1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * PEAQ 2-in-1 WMI hotkey driver
4 * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
5 */
6
7 #include <linux/acpi.h>
8 #include <linux/dmi.h>
9 #include <linux/input.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12
13 #define PEAQ_DOLBY_BUTTON_GUID "ABBC0F6F-8EA1-11D1-00A0-C90629100000"
14 #define PEAQ_DOLBY_BUTTON_METHOD_ID 5
15 #define PEAQ_POLL_INTERVAL_MS 250
16 #define PEAQ_POLL_IGNORE_MS 500
17 #define PEAQ_POLL_MAX_MS 1000
18
19 MODULE_ALIAS("wmi:"PEAQ_DOLBY_BUTTON_GUID);
20
21 static struct input_dev *peaq_poll_dev;
22
23 /*
24 * The Dolby button (yes really a Dolby button) causes an ACPI variable to get
25 * set on both press and release. The WMI method checks and clears that flag.
26 * So for a press + release we will get back One from the WMI method either once
27 * (if polling after the release) or twice (polling between press and release).
28 * We ignore events for 0.5s after the first event to avoid reporting 2 presses.
29 */
peaq_wmi_poll(struct input_dev * input_dev)30 static void peaq_wmi_poll(struct input_dev *input_dev)
31 {
32 static unsigned long last_event_time;
33 static bool had_events;
34 union acpi_object obj;
35 acpi_status status;
36 u32 dummy = 0;
37
38 struct acpi_buffer input = { sizeof(dummy), &dummy };
39 struct acpi_buffer output = { sizeof(obj), &obj };
40
41 status = wmi_evaluate_method(PEAQ_DOLBY_BUTTON_GUID, 0,
42 PEAQ_DOLBY_BUTTON_METHOD_ID,
43 &input, &output);
44 if (ACPI_FAILURE(status))
45 return;
46
47 if (obj.type != ACPI_TYPE_INTEGER) {
48 dev_err(&input_dev->dev,
49 "Error WMBC did not return an integer\n");
50 return;
51 }
52
53 if (!obj.integer.value)
54 return;
55
56 if (had_events && time_before(jiffies, last_event_time +
57 msecs_to_jiffies(PEAQ_POLL_IGNORE_MS)))
58 return;
59
60 input_event(input_dev, EV_KEY, KEY_SOUND, 1);
61 input_sync(input_dev);
62 input_event(input_dev, EV_KEY, KEY_SOUND, 0);
63 input_sync(input_dev);
64
65 last_event_time = jiffies;
66 had_events = true;
67 }
68
69 /* Some other devices (Shuttle XS35) use the same WMI GUID for other purposes */
70 static const struct dmi_system_id peaq_dmi_table[] __initconst = {
71 {
72 .matches = {
73 DMI_MATCH(DMI_SYS_VENDOR, "PEAQ"),
74 DMI_MATCH(DMI_PRODUCT_NAME, "PEAQ PMM C1010 MD99187"),
75 },
76 },
77 {}
78 };
79
peaq_wmi_init(void)80 static int __init peaq_wmi_init(void)
81 {
82 int err;
83
84 /* WMI GUID is not unique, also check for a DMI match */
85 if (!dmi_check_system(peaq_dmi_table))
86 return -ENODEV;
87
88 if (!wmi_has_guid(PEAQ_DOLBY_BUTTON_GUID))
89 return -ENODEV;
90
91 peaq_poll_dev = input_allocate_device();
92 if (!peaq_poll_dev)
93 return -ENOMEM;
94
95 peaq_poll_dev->name = "PEAQ WMI hotkeys";
96 peaq_poll_dev->phys = "wmi/input0";
97 peaq_poll_dev->id.bustype = BUS_HOST;
98 input_set_capability(peaq_poll_dev, EV_KEY, KEY_SOUND);
99
100 err = input_setup_polling(peaq_poll_dev, peaq_wmi_poll);
101 if (err)
102 goto err_out;
103
104 input_set_poll_interval(peaq_poll_dev, PEAQ_POLL_INTERVAL_MS);
105 input_set_max_poll_interval(peaq_poll_dev, PEAQ_POLL_MAX_MS);
106
107 err = input_register_device(peaq_poll_dev);
108 if (err)
109 goto err_out;
110
111 return 0;
112
113 err_out:
114 input_free_device(peaq_poll_dev);
115 return err;
116 }
117
peaq_wmi_exit(void)118 static void __exit peaq_wmi_exit(void)
119 {
120 input_unregister_device(peaq_poll_dev);
121 }
122
123 module_init(peaq_wmi_init);
124 module_exit(peaq_wmi_exit);
125
126 MODULE_DESCRIPTION("PEAQ 2-in-1 WMI hotkey driver");
127 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
128 MODULE_LICENSE("GPL");
129