Drivers/I2c/MvI2cDxe/MvI2cDxe.c

/********************************************************************************
Copyright (C) 2016 Marvell International Ltd.

Marvell BSD License Option

If you received this File from Marvell, you may opt to use, redistribute and/or
modify this File under the following licensing terms.
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
  documentation and/or other materials provided with the distribution.

* Neither the name of Marvell nor the names of its contributors may be
  used to endorse or promote products derived from this software without
  specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*******************************************************************************/

#include <Protocol/I2cMaster.h>
#include <Protocol/I2cEnumerate.h>
#include <Protocol/I2cBusConfigurationManagement.h>
#include <Protocol/DevicePath.h>

#include <Library/BaseLib.h>
#include <Library/IoLib.h>
#include <Library/DebugLib.h>
#include <Library/PcdLib.h>
#include <Library/UefiLib.h>
#include <Library/ParsePcdLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>

#include "MvI2cDxe.h"

STATIC MV_I2C_BAUD_RATE baud_rate;

STATIC MV_I2C_DEVICE_PATH MvI2cDevicePathProtocol = {
  {
    {
      HARDWARE_DEVICE_PATH,
      HW_VENDOR_DP,
      {
  (UINT8) (sizeof(VENDOR_DEVICE_PATH)),
  (UINT8) (sizeof(VENDOR_DEVICE_PATH) >> 8),
      },
    },
    EFI_CALLER_ID_GUID
  },
  {
    END_DEVICE_PATH_TYPE,
    END_ENTIRE_DEVICE_PATH_SUBTYPE,
    {
      sizeof(EFI_DEVICE_PATH_PROTOCOL),
      0
    }
  }
};

STATIC
UINT32
I2C_READ(
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN UINTN off)
{
  ASSERT (I2cMasterContext != NULL);
  return MmioRead32 (I2cMasterContext->BaseAddress + off);
}

STATIC
EFI_STATUS
I2C_WRITE (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN UINTN off,
  IN UINT32 Value)
{
  ASSERT (I2cMasterContext != NULL);
  return MmioWrite32 (I2cMasterContext->BaseAddress + off, Value);
}

EFI_STATUS
EFIAPI
MvI2cInitialiseController (
  IN EFI_HANDLE  ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable,
  IN EFI_PHYSICAL_ADDRESS BaseAddress
  )
{
  EFI_STATUS Status;
  I2C_MASTER_CONTEXT *I2cMasterContext;
  STATIC INTN Bus = 0;
  MV_I2C_DEVICE_PATH *DevicePath;

  DevicePath = AllocateCopyPool (sizeof(MvI2cDevicePathProtocol),
                                 &MvI2cDevicePathProtocol);
  if (DevicePath == NULL) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: I2C device path allocation failed\n"));
    return EFI_OUT_OF_RESOURCES;
  }
  DevicePath->Guid.Guid.Data4[0] = Bus;

  /* if attachment succeeds, this gets freed at ExitBootServices */
  I2cMasterContext = AllocateZeroPool (sizeof (I2C_MASTER_CONTEXT));
  if (I2cMasterContext == NULL) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: I2C master context allocation failed\n"));
    return EFI_OUT_OF_RESOURCES;
  }
  I2cMasterContext->Signature = I2C_MASTER_SIGNATURE;
  I2cMasterContext->I2cMaster.Reset = MvI2cReset;
  I2cMasterContext->I2cMaster.StartRequest = MvI2cStartRequest;
  I2cMasterContext->I2cEnumerate.Enumerate = MvI2cEnumerate;
  I2cMasterContext->I2cBusConf.EnableI2cBusConfiguration = MvI2cEnableConf;
  I2cMasterContext->TclkFrequency = PcdGet32 (PcdI2cClockFrequency);
  I2cMasterContext->BaseAddress = BaseAddress;
  I2cMasterContext->Bus = Bus;
  /* I2cMasterContext->Lock is responsible for serializing I2C operations */
  EfiInitializeLock(&I2cMasterContext->Lock, TPL_NOTIFY);

  MvI2cCalBaudRate( I2cMasterContext,
                    PcdGet32 (PcdI2cBaudRate),
                    &baud_rate,
                    I2cMasterContext->TclkFrequency
                  );

