Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface.Required properties:- compatible : "snps,dw-apb-ssi"- reg : The register base for the controller.- interrupts : One interrupt, used by the controller.- #address-cells : <1>, as required by generic SPI binding.- #size-cells : <0>, also as required by generic SPI binding.Optional properties:- cs-gpios : Specifies the gpio pis to be used for chipselects.- num-cs : The number of chipselects. If omitted, this will default to 4.- reg-io-width : The I/O register width (in bytes) implemented by this device. Supported values are 2 or 4 (the default).Child nodes as per the generic SPI binding.Example: spi@fff00000 { compatible = "snps,dw-apb-ssi"; reg = <0xfff00000 0x1000>; interrupts = <0 154 4>; #address-cells = <1>; #size-cells = <0>; num-cs = <2>; cs-gpios = <&gpio0 13 0>, <&gpio0 14 0>; };