mtd: rawnand: xway: Move the ECC initialization to ->attach_chip()

The probe function is only supposed to initialize the controller
hardware but not the ECC engine. Indeed, we don't know anything about
the NAND chip(s) at this stage. Let's move the logic initializing the
ECC engine, even pretty simple, to the ->attach_chip() hook which gets
called during nand_scan() routine, after the NAND chip discovery. As
the previously mentioned logic is supposed to parse the DT for us, it
is likely that the chip->ecc.* entries be overwritten. So let's avoid
this by moving these lines to ->attach_chip(), a NAND controller
hook.

Fixes: d7157ff4 ("mtd: rawnand: Use the ECC framework user input parsing bits")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201113123424.32233-3-miquel.raynal@bootlin.com

drivers/mtd/nand/raw/xway_nand.c

@@ -62,6 +62,7 @@
 #define NAND_CON_NANDM		1
 
 struct xway_nand_data {
+	struct nand_controller	controller;
 	struct nand_chip	chip;
 	unsigned long		csflags;
 	void __iomem		*nandaddr;
@@ -145,6 +146,18 @@ static void xway_write_buf(struct nand_chip *chip, const u_char *buf, int len)
 		xway_writeb(nand_to_mtd(chip), NAND_WRITE_DATA, buf[i]);
 }
 
+static int xway_attach_chip(struct nand_chip *chip)
+{
+	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
+	chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
+
+	return 0;
+}
+
+static const struct nand_controller_ops xway_nand_ops = {
+	.attach_chip = xway_attach_chip,
+};
+
 /*
  * Probe for the NAND device.
  */
@@ -180,8 +193,9 @@ static int xway_nand_probe(struct platform_device *pdev)
 	data->chip.legacy.read_byte = xway_read_byte;
 	data->chip.legacy.chip_delay = 30;
 
-	data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
-	data->chip.ecc.algo = NAND_ECC_ALGO_HAMMING;
+	nand_controller_init(&data->controller);
+	data->controller.ops = &xway_nand_ops;
+	data->chip.controller = &data->controller;
 
 	platform_set_drvdata(pdev, data);
 	nand_set_controller_data(&data->chip, data);