text: /**
    ******************************************************************************
    * @file    usbd_msc_scsi.c
    * @author  MCD Application Team
    * @brief   This file provides all the USBD SCSI layer functions.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; Copyright (c) 2015 STMicroelectronics.
    * All rights reserved.</center></h2>
    *
    * This software component is licensed by ST under Ultimate Liberty license
    * SLA0044, the "License"; You may not use this file except in compliance with
    * the License. You may obtain a copy of the License at:
    *                      www.st.com/SLA0044
    *
    ******************************************************************************
    */
  
  /* BSPDependencies
  - "stm32xxxxx_{eval}{discovery}{nucleo_144}.c"
  - "stm32xxxxx_{eval}{discovery}_io.c"
  - "stm32xxxxx_{eval}{discovery}{adafruit}_sd.c"
  EndBSPDependencies */
  
  /* Includes ------------------------------------------------------------------*/
  #include "usbd_msc_bot.h"
  #include "usbd_msc_scsi.h"
  #include "usbd_msc.h"
  #include "usbd_msc_data.h"
  
  
  
  /** @addtogroup STM32_USB_DEVICE_LIBRARY
    * @{
    */
  
  
  /** @defgroup MSC_SCSI
    * @brief Mass storage SCSI layer module
    * @{
    */
  
  /** @defgroup MSC_SCSI_Private_TypesDefinitions
    * @{
    */
  /**
    * @}
    */
  
  
  /** @defgroup MSC_SCSI_Private_Defines
    * @{
    */
  
  /**
    * @}
    */
  
  
  /** @defgroup MSC_SCSI_Private_Macros
    * @{
    */
  /**
    * @}
    */
  
  
  /** @defgroup MSC_SCSI_Private_Variables
    * @{
    */
  
  /**
    * @}
    */
  
  
  /** @defgroup MSC_SCSI_Private_FunctionPrototypes
    * @{
    */
  static int8_t SCSI_TestUnitReady(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_Inquiry(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_ReadFormatCapacity(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_ReadCapacity10(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_RequestSense(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_StartStopUnit(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_ModeSense6(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_ModeSense10(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_Write10(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_Read10(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_Verify10(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params);
  static int8_t SCSI_CheckAddressRange(USBD_HandleTypeDef *pdev, uint8_t lun,
                                       uint32_t blk_offset, uint32_t blk_nbr);
  
  static int8_t SCSI_ProcessRead(USBD_HandleTypeDef *pdev, uint8_t lun);
  static int8_t SCSI_ProcessWrite(USBD_HandleTypeDef *pdev, uint8_t lun);
  /**
    * @}
    */
  
  
  /** @defgroup MSC_SCSI_Private_Functions
    * @{
    */
  
  
  /**
  * @brief  SCSI_ProcessCmd
  *         Process SCSI commands
  * @param  pdev: device instance
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  int8_t SCSI_ProcessCmd(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *cmd)
  {
    switch (cmd[0])
    {
      case SCSI_TEST_UNIT_READY:
        SCSI_TestUnitReady(pdev, lun, cmd);
        break;
  
      case SCSI_REQUEST_SENSE:
        SCSI_RequestSense(pdev, lun, cmd);
        break;
      case SCSI_INQUIRY:
        SCSI_Inquiry(pdev, lun, cmd);
        break;
  
      case SCSI_START_STOP_UNIT:
        SCSI_StartStopUnit(pdev, lun, cmd);
        break;
  
      case SCSI_ALLOW_MEDIUM_REMOVAL:
        SCSI_StartStopUnit(pdev, lun, cmd);
        break;
  
      case SCSI_MODE_SENSE6:
        SCSI_ModeSense6(pdev, lun, cmd);
        break;
  
      case SCSI_MODE_SENSE10:
        SCSI_ModeSense10(pdev, lun, cmd);
        break;
  
      case SCSI_READ_FORMAT_CAPACITIES:
        SCSI_ReadFormatCapacity(pdev, lun, cmd);
        break;
  
      case SCSI_READ_CAPACITY10:
        SCSI_ReadCapacity10(pdev, lun, cmd);
        break;
  
      case SCSI_READ10:
        SCSI_Read10(pdev, lun, cmd);
        break;
  
      case SCSI_WRITE10:
        SCSI_Write10(pdev, lun, cmd);
        break;
  
      case SCSI_VERIFY10:
        SCSI_Verify10(pdev, lun, cmd);
        break;
  
      default:
        SCSI_SenseCode(pdev, lun, ILLEGAL_REQUEST, INVALID_CDB);
        return -1;
    }
  
    return 0;
  }
  
  
  /**
  * @brief  SCSI_TestUnitReady
  *         Process SCSI Test Unit Ready Command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t SCSI_TestUnitReady(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
  
