[PATCH v9 17/18] dt-bindings: mtd: sunxi: Add randomized OOB flag

[James Hilliard]

Allwinner NAND firmware writes the bad-block marker as part of the
controller's randomizer stream. The mainline driver compensates those
two bytes so that the physical marker instead remains plain, even when
the rest of the page is scrambled. On H6/H616, the firmware also places
a fixed amount of ECC-protected user data before the first parity
region, whereas mainline distributes available OOB space among the ECC
steps.

Add an opt-in property selecting that firmware page format for the
configured controller hardware-ECC geometry. It identifies how existing
flash contents must be interpreted, rather than changing the format of
all NAND attached to a controller compatible. Without it, retain the
mainline marker representation and protected-OOB placement.

The property applies to normal ECC transfers. Raw operations still
bypass ECC and randomization and expose physical main and OOB bytes,
including the physical randomized marker.

Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
---
 .../devicetree/bindings/mtd/allwinner,sun4i-a10-nand.yaml      | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/allwinner,sun4i-a10-nand.yaml b/Documentation/devicetree/bindings/mtd/allwinner,sun4i-a10-nand.yaml
index 9d061e2216cb..8ecafc40ddcb 100644
--- a/Documentation/devicetree/bindings/mtd/allwinner,sun4i-a10-nand.yaml
+++ b/Documentation/devicetree/bindings/mtd/allwinner,sun4i-a10-nand.yaml
@@ -79,6 +79,16 @@ patternProperties:
           minimum: 0
           maximum: 1
 
+      allwinner,randomized-oob:
+        type: boolean
+        description:
+          Select the normal-page format used by Allwinner NAND firmware for
+          the configured controller hardware-ECC geometry. Normal page
+          transfers use the controller randomizer, the bad block marker remains
+          in its data stream instead of being compensated to stay plain on
+          flash, and protected user data uses the controller-specific placement
+          expected by the firmware.
+
     unevaluatedProperties: false
 
 required:

-- 
2.53.0