1 files changed, 76 insertions, 0 deletions
diff --git a/zephyr/shim/chip/it8xxx2/power_policy.c b/zephyr/shim/chip/it8xxx2/power_policy.c
new file mode 100644
index 0000000000..92613710fe
--- /dev/null
+++ b/zephyr/shim/chip/it8xxx2/power_policy.c
@@ -0,0 +1,76 @@
+/* Copyright 2021 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <pm/pm.h>
+#include <pm/policy.h>
+#include <soc.h>
+#include <zephyr.h>
+
+#include "system.h"
+#include "timer.h"
+
+static const struct pm_state_info pm_states[] =
+	PM_STATE_INFO_LIST_FROM_DT_CPU(DT_NODELABEL(cpu0));
+
+#define CONSOLE_IN_USE_ON_BOOT_TIME (5 * SECOND)
+#define CONSOLE_IN_USE_TIMEOUT_SEC (5 * SECOND)
+
+static timestamp_t console_expire_time;
+static timestamp_t sleep_mode_t0;
+
+void uart1_wui_isr_late(void)
+{
+	/* Set console in use expire time. */
+	console_expire_time = get_time();
+	console_expire_time.val += CONSOLE_IN_USE_TIMEOUT_SEC;
+}
+
+static int clock_allow_low_power_idle(void)
+{
+	sleep_mode_t0 = get_time();
+
+	/* If we are waked up by console, then keep awake at least 5s. */
+	if (sleep_mode_t0.val < console_expire_time.val)
+		return 0;
+
+	return 1;
+}
+
+/* CROS PM policy handler */
+struct pm_state_info pm_policy_next_state(uint8_t cpu, int32_t ticks)
+{
+	ARG_UNUSED(cpu);
+
+	/* Deep sleep is allowed and an interval of five seconds. */
+	if (DEEP_SLEEP_ALLOWED && clock_allow_low_power_idle()) {
+		/*
+		 * If there are multiple power states, iterating backward
+		 * is needed to take priority into account.
+		 */
+		for (int i = 0; i < ARRAY_SIZE(pm_states); i++) {
+			/*
+			 * To check if given power state is enabled and
+			 * could be used.
+			 */
+			if (!pm_constraint_get(pm_states[i].state)) {
+				continue;
+			}
+
+			return pm_states[i];
+		}
+	}
+
+	return (struct pm_state_info){PM_STATE_ACTIVE, 0, 0};
+}
+
+static int power_policy_init(const struct device *arg)
+{
+	ARG_UNUSED(arg);
+
+	console_expire_time.val = get_time().val + CONSOLE_IN_USE_ON_BOOT_TIME;
+
+	return 0;
+}
+SYS_INIT(power_policy_init, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);