device *bus_find_device(struct bus_type *bus, struct device *start,
83 			       void *data,
84 			       int (*match)(struct device *dev, void *data));
85 struct device *bus_find_device_by_name(struct bus_type *bus,
86 				       struct device *start,
87 				       const char *name);
88 
89 int __must_check bus_for_each_drv(struct bus_type *bus,
90 				  struct device_driver *start, void *data,
91 				  int (*fn)(struct device_driver *, void *));
92 
93 void bus_sort_breadthfirst(struct bus_type *bus,
94 			   int (*compare)(const struct device *a,
95 					  const struct device *b));
96 /*
97  * Bus notifiers: Get notified of addition/removal of devices
98  * and binding/unbinding of drivers to devices.
99  * In the long run, it should be a replacement for the platform
100  * notify hooks.
101  */
102 struct notifier_block;
103 
104 extern int bus_register_notifier(struct bus_type *bus,
105 				 struct notifier_block *nb);
106 extern int bus_unregister_notifier(struct bus_type *bus,
107 				   struct notifier_block *nb);
108 
109 /* All 4 notifers below get called with the target struct device *
110  * as an argument. Note that those functions are likely to be called
111  * with the device semaphore held in the core, so be careful.
112  */
113 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
114 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device removed */
115 #define BUS_NOTIFY_BOUND_DRIVER		0x00000003 /* driver bound to device */
116 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000004 /* driver about to be
117 						      unbound */
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 	struct attribute_group **groups;
135 
136 	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 
151 /* sysfs interface for exporting driver attributes */
152 
153 struct driver_attribute {
154 	struct attribute attr;
155 	ssize_t (*show)(struct device_driver *driver, char *buf);
156 	ssize_t (*store)(struct device_driver *driver, const char *buf,
157 			 size_t count);
158 };
159 
160 #define DRIVER_ATTR(_name, _mode, _show, _store)	\
161 struct driver_attribute driver_attr_##_name =		\
162 	__ATTR(_name, _mode, _show, _store)
163 
164 extern int __must_check driver_create_file(struct device_driver *driver,
165 					   struct driver_attribute *attr);
166 extern void driver_remove_file(struct device_driver *driver,
167 			       struct driver_attribute *attr);
168 
169 extern int __must_check driver_add_kobj(struct device_driver *drv,
170 					struct kobject *kobj,
171 					const char *fmt, ...);
172 
173 extern int __must_check driver_for_each_device(struct device_driver *drv,
174 					       struct device *start,
175 					       void *data,
176 					       int (*fn)(struct device *dev,
177 							 void *));
178 struct device *driver_find_device(struct device_driver *drv,
179 				  struct device *start, void *data,
180 				  int (*match)(struct device *dev, void *data));
181 
182 /*
183  * device classes
184  */
185 struct class {
186 	const char		*name;
187 	struct module		*owner;
188 
189 	struct class_attribute		*class_attrs;
190 	struct device_attribute		*dev_attrs;
191 	struct kobject			*dev_kobj;
192 
193 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
194 
195 	void (*class_release)(struct class *class);
196 	void (*dev_release)(struct device *dev);
197 
198 	int (*suspend)(struct device *dev, pm_message_t state);
199 	int (*resume)(struct device *dev);
200 
201 	struct dev_pm_ops *pm;
202 	struct class_private *p;
203 };
204 
205 struct class_dev_iter {
206 	struct klist_iter		ki;
207 	const struct device_type	*type;
208 };
209 
210 extern struct kobject *sysfs_dev_block_kobj;
211 extern struct kobject *sysfs_dev_char_kobj;
212 extern int __must_check __class_register(struct class *class,
213 					 struct lock_class_key *key);
214 extern void class_unregister(struct class *class);
215 
216 /* This is a #define to keep the compiler from merging different
217  * instances of the __key variable */
218 #define class_register(class)			\
219 ({						\
220 	static struct lock_class_key __key;	\
221 	__class_register(class, &__key);	\
222 })
223 
224 extern void class_dev_iter_init(struct class_dev_iter *iter,
225 				struct class *class,
226 				struct device *start,
227 				const struct device_type *type);
228 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
229 extern void class_dev_iter_exit(struct class_dev_iter *iter);
230 
231 extern int class_for_each_device(struct class *class, struct device *start,
232 				 void *data,
233 				 int (*fn)(struct device *dev, void *data));
234 extern struct device *class_find_device(struct class *class,
235 					struct device *start, void *data,
236 					int (*match)(struct device *, void *));
237 
238 struct class_attribute {
239 	struct attribute attr;
240 	ssize_t (*show)(struct class *class, char *buf);
