如何在linux内核设备树中定义时钟多路复用器(How to define a clock multiplexer in a linux kernel device tree)

 我正在编写Linux设备驱动程序，需要在设备树文件中定义以下时钟树： 
 
 
 注意：在多路复用器中选择振荡器是通过将gpio输出拉高或拉低来完成的。 时钟发生器通过I2C编程。 
 
 这是我到目前为止的一个例子： 
 
clocks {
    /* fixed clock oscillators */
    osc22: oscillator22 {
        compatible = "fixed-clock";
        #clock-cells = <0>;
        clock-frequency = <22579200>;
    };

    osc24: oscillator24 {
        compatible = "fixed-clock";
        #clock-cells = <0>;
        clock-frequency = <24576000>;
    };

    /* clock multiplexer
     * I'm afraid the following is not going to work :( ?
     */
    mux: multiplexer {
        compatible = "mux-clock";     /* <-------- ??? */
        clocks = <&osc22>, <&osc24>;  /* parent clocks */
    };
};

i2c1 {
    /* clock generator */
    si5351: si5351c@60 {
        #address-cells = <1>;
        #size-cells = <0>;
        #clock-cells = <1>;
        compatible = "silabs,si5351c";
        reg = <0x60>;
        clocks = <0>, <&mux>;
        clock-names = "xtal", "clkin";
        status = "okay";

        clkout0 {
            reg = <0>;
            silabs,disable-state = <2>;
            silabs,clock-source = <3>;
        };
    };
};
 
 参考文献 ： 
 
 
 
 时钟绑定 
 
 
 绑定简单的固定速率时钟源 
 
 
 Silicon Labs Si5351a / b / c可编程i2c时钟发生器的绑定 
 
 
 如何在设备树中定义简单的gpio控制时钟多路复用器？ 

I am writing a linux device driver and need to define the following clock-tree in a device tree file:
 
 
Note: Selecting an oscillator in the multiplexer is done by pulling an gpio output high or low. The clock generator is programmed via I2C.
 
Here is an example of what I have so far:
 
clocks {
    /* fixed clock oscillators */
    osc22: oscillator22 {
        compatible = "fixed-clock";
        #clock-cells = <0>;
        clock-frequency = <22579200>;
    };

    osc24: oscillator24 {
        compatible = "fixed-clock";
        #clock-cells = <0>;
        clock-frequency = <24576000>;
    };

    /* clock multiplexer
     * I'm afraid the following is not going to work :( ?
     */
    mux: multiplexer {
        compatible = "mux-clock";     /* <-------- ??? */
        clocks = <&osc22>, <&osc24>;  /* parent clocks */
    };
};

i2c1 {
    /* clock generator */
    si5351: si5351c@60 {
        #address-cells = <1>;
        #size-cells = <0>;
        #clock-cells = <1>;
        compatible = "silabs,si5351c";
        reg = <0x60>;
        clocks = <0>, <&mux>;
        clock-names = "xtal", "clkin";
        status = "okay";

        clkout0 {
            reg = <0>;
            silabs,disable-state = <2>;
            silabs,clock-source = <3>;
        };
    };
};
 
References:
 
 
 
Clock Bindings
 
 
Binding for simple fixed-rate clock sources
 
 
Binding for Silicon Labs Si5351a/b/c programmable i2c clock generator
 
 
How do I define a simple gpio-controlled clock multiplexer in a device tree?

原文：https://stackoverflow.com/questions/29153415