1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2017 Free Electrons
4 * Copyright (C) 2017 NextThing Co
5 *
6 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
7 */
8
9#include "internals.h"
10
11static void samsung_nand_decode_id(struct nand_chip *chip)
12{
13 struct nand_device *base = &chip->base;
14 struct nand_ecc_props requirements = {};
15 struct mtd_info *mtd = nand_to_mtd(chip);
16 struct nand_memory_organization *memorg;
17
18 memorg = nanddev_get_memorg(nand: &chip->base);
19
20 /* New Samsung (6 byte ID): Samsung K9GAG08U0F (p.44) */
21 if (chip->id.len == 6 && !nand_is_slc(chip) &&
22 chip->id.data[5] != 0x00) {
23 u8 extid = chip->id.data[3];
24
25 /* Get pagesize */
26 memorg->pagesize = 2048 << (extid & 0x03);
27 mtd->writesize = memorg->pagesize;
28
29 extid >>= 2;
30
31 /* Get oobsize */
32 switch (((extid >> 2) & 0x4) | (extid & 0x3)) {
33 case 1:
34 memorg->oobsize = 128;
35 break;
36 case 2:
37 memorg->oobsize = 218;
38 break;
39 case 3:
40 memorg->oobsize = 400;
41 break;
42 case 4:
43 memorg->oobsize = 436;
44 break;
45 case 5:
46 memorg->oobsize = 512;
47 break;
48 case 6:
49 memorg->oobsize = 640;
50 break;
51 default:
52 /*
53 * We should never reach this case, but if that
54 * happens, this probably means Samsung decided to use
55 * a different extended ID format, and we should find
56 * a way to support it.
57 */
58 WARN(1, "Invalid OOB size value");
59 break;
60 }
61
62 mtd->oobsize = memorg->oobsize;
63
64 /* Get blocksize */
65 extid >>= 2;
66 memorg->pages_per_eraseblock = (128 * 1024) <<
67 (((extid >> 1) & 0x04) |
68 (extid & 0x03)) /
69 memorg->pagesize;
70 mtd->erasesize = (128 * 1024) <<
71 (((extid >> 1) & 0x04) | (extid & 0x03));
72
73 /* Extract ECC requirements from 5th id byte*/
74 extid = (chip->id.data[4] >> 4) & 0x07;
75 if (extid < 5) {
76 requirements.step_size = 512;
77 requirements.strength = 1 << extid;
78 } else {
79 requirements.step_size = 1024;
80 switch (extid) {
81 case 5:
82 requirements.strength = 24;
83 break;
84 case 6:
85 requirements.strength = 40;
86 break;
87 case 7:
88 requirements.strength = 60;
89 break;
90 default:
91 WARN(1, "Could not decode ECC info");
92 requirements.step_size = 0;
93 }
94 }
95 } else {
96 nand_decode_ext_id(chip);
97
98 if (nand_is_slc(chip)) {
99 switch (chip->id.data[1]) {
100 /* K9F4G08U0D-S[I|C]B0(T00) */
101 case 0xDC:
102 requirements.step_size = 512;
103 requirements.strength = 1;
104 break;
105
106 /* K9F1G08U0E 21nm chips do not support subpage write */
107 case 0xF1:
108 if (chip->id.len > 4 &&
109 (chip->id.data[4] & GENMASK(1, 0)) == 0x1)
110 chip->options |= NAND_NO_SUBPAGE_WRITE;
111 break;
112 default:
113 break;
114 }
115 }
116 }
117
118 nanddev_set_ecc_requirements(nand: base, reqs: &requirements);
119}
120
121static int samsung_nand_init(struct nand_chip *chip)
122{
123 struct mtd_info *mtd = nand_to_mtd(chip);
124
125 if (mtd->writesize > 512)
126 chip->options |= NAND_SAMSUNG_LP_OPTIONS;
127
128 if (!nand_is_slc(chip))
129 chip->options |= NAND_BBM_LASTPAGE;
130 else
131 chip->options |= NAND_BBM_FIRSTPAGE | NAND_BBM_SECONDPAGE;
132
133 return 0;
134}
135
136const struct nand_manufacturer_ops samsung_nand_manuf_ops = {
137 .detect = samsung_nand_decode_id,
138 .init = samsung_nand_init,
139};
140

source code of linux/drivers/mtd/nand/raw/nand_samsung.c