USBAudioDeviceESP32.h

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#pragma once
#include <Arduino.h>
 
#ifdef ESP32
 
#if ARDUINO_USB_CDC_ON_BOOT
#error USB Audio is only available in OTG mode, not CDC-on-boot mode
#else
 
#include <USB.h>
 
#include <cstring>
 
#include "AudioTools/Communication/USB/USBAudioBackendTinyUSB.h"
#include "AudioTools/Communication/USB/USBAudioDeviceBase.h"
#include "AudioTools/Concurrency/RTOS/SynchronizedNBufferRTOS.h"
#include "esp32-hal-tinyusb.h"
 
namespace audio_tools {
 
class Emulated_TinyUSB;
 
class USBAudioDeviceESP32 : public USBAudioDeviceBase {
  friend class Emulated_TinyUSB;
 
 public:
  USBAudioDeviceESP32() = default;
  USBAudioDeviceESP32(USBAudioConfig cfg) : USBAudioDeviceBase(cfg) {}
 
  // ── ESP32 descriptor callback
  // ───────────────────────────────────────────────
  // Called by the arduino-esp32 framework when it builds the configuration
  // descriptor. The callback reads the current descriptor at call time, so any
  // format change callback reads the current descriptor at call time, so any
  // format change made via setConfig() before re-enumeration is picked up
  // automatically without re-registering the interface.
 
  static uint16_t descriptorCallback(uint8_t* dst, uint8_t* itf) {
    auto& dev = getActualInstance();
    // *itf carries the running interface index: set our base from it so that
    // composite configurations (e.g. CDC + Audio) get non-overlapping
    // numbers.
    if (itf) dev.config_.itf_num_ac = *itf;
    uint16_t len = dev.getDescriptor(dst);
    if (itf) *itf += dev.numInterfaces();
    return len;
  }
 
  static USBAudioDeviceESP32& getActualInstance() {
    return static_cast<USBAudioDeviceESP32&>(
        USBAudioDeviceBase::activeInstance());
  }
 
  bool setupUSB() {
    if (setup_called) return true;
    setup_called = true;
    USB.VID(config_.vid);
    USB.PID(config_.pid);
    USB.productName(config_.product);
    USB.manufacturerName(config_.manufacturer);
    USB.serialNumber(config_.serial);
    USB.usbClass(TUSB_CLASS_MISC);
    USB.usbSubClass(MISC_SUBCLASS_COMMON);
    USB.usbProtocol(MISC_PROTOCOL_IAD);
    USB.usbAttributes(
        (uint8_t)(0x80u | (config_.self_powered ? 0x40u : 0x00u)));
    USB.usbPower(config_.max_power_ma);
    resolveEndpoints();
    static uint8_t desc[USB_DESCR_MAX_LEN];
    uint16_t audio_len = getDescriptor(desc);
    assert(audio_len <= USB_DESCR_MAX_LEN);
    tinyusb_enable_interface(USB_INTERFACE_AUDIO, audio_len,
                             descriptorCallback);
    return true;
  }
 
  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:
  USBAudioBackendTinyUSB backend_impl_;
  USBAudioBackend& backend() override { return backend_impl_; }
 
  void resolveEndpoints() {
    if (config_.enable_ep_in) {
      if (config_.ep_in < 0) config_.ep_in = allocInEndpoint();
    } else if (isFeedbackEpEnabled()) {
      if (config_.ep_fb < 0) config_.ep_fb = allocInEndpoint();
    }
    if (config_.enable_ep_out) {
      if (config_.ep_out < 0) config_.ep_out = allocOutEndpoint();
    }
    if (config_.enable_interrupt_ep) {
      if (config_.ep_int < 0) config_.ep_int = allocInEndpoint();
    }
  }
 
  static int16_t allocInEndpoint() {
    uint8_t n = tinyusb_get_free_in_endpoint();
    if (n == 0) {
      LOGE("No free USB IN endpoint available");
      return -1;
    }
    return (int16_t)(0x80u | n);
  }
 
  static int16_t allocOutEndpoint() {
    uint8_t n = tinyusb_get_free_out_endpoint();
    if (n == 0) {
      LOGE("No free USB OUT endpoint available");
      return -1;
    }
    return (int16_t)n;
  }
 
 
  void resizeBuffers() override {
    uint16_t block_sz = packetSize();
    uint8_t block_cnt = config_.fifo_packets;
    if (isEpInEnabled()) buffer_tx_.resize(block_sz * block_cnt);
    if (isEpOutEnabled()) buffer_rx_.resize(block_sz * block_cnt);
  }
 
  bool beginUSB() override {
    if (begin_called) return true;
    setupUSB();
    bool rc = true;
    if (config_.begin_usb) {
      begin_called = true;
      rc = USB.begin();
    }
    return rc;
  }
 
  bool begin_called = false;
  bool setup_called = false;
  // Block-pool buffers with FreeRTOS queues for cross-core safety.
  // TX: writeMaxWait=5ms (copier blocks briefly for free block),
  //     readMaxWait=0 (xfer_cb never blocks).
  // RX: writeMaxWait=0 (xfer_cb never blocks),
  //     readMaxWait=0 (sketch polls via copier, never blocks).
  // SynchronizedNBufferRTOS buffer_tx_{0, 0, 5, 0};
  // SynchronizedNBufferRTOS buffer_rx_{0, 0, 0, 0};
 
  // size_t streamBufferSize, size_t xTriggerLevel = 1  TickType_t writeMaxWait
  // = portMAX_DELAY,  TickType_t readMaxWait = portMAX_DELAY,
  BufferRTOS<uint8_t> buffer_tx_{0, 0, 5, 0};
  BufferRTOS<uint8_t> buffer_rx_{0, 1, 0, 0};
};
 
class Emulated_TinyUSB {
 public:
  bool isInitialized() { return tud_inited(); }
  bool begin(int) { return true; }
  bool mounted(void) {
    if (!device().begin_called) return true;
    return tud_mounted();
  }
  bool suspended(void) { return tud_suspended(); }
  bool ready(void) { return tud_ready(); }
  bool remoteWakeup(void) { return tud_remote_wakeup(); }
  bool detach(void) {
    if (!device().begin_called) return true;
    return tud_disconnect();
  }
  bool attach(void) {
    if (!device().begin_called) {
      device().beginUSB();
      return USB.begin();
    }
 
    return tud_connect();
  }
  // bool beginUSB() { return device().beginUSB(); }
  USBAudioDeviceESP32& device() {
    return static_cast<USBAudioDeviceESP32&>(
        USBAudioDeviceBase::activeInstance());
  }
};
 
static Emulated_TinyUSB TinyUSBDevice;
 
using USBAudioStream = USBAudioDeviceESP32;
 
}  // namespace audio_tools
 
#endif  // ARDUINO_USB_CDC_ON_BOOT
#endif  // ESP32