1 /*
2 * Copyright (C) 2012 Freescale Semiconductor, Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9 #include <linux/cpuidle.h>
10 #include <linux/module.h>
11 #include <asm/cpuidle.h>
12
13 #include "common.h"
14 #include "cpuidle.h"
15 #include "hardware.h"
16
17 static int num_idle_cpus = 0;
18 static DEFINE_SPINLOCK(cpuidle_lock);
19
imx6q_enter_wait(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)20 static int imx6q_enter_wait(struct cpuidle_device *dev,
21 struct cpuidle_driver *drv, int index)
22 {
23 spin_lock(&cpuidle_lock);
24 if (++num_idle_cpus == num_online_cpus())
25 imx6_set_lpm(WAIT_UNCLOCKED);
26 spin_unlock(&cpuidle_lock);
27
28 cpu_do_idle();
29
30 spin_lock(&cpuidle_lock);
31 if (num_idle_cpus-- == num_online_cpus())
32 imx6_set_lpm(WAIT_CLOCKED);
33 spin_unlock(&cpuidle_lock);
34
35 return index;
36 }
37
38 static struct cpuidle_driver imx6q_cpuidle_driver = {
39 .name = "imx6q_cpuidle",
40 .owner = THIS_MODULE,
41 .states = {
42 /* WFI */
43 ARM_CPUIDLE_WFI_STATE,
44 /* WAIT */
45 {
46 .exit_latency = 50,
47 .target_residency = 75,
48 .flags = CPUIDLE_FLAG_TIMER_STOP,
49 .enter = imx6q_enter_wait,
50 .name = "WAIT",
51 .desc = "Clock off",
52 },
53 },
54 .state_count = 2,
55 .safe_state_index = 0,
56 };
57
imx6q_cpuidle_init(void)58 int __init imx6q_cpuidle_init(void)
59 {
60 /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
61 imx6q_set_int_mem_clk_lpm(true);
62
63 return cpuidle_register(&imx6q_cpuidle_driver, NULL);
64 }
65