IntelFrameworkPkg/Library/PeiSmbusLibSmbusPpi/PeiSmbusLib.c

   1 /** @file
   2   Implementation of SmBusLib class library for PEI phase.
   3
   4 Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include "InternalSmbusLib.h"
  10
  11 /**
  12   Gets Smbus PPIs.
  13
  14   This internal function retrieves Smbus PPI from PPI database.
  15   If gEfiPeiSmbusPpiGuid can not be located, then ASSERT()
  16
  17   @return The pointer to Smbus PPI.
  18
  19 **/
  20 EFI_PEI_SMBUS_PPI *
  21 InternalGetSmbusPpi (
  22   VOID
  23   )
  24 {
  25   EFI_STATUS            Status;
  26   EFI_PEI_SMBUS_PPI     *SmbusPpi;
  27
  28   Status = PeiServicesLocatePpi (&gEfiPeiSmbusPpiGuid, 0, NULL, (VOID **) &SmbusPpi);
  29   ASSERT_EFI_ERROR (Status);
  30   ASSERT (SmbusPpi != NULL);
  31
  32   return SmbusPpi;
  33 }
  34
  35 /**
  36   Executes an SMBus operation to an SMBus controller.
  37
  38   This function provides a standard way to execute Smbus script
  39   as defined in the SmBus Specification. The data can either be of
  40   the Length byte, word, or a block of data.
  41
  42   @param  SmbusOperation  Signifies which particular SMBus hardware protocol instance that it will use to
  43                           execute the SMBus transactions.
  44   @param  SmBusAddress    Address that encodes the SMBUS Slave Address,
  45                           SMBUS Command, SMBUS Data Length, and PEC.
  46   @param  Length          Signifies the number of bytes that this operation will do. The maximum number of
  47                           bytes can be revision specific and operation specific.
  48   @param  Buffer          Contains the value of data to execute to the SMBus slave device. Not all operations
  49                           require this argument. The length of this buffer is identified by Length.
  50   @param  Status          Return status for the executed command.
  51                           This is an optional parameter and may be NULL.
  52
  53   @return The actual number of bytes that are executed for this operation..
  54
  55 **/
  56 UINTN
  57 InternalSmBusExec (
  58   IN     EFI_SMBUS_OPERATION        SmbusOperation,
  59   IN     UINTN                      SmBusAddress,
  60   IN     UINTN                      Length,
  61   IN OUT VOID                       *Buffer,
  62      OUT RETURN_STATUS              *Status        OPTIONAL
  63   )
  64 {
  65   EFI_PEI_SMBUS_PPI         *SmbusPpi;
  66   CONST EFI_PEI_SERVICES    **PeiServices;
  67   RETURN_STATUS             ReturnStatus;
  68   EFI_SMBUS_DEVICE_ADDRESS  SmbusDeviceAddress;
  69
  70   PeiServices = GetPeiServicesTablePointer ();
  71   SmbusPpi    = InternalGetSmbusPpi ();
  72   SmbusDeviceAddress.SmbusDeviceAddress = SMBUS_LIB_SLAVE_ADDRESS (SmBusAddress);
  73
  74   ReturnStatus = SmbusPpi->Execute (
  75                              (EFI_PEI_SERVICES  **) PeiServices,
  76                              SmbusPpi,
  77                              SmbusDeviceAddress,
  78                              SMBUS_LIB_COMMAND (SmBusAddress),
  79                              SmbusOperation,
  80                              SMBUS_LIB_PEC (SmBusAddress),
  81                              &Length,
  82                              Buffer
  83                              );
  84   if (Status != NULL) {
  85     *Status = ReturnStatus;
  86   }
  87
  88   return Length;
  89 }