    /* case 9 : Hi > D0 */
    if (hmsc->cbw.dDataLength != 0U)
    {
      SCSI_SenseCode(pdev, hmsc->cbw.bLUN, ILLEGAL_REQUEST, INVALID_CDB);
  
      return -1;
    }
  
    if (((USBD_StorageTypeDef *)pdev->pUserData)->IsReady(lun) != 0)
    {
      SCSI_SenseCode(pdev, lun, NOT_READY, MEDIUM_NOT_PRESENT);
      hmsc->bot_state = USBD_BOT_NO_DATA;
  
      return -1;
    }
    hmsc->bot_data_length = 0U;
  
    return 0;
  }
  
  /**
  * @brief  SCSI_Inquiry
  *         Process Inquiry command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t  SCSI_Inquiry(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    uint8_t *pPage;
    uint16_t len;
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
  
    if (params[1] & 0x01U)/*Evpd is set*/
    {
      len = LENGTH_INQUIRY_PAGE00;
      hmsc->bot_data_length = len;
  
      while (len)
      {
        len--;
        hmsc->bot_data[len] = MSC_Page00_Inquiry_Data[len];
      }
    }
    else
    {
      pPage = (uint8_t *)(void *) & ((USBD_StorageTypeDef *)pdev->pUserData)->pInquiry[lun * STANDARD_INQUIRY_DATA_LEN];
      len = (uint16_t)pPage[4] + 5U;
  
      if (params[4] <= len)
      {
        len = params[4];
      }
      hmsc->bot_data_length = len;
  
      while (len)
      {
        len--;
        hmsc->bot_data[len] = pPage[len];
      }
    }
  
    return 0;
  }
  
  /**
  * @brief  SCSI_ReadCapacity10
  *         Process Read Capacity 10 command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t SCSI_ReadCapacity10(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
  
    if (((USBD_StorageTypeDef *)pdev->pUserData)->GetCapacity(lun, &hmsc->scsi_blk_nbr, &hmsc->scsi_blk_size) != 0)
    {
      SCSI_SenseCode(pdev, lun, NOT_READY, MEDIUM_NOT_PRESENT);
      return -1;
    }
    else
    {
  
      hmsc->bot_data[0] = (uint8_t)((hmsc->scsi_blk_nbr - 1U) >> 24);
      hmsc->bot_data[1] = (uint8_t)((hmsc->scsi_blk_nbr - 1U) >> 16);
      hmsc->bot_data[2] = (uint8_t)((hmsc->scsi_blk_nbr - 1U) >>  8);
      hmsc->bot_data[3] = (uint8_t)(hmsc->scsi_blk_nbr - 1U);
  
      hmsc->bot_data[4] = (uint8_t)(hmsc->scsi_blk_size >>  24);
      hmsc->bot_data[5] = (uint8_t)(hmsc->scsi_blk_size >>  16);
      hmsc->bot_data[6] = (uint8_t)(hmsc->scsi_blk_size >>  8);
      hmsc->bot_data[7] = (uint8_t)(hmsc->scsi_blk_size);
  
      hmsc->bot_data_length = 8U;
      return 0;
    }
  }
  /**
  * @brief  SCSI_ReadFormatCapacity
  *         Process Read Format Capacity command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t SCSI_ReadFormatCapacity(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
  
    uint16_t blk_size;
    uint32_t blk_nbr;
    uint16_t i;
  
    for (i = 0U; i < 12U ; i++)
    {
      hmsc->bot_data[i] = 0U;
    }
  
    if (((USBD_StorageTypeDef *)pdev->pUserData)->GetCapacity(lun, &blk_nbr, &blk_size) != 0U)
    {
      SCSI_SenseCode(pdev, lun, NOT_READY, MEDIUM_NOT_PRESENT);
      return -1;
    }
    else
    {
      hmsc->bot_data[3] = 0x08U;
      hmsc->bot_data[4] = (uint8_t)((blk_nbr - 1U) >> 24);
      hmsc->bot_data[5] = (uint8_t)((blk_nbr - 1U) >> 16);
      hmsc->bot_data[6] = (uint8_t)((blk_nbr - 1U) >>  8);
      hmsc->bot_data[7] = (uint8_t)(blk_nbr - 1U);
  
