1 files changed, 88 insertions, 0 deletions
diff --git a/Core/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c b/Core/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c
new file mode 100644
index 0000000000..ab655e7657
--- /dev/null
+++ b/Core/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c
@@ -0,0 +1,88 @@
+/** @file
+  Power management support fucntions implementation for PCI Bus module.
+
+Copyright (c) 2006 - 2012, 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 "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
+  //
+
+  //
+  // Read PMCSR
+  //
+  Status = PciIoDevice->PciIo.Pci.Read (
+                                    &PciIoDevice->PciIo,
+                                    EfiPciIoWidthUint16,
+                                    PowerManagementRegBlock + 4,
+                                    1,
+                                    &PowerManagementCSR
+                                    );
+
+  if (!EFI_ERROR (Status)) {
+    //
+    // Clear PME_Status bit
+    //
+    PowerManagementCSR |= BIT15;
+    //
+    // Clear PME_En bit. PowerState = D0.
+    //
+    PowerManagementCSR &= ~(BIT8 | BIT1 | BIT0);
+
+    //
+    // Write PMCSR
+    //
+    Status = PciIoDevice->PciIo.Pci.Write (
+                                      &PciIoDevice->PciIo,
+                                      EfiPciIoWidthUint16,
+                                      PowerManagementRegBlock + 4,
+                                      1,
+                                      &PowerManagementCSR
+                                      );
+  }
+  return Status;
+}
+