xref: /linux-6.15/include/linux/device.h (revision d289bf7b)
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/compiler.h>
20 #include <linux/types.h>
21 #include <linux/module.h>
22 #include <linux/pm.h>
23 #include <asm/semaphore.h>
24 #include <asm/atomic.h>
25 #include <asm/device.h>
26 
27 #define DEVICE_NAME_SIZE	50
28 /* DEVICE_NAME_HALF is really less than half to accommodate slop */
29 #define DEVICE_NAME_HALF	__stringify(20)
30 #define DEVICE_ID_SIZE		32
31 #define BUS_ID_SIZE		KOBJ_NAME_LEN
32 
33 
34 struct device;
35 struct device_driver;
36 struct driver_private;
37 struct class;
38 struct class_device;
39 struct bus_type;
40 struct bus_type_private;
41 
42 struct bus_attribute {
43 	struct attribute	attr;
44 	ssize_t (*show)(struct bus_type *bus, char *buf);
45 	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
46 };
47 
48 #define BUS_ATTR(_name, _mode, _show, _store)	\
49 struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
50 
51 extern int __must_check bus_create_file(struct bus_type *,
52 					struct bus_attribute *);
53 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
54 
55 struct bus_type {
56 	const char		*name;
57 	struct bus_attribute	*bus_attrs;
58 	struct device_attribute	*dev_attrs;
59 	struct driver_attribute	*drv_attrs;
60 
61 	int (*match)(struct device *dev, struct device_driver *drv);
62 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
63 	int (*probe)(struct device *dev);
64 	int (*remove)(struct device *dev);
65 	void (*shutdown)(struct device *dev);
66 
67 	int (*suspend)(struct device *dev, pm_message_t state);
68 	int (*suspend_late)(struct device *dev, pm_message_t state);
69 	int (*resume_early)(struct device *dev);
70 	int (*resume)(struct device *dev);
71 
72 	struct bus_type_private *p;
73 };
74 
75 extern int __must_check bus_register(struct bus_type *bus);
76 extern void bus_unregister(struct bus_type *bus);
77 
78 extern int __must_check bus_rescan_devices(struct bus_type *bus);
79 
80 /* iterator helpers for buses */
81 
82 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
83 		     int (*fn)(struct device *dev, void *data));
84 struct device *bus_find_device(struct bus_type *bus, struct device *start,
85 			       void *data,
86 			       int (*match)(struct device *dev, void *data));
87 struct device *bus_find_device_by_name(struct bus_type *bus,
88 				       struct device *start,
89 				       const char *name);
90 
91 int __must_check bus_for_each_drv(struct bus_type *bus,
92 				  struct device_driver *start, void *data,
93 				  int (*fn)(struct device_driver *, void *));
94 
95 /*
96  * Bus notifiers: Get notified of addition/removal of devices
97  * and binding/unbinding of drivers to devices.
98  * In the long run, it should be a replacement for the platform
99  * notify hooks.
100  */
101 struct notifier_block;
102 
103 extern int bus_register_notifier(struct bus_type *bus,
104 				 struct notifier_block *nb);
105 extern int bus_unregister_notifier(struct bus_type *bus,
106 				   struct notifier_block *nb);
107 
108 /* All 4 notifers below get called with the target struct device *
109  * as an argument. Note that those functions are likely to be called
110  * with the device semaphore held in the core, so be careful.
