File content as of revision 167:356ef919c855:

/**
 * @file adc.c
 * @brief      This file contains the function implementations for the Analog to
 *             Digital Converter (ADC) peripheral module.
 */

/* ****************************************************************************
 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
 *
 * 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 MAXIM INTEGRATED 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.
 *
 * Except as contained in this notice, the name of Maxim Integrated
 * Products, Inc. shall not be used except as stated in the Maxim Integrated
 * Products, Inc. Branding Policy.
 *
 * The mere transfer of this software does not imply any licenses
 * of trade secrets, proprietary technology, copyrights, patents,
 * trademarks, maskwork rights, or any other form of intellectual
 * property whatsoever. Maxim Integrated Products, Inc. retains all
 * ownership rights.
 *
 * $Date: 2016-08-02 13:32:46 -0500 (Tue, 02 Aug 2016) $
 * $Revision: 23893 $
 *
 *************************************************************************** */

/**
 * @ingroup adc
 * @{
 */

/* **** Includes **** */
#include "mxc_config.h"
#include "mxc_assert.h"
#include "mxc_sys.h"
#include "adc.h"

/* **** Definitions **** */

/* **** Globals **** */

/* **** Functions **** */

/* ************************************************************************* */
int ADC_Init(void)
{
    int err;

    if ((err = SYS_ADC_Init()) != E_NO_ERROR) {
        return err;
    }

    /* Wipe previous configuration */
    MXC_ADC->intr = 0;

    /* Clear all ADC interrupt flags (W1C) */
    MXC_ADC->intr = MXC_ADC->intr;

    /* Enable done interrupt */
    MXC_ADC->intr = MXC_F_ADC_INTR_ADC_DONE_IE;

    /* Power up the ADC */
    MXC_ADC->ctrl = (MXC_F_ADC_CTRL_ADC_PU |
                     MXC_F_ADC_CTRL_ADC_CLK_EN |
                     MXC_F_ADC_CTRL_BUF_PU |
                     MXC_F_ADC_CTRL_ADC_REFBUF_PU |
                     MXC_F_ADC_CTRL_ADC_CHGPUMP_PU);

    return E_NO_ERROR;
}

/* ************************************************************************* */
void ADC_StartConvert(mxc_adc_chsel_t channel, unsigned int adc_scale, unsigned int bypass)
{
    uint32_t ctrl_tmp;

    /* Clear the ADC done flag */
    ADC_ClearFlags(MXC_F_ADC_INTR_ADC_DONE_IF);

    /* Insert channel selection */
    ctrl_tmp = MXC_ADC->ctrl;
    ctrl_tmp &= ~(MXC_F_ADC_CTRL_ADC_CHSEL);
    ctrl_tmp |= ((channel << MXC_F_ADC_CTRL_ADC_CHSEL_POS) & MXC_F_ADC_CTRL_ADC_CHSEL);

    /* Clear channel configuration */
    ctrl_tmp &= ~(MXC_F_ADC_CTRL_ADC_REFSCL | MXC_F_ADC_CTRL_ADC_SCALE | MXC_F_ADC_CTRL_BUF_BYPASS);

    /* ADC reference scaling must be set for all channels but two*/
    if ((channel != ADC_CH_VDD18) && (channel != ADC_CH_VDD12)) {
        ctrl_tmp |= MXC_F_ADC_CTRL_ADC_REFSCL;
    }

    /* Finalize user-requested channel configuration */
    if (adc_scale || channel > ADC_CH_3) {
        ctrl_tmp |= MXC_F_ADC_CTRL_ADC_SCALE;
    }
    if (bypass) {
        ctrl_tmp |= MXC_F_ADC_CTRL_BUF_BYPASS;
    }

    /* Write this configuration */
    MXC_ADC->ctrl = ctrl_tmp;

    /* Start conversion */
    MXC_ADC->ctrl |= MXC_F_ADC_CTRL_CPU_ADC_START;

}

/* ************************************************************************* */
int ADC_GetData(uint16_t *outdata)
{
    /* See if a conversion is in process */
    if (MXC_ADC->status & MXC_F_ADC_STATUS_ADC_ACTIVE) {
        /* Wait for conversion to complete */
        while ((MXC_ADC->intr & MXC_F_ADC_INTR_ADC_DONE_IF) == 0);
    }

    /* Read 32-bit value and truncate to 16-bit for output depending on data align bit*/
    if((MXC_ADC->ctrl & MXC_F_ADC_CTRL_ADC_DATAALIGN) == 0)
        *outdata = (uint16_t)(MXC_ADC->data); /* LSB justified */
    else
        *outdata = (uint16_t)(MXC_ADC->data >> 6); /* MSB justified */

    /* Check for overflow */
    if (MXC_ADC->status & MXC_F_ADC_STATUS_ADC_OVERFLOW) {
        return E_OVERFLOW;
    }

    return E_NO_ERROR;
}

/* ************************************************************************* */
int ADC_SetLimit(mxc_adc_limitsel_t unit, mxc_adc_chsel_t channel,
                 unsigned int low_enable, unsigned int low_limit,
                 unsigned int high_enable, unsigned int high_limit)
{
    /* Check args */
    if ((unit >= ADC_LIMIT_MAX) || (channel >= ADC_CH_MAX))
        return E_BAD_PARAM;

    /* set channel using the limit */
    MXC_ADC->limit[unit] = ((channel << MXC_F_ADC_LIMIT0_CH_SEL_POS) & MXC_F_ADC_LIMIT0_CH_SEL);

    /* enable/disable the limit*/
    if (low_enable) {
        MXC_ADC->limit[unit] |= MXC_F_ADC_LIMIT0_CH_LO_LIMIT_EN |
                                ((low_limit << MXC_F_ADC_LIMIT0_CH_LO_LIMIT_POS) & MXC_F_ADC_LIMIT0_CH_LO_LIMIT);
    } else {
        MXC_ADC->limit[unit] &= ~MXC_F_ADC_LIMIT0_CH_LO_LIMIT_EN;
    }

    if (high_enable) {
        MXC_ADC->limit[unit] |= MXC_F_ADC_LIMIT0_CH_HI_LIMIT_EN |
                                ((high_limit << MXC_F_ADC_LIMIT0_CH_HI_LIMIT_POS) & MXC_F_ADC_LIMIT0_CH_HI_LIMIT);
    } else {
        MXC_ADC->limit[unit] &= ~MXC_F_ADC_LIMIT0_CH_HI_LIMIT_EN;
    }

    return E_NO_ERROR;
}

/**@} end of group adc */