mtd: nand: atmel: Fix DT backward compatibility in pmecc.c

commit 3aa09076 upstream.

PMECC caps extraction from old DT bindings is broken, thus leading to
erroneous EL registers offset, which in turn make HW ECC unusable on
sama5d2 when old bindings are in use.

Passing the NAND dev node instead of the NFC node to of_match_node()
solves the problem.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Fixes: f88fc122 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Tested-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mtd/nand/atmel/pmecc.c

@@ -945,6 +945,7 @@ struct atmel_pmecc *devm_atmel_pmecc_get(struct device *userdev)
 		 */
 		struct platform_device *pdev = to_platform_device(userdev);
 		const struct atmel_pmecc_caps *caps;
+		const struct of_device_id *match;
 
 		/* No PMECC engine available. */
 		if (!of_property_read_bool(userdev->of_node,
@@ -953,22 +954,12 @@ struct atmel_pmecc *devm_atmel_pmecc_get(struct device *userdev)
 
 		caps = &at91sam9g45_caps;
 
-		/*
-		 * Try to find the NFC subnode and extract the associated caps
-		 * from there.
-		 */
-		np = of_find_compatible_node(userdev->of_node, NULL,
-					     "atmel,sama5d3-nfc");
-		if (np) {
-			const struct of_device_id *match;
-
-			match = of_match_node(atmel_pmecc_legacy_match, np);
+		/* Find the caps associated to the NAND dev node. */
+		match = of_match_node(atmel_pmecc_legacy_match,
+				      userdev->of_node);
 		if (match && match->data)
 			caps = match->data;
 
-			of_node_put(np);
-		}
-
 		pmecc = atmel_pmecc_create(pdev, caps, 1, 2);
 	}