drivers: adc: Add support for Apollo510 ADC

This commit adds support for Apollo510 SoC in ambiq adc driver

Signed-off-by: Hao Luo <hluo@ambiq.com>

Author: AlessandroLuo

boards/ambiq/apollo510_evb/apollo510_evb-pinctrl.dtsi

@@ -24,6 +24,13 @@
 		};
 	};
 
+	adc0_default: adc0_default{
+		group1 {
+			pinmux = <ADCSE4_P15>, <ADCSE7_P12>;
+			drive-strength = "0.1";
+		};
+	};
+
 	i2c0_default: i2c0_default {
 		group1 {
 			pinmux = <M0SCL_P5>, <M0SDAWIR3_P6>;

boards/ambiq/apollo510_evb/apollo510_evb.dts

@@ -89,6 +89,12 @@
 	pinctrl-names = "default";
 };
 
+&adc0 {
+	pinctrl-0 = <&adc0_default>;
+	pinctrl-names = "default";
+	status = "disabled";
+};
+
 &counter0 {
 	status = "disabled";
 };

boards/ambiq/apollo510_evb/apollo510_evb.yaml

@@ -9,6 +9,7 @@ toolchain:
   - gnuarmemb
 supported:
   - uart
+  - adc
   - watchdog
   - counter
   - gpio

drivers/adc/adc_ambiq.c

@@ -52,7 +52,7 @@ static int adc_ambiq_set_resolution(am_hal_adc_slot_prec_e *prec, uint8_t adc_re
 	case 12:
 		*prec = AM_HAL_ADC_SLOT_12BIT;
 		break;
-#if !defined(CONFIG_SOC_SERIES_APOLLO4X)
+#if defined(CONFIG_SOC_SERIES_APOLLO3X)
 	case 14:
 		*prec = AM_HAL_ADC_SLOT_14BIT;
 		break;
@@ -80,7 +80,7 @@ static int adc_ambiq_slot_config(const struct device *dev, const struct adc_sequ
 	ADCSlotConfig.eChannel = channel;
 	ADCSlotConfig.bWindowCompare = false;
 	ADCSlotConfig.bEnabled = true;
-#if defined(CONFIG_SOC_SERIES_APOLLO4X)
+#if !defined(CONFIG_SOC_SERIES_APOLLO3X)
 	ADCSlotConfig.ui32TrkCyc = AM_HAL_ADC_MIN_TRKCYC;
 #endif
 	if (AM_HAL_STATUS_SUCCESS !=
@@ -101,8 +101,6 @@ static void adc_ambiq_isr(const struct device *dev)
 
 	/* Read the interrupt status. */
 	am_hal_adc_interrupt_status(data->adcHandle, &ui32IntMask, true);
-	/* Clear the ADC interrupt.*/
-	am_hal_adc_interrupt_clear(data->adcHandle, ui32IntMask);
 
 	/*
 	 * If we got a conversion completion interrupt (which should be our only
@@ -119,6 +117,8 @@ static void adc_ambiq_isr(const struct device *dev)
 		am_hal_adc_disable(data->adcHandle);
 		adc_context_on_sampling_done(&data->ctx, dev);
 	}
+	/* Clear the ADC interrupt.*/
+	am_hal_adc_interrupt_clear(data->adcHandle, ui32IntMask);
 }
 
 static int adc_ambiq_check_buffer_size(const struct adc_sequence *sequence, uint8_t active_channels)
@@ -280,9 +280,9 @@ static int adc_ambiq_init(const struct device *dev)
 
 	/* Initialize the ADC and get the handle*/
 	if (AM_HAL_STATUS_SUCCESS !=
-	    am_hal_adc_initialize((cfg->base - ADC_BASE) / (cfg->size * 4), &data->adcHandle)) {
+		am_hal_adc_initialize(0, &data->adcHandle)) {
 		ret = -ENODEV;
-		LOG_ERR("Faile to initialize ADC, code:%d", ret);
+		LOG_ERR("Failed to initialize ADC, code:%d", ret);
 		return ret;
 	}
 
@@ -292,7 +292,7 @@ static int adc_ambiq_init(const struct device *dev)
 	/* Set up the ADC configuration parameters. These settings are reasonable
 	 *  for accurate measurements at a low sample rate.
 	 */
-#if !defined(CONFIG_SOC_SERIES_APOLLO4X)
+#if defined(CONFIG_SOC_SERIES_APOLLO3X)
 	ADCConfig.eClock = AM_HAL_ADC_CLKSEL_HFRC;
 	ADCConfig.eReference = AM_HAL_ADC_REFSEL_INT_1P5;
 #else

dts/arm/ambiq/ambiq_apollo510.dtsi

@@ -549,6 +549,17 @@
 			status = "disabled";
 		};
 
+		adc0: adc@ADC_BASE_NAME {
+			compatible = "ambiq,adc";
+			reg = <ADC_REG_BASE ADC_REG_SIZE>;
+			interrupts = <19 0>;
+			interrupt-names = "ADC";
+			channel-count = <10>;
+			internal-vref-mv = <1190>;
+			status = "disabled";
+			#io-channel-cells = <1>;
+		};
+
 		pinctrl: pin-controller@GPIO_BASE_NAME {
 			compatible = "ambiq,apollo5-pinctrl";
 			reg = <GPIO_REG_BASE GPIO_REG_SIZE>;

samples/drivers/adc/adc_dt/boards/apollo510_evb.overlay

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2025 Ambiq Micro Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+/ {
+	zephyr,user {
+		io-channels = <&adc0 4>, <&adc0 7>;
+	};
+};
+
+&adc0 {
+	status = "okay";
+	interrupt-parent = <&nvic>;
+	interrupts = <19 0>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	channel@4 {
+		reg = <4>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+	};
+
+	channel@7 {
+		reg = <7>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+	};
+};

tests/drivers/adc/adc_api/boards/apollo510_evb.overlay

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025 Ambiq Micro Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+/ {
+	zephyr,user {
+		io-channels = <&adc0 4>, <&adc0 7>;
+	};
+};
+
+&adc0 {
+	status = "okay";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	channel@4 {
+		reg = <4>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+	};
+
+	channel@7 {
+		reg = <7>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+	};
+};