Linux下的clk学习

先看某主板的时钟dts描述，如

1.1固定时钟 fixed-clock

ext_26m: ext-26m {
	compatible = "fixed-clock";
	#clock-cells = <0>;
	clock-frequency = <26000000>;
	clock-output-names = "ext_26m";
 };

ext_6m5: ext-6m5 {
     compatible = "fixed-clock";
     #clock-cells = <0>;
     clock-frequency = <6500000>;
     clock-output-names = "ext_6m5";
 };

该主板有一个外接的26M晶振，ext_26m即外部的26M晶振，有一个固定的ext_6m5时钟，应该是从ext_26m分频而来。

 

1.2固定因子时钟 fixed-factor-clock

ext_26m: ext-26m {
	compatible = "fixed-clock";
	#clock-cells = <0>;
	clock-frequency = <26000000>;
	clock-output-names = "ext_26m";
};

clk_twpll: clk@40353004 {
	compatible = "sprd,sc9863a-adjustable-pll-clock";
	#clock-cells = <0>;
	reg = <0x0 0x40353004 0x0 0x4>,
		<0x0 0x40353008 0x0 0x4>,