[PATCH 4.12 09/65] mtd: nand: atmel: Fix DT backward compatibility in pmecc.c

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>

commit 3aa0907675a38498d8f2d343e94207ad28a117cf 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@xxxxxxxxxxxxxxxxxx>
Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Tested-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/mtd/nand/atmel/pmecc.c |   21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

--- a/drivers/mtd/nand/atmel/pmecc.c
+++ b/drivers/mtd/nand/atmel/pmecc.c
@@ -945,6 +945,7 @@ struct atmel_pmecc *devm_atmel_pmecc_get
 		 */
 		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,
@@ -953,21 +954,11 @@ struct atmel_pmecc *devm_atmel_pmecc_get
 
 		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);
-			if (match && match->data)
-				caps = match->data;
-
-			of_node_put(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;
 
 		pmecc = atmel_pmecc_create(pdev, caps, 1, 2);
 	}