SysCon Reset Controller
=======================

Almost all SoCs have hardware modules that require reset control in addition
to clock and power control for their functionality. The reset control is
typically provided by means of memory-mapped I/O registers. These registers are
sometimes a part of a larger register space region implementing various
functionalities. This register range is best represented as a syscon node to
allow multiple entities to access their relevant registers in the common
register space.

A SysCon Reset Controller node defines a device that uses a syscon node
and provides reset management functionality for various hardware modules
present on the SoC.

SysCon Reset Controller Node
============================
Each of the reset provider/controller nodes should be a child of a syscon
node and have the following properties.

Required properties:
--------------------
 - compatible		: Should be "syscon-reset"
 - #reset-cells		: Should be 1. Please see the reset consumer node below
			  for usage details
 - #address-cells	: Should be 1
 - #size-cells		: Should be 0

SysCon Reset Child Node
============================
Each reset provider/controller node should have a child node for each reset
it would like to expose to consumers.

Required properties:
--------------------
 - reg			: Reset's logical number, this value will be used by
			  consumers of this reset as their reset specifier value
 - reset-control	: Contains the reset control register information,
			  Should contain 3 cells defined as:
			    Cell #1 : register offset of the reset
			              control/status register from the syscon
			              register base
			    Cell #2 : bit shift value for the reset in the
			              respective reset control/status register
			    Cell #3 : polarity of the reset bit, should use the
				      definitions defined in the DT include file
					include/dt-bindings/reset/syscon.h
				      Should be RESET_ASSERT_SET for resets
				      that are asserted when the bit is set,
				      and RESET_ASSERT_CLEAR for resets that
				      are asserted when the bit is cleared.

Optional properties:
--------------------
 - reset-status		: Contains the reset status register information. The
			  contents of this property are the equivalent to
			  reset-control as defined above. If this property is
			  not present and the toggle flag is not set, the
			  reset register is assumed to be the same as the
			  control register
 - toggle		: Mark this reset as a toggle only reset, this is used
			  when no status register is available.

SysCon Reset Consumer Nodes
===========================
Each of the reset consumer nodes should have the following properties,
in addition to their own properties.

Required properties:
--------------------
 - resets	: A phandle and a reset specifier, the reset specifier should
		  be a numerical address matching the desired reset as set
		  by the reg property defined above.

Please also refer to Documentation/devicetree/bindings/reset/reset.txt for
common reset controller usage by consumers.

Example:
--------
The following example demonstrates a syscon node, the reset controller node
using the syscon node, and a consumer (a DSP device) on the TI Keystone 2
Edison SoC.

/ {
	soc {
		psc: power-sleep-controller@02350000 {
			compatible = "syscon", "simple-mfd";
			reg = <0x02350000 0x1000>;

			pscrst: psc-reset {
				compatible = "syscon-reset";
				#reset-cells = <1>;
				#address-cells = <1>;
				#size-cells = <0>;

				dsp@0 {
					reg = <0>;
					reset-control = <0xa3c 8 RESET_ASSERT_CLEAR>;
					reset-status = <0x83c 8 RESET_ASSERT_CLEAR>;
				};
			};
		};

		dsp0: dsp0 {
			...
			resets = <&pscrst 0>;
			...
		};
	};
};