soc: nordic: common: CONFIG_SOC_NRF_FORCE_CONSTLAT

Move the option to force constant latency mode outside of nRF54l, since
it is an option applicable to most Nordic SoCs.

Signed-off-by: Jordan Yates <[email protected]>

Author: JordanYates

soc/nordic/common/CMakeLists.txt

@@ -39,4 +39,5 @@ if(CONFIG_TFM_PARTITION_PLATFORM)
 endif()
 
 zephyr_library_sources_ifdef(CONFIG_NRF_SYS_EVENT nrf_sys_event.c)
+zephyr_library_sources_ifdef(CONFIG_SOC_NRF_FORCE_CONSTLAT nrf_constlat.c)
 zephyr_library_sources_ifdef(CONFIG_MRAM_LATENCY mram_latency.c)

soc/nordic/common/Kconfig

@@ -21,6 +21,15 @@ config NRF_SYS_EVENT
 	bool "nRF system event support"
 	select NRFX_POWER if !NRF_PLATFORM_HALTIUM
 
+config SOC_NRF_FORCE_CONSTLAT
+	bool "Force constant latency mode in system ON"
+	depends on NRF_SYS_EVENT && !RISCV
+	help
+	  In constant latency mode the CPU wakeup latency and the PPI task response
+	  will be constant and kept at a minimum. This is secured by forcing a set
+	  of base resources on while in sleep. The advantage of having a constant
+	  and predictable latency will be at the cost of having increased power consumption.
+
 config MRAM_LATENCY
 	bool "MRAM latency manager"
 	depends on NRFS_HAS_MRAM_SERVICE

soc/nordic/common/nrf_constlat.c

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2025 Embeint Pty Ltd
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/init.h>
+
+#include <nrf_sys_event.h>
+
+static int nrf_const_lat(void)
+{
+	return nrf_sys_event_request_global_constlat();
+}
+
+/* Immediately after the SoC init functions */
+SYS_INIT(nrf_const_lat, PRE_KERNEL_1, 1);

soc/nordic/nrf54l/Kconfig

@@ -76,14 +76,6 @@ config SOC_NRF54LX_SKIP_GLITCHDETECTOR_DISABLE
 	  With this option, the glitch detector is not disabled during system initialization.
 	  The CPU runs with the default state of glitch detector.
 
-config SOC_NRF_FORCE_CONSTLAT
-	bool "Force constant-latency mode"
-	help
-	  In constant latency mode the CPU wakeup latency and the PPI task response
-	  will be constant and kept at a minimum. This is secured by forcing a set
-	  of base resources on while in sleep. The advantage of having a constant
-	  and predictable latency will be at the cost of having increased power consumption.
-
 config SOC_NRF54L_ANOMALY_56_WORKAROUND
 	bool "Apply workaround 56 for nRF54L SoCs"
 	default y

soc/nordic/nrf54l/soc.c

@@ -138,10 +138,6 @@ static inline void power_and_clock_configuration(void)
 	nrf_oscillators_hfxo_cap_set(NRF_OSCILLATORS, false, 0);
 #endif
 
-	if (IS_ENABLED(CONFIG_SOC_NRF_FORCE_CONSTLAT)) {
-		nrf_power_task_trigger(NRF_POWER, NRF_POWER_TASK_CONSTLAT);
-	}
-
 #if (DT_PROP(DT_NODELABEL(vregmain), regulator_initial_mode) == NRF5X_REG_MODE_DCDC)
 	nrf_regulators_vreg_enable_set(NRF_REGULATORS, NRF_REGULATORS_VREG_MAIN, true);
 #endif