From 5c543de856c463235cef0808c2b100e475fc8438 Mon Sep 17 00:00:00 2001 From: Amit Kumar Mahapatra Date: Wed, 4 Feb 2026 09:32:16 +0100 Subject: [PATCH] dt-bindings: mtd: Describe MTD partitions concatenation The AMD QSPI controller supports an advanced connection modes called Stacked mode which allow the controller to treat two different flashes as one storage. In Stacked connection mode flashes share the same SPI bus, but different CS line, controller driver asserts the CS of the flash to which it needs to communicate. Stacked mode is a software abstraction rather than a controller feature or capability. At any given time, the controller communicates with one of the two connected flash devices, as determined by the requested address and data length. If an operation starts on one flash and ends on the other, the mtd layer needs to split it into two separate operations and adjust the data length accordingly. For more information on the modes please feel free to go through the controller flash interface below [1]. To support stacked mode, the existing MTD concat driver has been extended to be more generic, enabling multiple sets of MTD partitions to be virtually concatenated, with each set forming a distinct logical MTD device. A new Device Tree property is introduced to facilitate this, containing phandles of the partitions to be concatenated with the one where the property is defined. This approach supports multiple sets of concatenated partitions. [1] https://docs.amd.com/r/en-US/am011-versal-acap-trm/QSPI-Flash-Device-Interface Suggested-by: Miquel Raynal Suggested-by: Rob Herring Signed-off-by: Amit Kumar Mahapatra Reviewed-by: Rob Herring (Arm) Signed-off-by: Luca Ceresoli Signed-off-by: Miquel Raynal --- .../bindings/mtd/partitions/partition.yaml | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml index 2397d97ecac5..eaeac2f2ea94 100644 --- a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml +++ b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml @@ -57,6 +57,15 @@ properties: user space from type: boolean + part-concat-next: + description: List of phandles to MTD partitions that need be concatenated + with the current partition. + $ref: /schemas/types.yaml#/definitions/phandle-array + minItems: 1 + maxItems: 16 + items: + maxItems: 1 + align: $ref: /schemas/types.yaml#/definitions/uint32 minimum: 2 @@ -180,4 +189,15 @@ examples: reg = <0x200000 0x100000>; align = <0x4000>; }; + + part0: partition@400000 { + part-concat-next = <&part1>; + label = "part0_0"; + reg = <0x400000 0x100000>; + }; + + part1: partition@800000 { + label = "part0_1"; + reg = <0x800000 0x800000>; + }; };