  Status = gBS->InstallMultipleProtocolInterfaces(
      &I2cMasterContext->Controller,
      &gEfiI2cMasterProtocolGuid,
      &I2cMasterContext->I2cMaster,
      &gEfiI2cEnumerateProtocolGuid,
      &I2cMasterContext->I2cEnumerate,
      &gEfiI2cBusConfigurationManagementProtocolGuid,
      &I2cMasterContext->I2cBusConf,
      &gEfiDevicePathProtocolGuid,
      (EFI_DEVICE_PATH_PROTOCOL *) DevicePath,
      NULL);

  if (EFI_ERROR(Status)) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: Installing protocol interfaces failed!\n"));
    goto fail;
  }
  DEBUG((DEBUG_ERROR, "Succesfully installed controller %d at 0x%llx\n", Bus,
        I2cMasterContext->BaseAddress));

  Bus++;

  return EFI_SUCCESS;

fail:
  FreePool(I2cMasterContext);
  return Status;
}

EFI_STATUS
EFIAPI
MvI2cInitialise (
  IN EFI_HANDLE  ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS Status;
  UINT32 BusCount;
  EFI_PHYSICAL_ADDRESS I2cBaseAddresses[PcdGet32 (PcdI2cBusCount)];
  INTN i;

  BusCount = PcdGet32 (PcdI2cBusCount);
  if (BusCount == 0)
    return EFI_SUCCESS;

  Status = ParsePcdString (
      (CHAR16 *) PcdGetPtr (PcdI2cBaseAddresses),
      BusCount,
      I2cBaseAddresses,
      NULL
      );
  if (EFI_ERROR(Status))
    return Status;

  for (i = 0; i < BusCount; i++) {
    Status = MvI2cInitialiseController(
        ImageHandle,
        SystemTable,
        I2cBaseAddresses[i]
        );
    if (EFI_ERROR(Status))
      return Status;
  }

  return Status;
}

STATIC
VOID
MvI2cControlClear (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN UINT32 Mask)
{
  UINT32 Value;

  /* clears given bits in I2C_CONTROL register */
  Value = I2C_READ(I2cMasterContext, I2C_CONTROL);
  Value &= ~Mask;
  I2C_WRITE(I2cMasterContext, I2C_CONTROL, Value);
}

STATIC
VOID
MvI2cControlSet (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN UINT32 Mask)
{
  UINT32 Value;

  /* sets given bits in I2C_CONTROL register */
  Value = I2C_READ(I2cMasterContext, I2C_CONTROL);
  Value |= Mask;
  I2C_WRITE(I2cMasterContext, I2C_CONTROL, Value);
}

STATIC
VOID
MvI2cClearIflg (
 IN I2C_MASTER_CONTEXT *I2cMasterContext
 )
{
  gBS->Stall(I2C_OPERATION_TIMEOUT);
  MvI2cControlClear(I2cMasterContext, I2C_CONTROL_IFLG);
  gBS->Stall(I2C_OPERATION_TIMEOUT);
}

/* Timeout is given in us */
STATIC
UINTN
MvI2cPollCtrl (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN UINTN Timeout,
  IN UINT32 Mask)
{
  Timeout /= 10;
  while (!(I2C_READ(I2cMasterContext, I2C_CONTROL) & Mask)) {
    gBS->Stall(10);
    if (--Timeout == 0)
      return (Timeout);
  }
  return (0);
}

/*
 * 'Timeout' is given in us. Note also that Timeout handling is not exact --
 * MvI2cLockedStart() total wait can be more than 2 x Timeout
 * (MvI2cPollCtrl() is called twice). 'Mask' can be either I2C_STATUS_START
 * or I2C_STATUS_RPTD_START
 */
STATIC
EFI_STATUS
MvI2cLockedStart (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN INT32 Mask,
  IN UINT8 Slave,
  IN UINTN Timeout
  )
{
  UINTN ReadAccess, IflgSet = 0;
  UINT32 I2cStatus;

  if (Mask == I2C_STATUS_RPTD_START) {
    /* read IFLG to know if it should be cleared later */
    IflgSet = I2C_READ(I2cMasterContext, I2C_CONTROL) & I2C_CONTROL_IFLG;
  }

