S3C2440内核为2.6.24上写18B20驱动温度总是随机的 第3页

static int temp_open(struct inode * pnode, struct file * pfile)
{
    _io_gpjcon = (unsigned long*)ioremap(GPJCON,4);
    _io_gpjdat = (unsigned long*)ioremap(GPJDAT,4);
    _io_gpjup  = (unsigned long*)ioremap(GPJUP,4);

    printk("18b20 open\n");
   
    return 0;

}

static int temp_release(struct inode *pnode, struct file *pfile)
{
    printk("18b20 release\n");
    return 0;
}

module_init(temp_init);
module_exit(temp_exit);

////////////////////////////registerover/////////////////////////////////

void DQ_OUTP()//GPJCON为输出模式
{
    unsigned long temp;
    temp = *(unsigned long*)_io_gpjcon;
    temp &=(~0x3);
    temp |= 0x1;
    *(unsigned long*)_io_gpjcon = temp;
}

void DQ_INTP()//GPJCON为输入状态
{
    unsigned long temp;
    temp = *(unsigned long*)_io_gpjcon;
    temp &=(~0x3);
    *(unsigned long*)_io_gpjcon = temp;
}

void set_DQ(unsigned int flag)//设置GPJ0的高低电平
{
    unsigned long temp;
    temp = *(unsigned long*)_io_gpjdat;
    temp &= ~0x1;
    if(flag&0x1)
    temp |= 0x1;
   
    *(unsigned long*)_io_gpjdat = temp;
}

unsigned long get_DQ()//获得当前18B20的DQ状态
{
    unsigned long temp;
    temp = *(unsigned long*)_io_gpjdat;
    temp &=0x01;
    return temp;
}

/*
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