linux-imx

/*

 * Dell WMI descriptor driver

 *

 * Copyright (C) 2017 Dell Inc. All Rights Reserved.

 *

 *  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.

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/acpi.h>

#include <linux/list.h>

#include <linux/module.h>

#include <linux/wmi.h>

#include "dell-wmi-descriptor.h"

​

#define DELL_WMI_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"

​

struct descriptor_priv {

    struct list_head list;

    u32 interface_version;

    u32 size;

    u32 hotfix;

};

static int descriptor_valid = -EPROBE_DEFER;

static LIST_HEAD(wmi_list);

static DEFINE_MUTEX(list_mutex);

​

int dell_wmi_get_descriptor_valid(void)

{

    if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID))

        return -ENODEV;

​

    return descriptor_valid;

}

EXPORT_SYMBOL_GPL(dell_wmi_get_descriptor_valid);

​

bool dell_wmi_get_interface_version(u32 *version)

{

    struct descriptor_priv *priv;

    bool ret = false;

​

    mutex_lock(&list_mutex);

    priv = list_first_entry_or_null(&wmi_list,

                    struct descriptor_priv,

                    list);

    if (priv) {

        *version = priv->interface_version;

        ret = true;

    }

    mutex_unlock(&list_mutex);

    return ret;

}

EXPORT_SYMBOL_GPL(dell_wmi_get_interface_version);

​

bool dell_wmi_get_size(u32 *size)

{

    struct descriptor_priv *priv;

    bool ret = false;

​

    mutex_lock(&list_mutex);

    priv = list_first_entry_or_null(&wmi_list,

                    struct descriptor_priv,

                    list);

    if (priv) {

        *size = priv->size;

        ret = true;

    }

    mutex_unlock(&list_mutex);

    return ret;

}

EXPORT_SYMBOL_GPL(dell_wmi_get_size);

​

bool dell_wmi_get_hotfix(u32 *hotfix)

{

    struct descriptor_priv *priv;

    bool ret = false;

​

    mutex_lock(&list_mutex);

    priv = list_first_entry_or_null(&wmi_list,

                    struct descriptor_priv,

                    list);

    if (priv) {

        *hotfix = priv->hotfix;

        ret = true;