tinyusb/examples/device/cdc_msc_hid/src/msc_app.c

/* 
 * The MIT License (MIT)
 *
 * Copyright (c) 2018, hathach (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 "bsp/board.h"
#include "tusb.h"

#if CFG_TUD_MSC

//--------------------------------------------------------------------+
// MACRO CONSTANT TYPEDEF
//--------------------------------------------------------------------+

//--------------------------------------------------------------------+
// tinyusb callbacks
//--------------------------------------------------------------------+

// Callback invoked when received an SCSI command not in built-in list below
// - READ_CAPACITY10, READ_FORMAT_CAPACITY, INQUIRY, MODE_SENSE6, REQUEST_SENSE
// - READ10 and WRITE10 has their own callbacks
int32_t tud_msc_scsi_cb (uint8_t lun, uint8_t const scsi_cmd[16], void* buffer, uint16_t bufsize)
{
  // read10 & write10 has their own callback and MUST not be handled here

  void const* response = NULL;
  uint16_t resplen = 0;

  // most scsi handled is input
  bool in_xfer = true;

  switch (scsi_cmd[0])
  {
    case SCSI_CMD_TEST_UNIT_READY:
      // Command that host uses to check our readiness before sending other commands
      resplen = 0;
    break;

    case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
      // Host is about to read/write etc ... better not to disconnect disk
      resplen = 0;
    break;

    case SCSI_CMD_START_STOP_UNIT:
      // Host try to eject/safe remove/poweroff us. We could safely disconnect with disk storage, or go into lower power
      /* scsi_start_stop_unit_t const * start_stop = (scsi_start_stop_unit_t const *) scsi_cmd;
        // Start bit = 0 : low power mode, if load_eject = 1 : unmount disk storage as well
        // Start bit = 1 : Ready mode, if load_eject = 1 : mount disk storage
        start_stop->start;
        start_stop->load_eject;
       */
       resplen = 0;
    break;


    default:
      // Set Sense = Invalid Command Operation
      tud_msc_set_sense(lun, SCSI_SENSE_ILLEGAL_REQUEST, 0x20, 0x00);

      // negative means error -> tinyusb could stall and/or response with failed status
      resplen = -1;
    break;
  }

  // return resplen must not larger than bufsize
  if ( resplen > bufsize ) resplen = bufsize;

  if ( response && (resplen > 0) )
  {
    if(in_xfer)
    {
      memcpy(buffer, response, resplen);
    }else
    {
      // SCSI output
    }
  }

  return resplen;
}


#endif