1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sh/kernel/cpu/shmobile/cpuidle.c
4 *
5 * Cpuidle support code for SuperH Mobile
6 *
7 * Copyright (C) 2009 Magnus Damm
8 */
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/io.h>
12 #include <linux/suspend.h>
13 #include <linux/cpuidle.h>
14 #include <linux/export.h>
15 #include <asm/suspend.h>
16 #include <linux/uaccess.h>
17
18 static unsigned long cpuidle_mode[] = {
19 SUSP_SH_SLEEP, /* regular sleep mode */
20 SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */
21 SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */
22 };
23
cpuidle_sleep_enter(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)24 static int cpuidle_sleep_enter(struct cpuidle_device *dev,
25 struct cpuidle_driver *drv,
26 int index)
27 {
28 unsigned long allowed_mode = SUSP_SH_SLEEP;
29 int requested_state = index;
30 int allowed_state;
31 int k;
32
33 /* convert allowed mode to allowed state */
34 for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
35 if (cpuidle_mode[k] == allowed_mode)
36 break;
37
38 allowed_state = k;
39
40 /* take the following into account for sleep mode selection:
41 * - allowed_state: best mode allowed by hardware (clock deps)
42 * - requested_state: best mode allowed by software (latencies)
43 */
44 k = min_t(int, allowed_state, requested_state);
45
46 sh_mobile_call_standby(cpuidle_mode[k]);
47
48 return k;
49 }
50
51 static struct cpuidle_driver cpuidle_driver = {
52 .name = "sh_idle",
53 .owner = THIS_MODULE,
54 .states = {
55 {
56 .exit_latency = 1,
57 .target_residency = 1 * 2,
58 .power_usage = 3,
59 .enter = cpuidle_sleep_enter,
60 .name = "C1",
61 .desc = "SuperH Sleep Mode",
62 },
63 {
64 .exit_latency = 100,
65 .target_residency = 1 * 2,
66 .power_usage = 1,
67 .enter = cpuidle_sleep_enter,
68 .name = "C2",
69 .desc = "SuperH Sleep Mode [SF]",
70 .flags = CPUIDLE_FLAG_UNUSABLE,
71 },
72 {
73 .exit_latency = 2300,
74 .target_residency = 1 * 2,
75 .power_usage = 1,
76 .enter = cpuidle_sleep_enter,
77 .name = "C3",
78 .desc = "SuperH Mobile Standby Mode [SF]",
79 .flags = CPUIDLE_FLAG_UNUSABLE,
80 },
81 },
82 .safe_state_index = 0,
83 .state_count = 3,
84 };
85
sh_mobile_setup_cpuidle(void)86 int __init sh_mobile_setup_cpuidle(void)
87 {
88 if (sh_mobile_sleep_supported & SUSP_SH_SF)
89 cpuidle_driver.states[1].flags = CPUIDLE_FLAG_NONE;
90
91 if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
92 cpuidle_driver.states[2].flags = CPUIDLE_FLAG_NONE;
93
94 return cpuidle_register(&cpuidle_driver, NULL);
95 }
96