summaryrefslogtreecommitdiffstats
path: root/drivers/cpuidle/cpuidle-exynos.c
blob: 00cd129b10a4614709b7501dd04f927b6d06fa17 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/*
 * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * Coupled cpuidle support based on the work of:
 *	Colin Cross <ccross@android.com>
 *	Daniel Lezcano <daniel.lezcano@linaro.org>
 *
 * 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/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/platform_data/cpuidle-exynos.h>

#include <asm/suspend.h>
#include <asm/cpuidle.h>

static atomic_t exynos_idle_barrier;

static struct cpuidle_exynos_data *exynos_cpuidle_pdata;
static void (*exynos_enter_aftr)(void);

static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev,
					 struct cpuidle_driver *drv,
					 int index)
{
	int ret;

	exynos_cpuidle_pdata->pre_enter_aftr();

	/*
	 * Waiting all cpus to reach this point at the same moment
	 */
	cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);

	/*
	 * Both cpus will reach this point at the same time
	 */
	ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown()
		       : exynos_cpuidle_pdata->cpu0_enter_aftr();
	if (ret)
		index = ret;

	/*
	 * Waiting all cpus to finish the power sequence before going further
	 */
	cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);

	exynos_cpuidle_pdata->post_enter_aftr();

	return index;
}

static int exynos_enter_lowpower(struct cpuidle_device *dev,
				struct cpuidle_driver *drv,
				int index)
{
	int new_index = index;

	/* AFTR can only be entered when cores other than CPU0 are offline */
	if (num_online_cpus() > 1 || dev->cpu != 0)
		new_index = drv->safe_state_index;

	if (new_index == 0)
		return arm_cpuidle_simple_enter(dev, drv, new_index);

	exynos_enter_aftr();

	return new_index;
}

static struct cpuidle_driver exynos_idle_driver = {
	.name			= "exynos_idle",
	.owner			= THIS_MODULE,
	.states = {
		[0] = ARM_CPUIDLE_WFI_STATE,
		[1] = {
			.enter			= exynos_enter_lowpower,
			.exit_latency		= 300,
			.target_residency	= 100000,
			.name			= "C1",
			.desc			= "ARM power down",
		},
	},
	.state_count = 2,
	.safe_state_index = 0,
};

static struct cpuidle_driver exynos_coupled_idle_driver = {
	.name			= "exynos_coupled_idle",
	.owner			= THIS_MODULE,
	.states = {
		[0] = ARM_CPUIDLE_WFI_STATE,
		[1] = {
			.enter			= exynos_enter_coupled_lowpower,
			.exit_latency		= 5000,
			.target_residency	= 10000,
			.flags			= CPUIDLE_FLAG_COUPLED |
						  CPUIDLE_FLAG_TIMER_STOP,
			.name			= "C1",
			.desc			= "ARM power down",
		},
	},
	.state_count = 2,
	.safe_state_index = 0,
};

static int exynos_cpuidle_probe(struct platform_device *pdev)
{
	int ret;

	if (IS_ENABLED(CONFIG_SMP) &&
	    of_machine_is_compatible("samsung,exynos4210")) {
		exynos_cpuidle_pdata = pdev->dev.platform_data;

		ret = cpuidle_register(&exynos_coupled_idle_driver,
				       cpu_possible_mask);
	} else {
		exynos_enter_aftr = (void *)(pdev->dev.platform_data);

		ret = cpuidle_register(&exynos_idle_driver, NULL);
	}

	if (ret) {
		dev_err(&pdev->dev, "failed to register cpuidle driver\n");
		return ret;
	}

	return 0;
}

static struct platform_driver exynos_cpuidle_driver = {
	.probe	= exynos_cpuidle_probe,
	.driver = {
		.name = "exynos_cpuidle",
	},
};
builtin_platform_driver(exynos_cpuidle_driver);