OpenRTX/platform/drivers/ADC/adc_stm32h7.c

132 lines
4.0 KiB
C

/***************************************************************************
* Copyright (C) 2024 by Silvano Seva IU2KWO *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#include <stm32h7xx.h>
#include <pthread.h>
#include <errno.h>
#include "adc_stm32.h"
int adcStm32_init(const struct Adc *adc)
{
/*
* Configure ADC for synchronous clock mode (clocked by AHB clock), divided
* by 4. This gives an ADC clock of 50MHz when AHB clock is 200MHz.
*
* NOTE: ADC1 and ADC2 share the same clock tree!
*/
switch((uint32_t) adc->priv)
{
case ADC1_BASE:
case ADC2_BASE:
RCC->AHB1ENR |= RCC_AHB1ENR_ADC12EN;
__DSB();
ADC12_COMMON->CCR = ADC_CCR_CKMODE_1
| ADC_CCR_CKMODE_0;
break;
case ADC3_BASE:
RCC->AHB4ENR |= RCC_AHB4ENR_ADC3EN;
__DSB();
ADC3_COMMON->CCR = ADC_CCR_CKMODE_1
| ADC_CCR_CKMODE_0;
break;
default:
return -EINVAL;
break;
}
ADC_TypeDef *pAdc = ((ADC_TypeDef *) adc->priv);
// Enable ADC voltage regulator, enable boost mode. Wait until LDO regulator
// is ready.
pAdc->CR = ADC_CR_ADVREGEN
| ADC_CR_BOOST_1
| ADC_CR_BOOST_0;
while((pAdc->ISR & ADC_ISR_LDORDY) == 0) ;
// Start calibration, both offset and linearity.
pAdc->CR |= ADC_CR_ADCAL
| ADC_CR_ADCALLIN;
while((pAdc->CR & ADC_CR_ADCAL) != 0) ;
/*
* ADC clock is 50MHz. We set the sample time of each channel to 387.5 ADC
* cycles, giving a total conversion time of ~7us.
*/
pAdc->SMPR2 = 0x36DB6DB6;
pAdc->SMPR1 = 0x36DB6DB6;
// Finally,turn on the ADC
pAdc->CR |= ADC_CR_ADEN;
while((pAdc->ISR & ADC_ISR_ADRDY) != 0) ;
if(adc->mutex != NULL)
pthread_mutex_init((pthread_mutex_t *) adc->mutex, NULL);
return 0;
}
void adcStm32_terminate(const struct Adc *adc)
{
// A conversion may be in progress, wait until it finishes
if(adc->mutex != NULL)
pthread_mutex_lock((pthread_mutex_t *) adc->mutex);
((ADC_TypeDef *) adc->priv)->CR = 0;
switch((uint32_t) adc->priv)
{
case ADC1_BASE:
case ADC2_BASE:
if((ADC1->CR == 0) && (ADC2->CR == 0))
RCC->AHB1ENR &= ~RCC_AHB1ENR_ADC12EN;
__DSB();
break;
case ADC3_BASE:
RCC->AHB4ENR &= ~RCC_AHB4ENR_ADC3EN;
__DSB();
break;
default:
break;
}
if(adc->mutex != NULL)
pthread_mutex_destroy((pthread_mutex_t *) adc->mutex);
}
uint16_t adcStm32_sample(const struct Adc *adc, const uint32_t channel)
{
if(channel > 16)
return 0;
ADC_TypeDef *pAdc = ((ADC_TypeDef *) adc->priv);
pAdc->SQR1 = channel << ADC_SQR1_SQ1_Pos;
pAdc->PCSEL = 1 << channel;
pAdc->CR |= ADC_CR_ADSTART;
while((pAdc->ISR & ADC_ISR_EOC) == 0) ;
return pAdc->DR;
}