1 // SPDX-License-Identifier: GPL-2.0
3 * device.h - generic, centralized driver model
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.
9 * See Documentation/driver-api/driver-model/ for more information.
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>
26 #include <linux/atomic.h>
27 #include <linux/uidgid.h>
28 #include <linux/gfp.h>
29 #include <linux/overflow.h>
30 #include <linux/device/bus.h>
31 #include <linux/device/class.h>
32 #include <linux/device/driver.h>
33 #include <linux/cleanup.h>
34 #include <asm/device.h>
37 struct device_private;
39 struct driver_private;
42 struct subsys_private;
49 struct msi_device_data;
52 * struct subsys_interface - interfaces to device functions
53 * @name: name of the device function
54 * @subsys: subsystem of the devices to attach to
55 * @node: the list of functions registered at the subsystem
56 * @add_dev: device hookup to device function handler
57 * @remove_dev: device hookup to device function handler
59 * Simple interfaces attached to a subsystem. Multiple interfaces can
60 * attach to a subsystem and its devices. Unlike drivers, they do not
61 * exclusively claim or control devices. Interfaces usually represent
62 * a specific functionality of a subsystem/class of devices.
64 struct subsys_interface {
66 struct bus_type *subsys;
67 struct list_head node;
68 int (*add_dev)(struct device *dev, struct subsys_interface *sif);
69 void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
72 int subsys_interface_register(struct subsys_interface *sif);
73 void subsys_interface_unregister(struct subsys_interface *sif);
75 int subsys_system_register(struct bus_type *subsys,
76 const struct attribute_group **groups);
77 int subsys_virtual_register(struct bus_type *subsys,
78 const struct attribute_group **groups);
81 * The type of device, "struct device" is embedded in. A class
82 * or bus can contain devices of different types
83 * like "partitions" and "disks", "mouse" and "event".
84 * This identifies the device type and carries type-specific
85 * information, equivalent to the kobj_type of a kobject.
86 * If "name" is specified, the uevent will contain it in
87 * the DEVTYPE variable.
91 const struct attribute_group **groups;
92 int (*uevent)(const struct device *dev, struct kobj_uevent_env *env);
93 char *(*devnode)(const struct device *dev, umode_t *mode,
94 kuid_t *uid, kgid_t *gid);
95 void (*release)(struct device *dev);
97 const struct dev_pm_ops *pm;
101 * struct device_attribute - Interface for exporting device attributes.
102 * @attr: sysfs attribute definition.
103 * @show: Show handler.
104 * @store: Store handler.
106 struct device_attribute {
107 struct attribute attr;
108 ssize_t (*show)(struct device *dev, struct device_attribute *attr,
110 ssize_t (*store)(struct device *dev, struct device_attribute *attr,
111 const char *buf, size_t count);
115 * struct dev_ext_attribute - Exported device attribute with extra context.
116 * @attr: Exported device attribute.
117 * @var: Pointer to context.
119 struct dev_ext_attribute {
120 struct device_attribute attr;
124 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
126 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
127 const char *buf, size_t count);
128 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
130 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
131 const char *buf, size_t count);
132 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
134 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
135 const char *buf, size_t count);
138 * DEVICE_ATTR - Define a device attribute.
139 * @_name: Attribute name.
141 * @_show: Show handler. Optional, but mandatory if attribute is readable.
142 * @_store: Store handler. Optional, but mandatory if attribute is writable.
144 * Convenience macro for defining a struct device_attribute.
146 * For example, ``DEVICE_ATTR(foo, 0644, foo_show, foo_store);`` expands to:
150 * struct device_attribute dev_attr_foo = {
151 * .attr = { .name = "foo", .mode = 0644 },
153 * .store = foo_store,
156 #define DEVICE_ATTR(_name, _mode, _show, _store) \
157 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
160 * DEVICE_ATTR_PREALLOC - Define a preallocated device attribute.
161 * @_name: Attribute name.
163 * @_show: Show handler. Optional, but mandatory if attribute is readable.
164 * @_store: Store handler. Optional, but mandatory if attribute is writable.
166 * Like DEVICE_ATTR(), but ``SYSFS_PREALLOC`` is set on @_mode.
168 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
169 struct device_attribute dev_attr_##_name = \
170 __ATTR_PREALLOC(_name, _mode, _show, _store)
173 * DEVICE_ATTR_RW - Define a read-write device attribute.
174 * @_name: Attribute name.
176 * Like DEVICE_ATTR(), but @_mode is 0644, @_show is <_name>_show,
177 * and @_store is <_name>_store.
