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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * device.h - generic, centralized driver model
4 *
5 * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
6 * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
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/energy_model.h>
17#include <linux/ioport.h>
18#include <linux/kobject.h>
19#include <linux/klist.h>
20#include <linux/list.h>
21#include <linux/lockdep.h>
22#include <linux/compiler.h>
23#include <linux/types.h>
24#include <linux/mutex.h>
25#include <linux/pm.h>
26#include <linux/atomic.h>
27#include <linux/uidgid.h>
28#include <linux/gfp.h>
29#include <linux/device/bus.h>
30#include <linux/device/class.h>
31#include <linux/device/devres.h>
32#include <linux/device/driver.h>
33#include <linux/cleanup.h>
34#include <asm/device.h>
35
36struct device;
37struct device_private;
38struct device_driver;
39struct driver_private;
40struct module;
41struct class;
42struct subsys_private;
43struct device_node;
44struct fwnode_handle;
45struct iommu_group;
46struct dev_pin_info;
47struct dev_iommu;
48struct msi_device_data;
49
50/**
51 * struct subsys_interface - interfaces to device functions
52 * @name: name of the device function
53 * @subsys: subsystem of the devices to attach to
54 * @node: the list of functions registered at the subsystem
55 * @add_dev: device hookup to device function handler
56 * @remove_dev: device hookup to device function handler
57 *
58 * Simple interfaces attached to a subsystem. Multiple interfaces can
59 * attach to a subsystem and its devices. Unlike drivers, they do not
60 * exclusively claim or control devices. Interfaces usually represent
61 * a specific functionality of a subsystem/class of devices.
62 */
63struct subsys_interface {
64 const char *name;
65 const struct bus_type *subsys;
66 struct list_head node;
67 int (*add_dev)(struct device *dev, struct subsys_interface *sif);
68 void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
69};
70
71int subsys_interface_register(struct subsys_interface *sif);
72void subsys_interface_unregister(struct subsys_interface *sif);
73
74int subsys_system_register(const struct bus_type *subsys,
75 const struct attribute_group **groups);
76int subsys_virtual_register(const struct bus_type *subsys,
77 const struct attribute_group **groups);
78
79/*
80 * The type of device, "struct device" is embedded in. A class
81 * or bus can contain devices of different types
82 * like "partitions" and "disks", "mouse" and "event".
83 * This identifies the device type and carries type-specific
84 * information, equivalent to the kobj_type of a kobject.
85 * If "name" is specified, the uevent will contain it in
86 * the DEVTYPE variable.
87 */
88struct device_type {
89 const char *name;
90 const struct attribute_group **groups;
91 int (*uevent)(const struct device *dev, struct kobj_uevent_env *env);
92 char *(*devnode)(const struct device *dev, umode_t *mode,
93 kuid_t *uid, kgid_t *gid);
94 void (*release)(struct device *dev);
95
96 const struct dev_pm_ops *pm;
97};
98
99/**
100 * struct device_attribute - Interface for exporting device attributes.
101 * @attr: sysfs attribute definition.
102 * @show: Show handler.
103 * @store: Store handler.
104 */
105struct device_attribute {
106 struct attribute attr;
107 ssize_t (*show)(struct device *dev, struct device_attribute *attr,
108 char *buf);
109 ssize_t (*store)(struct device *dev, struct device_attribute *attr,
110 const char *buf, size_t count);
111};
112
113/**
114 * struct dev_ext_attribute - Exported device attribute with extra context.
115 * @attr: Exported device attribute.
116 * @var: Pointer to context.
117 */
118struct dev_ext_attribute {
119 struct device_attribute attr;
120 void *var;
121};
122
123ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
124 char *buf);
125ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
126 const char *buf, size_t count);
127ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
128 char *buf);
129ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
130 const char *buf, size_t count);
131ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
132 char *buf);
133ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
134 const char *buf, size_t count);
135ssize_t device_show_string(struct device *dev, struct device_attribute *attr,
136 char *buf);
137
138/**
139 * DEVICE_ATTR - Define a device attribute.
140 * @_name: Attribute name.
141 * @_mode: File mode.
142 * @_show: Show handler. Optional, but mandatory if attribute is readable.
143 * @_store: Store handler. Optional, but mandatory if attribute is writable.
144 *
145 * Convenience macro for defining a struct device_attribute.
146 *
147 * For example, ``DEVICE_ATTR(foo, 0644, foo_show, foo_store);`` expands to:
148 *
149 * .. code-block:: c
150 *
151 * struct device_attribute dev_attr_foo = {
152 * .attr = { .name = "foo", .mode = 0644 },
153 * .show = foo_show,
154 * .store = foo_store,
155 * };
156 */
157#define DEVICE_ATTR(_name, _mode, _show, _store) \
158 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
159
160/**
161 * DEVICE_ATTR_PREALLOC - Define a preallocated device attribute.
162 * @_name: Attribute name.
163 * @_mode: File mode.
164 * @_show: Show handler. Optional, but mandatory if attribute is readable.
165 * @_store: Store handler. Optional, but mandatory if attribute is writable.
166 *
167 * Like DEVICE_ATTR(), but ``SYSFS_PREALLOC`` is set on @_mode.
168 */
169#define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
170 struct device_attribute dev_attr_##_name = \
171 __ATTR_PREALLOC(_name, _mode, _show, _store)
172
173/**
174 * DEVICE_ATTR_RW - Define a read-write device attribute.
175 * @_name: Attribute name.
176 *
177 * Like DEVICE_ATTR(), but @_mode is 0644, @_show is <_name>_show,
178 * and @_store is <_name>_store.
179 */
180#define DEVICE_ATTR_RW(_name) \
181 struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
182
183/**
184 * DEVICE_ATTR_ADMIN_RW - Define an admin-only read-write device attribute.
185 * @_name: Attribute name.
186 *
187 * Like DEVICE_ATTR_RW(), but @_mode is 0600.
