linux gpio模拟i2c

  linux gpio模拟i2c 收藏/*这是我模仿其他人写的程序，仅仅是把他改写成适合自己开发板的程序*/#include <linux/miscdevice.h>#include <mach/regs-gpio.h>#include <mach/hardware.h>#include <linux/fs.h>#define  DEVICE_NAME  "FINALL"#define RETRY_TIMES  1#define GPIO_SCL  S3C2410_GPF3#define GPIO_SDA  S3C2410_GPF0#define GPIO_SDA_OUTP S3C2410_GPF0_OUTP#define GPIO_SDA_INP S3C2410_GPF0_INP#define GPIO_SCL_OUTP S3C2410_GPF3_OUTPvoid I2C_SCL_OUTP( void ){ s3c2410_gpio_cfgpin(GPIO_SCL,GPIO_SCL_OUTP);}void I2C_SDA_Mode(u8 v_mode){    if(v_mode)    {                                                        s3c2410_gpio_cfgpin(GPIO_SDA, GPIO_SDA_OUTP);       }    else    {        s3c2410_gpio_cfgpin(GPIO_SDA, GPIO_SDA_INP);       }}u8 I2C_SDA_Read(void){    return s3c2410_gpio_getpin(GPIO_SDA);  }void I2C_SDA_Output(u8 value){    if(value)    {                                                        s3c2410_gpio_setpin(GPIO_SDA,value);      }    else    {        s3c2410_gpio_setpin(GPIO_SDA,value );      }}void I2C_SCL_Output(u8 value){    if(value)    {                                                        s3c2410_gpio_setpin(GPIO_SCL,value);      }    else    {        s3c2410_gpio_setpin(GPIO_SCL,value );      }}//static u8 Flag_Timeout;void I2C_Init(void){  I2C_SDA_Output(1); I2C_SCL_Output(1);}void I2C_Wait(void){    u16 i;       for(i=0;i<0x1000;i++);     for(i=0;i<200;i++);}void I2C_Start(void) {    I2C_SDA_Output(1);    I2C_SCL_Output(1);    I2C_Wait();    I2C_SDA_Output(0);    I2C_Wait();    I2C_SCL_Output(0);}void I2C_Stop(void) {    I2C_SDA_Output(0);    I2C_Wait();    I2C_SCL_Output(1);    I2C_Wait();    I2C_SDA_Output(1);}u8 I2C_Send_Byte(u8 bytedata) {    u8 i;    u8 ack;  I2C_SDA_Mode(1);//自己添加  I2C_SCL_OUTP();        for (i = 0; i < 8; i++)          {              if (bytedata & 0x80)               {                     I2C_SDA_Output(1);              }              else              {                    I2C_SDA_Output(0);              }              bytedata <<= 1;              I2C_Wait();                            I2C_SCL_Output(1);              I2C_Wait();              I2C_SCL_Output(0);              I2C_Wait();        }                I2C_SDA_Output(1);         I2C_Wait();                I2C_SDA_Mode(0);         I2C_SCL_Output(1);         I2C_Wait();        s3c2410_gpio_setpin(GPIO_SDA,0);          ack = I2C_SDA_Read();          printk("ack is:%x\n",ack);        I2C_SDA_Mode(1);         I2C_SCL_Output(0);         I2C_Wait();                 return ack; }u8 I2C_Receive_Byte(void)  {    u8 i;    u8 bytedata = 0;    u8 temp;     I2C_SDA_Mode(0);     for ( i = 0; i < 8; i++)    {        I2C_SCL_Output(1);        I2C_Wait();        bytedata <<= 1;        temp = I2C_SDA_Read();         if (temp)          bytedata |= 0x01;                   I2C_SCL_Output(0);        I2C_Wait();    }    I2C_SDA_Mode(1);      return bytedata;}void Send_Ack(u8 ack) {    I2C_SDA_Output(ack);    I2C_SCL_Output(1);    I2C_Wait();    I2C_SCL_Output(0);}u8 I2C_Byte_Write(u8 device_ID,u8 address,u8 bytedata){       u8 ack;     printk("device_ID is:%x\n",device_ID);     printk("address is:%x\n",address); printk("date is:%x\n",bytedata);        I2C_Start();        ack = I2C_Send_Byte(device_ID);        if (ack)        {                I2C_Stop();                return 0;        }          ack = I2C_Send_Byte(address);        if (ack)        {                I2C_Stop();                return 0;        }        ack = I2C_Send_Byte(bytedata);        if (ack)        {                I2C_Stop();                return 0;        }                I2C_Stop();        I2C_Wait();    return ack;}u8 I2C_Byte_Read(u8 device_ID,u8 address){       u8 bytedata;    I2C_Start();    I2C_Send_Byte(device_ID);    I2C_Send_Byte(address);    I2C_Start();    I2C_Send_Byte(device_ID+1);    bytedata = I2C_Receive_Byte();    Send_Ack(1);    I2C_Stop();        return bytedata;}void I2C_Test(u8 device_ID,u8 address){ int i; I2C_Init();  I2C_Byte_Write(device_ID,address,0x54); for(i = 0; i < 50; i++);}static int s3c2410_i2c_ioctl(struct inode *inode,struct file *file,unsigned int cmd,unsigned long arg){ u8 k; switch(cmd)  {  case 0 :   I2C_Test(0xa0,0x00);   break;  case 1 :   k=I2C_Byte_Read(0xa0,0x00);   printk("k is:%x\n",k);   return k;   break;  default :   return -EINVAL;  } return 0;} static struct file_operations dev_fops={ .owner = THIS_MODULE, .ioctl = s3c2410_i2c_ioctl,};static struct miscdevice misc = { .minor = MISC_DYNAMIC_MINOR, .name = DEVICE_NAME, .fops = &dev_fops,};static int __init dev_init(void){ int ret; ret = misc_register(&misc); printk (DEVICE_NAME"\tinitialized\n"); return ret;}static void __exit dev_exit(void){ misc_deregister(&misc);}module_init(dev_init);module_exit(dev_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("WEI XIAO HUA");