summaryrefslogtreecommitdiffstats
path: root/Documentation/devicetree/bindings/mux/reg-mux.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/mux/reg-mux.txt')
-rw-r--r--Documentation/devicetree/bindings/mux/reg-mux.txt129
1 files changed, 129 insertions, 0 deletions
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>;
+ };
+ };
+};