MNC-12x5/Src/ds3231.c

#include "main.h"

#define RTC_TX_BUF_SIZE 4

static uint8_t i2cBufTX[RTC_TX_BUF_SIZE] = {0};

/**
 * @brief Инициализация RTC
 */
void RTC_Init(void) {
  /* Clear flags */
  Flag.I2C_TX_End = 0;

  /* Source: Address of the I2C TX buffer. */
  DMA1_Channel3->CMAR = (uint32_t)&i2cBufTX;
  /* Destination: I2C TX data register. */
  DMA1_Channel3->CPAR = (uint32_t)&(I2C1->TXDR);
  /* Set DMA data transfer length (I2C TX buffer length). */
  DMA1_Channel3->CNDTR = 3; // hardcode / magic number
  /* Enable DMA channels for I2C */
  DMA1_Channel3->CCR |= DMA_CCR_EN;

  /* Fill buffer with register address and register value */
  i2cBufTX[0] = DS3231_ADDR_CONTROL;
  i2cBufTX[1] = DS3231_1HZ; // set 1 Hz output squware
  i2cBufTX[2] = 0x0; // disable 32 kHz output

  /* Wait for I2C */
  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  /* Set the device address and number bytes to send. */
  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | 3 << I2C_CR2_NBYTES_Pos );
  /* Enable I2C DMA requests. */
  I2C1->CR1 |= ( I2C_CR1_TXDMAEN );
  /* Send a start signal. */
  I2C1->CR2 |= ( I2C_CR2_START );
  /* (DMA is now running.) */
}

/**
 * @brief Чтение всех регистров DS3231
 */
void RTC_ReadAll(rtc_t * data) {
  Flag.I2C_RX_End = 0;
  Flag.I2C_TX_End = 0;

  /* Source: Address of the I2C RX buffer. */
  DMA1_Channel2->CMAR = (uint32_t)data;
  /* Destination: I2C RX data register. */
  DMA1_Channel2->CPAR = (uint32_t)&(I2C1->RXDR);
  /* Set DMA data transfer length (I2C RX buffer length). */
  DMA1_Channel2->CNDTR = DS3231_SIZE_ALL;
  /* Enable DMA channels for I2C RX */
  DMA1_Channel2->CCR |= DMA_CCR_EN;

  /* wait for i2c */
  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  /* send first register address 00h */
  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | 1 << I2C_CR2_NBYTES_Pos );

  I2C1->CR2 |= ( I2C_CR2_START );

  while ( !( I2C1->CR2 & I2C_CR2_START ) ) {};
  I2C1->TXDR = DS3231_ADDR_TIME;

  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  /* Reading all */
  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | DS3231_SIZE_ALL << I2C_CR2_NBYTES_Pos | I2C_CR2_RD_WRN);

  I2C1->CR1 |= ( I2C_CR1_RXDMAEN );
  I2C1->CR2 |= ( I2C_CR2_START );
}

/**
 * @brief Запись времени и календаря
 */
void RTC_WriteTimeCalendar(rtc_t * data) {
  Flag.I2C_TX_End = 0;

  DMA1_Channel3->CCR &= ~DMA_CCR_EN;
  DMA1_Channel3->CMAR = (uint32_t)data;
  DMA1_Channel3->CPAR = (uint32_t)&(I2C1->TXDR);
  DMA1_Channel3->CNDTR = DS3231_SIZE_TIME + DS3231_SIZE_CALENDAR;

  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | (DS3231_SIZE_TIME + DS3231_SIZE_CALENDAR + 1) << I2C_CR2_NBYTES_Pos );
  I2C1->CR1 |= ( I2C_CR1_TXDMAEN );
  I2C1->CR2 |= ( I2C_CR2_START );

  while ( !( I2C1->CR2 & I2C_CR2_START ) ) {};
  I2C1->TXDR = DS3231_ADDR_TIME; // send reg addr when START finish