179 #define DEVICE_ATTR_RW(_name) \
180 struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
183 * DEVICE_ATTR_ADMIN_RW - Define an admin-only read-write device attribute.
184 * @_name: Attribute name.
186 * Like DEVICE_ATTR_RW(), but @_mode is 0600.
188 #define DEVICE_ATTR_ADMIN_RW(_name) \
189 struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
192 * DEVICE_ATTR_RO - Define a readable device attribute.
193 * @_name: Attribute name.
195 * Like DEVICE_ATTR(), but @_mode is 0444 and @_show is <_name>_show.
197 #define DEVICE_ATTR_RO(_name) \
198 struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
201 * DEVICE_ATTR_ADMIN_RO - Define an admin-only readable device attribute.
202 * @_name: Attribute name.
204 * Like DEVICE_ATTR_RO(), but @_mode is 0400.
206 #define DEVICE_ATTR_ADMIN_RO(_name) \
207 struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
210 * DEVICE_ATTR_WO - Define an admin-only writable device attribute.
211 * @_name: Attribute name.
213 * Like DEVICE_ATTR(), but @_mode is 0200 and @_store is <_name>_store.
215 #define DEVICE_ATTR_WO(_name) \
216 struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
219 * DEVICE_ULONG_ATTR - Define a device attribute backed by an unsigned long.
220 * @_name: Attribute name.
222 * @_var: Identifier of unsigned long.
224 * Like DEVICE_ATTR(), but @_show and @_store are automatically provided
225 * such that reads and writes to the attribute from userspace affect @_var.
227 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
228 struct dev_ext_attribute dev_attr_##_name = \
229 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
232 * DEVICE_INT_ATTR - Define a device attribute backed by an int.
233 * @_name: Attribute name.
235 * @_var: Identifier of int.
237 * Like DEVICE_ULONG_ATTR(), but @_var is an int.
239 #define DEVICE_INT_ATTR(_name, _mode, _var) \
240 struct dev_ext_attribute dev_attr_##_name = \
241 { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
244 * DEVICE_BOOL_ATTR - Define a device attribute backed by a bool.
245 * @_name: Attribute name.
247 * @_var: Identifier of bool.
249 * Like DEVICE_ULONG_ATTR(), but @_var is a bool.
251 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
252 struct dev_ext_attribute dev_attr_##_name = \
253 { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
255 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
256 struct device_attribute dev_attr_##_name = \
257 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
259 int device_create_file(struct device *device,
260 const struct device_attribute *entry);
261 void device_remove_file(struct device *dev,
262 const struct device_attribute *attr);
263 bool device_remove_file_self(struct device *dev,
264 const struct device_attribute *attr);
265 int __must_check device_create_bin_file(struct device *dev,
266 const struct bin_attribute *attr);
267 void device_remove_bin_file(struct device *dev,
268 const struct bin_attribute *attr);
270 /* device resource management */
271 typedef void (*dr_release_t)(struct device *dev, void *res);
272 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
274 void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
275 int nid, const char *name) __malloc;
276 #define devres_alloc(release, size, gfp) \
277 __devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
278 #define devres_alloc_node(release, size, gfp, nid) \
279 __devres_alloc_node(release, size, gfp, nid, #release)
281 void devres_for_each_res(struct device *dev, dr_release_t release,
282 dr_match_t match, void *match_data,
283 void (*fn)(struct device *, void *, void *),
285 void devres_free(void *res);
286 void devres_add(struct device *dev, void *res);
287 void *devres_find(struct device *dev, dr_release_t release,
288 dr_match_t match, void *match_data);
289 void *devres_get(struct device *dev, void *new_res,
290 dr_match_t match, void *match_data);
291 void *devres_remove(struct device *dev, dr_release_t release,
292 dr_match_t match, void *match_data);
293 int devres_destroy(struct device *dev, dr_release_t release,
294 dr_match_t match, void *match_data);
295 int devres_release(struct device *dev, dr_release_t release,
296 dr_match_t match, void *match_data);
299 void * __must_check devres_open_group(struct device *dev, void *id, gfp_t gfp);
300 void devres_close_group(struct device *dev, void *id);
301 void devres_remove_group(struct device *dev, void *id);
302 int devres_release_group(struct device *dev, void *id);
304 /* managed devm_k.alloc/kfree for device drivers */
305 void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __alloc_size(2);
306 void *devm_krealloc(struct device *dev, void *ptr, size_t size,
307 gfp_t gfp) __must_check __realloc_size(3);
308 __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
309 const char *fmt, va_list ap) __malloc;
310 __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
311 const char *fmt, ...) __malloc;
312 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
314 return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
