293 lines
11 KiB
C
293 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* bus.h - the bus-specific portions of the driver model
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*
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* Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
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* Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
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* Copyright (c) 2008-2009 Novell Inc.
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* Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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* Copyright (c) 2012-2019 Linux Foundation
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*
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* See Documentation/driver-api/driver-model/ for more information.
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*/
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#ifndef _DEVICE_BUS_H_
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#define _DEVICE_BUS_H_
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#include <linux/kobject.h>
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#include <linux/klist.h>
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#include <linux/pm.h>
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struct device_driver;
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struct fwnode_handle;
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/**
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* struct bus_type - The bus type of the device
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*
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* @name: The name of the bus.
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* @dev_name: Used for subsystems to enumerate devices like ("foo%u", dev->id).
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* @dev_root: Default device to use as the parent.
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* @bus_groups: Default attributes of the bus.
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* @dev_groups: Default attributes of the devices on the bus.
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* @drv_groups: Default attributes of the device drivers on the bus.
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* @match: Called, perhaps multiple times, whenever a new device or driver
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* is added for this bus. It should return a positive value if the
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* given device can be handled by the given driver and zero
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* otherwise. It may also return error code if determining that
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* the driver supports the device is not possible. In case of
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* -EPROBE_DEFER it will queue the device for deferred probing.
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* @uevent: Called when a device is added, removed, or a few other things
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* that generate uevents to add the environment variables.
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* @probe: Called when a new device or driver add to this bus, and callback
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* the specific driver's probe to initial the matched device.
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* @sync_state: Called to sync device state to software state after all the
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* state tracking consumers linked to this device (present at
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* the time of late_initcall) have successfully bound to a
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* driver. If the device has no consumers, this function will
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* be called at late_initcall_sync level. If the device has
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* consumers that are never bound to a driver, this function
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* will never get called until they do.
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* @remove: Called when a device removed from this bus.
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* @shutdown: Called at shut-down time to quiesce the device.
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*
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* @online: Called to put the device back online (after offlining it).
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* @offline: Called to put the device offline for hot-removal. May fail.
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*
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* @suspend: Called when a device on this bus wants to go to sleep mode.
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* @resume: Called to bring a device on this bus out of sleep mode.
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* @num_vf: Called to find out how many virtual functions a device on this
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* bus supports.
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* @dma_configure: Called to setup DMA configuration on a device on
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* this bus.
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* @dma_cleanup: Called to cleanup DMA configuration on a device on
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* this bus.
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* @pm: Power management operations of this bus, callback the specific
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* device driver's pm-ops.
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* @iommu_ops: IOMMU specific operations for this bus, used to attach IOMMU
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* driver implementations to a bus and allow the driver to do
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* bus-specific setup
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* @p: The private data of the driver core, only the driver core can
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* touch this.
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* @lock_key: Lock class key for use by the lock validator
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* @need_parent_lock: When probing or removing a device on this bus, the
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* device core should lock the device's parent.
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*
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* A bus is a channel between the processor and one or more devices. For the
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* purposes of the device model, all devices are connected via a bus, even if
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* it is an internal, virtual, "platform" bus. Buses can plug into each other.
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* A USB controller is usually a PCI device, for example. The device model
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* represents the actual connections between buses and the devices they control.
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* A bus is represented by the bus_type structure. It contains the name, the
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* default attributes, the bus' methods, PM operations, and the driver core's
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* private data.
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*/
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struct bus_type {
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const char *name;
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const char *dev_name;
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struct device *dev_root;
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const struct attribute_group **bus_groups;
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const struct attribute_group **dev_groups;
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const struct attribute_group **drv_groups;
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int (*match)(struct device *dev, struct device_driver *drv);
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int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
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int (*probe)(struct device *dev);
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void (*sync_state)(struct device *dev);
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void (*remove)(struct device *dev);
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void (*shutdown)(struct device *dev);
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int (*online)(struct device *dev);
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int (*offline)(struct device *dev);
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int (*suspend)(struct device *dev, pm_message_t state);
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int (*resume)(struct device *dev);
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int (*num_vf)(struct device *dev);
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int (*dma_configure)(struct device *dev);
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void (*dma_cleanup)(struct device *dev);
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const struct dev_pm_ops *pm;
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const struct iommu_ops *iommu_ops;
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struct subsys_private *p;
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struct lock_class_key lock_key;
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bool need_parent_lock;
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};
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extern int __must_check bus_register(struct bus_type *bus);
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extern void bus_unregister(struct bus_type *bus);
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extern int __must_check bus_rescan_devices(struct bus_type *bus);
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struct bus_attribute {
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struct attribute attr;
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ssize_t (*show)(struct bus_type *bus, char *buf);
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ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
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};
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#define BUS_ATTR_RW(_name) \
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struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
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#define BUS_ATTR_RO(_name) \
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struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
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#define BUS_ATTR_WO(_name) \
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struct bus_attribute bus_attr_##_name = __ATTR_WO(_name)
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extern int __must_check bus_create_file(struct bus_type *,
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struct bus_attribute *);
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extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
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/* Generic device matching functions that all busses can use to match with */
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int device_match_name(struct device *dev, const void *name);
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int device_match_of_node(struct device *dev, const void *np);
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int device_match_fwnode(struct device *dev, const void *fwnode);
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int device_match_devt(struct device *dev, const void *pdevt);
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int device_match_acpi_dev(struct device *dev, const void *adev);
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int device_match_acpi_handle(struct device *dev, const void *handle);
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int device_match_any(struct device *dev, const void *unused);
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/* iterator helpers for buses */
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struct subsys_dev_iter {
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struct klist_iter ki;
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const struct device_type *type;
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};
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void subsys_dev_iter_init(struct subsys_dev_iter *iter,
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struct bus_type *subsys,
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struct device *start,
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const struct device_type *type);
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struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
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void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
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int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
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int (*fn)(struct device *dev, void *data));
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struct device *bus_find_device(struct bus_type *bus, struct device *start,
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const void *data,
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int (*match)(struct device *dev, const void *data));
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/**
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* bus_find_device_by_name - device iterator for locating a particular device
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* of a specific name.
