119 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			119 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (C) 2014 Freescale Semiconductor, Inc.
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  */
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| 
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| #include <linux/cpuidle.h>
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| #include <linux/cpu_pm.h>
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| #include <linux/module.h>
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| #include <asm/cacheflush.h>
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| #include <asm/cpuidle.h>
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| #include <asm/suspend.h>
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| 
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| #include "common.h"
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| #include "cpuidle.h"
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| #include "hardware.h"
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| 
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| static int imx6sx_idle_finish(unsigned long val)
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| {
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| 	/*
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| 	 * for Cortex-A7 which has an internal L2
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| 	 * cache, need to flush it before powering
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| 	 * down ARM platform, since flushing L1 cache
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| 	 * here again has very small overhead, compared
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| 	 * to adding conditional code for L2 cache type,
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| 	 * just call flush_cache_all() is fine.
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| 	 */
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| 	flush_cache_all();
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| 	cpu_do_idle();
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| 
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| 	return 0;
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| }
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| 
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| static int imx6sx_enter_wait(struct cpuidle_device *dev,
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| 			    struct cpuidle_driver *drv, int index)
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| {
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| 	imx6_set_lpm(WAIT_UNCLOCKED);
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| 
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| 	switch (index) {
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| 	case 1:
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| 		cpu_do_idle();
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| 		break;
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| 	case 2:
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| 		imx6_enable_rbc(true);
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| 		imx_gpc_set_arm_power_in_lpm(true);
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| 		imx_set_cpu_jump(0, v7_cpu_resume);
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| 		/* Need to notify there is a cpu pm operation. */
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| 		cpu_pm_enter();
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| 		cpu_cluster_pm_enter();
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| 
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| 		cpu_suspend(0, imx6sx_idle_finish);
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| 
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| 		cpu_cluster_pm_exit();
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| 		cpu_pm_exit();
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| 		imx_gpc_set_arm_power_in_lpm(false);
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| 		imx6_enable_rbc(false);
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| 		break;
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| 	default:
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| 		break;
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| 	}
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| 
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| 	imx6_set_lpm(WAIT_CLOCKED);
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| 
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| 	return index;
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| }
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| 
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| static struct cpuidle_driver imx6sx_cpuidle_driver = {
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| 	.name = "imx6sx_cpuidle",
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| 	.owner = THIS_MODULE,
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| 	.states = {
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| 		/* WFI */
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| 		ARM_CPUIDLE_WFI_STATE,
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| 		/* WAIT */
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| 		{
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| 			.exit_latency = 50,
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| 			.target_residency = 75,
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| 			.flags = CPUIDLE_FLAG_TIMER_STOP,
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| 			.enter = imx6sx_enter_wait,
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| 			.name = "WAIT",
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| 			.desc = "Clock off",
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| 		},
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| 		/* WAIT + ARM power off  */
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| 		{
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| 			/*
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| 			 * ARM gating 31us * 5 + RBC clear 65us
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| 			 * and some margin for SW execution, here set it
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| 			 * to 300us.
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| 			 */
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| 			.exit_latency = 300,
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| 			.target_residency = 500,
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| 			.flags = CPUIDLE_FLAG_TIMER_STOP,
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| 			.enter = imx6sx_enter_wait,
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| 			.name = "LOW-POWER-IDLE",
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| 			.desc = "ARM power off",
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| 		},
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| 	},
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| 	.state_count = 3,
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| 	.safe_state_index = 0,
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| };
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| 
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| int __init imx6sx_cpuidle_init(void)
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| {
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| 	imx6_set_int_mem_clk_lpm(true);
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| 	imx6_enable_rbc(false);
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| 	imx_gpc_set_l2_mem_power_in_lpm(false);
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| 	/*
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| 	 * set ARM power up/down timing to the fastest,
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| 	 * sw2iso and sw can be set to one 32K cycle = 31us
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| 	 * except for power up sw2iso which need to be
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| 	 * larger than LDO ramp up time.
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| 	 */
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| 	imx_gpc_set_arm_power_up_timing(cpu_is_imx6sx() ? 0xf : 0x2, 1);
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| 	imx_gpc_set_arm_power_down_timing(1, 1);
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| 
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| 	return cpuidle_register(&imx6sx_cpuidle_driver, NULL);
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| }
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