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Albin Tonnerre1ea60cf2009-11-01 18:40:50 +01001/*
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>
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010020#include <linux/io.h>
Paul Gortmakerdc280942011-07-31 16:17:29 -040021#include <linux/export.h>
Robert Lee7e348b92012-03-20 15:22:43 -050022#include <asm/proc-fns.h>
23#include <asm/cpuidle.h>
Jean-Christophe PLAGNIOL-VILLARDefd09162012-02-13 14:58:30 +080024#include <mach/cpu.h>
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010025
26#include "pm.h"
27
28#define AT91_MAX_STATES 2
29
30static DEFINE_PER_CPU(struct cpuidle_device, at91_cpuidle_device);
31
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010032/* Actual code that puts the SoC in different idle states */
33static int at91_enter_idle(struct cpuidle_device *dev,
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +053034 struct cpuidle_driver *drv,
Deepthi Dharware978aa72011-10-28 16:20:09 +053035 int index)
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010036{
Jean-Christophe PLAGNIOL-VILLARDefd09162012-02-13 14:58:30 +080037 if (cpu_is_at91rm9200())
38 at91rm9200_standby();
39 else if (cpu_is_at91sam9g45())
40 at91sam9g45_standby();
Arnd Bergmannf5fa4092013-01-25 22:44:17 +000041 else if (cpu_is_at91sam9263())
42 at91sam9263_standby();
Jean-Christophe PLAGNIOL-VILLARDefd09162012-02-13 14:58:30 +080043 else
44 at91sam9_standby();
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010045
Deepthi Dharware978aa72011-10-28 16:20:09 +053046 return index;
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010047}
48
Robert Lee7e348b92012-03-20 15:22:43 -050049static struct cpuidle_driver at91_idle_driver = {
50 .name = "at91_idle",
51 .owner = THIS_MODULE,
52 .en_core_tk_irqen = 1,
53 .states[0] = ARM_CPUIDLE_WFI_STATE,
54 .states[1] = {
55 .enter = at91_enter_idle,
56 .exit_latency = 10,
57 .target_residency = 100000,
58 .flags = CPUIDLE_FLAG_TIME_VALID,
59 .name = "RAM_SR",
60 .desc = "WFI and DDR Self Refresh",
61 },
62 .state_count = AT91_MAX_STATES,
63};
64
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010065/* Initialize CPU idle by registering the idle states */
66static int at91_init_cpuidle(void)
67{
68 struct cpuidle_device *device;
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010069
70 device = &per_cpu(at91_cpuidle_device, smp_processor_id());
71 device->state_count = AT91_MAX_STATES;
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +053072
73 cpuidle_register_driver(&at91_idle_driver);
Albin Tonnerre1ea60cf2009-11-01 18:40:50 +010074
75 if (cpuidle_register_device(device)) {
76 printk(KERN_ERR "at91_init_cpuidle: Failed registering\n");
77 return -EIO;
78 }
79 return 0;
80}
81
82device_initcall(at91_init_cpuidle);