698 lines
16 KiB
C
698 lines
16 KiB
C
/** @defgroup rcc_file RCC peripheral API
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*
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* @ingroup peripheral_apis
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*
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* @brief <b>libopencm3 STM32F0xx Reset and Clock Control</b>
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*
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* @version 1.0.0
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*
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* @date 29 Jun 2013
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*
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* This library supports the Reset and Clock Control System in the STM32F0xx
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* series of ARM Cortex Microcontrollers by ST Microelectronics.
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*
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* LGPL License Terms @ref lgpl_license
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*/
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/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2009 Federico Ruiz-Ugalde <memeruiz at gmail dot com>
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* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
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* Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**@{*/
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#include <libopencm3/cm3/assert.h>
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#include <libopencm3/stm32/rcc.h>
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#include <libopencm3/stm32/flash.h>
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#include <libopencm3/stm32/i2c.h>
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/* Set the default clock frequencies */
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uint32_t rcc_ahb_frequency = 8000000; /* 8MHz after reset */
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uint32_t rcc_apb1_frequency = 8000000; /* 8MHz after reset */
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Clear the Oscillator Ready Interrupt Flag
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*
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* Clear the interrupt flag that was set when a clock oscillator became ready
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* to use.
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*
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* @param osc Oscillator ID
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*/
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void rcc_osc_ready_int_clear(enum rcc_osc osc)
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{
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switch (osc) {
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case RCC_HSI48:
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RCC_CIR |= RCC_CIR_HSI48RDYC;
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break;
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case RCC_HSI14:
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RCC_CIR |= RCC_CIR_HSI14RDYC;
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break;
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case RCC_HSI:
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RCC_CIR |= RCC_CIR_HSIRDYC;
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break;
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case RCC_HSE:
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RCC_CIR |= RCC_CIR_HSERDYC;
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break;
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case RCC_PLL:
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RCC_CIR |= RCC_CIR_PLLRDYC;
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break;
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case RCC_LSE:
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RCC_CIR |= RCC_CIR_LSERDYC;
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break;
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case RCC_LSI:
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RCC_CIR |= RCC_CIR_LSIRDYC;
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Enable the Oscillator Ready Interrupt
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*
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* @param osc Oscillator ID
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*/
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void rcc_osc_ready_int_enable(enum rcc_osc osc)
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{
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switch (osc) {
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case RCC_HSI48:
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RCC_CIR |= RCC_CIR_HSI48RDYIE;
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break;
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case RCC_HSI14:
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RCC_CIR |= RCC_CIR_HSI14RDYIE;
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break;
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case RCC_HSI:
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RCC_CIR |= RCC_CIR_HSIRDYIE;
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break;
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case RCC_HSE:
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RCC_CIR |= RCC_CIR_HSERDYIE;
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break;
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case RCC_PLL:
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RCC_CIR |= RCC_CIR_PLLRDYIE;
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break;
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case RCC_LSE:
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RCC_CIR |= RCC_CIR_LSERDYIE;
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break;
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case RCC_LSI:
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RCC_CIR |= RCC_CIR_LSIRDYIE;
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Disable the Oscillator Ready Interrupt
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*
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* @param osc Oscillator ID
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*/
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void rcc_osc_ready_int_disable(enum rcc_osc osc)
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{
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switch (osc) {
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case RCC_HSI48:
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RCC_CIR &= ~RCC_CIR_HSI48RDYC;
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break;
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case RCC_HSI14:
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RCC_CIR &= ~RCC_CIR_HSI14RDYC;
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break;
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case RCC_HSI:
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RCC_CIR &= ~RCC_CIR_HSIRDYC;
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break;
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case RCC_HSE:
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RCC_CIR &= ~RCC_CIR_HSERDYC;
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break;
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case RCC_PLL:
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RCC_CIR &= ~RCC_CIR_PLLRDYC;
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break;
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case RCC_LSE:
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RCC_CIR &= ~RCC_CIR_LSERDYC;
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break;
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case RCC_LSI:
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RCC_CIR &= ~RCC_CIR_LSIRDYC;
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Read the Oscillator Ready Interrupt Flag
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*
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* @param osc Oscillator ID
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* @returns int. Boolean value for flag set.