111  */
112 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
113 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device removed */
114 #define BUS_NOTIFY_BOUND_DRIVER		0x00000003 /* driver bound to device */
115 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000004 /* driver about to be
116 						      unbound */
117 
118 extern struct kset *bus_get_kset(struct bus_type *bus);
119 extern struct klist *bus_get_device_klist(struct bus_type *bus);
120 
121 struct device_driver {
122 	const char		*name;
123 	struct bus_type		*bus;
124 
125 	struct module		*owner;
126 	const char 		*mod_name;	/* used for built-in modules */
127 
128 	int (*probe) (struct device *dev);
129 	int (*remove) (struct device *dev);
130 	void (*shutdown) (struct device *dev);
131 	int (*suspend) (struct device *dev, pm_message_t state);
132 	int (*resume) (struct device *dev);
133 	struct attribute_group **groups;
134 
135 	struct driver_private *p;
136 };
137 
138 
139 extern int __must_check driver_register(struct device_driver *drv);
140 extern void driver_unregister(struct device_driver *drv);
141 
142 extern struct device_driver *get_driver(struct device_driver *drv);
143 extern void put_driver(struct device_driver *drv);
144 extern struct device_driver *driver_find(const char *name,
145 					 struct bus_type *bus);
146 extern int driver_probe_done(void);
147 
148 /* sysfs interface for exporting driver attributes */
149 
150 struct driver_attribute {
151 	struct attribute attr;
152 	ssize_t (*show)(struct device_driver *driver, char *buf);
153 	ssize_t (*store)(struct device_driver *driver, const char *buf,
154 			 size_t count);
155 };
156 
157 #define DRIVER_ATTR(_name, _mode, _show, _store)	\
158 struct driver_attribute driver_attr_##_name =		\
159 	__ATTR(_name, _mode, _show, _store)
160 
161 extern int __must_check driver_create_file(struct device_driver *driver,
162 					   struct driver_attribute *attr);
163 extern void driver_remove_file(struct device_driver *driver,
164 			       struct driver_attribute *attr);
165 
166 extern int __must_check driver_add_kobj(struct device_driver *drv,
167 					struct kobject *kobj,
168 					const char *fmt, ...);
169 
170 extern int __must_check driver_for_each_device(struct device_driver *drv,
171 					       struct device *start,
172 					       void *data,
173 					       int (*fn)(struct device *dev,
174 							 void *));
175 struct device *driver_find_device(struct device_driver *drv,
176 				  struct device *start, void *data,
177 				  int (*match)(struct device *dev, void *data));
178 
179 /*
180  * device classes
181  */
182 struct class {
183 	const char		*name;
184 	struct module		*owner;
185 
186 	struct kset		subsys;
187 	struct list_head	children;
188 	struct list_head	devices;
189 	struct list_head	interfaces;
190 	struct kset		class_dirs;
191 	struct semaphore	sem; /* locks children, devices, interfaces */
192 	struct class_attribute		*class_attrs;
193 	struct class_device_attribute	*class_dev_attrs;
194 	struct device_attribute		*dev_attrs;
195 
196 	int (*uevent)(struct class_device *dev, struct kobj_uevent_env *env);
197 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
198 
199 	void (*release)(struct class_device *dev);
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 
207 extern int __must_check class_register(struct class *class);
208 extern void class_unregister(struct class *class);
209 extern int class_for_each_device(struct class *class, void *data,
210 				 int (*fn)(struct device *dev, void *data));
211 extern struct device *class_find_device(struct class *class, void *data,
212 					int (*match)(struct device *, void *));
213 extern struct class_device *class_find_child(struct class *class, void *data,
214 				   int (*match)(struct class_device *, void *));
215 
216 
217 struct class_attribute {
218 	struct attribute attr;
219 	ssize_t (*show)(struct class *class, char *buf);
220 	ssize_t (*store)(struct class *class, const char *buf, size_t count);
221 };
222 
223 #define CLASS_ATTR(_name, _mode, _show, _store)			\
224 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
225 
226 extern int __must_check class_create_file(struct class *class,
227 					  const struct class_attribute *attr);
228 extern void class_remove_file(struct class *class,
229 			      const struct class_attribute *attr);
230 
231 struct class_device_attribute {
232 	struct attribute attr;
233 	ssize_t (*show)(struct class_device *, char *buf);
234 	ssize_t (*store)(struct class_device *, const char *buf, size_t count);
235 };
236 
237 #define CLASS_DEVICE_ATTR(_name, _mode, _show, _store)		\
238 struct class_device_attribute class_device_attr_##_name = 	\
239 	__ATTR(_name, _mode, _show, _store)
240 
241 extern int __must_check class_device_create_file(struct class_device *,
242 				    const struct class_device_attribute *);
243 
244 /**
245  * struct class_device - class devices
246  * @class: pointer to the parent class for this class device.  This is required.
247  * @devt: for internal use by the driver core only.
248  * @node: for internal use by the driver core only.
249  * @kobj: for internal use by the driver core only.
250  * @groups: optional additional groups to be created
251  * @dev: if set, a symlink to the struct device is created in the sysfs
252  * directory for this struct class device.
253  * @class_data: pointer to whatever you want to store here for this struct
254  * class_device.  Use class_get_devdata() and class_set_devdata() to get and
255  * set this pointer.
256  * @parent: pointer to a struct class_device that is the parent of this struct
257  * class_device.  If NULL, this class_device will show up at the root of the
258  * struct class in sysfs (which is probably what you want to have happen.)
259  * @release: pointer to a release function for this struct class_device.  If
260  * set, this will be called instead of the class specific release function.
