1 /*
2 * Copyright (C) 2014 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/cpu_pm.h>
11 #include <linux/module.h>
12 #include <asm/cpuidle.h>
13 #include <asm/suspend.h>
14
15 #include "common.h"
16 #include "cpuidle.h"
17 #include "hardware.h"
18
imx6sx_idle_finish(unsigned long val)19 static int imx6sx_idle_finish(unsigned long val)
20 {
21 cpu_do_idle();
22
23 return 0;
24 }
25
imx6sx_enter_wait(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)26 static int imx6sx_enter_wait(struct cpuidle_device *dev,
27 struct cpuidle_driver *drv, int index)
28 {
29 imx6_set_lpm(WAIT_UNCLOCKED);
30
31 switch (index) {
32 case 1:
33 cpu_do_idle();
34 break;
35 case 2:
36 imx6_enable_rbc(true);
37 imx_gpc_set_arm_power_in_lpm(true);
38 imx_set_cpu_jump(0, v7_cpu_resume);
39 /* Need to notify there is a cpu pm operation. */
40 cpu_pm_enter();
41 cpu_cluster_pm_enter();
42
43 cpu_suspend(0, imx6sx_idle_finish);
44
45 cpu_cluster_pm_exit();
46 cpu_pm_exit();
47 imx_gpc_set_arm_power_in_lpm(false);
48 imx6_enable_rbc(false);
49 break;
50 default:
51 break;
52 }
53
54 imx6_set_lpm(WAIT_CLOCKED);
55
56 return index;
57 }
58
59 static struct cpuidle_driver imx6sx_cpuidle_driver = {
60 .name = "imx6sx_cpuidle",
61 .owner = THIS_MODULE,
62 .states = {
63 /* WFI */
64 ARM_CPUIDLE_WFI_STATE,
65 /* WAIT */
66 {
67 .exit_latency = 50,
68 .target_residency = 75,
69 .flags = CPUIDLE_FLAG_TIMER_STOP,
70 .enter = imx6sx_enter_wait,
71 .name = "WAIT",
72 .desc = "Clock off",
73 },
74 /* WAIT + ARM power off */
75 {
76 /*
77 * ARM gating 31us * 5 + RBC clear 65us
78 * and some margin for SW execution, here set it
79 * to 300us.
80 */
81 .exit_latency = 300,
82 .target_residency = 500,
83 .enter = imx6sx_enter_wait,
84 .name = "LOW-POWER-IDLE",
85 .desc = "ARM power off",
86 },
87 },
88 .state_count = 3,
89 .safe_state_index = 0,
90 };
91
imx6sx_cpuidle_init(void)92 int __init imx6sx_cpuidle_init(void)
93 {
94 imx6_enable_rbc(false);
95 /*
96 * set ARM power up/down timing to the fastest,
97 * sw2iso and sw can be set to one 32K cycle = 31us
98 * except for power up sw2iso which need to be
99 * larger than LDO ramp up time.
100 */
101 imx_gpc_set_arm_power_up_timing(cpu_is_imx6sx() ? 0xf : 0x2, 1);
102 imx_gpc_set_arm_power_down_timing(1, 1);
103
104 return cpuidle_register(&imx6sx_cpuidle_driver, NULL);
105 }
106