zephyr/include/random.h
Marcus Shawcroft 4127775bcf random: Introduce random device API.
Introduce random device API analgous to other device driver classes in
Zephyr.  Modify the the KSDK random driver to implement the API.

We retain the sys_rand32_get() interface for now on the assumption it
will eventually relocate to or be otherwise replaced by an entropy
management system.

The existing TEST_RANDOM_GENERATOR related drivers that do not
generate entropy are not modified to expose this driver API since they
cannot generate entropy.

Change-Id: I60b2d5afddf242e802a1d9014c99579870fb7472
Signed-off-by: Marcus Shawcroft <marcus.shawcroft@arm.com>
2016-12-24 16:40:11 +00:00

83 lines
1.8 KiB
C

/**
* @file random.h
*
* @brief Public APIs for the random driver.
*/
/*
* Copyright (c) 2016 ARM Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __RANDOM_H__
#define __RANDOM_H__
/**
* @brief Random Interface
* @defgroup random_interface Random Interface
* @ingroup io_interfaces
* @{
*/
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <device.h>
/**
* @typedef random_get_entropy_t
* @brief Callback API to get entropy.
*
* See random_get_entropy() for argument description
*/
typedef int (*random_get_entropy_t)(struct device *dev,
uint8_t *buffer,
uint16_t length);
struct random_driver_api {
random_get_entropy_t get_entropy;
};
/**
* @brief Get entropy from the random driver.
*
* Fill a buffer with entropy from the random driver.
*
* @param dev Pointer to the random device.
* @param buffer Buffer to fill with entropy.
* @param length Buffer length.
* @retval 0 on success.
* @retval -ERRNO errno code on error.
*/
static inline int random_get_entropy(struct device *dev,
uint8_t *buffer,
uint16_t length)
{
const struct random_driver_api *api = dev->driver_api;
__ASSERT(api->get_entropy, "Callback pointer should not be NULL");
return api->get_entropy(dev, buffer, length);
}
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* __RANDOM_H__ */