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*/
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int rcc_osc_ready_int_flag(enum rcc_osc osc)
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{
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switch (osc) {
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case RCC_HSI48:
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return (RCC_CIR & RCC_CIR_HSI48RDYF) != 0;
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break;
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case RCC_HSI14:
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return (RCC_CIR & RCC_CIR_HSI14RDYF) != 0;
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break;
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case RCC_HSI:
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return (RCC_CIR & RCC_CIR_HSIRDYF) != 0;
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break;
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case RCC_HSE:
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return (RCC_CIR & RCC_CIR_HSERDYF) != 0;
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break;
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case RCC_PLL:
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return (RCC_CIR & RCC_CIR_PLLRDYF) != 0;
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break;
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case RCC_LSE:
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return (RCC_CIR & RCC_CIR_LSERDYF) != 0;
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break;
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case RCC_LSI:
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return (RCC_CIR & RCC_CIR_LSIRDYF) != 0;
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break;
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}
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cm3_assert_not_reached();
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Clear the Clock Security System Interrupt Flag
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*/
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void rcc_css_int_clear(void)
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{
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RCC_CIR |= RCC_CIR_CSSC;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Read the Clock Security System Interrupt Flag
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*
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* @returns int. Boolean value for flag set.
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*/
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int rcc_css_int_flag(void)
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{
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return ((RCC_CIR & RCC_CIR_CSSF) != 0);
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}
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bool rcc_is_osc_ready(enum rcc_osc osc)
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{
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switch (osc) {
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case RCC_HSI48:
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return RCC_CR2 & RCC_CR2_HSI48RDY;
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case RCC_HSI14:
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return RCC_CR2 & RCC_CR2_HSI14RDY;
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case RCC_HSI:
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return RCC_CR & RCC_CR_HSIRDY;
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case RCC_HSE:
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return RCC_CR & RCC_CR_HSERDY;
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case RCC_PLL:
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return RCC_CR & RCC_CR_PLLRDY;
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case RCC_LSE:
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return RCC_BDCR & RCC_BDCR_LSERDY;
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case RCC_LSI:
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return RCC_CSR & RCC_CSR_LSIRDY;
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}
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return false;
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}
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void rcc_wait_for_osc_ready(enum rcc_osc osc)
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{
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while (!rcc_is_osc_ready(osc));
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Turn on an Oscillator.
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*
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* Enable an oscillator and power on. Each oscillator requires an amount of
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* time to settle to a usable state. Refer to datasheets for time delay
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* information. A status flag is available to indicate when the oscillator
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* becomes ready (see @ref rcc_osc_ready_int_flag and @ref
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* rcc_wait_for_osc_ready).
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*
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* @param osc Oscillator ID
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*/
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void rcc_osc_on(enum rcc_osc osc)
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{
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switch (osc) {
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case RCC_HSI48:
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RCC_CR2 |= RCC_CR2_HSI48ON;
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break;
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case RCC_HSI14:
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RCC_CR2 |= RCC_CR2_HSI14ON;
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break;
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case RCC_HSI:
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RCC_CR |= RCC_CR_HSION;
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break;
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case RCC_HSE:
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RCC_CR |= RCC_CR_HSEON;
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break;
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case RCC_LSE:
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RCC_BDCR |= RCC_BDCR_LSEON;
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break;
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case RCC_LSI:
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RCC_CSR |= RCC_CSR_LSION;
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break;
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case RCC_PLL:
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RCC_CR |= RCC_CR_PLLON;
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Turn off an Oscillator.
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*
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* Disable an oscillator and power off.
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*
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* @note An oscillator cannot be turned off if it is selected as the system
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* clock.
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*
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* @param osc Oscillator ID
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*/
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void rcc_osc_off(enum rcc_osc osc)
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{
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switch (osc) {
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case RCC_HSI48:
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RCC_CR2 &= ~RCC_CR2_HSI48ON;
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break;
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case RCC_HSI14:
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RCC_CR2 &= ~RCC_CR2_HSI14ON;
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break;
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case RCC_HSI:
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RCC_CR &= ~RCC_CR_HSION;
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break;
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case RCC_HSE:
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RCC_CR &= ~RCC_CR_HSEON;
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break;
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case RCC_LSE:
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RCC_BDCR &= ~RCC_BDCR_LSEON;
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break;
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case RCC_LSI:
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RCC_CSR &= ~RCC_CSR_LSION;
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break;
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case RCC_PLL:
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/* don't do anything */
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Enable the Clock Security System.
