sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

PcAtChipsetPkg: Add MMIO Support to RTC driver

Browse Source 
Some virtual machine managers like Kvmtool emulate the MC146818
RTC controller in the MMIO space so that architectures that do
not support I/O Mapped I/O can use the RTC. This patch adds MMIO
support to the RTC controller driver.

The PCD PcdRtcUseMmio has been added to select I/O or MMIO support.
  If PcdRtcUseMmio is:
    TRUE  - Indicates the RTC port registers are in MMIO space.
    FALSE - Indicates the RTC port registers are in I/O space.
            Default is I/O space.

Additionally two new PCDs PcdRtcIndexRegister64 and
PcdRtcTargetRegister64 have been introduced to provide the base
address for the RTC registers in the MMIO space.

When MMIO support is selected (PcdRtcUseMmio == TRUE) the driver
converts the pointers to the RTC MMIO registers so that the
RTC registers are accessible post ExitBootServices.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Sami Mujawar
2020-10-02 22:13:55 +01:00
committed by mergify[bot]
parent a7d977040b
commit 015be4075f
4 changed files with 187 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

122
PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
View File

@@ -3,6 +3,7 @@
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -10,6 +11,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
#include "PcRtc.h"
extern UINTN mRtcIndexRegister;
extern UINTN mRtcTargetRegister;
//
// Days of month.
//
@@ -54,38 +58,132 @@ IsWithinOneDay (
);
/**
Read RTC content through its registers.
Read RTC content through its registers using IO access.
@param Address Address offset of RTC. It is recommended to use macros such as
RTC_ADDRESS_SECONDS.
@param Address Address offset of RTC. It is recommended to use
macros such as RTC_ADDRESS_SECONDS.
@return The data of UINT8 type read from RTC.
**/
STATIC
UINT8
RtcRead (
IN UINT8 Address
IoRtcRead (
IN UINTN Address
)
{
IoWrite8 (PcdGet8 (PcdRtcIndexRegister), (UINT8) (Address | (UINT8) (IoRead8 (PcdGet8 (PcdRtcIndexRegister)) & 0x80)));
IoWrite8 (
PcdGet8 (PcdRtcIndexRegister),
(UINT8)(Address | (UINT8)(IoRead8 (PcdGet8 (PcdRtcIndexRegister)) & 0x80))
);
return IoRead8 (PcdGet8 (PcdRtcTargetRegister));
}
/**
Write RTC through its registers using IO access.
@param Address Address offset of RTC. It is recommended to use
macros such as RTC_ADDRESS_SECONDS.
@param Data The content you want to write into RTC.
**/
STATIC
VOID
IoRtcWrite (
IN UINTN Address,
IN UINT8 Data
)
{
IoWrite8 (
PcdGet8 (PcdRtcIndexRegister),
(UINT8)(Address | (UINT8)(IoRead8 (PcdGet8 (PcdRtcIndexRegister)) & 0x80))
);
IoWrite8 (PcdGet8 (PcdRtcTargetRegister), Data);
}
/**
Read RTC content through its registers using MMIO access.
@param Address Address offset of RTC. It is recommended to use
macros such as RTC_ADDRESS_SECONDS.
@return The data of UINT8 type read from RTC.
**/
STATIC
UINT8
MmioRtcRead (
IN UINTN Address
)
{
MmioWrite8 (
mRtcIndexRegister,
(UINT8)(Address | (UINT8)(MmioRead8 (mRtcIndexRegister) & 0x80))
);
return MmioRead8 (mRtcTargetRegister);
}
/**
Write RTC through its registers using MMIO access.
@param Address Address offset of RTC. It is recommended to use
macros such as RTC_ADDRESS_SECONDS.
@param Data The content you want to write into RTC.
**/
STATIC
VOID
MmioRtcWrite (
IN UINTN Address,
IN UINT8 Data
)
{
MmioWrite8 (
mRtcIndexRegister,
(UINT8)(Address | (UINT8)(MmioRead8 (mRtcIndexRegister) & 0x80))
);
MmioWrite8 (mRtcTargetRegister, Data);
}
/**
Read RTC content through its registers.
@param Address Address offset of RTC. It is recommended to use
macros such as RTC_ADDRESS_SECONDS.
@return The data of UINT8 type read from RTC.
**/
STATIC
UINT8
RtcRead (
IN UINTN Address
)
{
if (FeaturePcdGet (PcdRtcUseMmio)) {
return MmioRtcRead (Address);
}
return IoRtcRead (Address);
}
/**
Write RTC through its registers.
@param Address Address offset of RTC. It is recommended to use macros such as
RTC_ADDRESS_SECONDS.
@param Data The content you want to write into RTC.
@param Address Address offset of RTC. It is recommended to use
macros such as RTC_ADDRESS_SECONDS.
@param Data The content you want to write into RTC.
**/
STATIC
VOID
RtcWrite (
IN UINT8 Address,
IN UINTN Address,
IN UINT8 Data
)
{
IoWrite8 (PcdGet8 (PcdRtcIndexRegister), (UINT8) (Address | (UINT8) (IoRead8 (PcdGet8 (PcdRtcIndexRegister)) & 0x80)));
IoWrite8 (PcdGet8 (PcdRtcTargetRegister), Data);
if (FeaturePcdGet (PcdRtcUseMmio)) {
MmioRtcWrite (Address, Data);
} else {
IoRtcWrite (Address, Data);
}
}
/**