sl-firmware
c3ada4a156
Add I2S3/DMA audio output driver for MAX98357A/PCM5102A class-D amps: - audio_init(): PLLI2S N=192/R=2 → 96 MHz → FS≈22058 Hz (<0.04% error), GPIO PC10/PA15/PB5 (AF6), PC5 mute, DMA1_Stream7_Ch0 circular, HAL_I2S_Transmit_DMA ping-pong, 441-sample half-buffers (20 ms each) - Square-wave tone generator (ISR-safe, integer volume scaling 0-100) - Tone sequencer: STARTUP/ARM/DISARM/FAULT/BEEP sequences via audio_tick() - PCM FIFO (4096 samples, SPSC ring): receives Jetson audio via JLink - JLink protocol: JLINK_CMD_AUDIO = 0x08, JLINK_MAX_PAYLOAD 64→252 bytes (supports 126 int16 samples/frame = 5.7 ms @22050 Hz) - main.c: audio_init(), STARTUP tone on boot, ARM/FAULT tones, audio_tick() - config.h: AUDIO_BCLK/LRCK/DOUT/MUTE pin defines + PLLI2S constants - test_audio.py: 45 tests, all passing Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
107 lines
3.4 KiB
C
107 lines
3.4 KiB
C
#ifndef AUDIO_H
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#define AUDIO_H
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#include <stdint.h>
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#include <stdbool.h>
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/*
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* audio.h — I2S audio output driver (Issue #143)
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*
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* Hardware: SPI3 repurposed as I2S3 master TX (blackbox flash not used
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* on balance bot). Supports MAX98357A (I2S class-D amp) and PCM5102A
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* (I2S DAC + external amp) — both use standard Philips I2S.
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*
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* Pin assignment (SPI3 / I2S3, defined in config.h):
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* PC10 I2S3_CK (BCLK) AF6
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* PA15 I2S3_WS (LRCLK) AF6
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* PB5 I2S3_SD (DIN) AF6
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* PC5 AUDIO_MUTE (GPIO) active-high = enabled; low = muted/shutdown
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*
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* PLLI2S: N=192, R=2 → 96 MHz I2S clock → 22058 Hz (< 0.04% from 22050)
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* DMA1 Stream7 Channel0 (SPI3_TX), circular, double-buffer ping-pong.
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*
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* Mixer priority (highest to lowest):
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* 1. PCM audio chunks from Jetson (via JLINK_CMD_AUDIO, written to FIFO)
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* 2. Notification tones (queued by audio_play_tone)
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* 3. Silence
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*
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* Volume applies to all sources via integer sample scaling (0–100).
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*/
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/* Maximum int16_t samples per JLINK_CMD_AUDIO frame (252-byte payload / 2) */
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#define AUDIO_CHUNK_MAX_SAMPLES 126u
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/* Pre-defined notification tones */
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typedef enum {
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AUDIO_TONE_BEEP_SHORT = 0, /* 880 Hz, 100 ms — acknowledge / UI feedback */
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AUDIO_TONE_BEEP_LONG = 1, /* 880 Hz, 500 ms — generic warning */
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AUDIO_TONE_STARTUP = 2, /* C5→E5→G5 arpeggio (3 × 120 ms) */
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AUDIO_TONE_ARM = 3, /* 880 Hz→1047 Hz two-beep ascending */
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AUDIO_TONE_DISARM = 4, /* 880 Hz→659 Hz two-beep descending */
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AUDIO_TONE_FAULT = 5, /* 200 Hz buzz, 500 ms — tilt/safety fault */
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AUDIO_TONE_COUNT
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} AudioTone;
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/*
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* audio_init()
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*
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* Configure PLLI2S, GPIO, DMA1 Stream7, and SPI3/I2S3.
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* Pre-fills DMA buffer with silence, starts circular DMA TX, then
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* unmutes the amp. Call once before safety_init().
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*/
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void audio_init(void);
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/*
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* audio_mute(mute)
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*
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* Drive AUDIO_MUTE_PIN: false = hardware-muted (SD/XSMT low),
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* true = active (amp enabled). Does NOT stop DMA; allows instant
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* un-mute without DMA restart clicks.
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*/
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void audio_mute(bool active);
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/*
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* audio_set_volume(vol)
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*
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* Software volume 0–100. Applied in ISR fill path via integer scaling.
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* 0 = silence, 100 = full scale (±16384 for square wave, passthrough for PCM).
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*/
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void audio_set_volume(uint8_t vol);
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/*
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* audio_play_tone(tone)
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*
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* Queue a pre-defined notification tone. The tone plays after any tones
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* already in the queue. Returns false if the tone queue is full (depth 4).
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* Tones are pre-empted by incoming PCM audio from the Jetson.
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*/
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bool audio_play_tone(AudioTone tone);
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/*
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* audio_write_pcm(samples, n)
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*
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* Write mono 16-bit 22050 Hz PCM samples into the Jetson PCM FIFO.
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* Called from jlink_process() dispatch on JLINK_CMD_AUDIO (main-loop context).
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* Returns the number of samples actually accepted (0 if FIFO is full).
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*/
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uint16_t audio_write_pcm(const int16_t *samples, uint16_t n);
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/*
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* audio_tick(now_ms)
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*
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* Advance the tone sequencer state machine. Must be called every 1 ms
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* from the main loop. Manages step transitions and gap timing; updates
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* the volatile active-tone parameters read by the ISR fill path.
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*/
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void audio_tick(uint32_t now_ms);
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/*
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* audio_is_playing()
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*
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* Returns true if the DMA is running (always true after audio_init()
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* unless the amp is hardware-muted or the I2S peripheral has an error).
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*/
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bool audio_is_playing(void);
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#endif /* AUDIO_H */
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