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.lufa-lib.org
   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         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, StreamCallback_AbortOnMassStoreReset);
 170
 171         uint8_t PadBytes[AllocationLength - BytesTransferred];
 172
 173         /* Pad out remaining bytes with 0x00 */
 174         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 175
 176         /* Finalize the stream transfer to send the last packet */
 177         Endpoint_ClearIN();
 178
 179         /* Succeed the command and update the bytes transferred counter */
 180         CommandBlock.DataTransferLength -= BytesTransferred;
 181
 182         return true;
 183 }
 184
 185 /** Command processing for an issued SCSI REQUEST SENSE command. This command returns information about the last issued command,
 186  *  including the error code and additional error information so that the host can determine why a command failed to complete.
 187  *
 188  *  \return Boolean true if the command completed successfully, false otherwise.
 189  */
 190 static bool SCSI_Command_Request_Sense(void)
 191 {
 192         uint8_t  AllocationLength = CommandBlock.SCSICommandData[4];
 193         uint8_t  BytesTransferred = (AllocationLength < sizeof(SenseData))? AllocationLength : sizeof(SenseData);
 194
 195         /* Send the SENSE data - this indicates to the host the status of the last command */
 196         Endpoint_Write_Stream_LE(&SenseData, BytesTransferred, StreamCallback_AbortOnMassStoreReset);
 197
 198         uint8_t PadBytes[AllocationLength - BytesTransferred];
 199
 200         /* Pad out remaining bytes with 0x00 */
 201         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 202
 203         /* Finalize the stream transfer to send the last packet */
 204         Endpoint_ClearIN();
 205
 206         /* Succeed the command and update the bytes transferred counter */
 207         CommandBlock.DataTransferLength -= BytesTransferred;
 208
 209         return true;
 210 }
 211
 212 /** Command processing for an issued SCSI READ CAPACITY (10) command. This command returns information about the device's capacity
 213  *  on the selected Logical Unit (drive), as a number of OS-sized blocks.
 214  *
 215  *  \return Boolean true if the command completed successfully, false otherwise.
 216  */
 217 static bool SCSI_Command_Read_Capacity_10(void)
 218 {
 219         /* Send the total number of logical blocks in the current LUN */
 220         Endpoint_Write_DWord_BE(LUN_MEDIA_BLOCKS - 1);
 221
 222         /* Send the logical block size of the device (must be 512 bytes) */
 223         Endpoint_Write_DWord_BE(VIRTUAL_MEMORY_BLOCK_SIZE);
 224
 225         /* Check if the current command is being aborted by the host */
 226         if (IsMassStoreReset)
 227           return false;
 228
 229         /* Send the endpoint data packet to the host */
 230         Endpoint_ClearIN();
 231
 232         /* Succeed the command and update the bytes transferred counter */
 233         CommandBlock.DataTransferLength -= 8;
 234
 235         return true;
 236 }
 237
 238 /** Command processing for an issued SCSI SEND DIAGNOSTIC command. This command performs a quick check of the Dataflash ICs on the
 239  *  board, and indicates if they are present and functioning correctly. Only the Self-Test portion of the diagnostic command is
 240  *  supported.
 241  *
 242  *  \return Boolean true if the command completed successfully, false otherwise.
 243  */
 244 static bool SCSI_Command_Send_Diagnostic(void)
 245 {
 246         /* Check to see if the SELF TEST bit is not set */
 247         if (!(CommandBlock.SCSICommandData[1] & (1 << 2)))
 248         {
 249                 /* Only self-test supported - update SENSE key and fail the command */
 250                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 251                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 252                                SCSI_ASENSEQ_NO_QUALIFIER);
 253
 254                 return false;
 255         }
 256
 257         /* Check to see if all attached Dataflash ICs are functional */
 258         if (!(DataflashManager_CheckDataflashOperation()))
 259         {
 260                 /* Update SENSE key with a hardware error condition and return command fail */
 261                 SCSI_SET_SENSE(SCSI_SENSE_KEY_HARDWARE_ERROR,
 262                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 263                                SCSI_ASENSEQ_NO_QUALIFIER);
 264
 265                 return false;
 266         }
 267
 268         /* Succeed the command and update the bytes transferred counter */
 269         CommandBlock.DataTransferLength = 0;
 270
 271         return true;
 272 }
 273
 274 /** Command processing for an issued SCSI READ (10) or WRITE (10) command. This command reads in the block start address
 275  *  and total number of blocks to process, then calls the appropriate low-level Dataflash routine to handle the actual
 276  *  reading and writing of the data.
 277  *
 278  *  \param[in] IsDataRead  Indicates if the command is a READ (10) command or WRITE (10) command (DATA_READ or DATA_WRITE)
 279  *
 280  *  \return Boolean true if the command completed successfully, false otherwise.
 281  */
 282 static bool SCSI_Command_ReadWrite_10(const bool IsDataRead)
 283 {
 284         uint32_t BlockAddress;
 285         uint16_t TotalBlocks;
 286
 287         /* Check if the disk is write protected or not */
 288         if ((IsDataRead == DATA_WRITE) && DISK_READ_ONLY)
 289         {
 290                 /* Block address is invalid, update SENSE key and return command fail */
 291                 SCSI_SET_SENSE(SCSI_SENSE_KEY_DATA_PROTECT,
 292                                SCSI_ASENSE_WRITE_PROTECTED,
 293                                SCSI_ASENSEQ_NO_QUALIFIER);
 294
 295                 return false;
 296         }
 297
 298         BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
 299         TotalBlocks  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[7]);
 300
 301         /* Check if the block address is outside the maximum allowable value for the LUN */
 302         if (BlockAddress >= LUN_MEDIA_BLOCKS)
 303         {
 304                 /* Block address is invalid, update SENSE key and return command fail */
 305                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 306                                SCSI_ASENSE_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,
 307                                SCSI_ASENSEQ_NO_QUALIFIER);
 308
 309                 return false;
 310         }
 311
 312         #if (TOTAL_LUNS > 1)
 313         /* Adjust the given block address to the real media address based on the selected LUN */
 314         BlockAddress += ((uint32_t)CommandBlock.LUN * LUN_MEDIA_BLOCKS);
 315         #endif
 316
 317         /* Determine if the packet is a READ (10) or WRITE (10) command, call appropriate function */
 318         if (IsDataRead == DATA_READ)
 319           DataflashManager_ReadBlocks(BlockAddress, TotalBlocks);
 320         else
 321           DataflashManager_WriteBlocks(BlockAddress, TotalBlocks);
 322
 323         /* Update the bytes transferred counter and succeed the command */
 324         CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
 325
 326         return true;
 327 }
 328
 329 /** Command processing for an issued SCSI MODE SENSE (6) command. This command returns various informational pages about
 330  *  the SCSI device, as well as the device's Write Protect status.
 331  *
 332  *  \return Boolean true if the command completed successfully, false otherwise.
 333  */
 334 static bool SCSI_Command_ModeSense_6(void)
 335 {
 336         /* Send an empty header response with the Write Protect flag status */
 337         Endpoint_Write_Byte(0x00);
 338         Endpoint_Write_Byte(0x00);
 339         Endpoint_Write_Byte(DISK_READ_ONLY ? 0x80 : 0x00);
 340         Endpoint_Write_Byte(0x00);
 341         Endpoint_ClearIN();
 342
 343         /* Update the bytes transferred counter and succeed the command */
 344         CommandBlock.DataTransferLength -= 4;
 345
 346         return true;
 347 }