mirror of
https://github.com/RIOT-OS/RIOT.git
synced 2024-12-29 04:50:03 +01:00
67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
/*
|
|
* Copyright (C) 2014-2016 Freie Universität Berlin
|
|
* 2015 Jan Wagner <mail@jwagner.eu>
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU Lesser
|
|
* General Public License v2.1. See the file LICENSE in the top level
|
|
* directory for more details.
|
|
*/
|
|
|
|
/**
|
|
* @ingroup cpu_nrf5x_common
|
|
* @ingroup drivers_periph_hwrng
|
|
* @{
|
|
*
|
|
* @file
|
|
* @brief Implementation of the hardware random number generator interface
|
|
*
|
|
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
|
|
* @author Frank Holtz <frank-riot2015@holtznet.de>
|
|
* @author Jan Wagner <mail@jwagner.eu>
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
#include "cpu.h"
|
|
#include "periph/hwrng.h"
|
|
#include "assert.h"
|
|
|
|
void hwrng_init(void)
|
|
{
|
|
/* enable bias correction */
|
|
NRF_RNG->CONFIG = 1;
|
|
}
|
|
|
|
void hwrng_read(void *buf, unsigned int num)
|
|
{
|
|
unsigned int count = 0;
|
|
uint8_t *b = (uint8_t *)buf;
|
|
|
|
/* power on RNG */
|
|
#ifdef CPU_FAM_NRF51
|
|
NRF_RNG->POWER = 1;
|
|
#endif
|
|
NRF_RNG->INTENSET = RNG_INTENSET_VALRDY_Msk;
|
|
NRF_RNG->TASKS_START = 1;
|
|
|
|
/* read the actual random data */
|
|
while (count < num) {
|
|
/* sleep until number is generated */
|
|
while (NRF_RNG->EVENTS_VALRDY == 0) {
|
|
cortexm_sleep_until_event();
|
|
}
|
|
|
|
b[count++] = (uint8_t)NRF_RNG->VALUE;
|
|
/* NRF51 PAN #21 -> read value before clearing VALRDY */
|
|
NRF_RNG->EVENTS_VALRDY = 0;
|
|
NVIC_ClearPendingIRQ(RNG_IRQn);
|
|
}
|
|
|
|
/* power off RNG */
|
|
NRF_RNG->INTENCLR = RNG_INTENSET_VALRDY_Msk;
|
|
NRF_RNG->TASKS_STOP = 1;
|
|
#ifdef CPU_FAM_NRF51
|
|
NRF_RNG->POWER = 0;
|
|
#endif
|
|
}
|