From a75a1dec037ff3de863375fa3a74569619667184 Mon Sep 17 00:00:00 2001
From: Ahmed Naseef <naseefkm@gmail.com>
Date: Tue, 9 Dec 2025 11:16:02 +0400
Subject: [PATCH] mtd: spinand: add support for Dosilicon DS35Q1GA/DS35M1GA

Add support for Dosilicon DS35Q1GA (3.3V) and DS35M1GA (1.8V) SPI NAND.

These are 1Gbit (128MB) devices with:
  - 2048 byte pages + 64 byte OOB
  - 64 pages per block, 1024 blocks
  - On-die 4-bit ECC per 512 byte sector

The 64-byte OOB area is divided into 4 segments of 16 bytes, with each
segment containing 8 bytes of user data (M2+M1) and 8 bytes of ECC
parity (R1). This provides 30 bytes of usable OOB space after reserving
2 bytes for the bad block marker.

Tested on Genexis Platinum 4410 (EcoNet EN751221) by writing known
patterns to OOB and verifying ECC parity placement in R1 regions.

Datasheet:
  https://www.dosilicon.com/resources/SPI%20NAND/DS35X1GAXXX_rev08.pdf

Signed-off-by: Ahmed Naseef <naseefkm@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/spi/Makefile    |  4 +-
 drivers/mtd/nand/spi/core.c      |  1 +
 drivers/mtd/nand/spi/dosilicon.c | 91 ++++++++++++++++++++++++++++++++
 include/linux/mtd/spinand.h      |  1 +
 4 files changed, 95 insertions(+), 2 deletions(-)
 create mode 100644 drivers/mtd/nand/spi/dosilicon.c

--- a/drivers/mtd/nand/spi/Makefile
+++ b/drivers/mtd/nand/spi/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 spinand-objs := core.o otp.o
-spinand-objs += alliancememory.o ato.o esmt.o etron.o fmsh.o foresee.o gigadevice.o
-spinand-objs += macronix.o micron.o paragon.o skyhigh.o toshiba.o winbond.o xtx.o
+spinand-objs += alliancememory.o ato.o dosilicon.o esmt.o etron.o fmsh.o foresee.o
+spinand-objs += gigadevice.o macronix.o micron.o paragon.o skyhigh.o toshiba.o
+spinand-objs += winbond.o xtx.o
 obj-$(CONFIG_MTD_SPI_NAND) += spinand.o
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1226,6 +1226,7 @@ static const struct nand_ops spinand_ops
 static const struct spinand_manufacturer *spinand_manufacturers[] = {
 	&alliancememory_spinand_manufacturer,
 	&ato_spinand_manufacturer,
+	&dosilicon_spinand_manufacturer,
 	&esmt_8c_spinand_manufacturer,
 	&esmt_c8_spinand_manufacturer,
 	&etron_spinand_manufacturer,
--- /dev/null
+++ b/drivers/mtd/nand/spi/dosilicon.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Ahmed Naseef <naseefkm@gmail.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_DOSILICON        0xE5
+
+static SPINAND_OP_VARIANTS(read_cache_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_4S_OP(0, 1, NULL, 0, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_2S_OP(0, 1, NULL, 0, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_FAST_1S_1S_1S_OP(0, 1, NULL, 0, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_1S_OP(0, 1, NULL, 0, 0));
+
+static SPINAND_OP_VARIANTS(write_cache_variants,
+		SPINAND_PROG_LOAD_1S_1S_4S_OP(true, 0, NULL, 0),
+		SPINAND_PROG_LOAD_1S_1S_1S_OP(true, 0, NULL, 0));
+
+static SPINAND_OP_VARIANTS(update_cache_variants,
+		SPINAND_PROG_LOAD_1S_1S_4S_OP(false, 0, NULL, 0),
+		SPINAND_PROG_LOAD_1S_1S_1S_OP(false, 0, NULL, 0));
+
+static int ds35xx_ooblayout_ecc(struct mtd_info *mtd, int section,
+				struct mtd_oob_region *region)
+{
+	if (section > 3)
+		return -ERANGE;
+
+	region->offset = 8 + (section * 16);
+	region->length = 8;
+
+	return 0;
+}
+
+static int ds35xx_ooblayout_free(struct mtd_info *mtd, int section,
+				 struct mtd_oob_region *region)
+{
+	if (section > 3)
+		return -ERANGE;
+
+	if (section == 0) {
+		/* reserve 2 bytes for the BBM */
+		region->offset = 2;
+		region->length = 6;
+	} else {
+		region->offset = section * 16;
+		region->length = 8;
+	}
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops ds35xx_ooblayout = {
+	.ecc = ds35xx_ooblayout_ecc,
+	.free = ds35xx_ooblayout_free,
+};
+
+static const struct spinand_info dosilicon_spinand_table[] = {
+	SPINAND_INFO("DS35Q1GA",
+		SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x71),
+		NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
+		NAND_ECCREQ(4, 512),
+		SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					 &write_cache_variants,
+					 &update_cache_variants),
+		SPINAND_HAS_QE_BIT,
+		SPINAND_ECCINFO(&ds35xx_ooblayout, NULL)),
+	SPINAND_INFO("DS35M1GA",
+		SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x21),
+		NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
+		NAND_ECCREQ(4, 512),
+		SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					 &write_cache_variants,
+					 &update_cache_variants),
+		SPINAND_HAS_QE_BIT,
+		SPINAND_ECCINFO(&ds35xx_ooblayout, NULL)),
+};
+
+static const struct spinand_manufacturer_ops dosilicon_spinand_manuf_ops = {
+};
+
+const struct spinand_manufacturer dosilicon_spinand_manufacturer = {
+	.id = SPINAND_MFR_DOSILICON,
+	.name = "Dosilicon",
+	.chips = dosilicon_spinand_table,
+	.nchips = ARRAY_SIZE(dosilicon_spinand_table),
+	.ops = &dosilicon_spinand_manuf_ops,
+};
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -360,6 +360,7 @@ struct spinand_manufacturer {
 /* SPI NAND manufacturers */
 extern const struct spinand_manufacturer alliancememory_spinand_manufacturer;
 extern const struct spinand_manufacturer ato_spinand_manufacturer;
+extern const struct spinand_manufacturer dosilicon_spinand_manufacturer;
 extern const struct spinand_manufacturer esmt_8c_spinand_manufacturer;
 extern const struct spinand_manufacturer esmt_c8_spinand_manufacturer;
 extern const struct spinand_manufacturer etron_spinand_manufacturer;
