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 <linux/export.h>
18 #include <asm/suspend.h>
19 #include <asm/uaccess.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
cpuidle_sleep_enter(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)27 static int cpuidle_sleep_enter(struct cpuidle_device *dev,
28 struct cpuidle_driver *drv,
29 int index)
30 {
31 unsigned long allowed_mode = SUSP_SH_SLEEP;
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 sh_mobile_call_standby(cpuidle_mode[k]);
50
51 return k;
52 }
53
54 static struct cpuidle_device cpuidle_dev;
55 static struct cpuidle_driver cpuidle_driver = {
56 .name = "sh_idle",
57 .owner = THIS_MODULE,
58 .en_core_tk_irqen = 1,
59 };
60
sh_mobile_setup_cpuidle(void)61 void sh_mobile_setup_cpuidle(void)
62 {
63 struct cpuidle_device *dev = &cpuidle_dev;
64 struct cpuidle_driver *drv = &cpuidle_driver;
65 struct cpuidle_state *state;
66 int i;
67
68
69 for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
70 drv->states[i].name[0] = '\0';
71 drv->states[i].desc[0] = '\0';
72 }
73
74 i = CPUIDLE_DRIVER_STATE_START;
75
76 state = &drv->states[i++];
77 snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
78 strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN);
79 state->exit_latency = 1;
80 state->target_residency = 1 * 2;
81 state->power_usage = 3;
82 state->flags = 0;
83 state->flags |= CPUIDLE_FLAG_TIME_VALID;
84 state->enter = cpuidle_sleep_enter;
85
86 drv->safe_state_index = i-1;
87
88 if (sh_mobile_sleep_supported & SUSP_SH_SF) {
89 state = &drv->states[i++];
90 snprintf(state->name, CPUIDLE_NAME_LEN, "C2");
91 strncpy(state->desc, "SuperH Sleep Mode [SF]",
92 CPUIDLE_DESC_LEN);
93 state->exit_latency = 100;
94 state->target_residency = 1 * 2;
95 state->power_usage = 1;
96 state->flags = 0;
97 state->flags |= CPUIDLE_FLAG_TIME_VALID;
98 state->enter = cpuidle_sleep_enter;
99 }
100
101 if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) {
102 state = &drv->states[i++];
103 snprintf(state->name, CPUIDLE_NAME_LEN, "C3");
104 strncpy(state->desc, "SuperH Mobile Standby Mode [SF]",
105 CPUIDLE_DESC_LEN);
106 state->exit_latency = 2300;
107 state->target_residency = 1 * 2;
108 state->power_usage = 1;
109 state->flags = 0;
110 state->flags |= CPUIDLE_FLAG_TIME_VALID;
111 state->enter = cpuidle_sleep_enter;
112 }
113
114 drv->state_count = i;
115 dev->state_count = i;
116
117 cpuidle_register_driver(&cpuidle_driver);
118
119 cpuidle_register_device(dev);
120 }
121