mtd: rawnand: mpc5121: 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().

Fixes: d7157ff ("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/20201113123424.32233-12-miquel.raynal@bootlin.com

drivers/mtd/nand/raw/mpc5121_nfc.c

@@ -104,6 +104,7 @@
 #define NFC_TIMEOUT		(HZ / 10)	/* 1/10 s */
 
 struct mpc5121_nfc_prv {
+	struct nand_controller	controller;
 	struct nand_chip	chip;
 	int			irq;
 	void __iomem		*regs;
@@ -602,6 +603,18 @@ static void mpc5121_nfc_free(struct device *dev, struct mtd_info *mtd)
 		iounmap(prv->csreg);
 }
 
+static int mpc5121_nfc_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 mpc5121_nfc_ops = {
+	.attach_chip = mpc5121_nfc_attach_chip,
+};
+
 static int mpc5121_nfc_probe(struct platform_device *op)
 {
 	struct device_node *dn = op->dev.of_node;
@@ -634,6 +647,10 @@ static int mpc5121_nfc_probe(struct platform_device *op)
 	chip = &prv->chip;
 	mtd = nand_to_mtd(chip);
 
+	nand_controller_init(&prv->controller);
+	prv->controller.ops = &mpc5121_nfc_ops;
+	chip->controller = &prv->controller;
+
 	mtd->dev.parent = dev;
 	nand_set_controller_data(chip, prv);
 	nand_set_flash_node(chip, dn);
@@ -688,8 +705,6 @@ static int mpc5121_nfc_probe(struct platform_device *op)
 	chip->legacy.set_features = nand_get_set_features_notsupp;
 	chip->legacy.get_features = nand_get_set_features_notsupp;
 	chip->bbt_options = NAND_BBT_USE_FLASH;
-	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
-	chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
 
 	/* Support external chip-select logic on ADS5121 board */
 	if (of_machine_is_compatible("fsl,mpc5121ads")) {