188 */
189#define DEVICE_ATTR_ADMIN_RW(_name) \
190 struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
191
192/**
193 * DEVICE_ATTR_RW_NAMED - Define a read-write device attribute with a sysfs name
194 * that differs from the function name.
195 * @_name: Attribute function preface
196 * @_attrname: Attribute name as it wil be exposed in the sysfs.
197 *
198 * Like DEVICE_ATTR_RW(), but allows for reusing names under separate paths in
199 * the same driver.
200 */
201#define DEVICE_ATTR_RW_NAMED(_name, _attrname) \
202 struct device_attribute dev_attr_##_name = { \
203 .attr = { .name = _attrname, .mode = 0644 }, \
204 .show = _name##_show, \
205 .store = _name##_store, \
206 }
207
208/**
209 * DEVICE_ATTR_RO - Define a readable device attribute.
210 * @_name: Attribute name.
211 *
212 * Like DEVICE_ATTR(), but @_mode is 0444 and @_show is <_name>_show.
213 */
214#define DEVICE_ATTR_RO(_name) \
215 struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
216
217/**
218 * DEVICE_ATTR_ADMIN_RO - Define an admin-only readable device attribute.
219 * @_name: Attribute name.
220 *
221 * Like DEVICE_ATTR_RO(), but @_mode is 0400.
222 */
223#define DEVICE_ATTR_ADMIN_RO(_name) \
224 struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
225
226/**
227 * DEVICE_ATTR_RO_NAMED - Define a read-only device attribute with a sysfs name
228 * that differs from the function name.
229 * @_name: Attribute function preface
230 * @_attrname: Attribute name as it wil be exposed in the sysfs.
231 *
232 * Like DEVICE_ATTR_RO(), but allows for reusing names under separate paths in
233 * the same driver.
234 */
235#define DEVICE_ATTR_RO_NAMED(_name, _attrname) \
236 struct device_attribute dev_attr_##_name = { \
237 .attr = { .name = _attrname, .mode = 0444 }, \
238 .show = _name##_show, \
239 }
240
241/**
242 * DEVICE_ATTR_WO - Define an admin-only writable device attribute.
243 * @_name: Attribute name.
244 *
245 * Like DEVICE_ATTR(), but @_mode is 0200 and @_store is <_name>_store.
246 */
247#define DEVICE_ATTR_WO(_name) \
248 struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
249
250/**
251 * DEVICE_ATTR_WO_NAMED - Define a read-only device attribute with a sysfs name
252 * that differs from the function name.
253 * @_name: Attribute function preface
254 * @_attrname: Attribute name as it wil be exposed in the sysfs.
255 *
256 * Like DEVICE_ATTR_WO(), but allows for reusing names under separate paths in
257 * the same driver.
258 */
259#define DEVICE_ATTR_WO_NAMED(_name, _attrname) \
260 struct device_attribute dev_attr_##_name = { \
261 .attr = { .name = _attrname, .mode = 0200 }, \
262 .store = _name##_store, \
263 }
264
265/**
266 * DEVICE_ULONG_ATTR - Define a device attribute backed by an unsigned long.
267 * @_name: Attribute name.
268 * @_mode: File mode.
269 * @_var: Identifier of unsigned long.
270 *
271 * Like DEVICE_ATTR(), but @_show and @_store are automatically provided
272 * such that reads and writes to the attribute from userspace affect @_var.
273 */
274#define DEVICE_ULONG_ATTR(_name, _mode, _var) \
275 struct dev_ext_attribute dev_attr_##_name = \
276 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
277
278/**
279 * DEVICE_INT_ATTR - Define a device attribute backed by an int.
280 * @_name: Attribute name.
281 * @_mode: File mode.
282 * @_var: Identifier of int.
283 *
284 * Like DEVICE_ULONG_ATTR(), but @_var is an int.
285 */
286#define DEVICE_INT_ATTR(_name, _mode, _var) \
287 struct dev_ext_attribute dev_attr_##_name = \
288 { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
289
290/**
291 * DEVICE_BOOL_ATTR - Define a device attribute backed by a bool.
292 * @_name: Attribute name.
293 * @_mode: File mode.
294 * @_var: Identifier of bool.
295 *
296 * Like DEVICE_ULONG_ATTR(), but @_var is a bool.
297 */
298#define DEVICE_BOOL_ATTR(_name, _mode, _var) \
299 struct dev_ext_attribute dev_attr_##_name = \
300 { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
301
302/**
303 * DEVICE_STRING_ATTR_RO - Define a device attribute backed by a r/o string.
304 * @_name: Attribute name.
305 * @_mode: File mode.
306 * @_var: Identifier of string.
307 *
308 * Like DEVICE_ULONG_ATTR(), but @_var is a string. Because the length of the
309 * string allocation is unknown, the attribute must be read-only.
310 */
311#define DEVICE_STRING_ATTR_RO(_name, _mode, _var) \
312 struct dev_ext_attribute dev_attr_##_name = \
313 { __ATTR(_name, (_mode) & ~0222, device_show_string, NULL), (_var) }
314
315#define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
316 struct device_attribute dev_attr_##_name = \
317 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
318
319int device_create_file(struct device *device,
320 const struct device_attribute *entry);
321void device_remove_file(struct device *dev,
322 const struct device_attribute *attr);
323bool device_remove_file_self(struct device *dev,
324 const struct device_attribute *attr);
325int __must_check device_create_bin_file(struct device *dev,
326 const struct bin_attribute *attr);
327void device_remove_bin_file(struct device *dev,
328 const struct bin_attribute *attr);
329
330struct device_dma_parameters {
331 /*
332 * a low level driver may set these to teach IOMMU code about
333 * sg limitations.
334 */
335 unsigned int max_segment_size;
336 unsigned int min_align_mask;
337 unsigned long segment_boundary_mask;
338};
339
340/**
341 * enum device_link_state - Device link states.
342 * @DL_STATE_NONE: The presence of the drivers is not being tracked.
