tinyUSB/src/device/usbd_control.c

/*
 * 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 an 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