xref: /linux-6.15/include/linux/device.h (revision 48001ea5)
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/dev_printk.h>
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/mutex.h>
24 #include <linux/pm.h>
25 #include <linux/atomic.h>
26 #include <linux/uidgid.h>
27 #include <linux/gfp.h>
28 #include <linux/overflow.h>
29 #include <linux/device/bus.h>
30 #include <linux/device/class.h>
31 #include <linux/device/driver.h>
32 #include <asm/device.h>
33 
34 struct device;
35 struct device_private;
36 struct device_driver;
37 struct driver_private;
38 struct module;
39 struct class;
40 struct subsys_private;
41 struct device_node;
42 struct fwnode_handle;
43 struct iommu_ops;
44 struct iommu_group;
45 struct dev_pin_info;
46 struct dev_iommu;
47 
48 /**
49  * struct subsys_interface - interfaces to device functions
50  * @name:       name of the device function
51  * @subsys:     subsytem of the devices to attach to
52  * @node:       the list of functions registered at the subsystem
53  * @add_dev:    device hookup to device function handler
54  * @remove_dev: device hookup to device function handler
55  *
56  * Simple interfaces attached to a subsystem. Multiple interfaces can
57  * attach to a subsystem and its devices. Unlike drivers, they do not
58  * exclusively claim or control devices. Interfaces usually represent
59  * a specific functionality of a subsystem/class of devices.
60  */
61 struct subsys_interface {
62 	const char *name;
63 	struct bus_type *subsys;
64 	struct list_head node;
65 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
66 	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
67 };
68 
69 int subsys_interface_register(struct subsys_interface *sif);
70 void subsys_interface_unregister(struct subsys_interface *sif);
71 
72 int subsys_system_register(struct bus_type *subsys,
73 			   const struct attribute_group **groups);
74 int subsys_virtual_register(struct bus_type *subsys,
75 			    const struct attribute_group **groups);
76 
77 /*
78  * The type of device, "struct device" is embedded in. A class
79  * or bus can contain devices of different types
80  * like "partitions" and "disks", "mouse" and "event".
81  * This identifies the device type and carries type-specific
82  * information, equivalent to the kobj_type of a kobject.
83  * If "name" is specified, the uevent will contain it in
84  * the DEVTYPE variable.
85  */
86 struct device_type {
87 	const char *name;
88 	const struct attribute_group **groups;
89 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
90 	char *(*devnode)(struct device *dev, umode_t *mode,
91 			 kuid_t *uid, kgid_t *gid);
92 	void (*release)(struct device *dev);
93 
94 	const struct dev_pm_ops *pm;
95 };
96 
97 /* interface for exporting device attributes */
98 struct device_attribute {
99 	struct attribute	attr;
100 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
101 			char *buf);
102 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
103 			 const char *buf, size_t count);
104 };
105 
106 struct dev_ext_attribute {
107 	struct device_attribute attr;
108 	void *var;
109 };
110 
111 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
112 			  char *buf);
113 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
114 			   const char *buf, size_t count);
115 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
116 			char *buf);
117 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
118 			 const char *buf, size_t count);
119 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
120 			char *buf);
121 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
122 			 const char *buf, size_t count);
123 
124 #define DEVICE_ATTR(_name, _mode, _show, _store) \
125 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
126 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
127 	struct device_attribute dev_attr_##_name = \
128 		__ATTR_PREALLOC(_name, _mode, _show, _store)
129 #define DEVICE_ATTR_RW(_name) \
130 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
131 #define DEVICE_ATTR_ADMIN_RW(_name) \
132 	struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
133 #define DEVICE_ATTR_RO(_name) \
134 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
135 #define DEVICE_ATTR_ADMIN_RO(_name) \
136 	struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
137 #define DEVICE_ATTR_WO(_name) \
138 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
139 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
140 	struct dev_ext_attribute dev_attr_##_name = \
141 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
142 #define DEVICE_INT_ATTR(_name, _mode, _var) \
143 	struct dev_ext_attribute dev_attr_##_name = \
144 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
145 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
146 	struct dev_ext_attribute dev_attr_##_name = \
147 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
148 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
149 	struct device_attribute dev_attr_##_name =		\
150 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
151 
