[PATCH v3 4/4] dt-bindings: firmware: Document ffitbl binding

[Yunhui Cui]

Add the description for ffitbl subnode.

Signed-off-by: Yunhui Cui <cuiyunhui at bytedance.com>
---
 .../devicetree/bindings/firmware/ffitbl.txt   | 27 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 28 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/firmware/ffitbl.txt

diff --git a/Documentation/devicetree/bindings/firmware/ffitbl.txt b/Documentation/devicetree/bindings/firmware/ffitbl.txt
new file mode 100644
index 000000000000..c42368626199
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/ffitbl.txt
@@ -0,0 +1,27 @@
+FFI(FDT FIRMWARE INTERFACE) driver
+
+Required properties:
+ - entry		: acpi or smbios root pointer, u64
+ - reg			: acpi or smbios version, u32
+
+Some bootloaders, such as Coreboot do not support EFI,
+only devicetree and some arches do not have a reserved
+address segment. Add "ffitbl" subnode to obtain ACPI RSDP
+and SMBIOS entry.
+This feature is known as FDT Firmware Interface (FFI).
+
+Example:
+	ffitbl {
+
+		smbios {
+				entry = "";
+				reg = < 0x03 >;
+
+		}
+		acpi {
+				entry = "";
+				reg = < 0x06 >;
+
+		}
+	}
+
diff --git a/MAINTAINERS b/MAINTAINERS
index 9b886ef36587..008257e55062 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7874,6 +7874,7 @@ F:	include/linux/efi*.h
 FDT FIRMWARE INTERFACE (FFI)
 M:	Yunhui Cui cuiyunhui at bytedance.com
 S:	Maintained
+F:	Documentation/devicetree/bindings/firmware/ffitbl.txt
 F:	drivers/firmware/ffi.c
 F:	include/linux/ffi.h
 
-- 
2.20.1