241 	ssize_t (*store)(struct class *class, const char *buf, size_t count);
242 };
243 
244 #define CLASS_ATTR(_name, _mode, _show, _store)			\
245 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
246 
247 extern int __must_check class_create_file(struct class *class,
248 					  const struct class_attribute *attr);
249 extern void class_remove_file(struct class *class,
250 			      const struct class_attribute *attr);
251 
252 struct class_interface {
253 	struct list_head	node;
254 	struct class		*class;
255 
256 	int (*add_dev)		(struct device *, struct class_interface *);
257 	void (*remove_dev)	(struct device *, struct class_interface *);
258 };
259 
260 extern int __must_check class_interface_register(struct class_interface *);
261 extern void class_interface_unregister(struct class_interface *);
262 
263 extern struct class * __must_check __class_create(struct module *owner,
264 						  const char *name,
265 						  struct lock_class_key *key);
266 extern void class_destroy(struct class *cls);
267 
268 /* This is a #define to keep the compiler from merging different
269  * instances of the __key variable */
270 #define class_create(owner, name)		\
271 ({						\
272 	static struct lock_class_key __key;	\
273 	__class_create(owner, name, &__key);	\
274 })
275 
276 /*
277  * The type of device, "struct device" is embedded in. A class
278  * or bus can contain devices of different types
279  * like "partitions" and "disks", "mouse" and "event".
280  * This identifies the device type and carries type-specific
281  * information, equivalent to the kobj_type of a kobject.
282  * If "name" is specified, the uevent will contain it in
283  * the DEVTYPE variable.
284  */
285 struct device_type {
286 	const char *name;
287 	struct attribute_group **groups;
288 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
289 	void (*release)(struct device *dev);
290 
291 	int (*suspend)(struct device *dev, pm_message_t state);
292 	int (*resume)(struct device *dev);
293 
294 	struct dev_pm_ops *pm;
295 };
296 
297 /* interface for exporting device attributes */
298 struct device_attribute {
299 	struct attribute	attr;
300 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
301 			char *buf);
302 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
303 			 const char *buf, size_t count);
304 };
305 
306 #define DEVICE_ATTR(_name, _mode, _show, _store) \
307 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
308 
309 extern int __must_check device_create_file(struct device *device,
310 					   struct device_attribute *entry);
311 extern void device_remove_file(struct device *dev,
312 			       struct device_attribute *attr);
313 extern int __must_check device_create_bin_file(struct device *dev,
314 					       struct bin_attribute *attr);
315 extern void device_remove_bin_file(struct device *dev,
316 				   struct bin_attribute *attr);
317 extern int device_schedule_callback_owner(struct device *dev,
318 		void (*func)(struct device *dev), struct module *owner);
319 
320 /* This is a macro to avoid include problems with THIS_MODULE */
321 #define device_schedule_callback(dev, func)			\
322 	device_schedule_callback_owner(dev, func, THIS_MODULE)
323 
324 /* device resource management */
325 typedef void (*dr_release_t)(struct device *dev, void *res);
326 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
327 
328 #ifdef CONFIG_DEBUG_DEVRES
329 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
330 			     const char *name);
331 #define devres_alloc(release, size, gfp) \
332 	__devres_alloc(release, size, gfp, #release)
333 #else
334 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
335 #endif
336 extern void devres_free(void *res);
337 extern void devres_add(struct device *dev, void *res);
338 extern void *devres_find(struct device *dev, dr_release_t release,
339 			 dr_match_t match, void *match_data);
340 extern void *devres_get(struct device *dev, void *new_res,
341 			dr_match_t match, void *match_data);
342 extern void *devres_remove(struct device *dev, dr_release_t release,
343 			   dr_match_t match, void *match_data);
344 extern int devres_destroy(struct device *dev, dr_release_t release,
345 			  dr_match_t match, void *match_data);
346 
347 /* devres group */
348 extern void * __must_check devres_open_group(struct device *dev, void *id,
349 					     gfp_t gfp);
350 extern void devres_close_group(struct device *dev, void *id);
351 extern void devres_remove_group(struct device *dev, void *id);
352 extern int devres_release_group(struct device *dev, void *id);
353 
354 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
355 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
356 extern void devm_kfree(struct device *dev, void *p);
357 
358 struct device_dma_parameters {
359 	/*
360 	 * a low level driver may set these to teach IOMMU code about
361 	 * sg limitations.