152 extern int device_create_file(struct device *device,
153 			      const struct device_attribute *entry);
154 extern void device_remove_file(struct device *dev,
155 			       const struct device_attribute *attr);
156 extern bool device_remove_file_self(struct device *dev,
157 				    const struct device_attribute *attr);
158 extern int __must_check device_create_bin_file(struct device *dev,
159 					const struct bin_attribute *attr);
160 extern void device_remove_bin_file(struct device *dev,
161 				   const struct bin_attribute *attr);
162 
163 /* device resource management */
164 typedef void (*dr_release_t)(struct device *dev, void *res);
165 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
166 
167 #ifdef CONFIG_DEBUG_DEVRES
168 extern void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
169 				 int nid, const char *name) __malloc;
170 #define devres_alloc(release, size, gfp) \
171 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
172 #define devres_alloc_node(release, size, gfp, nid) \
173 	__devres_alloc_node(release, size, gfp, nid, #release)
174 #else
175 extern void *devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
176 			       int nid) __malloc;
177 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
178 {
179 	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
180 }
181 #endif
182 
183 extern void devres_for_each_res(struct device *dev, dr_release_t release,
184 				dr_match_t match, void *match_data,
185 				void (*fn)(struct device *, void *, void *),
186 				void *data);
187 extern void devres_free(void *res);
188 extern void devres_add(struct device *dev, void *res);
189 extern void *devres_find(struct device *dev, dr_release_t release,
190 			 dr_match_t match, void *match_data);
191 extern void *devres_get(struct device *dev, void *new_res,
192 			dr_match_t match, void *match_data);
193 extern void *devres_remove(struct device *dev, dr_release_t release,
194 			   dr_match_t match, void *match_data);
195 extern int devres_destroy(struct device *dev, dr_release_t release,
196 			  dr_match_t match, void *match_data);
197 extern int devres_release(struct device *dev, dr_release_t release,
198 			  dr_match_t match, void *match_data);
199 
200 /* devres group */
201 extern void * __must_check devres_open_group(struct device *dev, void *id,
202 					     gfp_t gfp);
203 extern void devres_close_group(struct device *dev, void *id);
204 extern void devres_remove_group(struct device *dev, void *id);
205 extern int devres_release_group(struct device *dev, void *id);
206 
207 /* managed devm_k.alloc/kfree for device drivers */
208 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
209 extern __printf(3, 0)
210 char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
211 		      va_list ap) __malloc;
212 extern __printf(3, 4)
213 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...) __malloc;
214 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
215 {
216 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
217 }
218 static inline void *devm_kmalloc_array(struct device *dev,
219 				       size_t n, size_t size, gfp_t flags)
220 {
221 	size_t bytes;
222 
223 	if (unlikely(check_mul_overflow(n, size, &bytes)))
224 		return NULL;
225 
226 	return devm_kmalloc(dev, bytes, flags);
227 }
228 static inline void *devm_kcalloc(struct device *dev,
229 				 size_t n, size_t size, gfp_t flags)
230 {
231 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
232 }
233 extern void devm_kfree(struct device *dev, const void *p);
234 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
235 extern const char *devm_kstrdup_const(struct device *dev,
236 				      const char *s, gfp_t gfp);
237 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
238 			  gfp_t gfp);
239 
240 extern unsigned long devm_get_free_pages(struct device *dev,
241 					 gfp_t gfp_mask, unsigned int order);
242 extern void devm_free_pages(struct device *dev, unsigned long addr);
243 
244 void __iomem *devm_ioremap_resource(struct device *dev,
245 				    const struct resource *res);
246 void __iomem *devm_ioremap_resource_wc(struct device *dev,
247 				       const struct resource *res);
248 
249 void __iomem *devm_of_iomap(struct device *dev,
250 			    struct device_node *node, int index,
251 			    resource_size_t *size);
252 
253 /* allows to add/remove a custom action to devres stack */
254 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
255 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
256 void devm_release_action(struct device *dev, void (*action)(void *), void *data);
257 
258 static inline int devm_add_action_or_reset(struct device *dev,
259 					   void (*action)(void *), void *data)
260 {
261 	int ret;
262 
263 	ret = devm_add_action(dev, action, data);
264 	if (ret)
265 		action(data);
266 
267 	return ret;
268 }
269 
270 /**
271  * devm_alloc_percpu - Resource-managed alloc_percpu
272  * @dev: Device to allocate per-cpu memory for
273  * @type: Type to allocate per-cpu memory for
274  *
275  * Managed alloc_percpu. Per-cpu memory allocated with this function is
276  * automatically freed on driver detach.
