1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * WMI embedded Binary MOF driver
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (c) 2015 Andrew Lutomirski
6*4882a593Smuzhiyun * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include <linux/acpi.h>
12*4882a593Smuzhiyun #include <linux/device.h>
13*4882a593Smuzhiyun #include <linux/fs.h>
14*4882a593Smuzhiyun #include <linux/kernel.h>
15*4882a593Smuzhiyun #include <linux/module.h>
16*4882a593Smuzhiyun #include <linux/string.h>
17*4882a593Smuzhiyun #include <linux/sysfs.h>
18*4882a593Smuzhiyun #include <linux/types.h>
19*4882a593Smuzhiyun #include <linux/wmi.h>
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun struct bmof_priv {
24*4882a593Smuzhiyun union acpi_object *bmofdata;
25*4882a593Smuzhiyun struct bin_attribute bmof_bin_attr;
26*4882a593Smuzhiyun };
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun static ssize_t
read_bmof(struct file * filp,struct kobject * kobj,struct bin_attribute * attr,char * buf,loff_t off,size_t count)29*4882a593Smuzhiyun read_bmof(struct file *filp, struct kobject *kobj,
30*4882a593Smuzhiyun struct bin_attribute *attr,
31*4882a593Smuzhiyun char *buf, loff_t off, size_t count)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun struct bmof_priv *priv =
34*4882a593Smuzhiyun container_of(attr, struct bmof_priv, bmof_bin_attr);
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun if (off < 0)
37*4882a593Smuzhiyun return -EINVAL;
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun if (off >= priv->bmofdata->buffer.length)
40*4882a593Smuzhiyun return 0;
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun if (count > priv->bmofdata->buffer.length - off)
43*4882a593Smuzhiyun count = priv->bmofdata->buffer.length - off;
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun memcpy(buf, priv->bmofdata->buffer.pointer + off, count);
46*4882a593Smuzhiyun return count;
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun
wmi_bmof_probe(struct wmi_device * wdev,const void * context)49*4882a593Smuzhiyun static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
50*4882a593Smuzhiyun {
51*4882a593Smuzhiyun struct bmof_priv *priv;
52*4882a593Smuzhiyun int ret;
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun priv = devm_kzalloc(&wdev->dev, sizeof(struct bmof_priv), GFP_KERNEL);
55*4882a593Smuzhiyun if (!priv)
56*4882a593Smuzhiyun return -ENOMEM;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun dev_set_drvdata(&wdev->dev, priv);
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun priv->bmofdata = wmidev_block_query(wdev, 0);
61*4882a593Smuzhiyun if (!priv->bmofdata) {
62*4882a593Smuzhiyun dev_err(&wdev->dev, "failed to read Binary MOF\n");
63*4882a593Smuzhiyun return -EIO;
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun if (priv->bmofdata->type != ACPI_TYPE_BUFFER) {
67*4882a593Smuzhiyun dev_err(&wdev->dev, "Binary MOF is not a buffer\n");
68*4882a593Smuzhiyun ret = -EIO;
69*4882a593Smuzhiyun goto err_free;
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun sysfs_bin_attr_init(&priv->bmof_bin_attr);
73*4882a593Smuzhiyun priv->bmof_bin_attr.attr.name = "bmof";
74*4882a593Smuzhiyun priv->bmof_bin_attr.attr.mode = 0400;
75*4882a593Smuzhiyun priv->bmof_bin_attr.read = read_bmof;
76*4882a593Smuzhiyun priv->bmof_bin_attr.size = priv->bmofdata->buffer.length;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun ret = sysfs_create_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr);
79*4882a593Smuzhiyun if (ret)
80*4882a593Smuzhiyun goto err_free;
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun return 0;
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun err_free:
85*4882a593Smuzhiyun kfree(priv->bmofdata);
86*4882a593Smuzhiyun return ret;
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun
wmi_bmof_remove(struct wmi_device * wdev)89*4882a593Smuzhiyun static int wmi_bmof_remove(struct wmi_device *wdev)
90*4882a593Smuzhiyun {
91*4882a593Smuzhiyun struct bmof_priv *priv = dev_get_drvdata(&wdev->dev);
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun sysfs_remove_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr);
94*4882a593Smuzhiyun kfree(priv->bmofdata);
95*4882a593Smuzhiyun return 0;
96*4882a593Smuzhiyun }
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun static const struct wmi_device_id wmi_bmof_id_table[] = {
99*4882a593Smuzhiyun { .guid_string = WMI_BMOF_GUID },
100*4882a593Smuzhiyun { },
101*4882a593Smuzhiyun };
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun static struct wmi_driver wmi_bmof_driver = {
104*4882a593Smuzhiyun .driver = {
105*4882a593Smuzhiyun .name = "wmi-bmof",
106*4882a593Smuzhiyun },
107*4882a593Smuzhiyun .probe = wmi_bmof_probe,
108*4882a593Smuzhiyun .remove = wmi_bmof_remove,
109*4882a593Smuzhiyun .id_table = wmi_bmof_id_table,
110*4882a593Smuzhiyun };
111*4882a593Smuzhiyun
112*4882a593Smuzhiyun module_wmi_driver(wmi_bmof_driver);
113*4882a593Smuzhiyun
114*4882a593Smuzhiyun MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table);
115*4882a593Smuzhiyun MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");
116*4882a593Smuzhiyun MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
117*4882a593Smuzhiyun MODULE_LICENSE("GPL");
118