316 static inline void *devm_kmalloc_array(struct device *dev,
317 size_t n, size_t size, gfp_t flags)
321 if (unlikely(check_mul_overflow(n, size, &bytes)))
324 return devm_kmalloc(dev, bytes, flags);
326 static inline void *devm_kcalloc(struct device *dev,
327 size_t n, size_t size, gfp_t flags)
329 return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
331 static inline __realloc_size(3, 4) void * __must_check
332 devm_krealloc_array(struct device *dev, void *p, size_t new_n, size_t new_size, gfp_t flags)
336 if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
339 return devm_krealloc(dev, p, bytes, flags);
342 void devm_kfree(struct device *dev, const void *p);
343 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
344 const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
345 void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
348 unsigned long devm_get_free_pages(struct device *dev,
349 gfp_t gfp_mask, unsigned int order);
350 void devm_free_pages(struct device *dev, unsigned long addr);
352 void __iomem *devm_ioremap_resource(struct device *dev,
353 const struct resource *res);
354 void __iomem *devm_ioremap_resource_wc(struct device *dev,
355 const struct resource *res);
357 void __iomem *devm_of_iomap(struct device *dev,
358 struct device_node *node, int index,
359 resource_size_t *size);
361 /* allows to add/remove a custom action to devres stack */
362 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
363 void devm_release_action(struct device *dev, void (*action)(void *), void *data);
365 int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name);
366 #define devm_add_action(release, action, data) \
367 __devm_add_action(release, action, data, #action)
369 static inline int __devm_add_action_or_reset(struct device *dev, void (*action)(void *),
370 void *data, const char *name)
374 ret = __devm_add_action(dev, action, data, name);
380 #define devm_add_action_or_reset(release, action, data) \
381 __devm_add_action_or_reset(release, action, data, #action)
384 * devm_alloc_percpu - Resource-managed alloc_percpu
385 * @dev: Device to allocate per-cpu memory for
386 * @type: Type to allocate per-cpu memory for
388 * Managed alloc_percpu. Per-cpu memory allocated with this function is
389 * automatically freed on driver detach.
392 * Pointer to allocated memory on success, NULL on failure.
394 #define devm_alloc_percpu(dev, type) \
395 ((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
398 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
400 void devm_free_percpu(struct device *dev, void __percpu *pdata);
402 struct device_dma_parameters {
404 * a low level driver may set these to teach IOMMU code about
407 unsigned int max_segment_size;
408 unsigned int min_align_mask;
409 unsigned long segment_boundary_mask;
413 * enum device_link_state - Device link states.
414 * @DL_STATE_NONE: The presence of the drivers is not being tracked.
415 * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
416 * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
417 * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
418 * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
419 * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
421 enum device_link_state {
423 DL_STATE_DORMANT = 0,
425 DL_STATE_CONSUMER_PROBE,
427 DL_STATE_SUPPLIER_UNBIND,
433 * STATELESS: The core will not remove this link automatically.
434 * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
435 * PM_RUNTIME: If set, the runtime PM framework will use this link.
436 * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
437 * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
438 * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
439 * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
440 * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
441 * INFERRED: Inferred from data (eg: firmware) and not from driver actions.
443 #define DL_FLAG_STATELESS BIT(0)
444 #define DL_FLAG_AUTOREMOVE_CONSUMER BIT(1)
445 #define DL_FLAG_PM_RUNTIME BIT(2)
446 #define DL_FLAG_RPM_ACTIVE BIT(3)
447 #define DL_FLAG_AUTOREMOVE_SUPPLIER BIT(4)
448 #define DL_FLAG_AUTOPROBE_CONSUMER BIT(5)
449 #define DL_FLAG_MANAGED BIT(6)
450 #define DL_FLAG_SYNC_STATE_ONLY BIT(7)
451 #define DL_FLAG_INFERRED BIT(8)
452 #define DL_FLAG_CYCLE BIT(9)
455 * enum dl_dev_state - Device driver presence tracking information.
456 * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
457 * @DL_DEV_PROBING: A driver is probing.
458 * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
459 * @DL_DEV_UNBINDING: The driver is unbinding from the device.
462 DL_DEV_NO_DRIVER = 0,
469 * enum device_removable - Whether the device is removable. The criteria for a
470 * device to be classified as removable is determined by its subsystem or bus.
471 * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this
473 * @DEVICE_REMOVABLE_UNKNOWN: Device location is Unknown.
474 * @DEVICE_FIXED: Device is not removable by the user.
475 * @DEVICE_REMOVABLE: Device is removable by the user.
