MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.c

   1 /** @file
   2 Null implementation of SmBusLib class library.
   3
   4 Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <Base.h>
  10 #include <Library/SmbusLib.h>
  11 #include <Library/DebugLib.h>
  12
  13 /**
  14   Executes an SMBUS quick read command.
  15
  16   Executes an SMBUS quick read command on the SMBUS device specified by SmBusAddress.
  17   Only the SMBUS slave address field of SmBusAddress is required.
  18   If Status is not NULL, then the status of the executed command is returned in Status.
  19   If PEC is set in SmBusAddress, then ASSERT().
  20   If Command in SmBusAddress is not zero, then ASSERT().
  21   If Length in SmBusAddress is not zero, then ASSERT().
  22   If any reserved bits of SmBusAddress are set, then ASSERT().
  23
  24   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
  25                         SMBUS Command, SMBUS Data Length, and PEC.
  26   @param  Status        Return status for the executed command.
  27                         This is an optional parameter and may be NULL.
  28                         RETURN_SUCCESS  The SMBUS command was executed.
  29                         RETURN_TIMEOUT  A timeout occurred while executing the SMBUS command.
  30                         RETURN_DEVICE_ERROR The request was not completed because a failure
  31                         reflected in the Host Status Register bit.  Device errors are a result
  32                         of a transaction collision, illegal command field, unclaimed cycle
  33                         (host initiated), or bus errors (collisions).
  34                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
  35
  36 **/
  37 VOID
  38 EFIAPI
  39 SmBusQuickRead (
  40   IN  UINTN                     SmBusAddress,
  41   OUT RETURN_STATUS             *Status       OPTIONAL
  42   )
  43 {
  44   ASSERT (!SMBUS_LIB_PEC (SmBusAddress));
  45   ASSERT (SMBUS_LIB_COMMAND (SmBusAddress) == 0);
  46   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
  47   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
  48   if (Status != NULL) {
  49     *Status = RETURN_UNSUPPORTED;
  50   }
  51 }
  52
  53 /**
  54   Executes an SMBUS quick write command.
  55
  56   Executes an SMBUS quick write command on the SMBUS device specified by SmBusAddress.
  57   Only the SMBUS slave address field of SmBusAddress is required.
  58   If Status is not NULL, then the status of the executed command is returned in Status.
  59   If PEC is set in SmBusAddress, then ASSERT().
  60   If Command in SmBusAddress is not zero, then ASSERT().
  61   If Length in SmBusAddress is not zero, then ASSERT().
  62   If any reserved bits of SmBusAddress are set, then ASSERT().
  63
  64   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
  65                         SMBUS Command, SMBUS Data Length, and PEC.
  66   @param  Status        Return status for the executed command.
  67                         This is an optional parameter and may be NULL.
  68                         RETURN_SUCCESS The SMBUS command was executed.
  69                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
  70                         RETURN_DEVICE_ERROR  The request was not completed because a failure
  71                         reflected in the Host Status Register bit.  Device errors are a result
  72                         of a transaction collision, illegal command field, unclaimed cycle
  73                         (host initiated), or bus errors (collisions).
  74                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
  75
  76 **/
  77 VOID
  78 EFIAPI
  79 SmBusQuickWrite (
  80   IN  UINTN                     SmBusAddress,
  81   OUT RETURN_STATUS             *Status       OPTIONAL
  82   )
  83 {
  84   ASSERT (!SMBUS_LIB_PEC (SmBusAddress));
  85   ASSERT (SMBUS_LIB_COMMAND (SmBusAddress) == 0);
  86   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
  87   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
  88   if (Status != NULL) {
  89     *Status = RETURN_UNSUPPORTED;
  90   }
  91 }
  92
  93 /**
  94   Executes an SMBUS receive byte command.
  95
  96   Executes an SMBUS receive byte command on the SMBUS device specified by SmBusAddress.
  97   Only the SMBUS slave address field of SmBusAddress is required.
  98   The byte received from the SMBUS is returned.
  99   If Status is not NULL, then the status of the executed command is returned in Status.
 100   If Command in SmBusAddress is not zero, then ASSERT().
 101   If Length in SmBusAddress is not zero, then ASSERT().
 102   If any reserved bits of SmBusAddress are set, then ASSERT().
 103
 104   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 105                         SMBUS Command, SMBUS Data Length, and PEC.
