1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/cpuidle/governors/scheduled.c b/drivers/cpuidle/governors/scheduled.c
new file mode 100644
index 000000000000..b597bd267932
--- /dev/null
+++ b/drivers/cpuidle/governors/scheduled.c
@@ -0,0 +1,113 @@
+/*
+ * scheduled.c - A governor that selects idle state based on external input
+ *
+ * Copyright 2013 Linaro Limited
+ * Author:
+ *        Tuukka Tikkanen <tuukka.tikkanen@linaro.org>
+ *
+ * This code is licenced under the GPL version 2 as described
+ * in the COPYING file that acompanies the Linux Kernel.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle_scheduled.h>
+#include <linux/cpuidle.h>
+#include <linux/pm_qos.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+
+/**
+ * scheduled_select - selects the next idle state to enter
+ * @drv: cpuidle driver containing state data
+ * @dev: the CPU
+ */
+static int scheduled_select(struct cpuidle_driver *drv,
+				struct cpuidle_device *dev)
+{
+	int state;
+	struct sched_pm *pmdata = this_cpu_ptr(&sched_stat);
+
+	state = cpuidle_cstate_lookup(drv, dev,
+			pmdata->idle_time_until_timer,
+			pmdata->idle_length_estimate,
+			pmdata->idle_max_latency,
+			NULL);
+	pmdata->idle_current_state = &drv->states[state];
+
+	return state;
+}
+
+/**
+ * scheduled_reflect - records the actual idle period length
+ * @dev: the CPU
+ * @index: the index of actual entered state
+ */
+static void scheduled_reflect(struct cpuidle_device *dev, int index)
+{
+	unsigned int last_idle_us;
+	struct sched_pm *pmdata = this_cpu_ptr(&sched_stat);
+	unsigned int timer_limit = pmdata->idle_time_until_timer;
+	struct cpuidle_state *state = pmdata->idle_current_state;
+
+	if (unlikely(!(state->flags & CPUIDLE_FLAG_TIME_VALID))) {
+		last_idle_us = timer_limit;
+	} else {
+		last_idle_us = cpuidle_get_last_residency(dev);
+		if (last_idle_us > state->exit_latency)
+			last_idle_us -= state->exit_latency;
+		if (last_idle_us > timer_limit)
+			last_idle_us = timer_limit;
+	}
+
+	cpuidle_scheduled_result(state, last_idle_us);
+
+	pmdata->idle_current_state = NULL;
+}
+
+
+/**
+ * scheduled_enable_device - reset per cpu variables after hotplug
+ * @drv: cpuidle driver
+ * @dev: the CPU
+ */
+static int scheduled_enable_device(struct cpuidle_driver *drv,
+				struct cpuidle_device *dev)
+{
+	struct sched_pm *pmdata = &per_cpu(sched_stat, dev->cpu);
+
+	pmdata->idle_time_until_timer = UINT_MAX;
+	pmdata->idle_length_estimate = UINT_MAX;
+	pmdata->idle_max_latency = INT_MAX;
+	pmdata->idle_current_state = NULL;
+
+	return 0;
+}
+
+static struct cpuidle_governor scheduled_governor = {
+	.name =		"scheduled",
+	.rating =	100,
+	.enable =	scheduled_enable_device,
+	.select =	scheduled_select,
+	.reflect =	scheduled_reflect,
+	.owner =	THIS_MODULE,
+};
+
+/**
+ * init_scheduled_idle_gov - initializes the governor
+ */
+static int __init init_scheduled_idle_gov(void)
+{
+	return cpuidle_register_governor(&scheduled_governor);
+}
+
+/**
+ * exit_scheduled_idle_gov - exits the governor
+ */
+static void __exit exit_scheduled_idle_gov(void)
+{
+	cpuidle_unregister_governor(&scheduled_governor);
+}
+
+MODULE_LICENSE("GPL");
+module_init(init_scheduled_idle_gov);
+module_exit(exit_scheduled_idle_gov);