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1Lantiq SoC External Bus memory mapped GPIO controller2 3By attaching hardware latches to the EBU it is possible to create output4only gpios. This driver configures a special memory address, which when5written to outputs 16 bit to the latches.6 7The node describing the memory mapped GPIOs needs to be a child of the node8describing the "lantiq,localbus".9 10Required properties:11- compatible : Should be "lantiq,gpio-mm-lantiq"12- reg : Address and length of the register set for the device13- #gpio-cells : Should be two. The first cell is the pin number and14 the second cell is used to specify optional parameters (currently15 unused).16- gpio-controller : Marks the device node as a gpio controller.17 18Optional properties:19- lantiq,shadow : The default value that we shall assume as already set on the20 shift register cascade.21 22Example:23 24localbus@0 {25 #address-cells = <2>;26 #size-cells = <1>;27 ranges = <0 0 0x0 0x3ffffff /* addrsel0 */28 1 0 0x4000000 0x4000010>; /* addsel1 */29 compatible = "lantiq,localbus", "simple-bus";30 31 gpio_mm0: gpio@4000000 {32 compatible = "lantiq,gpio-mm";33 reg = <1 0x0 0x10>;34 gpio-controller;35 #gpio-cells = <2>;36 lantiq,shadow = <0x77f>37 };38}39