From e1dbd13d34069f9ce95036180ad6db9c67d68217 Mon Sep 17 00:00:00 2001
From: Claudio Indellicati <c.indellicati@arduino.cc>
Date: Fri, 13 Mar 2015 19:30:41 +0100
Subject: [PATCH] Added first tone library implementation.
Interrupt based implementation that works on every pin.
---
cores/arduino/Tone.cpp | 173 ++++++++++++++++++++++++++++++++++++++++
cores/arduino/Tone.h | 12 ++-
cores/arduino/startup.c | 2 +-
3 files changed, 185 insertions(+), 2 deletions(-)
diff --git a/cores/arduino/Tone.cpp b/cores/arduino/Tone.cpp
index 91c95c88..739eab83 100644
--- a/cores/arduino/Tone.cpp
+++ b/cores/arduino/Tone.cpp
@@ -15,3 +15,176 @@
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
+
+#include "Tone.h"
+#include "variant.h"
+
+#define WAIT_TC16_REGS_SYNC(x) while(x->COUNT16.STATUS.bit.SYNCBUSY);
+
+uint32_t toneMaxFrequency = SystemCoreClock / 2;
+uint32_t lastOutputPin = 0xFFFFFFFF;
+
+volatile uint32_t *portToggleRegister;
+volatile uint32_t *portClearRegister;
+volatile uint32_t portBitMask;
+volatile int64_t toggleCount;
+volatile bool toneIsActive = false;
+
+#define TONE_TC TC5
+#define TONE_TC_IRQn TC5_IRQn
+#define TONE_TC_TOP 0xFFFF
+#define TONE_TC_CHANNEL 0
+
+static inline void resetTC (Tc* TCx)
+{
+ // Disable TCx
+ TCx->COUNT16.CTRLA.reg &= ~TC_CTRLA_ENABLE;
+ WAIT_TC16_REGS_SYNC(TCx)
+
+ // Reset TCx
+ TCx->COUNT16.CTRLA.reg = TC_CTRLA_SWRST;
+ WAIT_TC16_REGS_SYNC(TCx)
+ while (TCx->COUNT16.CTRLA.bit.SWRST);
+}
+
+void toneAccurateClock (uint32_t accurateSystemCoreClockFrequency)
+{
+ toneMaxFrequency = accurateSystemCoreClockFrequency / 2;
+}
+
+void tone (uint32_t outputPin, uint32_t frequency, uint32_t duration)
+{
+ if (toneIsActive && (outputPin != lastOutputPin))
+ noTone(lastOutputPin);
+
+ //
+ // Calculate best prescaler divider and comparator value for a 16 bit TC peripheral
+ //
+
+ uint32_t prescalerConfigBits;
+ uint32_t ccValue;
+
+ ccValue = toneMaxFrequency / frequency - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV1;
+
+ if (ccValue > TONE_TC_TOP)
+ {
+ ccValue = toneMaxFrequency / frequency / 2 - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV2;
+
+ if (ccValue > TONE_TC_TOP)
+ {
+ ccValue = toneMaxFrequency / frequency / 4 - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV4;
+
+ if (ccValue > TONE_TC_TOP)
+ {
+ ccValue = toneMaxFrequency / frequency / 8 - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV8;
+
+ if (ccValue > TONE_TC_TOP)
+ {
+ ccValue = toneMaxFrequency / frequency / 16 - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV16;
+
+ if (ccValue > TONE_TC_TOP)
+ {
+ ccValue = toneMaxFrequency / frequency / 64 - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV64;
+
+ if (ccValue > TONE_TC_TOP)
+ {
+ ccValue = toneMaxFrequency / frequency / 256 - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV256;
+
+ if (ccValue > TONE_TC_TOP)
+ {
+ ccValue = toneMaxFrequency / frequency / 1024 - 1;
+ prescalerConfigBits = TC_CTRLA_PRESCALER_DIV1024;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+ toggleCount = (duration > 0 ? frequency * duration * 2 / 1000UL : -1);
+
+ // Enable GCLK for TC4 and TC5 (timer counter input clock)
+ GCLK->CLKCTRL.reg = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0 | GCLK_CLKCTRL_ID(GCM_TC4_TC5));
