linux-imx

/*

 * drivers/acpi/device_pm.c - ACPI device power management routines.

 *

 * Copyright (C) 2012, Intel Corp.

 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.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.

 *

 *  This program is distributed in the hope that it will be useful, but

 *  WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *  General Public License for more details.

 *

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 */

​

#include <linux/acpi.h>

#include <linux/export.h>

#include <linux/mutex.h>

#include <linux/pm_qos.h>

#include <linux/pm_domain.h>

#include <linux/pm_runtime.h>

#include <linux/suspend.h>

​

#include "internal.h"

​

#define _COMPONENT  ACPI_POWER_COMPONENT

ACPI_MODULE_NAME("device_pm");

​

/**

 * acpi_power_state_string - String representation of ACPI device power state.

 * @state: ACPI device power state to return the string representation of.

 */

const char *acpi_power_state_string(int state)

{

    switch (state) {

    case ACPI_STATE_D0:

        return "D0";

    case ACPI_STATE_D1:

        return "D1";

    case ACPI_STATE_D2:

        return "D2";

    case ACPI_STATE_D3_HOT:

        return "D3hot";

    case ACPI_STATE_D3_COLD:

        return "D3cold";

    default:

        return "(unknown)";

    }

}

​

/**

 * acpi_device_get_power - Get power state of an ACPI device.

 * @device: Device to get the power state of.

 * @state: Place to store the power state of the device.

 *

 * This function does not update the device's power.state field, but it may

 * update its parent's power.state field (when the parent's power state is

 * unknown and the device's power state turns out to be D0).

 */

int acpi_device_get_power(struct acpi_device *device, int *state)

{

    int result = ACPI_STATE_UNKNOWN;

​

    if (!device || !state)

        return -EINVAL;

​

    if (!device->flags.power_manageable) {

        /* TBD: Non-recursive algorithm for walking up hierarchy. */

        *state = device->parent ?

            device->parent->power.state : ACPI_STATE_D0;

        goto out;

    }

​

    /*

     * Get the device's power state from power resources settings and _PSC,

     * if available.

     */

    if (device->power.flags.power_resources) {

        int error = acpi_power_get_inferred_state(device, &result);

        if (error)

            return error;

    }

    if (device->power.flags.explicit_get) {

        acpi_handle handle = device->handle;

        unsigned long long psc;

        acpi_status status;

​