xref: /freebsd-src/sys/contrib/device-tree/Bindings/clock/imx7ulp-clock.txt (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)

* Clock bindings for Freescale i.MX7ULP

i.MX7ULP Clock functions are under joint control of the System
Clock Generation (SCG) modules, Peripheral Clock Control (PCC)
modules, and Core Mode Controller (CMC)1 blocks

The clocking scheme provides clear separation between M4 domain
and A7 domain. Except for a few clock sources shared between two
domains, such as the System Oscillator clock, the Slow IRC (SIRC),
and and the Fast IRC clock (FIRCLK), clock sources and clock
management are separated and contained within each domain.

M4 clock management consists of SCG0, PCC0, PCC1, and CMC0 modules.
A7 clock management consists of SCG1, PCC2, PCC3, and CMC1 modules.

Note: this binding doc is only for A7 clock domain.

System Clock Generation (SCG) modules:
---------------------------------------------------------------------
The System Clock Generation (SCG) is responsible for clock generation
and distribution across this device. Functions performed by the SCG
include: clock reference selection, generation of clock used to derive
processor, system, peripheral bus and external memory interface clocks,
source selection for peripheral clocks and control of power saving
clock gating mode.

Required properties:

- compatible:	Should be "fsl,imx7ulp-scg1".
- reg : 	Should contain registers location and length.
- #clock-cells:	Should be <1>.
- clocks:	Should contain the fixed input clocks.
- clock-names:  Should contain the following clock names:
		"rosc", "sosc", "sirc", "firc", "upll", "mpll".

Peripheral Clock Control (PCC) modules:
---------------------------------------------------------------------
The Peripheral Clock Control (PCC) is responsible for clock selection,
optional division and clock gating mode for peripherals in their
respected power domain

Required properties:
- compatible:	Should be one of:
		  "fsl,imx7ulp-pcc2",
		  "fsl,imx7ulp-pcc3".
- reg : 	Should contain registers location and length.
- #clock-cells:	Should be <1>.
- clocks:	Should contain the fixed input clocks.
- clock-names:  Should contain the following clock names:
		"nic1_bus_clk", "nic1_clk", "ddr_clk", "apll_pfd2",
		"apll_pfd1", "apll_pfd0", "upll", "sosc_bus_clk",
		"mpll", "firc_bus_clk", "rosc", "spll_bus_clk";

The clock consumer should specify the desired clock by having the clock
ID in its "clocks" phandle cell.
See include/dt-bindings/clock/imx7ulp-clock.h
for the full list of i.MX7ULP clock IDs of each module.

Examples:

#include <dt-bindings/clock/imx7ulp-clock.h>

scg1: scg1@403e0000 {
	compatible = "fsl,imx7ulp-scg1;
	reg = <0x403e0000 0x10000>;
	clocks = <&rosc>, <&sosc>, <&sirc>,
		 <&firc>, <&upll>, <&mpll>;
	clock-names = "rosc", "sosc", "sirc",
		      "firc", "upll", "mpll";
	#clock-cells = <1>;
};

pcc2: pcc2@403f0000 {
	compatible = "fsl,imx7ulp-pcc2";
	reg = <0x403f0000 0x10000>;
	#clock-cells = <1>;
	clocks = <&scg1 IMX7ULP_CLK_NIC1_BUS_DIV>,
		 <&scg1 IMX7ULP_CLK_NIC1_DIV>,
		 <&scg1 IMX7ULP_CLK_DDR_DIV>,
		 <&scg1 IMX7ULP_CLK_APLL_PFD2>,
		 <&scg1 IMX7ULP_CLK_APLL_PFD1>,
		 <&scg1 IMX7ULP_CLK_APLL_PFD0>,
		 <&scg1 IMX7ULP_CLK_UPLL>,
		 <&scg1 IMX7ULP_CLK_SOSC_BUS_CLK>,
		 <&scg1 IMX7ULP_CLK_FIRC_BUS_CLK>,
		 <&scg1 IMX7ULP_CLK_ROSC>,
		 <&scg1 IMX7ULP_CLK_SPLL_BUS_CLK>;
	clock-names = "nic1_bus_clk", "nic1_clk", "ddr_clk",
		      "apll_pfd2", "apll_pfd1", "apll_pfd0",
		      "upll", "sosc_bus_clk", "mpll",
		      "firc_bus_clk", "rosc", "spll_bus_clk";
};

usdhc1: usdhc@40380000 {
	compatible = "fsl,imx7ulp-usdhc";
	reg = <0x40380000 0x10000>;
	interrupts = <GIC_SPI 43 IRQ_TYPE_LEVEL_HIGH>;
	clocks = <&scg1 IMX7ULP_CLK_NIC1_BUS_DIV>,
		 <&scg1 IMX7ULP_CLK_NIC1_DIV>,
		 <&pcc2 IMX7ULP_CLK_USDHC1>;
	clock-names ="ipg", "ahb", "per";
	bus-width = <4>;
};