1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (C) 2021 Thomas Weißschuh <thomas@weissschuh.net>
4  */
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6 
7 #include <linux/acpi.h>
8 #include <linux/dmi.h>
9 #include <linux/hwmon.h>
10 #include <linux/module.h>
11 #include <linux/wmi.h>
12 
13 #define GIGABYTE_WMI_GUID	"DEADBEEF-2001-0000-00A0-C90629100000"
14 #define NUM_TEMPERATURE_SENSORS	6
15 
16 static bool force_load;
17 module_param(force_load, bool, 0444);
18 MODULE_PARM_DESC(force_load, "Force loading on unknown platform");
19 
20 static u8 usable_sensors_mask;
21 
22 enum gigabyte_wmi_commandtype {
23 	GIGABYTE_WMI_BUILD_DATE_QUERY       =   0x1,
24 	GIGABYTE_WMI_MAINBOARD_TYPE_QUERY   =   0x2,
25 	GIGABYTE_WMI_FIRMWARE_VERSION_QUERY =   0x4,
26 	GIGABYTE_WMI_MAINBOARD_NAME_QUERY   =   0x5,
27 	GIGABYTE_WMI_TEMPERATURE_QUERY      = 0x125,
28 };
29 
30 struct gigabyte_wmi_args {
31 	u32 arg1;
32 };
33 
34 static int gigabyte_wmi_perform_query(struct wmi_device *wdev,
35 				      enum gigabyte_wmi_commandtype command,
36 				      struct gigabyte_wmi_args *args, struct acpi_buffer *out)
37 {
38 	const struct acpi_buffer in = {
39 		.length = sizeof(*args),
40 		.pointer = args,
41 	};
42 
43 	acpi_status ret = wmidev_evaluate_method(wdev, 0x0, command, &in, out);
44 
45 	if (ACPI_FAILURE(ret))
46 		return -EIO;
47 
48 	return 0;
49 }
50 
51 static int gigabyte_wmi_query_integer(struct wmi_device *wdev,
52 				      enum gigabyte_wmi_commandtype command,
53 				      struct gigabyte_wmi_args *args, u64 *res)
54 {
55 	union acpi_object *obj;
56 	struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
57 	int ret;
58 
59 	ret = gigabyte_wmi_perform_query(wdev, command, args, &result);
60 	if (ret)
61 		return ret;
62 	obj = result.pointer;
63 	if (obj && obj->type == ACPI_TYPE_INTEGER)
64 		*res = obj->integer.value;
65 	else
66 		ret = -EIO;
67 	kfree(result.pointer);
68 	return ret;
69 }
70 
71 static int gigabyte_wmi_temperature(struct wmi_device *wdev, u8 sensor, long *res)
72 {
73 	struct gigabyte_wmi_args args = {
74 		.arg1 = sensor,
75 	};
76 	u64 temp;
77 	acpi_status ret;
78 
79 	ret = gigabyte_wmi_query_integer(wdev, GIGABYTE_WMI_TEMPERATURE_QUERY, &args, &temp);
80 	if (ret == 0) {
81 		if (temp == 0)
82 			return -ENODEV;
83 		*res = (s8)temp * 1000; // value is a signed 8-bit integer
84 	}
85 	return ret;
86 }
87 
88 static int gigabyte_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
89 				   u32 attr, int channel, long *val)
90 {
91 	struct wmi_device *wdev = dev_get_drvdata(dev);
92 
93 	return gigabyte_wmi_temperature(wdev, channel, val);
94 }
95 
96 static umode_t gigabyte_wmi_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
97 					     u32 attr, int channel)
98 {
99 	return usable_sensors_mask & BIT(channel) ? 0444  : 0;
100 }
101 
102 static const struct hwmon_channel_info *gigabyte_wmi_hwmon_info[] = {
103 	HWMON_CHANNEL_INFO(temp,
104 			   HWMON_T_INPUT,
105 			   HWMON_T_INPUT,
106 			   HWMON_T_INPUT,
107 			   HWMON_T_INPUT,
108 			   HWMON_T_INPUT,
109 			   HWMON_T_INPUT),
110 	NULL
111 };
112 
113 static const struct hwmon_ops gigabyte_wmi_hwmon_ops = {
114 	.read = gigabyte_wmi_hwmon_read,
115 	.is_visible = gigabyte_wmi_hwmon_is_visible,
116 };
117 
118 static const struct hwmon_chip_info gigabyte_wmi_hwmon_chip_info = {
119 	.ops = &gigabyte_wmi_hwmon_ops,
120 	.info = gigabyte_wmi_hwmon_info,
121 };
122 
123 static u8 gigabyte_wmi_detect_sensor_usability(struct wmi_device *wdev)
124 {
125 	int i;
126 	long temp;
127 	u8 r = 0;
128 
129 	for (i = 0; i < NUM_TEMPERATURE_SENSORS; i++) {
130 		if (!gigabyte_wmi_temperature(wdev, i, &temp))
131 			r |= BIT(i);
132 	}
133 	return r;
134 }
135 
136 #define DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME(name) \
137 	{ .matches = { \
138 		DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."), \
139 		DMI_EXACT_MATCH(DMI_BOARD_NAME, name), \
140 	}}
141 
142 static const struct dmi_system_id gigabyte_wmi_known_working_platforms[] = {
143 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("B450M S2H V2"),
144 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("B550 AORUS ELITE"),
145 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("B550 AORUS ELITE V2"),
146 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("B550 GAMING X V2"),
147 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("B550M AORUS PRO-P"),
148 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("B550M DS3H"),
149 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("Z390 I AORUS PRO WIFI-CF"),
150 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("X570 AORUS ELITE"),
151 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("X570 GAMING X"),
152 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("X570 I AORUS PRO WIFI"),
153 	DMI_EXACT_MATCH_GIGABYTE_BOARD_NAME("X570 UD"),
154 	{ }
155 };
156 
157 static int gigabyte_wmi_probe(struct wmi_device *wdev, const void *context)
158 {
159 	struct device *hwmon_dev;
160 
161 	if (!dmi_check_system(gigabyte_wmi_known_working_platforms)) {
162 		if (!force_load)
163 			return -ENODEV;
164 		dev_warn(&wdev->dev, "Forcing load on unknown platform");
165 	}
166 
167 	usable_sensors_mask = gigabyte_wmi_detect_sensor_usability(wdev);
168 	if (!usable_sensors_mask) {
169 		dev_info(&wdev->dev, "No temperature sensors usable");
170 		return -ENODEV;
171 	}
172 
173 	hwmon_dev = devm_hwmon_device_register_with_info(&wdev->dev, "gigabyte_wmi", wdev,
174 							 &gigabyte_wmi_hwmon_chip_info, NULL);
175 
176 	return PTR_ERR_OR_ZERO(hwmon_dev);
177 }
178 
179 static const struct wmi_device_id gigabyte_wmi_id_table[] = {
180 	{ GIGABYTE_WMI_GUID, NULL },
181 	{ }
182 };
183 
184 static struct wmi_driver gigabyte_wmi_driver = {
185 	.driver = {
186 		.name = "gigabyte-wmi",
187 	},
188 	.id_table = gigabyte_wmi_id_table,
189 	.probe = gigabyte_wmi_probe,
190 };
191 module_wmi_driver(gigabyte_wmi_driver);
192 
193 MODULE_DEVICE_TABLE(wmi, gigabyte_wmi_id_table);
194 MODULE_AUTHOR("Thomas Weißschuh <thomas@weissschuh.net>");
195 MODULE_DESCRIPTION("Gigabyte WMI temperature driver");
196 MODULE_LICENSE("GPL");
197