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电梯直达

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发表于 2009-06-04 09:52 |只看该作者 |倒序浏览

#include <linux/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/delay.h>
#include <linux/fcntl.h>
#include <asm/uaccess.h>

#define uchar unsigned char

#define AUCUBA_GPIO_C_BASE (0xf60700000) //GPIO C Address Base

#define I2C_SDA (*(volatile unsigned short int *)(AUCUBA_GPIO_C_BASE+0x00

)    //GPIO_C1 SDA
#define I2C_SCL    (*(volatile unsigned short int *)(AUCUBA_GPIO_C_BASE+0x004))    //GPIO_C0 SCL
#define GPIODIR (*(volatile unsigned short int *)(AUCUBA_GPIO_C_BASE+0x400))    //GPIO direction
#define GPIOFUNCTION (*(volatile unsigned short int *)(AUCUBA_GPIO_C_BASE+0x420))    //GPIO Mode select
#define OUT_IN (GPIODIR |= 0x1)          //C1 input,C0 output
#define IN_OUT (GPIODIR |= 0x2)          //C1 output,C0 input
#define IN_IN      (GPIODIR |= 0x0)          //C1 ,C0 input

#define I2C_READ 0x01

static int major = 250;
char MU_name[] = "I2C_input";

#define SomeNOP() udelay(300);

/**//*-----------------------------------------------------------------------
----
调用方式：uchar I2CReceive(void)
函数说明：私有函数，I2C专用
------------------------------------------------------------------------------
---*/
unsigned char I2CReceiveByte(void)
{
uchar BitCnt;
uchar Retc;
uchar errtime;
uchar RSDA;
Retc=0x00;
GPIODIR |= 0x00;
GPIOFUNCTION &= ~0x00;
I2C_SCL = 0x0;
for(BitCnt=0;BitCnt<8;BitCnt++)
{
    Retc=Retc<<1;
    errtime=255;
    while(!I2C_SCL)
    {
errtime--;
   if(!errtime) return(0xff); /*超时返回*/
    }
    while(I2C_SCL)
    {
   RSDA=I2C_SDA;
   if(RSDA==1) Retc="Retc"+1;
   errtime=255;
   while(I2C_SCL)
   {
     errtime--;
   if(!errtime) return(0xff); /*超时返回*/
   }
       break;
   }
}
return(Retc);
}

//****************************************************
void ACK(void)
{

}

/**//*------------------------------------------------------------------------
----
调用方式：MU_ioctl()
函数说明：ioctl函数
----------------------------------------------------------------------------
---*/
static int MU_ioctl(struct inode *s_node,struct file *s_file,unsigned int cmd,unsigned long arg)
{
int retv;
unsigned char data;
switch(cmd)
   {
case I2C_READ:
//I2CInit();
//I2CStart();
data = I2CReceiveByte();
put_user(data,(unsigned long*)arg);
data = 0;
//printk(" \n",data);
break;

default:
      break;
   }
   return 0;
}

static struct file_operations mu_fops=
{
  ioctl : MU_ioctl
};

static int __init MUdrv_init_module(void)
{
  int retv;
  retv=register_chrdev(major,MU_name,&mu_fops);
  if(retv<0)
{
   printk("<1>register fail!\n"

;
   return retv;
}
  if(major==0)
   major=retv;
printk("major=%d\n",major);
printk("<1>hello MUdrv!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n"

;

return 0;
}

static void __exit MUdrv_cleanup(void)
{
int retv;
retv=unregister_chrdev(major,MU_name);
if(retv<0)
   {
      printk("<1>unreginster fail!\n"

;
return;
}
printk("<1>MUdrv:good_bye!\n"

;
}

module_init(MUdrv_init_module);
module_exit(MUdrv_cleanup);