#include <linux/mtd/rawnand.h>
/*
- * Special Micron status bit that indicates when the block has been
- * corrected by on-die ECC and should be rewritten
+ * Special Micron status bit 3 indicates that the block has been
+ * corrected by on-die ECC and should be rewritten.
*/
-#define NAND_STATUS_WRITE_RECOMMENDED BIT(3)
+#define NAND_ECC_STATUS_WRITE_RECOMMENDED BIT(3)
+
+/*
+ * On chips with 8-bit ECC and additional bit can be used to distinguish
+ * cases where a errors were corrected without needing a rewrite
+ *
+ * Bit 4 Bit 3 Bit 0 Description
+ * ----- ----- ----- -----------
+ * 0 0 0 No Errors
+ * 0 0 1 Multiple uncorrected errors
+ * 0 1 0 4 - 6 errors corrected, recommend rewrite
+ * 0 1 1 Reserved
+ * 1 0 0 1 - 3 errors corrected
+ * 1 0 1 Reserved
+ * 1 1 0 7 - 8 errors corrected, recommend rewrite
+ */
+#define NAND_ECC_STATUS_MASK (BIT(4) | BIT(3) | BIT(0))
+#define NAND_ECC_STATUS_UNCORRECTABLE BIT(0)
+#define NAND_ECC_STATUS_4_6_CORRECTED BIT(3)
+#define NAND_ECC_STATUS_1_3_CORRECTED BIT(4)
+#define NAND_ECC_STATUS_7_8_CORRECTED (BIT(4) | BIT(3))
struct nand_onfi_vendor_micron {
u8 two_plane_read;
return 0;
}
-static int micron_nand_on_die_ooblayout_ecc(struct mtd_info *mtd, int section,
- struct mtd_oob_region *oobregion)
+static int micron_nand_on_die_4_ooblayout_ecc(struct mtd_info *mtd,
+ int section,
+ struct mtd_oob_region *oobregion)
{
if (section >= 4)
return -ERANGE;
return 0;
}
-static int micron_nand_on_die_ooblayout_free(struct mtd_info *mtd, int section,
- struct mtd_oob_region *oobregion)
+static int micron_nand_on_die_4_ooblayout_free(struct mtd_info *mtd,
+ int section,
+ struct mtd_oob_region *oobregion)
{
if (section >= 4)
return -ERANGE;
return 0;
}
-static const struct mtd_ooblayout_ops micron_nand_on_die_ooblayout_ops = {
- .ecc = micron_nand_on_die_ooblayout_ecc,
- .free = micron_nand_on_die_ooblayout_free,
+static const struct mtd_ooblayout_ops micron_nand_on_die_4_ooblayout_ops = {
+ .ecc = micron_nand_on_die_4_ooblayout_ecc,
+ .free = micron_nand_on_die_4_ooblayout_free,
+};
+
+static int micron_nand_on_die_8_ooblayout_ecc(struct mtd_info *mtd,
+ int section,
+ struct mtd_oob_region *oobregion)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+
+ if (section)
+ return -ERANGE;
+
+ oobregion->offset = mtd->oobsize - chip->ecc.total;
+ oobregion->length = chip->ecc.total;
+
+ return 0;
+}
+
+static int micron_nand_on_die_8_ooblayout_free(struct mtd_info *mtd,
+ int section,
+ struct mtd_oob_region *oobregion)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+
+ if (section)
+ return -ERANGE;
+
+ oobregion->offset = 2;
+ oobregion->length = mtd->oobsize - chip->ecc.total - 2;
+
+ return 0;
+}
+
+static const struct mtd_ooblayout_ops micron_nand_on_die_8_ooblayout_ops = {
+ .ecc = micron_nand_on_die_8_ooblayout_ecc,
+ .free = micron_nand_on_die_8_ooblayout_free,
};
static int micron_nand_on_die_ecc_setup(struct nand_chip *chip, bool enable)
return nand_set_features(chip, ONFI_FEATURE_ON_DIE_ECC, feature);
}
+static int micron_nand_on_die_ecc_status_4(struct nand_chip *chip, u8 status)
+{
+ struct mtd_info *mtd = nand_to_mtd(chip);
+
+ /*
+ * The internal ECC doesn't tell us the number of bitflips
+ * that have been corrected, but tells us if it recommends to
+ * rewrite the block. If it's the case, then we pretend we had
+ * a number of bitflips equal to the ECC strength, which will
+ * hint the NAND core to rewrite the block.
