// SPDX-License-Identifier: GPL-2.0+ /* * Surface System Aggregator Module bus and device integration. * * Copyright (C) 2019-2022 Maximilian Luz <[email protected]> */ #include <linux/device.h> #include <linux/property.h> #include <linux/slab.h> #include <linux/surface_aggregator/controller.h> #include <linux/surface_aggregator/device.h> #include "bus.h" #include "controller.h" /* -- Device and bus functions. --------------------------------------------- */ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static DEVICE_ATTR_RO(modalias); static struct attribute *ssam_device_attrs[] = …; ATTRIBUTE_GROUPS(…); static const struct bus_type ssam_bus_type; static int ssam_device_uevent(const struct device *dev, struct kobj_uevent_env *env) { … } static void ssam_device_release(struct device *dev) { … } const struct device_type ssam_device_type = …; EXPORT_SYMBOL_GPL(…); /** * ssam_device_alloc() - Allocate and initialize a SSAM client device. * @ctrl: The controller under which the device should be added. * @uid: The UID of the device to be added. * * Allocates and initializes a new client device. The parent of the device * will be set to the controller device and the name will be set based on the * UID. Note that the device still has to be added via ssam_device_add(). * Refer to that function for more details. * * Return: Returns the newly allocated and initialized SSAM client device, or * %NULL if it could not be allocated. */ struct ssam_device *ssam_device_alloc(struct ssam_controller *ctrl, struct ssam_device_uid uid) { … } EXPORT_SYMBOL_GPL(…); /** * ssam_device_add() - Add a SSAM client device. * @sdev: The SSAM client device to be added. * * Added client devices must be guaranteed to always have a valid and active * controller. Thus, this function will fail with %-ENODEV if the controller * of the device has not been initialized yet, has been suspended, or has been * shut down. * * The caller of this function should ensure that the corresponding call to * ssam_device_remove() is issued before the controller is shut down. If the * added device is a direct child of the controller device (default), it will * be automatically removed when the controller is shut down. * * By default, the controller device will become the parent of the newly * created client device. The parent may be changed before ssam_device_add is * called, but care must be taken that a) the correct suspend/resume ordering * is guaranteed and b) the client device does not outlive the controller, * i.e. that the device is removed before the controller is being shut down. * In case these guarantees have to be manually enforced, please refer to the * ssam_client_link() and ssam_client_bind() functions, which are intended to * set up device-links for this purpose. * * Return: Returns zero on success, a negative error code on failure. */ int ssam_device_add(struct ssam_device *sdev) { … } EXPORT_SYMBOL_GPL(…); /** * ssam_device_remove() - Remove a SSAM client device. * @sdev: The device to remove. * * Removes and unregisters the provided SSAM client device. */ void ssam_device_remove(struct ssam_device *sdev) { … } EXPORT_SYMBOL_GPL(…); /** * ssam_device_id_compatible() - Check if a device ID matches a UID. * @id: The device ID as potential match. * @uid: The device UID matching against. * * Check if the given ID is a match for the given UID, i.e. if a device with * the provided UID is compatible to the given ID following the match rules * described in its &ssam_device_id.match_flags member. * * Return: Returns %true if the given UID is compatible to the match rule * described by the given ID, %false otherwise. */ static bool ssam_device_id_compatible(const struct ssam_device_id *id, struct ssam_device_uid uid) { … } /** * ssam_device_id_is_null() - Check if a device ID is null. * @id: The device ID to check. * * Check if a given device ID is null, i.e. all zeros. Used to check for the * end of ``MODULE_DEVICE_TABLE(ssam, ...)`` or similar lists. * * Return: Returns %true if the given ID represents a null ID, %false * otherwise. */ static bool ssam_device_id_is_null(const struct ssam_device_id *id) { … } /** * ssam_device_id_match() - Find the matching ID table entry for the given UID. * @table: The table to search in. * @uid: The UID to matched against the individual table entries. * * Find the first match for the provided device UID in the provided ID table * and return it. Returns %NULL if no match could be found. */ const struct ssam_device_id *ssam_device_id_match(const struct ssam_device_id *table, const struct ssam_device_uid uid) { … } EXPORT_SYMBOL_GPL(…); /** * ssam_device_get_match() - Find and return the ID matching the device in the * ID table of the bound driver. * @dev: The device for which to get the matching ID table entry. * * Find the fist match for the UID of the device in the ID table of the * currently bound driver and return it. Returns %NULL if the