drivers/mtd/nand/raw/nand_esmt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2018 Toradex AG
   4  *
   5  * Author: Marcel Ziswiler <marcel.ziswiler@toradex.com>
   6  */
   7
   8 #include <linux/mtd/rawnand.h>
   9 #include "internals.h"
  10
  11 static void esmt_nand_decode_id(struct nand_chip *chip)
  12 {
  13         struct nand_device *base = &chip->base;
  14         struct nand_ecc_props requirements = {};
  15
  16         nand_decode_ext_id(chip);
  17
  18         /* Extract ECC requirements from 5th id byte. */
  19         if (chip->id.len >= 5 && nand_is_slc(chip)) {
  20                 requirements.step_size = 512;
  21                 switch (chip->id.data[4] & 0x3) {
  22                 case 0x0:
  23                         requirements.strength = 4;
  24                         break;
  25                 case 0x1:
  26                         requirements.strength = 2;
  27                         break;
  28                 case 0x2:
  29                         requirements.strength = 1;
  30                         break;
  31                 default:
  32                         WARN(1, "Could not get ECC info");
  33                         requirements.step_size = 0;
  34                         break;
  35                 }
  36         }
  37
  38         nanddev_set_ecc_requirements(base, &requirements);
  39 }
  40
  41 static int esmt_nand_init(struct nand_chip *chip)
  42 {
  43         if (nand_is_slc(chip))
  44                 /*
  45                  * It is known that some ESMT SLC NANDs have been shipped
  46                  * with the factory bad block markers in the first or last page
  47                  * of the block, instead of the first or second page. To be on
  48                  * the safe side, let's check all three locations.
  49                  */
  50                 chip->options |= NAND_BBM_FIRSTPAGE | NAND_BBM_SECONDPAGE |
  51                                  NAND_BBM_LASTPAGE;
  52
  53         return 0;
  54 }
  55
  56 const struct nand_manufacturer_ops esmt_nand_manuf_ops = {
  57         .detect = esmt_nand_decode_id,
  58         .init = esmt_nand_init,
  59 };