psyco wrote:This appears to be an errata. See ES0418 2.6.2, "Writing ADC_CFGR1 register while ADEN bit is set resets RES[1:0] bitfield".
This must be it, moving this topic into the "bug reports" section. This could be an ugly fix if we have to stop the ADC each time we program a conversion...
/* 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. */
/*===========================================================================*/ /* Driver local variables and types. */ /*===========================================================================*/
/*===========================================================================*/ /* Driver local functions. */ /*===========================================================================*/
/** * @brief ADC voltage regulator enable. * * @param[in] adc pointer to the ADC registers block */ NOINLINE static void adc_lld_vreg_on(ADC_TypeDef *adc) {
/** * @brief Starts the ADC enable procedure. * * @param[in] adc pointer to the ADC registers block */ static void adc_lld_start_enable_adc(ADC_TypeDef *adc) {
adc->CR = ADC_CR_ADEN; }
/** * @brief Waits for the ADC enable procedure completion. * * @param[in] adc pointer to the ADC registers block */ static void adc_lld_wait_enable_adc(ADC_TypeDef *adc) {
while ((adc->ISR & ADC_ISR_ADRDY) == 0U) { /* Waiting for ADC to be stable.*/ } }
/** * @brief Stops an ongoing conversion, if any. * * @param[in] adc pointer to the ADC registers block */ static void adc_lld_stop_adc(ADC_TypeDef *adc) {
if (adc->CR & ADC_CR_ADSTART) { adc->CR |= ADC_CR_ADSTP; while (adc->CR & ADC_CR_ADSTP) ; adc->IER = 0; }
/* Disabling the ADC.*/ adc->CR |= ADC_CR_ADDIS; while ((adc->CR & ADC_CR_ADDIS) != 0U) { /* Waiting for ADC to be disabled.*/ } }
/** * @brief ADC DMA service routine. * * @param[in] adcp pointer to the @p ADCDriver object * @param[in] flags pre-shifted content of the ISR register */ static void adc_lld_serve_rx_interrupt(ADCDriver *adcp, uint32_t flags) {
/* DMA errors handling.*/ if ((flags & (STM32_DMA_ISR_TEIF | STM32_DMA_ISR_DMEIF)) != 0) { /* DMA, this could help only if the DMA tries to access an unmapped address space or violates alignment rules.*/ _adc_isr_error_code(adcp, ADC_ERR_DMAFAILURE); } else { /* It is possible that the conversion group has already be reset by the ADC error handler, in this case this interrupt is spurious.*/ if (adcp->grpp != NULL) { if ((flags & STM32_DMA_ISR_TCIF) != 0) { /* Transfer complete processing.*/ _adc_isr_full_code(adcp); } else if ((flags & STM32_DMA_ISR_HTIF) != 0) { /* Half transfer processing.*/ _adc_isr_half_code(adcp); } } } }
/** * @brief Configures and activates the ADC peripheral. * * @param[in] adcp pointer to the @p ADCDriver object * * @notapi */ void adc_lld_start(ADCDriver *adcp) {
/* If in stopped state then enables the ADC and DMA clocks.*/ if (adcp->state == ADC_STOP) { #if STM32_ADC_USE_ADC1 if (&ADCD1 == adcp) { adcp->dmastp = dmaStreamAllocI(STM32_ADC_ADC1_DMA_STREAM, STM32_ADC_ADC1_DMA_IRQ_PRIORITY, (stm32_dmaisr_t)adc_lld_serve_rx_interrupt, (void *)adcp); osalDbgAssert(adcp->dmastp != NULL, "unable to allocate stream"); rccEnableADC1(true);
/* Starting the ADC enable procedure.*/ adc_lld_start_enable_adc(adcp->adc);
/* DMA setup.*/ mode = adcp->dmamode; cfgr1 = grpp->cfgr1 | ADC_CFGR1_DMAEN; cfgr2 = adcp->adc->CFGR2 & STM32_ADC_CKMODE_MASK; if (grpp->circular) { mode |= STM32_DMA_CR_CIRC; cfgr1 |= ADC_CFGR1_DMACFG; if (adcp->depth > 1) { /* If circular buffer depth > 1, then the half transfer interrupt is enabled in order to allow streaming processing.*/ mode |= STM32_DMA_CR_HTIE; } } dmaStreamSetMemory0(adcp->dmastp, adcp->samples); dmaStreamSetTransactionSize(adcp->dmastp, (uint32_t)grpp->num_channels * (uint32_t)adcp->depth); dmaStreamSetMode(adcp->dmastp, mode); dmaStreamEnable(adcp->dmastp);
