xref: /freebsd/sys/contrib/device-tree/Bindings/clock/samsung,s3c64xx-clock.txt (revision ecaeac805b044f715c98960a8fbf19fe2b76ae6b)
1* Samsung S3C64xx Clock Controller
2
3The S3C64xx clock controller generates and supplies clock to various controllers
4within the SoC. The clock binding described here is applicable to all SoCs in
5the S3C64xx family.
6
7Required Properties:
8
9- compatible: should be one of the following.
10  - "samsung,s3c6400-clock" - controller compatible with S3C6400 SoC.
11  - "samsung,s3c6410-clock" - controller compatible with S3C6410 SoC.
12
13- reg: physical base address of the controller and length of memory mapped
14  region.
15
16- #clock-cells: should be 1.
17
18Each clock is assigned an identifier and client nodes can use this identifier
19to specify the clock which they consume. Some of the clocks are available only
20on a particular S3C64xx SoC and this is specified where applicable.
21
22All available clocks are defined as preprocessor macros in
23dt-bindings/clock/samsung,s3c64xx-clock.h header and can be used in device
24tree sources.
25
26External clocks:
27
28There are several clocks that are generated outside the SoC. It is expected
29that they are defined using standard clock bindings with following
30clock-output-names:
31 - "fin_pll" - PLL input clock (xtal/extclk) - required,
32 - "xusbxti" - USB xtal - required,
33 - "iiscdclk0" - I2S0 codec clock - optional,
34 - "iiscdclk1" - I2S1 codec clock - optional,
35 - "iiscdclk2" - I2S2 codec clock - optional,
36 - "pcmcdclk0" - PCM0 codec clock - optional,
37 - "pcmcdclk1" - PCM1 codec clock - optional, only S3C6410.
38
39Example: Clock controller node:
40
41	clock: clock-controller@7e00f000 {
42		compatible = "samsung,s3c6410-clock";
43		reg = <0x7e00f000 0x1000>;
44		#clock-cells = <1>;
45	};
46
47Example: Required external clocks:
48
49	fin_pll: clock-fin-pll {
50		compatible = "fixed-clock";
51		clock-output-names = "fin_pll";
52		clock-frequency = <12000000>;
53		#clock-cells = <0>;
54	};
55
56	xusbxti: clock-xusbxti {
57		compatible = "fixed-clock";
58		clock-output-names = "xusbxti";
59		clock-frequency = <48000000>;
60		#clock-cells = <0>;
61	};
62
63Example: UART controller node that consumes the clock generated by the clock
64  controller (refer to the standard clock bindings for information about
65  "clocks" and "clock-names" properties):
66
67		uart0: serial@7f005000 {
68			compatible = "samsung,s3c6400-uart";
69			reg = <0x7f005000 0x100>;
70			interrupt-parent = <&vic1>;
71			interrupts = <5>;
72			clock-names = "uart", "clk_uart_baud2",
73					"clk_uart_baud3";
74			clocks = <&clock PCLK_UART0>, <&clocks PCLK_UART0>,
75					<&clock SCLK_UART>;
76		};
77