soc: nxp s32k3: derive sys clock from devicetree

sumitbatra-nxp · sumitbatra-nxp · commit e05ffdbad6c0 · 2025-11-19T12:48:22.000+05:30
Use devicetree to provide the system clock frequency for S32K3
instead of hardcoding it in board defconfigs.

- Add clock-frequency to /cpus/cpu@0 in nxp_s32k344_m7.dtsi using
DT_FREQ_M(160).
- Define DT_SYSCLK_PATH and derive SYS_CLOCK_HW_CYCLES_PER_SEC from
the sysclk node via dt_node_int_prop_int() when CORTEX_M_SYSTICK.
- Remove CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC from mr_canhubk3 and
mr_canhubk3_s32k344_mcuboot defconfigs.

This keeps the clock configuration in a single SoC-level place,
aligns S32K3 with other NXP Cortex-M SoCs, and ensures both the
MCUboot and application builds share the same
SYS_CLOCK_HW_CYCLES_PER_SEC.

Signed-off-by: Sumit Batra &lt;sumit.batra@nxp.com&gt;
diff --git a/boards/nxp/mr_canhubk3/mr_canhubk3_defconfig b/boards/nxp/mr_canhubk3/mr_canhubk3_defconfig
@@ -3,9 +3,6 @@
 
 CONFIG_BUILD_OUTPUT_HEX=y
 
-# Use Systick as system clock
-CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=160000000
-
 # Run from internal Flash
 CONFIG_XIP=y
 
diff --git a/boards/nxp/mr_canhubk3/mr_canhubk3_s32k344_mcuboot_defconfig b/boards/nxp/mr_canhubk3/mr_canhubk3_s32k344_mcuboot_defconfig
@@ -3,9 +3,6 @@
 
 CONFIG_BUILD_OUTPUT_HEX=y
 
-# Use Systick as system clock
-CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=160000000
-
 # Enable MPU
 CONFIG_ARM_MPU=y
 
diff --git a/dts/arm/nxp/nxp_s32k344_m7.dtsi b/dts/arm/nxp/nxp_s32k344_m7.dtsi
@@ -20,6 +20,7 @@
 			device_type = "cpu";
 			compatible = "arm,cortex-m7";
 			reg = <0>;
+			clock-frequency = <DT_FREQ_M(160)>;
 		};
 
 		cpu@1 {
diff --git a/soc/nxp/s32/s32k3/Kconfig.defconfig b/soc/nxp/s32/s32k3/Kconfig.defconfig
@@ -1,12 +1,12 @@
 # NXP S32K3XX MCU series
 
-# Copyright 2023-2024 NXP
+# Copyright 2023-2025 NXP
 # SPDX-License-Identifier: Apache-2.0
 
 if SOC_SERIES_S32K3
 
 config SYS_CLOCK_HW_CYCLES_PER_SEC
-	default 2000000
+	default $(dt_node_int_prop_int,/cpus/cpu@0,clock-frequency) if CORTEX_M_SYSTICK
 
 config NUM_IRQS
 	# must be >= the highest interrupt number used
