ok6410 android driver(9)

　　In this essay, I will write the JNI to test our leds device.

　　If you don't know how to create a jni project, I suggest you to have a read on the following website : 

http://www.cnblogs.com/plinx/p/3213824.html

　　1、string.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">ledsjni</string>
    <string name="action_settings">Settings</string>
    <string name="string_hello">String input:</string>
    <string name="str_button">Str Input</string>
    <string name="ioctl_hello">I/O control:</string>
    <string name="io_button">I/O Input</string>
    <string name="led1">Led1</string>
    <string name="led2">Led2</string>
    <string name="led3">Led3</string>
    <string name="led4">Led4</string>

</resources>

　　2、activity_main.xml

　　(1) graphical layout

　　TIPS :

Ok6410's screen is placing horizontally, so you should design your application horizontally to adapt the screen.

　　(2) activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <CheckBox
        android:id="@+id/checkBox_str1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView_str"
        android:text="@string/led1" />

    <TextView
        android:id="@+id/textView_str"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="@string/string_hello" />

    <TextView
        android:id="@+id/textView_io"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/checkBox_str1"
        android:layout_below="@+id/checkBox_str1"
        android:text="@string/ioctl_hello" />

    <Button
        android:id="@+id/onClick_strButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textView_io"
        android:layout_alignParentRight="true"
        android:onClick="onClick_strButton"
        android:text="@string/str_button" />

    <Button
        android:id="@+id/onClick_ioButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignRight="@+id/onClick_strButton"
        android:layout_below="@+id/textView_io"
        android:onClick="onClick_ioButton"
        android:text="@string/io_button" />

    <CheckBox
        android:id="@+id/checkBox_io1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView_io"
        android:text="@string/led1" />

    <CheckBox
        android:id="@+id/checkBox_io2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView_io"
        android:layout_toRightOf="@+id/checkBox_io1"
        android:text="@string/led2" />

    <CheckBox
        android:id="@+id/checkBox_io3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView_io"
        android:layout_toRightOf="@+id/checkBox_str2"
        android:text="@string/led3" />

    <CheckBox
        android:id="@+id/checkBox_io4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView_io"
        android:layout_toRightOf="@+id/checkBox_io3"
        android:text="@string/led4" />

    <CheckBox
        android:id="@+id/checkBox_str2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView_str"
        android:layout_toRightOf="@+id/checkBox_str1"
        android:text="@string/led2" />

    <CheckBox
        android:id="@+id/checkBox_str3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView_str"
        android:layout_toRightOf="@+id/checkBox_str2"
        android:text="@string/led3" />

    <CheckBox
        android:id="@+id/checkBox_str4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView_str"
        android:layout_toRightOf="@+id/checkBox_str3"
        android:text="@string/led4" />

</RelativeLayout>

　　3、MainActivity.java

package com.example.ledsjni;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.CheckBox;
import android.widget.TextView;

public class MainActivity extends Activity {
    private CheckBox[] cbox_str = new CheckBox[4];
    private CheckBox[] cbox_io  = new CheckBox[4];
    private TextView tview_str;
    private TextView tview_io;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tview_str = (TextView)findViewById(R.id.textView_str);
        tview_io = (TextView)findViewById(R.id.textView_io);
        
        cbox_str[0] = (CheckBox)findViewById(R.id.checkBox_str1);
        cbox_str[1] = (CheckBox)findViewById(R.id.checkBox_str2);
        cbox_str[2] = (CheckBox)findViewById(R.id.checkBox_str3);
        cbox_str[3] = (CheckBox)findViewById(R.id.checkBox_str4);
        
        cbox_io[0] = (CheckBox)findViewById(R.id.checkBox_io1);
        cbox_io[1] = (CheckBox)findViewById(R.id.checkBox_io2);
        cbox_io[2] = (CheckBox)findViewById(R.id.checkBox_io3);
        cbox_io[3] = (CheckBox)findViewById(R.id.checkBox_io4);
    }
    
    public void onClick_strButton(View view) {
        tview_io.setText("I/O control:");
        String str = "";
        for (int i = 0; i < 4; i++) {
            if(cbox_str[i].isChecked())
                str += "1";
            else
                str += "0";
        }
        tview_str.setText("Leds :" + str);
        strLeds(str);
    }
    
    public void onClick_ioButton(View view) {
        tview_str.setText("I/O control:");
        String str = "";
        for (int i = 0; i < 4; i++) {
            if(cbox_io[i].isChecked()) {
                ioLeds(1, i);
                str += "1";
            } else {  
                ioLeds(0, i);
                str += "0";
            }
        }
        tview_io.setText("Leds :" + str);
    }
    
    public native void strLeds(String str);
    public native void ioLeds(int cmd, int arg);
    
    static {
        System.loadLibrary("ledsjni");
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

　　4、ledsjni.h

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class com_example_ledsjni_MainActivity */

#ifndef _Included_com_example_ledsjni_MainActivity
#define _Included_com_example_ledsjni_MainActivity
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     com_example_ledsjni_MainActivity
 * Method:    strLeds
 * Signature: (Ljava/lang/String;)V
 */
JNIEXPORT void JNICALL Java_com_example_ledsjni_MainActivity_strLeds
  (JNIEnv *, jobject, jstring);

/*
 * Class:     com_example_ledsjni_MainActivity
 * Method:    ioLeds
 * Signature: (II)V
 */
JNIEXPORT void JNICALL Java_com_example_ledsjni_MainActivity_ioLeds
  (JNIEnv *, jobject, jint, jint);

#ifdef __cplusplus
}
#endif
#endif

　　5、ledsjni.cpp

#include <jni.h>
#include <string.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>

#include "ledsjni.h"

char* jstring_to_pchar(JNIEnv* env, jstring str)
{
    char* pstr = NULL;
    jclass clsstring = env->FindClass("java/lang/String");
    jstring strencode = env->NewStringUTF("utf-8");
    jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
    jbyteArray byteArray = (jbyteArray)(env->CallObjectMethod(str, mid, strencode));
    jsize size = env->GetArrayLength(byteArray);
    jbyte* pbyte = env->GetByteArrayElements(byteArray, JNI_FALSE);
    if (size > 0) {
        pstr = (char*) malloc(size);
        memcpy(pstr, pbyte, size);
    }
    return pstr;
}


JNIEXPORT void JNICALL Java_com_example_ledsjni_MainActivity_strLeds
  (JNIEnv* env, jobject thiz, jstring str)
{
    int fd_leds;
    fd_leds = open("/dev/s3c6410_leds", O_WRONLY);
    char* pstr = jstring_to_pchar(env, str);
    if (pstr != NULL) {
        write(fd_leds, pstr, strlen(pstr));
    }

    close(fd_leds);
}

JNIEXPORT void JNICALL Java_com_example_ledsjni_MainActivity_ioLeds
  (JNIEnv* env, jobject thiz, jint cmd, jint arg)
{
    int fd_leds;
    fd_leds = open("/dev/s3c6410_leds", O_WRONLY);
    ioctl(fd_leds, cmd, arg);

    close(fd_leds);
}

　　That's all about the ledsjni and leds device driver.