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

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2011.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2011  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         bool CommandSuccess = false;
  92
  93         /* Run the appropriate SCSI command hander function based on the passed command */
  94         switch (CommandBlock.SCSICommandData[0])
  95         {
  96                 case SCSI_CMD_INQUIRY:
  97                         CommandSuccess = SCSI_Command_Inquiry();
  98                         break;
  99                 case SCSI_CMD_REQUEST_SENSE:
 100                         CommandSuccess = SCSI_Command_Request_Sense();
 101                         break;
 102                 case SCSI_CMD_READ_CAPACITY_10:
 103                         CommandSuccess = SCSI_Command_Read_Capacity_10();
 104                         break;
 105                 case SCSI_CMD_SEND_DIAGNOSTIC:
 106                         CommandSuccess = SCSI_Command_Send_Diagnostic();
 107                         break;
 108                 case SCSI_CMD_WRITE_10:
 109                         CommandSuccess = SCSI_Command_ReadWrite_10(DATA_WRITE);
 110                         break;
 111                 case SCSI_CMD_READ_10:
 112                         CommandSuccess = SCSI_Command_ReadWrite_10(DATA_READ);
 113                         break;
 114                 case SCSI_CMD_MODE_SENSE_6:
 115                         CommandSuccess = SCSI_Command_ModeSense_6();
 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                         CommandSuccess = true;
 122                         CommandBlock.DataTransferLength = 0;
 123                         break;
 124                 default:
 125                         /* Update the SENSE key to reflect the invalid command */
 126                         SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 127                                    SCSI_ASENSE_INVALID_COMMAND,
 128                                    SCSI_ASENSEQ_NO_QUALIFIER);
 129                         break;
 130         }
 131
 132         /* Check if command was successfully processed */
 133         if (CommandSuccess)
 134         {
 135                 SCSI_SET_SENSE(SCSI_SENSE_KEY_GOOD,
 136                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 137                                SCSI_ASENSEQ_NO_QUALIFIER);
 138
 139                 return true;
 140         }
 141
 142         return false;
 143 }
 144
 145 /** Command processing for an issued SCSI INQUIRY command. This command returns information about the device's features
 146  *  and capabilities to the host.
 147  *
 148  *  \return Boolean true if the command completed successfully, false otherwise.
 149  */
 150 static bool SCSI_Command_Inquiry(void)
 151 {
 152         uint16_t AllocationLength  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[3]);
 153         uint16_t BytesTransferred  = (AllocationLength < sizeof(InquiryData))? AllocationLength :
 154                                                                                sizeof(InquiryData);
 155
 156         /* Only the standard INQUIRY data is supported, check if any optional INQUIRY bits set */
 157         if ((CommandBlock.SCSICommandData[1] & ((1 << 0) | (1 << 1))) ||
 158              CommandBlock.SCSICommandData[2])
 159         {
 160                 /* Optional but unsupported bits set - update the SENSE key and fail the request */
 161                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 162                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 163                                SCSI_ASENSEQ_NO_QUALIFIER);
 164
 165                 return false;
 166         }
 167
 168         /* Write the INQUIRY data to the endpoint */
 169         Endpoint_Write_Stream_LE(&InquiryData, BytesTransferred, NULL);
 170
 171         /* Pad out remaining bytes with 0x00 */
 172         Endpoint_Null_Stream((AllocationLength - BytesTransferred), NULL);
 173
 174         /* Finalize the stream transfer to send the last packet */
 175         Endpoint_ClearIN();
 176
 177         /* Succeed the command and update the bytes transferred counter */
 178         CommandBlock.DataTransferLength -= BytesTransferred;
 179
 180         return true;
 181 }
 182
 183 /** Command processing for an issued SCSI REQUEST SENSE command. This command returns information about the last issued command,
 184  *  including the error code and additional error information so that the host can determine why a command failed to complete.
 185  *
 186  *  \return Boolean true if the command completed successfully, false otherwise.
 187  */
 188 static bool SCSI_Command_Request_Sense(void)
 189 {
 190         uint8_t  AllocationLength = CommandBlock.SCSICommandData[4];
 191         uint8_t  BytesTransferred = (AllocationLength < sizeof(SenseData))? AllocationLength : sizeof(SenseData);
 192
 193         /* Send the SENSE data - this indicates to the host the status of the last command */
 194         Endpoint_Write_Stream_LE(&SenseData, BytesTransferred, NULL);
 195
 196         /* Pad out remaining bytes with 0x00 */
 197         Endpoint_Null_Stream((AllocationLength - BytesTransferred), NULL);
 198
 199         /* Finalize the stream transfer to send the last packet */
 200         Endpoint_ClearIN();
 201
 202         /* Succeed the command and update the bytes transferred counter */
 203         CommandBlock.DataTransferLength -= BytesTransferred;
 204
 205         return true;
 206 }
 207
 208 /** Command processing for an issued SCSI READ CAPACITY (10) command. This command returns information about the device's capacity
 209  *  on the selected Logical Unit (drive), as a number of OS-sized blocks.
 210  *
 211  *  \return Boolean true if the command completed successfully, false otherwise.
