text: /* 
   * The MIT License (MIT)
   *
   * Copyright (c) 2019 Ha Thach (tinyusb.org)
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   *
   * This file is part of the TinyUSB stack.
   */
  
  #include "tusb_option.h"
  
  #if (TUSB_OPT_DEVICE_ENABLED && CFG_TUD_VENDOR)
  
  #include "vendor_device.h"
  #include "device/usbd_pvt.h"
  
  //--------------------------------------------------------------------+
  // MACRO CONSTANT TYPEDEF
  //--------------------------------------------------------------------+
  typedef struct
  {
    uint8_t itf_num;
    uint8_t ep_in;
    uint8_t ep_out;
  
    /*------------- From this point, data is not cleared by bus reset -------------*/
    tu_fifo_t rx_ff;
    tu_fifo_t tx_ff;
  
    uint8_t rx_ff_buf[CFG_TUD_VENDOR_RX_BUFSIZE];
    uint8_t tx_ff_buf[CFG_TUD_VENDOR_TX_BUFSIZE];
  
  #if CFG_FIFO_MUTEX
    osal_mutex_def_t rx_ff_mutex;
    osal_mutex_def_t tx_ff_mutex;
  #endif
  
    // Endpoint Transfer buffer
    CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_VENDOR_EPSIZE];
    CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_VENDOR_EPSIZE];
  } vendord_interface_t;
  
  CFG_TUSB_MEM_SECTION static vendord_interface_t _vendord_itf[CFG_TUD_VENDOR];
  
  #define ITF_MEM_RESET_SIZE   offsetof(vendord_interface_t, rx_ff)
  
  
  bool tud_vendor_n_mounted (uint8_t itf)
  {
    return _vendord_itf[itf].ep_in && _vendord_itf[itf].ep_out;
  }
  
  uint32_t tud_vendor_n_available (uint8_t itf)
  {
    return tu_fifo_count(&_vendord_itf[itf].rx_ff);
  }
  
  bool tud_vendor_n_peek(uint8_t itf, int pos, uint8_t* u8)
  {
    return tu_fifo_peek_at(&_vendord_itf[itf].rx_ff, pos, u8);
  }
  
  //--------------------------------------------------------------------+
  // Read API
  //--------------------------------------------------------------------+
  static void _prep_out_transaction (vendord_interface_t* p_itf)
  {
    // skip if previous transfer not complete
    if ( usbd_edpt_busy(TUD_OPT_RHPORT, p_itf->ep_out) ) return;
  
    // Prepare for incoming data but only allow what we can store in the ring buffer.
    uint16_t max_read = tu_fifo_remaining(&p_itf->rx_ff);
    if ( max_read >= CFG_TUD_VENDOR_EPSIZE )
    {
      usbd_edpt_xfer(TUD_OPT_RHPORT, p_itf->ep_out, p_itf->epout_buf, CFG_TUD_VENDOR_EPSIZE);
    }
  }
  
  uint32_t tud_vendor_n_read (uint8_t itf, void* buffer, uint32_t bufsize)
  {
    vendord_interface_t* p_itf = &_vendord_itf[itf];
    uint32_t num_read = tu_fifo_read_n(&p_itf->rx_ff, buffer, bufsize);
    _prep_out_transaction(p_itf);
    return num_read;
  }
  
  //--------------------------------------------------------------------+
  // Write API
  //--------------------------------------------------------------------+
  static bool maybe_transmit(vendord_interface_t* p_itf)
  {
    // skip if previous transfer not complete
    TU_VERIFY( !usbd_edpt_busy(TUD_OPT_RHPORT, p_itf->ep_in) );
  
    uint16_t count = tu_fifo_read_n(&p_itf->tx_ff, p_itf->epin_buf, CFG_TUD_VENDOR_EPSIZE);
    if (count > 0)
    {
      TU_ASSERT( usbd_edpt_xfer(TUD_OPT_RHPORT, p_itf->ep_in, p_itf->epin_buf, count) );
    }
    return true;
  }
  
  uint32_t tud_vendor_n_write (uint8_t itf, void const* buffer, uint32_t bufsize)
  {
    vendord_interface_t* p_itf = &_vendord_itf[itf];
    uint16_t ret = tu_fifo_write_n(&p_itf->tx_ff, buffer, bufsize);
    maybe_transmit(p_itf);
    return ret;
  }
  
