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- 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";
- };
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