linux input&&uevent使用
时间：2022-09-02 00:00:00
input 输入子系统
使用应用层时，很容易找不到UEventObserver.java 此时需要导入jar包
导入classes.jar这个jar包
weiqifa@weiqifa-Inspiron-3847:~/weiqifa/tm100$ ls out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/ classes classes.dex classes-full-debug.jar classes.jar classes-jarjar.jar emma_out javalib.jar noproguard.classes.jar noproguard.classes-with-local.dex weiqifa@weiqifa-Inspiron-3847:~/weiqifa/tm100$ 问题：最近，我比较了这两个角色。我们以前经常用这个来获得底层报告的值usb插入、键盘输入等
区别： input 若报告值为1 ,在framework这个键值一直在里面获得，这是键的特性
D/WindowManager( 632): interceptKeyTi keyCode=42 down=true repeatCount=1427 keyguardOn=true mHomePressed=false canceled=false metaState:0 D/WindowManager( 632): interceptKeyTi keyCode=42 down=true repeatCount=1428 keyguardOn=true mHomePressed=false canceled=false metaState:0 D/WindowManager( 632): interceptKeyTi keyCode=42 down=true repeatCount=1429 keyguardOn=true mHomePressed=false canceled=false metaState:0 D/WindowManager( 632): interceptKeyTi keyCode=42 down=true repeatCount=1430 keyguardOn=true mHomePressed=false canceled=false metaState:0 D/WindowManager( 632): interceptKeyTi keyCode=42 down=true repeatCount=1431 keyguardOn=true mHomePressed=false canceled=false metaState:0linux uevent
这个就是比input区别在于输入时不会一直上报1，使用方便
底层发送的关键代码
char *envp[2]; int ret; if(work_flag==true) { envp[0]="CAMERA=close"; envp[1]=NULL; //关键是kobj这个kobj 要从生成dev找个地方 ret = kobject_uevent_env(&hdyrodent_hall_class_dev->kobj, KOBJ_CHANGE,envp); if(ret<0){ printk("%s kobject error\n",__func__); }else{ printk("%s kobject uevent report close success!!!\n",__func__); } printk("------------>%s<------------%s\n",__FUNCTION__,kobject_get_path(&hdyrodent_hall_class_dev->kobj,GFP_KERNEL)); }
event.get(“CAMERA”); 这个是上报的=号前面的，然后就可以获取来比较就可以了
//weiqifa modify for the hall uevent
private UEventObserver mHALLObserver = new UEventObserver() {
@Override
public void onUEvent(UEventObserver.UEvent event) {
String camera = event.get("CAMERA");
Slog.d(TAG, "------------------------------->camera=" + camera);
if("open".equals(event.get("CAMERA"))){ //磁铁离开的时候这时候应该是打开摄像头的时候
Slog.d(TAG, "------------------------------->Open the camera app!!!!=" + camera);
Intent intent = new Intent("com.key.android.KEY_CAMERA_OPEN");
mContext.sendBroadcast(intent);
startAPP("com.android.gallery3d");
}else if("close".equals(event.get("CAMERA"))){
//磁铁接触的时候就会一直发送down 过来 这时候应该是关闭摄像头的
Slog.d(TAG, "------------------------------->Close the camera app!!!!=" + camera);
Intent intent = new Intent("com.key.android.KEY_CAMERA_CLOSE");
mContext.sendBroadcast(intent);
stopAPP("com.android.gallery3d");
WriteInt("/sys/class/hdyrodent/cameraflash",0);//关闭闪光灯
}
}
};然后再找个地方运行一下这句代码
//weiqifa modify add
mHALLObserver.startObserving("DEVPATH=/devices/virtual/hdyrodent_hall_class/hdyrodent_hall");/devices/virtual/hdyrodent_hall_class/hdyrodent_hall 这个是我们在驱动下面生成的，驱动上报的时候我用个函数把它打印出来了，前面的DEVPATH=这个是一定要加的。
然后我还是写一下这个目录是怎么来的，看下面的代码
//weiqifa modify for hall
hdyrodent_hall_class = class_create(THIS_MODULE,"hdyrodent_hall_class");
if (IS_ERR(hdyrodent_hall_class)) {
pr_err("%s: class_create() failed hdyrodent_hall_class\n", __func__);
class_destroy(hdyrodent_hall_class);
}
//add device to class
hdyrodent_hall_class_dev = device_create(hdyrodent_hall_class, NULL,
hdyrodent_hall_device_no, NULL, "hdyrodent_hall");
if (!hdyrodent_hall_class_dev) {
pr_err("%s: class_device_create failed hdyrodent_hall \n", __func__);
device_destroy(hdyrodent_hall_class, hdyrodent_hall_device_no);
}
//weiqifa modify for hall end底层例子
/* * drivers/leds/leds-mt65xx.c * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of this archive for * more details. * * Hydrodent weiqifa modify add * */
#include 
