各位大神，麻烦帮忙看一下如下程序，我在应用程序调用底层的open函数时，在jni那里老是open失败，字符设备已经注册进系统，相应的文件节点也有，就是fd返回老是-1，还请各位帮忙看一下

jni file:

/*

* Copyright (C) 2008 The Android Open Source Project

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

*      http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

#define LOG_TAG "HardControl hardcontrol.cpp"

#include

#include

#include

#include

#include

#include

#include

#include "jni.h"

jint fd;

jint ledOpen(JNIEnv *env, jobject cls)

{

ALOGI("jkk native ledOpen 1:%d",fd);

fd = open("/dev/leds_test", O_RDWR);

ALOGI("jkk native ledOpen 2:%d",fd);

if (fd >= 0)

return 0;

else{

ALOGI("jkk native ledOpen failed,fd=%d",fd);

return -1;

}

//    return 0;

}

jint ledClose(JNIEnv *env, jobject cls)

{

ALOGI("native ledClose ...");

return 0;

}

jint ledCtrl(JNIEnv *env, jobject cls, jint which, jint status)

{

int ret = ioctl(fd, status, which);

ALOGI("native ledCtrl: %d, %d, %d",which,status,ret);

return ret;

}

static const char *classPathName = "com/lenovo/hardlibrary/HardControl";

static JNINativeMethod methods[] = {

{"ledOpen", "()I", (void *)ledOpen},

{"ledClose", "()I", (void *)ledClose},

{"ledCtrl", "(II)I", (void *)ledCtrl},

};

/*

* Register several native methods for one class.

*/

static int registerNativeMethods(JNIEnv* env, const char* className,

JNINativeMethod* gMethods, int numMethods)

{

jclass clazz;

clazz = env->FindClass(className);

if (clazz == NULL) {

ALOGE("Native registration unable to find class '%s'", className);

return JNI_FALSE;

}

if (env->RegisterNatives(clazz, gMethods, numMethods) < 0) {

ALOGE("RegisterNatives failed for '%s'", className);

return JNI_FALSE;

}

return JNI_TRUE;

}

/*

* Register native methods for all classes we know about.

*

* returns JNI_TRUE on success.

*/

static int registerNatives(JNIEnv* env)

{

if (!registerNativeMethods(env, classPathName,

methods, sizeof(methods) / sizeof(methods[0]))) {

return JNI_FALSE;

}

return JNI_TRUE;

}

// ----------------------------------------------------------------------------

/*

* This is called by the VM when the shared library is first loaded.

*/

typedef union {

JNIEnv* env;

void* venv;

} UnionJNIEnvToVoid;

jint JNI_OnLoad(JavaVM* vm, void* reserved)

{

UnionJNIEnvToVoid uenv;

uenv.venv = NULL;

jint result = -1;

JNIEnv* env = NULL;

ALOGI("JNI_OnLoad");

if (vm->GetEnv(&uenv.venv, JNI_VERSION_1_4) != JNI_OK) {

ALOGE("ERROR: GetEnv failed");

goto bail;

}

env = uenv.env;

if (registerNatives(env) != JNI_TRUE) {

ALOGE("ERROR: registerNatives failed");

goto bail;

}

result = JNI_VERSION_1_4;

bail:

return result;

}

driver file:

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

static int major;

static struct class *cls;

//struct cdev *my_cdev;

static int led_open(struct inode * inode, struct file * file)

{

/*

int err;

err = gpio_request(0, "led1");

err = gpio_direction_output(0,1);

err = gpio_request(1, "led2");

err = gpio_direction_output(1,1);

err = gpio_request(2, "led3");

err = gpio_direction_output(2,1);

err = gpio_request(3, "led4");

err = gpio_direction_output(3,1);

*/

printk("jkk led_open.\n");

return 0;

}

static long led_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{

printk("jkk led_ioctl, %d,%lu.\n",cmd,arg);

return 0;

}

static struct file_operations leds_ops={

.owner = THIS_MODULE,

.open = led_open,

.unlocked_ioctl = led_ioctl,

};

int leds_init(void)

{

//   int err,devno = MKDEV(major,minor);

//    cdev_init(my_cdev,&leds_ops);

//    my_cdev->owner = THIS_MODULE;

//    my_cdev->ops = &leds_ops;

//    err = cdev_add(my_cdev,devno,1);

//    if(err)

//        printk("add failed,err=%d.\n",err);

printk("jkk leds_init.\n");

major = register_chrdev(0, "leds_test", &leds_ops);

printk("jkk leds_init  major=%d.\n",major);

cls = class_create(THIS_MODULE, "leds_test");

device_create(cls, NULL, MKDEV(major, 0), NULL, "leds_test"); /* /dev/leds_jkk */

return 0;

}

void leds_exit(void)

{

device_destroy(cls, MKDEV(major, 0));

class_destroy(cls);

unregister_chrdev(major, "leds_test");

}

module_init(leds_init);

module_exit(leds_exit);

MODULE_LICENSE("GPL");