From 5f284dc15ca8695d0394414045ac64616a3b0e69 Mon Sep 17 00:00:00 2001
From: Tianling Shen <cnsztl@gmail.com>
Date: Mon, 25 Aug 2025 01:00:13 +0800
Subject: [PATCH] mtd: spinand: add support for FudanMicro FM25S01A

Add support for FudanMicro FM25S01A SPI NAND.
Datasheet: http://eng.fmsh.com/nvm/FM25S01A_ds_eng.pdf

Signed-off-by: Tianling Shen <cnsztl@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/spi/Makefile |  2 +-
 drivers/mtd/nand/spi/core.c   |  1 +
 drivers/mtd/nand/spi/fmsh.c   | 74 +++++++++++++++++++++++++++++++++++
 include/linux/mtd/spinand.h   |  1 +
 4 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 drivers/mtd/nand/spi/fmsh.c

--- a/drivers/mtd/nand/spi/Makefile
+++ b/drivers/mtd/nand/spi/Makefile
@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-spinand-objs := core.o alliancememory.o ato.o esmt.o foresee.o gigadevice.o macronix.o
+spinand-objs := core.o alliancememory.o ato.o esmt.o fmsh.o foresee.o gigadevice.o macronix.o
 spinand-objs += micron.o paragon.o toshiba.o 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
@@ -943,6 +943,7 @@ static const struct spinand_manufacturer
 	&alliancememory_spinand_manufacturer,
 	&ato_spinand_manufacturer,
 	&esmt_c8_spinand_manufacturer,
+	&fmsh_spinand_manufacturer,
 	&foresee_spinand_manufacturer,
 	&gigadevice_spinand_manufacturer,
 	&macronix_spinand_manufacturer,
--- /dev/null
+++ b/drivers/mtd/nand/spi/fmsh.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020-2021 Rockchip Electronics Co., Ltd.
+ *
+ * Author: Dingqiang Lin <jon.lin@rock-chips.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_FMSH		0xA1
+
+static SPINAND_OP_VARIANTS(read_cache_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_QUADIO_OP(0, 2, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_X4_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_DUALIO_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_X2_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_OP(true, 0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_OP(false, 0, 1, NULL, 0));
+
+static SPINAND_OP_VARIANTS(write_cache_variants,
+		SPINAND_PROG_LOAD_X4(true, 0, NULL, 0),
+		SPINAND_PROG_LOAD(true, 0, NULL, 0));
+
+static SPINAND_OP_VARIANTS(update_cache_variants,
+		SPINAND_PROG_LOAD_X4(false, 0, NULL, 0),
+		SPINAND_PROG_LOAD(false, 0, NULL, 0));
+
+static int fm25s01a_ooblayout_ecc(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *region)
+{
+	return -ERANGE;
+}
+
+static int fm25s01a_ooblayout_free(struct mtd_info *mtd, int section,
+				   struct mtd_oob_region *region)
+{
+	if (section)
+		return -ERANGE;
+
+	region->offset = 2;
+	region->length = 62;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops fm25s01a_ooblayout = {
+	.ecc = fm25s01a_ooblayout_ecc,
+	.free = fm25s01a_ooblayout_free,
+};
+
+static const struct spinand_info fmsh_spinand_table[] = {
+	SPINAND_INFO("FM25S01A",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xE4),
+		     NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
+		     NAND_ECCREQ(1, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&fm25s01a_ooblayout, NULL)),
+};
+
+static const struct spinand_manufacturer_ops fmsh_spinand_manuf_ops = {
+};
+
+const struct spinand_manufacturer fmsh_spinand_manufacturer = {
+	.id = SPINAND_MFR_FMSH,
+	.name = "Fudan Micro",
+	.chips = fmsh_spinand_table,
+	.nchips = ARRAY_SIZE(fmsh_spinand_table),
+	.ops = &fmsh_spinand_manuf_ops,
+};
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -263,6 +263,7 @@ struct spinand_manufacturer {
 extern const struct spinand_manufacturer alliancememory_spinand_manufacturer;
 extern const struct spinand_manufacturer ato_spinand_manufacturer;
 extern const struct spinand_manufacturer esmt_c8_spinand_manufacturer;
+extern const struct spinand_manufacturer fmsh_spinand_manufacturer;
 extern const struct spinand_manufacturer foresee_spinand_manufacturer;
 extern const struct spinand_manufacturer gigadevice_spinand_manufacturer;
 extern const struct spinand_manufacturer macronix_spinand_manufacturer;
