mpsl: unify CONSTLAT/low-power hooks; add NVM low-latency handling

The `mpsl_constlat_request_callback` and `mpsl_lowpower_request-
_callback` will be replaced with a single low-latency acquire/release
API. The new API is added in this commit. The former one will be
removed in followin commit when the modified MPSL library is
available in nrfxlib.

The MPSL library expects implementations of the new public functions
handle acquire/release of low-latency mode on the NVM controller.

The integration layer supplies this for all MPSL users in the SDK.
The implementation allows to control the NVM latency by nrf_sys_event
subsystem. For that an application has the select the NRF_SYS_EVENT
KConfig.

As of now the new API and NVM latency control is required for
nRF54Lxx SoCs.

Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>

Author: ppryga-nordic

subsys/mpsl/init/mpsl_init.c

@@ -23,6 +23,10 @@
 #if IS_ENABLED(CONFIG_SOC_COMPATIBLE_NRF54LX)
 #include <nrfx_power.h>
 #endif
+#if IS_ENABLED(CONFIG_SOC_SERIES_NRF54L)
+#include <nrf_sys_event.h>
+#endif
+
 #if defined(CONFIG_SOC_SERIES_NRF54H)
 #include <hal/nrf_dppi.h>
 #endif
@@ -190,6 +194,14 @@ static struct k_work mpsl_low_prio_work;
 struct k_work_q mpsl_work_q;
 static K_THREAD_STACK_DEFINE(mpsl_work_stack, CONFIG_MPSL_WORK_STACK_SIZE);
 
+#if IS_ENABLED(CONFIG_SOC_SERIES_NRF54L) && !IS_ENABLED(CONFIG_TRUSTED_EXECUTION_NONSECURE)
+#if IS_ENABLED(CONFIG_NRF_SYS_EVENT_IRQ_LATENCY)
+static int m_nvm_low_latency_event_handle = -1;
+#else
+static uint32_t m_rram_lowpower_config;
+#endif /* IS_ENABLED(CONFIG_NRF_SYS_EVENT_IRQ_LATENCY) */
+#endif /* IS_ENABLED(CONFIG_SOC_SERIES_NRF54L) && !IS_ENABLED(CONFIG_TRUSTED_EXECUTION_NONSECURE) */
+
 #define MPSL_TIMESLOT_SESSION_COUNT (\
 	CONFIG_MPSL_TIMESLOT_SESSION_COUNT + \
 	CONFIG_SOC_FLASH_NRF_RADIO_SYNC_MPSL_TIMESLOT_SESSION_COUNT)
@@ -603,6 +615,69 @@ void mpsl_lowpower_request_callback(void)
 	nrf_power_task_trigger(NRF_POWER, NRF_POWER_TASK_LOWPWR);
 #endif
 }
+
+void mpsl_low_latency_acquire_callback(void)
+{
+#if IS_ENABLED(CONFIG_SOC_SERIES_NRF54L) && !IS_ENABLED(CONFIG_TRUSTED_EXECUTION_NONSECURE)
+#if IS_ENABLED(CONFIG_NRF_SYS_EVENT)
+	int err;
+
+	err = nrf_sys_event_request_global_constlat();
+	if (err) {
+		LOG_ERR("NVM low latency request has failed (%d)", err);
+	}
+#elif IS_ENABLED(CONFIG_NRFX_POWER)
+	nrfx_power_constlat_mode_request();
+#else
+	nrf_power_task_trigger(NRF_POWER, NRF_POWER_TASK_CONSTLAT);
+#endif /* IS_ENABLED(CONFIG_NRF_SYS_EVENT) */
+
+#if IS_ENABLED(CONFIG_NRF_SYS_EVENT_IRQ_LATENCY)
+	int event_handle;
+
+	event_handle = nrf_sys_event_register(0, true);
+	if (event_handle < 0) {
+		LOG_ERR("NVM low latency request has failed (%d)", event_handle);
+	}
+
+	m_nvm_low_latency_event_handle = event_handle;
+#else
+	m_rram_lowpower_config = NRF_RRAMC->POWER.LOWPOWERCONFIG;
+	NRF_RRAMC->POWER.LOWPOWERCONFIG = RRAMC_POWER_LOWPOWERCONFIG_MODE_Standby
+					  << RRAMC_POWER_LOWPOWERCONFIG_MODE_Pos;
+#endif /* IS_ENABLED(CONFIG_NRF_SYS_EVENT_IRQ_LATENCY) */
+#endif /* IS_ENABLED(CONFIG_SOC_SERIES_NRF54L) && !IS_ENABLED(CONFIG_TRUSTED_EXECUTION_NONSECURE) */
+}
+
+void mpsl_low_latency_release_callback(void)
+{
+#if IS_ENABLED(CONFIG_SOC_SERIES_NRF54L) && !IS_ENABLED(CONFIG_TRUSTED_EXECUTION_NONSECURE)
+
+#if IS_ENABLED(CONFIG_NRF_SYS_EVENT)
+	int ret;
+
+	ret = nrf_sys_event_release_global_constlat();
+	if (ret) {
+		LOG_ERR("NVM low latency release has failed (%d)", ret);
+	}
+#elif IS_ENABLED(CONFIG_NRFX_POWER)
+	nrfx_power_constlat_mode_free();
+#else
+	nrf_power_task_trigger(NRF_POWER, NRF_POWER_TASK_LOWPWR);
+#endif /* IS_ENABLED(CONFIG_NRF_SYS_EVENT) */
+
+#if IS_ENABLED(CONFIG_NRF_SYS_EVENT_IRQ_LATENCY)
+	ret = nrf_sys_event_unregister(m_nvm_low_latency_event_handle, false);
+	if (ret != 0) {
+		LOG_ERR("NVM low latency release has failed (%d)", ret);
+	}
+
+	m_nvm_low_latency_event_handle = -1;
+#else
+	NRF_RRAMC->POWER.LOWPOWERCONFIG = m_rram_lowpower_config;
+#endif /* IS_ENABLED(CONFIG_NRF_SYS_EVENT_IRQ_LATENCY) */
+#endif /* IS_ENABLED(CONFIG_SOC_SERIES_NRF54L) && !IS_ENABLED(CONFIG_TRUSTED_EXECUTION_NONSECURE) */
+}
 #endif /* defined(CONFIG_SOC_COMPATIBLE_NRF54LX) */
 
 #if defined(CONFIG_MPSL_USE_EXTERNAL_CLOCK_CONTROL)