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authorMarek BehĂșn <marek.behun@nic.cz>2019-08-12 19:11:15 +0300
committerArnd Bergmann <arnd@arndb.de>2019-08-14 16:30:43 +0300
commit20e6cf7e747815461ac8bcb526f7079ce48866b5 (patch)
treec96e60975ab9109bdc8aca8fcd49e25ff8e64111 /Documentation/devicetree/bindings/bus
parent5bc7f990cd98f3f7977d62bfe75c50b4b33d13f6 (diff)
downloadlinux-20e6cf7e747815461ac8bcb526f7079ce48866b5.tar.xz
dt-bindings: bus: Document moxtet bus binding
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. Link: https://lore.kernel.org/r/20190812161118.21476-3-marek.behun@nic.cz Signed-off-by: Marek BehĂșn <marek.behun@nic.cz> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'Documentation/devicetree/bindings/bus')
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diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
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+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>;
+ }
+ };