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
21static 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
27static 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
54static struct cpuidle_driver cpuidle_driver = {
55	.name   = "sh_idle",
56	.owner  = THIS_MODULE,
57	.states = {
58		{
59			.exit_latency = 1,
60			.target_residency = 1 * 2,
61			.power_usage = 3,
62			.enter = cpuidle_sleep_enter,
63			.name = "C1",
64			.desc = "SuperH Sleep Mode",
65		},
66		{
67			.exit_latency = 100,
68			.target_residency = 1 * 2,
69			.power_usage = 1,
70			.enter = cpuidle_sleep_enter,
71			.name = "C2",
72			.desc = "SuperH Sleep Mode [SF]",
73			.disabled = true,
74		},
75		{
76			.exit_latency = 2300,
77			.target_residency = 1 * 2,
78			.power_usage = 1,
79			.enter = cpuidle_sleep_enter,
80			.name = "C3",
81			.desc = "SuperH Mobile Standby Mode [SF]",
82			.disabled = true,
83		},
84	},
85	.safe_state_index = 0,
86	.state_count = 3,
87};
88
89int __init sh_mobile_setup_cpuidle(void)
90{
91	if (sh_mobile_sleep_supported & SUSP_SH_SF)
92		cpuidle_driver.states[1].disabled = false;
93
94	if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
95		cpuidle_driver.states[2].disabled = false;
96
97	return cpuidle_register(&cpuidle_driver, NULL);
98}
99