+ while (GCLK->STATUS.bit.SYNCBUSY);
+
+ resetTC(TONE_TC);
+
+ // Set Timer counter Mode to 16 bits
+ TONE_TC->COUNT16.CTRLA.reg |= TC_CTRLA_MODE_COUNT16;
+
+ // Set TONE_TC mode as match frequency
+ TONE_TC->COUNT16.CTRLA.reg |= TC_CTRLA_WAVEGEN_MFRQ;
+
+ TONE_TC->COUNT16.CTRLA.reg |= prescalerConfigBits;
+
+ TONE_TC->COUNT16.CC[TONE_TC_CHANNEL].reg = (uint16_t) ccValue;
+ WAIT_TC16_REGS_SYNC(TONE_TC)
+
+ // Configure interrupt request
+ NVIC_DisableIRQ(TONE_TC_IRQn);
+ NVIC_ClearPendingIRQ(TONE_TC_IRQn);
+ NVIC_SetPriority(TONE_TC_IRQn, 0);
+ NVIC_EnableIRQ(TONE_TC_IRQn);
+
+ portToggleRegister = &(PORT->Group[g_APinDescription[outputPin].ulPort].OUTTGL.reg);
+ portClearRegister = &(PORT->Group[g_APinDescription[outputPin].ulPort].OUTCLR.reg);
+ portBitMask = (1ul << g_APinDescription[outputPin].ulPin);
+
+ // Enable the TONE_TC interrupt request
+ TONE_TC->COUNT16.INTENSET.bit.MC0 = 1;
+
+ lastOutputPin = outputPin;
+ digitalWrite(outputPin, LOW);
+ pinMode(outputPin, OUTPUT);
+ toneIsActive = true;
+
+ // Enable TONE_TC
+ TONE_TC->COUNT16.CTRLA.reg |= TC_CTRLA_ENABLE;
+ WAIT_TC16_REGS_SYNC(TONE_TC)
+}
+
+void noTone (uint32_t outputPin)
+{
+ resetTC(TONE_TC);
+ digitalWrite(outputPin, LOW);
+ toneIsActive = false;
+}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void Tone_Handler (void)
+{
+ if (toggleCount != 0)
+ {
+ // Toggle the ouput pin
+ *portToggleRegister = portBitMask;
+
+ if (toggleCount > 0)
+ --toggleCount;
+
+ // Clear the interrupt
+ TONE_TC->COUNT16.INTFLAG.bit.MC0 = 1;
+ }
+ else
+ {
+ resetTC(TONE_TC);
+ *portClearRegister = portBitMask;
+ toneIsActive = false;
+ }
+}
+
+void TC5_Handler (void) __attribute__ ((weak, alias("Tone_Handler")));
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/cores/arduino/Tone.h b/cores/arduino/Tone.h
index be29d3e2..af481631 100644
--- a/cores/arduino/Tone.h
+++ b/cores/arduino/Tone.h
@@ -1,5 +1,5 @@
/*
- Copyright (c) 2014 Arduino. All right reserved.
+ Copyright (c) 2015 Arduino. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
@@ -19,5 +19,15 @@
#ifndef _WIRING_TONE_
#define _WIRING_TONE_
+#ifdef __cplusplus
+
+#include "Arduino.h"
+
+void tone(uint32_t _pin, uint32_t frequency, uint32_t duration = 0);
+void noTone(uint32_t _pin);
+
+void toneAccurateClock (uint32_t);
+
+#endif /* __cplusplus */
#endif /* _WIRING_TONE_ */
diff --git a/cores/arduino/startup.c b/cores/arduino/startup.c
index 82e687fd..ef519302 100644
--- a/cores/arduino/startup.c
+++ b/cores/arduino/startup.c
@@ -93,7 +93,7 @@ void TCC1_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler
void TCC2_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler")));
void TC3_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler")));
void TC4_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler")));
-void TC5_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler")));
+void TC5_Handler ( void ) __attribute__ ((weak));
void TC6_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler")));
void TC7_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler")));
void ADC_Handler ( void ) __attribute__ ((weak, alias("Dummy_Handler")));
--
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