diff options
| author |   Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
|---|---|---|
| committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
| commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
| tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/edk2/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c')
| -rw-r--r-- | roms/edk2/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/roms/edk2/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c b/roms/edk2/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c new file mode 100644 index 000000000..c7f3ea509 --- /dev/null +++ b/roms/edk2/MdeModulePkg/Bus/Pci/PciBusDxe/PciPowerManagement.c @@ -0,0 +1,82 @@ +/** @file
+ Power management support functions implementation for PCI Bus module.
+
+Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#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;
+}
+
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