tinySA/os/hal/platforms/STM32/adc_lld.c

/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file    STM32/adc_lld.c
 * @brief   STM32 ADC subsystem low level driver source.
 *
 * @addtogroup ADC
 * @{
 */

#include "ch.h"
#include "hal.h"

#if HAL_USE_ADC || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/** @brief ADC1 driver identifier.*/
#if STM32_ADC_USE_ADC1 || defined(__DOXYGEN__)
ADCDriver ADCD1;
#endif

/*===========================================================================*/
/* Driver local variables.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver interrupt handlers.                                                */
/*===========================================================================*/

#if STM32_ADC_USE_ADC1 || defined(__DOXYGEN__)
/**
 * @brief   ADC1 DMA interrupt handler (channel 1).
 *
 * @isr
 */
CH_IRQ_HANDLER(DMA1_Ch1_IRQHandler) {
  uint32_t isr;

  CH_IRQ_PROLOGUE();

  isr = STM32_DMA1->ISR;
  dmaClearChannel(STM32_DMA1, STM32_DMA_CHANNEL_1);
  if ((isr & DMA_ISR_TEIF1) != 0) {
    /* DMA error processing.*/
    STM32_ADC1_DMA_ERROR_HOOK();
  }
  if ((isr & DMA_ISR_HTIF1) != 0) {
    /* Half transfer processing.*/
    _adc_isr_half_code(&ADCD1);
  }
  if ((isr & DMA_ISR_TCIF1) != 0) {
    /* Transfer complete processing.*/
    _adc_isr_full_code(&ADCD1);
  }

  CH_IRQ_EPILOGUE();
}
#endif

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   Low level ADC driver initialization.
 *
 * @notapi
 */
void adc_lld_init(void) {

#if STM32_ADC_USE_ADC1
  /* Driver initialization.*/
  adcObjectInit(&ADCD1);
  ADCD1.adc = ADC1;
  ADCD1.dmachp = STM32_DMA1_CH1;
  ADCD1.dmaccr = (STM32_ADC_ADC1_DMA_PRIORITY << 12) |
                    DMA_CCR1_EN   | DMA_CCR1_MSIZE_0 | DMA_CCR1_PSIZE_0 |
                    DMA_CCR1_MINC | DMA_CCR1_TCIE    | DMA_CCR1_TEIE;

  /* Temporary activation.*/
  RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
  ADC1->CR1 = 0;
  ADC1->CR2 = ADC_CR2_ADON;

  /* Reset calibration just to be safe.*/
  ADC1->CR2 = ADC_CR2_ADON | ADC_CR2_RSTCAL;
  while ((ADC1->CR2 & ADC_CR2_RSTCAL) != 0)
    ;

  /* Calibration.*/
  ADC1->CR2 = ADC_CR2_ADON | ADC_CR2_CAL;
  while ((ADC1->CR2 & ADC_CR2_CAL) != 0)
    ;

  /* Return the ADC in low power mode.*/
  ADC1->CR2 = 0;
  RCC->APB2ENR &= ~RCC_APB2ENR_ADC1EN;
#endif
}

/**
 * @brief   Configures and activates the ADC peripheral.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @notapi
 */
void adc_lld_start(ADCDriver *adcp) {

  /* If in stopped state then enables the ADC and DMA clocks.*/
  if (adcp->state == ADC_STOP) {
#if STM32_ADC_USE_ADC1
    if (&ADCD1 == adcp) {
      dmaEnable(DMA1_ID);   /* NOTE: Must be enabled before the IRQs.*/
      NVICEnableVector(DMA1_Channel1_IRQn,
                       CORTEX_PRIORITY_MASK(STM32_ADC_ADC1_IRQ_PRIORITY));
      dmaChannelSetPeripheral(adcp->dmachp, &ADC1->DR);
      RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
    }
#endif

    /* ADC setup, the calibration procedure has already been performed
       during initialization.*/
    adcp->adc->CR1 = ADC_CR1_SCAN;
    adcp->adc->CR2 = 0;
  }
}

/**
 * @brief   Deactivates the ADC peripheral.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @notapi
 */
void adc_lld_stop(ADCDriver *adcp) {

  /* If in ready state then disables the ADC clock.*/
  if (adcp->state == ADC_READY) {
#if STM32_ADC_USE_ADC1
    if (&ADCD1 == adcp) {
      ADC1->CR1 = 0;
      ADC1->CR2 = 0;
      NVICDisableVector(DMA1_Channel1_IRQn);
      dmaDisable(DMA1_ID);
      RCC->APB2ENR &= ~RCC_APB2ENR_ADC1EN;
    }
#endif
  }
}

/**
 * @brief   Starts an ADC conversion.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @notapi
 */
void adc_lld_start_conversion(ADCDriver *adcp) {
  uint32_t ccr, n;
  const ADCConversionGroup *grpp = adcp->grpp;

  /* DMA setup.*/
  ccr = adcp->dmaccr;
  if (grpp->circular)
    ccr |= DMA_CCR1_CIRC;
  if (adcp->depth > 1) {
    /* If the buffer depth is greater than one then the half transfer interrupt
       interrupt is enabled in order to allows streaming processing.*/
    ccr |= DMA_CCR1_HTIE;
    n = (uint32_t)grpp->num_channels * (uint32_t)adcp->depth;
  }
  else
    n = (uint32_t)grpp->num_channels;
  dmaChannelSetup(adcp->dmachp, n, adcp->samples, ccr);

  /* ADC setup.*/
  adcp->adc->CR1   = grpp->cr1 | ADC_CR1_SCAN;
  adcp->adc->CR2   = grpp->cr2 | ADC_CR2_DMA |
                        ADC_CR2_CONT | ADC_CR2_ADON;
  adcp->adc->SMPR1 = grpp->smpr1;
  adcp->adc->SMPR2 = grpp->smpr2;
  adcp->adc->SQR1  = grpp->sqr1;
  adcp->adc->SQR2  = grpp->sqr2;
  adcp->adc->SQR3  = grpp->sqr3;

  /* ADC start by writing ADC_CR2_ADON a second time.*/
  adcp->adc->CR2   = grpp->cr2 | ADC_CR2_DMA |
                        ADC_CR2_CONT | ADC_CR2_ADON;
}

/**
 * @brief   Stops an ongoing conversion.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @notapi
 */
void adc_lld_stop_conversion(ADCDriver *adcp) {

  dmaChannelDisable(adcp->dmachp);
  adcp->adc->CR2 = 0;
}

#endif /* HAL_USE_ADC */

/** @} */