/* * Copyright (C) 2014 Freescale Semiconductor, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/cpuidle.h> #include <linux/cpu_pm.h> #include <linux/module.h> #include <asm/cacheflush.h> #include <asm/cpuidle.h> #include <asm/suspend.h> #include "common.h" #include "cpuidle.h" static int imx6sx_idle_finish(unsigned long val) { /* * for Cortex-A7 which has an internal L2 * cache, need to flush it before powering * down ARM platform, since flushing L1 cache * here again has very small overhead, compared * to adding conditional code for L2 cache type, * just call flush_cache_all() is fine. */ flush_cache_all(); cpu_do_idle(); return 0; } static int imx6sx_enter_wait(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { imx6_set_lpm(WAIT_UNCLOCKED); switch (index) { case 1: cpu_do_idle(); break; case 2: imx6_enable_rbc(true); imx_gpc_set_arm_power_in_lpm(true); imx_set_cpu_jump(0, v7_cpu_resume); /* Need to notify there is a cpu pm operation. */ cpu_pm_enter(); cpu_cluster_pm_enter(); cpu_suspend(0, imx6sx_idle_finish); cpu_cluster_pm_exit(); cpu_pm_exit(); imx_gpc_set_arm_power_in_lpm(false); imx6_enable_rbc(false); break; default: break; } imx6_set_lpm(WAIT_CLOCKED); return index; } static struct cpuidle_driver imx6sx_cpuidle_driver = { .name = "imx6sx_cpuidle", .owner = THIS_MODULE, .states = { /* WFI */ ARM_CPUIDLE_WFI_STATE, /* WAIT */ { .exit_latency = 50, .target_residency = 75, .flags = CPUIDLE_FLAG_TIMER_STOP, .enter = imx6sx_enter_wait, .name = "WAIT", .desc = "Clock off", }, /* WAIT + ARM power off */ { /* * ARM gating 31us * 5 + RBC clear 65us * and some margin for SW execution, here set it * to 300us. */ .exit_latency = 300, .target_residency = 500, .flags = CPUIDLE_FLAG_TIMER_STOP, .enter = imx6sx_enter_wait, .name = "LOW-POWER-IDLE", .desc = "ARM power off", }, }, .state_count = 3, .safe_state_index = 0, }; int __init imx6sx_cpuidle_init(void) { imx6_set_int_mem_clk_lpm(true); imx6_enable_rbc(false); imx_gpc_set_l2_mem_power_in_lpm(false); /* * set ARM power up/down timing to the fastest, * sw2iso and sw can be set to one 32K cycle = 31us * except for power up sw2iso which need to be * larger than LDO ramp up time. */ imx_gpc_set_arm_power_up_timing(0xf, 1); imx_gpc_set_arm_power_down_timing(1, 1); return cpuidle_register(&imx6sx_cpuidle_driver, NULL); }