spi: spi-ath79: add binding documentation for the AR7100 SPI controller

Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/Documentation/devicetree/bindings/spi/spi-ath79.txt b/Documentation/devicetree/bindings/spi/spi-ath79.txt
new file mode 100644 (file)
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+++ b/Documentation/devicetree/bindings/spi/spi-ath79.txt
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+Binding for Qualcomm Atheros AR7xxx/AR9xxx SPI controller
+
+Required properties:
+- compatible: has to be "qca,<soc-type>-spi", "qca,ar7100-spi" as fallback.
+- reg: Base address and size of the controllers memory area
+- clocks: phandle to the AHB clock.
+- clock-names: has to be "ahb".
+- #address-cells: <1>, as required by generic SPI binding.
+- #size-cells: <0>, also as required by generic SPI binding.
+
+Child nodes as per the generic SPI binding.
+
+Example:
+
+       spi@1F000000 {
+               compatible = "qca,ar9132-spi", "qca,ar7100-spi";
+               reg = <0x1F000000 0x10>;
+
+               clocks = <&pll 2>;
+               clock-names = "ahb";
+
+               #address-cells = <1>;
+               #size-cells = <0>;
+       };