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
36 struct device;
37 struct device_private;
38 struct device_driver;
39 struct driver_private;
40 struct module;
41 struct class;
42 struct subsys_private;
43 struct device_node;
44 struct fwnode_handle;
45 struct iommu_group;
46 struct dev_pin_info;
47 struct dev_iommu;
48 struct 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 */
63 struct 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
71 int subsys_interface_register(struct subsys_interface *sif);
72 void subsys_interface_unregister(struct subsys_interface *sif);
73
74 int subsys_system_register(const struct bus_type *subsys,
75 const struct attribute_group **groups);
76 int 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 */
88 struct 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 */
105 struct 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 */
118 struct dev_ext_attribute {
119 struct device_attribute attr;
120 void *var;
121 };
122
123 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
124 char *buf);
125 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
126 const char *buf, size_t count);
127 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
128 char *buf);
129 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
130 const char *buf, size_t count);
131 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
132 char *buf);
133 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
134 const char *buf, size_t count);
135 ssize_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_RO - Define a readable device attribute.
194 * @_name: Attribute name.
195 *
196 * Like DEVICE_ATTR(), but @_mode is 0444 and @_show is <_name>_show.
197 */
198 #define DEVICE_ATTR_RO(_name) \
199 struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
200
201 /**
202 * DEVICE_ATTR_ADMIN_RO - Define an admin-only readable device attribute.
203 * @_name: Attribute name.
204 *
205 * Like DEVICE_ATTR_RO(), but @_mode is 0400.
206 */
207 #define DEVICE_ATTR_ADMIN_RO(_name) \
208 struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
209
210 /**
211 * DEVICE_ATTR_WO - Define an admin-only writable device attribute.
212 * @_name: Attribute name.
213 *
214 * Like DEVICE_ATTR(), but @_mode is 0200 and @_store is <_name>_store.
215 */
216 #define DEVICE_ATTR_WO(_name) \
217 struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
218
219 /**
220 * DEVICE_ULONG_ATTR - Define a device attribute backed by an unsigned long.
221 * @_name: Attribute name.
222 * @_mode: File mode.
223 * @_var: Identifier of unsigned long.
224 *
225 * Like DEVICE_ATTR(), but @_show and @_store are automatically provided
226 * such that reads and writes to the attribute from userspace affect @_var.
227 */
228 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
229 struct dev_ext_attribute dev_attr_##_name = \
230 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
231
232 /**
233 * DEVICE_INT_ATTR - Define a device attribute backed by an int.
234 * @_name: Attribute name.
235 * @_mode: File mode.
236 * @_var: Identifier of int.
237 *
238 * Like DEVICE_ULONG_ATTR(), but @_var is an int.
239 */
240 #define DEVICE_INT_ATTR(_name, _mode, _var) \
241 struct dev_ext_attribute dev_attr_##_name = \
242 { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
243
244 /**
245 * DEVICE_BOOL_ATTR - Define a device attribute backed by a bool.
246 * @_name: Attribute name.
247 * @_mode: File mode.
248 * @_var: Identifier of bool.
249 *
250 * Like DEVICE_ULONG_ATTR(), but @_var is a bool.
251 */
252 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
253 struct dev_ext_attribute dev_attr_##_name = \
254 { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
255
256 /**
257 * DEVICE_STRING_ATTR_RO - Define a device attribute backed by a r/o string.
258 * @_name: Attribute name.
259 * @_mode: File mode.
260 * @_var: Identifier of string.
261 *
262 * Like DEVICE_ULONG_ATTR(), but @_var is a string. Because the length of the
263 * string allocation is unknown, the attribute must be read-only.
264 */
265 #define DEVICE_STRING_ATTR_RO(_name, _mode, _var) \
266 struct dev_ext_attribute dev_attr_##_name = \
267 { __ATTR(_name, (_mode) & ~0222, device_show_string, NULL), (_var) }
268
269 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
270 struct device_attribute dev_attr_##_name = \
271 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
272
273 int device_create_file(struct device *device,
274 const struct device_attribute *entry);
275 void device_remove_file(struct device *dev,
276 const struct device_attribute *attr);
277 bool device_remove_file_self(struct device *dev,
278 const struct device_attribute *attr);
279 int __must_check device_create_bin_file(struct device *dev,
280 const struct bin_attribute *attr);
281 void device_remove_bin_file(struct device *dev,
282 const struct bin_attribute *attr);
283
284 /**
285 * devm_alloc_percpu - Resource-managed alloc_percpu
286 * @dev: Device to allocate per-cpu memory for
287 * @type: Type to allocate per-cpu memory for
288 *
289 * Managed alloc_percpu. Per-cpu memory allocated with this function is
290 * automatically freed on driver detach.
