1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Lenovo WMI Camera Button Driver 4 * 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 19 struct lenovo_wmi_priv { 20 struct input_dev *idev; 21 struct mutex notify_lock; /* lenovo WMI camera button notify lock */ 22 }; 23 24 enum { 25 SW_CAMERA_OFF = 0, 26 SW_CAMERA_ON = 1, 27 }; 28 29 static 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 close 48 * 1 camera open 49 */ 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 68 static 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 99 static 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 } 105 106 static const struct wmi_device_id lenovo_wmi_id_table[] = { 107 { .guid_string = WMI_LENOVO_CAMERABUTTON_EVENT_GUID }, 108 { } 109 }; 110 MODULE_DEVICE_TABLE(wmi, lenovo_wmi_id_table); 111 112 static 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 }; 123 module_wmi_driver(lenovo_wmi_driver); 124 125 MODULE_AUTHOR("Ai Chao <aichao@kylinos.cn>"); 126 MODULE_DESCRIPTION("Lenovo WMI Camera Button Driver"); 127 MODULE_LICENSE("GPL"); 128