linux gpio emulate i2c

/*

This is a program I wrote imitating someone else.

Just rewrite it into a program suitable for your own development board

*/

#include

#include

#include

#include

#define DEVICE_NAME "FINAL"

#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_OUTP

void 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 and;

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 alas;

I2C_SDA_Mode(1);//Add it yourself

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:%xn",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 alas;

printk("device_ID is:%xn",device_ID);

printk("address is:%xn",address);

printk("date is:%xn",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_Heat();

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:%xn",k);

return k;

break;

default :

return -SINGLE SELECT;

}

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"tinitializedn");

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");