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#include "i2c.h"
#include "stm32.h"
#include "thread.h"
I2C* I2C::self;
template <>
void interrupt<Interrupt::I2C1_EV>() {
I2C::self->irq_ev();
}
template <>
void interrupt<Interrupt::I2C1_ER>() {
I2C::self->irq_er();
}
void I2C::irq_ev() {
uint32_t sr1 = I2C1.SR1;
uint32_t sr2 = I2C1.SR2;
// EV5, SB = 1: Start condition sent.
if(sr1 & 0x01) {
// Send address.
I2C1.DR = (addr << 1) | (writing ? 0 : 1);
}
// EV6, ADDR = 1: Address sent.
if(sr1 & 0x02) {
if(writing) {
I2C1.DR = *write_p++;
writing--;
} else {
if(reading > 1) {
I2C1.CR1 |= 0x400; // Set ACK.
} else {
I2C1.CR1 |= 0x200; // Set STOP.
}
}
}
// EV7, RxNE = 1: Receive buffer not empty.
if(sr1 & 0x40) {
*read_p++ = I2C1.DR;
reading--;
if(reading == 1) {
// Unset ACK, set STOP.
I2C1.CR1 = (I2C1.CR1 & ~0x400) | 0x200;
}
if(reading == 0) {
busy = 0;
}
}
//I2C1.CR1 &= ~0x400;
// EV8, TxE = 1, BTF = 0: Transmit buffer empty, still writing.
if(sr1 & 0x80 && !(sr1 & 0x04)) {
if(writing) {
// Send data.
I2C1.DR = *write_p++;
writing--;
} else {
// All data sent.
if(reading) {
// Send repeat start.
I2C1.CR1 |= 0x100;
} else {
// Send stop.
I2C1.CR1 |= 0x200;
busy = 0;
}
}
}
}
void I2C::irq_er() {
handle_error();
}
void I2C::handle_error() {
I2C1.SR1;
I2C1.SR2;
//while(1);
I2C1.CR1 |= 0x200;
busy = 0;
}
void I2C::enable() {
RCC.enable(RCC.I2C1);
asm volatile("nop");
I2C1.CR1 = 0x8000;
I2C1.CR1 = 0;
I2C1.CR2 = 0x700 | 36;
I2C1.TRISE = 37;
I2C1.CCR = 180;
Interrupt::enable(Interrupt::I2C1_EV);
Interrupt::enable(Interrupt::I2C1_ER);
I2C1.CR1 = 1;
}
void I2C::write_reg(uint8_t addr_, uint8_t reg, uint8_t data) {
addr = addr_;
writing = 2;
reading = 0;
volatile uint8_t buf[] = {reg, data};
write_p = buf;
busy = 1;
I2C1.CR1 |= 0x100;
while(busy) {
Thread::yield();
}
/*
while(!(I2C1.SR1 & 0x01)); // Wait for SB.
I2C1.DR = (addr << 1) | 0;
while (!(I2C1.SR1 & 0x02)); // Wait for ADDR.
I2C1.SR2;
I2C1.DR = reg;
while (!(I2C1.SR1 & 0x80)); // Wait for TxE.
I2C1.DR = data;
while (!(I2C1.SR1 & 0x04)); // Wait for BTF.
I2C1.CR1 |= 0x200;*/
}
void I2C::read_reg(uint8_t addr_, uint8_t reg, uint8_t len, uint8_t* buf) {
addr = addr_;
writing = 1;
reading = len;
write_p = ®
read_p = buf;
busy = 1;
I2C1.CR1 |= 0x100;
while(busy) {
Thread::yield();
}
/*
I2C1.CR1 |= 0x100;
while(!(I2C1.SR1 & 0x01)); // Wait for SB.
I2C1.DR = (addr << 1) | 0;
while (!(I2C1.SR1 & 0x02)); // Wait for ADDR.
I2C1.SR2;
I2C1.DR = reg;
while (!(I2C1.SR1 & 0x80)); // Wait for TxE.
I2C1.CR1 |= 0x100;
while(!(I2C1.SR1 & 0x01)); // Wait for SB.
I2C1.DR = (addr << 1) | 1;
while (!(I2C1.SR1 & 0x02)); // Wait for ADDR.
I2C1.SR2;
I2C1.CR1 |= 0x400; // Set ACK.
while(len) {
if(len == 3) {
while (!(I2C1.SR1 & 0x04)); // Wait for BTF.
I2C1.CR1 &= ~0x400; // Clear ACK.
*buf++ = I2C1.DR;
len--;
I2C1.CR1 |= 0x200; // Set STOP.
*buf++ = I2C1.DR;
len--;
} else {
while (!(I2C1.SR1 & 0x40)); // Wait for RxNE.
*buf++ = I2C1.DR;
len--;
}
}
*/
}
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