Demos/Device/LowLevel/MassStorage/Lib/SCSI.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  SCSI command processing routines, for SCSI commands issued by the host. Mass Storage
  34  *  devices use a thin "Bulk-Only Transport" protocol for issuing commands and status information,
  35  *  which wrap around standard SCSI device commands for controlling the actual storage medium.
  36  */
  37
  38 #define  INCLUDE_FROM_SCSI_C
  39 #include "SCSI.h"
  40
  41 /** Structure to hold the SCSI response data to a SCSI INQUIRY command. This gives information about the device's
  42  *  features and capabilities.
  43  */
  44 SCSI_Inquiry_Response_t InquiryData =
  45         {
  46                 .DeviceType          = DEVICE_TYPE_BLOCK,
  47                 .PeripheralQualifier = 0,
  48
  49                 .Removable           = true,
  50
  51                 .Version             = 0,
  52
  53                 .ResponseDataFormat  = 2,
  54                 .NormACA             = false,
  55                 .TrmTsk              = false,
  56                 .AERC                = false,
  57
  58                 .AdditionalLength    = 0x1F,
  59
  60                 .SoftReset           = false,
  61                 .CmdQue              = false,
  62                 .Linked              = false,
  63                 .Sync                = false,
  64                 .WideBus16Bit        = false,
  65                 .WideBus32Bit        = false,
  66                 .RelAddr             = false,
  67
  68                 .VendorID            = "LUFA",
  69                 .ProductID           = "Dataflash Disk",
  70                 .RevisionID          = {'0','.','0','0'},
  71         };
  72
  73 /** Structure to hold the sense data for the last issued SCSI command, which is returned to the host after a SCSI REQUEST SENSE
  74  *  command is issued. This gives information on exactly why the last command failed to complete.
  75  */
  76 SCSI_Request_Sense_Response_t SenseData =
  77         {
  78                 .ResponseCode        = 0x70,
  79                 .AdditionalLength    = 0x0A,
  80         };
  81
  82
  83 /** Main routine to process the SCSI command located in the Command Block Wrapper read from the host. This dispatches
  84  *  to the appropriate SCSI command handling routine if the issued command is supported by the device, else it returns
  85  *  a command failure due to a ILLEGAL REQUEST.
  86  *
  87  *  \return Boolean true if the command completed successfully, false otherwise
  88  */
  89 bool SCSI_DecodeSCSICommand(void)
  90 {
  91         /* Set initial sense data, before the requested command is processed */
  92         SCSI_SET_SENSE(SCSI_SENSE_KEY_GOOD,
  93                        SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
  94                        SCSI_ASENSEQ_NO_QUALIFIER);
  95
  96         /* Run the appropriate SCSI command hander function based on the passed command */
  97         switch (CommandBlock.SCSICommandData[0])
  98         {
  99                 case SCSI_CMD_INQUIRY:
 100                         SCSI_Command_Inquiry();
 101                         break;
 102                 case SCSI_CMD_REQUEST_SENSE:
 103                         SCSI_Command_Request_Sense();
 104                         break;
 105                 case SCSI_CMD_READ_CAPACITY_10:
 106                         SCSI_Command_Read_Capacity_10();
 107                         break;
 108                 case SCSI_CMD_SEND_DIAGNOSTIC:
 109                         SCSI_Command_Send_Diagnostic();
 110                         break;
 111                 case SCSI_CMD_WRITE_10:
 112                         SCSI_Command_ReadWrite_10(DATA_WRITE);
 113                         break;
 114                 case SCSI_CMD_READ_10:
 115                         SCSI_Command_ReadWrite_10(DATA_READ);
 116                         break;
 117                 case SCSI_CMD_TEST_UNIT_READY:
 118                 case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
 119                 case SCSI_CMD_VERIFY_10:
 120                         /* These commands should just succeed, no handling required */
 121                         CommandBlock.DataTransferLength = 0;
 122                         break;
 123                 default:
 124                         /* Update the SENSE key to reflect the invalid command */
 125                         SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 126                                    SCSI_ASENSE_INVALID_COMMAND,
 127                                    SCSI_ASENSEQ_NO_QUALIFIER);
 128                         break;
 129         }
 130
 131         return (SenseData.SenseKey == SCSI_SENSE_KEY_GOOD);
 132 }
 133
 134 /** Command processing for an issued SCSI INQUIRY command. This command returns information about the device's features
 135  *  and capabilities to the host.
 136  */
 137 static void SCSI_Command_Inquiry(void)
 138 {
 139         uint16_t AllocationLength  = (((uint16_t)CommandBlock.SCSICommandData[3] << 8) |
 140                                                  CommandBlock.SCSICommandData[4]);
 141         uint16_t BytesTransferred  = (AllocationLength < sizeof(InquiryData))? AllocationLength :
 142                                                                                sizeof(InquiryData);
 143
 144         /* Only the standard INQUIRY data is supported, check if any optional INQUIRY bits set */
 145         if ((CommandBlock.SCSICommandData[1] & ((1 << 0) | (1 << 1))) ||
 146              CommandBlock.SCSICommandData[2])
 147         {
 148                 /* Optional but unsupported bits set - update the SENSE key and fail the request */
 149                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 150                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 151                                SCSI_ASENSEQ_NO_QUALIFIER);
 152
 153                 return;
 154         }
 155
 156         /* Write the INQUIRY data to the endpoint */
 157         Endpoint_Write_Stream_LE(&InquiryData, BytesTransferred, StreamCallback_AbortOnMassStoreReset);
 158
 159         uint8_t PadBytes[AllocationLength - BytesTransferred];
 160
 161         /* Pad out remaining bytes with 0x00 */
 162         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 163
 164         /* Finalize the stream transfer to send the last packet */
 165         Endpoint_ClearIN();
 166
 167         /* Succeed the command and update the bytes transferred counter */
 168         CommandBlock.DataTransferLength -= BytesTransferred;
 169 }
 170
 171 /** Command processing for an issued SCSI REQUEST SENSE command. This command returns information about the last issued command,
 172  *  including the error code and additional error information so that the host can determine why a command failed to complete.
