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bouwhuim.nikhef.nl dee2668a61 newest version WRPC
2013-09-10 08:08:59 +00:00

131 lines
2.4 KiB
C

/*
* This work is part of the White Rabbit project
*
* Copyright (C) 2011,2012 CERN (www.cern.ch)
* Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
* Author: Grzegorz Daniluk <grzegorz.daniluk@cern.ch>
*
* Released according to the GNU GPL, version 2 or any later version.
*/
#include "types.h"
#include "board.h"
#include "syscon.h"
#define I2C_DELAY 300
void mi2c_delay()
{
int i;
for (i = 0; i < I2C_DELAY; i++)
asm volatile ("nop");
}
#define M_SDA_OUT(i, x) { gpio_out(i2c_if[i].sda, x); mi2c_delay(); }
#define M_SCL_OUT(i, x) { gpio_out(i2c_if[i].scl, x); mi2c_delay(); }
#define M_SDA_IN(i) gpio_in(i2c_if[i].sda)
void mi2c_start(uint8_t i2cif)
{
M_SDA_OUT(i2cif, 0);
M_SCL_OUT(i2cif, 0);
}
void mi2c_repeat_start(uint8_t i2cif)
{
M_SDA_OUT(i2cif, 1);
M_SCL_OUT(i2cif, 1);
M_SDA_OUT(i2cif, 0);
M_SCL_OUT(i2cif, 0);
}
void mi2c_stop(uint8_t i2cif)
{
M_SDA_OUT(i2cif, 0);
M_SCL_OUT(i2cif, 1);
M_SDA_OUT(i2cif, 1);
}
unsigned char mi2c_put_byte(uint8_t i2cif, unsigned char data)
{
char i;
unsigned char ack;
for (i = 0; i < 8; i++, data <<= 1) {
M_SDA_OUT(i2cif, data & 0x80);
M_SCL_OUT(i2cif, 1);
M_SCL_OUT(i2cif, 0);
}
M_SDA_OUT(i2cif, 1);
M_SCL_OUT(i2cif, 1);
ack = M_SDA_IN(i2cif); /* ack: sda is pulled low ->success. */
M_SCL_OUT(i2cif, 0);
M_SDA_OUT(i2cif, 0);
return ack != 0;
}
void mi2c_get_byte(uint8_t i2cif, unsigned char *data, uint8_t last)
{
int i;
unsigned char indata = 0;
M_SDA_OUT(i2cif, 1);
/* assert: scl is low */
M_SCL_OUT(i2cif, 0);
for (i = 0; i < 8; i++) {
M_SCL_OUT(i2cif, 1);
indata <<= 1;
if (M_SDA_IN(i2cif))
indata |= 0x01;
M_SCL_OUT(i2cif, 0);
}
if (last) {
M_SDA_OUT(i2cif, 1); //noack
M_SCL_OUT(i2cif, 1);
M_SCL_OUT(i2cif, 0);
} else {
M_SDA_OUT(i2cif, 0); //ack
M_SCL_OUT(i2cif, 1);
M_SCL_OUT(i2cif, 0);
}
*data = indata;
}
void mi2c_init(uint8_t i2cif)
{
M_SCL_OUT(i2cif, 1);
M_SDA_OUT(i2cif, 1);
}
uint8_t mi2c_devprobe(uint8_t i2cif, uint8_t i2c_addr)
{
uint8_t ret;
mi2c_start(i2cif);
ret = !mi2c_put_byte(i2cif, i2c_addr << 1);
mi2c_stop(i2cif);
return ret;
}
//void mi2c_scan(uint8_t i2cif)
//{
// int i;
//
// //for(i=0;i<0x80;i++)
// for(i=0x50;i<0x51;i++)
// {
// mi2c_start(i2cif);
// if(!mi2c_put_byte(i2cif, i<<1)) mprintf("found : %x\n", i);
// mi2c_stop(i2cif);
//
// }
// mprintf("Nothing more found...\n");
//}