Initial import.

Most sources are split off from suzumebachi project revision 2fc77d2 as is with some path changes. New build rules introduced.

2 files changed, 75 insertions, 0 deletions

diff --git a/usart/usart.cpp b/usart/usart.cpp
new file mode 100644
index 0000000..61fe393
--- /dev/null
+++ b/usart/usart.cpp
@@ -0,0 +1,7 @@
+#include "usart.h"
+
+template<>
+void interrupt<Interrupt::USART1>() {
+	USART1.recv();
+	//GPIOB.ODR ^= 1 << 1;
+}
diff --git a/usart/usart.h b/usart/usart.h
new file mode 100644
index 0000000..38f1879
--- /dev/null
+++ b/usart/usart.h
@@ -0,0 +1,68 @@
+#ifndef USART_H
+#define USART_H
+
+#include <rcc/rcc.h>
+#include <interrupt/interrupt.h>
+#include <os/thread.h>
+
+struct USART_reg_t {
+	volatile uint32_t SR;
+	volatile uint32_t DR;
+	volatile uint32_t BRR;
+	volatile uint32_t CR1;
+	volatile uint32_t CR2;
+	volatile uint32_t CR3;
+	volatile uint32_t GTPR;
+};
+
+class USART_t {
+	public:
+		USART_reg_t& reg;
+		const uint32_t clk;
+		
+		USART_t(uint32_t reg_addr, uint32_t bus_clk) : reg(*(USART_reg_t*)reg_addr), clk(bus_clk) {}
+		
+		inline void set_baudrate(uint32_t baudrate) {
+			reg.BRR = clk / baudrate;
+		}
+		
+		inline void enable() {
+			reg.CR1 = 0x202c;
+		}
+		
+		inline void send(uint8_t data) {
+			while(!(reg.SR & 0x80)) {
+				Thread::yield();
+			} // Wait for TXE.
+			
+			reg.DR = data;
+		}
+		
+		inline uint8_t recv() {
+			return reg.DR;
+		}
+};
+
+#if defined(STM32F1)
+static USART_t USART1(0x40013800, 72000000);
+static USART_t USART2(0x40004400, 36000000);
+static USART_t USART3(0x40004800, 36000000);
+#elif defined(STM32F4)
+static USART_t USART1(0x40011000, 84000000);
+static USART_t USART2(0x40004400, 42000000);
+static USART_t USART3(0x40004800, 42000000);
+#endif
+
+inline void usart_enable() {
+	RCC.enable(RCC.USART1);
+	USART1.set_baudrate(115200);
+	USART1.enable();
+	
+	//Interrupt::enable(Interrupt::USART1);
+}
+
+inline void usart_send(uint8_t data) {
+	USART1.send(data);
+}
+
+#endif