xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/clock/rockchip,rk3308.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun* Rockchip RK3308 Clock and Reset Unit
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunThe RK3308 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: CRU should be "rockchip,rk3308-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/rk3308-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 - "xin32k" - rtc clock - optional,
33*4882a593Smuzhiyun - "mclk_i2sx_xch_in" - external I2S or SPDIF clock - optional,
34*4882a593Smuzhiyun - "mac_clkin" - external MAC clock - optional
35*4882a593Smuzhiyun
36*4882a593SmuzhiyunExample: Clock controller node:
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun	cru: clock-controller@ff500000 {
39*4882a593Smuzhiyun		compatible = "rockchip,rk3308-cru";
40*4882a593Smuzhiyun		reg = <0x0 0xff500000 0x0 0x1000>;
41*4882a593Smuzhiyun		rockchip,grf = <&grf>;
42*4882a593Smuzhiyun		#clock-cells = <1>;
43*4882a593Smuzhiyun		#reset-cells = <1>;
44*4882a593Smuzhiyun	};
45*4882a593Smuzhiyun
46*4882a593SmuzhiyunExample: UART controller node that consumes the clock generated by the clock
47*4882a593Smuzhiyun  controller:
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun	uart0: serial@ff0a0000 {
50*4882a593Smuzhiyun		compatible = "rockchip,rk3308-uart", "snps,dw-apb-uart";
51*4882a593Smuzhiyun		reg = <0x0 0xff0a0000 0x0 0x100>;
52*4882a593Smuzhiyun		interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>;
53*4882a593Smuzhiyun		clocks = <&cru SCLK_UART0>, <&cru PCLK_UART0>;
54*4882a593Smuzhiyun		clock-names = "baudclk", "apb_pclk";
55*4882a593Smuzhiyun		reg-shift = <2>;
56*4882a593Smuzhiyun		reg-io-width = <4>;
57*4882a593Smuzhiyun		status = "disabled";
58*4882a593Smuzhiyun	};
59