 212  */
 213 static bool SCSI_Command_Read_Capacity_10(void)
 214 {
 215         /* Send the total number of logical blocks in the current LUN */
 216         Endpoint_Write_DWord_BE(LUN_MEDIA_BLOCKS - 1);
 217
 218         /* Send the logical block size of the device (must be 512 bytes) */
 219         Endpoint_Write_DWord_BE(VIRTUAL_MEMORY_BLOCK_SIZE);
 220
 221         /* Check if the current command is being aborted by the host */
 222         if (IsMassStoreReset)
 223           return false;
 224
 225         /* Send the endpoint data packet to the host */
 226         Endpoint_ClearIN();
 227
 228         /* Succeed the command and update the bytes transferred counter */
 229         CommandBlock.DataTransferLength -= 8;
 230
 231         return true;
 232 }
 233
 234 /** Command processing for an issued SCSI SEND DIAGNOSTIC command. This command performs a quick check of the Dataflash ICs on the
 235  *  board, and indicates if they are present and functioning correctly. Only the Self-Test portion of the diagnostic command is
 236  *  supported.
 237  *
 238  *  \return Boolean true if the command completed successfully, false otherwise.
 239  */
 240 static bool SCSI_Command_Send_Diagnostic(void)
 241 {
 242         /* Check to see if the SELF TEST bit is not set */
 243         if (!(CommandBlock.SCSICommandData[1] & (1 << 2)))
 244         {
 245                 /* Only self-test supported - update SENSE key and fail the command */
 246                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 247                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 248                                SCSI_ASENSEQ_NO_QUALIFIER);
 249
 250                 return false;
 251         }
 252
 253         /* Check to see if all attached Dataflash ICs are functional */
 254         if (!(DataflashManager_CheckDataflashOperation()))
 255         {
 256                 /* Update SENSE key with a hardware error condition and return command fail */
 257                 SCSI_SET_SENSE(SCSI_SENSE_KEY_HARDWARE_ERROR,
 258                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 259                                SCSI_ASENSEQ_NO_QUALIFIER);
 260
 261                 return false;
 262         }
 263
 264         /* Succeed the command and update the bytes transferred counter */
 265         CommandBlock.DataTransferLength = 0;
 266
 267         return true;
 268 }
 269
 270 /** Command processing for an issued SCSI READ (10) or WRITE (10) command. This command reads in the block start address
 271  *  and total number of blocks to process, then calls the appropriate low-level Dataflash routine to handle the actual
 272  *  reading and writing of the data.
 273  *
 274  *  \param[in] IsDataRead  Indicates if the command is a READ (10) command or WRITE (10) command (DATA_READ or DATA_WRITE)
 275  *
 276  *  \return Boolean true if the command completed successfully, false otherwise.
 277  */
 278 static bool SCSI_Command_ReadWrite_10(const bool IsDataRead)
 279 {
 280         uint32_t BlockAddress;
 281         uint16_t TotalBlocks;
 282
 283         /* Check if the disk is write protected or not */
 284         if ((IsDataRead == DATA_WRITE) && DISK_READ_ONLY)
 285         {
 286                 /* Block address is invalid, update SENSE key and return command fail */
 287                 SCSI_SET_SENSE(SCSI_SENSE_KEY_DATA_PROTECT,
 288                                SCSI_ASENSE_WRITE_PROTECTED,
 289                                SCSI_ASENSEQ_NO_QUALIFIER);
 290
 291                 return false;
 292         }
 293
 294         BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
 295         TotalBlocks  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[7]);
 296
 297         /* Check if the block address is outside the maximum allowable value for the LUN */
 298         if (BlockAddress >= LUN_MEDIA_BLOCKS)
 299         {
 300                 /* Block address is invalid, update SENSE key and return command fail */
 301                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 302                                SCSI_ASENSE_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,
 303                                SCSI_ASENSEQ_NO_QUALIFIER);
 304
 305                 return false;
 306         }
 307
 308         #if (TOTAL_LUNS > 1)
 309         /* Adjust the given block address to the real media address based on the selected LUN */
 310         BlockAddress += ((uint32_t)CommandBlock.LUN * LUN_MEDIA_BLOCKS);
 311         #endif
 312
 313         /* Determine if the packet is a READ (10) or WRITE (10) command, call appropriate function */
 314         if (IsDataRead == DATA_READ)
 315           DataflashManager_ReadBlocks(BlockAddress, TotalBlocks);
 316         else
 317           DataflashManager_WriteBlocks(BlockAddress, TotalBlocks);
 318
 319         /* Update the bytes transferred counter and succeed the command */
 320         CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
 321
 322         return true;
 323 }
 324
 325 /** Command processing for an issued SCSI MODE SENSE (6) command. This command returns various informational pages about
 326  *  the SCSI device, as well as the device's Write Protect status.
 327  *
 328  *  \return Boolean true if the command completed successfully, false otherwise.
 329  */
 330 static bool SCSI_Command_ModeSense_6(void)
 331 {
 332         /* Send an empty header response with the Write Protect flag status */
 333         Endpoint_Write_Byte(0x00);
 334         Endpoint_Write_Byte(0x00);
 335         Endpoint_Write_Byte(DISK_READ_ONLY ? 0x80 : 0x00);
 336         Endpoint_Write_Byte(0x00);
 337         Endpoint_ClearIN();
 338
 339         /* Update the bytes transferred counter and succeed the command */
 340         CommandBlock.DataTransferLength -= 4;
 341
 342         return true;
 343 }