From e521c7d49e0141d2d8d96b6f83e44cedefb363a4 Mon Sep 17 00:00:00 2001
From: Alexander Mihajlovic <a@abxy.se>
Date: Mon, 3 Jan 2022 18:45:58 +0100
Subject: [PATCH] drivers: adc: stm32: Add function to enable ADC consistently

Use a wrapper for LL_ADC_Enable that also waits for ADRDY if required
by the SoC to make sure it's properly enabled everywhere this is done.

Signed-off-by: Alexander Mihajlovic <a@abxy.se>
---
 drivers/adc/adc_stm32.c | 81 ++++++++++++++++++++++++-----------------
 1 file changed, 48 insertions(+), 33 deletions(-)

diff --git a/drivers/adc/adc_stm32.c b/drivers/adc/adc_stm32.c
index 471d91b49e2..ac311460e9b 100644
--- a/drivers/adc/adc_stm32.c
+++ b/drivers/adc/adc_stm32.c
@@ -407,6 +407,44 @@ static void adc_stm32_oversampling(ADC_TypeDef *adc, uint8_t ratio, uint32_t shi
 }
 #endif /* CONFIG_SOC_SERIES_STM32xxx */
 
+/*
+ * Enable ADC peripheral, and wait until ready if required by SOC.
+ */
+static int adc_stm32_enable(ADC_TypeDef *adc)
+{
+	if (LL_ADC_IsEnabled(adc) == 1UL) {
+		return 0;
+	}
+	LL_ADC_Enable(adc);
+
+#if defined(CONFIG_SOC_SERIES_STM32L4X) || \
+	defined(CONFIG_SOC_SERIES_STM32L5X) || \
+	defined(CONFIG_SOC_SERIES_STM32WBX) || \
+	defined(CONFIG_SOC_SERIES_STM32G0X) || \
+	defined(CONFIG_SOC_SERIES_STM32G4X) || \
+	defined(CONFIG_SOC_SERIES_STM32H7X) || \
+	defined(CONFIG_SOC_SERIES_STM32WLX)
+	/*
+	 * Enabling ADC modules in L4, WB, G0 and G4 series may fail if they are
+	 * still not stabilized, this will wait for a short time to ensure ADC
+	 * modules are properly enabled.
+	 */
+	uint32_t count_timeout = 0;
+
+	while (LL_ADC_IsActiveFlag_ADRDY(adc) == 0) {
+		if (LL_ADC_IsEnabled(adc) == 0UL) {
+			LL_ADC_Enable(adc);
+			count_timeout++;
+			if (count_timeout == 10) {
+				return -ETIMEDOUT;
+			}
+		}
+	}
+#endif
+
+	return 0;
+}
+
 static int start_read(const struct device *dev,
 		      const struct adc_sequence *sequence)
 {
@@ -513,9 +551,7 @@ static int start_read(const struct device *dev,
 	while (LL_ADC_IsEnabled(adc) == 1UL) {
 	}
 	LL_ADC_SetResolution(adc, resolution);
-	LL_ADC_Enable(adc);
-	while (LL_ADC_IsActiveFlag_ADRDY(adc) != 1UL) {
-	}
+	adc_stm32_enable(adc);
 #elif !defined(CONFIG_SOC_SERIES_STM32F1X) && \
 	!defined(STM32F3X_ADC_V2_5)
 	LL_ADC_SetResolution(adc, resolution);
@@ -530,7 +566,8 @@ static int start_read(const struct device *dev,
 	LL_ADC_Disable(adc);
 	while (LL_ADC_IsEnabled(adc) == 1UL) {
 	}
-#endif /* CONFIG_SOC_SERIES_STM32L0X */
+#endif
+
 #if defined(CONFIG_SOC_SERIES_STM32G0X) || \
 	defined(CONFIG_SOC_SERIES_STM32G4X) || \
 	defined(CONFIG_SOC_SERIES_STM32H7X) || \
@@ -580,11 +617,11 @@ static int start_read(const struct device *dev,
 #endif /* CONFIG_SOC_SERIES_STM32H7X */
 	default:
 		LOG_ERR("Invalid oversampling");
-		LL_ADC_Enable(adc);
+		adc_stm32_enable(adc);
 		return -EINVAL;
 	}
 	/* re-enable ADC after changing the OVS */
-	LL_ADC_Enable(adc);
+	adc_stm32_enable(adc);
 #else
 	if (sequence->oversampling) {
 		LOG_ERR("Oversampling not supported");
@@ -606,7 +643,7 @@ static int start_read(const struct device *dev,
 		}
 		adc_stm32_calib(dev);
 		/* re-enable ADC after calibration */
-		LL_ADC_Enable(adc);
+		adc_stm32_enable(adc);
 #else
 		LOG_ERR("Calibration not supported");
 		return -ENOTSUP;
@@ -628,7 +665,7 @@ static int start_read(const struct device *dev,
 #elif defined(CONFIG_SOC_SERIES_STM32F1X)
 	LL_ADC_EnableIT_EOS(adc);
 #elif defined(STM32F3X_ADC_V2_5)
-	LL_ADC_Enable(adc);
+	adc_stm32_enable(adc);
 	LL_ADC_EnableIT_EOS(adc);
 #else
 	LL_ADC_EnableIT_EOCS(adc);
@@ -975,32 +1012,10 @@ static int adc_stm32_init(const struct device *dev)
 	}
 #endif
 
-	LL_ADC_Enable(adc);
-
-#if defined(CONFIG_SOC_SERIES_STM32L4X) || \
-	defined(CONFIG_SOC_SERIES_STM32L5X) || \
-	defined(CONFIG_SOC_SERIES_STM32WBX) || \
-	defined(CONFIG_SOC_SERIES_STM32G0X) || \
-	defined(CONFIG_SOC_SERIES_STM32G4X) || \
-	defined(CONFIG_SOC_SERIES_STM32H7X) || \
-	defined(CONFIG_SOC_SERIES_STM32WLX)
-	/*
-	 * Enabling ADC modules in L4, WB, G0 and G4 series may fail if they are
-	 * still not stabilized, this will wait for a short time to ensure ADC
-	 * modules are properly enabled.
-	 */
-	uint32_t countTimeout = 0;
-
-	while (LL_ADC_IsActiveFlag_ADRDY(adc) == 0) {
-		if (LL_ADC_IsEnabled(adc) == 0UL) {
-			LL_ADC_Enable(adc);
-			countTimeout++;
-			if (countTimeout == 10) {
-				return -ETIMEDOUT;
-			}
-		}
+	err = adc_stm32_enable(adc);
+	if (err < 0) {
+		return err;
 	}
-#endif
 
 	config->irq_cfg_func();