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Commit f23a481c authored by Brian Norris's avatar Brian Norris Committed by David Woodhouse
Browse files

mtd: nand: split simple ID decode 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 simple ID decode functionality, where all the
information regarding NAND size/blocksize/pagesize/oobsize/busw is encoded in
the first two bytes of the ID string.

Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent fc09bbc0

drivers/mtd/nand/nand_base.c

+31 −20
Original line number Diff line number Diff line
@@ -2970,6 +2970,36 @@ static void nand_decode_ext_id(struct mtd_info *mtd, struct nand_chip *chip, 
	}

}



/*

 * Old devices have chip data hardcoded in the device ID table. nand_decode_id

 * decodes a matching ID table entry and assigns the MTD size parameters for

 * the chip.

 */

static void nand_decode_id(struct mtd_info *mtd, struct nand_chip *chip,

				struct nand_flash_dev *type, u8 id_data[8],

				int *busw)

{

	int maf_id = id_data[0];



	mtd->erasesize = type->erasesize;

	mtd->writesize = type->pagesize;

	mtd->oobsize = mtd->writesize / 32;

	*busw = type->options & NAND_BUSWIDTH_16;



	/*

	 * Check for Spansion/AMD ID + repeating 5th, 6th byte since

	 * some Spansion chips have erasesize that conflicts with size

	 * listed in nand_ids table.

	 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)

	 */

	if (maf_id == NAND_MFR_AMD && id_data[4] != 0x00 && id_data[5] == 0x00

			&& id_data[6] == 0x00 && id_data[7] == 0x00

			&& mtd->writesize == 512) {

		mtd->erasesize = 128 * 1024;

		mtd->erasesize <<= ((id_data[3] & 0x03) << 1);

	}

}



/*

 * Set the bad block marker/indicator (BBM/BBI) patterns according to some

 * heuristic patterns using various detected parameters (e.g., manufacturer,
@@ -3084,26 +3114,7 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd, 
		/* 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.

		 */

		mtd->erasesize = type->erasesize;

		mtd->writesize = type->pagesize;

		mtd->oobsize = mtd->writesize / 32;

		busw = type->options & NAND_BUSWIDTH_16;



		/*

		 * Check for Spansion/AMD ID + repeating 5th, 6th byte since

		 * some Spansion chips have erasesize that conflicts with size

		 * listed in nand_ids table.

		 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)

		 */

		if (*maf_id == NAND_MFR_AMD && id_data[4] != 0x00 &&

				id_data[5] == 0x00 && id_data[6] == 0x00 &&

				id_data[7] == 0x00 && mtd->writesize == 512) {

			mtd->erasesize = 128 * 1024;

			mtd->erasesize <<= ((id_data[3] & 0x03) << 1);

		}

		nand_decode_id(mtd, chip, type, id_data, &busw);

	}

	/* Get chip options */

	chip->options |= type->options;