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_TEST_UNIT_READY:
 115                 case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
 116                 case SCSI_CMD_VERIFY_10:
 117                         /* These commands should just succeed, no handling required */
 118                         CommandSuccess = true;
 119                         CommandBlock.DataTransferLength = 0;
 120                         break;
 121                 default:
 122                         /* Update the SENSE key to reflect the invalid command */
 123                         SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 124                                    SCSI_ASENSE_INVALID_COMMAND,
 125                                    SCSI_ASENSEQ_NO_QUALIFIER);
 126                         break;
 127         }
 128
 129         /* Check if command was successfully processed */
 130         if (CommandSuccess)
 131         {
 132                 SCSI_SET_SENSE(SCSI_SENSE_KEY_GOOD,
 133                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 134                                SCSI_ASENSEQ_NO_QUALIFIER);
 135
 136                 return true;
 137         }
 138
 139         return false;
 140 }
 141
 142 /** Command processing for an issued SCSI INQUIRY command. This command returns information about the device's features
 143  *  and capabilities to the host.
 144  *
 145  *  \return Boolean true if the command completed successfully, false otherwise.
 146  */
 147 static bool SCSI_Command_Inquiry(void)
 148 {
 149         uint16_t AllocationLength  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[3]);
 150         uint16_t BytesTransferred  = (AllocationLength < sizeof(InquiryData))? AllocationLength :
 151                                                                                sizeof(InquiryData);
 152
 153         /* Only the standard INQUIRY data is supported, check if any optional INQUIRY bits set */
 154         if ((CommandBlock.SCSICommandData[1] & ((1 << 0) | (1 << 1))) ||
 155              CommandBlock.SCSICommandData[2])
 156         {
 157                 /* Optional but unsupported bits set - update the SENSE key and fail the request */
 158                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 159                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 160                                SCSI_ASENSEQ_NO_QUALIFIER);
 161
 162                 return false;
 163         }
 164
 165         /* Write the INQUIRY data to the endpoint */
 166         Endpoint_Write_Stream_LE(&InquiryData, BytesTransferred, StreamCallback_AbortOnMassStoreReset);
 167
 168         uint8_t PadBytes[AllocationLength - BytesTransferred];
 169
 170         /* Pad out remaining bytes with 0x00 */
 171         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 172
 173         /* Finalize the stream transfer to send the last packet */
 174         Endpoint_ClearIN();
 175
 176         /* Succeed the command and update the bytes transferred counter */
 177         CommandBlock.DataTransferLength -= BytesTransferred;
 178
 179         return true;
 180 }
 181
 182 /** Command processing for an issued SCSI REQUEST SENSE command. This command returns information about the last issued command,
 183  *  including the error code and additional error information so that the host can determine why a command failed to complete.
 184  *
 185  *  \return Boolean true if the command completed successfully, false otherwise.
 186  */
 187 static bool SCSI_Command_Request_Sense(void)
 188 {
 189         uint8_t  AllocationLength = CommandBlock.SCSICommandData[4];
 190         uint8_t  BytesTransferred = (AllocationLength < sizeof(SenseData))? AllocationLength : sizeof(SenseData);
 191
 192         /* Send the SENSE data - this indicates to the host the status of the last command */
 193         Endpoint_Write_Stream_LE(&SenseData, BytesTransferred, StreamCallback_AbortOnMassStoreReset);
 194
 195         uint8_t PadBytes[AllocationLength - BytesTransferred];
 196
 197         /* Pad out remaining bytes with 0x00 */
 198         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 199
 200         /* Finalize the stream transfer to send the last packet */
 201         Endpoint_ClearIN();
 202
 203         /* Succeed the command and update the bytes transferred counter */
 204         CommandBlock.DataTransferLength -= BytesTransferred;
 205
 206         return true;
 207 }
 208
 209 /** Command processing for an issued SCSI READ CAPACITY (10) command. This command returns information about the device's capacity
 210  *  on the selected Logical Unit (drive), as a number of OS-sized blocks.
 211  *
 212  *  \return Boolean true if the command completed successfully, false otherwise.
