dt-bindings: bus: Minimal TI sysc interconnect target module binding

Texas Instruments sysc interconnect target module wrapper binding

Texas Instruments SoCs can have a generic interconnect target module

hardware for devices connected to various interconnects such as L3

interconnect (Arteris NoC) and L4 interconnect (Sonics s3220). The sysc

is mostly used for interaction between module and PRCM. It participates

in the OCP Disconnect Protocol but other than that is mostly independent

of the interconnect.

Each interconnect target module can have one or more devices connected to

it. There is a set of control registers for managing interconnect target

module clocks, idle modes and interconnect level resets for the module.

These control registers are sprinkled into the unused register address

space of the first child device IP block managed by the interconnect

target module and typically are named REVISION, SYSCONFIG and SYSSTATUS.

Required standard properties:

- compatible	shall be one of the following generic types:

		"ti,sysc-omap2"

		"ti,sysc-omap4"

		"ti,sysc-omap4-simple"

		or one of the following derivative types for hardware

		needing special workarounds:

		"ti,sysc-omap3430-sr"

		"ti,sysc-omap3630-sr"

		"ti,sysc-omap4-sr"

		"ti,sysc-omap3-sham"

		"ti,sysc-omap-aes"

		"ti,sysc-mcasp"

		"ti,sysc-usb-host-fs"

- reg		shall have register areas implemented for the interconnect

		target module in question such as revision, sysc and syss

- reg-names	shall contain the register names implemented for the

		interconnect target module in question such as

		"rev, "sysc", and "syss"

- ranges	shall contain the interconnect target module IO range

		available for one or more child device IP blocks managed

		by the interconnect target module, the ranges may include

		multiple ranges such as device L4 range for control and

		parent L3 range for DMA access

Optional properties:

- clocks	clock specifier for each name in the clock-names as

		specified in the binding documentation for ti-clkctrl,

		typically available for all interconnect targets on TI SoCs

		based on omap4 except if it's read-only register in hwauto

		mode as for example omap4 L4_CFG_CLKCTRL

- clock-names	should contain at least "fck", and optionally also "ick"

		depending on the SoC and the interconnect target module

- ti,hwmods	optional TI interconnect module name to use legacy

		hwmod platform data

Example: Single instance of MUSB controller on omap4 using interconnect ranges

using offsets from l4_cfg second segment (0x4a000000 + 0x80000 = 0x4a0ab000):

	target-module@2b000 {		/* 0x4a0ab000, ap 84 12.0 */

		compatible = "ti,sysc-omap2";

		ti,hwmods = "usb_otg_hs";

		reg = <0x2b400 0x4>,

		      <0x2b404 0x4>,

		      <0x2b408 0x4>;

		reg-names = "rev", "sysc", "syss";

		clocks = <&l3_init_clkctrl OMAP4_USB_OTG_HS_CLKCTRL 0>;

		clock-names = "fck";

		#address-cells = <1>;

		#size-cells = <1>;

		ranges = <0 0x2b000 0x1000>;

		usb_otg_hs: otg@0 {

			compatible = "ti,omap4-musb";

			reg = <0x0 0x7ff>;

			interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_HIGH>,

				     <GIC_SPI 93 IRQ_TYPE_LEVEL_HIGH>;

			usb-phy = <&usb2_phy>;

			...

		};

	};

Note that other SoCs, such as am335x can have multipe child devices. On am335x

there are two MUSB instances, two USB PHY instances, and a single CPPI41 DMA

instance as children of a single interconnet target module.