MdePkg/Library/DxeSmbusLib/DxeSmbusLib.c

   1 /** @file
   2 Implementation of SmBusLib class library for PEI phase.
   3
   4 Copyright (c) 2006, Intel Corporation<BR>
   5 All rights reserved. This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13
  14 Module Name: DxeSmbusLib.c
  15
  16 **/
  17
  18 #include "InternalSmbusLib.h"
  19
  20 //
  21 // Globle varible to cache pointer to Smbus protocol.
  22 //
  23 STATIC EFI_SMBUS_HC_PROTOCOL      *mSmbus = NULL;
  24
  25 /**
  26   The constructor function caches the pointer to Smbus protocol.
  27
  28   The constructor function locates Smbus protocol from protocol database.
  29   It will ASSERT() if that operation fails and it will always return EFI_SUCCESS.
  30
  31   @param  ImageHandle   The firmware allocated handle for the EFI image.
  32   @param  SystemTable   A pointer to the EFI System Table.
  33
  34   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  35
  36 **/
  37 EFI_STATUS
  38 EFIAPI
  39 SmbusLibConstructor (
  40   IN EFI_HANDLE                ImageHandle,
  41   IN EFI_SYSTEM_TABLE          *SystemTable
  42   )
  43 {
  44   EFI_STATUS  Status;
  45
  46   Status = gBS->LocateProtocol (
  47                   &gEfiCpuIoProtocolGuid,
  48                   NULL,
  49                   (VOID**) &mSmbus
  50                   );
  51   ASSERT_EFI_ERROR (Status);
  52   ASSERT (mSmbus != NULL);
  53
  54   return Status;
  55 }
  56
  57 /**
  58   Executes an SMBus operation to an SMBus controller.
  59
  60   This function provides a standard way to execute Smbus script
  61   as defined in the SmBus Specification. The data can either be of
  62   the Length byte, word, or a block of data.
  63
  64   @param  SmbusOperation  Signifies which particular SMBus hardware protocol instance that it will use to
  65                           execute the SMBus transactions.
  66   @param  SmBusAddress    Address that encodes the SMBUS Slave Address,
  67                           SMBUS Command, SMBUS Data Length, and PEC.
  68   @param  Length          Signifies the number of bytes that this operation will do. The maximum number of
  69                           bytes can be revision specific and operation specific.
  70   @param  Buffer          Contains the value of data to execute to the SMBus slave device. Not all operations
  71                           require this argument. The length of this buffer is identified by Length.
  72   @param  Status          Return status for the executed command.
  73                           This is an optional parameter and may be NULL.
  74
  75   @return The actual number of bytes that are executed for this operation..
  76
  77 **/
  78 UINTN
  79 InternalSmBusExec (
  80   IN     EFI_SMBUS_OPERATION        SmbusOperation,
  81   IN     UINTN                      SmBusAddress,
  82   IN     UINTN                      Length,
  83   IN     VOID                       *Buffer,
  84      OUT RETURN_STATUS              *Status        OPTIONAL
  85   )
  86 {
  87   RETURN_STATUS             ReturnStatus;
  88   EFI_SMBUS_DEVICE_ADDRESS  SmbusDeviceAddress;
  89
  90   SmbusDeviceAddress.SmbusDeviceAddress = SMBUS_LIB_SLAVE_ADDRESS (SmBusAddress);
  91
  92   ReturnStatus = mSmbus->Execute (
  93                            mSmbus,
  94                            SmbusDeviceAddress,
  95                            SMBUS_LIB_COMMAND (SmBusAddress),
  96                            SmbusOperation,
  97                            SMBUS_LIB_PEC (SmBusAddress),
  98                            &Length,
  99                            Buffer
 100                            );
 101   if (Status != NULL) {
 102     *Status = ReturnStatus;
 103   }
 104
 105   return Length;
 106 }
 107
 108 /**
 109   Assigns an SMBUS slave addresses.
 110
 111   Assigns the SMBUS device specified by Uuid the slave address specified by SmBusAddress.
 112   The status of the executed command is returned.
 113
 114   @param  SmBusAddress        Address that encodes the SMBUS Slave Address,
 115                               SMBUS Command, SMBUS Data Length, and PEC.
 116   @param  Uuid                Pointer to the UUID of the device to assign a slave address.
 117                               It will assign to all SMBUS slave devices if it is NULL.
 118
 119   @retval RETURN_SUCCESS      The SMBUS command was executed.
 120   @retval RETURN_TIMEOUT      A timeout occurred while executing the SMBUS command.
 121   @retval RETURN_DEVICE_ERROR The request was not completed because a failure reflected
 122                               in the Host Status Register bit.
 123                               Device errors are a result of a transaction collision, illegal command field,
 124                               unclaimed cycle (host initiated), or bus errors (collisions).
 125
 126 **/
 127 RETURN_STATUS
 128 InternalSmBusArpDevice (
 129   IN UINTN          SmBusAddress,
 130   IN CONST GUID     *Uuid       OPTIONAL
 131   )
 132 {
 133   EFI_SMBUS_DEVICE_ADDRESS  SmbusDeviceAddress;
 134
 135   SmbusDeviceAddress.SmbusDeviceAddress = SMBUS_LIB_SLAVE_ADDRESS (SmBusAddress);
 136   return (RETURN_STATUS) mSmbus->ArpDevice (
 137                                    mSmbus,
 138                                    (BOOLEAN) (Uuid == NULL),
 139                                    (EFI_SMBUS_UDID *) Uuid,
 140                                    &SmbusDeviceAddress
 141                                    );
 142 }
 143
 144 /**
 145   Retrieves the mapping of all the SMBus devices.
 146
 147   The GetArpMap() function returns the mapping of all the SMBus devices
 148   that are enumerated by the SMBus host driver.
 149
 150   @param  Length              Size of the buffer that contains the SMBus device map.
 151   @param  SmbusDeviceMap      The pointer to the device map as enumerated by the SMBus controller driver.
 152
 153   @retval RETURN_SUCCESS      The SMBUS command was executed.
 154   @retval RETURN_TIMEOUT      A timeout occurred while executing the SMBUS command.
 155   @retval RETURN_DEVICE_ERROR The request was not completed because a failure reflected
 156                               in the Host Status Register bit.
 157                               Device errors are a result of a transaction collision, illegal command field,
 158                               unclaimed cycle (host initiated), or bus errors (collisions).
 159
 160 **/
 161 RETURN_STATUS
 162 InternalGetArpMap (
 163   OUT UINTN                         *Length,
 164   OUT EFI_SMBUS_DEVICE_MAP          **SmbusDeviceMap
 165   )
 166 {
 167   return (RETURN_STATUS) mSmbus->GetArpMap (mSmbus, Length, SmbusDeviceMap);
 168 }