soc: arm: nrf51: Backport power management code from nRF52

This commit ports power management code from nRF52 to the nRF51 SoC,
enabling usage of Zephyr Power Management policies on this platform.

Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>

soc/arm/nordic_nrf/nrf51/Kconfig.series

@@ -13,7 +13,8 @@ config  SOC_SERIES_NRF51X
 	select NRF_RTC_TIMER
 	select CLOCK_CONTROL
 	select CLOCK_CONTROL_NRF
-	select SYS_POWER_LOW_POWER_STATE_SUPPORTED
+	select SYS_POWER_DEEP_SLEEP_SUPPORTED
+	select SYS_POWER_STATE_DEEP_SLEEP_SUPPORTED
 	select XIP
 	select HAS_CMSIS
 	select HAS_NRFX

soc/arm/nordic_nrf/nrf51/power.c

@@ -1,11 +1,95 @@
 /*
- * Copyright (c) 2018 Intel Corporation.
+ * Copyright (c) 2017 Intel Corporation.
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 #include <zephyr.h>
+#include <soc_power.h>
 #include <nrf_power.h>
 
+#include <logging/log.h>
+LOG_MODULE_DECLARE(soc, CONFIG_SOC_LOG_LEVEL);
+
+/* Invoke Low Power/System Off specific Tasks */
+void sys_set_power_state(enum power_states state)
+{
+	switch (state) {
+#ifdef CONFIG_SYS_POWER_DEEP_SLEEP
+ #ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_SUPPORTED
+	case SYS_POWER_STATE_DEEP_SLEEP:
+		nrf_power_system_off();
+		break;
+ #endif
+#endif
+	default:
+		LOG_ERR("Unsupported power state %u", state);
+		break;
+	}
+}
+
+/* Handle SOC specific activity after Low Power Mode Exit */
+void sys_power_state_post_ops(enum power_states state)
+{
+	switch (state) {
+#ifdef CONFIG_SYS_POWER_DEEP_SLEEP
+ #ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_SUPPORTED
+	case SYS_POWER_STATE_DEEP_SLEEP:
+		/* Nothing to do. */
+		break;
+ #endif
+#endif
+	default:
+		LOG_ERR("Unsupported power state %u", state);
+		break;
+	}
+
+	/*
+	 * System is now in active mode. Reenable interrupts which were disabled
+	 * when OS started idling code.
+	 */
+	irq_unlock(0);
+}
+
+bool sys_is_valid_power_state(enum power_states state)
+{
+	switch (state) {
+#ifdef CONFIG_SYS_POWER_LOW_POWER_STATE
+ #ifdef CONFIG_SYS_POWER_STATE_CPU_LPS_SUPPORTED
+	case SYS_POWER_STATE_CPU_LPS:
+		return true;
+ #endif
+ #ifdef CONFIG_SYS_POWER_STATE_CPU_LPS_1_SUPPORTED
+	case SYS_POWER_STATE_CPU_LPS_1:
+		return true;
+ #endif
+ #ifdef CONFIG_SYS_POWER_STATE_CPU_LPS_2_SUPPORTED
+	case SYS_POWER_STATE_CPU_LPS_2:
+		return true;
+ #endif
+#endif /* CONFIG_SYS_POWER_LOW_POWER_STATE */
+
+#ifdef CONFIG_SYS_POWER_DEEP_SLEEP
+ #ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_SUPPORTED
+	case SYS_POWER_STATE_DEEP_SLEEP:
+		return true;
+ #endif
+ #ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_1_SUPPORTED
+	case SYS_POWER_STATE_DEEP_SLEEP_1:
+		return true;
+ #endif
+ #ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_2_SUPPORTED
+	case SYS_POWER_STATE_DEEP_SLEEP_2:
+		return true;
+ #endif
+#endif /* CONFIG_SYS_POWER_DEEP_SLEEP */
+
+	default:
+		return false;
+	}
+
+	/* Not reached */
+}
+
 /* Overrides the weak ARM implementation:
    Set general purpose retention register and reboot */
 void sys_arch_reboot(int type)

soc/arm/nordic_nrf/nrf51/soc.h

@@ -16,6 +16,8 @@
 #include <nrf_common.h>
 #include <nrf.h>
 
+#include <soc_power.h>
+
 /* Add include for DTS generated information */
 #include <generated_dts_board.h>
 

soc/arm/nordic_nrf/nrf51/soc_power.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2017 Intel Corporation.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _SOC_POWER_H_
+#define _SOC_POWER_H_
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum power_states {
+#ifdef CONFIG_SYS_POWER_LOW_POWER_STATE
+# ifdef CONFIG_SYS_POWER_STATE_CPU_LPS_SUPPORTED
+	SYS_POWER_STATE_CPU_LPS,	/* Not used */
+# endif
+# ifdef CONFIG_SYS_POWER_STATE_CPU_LPS_1_SUPPORTED
+	SYS_POWER_STATE_CPU_LPS_1,	/* Not used */
+# endif
+# ifdef CONFIG_SYS_POWER_STATE_CPU_LPS_2_SUPPORTED
+	SYS_POWER_STATE_CPU_LPS_2,	/* Not used */
+# endif
+#endif /* CONFIG_SYS_POWER_LOW_POWER_STATE */
+
+#ifdef CONFIG_SYS_POWER_DEEP_SLEEP
+# ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_SUPPORTED
+	SYS_POWER_STATE_DEEP_SLEEP,	/* System OFF */
+# endif
+# ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_1_SUPPORTED
+	SYS_POWER_STATE_DEEP_SLEEP_1,	/* Not used */
+# endif
+# ifdef CONFIG_SYS_POWER_STATE_DEEP_SLEEP_2_SUPPORTED
+	SYS_POWER_STATE_DEEP_SLEEP_2,	/* Not used */
+# endif
+#endif /* CONFIG_SYS_POWER_DEEP_SLEEP */
+	SYS_POWER_STATE_MAX		/* Do nothing */
+};
+
+/**
+ * @brief Put processor into low power state
+ */
+void sys_set_power_state(enum power_states state);
+
+/**
+ * @brief Check the low power state is supported by SoC
+ */
+bool sys_is_valid_power_state(enum power_states state);
+
+/**
+ * @brief Do any SoC or architecture specific post ops after low power states.
+ */
+void sys_power_state_post_ops(enum power_states state);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SOC_POWER_H_ */