boards: lpcxpresso55s28/lpcxpresso55s69: add pinmux for lpadc

Add pinmux settings for lpadc to LPCXpresso55s69 and LPCXpresso55s28
boards. Enable ADC driver sample for LPCXpresso55s69, to aid in testing
pinmux settings.

Fixes #45401

Signed-off-by: Daniel DeGrasse <[email protected]>

Author: danieldegrasse

boards/arm/lpcxpresso55s28/lpcxpresso55s28-pinctrl.dtsi

@@ -37,4 +37,13 @@
 		};
 	};
 
+	pinmux_lpadc0: pinmux_lpadc0 {
+		group0 {
+			pinmux = <ADC0_CH0_PIO0_23>,
+				<ADC0_CH1_PIO0_10>;
+			slew-rate = "standard";
+			nxp,analog-mode;
+		};
+	};
+
 };

boards/arm/lpcxpresso55s28/lpcxpresso55s28.dts

@@ -80,6 +80,8 @@
 
 &adc0 {
 	status = "okay";
+	pinctrl-0 = <&pinmux_lpadc0>;
+	pinctrl-names = "default";
 };
 
 &dma0 {

boards/arm/lpcxpresso55s69/lpcxpresso55s69-pinctrl.dtsi

@@ -2,7 +2,7 @@
  * NOTE: File generated by lpc_cfg_utils.py
  * from LPCXpresso55S69.mex
  *
- * Copyright (c) 2022, NXP
+ * Copyright 2022 NXP
  * SPDX-License-Identifier: Apache-2.0
  */
 
@@ -64,6 +64,15 @@
 		};
 	};
 
+	pinmux_lpadc0: pinmux_lpadc0 {
+		group0 {
+			pinmux = <ADC0_CH0_PIO0_23>,
+				<ADC0_CH1_PIO0_10>;
+			slew-rate = "standard";
+			nxp,analog-mode;
+		};
+	};
+
 	pinmux_sctimer_default: pinmux_sctimer_default {
 		group0 {
 			pinmux = <SCT0_OUT2_PIO0_15>,

boards/arm/lpcxpresso55s69/lpcxpresso55s69_cpu0.dts

@@ -129,6 +129,8 @@
 
 &adc0 {
 	status = "okay";
+	pinctrl-0 = <&pinmux_lpadc0>;
+	pinctrl-names = "default";
 };
 
 &dma0 {

samples/drivers/adc/boards/lpcxpresso55s69_cpu0.overlay

@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2022 NXP
+ */
+
+/ {
+	zephyr,user {
+		/* adjust channel number according to pinmux in board.dts */
+		io-channels = <&adc0 0>;
+	};
+};