boards/p-nucleo-wb55: enable ADC support

boards/p-nucleo-wb55/Makefile.features

@@ -3,6 +3,7 @@ CPU = stm32
 CPU_MODEL = stm32wb55rg
 
 # Put defined MCU peripherals here (in alphabetical order)
+FEATURES_PROVIDED += periph_adc
 FEATURES_PROVIDED += periph_i2c
 FEATURES_PROVIDED += periph_lpuart
 FEATURES_PROVIDED += periph_pwm

boards/p-nucleo-wb55/include/periph_conf.h

@@ -164,6 +164,48 @@ static const stm32_usbdev_fs_config_t stm32_usbdev_fs_config[] = {
  */
 #define USBDEV_NUMOF           ARRAY_SIZE(stm32_usbdev_fs_config)
 
+/**
+ * @brief    ADC configuration
+ *
+ * Note that we do not configure all ADC channels,
+ * and not in the STM32WB55RG order. Instead, we
+ * just define 6 ADC channels, for the Nucleo
+ * Arduino header pins A0-A5 and the internal VBAT channel.
+ *
+ * To find appropriate device and channel find in the
+ * board manual, table showing pin assignments and
+ * information about ADC - a text similar to ADC[X]_IN[Y],
+ * where:
+ * [X] - describes used device - indexed from 0,
+ * for example ADC1_IN10 is device 0,
+ * [Y] - describes used channel - indexed from 1,
+ * for example ADC1_IN10 is channel 10
+ *
+ * For P-NUCLEO-WB55 this information is in board manual,
+ * Table 10, page 39.
+ *
+ * VBAT is connected ADC1_IN18 or ADC3_IN18 and a voltage divider
+ * is used, so that only 1/3 of the actual VBAT is measured. This
+ * allows for a supply voltage higher than the reference voltage.
+ *
+ * For P-NUCLEO-WB55 more information is provided in the Reference Manual,
+ * in section 16.4.31 - Vbat supply monitoring, page 475.
+ * @{
+ */
+static const adc_conf_t adc_config[] = {
+    {GPIO_PIN(PORT_C, 0), 0, 1},  /*< ADC1_IN1 */
+    {GPIO_PIN(PORT_C, 1), 0, 2},  /*< ADC1_IN2 */
+    {GPIO_PIN(PORT_A, 1), 0, 6},  /*< ADC1_IN6 */
+    {GPIO_PIN(PORT_A, 0), 0, 5},  /*< ADC1_IN5 */
+    {GPIO_PIN(PORT_C, 3), 0, 4},  /*< ADC1_IN4 */
+    {GPIO_PIN(PORT_C, 2), 0, 3},  /*< ADC1_IN3 */
+    {GPIO_UNDEF, 0, 18}, /* VBAT */
+};
+
+#define VBAT_ADC            ADC_LINE(6) /**< VBAT ADC line */
+#define ADC_NUMOF           ARRAY_SIZE(adc_config)
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif