xref: /linux/drivers/platform/x86/redmi-wmi.c (revision 9100a28c8bb4270744942cf834efcd80f1acda7d)
1 // SPDX-License-Identifier: GPL-2.0
2 /* WMI driver for Xiaomi Redmibooks */
3 
4 #include <linux/acpi.h>
5 #include <linux/bits.h>
6 #include <linux/device.h>
7 #include <linux/input.h>
8 #include <linux/input/sparse-keymap.h>
9 #include <linux/module.h>
10 #include <linux/mutex.h>
11 #include <linux/unaligned.h>
12 #include <linux/wmi.h>
13 
14 #include <uapi/linux/input-event-codes.h>
15 
16 #define WMI_REDMIBOOK_KEYBOARD_EVENT_GUID "46C93E13-EE9B-4262-8488-563BCA757FEF"
17 
18 #define AI_KEY_VALUE_MASK BIT(8)
19 
20 static const struct key_entry redmi_wmi_keymap[] = {
21 	{KE_KEY, 0x00000201,	{KEY_SELECTIVE_SCREENSHOT}},
22 	{KE_KEY, 0x00000301,	{KEY_ALL_APPLICATIONS}},
23 	{KE_KEY, 0x00001b01,	{KEY_CONFIG}},
24 	{KE_KEY, 0x00011b01,	{KEY_CONFIG}},
25 	{KE_KEY, 0x00010101,	{KEY_SWITCHVIDEOMODE}},
26 	{KE_KEY, 0x00001a01,	{KEY_REFRESH_RATE_TOGGLE}},
27 
28 	/* AI button has code for each position */
29 	{KE_KEY, 0x00011801,	{KEY_ASSISTANT}},
30 	{KE_KEY, 0x00011901,	{KEY_ASSISTANT}},
31 
32 	/* Keyboard backlight */
33 	{KE_IGNORE, 0x00000501, {}},
34 	{KE_IGNORE, 0x00800501, {}},
35 	{KE_IGNORE, 0x00050501, {}},
36 	{KE_IGNORE, 0x000a0501, {}},
37 
38 	/* Xiaomi G Command Center */
39 	{KE_KEY, 0x00010a01,	{KEY_VENDOR}},
40 
41 	/* OEM preset power mode */
42 	{KE_IGNORE, 0x00011601, {}},
43 	{KE_IGNORE, 0x00021601, {}},
44 	{KE_IGNORE, 0x00031601, {}},
45 	{KE_IGNORE, 0x00041601, {}},
46 
47 	/* Fn Lock state */
48 	{KE_IGNORE, 0x00000701, {}},
49 	{KE_IGNORE, 0x00010701, {}},
50 
51 	/* Fn+`/1/2/3/4 */
52 	{KE_KEY, 0x00011101, {KEY_F13}},
53 	{KE_KEY, 0x00011201, {KEY_F14}},
54 	{KE_KEY, 0x00011301, {KEY_F15}},
55 	{KE_KEY, 0x00011401, {KEY_F16}},
56 	{KE_KEY, 0x00011501, {KEY_F17}},
57 
58 	{KE_END}
59 };
60 
61 struct redmi_wmi {
62 	struct input_dev *input_dev;
63 	/* Protects the key event sequence */
64 	struct mutex key_lock;
65 };
66 
67 static int redmi_wmi_probe(struct wmi_device *wdev, const void *context)
68 {
69 	struct redmi_wmi *data;
70 	int err;
71 
72 	/* Init dev */
73 	data = devm_kzalloc(&wdev->dev, sizeof(*data), GFP_KERNEL);
74 	if (!data)
75 		return -ENOMEM;
76 
77 	dev_set_drvdata(&wdev->dev, data);
78 
79 	err = devm_mutex_init(&wdev->dev, &data->key_lock);
80 	if (err)
81 		return err;
82 
83 	data->input_dev = devm_input_allocate_device(&wdev->dev);
84 	if (!data->input_dev)
85 		return -ENOMEM;
86 
87 	data->input_dev->name = "Redmibook WMI keys";
88 	data->input_dev->phys = "wmi/input0";
89 
90 	err = sparse_keymap_setup(data->input_dev, redmi_wmi_keymap, NULL);
91 	if (err)
92 		return err;
93 
94 	return input_register_device(data->input_dev);
95 }
96 
97 static void redmi_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
98 {
99 	struct key_entry *entry;
100 	struct redmi_wmi *data = dev_get_drvdata(&wdev->dev);
101 	bool autorelease = true;
102 	u32 payload;
103 	int value = 1;
104 
105 	if (obj->type != ACPI_TYPE_BUFFER) {
106 		dev_err(&wdev->dev, "Bad response type %u\n", obj->type);
107 		return;
108 	}
109 
110 	if (obj->buffer.length < 32) {
111 		dev_err(&wdev->dev, "Invalid buffer length %u\n", obj->buffer.length);
112 		return;
113 	}
114 
115 	payload = get_unaligned_le32(obj->buffer.pointer);
116 	entry = sparse_keymap_entry_from_scancode(data->input_dev, payload);
117 
118 	if (!entry) {
119 		dev_dbg(&wdev->dev, "Unknown WMI event with payload %u", payload);
120 		return;
121 	}
122 
123 	/* AI key quirk */
124 	if (entry->keycode == KEY_ASSISTANT) {
125 		value = !(payload & AI_KEY_VALUE_MASK);
126 		autorelease = false;
127 	}
128 
129 	guard(mutex)(&data->key_lock);
130 	sparse_keymap_report_entry(data->input_dev, entry, value, autorelease);
131 }
132 
133 static const struct wmi_device_id redmi_wmi_id_table[] = {
134 	{ WMI_REDMIBOOK_KEYBOARD_EVENT_GUID, NULL },
135 	{ }
136 };
137 
138 static struct wmi_driver redmi_wmi_driver = {
139 	.driver = {
140 		.name = "redmi-wmi",
141 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
142 	},
143 	.id_table = redmi_wmi_id_table,
144 	.probe = redmi_wmi_probe,
145 	.notify = redmi_wmi_notify,
146 	.no_singleton = true,
147 };
148 module_wmi_driver(redmi_wmi_driver);
149 
150 MODULE_DEVICE_TABLE(wmi, redmi_wmi_id_table);
151 MODULE_AUTHOR("Gladyshev Ilya <foxido@foxido.dev>");
152 MODULE_DESCRIPTION("Redmibook WMI driver");
153 MODULE_LICENSE("GPL");
154