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
  
  #include "tusb.h"
  #include "device/usbd_pvt.h"
  #include "dcd.h"
  
  enum
  {
    EDPT_CTRL_OUT = 0x00,
    EDPT_CTRL_IN  = 0x80
  };
  
  typedef struct
  {
    tusb_control_request_t request;
  
    uint8_t* buffer;
    uint16_t data_len;
    uint16_t total_xferred;
  
    bool (*complete_cb) (uint8_t, tusb_control_request_t const *);
  } usbd_control_xfer_t;
  
  static usbd_control_xfer_t _ctrl_xfer;
  
  CFG_TUSB_MEM_SECTION CFG_TUSB_MEM_ALIGN
  static uint8_t _usbd_ctrl_buf[CFG_TUD_ENDPOINT0_SIZE];
  
  //--------------------------------------------------------------------+
  // Application API
  //--------------------------------------------------------------------+
  
  // Queue ZLP status transaction
  static inline bool _status_stage_xact(uint8_t rhport, tusb_control_request_t const * request)
  {
    // Opposite to endpoint in Data Phase
    uint8_t const ep_addr = request->bmRequestType_bit.direction ? EDPT_CTRL_OUT : EDPT_CTRL_IN;
  
    TU_LOG2("  Queue EP %02X with zlp Status\r\n", ep_addr);
  
    // status direction is reversed to one in the setup packet
    // Note: Status must always be DATA1
    return dcd_edpt_xfer(rhport, ep_addr, NULL, 0);
  }
  
  // Status phase
  bool tud_control_status(uint8_t rhport, tusb_control_request_t const * request)
  {
    _ctrl_xfer.request       = (*request);
    _ctrl_xfer.buffer        = NULL;
    _ctrl_xfer.total_xferred = 0;
    _ctrl_xfer.data_len      = 0;
  
    return _status_stage_xact(rhport, request);
  }
  
  // Queue a transaction in Data Stage
  // Each transaction has up to Endpoint0's max packet size.
  // This function can also transfer an zero-length packet
  static bool _data_stage_xact(uint8_t rhport)
  {
    uint16_t const xact_len = tu_min16(_ctrl_xfer.data_len - _ctrl_xfer.total_xferred, CFG_TUD_ENDPOINT0_SIZE);
  
    uint8_t ep_addr = EDPT_CTRL_OUT;
  
    if ( _ctrl_xfer.request.bmRequestType_bit.direction == TUSB_DIR_IN )
    {
      ep_addr = EDPT_CTRL_IN;
      if ( xact_len ) memcpy(_usbd_ctrl_buf, _ctrl_xfer.buffer, xact_len);
    }
  
    TU_LOG2("  Queue EP %02X with %u bytes\r\n", ep_addr, xact_len);
  
    return dcd_edpt_xfer(rhport, ep_addr, xact_len ? _usbd_ctrl_buf : NULL, xact_len);
  }
  
  // Transmit data to/from the control endpoint.
  // If the request's wLength is zero, a status packet is sent instead.
  bool tud_control_xfer(uint8_t rhport, tusb_control_request_t const * request, void* buffer, uint16_t len)
  {
    _ctrl_xfer.request       = (*request);
    _ctrl_xfer.buffer        = (uint8_t*) buffer;
    _ctrl_xfer.total_xferred = 0U;
    _ctrl_xfer.data_len      = tu_min16(len, request->wLength);
    
    if (request->wLength > 0U)
    {
      if(_ctrl_xfer.data_len > 0U)
      {
        TU_ASSERT(buffer);
      }
  
  //    TU_LOG2("  Control total data length is %u bytes\r\n", _ctrl_xfer.data_len);
  
      // Data stage
      TU_ASSERT( _data_stage_xact(rhport) );
    }
    else
    {
      // Status stage
      TU_ASSERT( _status_stage_xact(rhport, request) );
    }
  
    return true;
  }
  
  //--------------------------------------------------------------------+
  // USBD API
  //--------------------------------------------------------------------+
  
  void usbd_control_reset(void)
  {
    tu_varclr(&_ctrl_xfer);
  }
  
  // TODO may find a better way
  void usbd_control_set_complete_callback( bool (*fp) (uint8_t, tusb_control_request_t const * ) )
  {
    _ctrl_xfer.complete_cb = fp;
  }
  
  // useful for dcd_set_address where DCD is responsible for status response
  void usbd_control_set_request(tusb_control_request_t const *request)
  {
    _ctrl_xfer.request       = (*request);
    _ctrl_xfer.buffer        = NULL;
    _ctrl_xfer.total_xferred = 0;
    _ctrl_xfer.data_len      = 0;
  }
  
  // callback when a transaction complete on
  // - DATA stage of control endpoint or
  // - Status stage
  bool usbd_control_xfer_cb (uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
  {
    (void) result;
  
    // Endpoint Address is opposite to direction bit, this is Status Stage complete event
    if ( tu_edpt_dir(ep_addr) != _ctrl_xfer.request.bmRequestType_bit.direction )
    {
      TU_ASSERT(0 == xferred_bytes);
      if (dcd_edpt0_status_complete) dcd_edpt0_status_complete(rhport, &_ctrl_xfer.request);
      return true;
    }
  
    if ( _ctrl_xfer.request.bmRequestType_bit.direction == TUSB_DIR_OUT )
    {
      TU_VERIFY(_ctrl_xfer.buffer);
      memcpy(_ctrl_xfer.buffer, _usbd_ctrl_buf, xferred_bytes);
    }
  
    _ctrl_xfer.total_xferred += xferred_bytes;
    _ctrl_xfer.buffer += xferred_bytes;
  
    // Data Stage is complete when all request's length are transferred or
    // a short packet is sent including zero-length packet.
    if ( (_ctrl_xfer.request.wLength == _ctrl_xfer.total_xferred) || (xferred_bytes < CFG_TUD_ENDPOINT0_SIZE) )
    {
      // DATA stage is complete
      bool is_ok = true;
  
      // invoke complete callback if set
      // callback can still stall control in status phase e.g out data does not make sense
      if ( _ctrl_xfer.complete_cb )
      {
        #if CFG_TUSB_DEBUG >= 2
        extern void usbd_driver_print_control_complete_name(bool (*control_complete) (uint8_t, tusb_control_request_t const *));
        usbd_driver_print_control_complete_name(_ctrl_xfer.complete_cb);
        #endif
  
        is_ok = _ctrl_xfer.complete_cb(rhport, &_ctrl_xfer.request);
      }
  
      if ( is_ok )
      {
        // Send status
        TU_ASSERT( _status_stage_xact(rhport, &_ctrl_xfer.request) );
      }else
      {
        // Stall both IN and OUT control endpoint
        dcd_edpt_stall(rhport, EDPT_CTRL_OUT);
        dcd_edpt_stall(rhport, EDPT_CTRL_IN);
      }
    }
    else
    {
      // More data to transfer
      TU_ASSERT( _data_stage_xact(rhport) );
    }
  
    return true;
  }
  
  #endif
  