[PATCH v3 4/5] mtd: nand: parse out the JEDEC compliant nand

[Huang Shijie]

This patch adds the parsing code for the JEDEC compliant nand.

Since we need the 0x40 as the column address, this patch also
makes the NAND_CMD_PARAM to use the 8-bit address only.

Signed-off-by: Huang Shijie <b32955 at freescale.com>
---
 drivers/mtd/nand/nand_base.c |   85 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/nand.h     |    2 +-
 2 files changed, 86 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 9be7842..42461f9 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3163,6 +3163,87 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
 }
 
 /*
+ * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
+ */
+static int nand_flash_detect_jedec(struct mtd_info *mtd, struct nand_chip *chip,
+					int *busw)
+{
+	struct nand_jedec_params *p = &chip->jedec_params;
+	struct jedec_ecc_info *ecc;
+	int val;
+	int i, j;
+
+	/* Try JEDEC for unknown chip or LP */
+	chip->cmdfunc(mtd, NAND_CMD_READID, 0x40, -1);
+	if (chip->read_byte(mtd) != 'J' || chip->read_byte(mtd) != 'E' ||
+		chip->read_byte(mtd) != 'D' || chip->read_byte(mtd) != 'E' ||
+		chip->read_byte(mtd) != 'C')
+		return 0;
+
+	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0x40, -1);
+	for (i = 0; i < 3; i++) {
+		for (j = 0; j < sizeof(*p); j++)
+			((uint8_t *)p)[j] = chip->read_byte(mtd);
+
+		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) ==
+				le16_to_cpu(p->crc))
+			break;
+	}
+
+	if (i == 3) {
+		pr_err("Could not find valid JEDEC parameter page; aborting\n");
+		return 0;
+	}
+
+	/* Check version */
+	val = le16_to_cpu(p->revision);
+	if (val & (1 << 2))
+		chip->jedec_version = 10;
+	else if (val & (1 << 1))
+		chip->jedec_version = 1; /* vendor specific version */
+
+	if (!chip->jedec_version) {
+		pr_info("unsupported JEDEC version: %d\n", val);
+		return 0;
+	}
+
+	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
+	sanitize_string(p->model, sizeof(p->model));
+	if (!mtd->name)
+		mtd->name = p->model;
+
+	mtd->writesize = le32_to_cpu(p->byte_per_page);
+
+	/* Please reference to the comment for nand_flash_detect_onfi. */
+	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
+	mtd->erasesize *= mtd->writesize;
+
+	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
+
+	/* Please reference to the comment for nand_flash_detect_onfi. */
+	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
+	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
+	chip->bits_per_cell = p->bits_per_cell;
+
+	if (jedec_feature(chip) & JEDEC_FEATURE_16_BIT_BUS)
+		*busw = NAND_BUSWIDTH_16;
+	else
+		*busw = 0;
+
+	/* ECC info */
+	ecc = &p->ecc_info[0];
+
+	if (ecc->codeword_size >= 9) {
+		chip->ecc_strength_ds = ecc->ecc_bits;
+		chip->ecc_step_ds = 1 << ecc->codeword_size;
+	} else {
+		pr_warn("Invalid codeword size\n");
+	}
+
+	return 1;
+}
+
+/*
  * nand_id_has_period - Check if an ID string has a given wraparound period
  * @id_data: the ID string
  * @arrlen: the length of the @id_data array
@@ -3527,6 +3608,10 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 		/* Check is chip is ONFI compliant */
 		if (nand_flash_detect_onfi(mtd, chip, &busw))
 			goto ident_done;
+
+		/* Check if the chip is JEDEC compliant */
+		if (nand_flash_detect_jedec(mtd, chip, &busw))
+			goto ident_done;
 	}
 
 	if (!type->name)
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index afd1cf9b..aa005e8 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -925,7 +925,7 @@ static inline bool nand_is_slc(struct nand_chip *chip)
  */
 static inline int nand_opcode_8bits(unsigned int command)
 {
-	return command == NAND_CMD_READID;
+	return command == NAND_CMD_READID || command == NAND_CMD_PARAM;
 }
 
 /* return the supported JEDEC features. */
-- 
1.7.2.rc3