Initial import.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@3 6f19259b-4bc3-4df7-8a09-765794883524

EdkModulePkg/Bus/Pci/PciBus/Dxe/PciPowerManagement.c

@@ -0,0 +1,83 @@
+/*++
+
+Copyright (c) 2006, 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.             
+
+Module Name:
+
+  PciPowerManagement.c
+  
+Abstract:
+
+  PCI Bus Driver
+
+Revision History
+
+--*/
+
+#include "Pcibus.h"
+
+EFI_STATUS
+ResetPowerManagementFeature (
+  IN PCI_IO_DEVICE *PciIoDevice
+  )
+/*++
+
+Routine Description:
+
+  This function is intended to turn off PWE assertion and
+  put the device to D0 state if the device supports
+  PCI Power Management.
+
+Arguments:
+
+Returns:
+  
+  None
+
+--*/
+// TODO:    PciIoDevice - add argument and description to function comment
+// TODO:    EFI_UNSUPPORTED - add return value to function comment
+// TODO:    EFI_SUCCESS - add return value to function comment
+{
+  EFI_STATUS  Status;
+  UINT8       PowerManagementRegBlock;
+  UINT16      PMCSR;
+
+  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
+  //
+  PMCSR = 0x8000;
+
+  //
+  // Write PMCSR
+  //
+  PciIoDevice->PciIo.Pci.Write (
+                          &PciIoDevice->PciIo,
+                          EfiPciIoWidthUint16,
+                          PowerManagementRegBlock + 4,
+                          1,
+                          &PMCSR
+                          );
+
+  return EFI_SUCCESS;
+}