362 	 */
363 	unsigned int max_segment_size;
364 	unsigned long segment_boundary_mask;
365 };
366 
367 struct device {
368 	struct klist		klist_children;
369 	struct klist_node	knode_parent;	/* node in sibling list */
370 	struct klist_node	knode_driver;
371 	struct klist_node	knode_bus;
372 	struct device		*parent;
373 
374 	struct kobject kobj;
375 	char	bus_id[BUS_ID_SIZE];	/* position on parent bus */
376 	unsigned		uevent_suppress:1;
377 	const char		*init_name; /* initial name of the device */
378 	struct device_type	*type;
379 
380 	struct semaphore	sem;	/* semaphore to synchronize calls to
381 					 * its driver.
382 					 */
383 
384 	struct bus_type	*bus;		/* type of bus device is on */
385 	struct device_driver *driver;	/* which driver has allocated this
386 					   device */
387 	void		*driver_data;	/* data private to the driver */
388 	void		*platform_data;	/* Platform specific data, device
389 					   core doesn't touch it */
390 	struct dev_pm_info	power;
391 
392 #ifdef CONFIG_NUMA
393 	int		numa_node;	/* NUMA node this device is close to */
394 #endif
395 	u64		*dma_mask;	/* dma mask (if dma'able device) */
396 	u64		coherent_dma_mask;/* Like dma_mask, but for
397 					     alloc_coherent mappings as
398 					     not all hardware supports
399 					     64 bit addresses for consistent
400 					     allocations such descriptors. */
401 
402 	struct device_dma_parameters *dma_parms;
403 
404 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
405 
406 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
407 					     override */
408 	/* arch specific additions */
409 	struct dev_archdata	archdata;
410 
411 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
412 
413 	spinlock_t		devres_lock;
414 	struct list_head	devres_head;
415 
416 	struct klist_node	knode_class;
417 	struct class		*class;
418 	struct attribute_group	**groups;	/* optional groups */
419 
420 	void	(*release)(struct device *dev);
421 };
422 
423 /* Get the wakeup routines, which depend on struct device */
424 #include <linux/pm_wakeup.h>
425 
426 static inline const char *dev_name(const struct device *dev)
427 {
428 	/* will be changed into kobject_name(&dev->kobj) in the near future */
429 	return dev->bus_id;
430 }
431 
432 extern int dev_set_name(struct device *dev, const char *name, ...)
433 			__attribute__((format(printf, 2, 3)));
434 
435 #ifdef CONFIG_NUMA
436 static inline int dev_to_node(struct device *dev)
437 {
438 	return dev->numa_node;
439 }
440 static inline void set_dev_node(struct device *dev, int node)
441 {
442 	dev->numa_node = node;
443 }
444 #else
445 static inline int dev_to_node(struct device *dev)
446 {
447 	return -1;
448 }
449 static inline void set_dev_node(struct device *dev, int node)
450 {
451 }
452 #endif
453 
454 static inline void *dev_get_drvdata(const struct device *dev)
455 {
456 	return dev->driver_data;
457 }
458 
459 static inline void dev_set_drvdata(struct device *dev, void *data)
460 {
461 	dev->driver_data = data;
462 }
463 
464 static inline int device_is_registered(struct device *dev)
465 {
466 	return dev->kobj.state_in_sysfs;
467 }
468 
469 void driver_init(void);
470 
471 /*
472  * High level routines for use by the bus drivers
473  */
474 extern int __must_check device_register(struct device *dev);
475 extern void device_unregister(struct device *dev);
476 extern void device_initialize(struct device *dev);
477 extern int __must_check device_add(struct device *dev);
478 extern void device_del(struct device *dev);
479 extern int device_for_each_child(struct device *dev, void *data,
480 		     int (*fn)(struct device *dev, void *data));
481 extern struct device *device_find_child(struct device *dev, void *data,
482 				int (*match)(struct device *dev, void *data));
483 extern int device_rename(struct device *dev, char *new_name);
484 extern int device_move(struct device *dev, struct device *new_parent);
485 
486 /*
487  * Root device objects for grouping under /sys/devices
488  */
489 extern struct device *__root_device_register(const char *name,
490 					     struct module *owner);
491 static inline struct device *root_device_register(const char *name)
492 {
493 	return __root_device_register(name, THIS_MODULE);
494 }
495 extern void root_device_unregister(struct device *root);
496 
497 /*
498  * Manual binding of a device to driver. See drivers/base/bus.c
499  * for information on use.