261  * Only use this if you want to override the default release function, like
262  * when you are nesting class_device structures.
263  * @uevent: pointer to a uevent function for this struct class_device.  If
264  * set, this will be called instead of the class specific uevent function.
265  * Only use this if you want to override the default uevent function, like
266  * when you are nesting class_device structures.
267  */
268 struct class_device {
269 	struct list_head	node;
270 
271 	struct kobject		kobj;
272 	struct class		*class;
273 	dev_t			devt;
274 	struct device		*dev;
275 	void			*class_data;
276 	struct class_device	*parent;
277 	struct attribute_group  **groups;
278 
279 	void (*release)(struct class_device *dev);
280 	int (*uevent)(struct class_device *dev, struct kobj_uevent_env *env);
281 	char class_id[BUS_ID_SIZE];
282 };
283 
284 static inline void *class_get_devdata(struct class_device *dev)
285 {
286 	return dev->class_data;
287 }
288 
289 static inline void class_set_devdata(struct class_device *dev, void *data)
290 {
291 	dev->class_data = data;
292 }
293 
294 
295 extern int __must_check class_device_register(struct class_device *);
296 extern void class_device_unregister(struct class_device *);
297 extern void class_device_initialize(struct class_device *);
298 extern int __must_check class_device_add(struct class_device *);
299 extern void class_device_del(struct class_device *);
300 
301 extern struct class_device *class_device_get(struct class_device *);
302 extern void class_device_put(struct class_device *);
303 
304 extern void class_device_remove_file(struct class_device *,
305 				     const struct class_device_attribute *);
306 extern int __must_check class_device_create_bin_file(struct class_device *,
307 					struct bin_attribute *);
308 extern void class_device_remove_bin_file(struct class_device *,
309 					 struct bin_attribute *);
310 
311 struct class_interface {
312 	struct list_head	node;
313 	struct class		*class;
314 
315 	int (*add)	(struct class_device *, struct class_interface *);
316 	void (*remove)	(struct class_device *, struct class_interface *);
317 	int (*add_dev)		(struct device *, struct class_interface *);
318 	void (*remove_dev)	(struct device *, struct class_interface *);
319 };
320 
321 extern int __must_check class_interface_register(struct class_interface *);
322 extern void class_interface_unregister(struct class_interface *);
323 
324 extern struct class *class_create(struct module *owner, const char *name);
325 extern void class_destroy(struct class *cls);
326 extern struct class_device *class_device_create(struct class *cls,
327 						struct class_device *parent,
328 						dev_t devt,
329 						struct device *device,
330 						const char *fmt, ...)
331 					__attribute__((format(printf, 5, 6)));
332 extern void class_device_destroy(struct class *cls, dev_t devt);
333 
334 /*
335  * The type of device, "struct device" is embedded in. A class
336  * or bus can contain devices of different types
337  * like "partitions" and "disks", "mouse" and "event".
338  * This identifies the device type and carries type-specific
339  * information, equivalent to the kobj_type of a kobject.
340  * If "name" is specified, the uevent will contain it in
341  * the DEVTYPE variable.
342  */
343 struct device_type {
344 	const char *name;
345 	struct attribute_group **groups;
346 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
347 	void (*release)(struct device *dev);
348 	int (*suspend)(struct device *dev, pm_message_t state);
349 	int (*resume)(struct device *dev);
350 };
351 
352 /* interface for exporting device attributes */
353 struct device_attribute {
354 	struct attribute	attr;
355 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
356 			char *buf);
357 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
358 			 const char *buf, size_t count);
359 };
360 
361 #define DEVICE_ATTR(_name, _mode, _show, _store) \
362 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
363 
364 extern int __must_check device_create_file(struct device *device,
365 					   struct device_attribute *entry);
366 extern void device_remove_file(struct device *dev,
367 			       struct device_attribute *attr);
368 extern int __must_check device_create_bin_file(struct device *dev,
369 					       struct bin_attribute *attr);
370 extern void device_remove_bin_file(struct device *dev,
371 				   struct bin_attribute *attr);
372 extern int device_schedule_callback_owner(struct device *dev,
373 		void (*func)(struct device *dev), struct module *owner);
374 
375 /* This is a macro to avoid include problems with THIS_MODULE */
376 #define device_schedule_callback(dev, func)			\
377 	device_schedule_callback_owner(dev, func, THIS_MODULE)
378 
379 /* device resource management */
380 typedef void (*dr_release_t)(struct device *dev, void *res);
381 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
382 
383 #ifdef CONFIG_DEBUG_DEVRES
384 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
