1/* linux/arch/arm/mach-exynos/cpuidle.c
2 *
3 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
4 *		http://www.samsung.com
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9*/
10
11#include <linux/cpuidle.h>
12#include <linux/cpu_pm.h>
13#include <linux/export.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16
17#include <asm/proc-fns.h>
18#include <asm/suspend.h>
19#include <asm/cpuidle.h>
20
21static void (*exynos_enter_aftr)(void);
22
23static int exynos_enter_lowpower(struct cpuidle_device *dev,
24				struct cpuidle_driver *drv,
25				int index)
26{
27	int new_index = index;
28
29	/* AFTR can only be entered when cores other than CPU0 are offline */
30	if (num_online_cpus() > 1 || dev->cpu != 0)
31		new_index = drv->safe_state_index;
32
33	if (new_index == 0)
34		return arm_cpuidle_simple_enter(dev, drv, new_index);
35
36	exynos_enter_aftr();
37
38	return new_index;
39}
40
41static struct cpuidle_driver exynos_idle_driver = {
42	.name			= "exynos_idle",
43	.owner			= THIS_MODULE,
44	.states = {
45		[0] = ARM_CPUIDLE_WFI_STATE,
46		[1] = {
47			.enter			= exynos_enter_lowpower,
48			.exit_latency		= 300,
49			.target_residency	= 100000,
50			.flags			= CPUIDLE_FLAG_TIME_VALID,
51			.name			= "C1",
52			.desc			= "ARM power down",
53		},
54	},
55	.state_count = 2,
56	.safe_state_index = 0,
57};
58
59static int exynos_cpuidle_probe(struct platform_device *pdev)
60{
61	int ret;
62
63	exynos_enter_aftr = (void *)(pdev->dev.platform_data);
64
65	ret = cpuidle_register(&exynos_idle_driver, NULL);
66	if (ret) {
67		dev_err(&pdev->dev, "failed to register cpuidle driver\n");
68		return ret;
69	}
70
71	return 0;
72}
73
74static struct platform_driver exynos_cpuidle_driver = {
75	.probe	= exynos_cpuidle_probe,
76	.driver = {
77		.name = "exynos_cpuidle",
78		.owner = THIS_MODULE,
79	},
80};
81
82module_platform_driver(exynos_cpuidle_driver);
83