From ec15c42ab8f5919d62d563798c62e12bed9c843e Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Thu, 15 Nov 2018 15:37:32 +0100
Subject: arduino-nano: Add counter driver. Conflicts with timer_s=1 / loop=1

---
 include/arch/arduino-nano/driver/counter.h | 27 +++++++++++++++++++++++++++
 src/arch/arduino-nano-168/Makefile.inc     |  4 ++++
 src/arch/arduino-nano/Makefile.inc         |  4 ++++
 src/arch/arduino-nano/driver/counter.cc    | 10 ++++++++++
 4 files changed, 45 insertions(+)
 create mode 100644 include/arch/arduino-nano/driver/counter.h
 create mode 100644 src/arch/arduino-nano/driver/counter.cc

diff --git a/include/arch/arduino-nano/driver/counter.h b/include/arch/arduino-nano/driver/counter.h
new file mode 100644
index 0000000..d387a35
--- /dev/null
+++ b/include/arch/arduino-nano/driver/counter.h
@@ -0,0 +1,27 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+class Counter {
+	private:
+		Counter(const Counter &copy);
+
+	public:
+		uint8_t overflowed;
+
+		Counter() : overflowed(0) {}
+
+		inline void start() {
+			overflowed = 0;
+			TCNT1 = 0;
+			TCCR1A = 0;
+			TCCR1B = _BV(CS10);
+			TIMSK1 = _BV(TOIE1);
+		}
+
+		inline uint16_t stop() {
+			TCCR1B = 0;
+			return TCNT1;
+		}
+};
+
+extern Counter counter;
diff --git a/src/arch/arduino-nano-168/Makefile.inc b/src/arch/arduino-nano-168/Makefile.inc
index 2f501f6..61492db 100644
--- a/src/arch/arduino-nano-168/Makefile.inc
+++ b/src/arch/arduino-nano-168/Makefile.inc
@@ -40,6 +40,10 @@ ifneq ($(findstring timer,${arch_drivers}), )
 	CXX_TARGETS += src/arch/arduino-nano/driver/timer.cc
 endif
 
+ifneq ($(findstring counter,${arch_drivers}), )
+	CXX_TARGETS += src/arch/arduino-nano/driver/counter.cc
+endif
+
 ifeq (${cpu_freq}, 16000000)
 	uart_baud = 57600
 else ifeq (${cpu_freq}, 8000000)
diff --git a/src/arch/arduino-nano/Makefile.inc b/src/arch/arduino-nano/Makefile.inc
index 30d9638..8896681 100644
--- a/src/arch/arduino-nano/Makefile.inc
+++ b/src/arch/arduino-nano/Makefile.inc
@@ -40,6 +40,10 @@ ifneq ($(findstring timer,${arch_drivers}), )
 	CXX_TARGETS += src/arch/arduino-nano/driver/timer.cc
 endif
 
+ifneq ($(findstring counter,${arch_drivers}), )
+	CXX_TARGETS += src/arch/arduino-nano/driver/counter.cc
+endif
+
 ifeq (${cpu_freq}, 16000000)
 	uart_baud = 57600
 else ifeq (${cpu_freq}, 8000000)
diff --git a/src/arch/arduino-nano/driver/counter.cc b/src/arch/arduino-nano/driver/counter.cc
new file mode 100644
index 0000000..4e62983
--- /dev/null
+++ b/src/arch/arduino-nano/driver/counter.cc
@@ -0,0 +1,10 @@
+#include "driver/counter.h"
+
+Counter counter;
+
+ISR(TIMER1_OVF_vect)
+{
+	if (counter.overflowed < 255) {
+		counter.overflowed++;
+	}
+}
-- 
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