samples: soft off with entering from idle/s2ram

This is new method of entering system off state.
Local domains do not shut down immediatelly but rather
go to deep sleep (idle or s2ram) and waits for other domains
to go to system off. This enable option to go back to normal
operation if there is something blocking system off. For example
application is not yet ready to soft off and wakes up radio.
This also enables GRTC to be used with system methods like
k_sleep to wake up from system off at scheduled time.

Signed-off-by: Łukasz Stępnicki <[email protected]>

Author: lstnl

samples/boards/nordic/system_off/boards/nrf54h20dk_nrf54h20_cpuapp.conf

@@ -5,3 +5,5 @@
 #
 
 CONFIG_SOC_NRF54H20_CPURAD_ENABLE=y
+CONFIG_PM_S2RAM=y
+CONFIG_PM_S2RAM_CUSTOM_MARKING=y

samples/boards/nordic/system_off/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

@@ -2,3 +2,21 @@
 	zephyr,pm-device-runtime-auto;
 	disable-rx;
 };
+
+/ {
+	cpus {
+		power-states {
+			soft_off: soft_off {
+			compatible = "zephyr,power-state";
+			power-state-name = "soft-off";
+			min-residency-us = <0>;
+			exit-latency-us = <0>;
+			status = "disabled";
+			};
+		};
+	};
+};
+
+&cpuapp {
+	cpu-power-states = <&idle_cache_disabled &s2ram &soft_off>;
+};

samples/boards/nordic/system_off/remote/boards/nrf54h20dk_nrf54h20_cpurad.overlay

@@ -1,5 +1,22 @@
 &uart135 {
-	status = "disabled";
 	zephyr,pm-device-runtime-auto;
 	disable-rx;
 };
+
+/ {
+	cpus {
+		power-states {
+			soft_off: soft_off {
+			compatible = "zephyr,power-state";
+			power-state-name = "soft-off";
+			min-residency-us = <0>;
+			exit-latency-us = <0>;
+			status = "disabled";
+			};
+		};
+	};
+};
+
+&cpurad {
+	cpu-power-states = <&idle_cache_disabled &soft_off>;
+};

samples/boards/nordic/system_off/remote/prj.conf

@@ -3,6 +3,3 @@ CONFIG_PM_DEVICE=y
 CONFIG_PM_DEVICE_RUNTIME=y
 CONFIG_POWEROFF=y
 CONFIG_UART_ASYNC_API=y
-CONFIG_SERIAL=n
-CONFIG_CONSOLE=n
-CONFIG_UART_CONSOLE=n

samples/boards/nordic/system_off/remote/src/main.c

@@ -7,8 +7,8 @@
 #include <zephyr/device.h>
 #include <zephyr/pm/device.h>
 #include <zephyr/pm/device_runtime.h>
+#include <zephyr/pm/pm.h>
 #include <zephyr/sys/poweroff.h>
-#include <hal/nrf_memconf.h>
 #include <zephyr/drivers/timer/nrf_grtc_timer.h>
 
 int main(void)
@@ -18,7 +18,9 @@ int main(void)
 		printf("%s system off demo. Ready for system off.\n", CONFIG_BOARD);
 	}
 
-	sys_poweroff();
+	k_msleep(8000);
+	pm_state_force(0u, &(struct pm_state_info){PM_STATE_SOFT_OFF, 0, 0});
+	k_sleep(K_FOREVER);
 
 	return 0;
 }

samples/boards/nordic/system_off/src/main.c

@@ -14,6 +14,7 @@
 #include <zephyr/drivers/hwinfo.h>
 #include <zephyr/drivers/comparator.h>
 #include <zephyr/kernel.h>
+#include <zephyr/pm/pm.h>
 #include <zephyr/pm/device.h>
 #include <zephyr/sys/poweroff.h>
 #include <zephyr/sys/util.h>
@@ -209,13 +210,19 @@ int main(void)
 		nrf_memconf_ramblock_ret_mask_enable_set(NRF_MEMCONF, 0, RAMBLOCK_RET_MASK, false);
 		nrf_memconf_ramblock_ret_mask_enable_set(NRF_MEMCONF, 1, RAMBLOCK_RET_MASK, false);
 #endif
-		sys_poweroff();
+
+		while (1) {
+			pm_state_force(0u, &(struct pm_state_info){PM_STATE_SOFT_OFF, 0, 0});
+			k_msleep(2000);
+			printk("Woke up from system off?\n");
+		}
 	} else {
 		k_sleep(K_FOREVER);
 	}
 
 	hwinfo_clear_reset_cause();
-	sys_poweroff();
+	pm_state_force(0u, &(struct pm_state_info){PM_STATE_SOFT_OFF, 0, 0});
+	k_sleep(K_FOREVER);
 
 	return 0;
 }

soc/nordic/nrf54h/power.c

@@ -83,9 +83,6 @@ void nrf_poweroff(void)
 #endif
 	common_suspend();
 
-	/* Disable all owned compare channels except the one used for wakeup from system-off. */
-	z_nrf_grtc_timer_disable_owned_cc_channels(z_nrf_grtc_timer_wakeup_channel_get());
-
 	/* Indicate that we are ready for system off. */
 	nrf_lrcconf_task_trigger(NRF_LRCCONF010, NRF_LRCCONF_TASK_SYSTEMOFFREADY);
 