+ */
+ if (status & NAND_STATUS_FAIL) {
+ mtd->ecc_stats.failed++;
+ } else if (status & NAND_ECC_STATUS_WRITE_RECOMMENDED) {
+ mtd->ecc_stats.corrected += chip->ecc.strength;
+ return chip->ecc.strength;
+ }
+
+ return 0;
+}
+
+static int micron_nand_on_die_ecc_status_8(struct nand_chip *chip, u8 status)
+{
+ struct mtd_info *mtd = nand_to_mtd(chip);
+
+ /*
+ * With 8/512 we have more information but still don't know precisely
+ * how many bit-flips were seen.
+ */
+ switch (status & NAND_ECC_STATUS_MASK) {
+ case NAND_ECC_STATUS_UNCORRECTABLE:
+ mtd->ecc_stats.failed++;
+ return 0;
+ case NAND_ECC_STATUS_1_3_CORRECTED:
+ mtd->ecc_stats.corrected += 3;
+ return 3;
+ case NAND_ECC_STATUS_4_6_CORRECTED:
+ mtd->ecc_stats.corrected += 6;
+ /* rewrite recommended */
+ return 6;
+ case NAND_ECC_STATUS_7_8_CORRECTED:
+ mtd->ecc_stats.corrected += 8;
+ /* rewrite recommended */
+ return 8;
+ default:
+ return 0;
+ }
+}
+
static int
micron_nand_read_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip,
uint8_t *buf, int oob_required,
if (ret)
goto out;
- if (status & NAND_STATUS_FAIL) {
- mtd->ecc_stats.failed++;
- } else if (status & NAND_STATUS_WRITE_RECOMMENDED) {
- /*
- * The internal ECC doesn't tell us the number of bitflips
- * that have been corrected, but tells us if it recommends to
- * rewrite the block. If it's the case, then we pretend we had
- * a number of bitflips equal to the ECC strength, which will
- * hint the NAND core to rewrite the block.
- */
- mtd->ecc_stats.corrected += chip->ecc.strength;
- max_bitflips = chip->ecc.strength;
- }
+ if (chip->ecc.strength == 4)
+ max_bitflips = micron_nand_on_die_ecc_status_4(chip, status);
+ else
+ max_bitflips = micron_nand_on_die_ecc_status_8(chip, status);
ret = nand_read_data_op(chip, buf, mtd->writesize, false);
if (!ret && oob_required)
return MICRON_ON_DIE_MANDATORY;
/*
- * Some Micron NANDs have an on-die ECC of 4/512, some other
- * 8/512. We only support the former.
+ * We only support on-die ECC of 4/512 or 8/512
*/
- if (chip->ecc_strength_ds != 4)
+ if (chip->ecc_strength_ds != 4 && chip->ecc_strength_ds != 8)
return MICRON_ON_DIE_UNSUPPORTED;
return MICRON_ON_DIE_SUPPORTED;
return -EINVAL;
}
- chip->ecc.bytes = 8;
+ if (chip->ecc_strength_ds == 4)
+ mtd_set_ooblayout(mtd,
+ µn_nand_on_die_4_ooblayout_ops);
+ else
+ mtd_set_ooblayout(mtd,
+ µn_nand_on_die_8_ooblayout_ops);
+
+ chip->ecc.bytes = chip->ecc_strength_ds * 2;
chip->ecc.size = 512;
- chip->ecc.strength = 4;
+ chip->ecc.strength = chip->ecc_strength_ds;
chip->ecc.algo = NAND_ECC_BCH;
chip->ecc.read_page = micron_nand_read_page_on_die_ecc;
chip->ecc.write_page = micron_nand_write_page_on_die_ecc;
chip->ecc.read_page_raw = nand_read_page_raw;
chip->ecc.write_page_raw = nand_write_page_raw;
-
- mtd_set_ooblayout(mtd, µn_nand_on_die_ooblayout_ops);
}
return 0;
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