291 *
292 * RETURNS:
293 * Pointer to allocated memory on success, NULL on failure.
294 */
295 #define devm_alloc_percpu(dev, type) \
296 ((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
297 __alignof__(type)))
298
299 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
300 size_t align);
301 void devm_free_percpu(struct device *dev, void __percpu *pdata);
302
303 struct device_dma_parameters {
304 /*
305 * a low level driver may set these to teach IOMMU code about
306 * sg limitations.
307 */
308 unsigned int max_segment_size;
309 unsigned int min_align_mask;
310 unsigned long segment_boundary_mask;
311 };
312
313 /**
314 * enum device_link_state - Device link states.
315 * @DL_STATE_NONE: The presence of the drivers is not being tracked.
316 * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
317 * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
318 * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
319 * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
320 * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
321 */
322 enum device_link_state {
323 DL_STATE_NONE = -1,
324 DL_STATE_DORMANT = 0,
325 DL_STATE_AVAILABLE,
326 DL_STATE_CONSUMER_PROBE,
327 DL_STATE_ACTIVE,
328 DL_STATE_SUPPLIER_UNBIND,
329 };
330
331 /*
332 * Device link flags.
333 *
334 * STATELESS: The core will not remove this link automatically.
335 * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
336 * PM_RUNTIME: If set, the runtime PM framework will use this link.
337 * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
338 * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
339 * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
340 * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
341 * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
342 * INFERRED: Inferred from data (eg: firmware) and not from driver actions.
343 */
344 #define DL_FLAG_STATELESS BIT(0)
345 #define DL_FLAG_AUTOREMOVE_CONSUMER BIT(1)
346 #define DL_FLAG_PM_RUNTIME BIT(2)
347 #define DL_FLAG_RPM_ACTIVE BIT(3)
348 #define DL_FLAG_AUTOREMOVE_SUPPLIER BIT(4)
349 #define DL_FLAG_AUTOPROBE_CONSUMER BIT(5)
350 #define DL_FLAG_MANAGED BIT(6)
351 #define DL_FLAG_SYNC_STATE_ONLY BIT(7)
352 #define DL_FLAG_INFERRED BIT(8)
353 #define DL_FLAG_CYCLE BIT(9)
354
355 /**
356 * enum dl_dev_state - Device driver presence tracking information.
357 * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
358 * @DL_DEV_PROBING: A driver is probing.
359 * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
360 * @DL_DEV_UNBINDING: The driver is unbinding from the device.
361 */
362 enum dl_dev_state {
363 DL_DEV_NO_DRIVER = 0,
364 DL_DEV_PROBING,
365 DL_DEV_DRIVER_BOUND,
366 DL_DEV_UNBINDING,
367 };
368
369 /**
370 * enum device_removable - Whether the device is removable. The criteria for a
371 * device to be classified as removable is determined by its subsystem or bus.
372 * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this
373 * device (default).
374 * @DEVICE_REMOVABLE_UNKNOWN: Device location is Unknown.
375 * @DEVICE_FIXED: Device is not removable by the user.
376 * @DEVICE_REMOVABLE: Device is removable by the user.
377 */
378 enum device_removable {
379 DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */
380 DEVICE_REMOVABLE_UNKNOWN,
381 DEVICE_FIXED,
382 DEVICE_REMOVABLE,
383 };
384
385 /**
386 * struct dev_links_info - Device data related to device links.
387 * @suppliers: List of links to supplier devices.
388 * @consumers: List of links to consumer devices.
389 * @defer_sync: Hook to global list of devices that have deferred sync_state.
390 * @status: Driver status information.
391 */
392 struct dev_links_info {
393 struct list_head suppliers;
394 struct list_head consumers;
395 struct list_head defer_sync;
396 enum dl_dev_state status;
397 };
398
399 /**
400 * struct dev_msi_info - Device data related to MSI
401 * @domain: The MSI interrupt domain associated to the device
402 * @data: Pointer to MSI device data
403 */
404 struct dev_msi_info {
405 #ifdef CONFIG_GENERIC_MSI_IRQ
406 struct irq_domain *domain;
407 struct msi_device_data *data;
408 #endif
409 };
410
411 /**
412 * enum device_physical_location_panel - Describes which panel surface of the
413 * system's housing the device connection point resides on.
414 * @DEVICE_PANEL_TOP: Device connection point is on the top panel.
415 * @DEVICE_PANEL_BOTTOM: Device connection point is on the bottom panel.
416 * @DEVICE_PANEL_LEFT: Device connection point is on the left panel.
417 * @DEVICE_PANEL_RIGHT: Device connection point is on the right panel.
418 * @DEVICE_PANEL_FRONT: Device connection point is on the front panel.
419 * @DEVICE_PANEL_BACK: Device connection point is on the back panel.
