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cpu/sam3: adapted HWRNG implementation

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This commit is contained in:
Hauke Petersen 2016-02-05 16:46:24 +01:00
parent 6f0179ce69
commit 79cf50db03
1 changed files with 16 additions and 32 deletions
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48
cpu/sam3/periph/random.c → cpu/sam3/periph/hwrng.c
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@ -1,13 +1,13 @@
/*
* Copyright (C) 2014 Freie Universität Berlin
* Copyright (C) 2014-2016 Freie Universität Berlin
*
* 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.
* 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 driver_periph
* @ingroup cpu_sam3
* @{
*
* @file
@ -19,11 +19,7 @@
*/
#include "cpu.h"
#include "periph_conf.h"
#include "periph/random.h"
/* only compile this driver if enabled in the board's periph_conf.h */
#if RANDOM_NUMOF
#include "periph/hwrng.h"
/**
* @name KEY needs to be written to the config register when en|disabling
@ -31,46 +27,34 @@
*/
#define KEY (0x524e4700)
void random_init(void)
void hwrng_init(void)
{
random_poweron();
/* no need for initialization */
}
int random_read(char *buf, unsigned int num)
void hwrng_read(uint8_t *buf, unsigned int num)
{
/* cppcheck-suppress variableScope */
uint32_t tmp;
unsigned count = 0;
/* enable clock signal for TRNG module */
PMC->PMC_PCER1 |= PMC_PCER1_PID41;
/* enable the generation of random numbers */
TRNG->TRNG_CR |= (KEY | TRNG_CR_ENABLE);
while (count < num) {
/* wait until new value is generated -> takes up to 84 cycles */
while (!(TRNG->TRNG_ISR & TRNG_ISR_DATRDY));
/* read 4 byte of random data */
tmp = TRNG->TRNG_ODATA;
uint32_t tmp = TRNG->TRNG_ODATA;
/* extract copy bytes to result */
for (int i = 0; i < 4 && count < num; i++) {
buf[count++] = (char)tmp;
buf[count++] = (uint8_t)tmp;
tmp = tmp >> 8;
}
}
return count;
}
void random_poweron(void)
{
/* enable clock signal for TRNG module */
PMC->PMC_PCER1 |= PMC_PCER1_PID41;
/* enable the generation of random numbers */
TRNG->TRNG_CR |= (KEY | TRNG_CR_ENABLE);
}
void random_poweroff(void)
{
/* disable the generation of random numbers */
TRNG->TRNG_CR &= ~(KEY | TRNG_CR_ENABLE);
/* disable clock signal for TRNG module */
PMC->PMC_PCER1 &= ~(PMC_PCER1_PID41);
}
#endif /* RANDOM_NUMOF */