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1// SPDX-License-Identifier: GPL-2.02/*3 * Lenovo WMI Camera Button Driver4 *5 * Author: Ai Chao <aichao@kylinos.cn>6 * Copyright (C) 2024 KylinSoft Corporation.7 */8 9#include <linux/acpi.h>10#include <linux/device.h>11#include <linux/input.h>12#include <linux/types.h>13#include <linux/module.h>14#include <linux/mutex.h>15#include <linux/wmi.h>16 17#define WMI_LENOVO_CAMERABUTTON_EVENT_GUID "50C76F1F-D8E4-D895-0A3D-62F4EA400013"18 19struct lenovo_wmi_priv {20 struct input_dev *idev;21 struct mutex notify_lock; /* lenovo WMI camera button notify lock */22};23 24enum {25 SW_CAMERA_OFF = 0,26 SW_CAMERA_ON = 1,27};28 29static void lenovo_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)30{31 struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);32 unsigned int keycode;33 u8 camera_mode;34 35 if (obj->type != ACPI_TYPE_BUFFER) {36 dev_err(&wdev->dev, "Bad response type %u\n", obj->type);37 return;38 }39 40 if (obj->buffer.length != 1) {41 dev_err(&wdev->dev, "Invalid buffer length %u\n", obj->buffer.length);42 return;43 }44 45 /*46 * obj->buffer.pointer[0] is camera mode:47 * 0 camera close48 * 1 camera open49 */50 camera_mode = obj->buffer.pointer[0];51 if (camera_mode > SW_CAMERA_ON) {52 dev_err(&wdev->dev, "Unknown camera mode %u\n", camera_mode);53 return;54 }55 56 mutex_lock(&priv->notify_lock);57 58 keycode = camera_mode == SW_CAMERA_ON ?59 KEY_CAMERA_ACCESS_ENABLE : KEY_CAMERA_ACCESS_DISABLE;60 input_report_key(priv->idev, keycode, 1);61 input_sync(priv->idev);62 input_report_key(priv->idev, keycode, 0);63 input_sync(priv->idev);64 65 mutex_unlock(&priv->notify_lock);66}67 68static int lenovo_wmi_probe(struct wmi_device *wdev, const void *context)69{70 struct lenovo_wmi_priv *priv;71 int ret;72 73 priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);74 if (!priv)75 return -ENOMEM;76 77 dev_set_drvdata(&wdev->dev, priv);78 79 priv->idev = devm_input_allocate_device(&wdev->dev);80 if (!priv->idev)81 return -ENOMEM;82 83 priv->idev->name = "Lenovo WMI Camera Button";84 priv->idev->phys = "wmi/input0";85 priv->idev->id.bustype = BUS_HOST;86 priv->idev->dev.parent = &wdev->dev;87 input_set_capability(priv->idev, EV_KEY, KEY_CAMERA_ACCESS_ENABLE);88 input_set_capability(priv->idev, EV_KEY, KEY_CAMERA_ACCESS_DISABLE);89 90 ret = input_register_device(priv->idev);91 if (ret)92 return ret;93 94 mutex_init(&priv->notify_lock);95 96 return 0;97}98 99static void lenovo_wmi_remove(struct wmi_device *wdev)100{101 struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);102 103 mutex_destroy(&priv->notify_lock);104}105 106static const struct wmi_device_id lenovo_wmi_id_table[] = {107 { .guid_string = WMI_LENOVO_CAMERABUTTON_EVENT_GUID },108 { }109};110MODULE_DEVICE_TABLE(wmi, lenovo_wmi_id_table);111 112static struct wmi_driver lenovo_wmi_driver = {113 .driver = {114 .name = "lenovo-wmi-camera",115 .probe_type = PROBE_PREFER_ASYNCHRONOUS,116 },117 .id_table = lenovo_wmi_id_table,118 .no_singleton = true,119 .probe = lenovo_wmi_probe,120 .notify = lenovo_wmi_notify,121 .remove = lenovo_wmi_remove,122};123module_wmi_driver(lenovo_wmi_driver);124 125MODULE_AUTHOR("Ai Chao <aichao@kylinos.cn>");126MODULE_DESCRIPTION("Lenovo WMI Camera Button Driver");127MODULE_LICENSE("GPL");128