420 * @DEVICE_PANEL_UNKNOWN: The panel with device connection point is unknown.
421 */
422 enum device_physical_location_panel {
423 DEVICE_PANEL_TOP,
424 DEVICE_PANEL_BOTTOM,
425 DEVICE_PANEL_LEFT,
426 DEVICE_PANEL_RIGHT,
427 DEVICE_PANEL_FRONT,
428 DEVICE_PANEL_BACK,
429 DEVICE_PANEL_UNKNOWN,
430 };
431
432 /**
433 * enum device_physical_location_vertical_position - Describes vertical
434 * position of the device connection point on the panel surface.
435 * @DEVICE_VERT_POS_UPPER: Device connection point is at upper part of panel.
436 * @DEVICE_VERT_POS_CENTER: Device connection point is at center part of panel.
437 * @DEVICE_VERT_POS_LOWER: Device connection point is at lower part of panel.
438 */
439 enum device_physical_location_vertical_position {
440 DEVICE_VERT_POS_UPPER,
441 DEVICE_VERT_POS_CENTER,
442 DEVICE_VERT_POS_LOWER,
443 };
444
445 /**
446 * enum device_physical_location_horizontal_position - Describes horizontal
447 * position of the device connection point on the panel surface.
448 * @DEVICE_HORI_POS_LEFT: Device connection point is at left part of panel.
449 * @DEVICE_HORI_POS_CENTER: Device connection point is at center part of panel.
450 * @DEVICE_HORI_POS_RIGHT: Device connection point is at right part of panel.
451 */
452 enum device_physical_location_horizontal_position {
453 DEVICE_HORI_POS_LEFT,
454 DEVICE_HORI_POS_CENTER,
455 DEVICE_HORI_POS_RIGHT,
456 };
457
458 /**
459 * struct device_physical_location - Device data related to physical location
460 * of the device connection point.
461 * @panel: Panel surface of the system's housing that the device connection
462 * point resides on.
463 * @vertical_position: Vertical position of the device connection point within
464 * the panel.
465 * @horizontal_position: Horizontal position of the device connection point
466 * within the panel.
467 * @dock: Set if the device connection point resides in a docking station or
468 * port replicator.
469 * @lid: Set if this device connection point resides on the lid of laptop
470 * system.
471 */
472 struct device_physical_location {
473 enum device_physical_location_panel panel;
474 enum device_physical_location_vertical_position vertical_position;
475 enum device_physical_location_horizontal_position horizontal_position;
476 bool dock;
477 bool lid;
478 };
479
480 /**
481 * struct device - The basic device structure
482 * @parent: The device's "parent" device, the device to which it is attached.
483 * In most cases, a parent device is some sort of bus or host
484 * controller. If parent is NULL, the device, is a top-level device,
485 * which is not usually what you want.
486 * @p: Holds the private data of the driver core portions of the device.
487 * See the comment of the struct device_private for detail.
488 * @kobj: A top-level, abstract class from which other classes are derived.
489 * @init_name: Initial name of the device.
490 * @type: The type of device.
491 * This identifies the device type and carries type-specific
492 * information.
493 * @mutex: Mutex to synchronize calls to its driver.
494 * @bus: Type of bus device is on.
495 * @driver: Which driver has allocated this
496 * @platform_data: Platform data specific to the device.
497 * Example: For devices on custom boards, as typical of embedded
498 * and SOC based hardware, Linux often uses platform_data to point
499 * to board-specific structures describing devices and how they
500 * are wired. That can include what ports are available, chip
501 * variants, which GPIO pins act in what additional roles, and so
502 * on. This shrinks the "Board Support Packages" (BSPs) and
503 * minimizes board-specific #ifdefs in drivers.
504 * @driver_data: Private pointer for driver specific info.
505 * @links: Links to suppliers and consumers of this device.
506 * @power: For device power management.
507 * See Documentation/driver-api/pm/devices.rst for details.
508 * @pm_domain: Provide callbacks that are executed during system suspend,
509 * hibernation, system resume and during runtime PM transitions
510 * along with subsystem-level and driver-level callbacks.
511 * @em_pd: device's energy model performance domain
512 * @pins: For device pin management.
513 * See Documentation/driver-api/pin-control.rst for details.
514 * @msi: MSI related data
515 * @numa_node: NUMA node this device is close to.
516 * @dma_ops: DMA mapping operations for this device.
517 * @dma_mask: Dma mask (if dma'ble device).
518 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
519 * hardware supports 64-bit addresses for consistent allocations
520 * such descriptors.
521 * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
522 * DMA limit than the device itself supports.
523 * @dma_range_map: map for DMA memory ranges relative to that of RAM
524 * @dma_parms: A low level driver may set these to teach IOMMU code about
525 * segment limitations.
526 * @dma_pools: Dma pools (if dma'ble device).
