dt-bindings: reset: Add TI SCI reset binding

Add TI SCI reset controller binding. This describes the DT binding
details for a reset controller node providing reset management services
to hardware blocks (reset consumers) using the Texas Instrument's System
Control Interface (TI SCI) protocol to communicate to a system controller
block present on the SoC.

Signed-off-by: Andrew F. Davis <afd@ti.com>
[s-anna@ti.com: revise the binding format]
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 62 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/reset/ti,sci-reset.txt b/Documentation/devicetree/bindings/reset/ti,sci-reset.txt
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+Texas Instruments System Control Interface (TI-SCI) Reset Controller
+=====================================================================
+
+Some TI SoCs contain a system controller (like the Power Management Micro
+Controller (PMMC) on Keystone 66AK2G SoC) that are responsible for controlling
+the state of the various hardware modules present on the SoC. Communication
+between the host processor running an OS and the system controller happens
+through a protocol called TI System Control Interface (TI-SCI protocol).
+For TI SCI details, please refer to the document,
+Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
+
+TI-SCI Reset Controller Node
+============================
+This reset controller node uses the TI SCI protocol to perform the reset
+management of various hardware modules present on the SoC. Must be a child
+node of the associated TI-SCI system controller node.
+
+Required properties:
+--------------------
+ - compatible	: Should be "ti,sci-reset"
+ - #reset-cells	: Should be 2. Please see the reset consumer node below for
+		  usage details.
+
+TI-SCI 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 reset specifier pair, one pair for each reset
+		  signal that affects the device, or that the device manages.
+		  The phandle should point to the TI-SCI reset controller node,
+		  and the reset specifier should have 2 cell-values. The first
+		  cell should contain the device ID. The second cell should
+		  contain the reset mask value used by system controller.
+		  Please refer to the protocol documentation for these values
+		  to be used for different devices,
+		  http://processors.wiki.ti.com/index.php/TISCI#66AK2G02_Data
+
+Please also refer to Documentation/devicetree/bindings/reset/reset.txt for
+common reset controller usage by consumers.
+
+Example:
+--------
+The following example demonstrates both a TI-SCI reset controller node and a
+consumer (a DSP device) on the 66AK2G SoC.
+
+pmmc: pmmc {
+	compatible = "ti,k2g-sci";
+
+	k2g_reset: reset-controller {
+		compatible = "ti,sci-reset";
+		#reset-cells = <2>;
+	};
+};
+
+dsp0: dsp@10800000 {
+	...
+	resets = <&k2g_reset 0x0046 0x1>;
+	...
+};