187 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * WMI hotkeys support for Dell All-In-One series4 */5 6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt7 8#include <linux/kernel.h>9#include <linux/module.h>10#include <linux/init.h>11#include <linux/types.h>12#include <linux/input.h>13#include <linux/input/sparse-keymap.h>14#include <linux/acpi.h>15#include <linux/string.h>16 17MODULE_DESCRIPTION("WMI hotkeys driver for Dell All-In-One series");18MODULE_LICENSE("GPL");19 20#define EVENT_GUID1 "284A0E6B-380E-472A-921F-E52786257FB4"21#define EVENT_GUID2 "02314822-307C-4F66-BF0E-48AEAEB26CC8"22 23struct dell_wmi_event {24 u16 length;25 /* 0x000: A hot key pressed or an event occurred26 * 0x00F: A sequence of hot keys are pressed */27 u16 type;28 u16 event[];29};30 31static const char *dell_wmi_aio_guids[] = {32 EVENT_GUID1,33 EVENT_GUID2,34 NULL35};36 37MODULE_ALIAS("wmi:"EVENT_GUID1);38MODULE_ALIAS("wmi:"EVENT_GUID2);39 40static const struct key_entry dell_wmi_aio_keymap[] = {41 { KE_KEY, 0xc0, { KEY_VOLUMEUP } },42 { KE_KEY, 0xc1, { KEY_VOLUMEDOWN } },43 { KE_KEY, 0xe030, { KEY_VOLUMEUP } },44 { KE_KEY, 0xe02e, { KEY_VOLUMEDOWN } },45 { KE_KEY, 0xe020, { KEY_MUTE } },46 { KE_KEY, 0xe027, { KEY_DISPLAYTOGGLE } },47 { KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },48 { KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },49 { KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },50 { KE_END, 0 }51};52 53static struct input_dev *dell_wmi_aio_input_dev;54 55/*56 * The new WMI event data format will follow the dell_wmi_event structure57 * So, we will check if the buffer matches the format58 */59static bool dell_wmi_aio_event_check(u8 *buffer, int length)60{61 struct dell_wmi_event *event = (struct dell_wmi_event *)buffer;62 63 if (event == NULL || length < 6)64 return false;65 66 if ((event->type == 0 || event->type == 0xf) &&67 event->length >= 2)68 return true;69 70 return false;71}72 73static void dell_wmi_aio_notify(union acpi_object *obj, void *context)74{75 struct dell_wmi_event *event;76 77 if (obj) {78 unsigned int scancode = 0;79 80 switch (obj->type) {81 case ACPI_TYPE_INTEGER:82 /* Most All-In-One correctly return integer scancode */83 scancode = obj->integer.value;84 sparse_keymap_report_event(dell_wmi_aio_input_dev,85 scancode, 1, true);86 break;87 case ACPI_TYPE_BUFFER:88 if (dell_wmi_aio_event_check(obj->buffer.pointer,89 obj->buffer.length)) {90 event = (struct dell_wmi_event *)91 obj->buffer.pointer;92 scancode = event->event[0];93 } else {94 /* Broken machines return the scancode in a95 buffer */96 if (obj->buffer.pointer &&97 obj->buffer.length > 0)98 scancode = obj->buffer.pointer[0];99 }100 if (scancode)101 sparse_keymap_report_event(102 dell_wmi_aio_input_dev,103 scancode, 1, true);104 break;105 }106 }107}108 109static int __init dell_wmi_aio_input_setup(void)110{111 int err;112 113 dell_wmi_aio_input_dev = input_allocate_device();114 115 if (!dell_wmi_aio_input_dev)116 return -ENOMEM;117 118 dell_wmi_aio_input_dev->name = "Dell AIO WMI hotkeys";119 dell_wmi_aio_input_dev->phys = "wmi/input0";120 dell_wmi_aio_input_dev->id.bustype = BUS_HOST;121 122 err = sparse_keymap_setup(dell_wmi_aio_input_dev,123 dell_wmi_aio_keymap, NULL);124 if (err) {125 pr_err("Unable to setup input device keymap\n");126 goto err_free_dev;127 }128 err = input_register_device(dell_wmi_aio_input_dev);129 if (err) {130 pr_info("Unable to register input device\n");131 goto err_free_dev;132 }133 return 0;134 135err_free_dev:136 input_free_device(dell_wmi_aio_input_dev);137 return err;138}139 140static const char *dell_wmi_aio_find(void)141{142 int i;143 144 for (i = 0; dell_wmi_aio_guids[i] != NULL; i++)145 if (wmi_has_guid(dell_wmi_aio_guids[i]))146 return dell_wmi_aio_guids[i];147 148 return NULL;149}150 151static int __init dell_wmi_aio_init(void)152{153 int err;154 const char *guid;155 156 guid = dell_wmi_aio_find();157 if (!guid) {158 pr_warn("No known WMI GUID found\n");159 return -ENXIO;160 }161 162 err = dell_wmi_aio_input_setup();163 if (err)164 return err;165 166 err = wmi_install_notify_handler(guid, dell_wmi_aio_notify, NULL);167 if (err) {168 pr_err("Unable to register notify handler - %d\n", err);169 input_unregister_device(dell_wmi_aio_input_dev);170 return err;171 }172 173 return 0;174}175 176static void __exit dell_wmi_aio_exit(void)177{178 const char *guid;179 180 guid = dell_wmi_aio_find();181 wmi_remove_notify_handler(guid);182 input_unregister_device(dell_wmi_aio_input_dev);183}184 185module_init(dell_wmi_aio_init);186module_exit(dell_wmi_aio_exit);187