343 * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
344 * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
345 * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
346 * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
347 * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
348 */
349enum device_link_state {
350 DL_STATE_NONE = -1,
351 DL_STATE_DORMANT = 0,
352 DL_STATE_AVAILABLE,
353 DL_STATE_CONSUMER_PROBE,
354 DL_STATE_ACTIVE,
355 DL_STATE_SUPPLIER_UNBIND,
356};
357
358/*
359 * Device link flags.
360 *
361 * STATELESS: The core will not remove this link automatically.
362 * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
363 * PM_RUNTIME: If set, the runtime PM framework will use this link.
364 * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
365 * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
366 * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
367 * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
368 * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
369 * INFERRED: Inferred from data (eg: firmware) and not from driver actions.
370 */
371#define DL_FLAG_STATELESS BIT(0)
372#define DL_FLAG_AUTOREMOVE_CONSUMER BIT(1)
373#define DL_FLAG_PM_RUNTIME BIT(2)
374#define DL_FLAG_RPM_ACTIVE BIT(3)
375#define DL_FLAG_AUTOREMOVE_SUPPLIER BIT(4)
376#define DL_FLAG_AUTOPROBE_CONSUMER BIT(5)
377#define DL_FLAG_MANAGED BIT(6)
378#define DL_FLAG_SYNC_STATE_ONLY BIT(7)
379#define DL_FLAG_INFERRED BIT(8)
380#define DL_FLAG_CYCLE BIT(9)
381
382/**
383 * enum dl_dev_state - Device driver presence tracking information.
384 * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
385 * @DL_DEV_PROBING: A driver is probing.
386 * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
387 * @DL_DEV_UNBINDING: The driver is unbinding from the device.
388 */
389enum dl_dev_state {
390 DL_DEV_NO_DRIVER = 0,
391 DL_DEV_PROBING,
392 DL_DEV_DRIVER_BOUND,
393 DL_DEV_UNBINDING,
394};
395
396/**
397 * enum device_removable - Whether the device is removable. The criteria for a
398 * device to be classified as removable is determined by its subsystem or bus.
399 * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this
400 * device (default).
401 * @DEVICE_REMOVABLE_UNKNOWN: Device location is Unknown.
402 * @DEVICE_FIXED: Device is not removable by the user.
403 * @DEVICE_REMOVABLE: Device is removable by the user.
404 */
405enum device_removable {
406 DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */
407 DEVICE_REMOVABLE_UNKNOWN,
408 DEVICE_FIXED,
409 DEVICE_REMOVABLE,
410};
411
412/**
413 * struct dev_links_info - Device data related to device links.
414 * @suppliers: List of links to supplier devices.
415 * @consumers: List of links to consumer devices.
416 * @defer_sync: Hook to global list of devices that have deferred sync_state.
417 * @status: Driver status information.
418 */
419struct dev_links_info {
420 struct list_head suppliers;
421 struct list_head consumers;
422 struct list_head defer_sync;
423 enum dl_dev_state status;
424};
425
426/**
427 * struct dev_msi_info - Device data related to MSI
428 * @domain: The MSI interrupt domain associated to the device
429 * @data: Pointer to MSI device data
430 */
431struct dev_msi_info {
432#ifdef CONFIG_GENERIC_MSI_IRQ
433 struct irq_domain *domain;
434 struct msi_device_data *data;
435#endif
436};
437
438/**
439 * enum device_physical_location_panel - Describes which panel surface of the
440 * system's housing the device connection point resides on.
441 * @DEVICE_PANEL_TOP: Device connection point is on the top panel.
442 * @DEVICE_PANEL_BOTTOM: Device connection point is on the bottom panel.
443 * @DEVICE_PANEL_LEFT: Device connection point is on the left panel.
444 * @DEVICE_PANEL_RIGHT: Device connection point is on the right panel.
445 * @DEVICE_PANEL_FRONT: Device connection point is on the front panel.
446 * @DEVICE_PANEL_BACK: Device connection point is on the back panel.
447 * @DEVICE_PANEL_UNKNOWN: The panel with device connection point is unknown.
448 */
449enum device_physical_location_panel {
450 DEVICE_PANEL_TOP,
451 DEVICE_PANEL_BOTTOM,
452 DEVICE_PANEL_LEFT,
453 DEVICE_PANEL_RIGHT,
454 DEVICE_PANEL_FRONT,
455 DEVICE_PANEL_BACK,
456 DEVICE_PANEL_UNKNOWN,
457};
458
459/**
460 * enum device_physical_location_vertical_position - Describes vertical
461 * position of the device connection point on the panel surface.
462 * @DEVICE_VERT_POS_UPPER: Device connection point is at upper part of panel.
463 * @DEVICE_VERT_POS_CENTER: Device connection point is at center part of panel.
464 * @DEVICE_VERT_POS_LOWER: Device connection point is at lower part of panel.
465 */
466enum device_physical_location_vertical_position {
467 DEVICE_VERT_POS_UPPER,
468 DEVICE_VERT_POS_CENTER,
469 DEVICE_VERT_POS_LOWER,
470};
471
472/**
473 * enum device_physical_location_horizontal_position - Describes horizontal
474 * position of the device connection point on the panel surface.
475 * @DEVICE_HORI_POS_LEFT: Device connection point is at left part of panel.
476 * @DEVICE_HORI_POS_CENTER: Device connection point is at center part of panel.
477 * @DEVICE_HORI_POS_RIGHT: Device connection point is at right part of panel.
478 */
479enum device_physical_location_horizontal_position {
480 DEVICE_HORI_POS_LEFT,
481 DEVICE_HORI_POS_CENTER,
482 DEVICE_HORI_POS_RIGHT,
483};
484
485/**
486 * struct device_physical_location - Device data related to physical location
487 * of the device connection point.
488 * @panel: Panel surface of the system's housing that the device connection
489 * point resides on.
490 * @vertical_position: Vertical position of the device connection point within
491 * the panel.
