/******************************************************************************
Function:
BYTE MSDWriteHandler(void)
Description:
This funtion processes a write command received through
the MSD class driver
PreCondition:
None
Parameters:
None
Return Values:
BYTE - the current state of the MSDWriteHandler state
machine. The valid values are defined in MSD.h under the
MSDWriteHandler state machine declaration section
Remarks:
None
*****************************************************************************/
BYTE MSDWriteHandler(void)
{
static BYTE MSDWriteState = MSD_WRITE10_WAIT;
switch(MSDWriteState)
{
case MSD_WRITE10_WAIT:
/* Read the LBA, TransferLength fields from Command Block
NOTE: CB is Big-Endian */
LBA.v[3]=gblCBW.CBWCB[2];
LBA.v[2]=gblCBW.CBWCB[3];
LBA.v[1]=gblCBW.CBWCB[4];
LBA.v[0]=gblCBW.CBWCB[5];
TransferLength.v[1]=gblCBW.CBWCB[7];
TransferLength.v[0]=gblCBW.CBWCB[8];
msd_csw.bCSWStatus=0x0;
MSD_State = MSD_WRITE10_BLOCK;
//Fall through to MSD_WRITE10_BLOCK
case MSD_WRITE10_BLOCK:
if(TransferLength.Val == 0)
{
MSDWriteState = MSD_WRITE10_WAIT;
break;
}
MSDWriteState = MSD_WRITE10_RX_SECTOR;
ptrNextData=(BYTE *)&msd_buffer[0];
msd_csw.dCSWDataResidue=BLOCKLEN_512;
//Fall through to MSD_WRITE10_RX_SECTOR
case MSD_WRITE10_RX_SECTOR:
{
/* Read 512B into msd_buffer*/
if(msd_csw.dCSWDataResidue>0)
{
if(USBHandleBusy(USBMSDOutHandle) == TRUE)
{
break;
}
USBMSDOutHandle = USBRxOnePacket(MSD_DATA_OUT_EP,ptrNextData,MSD_OUT_EP_SIZE);
MSDWriteState = MSD_WRITE10_RX_PACKET;
//Fall through to MSD_WRITE10_RX_PACKET
}
else
{
if(LUNWriteProtectState())
{
gblSenseData[LUN_INDEX].SenseKey=S_NOT_READY;
gblSenseData[LUN_INDEX].ASC=ASC_WRITE_PROTECTED;
gblSenseData[LUN_INDEX].ASCQ=ASCQ_WRITE_PROTECTED;
msd_csw.bCSWStatus=0x01;
//TODO: (DF) - what state should I return to?
}
else
{
MSDWriteState = MSD_WRITE10_SECTOR;
}
break;
}
}
//Fall through to MSD_WRITE10_RX_PACKET
case MSD_WRITE10_RX_PACKET:
if(USBHandleBusy(USBMSDOutHandle) == TRUE)
{
break;
}
gblCBW.dCBWDataTransferLength-=USBHandleGetLength(USBMSDOutHandle); // 64B read
msd_csw.dCSWDataResidue-=USBHandleGetLength(USBMSDOutHandle);
ptrNextData += MSD_OUT_EP_SIZE;
MSDWriteState = MSD_WRITE10_RX_SECTOR;
break;
case MSD_WRITE10_SECTOR:
{
if(LUNSectorWrite(LBA.Val, (BYTE*)&msd_buffer[0], (LBA.Val==0)?TRUE:FALSE) != TRUE)
{
break;
}
// if (status) {
// msd_csw.bCSWStatus=0x01;
// /* add some sense keys here*/
// }
LBA.Val++; // One LBA is written. Write the next LBA
TransferLength.Val--;
MSDWriteState = MSD_WRITE10_BLOCK;
break;
}
}
return MSDWriteState;
}
/******************************************************************************
Function:
BYTE MSDWriteHandler(void)
Description:
This funtion processes a write command received through
the MSD class driver
PreCondition:
None
Parameters:
None
Return Values:
BYTE - the current state of the MSDWriteHandler state
machine. The valid values are defined in MSD.h under the
MSDWriteHandler state machine declaration section
Remarks:
None
*****************************************************************************/
BYTE MSDWriteHandler(void)
{
switch(MSDWriteState)
{
case MSD_WRITE10_WAIT:
/* Read the LBA, TransferLength fields from Command Block
NOTE: CB is Big-Endian */
LBA.v[3]=gblCBW.CBWCB[2];
LBA.v[2]=gblCBW.CBWCB[3];
LBA.v[1]=gblCBW.CBWCB[4];
LBA.v[0]=gblCBW.CBWCB[5];
TransferLength.v[1]=gblCBW.CBWCB[7];
TransferLength.v[0]=gblCBW.CBWCB[8];
//Initially assume success, unless handler code later encounters an
//error condition and sets the status to 0x01 or 0x02.
