1 Motorola mc146818 compatible RTC 1 Motorola mc146818 compatible RTC
2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3 3
4 Required properties: 4 Required properties:
5 - compatible : "motorola,mc146818" 5 - compatible : "motorola,mc146818"
6 - reg : should contain registers location an 6 - reg : should contain registers location and length.
7 7
8 Optional properties: 8 Optional properties:
9 - interrupts : should contain interrupt. 9 - interrupts : should contain interrupt.
10 - ctrl-reg : Contains the initial value of t 10 - ctrl-reg : Contains the initial value of the control register also
11 called "Register B". 11 called "Register B".
12 - freq-reg : Contains the initial value of t 12 - freq-reg : Contains the initial value of the frequency register also
13 called "Register A". 13 called "Register A".
14 14
15 "Register A" and "B" are usually initialized b 15 "Register A" and "B" are usually initialized by the firmware (BIOS for
16 instance). If this is not done, it can be perf 16 instance). If this is not done, it can be performed by the driver.
17 17
18 ISA Example: 18 ISA Example:
19 19
20 rtc@70 { 20 rtc@70 {
21 compatible = "motorola,mc1468 21 compatible = "motorola,mc146818";
22 interrupts = <8 3>; 22 interrupts = <8 3>;
23 interrupt-parent = <&ioapic1> 23 interrupt-parent = <&ioapic1>;
24 ctrl-reg = <2>; 24 ctrl-reg = <2>;
25 freq-reg = <0x26>; 25 freq-reg = <0x26>;
26 reg = <1 0x70 2>; 26 reg = <1 0x70 2>;
27 }; 27 };
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