 173  */
 174 static void SCSI_Command_Request_Sense(void)
 175 {
 176         uint8_t  AllocationLength = CommandBlock.SCSICommandData[4];
 177         uint8_t  BytesTransferred = (AllocationLength < sizeof(SenseData))? AllocationLength : sizeof(SenseData);
 178
 179         /* Send the SENSE data - this indicates to the host the status of the last command */
 180         Endpoint_Write_Stream_LE(&SenseData, BytesTransferred, StreamCallback_AbortOnMassStoreReset);
 181
 182         uint8_t PadBytes[AllocationLength - BytesTransferred];
 183
 184         /* Pad out remaining bytes with 0x00 */
 185         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 186
 187         /* Finalize the stream transfer to send the last packet */
 188         Endpoint_ClearIN();
 189
 190         /* Succeed the command and update the bytes transferred counter */
 191         CommandBlock.DataTransferLength -= BytesTransferred;
 192 }
 193
 194 /** Command processing for an issued SCSI READ CAPACITY (10) command. This command returns information about the device's capacity
 195  *  on the selected Logical Unit (drive), as a number of OS-sized blocks.
 196  */
 197 static void SCSI_Command_Read_Capacity_10(void)
 198 {
 199         /* Send the total number of logical blocks in the current LUN */
 200         Endpoint_Write_DWord_BE(LUN_MEDIA_BLOCKS - 1);
 201
 202         /* Send the logical block size of the device (must be 512 bytes) */
 203         Endpoint_Write_DWord_BE(VIRTUAL_MEMORY_BLOCK_SIZE);
 204
 205         /* Check if the current command is being aborted by the host */
 206         if (IsMassStoreReset)
 207           return;
 208
 209         /* Send the endpoint data packet to the host */
 210         Endpoint_ClearIN();
 211
 212         /* Succeed the command and update the bytes transferred counter */
 213         CommandBlock.DataTransferLength -= 8;
 214 }
 215
 216 /** Command processing for an issued SCSI SEND DIAGNOSTIC command. This command performs a quick check of the Dataflash ICs on the
 217  *  board, and indicates if they are present and functioning correctly. Only the Self-Test portion of the diagnostic command is
 218  *  supported.
 219  */
 220 static void SCSI_Command_Send_Diagnostic(void)
 221 {
 222         /* Check to see if the SELF TEST bit is not set */
 223         if (!(CommandBlock.SCSICommandData[1] & (1 << 2)))
 224         {
 225                 /* Only self-test supported - update SENSE key and fail the command */
 226                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 227                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 228                                SCSI_ASENSEQ_NO_QUALIFIER);
 229
 230                 return;
 231         }
 232
 233         /* Check to see if all attached Dataflash ICs are functional */
 234         if (!(DataflashManager_CheckDataflashOperation()))
 235         {
 236                 /* Update SENSE key with a hardware error condition and return command fail */
 237                 SCSI_SET_SENSE(SCSI_SENSE_KEY_HARDWARE_ERROR,
 238                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 239                                SCSI_ASENSEQ_NO_QUALIFIER);
 240
 241                 return;
 242         }
 243
 244         /* Succeed the command and update the bytes transferred counter */
 245         CommandBlock.DataTransferLength = 0;
 246 }
 247
 248 /** Command processing for an issued SCSI READ (10) or WRITE (10) command. This command reads in the block start address
 249  *  and total number of blocks to process, then calls the appropriate low-level dataflash routine to handle the actual
 250  *  reading and writing of the data.
 251  *
 252  *  \param[in] IsDataRead  Indicates if the command is a READ (10) command or WRITE (10) command (DATA_READ or DATA_WRITE)
 253  */
 254 static void SCSI_Command_ReadWrite_10(const bool IsDataRead)
 255 {
 256         uint32_t BlockAddress;
 257         uint16_t TotalBlocks;
 258
 259         /* Load in the 32-bit block address (SCSI uses big-endian, so have to reverse the byte order) */
 260         BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
 261
 262         /* Load in the 16-bit total blocks (SCSI uses big-endian, so have to reverse the byte order) */
 263         TotalBlocks  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[7]);
 264
 265         /* Check if the block address is outside the maximum allowable value for the LUN */
 266         if (BlockAddress >= LUN_MEDIA_BLOCKS)
 267         {
 268                 /* Block address is invalid, update SENSE key and return command fail */
 269                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 270                                SCSI_ASENSE_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,
 271                                SCSI_ASENSEQ_NO_QUALIFIER);
 272
 273                 return;
 274         }
 275
 276         #if (TOTAL_LUNS > 1)
 277         /* Adjust the given block address to the real media address based on the selected LUN */
 278         BlockAddress += ((uint32_t)CommandBlock.LUN * LUN_MEDIA_BLOCKS);
 279         #endif
 280
 281         /* Determine if the packet is a READ (10) or WRITE (10) command, call appropriate function */
 282         if (IsDataRead == DATA_READ)
 283           DataflashManager_ReadBlocks(BlockAddress, TotalBlocks);
 284         else
 285           DataflashManager_WriteBlocks(BlockAddress, TotalBlocks);
 286
 287         /* Update the bytes transferred counter and succeed the command */
 288         CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
 289 }