From 1f7bf6935e766ef95569c06befebbad384058f1f Mon Sep 17 00:00:00 2001
From: Stephen Crane <jscrane@gmail.com>
Date: Thu, 6 Sep 2018 10:12:03 +0100
Subject: [PATCH] sound uses timed

---
 sound.cpp |  9 ++-------
 timed.cpp | 19 +++++++------------
 timed.h   |  7 +------
 3 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/sound.cpp b/sound.cpp
index 36c0a80..87840c2 100644
--- a/sound.cpp
+++ b/sound.cpp
@@ -12,17 +12,15 @@ static dac_channel_t channel;
 
 static volatile const uint8_t *_bytes;
 static volatile unsigned _size, _off;
-static hw_timer_t *timer;
 
 void IRAM_ATTR timer_callback() {
 	portENTER_CRITICAL_ISR(&mux);
 
 	if (_off < _size)
 		dac_output_voltage(channel, _bytes[_off++]);
-	else {
+	else if (_bytes) {
 		_bytes = 0;
 		dac_output_disable(channel);
-		timerAlarmDisable(timer);
 	}
 
 	portEXIT_CRITICAL_ISR(&mux);
@@ -34,9 +32,7 @@ void Sound::begin(unsigned pin, unsigned freq) {
 	else if (pin == 26)
 		channel = DAC_CHANNEL_2;
 
-	timer = timerBegin(1, 80, true);
-	timerAttachInterrupt(timer, &timer_callback, true);
-	timerAlarmWrite(timer, 1000000 / freq, true);
+	timer_create(freq, &timer_callback);
 }
 
 const uint8_t *Sound::play(const uint8_t *bytes, unsigned size) {
@@ -48,7 +44,6 @@ const uint8_t *Sound::play(const uint8_t *bytes, unsigned size) {
 		_size = size;
 		_off = 0;
 		dac_output_enable(channel);
-		timerAlarmEnable(timer);
 		play = bytes;
 	}
 
diff --git a/timed.cpp b/timed.cpp
index 9bdd7ba..cae7409 100644
--- a/timed.cpp
+++ b/timed.cpp
@@ -9,17 +9,16 @@
 
 #include "timed.h"
 
-static Timed *t;
-
-// FIXME: disable timer when tick() returns false
 #if defined(__LM4F120H5QR__)
+static void (*client_handler)(void);
+
 static void timer0isr(void) {
 	ROM_TimerIntClear(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
-	t->tick();
+	client_handler();
 }
 
-void timer_create(unsigned freq, Timed *client) {
-	t = client;
+void timer_create(unsigned freq, void (*handler)(void)) {
+	client_handler = handler;
 	ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
 	ROM_TimerConfigure(TIMER0_BASE, TIMER_CFG_PERIODIC);
 	TimerIntRegister(TIMER0_BASE, TIMER_A, timer0isr);
@@ -30,13 +29,9 @@ void timer_create(unsigned freq, Timed *client) {
 }
 #elif defined(ESP_PLATFORM)
 
-void IRAM_ATTR onTimer() {
-	t->tick();
-}
-
-void timer_create(unsigned freq, Timed *client) {
+void timer_create(unsigned freq, void (*handler)(void)) {
 	hw_timer_t *timer = timerBegin(3, 80, true);	// prescaler of 80
-	timerAttachInterrupt(timer, &onTimer, true);
+	timerAttachInterrupt(timer, handler, true);
 	timerAlarmWrite(timer, 1000000 / freq, true);
 	timerAlarmEnable(timer);
 }
diff --git a/timed.h b/timed.h
index 2644af5..7059e4d 100644
--- a/timed.h
+++ b/timed.h
@@ -1,11 +1,6 @@
 #ifndef __TIMED_H__
 #define __TIMED_H__
 
-class Timed {
-public:
-	virtual bool tick() = 0;
-};
-
-void timer_create(unsigned freq, Timed *client);
+void timer_create(unsigned freq, void (*handler)(void));
 
 #endif