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