277  *
278  * RETURNS:
279  * Pointer to allocated memory on success, NULL on failure.
280  */
281 #define devm_alloc_percpu(dev, type)      \
282 	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
283 						      __alignof__(type)))
284 
285 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
286 				   size_t align);
287 void devm_free_percpu(struct device *dev, void __percpu *pdata);
288 
289 struct device_dma_parameters {
290 	/*
291 	 * a low level driver may set these to teach IOMMU code about
292 	 * sg limitations.
293 	 */
294 	unsigned int max_segment_size;
295 	unsigned long segment_boundary_mask;
296 };
297 
298 /**
299  * struct device_connection - Device Connection Descriptor
300  * @fwnode: The device node of the connected device
301  * @endpoint: The names of the two devices connected together
302  * @id: Unique identifier for the connection
303  * @list: List head, private, for internal use only
304  *
305  * NOTE: @fwnode is not used together with @endpoint. @fwnode is used when
306  * platform firmware defines the connection. When the connection is registered
307  * with device_connection_add() @endpoint is used instead.
308  */
309 struct device_connection {
310 	struct fwnode_handle	*fwnode;
311 	const char		*endpoint[2];
312 	const char		*id;
313 	struct list_head	list;
314 };
315 
316 typedef void *(*devcon_match_fn_t)(struct device_connection *con, int ep,
317 				   void *data);
318 
319 void *fwnode_connection_find_match(struct fwnode_handle *fwnode,
320 				   const char *con_id, void *data,
321 				   devcon_match_fn_t match);
322 void *device_connection_find_match(struct device *dev, const char *con_id,
323 				   void *data, devcon_match_fn_t match);
324 
325 struct device *device_connection_find(struct device *dev, const char *con_id);
326 
327 void device_connection_add(struct device_connection *con);
328 void device_connection_remove(struct device_connection *con);
329 
330 /**
331  * device_connections_add - Add multiple device connections at once
332  * @cons: Zero terminated array of device connection descriptors
333  */
334 static inline void device_connections_add(struct device_connection *cons)
335 {
336 	struct device_connection *c;
337 
338 	for (c = cons; c->endpoint[0]; c++)
339 		device_connection_add(c);
340 }
341 
342 /**
343  * device_connections_remove - Remove multiple device connections at once
344  * @cons: Zero terminated array of device connection descriptors
345  */
346 static inline void device_connections_remove(struct device_connection *cons)
347 {
348 	struct device_connection *c;
349 
350 	for (c = cons; c->endpoint[0]; c++)
351 		device_connection_remove(c);
352 }
353 
354 /**
355  * enum device_link_state - Device link states.
356  * @DL_STATE_NONE: The presence of the drivers is not being tracked.
357  * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
358  * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
359  * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
360  * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
361  * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
362  */
363 enum device_link_state {
364 	DL_STATE_NONE = -1,
365 	DL_STATE_DORMANT = 0,
366 	DL_STATE_AVAILABLE,
367 	DL_STATE_CONSUMER_PROBE,
368 	DL_STATE_ACTIVE,
369 	DL_STATE_SUPPLIER_UNBIND,
370 };
371 
372 /*
373  * Device link flags.
374  *
375  * STATELESS: The core will not remove this link automatically.
376  * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
377  * PM_RUNTIME: If set, the runtime PM framework will use this link.
378  * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
379  * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
380  * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
381  * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
382  * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
383  */
384 #define DL_FLAG_STATELESS		BIT(0)
385 #define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)
386 #define DL_FLAG_PM_RUNTIME		BIT(2)
387 #define DL_FLAG_RPM_ACTIVE		BIT(3)
388 #define DL_FLAG_AUTOREMOVE_SUPPLIER	BIT(4)
389 #define DL_FLAG_AUTOPROBE_CONSUMER	BIT(5)
390 #define DL_FLAG_MANAGED			BIT(6)
391 #define DL_FLAG_SYNC_STATE_ONLY		BIT(7)
392 
393 /**
394  * struct device_link - Device link representation.
