1*a36e9a1cSJohn CrispinLantiq SoC External Bus memory mapped GPIO controller 2*a36e9a1cSJohn Crispin 3*a36e9a1cSJohn CrispinBy attaching hardware latches to the EBU it is possible to create output 4*a36e9a1cSJohn Crispinonly gpios. This driver configures a special memory address, which when 5*a36e9a1cSJohn Crispinwritten to outputs 16 bit to the latches. 6*a36e9a1cSJohn Crispin 7*a36e9a1cSJohn CrispinThe node describing the memory mapped GPIOs needs to be a child of the node 8*a36e9a1cSJohn Crispindescribing the "lantiq,localbus". 9*a36e9a1cSJohn Crispin 10*a36e9a1cSJohn CrispinRequired properties: 11*a36e9a1cSJohn Crispin- compatible : Should be "lantiq,gpio-mm-lantiq" 12*a36e9a1cSJohn Crispin- reg : Address and length of the register set for the device 13*a36e9a1cSJohn Crispin- #gpio-cells : Should be two. The first cell is the pin number and 14*a36e9a1cSJohn Crispin the second cell is used to specify optional parameters (currently 15*a36e9a1cSJohn Crispin unused). 16*a36e9a1cSJohn Crispin- gpio-controller : Marks the device node as a gpio controller. 17*a36e9a1cSJohn Crispin 18*a36e9a1cSJohn CrispinOptional properties: 19*a36e9a1cSJohn Crispin- lantiq,shadow : The default value that we shall assume as already set on the 20*a36e9a1cSJohn Crispin shift register cascade. 21*a36e9a1cSJohn Crispin 22*a36e9a1cSJohn CrispinExample: 23*a36e9a1cSJohn Crispin 24*a36e9a1cSJohn Crispinlocalbus@0 { 25*a36e9a1cSJohn Crispin #address-cells = <2>; 26*a36e9a1cSJohn Crispin #size-cells = <1>; 27*a36e9a1cSJohn Crispin ranges = <0 0 0x0 0x3ffffff /* addrsel0 */ 28*a36e9a1cSJohn Crispin 1 0 0x4000000 0x4000010>; /* addsel1 */ 29*a36e9a1cSJohn Crispin compatible = "lantiq,localbus", "simple-bus"; 30*a36e9a1cSJohn Crispin 31*a36e9a1cSJohn Crispin gpio_mm0: gpio@4000000 { 32*a36e9a1cSJohn Crispin compatible = "lantiq,gpio-mm"; 33*a36e9a1cSJohn Crispin reg = <1 0x0 0x10>; 34*a36e9a1cSJohn Crispin gpio-controller; 35*a36e9a1cSJohn Crispin #gpio-cells = <2>; 36*a36e9a1cSJohn Crispin lantiq,shadow = <0x77f> 37*a36e9a1cSJohn Crispin }; 38*a36e9a1cSJohn Crispin} 39