mtd: rawnand: plat_nand: 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/20201113123424.32233-17-miquel.raynal@bootlin.com

Author: miquelraynal

drivers/mtd/nand/raw/plat_nand.c

@@ -14,10 +14,23 @@
 #include <linux/mtd/platnand.h>
 
 struct plat_nand_data {
+	struct nand_controller	controller;
 	struct nand_chip	chip;
 	void __iomem		*io_base;
 };
 
+static int plat_nand_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 plat_nand_ops = {
+	.attach_chip = plat_nand_attach_chip,
+};
+
 /*
  * Probe for the NAND device.
  */
@@ -46,6 +59,10 @@ static int plat_nand_probe(struct platform_device *pdev)
 	if (!data)
 		return -ENOMEM;
 
+	data->controller.ops = &plat_nand_ops;
+	nand_controller_init(&data->controller);
+	data->chip.controller = &data->controller;
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	data->io_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(data->io_base))
@@ -66,9 +83,6 @@ static int plat_nand_probe(struct platform_device *pdev)
 	data->chip.options |= pdata->chip.options;
 	data->chip.bbt_options |= pdata->chip.bbt_options;
 
-	data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
-	data->chip.ecc.algo = NAND_ECC_ALGO_HAMMING;
-
 	platform_set_drvdata(pdev, data);
 
 	/* Handle any platform specific setup */