Momentum-Apps/flizzer_tracker_hal.c

#include "flizzer_tracker_hal.h"
#include "flizzer_tracker.h"

#define SPEAKER_PWM_TIMER TIM16
#define SAMPLE_RATE_TIMER TIM2
#define TRACKER_ENGINE_TIMER TIM1

#define SPEAKER_PWM_TIMER_CHANNEL LL_TIM_CHANNEL_CH1

#define TIMER_BASE_CLOCK 64000000 /* CPU frequency, 64 MHz */

#define DMA_INSTANCE DMA1, LL_DMA_CHANNEL_1

void sound_engine_dma_isr(void* ctx)
{
	SoundEngine* sound_engine = (SoundEngine*)ctx;

	// half of transfer
	if(LL_DMA_IsActiveFlag_HT1(DMA1))
	{
		LL_DMA_ClearFlag_HT1(DMA1);
		// fill first half of buffer
		uint16_t* audio_buffer = sound_engine->audio_buffer;
		uint32_t audio_buffer_length = sound_engine->audio_buffer_size / 2;
		sound_engine_fill_buffer(sound_engine, audio_buffer, audio_buffer_length);
	}

	// transfer complete
	if(LL_DMA_IsActiveFlag_TC1(DMA1))
	{
		LL_DMA_ClearFlag_TC1(DMA1);
		// fill second half of buffer
		uint32_t audio_buffer_length = sound_engine->audio_buffer_size / 2;
		uint16_t* audio_buffer = &sound_engine->audio_buffer[audio_buffer_length];
		sound_engine_fill_buffer(sound_engine, audio_buffer, audio_buffer_length);
	}
}

void sound_engine_PWM_timer_init(bool external_audio_output) //external audio on pin PA6
{
	LL_TIM_InitTypeDef TIM_InitStruct = {0};
	LL_TIM_OC_InitTypeDef TIM_OC_InitStruct = {0};

	TIM_InitStruct.Prescaler = 0;
	TIM_InitStruct.Autoreload = 1023; //10-bit PWM resolution at around 60 kHz PWM rate
	TIM_InitStruct.CounterMode = LL_TIM_COUNTERMODE_UP;
	LL_TIM_Init(SPEAKER_PWM_TIMER, &TIM_InitStruct);

	TIM_OC_InitStruct.OCMode = LL_TIM_OCMODE_PWM1;
	TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_ENABLE;
	TIM_OC_InitStruct.CompareValue = 0;
	LL_TIM_OC_Init(SPEAKER_PWM_TIMER, SPEAKER_PWM_TIMER_CHANNEL, &TIM_OC_InitStruct);

	if(external_audio_output)
	{
		furi_hal_gpio_init_ex(&gpio_ext_pa6, GpioModeAltFunctionPushPull, GpioPullNo, GpioSpeedVeryHigh, GpioAltFn14TIM16);
	}

	else
	{
		bool unu = furi_hal_speaker_acquire(1000);
		UNUSED(unu);
	}
}

void sound_engine_timer_init(uint32_t sample_rate) //external audio on pin PA6
{
	LL_TIM_InitTypeDef TIM_InitStruct = {0};
	LL_TIM_OC_InitTypeDef TIM_OC_InitStruct = {0};

	TIM_InitStruct.Prescaler = 0;
	TIM_InitStruct.Autoreload = TIMER_BASE_CLOCK / sample_rate; //to support various sample rates
	TIM_InitStruct.CounterMode = LL_TIM_COUNTERMODE_UP;
	LL_TIM_Init(SAMPLE_RATE_TIMER, &TIM_InitStruct);

	TIM_OC_InitStruct.OCMode = LL_TIM_OCMODE_PWM1;
	TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_ENABLE;
	LL_TIM_OC_Init(SAMPLE_RATE_TIMER, SPEAKER_PWM_TIMER_CHANNEL, &TIM_OC_InitStruct);
}

void sound_engine_dma_init(uint32_t address, uint32_t size)
{
	uint32_t dma_dst = (uint32_t) & (SPEAKER_PWM_TIMER->CCR1);

	LL_DMA_ConfigAddresses(DMA_INSTANCE, address, dma_dst, LL_DMA_DIRECTION_MEMORY_TO_PERIPH);
	LL_DMA_SetDataLength(DMA_INSTANCE, size);

	LL_DMA_SetPeriphRequest(DMA_INSTANCE, LL_DMAMUX_REQ_TIM2_UP);
	LL_DMA_SetDataTransferDirection(DMA_INSTANCE, LL_DMA_DIRECTION_MEMORY_TO_PERIPH);
	LL_DMA_SetChannelPriorityLevel(DMA_INSTANCE, LL_DMA_PRIORITY_VERYHIGH);
	LL_DMA_SetMode(DMA_INSTANCE, LL_DMA_MODE_CIRCULAR);
	LL_DMA_SetPeriphIncMode(DMA_INSTANCE, LL_DMA_PERIPH_NOINCREMENT);
	LL_DMA_SetMemoryIncMode(DMA_INSTANCE, LL_DMA_MEMORY_INCREMENT);
	LL_DMA_SetPeriphSize(DMA_INSTANCE, LL_DMA_PDATAALIGN_HALFWORD);
	LL_DMA_SetMemorySize(DMA_INSTANCE, LL_DMA_MDATAALIGN_HALFWORD);

	LL_DMA_EnableIT_TC(DMA_INSTANCE);
	LL_DMA_EnableIT_HT(DMA_INSTANCE);
}

void sound_engine_init_hardware(uint32_t sample_rate, bool external_audio_output, uint16_t* audio_buffer, uint32_t audio_buffer_size)
{
	sound_engine_dma_init((uint32_t)audio_buffer, audio_buffer_size);
	sound_engine_timer_init(sample_rate);
	sound_engine_PWM_timer_init(external_audio_output);
}

void sound_engine_dma_start()
{
	LL_DMA_EnableChannel(DMA_INSTANCE);
	LL_TIM_EnableDMAReq_UPDATE(SAMPLE_RATE_TIMER);
}

void sound_engine_dma_stop()
{
	LL_DMA_DisableChannel(DMA_INSTANCE);
}

void sound_engine_start()
{
	LL_TIM_EnableAllOutputs(SAMPLE_RATE_TIMER);
	LL_TIM_EnableCounter(SAMPLE_RATE_TIMER);

	LL_TIM_EnableAllOutputs(SPEAKER_PWM_TIMER);
	LL_TIM_EnableCounter(SPEAKER_PWM_TIMER);

	sound_engine_dma_start();
}

void sound_engine_stop()
{
	LL_TIM_DisableAllOutputs(SAMPLE_RATE_TIMER);
	LL_TIM_DisableCounter(SAMPLE_RATE_TIMER);

	LL_TIM_DisableAllOutputs(SPEAKER_PWM_TIMER);
	LL_TIM_DisableCounter(SPEAKER_PWM_TIMER);

	sound_engine_dma_stop();
}