blob: 86b5680ba60c86e493271efda99e3001a29feafd [file] [log] [blame]
/* ----------------------------------------------------------------------------
* 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 ┬Áseconds.
//------------------------------------------------------------------------------
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