1 // SPDX-License-Identifier: GPL-2.0
3  * bus.h - the bus-specific portions of the 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.
8  * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9  * Copyright (c) 2012-2019 Linux Foundation
11  * See Documentation/driver-api/driver-model/ for more information.
19 #include <linux/pm.h>
25  * struct bus_type - The bus type of the device
27  * @name:	The name of the bus.
28  * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
30  * @bus_groups:	Default attributes of the bus.
31  * @dev_groups:	Default attributes of the devices on the bus.
32  * @drv_groups: Default attributes of the device drivers on the bus.
34  *		is added for this bus. It should return a positive value if the
38  *		-EPROBE_DEFER it will queue the device for deferred probing.
41  * @probe:	Called when a new device or driver add to this bus, and callback
50  * @remove:	Called when a device removed from this bus.
51  * @shutdown:	Called at shut-down time to quiesce the device.
54  * @offline:	Called to put the device offline for hot-removal. May fail.
56  * @suspend:	Called when a device on this bus wants to go to sleep mode.
57  * @resume:	Called to bring a device on this bus out of sleep mode.
59  *		bus supports.
61  *			this bus.
63  *			this bus.
64  * @pm:		Power management operations of this bus, callback the specific
65  *		device driver's pm-ops.
66  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
67  *              driver implementations to a bus and allow the driver to do
68  *              bus-specific setup
72  * @need_parent_lock:	When probing or removing a device on this bus, the
75  * A bus is a channel between the processor and one or more devices. For the
76  * purposes of the device model, all devices are connected via a bus, even if
77  * it is an internal, virtual, "platform" bus. Buses can plug into each other.
80  * A bus is represented by the bus_type structure. It contains the name, the
81  * default attributes, the bus' methods, PM operations, and the driver core's
110 	const struct dev_pm_ops *pm;  member
120 extern int __must_check bus_register(struct bus_type *bus);
122 extern void bus_unregister(struct bus_type *bus);
124 extern int __must_check bus_rescan_devices(struct bus_type *bus);
128 	ssize_t (*show)(struct bus_type *bus, char *buf);
129 	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
164 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
166 struct device *bus_find_device(struct bus_type *bus, struct device *start,
170  * bus_find_device_by_name - device iterator for locating a particular device
172  * @bus: bus type
176 static inline struct device *bus_find_device_by_name(struct bus_type *bus,  in bus_find_device_by_name()  argument
180 	return bus_find_device(bus, start, name, device_match_name);  in bus_find_device_by_name()
186  * @bus: bus type
190 bus_find_device_by_of_node(struct bus_type *bus, const struct device_node *np)  in bus_find_device_by_of_node()  argument
192 	return bus_find_device(bus, NULL, np, device_match_of_node);  in bus_find_device_by_of_node()
198  * @bus: bus type
202 bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwnode)  in bus_find_device_by_fwnode()  argument
204 	return bus_find_device(bus, NULL, fwnode, device_match_fwnode);  in bus_find_device_by_fwnode()
210  * @bus: bus type
213 static inline struct device *bus_find_device_by_devt(struct bus_type *bus,  in bus_find_device_by_devt()  argument
216 	return bus_find_device(bus, NULL, &devt, device_match_devt);  in bus_find_device_by_devt()
220  * bus_find_next_device - Find the next device after a given device in a
221  * given bus.
222  * @bus: bus type
226 bus_find_next_device(struct bus_type *bus,struct device *cur)  in bus_find_next_device()  argument
228 	return bus_find_device(bus, cur, NULL, device_match_any);  in bus_find_next_device()
237  * @bus: bus type
241 bus_find_device_by_acpi_dev(struct bus_type *bus, const struct acpi_device *adev)  in bus_find_device_by_acpi_dev()  argument
243 	return bus_find_device(bus, NULL, adev, device_match_acpi_dev);  in bus_find_device_by_acpi_dev()
247 bus_find_device_by_acpi_dev(struct bus_type *bus, const void *adev)  in bus_find_device_by_acpi_dev()  argument
253 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
255 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
257 void bus_sort_breadthfirst(struct bus_type *bus,
261  * Bus notifiers: Get notified of addition/removal of devices
268 extern int bus_register_notifier(struct bus_type *bus,
270 extern int bus_unregister_notifier(struct bus_type *bus,
289 extern struct kset *bus_get_kset(struct bus_type *bus);
290 extern struct klist *bus_get_device_klist(struct bus_type *bus);