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*/
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void rcc_css_enable(void)
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{
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RCC_CR |= RCC_CR_CSSON;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Disable the Clock Security System.
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*/
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void rcc_css_disable(void)
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{
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RCC_CR &= ~RCC_CR_CSSON;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the Source for the System Clock.
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*
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* @param clk Oscillator ID. Only HSE, LSE and PLL have
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* effect.
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*/
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void rcc_set_sysclk_source(enum rcc_osc clk)
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{
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switch (clk) {
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case RCC_HSI:
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSI;
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break;
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case RCC_HSE:
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSE;
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break;
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case RCC_PLL:
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_PLL;
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break;
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case RCC_HSI48:
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSI48;
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break;
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case RCC_LSI:
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case RCC_LSE:
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case RCC_HSI14:
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/* do nothing */
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the Source for the USB Clock.
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*
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* @param clk Oscillator ID. Only HSI48 or PLL have
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* effect.
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*/
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void rcc_set_usbclk_source(enum rcc_osc clk)
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{
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switch (clk) {
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case RCC_PLL:
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RCC_CFGR3 |= RCC_CFGR3_USBSW;
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break;
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case RCC_HSI48:
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RCC_CFGR3 &= ~RCC_CFGR3_USBSW;
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break;
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case RCC_HSI:
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case RCC_HSE:
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case RCC_LSI:
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case RCC_LSE:
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case RCC_HSI14:
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/* do nothing */
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Enable the RTC clock
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*/
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void rcc_enable_rtc_clock(void)
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{
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RCC_BDCR |= RCC_BDCR_RTCEN;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Disable the RTC clock
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*/
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void rcc_disable_rtc_clock(void)
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{
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RCC_BDCR &= ~RCC_BDCR_RTCEN;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the Source for the RTC clock
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@param[in] clk RTC clock source. Only HSE/32, LSE and LSI.
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*/
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void rcc_set_rtc_clock_source(enum rcc_osc clk)
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{
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switch (clk) {
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case RCC_HSE:
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RCC_BDCR = (RCC_BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_HSE;
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break;
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case RCC_LSE:
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RCC_BDCR = (RCC_BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_LSE;
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break;
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case RCC_LSI:
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RCC_BDCR = (RCC_BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_LSI;
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break;
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default:
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/* do nothing */
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break;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the PLL Multiplication Factor.
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*
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* @note This only has effect when the PLL is disabled.
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*
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* @param[in] mul Unsigned int32. PLL multiplication factor @ref rcc_cfgr_pmf
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*/
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void rcc_set_pll_multiplication_factor(uint32_t mul)
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{
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PLLMUL) | mul;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the PLL Clock Source.
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@note This only has effect when the PLL is disabled.
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@param[in] pllsrc Unsigned int32. PLL clock source @ref rcc_cfgr_pcs
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*/
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void rcc_set_pll_source(uint32_t pllsrc)
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{
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PLLSRC) |
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(pllsrc << 16);
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the HSE Frequency Divider used as PLL Clock Source.
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@note This only has effect when the PLL is disabled.
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@param[in] pllxtpre Unsigned int32. HSE division factor @ref rcc_cfgr_hsepre
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*/
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void rcc_set_pllxtpre(uint32_t pllxtpre)
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{
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PLLXTPRE) |
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(pllxtpre << 17);
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the APB Prescale Factor.
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*
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* @param[in] ppre Unsigned int32. APB prescale factor @ref rcc_cfgr_apb1pre
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*/
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void rcc_set_ppre(uint32_t ppre)
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{
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PPRE) | ppre;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Set the AHB Prescale Factor.
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*
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* @param[in] hpre Unsigned int32. AHB prescale factor @ref rcc_cfgr_ahbpre
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*/
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void rcc_set_hpre(uint32_t hpre)
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{
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RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_HPRE) | hpre;
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}
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/**
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* Set PLL Source pre-divider **CAUTION**.
