From 43aea81778e280a4e1d7ef144b3511bbc4aace11 Mon Sep 17 00:00:00 2001 From: Heiko Stübner Date: Thu, 3 Jul 2014 02:00:44 +0200 Subject: dt-bindings: add documentation for rk3188 clock and reset unit This add bindings documentation for the clock and reset unit found on rk3188 and rk3066 SoCs from Rockchip. Also deprecate the old gate clock binding, as these shouldn't be used in the future. Signed-off-by: Heiko Stuebner Acked-By: Max Schwarz Tested-By: Max Schwarz Signed-off-by: Mike Turquette --- .../bindings/clock/rockchip,rk3188-cru.txt | 61 ++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.txt (limited to 'Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.txt') diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.txt new file mode 100644 index 000000000000..0c2bf5eba43e --- /dev/null +++ b/Documentation/devicetree/bindings/clock/rockchip,rk3188-cru.txt @@ -0,0 +1,61 @@ +* Rockchip RK3188/RK3066 Clock and Reset Unit + +The RK3188/RK3066 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,rk3188-cru", "rockchip,rk3188a-cru" or + "rockchip,rk3066a-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 changable, 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/rk3188-cru.h and +dt-bindings/clock/rk3066-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, + - "xin27m" - 27mhz crystal input on rk3066 - optional, + - "ext_hsadc" - external HSADC clock - optional, + - "ext_cif0" - external camera clock - optional, + - "ext_rmii" - external RMII clock - optional, + - "ext_jtag" - externalJTAG clock - optional + +Example: Clock controller node: + + cru: cru@20000000 { + compatible = "rockchip,rk3188-cru"; + reg = <0x20000000 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 = ; + reg-shift = <2>; + reg-io-width = <1>; + clocks = <&cru SCLK_UART0>; + }; -- cgit v1.2.3