492 * @horizontal_position: Horizontal position of the device connection point
493 * within the panel.
494 * @dock: Set if the device connection point resides in a docking station or
495 * port replicator.
496 * @lid: Set if this device connection point resides on the lid of laptop
497 * system.
498 */
499struct device_physical_location {
500 enum device_physical_location_panel panel;
501 enum device_physical_location_vertical_position vertical_position;
502 enum device_physical_location_horizontal_position horizontal_position;
503 bool dock;
504 bool lid;
505};
506
507/**
508 * enum struct_device_flags - Flags in struct device
509 *
510 * Each flag should have a set of accessor functions created via
511 * __create_dev_flag_accessors() for each access.
512 *
513 * @DEV_FLAG_READY_TO_PROBE: If set then device_add() has finished enough
514 * initialization that probe could be called.
515 * @DEV_FLAG_COUNT: Number of defined struct_device_flags.
516 */
517enum struct_device_flags {
518 DEV_FLAG_READY_TO_PROBE = 0,
519
520 DEV_FLAG_COUNT
521};
522
523/**
524 * struct device - The basic device structure
525 * @parent: The device's "parent" device, the device to which it is attached.
526 * In most cases, a parent device is some sort of bus or host
527 * controller. If parent is NULL, the device, is a top-level device,
528 * which is not usually what you want.
529 * @p: Holds the private data of the driver core portions of the device.
530 * See the comment of the struct device_private for detail.
531 * @kobj: A top-level, abstract class from which other classes are derived.
532 * @init_name: Initial name of the device.
533 * @type: The type of device.
534 * This identifies the device type and carries type-specific
535 * information.
536 * @mutex: Mutex to synchronize calls to its driver.
537 * @bus: Type of bus device is on.
538 * @driver: Which driver has allocated this
539 * @platform_data: Platform data specific to the device.
540 * Example: For devices on custom boards, as typical of embedded
541 * and SOC based hardware, Linux often uses platform_data to point
542 * to board-specific structures describing devices and how they
543 * are wired. That can include what ports are available, chip
544 * variants, which GPIO pins act in what additional roles, and so
545 * on. This shrinks the "Board Support Packages" (BSPs) and
546 * minimizes board-specific #ifdefs in drivers.
547 * @driver_data: Private pointer for driver specific info.
548 * @driver_override: Driver name to force a match. Do not touch directly; use
549 * device_set_driver_override() instead.
550 * @links: Links to suppliers and consumers of this device.
551 * @power: For device power management.
552 * See Documentation/driver-api/pm/devices.rst for details.
553 * @pm_domain: Provide callbacks that are executed during system suspend,
554 * hibernation, system resume and during runtime PM transitions
555 * along with subsystem-level and driver-level callbacks.
556 * @em_pd: device's energy model performance domain
557 * @pins: For device pin management.
558 * See Documentation/driver-api/pin-control.rst for details.
559 * @msi: MSI related data
560 * @numa_node: NUMA node this device is close to.
561 * @dma_ops: DMA mapping operations for this device.
562 * @dma_mask: Dma mask (if dma'ble device).
563 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
564 * hardware supports 64-bit addresses for consistent allocations
565 * such descriptors.
566 * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
567 * DMA limit than the device itself supports.
568 * @dma_range_map: map for DMA memory ranges relative to that of RAM
569 * @dma_parms: A low level driver may set these to teach IOMMU code about
570 * segment limitations.
571 * @dma_pools: Dma pools (if dma'ble device).
572 * @dma_mem: Internal for coherent mem override.
573 * @cma_area: Contiguous memory area for dma allocations
574 * @dma_io_tlb_mem: Software IO TLB allocator. Not for driver use.
575 * @dma_io_tlb_pools: List of transient swiotlb memory pools.
576 * @dma_io_tlb_lock: Protects changes to the list of active pools.
577 * @dma_uses_io_tlb: %true if device has used the software IO TLB.
578 * @archdata: For arch-specific additions.
579 * @of_node: Associated device tree node.
580 * @fwnode: Associated device node supplied by platform firmware.
581 * @devt: For creating the sysfs "dev".
582 * @id: device instance
583 * @devres_lock: Spinlock to protect the resource of the device.
584 * @devres_head: The resources list of the device.
585 * @class: The class of the device.
586 * @groups: Optional attribute groups.
587 * @release: Callback to free the device after all references have
588 * gone away. This should be set by the allocator of the
589 * device (i.e. the bus driver that discovered the device).
590 * @iommu_group: IOMMU group the device belongs to.
591 * @iommu: Per device generic IOMMU runtime data
592 * @physical_location: Describes physical location of the device connection
593 * point in the system housing.
594 * @removable: Whether the device can be removed from the system. This
595 * should be set by the subsystem / bus driver that discovered
596 * the device.
597 *
598 * @offline_disabled: If set, the device is permanently online.
599 * @offline: Set after successful invocation of bus type's .offline().
600 * @of_node_reused: Set if the device-tree node is shared with an ancestor
601 * device.
602 * @state_synced: The hardware state of this device has been synced to match
603 * the software state of this device by calling the driver/bus
604 * sync_state() callback.
605 * @can_match: The device has matched with a driver at least once or it is in
606 * a bus (like AMBA) which can't check for matching drivers until
607 * other devices probe successfully.
608 * @dma_coherent: this particular device is dma coherent, even if the
609 * architecture supports non-coherent devices.
610 * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
611 * streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
612 * and optionall (if the coherent mask is large enough) also
613 * for dma allocations. This flag is managed by the dma ops
614 * instance from ->dma_supported.
615 * @dma_skip_sync: DMA sync operations can be skipped for coherent buffers.
616 * @dma_iommu: Device is using default IOMMU implementation for DMA and
617 * doesn't rely on dma_ops structure.
618 * @flags: DEV_FLAG_XXX flags. Use atomic bitfield operations to modify.
