This adds device tree binding documentation for the Moxtet bus, a bus
via which the different modules connected to the Turris Mox router can
be configured.
Signed-off-by: Marek Behún <marek.be...@nic.cz>
Cc: Rob Herring <robh...@kernel.org>
Cc: devicet...@vger.kernel.org
---
.../devicetree/bindings/bus/moxtet.txt | 44 +++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 45 insertions(+)
create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt
b/Documentation/devicetree/bindings/bus/moxtet.txt
new file mode 100644
index 000000000000..7be9d00c1767
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/moxtet.txt
@@ -0,0 +1,46 @@
+Turris Mox module status and configuration bus (over SPI)
+
+Required properties:
+ - compatible : Should be "cznic,moxtet"
+ - #address-cells : Has to be 1
+ - #size-cells : Has to be 0
+ - spi-cpol : Required inverted clock polarity
+ - spi-cpha : Required shifted clock phase
+ - interrupts : Must contain reference to the shared interrupt line
+ - interrupt-controller : Required
+ - #interrupt-cells : Has to be 1
+
+For other required and optional properties of SPI slave nodes please refer to
+../spi/spi-bus.txt.
+
+Required properties of subnodes:
+ - reg : Should be position on the Moxtet bus (how many Moxtet
+ modules are between this module and CPU module, so
+ either 0 or a positive integer)
+
+The driver finds the devices connected to the bus by itself, but it may be
+needed to reference some of them from other parts of the device tree. In that
+case the devices can be defined as subnodes of the moxtet node.
+
+Example:
+
+ moxtet@1 {
+ compatible = "cznic,moxtet";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <1>;
+ spi-max-frequency = <10000000>;
+ spi-cpol;
+ spi-cpha;
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gpiosb>;
+ interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
+
+ moxtet_sfp: gpio@0 {
+ compatible = "cznic,moxtet-gpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0>;
+ }
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index d96d36c83bc3..3f461a2d776a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
M: Marek Behun <marek.be...@nic.cz>
W: http://mox.turris.cz
S: Maintained
+F: Documentation/devicetree/bindings/bus/moxtet.txt
F: include/linux/moxtet.h
F: drivers/bus/moxtet.c
--
2.19.2