  MvI2cControlSet(I2cMasterContext, I2C_CONTROL_START);

  if (Mask == I2C_STATUS_RPTD_START && IflgSet) {
    DEBUG((DEBUG_INFO, "MvI2cDxe: IFLG set, clearing\n"));
    MvI2cClearIflg(I2cMasterContext);
  }

  /* Without this delay we Timeout checking IFLG if the Timeout is 0 */
  gBS->Stall(I2C_OPERATION_TIMEOUT);

  if (MvI2cPollCtrl(I2cMasterContext, Timeout, I2C_CONTROL_IFLG)) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: Timeout sending %sSTART condition\n",
        Mask == I2C_STATUS_START ? "" : "repeated "));
    return EFI_NO_RESPONSE;
  }

  I2cStatus = I2C_READ(I2cMasterContext, I2C_STATUS);
  if (I2cStatus != Mask) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: wrong I2cStatus (%02x) after sending %sSTART condition\n",
        I2cStatus, Mask == I2C_STATUS_START ? "" : "repeated "));
    return EFI_DEVICE_ERROR;
  }

  I2C_WRITE(I2cMasterContext, I2C_DATA, Slave);
  gBS->Stall(I2C_OPERATION_TIMEOUT);
  MvI2cClearIflg(I2cMasterContext);

  if (MvI2cPollCtrl(I2cMasterContext, Timeout, I2C_CONTROL_IFLG)) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: Timeout sending Slave address\n"));
    return EFI_NO_RESPONSE;
  }

  ReadAccess = (Slave & 0x1) ? 1 : 0;
  I2cStatus = I2C_READ(I2cMasterContext, I2C_STATUS);
  if (I2cStatus != (ReadAccess ?
      I2C_STATUS_ADDR_R_ACK : I2C_STATUS_ADDR_W_ACK)) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: no ACK (I2cStatus: %02x) after sending Slave address\n",
        I2cStatus));
    return EFI_NO_RESPONSE;
  }

  return EFI_SUCCESS;
}

#define  ABSSUB(a,b)  (((a) > (b)) ? (a) - (b) : (b) - (a))
STATIC
VOID
MvI2cCalBaudRate (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN CONST UINT32 target,
  IN OUT MV_I2C_BAUD_RATE *rate,
  UINT32 clk
  )
{
  UINT32 cur, diff, diff0, baud;
  UINTN m, n, m0, n0;

  /* Read initial m0, n0 values from register */
  baud = I2C_READ(I2cMasterContext, I2C_BAUD_RATE);
  m0 = I2C_M_FROM_BAUD(baud);
  n0 = I2C_N_FROM_BAUD(baud);
  /* Calculate baud rate. */
  diff0 = 0xffffffff;

  for (n = 0; n < 8; n++) {
    for (m = 0; m < 16; m++) {
      cur = I2C_BAUD_RATE_RAW(clk,m,n);
      diff = ABSSUB(target, cur);
      if (diff < diff0) {
        m0 = m;
        n0 = n;
        diff0 = diff;
      }
    }
  }
  rate->raw = I2C_BAUD_RATE_RAW(clk, m0, n0);
  rate->param = I2C_BAUD_RATE_PARAM(m0, n0);
  rate->m = m0;
  rate->n = n0;
}

EFI_STATUS
EFIAPI
MvI2cReset (
  IN CONST EFI_I2C_MASTER_PROTOCOL *This
  )
{
  UINT32 param;
  I2C_MASTER_CONTEXT *I2cMasterContext = I2C_SC_FROM_MASTER(This);

  param = baud_rate.param;

  EfiAcquireLock (&I2cMasterContext->Lock);
  I2C_WRITE(I2cMasterContext, I2C_SOFT_RESET, 0x0);
  gBS->Stall(2 * I2C_OPERATION_TIMEOUT);
  I2C_WRITE(I2cMasterContext, I2C_BAUD_RATE, param);
  I2C_WRITE(I2cMasterContext, I2C_CONTROL, I2C_CONTROL_I2CEN | I2C_CONTROL_ACK);
  gBS->Stall(I2C_OPERATION_TIMEOUT);
  EfiReleaseLock (&I2cMasterContext->Lock);

  return EFI_SUCCESS;
}

/*
 * Timeout is given in us
 */
STATIC
EFI_STATUS
MvI2cRepeatedStart (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN UINT8 Slave,
  IN UINTN Timeout
  )
{
  EFI_STATUS Status;

