diff options
Diffstat (limited to 'platforms/avr/drivers/audio_pwm_hardware.c')
| -rw-r--r-- | platforms/avr/drivers/audio_pwm_hardware.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/platforms/avr/drivers/audio_pwm_hardware.c b/platforms/avr/drivers/audio_pwm_hardware.c new file mode 100644 index 0000000000..df03a4558c --- /dev/null +++ b/platforms/avr/drivers/audio_pwm_hardware.c @@ -0,0 +1,332 @@ +/* Copyright 2016 Jack Humbert + * Copyright 2020 JohSchneider + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#if defined(__AVR__) +# include <avr/pgmspace.h> +# include <avr/interrupt.h> +# include <avr/io.h> +#endif + +#include "audio.h" + +extern bool playing_note; +extern bool playing_melody; +extern uint8_t note_timbre; + +#define CPU_PRESCALER 8 + +/* + Audio Driver: PWM + + drive up to two speakers through the AVR PWM hardware-peripheral, using timer1 and/or timer3 on Atmega32U4. + + the primary channel_1 can be connected to either pin PC4 PC5 or PC6 (the later being used by most AVR based keyboards) with a PMW signal generated by timer3 + and an optional secondary channel_2 on either pin PB5, PB6 or PB7, with a PWM signal from timer1 + + alternatively, the PWM pins on PORTB can be used as only/primary speaker +*/ + +#if defined(AUDIO_PIN) && (AUDIO_PIN != C4) && (AUDIO_PIN != C5) && (AUDIO_PIN != C6) && (AUDIO_PIN != B5) && (AUDIO_PIN != B6) && (AUDIO_PIN != B7) && (AUDIO_PIN != D5) +# error "Audio feature enabled, but no suitable pin selected as AUDIO_PIN - see docs/feature_audio under the AVR settings for available options." +#endif + +#if (AUDIO_PIN == C4) || (AUDIO_PIN == C5) || (AUDIO_PIN == C6) +# define AUDIO1_PIN_SET +# define AUDIO1_TIMSKx TIMSK3 +# define AUDIO1_TCCRxA TCCR3A +# define AUDIO1_TCCRxB TCCR3B +# define AUDIO1_ICRx ICR3 +# define AUDIO1_WGMx0 WGM30 +# define AUDIO1_WGMx1 WGM31 +# define AUDIO1_WGMx2 WGM32 +# define AUDIO1_WGMx3 WGM33 +# define AUDIO1_CSx0 CS30 +# define AUDIO1_CSx1 CS31 +# define AUDIO1_CSx2 CS32 + +# if (AUDIO_PIN == C6) +# define AUDIO1_COMxy0 COM3A0 +# define AUDIO1_COMxy1 COM3A1 +# define AUDIO1_OCIExy OCIE3A +# define AUDIO1_OCRxy OCR3A +# define AUDIO1_PIN C6 +# define AUDIO1_TIMERx_COMPy_vect TIMER3_COMPA_vect +# elif (AUDIO_PIN == C5) +# define AUDIO1_COMxy0 COM3B0 +# define AUDIO1_COMxy1 COM3B1 +# define AUDIO1_OCIExy OCIE3B +# define AUDIO1_OCRxy OCR3B +# define AUDIO1_PIN C5 +# define AUDIO1_TIMERx_COMPy_vect TIMER3_COMPB_vect +# elif (AUDIO_PIN == C4) +# define AUDIO1_COMxy0 COM3C0 +# define AUDIO1_COMxy1 COM3C1 +# define AUDIO1_OCIExy OCIE3C +# define AUDIO1_OCRxy OCR3C +# define AUDIO1_PIN C4 +# define AUDIO1_TIMERx_COMPy_vect TIMER3_COMPC_vect +# endif +#endif + +#if defined(AUDIO_PIN) && defined(AUDIO_PIN_ALT) && (AUDIO_PIN == AUDIO_PIN_ALT) +# error "Audio feature: AUDIO_PIN and AUDIO_PIN_ALT on the same pin makes no sense." +#endif + +#if ((AUDIO_PIN == B5) && ((AUDIO_PIN_ALT == B6) || (AUDIO_PIN_ALT == B7))) || ((AUDIO_PIN == B6) && ((AUDIO_PIN_ALT == B5) || (AUDIO_PIN_ALT == B7))) || ((AUDIO_PIN == B7) && ((AUDIO_PIN_ALT == B5) || (AUDIO_PIN_ALT == B6))) +# error "Audio feature: PORTB as AUDIO_PIN and AUDIO_PIN_ALT at the same time is not supported." +#endif + +#if defined(AUDIO_PIN_ALT) && (AUDIO_PIN_ALT != B5) && (AUDIO_PIN_ALT != B6) && (AUDIO_PIN_ALT != B7) +# error "Audio feature: the pin selected as AUDIO_PIN_ALT is not supported." +#endif + +#if (AUDIO_PIN == B5) || (AUDIO_PIN == B6) || (AUDIO_PIN == B7) || (AUDIO_PIN_ALT == B5) || (AUDIO_PIN_ALT == B6) || (AUDIO_PIN_ALT == B7) || (AUDIO_PIN == D5) +# define AUDIO2_PIN_SET +# define AUDIO2_TIMSKx TIMSK1 +# define AUDIO2_TCCRxA TCCR1A +# define AUDIO2_TCCRxB TCCR1B +# define AUDIO2_ICRx ICR1 +# define AUDIO2_WGMx0 WGM10 +# define AUDIO2_WGMx1 WGM11 +# define AUDIO2_WGMx2 WGM12 +# define AUDIO2_WGMx3 WGM13 +# define AUDIO2_CSx0 CS10 +# define AUDIO2_CSx1 CS11 +# define AUDIO2_CSx2 CS12 + +# if (AUDIO_PIN == B5) || (AUDIO_PIN_ALT == B5) +# define AUDIO2_COMxy0 COM1A0 +# define AUDIO2_COMxy1 COM1A1 +# define AUDIO2_OCIExy OCIE1A +# define AUDIO2_OCRxy OCR1A +# define AUDIO2_PIN B5 +# define AUDIO2_TIMERx_COMPy_vect TIMER1_COMPA_vect +# elif (AUDIO_PIN == B6) || (AUDIO_PIN_ALT == B6) +# define AUDIO2_COMxy0 COM1B0 +# define AUDIO2_COMxy1 COM1B1 +# define AUDIO2_OCIExy OCIE1B +# define AUDIO2_OCRxy OCR1B +# define AUDIO2_PIN B6 +# define AUDIO2_TIMERx_COMPy_vect TIMER1_COMPB_vect +# elif (AUDIO_PIN == B7) || (AUDIO_PIN_ALT == B7) +# define AUDIO2_COMxy0 COM1C0 +# define AUDIO2_COMxy1 COM1C1 +# define AUDIO2_OCIExy OCIE1C +# define AUDIO2_OCRxy OCR1C +# define AUDIO2_PIN B7 +# define AUDIO2_TIMERx_COMPy_vect TIMER1_COMPC_vect +# elif (AUDIO_PIN == D5) && defined(__AVR_ATmega32A__) +# pragma message "Audio support for ATmega32A is experimental and can cause crashes." +# undef AUDIO2_TIMSKx +# define AUDIO2_TIMSKx TIMSK +# define AUDIO2_COMxy0 COM1A0 +# define AUDIO2_COMxy1 COM1A1 +# define AUDIO2_OCIExy OCIE1A +# define AUDIO2_OCRxy OCR1A +# define AUDIO2_PIN D5 +# define AUDIO2_TIMERx_COMPy_vect TIMER1_COMPA_vect +# endif +#endif + +// C6 seems to be the assumed default by many existing keyboard - but sill warn the user +#if !defined(AUDIO1_PIN_SET) && !defined(AUDIO2_PIN_SET) +# pragma message "Audio feature enabled, but no suitable pin selected - see docs/feature_audio under the AVR settings for available options. Don't expect to hear anything... :-)" +// TODO: make this an error - go through the breaking-change-process and change all keyboards to the new define +#endif +// ----------------------------------------------------------------------------- + +#ifdef AUDIO1_PIN_SET +static float channel_1_frequency = 0.0f; +void channel_1_set_frequency(float freq) { + if (freq == 0.0f) // a pause/rest is a valid "note" with freq=0 + { + // disable the output, but keep the pwm-ISR going (with the previous + // frequency) so the audio-state keeps getting updated + // Note: setting the duty-cycle 0 is not possible on non-inverting PWM mode - see the AVR data-sheet + AUDIO1_TCCRxA &= ~(_BV(AUDIO1_COMxy1) | _BV(AUDIO1_COMxy0)); + return; + } else { + AUDIO1_TCCRxA |= _BV(AUDIO1_COMxy1); // enable output, PWM mode + } + + channel_1_frequency = freq; + + // set pwm period + AUDIO1_ICRx = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER)); + // and duty cycle + AUDIO1_OCRxy = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre / 100); +} + +void channel_1_start(void) { + // enable timer-counter ISR + AUDIO1_TIMSKx |= _BV(AUDIO1_OCIExy); + // enable timer-counter output + AUDIO1_TCCRxA |= _BV(AUDIO1_COMxy1); +} + +void channel_1_stop(void) { + // disable timer-counter ISR + AUDIO1_TIMSKx &= ~_BV(AUDIO1_OCIExy); + // disable timer-counter output + AUDIO1_TCCRxA &= ~(_BV(AUDIO1_COMxy1) | _BV(AUDIO1_COMxy0)); +} +#endif + +#ifdef AUDIO2_PIN_SET +static float channel_2_frequency = 0.0f; +void channel_2_set_frequency(float freq) { + if (freq == 0.0f) { + AUDIO2_TCCRxA &= ~(_BV(AUDIO2_COMxy1) | _BV(AUDIO2_COMxy0)); + return; + } else { + AUDIO2_TCCRxA |= _BV(AUDIO2_COMxy1); + } + + channel_2_frequency = freq; + + AUDIO2_ICRx = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER)); + AUDIO2_OCRxy = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre / 100); +} + +float channel_2_get_frequency(void) { return channel_2_frequency; } + +void channel_2_start(void) { + AUDIO2_TIMSKx |= _BV(AUDIO2_OCIExy); + AUDIO2_TCCRxA |= _BV(AUDIO2_COMxy1); +} + +void channel_2_stop(void) { + AUDIO2_TIMSKx &= ~_BV(AUDIO2_OCIExy); + AUDIO2_TCCRxA &= ~(_BV(AUDIO2_COMxy1) | _BV(AUDIO2_COMxy0)); +} +#endif + +void audio_driver_initialize() { +#ifdef AUDIO1_PIN_SET + channel_1_stop(); + setPinOutput(AUDIO1_PIN); +#endif + +#ifdef AUDIO2_PIN_SET + channel_2_stop(); + setPinOutput(AUDIO2_PIN); +#endif + + // TCCR3A / TCCR3B: Timer/Counter #3 Control Registers TCCR3A/TCCR3B, TCCR1A/TCCR1B + // Compare Output Mode (COM3An and COM1An) = 0b00 = Normal port operation + // OC3A -- PC6 + // OC3B -- PC5 + // OC3C -- PC4 + // OC1A -- PB5 + // OC1B -- PB6 + // OC1C -- PB7 + + // Waveform Generation Mode (WGM3n) = 0b1110 = Fast PWM Mode 14. Period = ICR3, Duty Cycle OCR3A) + // OCR3A - PC6 + // OCR3B - PC5 + // OCR3C - PC4 + // OCR1A - PB5 + // OCR1B - PB6 + // OCR1C - PB7 + + // Clock Select (CS3n) = 0b010 = Clock / 8 +#ifdef AUDIO1_PIN_SET + // initialize timer-counter + AUDIO1_TCCRxA = (0 << AUDIO1_COMxy1) | (0 << AUDIO1_COMxy0) | (1 << AUDIO1_WGMx1) | (0 << AUDIO1_WGMx0); + AUDIO1_TCCRxB = (1 << AUDIO1_WGMx3) | (1 << AUDIO1_WGMx2) | (0 << AUDIO1_CSx2) | (1 << AUDIO1_CSx1) | (0 << AUDIO1_CSx0); +#endif + +#ifdef AUDIO2_PIN_SET + AUDIO2_TCCRxA = (0 << AUDIO2_COMxy1) | (0 << AUDIO2_COMxy0) | (1 << AUDIO2_WGMx1) | (0 << AUDIO2_WGMx0); + AUDIO2_TCCRxB = (1 << AUDIO2_WGMx3) | (1 << AUDIO2_WGMx2) | (0 << AUDIO2_CSx2) | (1 << AUDIO2_CSx1) | (0 << AUDIO2_CSx0); +#endif +} + +void audio_driver_stop() { +#ifdef AUDIO1_PIN_SET + channel_1_stop(); +#endif + +#ifdef AUDIO2_PIN_SET + channel_2_stop(); +#endif +} + +void audio_driver_start(void) { +#ifdef AUDIO1_PIN_SET + channel_1_start(); + if (playing_note) { + channel_1_set_frequency(audio_get_processed_frequency(0)); + } +#endif + +#if !defined(AUDIO1_PIN_SET) && defined(AUDIO2_PIN_SET) + channel_2_start(); + if (playing_note) { + channel_2_set_frequency(audio_get_processed_frequency(0)); + } +#endif +} + +static volatile uint32_t isr_counter = 0; +#ifdef AUDIO1_PIN_SET +ISR(AUDIO1_TIMERx_COMPy_vect) { + isr_counter++; + if (isr_counter < channel_1_frequency / (CPU_PRESCALER * 8)) return; + + isr_counter = 0; + bool state_changed = audio_update_state(); + + if (!playing_note && !playing_melody) { + channel_1_stop(); +# ifdef AUDIO2_PIN_SET + channel_2_stop(); +# endif + return; + } + + if (state_changed) { + channel_1_set_frequency(audio_get_processed_frequency(0)); +# ifdef AUDIO2_PIN_SET + if (audio_get_number_of_active_tones() > 1) { + channel_2_set_frequency(audio_get_processed_frequency(1)); + } else { + channel_2_stop(); + } +# endif + } +} +#endif + +#if !defined(AUDIO1_PIN_SET) && defined(AUDIO2_PIN_SET) +ISR(AUDIO2_TIMERx_COMPy_vect) { + isr_counter++; + if (isr_counter < channel_2_frequency / (CPU_PRESCALER * 8)) return; + + isr_counter = 0; + bool state_changed = audio_update_state(); + + if (!playing_note && !playing_melody) { + channel_2_stop(); + return; + } + + if (state_changed) { + channel_2_set_frequency(audio_get_processed_frequency(0)); + } +} +#endif |