395  * @supplier: The device on the supplier end of the link.
396  * @s_node: Hook to the supplier device's list of links to consumers.
397  * @consumer: The device on the consumer end of the link.
398  * @c_node: Hook to the consumer device's list of links to suppliers.
399  * @status: The state of the link (with respect to the presence of drivers).
400  * @flags: Link flags.
401  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
402  * @kref: Count repeated addition of the same link.
403  * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
404  * @supplier_preactivated: Supplier has been made active before consumer probe.
405  */
406 struct device_link {
407 	struct device *supplier;
408 	struct list_head s_node;
409 	struct device *consumer;
410 	struct list_head c_node;
411 	enum device_link_state status;
412 	u32 flags;
413 	refcount_t rpm_active;
414 	struct kref kref;
415 #ifdef CONFIG_SRCU
416 	struct rcu_head rcu_head;
417 #endif
418 	bool supplier_preactivated; /* Owned by consumer probe. */
419 };
420 
421 /**
422  * enum dl_dev_state - Device driver presence tracking information.
423  * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
424  * @DL_DEV_PROBING: A driver is probing.
425  * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
426  * @DL_DEV_UNBINDING: The driver is unbinding from the device.
427  */
428 enum dl_dev_state {
429 	DL_DEV_NO_DRIVER = 0,
430 	DL_DEV_PROBING,
431 	DL_DEV_DRIVER_BOUND,
432 	DL_DEV_UNBINDING,
433 };
434 
435 /**
436  * struct dev_links_info - Device data related to device links.
437  * @suppliers: List of links to supplier devices.
438  * @consumers: List of links to consumer devices.
439  * @needs_suppliers: Hook to global list of devices waiting for suppliers.
440  * @defer_sync: Hook to global list of devices that have deferred sync_state.
441  * @need_for_probe: If needs_suppliers is on a list, this indicates if the
442  *		    suppliers are needed for probe or not.
443  * @status: Driver status information.
444  */
445 struct dev_links_info {
446 	struct list_head suppliers;
447 	struct list_head consumers;
448 	struct list_head needs_suppliers;
449 	struct list_head defer_sync;
450 	bool need_for_probe;
451 	enum dl_dev_state status;
452 };
453 
454 /**
455  * struct device - The basic device structure
456  * @parent:	The device's "parent" device, the device to which it is attached.
457  * 		In most cases, a parent device is some sort of bus or host
458  * 		controller. If parent is NULL, the device, is a top-level device,
459  * 		which is not usually what you want.
460  * @p:		Holds the private data of the driver core portions of the device.
461  * 		See the comment of the struct device_private for detail.
462  * @kobj:	A top-level, abstract class from which other classes are derived.
463  * @init_name:	Initial name of the device.
464  * @type:	The type of device.
465  * 		This identifies the device type and carries type-specific
466  * 		information.
467  * @mutex:	Mutex to synchronize calls to its driver.
468  * @lockdep_mutex: An optional debug lock that a subsystem can use as a
469  * 		peer lock to gain localized lockdep coverage of the device_lock.
470  * @bus:	Type of bus device is on.
471  * @driver:	Which driver has allocated this
472  * @platform_data: Platform data specific to the device.
473  * 		Example: For devices on custom boards, as typical of embedded
474  * 		and SOC based hardware, Linux often uses platform_data to point
475  * 		to board-specific structures describing devices and how they
476  * 		are wired.  That can include what ports are available, chip
477  * 		variants, which GPIO pins act in what additional roles, and so
478  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
479  * 		minimizes board-specific #ifdefs in drivers.
480  * @driver_data: Private pointer for driver specific info.
481  * @links:	Links to suppliers and consumers of this device.
482  * @power:	For device power management.
483  *		See Documentation/driver-api/pm/devices.rst for details.
484  * @pm_domain:	Provide callbacks that are executed during system suspend,
485  * 		hibernation, system resume and during runtime PM transitions
486  * 		along with subsystem-level and driver-level callbacks.