  DMA1_Channel3->CCR |= DMA_CCR_EN; // and launch DMA for data to transfer
}

/**
 * @brief Запись времени
 */
void RTC_WriteTime(rtc_t * data) {
  Flag.I2C_TX_End = 0;

  DMA1_Channel3->CMAR = (uint32_t)data;
  DMA1_Channel3->CPAR = (uint32_t)&(I2C1->TXDR);
  DMA1_Channel3->CNDTR = DS3231_SIZE_TIME;

  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | (DS3231_SIZE_TIME + 1) << I2C_CR2_NBYTES_Pos );
  I2C1->CR1 |= ( I2C_CR1_TXDMAEN );
  I2C1->CR2 |= ( I2C_CR2_START );

  while ( !( I2C1->CR2 & I2C_CR2_START ) ) {};
  I2C1->TXDR = DS3231_ADDR_TIME;

  DMA1_Channel3->CCR |= DMA_CCR_EN;
}

/**
 * @brief Запись часов
 */
void RTC_WriteHH(rtc_t * data) {
  Flag.I2C_TX_End = 0; // некому установить этот флаг в 1

  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | 2 << I2C_CR2_NBYTES_Pos );
  I2C1->CR2 |= ( I2C_CR2_START );

  while ( !( I2C1->CR2 & I2C_CR2_START ) ) {};
  I2C1->TXDR = (DS3231_ADDR_TIME + 2);

  while ((I2C1->ISR & I2C_ISR_TXE) == 0) { __NOP(); };
  I2C1->TXDR = data->Hr;
}

/**
 * @brief Запись часов и минут
 */
void RTC_WriteHHMM(rtc_t * data) {
  Flag.I2C_TX_End = 0;

  DMA1_Channel3->CMAR = (uint32_t)&i2cBufTX;
  DMA1_Channel3->CPAR = (uint32_t)&(I2C1->TXDR);
  DMA1_Channel3->CNDTR = 3; // addr + mm + hh
  DMA1_Channel3->CCR |= DMA_CCR_EN;

  /* Fill buffer with register address and register value */
  i2cBufTX[0] = DS3231_ADDR_TIME + 1; // skip seconds
  i2cBufTX[1] = data->Min;
  i2cBufTX[2] = data->Hr;

  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | 3 << I2C_CR2_NBYTES_Pos );
  I2C1->CR1 |= ( I2C_CR1_TXDMAEN );
  I2C1->CR2 |= ( I2C_CR2_START );
}

/**
 * @brief Запись календаря
 */
void RTC_WriteCalendar(rtc_t * data) {
  Flag.I2C_TX_End = 0;

  DMA1_Channel3->CMAR = (uint32_t)&(data->WD);
  DMA1_Channel3->CPAR = (uint32_t)&(I2C1->TXDR);
  DMA1_Channel3->CNDTR = DS3231_SIZE_CALENDAR;

  while ( I2C1->ISR & I2C_ISR_BUSY ) {};

  I2C1->CR2 &= ~( I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RD_WRN);
  I2C1->CR2 |= ( DS3231_I2C_ADDR | (DS3231_SIZE_CALENDAR + 1) << I2C_CR2_NBYTES_Pos );
  I2C1->CR1 |= ( I2C_CR1_TXDMAEN );
  I2C1->CR2 |= ( I2C_CR2_START );

  while ( !( I2C1->CR2 & I2C_CR2_START ) ) {};
  I2C1->TXDR = DS3231_ADDR_CALENDAR;

  DMA1_Channel3->CCR |= DMA_CCR_EN;
}

/**
 * @brief Convert BCD value to Binary
 */
uint8_t bcd2bin(uint8_t bcd)
{
  return (10 * (bcd >> 4) + (bcd & 0x0f));
}

/**
 * @brief Convert Binary value to BCD
 */
uint8_t bin2bcd(uint8_t bin)
{
  return (((bin / 10 ) << 4) | (bin % 10));
}