cpuidle: Single/Global registration of idle states
[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                                 struct cpuidle_driver *drv,
29                                 int index)
30 {
31         unsigned long allowed_mode = arch_hwblk_sleep_mode();
32         ktime_t before, after;
33         int requested_state = index;
34         int allowed_state;
35         int k;
36
37         /* convert allowed mode to allowed state */
38         for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
39                 if (cpuidle_mode[k] == allowed_mode)
40                         break;
41
42         allowed_state = k;
43
44         /* take the following into account for sleep mode selection:
45          * - allowed_state: best mode allowed by hardware (clock deps)
46          * - requested_state: best mode allowed by software (latencies)
47          */
48         k = min_t(int, allowed_state, requested_state);
49
50         before = ktime_get();
51         sh_mobile_call_standby(cpuidle_mode[k]);
52         after = ktime_get();
53
54         dev->last_residency = (int)ktime_to_ns(ktime_sub(after, before)) >> 10;
55
56         return k;
57 }
58
59 static struct cpuidle_device cpuidle_dev;
60 static struct cpuidle_driver cpuidle_driver = {
61         .name =         "sh_idle",
62         .owner =        THIS_MODULE,
63 };
64
65 void sh_mobile_setup_cpuidle(void)
66 {
67         struct cpuidle_device *dev = &cpuidle_dev;
68         struct cpuidle_driver *drv = &cpuidle_driver;
69         struct cpuidle_state *state;
70         int i;
71
72
73         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
74                 drv->states[i].name[0] = '\0';
75                 drv->states[i].desc[0] = '\0';
76         }
77
78         i = CPUIDLE_DRIVER_STATE_START;
79
80         state = &drv->states[i++];
81         snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
82         strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN);
83         state->exit_latency = 1;
84         state->target_residency = 1 * 2;
85         state->power_usage = 3;
86         state->flags = 0;
87         state->flags |= CPUIDLE_FLAG_TIME_VALID;
88         state->enter = cpuidle_sleep_enter;
89
90         drv->safe_state_index = i-1;
91
92         if (sh_mobile_sleep_supported & SUSP_SH_SF) {
93                 state = &drv->states[i++];
94                 snprintf(state->name, CPUIDLE_NAME_LEN, "C2");
95                 strncpy(state->desc, "SuperH Sleep Mode [SF]",
96                         CPUIDLE_DESC_LEN);
97                 state->exit_latency = 100;
98                 state->target_residency = 1 * 2;
99                 state->power_usage = 1;
100                 state->flags = 0;
101                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
102                 state->enter = cpuidle_sleep_enter;
103         }
104
105         if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) {
106                 state = &drv->states[i++];
107                 snprintf(state->name, CPUIDLE_NAME_LEN, "C3");
108                 strncpy(state->desc, "SuperH Mobile Standby Mode [SF]",
109                         CPUIDLE_DESC_LEN);
110                 state->exit_latency = 2300;
111                 state->target_residency = 1 * 2;
112                 state->power_usage = 1;
113                 state->flags = 0;
114                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
115                 state->enter = cpuidle_sleep_enter;
116         }
117
118         drv->state_count = i;
119         dev->state_count = i;
120
121         cpuidle_register_driver(&cpuidle_driver);
122
123         cpuidle_register_device(dev);
124 }