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

Support lptmr for NXP frdm_mcxa156 board.
Test using tests/drivers/counter/counter_basic_api.

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

Author: NeilChen93

boards/nxp/frdm_mcxa156/board.c

@@ -129,6 +129,25 @@ static int frdm_mcxa156_init(void)
 	CLOCK_AttachClk(kFRO12M_to_ADC0);
 
 	CLOCK_EnableClock(kCLOCK_GateADC0);
+#endif
+
+#if DT_NODE_HAS_STATUS_OKAY(DT_NODELABEL(lptmr0))
+
+/*
+ * Clock Select Decides what input source the lptmr will clock from
+ *
+ * 0 <- Reserved
+ * 1 <- 16K FRO
+ * 2 <- Reserved
+ * 3 <- Combination of clocks configured in MRCC_LPTMR0_CLKSEL[MUX] field
+ */
+#if DT_PROP(DT_NODELABEL(lptmr0), clk_source) == 0x1
+	CLOCK_SetupFRO16KClocking(kCLKE_16K_SYSTEM | kCLKE_16K_COREMAIN);
+#elif DT_PROP(DT_NODELABEL(lptmr0), clk_source) == 0x3
+	CLOCK_SetClockDiv(kCLOCK_DivLPTMR0, 1u);
+	CLOCK_AttachClk(kFRO12M_to_LPTMR0);
+#endif /* DT_PROP(DT_NODELABEL(lptmr0), clk_source) */
+
 #endif
 
 	/* Set SystemCoreClock variable. */

boards/nxp/frdm_mcxa156/doc/index.rst

@@ -58,6 +58,8 @@ The FRDM-MCXA156 board configuration supports the following hardware features:
 +-----------+------------+-------------------------------------+
 | DAC       | on-chip    | dac                                 |
 +-----------+------------+-------------------------------------+
+| LPTMR     | on-chip    | counter                             |
++-----------+------------+-------------------------------------+
 | PWM       | on-chip    | pwm                                 |
 +-----------+------------+-------------------------------------+
 

boards/nxp/frdm_mcxa156/frdm_mcxa156.dts

@@ -107,3 +107,7 @@
 	pinctrl-0 = <&pinmux_lpadc0>;
 	pinctrl-names = "default";
 };
+
+&lptmr0 {
+	status = "okay";
+};

boards/nxp/frdm_mcxa156/frdm_mcxa156.yaml

@@ -18,6 +18,7 @@ supported:
   - adc
   - flash
   - gpio
+  - counter
   - dac
   - pwm
 vendor: nxp