 106   @param  Status        Return status for the executed command.
 107                         This is an optional parameter and may be NULL.
 108                         RETURN_SUCCESS The SMBUS command was executed.
 109                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 110                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 111                         reflected in the Host Status Register bit.  Device errors are a result
 112                         of a transaction collision, illegal command field, unclaimed cycle
 113                         (host initiated), or bus errors (collisions).
 114                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 115                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 116
 117   @return The byte received from the SMBUS.
 118
 119 **/
 120 UINT8
 121 EFIAPI
 122 SmBusReceiveByte (
 123   IN  UINTN          SmBusAddress,
 124   OUT RETURN_STATUS  *Status        OPTIONAL
 125   )
 126 {
 127   ASSERT (SMBUS_LIB_COMMAND (SmBusAddress) == 0);
 128   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 129   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 130   if (Status != NULL) {
 131     *Status = RETURN_UNSUPPORTED;
 132   }
 133   return 0;
 134 }
 135
 136 /**
 137   Executes an SMBUS send byte command.
 138
 139   Executes an SMBUS send byte command on the SMBUS device specified by SmBusAddress.
 140   The byte specified by Value is sent.
 141   Only the SMBUS slave address field of SmBusAddress is required.  Value is returned.
 142   If Status is not NULL, then the status of the executed command is returned in Status.
 143   If Command in SmBusAddress is not zero, then ASSERT().
 144   If Length in SmBusAddress is not zero, then ASSERT().
 145   If any reserved bits of SmBusAddress are set, then ASSERT().
 146
 147   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 148                         SMBUS Command, SMBUS Data Length, and PEC.
 149   @param  Value         The 8-bit value to send.
 150   @param  Status        Return status for the executed command.
 151                         This is an optional parameter and may be NULL.
 152                         RETURN_SUCCESS The SMBUS command was executed.
 153                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 154                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 155                         reflected in the Host Status Register bit.  Device errors are a result
 156                         of a transaction collision, illegal command field, unclaimed cycle
 157                         (host initiated), or bus errors (collisions).
 158                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 159                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 160
 161   @return The parameter of Value.
 162
 163 **/
 164 UINT8
 165 EFIAPI
 166 SmBusSendByte (
 167   IN  UINTN          SmBusAddress,
 168   IN  UINT8          Value,
 169   OUT RETURN_STATUS  *Status        OPTIONAL
 170   )
 171 {
 172   ASSERT (SMBUS_LIB_COMMAND (SmBusAddress) == 0);
 173   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 174   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 175   if (Status != NULL) {
 176     *Status = RETURN_UNSUPPORTED;
 177   }
 178   return 0;
 179 }
 180
 181 /**
 182   Executes an SMBUS read data byte command.
 183
 184   Executes an SMBUS read data byte command on the SMBUS device specified by SmBusAddress.
 185   Only the SMBUS slave address and SMBUS command fields of SmBusAddress are required.
 186   The 8-bit value read from the SMBUS is returned.
 187   If Status is not NULL, then the status of the executed command is returned in Status.
 188   If Length in SmBusAddress is not zero, then ASSERT().
 189   If any reserved bits of SmBusAddress are set, then ASSERT().
 190
 191   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 192                         SMBUS Command, SMBUS Data Length, and PEC.
 193   @param  Status        Return status for the executed command.
 194                         This is an optional parameter and may be NULL.
 195                         RETURN_SUCCESS The SMBUS command was executed.
 196                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 197                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 198                         reflected in the Host Status Register bit.  Device errors are a result
 199                         of a transaction collision, illegal command field, unclaimed cycle
 200                         (host initiated), or bus errors (collisions).
 201                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 202                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 203
 204   @return The byte read from the SMBUS.
