mtd: rawnand: Separate the ECC engine type and the ECC byte placement

The use of "syndrome" placement should not be encoded in the ECC
engine mode/type.

Create a "placement" field in NAND chip and change all occurrences of
the NAND_ECC_HW_SYNDROME enumeration to be just NAND_ECC_HW and
possibly a placement entry like NAND_ECC_PLACEMENT_INTERLEAVED.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200827085208.16276-10-miquel.raynal@bootlin.com

arch/arm/mach-davinci/board-dm355-leopard.c

@@ -76,7 +76,8 @@ static struct davinci_nand_pdata davinci_nand_data = {
 	.mask_chipsel		= BIT(14),
 	.parts			= davinci_nand_partitions,
 	.nr_parts		= ARRAY_SIZE(davinci_nand_partitions),
-	.ecc_mode		= NAND_ECC_HW_SYNDROME,
+	.ecc_mode		= NAND_HW_ECC_ENGINE,
+	.ecc_placement		= NAND_ECC_PLACEMENT_INTERLEAVED,
 	.ecc_bits		= 4,
 	.bbt_options		= NAND_BBT_USE_FLASH,
 };

drivers/mtd/nand/raw/cafe_nand.c

@@ -629,7 +629,8 @@ static int cafe_nand_attach_chip(struct nand_chip *chip)
 		goto out_free_dma;
 	}
 
-	cafe->nand.ecc.mode = NAND_ECC_HW_SYNDROME;
+	cafe->nand.ecc.mode = NAND_ECC_HW;
+	cafe->nand.ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
 	cafe->nand.ecc.size = mtd->writesize;
 	cafe->nand.ecc.bytes = 14;
 	cafe->nand.ecc.strength = 4;

drivers/mtd/nand/raw/davinci_nand.c

@@ -168,7 +168,7 @@ static int nand_davinci_correct_1bit(struct nand_chip *chip, u_char *dat,
 /*
  * 4-bit hardware ECC ... context maintained over entire AEMIF
  *
- * This is a syndrome engine, but we avoid NAND_ECC_HW_SYNDROME
+ * This is a syndrome engine, but we avoid NAND_ECC_PLACEMENT_INTERLEAVED
  * since that forces use of a problematic "infix OOB" layout.
  * Among other things, it trashes manufacturer bad block markers.
  * Also, and specific to this hardware, it ECC-protects the "prepad"
@@ -851,6 +851,7 @@ static int nand_davinci_probe(struct platform_device *pdev)
 
 	/* Use board-specific ECC config */
 	info->chip.ecc.mode	= pdata->ecc_mode;
+	info->chip.ecc.placement = pdata->ecc_placement;
 
 	spin_lock_irq(&davinci_nand_lock);
 
@@ -897,7 +898,7 @@ static int nand_davinci_remove(struct platform_device *pdev)
 	int ret;
 
 	spin_lock_irq(&davinci_nand_lock);
-	if (info->chip.ecc.mode == NAND_ECC_HW_SYNDROME)
+	if (info->chip.ecc.placement == NAND_ECC_PLACEMENT_INTERLEAVED)
 		ecc4_busy = false;
 	spin_unlock_irq(&davinci_nand_lock);
 

drivers/mtd/nand/raw/denali.c

@@ -1237,7 +1237,8 @@ int denali_chip_init(struct denali_controller *denali,
 	chip->bbt_options |= NAND_BBT_USE_FLASH;
 	chip->bbt_options |= NAND_BBT_NO_OOB;
 	chip->options |= NAND_NO_SUBPAGE_WRITE;
-	chip->ecc.mode = NAND_ECC_HW_SYNDROME;
+	chip->ecc.mode = NAND_ECC_HW;
+	chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
 	chip->ecc.read_page = denali_read_page;
 	chip->ecc.write_page = denali_write_page;
 	chip->ecc.read_page_raw = denali_read_page_raw;

drivers/mtd/nand/raw/diskonchip.c

@@ -1456,7 +1456,8 @@ static int __init doc_probe(unsigned long physadr)
 	nand->ecc.calculate	= doc200x_calculate_ecc;
 	nand->ecc.correct	= doc200x_correct_data;
 