487  * @pins:	For device pin management.
488  *		See Documentation/driver-api/pinctl.rst for details.
489  * @msi_list:	Hosts MSI descriptors
490  * @msi_domain: The generic MSI domain this device is using.
491  * @numa_node:	NUMA node this device is close to.
492  * @dma_ops:    DMA mapping operations for this device.
493  * @dma_mask:	Dma mask (if dma'ble device).
494  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
495  * 		hardware supports 64-bit addresses for consistent allocations
496  * 		such descriptors.
497  * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
498  *		DMA limit than the device itself supports.
499  * @dma_pfn_offset: offset of DMA memory range relatively of RAM
500  * @dma_parms:	A low level driver may set these to teach IOMMU code about
501  * 		segment limitations.
502  * @dma_pools:	Dma pools (if dma'ble device).
503  * @dma_mem:	Internal for coherent mem override.
504  * @cma_area:	Contiguous memory area for dma allocations
505  * @archdata:	For arch-specific additions.
506  * @of_node:	Associated device tree node.
507  * @fwnode:	Associated device node supplied by platform firmware.
508  * @devt:	For creating the sysfs "dev".
509  * @id:		device instance
510  * @devres_lock: Spinlock to protect the resource of the device.
511  * @devres_head: The resources list of the device.
512  * @knode_class: The node used to add the device to the class list.
513  * @class:	The class of the device.
514  * @groups:	Optional attribute groups.
515  * @release:	Callback to free the device after all references have
516  * 		gone away. This should be set by the allocator of the
517  * 		device (i.e. the bus driver that discovered the device).
518  * @iommu_group: IOMMU group the device belongs to.
519  * @iommu:	Per device generic IOMMU runtime data
520  *
521  * @offline_disabled: If set, the device is permanently online.
522  * @offline:	Set after successful invocation of bus type's .offline().
523  * @of_node_reused: Set if the device-tree node is shared with an ancestor
524  *              device.
525  * @state_synced: The hardware state of this device has been synced to match
526  *		  the software state of this device by calling the driver/bus
527  *		  sync_state() callback.
528  * @dma_coherent: this particular device is dma coherent, even if the
529  *		architecture supports non-coherent devices.
530  *
531  * At the lowest level, every device in a Linux system is represented by an
532  * instance of struct device. The device structure contains the information
533  * that the device model core needs to model the system. Most subsystems,
534  * however, track additional information about the devices they host. As a
535  * result, it is rare for devices to be represented by bare device structures;
536  * instead, that structure, like kobject structures, is usually embedded within
537  * a higher-level representation of the device.
538  */
539 struct device {
540 	struct kobject kobj;
541 	struct device		*parent;
542 
543 	struct device_private	*p;
544 
545 	const char		*init_name; /* initial name of the device */
546 	const struct device_type *type;
547 
548 	struct bus_type	*bus;		/* type of bus device is on */
549 	struct device_driver *driver;	/* which driver has allocated this
550 					   device */
551 	void		*platform_data;	/* Platform specific data, device
552 					   core doesn't touch it */
553 	void		*driver_data;	/* Driver data, set and get with
554 					   dev_set_drvdata/dev_get_drvdata */
555 #ifdef CONFIG_PROVE_LOCKING
556 	struct mutex		lockdep_mutex;
557 #endif
558 	struct mutex		mutex;	/* mutex to synchronize calls to
559 					 * its driver.
