From 5775b82e74d1b307b7dab670993b6b838c92f786 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Heiko=20St=C3=BCbner?= Date: Thu, 3 Jul 2014 02:02:12 +0200 Subject: [PATCH] dt-bindings: add documentation for rk3288 cru This adds the dt-binding documentation for the clock and reset unit found on Rockchip rk3288 SoCs. Signed-off-by: Heiko Stuebner Acked-By: Max Schwarz Tested-By: Max Schwarz Signed-off-by: Mike Turquette --- .../bindings/clock/rockchip,rk3288-cru.txt | 61 ++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/rockchip,rk3288-cru.txt diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3288-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk3288-cru.txt new file mode 100644 index 0000000..c9fbb76 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/rockchip,rk3288-cru.txt @@ -0,0 +1,61 @@ +* Rockchip RK3288 Clock and Reset Unit + +The RK3288 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,rk3288-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/rk3288-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_hsadc" - external HSADC clock - optional, + - "ext_edp_24m" - external display port clock - optional, + - "ext_vip" - external VIP clock - optional, + - "ext_isp" - external ISP clock - optional, + - "ext_jtag" - external JTAG 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>; + }; -- 2.7.4