[PATCH v6 1/7] dt-bindings: reset: microchip,rst: Allow to replace cpu-syscon by an additional reg item
From: Herve Codina <herve.codina@bootlin.com>
Date: 2024-09-30 12:16:11
Also in:
linux-arm-kernel, linux-devicetree, linux-pci, lkml
Subsystem:
open firmware and flattened device tree bindings, reset controller framework, the rest · Maintainers:
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Philipp Zabel, Linus Torvalds
In the LAN966x PCI device use case, syscon cannot be used as syscon devices do not support removal [1]. A syscon device is a core "system" device and not a device available in some addon boards and so, it is not supposed to be removed. In order to remove the syscon device usage, allow the reset controller to have a direct access to the address range it needs to use. Link: https://lore.kernel.org/all/20240923100741.11277439@bootlin.com/ (local) [1] Signed-off-by: Herve Codina <herve.codina@bootlin.com> --- .../bindings/reset/microchip,rst.yaml | 35 ++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/reset/microchip,rst.yaml b/Documentation/devicetree/bindings/reset/microchip,rst.yaml
index f2da0693b05a..5164239a372c 100644
--- a/Documentation/devicetree/bindings/reset/microchip,rst.yaml
+++ b/Documentation/devicetree/bindings/reset/microchip,rst.yaml@@ -25,12 +25,16 @@ properties: - microchip,lan966x-switch-reset reg: + minItems: 1 items: - description: global control block registers + - description: cpu system block registers reg-names: + minItems: 1 items: - const: gcb + - const: cpu "#reset-cells": const: 1
@@ -39,12 +43,29 @@ properties: $ref: /schemas/types.yaml#/definitions/phandle description: syscon used to access CPU reset +allOf: + # Allow to use the second reg item instead of cpu-syscon + - if: + required: + - cpu-syscon + then: + properties: + reg: + maxItems: 1 + reg-names: + maxItems: 1 + else: + properties: + reg: + minItems: 2 + reg-names: + minItems: 2 + required: - compatible - reg - reg-names - "#reset-cells" - - cpu-syscon additionalProperties: false
@@ -57,3 +78,15 @@ examples: #reset-cells = <1>; cpu-syscon = <&cpu_ctrl>; }; + + /* + * The following construction can be used if the cpu-syscon device is not + * present. This is the case when the LAN966x is used as a PCI device. + */ + reset-controller@22010008 { + compatible = "microchip,lan966x-switch-reset"; + reg = <0xe200400c 0x4>, + <0xe00c0000 0xa8>; + reg-names = "gcb", "cpu"; + #reset-cells = <1>; + };
--
2.46.1