Files
system76-edk2/UefiPayloadPkg/PciBusNoEnumerationDxe/PciPowerManagement.c
Tim Crawford 331d92a8ba UefiPayloadPkg: Add PCI support from DuetPkg
Skip PCI enumeration, which is already handled by Coreboot, by using
PciBusNoEnumerationDxe and PciRootBridgeNoEnumerationDxe from the
deleted DuetPkg.
2020-04-14 09:20:45 -06:00

101 lines
2.6 KiB
C

/*++
Copyright (c) 2005 - 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.
Module Name:
PciPowerManagement.c
Abstract:
PCI Bus Driver
Revision History
--*/
#include "PciBus.h"
EFI_STATUS
EFIAPI
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
--*/
{
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;
}