  EfiAcquireLock (&I2cMasterContext->Lock);
  Status = MvI2cLockedStart(I2cMasterContext, I2C_STATUS_RPTD_START, Slave,
      Timeout);
  EfiReleaseLock (&I2cMasterContext->Lock);

  if (EFI_ERROR(Status)) {
    MvI2cStop(I2cMasterContext);
  }
  return Status;
}

/*
 * Timeout is given in us
 */
STATIC
EFI_STATUS
MvI2cStart (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN UINT8 Slave,
  IN UINTN Timeout
  )
{
  EFI_STATUS Status;

  EfiAcquireLock (&I2cMasterContext->Lock);
  Status = MvI2cLockedStart(I2cMasterContext, I2C_STATUS_START, Slave, Timeout);
  EfiReleaseLock (&I2cMasterContext->Lock);

  if (EFI_ERROR(Status)) {
    MvI2cStop(I2cMasterContext);
  }
  return Status;
}

STATIC
EFI_STATUS
MvI2cStop (
  IN I2C_MASTER_CONTEXT *I2cMasterContext
  )
{
  EfiAcquireLock (&I2cMasterContext->Lock);
  MvI2cControlSet(I2cMasterContext, I2C_CONTROL_STOP);
  gBS->Stall(I2C_OPERATION_TIMEOUT);
  MvI2cClearIflg(I2cMasterContext);
  EfiReleaseLock (&I2cMasterContext->Lock);

  return EFI_SUCCESS;
}

STATIC
EFI_STATUS
MvI2cRead (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN OUT UINT8 *Buf,
  IN UINTN Length,
  IN OUT UINTN *read,
  IN UINTN last,
  IN UINTN delay
  )
{
  UINT32 I2cStatus;
  UINTN LastByte;
  EFI_STATUS Status;

  EfiAcquireLock (&I2cMasterContext->Lock);
  *read = 0;
  while (*read < Length) {
    /*
     * Check if we are reading last byte of the last Buffer,
     * do not send ACK then, per I2C specs
     */
    LastByte = ((*read == Length - 1) && last) ? 1 : 0;
    if (LastByte)
      MvI2cControlClear(I2cMasterContext, I2C_CONTROL_ACK);
    else
      MvI2cControlSet(I2cMasterContext, I2C_CONTROL_ACK);

    gBS->Stall (I2C_OPERATION_TIMEOUT);
    MvI2cClearIflg(I2cMasterContext);

    if (MvI2cPollCtrl(I2cMasterContext, delay, I2C_CONTROL_IFLG)) {
      DEBUG((DEBUG_ERROR, "MvI2cDxe: Timeout reading data\n"));
      Status = EFI_NO_RESPONSE;
      goto out;
    }

    I2cStatus = I2C_READ(I2cMasterContext, I2C_STATUS);
    if (I2cStatus != (LastByte ?
        I2C_STATUS_DATA_RD_NOACK : I2C_STATUS_DATA_RD_ACK)) {
      DEBUG((DEBUG_ERROR, "MvI2cDxe: wrong I2cStatus (%02x) while reading\n", I2cStatus));
      Status = EFI_DEVICE_ERROR;
      goto out;
    }

    *Buf++ = I2C_READ(I2cMasterContext, I2C_DATA);
    (*read)++;
  }
  Status = EFI_SUCCESS;
out:
  EfiReleaseLock (&I2cMasterContext->Lock);
  return (Status);
}

STATIC
EFI_STATUS
MvI2cWrite (
  IN I2C_MASTER_CONTEXT *I2cMasterContext,
  IN OUT CONST UINT8 *Buf,
  IN UINTN Length,
  IN OUT UINTN *Sent,
  IN UINTN Timeout
  )
{
  UINT32 status;
  EFI_STATUS Status;

  EfiAcquireLock (&I2cMasterContext->Lock);
  *Sent = 0;
  while (*Sent < Length) {
    I2C_WRITE(I2cMasterContext, I2C_DATA, *Buf++);

