DynamicTablesPkg: Add an override for 16550 HID in SSDT

Some platforms advertise support for a 16550 UART, but are not
compatible with the PNP0500 HID. Allow them to override the HID by
setting PcdNonBsaCompliant16550SerialHid.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

3 files changed, 17 insertions, 4 deletions

diff --git a/DynamicTablesPkg/DynamicTablesPkg.dec b/DynamicTablesPkg/DynamicTablesPkg.dec
index 291a45a696..b242df0105 100644
--- a/DynamicTablesPkg/DynamicTablesPkg.dec
+++ b/DynamicTablesPkg/DynamicTablesPkg.dec
@@ -44,5 +44,8 @@
   # Maximum number of Custom DT Generators

   gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdMaxCustomDTGenerators|1|UINT16|0xC0000003

 

+  # Non BSA Compliant 16550 Serial HID

+  gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdNonBsaCompliant16550SerialHid|""|VOID*|0x40000008

+

 [Guids]

   gEdkiiDynamicTablesPkgTokenSpaceGuid = { 0xab226e66, 0x31d8, 0x4613, { 0x87, 0x9d, 0xd2, 0xfa, 0xb6, 0x10, 0x26, 0x3c } }

diff --git a/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.c b/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.c
index 0ff071485e..3c4356097c 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             * NonBsaHid;

 

   // 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-BSA compliant HID, use that.

+      NonBsaHid = (CONST CHAR8*)PcdGetPtr (PcdNonBsaCompliant16550SerialHid);

+      if ((NonBsaHid != NULL) && (AsciiStrLen (NonBsaHid) != 0)) {

+        HidString = NonBsaHid;

+        CidString = "";

+      } else {

+        HidString = "PNP0501";

+        CidString = "PNP0500";

+      }

       break;

     }

     case EFI_ACPI_DBG2_PORT_SUBTYPE_SERIAL_ARM_PL011_UART:

diff --git a/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf b/DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf
index af3d404393..54bf71a3b7 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 @@
   AmlLib

   BaseLib

 

+[Pcd]

+  gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdNonBsaCompliant16550SerialHid