/* ADC setup, if it is defined a callback for the analog watch dog then it is enabled.*/ adcp->adc->ISR = adcp->adc->ISR; if (grpp->error_cb != NULL) { adcp->adc->IER = ADC_IER_OVRIE | ADC_IER_AWD1IE | ADC_IER_AWD2IE | ADC_IER_AWD3IE; adcp->adc->TR1 = grpp->tr1; adcp->adc->TR2 = grpp->tr2; adcp->adc->TR3 = grpp->tr3; adcp->adc->AWD2CR = grpp->awd2cr; adcp->adc->AWD3CR = grpp->awd3cr; } adcp->adc->SMPR = grpp->smpr; adcp->adc->CHSELR = grpp->chselr;
/* Ensuring that the ADC finished the enable procedure.*/ adc_lld_wait_enable_adc(adcp->adc);
/* It could be a spurious interrupt caused by overflows after DMA disabling, just ignore it in this case.*/ if (adcp->grpp != NULL) { adcerror_t emask = 0U;
/* Note, an overflow may occur after the conversion ended before the driver is able to stop the ADC, this is why the state is checked too.*/ if ((isr & ADC_ISR_OVR) && (adcp->state == ADC_ACTIVE)) { /* ADC overflow condition, this could happen only if the DMA is unable to read data fast enough.*/ emask |= ADC_ERR_OVERFLOW; } if (isr & ADC_ISR_AWD1) { /* Analog watchdog 1 error.*/ emask |= ADC_ERR_AWD1; } if (isr & ADC_ISR_AWD2) { /* Analog watchdog 2 error.*/ emask |= ADC_ERR_AWD2; } if (isr & ADC_ISR_AWD3) { /* Analog watchdog 3 error.*/ emask |= ADC_ERR_AWD3; } if (emask != 0U) { _adc_isr_error_code(adcp, emask); } } }
/** * @brief Enables the VREFEN bit. * @details The VREFEN bit is required in order to sample the VREF channel. * @note This is an STM32-only functionality. * @note This function is meant to be called after @p adcStart(). * * @param[in] adcp pointer to the @p ADCDriver object * * @notapi */ void adcSTM32EnableVREF(ADCDriver *adcp) {
(void)adcp;
ADC1_COMMON->CCR |= ADC_CCR_VREFEN; }
/** * @brief Disables the VREFEN bit. * @details The VREFEN bit is required in order to sample the VREF channel. * @note This is an STM32-only functionality. * @note This function is meant to be called after @p adcStart(). * * @param[in] adcp pointer to the @p ADCDriver object * * @notapi */ void adcSTM32DisableVREF(ADCDriver *adcp) {
(void)adcp;
ADC1_COMMON->CCR &= ~ADC_CCR_VREFEN; }
/** * @brief Enables the TSEN bit. * @details The TSEN bit is required in order to sample the internal * temperature sensor and internal reference voltage. * @note This is an STM32-only functionality. * * @param[in] adcp pointer to the @p ADCDriver object * * @notapi */ void adcSTM32EnableTS(ADCDriver *adcp) {
(void)adcp;
ADC1_COMMON->CCR |= ADC_CCR_TSEN; }
/** * @brief Disables the TSEN bit. * @details The TSEN bit is required in order to sample the internal * temperature sensor and internal reference voltage. * @note This is an STM32-only functionality. * * @param[in] adcp pointer to the @p ADCDriver object * * @notapi */ void adcSTM32DisableTS(ADCDriver *adcp) {
(void)adcp;
ADC1_COMMON->CCR &= ~ADC_CCR_TSEN; }
#if defined(ADC_CCR_VBATEN) || defined(__DOXYGEN__) /** * @brief Enables the VBATEN bit. * @details The VBATEN bit is required in order to sample the VBAT channel. * @note This is an STM32-only functionality. * @note This function is meant to be called after @p adcStart(). * * @param[in] adcp pointer to the @p ADCDriver object * * @notapi */ void adcSTM32EnableVBAT(ADCDriver *adcp) {
(void)adcp;
ADC1_COMMON->CCR |= ADC_CCR_VBATEN; }
/** * @brief Disables the VBATEN bit. * @details The VBATEN bit is required in order to sample the VBAT channel. * @note This is an STM32-only functionality. * @note This function is meant to be called after @p adcStart(). * * @param[in] adcp pointer to the @p ADCDriver object * * @notapi */ void adcSTM32DisableVBAT(ADCDriver *adcp) {