mtd: nand: parse out the JEDEC compliant NAND

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=913618185e51ee1fcbc193b2f121a9d072405619
Commit:     913618185e51ee1fcbc193b2f121a9d072405619
Parent:     7852f8962f0f022b11fc56d63de06226a9f70d88
Author:     Huang Shijie <b32955 at freescale.com>
AuthorDate: Fri Feb 21 13:39:40 2014 +0800
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Mon Mar 10 22:42:27 2014 -0700

    mtd: nand: parse out the JEDEC compliant NAND
    
    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>
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 drivers/mtd/nand/nand_base.c | 85 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/nand.h     |  2 +-
 2 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 3cb1cef..30416ec 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. */