1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2014 Freescale Semiconductor, Inc. 4 */ 5 6 #include <linux/cpuidle.h> 7 #include <linux/cpu_pm.h> 8 #include <linux/module.h> 9 #include <asm/cacheflush.h> 10 #include <asm/cpuidle.h> 11 #include <asm/suspend.h> 12 13 #include "common.h" 14 #include "cpuidle.h" 15 #include "hardware.h" 16 17 static int imx6sx_idle_finish(unsigned long val) 18 { 19 /* 20 * for Cortex-A7 which has an internal L2 21 * cache, need to flush it before powering 22 * down ARM platform, since flushing L1 cache 23 * here again has very small overhead, compared 24 * to adding conditional code for L2 cache type, 25 * just call flush_cache_all() is fine. 26 */ 27 flush_cache_all(); 28 cpu_do_idle(); 29 30 return 0; 31 } 32 33 static __cpuidle int imx6sx_enter_wait(struct cpuidle_device *dev, 34 struct cpuidle_driver *drv, int index) 35 { 36 imx6_set_lpm(WAIT_UNCLOCKED); 37 38 switch (index) { 39 case 1: 40 cpu_do_idle(); 41 break; 42 case 2: 43 imx6_enable_rbc(true); 44 imx_gpc_set_arm_power_in_lpm(true); 45 imx_set_cpu_jump(0, v7_cpu_resume); 46 /* Need to notify there is a cpu pm operation. */ 47 cpu_pm_enter(); 48 cpu_cluster_pm_enter(); 49 50 ct_cpuidle_enter(); 51 cpu_suspend(0, imx6sx_idle_finish); 52 ct_cpuidle_exit(); 53 54 cpu_cluster_pm_exit(); 55 cpu_pm_exit(); 56 imx_gpc_set_arm_power_in_lpm(false); 57 imx6_enable_rbc(false); 58 break; 59 default: 60 break; 61 } 62 63 imx6_set_lpm(WAIT_CLOCKED); 64 65 return index; 66 } 67 68 static struct cpuidle_driver imx6sx_cpuidle_driver = { 69 .name = "imx6sx_cpuidle", 70 .owner = THIS_MODULE, 71 .states = { 72 /* WFI */ 73 ARM_CPUIDLE_WFI_STATE, 74 /* WAIT */ 75 { 76 .exit_latency = 50, 77 .target_residency = 75, 78 .flags = CPUIDLE_FLAG_TIMER_STOP, 79 .enter = imx6sx_enter_wait, 80 .name = "WAIT", 81 .desc = "Clock off", 82 }, 83 /* WAIT + ARM power off */ 84 { 85 /* 86 * ARM gating 31us * 5 + RBC clear 65us 87 * and some margin for SW execution, here set it 88 * to 300us. 89 */ 90 .exit_latency = 300, 91 .target_residency = 500, 92 .flags = CPUIDLE_FLAG_TIMER_STOP | 93 CPUIDLE_FLAG_RCU_IDLE, 94 .enter = imx6sx_enter_wait, 95 .name = "LOW-POWER-IDLE", 96 .desc = "ARM power off", 97 }, 98 }, 99 .state_count = 3, 100 .safe_state_index = 0, 101 }; 102 103 int __init imx6sx_cpuidle_init(void) 104 { 105 imx6_set_int_mem_clk_lpm(true); 106 imx6_enable_rbc(false); 107 imx_gpc_set_l2_mem_power_in_lpm(false); 108 /* 109 * set ARM power up/down timing to the fastest, 110 * sw2iso and sw can be set to one 32K cycle = 31us 111 * except for power up sw2iso which need to be 112 * larger than LDO ramp up time. 113 */ 114 imx_gpc_set_arm_power_up_timing(cpu_is_imx6sx() ? 0xf : 0x2, 1); 115 imx_gpc_set_arm_power_down_timing(1, 1); 116 117 return cpuidle_register(&imx6sx_cpuidle_driver, NULL); 118 } 119