1/*
2 * based on arch/arm/mach-kirkwood/cpuidle.c
3 *
4 * CPU idle support for AT91 SoC
5 *
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2.  This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
9 *
10 * The cpu idle uses wait-for-interrupt and RAM self refresh in order
11 * to implement two idle states -
12 * #1 wait-for-interrupt
13 * #2 wait-for-interrupt and RAM self refresh
14 */
15
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/platform_device.h>
19#include <linux/cpuidle.h>
20#include <linux/io.h>
21#include <linux/export.h>
22#include <asm/cpuidle.h>
23
24#define AT91_MAX_STATES	2
25
26static void (*at91_standby)(void);
27
28/* Actual code that puts the SoC in different idle states */
29static int at91_enter_idle(struct cpuidle_device *dev,
30			struct cpuidle_driver *drv,
31			       int index)
32{
33	at91_standby();
34	return index;
35}
36
37static struct cpuidle_driver at91_idle_driver = {
38	.name			= "at91_idle",
39	.owner			= THIS_MODULE,
40	.states[0]		= ARM_CPUIDLE_WFI_STATE,
41	.states[1]		= {
42		.enter			= at91_enter_idle,
43		.exit_latency		= 10,
44		.target_residency	= 10000,
45		.name			= "RAM_SR",
46		.desc			= "WFI and DDR Self Refresh",
47	},
48	.state_count = AT91_MAX_STATES,
49};
50
51/* Initialize CPU idle by registering the idle states */
52static int at91_cpuidle_probe(struct platform_device *dev)
53{
54	at91_standby = (void *)(dev->dev.platform_data);
55
56	return cpuidle_register(&at91_idle_driver, NULL);
57}
58
59static struct platform_driver at91_cpuidle_driver = {
60	.driver = {
61		.name = "cpuidle-at91",
62	},
63	.probe = at91_cpuidle_probe,
64};
65builtin_platform_driver(at91_cpuidle_driver);
66