msp430fr5969 counter: Track overflows

2 files changed, 18 insertions, 3 deletions

diff --git a/include/arch/msp430fr5969lp/driver/counter.h b/include/arch/msp430fr5969lp/driver/counter.h
index b95aba1..0d7e140 100644
--- a/include/arch/msp430fr5969lp/driver/counter.h
+++ b/include/arch/msp430fr5969lp/driver/counter.h
@@ -13,7 +13,7 @@ class Counter {
 
 	public:
 		uint16_t value;
-		uint8_t overflow;
+		volatile uint8_t overflow;
 
 		Counter() : overflow(0) {}
 
@@ -21,12 +21,16 @@ class Counter {
 			overflow = 0;
 			TA2CTL = TASSEL__SMCLK | ID__1 | MC__CONTINUOUS;
 			TA2EX0 = 0;
-			TA2CTL |= TACLR;
+			TA2CTL |= TACLR | TAIE;
+			asm volatile("nop");
+			__eint();
+			asm volatile("nop");
 		}
 
 		inline void stop() {
-			TA2CTL = 0;
+			__dint();
 			value = TA2R;
+			TA2CTL = 0;
 		}
 };
 
diff --git a/src/arch/msp430fr5969lp/driver/counter.cc b/src/arch/msp430fr5969lp/driver/counter.cc
index 62ac778..cd10b5c 100644
--- a/src/arch/msp430fr5969lp/driver/counter.cc
+++ b/src/arch/msp430fr5969lp/driver/counter.cc
@@ -1,7 +1,18 @@
+#include "arch.h"
 #include "driver/counter.h"
+#include "driver/gpio.h"
 
 #if defined(TIMER_CYCLES)
 #warn "timer_cycles and counter are mutually exclusive. Expect odd behaviour."
 #endif
 
 Counter counter;
+
+__attribute__((interrupt(TIMER2_A1_VECTOR))) void handle_timer2_overflow()
+{
+	if (TA2IV == 0x0e) {
+		if (counter.overflow < 255) {
+			counter.overflow++;
+		}
+	}
+}