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  = SwapEndian_16(*(uint32_t*)&CommandBlock.SCSICommandData[3]);
 140         uint16_t BytesTransferred  = (AllocationLength < sizeof(InquiryData))? AllocationLength :
 141                                                                                sizeof(InquiryData);
 142
 143         /* Only the standard INQUIRY data is supported, check if any optional INQUIRY bits set */
 144         if ((CommandBlock.SCSICommandData[1] & ((1 << 0) | (1 << 1))) ||
 145              CommandBlock.SCSICommandData[2])
 146         {
 147                 /* Optional but unsupported bits set - update the SENSE key and fail the request */
 148                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 149                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 150                                SCSI_ASENSEQ_NO_QUALIFIER);
 151
 152                 return;
 153         }
 154
 155         /* Write the INQUIRY data to the endpoint */
 156         Endpoint_Write_Stream_LE(&InquiryData, BytesTransferred, StreamCallback_AbortOnMassStoreReset);
 157
 158         uint8_t PadBytes[AllocationLength - BytesTransferred];
 159
 160         /* Pad out remaining bytes with 0x00 */
 161         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 162
 163         /* Finalize the stream transfer to send the last packet */
 164         Endpoint_ClearIN();
 165
 166         /* Succeed the command and update the bytes transferred counter */
 167         CommandBlock.DataTransferLength -= BytesTransferred;
 168 }
 169
 170 /** Command processing for an issued SCSI REQUEST SENSE command. This command returns information about the last issued command,
 171  *  including the error code and additional error information so that the host can determine why a command failed to complete.
 172  */
 173 static void SCSI_Command_Request_Sense(void)
 174 {
 175         uint8_t  AllocationLength = CommandBlock.SCSICommandData[4];
 176         uint8_t  BytesTransferred = (AllocationLength < sizeof(SenseData))? AllocationLength : sizeof(SenseData);
 177
 178         /* Send the SENSE data - this indicates to the host the status of the last command */
 179         Endpoint_Write_Stream_LE(&SenseData, BytesTransferred, StreamCallback_AbortOnMassStoreReset);
 180
 181         uint8_t PadBytes[AllocationLength - BytesTransferred];
 182
 183         /* Pad out remaining bytes with 0x00 */
 184         Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 185
 186         /* Finalize the stream transfer to send the last packet */
 187         Endpoint_ClearIN();
 188
 189         /* Succeed the command and update the bytes transferred counter */
 190         CommandBlock.DataTransferLength -= BytesTransferred;
 191 }
 192
 193 /** Command processing for an issued SCSI READ CAPACITY (10) command. This command returns information about the device's capacity
 194  *  on the selected Logical Unit (drive), as a number of OS-sized blocks.
 195  */
 196 static void SCSI_Command_Read_Capacity_10(void)
 197 {
 198         /* Send the total number of logical blocks in the current LUN */
 199         Endpoint_Write_DWord_BE(LUN_MEDIA_BLOCKS - 1);
 200
 201         /* Send the logical block size of the device (must be 512 bytes) */
 202         Endpoint_Write_DWord_BE(VIRTUAL_MEMORY_BLOCK_SIZE);
 203
 204         /* Check if the current command is being aborted by the host */
 205         if (IsMassStoreReset)
 206           return;
 207
 208         /* Send the endpoint data packet to the host */
 209         Endpoint_ClearIN();
 210
 211         /* Succeed the command and update the bytes transferred counter */
 212         CommandBlock.DataTransferLength -= 8;
 213 }
 214
 215 /** Command processing for an issued SCSI SEND DIAGNOSTIC command. This command performs a quick check of the Dataflash ICs on the
 216  *  board, and indicates if they are present and functioning correctly. Only the Self-Test portion of the diagnostic command is
 217  *  supported.
 218  */
 219 static void SCSI_Command_Send_Diagnostic(void)
 220 {
 221         /* Check to see if the SELF TEST bit is not set */
 222         if (!(CommandBlock.SCSICommandData[1] & (1 << 2)))
 223         {
 224                 /* Only self-test supported - update SENSE key and fail the command */
 225                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 226                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 227                                SCSI_ASENSEQ_NO_QUALIFIER);
 228
 229                 return;
 230         }
 231
 232         /* Check to see if all attached Dataflash ICs are functional */
 233         if (!(DataflashManager_CheckDataflashOperation()))
 234         {
 235                 /* Update SENSE key with a hardware error condition and return command fail */
 236                 SCSI_SET_SENSE(SCSI_SENSE_KEY_HARDWARE_ERROR,
 237                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 238                                SCSI_ASENSEQ_NO_QUALIFIER);
 239
 240                 return;
 241         }
 242
 243         /* Succeed the command and update the bytes transferred counter */
 244         CommandBlock.DataTransferLength = 0;
 245 }
 246
 247 /** Command processing for an issued SCSI READ (10) or WRITE (10) command. This command reads in the block start address
 248  *  and total number of blocks to process, then calls the appropriate low-level dataflash routine to handle the actual
 249  *  reading and writing of the data.
 250  *
 251  *  \param[in] IsDataRead  Indicates if the command is a READ (10) command or WRITE (10) command (DATA_READ or DATA_WRITE)
 252  */
 253 static void SCSI_Command_ReadWrite_10(const bool IsDataRead)
 254 {
 255         uint32_t BlockAddress;
 256         uint16_t TotalBlocks;
 257
 258         /* Load in the 32-bit block address (SCSI uses big-endian, so have to reverse the byte order) */
 259         BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
 260
 261         /* Load in the 16-bit total blocks (SCSI uses big-endian, so have to reverse the byte order) */
 262         TotalBlocks  = SwapEndian_16(*(uint32_t*)&CommandBlock.SCSICommandData[7]);
 263
 264         /* Check if the block address is outside the maximum allowable value for the LUN */
 265         if (BlockAddress >= LUN_MEDIA_BLOCKS)
 266         {
 267                 /* Block address is invalid, update SENSE key and return command fail */
 268                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 269                                SCSI_ASENSE_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,
 270                                SCSI_ASENSEQ_NO_QUALIFIER);
 271
 272                 return;
 273         }
 274
 275         #if (TOTAL_LUNS > 1)
 276         /* Adjust the given block address to the real media address based on the selected LUN */
 277         BlockAddress += ((uint32_t)CommandBlock.LUN * LUN_MEDIA_BLOCKS);
 278         #endif
 279
 280         /* Determine if the packet is a READ (10) or WRITE (10) command, call appropriate function */
 281         if (IsDataRead == DATA_READ)
 282           DataflashManager_ReadBlocks(BlockAddress, TotalBlocks);
 283         else
 284           DataflashManager_WriteBlocks(BlockAddress, TotalBlocks);
 285
 286         /* Update the bytes transferred counter and succeed the command */
 287         CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
 288 }