477 enum device_removable {
478 DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */
479 DEVICE_REMOVABLE_UNKNOWN,
485 * struct dev_links_info - Device data related to device links.
486 * @suppliers: List of links to supplier devices.
487 * @consumers: List of links to consumer devices.
488 * @defer_sync: Hook to global list of devices that have deferred sync_state.
489 * @status: Driver status information.
491 struct dev_links_info {
492 struct list_head suppliers;
493 struct list_head consumers;
494 struct list_head defer_sync;
495 enum dl_dev_state status;
499 * struct dev_msi_info - Device data related to MSI
500 * @domain: The MSI interrupt domain associated to the device
501 * @data: Pointer to MSI device data
503 struct dev_msi_info {
504 #ifdef CONFIG_GENERIC_MSI_IRQ
505 struct irq_domain *domain;
506 struct msi_device_data *data;
511 * enum device_physical_location_panel - Describes which panel surface of the
512 * system's housing the device connection point resides on.
513 * @DEVICE_PANEL_TOP: Device connection point is on the top panel.
514 * @DEVICE_PANEL_BOTTOM: Device connection point is on the bottom panel.
515 * @DEVICE_PANEL_LEFT: Device connection point is on the left panel.
516 * @DEVICE_PANEL_RIGHT: Device connection point is on the right panel.
517 * @DEVICE_PANEL_FRONT: Device connection point is on the front panel.
518 * @DEVICE_PANEL_BACK: Device connection point is on the back panel.
519 * @DEVICE_PANEL_UNKNOWN: The panel with device connection point is unknown.
521 enum device_physical_location_panel {
528 DEVICE_PANEL_UNKNOWN,
532 * enum device_physical_location_vertical_position - Describes vertical
533 * position of the device connection point on the panel surface.
534 * @DEVICE_VERT_POS_UPPER: Device connection point is at upper part of panel.
535 * @DEVICE_VERT_POS_CENTER: Device connection point is at center part of panel.
536 * @DEVICE_VERT_POS_LOWER: Device connection point is at lower part of panel.
538 enum device_physical_location_vertical_position {
539 DEVICE_VERT_POS_UPPER,
540 DEVICE_VERT_POS_CENTER,
541 DEVICE_VERT_POS_LOWER,
545 * enum device_physical_location_horizontal_position - Describes horizontal
546 * position of the device connection point on the panel surface.
547 * @DEVICE_HORI_POS_LEFT: Device connection point is at left part of panel.
548 * @DEVICE_HORI_POS_CENTER: Device connection point is at center part of panel.
549 * @DEVICE_HORI_POS_RIGHT: Device connection point is at right part of panel.
551 enum device_physical_location_horizontal_position {
552 DEVICE_HORI_POS_LEFT,
553 DEVICE_HORI_POS_CENTER,
554 DEVICE_HORI_POS_RIGHT,
558 * struct device_physical_location - Device data related to physical location
559 * of the device connection point.
560 * @panel: Panel surface of the system's housing that the device connection
562 * @vertical_position: Vertical position of the device connection point within
564 * @horizontal_position: Horizontal position of the device connection point
566 * @dock: Set if the device connection point resides in a docking station or
568 * @lid: Set if this device connection point resides on the lid of laptop
571 struct device_physical_location {
572 enum device_physical_location_panel panel;
573 enum device_physical_location_vertical_position vertical_position;
574 enum device_physical_location_horizontal_position horizontal_position;
580 * struct device - The basic device structure
581 * @parent: The device's "parent" device, the device to which it is attached.
582 * In most cases, a parent device is some sort of bus or host
583 * controller. If parent is NULL, the device, is a top-level device,
584 * which is not usually what you want.
585 * @p: Holds the private data of the driver core portions of the device.
586 * See the comment of the struct device_private for detail.
587 * @kobj: A top-level, abstract class from which other classes are derived.
588 * @init_name: Initial name of the device.
589 * @type: The type of device.
590 * This identifies the device type and carries type-specific
592 * @mutex: Mutex to synchronize calls to its driver.
593 * @bus: Type of bus device is on.
594 * @driver: Which driver has allocated this
595 * @platform_data: Platform data specific to the device.
596 * Example: For devices on custom boards, as typical of embedded
597 * and SOC based hardware, Linux often uses platform_data to point
598 * to board-specific structures describing devices and how they
599 * are wired. That can include what ports are available, chip
600 * variants, which GPIO pins act in what additional roles, and so
601 * on. This shrinks the "Board Support Packages" (BSPs) and
602 * minimizes board-specific #ifdefs in drivers.
603 * @driver_data: Private pointer for driver specific info.
