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// SPDX-License-Identifier: GPL-2.0-or-later
/****************************************************************************
File : i2c.cpp *
Contents : i2c bit-bang library *
Copyright 2023, Ahmed Errached BOUDJELIDA, NanoXplore SAS. *
<aboudjelida@nanoxplore.com> *
<ahmederrachedbjld@gmail.com> *
*****************************************************************************/
#include "i2c.h"
#include "io.h"
#include "delay.h"
#include "reg_ezusb.h"
void start_cd(void)
{
PIN_SDA = 0; //SDA = 1;
delay_us(1);
PIN_SCL = 0; //SCL = 1;
delay_us(1);
}
void repeated_start(void)
{
PIN_SDA = 1;
delay_us(1);
PIN_SCL = 1;
delay_us(1);
PIN_SDA = 0;
delay_us(1);
PIN_SCL = 0;
delay_us(1);
}
void stop_cd(void)
{
PIN_SDA = 0;
delay_us(1);
PIN_SCL = 1;
delay_us(1);
PIN_SDA = 1;
delay_us(1);
}
void clock_cd(void)
{
PIN_SCL = 1;
delay_us(1);
PIN_SCL = 0;
delay_us(1);
}
void send_ack(void)
{
PIN_SDA = 0;
delay_us(1);
PIN_SCL = 1;
delay_us(1);
PIN_SCL = 0;
delay_us(1);
}
void send_nack(void)
{
PIN_SDA = 1;
delay_us(1);
PIN_SCL = 1;
delay_us(1);
PIN_SCL = 0;
delay_us(1);
}
bool get_ack(void)
{
PIN_SDA_DIR = 1;
delay_us(1);
OED = 0xFE;
PIN_SCL = 1;
delay_us(1);
bool ack = PIN_SDA;
PIN_SCL = 0;
delay_us(1);
OED = 0xFF;
PIN_SDA_DIR = 0;
delay_us(1);
return ack;
}
/* here address(8 bits) = adr (7 bits) + type (1 bit) */
uint8_t get_address(uint8_t adr, uint8_t rdwr)
{
adr &= 0x7F;
adr = adr << 1;
adr |= (rdwr & 0x01);
return adr;
}
/* here send bit after bit and clocking scl with each bit */
void send_byte(uint8_t input)
{
for (uint8_t i = 0; i < 8; i++) {
if ((input & 0x80)) {
PIN_SDA = 1;
delay_us(1);
clock_cd();
} else {
PIN_SDA = 0;
delay_us(1);
clock_cd();
}
input = input << 1;
}
}
/* here receive bit after bit and clocking scl with each bit */
uint8_t receive_byte(void)
{
PIN_SDA_DIR = 1; //FX2 <-- FPGA
OED = 0xFE;
uint8_t input = 0x00;
for (uint8_t i = 0; i < 8; i++) {
PIN_SCL = 1;
delay_us(1);
input = input << 1;
if (PIN_SDA == 1)
input |= 0x01;
else
input |= 0X00;
PIN_SCL = 0;
delay_us(1);
}
OED = 0xFF;
PIN_SDA_DIR = 0;
return input;
}
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