[PATCH 6/8] mtd: rawnand: mtk: Introduce mtk_ecc_calc_parity_bytes() function

[Xiaolei Li]

Introduce mtk_ecc_calc_parity_bytes() function to calculate ECC
parity byte number.

Signed-off-by: Xiaolei Li <xiaolei.li at mediatek.com>
---
 drivers/mtd/nand/raw/mtk_ecc.c  | 10 ++++++++--
 drivers/mtd/nand/raw/mtk_ecc.h  |  1 +
 drivers/mtd/nand/raw/mtk_nand.c |  6 ++----
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/nand/raw/mtk_ecc.c b/drivers/mtd/nand/raw/mtk_ecc.c
index 40d86a8..717d553 100644
--- a/drivers/mtd/nand/raw/mtk_ecc.c
+++ b/drivers/mtd/nand/raw/mtk_ecc.c
@@ -408,7 +408,7 @@ int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config,
 	mtk_ecc_wait_idle(ecc, ECC_ENCODE);
 
 	/* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */
-	len = (config->strength * ecc->caps->parity_bits + 7) >> 3;
+	len = mtk_ecc_calc_parity_bytes(ecc, config->strength);
 
 	/* write the parity bytes generated by the ECC back to temp buffer */
 	__ioread32_copy(ecc->eccdata,
@@ -451,6 +451,12 @@ unsigned int mtk_ecc_get_parity_bits(struct mtk_ecc *ecc)
 }
 EXPORT_SYMBOL(mtk_ecc_get_parity_bits);
 
+int mtk_ecc_calc_parity_bytes(struct mtk_ecc *ecc, int ecc_strength)
+{
+	return DIV_ROUND_UP(ecc->caps->parity_bits * ecc_strength, 8);
+}
+EXPORT_SYMBOL(mtk_ecc_calc_parity_bytes);
+
 static const struct mtk_ecc_caps mtk_ecc_caps_mt2701 = {
 	.err_mask = 0x3f,
 	.ecc_strength = ecc_strength_mt2701,
@@ -516,7 +522,7 @@ static int mtk_ecc_probe(struct platform_device *pdev)
 
 	max_eccdata_size = ecc->caps->num_ecc_strength - 1;
 	max_eccdata_size = ecc->caps->ecc_strength[max_eccdata_size];
-	max_eccdata_size = (max_eccdata_size * ecc->caps->parity_bits + 7) >> 3;
+	max_eccdata_size = mtk_ecc_calc_parity_bytes(ecc, max_eccdata_size);
 	max_eccdata_size = round_up(max_eccdata_size, 4);
 	ecc->eccdata = devm_kzalloc(dev, max_eccdata_size, GFP_KERNEL);
 	if (!ecc->eccdata)
diff --git a/drivers/mtd/nand/raw/mtk_ecc.h b/drivers/mtd/nand/raw/mtk_ecc.h
index a455df0..c1546f9 100644
--- a/drivers/mtd/nand/raw/mtk_ecc.h
+++ b/drivers/mtd/nand/raw/mtk_ecc.h
@@ -42,6 +42,7 @@ struct mtk_ecc_config {
 void mtk_ecc_disable(struct mtk_ecc *);
 void mtk_ecc_adjust_strength(struct mtk_ecc *ecc, u32 *p);
 unsigned int mtk_ecc_get_parity_bits(struct mtk_ecc *ecc);
+int mtk_ecc_calc_parity_bytes(struct mtk_ecc *ecc, int ecc_strength);
 
 struct mtk_ecc *of_mtk_ecc_get(struct device_node *);
 void mtk_ecc_release(struct mtk_ecc *);
diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c
index 2c244c2..249b3fb 100644
--- a/drivers/mtd/nand/raw/mtk_nand.c
+++ b/drivers/mtd/nand/raw/mtk_nand.c
@@ -1143,8 +1143,7 @@ static int mtk_nfc_set_fdm(struct mtk_nfc_fdm *fdm, struct mtd_info *mtd)
 	struct mtk_nfc *nfc = nand_get_controller_data(nand);
 	u32 ecc_bytes;
 
-	ecc_bytes = DIV_ROUND_UP(nand->ecc.strength *
-				 mtk_ecc_get_parity_bits(nfc->ecc), 8);
+	ecc_bytes = mtk_ecc_calc_parity_bytes(nfc->ecc, nand->ecc.strength);
 
 	fdm->reg_size = chip->spare_per_sector - ecc_bytes;
 	if (fdm->reg_size > NFI_FDM_MAX_SIZE) {
@@ -1245,8 +1244,7 @@ static int mtk_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
 			return ret;
 
 		/* calculate oob bytes except ecc parity data */
-		free = (nand->ecc.strength * mtk_ecc_get_parity_bits(nfc->ecc)
-			+ 7) >> 3;
+		free = mtk_ecc_calc_parity_bytes(nfc->ecc, nand->ecc.strength);
 		free = spare - free;
 
 		/*
-- 
1.9.1