xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/rtc/rtc-cmos.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun Motorola mc146818 compatible RTC
2*4882a593Smuzhiyun~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunRequired properties:
5*4882a593Smuzhiyun  - compatible : "motorola,mc146818"
6*4882a593Smuzhiyun  - reg : should contain registers location and length.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunOptional properties:
9*4882a593Smuzhiyun  - interrupts : should contain interrupt.
10*4882a593Smuzhiyun  - ctrl-reg : Contains the initial value of the control register also
11*4882a593Smuzhiyun    called "Register B".
12*4882a593Smuzhiyun  - freq-reg : Contains the initial value of the frequency register also
13*4882a593Smuzhiyun    called "Regsiter A".
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun"Register A" and "B" are usually initialized by the firmware (BIOS for
16*4882a593Smuzhiyuninstance). If this is not done, it can be performed by the driver.
17*4882a593Smuzhiyun
18*4882a593SmuzhiyunISA Example:
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun	rtc@70 {
21*4882a593Smuzhiyun	         compatible = "motorola,mc146818";
22*4882a593Smuzhiyun	         interrupts = <8 3>;
23*4882a593Smuzhiyun	         interrupt-parent = <&ioapic1>;
24*4882a593Smuzhiyun	         ctrl-reg = <2>;
25*4882a593Smuzhiyun	         freq-reg = <0x26>;
26*4882a593Smuzhiyun	         reg = <1 0x70 2>;
27*4882a593Smuzhiyun	 };
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