blob: ce23964e50256bf8531b6640908319ca10806028 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
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;
}
|
