[PATCH v1 2/2] DynamicTablesPkg: Add an override for 16550 HID in SSDT


Joey Gouly
 

Some platforms advertise support for a 16550 UART, but are not
compatible with the PNP0500 HID. Allow them to override the HID by
setting PcdNonSbsaCompliantSerialHid.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
---
DynamicTablesPkg/DynamicTablesPkg.dec | 3 +++
DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf | 4 +++-
DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.c | 14 +++++++++++---
3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/DynamicTablesPkg/DynamicTablesPkg.dec b/DynamicTablesPkg/DynamicTablesPkg.dec
index 291a45a69679ae82219ecd2f26dfabfbab1f7f65..3ec4fff116a8f538be331edf341867948c025116 100644
--- a/DynamicTablesPkg/DynamicTablesPkg.dec
+++ b/DynamicTablesPkg/DynamicTablesPkg.dec
@@ -44,5 +44,8 @@ [PcdsFixedAtBuild]
# Maximum number of Custom DT Generators
gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdMaxCustomDTGenerators|1|UINT16|0xC0000003

+ # Non SBSA Compliant Serial HID
+ gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdNonSbsaCompliantSerialHid|""|VOID*|0x40000008
+
[Guids]
gEdkiiDynamicTablesPkgTokenSpaceGuid = { 0xab226e66, 0x31d8, 0x4613, { 0x87, 0x9d, 0xd2, 0xfa, 0xb6, 0x10, 0x26, 0x3c } }
diff --git a/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf b/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf
index af3d404393f5f1385ab2d40f45f7222ab66f9b3a..b64825982e8fb7aaf78f3fd68992e1c78d20c408 100644
--- a/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf
+++ b/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf
@@ -1,7 +1,7 @@
## @file
# SSDT Serial Port fixup Library
#
-# Copyright (c) 2020, Arm Limited. All rights reserved.<BR>
+# Copyright (c) 2020 - 2021, Arm Limited. All rights reserved.<BR>
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
##
@@ -28,3 +28,5 @@ [LibraryClasses]
AmlLib
BaseLib

+[Pcd]
+ gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdNonSbsaCompliantSerialHid
diff --git a/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.c b/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.c
index 0ff071485ef25f4ca63de0eeab5120d1beece4db..73a8087ed8a8ff84b64531a3c73d319585dfb6cf 100644
--- a/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.c
+++ b/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.c
@@ -1,7 +1,7 @@
/** @file
SSDT Serial Port Fixup Library.

- Copyright (c) 2019 - 2020, Arm Limited. All rights reserved.<BR>
+ Copyright (c) 2019 - 2021, Arm Limited. All rights reserved.<BR>

SPDX-License-Identifier: BSD-2-Clause-Patent

@@ -139,13 +139,21 @@ FixupIds (
AML_OBJECT_NODE_HANDLE NameOpIdNode;
CONST CHAR8 * HidString;
CONST CHAR8 * CidString;
+ CONST CHAR8 * NonSbsaHid;

// Get the _CID and _HID value to write.
switch (SerialPortInfo->PortSubtype) {
case EFI_ACPI_DBG2_PORT_SUBTYPE_SERIAL_FULL_16550:
{
- HidString = "PNP0501";
- CidString = "PNP0500";
+ // If there is a non-SBSA compliant HID, use that.
+ NonSbsaHid = (CONST CHAR8*)PcdGetPtr (PcdNonSbsaCompliantSerialHid);
+ if ((NonSbsaHid != NULL) && (AsciiStrLen (NonSbsaHid) != 0)) {
+ HidString = NonSbsaHid;
+ CidString = "";
+ } else {
+ HidString = "PNP0501";
+ CidString = "PNP0500";
+ }
break;
}
case EFI_ACPI_DBG2_PORT_SUBTYPE_SERIAL_ARM_PL011_UART:
--
Guid("CE165669-3EF3-493F-B85D-6190EE5B9759")

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