560 					 */
561 
562 	struct dev_links_info	links;
563 	struct dev_pm_info	power;
564 	struct dev_pm_domain	*pm_domain;
565 
566 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
567 	struct irq_domain	*msi_domain;
568 #endif
569 #ifdef CONFIG_PINCTRL
570 	struct dev_pin_info	*pins;
571 #endif
572 #ifdef CONFIG_GENERIC_MSI_IRQ
573 	struct list_head	msi_list;
574 #endif
575 
576 	const struct dma_map_ops *dma_ops;
577 	u64		*dma_mask;	/* dma mask (if dma'able device) */
578 	u64		coherent_dma_mask;/* Like dma_mask, but for
579 					     alloc_coherent mappings as
580 					     not all hardware supports
581 					     64 bit addresses for consistent
582 					     allocations such descriptors. */
583 	u64		bus_dma_limit;	/* upstream dma constraint */
584 	unsigned long	dma_pfn_offset;
585 
586 	struct device_dma_parameters *dma_parms;
587 
588 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
589 
590 #ifdef CONFIG_DMA_DECLARE_COHERENT
591 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
592 					     override */
593 #endif
594 #ifdef CONFIG_DMA_CMA
595 	struct cma *cma_area;		/* contiguous memory area for dma
596 					   allocations */
597 #endif
598 	/* arch specific additions */
599 	struct dev_archdata	archdata;
600 
601 	struct device_node	*of_node; /* associated device tree node */
602 	struct fwnode_handle	*fwnode; /* firmware device node */
603 
604 #ifdef CONFIG_NUMA
605 	int		numa_node;	/* NUMA node this device is close to */
606 #endif
607 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
608 	u32			id;	/* device instance */
609 
610 	spinlock_t		devres_lock;
611 	struct list_head	devres_head;
612 
613 	struct class		*class;
614 	const struct attribute_group **groups;	/* optional groups */
615 
616 	void	(*release)(struct device *dev);
617 	struct iommu_group	*iommu_group;
618 	struct dev_iommu	*iommu;
619 
620 	bool			offline_disabled:1;
621 	bool			offline:1;
622 	bool			of_node_reused:1;
623 	bool			state_synced:1;
624 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
625     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
626     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
627 	bool			dma_coherent:1;
628 #endif
629 };
630 
631 static inline struct device *kobj_to_dev(struct kobject *kobj)
632 {
633 	return container_of(kobj, struct device, kobj);
634 }
635 
636 /**
637  * device_iommu_mapped - Returns true when the device DMA is translated
638  *			 by an IOMMU
639  * @dev: Device to perform the check on
640  */
641 static inline bool device_iommu_mapped(struct device *dev)
642 {
643 	return (dev->iommu_group != NULL);
644 }
645 
646 /* Get the wakeup routines, which depend on struct device */
647 #include <linux/pm_wakeup.h>
648 
649 static inline const char *dev_name(const struct device *dev)
650 {
651 	/* Use the init name until the kobject becomes available */
652 	if (dev->init_name)
653 		return dev->init_name;
654 
655 	return kobject_name(&dev->kobj);
656 }
657 
658 extern __printf(2, 3)
659 int dev_set_name(struct device *dev, const char *name, ...);
660 
661 #ifdef CONFIG_NUMA
662 static inline int dev_to_node(struct device *dev)
663 {
664 	return dev->numa_node;
665 }
666 static inline void set_dev_node(struct device *dev, int node)
667 {
668 	dev->numa_node = node;
669 }
670 #else
671 static inline int dev_to_node(struct device *dev)
672 {
673 	return NUMA_NO_NODE;
674 }
675 static inline void set_dev_node(struct device *dev, int node)
676 {
677 }
678 #endif
679 
680 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
681 {
682 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
683 	return dev->msi_domain;
684 #else
685 	return NULL;
686 #endif
687 }
688 
689 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
690 {
691 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
692 	dev->msi_domain = d;
693 #endif
694 }
695 
696 static inline void *dev_get_drvdata(const struct device *dev)
697 {
698 	return dev->driver_data;
699 }
700 
701 static inline void dev_set_drvdata(struct device *dev, void *data)
702 {
703 	dev->driver_data = data;
704 }
705 
706 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
707 {
708 	return dev ? dev->power.subsys_data : NULL;
709 }
710 
711 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
712 {
713 	return dev->kobj.uevent_suppress;
714 }
715 
716 static inline void dev_set_uevent_suppress(struct device *dev, int val)
717 {
718 	dev->kobj.uevent_suppress = val;
719 }
720 
721 static inline int device_is_registered(struct device *dev)
722 {
723 	return dev->kobj.state_in_sysfs;
724 }
725 
726 static inline void device_enable_async_suspend(struct device *dev)
