[PATCH 11/14] dt-bindings: fsi: Document binding for the fsi-master-ast-cf "device"

[Benjamin Herrenschmidt]

This isn't per-se a real device, it's a pseudo-device that
represents the use of the Aspeed built-in ColdFire to
implement the FSI protocol by bitbanging the GPIOs instead
of doing it from the ARM core.

Thus it's a drop-in replacement for the existing
fsi-master-gpio pseudo-device for use on systems for which
a corresponding firmware file exists. It has most of the
same properties, plus some more needed to operate the
coprocessor.

Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
---
 .../bindings/fsi/fsi-master-ast-cf.txt        | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt

diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt b/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt
new file mode 100644
index 000000000000..50913ae685cc
--- /dev/null
+++ b/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt
@@ -0,0 +1,36 @@
+Device-tree bindings for ColdFire offloaded gpio-based FSI master driver
+------------------------------------------------------------------------
+
+Required properties:
+ - compatible =
+   	      "fsi-master-ast-2400-cf" for an AST2400 based system
+	    or
+	      "fsi-master-ast-2500-cf" for an AST2500 based system
+
+ - clock-gpios = <gpio-descriptor>;	: GPIO for FSI clock
+ - data-gpios = <gpio-descriptor>;	: GPIO for FSI data signal
+ - enable-gpios = <gpio-descriptor>;	: GPIO for enable signal
+ - trans-gpios = <gpio-descriptor>;	: GPIO for voltage translator enable
+ - mux-gpios = <gpio-descriptor>;	: GPIO for pin multiplexing with other
+                                          functions (eg, external FSI masters)
+ - memory-region = <phandle>;		: Reference to the reserved memory for
+                                          the ColdFire. Must be 2M aligned on
+					  AST2400 and 1M aligned on AST2500
+ - sram = <phandle>;			: Reference to the SRAM node.
+ - cvic = <phandle>;			: Reference to the CVIC node.
+ - fw-name = <string>;			: The name used to construct the firmware
+   	     				  file name (cf-fsi-<name>.bin)
+ - fw-platform-sig = <value>;		: A signature value that must match the one
+   		     			  contained in the firmware image. Known
+					  values are listed in the firmware interface
+					  file cf-fsi-fw.h
+Examples:
+
+    fsi-master {
+        compatible = "fsi-master-gpio", "fsi-master";
+        clock-gpios = <&gpio 0>;
+        data-gpios = <&gpio 1>;
+        enable-gpios = <&gpio 2>;
+        trans-gpios = <&gpio 3>;
+        mux-gpios = <&gpio 4>;
+    }
-- 
2.17.1