      hmsc->bot_data[8] = 0x02U;
      hmsc->bot_data[9] = (uint8_t)(blk_size >>  16);
      hmsc->bot_data[10] = (uint8_t)(blk_size >>  8);
      hmsc->bot_data[11] = (uint8_t)(blk_size);
  
      hmsc->bot_data_length = 12U;
      return 0;
    }
  }
  /**
  * @brief  SCSI_ModeSense6
  *         Process Mode Sense6 command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t SCSI_ModeSense6(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
    uint16_t len = 8U;
    hmsc->bot_data_length = len;
  
    while (len)
    {
      len--;
      hmsc->bot_data[len] = MSC_Mode_Sense6_data[len];
    }
    return 0;
  }
  
  /**
  * @brief  SCSI_ModeSense10
  *         Process Mode Sense10 command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t SCSI_ModeSense10(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    uint16_t len = 8U;
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
  
    hmsc->bot_data_length = len;
  
    while (len)
    {
      len--;
      hmsc->bot_data[len] = MSC_Mode_Sense10_data[len];
    }
  
    return 0;
  }
  
  /**
  * @brief  SCSI_RequestSense
  *         Process Request Sense command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  
  static int8_t SCSI_RequestSense(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    uint8_t i;
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
  
    for (i = 0U ; i < REQUEST_SENSE_DATA_LEN; i++)
    {
      hmsc->bot_data[i] = 0U;
    }
  
    hmsc->bot_data[0] = 0x70U;
    hmsc->bot_data[7] = REQUEST_SENSE_DATA_LEN - 6U;
  
    if ((hmsc->scsi_sense_head != hmsc->scsi_sense_tail))
    {
  
      hmsc->bot_data[2]     = hmsc->scsi_sense[hmsc->scsi_sense_head].Skey;
      hmsc->bot_data[12]    = hmsc->scsi_sense[hmsc->scsi_sense_head].w.b.ASCQ;
      hmsc->bot_data[13]    = hmsc->scsi_sense[hmsc->scsi_sense_head].w.b.ASC;
      hmsc->scsi_sense_head++;
  
      if (hmsc->scsi_sense_head == SENSE_LIST_DEEPTH)
      {
        hmsc->scsi_sense_head = 0U;
      }
    }
    hmsc->bot_data_length = REQUEST_SENSE_DATA_LEN;
  
    if (params[4] <= REQUEST_SENSE_DATA_LEN)
    {
      hmsc->bot_data_length = params[4];
    }
    return 0;
  }
  
  /**
  * @brief  SCSI_SenseCode
  *         Load the last error code in the error list
  * @param  lun: Logical unit number
  * @param  sKey: Sense Key
  * @param  ASC: Additional Sense Key
  * @retval none
  
  */
  void SCSI_SenseCode(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t sKey, uint8_t ASC)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
  
    hmsc->scsi_sense[hmsc->scsi_sense_tail].Skey  = sKey;
    hmsc->scsi_sense[hmsc->scsi_sense_tail].w.ASC = ASC << 8;
    hmsc->scsi_sense_tail++;
    if (hmsc->scsi_sense_tail == SENSE_LIST_DEEPTH)
    {
      hmsc->scsi_sense_tail = 0U;
    }
  }
  /**
  * @brief  SCSI_StartStopUnit
  *         Process Start Stop Unit command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t SCSI_StartStopUnit(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *) pdev->pClassData;
    hmsc->bot_data_length = 0U;
    return 0;
  }
  
  /**
  * @brief  SCSI_Read10
  *         Process Read10 command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  static int8_t SCSI_Read10(USBD_HandleTypeDef *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *) pdev->pClassData;
  
    if (hmsc->bot_state == USBD_BOT_IDLE) /* Idle */
    {
      /* case 10 : Ho <> Di */
      if ((hmsc->cbw.bmFlags & 0x80U) != 0x80U)
      {
        SCSI_SenseCode(pdev, hmsc->cbw.bLUN, ILLEGAL_REQUEST, INVALID_CDB);
        return -1;
      }
  
