1// SPDX-License-Identifier: GPL-2.0+
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 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 */
18
19#include <linux/bug.h>
20#include <linux/mtd/rawnand.h>
21
22static void samsung_nand_decode_id(struct nand_chip *chip)
23{
24	struct mtd_info *mtd = nand_to_mtd(chip);
25
26	/* New Samsung (6 byte ID): Samsung K9GAG08U0F (p.44) */
27	if (chip->id.len == 6 && !nand_is_slc(chip) &&
28	    chip->id.data[5] != 0x00) {
29		u8 extid = chip->id.data[3];
30
31		/* Get pagesize */
32		mtd->writesize = 2048 << (extid & 0x03);
33
34		extid >>= 2;
35
36		/* Get oobsize */
37		switch (((extid >> 2) & 0x4) | (extid & 0x3)) {
38		case 1:
39			mtd->oobsize = 128;
40			break;
41		case 2:
42			mtd->oobsize = 218;
43			break;
44		case 3:
45			mtd->oobsize = 400;
46			break;
47		case 4:
48			mtd->oobsize = 436;
49			break;
50		case 5:
51			mtd->oobsize = 512;
52			break;
53		case 6:
54			mtd->oobsize = 640;
55			break;
56		case 7:
57		default: /* Other cases are "reserved" (unknown) */
58			WARN(1, "Invalid OOB size value");
59			mtd->oobsize = 1024;
60			break;
61		}
62
63		/* Get blocksize */
64		extid >>= 2;
65		mtd->erasesize = (128 * 1024) <<
66				 (((extid >> 1) & 0x04) | (extid & 0x03));
67
68		/* Extract ECC requirements from 5th id byte*/
69		extid = (chip->id.data[4] >> 4) & 0x07;
70		if (extid < 5) {
71			chip->ecc_step_ds = 512;
72			chip->ecc_strength_ds = 1 << extid;
73		} else {
74			chip->ecc_step_ds = 1024;
75			switch (extid) {
76			case 5:
77				chip->ecc_strength_ds = 24;
78				break;
79			case 6:
80				chip->ecc_strength_ds = 40;
81				break;
82			case 7:
83				chip->ecc_strength_ds = 60;
84				break;
85			}
86		}
87	} else {
88		nand_decode_ext_id(chip);
89	}
90}
91
92static int samsung_nand_init(struct nand_chip *chip)
93{
94	struct mtd_info *mtd = nand_to_mtd(chip);
95
96	if (mtd->writesize > 512)
97		chip->options |= NAND_SAMSUNG_LP_OPTIONS;
98
99	if (!nand_is_slc(chip))
100		chip->bbt_options |= NAND_BBT_SCANLASTPAGE;
101	else
102		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
103
104	return 0;
105}
106
107const struct nand_manufacturer_ops samsung_nand_manuf_ops = {
108	.detect = samsung_nand_decode_id,
109	.init = samsung_nand_init,
110};
111