1 files changed, 194 insertions, 0 deletions
diff --git a/hal/i2c.cpp b/hal/i2c.cpp
new file mode 100644
index 0000000..cee72ec
--- /dev/null
+++ b/hal/i2c.cpp
@@ -0,0 +1,194 @@
+#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;
+	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 = &reg;
+	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--;
+		}
+	}
+	*/
+}