drivers/mtd/nand/nand_toshiba.c

   1 /*
   2  * Copyright (C) 2017 Free Electrons
   3  * Copyright (C) 2017 NextThing Co
   4  *
   5  * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/mtd/rawnand.h>
  19
  20 static void toshiba_nand_decode_id(struct nand_chip *chip)
  21 {
  22         struct mtd_info *mtd = nand_to_mtd(chip);
  23
  24         nand_decode_ext_id(chip);
  25
  26         /*
  27          * Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
  28          * 512B page. For Toshiba SLC, we decode the 5th/6th byte as
  29          * follows:
  30          * - ID byte 6, bits[2:0]: 100b -> 43nm, 101b -> 32nm,
  31          *                         110b -> 24nm
  32          * - ID byte 5, bit[7]:    1 -> BENAND, 0 -> raw SLC
  33          */
  34         if (chip->id.len >= 6 && nand_is_slc(chip) &&
  35             (chip->id.data[5] & 0x7) == 0x6 /* 24nm */ &&
  36             !(chip->id.data[4] & 0x80) /* !BENAND */)
  37                 mtd->oobsize = 32 * mtd->writesize >> 9;
  38 }
  39
  40 static int toshiba_nand_init(struct nand_chip *chip)
  41 {
  42         if (nand_is_slc(chip))
  43                 chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
  44
  45         return 0;
  46 }
  47
  48 const struct nand_manufacturer_ops toshiba_nand_manuf_ops = {
  49         .detect = toshiba_nand_decode_id,
  50         .init = toshiba_nand_init,
  51 };