From fc09bbc04ccd7f069c1928a0156968b888393833 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Mon, 24 Sep 2012 20:40:50 -0700 Subject: [PATCH] mtd: nand: split extended ID decoding into its own function When detecting NAND parameters, the code gets a little ugly so that the logic is obscured. Try to remedy that by moving code to separate functions that have well-defined purposes. This patch splits out the extended ID decode functionality, which handles decoding the 3rd-8th ID bytes to determine NAND device parameters. Signed-off-by: Brian Norris Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/nand/nand_base.c | 122 +++++++++++++++++++---------------- 1 file changed, 67 insertions(+), 55 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 16bb17f93997..e017af02da1c 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -2905,6 +2905,71 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip, return 1; } +/* + * Many new NAND share similar device ID codes, which represent the size of the + * chip. The rest of the parameters must be decoded according to generic or + * manufacturer-specific "extended ID" decoding patterns. + */ +static void nand_decode_ext_id(struct mtd_info *mtd, struct nand_chip *chip, + u8 id_data[8], int *busw) +{ + int extid; + /* The 3rd id byte holds MLC / multichip data */ + chip->cellinfo = id_data[2]; + /* The 4th id byte is the important one */ + extid = id_data[3]; + + /* + * Field definitions are in the following datasheets: + * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32) + * New style (6 byte ID): Samsung K9GBG08U0M (p.40) + * + * Check for wraparound + Samsung ID + nonzero 6th byte + * to decide what to do. + */ + if (id_data[0] == id_data[6] && id_data[1] == id_data[7] && + id_data[0] == NAND_MFR_SAMSUNG && + (chip->cellinfo & NAND_CI_CELLTYPE_MSK) && + id_data[5] != 0x00) { + /* Calc pagesize */ + mtd->writesize = 2048 << (extid & 0x03); + extid >>= 2; + /* Calc oobsize */ + switch (extid & 0x03) { + case 1: + mtd->oobsize = 128; + break; + case 2: + mtd->oobsize = 218; + break; + case 3: + mtd->oobsize = 400; + break; + default: + mtd->oobsize = 436; + break; + } + extid >>= 2; + /* Calc blocksize */ + mtd->erasesize = (128 * 1024) << + (((extid >> 1) & 0x04) | (extid & 0x03)); + *busw = 0; + } else { + /* Calc pagesize */ + mtd->writesize = 1024 << (extid & 0x03); + extid >>= 2; + /* Calc oobsize */ + mtd->oobsize = (8 << (extid & 0x01)) * + (mtd->writesize >> 9); + extid >>= 2; + /* Calc blocksize. Blocksize is multiples of 64KiB */ + mtd->erasesize = (64 * 1024) << (extid & 0x03); + extid >>= 2; + /* Get buswidth information */ + *busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0; + } +} + /* * Set the bad block marker/indicator (BBM/BBI) patterns according to some * heuristic patterns using various detected parameters (e.g., manufacturer, @@ -3016,61 +3081,8 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd, /* Set the pagesize, oobsize, erasesize by the driver */ busw = chip->init_size(mtd, chip, id_data); } else if (!type->pagesize) { - int extid; - /* The 3rd id byte holds MLC / multichip data */ - chip->cellinfo = id_data[2]; - /* The 4th id byte is the important one */ - extid = id_data[3]; - - /* - * Field definitions are in the following datasheets: - * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32) - * New style (6 byte ID): Samsung K9GBG08U0M (p.40) - * - * Check for wraparound + Samsung ID + nonzero 6th byte - * to decide what to do. - */ - if (id_data[0] == id_data[6] && id_data[1] == id_data[7] && - id_data[0] == NAND_MFR_SAMSUNG && - (chip->cellinfo & NAND_CI_CELLTYPE_MSK) && - id_data[5] != 0x00) { - /* Calc pagesize */ - mtd->writesize = 2048 << (extid & 0x03); - extid >>= 2; - /* Calc oobsize */ - switch (extid & 0x03) { - case 1: - mtd->oobsize = 128; - break; - case 2: - mtd->oobsize = 218; - break; - case 3: - mtd->oobsize = 400; - break; - default: - mtd->oobsize = 436; - break; - } - extid >>= 2; - /* Calc blocksize */ - mtd->erasesize = (128 * 1024) << - (((extid >> 1) & 0x04) | (extid & 0x03)); - busw = 0; - } else { - /* Calc pagesize */ - mtd->writesize = 1024 << (extid & 0x03); - extid >>= 2; - /* Calc oobsize */ - mtd->oobsize = (8 << (extid & 0x01)) * - (mtd->writesize >> 9); - extid >>= 2; - /* Calc blocksize. Blocksize is multiples of 64KiB */ - mtd->erasesize = (64 * 1024) << (extid & 0x03); - extid >>= 2; - /* Get buswidth information */ - busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0; - } + /* Decode parameters from extended ID */ + nand_decode_ext_id(mtd, chip, id_data, &busw); } else { /* * Old devices have chip data hardcoded in the device id table. -- 2.34.1