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Diffstat (limited to 'Documentation/devicetree/bindings/clock/rockchip,rk3368-cru.txt')
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diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3368-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk3368-cru.txt new file mode 100644 index 0000000..7c8bbcf --- /dev/null +++ b/Documentation/devicetree/bindings/clock/rockchip,rk3368-cru.txt @@ -0,0 +1,61 @@ +* Rockchip RK3368 Clock and Reset Unit + +The RK3368 clock controller generates and supplies clock to various +controllers within the SoC and also implements a reset controller for SoC +peripherals. + +Required Properties: + +- compatible: should be "rockchip,rk3368-cru" +- reg: physical base address of the controller and length of memory mapped + region. +- #clock-cells: should be 1. +- #reset-cells: should be 1. + +Optional Properties: + +- rockchip,grf: phandle to the syscon managing the "general register files" + If missing, pll rates are not changeable, due to the missing pll lock status. + +Each clock is assigned an identifier and client nodes can use this identifier +to specify the clock which they consume. All available clocks are defined as +preprocessor macros in the dt-bindings/clock/rk3368-cru.h headers and can be +used in device tree sources. Similar macros exist for the reset sources in +these files. + +External clocks: + +There are several clocks that are generated outside the SoC. It is expected +that they are defined using standard clock bindings with following +clock-output-names: + - "xin24m" - crystal input - required, + - "xin32k" - rtc clock - optional, + - "ext_i2s" - external I2S clock - optional, + - "ext_gmac" - external GMAC clock - optional + - "ext_hsadc" - external HSADC clock - optional, + - "ext_isp" - external ISP clock - optional, + - "ext_jtag" - external JTAG clock - optional + - "ext_vip" - external VIP clock - optional, + - "usbotg_out" - output clock of the pll in the otg phy + +Example: Clock controller node: + + cru: clock-controller@ff760000 { + compatible = "rockchip,rk3368-cru"; + reg = <0x0 0xff760000 0x0 0x1000>; + rockchip,grf = <&grf>; + #clock-cells = <1>; + #reset-cells = <1>; + }; + +Example: UART controller node that consumes the clock generated by the clock + controller: + + uart0: serial@10124000 { + compatible = "snps,dw-apb-uart"; + reg = <0x10124000 0x400>; + interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>; + reg-shift = <2>; + reg-io-width = <1>; + clocks = <&cru SCLK_UART0>; + }; |