linux-sg2042/drivers/platform/x86/wmi-bmof.c

126 lines
3.0 KiB
C

/*
* WMI embedded Binary MOF driver
*
* Copyright (c) 2015 Andrew Lutomirski
* Copyright (C) 2017 VMware, 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/device.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/wmi.h>
#define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
struct bmof_priv {
union acpi_object *bmofdata;
struct bin_attribute bmof_bin_attr;
};
static ssize_t
read_bmof(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr,
char *buf, loff_t off, size_t count)
{
struct bmof_priv *priv =
container_of(attr, struct bmof_priv, bmof_bin_attr);
if (off < 0)
return -EINVAL;
if (off >= priv->bmofdata->buffer.length)
return 0;
if (count > priv->bmofdata->buffer.length - off)
count = priv->bmofdata->buffer.length - off;
memcpy(buf, priv->bmofdata->buffer.pointer + off, count);
return count;
}
static int wmi_bmof_probe(struct wmi_device *wdev)
{
struct bmof_priv *priv;
int ret;
priv = devm_kzalloc(&wdev->dev, sizeof(struct bmof_priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
dev_set_drvdata(&wdev->dev, priv);
priv->bmofdata = wmidev_block_query(wdev, 0);
if (!priv->bmofdata) {
dev_err(&wdev->dev, "failed to read Binary MOF\n");
return -EIO;
}
if (priv->bmofdata->type != ACPI_TYPE_BUFFER) {
dev_err(&wdev->dev, "Binary MOF is not a buffer\n");
ret = -EIO;
goto err_free;
}
sysfs_bin_attr_init(&priv->bmof_bin_attr);
priv->bmof_bin_attr.attr.name = "bmof";
priv->bmof_bin_attr.attr.mode = 0400;
priv->bmof_bin_attr.read = read_bmof;
priv->bmof_bin_attr.size = priv->bmofdata->buffer.length;
ret = sysfs_create_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr);
if (ret)
goto err_free;
return 0;
err_free:
kfree(priv->bmofdata);
return ret;
}
static int wmi_bmof_remove(struct wmi_device *wdev)
{
struct bmof_priv *priv = dev_get_drvdata(&wdev->dev);
sysfs_remove_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr);
kfree(priv->bmofdata);
return 0;
}
static const struct wmi_device_id wmi_bmof_id_table[] = {
{ .guid_string = WMI_BMOF_GUID },
{ },
};
static struct wmi_driver wmi_bmof_driver = {
.driver = {
.name = "wmi-bmof",
},
.probe = wmi_bmof_probe,
.remove = wmi_bmof_remove,
.id_table = wmi_bmof_id_table,
};
module_wmi_driver(wmi_bmof_driver);
MODULE_ALIAS("wmi:" WMI_BMOF_GUID);
MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");
MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
MODULE_LICENSE("GPL");