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+Register-based I2C Bus Mux
+
+This binding describes an I2C bus multiplexer that uses a single register
+to route the I2C signals.
+
+Required properties:
+- compatible: i2c-mux-reg
+- i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
+ port is connected to.
+* Standard I2C mux properties. See i2c-mux.yaml in this directory.
+* I2C child bus nodes. See i2c-mux.yaml in this directory.
+
+Optional properties:
+- reg: this pair of <offset size> specifies the register to control the mux.
+ The <offset size> depends on its parent node. It can be any memory-mapped
+ address. The size must be either 1, 2, or 4 bytes. If reg is omitted, the
+ resource of this device will be used.
+- little-endian: The existence indicates the register is in little endian.
+- big-endian: The existence indicates the register is in big endian.
+ If both little-endian and big-endian are omitted, the endianness of the
+ CPU will be used.
+- write-only: The existence indicates the register is write-only.
+- idle-state: value to set the muxer to when idle. When no value is
+ given, it defaults to the last value used.
+
+Whenever an access is made to a device on a child bus, the value set
+in the relevant node's reg property will be output to the register.
+
+If an idle state is defined, using the idle-state (optional) property,
+whenever an access is not being made to a device on a child bus, the
+register will be set according to the idle value.
+
+If an idle state is not defined, the most recently used value will be
+left programmed into the register.
+
+Example of a mux on PCIe card, the host is a powerpc SoC (big endian):
+
+ i2c-mux {
+ /* the <offset size> depends on the address translation
+ * of the parent device. If omitted, device resource
+ * will be used instead. The size is to determine
+ * whether iowrite32, iowrite16, or iowrite8 will be used.
+ */
+ reg = <0x6028 0x4>;
+ little-endian; /* little endian register on PCIe */
+ compatible = "i2c-mux-reg";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ i2c-parent = <&i2c1>;
+ i2c@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ si5338: clock-generator@70 {
+ compatible = "silabs,si5338";
+ reg = <0x70>;
+ /* other stuff */
+ };
+ };
+
+ i2c@1 {
+ /* data is written using iowrite32 */
+ reg = <1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ si5338: clock-generator@70 {
+ compatible = "silabs,si5338";
+ reg = <0x70>;
+ /* other stuff */
+ };
+ };
+ };