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drivers: adc: stm32 adc driver must wait about 1ms after enabling

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After enabling the ADC, the peripheral has a certain delay (about 1ms)
to set its ADC Ready flag in the ADC ISR register.
In between, the ADRDY is still 0 and the ADEN is 1 in the CR.
The ADC can be used for conversion, only when the ADRDY bit is set

Signed-off-by: Francois Ramu <francois.ramu@st.com>
This commit is contained in:
Francois Ramu 2023-03-21 17:26:23 +01:00 committed by Carles Cufí
parent 5ec4aaff5c
commit f7f47dc437
1 changed files with 8 additions and 8 deletions
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16
drivers/adc/adc_stm32.c
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@ -666,21 +666,21 @@ static int adc_stm32_enable(ADC_TypeDef *adc)
LL_ADC_ClearFlag_ADRDY(adc); LL_ADC_ClearFlag_ADRDY(adc);
LL_ADC_Enable(adc); LL_ADC_Enable(adc);
/* /*
* Enabling ADC modules in L4, WB, G0 and G4 series may fail if they are * Enabling ADC modules in WL, L4, WB, G0 and G4 series may fail if they are
* still not stabilized, this will wait for a short time to ensure ADC * still not stabilized, this will wait for a short time (about 1ms)
* modules are properly enabled. * to ensure ADC modules are properly enabled.
*/ */
uint32_t count_timeout = 0; uint32_t count_timeout = 0;
while (LL_ADC_IsActiveFlag_ADRDY(adc) == 0) { while (LL_ADC_IsActiveFlag_ADRDY(adc) == 0) {
if (LL_ADC_IsEnabled(adc) == 0UL) { if (LL_ADC_IsEnabled(adc) == 0UL) {
LL_ADC_Enable(adc); LL_ADC_Enable(adc);
count_timeout++; }
if (count_timeout == 10) { count_timeout++;
return -ETIMEDOUT; k_busy_wait(100);
} if (count_timeout >= 10) {
return -ETIMEDOUT;
} }
} }
#else #else