/* This code shows usage of the USB_HOST_MSD_Transfer function. The SCSI Block
 * Driver Library uses this function to send a SCSI Inquiry Command to the
 * device. Note how the commandCompleted flag in the SCSI instance object
 * tracks the completion of the transfer. This flag is updated in the transfer
 * callback. */

void _USB_HOST_SCSI_TransferCallback
(
    USB_HOST_MSD_LUN_HANDLE lunHandle,
    USB_HOST_MSD_TRANSFER_HANDLE transferHandle,
    USB_HOST_MSD_RESULT result,
    size_t size,
    uintptr_t context
)
{
    int scsiObjIndex;
    USB_HOST_SCSI_OBJ * scsiObj;
    USB_HOST_SCSI_COMMAND_OBJ * commandObj;
    USB_HOST_SCSI_EVENT event;

    /* Get the SCSI object index from the lunHandle */
    scsiObjIndex = _USB_HOST_SCSI_LUNHandleToSCSIInstance(lunHandle);

    /* Get the pointer to the SCSI object */
    scsiObj = &gUSBHostSCSIObj[scsiObjIndex];

    /* Pointer to the command object */
    commandObj = &scsiObj->commandObj;

    /* The processed size */
    commandObj->size = size;

    /* The result of the command */
    commandObj->result = result;

    /* Let the main state machine know that the command is completed */
    commandObj->commandCompleted = true;

    /* The rest of code is not shown here for the sake of brevity */
}

void USB_HOST_SCSI_Tasks(USB_HOST_MSD_LUN_HANDLE lunHandle)
{
    switch(scsiObj->state)
    {
        /* For the sake of brevity, only one SCSI command is show here */
        case USB_HOST_SCSI_STATE_INQUIRY_RESPONSE:

            /* We get the SCSI Enquiry response. Although there isn't much
             * that we can do with this data */
            _USB_HOST_SCSI_InquiryResponseCommand(scsiObj->commandObj.cdb);

            /* The commandCompleted flag will be updated in the callback.
             * Update the state and send the command.   */
            scsiObj->commandObj.inUse = true;
            scsiObj->commandObj.commandCompleted = false;
            scsiObj->commandObj.generateEvent = false;

            result = USB_HOST_MSD_Transfer(scsiObj->lunHandle,
                    scsiObj->commandObj.cdb, 6, scsiObj->buffer, 36,
                    USB_HOST_MSD_TRANSFER_DIRECTION_DEVICE_TO_HOST,
                    _USB_HOST_SCSI_TransferCallback, (uintptr_t)(scsiObj));

            if(result == USB_HOST_MSD_RESULT_SUCCESS)
            {
                scsiObj->state = USB_HOST_SCSI_STATE_WAIT_INQUIRY_RESPONSE;
            }

            break;

        default:
            break;

    }
}