-	nand->ecc.mode		= NAND_ECC_HW_SYNDROME;
+	nand->ecc.mode		= NAND_ECC_HW;
+	nand->ecc.placement	= NAND_ECC_PLACEMENT_INTERLEAVED;
 	nand->ecc.size		= 512;
 	nand->ecc.bytes		= 6;
 	nand->ecc.strength	= 2;

drivers/mtd/nand/raw/lpc32xx_slc.c

@@ -881,7 +881,8 @@ static int lpc32xx_nand_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, host);
 
 	/* NAND callbacks for LPC32xx SLC hardware */
-	chip->ecc.mode = NAND_ECC_HW_SYNDROME;
+	chip->ecc.mode = NAND_ECC_HW;
+	chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
 	chip->legacy.read_byte = lpc32xx_nand_read_byte;
 	chip->legacy.read_buf = lpc32xx_nand_read_buf;
 	chip->legacy.write_buf = lpc32xx_nand_write_buf;

drivers/mtd/nand/raw/nand_base.c

@@ -5790,47 +5790,59 @@ static int nand_scan_tail(struct nand_chip *chip)
 
 	switch (ecc->mode) {
 	case NAND_ECC_HW:
-		/* Use standard hwecc read page function? */
+		switch (ecc->placement) {
-		if (!ecc->read_page)
+		case NAND_ECC_PLACEMENT_UNKNOWN:
-			ecc->read_page = nand_read_page_hwecc;
+		case NAND_ECC_PLACEMENT_OOB:
-		if (!ecc->write_page)
+			/* Use standard hwecc read page function? */
-			ecc->write_page = nand_write_page_hwecc;
+			if (!ecc->read_page)
-		if (!ecc->read_page_raw)
+				ecc->read_page = nand_read_page_hwecc;
-			ecc->read_page_raw = nand_read_page_raw;
+			if (!ecc->write_page)
-		if (!ecc->write_page_raw)
+				ecc->write_page = nand_write_page_hwecc;
-			ecc->write_page_raw = nand_write_page_raw;
+			if (!ecc->read_page_raw)
-		if (!ecc->read_oob)
+				ecc->read_page_raw = nand_read_page_raw;
-			ecc->read_oob = nand_read_oob_std;
+			if (!ecc->write_page_raw)
-		if (!ecc->write_oob)
+				ecc->write_page_raw = nand_write_page_raw;
-			ecc->write_oob = nand_write_oob_std;
+			if (!ecc->read_oob)
-		if (!ecc->read_subpage)
+				ecc->read_oob = nand_read_oob_std;
-			ecc->read_subpage = nand_read_subpage;
+			if (!ecc->write_oob)
-		if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
+				ecc->write_oob = nand_write_oob_std;
-			ecc->write_subpage = nand_write_subpage_hwecc;
+			if (!ecc->read_subpage)
-		fallthrough;
+				ecc->read_subpage = nand_read_subpage;
-	case NAND_ECC_HW_SYNDROME:
+			if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
-		if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
+				ecc->write_subpage = nand_write_subpage_hwecc;
-		    (!ecc->read_page ||
+			fallthrough;
-		     ecc->read_page == nand_read_page_hwecc ||
+
-		     !ecc->write_page ||
+		case NAND_ECC_PLACEMENT_INTERLEAVED:
-		     ecc->write_page == nand_write_page_hwecc)) {
+			if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
-			WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
+			    (!ecc->read_page ||
+			     ecc->read_page == nand_read_page_hwecc ||
+			     !ecc->write_page ||
+			     ecc->write_page == nand_write_page_hwecc)) {
+				WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
+				ret = -EINVAL;
+				goto err_nand_manuf_cleanup;
+			}
+			/* Use standard syndrome read/write page function? */
+			if (!ecc->read_page)
+				ecc->read_page = nand_read_page_syndrome;
+			if (!ecc->write_page)
+				ecc->write_page = nand_write_page_syndrome;
+			if (!ecc->read_page_raw)
+				ecc->read_page_raw = nand_read_page_raw_syndrome;
+			if (!ecc->write_page_raw)
+				ecc->write_page_raw = nand_write_page_raw_syndrome;
+			if (!ecc->read_oob)
+				ecc->read_oob = nand_read_oob_syndrome;
+			if (!ecc->write_oob)
+				ecc->write_oob = nand_write_oob_syndrome;
+			break;
+
+		default:
+			pr_warn("Invalid NAND_ECC_PLACEMENT %d\n",
+				ecc->placement);
 			ret = -EINVAL;
 			goto err_nand_manuf_cleanup;
 		}
-		/* Use standard syndrome read/write page function? */
-		if (!ecc->read_page)
-			ecc->read_page = nand_read_page_syndrome;
-		if (!ecc->write_page)
-			ecc->write_page = nand_write_page_syndrome;
-		if (!ecc->read_page_raw)
-			ecc->read_page_raw = nand_read_page_raw_syndrome;
-		if (!ecc->write_page_raw)
-			ecc->write_page_raw = nand_write_page_raw_syndrome;
-		if (!ecc->read_oob)
-			ecc->read_oob = nand_read_oob_syndrome;
-		if (!ecc->write_oob)
-			ecc->write_oob = nand_write_oob_syndrome;
 
