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