/**
 * Copyright (c) 2016 - 2017, Nordic Semiconductor ASA
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 * 
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 * 
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 * 
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 * 
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

#ifndef NRF_DRV_RNG_H__
#define NRF_DRV_RNG_H__

#include <stdbool.h>
#include <stdint.h>

#include "nrf_rng.h"
#include "sdk_errors.h"
#include "sdk_config.h"
#include "nrf_drv_common.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @addtogroup nrf_rng RNG HAL and driver
 * @ingroup nrf_drivers
 * @brief Random number generator (RNG) APIs.
 * @details The RNG HAL provides basic APIs for accessing the registers of the random number
 * generator. The RNG driver provides APIs on a higher level.
 *
 * @defgroup nrf_drv_rng RNG driver
 * @{
 * @ingroup nrf_rng
 * @brief Driver for managing the random number generator (RNG).
 */

/**@brief Struct for RNG configuration. */
typedef struct
{
    bool     error_correction;      /**< Error correction flag. */
    uint8_t  interrupt_priority;    /**< interrupt priority */
} nrf_drv_rng_config_t;

/**@brief RNG default configuration. */
#define NRF_DRV_RNG_DEFAULT_CONFIG                                                    \
    {                                                                                 \
        .error_correction   = RNG_CONFIG_ERROR_CORRECTION,                            \
        .interrupt_priority = RNG_CONFIG_IRQ_PRIORITY,                                \
    }

/**
 * @brief Function for initializing the nrf_drv_rng module.
 *
 * @param[in]  p_config                 Initial configuration. Default configuration used if NULL.
 *
 * @retval  NRF_SUCCESS                             Driver was successfully initialized.
 * @retval  NRF_ERROR_MODULE_ALREADY_INITIALIZED    Driver was already initialized.
 */
ret_code_t nrf_drv_rng_init(nrf_drv_rng_config_t const * p_config);

/**
 * @brief Function for uninitializing the nrf_drv_rng module.
 */
void nrf_drv_rng_uninit(void);

/**
 * @brief Function for getting the number of currently available random bytes.
 *
 * @param[out] p_bytes_available        The number of bytes currently available in the pool.
 */
void nrf_drv_rng_bytes_available(uint8_t * p_bytes_available);

/**
 * @brief Function for getting the vector of random numbers.
 *
 * @param[out] p_buff                   Pointer to uint8_t buffer for storing the bytes.
 * @param[in]  length                   Number of bytes to take from the pool and place in p_buff.
 *
 * @retval     NRF_SUCCESS              If the requested bytes were written to p_buff.
 * @retval     NRF_ERROR_NOT_FOUND      If no bytes were written to the buffer because there were
 *                                      not enough bytes available in the pool.
 */
ret_code_t nrf_drv_rng_rand(uint8_t * p_buff, uint8_t length);

/**
 * @brief Blocking function for getting an arbitrary array of random numbers.
 *
 * @note This function may execute for a substantial amount of time depending on the length
 *       of the buffer required and on the state of the current internal pool of random numbers.
 *
 * @param[out] p_buff                   Pointer to uint8_t buffer for storing the bytes.
 * @param[in]  length                   Number of bytes place in p_buff.
 */
void nrf_drv_rng_block_rand(uint8_t * p_buff, uint32_t length);

#ifdef SOFTDEVICE_PRESENT
/**
 * @brief Function called by the SoftDevice handler when the SoftDevice has been disabled.
 *
 * This function is called just after the SoftDevice has been properly disabled.
 * It has two purposes:
 * 1. Reinitializes RNG hardware.
 * 2. Trigger new random numbers generation.
 */
void nrf_drv_rng_on_sd_disable(void);

#endif
/**
 *@}
 **/

#ifdef __cplusplus
}
#endif

#endif // NRF_DRV_RNG_H__
