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authorBrian Norris <computersforpeace@gmail.com>2012-09-24 20:40:50 -0700
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-09-29 15:57:38 +0100
commitfc09bbc04ccd7f069c1928a0156968b888393833 (patch)
tree75d7b13a28849caf125cb7cdf82f291dff716907 /drivers/mtd
parent7e74c2d7141e8929049233e28c74cd089f6ae962 (diff)
downloadlinux-fc09bbc04ccd7f069c1928a0156968b888393833.tar.bz2
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 <computersforpeace@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/nand_base.c122
1 files 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
@@ -2906,6 +2906,71 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
}
/*
+ * 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,
* page size, cell-type information).
@@ -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.