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Diffstat (limited to 'include/linux/device/bus.h')
| -rw-r--r-- | include/linux/device/bus.h | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h new file mode 100644 index 000000000000..1ea5e1d1545b --- /dev/null +++ b/include/linux/device/bus.h @@ -0,0 +1,288 @@ +// 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); + int (*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_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 |