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/*
* 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(2, 1);
imx_gpc_set_arm_power_down_timing(1, 1);
return cpuidle_register(&imx6sx_cpuidle_driver, NULL);
}
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