527 * @dma_mem: Internal for coherent mem override.
528 * @cma_area: Contiguous memory area for dma allocations
529 * @dma_io_tlb_mem: Software IO TLB allocator. Not for driver use.
530 * @dma_io_tlb_pools: List of transient swiotlb memory pools.
531 * @dma_io_tlb_lock: Protects changes to the list of active pools.
532 * @dma_uses_io_tlb: %true if device has used the software IO TLB.
533 * @archdata: For arch-specific additions.
534 * @of_node: Associated device tree node.
535 * @fwnode: Associated device node supplied by platform firmware.
536 * @devt: For creating the sysfs "dev".
537 * @id: device instance
538 * @devres_lock: Spinlock to protect the resource of the device.
539 * @devres_head: The resources list of the device.
540 * @class: The class of the device.
541 * @groups: Optional attribute groups.
542 * @release: Callback to free the device after all references have
543 * gone away. This should be set by the allocator of the
544 * device (i.e. the bus driver that discovered the device).
545 * @iommu_group: IOMMU group the device belongs to.
546 * @iommu: Per device generic IOMMU runtime data
547 * @physical_location: Describes physical location of the device connection
548 * point in the system housing.
549 * @removable: Whether the device can be removed from the system. This
550 * should be set by the subsystem / bus driver that discovered
551 * the device.
552 *
553 * @offline_disabled: If set, the device is permanently online.
554 * @offline: Set after successful invocation of bus type's .offline().
555 * @of_node_reused: Set if the device-tree node is shared with an ancestor
556 * device.
557 * @state_synced: The hardware state of this device has been synced to match
558 * the software state of this device by calling the driver/bus
559 * sync_state() callback.
560 * @can_match: The device has matched with a driver at least once or it is in
561 * a bus (like AMBA) which can't check for matching drivers until
562 * other devices probe successfully.
563 * @dma_coherent: this particular device is dma coherent, even if the
564 * architecture supports non-coherent devices.
565 * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
566 * streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
567 * and optionall (if the coherent mask is large enough) also
568 * for dma allocations. This flag is managed by the dma ops
569 * instance from ->dma_supported.
570 * @dma_skip_sync: DMA sync operations can be skipped for coherent buffers.
571 * @dma_iommu: Device is using default IOMMU implementation for DMA and
572 * doesn't rely on dma_ops structure.
573 *
574 * At the lowest level, every device in a Linux system is represented by an
575 * instance of struct device. The device structure contains the information
576 * that the device model core needs to model the system. Most subsystems,
577 * however, track additional information about the devices they host. As a
578 * result, it is rare for devices to be represented by bare device structures;
579 * instead, that structure, like kobject structures, is usually embedded within
580 * a higher-level representation of the device.
581 */
582 struct device {
583 struct kobject kobj;
584 struct device *parent;
585
586 struct device_private *p;
587
588 const char *init_name; /* initial name of the device */
589 const struct device_type *type;
590
591 const struct bus_type *bus; /* type of bus device is on */
592 struct device_driver *driver; /* which driver has allocated this
593 device */
594 void *platform_data; /* Platform specific data, device
595 core doesn't touch it */
596 void *driver_data; /* Driver data, set and get with
597 dev_set_drvdata/dev_get_drvdata */
598 struct mutex mutex; /* mutex to synchronize calls to
599 * its driver.
