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
redmi_wmi_probe(struct wmi_device * wdev,const void * context)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
redmi_wmi_notify(struct wmi_device * wdev,union acpi_object * obj)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 .min_event_size = 32,
145 .probe = redmi_wmi_probe,
146 .notify = redmi_wmi_notify,
147 .no_singleton = true,
148 };
149 module_wmi_driver(redmi_wmi_driver);
150
151 MODULE_DEVICE_TABLE(wmi, redmi_wmi_id_table);
152 MODULE_AUTHOR("Gladyshev Ilya <foxido@foxido.dev>");
153 MODULE_DESCRIPTION("Redmibook WMI driver");
154 MODULE_LICENSE("GPL");
155