GNU Linux-libre 4.19.314-gnu1
[releases.git] / arch / arm / mach-imx / cpuidle-imx6q.c
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 <soc/imx/cpuidle.h>
14
15 #include "common.h"
16 #include "cpuidle.h"
17 #include "hardware.h"
18
19 static int num_idle_cpus = 0;
20 static DEFINE_SPINLOCK(cpuidle_lock);
21
22 static int imx6q_enter_wait(struct cpuidle_device *dev,
23                             struct cpuidle_driver *drv, int index)
24 {
25         spin_lock(&cpuidle_lock);
26         if (++num_idle_cpus == num_online_cpus())
27                 imx6_set_lpm(WAIT_UNCLOCKED);
28         spin_unlock(&cpuidle_lock);
29
30         cpu_do_idle();
31
32         spin_lock(&cpuidle_lock);
33         if (num_idle_cpus-- == num_online_cpus())
34                 imx6_set_lpm(WAIT_CLOCKED);
35         spin_unlock(&cpuidle_lock);
36
37         return index;
38 }
39
40 static struct cpuidle_driver imx6q_cpuidle_driver = {
41         .name = "imx6q_cpuidle",
42         .owner = THIS_MODULE,
43         .states = {
44                 /* WFI */
45                 ARM_CPUIDLE_WFI_STATE,
46                 /* WAIT */
47                 {
48                         .exit_latency = 50,
49                         .target_residency = 75,
50                         .flags = CPUIDLE_FLAG_TIMER_STOP,
51                         .enter = imx6q_enter_wait,
52                         .name = "WAIT",
53                         .desc = "Clock off",
54                 },
55         },
56         .state_count = 2,
57         .safe_state_index = 0,
58 };
59
60 /*
61  * i.MX6 Q/DL has an erratum (ERR006687) that prevents the FEC from waking the
62  * CPUs when they are in wait(unclocked) state. As the hardware workaround isn't
63  * applicable to all boards, disable the deeper idle state when the workaround
64  * isn't present and the FEC is in use.
65  */
66 void imx6q_cpuidle_fec_irqs_used(void)
67 {
68         imx6q_cpuidle_driver.states[1].disabled = true;
69 }
70 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used);
71
72 void imx6q_cpuidle_fec_irqs_unused(void)
73 {
74         imx6q_cpuidle_driver.states[1].disabled = false;
75 }
76 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused);
77
78 int __init imx6q_cpuidle_init(void)
79 {
80         /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
81         imx6_set_int_mem_clk_lpm(true);
82
83         return cpuidle_register(&imx6q_cpuidle_driver, NULL);
84 }