619 *
620 * At the lowest level, every device in a Linux system is represented by an
621 * instance of struct device. The device structure contains the information
622 * that the device model core needs to model the system. Most subsystems,
623 * however, track additional information about the devices they host. As a
624 * result, it is rare for devices to be represented by bare device structures;
625 * instead, that structure, like kobject structures, is usually embedded within
626 * a higher-level representation of the device.
627 */
628struct device {
629 struct kobject kobj;
630 struct device *parent;
631
632 struct device_private *p;
633
634 const char *init_name; /* initial name of the device */
635 const struct device_type *type;
636
637 const struct bus_type *bus; /* type of bus device is on */
638 struct device_driver *driver; /* which driver has allocated this
639 device */
640 void *platform_data; /* Platform specific data, device
641 core doesn't touch it */
642 void *driver_data; /* Driver data, set and get with
643 dev_set_drvdata/dev_get_drvdata */
644 struct {
645 const char *name;
646 spinlock_t lock;
647 } driver_override;
648 struct mutex mutex; /* mutex to synchronize calls to
649 * its driver.
650 */
651
652 struct dev_links_info links;
653 struct dev_pm_info power;
654 struct dev_pm_domain *pm_domain;
655
656#ifdef CONFIG_ENERGY_MODEL
657 struct em_perf_domain *em_pd;
658#endif
659
660#ifdef CONFIG_PINCTRL
661 struct dev_pin_info *pins;
662#endif
663 struct dev_msi_info msi;
664#ifdef CONFIG_ARCH_HAS_DMA_OPS
665 const struct dma_map_ops *dma_ops;
666#endif
667 u64 *dma_mask; /* dma mask (if dma'able device) */
668 u64 coherent_dma_mask;/* Like dma_mask, but for
669 alloc_coherent mappings as
670 not all hardware supports
671 64 bit addresses for consistent
672 allocations such descriptors. */
673 u64 bus_dma_limit; /* upstream dma constraint */
674 const struct bus_dma_region *dma_range_map;
675
676 struct device_dma_parameters *dma_parms;
677
678 struct list_head dma_pools; /* dma pools (if dma'ble) */
679
680#ifdef CONFIG_DMA_DECLARE_COHERENT
681 struct dma_coherent_mem *dma_mem; /* internal for coherent mem
682 override */
683#endif
684#ifdef CONFIG_DMA_CMA
685 struct cma *cma_area; /* contiguous memory area for dma
686 allocations */
687#endif
688#ifdef CONFIG_SWIOTLB
689 struct io_tlb_mem *dma_io_tlb_mem;
690#endif
691#ifdef CONFIG_SWIOTLB_DYNAMIC
692 struct list_head dma_io_tlb_pools;
693 spinlock_t dma_io_tlb_lock;
694 bool dma_uses_io_tlb;
695#endif
696 /* arch specific additions */
697 struct dev_archdata archdata;
698
699 struct device_node *of_node; /* associated device tree node */
700 struct fwnode_handle *fwnode; /* firmware device node */
701
702#ifdef CONFIG_NUMA
703 int numa_node; /* NUMA node this device is close to */
704#endif
705 dev_t devt; /* dev_t, creates the sysfs "dev" */
706 u32 id; /* device instance */
707
708 spinlock_t devres_lock;
709 struct list_head devres_head;
710
711 const struct class *class;
712 const struct attribute_group **groups; /* optional groups */
713
714 void (*release)(struct device *dev);
715 struct iommu_group *iommu_group;
716 struct dev_iommu *iommu;
717
718 struct device_physical_location *physical_location;
719
720 enum device_removable removable;
721
722 bool offline_disabled:1;
723 bool offline:1;
724 bool of_node_reused:1;
725 bool state_synced:1;
726 bool can_match:1;
727#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
728 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
729 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
730 bool dma_coherent:1;
731#endif
732#ifdef CONFIG_DMA_OPS_BYPASS
733 bool dma_ops_bypass : 1;
734#endif
735#ifdef CONFIG_DMA_NEED_SYNC
736 bool dma_skip_sync:1;
737#endif
738#ifdef CONFIG_IOMMU_DMA
739 bool dma_iommu:1;
740#endif
741
742 DECLARE_BITMAP(flags, DEV_FLAG_COUNT);
743};
744
745#define __create_dev_flag_accessors(accessor_name, flag_name) \
746static inline bool dev_##accessor_name(const struct device *dev) \
747{ \
748 return test_bit(flag_name, dev->flags); \
749} \
750static inline void dev_set_##accessor_name(struct device *dev) \
751{ \
752 set_bit(flag_name, dev->flags); \
753} \
754static inline void dev_clear_##accessor_name(struct device *dev) \
755{ \
756 clear_bit(flag_name, dev->flags); \
757} \
758static inline void dev_assign_##accessor_name(struct device *dev, bool value) \
759{ \
760 assign_bit(flag_name, dev->flags, value); \
761} \
762static inline bool dev_test_and_set_##accessor_name(struct device *dev) \
763{ \
764 return test_and_set_bit(flag_name, dev->flags); \
765}
766
767__create_dev_flag_accessors(ready_to_probe, DEV_FLAG_READY_TO_PROBE);
768
769#undef __create_dev_flag_accessors
770
771/**
772 * struct device_link - Device link representation.
773 * @supplier: The device on the supplier end of the link.
774 * @s_node: Hook to the supplier device's list of links to consumers.
775 * @consumer: The device on the consumer end of the link.
776 * @c_node: Hook to the consumer device's list of links to suppliers.
777 * @link_dev: device used to expose link details in sysfs
778 * @status: The state of the link (with respect to the presence of drivers).
779 * @flags: Link flags.
780 * @rpm_active: Whether or not the consumer device is runtime-PM-active.
781 * @kref: Count repeated addition of the same link.
782 * @rm_work: Work structure used for removing the link.
783 * @supplier_preactivated: Supplier has been made active before consumer probe.
