cpuidle: Single/Global registration of idle states
[linux-2.6.git] / arch / arm / mach-exynos4 / cpuidle.c
1 /* linux/arch/arm/mach-exynos4/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/kernel.h>
12 #include <linux/init.h>
13 #include <linux/cpuidle.h>
14 #include <linux/io.h>
15
16 #include <asm/proc-fns.h>
17
18 static int exynos4_enter_idle(struct cpuidle_device *dev,
19                         struct cpuidle_driver *drv,
20                               int index);
21
22 static struct cpuidle_state exynos4_cpuidle_set[] = {
23         [0] = {
24                 .enter                  = exynos4_enter_idle,
25                 .exit_latency           = 1,
26                 .target_residency       = 100000,
27                 .flags                  = CPUIDLE_FLAG_TIME_VALID,
28                 .name                   = "IDLE",
29                 .desc                   = "ARM clock gating(WFI)",
30         },
31 };
32
33 static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
34
35 static struct cpuidle_driver exynos4_idle_driver = {
36         .name           = "exynos4_idle",
37         .owner          = THIS_MODULE,
38 };
39
40 static int exynos4_enter_idle(struct cpuidle_device *dev,
41                                 struct cpuidle_driver *drv,
42                               int index)
43 {
44         struct timeval before, after;
45         int idle_time;
46
47         local_irq_disable();
48         do_gettimeofday(&before);
49
50         cpu_do_idle();
51
52         do_gettimeofday(&after);
53         local_irq_enable();
54         idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
55                     (after.tv_usec - before.tv_usec);
56
57         dev->last_residency = idle_time;
58         return index;
59 }
60
61 static int __init exynos4_init_cpuidle(void)
62 {
63         int i, max_cpuidle_state, cpu_id;
64         struct cpuidle_device *device;
65         struct cpuidle_driver *drv = &exynos4_idle_driver;
66
67         /* Setup cpuidle driver */
68         drv->state_count = (sizeof(exynos4_cpuidle_set) /
69                                        sizeof(struct cpuidle_state));
70         max_cpuidle_state = drv->state_count;
71         for (i = 0; i < max_cpuidle_state; i++) {
72                 memcpy(&drv->states[i], &exynos4_cpuidle_set[i],
73                                 sizeof(struct cpuidle_state));
74         }
75         cpuidle_register_driver(&exynos4_idle_driver);
76
77         for_each_cpu(cpu_id, cpu_online_mask) {
78                 device = &per_cpu(exynos4_cpuidle_device, cpu_id);
79                 device->cpu = cpu_id;
80
81                 device->state_count = drv->state_count;
82
83                 if (cpuidle_register_device(device)) {
84                         printk(KERN_ERR "CPUidle register device failed\n,");
85                         return -EIO;
86                 }
87         }
88         return 0;
89 }
90 device_initcall(exynos4_init_cpuidle);