604 * @links: Links to suppliers and consumers of this device.
605 * @power: For device power management.
606 * See Documentation/driver-api/pm/devices.rst for details.
607 * @pm_domain: Provide callbacks that are executed during system suspend,
608 * hibernation, system resume and during runtime PM transitions
609 * along with subsystem-level and driver-level callbacks.
610 * @em_pd: device's energy model performance domain
611 * @pins: For device pin management.
612 * See Documentation/driver-api/pin-control.rst for details.
613 * @msi: MSI related data
614 * @numa_node: NUMA node this device is close to.
615 * @dma_ops: DMA mapping operations for this device.
616 * @dma_mask: Dma mask (if dma'ble device).
617 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
618 * hardware supports 64-bit addresses for consistent allocations
620 * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
621 * DMA limit than the device itself supports.
622 * @dma_range_map: map for DMA memory ranges relative to that of RAM
623 * @dma_parms: A low level driver may set these to teach IOMMU code about
624 * segment limitations.
625 * @dma_pools: Dma pools (if dma'ble device).
626 * @dma_mem: Internal for coherent mem override.
627 * @cma_area: Contiguous memory area for dma allocations
628 * @dma_io_tlb_mem: Pointer to the swiotlb pool used. Not for driver use.
629 * @archdata: For arch-specific additions.
630 * @of_node: Associated device tree node.
631 * @fwnode: Associated device node supplied by platform firmware.
632 * @devt: For creating the sysfs "dev".
633 * @id: device instance
634 * @devres_lock: Spinlock to protect the resource of the device.
635 * @devres_head: The resources list of the device.
636 * @knode_class: The node used to add the device to the class list.
637 * @class: The class of the device.
638 * @groups: Optional attribute groups.
639 * @release: Callback to free the device after all references have
640 * gone away. This should be set by the allocator of the
641 * device (i.e. the bus driver that discovered the device).
642 * @iommu_group: IOMMU group the device belongs to.
643 * @iommu: Per device generic IOMMU runtime data
644 * @physical_location: Describes physical location of the device connection
645 * point in the system housing.
646 * @removable: Whether the device can be removed from the system. This
647 * should be set by the subsystem / bus driver that discovered
650 * @offline_disabled: If set, the device is permanently online.
651 * @offline: Set after successful invocation of bus type's .offline().
652 * @of_node_reused: Set if the device-tree node is shared with an ancestor
654 * @state_synced: The hardware state of this device has been synced to match
655 * the software state of this device by calling the driver/bus
656 * sync_state() callback.
657 * @can_match: The device has matched with a driver at least once or it is in
658 * a bus (like AMBA) which can't check for matching drivers until
659 * other devices probe successfully.
660 * @dma_coherent: this particular device is dma coherent, even if the
661 * architecture supports non-coherent devices.
662 * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
663 * streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
664 * and optionall (if the coherent mask is large enough) also
665 * for dma allocations. This flag is managed by the dma ops
666 * instance from ->dma_supported.
668 * At the lowest level, every device in a Linux system is represented by an
669 * instance of struct device. The device structure contains the information
670 * that the device model core needs to model the system. Most subsystems,
671 * however, track additional information about the devices they host. As a
672 * result, it is rare for devices to be represented by bare device structures;
673 * instead, that structure, like kobject structures, is usually embedded within
674 * a higher-level representation of the device.
