1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Author: Mario Kicherer <dev@kicherer.org>
4 */
5
6#include <linux/device.h>
7#include <linux/kernel.h>
8#include <linux/mtd/spinand.h>
9
10#define SPINAND_MFR_ALLIANCEMEMORY	0x52
11
12#define AM_STATUS_ECC_BITMASK		(3 << 4)
13
14#define AM_STATUS_ECC_NONE_DETECTED	(0 << 4)
15#define AM_STATUS_ECC_CORRECTED		(1 << 4)
16#define AM_STATUS_ECC_ERRORED		(2 << 4)
17#define AM_STATUS_ECC_MAX_CORRECTED	(3 << 4)
18
19static SPINAND_OP_VARIANTS(read_cache_variants,
20		SPINAND_PAGE_READ_FROM_CACHE_QUADIO_OP(0, 1, NULL, 0),
21		SPINAND_PAGE_READ_FROM_CACHE_X4_OP(0, 1, NULL, 0),
22		SPINAND_PAGE_READ_FROM_CACHE_DUALIO_OP(0, 1, NULL, 0),
23		SPINAND_PAGE_READ_FROM_CACHE_X2_OP(0, 1, NULL, 0),
24		SPINAND_PAGE_READ_FROM_CACHE_OP(true, 0, 1, NULL, 0),
25		SPINAND_PAGE_READ_FROM_CACHE_OP(false, 0, 1, NULL, 0));
26
27static SPINAND_OP_VARIANTS(write_cache_variants,
28			   SPINAND_PROG_LOAD_X4(true, 0, NULL, 0),
29			   SPINAND_PROG_LOAD(true, 0, NULL, 0));
30
31static SPINAND_OP_VARIANTS(update_cache_variants,
32			   SPINAND_PROG_LOAD_X4(false, 0, NULL, 0),
33			   SPINAND_PROG_LOAD(false, 0, NULL, 0));
34
35static int am_get_eccsize(struct mtd_info *mtd)
36{
37	if (mtd->oobsize == 64)
38		return 0x20;
39	else if (mtd->oobsize == 128)
40		return 0x38;
41	else if (mtd->oobsize == 256)
42		return 0x70;
43	else
44		return -EINVAL;
45}
46
47static int am_ooblayout_ecc(struct mtd_info *mtd, int section,
48			    struct mtd_oob_region *region)
49{
50	int ecc_bytes;
51
52	ecc_bytes = am_get_eccsize(mtd);
53	if (ecc_bytes < 0)
54		return ecc_bytes;
55
56	region->offset = mtd->oobsize - ecc_bytes;
57	region->length = ecc_bytes;
58
59	return 0;
60}
61
62static int am_ooblayout_free(struct mtd_info *mtd, int section,
63			     struct mtd_oob_region *region)
64{
65	int ecc_bytes;
66
67	if (section)
68		return -ERANGE;
69
70	ecc_bytes = am_get_eccsize(mtd);
71	if (ecc_bytes < 0)
72		return ecc_bytes;
73
74	/*
75	 * It is unclear how many bytes are used for the bad block marker. We
76	 * reserve the common two bytes here.
77	 *
78	 * The free area in this kind of flash is divided into chunks where the
79	 * first 4 bytes of each chunk are unprotected. The number of chunks
80	 * depends on the specific model. The models with 4096+256 bytes pages
81	 * have 8 chunks, the others 4 chunks.
82	 */
83
84	region->offset = 2;
85	region->length = mtd->oobsize - 2 - ecc_bytes;
86
87	return 0;
88}
89
90static const struct mtd_ooblayout_ops am_ooblayout = {
91	.ecc = am_ooblayout_ecc,
92	.free = am_ooblayout_free,
93};
94
95static int am_ecc_get_status(struct spinand_device *spinand, u8 status)
96{
97	switch (status & AM_STATUS_ECC_BITMASK) {
98	case AM_STATUS_ECC_NONE_DETECTED:
99		return 0;
100
101	case AM_STATUS_ECC_CORRECTED:
102		/*
103		 * use oobsize to determine the flash model and the maximum of
104		 * correctable errors and return maximum - 1 by convention
105		 */
106		if (spinand->base.mtd.oobsize == 64)
107			return 3;
108		else
109			return 7;
110
111	case AM_STATUS_ECC_ERRORED:
112		return -EBADMSG;
113
114	case AM_STATUS_ECC_MAX_CORRECTED:
115		/*
116		 * use oobsize to determine the flash model and the maximum of
117		 * correctable errors
118		 */
119		if (spinand->base.mtd.oobsize == 64)
120			return 4;
121		else
122			return 8;
123
124	default:
125		break;
126	}
127
128	return -EINVAL;
129}
130
131static const struct spinand_info alliancememory_spinand_table[] = {
132	SPINAND_INFO("AS5F34G04SND",
133		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x2f),
134		     NAND_MEMORG(1, 2048, 128, 64, 4096, 80, 1, 1, 1),
135		     NAND_ECCREQ(4, 512),
136		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
137					      &write_cache_variants,
138					      &update_cache_variants),
139		     SPINAND_HAS_QE_BIT,
140		     SPINAND_ECCINFO(&am_ooblayout,
141				     am_ecc_get_status)),
142};
143
144static const struct spinand_manufacturer_ops alliancememory_spinand_manuf_ops = {
145};
146
147const struct spinand_manufacturer alliancememory_spinand_manufacturer = {
148	.id = SPINAND_MFR_ALLIANCEMEMORY,
149	.name = "AllianceMemory",
150	.chips = alliancememory_spinand_table,
151	.nchips = ARRAY_SIZE(alliancememory_spinand_table),
152	.ops = &alliancememory_spinand_manuf_ops,
153};
154