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

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2012.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2012  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 static const 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 static 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  = MIN(AllocationLength, sizeof(InquiryData));
 154
 155         /* Only the standard INQUIRY data is supported, check if any optional INQUIRY bits set */
 156         if ((CommandBlock.SCSICommandData[1] & ((1 << 0) | (1 << 1))) ||
 157              CommandBlock.SCSICommandData[2])
 158         {
 159                 /* Optional but unsupported bits set - update the SENSE key and fail the request */
 160                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 161                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 162                                SCSI_ASENSEQ_NO_QUALIFIER);
 163
 164                 return false;
 165         }
 166
 167         /* Write the INQUIRY data to the endpoint */
 168         Endpoint_Write_Stream_LE(&InquiryData, BytesTransferred, NULL);
 169
 170         /* Pad out remaining bytes with 0x00 */
 171         Endpoint_Null_Stream((AllocationLength - BytesTransferred), NULL);
 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 = MIN(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, NULL);
 194
 195         /* Pad out remaining bytes with 0x00 */
 196         Endpoint_Null_Stream((AllocationLength - BytesTransferred), NULL);
 197
 198         /* Finalize the stream transfer to send the last packet */
 199         Endpoint_ClearIN();
 200
 201         /* Succeed the command and update the bytes transferred counter */
 202         CommandBlock.DataTransferLength -= BytesTransferred;
 203
 204         return true;
 205 }
 206
 207 /** Command processing for an issued SCSI READ CAPACITY (10) command. This command returns information about the device's capacity
 208  *  on the selected Logical Unit (drive), as a number of OS-sized blocks.
 209  *
 210  *  \return Boolean true if the command completed successfully, false otherwise.
 211  */
 212 static bool SCSI_Command_Read_Capacity_10(void)
 213 {
 214         /* Send the total number of logical blocks in the current LUN */
 215         Endpoint_Write_32_BE(LUN_MEDIA_BLOCKS - 1);
 216
 217         /* Send the logical block size of the device (must be 512 bytes) */
 218         Endpoint_Write_32_BE(VIRTUAL_MEMORY_BLOCK_SIZE);
 219
 220         /* Check if the current command is being aborted by the host */
 221         if (IsMassStoreReset)
 222           return false;
 223
 224         /* Send the endpoint data packet to the host */
 225         Endpoint_ClearIN();
 226
 227         /* Succeed the command and update the bytes transferred counter */
 228         CommandBlock.DataTransferLength -= 8;
 229
 230         return true;
 231 }
 232
 233 /** Command processing for an issued SCSI SEND DIAGNOSTIC command. This command performs a quick check of the Dataflash ICs on the
 234  *  board, and indicates if they are present and functioning correctly. Only the Self-Test portion of the diagnostic command is
 235  *  supported.
 236  *
 237  *  \return Boolean true if the command completed successfully, false otherwise.
 238  */
 239 static bool SCSI_Command_Send_Diagnostic(void)
 240 {
 241         /* Check to see if the SELF TEST bit is not set */
 242         if (!(CommandBlock.SCSICommandData[1] & (1 << 2)))
 243         {
 244                 /* Only self-test supported - update SENSE key and fail the command */
 245                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 246                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 247                                SCSI_ASENSEQ_NO_QUALIFIER);
 248
 249                 return false;
 250         }
 251
 252         /* Check to see if all attached Dataflash ICs are functional */
 253         if (!(DataflashManager_CheckDataflashOperation()))
 254         {
 255                 /* Update SENSE key with a hardware error condition and return command fail */
 256                 SCSI_SET_SENSE(SCSI_SENSE_KEY_HARDWARE_ERROR,
 257                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 258                                SCSI_ASENSEQ_NO_QUALIFIER);
 259
 260                 return false;
 261         }
 262
 263         /* Succeed the command and update the bytes transferred counter */
 264         CommandBlock.DataTransferLength = 0;
 265
 266         return true;
 267 }
 268
 269 /** Command processing for an issued SCSI READ (10) or WRITE (10) command. This command reads in the block start address
 270  *  and total number of blocks to process, then calls the appropriate low-level Dataflash routine to handle the actual
 271  *  reading and writing of the data.
 272  *
 273  *  \param[in] IsDataRead  Indicates if the command is a READ (10) command or WRITE (10) command (DATA_READ or DATA_WRITE)
 274  *
 275  *  \return Boolean true if the command completed successfully, false otherwise.
 276  */
 277 static bool SCSI_Command_ReadWrite_10(const bool IsDataRead)
 278 {
 279         uint32_t BlockAddress;
 280         uint16_t TotalBlocks;
 281
 282         /* Check if the disk is write protected or not */
 283         if ((IsDataRead == DATA_WRITE) && DISK_READ_ONLY)
 284         {
 285                 /* Block address is invalid, update SENSE key and return command fail */
 286                 SCSI_SET_SENSE(SCSI_SENSE_KEY_DATA_PROTECT,
 287                                SCSI_ASENSE_WRITE_PROTECTED,
 288                                SCSI_ASENSEQ_NO_QUALIFIER);
 289
 290                 return false;
 291         }
 292
 293         BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
 294         TotalBlocks  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[7]);
 295
 296         /* Check if the block address is outside the maximum allowable value for the LUN */
 297         if (BlockAddress >= LUN_MEDIA_BLOCKS)
 298         {
 299                 /* Block address is invalid, update SENSE key and return command fail */
 300                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 301                                SCSI_ASENSE_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,
 302                                SCSI_ASENSEQ_NO_QUALIFIER);
 303
 304                 return false;
 305         }
 306
 307         #if (TOTAL_LUNS > 1)
 308         /* Adjust the given block address to the real media address based on the selected LUN */
 309         BlockAddress += ((uint32_t)CommandBlock.LUN * LUN_MEDIA_BLOCKS);
 310         #endif
 311
 312         /* Determine if the packet is a READ (10) or WRITE (10) command, call appropriate function */
 313         if (IsDataRead == DATA_READ)
 314           DataflashManager_ReadBlocks(BlockAddress, TotalBlocks);
 315         else
 316           DataflashManager_WriteBlocks(BlockAddress, TotalBlocks);
 317
 318         /* Update the bytes transferred counter and succeed the command */
 319         CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
 320
 321         return true;
 322 }
 323
 324 /** Command processing for an issued SCSI MODE SENSE (6) command. This command returns various informational pages about
 325  *  the SCSI device, as well as the device's Write Protect status.
 326  *
 327  *  \return Boolean true if the command completed successfully, false otherwise.
 328  */
 329 static bool SCSI_Command_ModeSense_6(void)
 330 {
 331         /* Send an empty header response with the Write Protect flag status */
 332         Endpoint_Write_8(0x00);
 333         Endpoint_Write_8(0x00);
 334         Endpoint_Write_8(DISK_READ_ONLY ? 0x80 : 0x00);
 335         Endpoint_Write_8(0x00);
 336         Endpoint_ClearIN();
 337
 338         /* Update the bytes transferred counter and succeed the command */
 339         CommandBlock.DataTransferLength -= 4;
 340
 341         return true;
 342 }
 343