alliancememory.c

  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_1S_4S_4S_OP(0, 1, NULL, 0, 0),
 21		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_4S_OP(0, 1, NULL, 0, 0),
 22		SPINAND_PAGE_READ_FROM_CACHE_1S_2S_2S_OP(0, 1, NULL, 0, 0),
 23		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_2S_OP(0, 1, NULL, 0, 0),
 24		SPINAND_PAGE_READ_FROM_CACHE_FAST_1S_1S_1S_OP(0, 1, NULL, 0, 0),
 25		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_1S_OP(0, 1, NULL, 0, 0));
 26
 27static SPINAND_OP_VARIANTS(write_cache_variants,
 28			   SPINAND_PROG_LOAD_1S_1S_4S_OP(true, 0, NULL, 0),
 29			   SPINAND_PROG_LOAD_1S_1S_1S_OP(true, 0, NULL, 0));
 30
 31static SPINAND_OP_VARIANTS(update_cache_variants,
 32			   SPINAND_PROG_LOAD_1S_1S_4S_OP(false, 0, NULL, 0),
 33			   SPINAND_PROG_LOAD_1S_1S_1S_OP(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};