circuitpython/ports/stm/peripherals/stm32l4/clocks.c

/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2021 Blues Wireless Contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "stm32l4xx_hal.h"
#include "supervisor/shared/safe_mode.h"
#include <stdbool.h>

// L4 Series
#ifdef STM32L4R5xx
#include "stm32l4/stm32l4r5xx/clocks.h"
#else
#error Please add other MCUs here so that they are not silently ignored due to #define typos
#endif

#if BOARD_HAS_HIGH_SPEED_CRYSTAL
#error HSE support needs to be added for the L4 family.
#elif !BOARD_HAS_LOW_SPEED_CRYSTAL
  #error LSE clock source required
#endif

void Error_Handler(void) {
    for (;;) {

    }
}

#define HAL_CHECK(x) if (x != HAL_OK) Error_Handler()

void stm32_peripherals_clocks_init(void) {

    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};

    // Configure LSE Drive
    HAL_PWR_EnableBkUpAccess();
    __HAL_RCC_LSEDRIVE_CONFIG(RCC_LSEDRIVE_LOW);
    __HAL_RCC_PWR_CLK_ENABLE();

    /** Configure the main internal regulator output voltage
  */
    if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1_BOOST) != HAL_OK) {
        Error_Handler();
    }


    /* Activate PLL with MSI , stabilizied via PLL by LSE */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE | RCC_OSCILLATORTYPE_MSI;
    RCC_OscInitStruct.MSIState = RCC_MSI_ON;
    RCC_OscInitStruct.LSEState = RCC_LSE_ON;
    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_11;
    RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
    RCC_OscInitStruct.PLL.PLLM = 6;
    RCC_OscInitStruct.PLL.PLLN = 30;
    RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV5;
    RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
    RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
    HAL_CHECK(HAL_RCC_OscConfig(&RCC_OscInitStruct));

    /* Enable MSI Auto-calibration through LSE */
    HAL_RCCEx_EnableMSIPLLMode();

    /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2
    clocks dividers */
    RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    // Avoid overshoot and start with HCLK 60 MHz
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
    HAL_CHECK(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3));

    /* AHB prescaler divider at 1 as second step */
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    HAL_CHECK(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5));

    /* Select MSI output as USB clock source */
    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB | RCC_PERIPHCLK_RTC | RCC_PERIPHCLK_ADC;
    PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_MSI;
    PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
    PeriphClkInitStruct.AdcClockSelection = RCC_ADCCLKSOURCE_SYSCLK;
    HAL_CHECK(HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct));

}