385 			     const char *name);
386 #define devres_alloc(release, size, gfp) \
387 	__devres_alloc(release, size, gfp, #release)
388 #else
389 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
390 #endif
391 extern void devres_free(void *res);
392 extern void devres_add(struct device *dev, void *res);
393 extern void *devres_find(struct device *dev, dr_release_t release,
394 			 dr_match_t match, void *match_data);
395 extern void *devres_get(struct device *dev, void *new_res,
396 			dr_match_t match, void *match_data);
397 extern void *devres_remove(struct device *dev, dr_release_t release,
398 			   dr_match_t match, void *match_data);
399 extern int devres_destroy(struct device *dev, dr_release_t release,
400 			  dr_match_t match, void *match_data);
401 
402 /* devres group */
403 extern void * __must_check devres_open_group(struct device *dev, void *id,
404 					     gfp_t gfp);
405 extern void devres_close_group(struct device *dev, void *id);
406 extern void devres_remove_group(struct device *dev, void *id);
407 extern int devres_release_group(struct device *dev, void *id);
408 
409 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
410 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
411 extern void devm_kfree(struct device *dev, void *p);
412 
413 struct device_dma_parameters {
414 	/*
415 	 * a low level driver may set these to teach IOMMU code about
416 	 * sg limitations.
417 	 */
418 	unsigned int max_segment_size;
419 	unsigned long segment_boundary_mask;
420 };
421 
422 struct device {
423 	struct klist		klist_children;
424 	struct klist_node	knode_parent;	/* node in sibling list */
425 	struct klist_node	knode_driver;
426 	struct klist_node	knode_bus;
427 	struct device		*parent;
428 
429 	struct kobject kobj;
430 	char	bus_id[BUS_ID_SIZE];	/* position on parent bus */
431 	struct device_type	*type;
432 	unsigned		is_registered:1;
433 	unsigned		uevent_suppress:1;
434 
435 	struct semaphore	sem;	/* semaphore to synchronize calls to
436 					 * its driver.
437 					 */
438 
439 	struct bus_type	*bus;		/* type of bus device is on */
440 	struct device_driver *driver;	/* which driver has allocated this
441 					   device */
442 	void		*driver_data;	/* data private to the driver */
443 	void		*platform_data;	/* Platform specific data, device
444 					   core doesn't touch it */
445 	struct dev_pm_info	power;
446 
447 #ifdef CONFIG_NUMA
448 	int		numa_node;	/* NUMA node this device is close to */
449 #endif
450 	u64		*dma_mask;	/* dma mask (if dma'able device) */
451 	u64		coherent_dma_mask;/* Like dma_mask, but for
452 					     alloc_coherent mappings as
453 					     not all hardware supports
454 					     64 bit addresses for consistent
455 					     allocations such descriptors. */
456 
457 	struct device_dma_parameters *dma_parms;
458 
459 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
460 
461 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
462 					     override */
463 	/* arch specific additions */
464 	struct dev_archdata	archdata;
465 
466 	spinlock_t		devres_lock;
467 	struct list_head	devres_head;
468 
469 	/* class_device migration path */
470 	struct list_head	node;
471 	struct class		*class;
472 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
473 	struct attribute_group	**groups;	/* optional groups */
474 
475 	void	(*release)(struct device *dev);
476 };
477 
478 #ifdef CONFIG_NUMA
479 static inline int dev_to_node(struct device *dev)
480 {
481 	return dev->numa_node;
482 }
483 static inline void set_dev_node(struct device *dev, int node)
484 {
485 	dev->numa_node = node;
486 }
487 #else
488 static inline int dev_to_node(struct device *dev)
489 {
490 	return -1;
491 }
492 static inline void set_dev_node(struct device *dev, int node)
493 {
494 }
495 #endif
496 
497 static inline void *dev_get_drvdata(struct device *dev)
498 {
499 	return dev->driver_data;
500 }
501 
502 static inline void dev_set_drvdata(struct device *dev, void *data)
503 {
504 	dev->driver_data = data;
505 }
506 
507 static inline int device_is_registered(struct device *dev)
508 {
509 	return dev->is_registered;
510 }
511 
512 void driver_init(void);
513 
514 /*
515  * High level routines for use by the bus drivers
516  */
517 extern int __must_check device_register(struct device *dev);
518 extern void device_unregister(struct device *dev);
519 extern void device_initialize(struct device *dev);
520 extern int __must_check device_add(struct device *dev);
521 extern void device_del(struct device *dev);
522 extern int device_for_each_child(struct device *dev, void *data,
523 		     int (*fn)(struct device *dev, void *data));
524 extern struct device *device_find_child(struct device *dev, void *data,
525 				int (*match)(struct device *dev, void *data));
526 extern int device_rename(struct device *dev, char *new_name);
527 extern int device_move(struct device *dev, struct device *new_parent);
528 
529 /*
530  * Manual binding of a device to driver. See drivers/base/bus.c
531  * for information on use.
