STM32L0 ADC: remove adc_inited flag

Author: bcostm

targets/TARGET_STM/TARGET_STM32L0/analogin_api.c

@@ -36,12 +36,10 @@
 #include "mbed_error.h"
 #include "PeripheralPins.h"
 
-int adc_inited = 0;
-
 void analogin_init(analogin_t *obj, PinName pin)
 {
+    static int adc_calibrated = 0;
     uint32_t function = (uint32_t)NC;
-    obj->handle.Instance = (ADC_TypeDef *)NC;
 
     // ADC Internal Channels "pins"  (Temperature, Vref, Vbat, ...)
     //   are described in PinNames.h and PeripheralPins.c
@@ -68,41 +66,38 @@ void analogin_init(analogin_t *obj, PinName pin)
     // Save pin number for the read function
     obj->pin = pin;
 
-    // The ADC initialization is done once
-    if (adc_inited == 0) {
-        adc_inited = 1;
-
-        obj->handle.State = HAL_ADC_STATE_RESET;
-        // Enable ADC clock
-        __ADC1_CLK_ENABLE();
-
-        // Configure ADC
-        obj->handle.Init.OversamplingMode      = DISABLE;
-        obj->handle.Init.ClockPrescaler        = ADC_CLOCKPRESCALER_PCLK_DIV1;
-        obj->handle.Init.Resolution            = ADC_RESOLUTION12b;
-        obj->handle.Init.SamplingTime          = ADC_SAMPLETIME_239CYCLES_5;
-        obj->handle.Init.ScanConvMode          = ADC_SCAN_DIRECTION_FORWARD;
-        obj->handle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
-        obj->handle.Init.ContinuousConvMode    = DISABLE;
-        obj->handle.Init.DiscontinuousConvMode = DISABLE;
-        obj->handle.Init.ExternalTrigConvEdge  = ADC_EXTERNALTRIG_EDGE_NONE;
-        obj->handle.Init.ExternalTrigConv      = ADC_EXTERNALTRIG0_T6_TRGO; // Not used here
-        obj->handle.Init.DMAContinuousRequests = DISABLE;
-        obj->handle.Init.EOCSelection          = EOC_SINGLE_CONV;
-        obj->handle.Init.Overrun               = OVR_DATA_OVERWRITTEN;
-        obj->handle.Init.LowPowerAutoWait      = ENABLE;
-        obj->handle.Init.LowPowerFrequencyMode = DISABLE; // To be enabled only if ADC clock < 2.8 MHz
-        obj->handle.Init.LowPowerAutoPowerOff  = DISABLE;
-
-        if (HAL_ADC_Init(&obj->handle) != HAL_OK) {
-            error("Cannot initialize ADC");
-        }
-
-        // Calibration
-        HAL_ADCEx_Calibration_Start(&obj->handle, ADC_SINGLE_ENDED);
+    // Configure ADC object structures
+    obj->handle.State = HAL_ADC_STATE_RESET;
+    obj->handle.Init.OversamplingMode      = DISABLE;
+    obj->handle.Init.ClockPrescaler        = ADC_CLOCK_SYNC_PCLK_DIV1;
+    obj->handle.Init.Resolution            = ADC_RESOLUTION_12B;
+    obj->handle.Init.SamplingTime          = ADC_SAMPLETIME_239CYCLES_5;
+    obj->handle.Init.ScanConvMode          = ADC_SCAN_DIRECTION_FORWARD;
+    obj->handle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
+    obj->handle.Init.ContinuousConvMode    = DISABLE;
+    obj->handle.Init.DiscontinuousConvMode = DISABLE;
+    obj->handle.Init.ExternalTrigConvEdge  = ADC_EXTERNALTRIG_EDGE_NONE;
+    obj->handle.Init.ExternalTrigConv      = ADC_EXTERNALTRIG0_T6_TRGO; // Not used here
+    obj->handle.Init.DMAContinuousRequests = DISABLE;
+    obj->handle.Init.EOCSelection          = EOC_SINGLE_CONV;
+    obj->handle.Init.Overrun               = OVR_DATA_OVERWRITTEN;
+    obj->handle.Init.LowPowerAutoWait      = ENABLE;
+    obj->handle.Init.LowPowerFrequencyMode = DISABLE; // To be enabled only if ADC clock < 2.8 MHz
+    obj->handle.Init.LowPowerAutoPowerOff  = DISABLE;
+
+    __HAL_RCC_ADC1_CLK_ENABLE();
+
+    if (HAL_ADC_Init(&obj->handle) != HAL_OK) {
+        error("Cannot initialize ADC");
+    }
 
-        __HAL_ADC_ENABLE(&obj->handle);
+    // ADC calibration is done only once
+    if (adc_calibrated == 0) {
+        adc_calibrated = 1;
+        HAL_ADCEx_Calibration_Start(&obj->handle, ADC_SINGLE_ENDED);
     }
+
+    __HAL_ADC_ENABLE(&obj->handle);
 }
 
 static inline uint16_t adc_read(analogin_t *obj)
@@ -182,7 +177,7 @@ static inline uint16_t adc_read(analogin_t *obj)
 
     // Wait end of conversion and get value
     if (HAL_ADC_PollForConversion(&obj->handle, 10) == HAL_OK) {
-        return (HAL_ADC_GetValue(&obj->handle));
+        return (uint16_t)HAL_ADC_GetValue(&obj->handle);
     } else {
         return 0;
     }