A simple common binding for matrix-connected key boards. Currently targeted at defining the keys in the scope of linux key codes since that is a stable and standardized interface at this time. Required properties: - linux,keymap: an array of packed 1-cell entries containing the equivalent of row, column and linux key-code. The 32-bit big endian cell is packed as: row << 24 | column << 16 | key-code Optional properties: Properties for the number of rows and columns are optional because some drivers will use fixed values for these. - keypad,num-rows: Number of row lines connected to the keypad controller. - keypad,num-columns: Number of column lines connected to the keypad controller. Some users of this binding might choose to specify secondary keymaps for cases where there is a modifier key such as a Fn key. Proposed names for said properties are "linux,fn-keymap" or with another descriptive word for the modifier other from "Fn". Example: linux,keymap = < 0x00030012 0x0102003a >; keypad,num-rows = <2>; keypad,num-columns = <8>;