500  */
501 extern int __must_check device_bind_driver(struct device *dev);
502 extern void device_release_driver(struct device *dev);
503 extern int  __must_check device_attach(struct device *dev);
504 extern int __must_check driver_attach(struct device_driver *drv);
505 extern int __must_check device_reprobe(struct device *dev);
506 
507 /*
508  * Easy functions for dynamically creating devices on the fly
509  */
510 extern struct device *device_create_vargs(struct class *cls,
511 					  struct device *parent,
512 					  dev_t devt,
513 					  void *drvdata,
514 					  const char *fmt,
515 					  va_list vargs);
516 extern struct device *device_create(struct class *cls, struct device *parent,
517 				    dev_t devt, void *drvdata,
518 				    const char *fmt, ...)
519 				    __attribute__((format(printf, 5, 6)));
520 extern void device_destroy(struct class *cls, dev_t devt);
521 
522 /*
523  * Platform "fixup" functions - allow the platform to have their say
524  * about devices and actions that the general device layer doesn't
525  * know about.
526  */
527 /* Notify platform of device discovery */
528 extern int (*platform_notify)(struct device *dev);
529 
530 extern int (*platform_notify_remove)(struct device *dev);
531 
532 
533 /**
534  * get_device - atomically increment the reference count for the device.
535  *
536  */
537 extern struct device *get_device(struct device *dev);
538 extern void put_device(struct device *dev);
539 
540 
541 /* drivers/base/power/shutdown.c */
542 extern void device_shutdown(void);
543 
544 /* drivers/base/sys.c */
545 extern void sysdev_shutdown(void);
546 
547 /* debugging and troubleshooting/diagnostic helpers. */
548 extern const char *dev_driver_string(const struct device *dev);
549 #define dev_printk(level, dev, format, arg...)	\
550 	printk(level "%s %s: " format , dev_driver_string(dev) , \
551 	       dev_name(dev) , ## arg)
552 
553 #define dev_emerg(dev, format, arg...)		\
554 	dev_printk(KERN_EMERG , dev , format , ## arg)
555 #define dev_alert(dev, format, arg...)		\
556 	dev_printk(KERN_ALERT , dev , format , ## arg)
557 #define dev_crit(dev, format, arg...)		\
558 	dev_printk(KERN_CRIT , dev , format , ## arg)
559 #define dev_err(dev, format, arg...)		\
560 	dev_printk(KERN_ERR , dev , format , ## arg)
561 #define dev_warn(dev, format, arg...)		\
562 	dev_printk(KERN_WARNING , dev , format , ## arg)
563 #define dev_notice(dev, format, arg...)		\
564 	dev_printk(KERN_NOTICE , dev , format , ## arg)
565 #define dev_info(dev, format, arg...)		\
566 	dev_printk(KERN_INFO , dev , format , ## arg)
567 
568 #if defined(DEBUG)
569 #define dev_dbg(dev, format, arg...)		\
570 	dev_printk(KERN_DEBUG , dev , format , ## arg)
571 #elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
572 #define dev_dbg(dev, format, ...) do { \
573 	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
574 	} while (0)
575 #else
576 #define dev_dbg(dev, format, arg...)		\
577 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
578 #endif
579 
580 #ifdef VERBOSE_DEBUG
581 #define dev_vdbg	dev_dbg
582 #else
583 
584 #define dev_vdbg(dev, format, arg...)		\
585 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
586 #endif
587 
588 /*
589  * dev_WARN() acts like dev_printk(), but with the key difference
590  * of using a WARN/WARN_ON to get the message out, including the
591  * file/line information and a backtrace.
592  */
593 #define dev_WARN(dev, format, arg...) \
594 	WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg);
595 
596 /* Create alias, so I can be autoloaded. */
597 #define MODULE_ALIAS_CHARDEV(major,minor) \
598 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
599 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
600 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
601 #endif /* _DEVICE_H_ */
602