This adds device tree binding documentation for generic register
based multiplexer controlled by a bitfields in a parent device's
register range.
Signed-off-by: Pankaj Bansal <pankaj.bansal@xxxxxxx>
---
.../devicetree/bindings/mux/reg-mux.txt | 84 ++++++++++++++++++
1 file changed, 84 insertions(+)
diff --git a/Documentation/devicetree/bindings/mux/reg-mux.txt b/Documentation/devicetree/bindings/mux/reg-mux.txt
new file mode 100644
index 000000000000..c5e6faa2a7cf
--- /dev/null
+++ b/Documentation/devicetree/bindings/mux/reg-mux.txt
@@ -0,0 +1,84 @@
+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 : "reg-mux"
+- #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, accessed through the parent syscon.
+
+Example:
+
+&i2c0 {
+ status = "okay";
+
+ fpga@66 { // fpga connected to i2c
+ compatible = "fsl,lx2160aqds-fpga", "fsl,fpga-qixis-i2c",
+ "simple-mfd";
+ reg = <0x66>;
+
+ mux: mux-controller { // Mux Producer
+ compatible = "reg-mux";
+ #mux-control-cells = <1>;
+ mux-reg-masks = <0x54 0xf8>, /* 0: reg 0x54, bits 7:3 */
+ <0x54 0x07>; /* 1: reg 0x54, bit 2:0 */
+ };
+ };
+};
+
+ mdio-mux-1 { // Mux consumer
+ compatible = "mdio-mux";
+ mux-controls = <&mux 0>;
+ mdio-parent-bus = <&emdio1>;
+ #address-cells=<1>;
+ #size-cells = <0>;
+
+ mdio@0 {
+ reg = <0x00>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ mdio@40 {
+ reg = <0x40>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ ..
+ ..
+ };
+
+ mdio-mux-2 { // Mux consumer
+ compatible = "mdio-mux";
+ mux-controls = <&mux 1>;
+ mdio-parent-bus = <&emdio2>;
+ #address-cells=<1>;
+ #size-cells = <0>;
+
+ mdio@0 {
+ reg = <0x00>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ mdio@1 {
+ reg = <0x01>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ ..
+ ..
+ };
--
2.17.1
