Commit 3d739985 authored by Jaecheol Lee's avatar Jaecheol Lee Committed by Kukjin Kim
Browse files

ARM: EXYNOS4: CPUIDLE Support 



This patch supports cpuidle framework for EXYNOS4210. Currently,
Only one idle state is possible to use, but more idle states can
be added following by this patch.

Signed-off-by: default avatarJaecheol Lee <jc.lee@samsung.com>
Signed-off-by: default avatarKukjin Kim <kgene.kim@samsung.com>
parent 0ee5623f

arch/arm/mach-exynos4/Makefile

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Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ obj-$(CONFIG_CPU_EXYNOS4210) += cpu.o init.o clock.o irq-combiner.o 
obj-$(CONFIG_CPU_EXYNOS4210)	+= setup-i2c0.o gpiolib.o irq-eint.o dma.o

obj-$(CONFIG_PM)		+= pm.o sleep.o

obj-$(CONFIG_CPU_FREQ)		+= cpufreq.o

obj-$(CONFIG_CPU_IDLE)		+= cpuidle.o



obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o

arch/arm/mach-exynos4/cpuidle.c

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+86 −0
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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);