784 */
785struct device_link {
786 struct device *supplier;
787 struct list_head s_node;
788 struct device *consumer;
789 struct list_head c_node;
790 struct device link_dev;
791 enum device_link_state status;
792 u32 flags;
793 refcount_t rpm_active;
794 struct kref kref;
795 struct work_struct rm_work;
796 bool supplier_preactivated; /* Owned by consumer probe. */
797};
798
799#define kobj_to_dev(__kobj) container_of_const(__kobj, struct device, kobj)
800
801int __device_set_driver_override(struct device *dev, const char *s, size_t len);
802
803/**
804 * device_set_driver_override() - Helper to set or clear driver override.
805 * @dev: Device to change
806 * @s: NUL-terminated string, new driver name to force a match, pass empty
807 * string to clear it ("" or "\n", where the latter is only for sysfs
808 * interface).
809 *
810 * Helper to set or clear driver override of a device.
811 *
812 * Returns: 0 on success or a negative error code on failure.
813 */
814static inline int device_set_driver_override(struct device *dev, const char *s)
815{
816 return __device_set_driver_override(dev, s, s ? strlen(s) : 0);
817}
818
819/**
820 * device_has_driver_override() - Check if a driver override has been set.
821 * @dev: device to check
822 *
823 * Returns true if a driver override has been set for this device.
824 */
825static inline bool device_has_driver_override(struct device *dev)
826{
827 guard(spinlock)(&dev->driver_override.lock);
828 return !!dev->driver_override.name;
829}
830
831/**
832 * device_match_driver_override() - Match a driver against the device's driver_override.
833 * @dev: device to check
834 * @drv: driver to match against
835 *
836 * Returns > 0 if a driver override is set and matches the given driver, 0 if a
837 * driver override is set but does not match, or < 0 if a driver override is not
838 * set at all.
839 */
840static inline int device_match_driver_override(struct device *dev,
841 const struct device_driver *drv)
842{
843 guard(spinlock)(&dev->driver_override.lock);
844 if (dev->driver_override.name)
845 return !strcmp(dev->driver_override.name, drv->name);
846 return -1;
847}
848
849/**
850 * device_iommu_mapped - Returns true when the device DMA is translated
851 * by an IOMMU
852 * @dev: Device to perform the check on
853 */
854static inline bool device_iommu_mapped(struct device *dev)
855{
856 return (dev->iommu_group != NULL);
857}
858
859/* Get the wakeup routines, which depend on struct device */
860#include <linux/pm_wakeup.h>
861
862/**
863 * dev_name - Return a device's name.
864 * @dev: Device with name to get.
865 * Return: The kobject name of the device, or its initial name if unavailable.
866 */
867static inline const char *dev_name(const struct device *dev)
868{
869 /* Use the init name until the kobject becomes available */
870 if (dev->init_name)
871 return dev->init_name;
872
873 return kobject_name(&dev->kobj);
874}
875
876/**
877 * dev_bus_name - Return a device's bus/class name, if at all possible
878 * @dev: struct device to get the bus/class name of
879 *
880 * Will return the name of the bus/class the device is attached to. If it is
881 * not attached to a bus/class, an empty string will be returned.
882 */
883static inline const char *dev_bus_name(const struct device *dev)
884{
885 return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "");
886}
887
888__printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
889
890#ifdef CONFIG_NUMA
891static inline int dev_to_node(struct device *dev)
892{
893 return dev->numa_node;
894}
895static inline void set_dev_node(struct device *dev, int node)
896{
897 dev->numa_node = node;
898}
899#else
900static inline int dev_to_node(struct device *dev)
901{
902 return NUMA_NO_NODE;
903}
904static inline void set_dev_node(struct device *dev, int node)
905{
906}
907#endif
908
909static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
910{
911#ifdef CONFIG_GENERIC_MSI_IRQ
912 return dev->msi.domain;
913#else
914 return NULL;
915#endif
916}
917
918static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
919{
920#ifdef CONFIG_GENERIC_MSI_IRQ
921 dev->msi.domain = d;
922#endif
923}
924
925static inline void *dev_get_drvdata(const struct device *dev)
926{
927 return dev->driver_data;
928}
929
930static inline void dev_set_drvdata(struct device *dev, void *data)
931{
932 dev->driver_data = data;
933}
934
935static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
936{
937 return dev ? dev->power.subsys_data : NULL;
938}
939
940static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
941{
942 return dev->kobj.uevent_suppress;
943}
944
945static inline void dev_set_uevent_suppress(struct device *dev, int val)
946{
947 dev->kobj.uevent_suppress = val;
948}
949
950static inline int device_is_registered(struct device *dev)
951{
952 return dev->kobj.state_in_sysfs;
953}
954
955static inline void device_enable_async_suspend(struct device *dev)
956{
957 if (!dev->power.is_prepared)
958 dev->power.async_suspend = true;
959}
960
961static inline void device_disable_async_suspend(struct device *dev)
962{
963 if (!dev->power.is_prepared)
964 dev->power.async_suspend = false;
965}
966
967static inline bool device_async_suspend_enabled(struct device *dev)
968{
969 return !!dev->power.async_suspend;
970}
971
972static inline bool device_pm_not_required(struct device *dev)
973{
974 return dev->power.no_pm;
975}
976
977static inline void device_set_pm_not_required(struct device *dev)
978{
979 dev->power.no_pm = true;
980#ifdef CONFIG_PM
981 dev->power.no_callbacks = true;
982#endif
983}
984
985static inline void dev_pm_syscore_device(struct device *dev, bool val)
986{
987#ifdef CONFIG_PM_SLEEP
988 dev->power.syscore = val;
989#endif
990}
991
992static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
993{
994 dev->power.driver_flags = flags;
995}
996
997static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
998{
999 return !!(dev->power.driver_flags & flags);
1000}
1001
1002static inline bool dev_pm_smart_suspend(struct device *dev)
1003{
1004#ifdef CONFIG_PM_SLEEP
1005 return dev->power.smart_suspend;
1006#else
1007 return false;
1008#endif
1009}
1010
1011/*
1012 * dev_pm_set_strict_midlayer - Update the device's power.strict_midlayer flag
1013 * @dev: Target device.