727 {
728 	if (!dev->power.is_prepared)
729 		dev->power.async_suspend = true;
730 }
731 
732 static inline void device_disable_async_suspend(struct device *dev)
733 {
734 	if (!dev->power.is_prepared)
735 		dev->power.async_suspend = false;
736 }
737 
738 static inline bool device_async_suspend_enabled(struct device *dev)
739 {
740 	return !!dev->power.async_suspend;
741 }
742 
743 static inline bool device_pm_not_required(struct device *dev)
744 {
745 	return dev->power.no_pm;
746 }
747 
748 static inline void device_set_pm_not_required(struct device *dev)
749 {
750 	dev->power.no_pm = true;
751 }
752 
753 static inline void dev_pm_syscore_device(struct device *dev, bool val)
754 {
755 #ifdef CONFIG_PM_SLEEP
756 	dev->power.syscore = val;
757 #endif
758 }
759 
760 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
761 {
762 	dev->power.driver_flags = flags;
763 }
764 
765 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
766 {
767 	return !!(dev->power.driver_flags & flags);
768 }
769 
770 static inline void device_lock(struct device *dev)
771 {
772 	mutex_lock(&dev->mutex);
773 }
774 
775 static inline int device_lock_interruptible(struct device *dev)
776 {
777 	return mutex_lock_interruptible(&dev->mutex);
778 }
779 
780 static inline int device_trylock(struct device *dev)
781 {
782 	return mutex_trylock(&dev->mutex);
783 }
784 
785 static inline void device_unlock(struct device *dev)
786 {
787 	mutex_unlock(&dev->mutex);
788 }
789 
790 static inline void device_lock_assert(struct device *dev)
791 {
792 	lockdep_assert_held(&dev->mutex);
793 }
794 
795 static inline struct device_node *dev_of_node(struct device *dev)
796 {
797 	if (!IS_ENABLED(CONFIG_OF) || !dev)
798 		return NULL;
799 	return dev->of_node;
800 }
801 
802 static inline bool dev_has_sync_state(struct device *dev)
803 {
804 	if (!dev)
805 		return false;
806 	if (dev->driver && dev->driver->sync_state)
807 		return true;
808 	if (dev->bus && dev->bus->sync_state)
809 		return true;
810 	return false;
811 }
812 
813 /*
814  * High level routines for use by the bus drivers
815  */
816 extern int __must_check device_register(struct device *dev);
817 extern void device_unregister(struct device *dev);
818 extern void device_initialize(struct device *dev);
819 extern int __must_check device_add(struct device *dev);
820 extern void device_del(struct device *dev);
821 extern int device_for_each_child(struct device *dev, void *data,
822 		     int (*fn)(struct device *dev, void *data));
823 extern int device_for_each_child_reverse(struct device *dev, void *data,
824 		     int (*fn)(struct device *dev, void *data));
825 extern struct device *device_find_child(struct device *dev, void *data,
826 				int (*match)(struct device *dev, void *data));
827 extern struct device *device_find_child_by_name(struct device *parent,
828 						const char *name);
829 extern int device_rename(struct device *dev, const char *new_name);
830 extern int device_move(struct device *dev, struct device *new_parent,
831 		       enum dpm_order dpm_order);
832 extern int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
833 extern const char *device_get_devnode(struct device *dev,
834 				      umode_t *mode, kuid_t *uid, kgid_t *gid,
835 				      const char **tmp);
836 
837 static inline bool device_supports_offline(struct device *dev)
838 {
839 	return dev->bus && dev->bus->offline && dev->bus->online;
840 }
841 
842 extern void lock_device_hotplug(void);
843 extern void unlock_device_hotplug(void);
844 extern int lock_device_hotplug_sysfs(void);
845 extern int device_offline(struct device *dev);
846 extern int device_online(struct device *dev);
847 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
848 extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
849 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
850 
851 static inline int dev_num_vf(struct device *dev)
852 {
853 	if (dev->bus && dev->bus->num_vf)
854 		return dev->bus->num_vf(dev);
855 	return 0;
856 }
857 
858 /*
859  * Root device objects for grouping under /sys/devices
860  */
861 extern struct device *__root_device_register(const char *name,
862 					     struct module *owner);
863 
864 /* This is a macro to avoid include problems with THIS_MODULE */
865 #define root_device_register(name) \
866 	__root_device_register(name, THIS_MODULE)
867 
868 extern void root_device_unregister(struct device *root);
869 
870 static inline void *dev_get_platdata(const struct device *dev)
871 {
872 	return dev->platform_data;
873 }
874 
875 /*
876  * Manual binding of a device to driver. See drivers/base/bus.c
877  * for information on use.
