xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/clock/nuvoton,npcm750-clk.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun* Nuvoton NPCM7XX Clock Controller
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunNuvoton Poleg BMC NPCM7XX contains an integrated clock controller, which
4*4882a593Smuzhiyungenerates and supplies clocks to all modules within the BMC.
5*4882a593Smuzhiyun
6*4882a593SmuzhiyunExternal clocks:
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunThere are six fixed clocks that are generated outside the BMC. All clocks are of
9*4882a593Smuzhiyuna known fixed value that cannot be changed. clk_refclk, clk_mcbypck and
10*4882a593Smuzhiyunclk_sysbypck are inputs to the clock controller.
11*4882a593Smuzhiyunclk_rg1refck, clk_rg2refck and clk_xin are external clocks suppling the
12*4882a593Smuzhiyunnetwork. They are set on the device tree, but not used by the clock module. The
13*4882a593Smuzhiyunnetwork devices use them directly.
14*4882a593SmuzhiyunExample can be found below.
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunAll available clocks are defined as preprocessor macros in:
17*4882a593Smuzhiyundt-bindings/clock/nuvoton,npcm7xx-clock.h
18*4882a593Smuzhiyunand can be reused as DT sources.
19*4882a593Smuzhiyun
20*4882a593SmuzhiyunRequired Properties of clock controller:
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun	- compatible: "nuvoton,npcm750-clk" : for clock controller of Nuvoton
23*4882a593Smuzhiyun		  Poleg BMC NPCM750
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun	- reg: physical base address of the clock controller and length of
26*4882a593Smuzhiyun		memory mapped region.
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun	- #clock-cells: should be 1.
29*4882a593Smuzhiyun
30*4882a593SmuzhiyunExample: Clock controller node:
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun	clk: clock-controller@f0801000 {
33*4882a593Smuzhiyun		compatible = "nuvoton,npcm750-clk";
34*4882a593Smuzhiyun		#clock-cells = <1>;
35*4882a593Smuzhiyun		reg = <0xf0801000 0x1000>;
36*4882a593Smuzhiyun		clock-names = "refclk", "sysbypck", "mcbypck";
37*4882a593Smuzhiyun		clocks = <&clk_refclk>, <&clk_sysbypck>, <&clk_mcbypck>;
38*4882a593Smuzhiyun	};
39*4882a593Smuzhiyun
40*4882a593SmuzhiyunExample: Required external clocks for network:
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun	/* external reference clock */
43*4882a593Smuzhiyun	clk_refclk: clk-refclk {
44*4882a593Smuzhiyun		compatible = "fixed-clock";
45*4882a593Smuzhiyun		#clock-cells = <0>;
46*4882a593Smuzhiyun		clock-frequency = <25000000>;
47*4882a593Smuzhiyun		clock-output-names = "refclk";
48*4882a593Smuzhiyun	};
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun	/* external reference clock for cpu. float in normal operation */
51*4882a593Smuzhiyun	clk_sysbypck: clk-sysbypck {
52*4882a593Smuzhiyun		compatible = "fixed-clock";
53*4882a593Smuzhiyun		#clock-cells = <0>;
54*4882a593Smuzhiyun		clock-frequency = <800000000>;
55*4882a593Smuzhiyun		clock-output-names = "sysbypck";
56*4882a593Smuzhiyun	};
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun	/* external reference clock for MC. float in normal operation */
59*4882a593Smuzhiyun	clk_mcbypck: clk-mcbypck {
60*4882a593Smuzhiyun		compatible = "fixed-clock";
61*4882a593Smuzhiyun		#clock-cells = <0>;
62*4882a593Smuzhiyun		clock-frequency = <800000000>;
63*4882a593Smuzhiyun		clock-output-names = "mcbypck";
64*4882a593Smuzhiyun	};
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun	 /* external clock signal rg1refck, supplied by the phy */
67*4882a593Smuzhiyun	clk_rg1refck: clk-rg1refck {
68*4882a593Smuzhiyun		compatible = "fixed-clock";
69*4882a593Smuzhiyun		#clock-cells = <0>;
70*4882a593Smuzhiyun		clock-frequency = <125000000>;
71*4882a593Smuzhiyun		clock-output-names = "clk_rg1refck";
72*4882a593Smuzhiyun	};
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun	 /* external clock signal rg2refck, supplied by the phy */
75*4882a593Smuzhiyun	clk_rg2refck: clk-rg2refck {
76*4882a593Smuzhiyun		compatible = "fixed-clock";
77*4882a593Smuzhiyun		#clock-cells = <0>;
78*4882a593Smuzhiyun		clock-frequency = <125000000>;
79*4882a593Smuzhiyun		clock-output-names = "clk_rg2refck";
80*4882a593Smuzhiyun	};
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun	clk_xin: clk-xin {
83*4882a593Smuzhiyun		compatible = "fixed-clock";
84*4882a593Smuzhiyun		#clock-cells = <0>;
85*4882a593Smuzhiyun		clock-frequency = <50000000>;
86*4882a593Smuzhiyun		clock-output-names = "clk_xin";
87*4882a593Smuzhiyun	};
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun
90*4882a593SmuzhiyunExample: GMAC controller node that consumes two clocks: a generated clk by the
91*4882a593Smuzhiyunclock controller and a fixed clock from DT (clk_rg1refck).
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun	ethernet0: ethernet@f0802000 {
94*4882a593Smuzhiyun		compatible = "snps,dwmac";
95*4882a593Smuzhiyun		reg = <0xf0802000 0x2000>;
96*4882a593Smuzhiyun		interrupts = <0 14 4>;
97*4882a593Smuzhiyun		interrupt-names = "macirq";
98*4882a593Smuzhiyun		clocks	= <&clk_rg1refck>, <&clk NPCM7XX_CLK_AHB>;
99*4882a593Smuzhiyun		clock-names = "stmmaceth", "clk_gmac";
100*4882a593Smuzhiyun	};
101