600 */
601
602 struct dev_links_info links;
603 struct dev_pm_info power;
604 struct dev_pm_domain *pm_domain;
605
606 #ifdef CONFIG_ENERGY_MODEL
607 struct em_perf_domain *em_pd;
608 #endif
609
610 #ifdef CONFIG_PINCTRL
611 struct dev_pin_info *pins;
612 #endif
613 struct dev_msi_info msi;
614 #ifdef CONFIG_ARCH_HAS_DMA_OPS
615 const struct dma_map_ops *dma_ops;
616 #endif
617 u64 *dma_mask; /* dma mask (if dma'able device) */
618 u64 coherent_dma_mask;/* Like dma_mask, but for
619 alloc_coherent mappings as
620 not all hardware supports
621 64 bit addresses for consistent
622 allocations such descriptors. */
623 u64 bus_dma_limit; /* upstream dma constraint */
624 const struct bus_dma_region *dma_range_map;
625
626 struct device_dma_parameters *dma_parms;
627
628 struct list_head dma_pools; /* dma pools (if dma'ble) */
629
630 #ifdef CONFIG_DMA_DECLARE_COHERENT
631 struct dma_coherent_mem *dma_mem; /* internal for coherent mem
632 override */
633 #endif
634 #ifdef CONFIG_DMA_CMA
635 struct cma *cma_area; /* contiguous memory area for dma
636 allocations */
637 #endif
638 #ifdef CONFIG_SWIOTLB
639 struct io_tlb_mem *dma_io_tlb_mem;
640 #endif
641 #ifdef CONFIG_SWIOTLB_DYNAMIC
642 struct list_head dma_io_tlb_pools;
643 spinlock_t dma_io_tlb_lock;
644 bool dma_uses_io_tlb;
645 #endif
646 /* arch specific additions */
647 struct dev_archdata archdata;
648
649 struct device_node *of_node; /* associated device tree node */
650 struct fwnode_handle *fwnode; /* firmware device node */
651
652 #ifdef CONFIG_NUMA
653 int numa_node; /* NUMA node this device is close to */
654 #endif
655 dev_t devt; /* dev_t, creates the sysfs "dev" */
656 u32 id; /* device instance */
657
658 spinlock_t devres_lock;
659 struct list_head devres_head;
660
661 const struct class *class;
662 const struct attribute_group **groups; /* optional groups */
663
664 void (*release)(struct device *dev);
665 struct iommu_group *iommu_group;
666 struct dev_iommu *iommu;
667
668 struct device_physical_location *physical_location;
669
670 enum device_removable removable;
671
672 bool offline_disabled:1;
673 bool offline:1;
674 bool of_node_reused:1;
675 bool state_synced:1;
676 bool can_match:1;
677 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
678 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
679 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
680 bool dma_coherent:1;
681 #endif
682 #ifdef CONFIG_DMA_OPS_BYPASS
683 bool dma_ops_bypass : 1;
684 #endif
685 #ifdef CONFIG_DMA_NEED_SYNC
686 bool dma_skip_sync:1;
687 #endif
688 #ifdef CONFIG_IOMMU_DMA
689 bool dma_iommu:1;
690 #endif
691 };
692
693 /**
694 * struct device_link - Device link representation.
695 * @supplier: The device on the supplier end of the link.
696 * @s_node: Hook to the supplier device's list of links to consumers.
697 * @consumer: The device on the consumer end of the link.
698 * @c_node: Hook to the consumer device's list of links to suppliers.
699 * @link_dev: device used to expose link details in sysfs
700 * @status: The state of the link (with respect to the presence of drivers).
701 * @flags: Link flags.
702 * @rpm_active: Whether or not the consumer device is runtime-PM-active.
703 * @kref: Count repeated addition of the same link.
704 * @rm_work: Work structure used for removing the link.
705 * @supplier_preactivated: Supplier has been made active before consumer probe.
706 */
707 struct device_link {
708 struct device *supplier;
709 struct list_head s_node;
710 struct device *consumer;
711 struct list_head c_node;
712 struct device link_dev;
713 enum device_link_state status;
714 u32 flags;
715 refcount_t rpm_active;
716 struct kref kref;
717 struct work_struct rm_work;
718 bool supplier_preactivated; /* Owned by consumer probe. */
719 };
720
721 #define kobj_to_dev(__kobj) container_of_const(__kobj, struct device, kobj)
722
723 /**
724 * device_iommu_mapped - Returns true when the device DMA is translated
725 * by an IOMMU
726 * @dev: Device to perform the check on
727 */
device_iommu_mapped(struct device * dev)728 static inline bool device_iommu_mapped(struct device *dev)
729 {
730 return (dev->iommu_group != NULL);
731 }
732
733 /* Get the wakeup routines, which depend on struct device */
734 #include <linux/pm_wakeup.h>
735
736 /**
737 * dev_name - Return a device's name.
738 * @dev: Device with name to get.
739 * Return: The kobject name of the device, or its initial name if unavailable.
740 */
dev_name(const struct device * dev)741 static inline const char *dev_name(const struct device *dev)
742 {
743 /* Use the init name until the kobject becomes available */
744 if (dev->init_name)
745 return dev->init_name;
746
747 return kobject_name(&dev->kobj);
748 }
749
750 /**
751 * dev_bus_name - Return a device's bus/class name, if at all possible
752 * @dev: struct device to get the bus/class name of
753 *
754 * Will return the name of the bus/class the device is attached to. If it is
755 * not attached to a bus/class, an empty string will be returned.
