mtd: rawnand: fix ecc parameters for mt7622

[ Upstream commit 9fe4e0d3cbfe90152137963cc024ecb63db6e8e6 ]

According to the datasheet, mt7622 only has 5 ECC capabilities instead
of 7, and the decoding error register is arranged  as follows:
+------+---------+---------+---------+---------+
| Bits |  19:15  |  14:10  |   9:5   |   4:0   |
+------+---------+---------+---------+---------+
| Name | ERRNUM3 | ERRNUM2 | ERRNUM1 | ERRNUM0 |
+------+---------+---------+---------+---------+
This means err_mask should be 0x1f instead of 0x3f and the number of
bits shifted in mtk_ecc_get_stats should be 5 instead of 8.

This commit introduces err_shift for the difference in this register
and fix other existing parameters.

Public MT7622 reference manual can be found on [0] and the info this
commit is based on is from page 656 and page 660.

[0]: https://wiki.banana-pi.org/Banana_Pi_BPI-R64#Documents

Fixes: 98dea8d71931 ("mtd: nand: mtk: Support MT7622 NAND flash controller.")
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220402160315.919094-1-gch981213@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/mtd/nand/raw/mtk_ecc.c b/drivers/mtd/nand/raw/mtk_ecc.c
index c437d97..ec9d1fb 100644 (file)
--- a/drivers/mtd/nand/raw/mtk_ecc.c
+++ b/drivers/mtd/nand/raw/mtk_ecc.c
@@ -43,6 +43,7 @@
 
 struct mtk_ecc_caps {
        u32 err_mask;
+       u32 err_shift;
        const u8 *ecc_strength;
        const u32 *ecc_regs;
        u8 num_ecc_strength;
@@ -76,7 +77,7 @@ static const u8 ecc_strength_mt2712[] = {
 };
 
 static const u8 ecc_strength_mt7622[] = {
-       4, 6, 8, 10, 12, 14, 16
+       4, 6, 8, 10, 12
 };
 
 enum mtk_ecc_regs {
@@ -221,7 +222,7 @@ void mtk_ecc_get_stats(struct mtk_ecc *ecc, struct mtk_ecc_stats *stats,
        for (i = 0; i < sectors; i++) {
                offset = (i >> 2) << 2;
                err = readl(ecc->regs + ECC_DECENUM0 + offset);
-               err = err >> ((i % 4) * 8);
+               err = err >> ((i % 4) * ecc->caps->err_shift);
                err &= ecc->caps->err_mask;
                if (err == ecc->caps->err_mask) {
                        /* uncorrectable errors */
@@ -449,6 +450,7 @@ EXPORT_SYMBOL(mtk_ecc_get_parity_bits);
 
 static const struct mtk_ecc_caps mtk_ecc_caps_mt2701 = {
        .err_mask = 0x3f,
+       .err_shift = 8,
        .ecc_strength = ecc_strength_mt2701,
        .ecc_regs = mt2701_ecc_regs,
        .num_ecc_strength = 20,
@@ -459,6 +461,7 @@ static const struct mtk_ecc_caps mtk_ecc_caps_mt2701 = {
 
 static const struct mtk_ecc_caps mtk_ecc_caps_mt2712 = {
        .err_mask = 0x7f,
+       .err_shift = 8,
        .ecc_strength = ecc_strength_mt2712,
        .ecc_regs = mt2712_ecc_regs,
        .num_ecc_strength = 23,
@@ -468,10 +471,11 @@ static const struct mtk_ecc_caps mtk_ecc_caps_mt2712 = {
 };
 
 static const struct mtk_ecc_caps mtk_ecc_caps_mt7622 = {
-       .err_mask = 0x3f,
+       .err_mask = 0x1f,
+       .err_shift = 5,
        .ecc_strength = ecc_strength_mt7622,
        .ecc_regs = mt7622_ecc_regs,
-       .num_ecc_strength = 7,
+       .num_ecc_strength = 5,
        .ecc_mode_shift = 4,
        .parity_bits = 13,
        .pg_irq_sel = 0,