1 /* linux/arch/arm/mach-s3c64xx/cpuidle.c
2 *
3 * Copyright (c) 2011 Wolfson Microelectronics, plc
4 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/cpuidle.h>
15 #include <linux/io.h>
16 #include <linux/export.h>
17 #include <linux/time.h>
18
19 #include <asm/proc-fns.h>
20
21 #include <mach/map.h>
22
23 #include <mach/regs-sys.h>
24 #include <mach/regs-syscon-power.h>
25
s3c64xx_enter_idle(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)26 static int s3c64xx_enter_idle(struct cpuidle_device *dev,
27 struct cpuidle_driver *drv,
28 int index)
29 {
30 struct timeval before, after;
31 unsigned long tmp;
32 int idle_time;
33
34 local_irq_disable();
35 do_gettimeofday(&before);
36
37 /* Setup PWRCFG to enter idle mode */
38 tmp = __raw_readl(S3C64XX_PWR_CFG);
39 tmp &= ~S3C64XX_PWRCFG_CFG_WFI_MASK;
40 tmp |= S3C64XX_PWRCFG_CFG_WFI_IDLE;
41 __raw_writel(tmp, S3C64XX_PWR_CFG);
42
43 cpu_do_idle();
44
45 do_gettimeofday(&after);
46 local_irq_enable();
47 idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
48 (after.tv_usec - before.tv_usec);
49
50 dev->last_residency = idle_time;
51 return index;
52 }
53
54 static struct cpuidle_state s3c64xx_cpuidle_set[] = {
55 [0] = {
56 .enter = s3c64xx_enter_idle,
57 .exit_latency = 1,
58 .target_residency = 1,
59 .flags = CPUIDLE_FLAG_TIME_VALID,
60 .name = "IDLE",
61 .desc = "System active, ARM gated",
62 },
63 };
64
65 static struct cpuidle_driver s3c64xx_cpuidle_driver = {
66 .name = "s3c64xx_cpuidle",
67 .owner = THIS_MODULE,
68 .state_count = ARRAY_SIZE(s3c64xx_cpuidle_set),
69 };
70
71 static struct cpuidle_device s3c64xx_cpuidle_device = {
72 .state_count = ARRAY_SIZE(s3c64xx_cpuidle_set),
73 };
74
s3c64xx_init_cpuidle(void)75 static int __init s3c64xx_init_cpuidle(void)
76 {
77 int ret;
78
79 memcpy(s3c64xx_cpuidle_driver.states, s3c64xx_cpuidle_set,
80 sizeof(s3c64xx_cpuidle_set));
81 cpuidle_register_driver(&s3c64xx_cpuidle_driver);
82
83 ret = cpuidle_register_device(&s3c64xx_cpuidle_device);
84 if (ret) {
85 pr_err("Failed to register cpuidle device: %d\n", ret);
86 return ret;
87 }
88
89 return 0;
90 }
91 device_initcall(s3c64xx_init_cpuidle);
92