drivers: adc: stm32 disable the ADC before setting the Oversampling (97c03182) · Commits · Wenxi XU / zephyr

On those STM32 series, setting of this feature is conditioned to the ADC state: it is allowed to set/reset the oversampler (OVSE bit) and set the Oversampling ratio (OVSR bits) in the ADC_CFGR2 register only when ADC is disabled or enabled without conversion on going. Then is the ADC re-enabled. Signed-off-by:

Francois Ramu <francois.ramu@st.com>

drivers/adc/adc_stm32.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -441,8 +441,16 @@ static int start_read(const struct device *dev,
		defined(CONFIG_SOC_SERIES_STM32H7X) \|\| \
		defined(CONFIG_SOC_SERIES_STM32L0X) \|\| \
		defined(CONFIG_SOC_SERIES_STM32L4X) \|\| \
		defined(CONFIG_SOC_SERIES_STM32L5X) \|\| \
		defined(CONFIG_SOC_SERIES_STM32WBX) \|\| \
		defined(CONFIG_SOC_SERIES_STM32WLX)
		/*
		* setting OVS bits is conditioned to ADC state: ADC must be disabled
		* or enabled without conversion on going : disable it, it will stop
		*/
		LL_ADC_Disable(adc);
		while (LL_ADC_IsEnabled(adc) == 1UL) {
		}
		switch (sequence->oversampling) {
		case 0:
		LL_ADC_SetOverSamplingScope(adc, LL_ADC_OVS_DISABLE);
		@@ -521,8 +529,11 @@ static int start_read(const struct device *dev,
		break;
		default:
		LOG_ERR("Invalid oversampling");
		LL_ADC_Enable(adc);
		return -EINVAL;
		}
		/* re-enable ADC after changing the OVS */
		LL_ADC_Enable(adc);
		#else
		if (sequence->oversampling) {
		LOG_ERR("Oversampling not supported");

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