    MvI2cClearIflg(I2cMasterContext);
    if (MvI2cPollCtrl(I2cMasterContext, Timeout, I2C_CONTROL_IFLG)) {
      DEBUG((DEBUG_ERROR, "MvI2cDxe: Timeout writing data\n"));
      Status = EFI_NO_RESPONSE;
      goto out;
    }

    status = I2C_READ(I2cMasterContext, I2C_STATUS);
    if (status != I2C_STATUS_DATA_WR_ACK) {
      DEBUG((DEBUG_ERROR, "MvI2cDxe: wrong status (%02x) while writing\n", status));
      Status = EFI_DEVICE_ERROR;
      goto out;
    }
    (*Sent)++;
  }
  Status = EFI_SUCCESS;
out:
  EfiReleaseLock (&I2cMasterContext->Lock);
  return (Status);
}

/*
 * MvI2cStartRequest should be called only by I2cHost.
 * I2C device drivers ought to use EFI_I2C_IO_PROTOCOL instead.
 */
STATIC
EFI_STATUS
MvI2cStartRequest (
  IN CONST EFI_I2C_MASTER_PROTOCOL *This,
  IN UINTN                         SlaveAddress,
  IN EFI_I2C_REQUEST_PACKET        *RequestPacket,
  IN EFI_EVENT                     Event      OPTIONAL,
  OUT EFI_STATUS                   *I2cStatus OPTIONAL
  )
{
  UINTN Count;
  UINTN ReadMode;
  UINTN Transmitted;
  I2C_MASTER_CONTEXT *I2cMasterContext = I2C_SC_FROM_MASTER(This);
  EFI_I2C_OPERATION *Operation;

  ASSERT (RequestPacket != NULL);
  ASSERT (I2cMasterContext != NULL);

  for (Count = 0; Count < RequestPacket->OperationCount; Count++) {
    Operation = &RequestPacket->Operation[Count];
    ReadMode = Operation->Flags & I2C_FLAG_READ;

    if (Count == 0) {
      MvI2cStart ( I2cMasterContext,
                   (SlaveAddress << 1) | ReadMode,
                   I2C_TRANSFER_TIMEOUT
                 );
    } else if (!(Operation->Flags & I2C_FLAG_NORESTART)) {
      MvI2cRepeatedStart ( I2cMasterContext,
                           (SlaveAddress << 1) | ReadMode,
                           I2C_TRANSFER_TIMEOUT
                         );
    }

    if (ReadMode) {
      MvI2cRead ( I2cMasterContext,
                  Operation->Buffer,
                  Operation->LengthInBytes,
                  &Transmitted,
                  Count == 1,
                  I2C_TRANSFER_TIMEOUT
                 );
    } else {
      MvI2cWrite ( I2cMasterContext,
                   Operation->Buffer,
                   Operation->LengthInBytes,
                   &Transmitted,
                   I2C_TRANSFER_TIMEOUT
                  );
    }
    if (Count == RequestPacket->OperationCount - 1) {
      MvI2cStop ( I2cMasterContext );
    }
  }

  if (I2cStatus != NULL)
    I2cStatus = EFI_SUCCESS;
  if (Event != NULL)
    gBS->SignalEvent(Event);
  return EFI_SUCCESS;
}

STATIC CONST EFI_GUID DevGuid = I2C_GUID;

#define I2C_DEVICE_INDEX(bus, address) (((address) & 0xffff) | (bus) << 16)
#define I2C_DEVICE_ADDRESS(index) ((index) & 0xffff)

STATIC
EFI_STATUS
MvI2cAllocDevice (
  IN UINT8 SlaveAddress,
  IN UINT8 Bus,
  IN OUT CONST EFI_I2C_DEVICE **Device
  )
{
  EFI_STATUS Status;
  EFI_I2C_DEVICE *Dev;
  UINT32 *TmpSlaveArray;
  EFI_GUID *TmpGuidP;

