Merge tag 'nfs-for-3.10-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[firefly-linux-kernel-4.4.55.git] / arch / arm / mach-at91 / cpuidle.c
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
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,
33                                int index)
34 {
35         if (cpu_is_at91rm9200())
36                 at91rm9200_standby();
37         else if (cpu_is_at91sam9g45())
38                 at91sam9g45_standby();
39         else if (cpu_is_at91sam9263())
40                 at91sam9263_standby();
41         else
42                 at91sam9_standby();
43
44         return index;
45 }
46
47 static struct cpuidle_driver at91_idle_driver = {
48         .name                   = "at91_idle",
49         .owner                  = THIS_MODULE,
50         .states[0]              = ARM_CPUIDLE_WFI_STATE,
51         .states[1]              = {
52                 .enter                  = at91_enter_idle,
53                 .exit_latency           = 10,
54                 .target_residency       = 100000,
55                 .flags                  = CPUIDLE_FLAG_TIME_VALID,
56                 .name                   = "RAM_SR",
57                 .desc                   = "WFI and DDR Self Refresh",
58         },
59         .state_count = AT91_MAX_STATES,
60 };
61
62 /* Initialize CPU idle by registering the idle states */
63 static int __init at91_init_cpuidle(void)
64 {
65         return cpuidle_register(&at91_idle_driver, NULL);
66 }
67
68 device_initcall(at91_init_cpuidle);