678 struct device *parent;
680 struct device_private *p;
682 const char *init_name; /* initial name of the device */
683 const struct device_type *type;
685 const struct bus_type *bus; /* type of bus device is on */
686 struct device_driver *driver; /* which driver has allocated this
688 void *platform_data; /* Platform specific data, device
689 core doesn't touch it */
690 void *driver_data; /* Driver data, set and get with
691 dev_set_drvdata/dev_get_drvdata */
692 struct mutex mutex; /* mutex to synchronize calls to
696 struct dev_links_info links;
697 struct dev_pm_info power;
698 struct dev_pm_domain *pm_domain;
700 #ifdef CONFIG_ENERGY_MODEL
701 struct em_perf_domain *em_pd;
704 #ifdef CONFIG_PINCTRL
705 struct dev_pin_info *pins;
707 struct dev_msi_info msi;
708 #ifdef CONFIG_DMA_OPS
709 const struct dma_map_ops *dma_ops;
711 u64 *dma_mask; /* dma mask (if dma'able device) */
712 u64 coherent_dma_mask;/* Like dma_mask, but for
713 alloc_coherent mappings as
714 not all hardware supports
715 64 bit addresses for consistent
716 allocations such descriptors. */
717 u64 bus_dma_limit; /* upstream dma constraint */
718 const struct bus_dma_region *dma_range_map;
720 struct device_dma_parameters *dma_parms;
722 struct list_head dma_pools; /* dma pools (if dma'ble) */
724 #ifdef CONFIG_DMA_DECLARE_COHERENT
725 struct dma_coherent_mem *dma_mem; /* internal for coherent mem
728 #ifdef CONFIG_DMA_CMA
729 struct cma *cma_area; /* contiguous memory area for dma
732 #ifdef CONFIG_SWIOTLB
733 struct io_tlb_mem *dma_io_tlb_mem;
735 /* arch specific additions */
736 struct dev_archdata archdata;
738 struct device_node *of_node; /* associated device tree node */
739 struct fwnode_handle *fwnode; /* firmware device node */
742 int numa_node; /* NUMA node this device is close to */
744 dev_t devt; /* dev_t, creates the sysfs "dev" */
745 u32 id; /* device instance */
747 spinlock_t devres_lock;
748 struct list_head devres_head;
750 const struct class *class;
751 const struct attribute_group **groups; /* optional groups */
753 void (*release)(struct device *dev);
754 struct iommu_group *iommu_group;
755 struct dev_iommu *iommu;
757 struct device_physical_location *physical_location;
759 enum device_removable removable;
761 bool offline_disabled:1;
763 bool of_node_reused:1;
766 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
767 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
768 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
771 #ifdef CONFIG_DMA_OPS_BYPASS
772 bool dma_ops_bypass : 1;
777 * struct device_link - Device link representation.
778 * @supplier: The device on the supplier end of the link.
779 * @s_node: Hook to the supplier device's list of links to consumers.
780 * @consumer: The device on the consumer end of the link.
781 * @c_node: Hook to the consumer device's list of links to suppliers.
782 * @link_dev: device used to expose link details in sysfs
783 * @status: The state of the link (with respect to the presence of drivers).
784 * @flags: Link flags.
785 * @rpm_active: Whether or not the consumer device is runtime-PM-active.
786 * @kref: Count repeated addition of the same link.
787 * @rm_work: Work structure used for removing the link.
788 * @supplier_preactivated: Supplier has been made active before consumer probe.
791 struct device *supplier;
792 struct list_head s_node;
793 struct device *consumer;
794 struct list_head c_node;
795 struct device link_dev;
796 enum device_link_state status;
798 refcount_t rpm_active;
800 struct work_struct rm_work;
801 bool supplier_preactivated; /* Owned by consumer probe. */
804 #define kobj_to_dev(__kobj) container_of_const(__kobj, struct device, kobj)
807 * device_iommu_mapped - Returns true when the device DMA is translated
809 * @dev: Device to perform the check on
811 static inline bool device_iommu_mapped(struct device *dev)
813 return (dev->iommu_group != NULL);
816 /* Get the wakeup routines, which depend on struct device */
817 #include <linux/pm_wakeup.h>
820 * dev_name - Return a device's name.
821 * @dev: Device with name to get.
822 * Return: The kobject name of the device, or its initial name if unavailable.
824 static inline const char *dev_name(const struct device *dev)
826 /* Use the init name until the kobject becomes available */
828 return dev->init_name;
830 return kobject_name(&dev->kobj);
834 * dev_bus_name - Return a device's bus/class name, if at all possible
835 * @dev: struct device to get the bus/class name of
837 * Will return the name of the bus/class the device is attached to. If it is
838 * not attached to a bus/class, an empty string will be returned.