device does not * have a driver bound to it, the driver does not have match_table (i.e. it is * %NULL), or there is no match in the driver's match_table. * * This function essentially calls ssam_device_id_match() with the ID table of * the bound device driver and the UID of the device. * * Return: Returns the first match for the UID of the device in the device * driver's match table, or %NULL if no such match could be found. */ const struct ssam_device_id *ssam_device_get_match(const struct ssam_device *dev) { … } EXPORT_SYMBOL_GPL(…); /** * ssam_device_get_match_data() - Find the ID matching the device in the * ID table of the bound driver and return its ``driver_data`` member. * @dev: The device for which to get the match data. * * Find the fist match for the UID of the device in the ID table of the * corresponding driver and return its driver_data. Returns %NULL if the * device does not have a driver bound to it, the driver does not have * match_table (i.e. it is %NULL), there is no match in the driver's * match_table, or the match does not have any driver_data. * * This function essentially calls ssam_device_get_match() and, if any match * could be found, returns its ``struct ssam_device_id.driver_data`` member. * * Return: Returns the driver data associated with the first match for the UID * of the device in the device driver's match table, or %NULL if no such match * could be found. */ const void *ssam_device_get_match_data(const struct ssam_device *dev) { … } EXPORT_SYMBOL_GPL(…); static int ssam_bus_match(struct device *dev, const struct device_driver *drv) { … } static int ssam_bus_probe(struct device *dev) { … } static void ssam_bus_remove(struct device *dev) { … } static const struct bus_type ssam_bus_type = …; /** * __ssam_device_driver_register() - Register a SSAM client device driver. * @sdrv: The driver to register. * @owner: The module owning the provided driver. * * Please refer to the ssam_device_driver_register() macro for the normal way * to register a driver from inside its owning module. */ int __ssam_device_driver_register(struct ssam_device_driver *sdrv, struct module *owner) { … } EXPORT_SYMBOL_GPL(…); /** * ssam_device_driver_unregister - Unregister a SSAM device driver. * @sdrv: The driver to unregister. */ void ssam_device_driver_unregister(struct ssam_device_driver *sdrv) { … } EXPORT_SYMBOL_GPL(…); /* -- Bus registration. ----------------------------------------------------- */ /** * ssam_bus_register() - Register and set-up the SSAM client device bus. */ int ssam_bus_register(void) { … } /** * ssam_bus_unregister() - Unregister the SSAM client device bus. */ void ssam_bus_unregister(void) { … } /* -- Helpers for controller and hub devices. ------------------------------- */ static int ssam_device_uid_from_string(const char *str, struct ssam_device_uid *uid) { … } static int ssam_get_uid_for_node(struct fwnode_handle *node, struct ssam_device_uid *uid) { … } static int ssam_add_client_device(struct device *parent, struct ssam_controller *ctrl, struct fwnode_handle *node) { … } /** * __ssam_register_clients() - Register client devices defined under the * given firmware node as children of the given device. * @parent: The parent device under which clients should be registered. * @ctrl: The controller with which client should be registered. * @node: The firmware node holding definitions of the devices to be added. * * Register all clients that have been defined as children of the given root * firmware node as children of the given parent device. The respective child * firmware nodes will be associated with the correspondingly created child * devices. * * The given controller will be used to instantiate the new devices. See * ssam_device_add() for details. * * Note that, generally, the use of either ssam_device_register_clients() or * ssam_register_clients() should be preferred as they directly use the * firmware node and/or controller associated with the given device. This * function is only intended for use when different device specifications (e.g. * ACPI and firmware nodes) need to be combined (as is done in the platform hub * of the device registry). * * Return: Returns zero on success, nonzero on failure. */ int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl, struct fwnode_handle *node) { … } EXPORT_SYMBOL_GPL(…); static int ssam_remove_device(struct device *dev, void *_data) { … } /** * ssam_remove_clients() - Remove SSAM client devices registered as direct * children under the given parent device. * @dev: The (parent) device to remove all direct clients for. * * Remove all SSAM client devices registered as direct children under the given * device. Note that this only accounts for direct children of the device. * Refer to ssam_device_add()/ssam_device_remove() for more details. */ void ssam_remove_clients(struct device *dev) { … } EXPORT_SYMBOL_GPL(…);
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