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* On F03x and F05, prediv only applies to HSE source. On others, this
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* is _after_ source selection. See also f3.
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* @param[in] prediv division by prediv+1 @ref rcc_cfgr2_prediv
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*/
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void rcc_set_prediv(uint32_t prediv)
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{
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RCC_CFGR2 = (RCC_CFGR2 & ~RCC_CFGR2_PREDIV) | prediv;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Get the System Clock Source.
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*
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* @returns current system clock source
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*/
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enum rcc_osc rcc_system_clock_source(void)
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{
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/* Return the clock source which is used as system clock. */
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switch (RCC_CFGR & RCC_CFGR_SWS) {
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case RCC_CFGR_SWS_HSI:
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return RCC_HSI;
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case RCC_CFGR_SWS_HSE:
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return RCC_HSE;
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case RCC_CFGR_SWS_PLL:
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return RCC_PLL;
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case RCC_CFGR_SWS_HSI48:
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return RCC_HSI48;
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}
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cm3_assert_not_reached();
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}
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void rcc_set_i2c_clock_hsi(uint32_t i2c)
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{
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if (i2c == I2C1) {
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RCC_CFGR3 &= ~RCC_CFGR3_I2C1SW;
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}
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}
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void rcc_set_i2c_clock_sysclk(uint32_t i2c)
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{
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if (i2c == I2C1) {
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RCC_CFGR3 |= RCC_CFGR3_I2C1SW;
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}
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}
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uint32_t rcc_get_i2c_clocks(void)
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{
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return RCC_CFGR3 & RCC_CFGR3_I2C1SW;
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}
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/*---------------------------------------------------------------------------*/
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/** @brief RCC Get the USB Clock Source.
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*
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* @returns Currently selected USB clock source
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*/
|
|
|
|
enum rcc_osc rcc_usb_clock_source(void)
|
|
{
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|
return (RCC_CFGR3 & RCC_CFGR3_USBSW) ? RCC_PLL : RCC_HSI48;
|
|
}
|
|
|
|
/**
|
|
* Set System Clock PLL at 48MHz from HSE at 8MHz.
|
|
*/
|
|
void rcc_clock_setup_in_hse_8mhz_out_48mhz(void)
|
|
{
|
|
rcc_osc_on(RCC_HSE);
|
|
rcc_wait_for_osc_ready(RCC_HSE);
|
|
rcc_set_sysclk_source(RCC_HSE);
|
|
|
|
rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
|
|
rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
|
|
|
|
flash_prefetch_enable();
|
|
flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
|
|
|
|
/* PLL: 8MHz * 6 = 48MHz */
|
|
rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL6);
|
|
rcc_set_pll_source(RCC_CFGR_PLLSRC_HSE_CLK);
|
|
rcc_set_pllxtpre(RCC_CFGR_PLLXTPRE_HSE_CLK);
|
|
|
|
rcc_osc_on(RCC_PLL);
|
|
rcc_wait_for_osc_ready(RCC_PLL);
|
|
rcc_set_sysclk_source(RCC_PLL);
|
|
|
|
rcc_apb1_frequency = 48000000;
|
|
rcc_ahb_frequency = 48000000;
|
|
}
|
|
|
|
/**
|
|
* Set System Clock PLL at 48MHz from HSI
|
|
*/
|
|
void rcc_clock_setup_in_hsi_out_48mhz(void)
|
|
{
|
|
rcc_osc_on(RCC_HSI);
|
|
rcc_wait_for_osc_ready(RCC_HSI);
|
|
rcc_set_sysclk_source(RCC_HSI);
|
|
|
|
rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
|
|
rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
|
|
|
|
flash_prefetch_enable();
|
|
flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
|
|
|
|
/* 8MHz * 12 / 2 = 48MHz */
|
|
rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL12);
|
|
rcc_set_pll_source(RCC_CFGR_PLLSRC_HSI_CLK_DIV2);
|
|
|
|
rcc_osc_on(RCC_PLL);
|
|
rcc_wait_for_osc_ready(RCC_PLL);
|
|
rcc_set_sysclk_source(RCC_PLL);
|
|
|
|
rcc_apb1_frequency = 48000000;
|
|
rcc_ahb_frequency = 48000000;
|
|
}
|
|
|
|
/**
|
|
* Set System Clock HSI48 at 48MHz
|
|
*/
|
|
void rcc_clock_setup_in_hsi48_out_48mhz(void)
|
|
{
|
|
rcc_osc_on(RCC_HSI48);
|
|
rcc_wait_for_osc_ready(RCC_HSI48);
|
|
|
|
rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
|
|
rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
|
|
|
|
flash_prefetch_enable();
|
|
flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
|
|
|
|
rcc_set_sysclk_source(RCC_HSI48);
|
|
|
|
rcc_apb1_frequency = 48000000;
|
|
rcc_ahb_frequency = 48000000;
|
|
}
|
|
|
|
static uint32_t rcc_get_usart_clksel_freq(uint8_t shift) {
|
|
uint8_t clksel = (RCC_CFGR3 >> shift) & RCC_CFGR3_USARTxSW_MASK;
|
|
uint8_t hpre = (RCC_CFGR >> RCC_CFGR_HPRE_SHIFT) & RCC_CFGR_HPRE_MASK;
|
|
switch (clksel) {
|
|
case RCC_CFGR3_USART1SW_PCLK:
|
|
return rcc_apb1_frequency;
|
|
case RCC_CFGR3_USART1SW_SYSCLK:
|
|
return rcc_ahb_frequency * rcc_get_div_from_hpre(hpre);
|
|
case RCC_CFGR3_USART1SW_HSI:
|
|
return 8000000U;
|
|
}
|
|
cm3_assert_not_reached();
|
|
}
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/** @brief Get the peripheral clock speed for the USART at base specified.
|
|
* @param usart Base address of USART to get clock frequency for.
|
|
*/
|
|
uint32_t rcc_get_usart_clk_freq(uint32_t usart)
|
|
{
|
|
if (usart == USART1_BASE) {
|
|
return rcc_get_usart_clksel_freq(RCC_CFGR3_USART1SW_SHIFT);
|
|
} else if (usart == USART2_BASE) {
|
|
return rcc_get_usart_clksel_freq(RCC_CFGR3_USART2SW_SHIFT);
|
|
} else if (usart == USART3_BASE) {
|
|
return rcc_get_usart_clksel_freq(RCC_CFGR3_USART3SW_SHIFT);
|
|
} else {
|
|
return rcc_apb1_frequency;
|
|
}
|
|
}
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/** @brief Get the peripheral clock speed for the Timer at base specified.
|
|
* @param timer Base address of TIM to get clock frequency for.
|
|
*/
|
|
uint32_t rcc_get_timer_clk_freq(uint32_t timer __attribute__((unused)))
|
|
{
|
|
uint8_t ppre = (RCC_CFGR >> RCC_CFGR_PPRE_SHIFT) & RCC_CFGR_PPRE_MASK;
|
|
return (ppre == RCC_CFGR_PPRE_NODIV) ? rcc_apb1_frequency
|
|
: 2 * rcc_apb1_frequency;
|
|
}
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/** @brief Get the peripheral clock speed for the I2C device at base specified.
|
|
* @param i2c Base address of I2C to get clock frequency for.
|
|
*/
|
|
uint32_t rcc_get_i2c_clk_freq(uint32_t i2c)
|
|
{
|
|
if (i2c == I2C1_BASE) {
|
|
if (RCC_CFGR3 & RCC_CFGR3_I2C1SW) {
|
|
uint8_t hpre = (RCC_CFGR >> RCC_CFGR_HPRE_SHIFT) & RCC_CFGR_HPRE_MASK;
|
|
return rcc_ahb_frequency * rcc_get_div_from_hpre(hpre);
|
|
} else {
|
|
return 8000000U;
|
|
}
|
|
} else {
|
|
return rcc_apb1_frequency;
|
|
}
|
|
}
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/** @brief Get the peripheral clock speed for the SPI device at base specified.
|
|
* @param spi Base address of SPI device to get clock frequency for (e.g. SPI1_BASE).
|
|
*/
|
|
uint32_t rcc_get_spi_clk_freq(uint32_t spi __attribute__((unused))) {
|
|
return rcc_apb1_frequency;
|
|
}
|
|
/**@}*/
|
|
|