atmega2560: add stdin driver

include/arch/atmega2560/driver/stdin.h

+/*
+ * Copyright 2021 Daniel Friesel
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+#ifndef STANDARDINPUT_H
+#define STANDARDINPUT_H
+
+class StandardInput {
+	private:
+		StandardInput(const StandardInput &copy);
+		static unsigned char const bufsize = 16;
+		char buffer[bufsize];
+		unsigned char write_pos, read_pos;
+
+	public:
+		StandardInput() : write_pos(0), read_pos(0) {}
+		void setup();
+		bool hasKey();
+		char getKey();
+
+		inline void addKey(char key) {
+			buffer[write_pos] = key;
+			write_pos = (write_pos + 1) % bufsize;
+		}
+};
+
+extern StandardInput kin;
+
+#endif

src/arch/atmega2560/Kconfig

@@ -2,7 +2,19 @@
 #
 # SPDX-License-Identifier: CC0-1.0
 
+config arch_atmega2560_driver_dmx
+bool "DMX"
+select meta_driver_dmx
+
 config arch_atmega2560_driver_i2c
 bool "I2C"
 select meta_driver_hardware_i2c
 select meta_driver_i2c
+
+config arch_atmega2560_driver_stdin
+bool "UART Input"
+select meta_driver_stdin
+
+config arch_atmega2560_driver_timer
+bool "Timer with Interrupts"
+select meta_driver_timer

src/arch/atmega2560/Makefile.inc

@@ -83,6 +83,10 @@ ifdef CONFIG_arch_atmega2560_driver_adc
 	CXX_TARGETS += src/arch/atmega2560/driver/adc.cc
 endif
 
+ifdef CONFIG_arch_atmega2560_driver_dmx
+	CXX_TARGETS += src/arch/atmega2560/driver/dmx.cc
+endif
+
 ifdef CONFIG_arch_atmega2560_driver_spi
 	CXX_TARGETS += src/arch/atmega2560/driver/spi.cc
 endif

src/arch/atmega2560/driver/stdin.cc

+/*
+ * Copyright 2020 Daniel Friesel
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+#include "driver/stdin.h"
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+void StandardInput::setup()
+{
+	UCSR0B |= _BV(RXCIE0);
+}
+
+bool StandardInput::hasKey()
+{
+	if (write_pos != read_pos) {
+		return true;
+	}
+	return false;
+}
+
+char StandardInput::getKey()
+{
+	char ret = buffer[read_pos++];
+	read_pos %= bufsize;
+	return ret;
+}
+
+StandardInput kin;
+
+ISR(USART0_RX_vect)
+{
+	kin.addKey(UDR0);
+}