1014 * @val: New flag value.
1015 *
1016 * When set, power.strict_midlayer means that the middle layer power management
1017 * code (typically, a bus type or a PM domain) does not expect its runtime PM
1018 * suspend callback to be invoked at all during system-wide PM transitions and
1019 * it does not expect its runtime PM resume callback to be invoked at any point
1020 * when runtime PM is disabled for the device during system-wide PM transitions.
1021 */
1022static inline void dev_pm_set_strict_midlayer(struct device *dev, bool val)
1023{
1024#ifdef CONFIG_PM_SLEEP
1025 dev->power.strict_midlayer = val;
1026#endif
1027}
1028
1029static inline bool dev_pm_strict_midlayer_is_set(struct device *dev)
1030{
1031#ifdef CONFIG_PM_SLEEP
1032 return dev->power.strict_midlayer;
1033#else
1034 return false;
1035#endif
1036}
1037
1038static inline void device_lock(struct device *dev)
1039{
1040 mutex_lock(&dev->mutex);
1041}
1042
1043static inline int device_lock_interruptible(struct device *dev)
1044{
1045 return mutex_lock_interruptible(&dev->mutex);
1046}
1047
1048static inline int device_trylock(struct device *dev)
1049{
1050 return mutex_trylock(&dev->mutex);
1051}
1052
1053static inline void device_unlock(struct device *dev)
1054{
1055 mutex_unlock(&dev->mutex);
1056}
1057
1058DEFINE_GUARD(device, struct device *, device_lock(_T), device_unlock(_T))
1059DEFINE_GUARD_COND(device, _intr, device_lock_interruptible(_T), _RET == 0)
1060
1061static inline void device_lock_assert(struct device *dev)
1062{
1063 lockdep_assert_held(&dev->mutex);
1064}
1065
1066static inline bool dev_has_sync_state(struct device *dev)
1067{
1068 if (!dev)
1069 return false;
1070 if (dev->driver && dev->driver->sync_state)
1071 return true;
1072 if (dev->bus && dev->bus->sync_state)
1073 return true;
1074 return false;
1075}
1076
1077static inline int dev_set_drv_sync_state(struct device *dev,
1078 void (*fn)(struct device *dev))
1079{
1080 if (!dev || !dev->driver)
1081 return 0;
1082 if (dev->driver->sync_state && dev->driver->sync_state != fn)
1083 return -EBUSY;
1084 if (!dev->driver->sync_state)
1085 dev->driver->sync_state = fn;
1086 return 0;
1087}
1088
1089static inline void dev_set_removable(struct device *dev,
1090 enum device_removable removable)
1091{
1092 dev->removable = removable;
1093}
1094
1095static inline bool dev_is_removable(struct device *dev)
1096{
1097 return dev->removable == DEVICE_REMOVABLE;
1098}
1099
1100static inline bool dev_removable_is_valid(struct device *dev)
1101{
1102 return dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED;
1103}
1104
1105/*
1106 * High level routines for use by the bus drivers
1107 */
1108int __must_check device_register(struct device *dev);
1109void device_unregister(struct device *dev);
1110void device_initialize(struct device *dev);
1111int __must_check device_add(struct device *dev);
1112void device_del(struct device *dev);
1113
1114DEFINE_FREE(device_del, struct device *, if (_T) device_del(_T))
1115
1116int device_for_each_child(struct device *parent, void *data,
1117 device_iter_t fn);
1118int device_for_each_child_reverse(struct device *parent, void *data,
1119 device_iter_t fn);
1120int device_for_each_child_reverse_from(struct device *parent,
1121 struct device *from, void *data,
1122 device_iter_t fn);
1123struct device *device_find_child(struct device *parent, const void *data,
1124 device_match_t match);
1125/**
1126 * device_find_child_by_name - device iterator for locating a child device.
1127 * @parent: parent struct device
1128 * @name: name of the child device
1129 *
1130 * This is similar to the device_find_child() function above, but it
1131 * returns a reference to a device that has the name @name.
1132 *
1133 * NOTE: you will need to drop the reference with put_device() after use.
1134 */
1135static inline struct device *device_find_child_by_name(struct device *parent,
1136 const char *name)
1137{
1138 return device_find_child(parent, name, device_match_name);
1139}
1140
1141/**
1142 * device_find_any_child - device iterator for locating a child device, if any.
1143 * @parent: parent struct device
1144 *
1145 * This is similar to the device_find_child() function above, but it
1146 * returns a reference to a child device, if any.
1147 *
1148 * NOTE: you will need to drop the reference with put_device() after use.
1149 */
1150static inline struct device *device_find_any_child(struct device *parent)
1151{
1152 return device_find_child(parent, NULL, device_match_any);
1153}
1154
1155int device_rename(struct device *dev, const char *new_name);
1156int device_move(struct device *dev, struct device *new_parent,
1157 enum dpm_order dpm_order);
1158int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
1159
1160static inline bool device_supports_offline(struct device *dev)
1161{
1162 return dev->bus && dev->bus->offline && dev->bus->online;
1163}
1164
1165#define __device_lock_set_class(dev, name, key) \
1166do { \
1167 struct device *__d2 __maybe_unused = dev; \
1168 lock_set_class(&__d2->mutex.dep_map, name, key, 0, _THIS_IP_); \
1169} while (0)
1170
1171/**
1172 * device_lock_set_class - Specify a temporary lock class while a device
1173 * is attached to a driver
1174 * @dev: device to modify
1175 * @key: lock class key data
1176 *
1177 * This must be called with the device_lock() already held, for example
1178 * from driver ->probe(). Take care to only override the default
1179 * lockdep_no_validate class.