756 */
dev_bus_name(const struct device * dev)757 static inline const char *dev_bus_name(const struct device *dev)
758 {
759 return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "");
760 }
761
762 __printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
763
764 #ifdef CONFIG_NUMA
dev_to_node(struct device * dev)765 static inline int dev_to_node(struct device *dev)
766 {
767 return dev->numa_node;
768 }
set_dev_node(struct device * dev,int node)769 static inline void set_dev_node(struct device *dev, int node)
770 {
771 dev->numa_node = node;
772 }
773 #else
dev_to_node(struct device * dev)774 static inline int dev_to_node(struct device *dev)
775 {
776 return NUMA_NO_NODE;
777 }
set_dev_node(struct device * dev,int node)778 static inline void set_dev_node(struct device *dev, int node)
779 {
780 }
781 #endif
782
dev_get_msi_domain(const struct device * dev)783 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
784 {
785 #ifdef CONFIG_GENERIC_MSI_IRQ
786 return dev->msi.domain;
787 #else
788 return NULL;
789 #endif
790 }
791
dev_set_msi_domain(struct device * dev,struct irq_domain * d)792 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
793 {
794 #ifdef CONFIG_GENERIC_MSI_IRQ
795 dev->msi.domain = d;
796 #endif
797 }
798
dev_get_drvdata(const struct device * dev)799 static inline void *dev_get_drvdata(const struct device *dev)
800 {
801 return dev->driver_data;
802 }
803
dev_set_drvdata(struct device * dev,void * data)804 static inline void dev_set_drvdata(struct device *dev, void *data)
805 {
806 dev->driver_data = data;
807 }
808
dev_to_psd(struct device * dev)809 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
810 {
811 return dev ? dev->power.subsys_data : NULL;
812 }
813
dev_get_uevent_suppress(const struct device * dev)814 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
815 {
816 return dev->kobj.uevent_suppress;
817 }
818
dev_set_uevent_suppress(struct device * dev,int val)819 static inline void dev_set_uevent_suppress(struct device *dev, int val)
820 {
821 dev->kobj.uevent_suppress = val;
822 }
823
device_is_registered(struct device * dev)824 static inline int device_is_registered(struct device *dev)
825 {
826 return dev->kobj.state_in_sysfs;
827 }
828
device_enable_async_suspend(struct device * dev)829 static inline void device_enable_async_suspend(struct device *dev)
830 {
831 if (!dev->power.is_prepared)
832 dev->power.async_suspend = true;
833 }
834
device_disable_async_suspend(struct device * dev)835 static inline void device_disable_async_suspend(struct device *dev)
836 {
837 if (!dev->power.is_prepared)
838 dev->power.async_suspend = false;
839 }
840
device_async_suspend_enabled(struct device * dev)841 static inline bool device_async_suspend_enabled(struct device *dev)
842 {
843 return !!dev->power.async_suspend;
844 }
845
device_pm_not_required(struct device * dev)846 static inline bool device_pm_not_required(struct device *dev)
847 {
848 return dev->power.no_pm;
849 }
850
device_set_pm_not_required(struct device * dev)851 static inline void device_set_pm_not_required(struct device *dev)
852 {
853 dev->power.no_pm = true;
854 }
855
dev_pm_syscore_device(struct device * dev,bool val)856 static inline void dev_pm_syscore_device(struct device *dev, bool val)
857 {
858 #ifdef CONFIG_PM_SLEEP
859 dev->power.syscore = val;
860 #endif
861 }
862
dev_pm_set_driver_flags(struct device * dev,u32 flags)863 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
864 {
865 dev->power.driver_flags = flags;
866 }
867
dev_pm_test_driver_flags(struct device * dev,u32 flags)868 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
869 {
870 return !!(dev->power.driver_flags & flags);
871 }
872
dev_pm_smart_suspend(struct device * dev)873 static inline bool dev_pm_smart_suspend(struct device *dev)
874 {
875 #ifdef CONFIG_PM_SLEEP
876 return dev->power.smart_suspend;
877 #else
878 return false;
879 #endif
880 }
881
device_lock(struct device * dev)882 static inline void device_lock(struct device *dev)
883 {
884 mutex_lock(&dev->mutex);
885 }
886
device_lock_interruptible(struct device * dev)887 static inline int device_lock_interruptible(struct device *dev)
888 {
889 return mutex_lock_interruptible(&dev->mutex);
890 }
891
device_trylock(struct device * dev)892 static inline int device_trylock(struct device *dev)
893 {
894 return mutex_trylock(&dev->mutex);
895 }
896
device_unlock(struct device * dev)897 static inline void device_unlock(struct device *dev)
898 {
899 mutex_unlock(&dev->mutex);
900 }
901
DEFINE_GUARD(device,struct device *,device_lock (_T),device_unlock (_T))902 DEFINE_GUARD(device, struct device *, device_lock(_T), device_unlock(_T))
903
904 static inline void device_lock_assert(struct device *dev)
905 {
906 lockdep_assert_held(&dev->mutex);
907 }
908
dev_has_sync_state(struct device * dev)909 static inline bool dev_has_sync_state(struct device *dev)
910 {
911 if (!dev)
912 return false;
913 if (dev->driver && dev->driver->sync_state)
914 return true;
915 if (dev->bus && dev->bus->sync_state)
916 return true;
917 return false;
918 }
919
dev_set_removable(struct device * dev,enum device_removable removable)920 static inline void dev_set_removable(struct device *dev,
921 enum device_removable removable)
922 {
923 dev->removable = removable;
924 }
925
dev_is_removable(struct device * dev)926 static inline bool dev_is_removable(struct device *dev)
927 {
928 return dev->removable == DEVICE_REMOVABLE;
929 }
930
dev_removable_is_valid(struct device * dev)931 static inline bool dev_removable_is_valid(struct device *dev)
932 {
933 return dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED;
934 }
935
936 /*
937 * High level routines for use by the bus drivers
938 */
939 int __must_check device_register(struct device *dev);
940 void device_unregister(struct device *dev);
941 void device_initialize(struct device *dev);
942 int __must_check device_add(struct device *dev);
943 void device_del(struct device *dev);
944
945 DEFINE_FREE(device_del, struct device *, if (_T) device_del(_T))
946
947 int device_for_each_child(struct device *parent, void *data,
948 device_iter_t fn);
949 int device_for_each_child_reverse(struct device *parent, void *data,
950 device_iter_t fn);
951 int device_for_each_child_reverse_from(struct device *parent,
952 struct device *from, void *data,
953 device_iter_t fn);
954 struct device *device_find_child(struct device *parent, const void *data,
955 device_match_t match);
956 /**
957 * device_find_child_by_name - device iterator for locating a child device.
