标题: s3c2440之iic驱动程序编写（2） [打印本页]

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作者: yuyang911220    时间: 2015-2-26 15:12     标题: s3c2440之iic驱动程序编写（2）

read函数的实现：static
int read_iic(struct file*file,const
char __user *userbuf,size_t count,loff_t
*off)
{

int i;
        ack =
0;
        writel(0xa0,IIC_IICDS);
        writel(0xf0,IIC_IICSTAT);


        udelay(100);

while(ack ==
0);
        ack =
0;
        writel(0x00,IIC_IICDS);
        writel(0xaf,IIC_IICCON);
        udelay(100);

while(ack ==
0);
        ack =
0;
        writel(0xa1,IIC_IICDS);
        writel(0xb0,IIC_IICSTAT);


        writel(0xaf,IIC_IICCON);
        udelay(100);

for(i=0;i<5;i++)

{

while(ack ==
0);
                ack =
0;
                writel(0xaf,IIC_IICCON);
                udelay(100);


                ra_data=readl(IIC_IICDS);
                printk("ra_data=%x\n",ra_data);







}
        writel(0x90,IIC_IICSTAT);
        writel(0xaf,IIC_IICCON);
        udelay(100);

if(copy_to_user(userbuf,ra_data,count)!=0)

{
                printk("read is error!!\n");

return EFAULT;

};

return count;


}
中断的实现
/**********************中断实现**************************/
static
irqreturn_t iic_interrupt(int irq,void
*dev_id)
{
        ack =
1;

return IRQ_HANDLED;
}
/*********************************************************/
这时，驱动基本完成，再加上必要的头文件和寄存器地址的定义
#include<linux/delay.h>
#include<linux/pci.h>
#include<linux/poll.h>
#include<linux/interrupt.h>
#include<mach/regs-gpio.h>
#include<plat/regs-iic.h>


#define IICCON 0x54000000

#define IICSTAT 0x54000004
#define IICDS 0x5400000c

#define IICADD 0x54000008
#define IICLC 0x54000010

#define CLKCON 0x4c00000c

static
unsigned
long
*IIC_IICCON ;

static
unsigned
long
*IIC_IICSTAT;
static
unsigned
long
*IIC_IICDS ;

static
unsigned
long
*IIC_IICADD;
static
unsigned
long
*IIC_IICLC ;

static
unsigned
long
*IIC_CLKCON;

static
int wr_data[5];
static
int ra_data[5];
static
int ack =
0;
完成。下面编写应用程序进行测试
#include
<stdio.h>
#include
<stdlib.h>
#include
<unistd.h>

int main()
{

int fd;

int wr_data[5]={0,1,2,3,4};

int ra_data[5];
        fd = open("dev/iic0",O_RDWR);
        write(fd,wr_data,sizeof(wr_data));
        sleep(2);
        read(fd,ra_data,sizeof(ra_data));
}
首先写入5个数字，再将其读出。

测试正常。

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