@@ -140,6 +137,34 @@ static void s2idle_exit(uint8_t substate_id)
 	}
 }
 
+#if defined(CONFIG_SOC_NRF54H20_CPURAD)
+
+static void s2idle_ready_for_soft_off_enter(void)
+{
+#if !defined(CONFIG_SOC_NRF54H20_CPURAD)
+	soc_lrcconf_poweron_request(&soc_node, NRF_LRCCONF_POWER_MAIN);
+#endif
+	common_suspend();
+	nrf_lrcconf_task_trigger(NRF_LRCCONF010, NRF_LRCCONF_TASK_SYSTEMOFFREADY);
+
+	__set_BASEPRI(0);
+	__ISB();
+	__DSB();
+	__WFI();
+}
+
+static void s2idle_ready_for_soft_off_exit(void)
+{
+	nrf_lrcconf_task_trigger(NRF_LRCCONF010, NRF_LRCCONF_TASK_SYSTEMOFFNOTREADY);
+
+	nrf_power_up_cache();
+	common_resume();
+#if !defined(CONFIG_SOC_NRF54H20_CPURAD)
+	soc_lrcconf_poweron_release(&soc_node, NRF_LRCCONF_POWER_MAIN);
+#endif
+}
+#endif
+
 #if defined(CONFIG_PM_S2RAM)
 /* Resume domain after local suspend to RAM. */
 static void s2ram_exit(void)
@@ -151,6 +176,17 @@ static void s2ram_exit(void)
 #endif
 }
 
+static void s2ram_ready_for_soft_off_exit(void)
+{
+	nrf_lrcconf_task_trigger(NRF_LRCCONF010, NRF_LRCCONF_TASK_SYSTEMOFFNOTREADY);
+
+	common_resume();
+#if !defined(CONFIG_SOC_NRF54H20_CPURAD)
+	/* Re-enable domain retention. */
+	nrf_lrcconf_retain_set(NRF_LRCCONF010, NRF_LRCCONF_POWER_DOMAIN_0, true);
+#endif
+}
+
 /* Function called during local domain suspend to RAM. */
 static int sys_suspend_to_ram(void)
 {
@@ -178,6 +214,35 @@ static int sys_suspend_to_ram(void)
 	return -EBUSY;
 }
 
+/* Function called during local domain suspend to RAM with soft off readiness. */
+static int sys_suspend_to_ram_ready_for_soft_off(void)
+{
+	/* Set intormation which is used on domain wakeup to determine if resume from RAM shall
+	 * be performed.
+	 */
+	nrf_resetinfo_resetreas_local_set(NRF_RESETINFO,
+					  NRF_RESETINFO_RESETREAS_LOCAL_UNRETAINED_MASK);
+	nrf_resetinfo_restore_valid_set(NRF_RESETINFO, true);
+
+#if !defined(CONFIG_SOC_NRF54H20_CPURAD)
+	/* Disable retention */
+	nrf_lrcconf_retain_set(NRF_LRCCONF010, NRF_LRCCONF_POWER_DOMAIN_0, false);
+#endif
+	common_suspend();
+
+	nrf_lrcconf_task_trigger(NRF_LRCCONF010, NRF_LRCCONF_TASK_SYSTEMOFFREADY);
+
+	__set_BASEPRI(0);
+	__ISB();
+	__DSB();
+	__WFI();
+	/*
+	 * We might reach this point is k_cpu_idle returns (there is a pre sleep hook that
+	 * can abort sleeping.
+	 */
+	return -EBUSY;
+}
+
 static void s2ram_enter(void)
 {
 	/*
@@ -188,6 +253,17 @@ static void s2ram_enter(void)
 		return;
 	}
 }
+
+static void s2ram_ready_for_soft_off_enter(void)
+{
+	/*
+	 * Save the CPU context (including the return address),set the SRAM
+	 * marker and power off the system.
+	 */
+	if (soc_s2ram_suspend(sys_suspend_to_ram_ready_for_soft_off)) {
+		return;
+	}
+}
 #endif /* defined(CONFIG_PM_S2RAM) */
 
 void pm_state_set(enum pm_state state, uint8_t substate_id)
@@ -201,6 +277,17 @@ void pm_state_set(enum pm_state state, uint8_t substate_id)
 		sys_trace_idle_exit();
 		__enable_irq();
 	}
+#if defined(CONFIG_SOC_NRF54H20_CPURAD) && defined(CONFIG_POWEROFF)
+	else if (state == PM_STATE_SOFT_OFF) {
+		__disable_irq();
+		sys_trace_idle();
+		s2idle_ready_for_soft_off_enter();
+		/* On resuming or error we return exactly *HERE* */
+		s2idle_ready_for_soft_off_exit();
+		sys_trace_idle_exit();
+		__enable_irq();
+	}
+#endif
 #if defined(CONFIG_PM_S2RAM)
 	else if (state == PM_STATE_SUSPEND_TO_RAM) {
 		__disable_irq();
@@ -211,6 +298,17 @@ void pm_state_set(enum pm_state state, uint8_t substate_id)
 		sys_trace_idle_exit();
 		__enable_irq();
 	}
+#if defined(CONFIG_POWEROFF)
+	else if (state == PM_STATE_SOFT_OFF) {
+		__disable_irq();
+		sys_trace_idle();
+		s2ram_ready_for_soft_off_enter();
+		/* On resuming or error we return exactly *HERE* */
+		s2ram_ready_for_soft_off_exit();
+		sys_trace_idle_exit();
+		__enable_irq();
+	}
+#endif
 #endif
 	else {
 		k_cpu_idle();