Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
[~shefty/rdma-dev.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
25 #include "pm.h"
26
27 #define AT91_MAX_STATES 2
28
29 static DEFINE_PER_CPU(struct cpuidle_device, at91_cpuidle_device);
30
31 /* Actual code that puts the SoC in different idle states */
32 static int at91_enter_idle(struct cpuidle_device *dev,
33                         struct cpuidle_driver *drv,
34                                int index)
35 {
36         at91_standby();
37
38         return index;
39 }
40
41 static struct cpuidle_driver at91_idle_driver = {
42         .name                   = "at91_idle",
43         .owner                  = THIS_MODULE,
44         .en_core_tk_irqen       = 1,
45         .states[0]              = ARM_CPUIDLE_WFI_STATE,
46         .states[1]              = {
47                 .enter                  = at91_enter_idle,
48                 .exit_latency           = 10,
49                 .target_residency       = 100000,
50                 .flags                  = CPUIDLE_FLAG_TIME_VALID,
51                 .name                   = "RAM_SR",
52                 .desc                   = "WFI and DDR Self Refresh",
53         },
54         .state_count = AT91_MAX_STATES,
55 };
56
57 /* Initialize CPU idle by registering the idle states */
58 static int at91_init_cpuidle(void)
59 {
60         struct cpuidle_device *device;
61
62         device = &per_cpu(at91_cpuidle_device, smp_processor_id());
63         device->state_count = AT91_MAX_STATES;
64
65         cpuidle_register_driver(&at91_idle_driver);
66
67         if (cpuidle_register_device(device)) {
68                 printk(KERN_ERR "at91_init_cpuidle: Failed registering\n");
69                 return -EIO;
70         }
71         return 0;
72 }
73
74 device_initcall(at91_init_cpuidle);