audk/IntelFrameworkPkg/Library/PeiSmbusLibSmbusPpi/PeiSmbusLib.c

90 lines
3.0 KiB
C

/** @file
Implementation of SmBusLib class library for PEI phase.
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "InternalSmbusLib.h"
/**
Gets Smbus PPIs.
This internal function retrieves Smbus PPI from PPI database.
If gEfiPeiSmbusPpiGuid can not be located, then ASSERT()
@return The pointer to Smbus PPI.
**/
EFI_PEI_SMBUS_PPI *
InternalGetSmbusPpi (
VOID
)
{
EFI_STATUS Status;
EFI_PEI_SMBUS_PPI *SmbusPpi;
Status = PeiServicesLocatePpi (&gEfiPeiSmbusPpiGuid, 0, NULL, (VOID **) &SmbusPpi);
ASSERT_EFI_ERROR (Status);
ASSERT (SmbusPpi != NULL);
return SmbusPpi;
}
/**
Executes an SMBus operation to an SMBus controller.
This function provides a standard way to execute Smbus script
as defined in the SmBus Specification. The data can either be of
the Length byte, word, or a block of data.
@param SmbusOperation Signifies which particular SMBus hardware protocol instance that it will use to
execute the SMBus transactions.
@param SmBusAddress Address that encodes the SMBUS Slave Address,
SMBUS Command, SMBUS Data Length, and PEC.
@param Length Signifies the number of bytes that this operation will do. The maximum number of
bytes can be revision specific and operation specific.
@param Buffer Contains the value of data to execute to the SMBus slave device. Not all operations
require this argument. The length of this buffer is identified by Length.
@param Status Return status for the executed command.
This is an optional parameter and may be NULL.
@return The actual number of bytes that are executed for this operation..
**/
UINTN
InternalSmBusExec (
IN EFI_SMBUS_OPERATION SmbusOperation,
IN UINTN SmBusAddress,
IN UINTN Length,
IN OUT VOID *Buffer,
OUT RETURN_STATUS *Status OPTIONAL
)
{
EFI_PEI_SMBUS_PPI *SmbusPpi;
CONST EFI_PEI_SERVICES **PeiServices;
RETURN_STATUS ReturnStatus;
EFI_SMBUS_DEVICE_ADDRESS SmbusDeviceAddress;
PeiServices = GetPeiServicesTablePointer ();
SmbusPpi = InternalGetSmbusPpi ();
SmbusDeviceAddress.SmbusDeviceAddress = SMBUS_LIB_SLAVE_ADDRESS (SmBusAddress);
ReturnStatus = SmbusPpi->Execute (
(EFI_PEI_SERVICES **) PeiServices,
SmbusPpi,
SmbusDeviceAddress,
SMBUS_LIB_COMMAND (SmBusAddress),
SmbusOperation,
SMBUS_LIB_PEC (SmBusAddress),
&Length,
Buffer
);
if (Status != NULL) {
*Status = ReturnStatus;
}
return Length;
}