958 * @parent: parent struct device
959 * @name: name of the child device
960 *
961 * This is similar to the device_find_child() function above, but it
962 * returns a reference to a device that has the name @name.
963 *
964 * NOTE: you will need to drop the reference with put_device() after use.
965 */
device_find_child_by_name(struct device * parent,const char * name)966 static inline struct device *device_find_child_by_name(struct device *parent,
967 const char *name)
968 {
969 return device_find_child(parent, name, device_match_name);
970 }
971
972 /**
973 * device_find_any_child - device iterator for locating a child device, if any.
974 * @parent: parent struct device
975 *
976 * This is similar to the device_find_child() function above, but it
977 * returns a reference to a child device, if any.
978 *
979 * NOTE: you will need to drop the reference with put_device() after use.
980 */
device_find_any_child(struct device * parent)981 static inline struct device *device_find_any_child(struct device *parent)
982 {
983 return device_find_child(parent, NULL, device_match_any);
984 }
985
986 int device_rename(struct device *dev, const char *new_name);
987 int device_move(struct device *dev, struct device *new_parent,
988 enum dpm_order dpm_order);
989 int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
990
device_supports_offline(struct device * dev)991 static inline bool device_supports_offline(struct device *dev)
992 {
993 return dev->bus && dev->bus->offline && dev->bus->online;
994 }
995
996 #define __device_lock_set_class(dev, name, key) \
997 do { \
998 struct device *__d2 __maybe_unused = dev; \
999 lock_set_class(&__d2->mutex.dep_map, name, key, 0, _THIS_IP_); \
1000 } while (0)
1001
1002 /**
1003 * device_lock_set_class - Specify a temporary lock class while a device
1004 * is attached to a driver
1005 * @dev: device to modify
1006 * @key: lock class key data
1007 *
1008 * This must be called with the device_lock() already held, for example
1009 * from driver ->probe(). Take care to only override the default
1010 * lockdep_no_validate class.
1011 */
1012 #ifdef CONFIG_LOCKDEP
1013 #define device_lock_set_class(dev, key) \
1014 do { \
1015 struct device *__d = dev; \
1016 dev_WARN_ONCE(__d, !lockdep_match_class(&__d->mutex, \
1017 &__lockdep_no_validate__), \
1018 "overriding existing custom lock class\n"); \
1019 __device_lock_set_class(__d, #key, key); \
1020 } while (0)
1021 #else
1022 #define device_lock_set_class(dev, key) __device_lock_set_class(dev, #key, key)
1023 #endif
1024
1025 /**
1026 * device_lock_reset_class - Return a device to the default lockdep novalidate state
1027 * @dev: device to modify
1028 *
1029 * This must be called with the device_lock() already held, for example
1030 * from driver ->remove().
