[net-next: PATCH v3 1/1] ACPI: SPCR: Add new 16550-compatible Serial Port Subtype

From: Marcin Wojtas
Date: Mon Jun 21 2021 - 16:05:37 EST


The Microsoft Debug Port Table 2 (DBG2) specification revision
May 31, 2017 adds support for 16550-compatible Serial Port
Subtype with parameters defined in Generic Address Structure (GAS) [1]

Add its support in SPCR parsing routine.

[1] https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/acpi-debug-port-table

Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>
---
include/acpi/actbl1.h | 1 +
drivers/acpi/spcr.c | 1 +
2 files changed, 2 insertions(+)

diff --git a/include/acpi/actbl1.h b/include/acpi/actbl1.h
index ce59903c2695..f746012eba8d 100644
--- a/include/acpi/actbl1.h
+++ b/include/acpi/actbl1.h
@@ -498,6 +498,7 @@ struct acpi_dbg2_device {
#define ACPI_DBG2_ARM_SBSA_GENERIC 0x000E
#define ACPI_DBG2_ARM_DCC 0x000F
#define ACPI_DBG2_BCM2835 0x0010
+#define ACPI_DBG2_16550_WITH_GAS 0x0012

#define ACPI_DBG2_1394_STANDARD 0x0000

diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c
index 88460bacd5ae..25c2d0be953e 100644
--- a/drivers/acpi/spcr.c
+++ b/drivers/acpi/spcr.c
@@ -136,6 +136,7 @@ int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console)
break;
case ACPI_DBG2_16550_COMPATIBLE:
case ACPI_DBG2_16550_SUBSET:
+ case ACPI_DBG2_16550_WITH_GAS:
uart = "uart";
break;
default:
--
2.29.0