summaryrefslogtreecommitdiff
path: root/arch/arm/mach-tegra/cpuidle-tegra30.c
blob: 82530bd9b8c223fdd0c15090a081513fe2bb2616 (plain)
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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/*
 * CPU idle driver for Tegra CPUs
 *
 * Copyright (c) 2010-2012, NVIDIA Corporation.
 * Copyright (c) 2011 Google, Inc.
 * Author: Colin Cross <ccross@android.com>
 *         Gary King <gking@nvidia.com>
 *
 * Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/clockchips.h>

#include <asm/cpuidle.h>
#include <asm/proc-fns.h>
#include <asm/suspend.h>
#include <asm/smp_plat.h>

#include "pm.h"
#include "sleep.h"
#include "tegra_cpu_car.h"

#ifdef CONFIG_PM_SLEEP
static int tegra30_idle_lp2(struct cpuidle_device *dev,
			    struct cpuidle_driver *drv,
			    int index);
#endif

static struct cpuidle_driver tegra_idle_driver = {
	.name = "tegra_idle",
	.owner = THIS_MODULE,
	.en_core_tk_irqen = 1,
#ifdef CONFIG_PM_SLEEP
	.state_count = 2,
#else
	.state_count = 1,
#endif
	.states = {
		[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
#ifdef CONFIG_PM_SLEEP
		[1] = {
			.enter			= tegra30_idle_lp2,
			.exit_latency		= 2000,
			.target_residency	= 2200,
			.power_usage		= 0,
			.flags			= CPUIDLE_FLAG_TIME_VALID,
			.name			= "powered-down",
			.desc			= "CPU power gated",
		},
#endif
	},
};

static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);

#ifdef CONFIG_PM_SLEEP
static bool tegra30_cpu_cluster_power_down(struct cpuidle_device *dev,
					   struct cpuidle_driver *drv,
					   int index)
{
	struct cpuidle_state *state = &drv->states[index];
	u32 cpu_on_time = state->exit_latency;
	u32 cpu_off_time = state->target_residency - state->exit_latency;

	/* All CPUs entering LP2 is not working.
	 * Don't let CPU0 enter LP2 when any secondary CPU is online.
	 */
	if (num_online_cpus() > 1 || !tegra_cpu_rail_off_ready()) {
		cpu_do_idle();
		return false;
	}

	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);

	tegra_idle_lp2_last(cpu_on_time, cpu_off_time);

	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);

	return true;
}

#ifdef CONFIG_SMP
static bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
					struct cpuidle_driver *drv,
					int index)
{
	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);

	smp_wmb();

	save_cpu_arch_register();

	cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);

	restore_cpu_arch_register();

	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);

	return true;
}
#else
static inline bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
					       struct cpuidle_driver *drv,
					       int index)
{
	return true;
}
#endif

static int tegra30_idle_lp2(struct cpuidle_device *dev,
			    struct cpuidle_driver *drv,
			    int index)
{
	u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;
	bool entered_lp2 = false;
	bool last_cpu;

	local_fiq_disable();

	last_cpu = tegra_set_cpu_in_lp2(cpu);
	cpu_pm_enter();

	if (cpu == 0) {
		if (last_cpu)
			entered_lp2 = tegra30_cpu_cluster_power_down(dev, drv,
								     index);
		else
			cpu_do_idle();
	} else {
		entered_lp2 = tegra30_cpu_core_power_down(dev, drv, index);
	}

	cpu_pm_exit();
	tegra_clear_cpu_in_lp2(cpu);

	local_fiq_enable();

	smp_rmb();

	return (entered_lp2) ? index : 0;
}
#endif

int __init tegra30_cpuidle_init(void)
{
	int ret;
	unsigned int cpu;
	struct cpuidle_device *dev;
	struct cpuidle_driver *drv = &tegra_idle_driver;

#ifdef CONFIG_PM_SLEEP
	tegra_tear_down_cpu = tegra30_tear_down_cpu;
#endif

	ret = cpuidle_register_driver(&tegra_idle_driver);
	if (ret) {
		pr_err("CPUidle driver registration failed\n");
		return ret;
	}

	for_each_possible_cpu(cpu) {
		dev = &per_cpu(tegra_idle_device, cpu);
		dev->cpu = cpu;

		dev->state_count = drv->state_count;
		ret = cpuidle_register_device(dev);
		if (ret) {
			pr_err("CPU%u: CPUidle device registration failed\n",
				cpu);
			return ret;
		}
	}
	return 0;
}