From 972126fd2406030dbd3abd1a705bb0ae1af9abb3 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Fri, 15 Dec 2017 14:55:27 +0100
Subject: Add AVR (Arduino Nano) support

---
 src/arch/arduino-nano/Makefile.inc     | 40 +++++++++++++++++++++++
 src/arch/arduino-nano/arch.cc          | 58 ++++++++++++++++++++++++++++++++++
 src/arch/arduino-nano/driver/gpio.cc   | 24 ++++++++++++++
 src/arch/arduino-nano/driver/stdout.cc | 32 +++++++++++++++++++
 src/arch/arduino-nano/driver/uptime.cc |  3 ++
 5 files changed, 157 insertions(+)
 create mode 100644 src/arch/arduino-nano/Makefile.inc
 create mode 100644 src/arch/arduino-nano/arch.cc
 create mode 100644 src/arch/arduino-nano/driver/gpio.cc
 create mode 100644 src/arch/arduino-nano/driver/stdout.cc
 create mode 100644 src/arch/arduino-nano/driver/uptime.cc

(limited to 'src/arch')

diff --git a/src/arch/arduino-nano/Makefile.inc b/src/arch/arduino-nano/Makefile.inc
new file mode 100644
index 0000000..e8ecd82
--- /dev/null
+++ b/src/arch/arduino-nano/Makefile.inc
@@ -0,0 +1,40 @@
+# vim:ft=make
+
+MCU = atmega328p
+PROGRAMMER ?= usbasp
+
+INCLUDES += -Iinclude/arduino-nano
+COMMON_FLAGS += -mmcu=${MCU} -DF_CPU=16000000UL
+
+CC = avr-gcc
+CXX = avr-g++
+NM = avr-nm
+OBJCOPY = avr-objcopy
+OBJDUMP = avr-objdump
+
+TARGETS += src/arch/arduino-nano/arch.cc
+TARGETS += src/arch/arduino-nano/driver/gpio.cc
+TARGETS += src/arch/arduino-nano/driver/stdout.cc
+TARGETS += src/arch/arduino-nano/driver/uptime.cc
+
+OBJECTS = ${TARGETS:.cc=.o}
+
+.cc.o:
+	${CXX} ${INCLUDES} ${COMMON_FLAGS} ${CXXFLAGS} -c -o $@ ${@:.o=.cc}
+
+build/system.elf: ${OBJECTS}
+	${CXX} ${COMMON_FLAGS} ${CXXFLAGS} -Wl,--gc-sections -o $@ ${OBJECTS}
+
+build/system.hex: build/system.elf
+	${OBJCOPY} -O ihex ${@:.hex=.elf} $@
+
+program: build/system.hex
+	avrdude -p ${MCU} -c arduino -P /dev/ttyUSB0 -b 57600 -U flash:w:build/system.hex
+
+arch_clean:
+	rm -f ${OBJECTS} build/system.hex
+
+monitor:
+	screen /dev/ttyUSB0 115200
+
+.PHONY: arch_clean monitor program
diff --git a/src/arch/arduino-nano/arch.cc b/src/arch/arduino-nano/arch.cc
new file mode 100644
index 0000000..28fe34b
--- /dev/null
+++ b/src/arch/arduino-nano/arch.cc
@@ -0,0 +1,58 @@
+#include "arch.h"
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+void Arch::setup(void)
+{
+#ifdef TIMER_CYCLES
+	TCCR0A = 0;
+	TCCR0B = _BV(CS00);
+#endif
+
+#if defined(WITH_LOOP) || defined(TIMER_S)
+	TCCR1A = 0;
+	TCCR1B = _BV(WGM12) | _BV(CS12) | _BV(CS10); // /1024
+	OCR1A = 15625;
+	TIMSK1 = _BV(OCIE1A);
+#endif
+
+#ifdef TIMER_US
+	// 16MHz/8 -> 2MHz timer
+	TCCR2A = 0;
+	TCCR2B = _BV(CS21);
+#endif
+	sei();
+}
+
+#if defined(WITH_LOOP) || defined(TIMER_S)
+
+#include "driver/uptime.h"
+extern void loop();
+
+#endif
+
+void Arch::idle_loop(void)
+{
+	while (1) {
+		SMCR = _BV(SE);
+		asm("sleep");
+		SMCR = 0;
+		asm("wdr");
+#ifdef WITH_LOOP
+		loop();
+#endif
+#ifdef TIMER_S
+		uptime.tick_s();
+#endif
+	}
+}
+
+Arch arch;
+
+#if defined(WITH_LOOP) || defined(TIMER_S)
+
+ISR(TIMER1_COMPA_vect)
+{
+}
+
+#endif
diff --git a/src/arch/arduino-nano/driver/gpio.cc b/src/arch/arduino-nano/driver/gpio.cc
new file mode 100644
index 0000000..66e24db
--- /dev/null
+++ b/src/arch/arduino-nano/driver/gpio.cc
@@ -0,0 +1,24 @@
+#include "driver/gpio.h"
+#include <avr/io.h>
+
+void GPIO::setup()
+{
+	DDRB = _BV(PB5);
+}
+
+void GPIO::led_on(unsigned char id)
+{
+	PORTB |= _BV(PB5);
+}
+
+void GPIO::led_off(unsigned char id)
+{
+	PORTB &= ~_BV(PB5);
+}
+
+void GPIO::led_toggle(unsigned char id)
+{
+	PINB = _BV(PB5);
+}
+
+GPIO gpio;
diff --git a/src/arch/arduino-nano/driver/stdout.cc b/src/arch/arduino-nano/driver/stdout.cc
new file mode 100644
index 0000000..a3d905d
--- /dev/null
+++ b/src/arch/arduino-nano/driver/stdout.cc
@@ -0,0 +1,32 @@
+#include "driver/stdout.h"
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+#define BAUD 119200L
+#include <util/setbaud.h>
+
+void StandardOutput::setup()
+{
+	UBRR0H = UBRRH_VALUE;
+	UBRR0L = UBRRL_VALUE;
+
+#if USE_2X
+	UCSR0A |= _BV(U2X0);
+#else
+	UCSR0A &= ~_BV(U2X0);
+#endif
+
+	UCSR0B |= _BV(RXEN0) | _BV(TXEN0);
+	UCSR0C = _BV(UCSZ01) | _BV(UCSZ00);
+}
+
+void StandardOutput::put(char c)
+{
+	while (!(UCSR0A & _BV(UDRE0)));
+	UDR0 = c;
+	if (c == '\n') {
+		put('\r');
+	}
+}
+
+StandardOutput kout;
diff --git a/src/arch/arduino-nano/driver/uptime.cc b/src/arch/arduino-nano/driver/uptime.cc
new file mode 100644
index 0000000..388edb6
--- /dev/null
+++ b/src/arch/arduino-nano/driver/uptime.cc
@@ -0,0 +1,3 @@
+#include "driver/uptime.h"
+
+Uptime uptime;
-- 
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