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#include "types.h"
#include "board.h"
#include "gpio.h"
#define I2C_DELAY 100
static void mi2c_delay()
{
int i;
for(i=0;i<I2C_DELAY;i++) asm volatile ("nop");
}
#define M_SDA_OUT(x) { gpio_out(GPIO_PIN_SDA_OUT, x); mi2c_delay(); }
#define M_SCL_OUT(x) { gpio_out(GPIO_PIN_SCL_OUT, x); mi2c_delay(); }
#define M_SDA_IN gpio_in(GPIO_PIN_SDA_IN)
void mi2c_start()
{
M_SDA_OUT(0);
M_SCL_OUT(0);
}
void mi2c_repeat_start()
{
M_SDA_OUT(1);
M_SCL_OUT(1);
M_SDA_OUT(0);
M_SCL_OUT(0);
}
void mi2c_stop()
{
M_SDA_OUT(0);
M_SCL_OUT(1);
M_SDA_OUT(1);
}
unsigned char mi2c_put_byte(unsigned char data)
{
char i;
unsigned char ack;
for (i=0;i<8;i++, data<<=1)
{
M_SDA_OUT(data&0x80);
M_SCL_OUT(1);
M_SCL_OUT(0);
}
M_SDA_OUT(1);
M_SCL_OUT(1);
ack = M_SDA_IN; /* ack: sda is pulled low ->success. */
M_SCL_OUT(0);
M_SDA_OUT(0);
return ack!=0;
}
void mi2c_get_byte(unsigned char *data)
{
int i;
unsigned char indata = 0;
/* assert: scl is low */
M_SCL_OUT(0);
for (i=0;i<8;i++)
{
M_SCL_OUT(1);
indata <<= 1;
if ( M_SDA_IN ) indata |= 0x01;
M_SCL_OUT(0);
}
M_SDA_OUT(1);
*data= indata;
}
void mi2c_init()
{
gpio_dir(GPIO_PIN_SDA_OUT, 1);
gpio_dir(GPIO_PIN_SCL_OUT, 1);
gpio_dir(GPIO_PIN_SDA_IN, 0);
M_SCL_OUT(1);
M_SDA_OUT(1);
}
void mi2c_scan()
{
int i;
for(i=0;i<0x80;i++)
{
mi2c_start();
mprintf("scan %d\n",i);
if(!mi2c_put_byte(i<<1)) mprintf("found : %x\n", i);
mi2c_stop();
}
}