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/device.h>
12 #include <linux/fs.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/string.h>
16 #include <linux/sysfs.h>
17 #include <linux/types.h>
18 #include <linux/wmi.h>
19
20 #define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
21
bmof_read(struct file * filp,struct kobject * kobj,const struct bin_attribute * attr,char * buf,loff_t off,size_t count)22 static ssize_t bmof_read(struct file *filp, struct kobject *kobj, const struct bin_attribute *attr,
23 char *buf, loff_t off, size_t count)
24 {
25 struct device *dev = kobj_to_dev(kobj);
26 struct wmi_buffer *buffer = dev_get_drvdata(dev);
27
28 return memory_read_from_buffer(buf, count, &off, buffer->data, buffer->length);
29 }
30
31 static const BIN_ATTR_ADMIN_RO(bmof, 0);
32
33 static const struct bin_attribute * const bmof_attrs[] = {
34 &bin_attr_bmof,
35 NULL
36 };
37
bmof_bin_size(struct kobject * kobj,const struct bin_attribute * attr,int n)38 static size_t bmof_bin_size(struct kobject *kobj, const struct bin_attribute *attr, int n)
39 {
40 struct device *dev = kobj_to_dev(kobj);
41 struct wmi_buffer *buffer = dev_get_drvdata(dev);
42
43 return buffer->length;
44 }
45
46 static const struct attribute_group bmof_group = {
47 .bin_size = bmof_bin_size,
48 .bin_attrs = bmof_attrs,
49 };
50
51 static const struct attribute_group *bmof_groups[] = {
52 &bmof_group,
53 NULL
54 };
55
wmi_bmof_probe(struct wmi_device * wdev,const void * context)56 static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
57 {
58 struct wmi_buffer *buffer;
59 int ret;
60
61 buffer = devm_kzalloc(&wdev->dev, sizeof(*buffer), GFP_KERNEL);
62 if (!buffer)
63 return -ENOMEM;
64
65 ret = wmidev_query_block(wdev, 0, buffer);
66 if (ret < 0)
67 return ret;
68
69 dev_set_drvdata(&wdev->dev, buffer);
70
71 return 0;
72 }
73
wmi_bmof_remove(struct wmi_device * wdev)74 static void wmi_bmof_remove(struct wmi_device *wdev)
75 {
76 struct wmi_buffer *buffer = dev_get_drvdata(&wdev->dev);
77
78 kfree(buffer->data);
79 }
80
81 static const struct wmi_device_id wmi_bmof_id_table[] = {
82 { .guid_string = WMI_BMOF_GUID },
83 { },
84 };
85
86 static struct wmi_driver wmi_bmof_driver = {
87 .driver = {
88 .name = "wmi-bmof",
89 .dev_groups = bmof_groups,
90 },
91 .probe = wmi_bmof_probe,
92 .remove = wmi_bmof_remove,
93 .id_table = wmi_bmof_id_table,
94 .no_singleton = true,
95 };
96
97 module_wmi_driver(wmi_bmof_driver);
98
99 MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table);
100 MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");
101 MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
102 MODULE_LICENSE("GPL");
103