1180 */
1181#ifdef CONFIG_LOCKDEP
1182#define device_lock_set_class(dev, key) \
1183do { \
1184 struct device *__d = dev; \
1185 dev_WARN_ONCE(__d, !lockdep_match_class(&__d->mutex, \
1186 &__lockdep_no_validate__), \
1187 "overriding existing custom lock class\n"); \
1188 __device_lock_set_class(__d, #key, key); \
1189} while (0)
1190#else
1191#define device_lock_set_class(dev, key) __device_lock_set_class(dev, #key, key)
1192#endif
1193
1194/**
1195 * device_lock_reset_class - Return a device to the default lockdep novalidate state
1196 * @dev: device to modify
1197 *
1198 * This must be called with the device_lock() already held, for example
1199 * from driver ->remove().
1200 */
1201#define device_lock_reset_class(dev) \
1202do { \
1203 struct device *__d __maybe_unused = dev; \
1204 lock_set_novalidate_class(&__d->mutex.dep_map, "&dev->mutex", \
1205 _THIS_IP_); \
1206} while (0)
1207
1208void lock_device_hotplug(void);
1209void unlock_device_hotplug(void);
1210int lock_device_hotplug_sysfs(void);
1211int device_offline(struct device *dev);
1212int device_online(struct device *dev);
1213
1214void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1215void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1216void device_set_node(struct device *dev, struct fwnode_handle *fwnode);
1217int device_add_of_node(struct device *dev, struct device_node *of_node);
1218void device_remove_of_node(struct device *dev);
1219void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
1220struct device *get_dev_from_fwnode(struct fwnode_handle *fwnode);
1221
1222static inline struct device_node *dev_of_node(struct device *dev)
1223{
1224 if (!IS_ENABLED(CONFIG_OF) || !dev)
1225 return NULL;
1226 return dev->of_node;
1227}
1228
1229static inline int dev_num_vf(struct device *dev)
1230{
1231 if (dev->bus && dev->bus->num_vf)
1232 return dev->bus->num_vf(dev);
1233 return 0;
1234}
1235
1236/*
1237 * Root device objects for grouping under /sys/devices
1238 */
1239struct device *__root_device_register(const char *name, struct module *owner);
1240
1241/* This is a macro to avoid include problems with THIS_MODULE */
1242#define root_device_register(name) \
1243 __root_device_register(name, THIS_MODULE)
1244
1245void root_device_unregister(struct device *root);
1246
1247static inline void *dev_get_platdata(const struct device *dev)
1248{
1249 return dev->platform_data;
1250}
1251
1252/*
1253 * Manual binding of a device to driver. See drivers/base/bus.c
1254 * for information on use.
1255 */
1256int __must_check device_driver_attach(const struct device_driver *drv,
1257 struct device *dev);
1258int __must_check device_bind_driver(struct device *dev);
1259void device_release_driver(struct device *dev);
1260int __must_check device_attach(struct device *dev);
1261int __must_check driver_attach(const struct device_driver *drv);
1262void device_initial_probe(struct device *dev);
1263int __must_check device_reprobe(struct device *dev);
1264
1265bool device_is_bound(struct device *dev);
1266
1267/*
1268 * Easy functions for dynamically creating devices on the fly
1269 */
1270__printf(5, 6) struct device *
1271device_create(const struct class *cls, struct device *parent, dev_t devt,
1272 void *drvdata, const char *fmt, ...);
1273__printf(6, 7) struct device *
1274device_create_with_groups(const struct class *cls, struct device *parent, dev_t devt,
1275 void *drvdata, const struct attribute_group **groups,
1276 const char *fmt, ...);
1277void device_destroy(const struct class *cls, dev_t devt);
1278
1279int __must_check device_add_groups(struct device *dev,
1280 const struct attribute_group *const *groups);
1281void device_remove_groups(struct device *dev,
1282 const struct attribute_group *const *groups);
1283
1284static inline int __must_check device_add_group(struct device *dev,
1285 const struct attribute_group *grp)
1286{
1287 const struct attribute_group *groups[] = { grp, NULL };
1288
1289 return device_add_groups(dev, groups);
1290}
1291
1292static inline void device_remove_group(struct device *dev,
1293 const struct attribute_group *grp)
1294{
1295 const struct attribute_group *groups[] = { grp, NULL };
1296
1297 device_remove_groups(dev, groups);
1298}
1299
1300int __must_check devm_device_add_group(struct device *dev,
1301 const struct attribute_group *grp);
1302
1303/*
1304 * get_device - atomically increment the reference count for the device.
1305 *
1306 */
1307struct device *get_device(struct device *dev);
1308void put_device(struct device *dev);
1309
1310DEFINE_FREE(put_device, struct device *, if (_T) put_device(_T))
1311
1312bool kill_device(struct device *dev);
1313
1314#ifdef CONFIG_DEVTMPFS
1315int devtmpfs_mount(void);
1316#else
1317static inline int devtmpfs_mount(void) { return 0; }
1318#endif
1319
1320/* drivers/base/power/shutdown.c */
1321void device_shutdown(void);
1322
1323/* debugging and troubleshooting/diagnostic helpers. */
1324const char *dev_driver_string(const struct device *dev);
1325
1326/* Device links interface. */
1327struct device_link *device_link_add(struct device *consumer,
1328 struct device *supplier, u32 flags);
1329void device_link_del(struct device_link *link);
1330void device_link_remove(void *consumer, struct device *supplier);
1331void device_links_supplier_sync_state_pause(void);
1332void device_links_supplier_sync_state_resume(void);
1333void device_link_wait_removal(void);
1334
1335static inline bool device_link_test(const struct device_link *link, u32 flags)
1336{
1337 return !!(link->flags & flags);
1338}
1339
1340/* Create alias, so I can be autoloaded. */
1341#define MODULE_ALIAS_CHARDEV(major,minor) \
1342 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1343#define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1344 MODULE_ALIAS("char-major-" __stringify(major) "-*")
1345
1346#endif /* _DEVICE_H_ */