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/* linux/arch/arm/mach-exynos4/cpuidle.c
*
* Copyright (c) 2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cpuidle.h>
#include <linux/io.h>
#include <asm/proc-fns.h>
static int exynos4_enter_idle(struct cpuidle_device *dev,
struct cpuidle_state *state);
static struct cpuidle_state exynos4_cpuidle_set[] = {
[0] = {
.enter = exynos4_enter_idle,
.exit_latency = 1,
.target_residency = 100000,
.flags = CPUIDLE_FLAG_TIME_VALID,
.name = "IDLE",
.desc = "ARM clock gating(WFI)",
},
};
static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
static struct cpuidle_driver exynos4_idle_driver = {
.name = "exynos4_idle",
.owner = THIS_MODULE,
};
static int exynos4_enter_idle(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct timeval before, after;
int idle_time;
local_irq_disable();
do_gettimeofday(&before);
cpu_do_idle();
do_gettimeofday(&after);
local_irq_enable();
idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
(after.tv_usec - before.tv_usec);
return idle_time;
}
static int __init exynos4_init_cpuidle(void)
{
int i, max_cpuidle_state, cpu_id;
struct cpuidle_device *device;
cpuidle_register_driver(&exynos4_idle_driver);
for_each_cpu(cpu_id, cpu_online_mask) {
device = &per_cpu(exynos4_cpuidle_device, cpu_id);
device->cpu = cpu_id;
device->state_count = (sizeof(exynos4_cpuidle_set) /
sizeof(struct cpuidle_state));
max_cpuidle_state = device->state_count;
for (i = 0; i < max_cpuidle_state; i++) {
memcpy(&device->states[i], &exynos4_cpuidle_set[i],
sizeof(struct cpuidle_state));
}
if (cpuidle_register_device(device)) {
printk(KERN_ERR "CPUidle register device failed\n,");
return -EIO;
}
}
return 0;
}
device_initcall(exynos4_init_cpuidle);
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