Merge git://bedivere.hansenpartnership.com/git/scsi-rc-fixes-2.6
[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_state *state);
20
21 static struct cpuidle_state exynos4_cpuidle_set[] = {
22         [0] = {
23                 .enter                  = exynos4_enter_idle,
24                 .exit_latency           = 1,
25                 .target_residency       = 100000,
26                 .flags                  = CPUIDLE_FLAG_TIME_VALID,
27                 .name                   = "IDLE",
28                 .desc                   = "ARM clock gating(WFI)",
29         },
30 };
31
32 static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
33
34 static struct cpuidle_driver exynos4_idle_driver = {
35         .name           = "exynos4_idle",
36         .owner          = THIS_MODULE,
37 };
38
39 static int exynos4_enter_idle(struct cpuidle_device *dev,
40                               struct cpuidle_state *state)
41 {
42         struct timeval before, after;
43         int idle_time;
44
45         local_irq_disable();
46         do_gettimeofday(&before);
47
48         cpu_do_idle();
49
50         do_gettimeofday(&after);
51         local_irq_enable();
52         idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
53                     (after.tv_usec - before.tv_usec);
54
55         return idle_time;
56 }
57
58 static int __init exynos4_init_cpuidle(void)
59 {
60         int i, max_cpuidle_state, cpu_id;
61         struct cpuidle_device *device;
62
63         cpuidle_register_driver(&exynos4_idle_driver);
64
65         for_each_cpu(cpu_id, cpu_online_mask) {
66                 device = &per_cpu(exynos4_cpuidle_device, cpu_id);
67                 device->cpu = cpu_id;
68
69                 device->state_count = (sizeof(exynos4_cpuidle_set) /
70                                                sizeof(struct cpuidle_state));
71
72                 max_cpuidle_state = device->state_count;
73
74                 for (i = 0; i < max_cpuidle_state; i++) {
75                         memcpy(&device->states[i], &exynos4_cpuidle_set[i],
76                                         sizeof(struct cpuidle_state));
77                 }
78
79                 if (cpuidle_register_device(device)) {
80                         printk(KERN_ERR "CPUidle register device failed\n,");
81                         return -EIO;
82                 }
83         }
84         return 0;
85 }
86 device_initcall(exynos4_init_cpuidle);