hal_adc.c

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/*
    ChibiOS - Copyright (C) 2006..2018 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    hal_adc.c
 * @brief   ADC Driver code.
 *
 * @addtogroup ADC
 * @{
 */

#include "hal.h"

#if (HAL_USE_ADC == TRUE) || defined(__DOXYGEN__)

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

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

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

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

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

/**
 * @brief   ADC Driver initialization.
 * @note    This function is implicitly invoked by @p halInit(), there is
 *          no need to explicitly initialize the driver.
 *
 * @init
 */
void adcInit(void) {

  adc_lld_init();
}

/**
 * @brief   Initializes the standard part of a @p ADCDriver structure.
 *
 * @param[out] adcp     pointer to the @p ADCDriver object
 *
 * @init
 */
void adcObjectInit(ADCDriver *adcp) {

  adcp->state    = ADC_STOP;
  adcp->config   = NULL;
  adcp->samples  = NULL;
  adcp->depth    = 0;
  adcp->grpp     = NULL;
#if ADC_USE_WAIT == TRUE
  adcp->thread   = NULL;
#endif
#if ADC_USE_MUTUAL_EXCLUSION == TRUE
  osalMutexObjectInit(&adcp->mutex);
#endif
#if defined(ADC_DRIVER_EXT_INIT_HOOK)
  ADC_DRIVER_EXT_INIT_HOOK(adcp);
#endif
}

/**
 * @brief   Configures and activates the ADC peripheral.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 * @param[in] config    pointer to the @p ADCConfig object. Depending on
 *                      the implementation the value can be @p NULL.
 *
 * @api
 */
void adcStart(ADCDriver *adcp, const ADCConfig *config) {

  osalDbgCheck(adcp != NULL);

  osalSysLock();
  osalDbgAssert((adcp->state == ADC_STOP) || (adcp->state == ADC_READY),
                "invalid state");
  adcp->config = config;
  adc_lld_start(adcp);
  adcp->state = ADC_READY;
  osalSysUnlock();
}

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

  osalDbgCheck(adcp != NULL);

  osalSysLock();

  osalDbgAssert((adcp->state == ADC_STOP) || (adcp->state == ADC_READY),
                "invalid state");

  adc_lld_stop(adcp);
  adcp->config = NULL;
  adcp->state  = ADC_STOP;

  osalSysUnlock();
}

/**
 * @brief   Starts an ADC conversion.
 * @details Starts an asynchronous conversion operation.
 * @note    The buffer is organized as a matrix of M*N elements where M is the
 *          channels number configured into the conversion group and N is the
 *          buffer depth. The samples are sequentially written into the buffer
 *          with no gaps.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 * @param[in] grpp      pointer to a @p ADCConversionGroup object
 * @param[out] samples  pointer to the samples buffer
 * @param[in] depth     buffer depth (matrix rows number). The buffer depth
 *                      must be one or an even number.
 *
 * @api
 */
void adcStartConversion(ADCDriver *adcp,
                        const ADCConversionGroup *grpp,
                        adcsample_t *samples,
                        size_t depth) {

  osalSysLock();
  adcStartConversionI(adcp, grpp, samples, depth);
  osalSysUnlock();
}

/**
 * @brief   Starts an ADC conversion.
 * @details Starts an asynchronous conversion operation.
 * @post    The callbacks associated to the conversion group will be invoked
 *          on buffer fill and error events.
 * @note    The buffer is organized as a matrix of M*N elements where M is the
 *          channels number configured into the conversion group and N is the
 *          buffer depth. The samples are sequentially written into the buffer
 *          with no gaps.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 * @param[in] grpp      pointer to a @p ADCConversionGroup object
 * @param[out] samples  pointer to the samples buffer
 * @param[in] depth     buffer depth (matrix rows number). The buffer depth
 *                      must be one or an even number.
 *
 * @iclass
 */
void adcStartConversionI(ADCDriver *adcp,
                         const ADCConversionGroup *grpp,
                         adcsample_t *samples,
                         size_t depth) {

  osalDbgCheckClassI();
  osalDbgCheck((adcp != NULL) && (grpp != NULL) && (samples != NULL) &&
               (depth > 0U) && ((depth == 1U) || ((depth & 1U) == 0U)));
  osalDbgAssert((adcp->state == ADC_READY) ||
                (adcp->state == ADC_COMPLETE) ||
                (adcp->state == ADC_ERROR),
                "not ready");

  adcp->samples  = samples;
  adcp->depth    = depth;
  adcp->grpp     = grpp;
  adcp->state    = ADC_ACTIVE;
  adc_lld_start_conversion(adcp);
}

