1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * WMI Thunderbolt driver
 4 *
 5 * Copyright (C) 2017 Dell Inc. All Rights Reserved.
 6 */
 7
 8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 9
10#include <linux/acpi.h>
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 INTEL_WMI_THUNDERBOLT_GUID "86CCFD48-205E-4A77-9C48-2021CBEDE341"
21
22static ssize_t force_power_store(struct device *dev,
23				 struct device_attribute *attr,
24				 const char *buf, size_t count)
25{
26	struct acpi_buffer input;
27	acpi_status status;
28	u8 mode;
29
30	input.length = sizeof(u8);
31	input.pointer = &mode;
32	mode = hex_to_bin(buf[0]);
33	dev_dbg(dev, "force_power: storing %#x\n", mode);
34	if (mode == 0 || mode == 1) {
35		status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1,
36					     &input, NULL);
37		if (ACPI_FAILURE(status)) {
38			dev_dbg(dev, "force_power: failed to evaluate ACPI method\n");
39			return -ENODEV;
40		}
41	} else {
42		dev_dbg(dev, "force_power: unsupported mode\n");
43		return -EINVAL;
44	}
45	return count;
46}
47
48static DEVICE_ATTR_WO(force_power);
49
50static struct attribute *tbt_attrs[] = {
51	&dev_attr_force_power.attr,
52	NULL
53};
54
55static const struct attribute_group tbt_attribute_group = {
56	.attrs = tbt_attrs,
57};
58
59static int intel_wmi_thunderbolt_probe(struct wmi_device *wdev,
60				       const void *context)
61{
62	int ret;
63
64	ret = sysfs_create_group(&wdev->dev.kobj, &tbt_attribute_group);
65	kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
66	return ret;
67}
68
69static int intel_wmi_thunderbolt_remove(struct wmi_device *wdev)
70{
71	sysfs_remove_group(&wdev->dev.kobj, &tbt_attribute_group);
72	kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
73	return 0;
74}
75
76static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = {
77	{ .guid_string = INTEL_WMI_THUNDERBOLT_GUID },
78	{ },
79};
80
81static struct wmi_driver intel_wmi_thunderbolt_driver = {
82	.driver = {
83		.name = "intel-wmi-thunderbolt",
84	},
85	.probe = intel_wmi_thunderbolt_probe,
86	.remove = intel_wmi_thunderbolt_remove,
87	.id_table = intel_wmi_thunderbolt_id_table,
88};
89
90module_wmi_driver(intel_wmi_thunderbolt_driver);
91
92MODULE_DEVICE_TABLE(wmi, intel_wmi_thunderbolt_id_table);
93MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
94MODULE_DESCRIPTION("Intel WMI Thunderbolt force power driver");
95MODULE_LICENSE("GPL v2");