[PATCH 5/6] mtd: rawnand: sunxi: make the code mode self-explanatory

[Richard Genoud <richard.genoud@bootlin.com>]

In sunxi_nfc_hw_ecc_{read,write}_chunk(), the ECC step was force to 0,
the reason is not trivial to get when reading the code.

The explanation is that, from the NAND flash controller perspective, we
are indeed at step 0 for user data length and ECC errors.

Just add a const value with an explanation to clarify things.

Signed-off-by: Richard Genoud <richard.genoud@bootlin.com>
---
 drivers/mtd/nand/raw/sunxi_nand.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index 5d925b59b618..b3a0f70dd4e9 100644
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c
@@ -969,6 +969,8 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
 	u32 pattern_found;
 	bool erased;
 	int ret;
+	/* From the controller point of view, we are at step 0 */
+	const int nfc_step = 0;
 
 	if (*cur_off != data_off)
 		nand_change_read_column_op(nand, data_off, NULL, 0, false);
@@ -983,7 +985,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
 		return ret;
 
 	sunxi_nfc_reset_user_data_len(nfc);
-	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, 0);
+	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, nfc_step);
 	sunxi_nfc_randomizer_config(nand, page, false);
 	sunxi_nfc_randomizer_enable(nand);
 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ECC_OP,
@@ -999,10 +1001,9 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
 	pattern_found = readl(nfc->regs + nfc->caps->reg_pat_found);
 	pattern_found = field_get(NFC_ECC_PAT_FOUND_MSK(nfc), pattern_found);
 
-	ret = sunxi_nfc_hw_ecc_correct(nand, data, oob_required ? oob : NULL, 0,
-				       readl(nfc->regs + NFC_REG_ECC_ST),
-				       pattern_found,
-				       &erased);
+	ret = sunxi_nfc_hw_ecc_correct(nand, data, oob_required ? oob : NULL,
+				       nfc_step, readl(nfc->regs + NFC_REG_ECC_ST),
+				       pattern_found, &erased);
 	if (erased)
 		return 1;
 
@@ -1035,7 +1036,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
 			sunxi_nfc_randomizer_read_buf(nand, oob, ecc->bytes + USER_DATA_SZ,
 						      true, page);
 
-			sunxi_nfc_hw_ecc_get_prot_oob_bytes(nand, oob, 0,
+			sunxi_nfc_hw_ecc_get_prot_oob_bytes(nand, oob, nfc_step,
 							    bbm, page);
 		}
 	}
@@ -1213,6 +1214,8 @@ static int sunxi_nfc_hw_ecc_write_chunk(struct nand_chip *nand,
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
 	struct nand_ecc_ctrl *ecc = &nand->ecc;
 	int ret;
+	/* From the controller point of view, we are at step 0 */
+	const int nfc_step = 0;
 
 	if (data_off != *cur_off)
 		nand_change_write_column_op(nand, data_off, NULL, 0, false);
@@ -1229,8 +1232,8 @@ static int sunxi_nfc_hw_ecc_write_chunk(struct nand_chip *nand,
 	sunxi_nfc_randomizer_config(nand, page, false);
 	sunxi_nfc_randomizer_enable(nand);
 	sunxi_nfc_reset_user_data_len(nfc);
-	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, 0);
-	sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, 0, bbm, page);
+	sunxi_nfc_set_user_data_len(nfc, USER_DATA_SZ, nfc_step);
+	sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, nfc_step, bbm, page);
 
 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
 	       NFC_ACCESS_DIR | NFC_ECC_OP,