 205
 206 **/
 207 UINT8
 208 EFIAPI
 209 SmBusReadDataByte (
 210   IN  UINTN          SmBusAddress,
 211   OUT RETURN_STATUS  *Status        OPTIONAL
 212   )
 213 {
 214   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 215   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 216   if (Status != NULL) {
 217     *Status = RETURN_UNSUPPORTED;
 218   }
 219   return 0;
 220 }
 221
 222 /**
 223   Executes an SMBUS write data byte command.
 224
 225   Executes an SMBUS write data byte command on the SMBUS device specified by SmBusAddress.
 226   The 8-bit value specified by Value is written.
 227   Only the SMBUS slave address and SMBUS command fields of SmBusAddress are required.
 228   Value is returned.
 229   If Status is not NULL, then the status of the executed command is returned in Status.
 230   If Length in SmBusAddress is not zero, then ASSERT().
 231   If any reserved bits of SmBusAddress are set, then ASSERT().
 232
 233   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 234                         SMBUS Command, SMBUS Data Length, and PEC.
 235   @param  Value         The 8-bit value to write.
 236   @param  Status        Return status for the executed command.
 237                         This is an optional parameter and may be NULL.
 238                         RETURN_SUCCESS The SMBUS command was executed.
 239                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 240                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 241                         reflected in the Host Status Register bit.  Device errors are a result
 242                         of a transaction collision, illegal command field, unclaimed cycle
 243                         (host initiated), or bus errors (collisions).
 244                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 245                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 246
 247   @return The parameter of Value.
 248
 249 **/
 250 UINT8
 251 EFIAPI
 252 SmBusWriteDataByte (
 253   IN  UINTN          SmBusAddress,
 254   IN  UINT8          Value,
 255   OUT RETURN_STATUS  *Status        OPTIONAL
 256   )
 257 {
 258   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 259   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 260   if (Status != NULL) {
 261     *Status = RETURN_UNSUPPORTED;
 262   }
 263   return 0;
 264 }
 265
 266 /**
 267   Executes an SMBUS read data word command.
 268
 269   Executes an SMBUS read data word command on the SMBUS device specified by SmBusAddress.
 270   Only the SMBUS slave address and SMBUS command fields of SmBusAddress are required.
 271   The 16-bit value read from the SMBUS is returned.
 272   If Status is not NULL, then the status of the executed command is returned in Status.
 273   If Length in SmBusAddress is not zero, then ASSERT().
 274   If any reserved bits of SmBusAddress are set, then ASSERT().
 275
 276   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 277                         SMBUS Command, SMBUS Data Length, and PEC.
 278   @param  Status        Return status for the executed command.
 279                         This is an optional parameter and may be NULL.
 280                         RETURN_SUCCESS The SMBUS command was executed.
 281                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 282                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 283                         reflected in the Host Status Register bit.  Device errors are a result
 284                         of a transaction collision, illegal command field, unclaimed cycle
 285                         (host initiated), or bus errors (collisions).
 286                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 287                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 288
 289   @return The byte read from the SMBUS.
 290
 291 **/
 292 UINT16
 293 EFIAPI
 294 SmBusReadDataWord (
 295   IN  UINTN          SmBusAddress,
 296   OUT RETURN_STATUS  *Status        OPTIONAL
 297   )
 298 {
 299   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 300   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 301   if (Status != NULL) {
 302     *Status = RETURN_UNSUPPORTED;
 303   }
 304   return 0;
 305 }
 306
 307 /**
 308   Executes an SMBUS write data word command.
 309
 310   Executes an SMBUS write data word command on the SMBUS device specified by SmBusAddress.
 311   The 16-bit value specified by Value is written.
 312   Only the SMBUS slave address and SMBUS command fields of SmBusAddress are required.
 313   Value is returned.
 314   If Status is not NULL, then the status of the executed command is returned in Status.
 315   If Length in SmBusAddress is not zero, then ASSERT().
 316   If any reserved bits of SmBusAddress are set, then ASSERT().
 317
 318   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 319                         SMBUS Command, SMBUS Data Length, and PEC.
 320   @param  Value         The 16-bit value to write.
 321   @param  Status        Return status for the executed command.
 322                         This is an optional parameter and may be NULL.
 323                         RETURN_SUCCESS The SMBUS command was executed.
 324                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 325                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 326                         reflected in the Host Status Register bit.  Device errors are a result
 327                         of a transaction collision, illegal command field, unclaimed cycle
 328                         (host initiated), or bus errors (collisions).
 329                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 330                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 331
 332   @return The parameter of Value.
