xref: /freebsd/sys/contrib/device-tree/Bindings/reset/st,sti-picophyreset.txt (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)

STMicroelectronics STi family Sysconfig Picophy SoftReset Controller
=============================================================================

This binding describes a reset controller device that is used to enable and
disable on-chip PicoPHY USB2 phy(s) using "softreset" control bits found in
the STi family SoC system configuration registers.

The actual action taken when softreset is asserted is hardware dependent.
However, when asserted it may not be possible to access the hardware's
registers and after an assert/deassert sequence the hardware's previous state
may no longer be valid.

Please refer to Documentation/devicetree/bindings/reset/reset.txt
for common reset controller binding usage.

Required properties:
- compatible: Should be "st,stih407-picophyreset"
- #reset-cells: 1, see below

Example:

	picophyreset: picophyreset-controller {
		compatible = "st,stih407-picophyreset";
		#reset-cells = <1>;
	};

Specifying picophyreset control of devices
=======================================

Device nodes should specify the reset channel required in their "resets"
property, containing a phandle to the picophyreset device node and an
index specifying which channel to use, as described in
Documentation/devicetree/bindings/reset/reset.txt.

Example:

	usb2_picophy0: usbpicophy@0 {
		resets = <&picophyreset STIH407_PICOPHY0_RESET>;
	};

Macro definitions for the supported reset channels can be found in:
include/dt-bindings/reset/stih407-resets.h