xref: /freebsd/sys/contrib/device-tree/Bindings/clock/amlogic,meson8b-clkc.txt (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1* Amlogic Meson8, Meson8b and Meson8m2 Clock and Reset Unit
2
3The Amlogic Meson8 / Meson8b / Meson8m2 clock controller generates and
4supplies clock to various controllers within the SoC.
5
6Required Properties:
7
8- compatible: must be one of:
9	- "amlogic,meson8-clkc" for Meson8 (S802) SoCs
10	- "amlogic,meson8b-clkc" for Meson8 (S805) SoCs
11	- "amlogic,meson8m2-clkc" for Meson8m2 (S812) SoCs
12- #clock-cells: should be 1.
13- #reset-cells: should be 1.
14- clocks: list of clock phandles, one for each entry in clock-names
15- clock-names: should contain the following:
16  * "xtal": the 24MHz system oscillator
17  * "ddr_pll": the DDR PLL clock
18  * "clk_32k": (if present) the 32kHz clock signal from GPIOAO_6 (CLK_32K_IN)
19
20Parent node should have the following properties :
21- compatible: "amlogic,meson-hhi-sysctrl", "simple-mfd", "syscon"
22- reg: base address and size of the HHI system control register space.
23
24Each clock is assigned an identifier and client nodes can use this identifier
25to specify the clock which they consume. All available clocks are defined as
26preprocessor macros in the dt-bindings/clock/meson8b-clkc.h header and can be
27used in device tree sources.
28
29Similarly a preprocessor macro for each reset line is defined in
30dt-bindings/reset/amlogic,meson8b-clkc-reset.h (which can be used from the
31device tree sources).
32
33
34Example: Clock controller node:
35
36	clkc: clock-controller {
37		compatible = "amlogic,meson8b-clkc";
38		#clock-cells = <1>;
39		#reset-cells = <1>;
40	};
41
42
43Example: UART controller node that consumes the clock generated by the clock
44  controller:
45
46	uart_AO: serial@c81004c0 {
47		compatible = "amlogic,meson-uart";
48		reg = <0xc81004c0 0x14>;
49		interrupts = <0 90 1>;
50		clocks = <&clkc CLKID_CLK81>;
51	};
52