summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/nand/raw/nand_toshiba.c
blob: f3dcd695b5dbfb66c006330c242c67c673aa4637 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2017 Free Electrons
 * Copyright (C) 2017 NextThing Co
 *
 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
 */

#include "internals.h"

/* Bit for detecting BENAND */
#define TOSHIBA_NAND_ID4_IS_BENAND		BIT(7)

/* Recommended to rewrite for BENAND */
#define TOSHIBA_NAND_STATUS_REWRITE_RECOMMENDED	BIT(3)

/* ECC Status Read Command for BENAND */
#define TOSHIBA_NAND_CMD_ECC_STATUS_READ	0x7A

/* ECC Status Mask for BENAND */
#define TOSHIBA_NAND_ECC_STATUS_MASK		0x0F

/* Uncorrectable Error for BENAND */
#define TOSHIBA_NAND_ECC_STATUS_UNCORR		0x0F

/* Max ECC Steps for BENAND */
#define TOSHIBA_NAND_MAX_ECC_STEPS		8

static int toshiba_nand_benand_read_eccstatus_op(struct nand_chip *chip,
						 u8 *buf)
{
	u8 *ecc_status = buf;

	if (nand_has_exec_op(chip)) {
		const struct nand_sdr_timings *sdr =
			nand_get_sdr_timings(&chip->data_interface);
		struct nand_op_instr instrs[] = {
			NAND_OP_CMD(TOSHIBA_NAND_CMD_ECC_STATUS_READ,
				    PSEC_TO_NSEC(sdr->tADL_min)),
			NAND_OP_8BIT_DATA_IN(chip->ecc.steps, ecc_status, 0),
		};
		struct nand_operation op = NAND_OPERATION(chip->cur_cs, instrs);

		return nand_exec_op(chip, &op);
	}

	return -ENOTSUPP;
}

static int toshiba_nand_benand_eccstatus(struct nand_chip *chip)
{
	struct mtd_info *mtd = nand_to_mtd(chip);
	int ret;
	unsigned int max_bitflips = 0;
	u8 status, ecc_status[TOSHIBA_NAND_MAX_ECC_STEPS];

	/* Check Status */
	ret = toshiba_nand_benand_read_eccstatus_op(chip, ecc_status);
	if (!ret) {
		unsigned int i, bitflips = 0;

		for (i = 0; i < chip->ecc.steps; i++) {
			bitflips = ecc_status[i] & TOSHIBA_NAND_ECC_STATUS_MASK;
			if (bitflips == TOSHIBA_NAND_ECC_STATUS_UNCORR) {
				mtd->ecc_stats.failed++;
			} else {
				mtd->ecc_stats.corrected += bitflips;
				max_bitflips = max(max_bitflips, bitflips);
			}
		}

		return max_bitflips;
	}

	/*
	 * Fallback to regular status check if
	 * toshiba_nand_benand_read_eccstatus_op() failed.
	 */
	ret = nand_status_op(chip, &status);
	if (ret)
		return ret;

	if (status & NAND_STATUS_FAIL) {
		/* uncorrected */
		mtd->ecc_stats.failed++;
	} else if (status & TOSHIBA_NAND_STATUS_REWRITE_RECOMMENDED) {
		/* corrected */
		max_bitflips = mtd->bitflip_threshold;
		mtd->ecc_stats.corrected += max_bitflips;
	}

	return max_bitflips;
}

static int
toshiba_nand_read_page_benand(struct nand_chip *chip, uint8_t *buf,
			      int oob_required, int page)
{
	int ret;

	ret = nand_read_page_raw(chip, buf, oob_required, page);
	if (ret)
		return ret;

	return toshiba_nand_benand_eccstatus(chip);
}

static int
toshiba_nand_read_subpage_benand(struct nand_chip *chip, uint32_t data_offs,
				 uint32_t readlen, uint8_t *bufpoi, int page)
{
	int ret;

	ret = nand_read_page_op(chip, page, data_offs,
				bufpoi + data_offs, readlen);
	if (ret)
		return ret;

	return toshiba_nand_benand_eccstatus(chip);
}

static void toshiba_nand_benand_init(struct nand_chip *chip)
{
	struct mtd_info *mtd = nand_to_mtd(chip);

	/*
	 * On BENAND, the entire OOB region can be used by the MTD user.
	 * The calculated ECC bytes are stored into other isolated
	 * area which is not accessible to users.
	 * This is why chip->ecc.bytes = 0.
	 */
	chip->ecc.bytes = 0;
	chip->ecc.size = 512;
	chip->ecc.strength = 8;
	chip->ecc.read_page = toshiba_nand_read_page_benand;
	chip->ecc.read_subpage = toshiba_nand_read_subpage_benand;
	chip->ecc.write_page = nand_write_page_raw;
	chip->ecc.read_page_raw = nand_read_page_raw_notsupp;
	chip->ecc.write_page_raw = nand_write_page_raw_notsupp;

	chip->options |= NAND_SUBPAGE_READ;

	mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
}

static void toshiba_nand_decode_id(struct nand_chip *chip)
{
	struct mtd_info *mtd = nand_to_mtd(chip);
	struct nand_memory_organization *memorg;

	memorg = nanddev_get_memorg(&chip->base);

	nand_decode_ext_id(chip);

	/*
	 * Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
	 * 512B page. For Toshiba SLC, we decode the 5th/6th byte as
	 * follows:
	 * - ID byte 6, bits[2:0]: 100b -> 43nm, 101b -> 32nm,
	 *                         110b -> 24nm
	 * - ID byte 5, bit[7]:    1 -> BENAND, 0 -> raw SLC
	 */
	if (chip->id.len >= 6 && nand_is_slc(chip) &&
	    (chip->id.data[5] & 0x7) == 0x6 /* 24nm */ &&
	    !(chip->id.data[4] & TOSHIBA_NAND_ID4_IS_BENAND) /* !BENAND */) {
		memorg->oobsize = 32 * memorg->pagesize >> 9;
		mtd->oobsize = memorg->oobsize;
	}

	/*
	 * Extract ECC requirements from 6th id byte.
	 * For Toshiba SLC, ecc requrements are as follows:
	 *  - 43nm: 1 bit ECC for each 512Byte is required.
	 *  - 32nm: 4 bit ECC for each 512Byte is required.
	 *  - 24nm: 8 bit ECC for each 512Byte is required.
	 */
	if (chip->id.len >= 6 && nand_is_slc(chip)) {
		chip->base.eccreq.step_size = 512;
		switch (chip->id.data[5] & 0x7) {
		case 0x4:
			chip->base.eccreq.strength = 1;
			break;
		case 0x5:
			chip->base.eccreq.strength = 4;
			break;
		case 0x6:
			chip->base.eccreq.strength = 8;
			break;
		default:
			WARN(1, "Could not get ECC info");
			chip->base.eccreq.step_size = 0;
			break;
		}
	}
}

static int toshiba_nand_init(struct nand_chip *chip)
{
	if (nand_is_slc(chip))
		chip->options |= NAND_BBM_FIRSTPAGE | NAND_BBM_SECONDPAGE;

	/* Check that chip is BENAND and ECC mode is on-die */
	if (nand_is_slc(chip) && chip->ecc.mode == NAND_ECC_ON_DIE &&
	    chip->id.data[4] & TOSHIBA_NAND_ID4_IS_BENAND)
		toshiba_nand_benand_init(chip);

	return 0;
}

const struct nand_manufacturer_ops toshiba_nand_manuf_ops = {
	.detect = toshiba_nand_decode_id,
	.init = toshiba_nand_init,
};