USBAudioHostESP32.h

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#pragma once
#include <Arduino.h>
 
#if !(CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3 || \
      CONFIG_IDF_TARGET_ESP32P4)
#error "USB Audio Host needs an ESP32 with USB-OTG (S2/S3/P4); for a MAX3421E define USE_TINYUSB to use the Adafruit TinyUSB host stack"
#endif
 
#if !__has_include("usb/usb_host.h")
#error "USB Audio Host: the ESP-IDF usb_host library is not available"
#endif
 
#include "AudioTools/Communication/USB/USBAudioHostBackendESP32.h"
#include "AudioTools/Communication/USB/USBAudioHostBase.h"
#include "AudioTools/Concurrency/RTOS/BufferRTOS.h"
#include "AudioTools/Concurrency/RTOS/Task.h"
 
namespace audio_tools {
 
class USBAudioHostESP32 : public USBAudioHostBase {
 public:
  USBAudioHostESP32() = default;
  USBAudioHostESP32(USBAudioConfig cfg) : USBAudioHostBase(cfg) {}
  ~USBAudioHostESP32() { stopUsbTask(); }
 
  BaseBuffer<uint8_t>& bufferTx() override { return buffer_tx_; }
 
  BaseBuffer<uint8_t>& bufferRx() override { return buffer_rx_; }
 
  int getActualCore() const override { return xPortGetCoreID(); }
 
  void serviceUSB() override {}
 
 protected:
  USBAudioHostBackendESP32 backend_impl_;
  // TX: blocking write (5 ms) so that the copier waits for free space;
  // RX: the USB task never blocks when writing.
  BufferRTOS<uint8_t> buffer_tx_{0, 0, 5, 0};
  BufferRTOS<uint8_t> buffer_rx_{0, 1, 0, 0};
  Task usb_task_;
 
  USBAudioHostBackend& backend() override { return backend_impl_; }
 
  bool beginUSB() override {
    if (!USBAudioHostBase::beginUSB()) return false;
    startUsbTask();
    return true;
  }
 
  void resizeBuffers() override {
    size_t size = (size_t)audioPacketSize() * config_.fifo_packets;
    if (isEpOutEnabled()) buffer_tx_.resize(size);
    if (isEpInEnabled()) buffer_rx_.resize(size);
  }
 
  void startUsbTask() {
    if (usb_task_.getTaskHandle() != nullptr) return;
    // the ESP32 FreeRTOS uses bytes for the stack size
    int stack = config_.usb_task_stack_size < 4096 ? 4096
                                                   : config_.usb_task_stack_size;
    usb_task_.create("usb_audio_host", stack, config_.usb_task_priority);
    // processUSB() blocks for at most 1 tick waiting for USB events
    usb_task_.begin([this]() { processUSB(); });
    usb_task_active_ = true;
  }
 
  void stopUsbTask() {
    if (usb_task_.getTaskHandle() == nullptr) return;
    usb_task_active_ = false;
    usb_task_.remove();
  }
};
 
}  // namespace audio_tools