2 * based on arch/arm/mach-kirkwood/cpuidle.c
4 * CPU idle support for AT91 SoC
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.
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
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/platform_device.h>
19 #include <linux/cpuidle.h>
21 #include <linux/export.h>
22 #include <asm/proc-fns.h>
23 #include <asm/cpuidle.h>
28 #define AT91_MAX_STATES 2
30 /* Actual code that puts the SoC in different idle states */
31 static int at91_enter_idle(struct cpuidle_device
*dev
,
32 struct cpuidle_driver
*drv
,
35 if (cpu_is_at91rm9200())
37 else if (cpu_is_at91sam9g45())
38 at91sam9g45_standby();
39 else if (cpu_is_at91sam9263())
40 at91sam9263_standby();
47 static struct cpuidle_driver at91_idle_driver
= {
50 .states
[0] = ARM_CPUIDLE_WFI_STATE
,
52 .enter
= at91_enter_idle
,
54 .target_residency
= 10000,
55 .flags
= CPUIDLE_FLAG_TIME_VALID
,
57 .desc
= "WFI and DDR Self Refresh",
59 .state_count
= AT91_MAX_STATES
,
62 /* Initialize CPU idle by registering the idle states */
63 static int __init
at91_init_cpuidle(void)
65 return cpuidle_register(&at91_idle_driver
, NULL
);
68 device_initcall(at91_init_cpuidle
);