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 
19 static 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 
27 static SPINAND_OP_VARIANTS(write_cache_variants,
28 			   SPINAND_PROG_LOAD_X4(true, 0, NULL, 0),
29 			   SPINAND_PROG_LOAD(true, 0, NULL, 0));
30 
31 static SPINAND_OP_VARIANTS(update_cache_variants,
32 			   SPINAND_PROG_LOAD_X4(false, 0, NULL, 0),
33 			   SPINAND_PROG_LOAD(false, 0, NULL, 0));
34 
35 static 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 
47 static 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 
62 static 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 
90 static const struct mtd_ooblayout_ops am_ooblayout = {
91 	.ecc = am_ooblayout_ecc,
92 	.free = am_ooblayout_free,
93 };
94 
95 static 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 
131 static 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 
144 static const struct spinand_manufacturer_ops alliancememory_spinand_manuf_ops = {
145 };
146 
147 const 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