tinySA/os/hal/platforms/STM32F0xx/adc_lld.c

/*
    ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

/**
 * @file    STM32F0xx/adc_lld.c
 * @brief   STM32F0xx ADC subsystem low level driver source.
 *
 * @addtogroup ADC
 * @{
 */

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

#if HAL_USE_ADC || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

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

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

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

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

/**
 * @brief   Stops an ongoing conversion, if any.
 *
 * @param[in] adc       pointer to the ADC registers block
 */
static void adc_lld_stop_adc(ADC_TypeDef *adc) {

  if (adc->CR & ADC_CR_ADSTART) {
    adc->CR |= ADC_CR_ADSTP;
    while (adc->CR & ADC_CR_ADSTP)
      ;
  }
}

/**
 * @brief   ADC DMA ISR service routine.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 * @param[in] flags     pre-shifted content of the ISR register
 */
static void adc_lld_serve_rx_interrupt(ADCDriver *adcp, uint32_t flags) {

  /* DMA errors handling.*/
  if ((flags & (STM32_DMA_ISR_TEIF | STM32_DMA_ISR_DMEIF)) != 0) {
    /* DMA, this could help only if the DMA tries to access an unmapped
       address space or violates alignment rules.*/
    _adc_isr_error_code(adcp, ADC_ERR_DMAFAILURE);
  }
  else {
    /* It is possible that the conversion group has already be reset by the
       ADC error handler, in this case this interrupt is spurious.*/
    if (adcp->grpp != NULL) {
      if ((flags & STM32_DMA_ISR_HTIF) != 0) {
        /* Half transfer processing.*/
        _adc_isr_half_code(adcp);
      }
      if ((flags & STM32_DMA_ISR_TCIF) != 0) {
        /* Transfer complete processing.*/
        _adc_isr_full_code(adcp);
      }
    }
  }
}

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

#if STM32_ADC_USE_ADC1 || defined(__DOXYGEN__)
/**
 * @brief   ADC interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(ADC1_COMP_IRQHandler) {
  uint32_t isr;

  CH_IRQ_PROLOGUE();

  isr = ADC1->ISR;
  ADC1->ISR = isr;

  /* It could be a spurious interrupt caused by overflows after DMA disabling,
     just ignore it in this case.*/
  if (ADCD1.grpp != NULL) {
    /* Note, an overflow may occur after the conversion ended before the driver
       is able to stop the ADC, this is why the DMA channel is checked too.*/
    if ((isr & ADC_ISR_OVR) &&
        (dmaStreamGetTransactionSize(ADCD1.dmastp) > 0)) {
      /* ADC overflow condition, this could happen only if the DMA is unable
         to read data fast enough.*/
      _adc_isr_error_code(&ADCD1, ADC_ERR_OVERFLOW);
    }
    if (isr & ADC_ISR_AWD) {
      /* Analog watchdog error.*/
      _adc_isr_error_code(&ADCD1, ADC_ERR_AWD);
    }
  }

  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.dmastp  = STM32_DMA1_STREAM1;
  ADCD1.dmamode = STM32_DMA_CR_PL(STM32_ADC_ADC1_DMA_PRIORITY) |
                  STM32_DMA_CR_DIR_P2M |
                  STM32_DMA_CR_MSIZE_HWORD | STM32_DMA_CR_PSIZE_HWORD |
                  STM32_DMA_CR_MINC        | STM32_DMA_CR_TCIE        |
                  STM32_DMA_CR_DMEIE       | STM32_DMA_CR_TEIE;
#endif

  /* The shared vector is initialized on driver initialization and never
     disabled.*/
  nvicEnableVector(ADC1_COMP_IRQn,
                   CORTEX_PRIORITY_MASK(STM32_ADC_IRQ_PRIORITY));

  /* Calibration procedure.*/
  rccEnableADC1(FALSE);
  chDbgAssert(ADC1->CR == 0, "adc_lld_init(), #1", "invalid register state");
  ADC1->CR |= ADC_CR_ADCAL;
  while (ADC1->CR & ADC_CR_ADCAL)
    ;
  rccDisableADC1(FALSE);
}

/**
 * @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) {
      bool_t b;
      b = dmaStreamAllocate(adcp->dmastp,
                            STM32_ADC_ADC1_DMA_IRQ_PRIORITY,
                            (stm32_dmaisr_t)adc_lld_serve_rx_interrupt,
                            (void *)adcp);
      chDbgAssert(!b, "adc_lld_start(), #1", "stream already allocated");
      dmaStreamSetPeripheral(adcp->dmastp, &ADC1->DR);
      rccEnableADC1(FALSE);
#if STM32_ADCSW == STM32_ADCSW_HSI14
      /* Clock from HSI14, no need for jitter removal.*/
      ADC1->CFGR2 = 0x00001000;
#else
#if STM32_ADCPRE == STM32_ADCPRE_DIV2
      ADC1->CFGR2 = 0x00001000 | ADC_CFGR2_JITOFFDIV2;
#else
      ADC1->CFGR2 = 0x00001000 | ADC_CFGR2_JITOFFDIV4;
#endif
#endif
    }
#endif /* STM32_ADC_USE_ADC1 */

    /* ADC initial setup, starting the analog part here in order to reduce
       the latency when starting a conversion.*/
    adcp->adc->CR = ADC_CR_ADEN;
    while (!(adcp->adc->ISR & ADC_ISR_ADRDY))
      ;
  }
}

/**
 * @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 and analog part.*/
  if (adcp->state == ADC_READY) {

    dmaStreamRelease(adcp->dmastp);

    /* Disabling ADC.*/
    if (adcp->adc->CR & ADC_CR_ADEN) {
      adc_lld_stop_adc(adcp->adc);
      adcp->adc->CR |= ADC_CR_ADDIS;
      while (adcp->adc->CR & ADC_CR_ADDIS)
        ;
    }

#if STM32_ADC_USE_ADC1
    if (&ADCD1 == adcp)
      rccDisableADC1(FALSE);
#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 mode;
  const ADCConversionGroup *grpp = adcp->grpp;

  /* DMA setup.*/
  mode = adcp->dmamode;
  if (grpp->circular) {
    mode |= STM32_DMA_CR_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.*/
    mode |= STM32_DMA_CR_HTIE;
  }
  dmaStreamSetMemory0(adcp->dmastp, adcp->samples);
  dmaStreamSetTransactionSize(adcp->dmastp, (uint32_t)grpp->num_channels *
                                            (uint32_t)adcp->depth);
  dmaStreamSetMode(adcp->dmastp, mode);
  dmaStreamEnable(adcp->dmastp);

  /* ADC setup, if it is defined a callback for the analog watch dog then it
     is enabled.*/
  adcp->adc->ISR    = adcp->adc->ISR;
  adcp->adc->IER    = ADC_IER_OVRIE | ADC_IER_AWDIE;
  adcp->adc->TR     = grpp->tr;
  adcp->adc->SMPR   = grpp->smpr;
  adcp->adc->CHSELR = grpp->chselr;

  /* ADC configuration and start.*/
  adcp->adc->CFGR1  = grpp->cfgr1 | ADC_CFGR1_CONT  | ADC_CFGR1_DMACFG |
                                    ADC_CFGR1_DMAEN;
  adcp->adc->CR    |= ADC_CR_ADSTART;
}

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

  dmaStreamDisable(adcp->dmastp);
  adc_lld_stop_adc(adcp->adc);
}

#endif /* HAL_USE_ADC */

/** @} */