第1课第4.4节_Android硬件访问服务编写HAL代码

#define LOG_TAG "LedService"

#include "jni.h"
#include "JNIHelp.h"
#include "android_runtime/AndroidRuntime.h"

#include <utils/misc.h>
#include <utils/Log.h>

#include <stdio.h>

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <hardware/led_hal.h>


namespace android
{

static led_device_t* led_device;

jint ledOpen(JNIEnv *env, jobject cls)
{
    jint err;
    hw_module_t* module;
    hw_device_t* device;

    ALOGI("native ledOpen ...");

    /* 1. hw_get_module */
    err = hw_get_module("led", (hw_module_t const**)&module);
    if (err == 0) {
        /* 2. get device : module->methods->open */
        err = module->methods->open(module, NULL, &device);
        if (err == 0) {
            /* 3. call led_open */
            led_device = (led_device_t *)device;
            return led_device->led_open(led_device);
        } else {
            return -1;
        }
    }
    
    return -1;    
}

void ledClose(JNIEnv *env, jobject cls)
{
    //ALOGI("native ledClose ...");
    //close(fd);
}


jint ledCtrl(JNIEnv *env, jobject cls, jint which, jint status)
{
    ALOGI("native ledCtrl %d, %d", which, status);
    return led_device->led_ctrl(led_device, which, status);
}


static const JNINativeMethod methods[] = {
    {"native_ledOpen", "()I", (void *)ledOpen},
    {"native_ledClose", "()V", (void *)ledClose},
    {"native_ledCtrl", "(II)I", (void *)ledCtrl},
};
    

int register_android_server_LedService(JNIEnv *env)
{
    return jniRegisterNativeMethods(env, "com/android/server/LedService",
            methods, NELEM(methods));
}

}

#define LOG_TAG "LedHal"


/* 1. 实现一个名为HMI的hw_module_t结构体 */

/* 2. 实现一个open函数, 它返回led_device_t结构体 */

/* 3. 实现led_device_t结构体 */

/* 参考 hardware\libhardware\modules\vibrator\vibrator.c
 */

#include <hardware/vibrator.h>
#include <hardware/hardware.h>

#include <cutils/log.h>

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include <hardware/led_hal.h>

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <utils/Log.h>


static int fd;


/** Close this device */
static int led_close(struct hw_device_t* device)
{
    close(fd);
    return 0;
}

static int led_open(struct led_device_t* dev)
{
    fd = open("/dev/leds", O_RDWR);
    ALOGI("led_open : %d", fd);
    if (fd >= 0)
        return 0;
    else
        return -1;
}

static int led_ctrl(struct led_device_t* dev, int which, int status)
{
    int ret = ioctl(fd, status, which);
    ALOGI("led_ctrl : %d, %d, %d", which, status, ret);
    return ret;
}




static struct led_device_t led_dev = {
    .common = {
        .tag   = HARDWARE_DEVICE_TAG,
        .close = led_close,
    },
    .led_open  = led_open,
    .led_ctrl  = led_ctrl,
};

static int led_device_open(const struct hw_module_t* module, const char* id,
        struct hw_device_t** device)
{
    *device = &led_dev;
    return 0;
}


static struct hw_module_methods_t led_module_methods = {
    .open = led_device_open,
};

struct hw_module_t HAL_MODULE_INFO_SYM = {
    .tag = HARDWARE_MODULE_TAG,
    .id = "led",
    .methods = &led_module_methods,
};

#ifndef ANDROID_LED_INTERFACE_H
#define ANDROID_LED_INTERFACE_H

#include <stdint.h>
#include <sys/cdefs.h>
#include <sys/types.h>

#include <hardware/hardware.h>

__BEGIN_DECLS

struct led_device_t {
    struct hw_device_t common;

    int (*led_open)(struct led_device_t* dev);
    int (*led_ctrl)(struct led_device_t* dev, int which, int status);
};


__END_DECLS

#endif  // ANDROID_LED_INTERFACE_H