7be50d4c42684ab2dac07fd8ecbb46268ddfa112
[linux-2.6.git] / arch / sh / kernel / cpu / shmobile / cpuidle.c
1 /*
2  * arch/sh/kernel/cpu/shmobile/cpuidle.c
3  *
4  * Cpuidle support code for SuperH Mobile
5  *
6  *  Copyright (C) 2009 Magnus Damm
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/io.h>
15 #include <linux/suspend.h>
16 #include <linux/cpuidle.h>
17 #include <asm/suspend.h>
18 #include <asm/uaccess.h>
19 #include <asm/hwblk.h>
20
21 static unsigned long cpuidle_mode[] = {
22         SUSP_SH_SLEEP, /* regular sleep mode */
23         SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */
24         SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */
25 };
26
27 static int cpuidle_sleep_enter(struct cpuidle_device *dev,
28                                 int index)
29 {
30         unsigned long allowed_mode = arch_hwblk_sleep_mode();
31         ktime_t before, after;
32         int requested_state = index;
33         int allowed_state;
34         int k;
35
36         /* convert allowed mode to allowed state */
37         for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
38                 if (cpuidle_mode[k] == allowed_mode)
39                         break;
40
41         allowed_state = k;
42
43         /* take the following into account for sleep mode selection:
44          * - allowed_state: best mode allowed by hardware (clock deps)
45          * - requested_state: best mode allowed by software (latencies)
46          */
47         k = min_t(int, allowed_state, requested_state);
48
49         before = ktime_get();
50         sh_mobile_call_standby(cpuidle_mode[k]);
51         after = ktime_get();
52
53         dev->last_residency = (int)ktime_to_ns(ktime_sub(after, before)) >> 10;
54
55         return k;
56 }
57
58 static struct cpuidle_device cpuidle_dev;
59 static struct cpuidle_driver cpuidle_driver = {
60         .name =         "sh_idle",
61         .owner =        THIS_MODULE,
62 };
63
64 void sh_mobile_setup_cpuidle(void)
65 {
66         struct cpuidle_device *dev = &cpuidle_dev;
67         struct cpuidle_state *state;
68         int i;
69
70         cpuidle_register_driver(&cpuidle_driver);
71
72         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
73                 dev->states[i].name[0] = '\0';
74                 dev->states[i].desc[0] = '\0';
75         }
76
77         i = CPUIDLE_DRIVER_STATE_START;
78
79         state = &dev->states[i++];
80         snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
81         strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN);
82         state->exit_latency = 1;
83         state->target_residency = 1 * 2;
84         state->power_usage = 3;
85         state->flags = 0;
86         state->flags |= CPUIDLE_FLAG_TIME_VALID;
87         state->enter = cpuidle_sleep_enter;
88
89         dev->safe_state_index = i-1;
90
91         if (sh_mobile_sleep_supported & SUSP_SH_SF) {
92                 state = &dev->states[i++];
93                 snprintf(state->name, CPUIDLE_NAME_LEN, "C2");
94                 strncpy(state->desc, "SuperH Sleep Mode [SF]",
95                         CPUIDLE_DESC_LEN);
96                 state->exit_latency = 100;
97                 state->target_residency = 1 * 2;
98                 state->power_usage = 1;
99                 state->flags = 0;
100                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
101                 state->enter = cpuidle_sleep_enter;
102         }
103
104         if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) {
105                 state = &dev->states[i++];
106                 snprintf(state->name, CPUIDLE_NAME_LEN, "C3");
107                 strncpy(state->desc, "SuperH Mobile Standby Mode [SF]",
108                         CPUIDLE_DESC_LEN);
109                 state->exit_latency = 2300;
110                 state->target_residency = 1 * 2;
111                 state->power_usage = 1;
112                 state->flags = 0;
113                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
114                 state->enter = cpuidle_sleep_enter;
115         }
116
117         dev->state_count = i;
118
119         cpuidle_register_device(dev);
120 }