msd_csw.bCSWStatus=0x0;
MSD_State = MSD_WRITE10_BLOCK;
//Fall through to MSD_WRITE10_BLOCK
case MSD_WRITE10_BLOCK:
if(TransferLength.Val == 0)
{
MSDWriteState = MSD_WRITE10_WAIT;
break;
}
MSDWriteState = MSD_WRITE10_RX_SECTOR;
ptrNextData=(BYTE *)&msd_buffer[0];
msd_csw.dCSWDataResidue=BLOCKLEN_512;
//Fall through to MSD_WRITE10_RX_SECTOR
case MSD_WRITE10_RX_SECTOR:
{
/* Read 512B into msd_buffer*/
if(msd_csw.dCSWDataResidue>0)
{
if(USBHandleBusy(USBMSDOutHandle) == TRUE)
{
break;
}
USBMSDOutHandle = USBRxOnePacket(MSD_DATA_OUT_EP,ptrNextData,MSD_OUT_EP_SIZE);
MSDWriteState = MSD_WRITE10_RX_PACKET;
//Fall through to MSD_WRITE10_RX_PACKET
}
else
{
//We finished receiving a sector worth of data from the host.
//Check if the media is write protected before deciding what
//to do with the data.
if(LUNWriteProtectState())
{
//The device appears to be write protected.
//Let host know error occurred. The bCSWStatus flag is also used by
//the write handler, to know not to even attempt the write sequence.
msd_csw.bCSWStatus=0x01;
//Set sense keys so the host knows what caused the error.
gblSenseData[LUN_INDEX].SenseKey=S_NOT_READY;
gblSenseData[LUN_INDEX].ASC=ASC_WRITE_PROTECTED;
gblSenseData[LUN_INDEX].ASCQ=ASCQ_WRITE_PROTECTED;
}
MSDWriteState = MSD_WRITE10_SECTOR;
break;
}
}
//Fall through to MSD_WRITE10_RX_PACKET
case MSD_WRITE10_RX_PACKET:
if(USBHandleBusy(USBMSDOutHandle) == TRUE)
{
break;
}
gblCBW.dCBWDataTransferLength-=USBHandleGetLength(USBMSDOutHandle); // 64B read
msd_csw.dCSWDataResidue-=USBHandleGetLength(USBMSDOutHandle);
ptrNextData += MSD_OUT_EP_SIZE;
MSDWriteState = MSD_WRITE10_RX_SECTOR;
break;
case MSD_WRITE10_SECTOR:
{
//Make sure that no error has been detected, before performing the write
//operation. If there was an error, skip the write operation, but allow
//the TransferLength to continue decrementing, so that we can eventually
//receive all OUT bytes that the host is planning on sending us. Only
//after that is complete will the host send the IN token for the CSW packet,
//which will contain the bCSWStatus letting it know an error occurred.
if(msd_csw.bCSWStatus == 0x00)
{
if(LUNSectorWrite(LBA.Val, (BYTE*)&msd_buffer[0], (LBA.Val==0)?TRUE:FALSE) != TRUE)
{
//The write operation failed for some reason. Keep track of retry
//attempts and abort if repeated write attempts also fail.
if(MSDRetryAttempt < MSD_FAILED_WRITE_MAX_ATTEMPTS)
{
MSDRetryAttempt++;
break;
}
else
{
//Too many consecutive failed write attempts have occurred.
//Need to give up and abandon the write attempt.
msd_csw.bCSWStatus=0x01; // Error 0x01 Refer page#18
// of BOT specifications
//Set error status sense keys, so the host can check them later
//to determine how to proceed.
gblSenseData[LUN_INDEX].SenseKey=S_MEDIUM_ERROR;
gblSenseData[LUN_INDEX].ASC=ASC_NO_ADDITIONAL_SENSE_INFORMATION;
gblSenseData[LUN_INDEX].ASCQ=ASCQ_NO_ADDITIONAL_SENSE_INFORMATION;
}
}
}
//One LBA is written (unless an error occurred). Advance state
//variables so we can eventually finish handling the CBW request.
LBA.Val++;
TransferLength.Val--;
MSDWriteState = MSD_WRITE10_BLOCK;
break;
}
default:
//Illegal condition which should not occur. If for some reason it
//does, try to let the host know know an error has occurred.
msd_csw.bCSWStatus=0x02; //Phase Error
MSDWriteState = MSD_WRITE10_WAIT;
}
return MSDWriteState;
}