840 static inline const char *dev_bus_name(const struct device *dev)
842 return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "");
845 __printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
848 static inline int dev_to_node(struct device *dev)
850 return dev->numa_node;
852 static inline void set_dev_node(struct device *dev, int node)
854 dev->numa_node = node;
857 static inline int dev_to_node(struct device *dev)
861 static inline void set_dev_node(struct device *dev, int node)
866 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
868 #ifdef CONFIG_GENERIC_MSI_IRQ
869 return dev->msi.domain;
875 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
877 #ifdef CONFIG_GENERIC_MSI_IRQ
882 static inline void *dev_get_drvdata(const struct device *dev)
884 return dev->driver_data;
887 static inline void dev_set_drvdata(struct device *dev, void *data)
889 dev->driver_data = data;
892 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
894 return dev ? dev->power.subsys_data : NULL;
897 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
899 return dev->kobj.uevent_suppress;
902 static inline void dev_set_uevent_suppress(struct device *dev, int val)
904 dev->kobj.uevent_suppress = val;
907 static inline int device_is_registered(struct device *dev)
909 return dev->kobj.state_in_sysfs;
912 static inline void device_enable_async_suspend(struct device *dev)
914 if (!dev->power.is_prepared)
915 dev->power.async_suspend = true;
918 static inline void device_disable_async_suspend(struct device *dev)
920 if (!dev->power.is_prepared)
921 dev->power.async_suspend = false;
924 static inline bool device_async_suspend_enabled(struct device *dev)
926 return !!dev->power.async_suspend;
929 static inline bool device_pm_not_required(struct device *dev)
931 return dev->power.no_pm;
934 static inline void device_set_pm_not_required(struct device *dev)
936 dev->power.no_pm = true;
939 static inline void dev_pm_syscore_device(struct device *dev, bool val)
941 #ifdef CONFIG_PM_SLEEP
942 dev->power.syscore = val;
946 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
948 dev->power.driver_flags = flags;
951 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
953 return !!(dev->power.driver_flags & flags);
956 static inline void device_lock(struct device *dev)
958 mutex_lock(&dev->mutex);
961 static inline int device_lock_interruptible(struct device *dev)
963 return mutex_lock_interruptible(&dev->mutex);
966 static inline int device_trylock(struct device *dev)
968 return mutex_trylock(&dev->mutex);
971 static inline void device_unlock(struct device *dev)
973 mutex_unlock(&dev->mutex);
976 static inline void device_lock_assert(struct device *dev)
978 lockdep_assert_held(&dev->mutex);
981 static inline struct device_node *dev_of_node(struct device *dev)
983 if (!IS_ENABLED(CONFIG_OF) || !dev)
988 static inline bool dev_has_sync_state(struct device *dev)
992 if (dev->driver && dev->driver->sync_state)
994 if (dev->bus && dev->bus->sync_state)
999 static inline void dev_set_removable(struct device *dev,
1000 enum device_removable removable)
1002 dev->removable = removable;
1005 static inline bool dev_is_removable(struct device *dev)
1007 return dev->removable == DEVICE_REMOVABLE;
1010 static inline bool dev_removable_is_valid(struct device *dev)
1012 return dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED;
1016 * High level routines for use by the bus drivers
1018 int __must_check device_register(struct device *dev);
1019 void device_unregister(struct device *dev);
1020 void device_initialize(struct device *dev);
1021 int __must_check device_add(struct device *dev);
1022 void device_del(struct device *dev);
1024 DEFINE_FREE(device_del, struct device *, if (_T) device_del(_T))
1026 int device_for_each_child(struct device *dev, void *data,
1027 int (*fn)(struct device *dev, void *data));
1028 int device_for_each_child_reverse(struct device *dev, void *data,
1029 int (*fn)(struct device *dev, void *data));
1030 struct device *device_find_child(struct device *dev, void *data,
1031 int (*match)(struct device *dev, void *data));
1032 struct device *device_find_child_by_name(struct device *parent,
1034 struct device *device_find_any_child(struct device *parent);
1036 int device_rename(struct device *dev, const char *new_name);
1037 int device_move(struct device *dev, struct device *new_parent,
1038 enum dpm_order dpm_order);
1039 int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
1040 int device_is_dependent(struct device *dev, void *target);
1042 static inline bool device_supports_offline(struct device *dev)
1044 return dev->bus && dev->bus->offline && dev->bus->online;
1047 #define __device_lock_set_class(dev, name, key) \
1049 struct device *__d2 __maybe_unused = dev; \
1050 lock_set_class(&__d2->mutex.dep_map, name, key, 0, _THIS_IP_); \
1054 * device_lock_set_class - Specify a temporary lock class while a device
1055 * is attached to a driver
1056 * @dev: device to modify
1057 * @key: lock class key data
1059 * This must be called with the device_lock() already held, for example
1060 * from driver ->probe(). Take care to only override the default
1061 * lockdep_no_validate class.
1063 #ifdef CONFIG_LOCKDEP
1064 #define device_lock_set_class(dev, key) \
1066 struct device *__d = dev; \
1067 dev_WARN_ONCE(__d, !lockdep_match_class(&__d->mutex, \
1068 &__lockdep_no_validate__), \
1069 "overriding existing custom lock class\n"); \
1070 __device_lock_set_class(__d, #key, key); \
1073 #define device_lock_set_class(dev, key) __device_lock_set_class(dev, #key, key)
1077 * device_lock_reset_class - Return a device to the default lockdep novalidate state
1078 * @dev: device to modify
1080 * This must be called with the device_lock() already held, for example
1081 * from driver ->remove().
