audk/Vlv2TbltDevicePkg/Library/I2CLibPei/I2CIoLibPei.c

/** @file
  Functions for access I2C MMIO register.

  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php.

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include <PiPei.h>
#include <Library/DebugLib.h>
#include <Library/PeiServicesTablePointerLib.h>

/**
  Reads an 8-bit MMIO register.

  Reads the 8-bit MMIO register specified by Address. The 8-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 8-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to read.

  @return The value read.

**/
UINT8
EFIAPI
I2CLibPeiMmioRead8 (
  IN UINTN Address
  )
{
  UINT8 Value;

  Value = *(volatile UINT8*)Address;
  return Value;
}

/**
  Reads a 16-bit MMIO register.

  Reads the 16-bit MMIO register specified by Address. The 16-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 16-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 16-bit boundary, then ASSERT().

  @param  Address The MMIO register to read.

  @return The value read.

**/
UINT16
EFIAPI
I2CLibPeiMmioRead16 (
  IN UINTN  Address
  )
{
  UINT16 Value;

  ASSERT ((Address & 1) == 0);
  Value = *(volatile UINT16*)Address;
  return Value;
}

/**
  Writes a 16-bit MMIO register.

  Writes the 16-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 16-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 16-bit boundary, then ASSERT().

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.

  @return Value.

**/
UINT16
EFIAPI
I2CLibPeiMmioWrite16 (
  IN  UINTN   Address,
  IN  UINT16  Value
  )
{
  ASSERT ((Address & 1) == 0);
  *(volatile UINT16*)Address = Value;
  return Value;
}

/**
  Reads a 32-bit MMIO register.

  Reads the 32-bit MMIO register specified by Address. The 32-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 32-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 32-bit boundary, then ASSERT().

  @param  Address The MMIO register to read.

  @return The value read.

**/
UINT32
EFIAPI
I2CLibPeiMmioRead32 (
  IN UINTN Address
  )
{
  UINT32  Value;

  ASSERT ((Address & 3) == 0);
  Value = *(volatile UINT32*)Address;

  return Value;
}

/**
  Writes a 32-bit MMIO register.

  Writes the 32-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 32-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 32-bit boundary, then ASSERT().

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.

  @return Value.

**/
UINT32
EFIAPI
I2CLibPeiMmioWrite32 (
  IN      UINTN                     Address,
  IN      UINT32                    Value
  )
{
  ASSERT ((Address & 3) == 0);
  *(volatile UINT32*)Address = Value;
  return Value;
}

/**
  OR a 32-bit MMIO register.

  OR the 32-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 32-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 32-bit boundary, then ASSERT().

  @param  Address The MMIO register to write OR.
  @param  Value   The value to OR to the MMIO register.

  @return Value.

**/
UINT32
EFIAPI
I2CLibPeiMmioOr32 (
  IN      UINTN                     Address,
  IN      UINT32                    OrData
  )
{
  return I2CLibPeiMmioWrite32 (Address, I2CLibPeiMmioRead32(Address) | OrData);
}