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

[Marcin Wojtas <mw@semihalf.com>]

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@semihalf.com>
---
 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