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Diffstat (limited to 'Documentation/devicetree/bindings/clock/zynq-7000.txt')
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diff --git a/Documentation/devicetree/bindings/clock/zynq-7000.txt b/Documentation/devicetree/bindings/clock/zynq-7000.txt new file mode 100644 index 00000000000..23ae1db1bc1 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/zynq-7000.txt @@ -0,0 +1,55 @@ +Device Tree Clock bindings for the Zynq 7000 EPP + +The Zynq EPP has several different clk providers, each with there own bindings. +The purpose of this document is to document their usage. + +See clock_bindings.txt for more information on the generic clock bindings. +See Chapter 25 of Zynq TRM for more information about Zynq clocks. + +== PLLs == + +Used to describe the ARM_PLL, DDR_PLL, and IO_PLL. + +Required properties: +- #clock-cells : shall be 0 (only one clock is output from this node) +- compatible : "xlnx,zynq-pll" +- reg : pair of u32 values, which are the address offsets within the SLCR + of the relevant PLL_CTRL register and PLL_CFG register respectively +- clocks : phandle for parent clock. should be the phandle for ps_clk + +Optional properties: +- clock-output-names : name of the output clock + +Example: + armpll: armpll { + #clock-cells = <0>; + compatible = "xlnx,zynq-pll"; + clocks = <&ps_clk>; + reg = <0x100 0x110>; + clock-output-names = "armpll"; + }; + +== Peripheral clocks == + +Describes clock node for the SDIO, SMC, SPI, QSPI, and UART clocks. + +Required properties: +- #clock-cells : shall be 1 +- compatible : "xlnx,zynq-periph-clock" +- reg : a single u32 value, describing the offset within the SLCR where + the CLK_CTRL register is found for this peripheral +- clocks : phandle for parent clocks. should hold phandles for + the IO_PLL, ARM_PLL, and DDR_PLL in order +- clock-output-names : names of the output clock(s). For peripherals that have + two output clocks (for example, the UART), two clocks + should be listed. + +Example: + uart_clk: uart_clk { + #clock-cells = <1>; + compatible = "xlnx,zynq-periph-clock"; + clocks = <&iopll &armpll &ddrpll>; + reg = <0x154>; + clock-output-names = "uart0_ref_clk", + "uart1_ref_clk"; + }; |