android访问I2C接口

Java部分的代码：
package xxxxxxx.xx;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

public class I2cRadioTest extends Activity {
private static final String TAG = "I2cRadioTest";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
int[] buf = new int[4];
int slaveAddr = 0xXX;
int fileHander;
int mode = 0xXX | 0xXX;
int i;

I2c i2c = new I2c();
fileHander = i2c.open("/dev/i2c-1");

i2c.read(fileHander, slaveAddr, buf, 4);

Log.w(TAG,
"buf0= " + Integer.toHexString(buf[0]) + " buf1= "
+ Integer.toHexString(buf[1]) + " buf2= "
+ Integer.toHexString(buf[2]) + " buf=3 "
+ Integer.toHexString(buf[3]));

buf[0] = 0x01;
i = 0;// i2c.write(fileHander, slaveAddr, mode, buf, 1);
Log.w(TAG, "write length " + i);

for (int j = 0; j < 4; j++) {
buf[i] = 0;
}

i2c.read(fileHander, slaveAddr, buf, 4);
Log.w(TAG,
"buf0= " + Integer.toHexString(buf[0]) + " buf1= "
+ Integer.toHexString(buf[1]) + " buf2= "
+ Integer.toHexString(buf[2]) + " buf=3 "
+ Integer.toHexString(buf[3]));

i2c.close(fileHander);

if ((buf[0] & 0x10) == 0x01) {
Log.w(TAG, "------success-----");
} else {
Log.w(TAG, "----fail-------");
}

setContentView(R.layout.main);
}
}

package xxxxxx.xxx;

/**
* This is a I2C operation class
*/
public class I2c {
/**
* @param nodeName
* node path name
* @return return file hander else return <0 on fail
*/
public native int open(String nodeName);

/**
* @param fileHander
* @param i2c_adr
* slave addr
* @param buf
* @param Lenth
* of buf
* @return read length
*/
public native int read(int fileHander, int i2c_adr, int buf[], int Length);

/**
* @param fileHander
* @param i2c_adr
* slave addr
* @param sub_adr
* sub addr
* @param buf
* @param Lenth
* of buf
* @return write length
*/
public native int write(int fileHander, int i2c_adr, int sub_adr,
int buf[], int Length);

public native void close(int fileHander);

static {
System.loadLibrary("test-i2c");
}
}

JNI部分的代码：
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class xxxxxx_xxx_I2c */
#include <stdio.h>
#include <android/log.h>
#include <fcntl.h>
#include <linux/i2c.h>
#include <memory.h>
#include <malloc.h>

#ifndef _Included_xxxxxx_xxx_I2c
#define _Included_xxxxxx_xxx_I2c
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: xxxxxx_xxx_I2c
* Method: open
* Signature: (Ljava/lang/String;)I
*/
JNIEXPORT jint JNICALL Java_xxxxxx_xxx_I2c_open
(JNIEnv *, jobject, jstring);

/*
* Class: xxxxxx_xxx_I2c
* Method: read
* Signature: (II[II)I
*/
JNIEXPORT jint JNICALL Java_xxxxxx_xxx_I2c_read
(JNIEnv *, jobject, jint, jint, jintArray, jint);

/*
* Class: xxxxxx_xxx_I2c
* Method: write
* Signature: (III[II)I
*/
JNIEXPORT jint JNICALL Java_xxxxxx_xxx_I2c_write
(JNIEnv *, jobject, jint, jint, jint, jintArray, jint);

/*
* Class: xxxxxx_xxx_I2c
* Method: close
* Signature: (I)V
*/
JNIEXPORT void JNICALL Java_xxxxxx_xxx_I2c_close
(JNIEnv *, jobject, jint);

#ifdef __cplusplus
}
#endif
#endif

#include "test-i2c.h"

#define LOG_TAG "i2c"
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS__)

JNIEXPORT jint JNICALL Java_xxxxxx_xxx_I2c_open
(JNIEnv *env, jobject obj, jstring file)
{
char fileName[64];
const jbyte *str;

str = (*env)->GetStringUTFChars(env, file, NULL);
if (str == NULL) {
LOGI("Can't get file name!");
return -1;
}
sprintf(fileName, "%s", str);
LOGI("will open i2c device node %s", fileName);
(*env)->ReleaseStringUTFChars(env, file, str);
return open(fileName, O_RDWR);
}

JNIEXPORT jint JNICALL Java_xxxxxx_xxx_I2c_read
(JNIEnv * env, jobject obj, jint fileHander, jint slaveAddr, jintArray bufArr, jint len)
{
jint *bufInt;
char *bufByte;
int res = 0, i = 0, j = 0;

if (len <= 0) {
LOGE("I2C: buf len <=0");
goto err0;
}

bufInt = (jint *) malloc(len * sizeof(int));
if (bufInt == 0) {
LOGE("I2C: nomem");
goto err0;
}
bufByte = (char*) malloc(len);
if (bufByte == 0) {
LOGE("I2C: nomem");
goto err1;
}

(*env)->GetIntArrayRegion(env, bufArr, 0, len, bufInt);

res = ioctl(fileHander, I2C_SLAVE, slaveAddr);
if (res != 0) {
LOGE("I2C: Can't set slave address");
goto err2;
}

memset(bufByte, '\0', len);
if ((j = read(fileHander, bufByte, len)) != len) {
LOGE("read fail in i2c read jni i = %d buf 4", i);
goto err2;
} else {
for (i = 0; i < j ; i++)
bufInt[i] = bufByte[i];
LOGI("return %d %d %d %d in i2c read jni", bufByte[0], bufByte[1], bufByte[2], bufByte[3]);
(*env)->SetIntArrayRegion(env, bufArr, 0, len, bufInt);
}

free(bufByte);
free(bufInt);

return j;

err2:
free(bufByte);
err1:
free(bufInt);
err0:
return -1;
}

JNIEXPORT jint JNICALL Java_xxxxxx_xxx_I2c_write
(JNIEnv *env, jobject obj, jint fileHander, jint slaveAddr, jint mode,
jintArray bufArr, jint len)
{
jint *bufInt;
char *bufByte;
int res = 0, i = 0, j = 0;

if (len <= 0) {
LOGE("I2C: buf len <=0");
goto err0;
}

bufInt = (jint *) malloc(len * sizeof(int));
if (bufInt == 0) {
LOGE("I2C: nomem");
goto err0;
}
bufByte = (char*) malloc(len + 1);
if (bufByte == 0) {
LOGE("I2C: nomem");
goto err1;
}

(*env)->GetIntArrayRegion(env, bufArr, 0, len, bufInt);
bufByte[0] = mode;
for (i = 0; i < len; i++)
bufByte[i + 1] = bufInt[i];

res = ioctl(fileHander, I2C_SLAVE, slaveAddr);
if (res != 0) {
LOGE("I2C: Can't set slave address");
goto err2;
}

if ((j = write(fileHander, bufByte, len + 1)) != len + 1) {
LOGE("write fail in i2c");
goto err2;
}

LOGI("I2C: write %d byte", j);
free(bufByte);
free(bufInt);

return j - 1;

err2:
free(bufByte);
err1:
free(bufInt);
err0:
return -1;
}

JNIEXPORT void JNICALL Java_xxxxxx_xxx_I2c_close
(JNIEnv *env, jobject obj, jint fileHander)
{
close(fileHander);
}

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