  //--------------------------------------------------------------------+
  // USBD Driver API
  //--------------------------------------------------------------------+
  void vendord_init(void)
  {
    tu_memclr(_vendord_itf, sizeof(_vendord_itf));
  
    for(uint8_t i=0; i<CFG_TUD_VENDOR; i++)
    {
      vendord_interface_t* p_itf = &_vendord_itf[i];
  
      // config fifo
      tu_fifo_config(&p_itf->rx_ff, p_itf->rx_ff_buf, CFG_TUD_VENDOR_RX_BUFSIZE, 1, false);
      tu_fifo_config(&p_itf->tx_ff, p_itf->tx_ff_buf, CFG_TUD_VENDOR_TX_BUFSIZE, 1, false);
  
  #if CFG_FIFO_MUTEX
      tu_fifo_config_mutex(&p_itf->rx_ff, osal_mutex_create(&p_itf->rx_ff_mutex));
      tu_fifo_config_mutex(&p_itf->tx_ff, osal_mutex_create(&p_itf->tx_ff_mutex));
  #endif
    }
  }
  
  void vendord_reset(uint8_t rhport)
  {
    (void) rhport;
  
    for(uint8_t i=0; i<CFG_TUD_VENDOR; i++)
    {
      vendord_interface_t* p_itf = &_vendord_itf[i];
  
      tu_memclr(p_itf, ITF_MEM_RESET_SIZE);
      tu_fifo_clear(&p_itf->rx_ff);
      tu_fifo_clear(&p_itf->tx_ff);
    }
  }
  
  bool vendord_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_len)
  {
    // Find available interface
    vendord_interface_t* p_vendor = NULL;
    for(uint8_t i=0; i<CFG_TUD_VENDOR; i++)
    {
      if ( _vendord_itf[i].ep_in == 0 && _vendord_itf[i].ep_out == 0 )
      {
        p_vendor = &_vendord_itf[i];
        break;
      }
    }
    TU_VERIFY(p_vendor);
  
    // Open endpoint pair with usbd helper
    TU_ASSERT(usbd_open_edpt_pair(rhport, tu_desc_next(itf_desc), 2, TUSB_XFER_BULK, &p_vendor->ep_out, &p_vendor->ep_in));
  
    p_vendor->itf_num = itf_desc->bInterfaceNumber;
    (*p_len) = sizeof(tusb_desc_interface_t) + 2*sizeof(tusb_desc_endpoint_t);
  
    // Prepare for incoming data
    TU_ASSERT(usbd_edpt_xfer(rhport, p_vendor->ep_out, p_vendor->epout_buf, sizeof(p_vendor->epout_buf)));
  
    return true;
  }
  
  bool vendord_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
  {
    (void) rhport;
    (void) result;
  
    // TODO Support multiple interfaces
    uint8_t const itf = 0;
    vendord_interface_t* p_itf = &_vendord_itf[itf];
  
    if ( ep_addr == p_itf->ep_out )
    {
      // Receive new data
      tu_fifo_write_n(&p_itf->rx_ff, p_itf->epout_buf, xferred_bytes);
  
      // Invoked callback if any
      if (tud_vendor_rx_cb) tud_vendor_rx_cb(itf);
  
      _prep_out_transaction(p_itf);
    }
    else if ( ep_addr == p_itf->ep_in )
    {
      // Send complete, try to send more if possible
      maybe_transmit(p_itf);
    }
  
    return true;
  }
  
  #endif
  