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/* ----------------------------------------------------------------------------

 *         ATMEL Microcontroller Software Support

 * ----------------------------------------------------------------------------

 * Copyright (c) 2008, Atmel Corporation

 *

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * - Redistributions of source code must retain the above copyright notice,

 * this list of conditions and the disclaimer below.

 *

 * Atmel's name may not be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE

 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,

 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,

 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 * ----------------------------------------------------------------------------

 */

//------------------------------------------------------------------------------

//         Headers

//------------------------------------------------------------------------------

#include <board.h>

#ifdef AT91C_BASE_TSADC

#include <utility/trace.h>

#include <utility/assert.h>

//------------------------------------------------------------------------------

//         Local variables

//------------------------------------------------------------------------------

/// TSADC clock frequency in Hz.

static unsigned int lAdcclk = 0;

//------------------------------------------------------------------------------

//         Global functions

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

/// Sets the operating mode of the TSADCC peripheral. The mode value can be

/// one of the following:

/// - AT91C_TSADC_TSAMOD_ADC_ONLY_MODE

/// - AT91C_TSADC_TSAMOD_TS_ONLY_MODE

/// \param mode  Desired mode for the TSADCC.

//------------------------------------------------------------------------------

void TSADCC_SetOperatingMode(unsigned int mode)

{

    SANITY_CHECK(  (mode == AT91C_TSADC_TSAMOD_ADC_ONLY_MODE)

                 | (mode == AT91C_TSADC_TSAMOD_TS_ONLY_MODE));

    AT91C_BASE_TSADC->TSADC_MR = (AT91C_BASE_TSADC->TSADC_MR

                                  & ~AT91C_TSADC_TSAMOD)

                                 | mode;

}

//------------------------------------------------------------------------------

/// Enables or disables the low resolution precision on the TSADC.

/// \param enable  If true, low resolution (8 bit) is used; otherwise the TSADC

///                will use a 10-bit resolution.

//------------------------------------------------------------------------------

void TSADCC_SetLowResolution(unsigned char enable)

{

    if (enable) {

        AT91C_BASE_TSADC->TSADC_MR |= AT91C_TSADC_LOWRES;

    }

    else {

        AT91C_BASE_TSADC->TSADC_MR &= ~AT91C_TSADC_LOWRES;

    }

}

//------------------------------------------------------------------------------

/// Enables or disable SLEEP mode on the TSADC.

/// \param enable  If true, the TSADC is put into sleep mode; in normal mode

///                otherwise.

//------------------------------------------------------------------------------

void TSADCC_SetSleepMode(unsigned char enable)

{

    if (enable) {

        AT91C_BASE_TSADC->TSADC_MR |= AT91C_TSADC_SLEEP;

    }

    else {

        AT91C_BASE_TSADC->TSADC_MR &= ~AT91C_TSADC_SLEEP;

    }

}

//------------------------------------------------------------------------------

/// Enables or disables pen detection on the TSADC.

/// \param enable  If true, pen detection is enabled; otherwise it is disabled.

//------------------------------------------------------------------------------

void TSADCC_SetPenDetect(unsigned char enable)

{

    if (enable) {

        AT91C_BASE_TSADC->TSADC_MR |= AT91C_TSADC_PENDET;

    }

    else {

        AT91C_BASE_TSADC->TSADC_MR &= ~AT91C_TSADC_PENDET;

    }

}

//------------------------------------------------------------------------------

/// Sets the TSADC clock to the desired frequency. The prescaler is calculated

/// by this function so the resulting frequency is equal or inferior to the

/// desired one.

/// \param adcclk  Desired ADC clock frequency in Hz.

/// \param mck  Master clock frequency in Hz.

//------------------------------------------------------------------------------

void TSADCC_SetAdcFrequency(unsigned int adcclk, unsigned int mck)

{

    unsigned int prescal;

    // Formula for PRESCAL is:

    // PRESCAL = (MCK / (2 * ADCCLK)) + 1

    // First, we do the division, multiplied by 10 to get higher precision

    // If the last digit is not zero, we round up to avoid generating a higher

    // than required frequency.

    prescal = (mck * 5) / adcclk;

    if ((prescal % 10) > 0) {

        prescal = (prescal / 10);

    }

    else {

        SANITY_CHECK((prescal / 10) != 0);

        prescal = (prescal / 10) - 1;

    }

    SANITY_CHECK((prescal & ~0x3F) == 0);

    AT91C_BASE_TSADC->TSADC_MR = (  AT91C_BASE_TSADC->TSADC_MR

                                  & ~AT91C_TSADC_PRESCAL)

                                 | (prescal << 8);

    // Save clock frequency for further timing calculations

    lAdcclk = adcclk;

}

//------------------------------------------------------------------------------

/// Sets the TSADC startup time. This function relies on the ADCCLK frequency

/// that has been set using TSADCC_SetAdcFrequency(), so it must have been

/// called first.

/// \param time  Startup time in µseconds.

