[PATCH 17/23] mtd: nand: implement the default mtd_ooblayout_ops

[Boris Brezillon]

Replace the default nand_ecclayout definitions for large and small page
devices with the equivalent mtd_ooblayout_ops.

Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
 drivers/mtd/nand/nand_base.c | 138 +++++++++++++++++++++++++++----------------
 include/linux/mtd/nand.h     |   3 +
 2 files changed, 90 insertions(+), 51 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 2b334cf..6440c5d 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -48,50 +48,6 @@
 #include <linux/mtd/partitions.h>
 #include <linux/of_mtd.h>
 
-/* Define default oob placement schemes for large and small page devices */
-static struct nand_ecclayout nand_oob_8 = {
-	.eccbytes = 3,
-	.eccpos = {0, 1, 2},
-	.oobfree = {
-		{.offset = 3,
-		 .length = 2},
-		{.offset = 6,
-		 .length = 2} }
-};
-
-static struct nand_ecclayout nand_oob_16 = {
-	.eccbytes = 6,
-	.eccpos = {0, 1, 2, 3, 6, 7},
-	.oobfree = {
-		{.offset = 8,
-		 . length = 8} }
-};
-
-static struct nand_ecclayout nand_oob_64 = {
-	.eccbytes = 24,
-	.eccpos = {
-		   40, 41, 42, 43, 44, 45, 46, 47,
-		   48, 49, 50, 51, 52, 53, 54, 55,
-		   56, 57, 58, 59, 60, 61, 62, 63},
-	.oobfree = {
-		{.offset = 2,
-		 .length = 38} }
-};
-
-static struct nand_ecclayout nand_oob_128 = {
-	.eccbytes = 48,
-	.eccpos = {
-		   80, 81, 82, 83, 84, 85, 86, 87,
-		   88, 89, 90, 91, 92, 93, 94, 95,
-		   96, 97, 98, 99, 100, 101, 102, 103,
-		   104, 105, 106, 107, 108, 109, 110, 111,
-		   112, 113, 114, 115, 116, 117, 118, 119,
-		   120, 121, 122, 123, 124, 125, 126, 127},
-	.oobfree = {
-		{.offset = 2,
-		 .length = 78} }
-};
-
 static int nand_get_device(struct mtd_info *mtd, int new_state);
 
 static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
@@ -103,6 +59,83 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
  */
 DEFINE_LED_TRIGGER(nand_led_trigger);
 
+/* Define default oob placement schemes for large and small page devices */
+static int nand_ooblayout_eccpos_sp(struct mtd_info *mtd, int eccbyte)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (eccbyte >= ecc->bytes * ecc->steps)
+		return -ERANGE;
+
+	if (eccbyte < 4)
+		return eccbyte;
+
+	return eccbyte + 2;
+}
+
+static int nand_ooblayout_oobfree_sp(struct mtd_info *mtd, int section,
+				     struct nand_oobfree *oobfree)
+{
+	if (section > 1)
+		return -ERANGE;
+
+	if (mtd->oobsize == 16) {
+		if (section)
+			return -ERANGE;
+
+		oobfree->length = 8;
+		oobfree->offset = 8;
+	} else {
+		oobfree->length = 2;
+		if (!section)
+			oobfree->offset = 3;
+		else
+			oobfree->offset = 6;
+	}
+
+	return 0;
+}
+
+const struct mtd_ooblayout_ops nand_ooblayout_sp_ops = {
+	.eccpos = nand_ooblayout_eccpos_sp,
+	.oobfree = nand_ooblayout_oobfree_sp,
+};
+EXPORT_SYMBOL_GPL(nand_ooblayout_sp_ops);
+
+static int nand_ooblayout_eccpos_lp(struct mtd_info *mtd, int eccbyte)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	int eccbytes = ecc->bytes * ecc->steps;
+
+	if (eccbyte >= eccbytes)
+		return -ERANGE;
+
+	return mtd->oobsize - eccbytes + eccbyte;
+}
+
+static int nand_ooblayout_oobfree_lp(struct mtd_info *mtd, int section,
+				     struct nand_oobfree *oobfree)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (section)
+		return -ERANGE;
+
+	oobfree->length = mtd->oobsize - (ecc->bytes * ecc->steps) - 2;
+	oobfree->offset = 2;
+
+	return 0;
+}
+
+const struct mtd_ooblayout_ops nand_ooblayout_lp_ops = {
+	.eccpos = nand_ooblayout_eccpos_lp,
+	.oobfree = nand_ooblayout_oobfree_lp,
+};
+EXPORT_SYMBOL_GPL(nand_ooblayout_lp_ops);
+
 static int check_offs_len(struct mtd_info *mtd,
 					loff_t ofs, uint64_t len)
 {
@@ -4115,21 +4148,24 @@ int nand_scan_tail(struct mtd_info *mtd)
 	chip->oob_poi = chip->buffers->databuf + mtd->writesize;
 
 	/*
+	 * Set the provided ECC layout. If ecc->layout is NULL, the MTD core
+	 * will just leave mtd->ooblayout to NULL, if it's not NULL, it will
+	 * set ->ooblayout to the default ecclayout wrapper.
+	 */
+	mtd_set_ecclayout(mtd, ecc->layout);
+
+	/*
 	 * If no default placement scheme is given, select an appropriate one.
 	 */
-	if (!ecc->layout && (ecc->mode != NAND_ECC_SOFT_BCH)) {
+	if (!mtd->ooblayout && (ecc->mode != NAND_ECC_SOFT_BCH)) {
 		switch (mtd->oobsize) {
 		case 8:
-			ecc->layout = &nand_oob_8;
-			break;
 		case 16:
-			ecc->layout = &nand_oob_16;
+			mtd_set_ooblayout(mtd, &nand_ooblayout_sp_ops);
 			break;
 		case 64:
-			ecc->layout = &nand_oob_64;
-			break;
 		case 128:
-			ecc->layout = &nand_oob_128;
+			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
 			break;
 		default:
 			pr_warn("No oob scheme defined for oobsize %d\n",
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index cbedcb0..9ba9daba 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -719,6 +719,9 @@ struct nand_chip {
 	void *priv;
 };
 
+extern const struct mtd_ooblayout_ops nand_ooblayout_sp_ops;
+extern const struct mtd_ooblayout_ops nand_ooblayout_lp_ops;
+
 static inline void nand_set_flash_node(struct nand_chip *chip,
 				       struct device_node *np)
 {
-- 
2.1.4