1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * WMI embedded Binary MOF driver
4 *
5 * Copyright (c) 2015 Andrew Lutomirski
6 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/acpi.h>
12#include <linux/device.h>
13#include <linux/fs.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/string.h>
17#include <linux/sysfs.h>
18#include <linux/types.h>
19#include <linux/wmi.h>
20
21#define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
22
23struct bmof_priv {
24 union acpi_object *bmofdata;
25 struct bin_attribute bmof_bin_attr;
26};
27
28static ssize_t read_bmof(struct file *filp, struct kobject *kobj, struct bin_attribute *attr,
29 char *buf, loff_t off, size_t count)
30{
31 struct bmof_priv *priv = container_of(attr, struct bmof_priv, bmof_bin_attr);
32
33 return memory_read_from_buffer(to: buf, count, ppos: &off, from: priv->bmofdata->buffer.pointer,
34 available: priv->bmofdata->buffer.length);
35}
36
37static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
38{
39 struct bmof_priv *priv;
40 int ret;
41
42 priv = devm_kzalloc(dev: &wdev->dev, size: sizeof(struct bmof_priv), GFP_KERNEL);
43 if (!priv)
44 return -ENOMEM;
45
46 dev_set_drvdata(dev: &wdev->dev, data: priv);
47
48 priv->bmofdata = wmidev_block_query(wdev, instance: 0);
49 if (!priv->bmofdata) {
50 dev_err(&wdev->dev, "failed to read Binary MOF\n");
51 return -EIO;
52 }
53
54 if (priv->bmofdata->type != ACPI_TYPE_BUFFER) {
55 dev_err(&wdev->dev, "Binary MOF is not a buffer\n");
56 ret = -EIO;
57 goto err_free;
58 }
59
60 sysfs_bin_attr_init(&priv->bmof_bin_attr);
61 priv->bmof_bin_attr.attr.name = "bmof";
62 priv->bmof_bin_attr.attr.mode = 0400;
63 priv->bmof_bin_attr.read = read_bmof;
64 priv->bmof_bin_attr.size = priv->bmofdata->buffer.length;
65
66 ret = device_create_bin_file(dev: &wdev->dev, attr: &priv->bmof_bin_attr);
67 if (ret)
68 goto err_free;
69
70 return 0;
71
72 err_free:
73 kfree(objp: priv->bmofdata);
74 return ret;
75}
76
77static void wmi_bmof_remove(struct wmi_device *wdev)
78{
79 struct bmof_priv *priv = dev_get_drvdata(dev: &wdev->dev);
80
81 device_remove_bin_file(dev: &wdev->dev, attr: &priv->bmof_bin_attr);
82 kfree(objp: priv->bmofdata);
83}
84
85static const struct wmi_device_id wmi_bmof_id_table[] = {
86 { .guid_string = WMI_BMOF_GUID },
87 { },
88};
89
90static struct wmi_driver wmi_bmof_driver = {
91 .driver = {
92 .name = "wmi-bmof",
93 },
94 .probe = wmi_bmof_probe,
95 .remove = wmi_bmof_remove,
96 .id_table = wmi_bmof_id_table,
97};
98
99module_wmi_driver(wmi_bmof_driver);
100
101MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table);
102MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");
103MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
104MODULE_LICENSE("GPL");
105

source code of linux/drivers/platform/x86/wmi-bmof.c