878  */
879 extern int __must_check device_bind_driver(struct device *dev);
880 extern void device_release_driver(struct device *dev);
881 extern int  __must_check device_attach(struct device *dev);
882 extern int __must_check driver_attach(struct device_driver *drv);
883 extern void device_initial_probe(struct device *dev);
884 extern int __must_check device_reprobe(struct device *dev);
885 
886 extern bool device_is_bound(struct device *dev);
887 
888 /*
889  * Easy functions for dynamically creating devices on the fly
890  */
891 extern __printf(5, 6)
892 struct device *device_create(struct class *cls, struct device *parent,
893 			     dev_t devt, void *drvdata,
894 			     const char *fmt, ...);
895 extern __printf(6, 7)
896 struct device *device_create_with_groups(struct class *cls,
897 			     struct device *parent, dev_t devt, void *drvdata,
898 			     const struct attribute_group **groups,
899 			     const char *fmt, ...);
900 extern void device_destroy(struct class *cls, dev_t devt);
901 
902 extern int __must_check device_add_groups(struct device *dev,
903 					const struct attribute_group **groups);
904 extern void device_remove_groups(struct device *dev,
905 				 const struct attribute_group **groups);
906 
907 static inline int __must_check device_add_group(struct device *dev,
908 					const struct attribute_group *grp)
909 {
910 	const struct attribute_group *groups[] = { grp, NULL };
911 
912 	return device_add_groups(dev, groups);
913 }
914 
915 static inline void device_remove_group(struct device *dev,
916 				       const struct attribute_group *grp)
917 {
918 	const struct attribute_group *groups[] = { grp, NULL };
919 
920 	return device_remove_groups(dev, groups);
921 }
922 
923 extern int __must_check devm_device_add_groups(struct device *dev,
924 					const struct attribute_group **groups);
925 extern void devm_device_remove_groups(struct device *dev,
926 				      const struct attribute_group **groups);
927 extern int __must_check devm_device_add_group(struct device *dev,
928 					const struct attribute_group *grp);
929 extern void devm_device_remove_group(struct device *dev,
930 				     const struct attribute_group *grp);
931 
932 /*
933  * Platform "fixup" functions - allow the platform to have their say
934  * about devices and actions that the general device layer doesn't
935  * know about.
936  */
937 /* Notify platform of device discovery */
938 extern int (*platform_notify)(struct device *dev);
939 
940 extern int (*platform_notify_remove)(struct device *dev);
941 
942 
943 /*
944  * get_device - atomically increment the reference count for the device.
945  *
946  */
947 extern struct device *get_device(struct device *dev);
948 extern void put_device(struct device *dev);
949 extern bool kill_device(struct device *dev);
950 
951 #ifdef CONFIG_DEVTMPFS
952 extern int devtmpfs_mount(void);
953 #else
954 static inline int devtmpfs_mount(void) { return 0; }
955 #endif
956 
957 /* drivers/base/power/shutdown.c */
958 extern void device_shutdown(void);
959 
960 /* debugging and troubleshooting/diagnostic helpers. */
961 extern const char *dev_driver_string(const struct device *dev);
962 
963 /* Device links interface. */
964 struct device_link *device_link_add(struct device *consumer,
965 				    struct device *supplier, u32 flags);
966 void device_link_del(struct device_link *link);
967 void device_link_remove(void *consumer, struct device *supplier);
968 void device_links_supplier_sync_state_pause(void);
969 void device_links_supplier_sync_state_resume(void);
970 
971 /* Create alias, so I can be autoloaded. */
972 #define MODULE_ALIAS_CHARDEV(major,minor) \
973 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
974 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
975 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
976 
977 #ifdef CONFIG_SYSFS_DEPRECATED
978 extern long sysfs_deprecated;
979 #else
980 #define sysfs_deprecated 0
981 #endif
982 
983 #endif /* _DEVICE_H_ */
984