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Diffstat (limited to 'Documentation/devicetree/bindings/mux/reg-mux.txt')
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diff --git a/Documentation/devicetree/bindings/mux/reg-mux.txt b/Documentation/devicetree/bindings/mux/reg-mux.txt new file mode 100644 index 000000000..4afd7ba73 --- /dev/null +++ b/Documentation/devicetree/bindings/mux/reg-mux.txt @@ -0,0 +1,129 @@ +Generic register bitfield-based multiplexer controller bindings + +Define register bitfields to be used to control multiplexers. The parent +device tree node must be a device node to provide register r/w access. + +Required properties: +- compatible : should be one of + "reg-mux" : if parent device of mux controller is not syscon device + "mmio-mux" : if parent device of mux controller is syscon device +- #mux-control-cells : <1> +- mux-reg-masks : an array of register offset and pre-shifted bitfield mask + pairs, each describing a single mux control. +* Standard mux-controller bindings as decribed in mux-controller.txt + +Optional properties: +- idle-states : if present, the state the muxes will have when idle. The + special state MUX_IDLE_AS_IS is the default. + +The multiplexer state of each multiplexer is defined as the value of the +bitfield described by the corresponding register offset and bitfield mask +pair in the mux-reg-masks array. + +Example 1: +The parent device of mux controller is not a syscon device. + +&i2c0 { + fpga@66 { // fpga connected to i2c + compatible = "fsl,lx2160aqds-fpga", "fsl,fpga-qixis-i2c", + "simple-mfd"; + reg = <0x66>; + + mux: mux-controller { + compatible = "reg-mux"; + #mux-control-cells = <1>; + mux-reg-masks = <0x54 0xf8>, /* 0: reg 0x54, bits 7:3 */ + <0x54 0x07>; /* 1: reg 0x54, bits 2:0 */ + }; + }; +}; + +mdio-mux-1 { + compatible = "mdio-mux-multiplexer"; + mux-controls = <&mux 0>; + mdio-parent-bus = <&emdio1>; + #address-cells = <1>; + #size-cells = <0>; + + mdio@0 { + reg = <0x0>; + #address-cells = <1>; + #size-cells = <0>; + }; + + mdio@8 { + reg = <0x8>; + #address-cells = <1>; + #size-cells = <0>; + }; + + .. + .. +}; + +mdio-mux-2 { + compatible = "mdio-mux-multiplexer"; + mux-controls = <&mux 1>; + mdio-parent-bus = <&emdio2>; + #address-cells = <1>; + #size-cells = <0>; + + mdio@0 { + reg = <0x0>; + #address-cells = <1>; + #size-cells = <0>; + }; + + mdio@1 { + reg = <0x1>; + #address-cells = <1>; + #size-cells = <0>; + }; + + .. + .. +}; + +Example 2: +The parent device of mux controller is syscon device. + +syscon { + compatible = "syscon"; + + mux: mux-controller { + compatible = "mmio-mux"; + #mux-control-cells = <1>; + + mux-reg-masks = <0x3 0x30>, /* 0: reg 0x3, bits 5:4 */ + <0x3 0x40>, /* 1: reg 0x3, bit 6 */ + idle-states = <MUX_IDLE_AS_IS>, <0>; + }; +}; + +video-mux { + compatible = "video-mux"; + mux-controls = <&mux 0>; + #address-cells = <1>; + #size-cells = <0>; + + ports { + /* inputs 0..3 */ + port@0 { + reg = <0>; + }; + port@1 { + reg = <1>; + }; + port@2 { + reg = <2>; + }; + port@3 { + reg = <3>; + }; + + /* output */ + port@4 { + reg = <4>; + }; + }; +}; |