/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2023, STMicroelectronics - All Rights Reserved */ #ifndef STM32_FIREWALL_DEVICE_H #define STM32_FIREWALL_DEVICE_H #include <linux/of.h> #include <linux/platform_device.h> #include <linux/types.h> #define STM32_FIREWALL_MAX_EXTRA_ARGS … /* Opaque reference to stm32_firewall_controller */ struct stm32_firewall_controller; /** * struct stm32_firewall - Information on a device's firewall. Each device can have more than one * firewall. * * @firewall_ctrl: Pointer referencing a firewall controller of the device. It is * opaque so a device cannot manipulate the controller's ops or access * the controller's data * @extra_args: Extra arguments that are implementation dependent * @entry: Name of the firewall entry * @extra_args_size: Number of extra arguments * @firewall_id: Firewall ID associated the device for this firewall controller */ struct stm32_firewall { … }; #if IS_ENABLED(CONFIG_STM32_FIREWALL) /** * stm32_firewall_get_firewall - Get the firewall(s) associated to given device. * The firewall controller reference is always the first argument * of each of the access-controller property entries. * The firewall ID is always the second argument of each of the * access-controller property entries. * If there's no argument linked to the phandle, then the firewall ID * field is set to U32_MAX, which is an invalid ID. * * @np: Device node to parse * @firewall: Array of firewall references * @nb_firewall: Number of firewall references to get. Must be at least 1. * * Returns 0 on success, -ENODEV if there's no match with a firewall controller or appropriate errno * code if error occurred. */ int stm32_firewall_get_firewall(struct device_node *np, struct stm32_firewall *firewall, unsigned int nb_firewall); /** * stm32_firewall_grant_access - Request firewall access rights and grant access. * * @firewall: Firewall reference containing the ID to check against its firewall * controller * * Returns 0 if access is granted, -EACCES if access is denied, -ENODEV if firewall is null or * appropriate errno code if error occurred */ int stm32_firewall_grant_access(struct stm32_firewall *firewall); /** * stm32_firewall_release_access - Release access granted from a call to * stm32_firewall_grant_access(). * * @firewall: Firewall reference containing the ID to check against its firewall * controller */ void stm32_firewall_release_access(struct stm32_firewall *firewall); /** * stm32_firewall_grant_access_by_id - Request firewall access rights of a given device * based on a specific firewall ID * * Warnings: * There is no way to ensure that the given ID will correspond to the firewall referenced in the * device node if the ID did not come from stm32_firewall_get_firewall(). In that case, this * function must be used with caution. * This function should be used for subsystem resources that do not have the same firewall ID * as their parent. * U32_MAX is an invalid ID. * * @firewall: Firewall reference containing the firewall controller * @subsystem_id: Firewall ID of the subsystem resource * * Returns 0 if access is granted, -EACCES if access is denied, -ENODEV if firewall is null or * appropriate errno code if error occurred */ int stm32_firewall_grant_access_by_id(struct stm32_firewall *firewall, u32 subsystem_id); /** * stm32_firewall_release_access_by_id - Release access granted from a call to * stm32_firewall_grant_access_by_id(). * * Warnings: * There is no way to ensure that the given ID will correspond to the firewall referenced in the * device node if the ID did not come from stm32_firewall_get_firewall(). In that case, this * function must be used with caution. * This function should be used for subsystem resources that do not have the same firewall ID * as their parent. * U32_MAX is an invalid ID. * * @firewall: Firewall reference containing the firewall controller * @subsystem_id: Firewall ID of the subsystem resource */ void stm32_firewall_release_access_by_id(struct stm32_firewall *firewall, u32 subsystem_id); #else /* CONFIG_STM32_FIREWALL */ int stm32_firewall_get_firewall(struct device_node *np, struct stm32_firewall *firewall, unsigned int nb_firewall); { return -ENODEV; } int stm32_firewall_grant_access(struct stm32_firewall *firewall) { return -ENODEV; } void stm32_firewall_release_access(struct stm32_firewall *firewall) { } int stm32_firewall_grant_access_by_id(struct stm32_firewall *firewall, u32 subsystem_id) { return -ENODEV; } void stm32_firewall_release_access_by_id(struct stm32_firewall *firewall, u32 subsystem_id) { } #endif /* CONFIG_STM32_FIREWALL */ #endif /* STM32_FIREWALL_DEVICE_H */