xref: /freebsd/sys/contrib/device-tree/Bindings/clock/lpc1850-creg-clk.txt (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1* NXP LPC1850 CREG clocks
2
3The NXP LPC18xx/43xx CREG (Configuration Registers) block contains
4control registers for two low speed clocks. One of the clocks is a
532 kHz oscillator driver with power up/down and clock gating. Next
6is a fixed divider that creates a 1 kHz clock from the 32 kHz osc.
7
8These clocks are used by the RTC and the Event Router peripherals.
9The 32 kHz can also be routed to other peripherals to enable low
10power modes.
11
12This binding uses the common clock binding:
13    Documentation/devicetree/bindings/clock/clock-bindings.txt
14
15Required properties:
16- compatible:
17	Should be "nxp,lpc1850-creg-clk"
18- #clock-cells:
19	Shall have value <1>.
20- clocks:
21	Shall contain a phandle to the fixed 32 kHz crystal.
22
23The creg-clk node must be a child of the creg syscon node.
24
25The following clocks are available from the clock node.
26
27Clock ID	Name
28   0		 1 kHz clock
29   1		32 kHz Oscillator
30
31Example:
32soc {
33	creg: syscon@40043000 {
34		compatible = "nxp,lpc1850-creg", "syscon", "simple-mfd";
35		reg = <0x40043000 0x1000>;
36
37		creg_clk: clock-controller {
38			compatible = "nxp,lpc1850-creg-clk";
39			clocks = <&xtal32>;
40			#clock-cells = <1>;
41		};
42
43		...
44	};
45
46	rtc: rtc@40046000 {
47		...
48		clocks = <&creg_clk 0>, <&ccu1 CLK_CPU_BUS>;
49		clock-names = "rtc", "reg";
50		...
51	};
52};
53