 333
 334 **/
 335 UINT16
 336 EFIAPI
 337 SmBusWriteDataWord (
 338   IN  UINTN          SmBusAddress,
 339   IN  UINT16         Value,
 340   OUT RETURN_STATUS  *Status        OPTIONAL
 341   )
 342 {
 343   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 344   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 345   if (Status != NULL) {
 346     *Status = RETURN_UNSUPPORTED;
 347   }
 348   return 0;
 349 }
 350
 351 /**
 352   Executes an SMBUS process call command.
 353
 354   Executes an SMBUS process call command on the SMBUS device specified by SmBusAddress.
 355   The 16-bit value specified by Value is written.
 356   Only the SMBUS slave address and SMBUS command fields of SmBusAddress are required.
 357   The 16-bit value returned by the process call command is returned.
 358   If Status is not NULL, then the status of the executed command is returned in Status.
 359   If Length in SmBusAddress is not zero, then ASSERT().
 360   If any reserved bits of SmBusAddress are set, then ASSERT().
 361
 362   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 363                         SMBUS Command, SMBUS Data Length, and PEC.
 364   @param  Value         The 16-bit value to write.
 365   @param  Status        Return status for the executed command.
 366                         This is an optional parameter and may be NULL.
 367                         RETURN_SUCCESS The SMBUS command was executed.
 368                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 369                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 370                         reflected in the Host Status Register bit.  Device errors are a result
 371                         of a transaction collision, illegal command field, unclaimed cycle
 372                         (host initiated), or bus errors (collisions).
 373                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 374                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 375
 376   @return The 16-bit value returned by the process call command.
 377
 378 **/
 379 UINT16
 380 EFIAPI
 381 SmBusProcessCall (
 382   IN  UINTN          SmBusAddress,
 383   IN  UINT16         Value,
 384   OUT RETURN_STATUS  *Status        OPTIONAL
 385   )
 386 {
 387   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 388   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 389   if (Status != NULL) {
 390     *Status = RETURN_UNSUPPORTED;
 391   }
 392   return 0;
 393 }
 394
 395 /**
 396   Executes an SMBUS read block command.
 397
 398   Executes an SMBUS read block command on the SMBUS device specified by SmBusAddress.
 399   Only the SMBUS slave address and SMBUS command fields of SmBusAddress are required.
 400   Bytes are read from the SMBUS and stored in Buffer.
 401   The number of bytes read is returned, and will never return a value larger than 32-bytes.
 402   If Status is not NULL, then the status of the executed command is returned in Status.
 403   It is the caller's responsibility to make sure Buffer is large enough for the total number of bytes read.
 404   SMBUS supports a maximum transfer size of 32 bytes, so Buffer does not need to be any larger than 32 bytes.
 405   If Length in SmBusAddress is not zero, then ASSERT().
 406   If Buffer is NULL, then ASSERT().
 407   If any reserved bits of SmBusAddress are set, then ASSERT().
 408
 409   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 410                         SMBUS Command, SMBUS Data Length, and PEC.
 411   @param  Buffer        Pointer to the buffer to store the bytes read from the SMBUS.
 412   @param  Status        Return status for the executed command.
 413                         This is an optional parameter and may be NULL.
 414                         RETURN_SUCCESS The SMBUS command was executed.
 415                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 416                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 417                         reflected in the Host Status Register bit.  Device errors are a result
 418                         of a transaction collision, illegal command field, unclaimed cycle
 419                         (host initiated), or bus errors (collisions).
 420                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 421                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 422
 423   @return The number of bytes read.
 424
 425 **/
 426 UINTN
 427 EFIAPI
 428 SmBusReadBlock (
 429   IN  UINTN          SmBusAddress,
 430   OUT VOID           *Buffer,
 431   OUT RETURN_STATUS  *Status        OPTIONAL
 432   )
 433 {
 434   ASSERT (Buffer != NULL);
 435   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) == 0);
 436   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 437   if (Status != NULL) {
 438     *Status = RETURN_UNSUPPORTED;
 439   }
 440   return 0;
 441 }
 442
 443 /**
 444   Executes an SMBUS write block command.
 445
 446   Executes an SMBUS write block command on the SMBUS device specified by SmBusAddress.
 447   The SMBUS slave address, SMBUS command, and SMBUS length fields of SmBusAddress are required.
 448   Bytes are written to the SMBUS from Buffer.
 449   The number of bytes written is returned, and will never return a value larger than 32-bytes.
 450   If Status is not NULL, then the status of the executed command is returned in Status.
 451   If Length in SmBusAddress is zero or greater than 32, then ASSERT().
 452   If Buffer is NULL, then ASSERT().
 453   If any reserved bits of SmBusAddress are set, then ASSERT().
 454
 455   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 456                         SMBUS Command, SMBUS Data Length, and PEC.
