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
23static ssize_t bmof_read(struct file *filp, struct kobject *kobj, const struct bin_attribute *attr,
24 char *buf, loff_t off, size_t count)
25{
26 struct device *dev = kobj_to_dev(kobj);
27 union acpi_object *obj = dev_get_drvdata(dev);
28
29 return memory_read_from_buffer(to: buf, count, ppos: &off, from: obj->buffer.pointer, available: obj->buffer.length);
30}
31
32static const BIN_ATTR_ADMIN_RO(bmof, 0);
33
34static const struct bin_attribute * const bmof_attrs[] = {
35 &bin_attr_bmof,
36 NULL
37};
38
39static size_t bmof_bin_size(struct kobject *kobj, const struct bin_attribute *attr, int n)
40{
41 struct device *dev = kobj_to_dev(kobj);
42 union acpi_object *obj = dev_get_drvdata(dev);
43
44 return obj->buffer.length;
45}
46
47static const struct attribute_group bmof_group = {
48 .bin_size = bmof_bin_size,
49 .bin_attrs = bmof_attrs,
50};
51
52static const struct attribute_group *bmof_groups[] = {
53 &bmof_group,
54 NULL
55};
56
57static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
58{
59 union acpi_object *obj;
60
61 obj = wmidev_block_query(wdev, instance: 0);
62 if (!obj) {
63 dev_err(&wdev->dev, "failed to read Binary MOF\n");
64 return -EIO;
65 }
66
67 if (obj->type != ACPI_TYPE_BUFFER) {
68 dev_err(&wdev->dev, "Binary MOF is not a buffer\n");
69 kfree(objp: obj);
70 return -EIO;
71 }
72
73 dev_set_drvdata(dev: &wdev->dev, data: obj);
74
75 return 0;
76}
77
78static void wmi_bmof_remove(struct wmi_device *wdev)
79{
80 union acpi_object *obj = dev_get_drvdata(dev: &wdev->dev);
81
82 kfree(objp: obj);
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 .dev_groups = bmof_groups,
94 },
95 .probe = wmi_bmof_probe,
96 .remove = wmi_bmof_remove,
97 .id_table = wmi_bmof_id_table,
98 .no_singleton = true,
99};
100
101module_wmi_driver(wmi_bmof_driver);
102
103MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table);
104MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");
105MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
106MODULE_LICENSE("GPL");
107