532  */
533 extern int __must_check device_bind_driver(struct device *dev);
534 extern void device_release_driver(struct device *dev);
535 extern int  __must_check device_attach(struct device *dev);
536 extern int __must_check driver_attach(struct device_driver *drv);
537 extern int __must_check device_reprobe(struct device *dev);
538 
539 /*
540  * Easy functions for dynamically creating devices on the fly
541  */
542 extern struct device *device_create(struct class *cls, struct device *parent,
543 				    dev_t devt, const char *fmt, ...)
544 				    __attribute__((format(printf, 4, 5)));
545 extern void device_destroy(struct class *cls, dev_t devt);
546 #ifdef CONFIG_PM_SLEEP
547 extern void destroy_suspended_device(struct class *cls, dev_t devt);
548 extern void device_pm_schedule_removal(struct device *);
549 #else /* !CONFIG_PM_SLEEP */
550 static inline void destroy_suspended_device(struct class *cls, dev_t devt)
551 {
552 	device_destroy(cls, devt);
553 }
554 
555 static inline void device_pm_schedule_removal(struct device *dev)
556 {
557 	device_unregister(dev);
558 }
559 #endif /* !CONFIG_PM_SLEEP */
560 
561 /*
562  * Platform "fixup" functions - allow the platform to have their say
563  * about devices and actions that the general device layer doesn't
564  * know about.
565  */
566 /* Notify platform of device discovery */
567 extern int (*platform_notify)(struct device *dev);
568 
569 extern int (*platform_notify_remove)(struct device *dev);
570 
571 
572 /**
573  * get_device - atomically increment the reference count for the device.
574  *
575  */
576 extern struct device *get_device(struct device *dev);
577 extern void put_device(struct device *dev);
578 
579 
580 /* drivers/base/power/shutdown.c */
581 extern void device_shutdown(void);
582 
583 /* drivers/base/sys.c */
584 extern void sysdev_shutdown(void);
585 
586 /* debugging and troubleshooting/diagnostic helpers. */
587 extern const char *dev_driver_string(struct device *dev);
588 #define dev_printk(level, dev, format, arg...)	\
589 	printk(level "%s %s: " format , dev_driver_string(dev) , \
590 	       (dev)->bus_id , ## arg)
591 
592 #define dev_emerg(dev, format, arg...)		\
593 	dev_printk(KERN_EMERG , dev , format , ## arg)
594 #define dev_alert(dev, format, arg...)		\
595 	dev_printk(KERN_ALERT , dev , format , ## arg)
596 #define dev_crit(dev, format, arg...)		\
597 	dev_printk(KERN_CRIT , dev , format , ## arg)
598 #define dev_err(dev, format, arg...)		\
599 	dev_printk(KERN_ERR , dev , format , ## arg)
600 #define dev_warn(dev, format, arg...)		\
601 	dev_printk(KERN_WARNING , dev , format , ## arg)
602 #define dev_notice(dev, format, arg...)		\
603 	dev_printk(KERN_NOTICE , dev , format , ## arg)
604 #define dev_info(dev, format, arg...)		\
605 	dev_printk(KERN_INFO , dev , format , ## arg)
606 
607 #ifdef DEBUG
608 #define dev_dbg(dev, format, arg...)		\
609 	dev_printk(KERN_DEBUG , dev , format , ## arg)
610 #else
611 #define dev_dbg(dev, format, arg...)		\
612 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
613 #endif
614 
615 #ifdef VERBOSE_DEBUG
616 #define dev_vdbg	dev_dbg
617 #else
618 
619 #define dev_vdbg(dev, format, arg...)		\
620 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
621 #endif
622 
623 /* Create alias, so I can be autoloaded. */
624 #define MODULE_ALIAS_CHARDEV(major,minor) \
625 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
626 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
627 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
628 #endif /* _DEVICE_H_ */
629