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