 		if (mtd->writesize >= ecc->size) {
 			if (!ecc->strength) {
@@ -5845,6 +5857,7 @@ static int nand_scan_tail(struct nand_chip *chip)
 		ecc->mode = NAND_ECC_SOFT;
 		ecc->algo = NAND_ECC_ALGO_HAMMING;
 		fallthrough;
+
 	case NAND_ECC_SOFT:
 		ret = nand_set_ecc_soft_ops(chip);
 		if (ret) {

drivers/mtd/nand/raw/r852.c

@@ -859,7 +859,8 @@ static int  r852_probe(struct pci_dev *pci_dev, const struct pci_device_id *id)
 	chip->legacy.write_buf = r852_write_buf;
 
 	/* ecc */
-	chip->ecc.mode = NAND_ECC_HW_SYNDROME;
+	chip->ecc.mode = NAND_ECC_HW;
+	chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
 	chip->ecc.size = R852_DMA_LEN;
 	chip->ecc.bytes = SM_OOB_SIZE;
 	chip->ecc.strength = 2;

include/linux/mtd/rawnand.h

@@ -304,6 +304,7 @@ static const struct nand_ecc_caps __name = {			\
 /**
  * struct nand_ecc_ctrl - Control structure for ECC
  * @mode:	ECC mode
+ * @placement:	OOB bytes placement
  * @algo:	ECC algorithm
  * @steps:	number of ECC steps per page
  * @size:	data bytes per ECC step
@@ -331,7 +332,7 @@ static const struct nand_ecc_caps __name = {			\
  *			controller and always return contiguous in-band and
  *			out-of-band data even if they're not stored
  *			contiguously on the NAND chip (e.g.
- *			NAND_ECC_HW_SYNDROME interleaves in-band and
+ *			NAND_ECC_PLACEMENT_INTERLEAVED interleaves in-band and
  *			out-of-band data).
  * @write_page_raw:	function to write a raw page without ECC. This function
  *			should hide the specific layout used by the ECC
@@ -339,7 +340,7 @@ static const struct nand_ecc_caps __name = {			\
  *			in-band and out-of-band data. ECC controller is
  *			responsible for doing the appropriate transformations
  *			to adapt to its specific layout (e.g.
- *			NAND_ECC_HW_SYNDROME interleaves in-band and
+ *			NAND_ECC_PLACEMENT_INTERLEAVED interleaves in-band and
  *			out-of-band data).
  * @read_page:	function to read a page according to the ECC generator
  *		requirements; returns maximum number of bitflips corrected in
@@ -356,6 +357,7 @@ static const struct nand_ecc_caps __name = {			\
  */
 struct nand_ecc_ctrl {
 	enum nand_ecc_mode mode;
+	enum nand_ecc_placement placement;
 	enum nand_ecc_algo algo;
 	int steps;
 	int size;

include/linux/platform_data/mtd-davinci.h

@@ -69,6 +69,7 @@ struct davinci_nand_pdata {		/* platform_data */
 	 * using it with large page chips.
 	 */
 	enum nand_ecc_mode	ecc_mode;
+	enum nand_ecc_placement ecc_placement;
 	u8			ecc_bits;
 
 	/* e.g. NAND_BUSWIDTH_16 */