  Status = gBS->AllocatePool ( EfiBootServicesData,
             sizeof(EFI_I2C_DEVICE),
             (VOID **) &Dev );
  if (EFI_ERROR(Status)) {
    DEBUG((DEBUG_ERROR, "MvI2cDxe: I2C device memory allocation failed\n"));
    return Status;
  }
  *Device = Dev;
  Dev->DeviceIndex = SlaveAddress;
  Dev->DeviceIndex = I2C_DEVICE_INDEX(Bus, SlaveAddress);
  Dev->SlaveAddressCount = 1;
  Dev->I2cBusConfiguration = 0;
  Status = gBS->AllocatePool ( EfiBootServicesData,
             sizeof(UINT32),
             (VOID **) &TmpSlaveArray);
  if (EFI_ERROR(Status)) {
    goto fail1;
  }
  TmpSlaveArray[0] = SlaveAddress;
  Dev->SlaveAddressArray = TmpSlaveArray;

  Status = gBS->AllocatePool ( EfiBootServicesData,
             sizeof(EFI_GUID),
             (VOID **) &TmpGuidP);
  if (EFI_ERROR(Status)) {
    goto fail2;
  }
  *TmpGuidP = DevGuid;
  Dev->DeviceGuid = TmpGuidP;

  DEBUG((DEBUG_INFO, "MvI2c: allocated device with address %x\n", (UINTN)SlaveAddress));
  return EFI_SUCCESS;

fail2:
  FreePool(TmpSlaveArray);
fail1:
  FreePool(Dev);

  return Status;
}

/*
 * It is called by I2cBus to enumerate devices on I2C bus. In this case,
 * enumeration is based on PCD configuration - all Slave addresses specified
 * in PCD get their corresponding EFI_I2C_DEVICE structures here.
 *
 * After enumeration succeeds, Supported() function of drivers that installed
 * DriverBinding protocol is called.
 */
STATIC
EFI_STATUS
EFIAPI
MvI2cEnumerate (
  IN CONST EFI_I2C_ENUMERATE_PROTOCOL *This,
  IN OUT CONST EFI_I2C_DEVICE         **Device
  )
{
  UINT8 *DevicesPcd;
  UINT8 *DeviceBusPcd;
  UINTN Index, NextIndex;
  UINT8 NextDeviceAddress;
  I2C_MASTER_CONTEXT *I2cMasterContext = I2C_SC_FROM_ENUMERATE(This);

  DevicesPcd = PcdGetPtr (PcdI2cSlaveAddresses);
  DeviceBusPcd = PcdGetPtr (PcdI2cSlaveBuses);
  if (*Device == NULL) {
    for (Index = 0; DevicesPcd[Index] != '\0'; Index++) {
      if (DeviceBusPcd[Index] != I2cMasterContext->Bus)
        continue;
      if (DevicesPcd[Index] != '\0')
        MvI2cAllocDevice (DevicesPcd[Index], I2cMasterContext->Bus, Device);
      return EFI_SUCCESS;
    }
  } else {
    /* Device is not NULL, so something was already allocated */
    for (Index = 0; DevicesPcd[Index] != '\0'; Index++) {
      if (DeviceBusPcd[Index] != I2cMasterContext->Bus)
        continue;
      if (DevicesPcd[Index] == I2C_DEVICE_ADDRESS((*Device)->DeviceIndex)) {
        for (NextIndex = Index + 1; DevicesPcd[NextIndex] != '\0'; NextIndex++) {
          if (DeviceBusPcd[NextIndex] != I2cMasterContext->Bus)
            continue;
          NextDeviceAddress = DevicesPcd[NextIndex];
          if (NextDeviceAddress != '\0')
            MvI2cAllocDevice(NextDeviceAddress, I2cMasterContext->Bus, Device);
          return EFI_SUCCESS;
        }
      }
    }
    *Device = NULL;
    return EFI_SUCCESS;
  }
  return EFI_SUCCESS;
}

STATIC
EFI_STATUS
EFIAPI
MvI2cEnableConf (
  IN CONST EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL *This,
  IN UINTN                                               I2cBusConfiguration,
  IN EFI_EVENT                                           Event      OPTIONAL,
  IN EFI_STATUS                                          *I2cStatus OPTIONAL
  )
{
  /* do nothing */
  if (I2cStatus != NULL)
    I2cStatus = EFI_SUCCESS;
  if (Event != NULL)
    gBS->SignalEvent(Event);
  return EFI_SUCCESS;
}