feat: I2C drivers

app/src/main.c

@@ -1,7 +1,87 @@
 #include "main.h"
+#include "i2c.h"
 
+#include "stm32f411xe.h"
 #include "stm32f4xx_hal.h"
 #include "stm32f4xx_hal_gpio.h"
+#include "stm32f4xx_ll_i2c.h"
+
+#include "gen_wrapper.h"
+
+#include "circular_buffer.h"
+
+#define CIRC_BUF_SIZE (2*1024)
+CIRCULAR_BUFFER_ALL(circ_buff, uint8_t, CIRC_BUF_SIZE)
+
+static volatile circ_buff_t i2c_buf;
+
+void I2C1_EV_IRQHandler()
+{
+	if (!LL_I2C_IsActiveFlag_ADDR(I2C1))
+		Error_Handler();
+
+	//Skip checking matched addr (should only be one)
+	//Skip checking if receiving or transmitting (should always be false)
+	LL_I2C_ClearFlag_ADDR(I2C1);
+
+	//Allow buffer to grow until full
+	while (i2c_buf.count < _CB_COUNT(&i2c_buf))
+	{
+		//Wait for data or stop flag
+		while (!LL_I2C_IsActiveFlag_STOP(I2C1) && !LL_I2C_IsActiveFlag_RXNE(I2C1));
+
+		if (LL_I2C_IsActiveFlag_STOP(I2C1))
+		{
+			LL_I2C_ClearFlag_STOP(I2C1);
+			break;
+		}
+		else //Data received
+		{
+			uint8_t data = LL_I2C_ReceiveData8(I2C1);
+			circ_buff_append_range(&i2c_buf, &data, 1);
+		}
+	}
+
+	//Overflow or stop condition reached
+	if (i2c_buf.count >= _CB_COUNT(&i2c_buf))
+		Error_Handler();
+}
+
+bool I2C1_transmit_master(uint8_t addr, uint8_t *buf, uint8_t count)
+{
+	while (LL_I2C_IsActiveFlag_BUSY(I2C1));
+
+	//Transmit start
+	LL_I2C_GenerateStartCondition(I2C1);
+	while (!LL_I2C_IsActiveFlag_SB(I2C1));
+
+	//Transmit address + write
+	LL_I2C_TransmitData8(I2C1, addr << 1);
+	while (!LL_I2C_IsActiveFlag_ADDR(I2C1));
+	LL_I2C_ClearFlag_ADDR(I2C1);
+
+	for (int i = 0; i < count; ++i)
+	{
+		while (!LL_I2C_IsActiveFlag_TXE(I2C1));
+
+		if (LL_I2C_IsActiveFlag_AF(I2C1))
+		{
+			//REVIEW: Anything else neeeded?
+			LL_I2C_Disable(I2C1);
+			LL_I2C_Enable(I2C1);
+			return false;
+		}
+
+		LL_I2C_TransmitData8(I2C1, buf[i]);
+	}
+
+	LL_I2C_GenerateStopCondition(I2C1);
+	while (LL_I2C_IsActiveFlag_STOP(I2C1));
+
+	LL_I2C_Disable(I2C1);
+	LL_I2C_Enable(I2C1);
+	return true;
+}
 
 int my_main()
 {