      if (((USBD_StorageTypeDef *)pdev->pUserData)->IsReady(lun) != 0)
      {
        SCSI_SenseCode(pdev, lun, NOT_READY, MEDIUM_NOT_PRESENT);
        return -1;
      }
  
      hmsc->scsi_blk_addr = ((uint32_t)params[2] << 24) |
                            ((uint32_t)params[3] << 16) |
                            ((uint32_t)params[4] <<  8) |
                            (uint32_t)params[5];
  
      hmsc->scsi_blk_len = ((uint32_t)params[7] <<  8) | (uint32_t)params[8];
  
      if (SCSI_CheckAddressRange(pdev, lun, hmsc->scsi_blk_addr,
                                 hmsc->scsi_blk_len) < 0)
      {
        return -1; /* error */
      }
  
      hmsc->bot_state = USBD_BOT_DATA_IN;
  
      /* cases 4,5 : Hi <> Dn */
      if (hmsc->cbw.dDataLength != (hmsc->scsi_blk_len * hmsc->scsi_blk_size))
      {
        SCSI_SenseCode(pdev, hmsc->cbw.bLUN, ILLEGAL_REQUEST, INVALID_CDB);
        return -1;
      }
    }
    hmsc->bot_data_length = MSC_MEDIA_PACKET;
  
    return SCSI_ProcessRead(pdev, lun);
  }
  
  /**
  * @brief  SCSI_Write10
  *         Process Write10 command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  
  static int8_t SCSI_Write10(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *) pdev->pClassData;
    uint32_t len;
  
    if (hmsc->bot_state == USBD_BOT_IDLE) /* Idle */
    {
      /* case 8 : Hi <> Do */
      if ((hmsc->cbw.bmFlags & 0x80U) == 0x80U)
      {
        SCSI_SenseCode(pdev, hmsc->cbw.bLUN, ILLEGAL_REQUEST, INVALID_CDB);
        return -1;
      }
  
      /* Check whether Media is ready */
      if (((USBD_StorageTypeDef *)pdev->pUserData)->IsReady(lun) != 0)
      {
        SCSI_SenseCode(pdev, lun, NOT_READY, MEDIUM_NOT_PRESENT);
        return -1;
      }
  
      /* Check If media is write-protected */
      if (((USBD_StorageTypeDef *)pdev->pUserData)->IsWriteProtected(lun) != 0)
      {
        SCSI_SenseCode(pdev, lun, NOT_READY, WRITE_PROTECTED);
        return -1;
      }
  
      hmsc->scsi_blk_addr = ((uint32_t)params[2] << 24) |
                            ((uint32_t)params[3] << 16) |
                            ((uint32_t)params[4] << 8) |
                            (uint32_t)params[5];
  
      hmsc->scsi_blk_len = ((uint32_t)params[7] << 8) |
                           (uint32_t)params[8];
  
      /* check if LBA address is in the right range */
      if (SCSI_CheckAddressRange(pdev, lun, hmsc->scsi_blk_addr,
                                 hmsc->scsi_blk_len) < 0)
      {
        return -1; /* error */
      }
  
      len = hmsc->scsi_blk_len * hmsc->scsi_blk_size;
  
      /* cases 3,11,13 : Hn,Ho <> D0 */
      if (hmsc->cbw.dDataLength != len)
      {
        SCSI_SenseCode(pdev, hmsc->cbw.bLUN, ILLEGAL_REQUEST, INVALID_CDB);
        return -1;
      }
  
      len = MIN(len, MSC_MEDIA_PACKET);
  
      /* Prepare EP to receive first data packet */
      hmsc->bot_state = USBD_BOT_DATA_OUT;
      USBD_LL_PrepareReceive(pdev, MSC_EPOUT_ADDR, hmsc->bot_data, len);
    }
    else /* Write Process ongoing */
    {
      return SCSI_ProcessWrite(pdev, lun);
    }
    return 0;
  }
  
  
  /**
  * @brief  SCSI_Verify10
  *         Process Verify10 command
  * @param  lun: Logical unit number
  * @param  params: Command parameters
  * @retval status
  */
  
  static int8_t SCSI_Verify10(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *) pdev->pClassData;
  
    if ((params[1] & 0x02U) == 0x02U)
    {
      SCSI_SenseCode(pdev, lun, ILLEGAL_REQUEST, INVALID_FIELED_IN_COMMAND);
      return -1; /* Error, Verify Mode Not supported*/
    }
  
    if (SCSI_CheckAddressRange(pdev, lun, hmsc->scsi_blk_addr,
                               hmsc->scsi_blk_len) < 0)
    {
      return -1; /* error */
    }
    hmsc->bot_data_length = 0U;
    return 0;
  }
  
