blob: d83a8c0296f5a2babaf161965aed5d5276fb95df [file] [log] [blame]
Peter De Schrijver22b8b852012-01-26 18:22:03 +02001/*
2 * arch/arm/mach-tegra/cpuidle.c
3 *
4 * CPU idle driver for Tegra CPUs
5 *
6 * Copyright (c) 2010-2012, NVIDIA Corporation.
7 * Copyright (c) 2011 Google, Inc.
8 * Author: Colin Cross <ccross@android.com>
9 * Gary King <gking@nvidia.com>
10 *
11 * Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful, but WITHOUT
19 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
20 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
21 * more details.
22 */
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/cpu.h>
27#include <linux/cpuidle.h>
28#include <linux/hrtimer.h>
29
30#include <mach/iomap.h>
31
32extern void tegra_cpu_wfi(void);
33
34static int tegra_idle_enter_lp3(struct cpuidle_device *dev,
35 struct cpuidle_driver *drv, int index);
36
37struct cpuidle_driver tegra_idle_driver = {
38 .name = "tegra_idle",
39 .owner = THIS_MODULE,
40 .state_count = 1,
41 .states = {
42 [0] = {
43 .enter = tegra_idle_enter_lp3,
44 .exit_latency = 10,
45 .target_residency = 10,
46 .power_usage = 600,
47 .flags = CPUIDLE_FLAG_TIME_VALID,
48 .name = "LP3",
49 .desc = "CPU flow-controlled",
50 },
51 },
52};
53
54static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);
55
56static int tegra_idle_enter_lp3(struct cpuidle_device *dev,
57 struct cpuidle_driver *drv, int index)
58{
59 ktime_t enter, exit;
60 s64 us;
61
62 local_irq_disable();
63 local_fiq_disable();
64
65 enter = ktime_get();
66
67 tegra_cpu_wfi();
68
69 exit = ktime_sub(ktime_get(), enter);
70 us = ktime_to_us(exit);
71
72 local_fiq_enable();
73 local_irq_enable();
74
75 dev->last_residency = us;
76
77 return index;
78}
79
80static int __init tegra_cpuidle_init(void)
81{
82 int ret;
83 unsigned int cpu;
84 struct cpuidle_device *dev;
85 struct cpuidle_driver *drv = &tegra_idle_driver;
86
87 ret = cpuidle_register_driver(&tegra_idle_driver);
88 if (ret) {
89 pr_err("CPUidle driver registration failed\n");
90 return ret;
91 }
92
93 for_each_possible_cpu(cpu) {
94 dev = &per_cpu(tegra_idle_device, cpu);
95 dev->cpu = cpu;
96
97 dev->state_count = drv->state_count;
98 ret = cpuidle_register_device(dev);
99 if (ret) {
100 pr_err("CPU%u: CPUidle device registration failed\n",
101 cpu);
102 return ret;
103 }
104 }
105 return 0;
106}
107device_initcall(tegra_cpuidle_init);