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RIOT/cpu/stm32_common/stmclk_common.c

104 lines
2.3 KiB
C

/*
* Copyright (C) 2017 Freie Universität Berlin
* 2017 OTA keys S.A.
*
* 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_stm32_common
* @{
*
* @file
* @brief Implementation of common STM32 clock configuration functions
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Vincent Dupont <vincent@otakeys.com>
* @}
*/
#include "cpu.h"
#include "stmclk.h"
#include "periph_conf.h"
#if defined(CPU_FAM_STM32L4) || defined(CPU_FAM_STM32F7)
#define REG_PWR_CR CR1
#define BIT_CR_DBP PWR_CR1_DBP
#else
#define REG_PWR_CR CR
#define BIT_CR_DBP PWR_CR_DBP
#endif
#if defined (CPU_FAM_STM32L0) || defined(CPU_FAM_STM32L1)
#define REG_LSE CSR
#define BIT_LSEON RCC_CSR_LSEON
#define BIT_LSERDY RCC_CSR_LSERDY
#else
#define REG_LSE BDCR
#define BIT_LSEON RCC_BDCR_LSEON
#define BIT_LSERDY RCC_BDCR_LSERDY
#endif
#ifndef CLOCK_HSE
#define CLOCK_HSE (0U)
#endif
#ifndef CLOCK_LSE
#define CLOCK_LSE (0U)
#endif
void stmclk_enable_hsi(void)
{
RCC->CR |= RCC_CR_HSION;
while (!(RCC->CR & RCC_CR_HSIRDY)) {}
}
void stmclk_disable_hsi(void)
{
/* we only disable the HSI clock if not used as input for the PLL and if
* not used directly as system clock */
if (CLOCK_HSE) {
if ((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_HSI) {
RCC->CR &= ~(RCC_CR_HSION);
}
}
}
void stmclk_enable_lfclk(void)
{
if (CLOCK_LSE) {
stmclk_dbp_unlock();
RCC->REG_LSE |= BIT_LSEON;
while (!(RCC->REG_LSE & BIT_LSERDY)) {}
stmclk_dbp_lock();
}
else {
RCC->CSR |= RCC_CSR_LSION;
while (!(RCC->CSR & RCC_CSR_LSIRDY)) {}
}
}
void stmclk_disable_lfclk(void)
{
if (CLOCK_LSE) {
stmclk_dbp_unlock();
RCC->REG_LSE &= ~(BIT_LSEON);
while (!(RCC->REG_LSE & BIT_LSERDY)) {}
stmclk_dbp_lock();
}
else {
RCC->CSR &= ~(RCC_CSR_LSION);
}
}
void stmclk_dbp_unlock(void)
{
PWR->REG_PWR_CR |= BIT_CR_DBP;
}
void stmclk_dbp_lock(void)
{
PWR->REG_PWR_CR &= ~(BIT_CR_DBP);
}