firmware/stm32/bootloader/clocks.c
2020-11-18 14:19:14 -05:00

137 lines
5.1 KiB
C

/*
* (c) Copyright 2018 by Coinkite Inc. This file is covered by license found in COPYING-CC.
*/
/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* 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 "basics.h"
#include "clocks.h"
#include "stm32l4xx_hal.h"
// HSE is used and is 8MHz
// - not doing a complete setup here, but enough
// - expect mainline code to refine this more
// - this chip is well made and can handle later changes to clocks
#define CKCC_CLK_PLLN (40)
#define CKCC_CLK_PLLM (2)
#define CKCC_CLK_PLLR (2)
#define CKCC_CLK_PLLP (7)
#define CKCC_CLK_PLLQ (4)
// expected value of HAL_RCC_GetHCLKFreq(): 80Mhz
#define HCLK_FREQUENCY 80000000
// systick_setup()
//
void
systick_setup(void)
{
const uint32_t ticks = HCLK_FREQUENCY/1000;
SysTick->LOAD = (ticks - 1);
SysTick->VAL = 0;
SysTick->CTRL = SYSTICK_CLKSOURCE_HCLK | SysTick_CTRL_ENABLE_Msk;
}
// clocks_setup()
//
void
clocks_setup(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
// Configure LSE Drive Capability
__HAL_RCC_LSEDRIVE_CONFIG(RCC_LSEDRIVE_LOW);
// Enable HSE Oscillator and activate PLL with HSE as source
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.LSEState = RCC_LSE_OFF;
RCC_OscInitStruct.MSIState = RCC_MSI_OFF;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
// 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;
RCC_OscInitStruct.PLL.PLLM = CKCC_CLK_PLLM;
RCC_OscInitStruct.PLL.PLLN = CKCC_CLK_PLLN;
RCC_OscInitStruct.PLL.PLLP = CKCC_CLK_PLLP;
RCC_OscInitStruct.PLL.PLLQ = CKCC_CLK_PLLQ;
RCC_OscInitStruct.PLL.PLLR = CKCC_CLK_PLLR;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
HAL_RCC_OscConfig(&RCC_OscInitStruct);
HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4);
// DIS-able MSI-Hardware auto calibration mode with LSE
CLEAR_BIT(RCC->CR, RCC_CR_MSIPLLEN);
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_SAI1|RCC_PERIPHCLK_I2C1
|RCC_PERIPHCLK_USB |RCC_PERIPHCLK_ADC
|RCC_PERIPHCLK_RNG |RCC_PERIPHCLK_RTC;
PeriphClkInitStruct.I2c1ClockSelection = RCC_I2C1CLKSOURCE_PCLK1;
// PLLSAI is used to clock USB, ADC, I2C1 and RNG. The frequency is
// HSE(8MHz)/PLLM(2)*PLLSAI1N(24)/PLLSAIQ(2) = 48MHz.
//
PeriphClkInitStruct.Sai1ClockSelection = RCC_SAI1CLKSOURCE_PLLSAI1;
PeriphClkInitStruct.AdcClockSelection = RCC_ADCCLKSOURCE_PLLSAI1;
PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_PLLSAI1;
PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
PeriphClkInitStruct.RngClockSelection = RCC_RNGCLKSOURCE_PLLSAI1;
PeriphClkInitStruct.PLLSAI1.PLLSAI1Source = RCC_PLLSOURCE_HSE;
PeriphClkInitStruct.PLLSAI1.PLLSAI1M = 2;
PeriphClkInitStruct.PLLSAI1.PLLSAI1N = 24;
PeriphClkInitStruct.PLLSAI1.PLLSAI1P = RCC_PLLP_DIV7;
PeriphClkInitStruct.PLLSAI1.PLLSAI1Q = RCC_PLLQ_DIV2;
PeriphClkInitStruct.PLLSAI1.PLLSAI1R = RCC_PLLR_DIV2;
PeriphClkInitStruct.PLLSAI1.PLLSAI1ClockOut = RCC_PLLSAI1_SAI1CLK
|RCC_PLLSAI1_48M2CLK
|RCC_PLLSAI1_ADC1CLK;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
__HAL_RCC_RTC_ENABLE();
// setup SYSTICK, but we don't have the irq hooked up and not using HAL
systick_setup();
}
// EOF