boards: nxp: frdm_mcxa156: Support adc for NXP frdm_mcxa156 board

Support adc for NXP frdm_mcxa156 board.

Signed-off-by: Neil Chen <cheng.chen_1@nxp.com>

Author: NeilChen93

boards/nxp/frdm_mcxa156/board.c

@@ -124,6 +124,13 @@ static int frdm_mcxa156_init(void)
 	CLOCK_EnableClock(kCLOCK_GateDAC0);
 #endif
 
+#if DT_NODE_HAS_STATUS_OKAY(DT_NODELABEL(lpadc0))
+	CLOCK_SetClockDiv(kCLOCK_DivADC0, 1u);
+	CLOCK_AttachClk(kFRO12M_to_ADC0);
+
+	CLOCK_EnableClock(kCLOCK_GateADC0);
+#endif
+
 	/* Set SystemCoreClock variable. */
 	SystemCoreClock = CLOCK_INIT_CORE_CLOCK;
 

boards/nxp/frdm_mcxa156/doc/index.rst

@@ -54,6 +54,8 @@ The FRDM-MCXA156 board configuration supports the following hardware features:
 +-----------+------------+-------------------------------------+
 | FLASH     | on-chip    | soc flash                           |
 +-----------+------------+-------------------------------------+
+| ADC       | on-chip    | adc                                 |
++-----------+------------+-------------------------------------+
 | DAC       | on-chip    | dac                                 |
 +-----------+------------+-------------------------------------+
 | PWM       | on-chip    | pwm                                 |

boards/nxp/frdm_mcxa156/frdm_mcxa156-pinctrl.dtsi

@@ -31,4 +31,12 @@
 			drive-strength = "low";
 		};
 	};
+	pinmux_lpadc0: pinmux_lpadc0 {
+		group0 {
+			pinmux = <ADC0_A0_P2_0>,
+				<ADC0_A1_P2_1>;
+			slew-rate = "fast";
+			drive-strength = "low";
+		};
+	};
 };

boards/nxp/frdm_mcxa156/frdm_mcxa156.dts

@@ -101,3 +101,9 @@
 	pinctrl-0 = <&pinmux_flexpwm0_pwm0>;
 	pinctrl-names = "default";
 };
+
+&lpadc0 {
+	status = "okay";
+	pinctrl-0 = <&pinmux_lpadc0>;
+	pinctrl-names = "default";
+};

boards/nxp/frdm_mcxa156/frdm_mcxa156.yaml

@@ -15,6 +15,7 @@ toolchain:
   - gnuarmemb
   - xtools
 supported:
+  - adc
   - flash
   - gpio
   - dac