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

From: Yunhui Cui
Date: Wed Jul 05 2023 - 07:45:51 EST


Add the description for ffitbl subnode.

Signed-off-by: Yunhui Cui <cuiyunhui@xxxxxxxxxxxxx>
---
.../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@xxxxxxxxxxxxx
S: Maintained
+F: Documentation/devicetree/bindings/firmware/ffitbl.txt
F: drivers/firmware/ffi.c
F: include/linux/ffi.h

--
2.20.1