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/proc-fns.h>
23#include <asm/cpuidle.h>
24#include <mach/cpu.h>
25
26#include "pm.h"
27
28#define AT91_MAX_STATES	2
29
30static DEFINE_PER_CPU(struct cpuidle_device, at91_cpuidle_device);
31
32/* Actual code that puts the SoC in different idle states */
33static int at91_enter_idle(struct cpuidle_device *dev,
34			struct cpuidle_driver *drv,
35			       int index)
36{
37	if (cpu_is_at91rm9200())
38		at91rm9200_standby();
39	else if (cpu_is_at91sam9g45())
40		at91sam9g45_standby();
41	else
42		at91sam9_standby();
43
44	return index;
45}
46
47static struct cpuidle_driver at91_idle_driver = {
48	.name			= "at91_idle",
49	.owner			= THIS_MODULE,
50	.en_core_tk_irqen	= 1,
51	.states[0]		= ARM_CPUIDLE_WFI_STATE,
52	.states[1]		= {
53		.enter			= at91_enter_idle,
54		.exit_latency		= 10,
55		.target_residency	= 100000,
56		.flags			= CPUIDLE_FLAG_TIME_VALID,
57		.name			= "RAM_SR",
58		.desc			= "WFI and DDR Self Refresh",
59	},
60	.state_count = AT91_MAX_STATES,
61};
62
63/* Initialize CPU idle by registering the idle states */
64static int at91_init_cpuidle(void)
65{
66	struct cpuidle_device *device;
67
68	device = &per_cpu(at91_cpuidle_device, smp_processor_id());
69	device->state_count = AT91_MAX_STATES;
70
71	cpuidle_register_driver(&at91_idle_driver);
72
73	if (cpuidle_register_device(device)) {
74		printk(KERN_ERR "at91_init_cpuidle: Failed registering\n");
75		return -EIO;
76	}
77	return 0;
78}
79
80device_initcall(at91_init_cpuidle);