  /**
  * @brief  SCSI_CheckAddressRange
  *         Check address range
  * @param  lun: Logical unit number
  * @param  blk_offset: first block address
  * @param  blk_nbr: number of block to be processed
  * @retval status
  */
  static int8_t SCSI_CheckAddressRange(USBD_HandleTypeDef *pdev, uint8_t lun,
                                       uint32_t blk_offset, uint32_t blk_nbr)
  {
    USBD_MSC_BOT_HandleTypeDef  *hmsc = (USBD_MSC_BOT_HandleTypeDef *) pdev->pClassData;
  
    if ((blk_offset + blk_nbr) > hmsc->scsi_blk_nbr)
    {
      SCSI_SenseCode(pdev, lun, ILLEGAL_REQUEST, ADDRESS_OUT_OF_RANGE);
      return -1;
    }
    return 0;
  }
  
  /**
  * @brief  SCSI_ProcessRead
  *         Handle Read Process
  * @param  lun: Logical unit number
  * @retval status
  */
  static int8_t SCSI_ProcessRead(USBD_HandleTypeDef  *pdev, uint8_t lun)
  {
    USBD_MSC_BOT_HandleTypeDef *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
    uint32_t len = hmsc->scsi_blk_len * hmsc->scsi_blk_size;
  
    len = MIN(len, MSC_MEDIA_PACKET);
  
    if (((USBD_StorageTypeDef *)pdev->pUserData)->Read(lun,
                                                       hmsc->bot_data,
                                                       hmsc->scsi_blk_addr,
                                                       (len / hmsc->scsi_blk_size)) < 0)
    {
      SCSI_SenseCode(pdev, lun, HARDWARE_ERROR, UNRECOVERED_READ_ERROR);
      return -1;
    }
  
    USBD_LL_Transmit(pdev, MSC_EPIN_ADDR, hmsc->bot_data, len);
  
    hmsc->scsi_blk_addr += (len / hmsc->scsi_blk_size);
    hmsc->scsi_blk_len -= (len / hmsc->scsi_blk_size);
  
    /* case 6 : Hi = Di */
    hmsc->csw.dDataResidue -= len;
  
    if (hmsc->scsi_blk_len == 0U)
    {
      hmsc->bot_state = USBD_BOT_LAST_DATA_IN;
    }
    return 0;
  }
  
  /**
  * @brief  SCSI_ProcessWrite
  *         Handle Write Process
  * @param  lun: Logical unit number
  * @retval status
  */
  
  static int8_t SCSI_ProcessWrite(USBD_HandleTypeDef  *pdev, uint8_t lun)
  {
    USBD_MSC_BOT_HandleTypeDef *hmsc = (USBD_MSC_BOT_HandleTypeDef *) pdev->pClassData;
    uint32_t len = hmsc->scsi_blk_len * hmsc->scsi_blk_size;
  
    len = MIN(len, MSC_MEDIA_PACKET);
  
    if (((USBD_StorageTypeDef *)pdev->pUserData)->Write(lun, hmsc->bot_data,
                                                        hmsc->scsi_blk_addr,
                                                        (len / hmsc->scsi_blk_size)) < 0)
    {
      SCSI_SenseCode(pdev, lun, HARDWARE_ERROR, WRITE_FAULT);
  
      return -1;
    }
  
    hmsc->scsi_blk_addr += (len / hmsc->scsi_blk_size);
    hmsc->scsi_blk_len -= (len / hmsc->scsi_blk_size);
  
    /* case 12 : Ho = Do */
    hmsc->csw.dDataResidue -= len;
  
    if (hmsc->scsi_blk_len == 0U)
    {
      MSC_BOT_SendCSW(pdev, USBD_CSW_CMD_PASSED);
    }
    else
    {
      len = MIN((hmsc->scsi_blk_len * hmsc->scsi_blk_size), MSC_MEDIA_PACKET);
      /* Prepare EP to Receive next packet */
      USBD_LL_PrepareReceive(pdev, MSC_EPOUT_ADDR, hmsc->bot_data, len);
    }
  
    return 0;
  }
  /**
    * @}
    */
  
  
  /**
    * @}
    */
  
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  