120 lines
2.8 KiB
C
120 lines
2.8 KiB
C
/**
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* @file drivers/entropy.h
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*
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* @brief Public APIs for the entropy driver.
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*/
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/*
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* Copyright (c) 2016 ARM Ltd.
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* Copyright (c) 2017 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef ZEPHYR_INCLUDE_DRIVERS_ENTROPY_H_
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#define ZEPHYR_INCLUDE_DRIVERS_ENTROPY_H_
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/**
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* @brief Entropy Interface
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* @defgroup entropy_interface Entropy Interface
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* @ingroup io_interfaces
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* @{
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*/
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#include <zephyr/types.h>
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#include <device.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/**
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* @typedef entropy_get_entropy_t
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* @brief Callback API to get entropy.
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*
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* See entropy_get_entropy() for argument description
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*/
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typedef int (*entropy_get_entropy_t)(const struct device *dev,
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uint8_t *buffer,
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uint16_t length);
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/**
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* @typedef entropy_get_entropy_isr_t
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* @brief Callback API to get entropy from an ISR.
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*
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* See entropy_get_entropy_isr() for argument description
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*/
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typedef int (*entropy_get_entropy_isr_t)(const struct device *dev,
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uint8_t *buffer,
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uint16_t length,
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uint32_t flags);
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__subsystem struct entropy_driver_api {
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entropy_get_entropy_t get_entropy;
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entropy_get_entropy_isr_t get_entropy_isr;
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};
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/**
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* @brief Fills a buffer with entropy. Blocks if required in order to
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* generate the necessary random data.
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*
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* @param dev Pointer to the entropy device.
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* @param buffer Buffer to fill with entropy.
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* @param length Buffer length.
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* @retval 0 on success.
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* @retval -ERRNO errno code on error.
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*/
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__syscall int entropy_get_entropy(const struct device *dev,
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uint8_t *buffer,
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uint16_t length);
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static inline int z_impl_entropy_get_entropy(const struct device *dev,
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uint8_t *buffer,
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uint16_t length)
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{
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const struct entropy_driver_api *api =
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(const struct entropy_driver_api *)dev->api;
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__ASSERT(api->get_entropy != NULL,
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"Callback pointer should not be NULL");
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return api->get_entropy(dev, buffer, length);
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}
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/* Busy-wait for random data to be ready */
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#define ENTROPY_BUSYWAIT BIT(0)
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/**
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* @brief Fills a buffer with entropy in a non-blocking or busy-wait manner.
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* Callable from ISRs.
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*
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* @param dev Pointer to the device structure.
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* @param buffer Buffer to fill with entropy.
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* @param length Buffer length.
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* @param flags Flags to modify the behavior of the call.
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* @retval number of bytes filled with entropy or -error.
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*/
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static inline int entropy_get_entropy_isr(const struct device *dev,
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uint8_t *buffer,
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uint16_t length,
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uint32_t flags)
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{
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const struct entropy_driver_api *api =
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(const struct entropy_driver_api *)dev->api;
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if (unlikely(!api->get_entropy_isr)) {
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return -ENOTSUP;
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}
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return api->get_entropy_isr(dev, buffer, length, flags);
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}
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#ifdef __cplusplus
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}
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#endif
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/**
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* @}
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*/
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#include <syscalls/entropy.h>
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#endif /* ZEPHYR_INCLUDE_DRIVERS_ENTROPY_H_ */
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