/**
 * @brief   Stops an ongoing conversion.
 * @details This function stops the currently ongoing conversion and returns
 *          the driver in the @p ADC_READY state. If there was no conversion
 *          being processed then the function does nothing.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @api
 */
void adcStopConversion(ADCDriver *adcp) {

  osalDbgCheck(adcp != NULL);

  osalSysLock();
  osalDbgAssert((adcp->state == ADC_READY) || (adcp->state == ADC_ACTIVE),
                "invalid state");
  if (adcp->state != ADC_READY) {
    adc_lld_stop_conversion(adcp);
    adcp->grpp  = NULL;
    adcp->state = ADC_READY;
    _adc_reset_s(adcp);
  }
  osalSysUnlock();
}

/**
 * @brief   Stops an ongoing conversion.
 * @details This function stops the currently ongoing conversion and returns
 *          the driver in the @p ADC_READY state. If there was no conversion
 *          being processed then the function does nothing.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @iclass
 */
void adcStopConversionI(ADCDriver *adcp) {

  osalDbgCheckClassI();
  osalDbgCheck(adcp != NULL);
  osalDbgAssert((adcp->state == ADC_READY) ||
                (adcp->state == ADC_ACTIVE) ||
                (adcp->state == ADC_COMPLETE),
                "invalid state");

  if (adcp->state != ADC_READY) {
    adc_lld_stop_conversion(adcp);
    adcp->grpp  = NULL;
    adcp->state = ADC_READY;
    _adc_reset_i(adcp);
  }
}

#if (ADC_USE_WAIT == TRUE) || defined(__DOXYGEN__)
/**
 * @brief   Performs an ADC conversion.
 * @details Performs a synchronous conversion operation.
 * @note    The buffer is organized as a matrix of M*N elements where M is the
 *          channels number configured into the conversion group and N is the
 *          buffer depth. The samples are sequentially written into the buffer
 *          with no gaps.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 * @param[in] grpp      pointer to a @p ADCConversionGroup object
 * @param[out] samples  pointer to the samples buffer
 * @param[in] depth     buffer depth (matrix rows number). The buffer depth
 *                      must be one or an even number.
 * @return              The operation result.
 * @retval MSG_OK       Conversion finished.
 * @retval MSG_RESET    The conversion has been stopped using
 *                      @p acdStopConversion() or @p acdStopConversionI(),
 *                      the result buffer may contain incorrect data.
 * @retval MSG_TIMEOUT  The conversion has been stopped because an hardware
 *                      error.
 *
 * @api
 */
msg_t adcConvert(ADCDriver *adcp,
                 const ADCConversionGroup *grpp,
                 adcsample_t *samples,
                 size_t depth) {
  msg_t msg;

  osalSysLock();
  osalDbgAssert(adcp->thread == NULL, "already waiting");
  adcStartConversionI(adcp, grpp, samples, depth);
  msg = osalThreadSuspendS(&adcp->thread);
  osalSysUnlock();
  return msg;
}
#endif /* ADC_USE_WAIT == TRUE */

#if (ADC_USE_MUTUAL_EXCLUSION == TRUE) || defined(__DOXYGEN__)
/**
 * @brief   Gains exclusive access to the ADC peripheral.
 * @details This function tries to gain ownership to the ADC bus, if the bus
 *          is already being used then the invoking thread is queued.
 * @pre     In order to use this function the option
 *          @p ADC_USE_MUTUAL_EXCLUSION must be enabled.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @api
 */
void adcAcquireBus(ADCDriver *adcp) {

  osalDbgCheck(adcp != NULL);

  osalMutexLock(&adcp->mutex);
}

/**
 * @brief   Releases exclusive access to the ADC peripheral.
 * @pre     In order to use this function the option
 *          @p ADC_USE_MUTUAL_EXCLUSION must be enabled.
 *
 * @param[in] adcp      pointer to the @p ADCDriver object
 *
 * @api
 */
void adcReleaseBus(ADCDriver *adcp) {

  osalDbgCheck(adcp != NULL);

  osalMutexUnlock(&adcp->mutex);
}
#endif /* ADC_USE_MUTUAL_EXCLUSION == TRUE */

#endif /* HAL_USE_ADC == TRUE */

/** @} */