 457   @param  Buffer        Pointer to the buffer to store the bytes read from the SMBUS.
 458   @param  Status        Return status for the executed command.
 459                         This is an optional parameter and may be NULL.
 460                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 461                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 462                         reflected in the Host Status Register bit.  Device errors are a result
 463                         of a transaction collision, illegal command field, unclaimed cycle
 464                         (host initiated), or bus errors (collisions).
 465                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 466                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 467
 468   @return The number of bytes written.
 469
 470 **/
 471 UINTN
 472 EFIAPI
 473 SmBusWriteBlock (
 474   IN  UINTN          SmBusAddress,
 475   OUT VOID           *Buffer,
 476   OUT RETURN_STATUS  *Status        OPTIONAL
 477   )
 478 {
 479   ASSERT (Buffer != NULL);
 480   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) >= 1);
 481   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) <= 32);
 482   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 483   if (Status != NULL) {
 484     *Status = RETURN_UNSUPPORTED;
 485   }
 486   return 0;
 487 }
 488
 489 /**
 490   Executes an SMBUS block process call command.
 491
 492   Executes an SMBUS block process call command on the SMBUS device specified by SmBusAddress.
 493   The SMBUS slave address, SMBUS command, and SMBUS length fields of SmBusAddress are required.
 494   Bytes are written to the SMBUS from WriteBuffer.  Bytes are then read from the SMBUS into ReadBuffer.
 495   If Status is not NULL, then the status of the executed command is returned in Status.
 496   It is the caller's responsibility to make sure ReadBuffer is large enough for the total number of bytes read.
 497   SMBUS supports a maximum transfer size of 32 bytes, so Buffer does not need to be any larger than 32 bytes.
 498   If Length in SmBusAddress is zero or greater than 32, then ASSERT().
 499   If WriteBuffer is NULL, then ASSERT().
 500   If ReadBuffer is NULL, then ASSERT().
 501   If any reserved bits of SmBusAddress are set, then ASSERT().
 502
 503   @param  SmBusAddress  Address that encodes the SMBUS Slave Address,
 504                         SMBUS Command, SMBUS Data Length, and PEC.
 505   @param  WriteBuffer   Pointer to the buffer of bytes to write to the SMBUS.
 506   @param  ReadBuffer    Pointer to the buffer of bytes to read from the SMBUS.
 507   @param  Status        Return status for the executed command.
 508                         This is an optional parameter and may be NULL.
 509                         RETURN_TIMEOUT A timeout occurred while executing the SMBUS command.
 510                         RETURN_DEVICE_ERROR  The request was not completed because a failure
 511                         reflected in the Host Status Register bit.  Device errors are a result
 512                         of a transaction collision, illegal command field, unclaimed cycle
 513                         (host initiated), or bus errors (collisions).
 514                         RETURN_CRC_ERROR  The checksum is not correct (PEC is incorrect)
 515                         RETURN_UNSUPPORTED  The SMBus operation is not supported.
 516
 517   @return The number of bytes written.
 518
 519 **/
 520 UINTN
 521 EFIAPI
 522 SmBusBlockProcessCall (
 523   IN  UINTN          SmBusAddress,
 524   IN  VOID           *WriteBuffer,
 525   OUT VOID           *ReadBuffer,
 526   OUT RETURN_STATUS  *Status        OPTIONAL
 527   )
 528 {
 529   ASSERT (WriteBuffer != NULL);
 530   ASSERT (ReadBuffer  != NULL);
 531   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) >= 1);
 532   ASSERT (SMBUS_LIB_LENGTH (SmBusAddress) <= 32);
 533   ASSERT (SMBUS_LIB_RESERVED (SmBusAddress) == 0);
 534   if (Status != NULL) {
 535     *Status = RETURN_UNSUPPORTED;
 536   }
 537   return 0;
 538 }