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