1 Motorola mc146818 compatible RTC 2~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 3 4Required properties: 5 - compatible : "motorola,mc146818" 6 - reg : should contain registers location and length. 7 8Optional properties: 9 - interrupts : should contain interrupt. 10 - ctrl-reg : Contains the initial value of the control register also 11 called "Register B". 12 - freq-reg : Contains the initial value of the frequency register also 13 called "Regsiter A". 14 15"Register A" and "B" are usually initialized by the firmware (BIOS for 16instance). If this is not done, it can be performed by the driver. 17 18ISA Example: 19 20 rtc@70 { 21 compatible = "motorola,mc146818"; 22 interrupts = <8 3>; 23 interrupt-parent = <&ioapic1>; 24 ctrl-reg = <2>; 25 freq-reg = <0x26>; 26 reg = <1 0x70 2>; 27 }; 28