1 files changed, 68 insertions, 0 deletions
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c
new file mode 100644
index 0000000000..860d427f35
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c
@@ -0,0 +1,68 @@
+/** @file
+  Power management support fucntions implementation for PCI Bus module.
+
+Copyright (c) 2006 - 2009, Intel Corporation
+All rights reserved. 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 "PciBus.h"
+
+/**
+  This function is intended to turn off PWE assertion and
+  put the device to D0 state if the device supports
+  PCI Power Management.
+
+  @param PciIoDevice      PCI device instance.
+
+  @retval EFI_UNSUPPORTED PCI Device does not support power management.
+  @retval EFI_SUCCESS     Turned off PWE successfully.
+
+**/
+EFI_STATUS
+ResetPowerManagementFeature (
+  IN PCI_IO_DEVICE *PciIoDevice
+  )
+{
+  EFI_STATUS  Status;
+  UINT8       PowerManagementRegBlock;
+  UINT16      PowerManagementCSR;
+
+  PowerManagementRegBlock = 0;
+
+  Status = LocateCapabilityRegBlock (
+            PciIoDevice,
+            EFI_PCI_CAPABILITY_ID_PMI,
+            &PowerManagementRegBlock,
+            NULL
+            );
+
+  if (EFI_ERROR (Status)) {
+    return EFI_UNSUPPORTED;
+  }
+
+  //
+  // Turn off the PWE assertion and put the device into D0 State
+  //
+  PowerManagementCSR = 0x8000;
+
+  //
+  // Write PMCSR
+  //
+  PciIoDevice->PciIo.Pci.Write (
+                           &PciIoDevice->PciIo,
+                           EfiPciIoWidthUint16,
+                           PowerManagementRegBlock + 4,
+                           1,
+                           &PowerManagementCSR
+                           );
+
+  return EFI_SUCCESS;
+}
+