linux-imx

/*

 * ARM/ARM64 generic CPU idle driver.

 *

 * Copyright (C) 2014 ARM Ltd.

 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

 *

 * 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.

 */

​

#define pr_fmt(fmt) "CPUidle arm: " fmt

​

#include <linux/cpuidle.h>

#include <linux/cpumask.h>

#include <linux/cpu_pm.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/slab.h>

#include <linux/topology.h>

​

#include <asm/cpuidle.h>

​

#include "dt_idle_states.h"

​

/*

 * arm_enter_idle_state - Programs CPU to enter the specified state

 *

 * dev: cpuidle device

 * drv: cpuidle driver

 * idx: state index

 *

 * Called from the CPUidle framework to program the device to the

 * specified target state selected by the governor.

 */

static int arm_enter_idle_state(struct cpuidle_device *dev,

                struct cpuidle_driver *drv, int idx)

{

    /*

     * Pass idle state index to arm_cpuidle_suspend which in turn

     * will call the CPU ops suspend protocol with idle index as a

     * parameter.

     */

    return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, idx);

}

​

static struct cpuidle_driver arm_idle_driver __initdata = {

    .name = "arm_idle",

    .owner = THIS_MODULE,

    /*

     * State at index 0 is standby wfi and considered standard

     * on all ARM platforms. If in some platforms simple wfi

     * can't be used as "state 0", DT bindings must be implemented

     * to work around this issue and allow installing a special

     * handler for idle state index 0.

     */

    .states[0] = {

        .enter                  = arm_enter_idle_state,

        .exit_latency           = 1,

        .target_residency       = 1,

        .power_usage        = UINT_MAX,

        .name                   = "WFI",