1083 #define device_lock_reset_class(dev) \
1085 struct device *__d __maybe_unused = dev; \
1086 lock_set_novalidate_class(&__d->mutex.dep_map, "&dev->mutex", \
1090 void lock_device_hotplug(void);
1091 void unlock_device_hotplug(void);
1092 int lock_device_hotplug_sysfs(void);
1093 int device_offline(struct device *dev);
1094 int device_online(struct device *dev);
1095 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1096 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
1097 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
1098 void device_set_node(struct device *dev, struct fwnode_handle *fwnode);
1100 static inline int dev_num_vf(struct device *dev)
1102 if (dev->bus && dev->bus->num_vf)
1103 return dev->bus->num_vf(dev);
1108 * Root device objects for grouping under /sys/devices
1110 struct device *__root_device_register(const char *name, struct module *owner);
1112 /* This is a macro to avoid include problems with THIS_MODULE */
1113 #define root_device_register(name) \
1114 __root_device_register(name, THIS_MODULE)
1116 void root_device_unregister(struct device *root);
1118 static inline void *dev_get_platdata(const struct device *dev)
1120 return dev->platform_data;
1124 * Manual binding of a device to driver. See drivers/base/bus.c
1125 * for information on use.
1127 int __must_check device_driver_attach(struct device_driver *drv,
1128 struct device *dev);
1129 int __must_check device_bind_driver(struct device *dev);
1130 void device_release_driver(struct device *dev);
1131 int __must_check device_attach(struct device *dev);
1132 int __must_check driver_attach(struct device_driver *drv);
1133 void device_initial_probe(struct device *dev);
1134 int __must_check device_reprobe(struct device *dev);
1136 bool device_is_bound(struct device *dev);
1139 * Easy functions for dynamically creating devices on the fly
1141 __printf(5, 6) struct device *
1142 device_create(const struct class *cls, struct device *parent, dev_t devt,
1143 void *drvdata, const char *fmt, ...);
1144 __printf(6, 7) struct device *
1145 device_create_with_groups(const struct class *cls, struct device *parent, dev_t devt,
1146 void *drvdata, const struct attribute_group **groups,
1147 const char *fmt, ...);
1148 void device_destroy(const struct class *cls, dev_t devt);
1150 int __must_check device_add_groups(struct device *dev,
1151 const struct attribute_group **groups);
1152 void device_remove_groups(struct device *dev,
1153 const struct attribute_group **groups);
1155 static inline int __must_check device_add_group(struct device *dev,
1156 const struct attribute_group *grp)
1158 const struct attribute_group *groups[] = { grp, NULL };
1160 return device_add_groups(dev, groups);
1163 static inline void device_remove_group(struct device *dev,
1164 const struct attribute_group *grp)
1166 const struct attribute_group *groups[] = { grp, NULL };
1168 return device_remove_groups(dev, groups);
1171 int __must_check devm_device_add_groups(struct device *dev,
1172 const struct attribute_group **groups);
1173 int __must_check devm_device_add_group(struct device *dev,
1174 const struct attribute_group *grp);
1177 * Platform "fixup" functions - allow the platform to have their say
1178 * about devices and actions that the general device layer doesn't
1181 /* Notify platform of device discovery */
1182 extern int (*platform_notify)(struct device *dev);
1184 extern int (*platform_notify_remove)(struct device *dev);
1188 * get_device - atomically increment the reference count for the device.
1191 struct device *get_device(struct device *dev);
1192 void put_device(struct device *dev);
1194 DEFINE_FREE(put_device, struct device *, if (_T) put_device(_T))
1196 bool kill_device(struct device *dev);
1198 #ifdef CONFIG_DEVTMPFS
1199 int devtmpfs_mount(void);
1201 static inline int devtmpfs_mount(void) { return 0; }
1204 /* drivers/base/power/shutdown.c */
1205 void device_shutdown(void);
1207 /* debugging and troubleshooting/diagnostic helpers. */
1208 const char *dev_driver_string(const struct device *dev);
1210 /* Device links interface. */
1211 struct device_link *device_link_add(struct device *consumer,
1212 struct device *supplier, u32 flags);
1213 void device_link_del(struct device_link *link);
1214 void device_link_remove(void *consumer, struct device *supplier);
1215 void device_links_supplier_sync_state_pause(void);
1216 void device_links_supplier_sync_state_resume(void);
1218 __printf(3, 4) int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
1220 /* Create alias, so I can be autoloaded. */
1221 #define MODULE_ALIAS_CHARDEV(major,minor) \
1222 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1223 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1224 MODULE_ALIAS("char-major-" __stringify(major) "-*")
1226 #endif /* _DEVICE_H_ */