nes-proj/drivers/cpu/nrf52832/dev/random.c

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2016-01-09 13:44:18 +00:00
/*
* Copyright (c) 2015, Nordic Semiconductor
* 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 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 the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE 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.
*
*/
/**
* \addtogroup nrf52832
* @{
*
* \addtogroup nrf52832-dev Device drivers
* @{
*
* \addtogroup nrf52832-rng Hardware random number generator
* @{
*
* \file
* Random number generator routines exploiting the nRF52 hardware
* capabilities.
*
* This file overrides core/lib/random.c.
*
* \author
* Wojciech Bober <wojciech.bober@nordicsemi.no>
*/
#include <stddef.h>
#include <nrf_drv_rng.h>
#include "app_error.h"
/*---------------------------------------------------------------------------*/
/**
* \brief Generates a new random number using the nRF52 RNG.
* \return a random number.
*/
unsigned short
random_rand(void)
{
unsigned short value = 42;
uint8_t available;
ret_code_t err_code;
do {
nrf_drv_rng_bytes_available(&available);
} while (available < sizeof(value));
err_code = nrf_drv_rng_rand((uint8_t *)&value, sizeof(value));
APP_ERROR_CHECK(err_code);
return value;
}
/*---------------------------------------------------------------------------*/
/**
* \brief Initialize the nRF52 random number generator.
* \param seed Ignored. It's here because the function prototype is in core.
*
*/
void
random_init(unsigned short seed)
{
(void)seed;
ret_code_t err_code = nrf_drv_rng_init(NULL);
APP_ERROR_CHECK(err_code);
}
/**
* @}
* @}
* @}
*/