1031 */
1032 #define device_lock_reset_class(dev) \
1033 do { \
1034 struct device *__d __maybe_unused = dev; \
1035 lock_set_novalidate_class(&__d->mutex.dep_map, "&dev->mutex", \
1036 _THIS_IP_); \
1037 } while (0)
1038
1039 void lock_device_hotplug(void);
1040 void unlock_device_hotplug(void);
1041 int lock_device_hotplug_sysfs(void);
1042 int device_offline(struct device *dev);
1043 int device_online(struct device *dev);
1044
1045 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1046 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1047 void device_set_node(struct device *dev, struct fwnode_handle *fwnode);
1048 int device_add_of_node(struct device *dev, struct device_node *of_node);
1049 void device_remove_of_node(struct device *dev);
1050 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
1051
dev_of_node(struct device * dev)1052 static inline struct device_node *dev_of_node(struct device *dev)
1053 {
1054 if (!IS_ENABLED(CONFIG_OF) || !dev)
1055 return NULL;
1056 return dev->of_node;
1057 }
1058
dev_num_vf(struct device * dev)1059 static inline int dev_num_vf(struct device *dev)
1060 {
1061 if (dev->bus && dev->bus->num_vf)
1062 return dev->bus->num_vf(dev);
1063 return 0;
1064 }
1065
1066 /*
1067 * Root device objects for grouping under /sys/devices
1068 */
1069 struct device *__root_device_register(const char *name, struct module *owner);
1070
1071 /* This is a macro to avoid include problems with THIS_MODULE */
1072 #define root_device_register(name) \
1073 __root_device_register(name, THIS_MODULE)
1074
1075 void root_device_unregister(struct device *root);
1076
dev_get_platdata(const struct device * dev)1077 static inline void *dev_get_platdata(const struct device *dev)
1078 {
1079 return dev->platform_data;
1080 }
1081
1082 /*
1083 * Manual binding of a device to driver. See drivers/base/bus.c
1084 * for information on use.
1085 */
1086 int __must_check device_driver_attach(const struct device_driver *drv,
1087 struct device *dev);
1088 int __must_check device_bind_driver(struct device *dev);
1089 void device_release_driver(struct device *dev);
1090 int __must_check device_attach(struct device *dev);
1091 int __must_check driver_attach(const struct device_driver *drv);
1092 void device_initial_probe(struct device *dev);
1093 int __must_check device_reprobe(struct device *dev);
1094
1095 bool device_is_bound(struct device *dev);
1096
1097 /*
1098 * Easy functions for dynamically creating devices on the fly
1099 */
1100 __printf(5, 6) struct device *
1101 device_create(const struct class *cls, struct device *parent, dev_t devt,
1102 void *drvdata, const char *fmt, ...);
1103 __printf(6, 7) struct device *
1104 device_create_with_groups(const struct class *cls, struct device *parent, dev_t devt,
1105 void *drvdata, const struct attribute_group **groups,
1106 const char *fmt, ...);
1107 void device_destroy(const struct class *cls, dev_t devt);
1108
1109 int __must_check device_add_groups(struct device *dev,
1110 const struct attribute_group **groups);
1111 void device_remove_groups(struct device *dev,
1112 const struct attribute_group **groups);
1113
device_add_group(struct device * dev,const struct attribute_group * grp)1114 static inline int __must_check device_add_group(struct device *dev,
1115 const struct attribute_group *grp)
1116 {
1117 const struct attribute_group *groups[] = { grp, NULL };
1118
1119 return device_add_groups(dev, groups);
1120 }
1121
device_remove_group(struct device * dev,const struct attribute_group * grp)1122 static inline void device_remove_group(struct device *dev,
1123 const struct attribute_group *grp)
1124 {
1125 const struct attribute_group *groups[] = { grp, NULL };
1126
1127 device_remove_groups(dev, groups);
1128 }
1129
1130 int __must_check devm_device_add_group(struct device *dev,
1131 const struct attribute_group *grp);
1132
1133 /*
1134 * get_device - atomically increment the reference count for the device.
1135 *
1136 */
1137 struct device *get_device(struct device *dev);
1138 void put_device(struct device *dev);
1139
1140 DEFINE_FREE(put_device, struct device *, if (_T) put_device(_T))
1141
1142 bool kill_device(struct device *dev);
1143
1144 #ifdef CONFIG_DEVTMPFS
1145 int devtmpfs_mount(void);
1146 #else
devtmpfs_mount(void)1147 static inline int devtmpfs_mount(void) { return 0; }
1148 #endif
1149
1150 /* drivers/base/power/shutdown.c */
1151 void device_shutdown(void);
1152
1153 /* debugging and troubleshooting/diagnostic helpers. */
1154 const char *dev_driver_string(const struct device *dev);
1155
1156 /* Device links interface. */
1157 struct device_link *device_link_add(struct device *consumer,
1158 struct device *supplier, u32 flags);
1159 void device_link_del(struct device_link *link);
1160 void device_link_remove(void *consumer, struct device *supplier);
1161 void device_links_supplier_sync_state_pause(void);
1162 void device_links_supplier_sync_state_resume(void);
1163 void device_link_wait_removal(void);
1164
1165 /* Create alias, so I can be autoloaded. */
1166 #define MODULE_ALIAS_CHARDEV(major,minor) \
1167 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1168 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1169 MODULE_ALIAS("char-major-" __stringify(major) "-*")
1170
1171 #endif /* _DEVICE_H_ */
1172