//------------------------------------------------------------------------------

void TSADCC_SetStartupTime(unsigned int time)

{

    unsigned int startup;

    SANITY_CHECK(lAdcclk != 0);

    // Formula for STARTUP is:

    // STARTUP = (time x ADCCLK) / (1000000 x 8) - 1

    // Division multiplied by 10 for higher precision

    startup = (time * lAdcclk) / (800000);

    if ((startup % 10) > 0) {

        startup /= 10;

    }

    else {

        startup /= 10;

        if (startup > 0) {

            startup--;

        }

    }

    SANITY_CHECK((startup & ~0x7F) == 0);

    AT91C_BASE_TSADC->TSADC_MR = (  AT91C_BASE_TSADC->TSADC_MR

                                  & ~AT91C_TSADC_STARTUP)

                                 | (startup << 16);

}

//------------------------------------------------------------------------------

/// Sets the TSADC track and hold time. This function relies on the ADCCLK

/// frequency that has been set with TSADCC_SetAdcFrequency(), to it must be

/// called first.

/// This function also sets the track and hold time in the TSADC_TSR register.

/// \param time  Track and hold time in nanoseconds.

//------------------------------------------------------------------------------

void TSADCC_SetTrackAndHoldTime(unsigned int time)

{

    unsigned int shtim;

    SANITY_CHECK(lAdcclk != 0);

    // Formula for SHTIM:

    // SHTIM = (time x ADCCLK) / 1000000000 - 1

    // Since 1 billion is close to the maximum value for an integer, we first

    // divide ADCCLK by 1000 to avoid an overflow

    shtim = (time * (lAdcclk / 1000)) / 100000;

    if ((shtim % 10) > 0) {

        shtim /= 10;

    }

    else {

        shtim /= 10;

        if (shtim > 0) shtim--;

    }

    SANITY_CHECK((shtim & ~0xF) == 0);

    AT91C_BASE_TSADC->TSADC_MR = (  AT91C_BASE_TSADC->TSADC_MR

                                  & ~AT91C_TSADC_SHTIM)

                                 | (shtim << 24);

    AT91C_BASE_TSADC->TSADC_TSR = shtim << 24;

}

//------------------------------------------------------------------------------

/// Sets the TSADC debounce time. This function relies on the ADCCLK

/// frequency that has been set with TSADCC_SetAdcFrequency(), to it must be

/// called first.

/// \param time  Debounce time in nanoseconds (cannot be 0).

//------------------------------------------------------------------------------

void TSADCC_SetDebounceTime(unsigned int time)

{

    unsigned int divisor = 1000000000;

    unsigned int clock = lAdcclk;

    unsigned int pendbc = 0;

    unsigned int targetValue;

    unsigned int currentValue;

    SANITY_CHECK(lAdcclk != 0);

    SANITY_CHECK(time != 0);

    // Divide time & ADCCLK first to avoid overflows

    while ((divisor > 1) && ((time % 10) == 0)) {

        time /= 10;

        divisor /= 10;

    }

    while ((divisor > 1) && ((clock % 10) == 0)) {

        clock /= 10;

        divisor /= 10;

    }

    // Compute PENDBC value

    targetValue = time * clock / divisor;

    currentValue = 1;

    while (currentValue < targetValue) {

        pendbc++;

        currentValue *= 2;

    }

    SANITY_CHECK((pendbc & ~0xF) == 0);

    AT91C_BASE_TSADC->TSADC_MR = (  AT91C_BASE_TSADC->TSADC_MR

                                  & ~AT91C_TSADC_PENDBC)

                                 | (pendbc << 28);

}

//------------------------------------------------------------------------------

/// Sets the trigger mode of the TSADCC to one of the following values:

/// - AT91C_TSADC_TRGMOD_NO_TRIGGER

/// - AT91C_TSADC_TRGMOD_EXTERNAL_TRIGGER_RE

/// - AT91C_TSADC_TRGMOD_EXTERNAL_TRIGGER_FE

/// - AT91C_TSADC_TRGMOD_EXTERNAL_TRIGGER_AE

/// - AT91C_TSADC_TRGMOD_PENDET_TRIGGER

/// - AT91C_TSADC_TRGMOD_PERIODIC_TRIGGER

/// - AT91C_TSADC_TRGMOD_CONT_TRIGGER

/// \param mode  Trigger mode.

//------------------------------------------------------------------------------

void TSADCC_SetTriggerMode(unsigned int mode)

{

    SANITY_CHECK(((mode & ~AT91C_TSADC_TRGMOD) == 0)

                 | ((mode & AT91C_TSADC_TRGMOD) != 0x7));

    AT91C_BASE_TSADC->TSADC_TRGR = (AT91C_BASE_TSADC->TSADC_TRGR

                                    & ~AT91C_TSADC_TRGMOD)

                                   | mode;

}

//------------------------------------------------------------------------------

/// Sets the trigger period when using the TSADCC in periodic trigger mode.

/// As usual, this function requires TSADCC_SetAdcFrequency() to be called

/// before it.

/// \param period  Trigger period in nanoseconds.

//------------------------------------------------------------------------------

void TSADCC_SetTriggerPeriod(unsigned int period)

{

    unsigned int trgper;

    unsigned int divisor = 100000000;

    while ((period >= 10) && (divisor >= 10)) {

        period /= 10;

        divisor /= 10;

    }

    trgper = (period * lAdcclk) / divisor;

    if ((trgper % 10) > 0) {

        trgper /= 10;

    }

    else {

        trgper /= 10;

        if (trgper > 0) trgper--;

    }

    SANITY_CHECK((trgper & ~0xFFFF) == 0);

    AT91C_BASE_TSADC->TSADC_TRGR = (AT91C_BASE_TSADC->TSADC_TRGR

                                    & ~AT91C_TSADC_TRGPER)

                                   | (trgper << 16);

}

#endif //#ifdef AT91C_BASE_TSADC