xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/clock/rockchip,rk3228-cru.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun* Rockchip RK3228 Clock and Reset Unit
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunThe RK3228 clock controller generates and supplies clock to various
4*4882a593Smuzhiyuncontrollers within the SoC and also implements a reset controller for SoC
5*4882a593Smuzhiyunperipherals.
6*4882a593Smuzhiyun
7*4882a593SmuzhiyunRequired Properties:
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun- compatible: should be "rockchip,rk3228-cru"
10*4882a593Smuzhiyun- reg: physical base address of the controller and length of memory mapped
11*4882a593Smuzhiyun  region.
12*4882a593Smuzhiyun- #clock-cells: should be 1.
13*4882a593Smuzhiyun- #reset-cells: should be 1.
14*4882a593Smuzhiyun
15*4882a593SmuzhiyunOptional Properties:
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun- rockchip,grf: phandle to the syscon managing the "general register files"
18*4882a593Smuzhiyun  If missing pll rates are not changeable, due to the missing pll lock status.
19*4882a593Smuzhiyun
20*4882a593SmuzhiyunEach clock is assigned an identifier and client nodes can use this identifier
21*4882a593Smuzhiyunto specify the clock which they consume. All available clocks are defined as
22*4882a593Smuzhiyunpreprocessor macros in the dt-bindings/clock/rk3228-cru.h headers and can be
23*4882a593Smuzhiyunused in device tree sources. Similar macros exist for the reset sources in
24*4882a593Smuzhiyunthese files.
25*4882a593Smuzhiyun
26*4882a593SmuzhiyunExternal clocks:
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunThere are several clocks that are generated outside the SoC. It is expected
29*4882a593Smuzhiyunthat they are defined using standard clock bindings with following
30*4882a593Smuzhiyunclock-output-names:
31*4882a593Smuzhiyun - "xin24m" - crystal input - required,
32*4882a593Smuzhiyun - "ext_i2s" - external I2S clock - optional,
33*4882a593Smuzhiyun - "ext_gmac" - external GMAC clock - optional
34*4882a593Smuzhiyun - "ext_hsadc" - external HSADC clock - optional
35*4882a593Smuzhiyun - "phy_50m_out" - output clock of the pll in the mac phy
36*4882a593Smuzhiyun
37*4882a593SmuzhiyunExample: Clock controller node:
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun	cru: cru@20000000 {
40*4882a593Smuzhiyun		compatible = "rockchip,rk3228-cru";
41*4882a593Smuzhiyun		reg = <0x20000000 0x1000>;
42*4882a593Smuzhiyun		rockchip,grf = <&grf>;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun		#clock-cells = <1>;
45*4882a593Smuzhiyun		#reset-cells = <1>;
46*4882a593Smuzhiyun	};
47*4882a593Smuzhiyun
48*4882a593SmuzhiyunExample: UART controller node that consumes the clock generated by the clock
49*4882a593Smuzhiyun  controller:
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun	uart0: serial@10110000 {
52*4882a593Smuzhiyun		compatible = "snps,dw-apb-uart";
53*4882a593Smuzhiyun		reg = <0x10110000 0x100>;
54*4882a593Smuzhiyun		interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
55*4882a593Smuzhiyun		reg-shift = <2>;
56*4882a593Smuzhiyun		reg-io-width = <4>;
57*4882a593Smuzhiyun		clocks = <&cru SCLK_UART0>;
58*4882a593Smuzhiyun	};
59