From feaa716adc514fb5fbcb60b3e1620ac5dcf8505a Mon Sep 17 00:00:00 2001
From: Conor Dooley <conor.dooley@microchip.com>
Date: Mon, 13 Oct 2025 18:45:33 +0100
Subject: [PATCH] dt-bindings: soc: microchip: document the simple-mfd syscon
 on PolarFire SoC

"mss-top-sysreg" contains clocks, pinctrl, resets, an interrupt controller
and more. At this point, only the reset controller child is described as
that's all that is described by the existing bindings.
The clock controller already has a dedicated node, and will retain it as
there are other clock regions, so like the mailbox, a compatible-based
lookup of the syscon is sufficient to keep the clock driver working as
before, so no child is needed. There's also an interrupt multiplexing
service provided by this syscon, for which there is work in progress at
[1].

Link: https://lore.kernel.org/linux-gpio/20240723-uncouple-enforcer-7c48e4a4fefe@wendy/ [1]
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../microchip,mpfs-mss-top-sysreg.yaml        | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml

diff --git a/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
new file mode 100644
index 000000000000..1ab691db8795
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PolarFire SoC Microprocessor Subsystem (MSS) sysreg register region
+
+maintainers:
+  - Conor Dooley <conor.dooley@microchip.com>
+
+description:
+  An wide assortment of registers that control elements of the MSS on PolarFire
+  SoC, including pinmuxing, resets and clocks among others.
+
+properties:
+  compatible:
+    items:
+      - const: microchip,mpfs-mss-top-sysreg
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  '#reset-cells':
+    description:
+      The AHB/AXI peripherals on the PolarFire SoC have reset support, so
+      from CLK_ENVM to CLK_CFM. The reset consumer should specify the
+      desired peripheral via the clock ID in its "resets" phandle cell.
+      See include/dt-bindings/clock/microchip,mpfs-clock.h for the full list
+      of PolarFire clock/reset IDs.
+    const: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    syscon@20002000 {
+      compatible = "microchip,mpfs-mss-top-sysreg", "syscon";
+      reg = <0x20002000 0x1000>;
+      #reset-cells = <1>;
+    };
+