17792Smullan// SPDX-License-Identifier: GPL-2.0 215381Svaleriep/* 37792Smullan * Lenovo WMI Camera Button Driver 47792Smullan * 57792Smullan * Author: Ai Chao <aichao@kylinos.cn> 67792Smullan * Copyright (C) 2024 KylinSoft Corporation. 77792Smullan */ 87792Smullan 97792Smullan#include <linux/acpi.h> 107792Smullan#include <linux/device.h> 117792Smullan#include <linux/input.h> 127792Smullan#include <linux/types.h> 137792Smullan#include <linux/module.h> 147792Smullan#include <linux/mutex.h> 157792Smullan#include <linux/wmi.h> 167792Smullan 177792Smullan#define WMI_LENOVO_CAMERABUTTON_EVENT_GUID "50C76F1F-D8E4-D895-0A3D-62F4EA400013" 187792Smullan 197792Smullanstruct lenovo_wmi_priv { 207792Smullan struct input_dev *idev; 217792Smullan struct mutex notify_lock; /* lenovo WMI camera button notify lock */ 227792Smullan}; 237792Smullan 247792Smullanenum { 257792Smullan SW_CAMERA_OFF = 0, 2615381Svaleriep SW_CAMERA_ON = 1, 277792Smullan}; 287792Smullan 297792Smullanstatic void lenovo_wmi_notify(struct wmi_device *wdev, union acpi_object *obj) 307792Smullan{ 317792Smullan struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev); 327792Smullan unsigned int keycode; 337792Smullan u8 camera_mode; 347792Smullan 357792Smullan if (obj->type != ACPI_TYPE_BUFFER) { 367792Smullan dev_err(&wdev->dev, "Bad response type %u\n", obj->type); 377792Smullan return; 387792Smullan } 397792Smullan 407792Smullan if (obj->buffer.length != 1) { 417792Smullan dev_err(&wdev->dev, "Invalid buffer length %u\n", obj->buffer.length); 427792Smullan return; 437792Smullan } 447792Smullan 457792Smullan /* 467792Smullan * obj->buffer.pointer[0] is camera mode: 477792Smullan * 0 camera close 487792Smullan * 1 camera open 497792Smullan */ 507792Smullan camera_mode = obj->buffer.pointer[0]; 517792Smullan if (camera_mode > SW_CAMERA_ON) { 527792Smullan dev_err(&wdev->dev, "Unknown camera mode %u\n", camera_mode); 537792Smullan return; 547792Smullan } 557792Smullan 5615381Svaleriep mutex_lock(&priv->notify_lock); 577792Smullan 587792Smullan keycode = camera_mode == SW_CAMERA_ON ? 597792Smullan 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