From 60cb80bde54265e1fdf3cc8d21e74292d5f769db Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Mon, 15 Oct 2018 12:24:16 +0200
Subject: add timertest app, improve msp430 timer driver

---
 include/arch/msp430fr5969lp/driver/timer.h | 49 +++++++++++++++++++++++++-----
 src/app/timertest/Makefile.inc             |  3 ++
 src/app/timertest/main.cc                  | 43 ++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 7 deletions(-)
 create mode 100644 src/app/timertest/Makefile.inc
 create mode 100644 src/app/timertest/main.cc

diff --git a/include/arch/msp430fr5969lp/driver/timer.h b/include/arch/msp430fr5969lp/driver/timer.h
index 34feb12..9585a64 100644
--- a/include/arch/msp430fr5969lp/driver/timer.h
+++ b/include/arch/msp430fr5969lp/driver/timer.h
@@ -1,8 +1,21 @@
 #include <msp430.h>
+#include <stdint.h>
 
 #define ON_TIMER_INTERRUPT_head __attribute__((interrupt(TIMER0_A1_VECTOR))) __attribute__((wakeup)) void handle_timer0_overflow() { if (TA0IV == 0x0e) {
 #define ON_TIMER_INTERRUPT_tail } }
 
+#if F_CPU == 16000000UL
+#define _TA0_MAIN_DIV ID__8
+#elif F_CPU == 8000000UL
+#define _TA0_MAIN_DIV ID__4
+#elif F_CPU == 4000000UL
+#define _TA0_MAIN_DIV ID__2
+#elif F_CPU == 1000000UL
+#define _TA0_MAIN_DIV ID__1
+#else
+#error Unsupported F_CPU
+#endif
+
 class Timer {
 	private:
 		Timer(const Timer &copy);
@@ -10,19 +23,41 @@ class Timer {
 	public:
 		Timer() {}
 
+#if F_CPU == 1000000UL
+		inline void setup_khz(uint16_t const frequency) {
+			TA0CTL = TASSEL__SMCLK | ID__1 | MC__UP; // -> 1 MHz base
+			TA0EX0 = 0;
+			TA0CCR0 = 1000UL / frequency;
+			TA0CTL |= TACLR;
+		}
+
+		inline void setup_hz(uint16_t const frequency) { // 1 MHz base
+			if (frequency < 20) {
+				TA0CTL = TASSEL__SMCLK | ID__8 | MC__UP; // /8
+				TA0EX0 = 1; // /2 -> /16 -> 62500 Hz
+				TA0CCR0 = 62500UL / frequency;
+			} else {
+				TA0CTL = TASSEL__SMCLK | ID__1 | MC__UP;
+				TA0EX0 = 0;
+				TA0CCR0 = 1000000UL / frequency;
+			}
+			TA0CTL |= TACLR;
+		}
+#else
 		inline void setup_khz(uint16_t const frequency) {
-			TA0CTL = TASSEL__SMCLK | ID__8 | MC__UP;
-			TA0EX0 = 1;
-			TA0CCR0 = 1000 / frequency;
+			TA0CTL = TASSEL__SMCLK | _TA0_MAIN_DIV | MC__UP; // -> 2 MHz base
+			TA0EX0 = 0;
+			TA0CCR0 = 2000UL / frequency;
 			TA0CTL |= TACLR;
 		}
 
-		inline void setup_hz(uint16_t const frequency) {
-			TA0CTL = TASSEL__SMCLK | ID__8 | MC__UP;
-			TA0EX0 = 1;
-			TA0CCR0 = 1000000 / frequency;
+		inline void setup_hz(uint16_t const frequency) { // 2 MHz base
+			TA0CTL = TASSEL__SMCLK | _TA0_MAIN_DIV | MC__UP;
+			TA0EX0 = 0;
+			TA0CCR0 = 2000000UL / frequency;
 			TA0CTL |= TACLR;
 		}
+#endif
 
 		inline void start(unsigned char const interrupt) {
 			if (interrupt) {
diff --git a/src/app/timertest/Makefile.inc b/src/app/timertest/Makefile.inc
new file mode 100644
index 0000000..9d375f1
--- /dev/null
+++ b/src/app/timertest/Makefile.inc
@@ -0,0 +1,3 @@
+loop ?= 1
+timer_s ?= 1
+arch_drivers += ,timer
diff --git a/src/app/timertest/main.cc b/src/app/timertest/main.cc
new file mode 100644
index 0000000..23f0b60
--- /dev/null
+++ b/src/app/timertest/main.cc
@@ -0,0 +1,43 @@
+#include "arch.h"
+#include "driver/gpio.h"
+#include "driver/stdout.h"
+#include "driver/timer.h"
+#include "driver/uptime.h"
+
+#ifndef F_TIMER
+#define F_TIMER 100000
+#endif
+
+volatile unsigned long int timer_val = 0;
+
+void loop(void)
+{
+	gpio.led_toggle(1);
+	kout << "Actual frequency: approx. " << timer_val << " Hz" << endl;
+	timer_val = 0;
+}
+
+int main(void)
+{
+	arch.setup();
+	gpio.setup();
+	kout.setup();
+#if F_TIMER > 999
+	timer.setup_khz(F_TIMER / 1000);
+#else
+	timer.setup_hz(F_TIMER);
+#endif
+	timer.start(1);
+
+	gpio.led_on(0);
+	kout << "Timer running at " << dec << F_TIMER << " Hz" << endl;
+
+	arch.idle_loop();
+
+	return 0;
+}
+
+ON_TIMER_INTERRUPT_head
+	gpio.led_toggle(0);
+	timer_val++;
+ON_TIMER_INTERRUPT_tail
-- 
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