platform/x86/peaq-wmi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * PEAQ 2-in-1 WMI hotkey driver
0004  * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
0005  */
0006
0007 #include <linux/acpi.h>
0008 #include <linux/dmi.h>
0009 #include <linux/input.h>
0010 #include <linux/kernel.h>
0011 #include <linux/module.h>
0012
0013 #define PEAQ_DOLBY_BUTTON_GUID      "ABBC0F6F-8EA1-11D1-00A0-C90629100000"
0014 #define PEAQ_DOLBY_BUTTON_METHOD_ID 5
0015 #define PEAQ_POLL_INTERVAL_MS       250
0016 #define PEAQ_POLL_IGNORE_MS     500
0017 #define PEAQ_POLL_MAX_MS        1000
0018
0019 MODULE_ALIAS("wmi:"PEAQ_DOLBY_BUTTON_GUID);
0020
0021 static struct input_dev *peaq_poll_dev;
0022
0023 /*
0024  * The Dolby button (yes really a Dolby button) causes an ACPI variable to get
0025  * set on both press and release. The WMI method checks and clears that flag.
0026  * So for a press + release we will get back One from the WMI method either once
0027  * (if polling after the release) or twice (polling between press and release).
0028  * We ignore events for 0.5s after the first event to avoid reporting 2 presses.
0029  */
0030 static void peaq_wmi_poll(struct input_dev *input_dev)
0031 {
0032     static unsigned long last_event_time;
0033     static bool had_events;
0034     union acpi_object obj;
0035     acpi_status status;
0036     u32 dummy = 0;
0037
0038     struct acpi_buffer input = { sizeof(dummy), &dummy };
0039     struct acpi_buffer output = { sizeof(obj), &obj };
0040
0041     status = wmi_evaluate_method(PEAQ_DOLBY_BUTTON_GUID, 0,
0042                      PEAQ_DOLBY_BUTTON_METHOD_ID,
0043                      &input, &output);
0044     if (ACPI_FAILURE(status))
0045         return;
0046
0047     if (obj.type != ACPI_TYPE_INTEGER) {
0048         dev_err(&input_dev->dev,
0049             "Error WMBC did not return an integer\n");
0050         return;
0051     }
0052
0053     if (!obj.integer.value)
0054         return;
0055
0056     if (had_events && time_before(jiffies, last_event_time +
0057                     msecs_to_jiffies(PEAQ_POLL_IGNORE_MS)))
0058         return;
0059
0060     input_event(input_dev, EV_KEY, KEY_SOUND, 1);
0061     input_sync(input_dev);
0062     input_event(input_dev, EV_KEY, KEY_SOUND, 0);
0063     input_sync(input_dev);
0064
0065     last_event_time = jiffies;
0066     had_events = true;
0067 }
0068
0069 /* Some other devices (Shuttle XS35) use the same WMI GUID for other purposes */
0070 static const struct dmi_system_id peaq_dmi_table[] __initconst = {
0071     {
0072         .matches = {
0073             DMI_MATCH(DMI_SYS_VENDOR, "PEAQ"),
0074             DMI_MATCH(DMI_PRODUCT_NAME, "PEAQ PMM C1010 MD99187"),
0075         },
0076     },
0077     {}
0078 };
0079
0080 static int __init peaq_wmi_init(void)
0081 {
0082     int err;
0083
0084     /* WMI GUID is not unique, also check for a DMI match */
0085     if (!dmi_check_system(peaq_dmi_table))
0086         return -ENODEV;
0087
0088     if (!wmi_has_guid(PEAQ_DOLBY_BUTTON_GUID))
0089         return -ENODEV;
0090
0091     peaq_poll_dev = input_allocate_device();
0092     if (!peaq_poll_dev)
0093         return -ENOMEM;
0094
0095     peaq_poll_dev->name = "PEAQ WMI hotkeys";
0096     peaq_poll_dev->phys = "wmi/input0";
0097     peaq_poll_dev->id.bustype = BUS_HOST;
0098     input_set_capability(peaq_poll_dev, EV_KEY, KEY_SOUND);
0099
0100     err = input_setup_polling(peaq_poll_dev, peaq_wmi_poll);
0101     if (err)
0102         goto err_out;
0103
0104     input_set_poll_interval(peaq_poll_dev, PEAQ_POLL_INTERVAL_MS);
0105     input_set_max_poll_interval(peaq_poll_dev, PEAQ_POLL_MAX_MS);
0106
0107     err = input_register_device(peaq_poll_dev);
0108     if (err)
0109         goto err_out;
0110
0111     return 0;
0112
0113 err_out:
0114     input_free_device(peaq_poll_dev);
0115     return err;
0116 }
0117
0118 static void __exit peaq_wmi_exit(void)
0119 {
0120     input_unregister_device(peaq_poll_dev);
0121 }
0122
0123 module_init(peaq_wmi_init);
0124 module_exit(peaq_wmi_exit);
0125
0126 MODULE_DESCRIPTION("PEAQ 2-in-1 WMI hotkey driver");
0127 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
0128 MODULE_LICENSE("GPL");