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
18static 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
24static 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
51static 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
86int __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