unleashed-firmware/applications/external/wav_player/wav_player_hal.c

#include "wav_player_hal.h"
#include <stm32wbxx_ll_tim.h>
#include <stm32wbxx_ll_dma.h>

#include <stm32wbxx_ll_gpio.h>
#include <furi_hal.h>
#include <furi_hal_gpio.h>
#include <furi_hal_resources.h>

//#define FURI_HAL_SPEAKER_TIMER TIM16

#define FURI_HAL_SPEAKER_TIMER TIM16

#define SAMPLE_RATE_TIMER TIM2

#define FURI_HAL_SPEAKER_CHANNEL LL_TIM_CHANNEL_CH1
#define DMA_INSTANCE DMA1, LL_DMA_CHANNEL_1

void wav_player_speaker_init(uint32_t sample_rate) {
    // Enable bus
    furi_hal_bus_enable(FuriHalBusTIM2);

    LL_TIM_InitTypeDef TIM_InitStruct = {0};
    //TIM_InitStruct.Prescaler = 4;
    TIM_InitStruct.Prescaler = 1;
    TIM_InitStruct.Autoreload =
        255; //in this fork used purely as PWM timer, the DMA now is triggered by SAMPLE_RATE_TIMER
    LL_TIM_Init(FURI_HAL_SPEAKER_TIMER, &TIM_InitStruct);

    LL_TIM_OC_InitTypeDef TIM_OC_InitStruct = {0};
    TIM_OC_InitStruct.OCMode = LL_TIM_OCMODE_PWM1;
    TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_ENABLE;
    TIM_OC_InitStruct.CompareValue = 127;
    LL_TIM_OC_Init(FURI_HAL_SPEAKER_TIMER, FURI_HAL_SPEAKER_CHANNEL, &TIM_OC_InitStruct);

    //======================================================

    TIM_InitStruct.Prescaler = 0;
    //TIM_InitStruct.Autoreload = 1451; //64 000 000 / 1451 ~= 44100 Hz

    TIM_InitStruct.Autoreload = 64000000 / sample_rate - 1; //to support various sample rates

    LL_TIM_Init(SAMPLE_RATE_TIMER, &TIM_InitStruct);

    //LL_TIM_OC_InitTypeDef TIM_OC_InitStruct = {0};
    TIM_OC_InitStruct.OCMode = LL_TIM_OCMODE_PWM1;
    TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_ENABLE;
    TIM_OC_InitStruct.CompareValue = 127;
    LL_TIM_OC_Init(SAMPLE_RATE_TIMER, FURI_HAL_SPEAKER_CHANNEL, &TIM_OC_InitStruct);

    //=========================================================
    //configuring PA6 pin as TIM16 output

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

void wav_player_hal_deinit() {
    furi_hal_gpio_init(&gpio_ext_pa6, GpioModeAnalog, GpioPullNo, GpioSpeedLow);

    // Disable bus
    furi_hal_bus_disable(FuriHalBusTIM2);
}

void wav_player_speaker_start() {
    LL_TIM_EnableAllOutputs(FURI_HAL_SPEAKER_TIMER);
    LL_TIM_EnableCounter(FURI_HAL_SPEAKER_TIMER);

    LL_TIM_EnableAllOutputs(SAMPLE_RATE_TIMER);
    LL_TIM_EnableCounter(SAMPLE_RATE_TIMER);
}

void wav_player_speaker_stop() {
    LL_TIM_DisableAllOutputs(FURI_HAL_SPEAKER_TIMER);
    LL_TIM_DisableCounter(FURI_HAL_SPEAKER_TIMER);

    LL_TIM_DisableAllOutputs(SAMPLE_RATE_TIMER);
    LL_TIM_DisableCounter(SAMPLE_RATE_TIMER);
}

void wav_player_dma_init(uint32_t address, size_t size) {
    uint32_t dma_dst = (uint32_t) & (FURI_HAL_SPEAKER_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 wav_player_dma_start() {
    LL_DMA_EnableChannel(DMA_INSTANCE);
    LL_TIM_EnableDMAReq_UPDATE(SAMPLE_RATE_TIMER);
}

void wav_player_dma_stop() {
    LL_DMA_DisableChannel(DMA_INSTANCE);
}