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* @bus: bus type
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* @start: Device to begin with
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* @name: name of the device to match
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*/
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static inline struct device *bus_find_device_by_name(struct bus_type *bus,
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struct device *start,
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const char *name)
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{
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return bus_find_device(bus, start, name, device_match_name);
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}
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/**
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* bus_find_device_by_of_node : device iterator for locating a particular device
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* matching the of_node.
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* @bus: bus type
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* @np: of_node of the device to match.
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*/
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static inline struct device *
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bus_find_device_by_of_node(struct bus_type *bus, const struct device_node *np)
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{
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return bus_find_device(bus, NULL, np, device_match_of_node);
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}
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/**
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* bus_find_device_by_fwnode : device iterator for locating a particular device
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* matching the fwnode.
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* @bus: bus type
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* @fwnode: fwnode of the device to match.
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*/
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static inline struct device *
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bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwnode)
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{
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return bus_find_device(bus, NULL, fwnode, device_match_fwnode);
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}
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/**
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* bus_find_device_by_devt : device iterator for locating a particular device
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* matching the device type.
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* @bus: bus type
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* @devt: device type of the device to match.
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*/
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static inline struct device *bus_find_device_by_devt(struct bus_type *bus,
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dev_t devt)
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{
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return bus_find_device(bus, NULL, &devt, device_match_devt);
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}
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/**
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* bus_find_next_device - Find the next device after a given device in a
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* given bus.
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* @bus: bus type
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* @cur: device to begin the search with.
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*/
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static inline struct device *
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bus_find_next_device(struct bus_type *bus,struct device *cur)
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{
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return bus_find_device(bus, cur, NULL, device_match_any);
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}
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#ifdef CONFIG_ACPI
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struct acpi_device;
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/**
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* bus_find_device_by_acpi_dev : device iterator for locating a particular device
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* matching the ACPI COMPANION device.
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* @bus: bus type
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* @adev: ACPI COMPANION device to match.
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*/
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static inline struct device *
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bus_find_device_by_acpi_dev(struct bus_type *bus, const struct acpi_device *adev)
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{
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return bus_find_device(bus, NULL, adev, device_match_acpi_dev);
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}
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#else
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static inline struct device *
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bus_find_device_by_acpi_dev(struct bus_type *bus, const void *adev)
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{
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return NULL;
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}
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#endif
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struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
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struct device *hint);
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int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
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void *data, int (*fn)(struct device_driver *, void *));
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void bus_sort_breadthfirst(struct bus_type *bus,
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int (*compare)(const struct device *a,
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const struct device *b));
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/*
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* Bus notifiers: Get notified of addition/removal of devices
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* and binding/unbinding of drivers to devices.
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* In the long run, it should be a replacement for the platform
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* notify hooks.
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*/
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struct notifier_block;
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extern int bus_register_notifier(struct bus_type *bus,
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struct notifier_block *nb);
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extern int bus_unregister_notifier(struct bus_type *bus,
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struct notifier_block *nb);
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/* All 4 notifers below get called with the target struct device *
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* as an argument. Note that those functions are likely to be called
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* with the device lock held in the core, so be careful.
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*/
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#define BUS_NOTIFY_ADD_DEVICE 0x00000001 /* device added */
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#define BUS_NOTIFY_DEL_DEVICE 0x00000002 /* device to be removed */
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#define BUS_NOTIFY_REMOVED_DEVICE 0x00000003 /* device removed */
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#define BUS_NOTIFY_BIND_DRIVER 0x00000004 /* driver about to be
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bound */
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#define BUS_NOTIFY_BOUND_DRIVER 0x00000005 /* driver bound to device */
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#define BUS_NOTIFY_UNBIND_DRIVER 0x00000006 /* driver about to be
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unbound */
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#define BUS_NOTIFY_UNBOUND_DRIVER 0x00000007 /* driver is unbound
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from the device */
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#define BUS_NOTIFY_DRIVER_NOT_BOUND 0x00000008 /* driver fails to be bound */
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extern struct kset *bus_get_kset(struct bus_type *bus);
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extern struct klist *bus_get_device_klist(struct bus_type *bus);
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#endif
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