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/proc-fns.h> 14 #include <asm/suspend.h> 15 16 #include "common.h" 17 #include "cpuidle.h" 18 19 static int imx6sx_idle_finish(unsigned long val) 20 { 21 cpu_do_idle(); 22 23 return 0; 24 } 25 26 static int imx6sx_enter_wait(struct cpuidle_device *dev, 27 struct cpuidle_driver *drv, int index) 28 { 29 imx6q_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 imx6q_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 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(2, 1); 102 imx_gpc_set_arm_power_down_timing(1, 1); 103 104 return cpuidle_register(&imx6sx_cpuidle_driver, NULL); 105 } 106