 213  */
 214 static bool SCSI_Command_Read_Capacity_10(void)
 215 {
 216         /* Send the total number of logical blocks in the current LUN */
 217         Endpoint_Write_DWord_BE(LUN_MEDIA_BLOCKS - 1);
 218
 219         /* Send the logical block size of the device (must be 512 bytes) */
 220         Endpoint_Write_DWord_BE(VIRTUAL_MEMORY_BLOCK_SIZE);
 221
 222         /* Check if the current command is being aborted by the host */
 223         if (IsMassStoreReset)
 224           return false;
 225
 226         /* Send the endpoint data packet to the host */
 227         Endpoint_ClearIN();
 228
 229         /* Succeed the command and update the bytes transferred counter */
 230         CommandBlock.DataTransferLength -= 8;
 231
 232         return true;
 233 }
 234
 235 /** Command processing for an issued SCSI SEND DIAGNOSTIC command. This command performs a quick check of the Dataflash ICs on the
 236  *  board, and indicates if they are present and functioning correctly. Only the Self-Test portion of the diagnostic command is
 237  *  supported.
 238  *
 239  *  \return Boolean true if the command completed successfully, false otherwise.
 240  */
 241 static bool SCSI_Command_Send_Diagnostic(void)
 242 {
 243         /* Check to see if the SELF TEST bit is not set */
 244         if (!(CommandBlock.SCSICommandData[1] & (1 << 2)))
 245         {
 246                 /* Only self-test supported - update SENSE key and fail the command */
 247                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 248                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 249                                SCSI_ASENSEQ_NO_QUALIFIER);
 250
 251                 return false;
 252         }
 253
 254         /* Check to see if all attached Dataflash ICs are functional */
 255         if (!(DataflashManager_CheckDataflashOperation()))
 256         {
 257                 /* Update SENSE key with a hardware error condition and return command fail */
 258                 SCSI_SET_SENSE(SCSI_SENSE_KEY_HARDWARE_ERROR,
 259                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 260                                SCSI_ASENSEQ_NO_QUALIFIER);
 261
 262                 return false;
 263         }
 264
 265         /* Succeed the command and update the bytes transferred counter */
 266         CommandBlock.DataTransferLength = 0;
 267
 268         return true;
 269 }
 270
 271 /** Command processing for an issued SCSI READ (10) or WRITE (10) command. This command reads in the block start address
 272  *  and total number of blocks to process, then calls the appropriate low-level Dataflash routine to handle the actual
 273  *  reading and writing of the data.
 274  *
 275  *  \param[in] IsDataRead  Indicates if the command is a READ (10) command or WRITE (10) command (DATA_READ or DATA_WRITE)
 276  *
 277  *  \return Boolean true if the command completed successfully, false otherwise.
 278  */
 279 static bool SCSI_Command_ReadWrite_10(const bool IsDataRead)
 280 {
 281         uint32_t BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
 282         uint16_t TotalBlocks  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[7]);
 283
 284         /* Check if the block address is outside the maximum allowable value for the LUN */
 285         if (BlockAddress >= LUN_MEDIA_BLOCKS)
 286         {
 287                 /* Block address is invalid, update SENSE key and return command fail */
 288                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 289                                SCSI_ASENSE_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,
 290                                SCSI_ASENSEQ_NO_QUALIFIER);
 291
 292                 return false;
 293         }
 294
 295         #if (TOTAL_LUNS > 1)
 296         /* Adjust the given block address to the real media address based on the selected LUN */
 297         BlockAddress += ((uint32_t)CommandBlock.LUN * LUN_MEDIA_BLOCKS);
 298         #endif
 299
 300         /* Determine if the packet is a READ (10) or WRITE (10) command, call appropriate function */
 301         if (IsDataRead == DATA_READ)
 302           DataflashManager_ReadBlocks(BlockAddress, TotalBlocks);
 303         else
 304           DataflashManager_WriteBlocks(BlockAddress, TotalBlocks);
 305
 306         /* Update the bytes transferred counter and succeed the command */
 307         CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
 308
 309         return true;
 310 }
 311