From: Ziyang Huang <hzyitc@outlook.com>
To: miquel.raynal@bootlin.com
Subject: [PATCH v3] mtd: spinand: fmsh: add support for FM25G{01,02}B
Date: Sun, 31 May 2026 21:05:17 +0800

Add support for FudanMicro FM25G01B SPI NAND and FudanMicro FM25G02B SPI
NAND.

FM25G01B datasheet: https://www.fmsh.com/nvm/FM25G01B_ds_eng.pdf
FM25G02B datasheet: https://www.fmsh.com/nvm/FM25G02B_ds_eng.pdf

Signed-off-by: Ziyang Huang <hzyitc@outlook.com>
Link: https://lore.kernel.org/all/SEYPR01MB58821E380C5DD8F7B3FFDA23C9142@SEYPR01MB5882.apcprd01.prod.exchangelabs.com/
[Fix chip names in the commit message, mask macro in the switch operator]
Signed-off-by: Mikhail Zhilkin <csharper2005@gmail.com>
---
Changes since v2:
  More verbose commit message.
  Use only one section in fm25g01b_ooblayout_free().

Changes since v1:
  Fix copy-paste issue. (Correct FM25G01B size.)

 drivers/mtd/nand/spi/fmsh.c | 96 +++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

--- a/drivers/mtd/nand/spi/fmsh.c
+++ b/drivers/mtd/nand/spi/fmsh.c
@@ -9,6 +9,16 @@
 #include <linux/kernel.h>
 #include <linux/mtd/spinand.h>
 
+#define FM25G01B_STATUS_ECC_MASK		(7 << 4)
+	#define FM25G01B_STATUS_ECC_NO_BITFLIPS		(0 << 4)
+	#define FM25G01B_STATUS_ECC_1_3_BITFLIPS	(1 << 4)
+	#define FM25G01B_STATUS_ECC_4_BITFLIPS		(2 << 4)
+	#define FM25G01B_STATUS_ECC_5_BITFLIPS		(3 << 4)
+	#define FM25G01B_STATUS_ECC_6_BITFLIPS		(4 << 4)
+	#define FM25G01B_STATUS_ECC_7_BITFLIPS		(5 << 4)
+	#define FM25G01B_STATUS_ECC_8_BITFLIPS		(6 << 4)
+	#define FM25G01B_STATUS_ECC_UNCOR_ERROR		(7 << 4)
+
 #define FM25S01BI3_STATUS_ECC_MASK		(7 << 4)
 	#define FM25S01BI3_STATUS_ECC_NO_BITFLIPS	(0 << 4)
 	#define FM25S01BI3_STATUS_ECC_1_3_BITFLIPS	(1 << 4)
@@ -34,6 +44,67 @@ static SPINAND_OP_VARIANTS(update_cache_
 		SPINAND_PROG_LOAD_1S_1S_4S_OP(false, 0, NULL, 0),
 		SPINAND_PROG_LOAD_1S_1S_1S_OP(false, 0, NULL, 0));
 
+
+static int fm25g01b_ooblayout_ecc(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *region)
+{
+	if (section)
+		return -ERANGE;
+
+	region->offset = 64;
+	region->length = 64;
+
+	return 0;
+}
+
+static int fm25g01b_ooblayout_free(struct mtd_info *mtd, int section,
+				   struct mtd_oob_region *region)
+{
+	if (section)
+		return -ERANGE;
+
+	/* reserve 2 bytes for the BBM */
+	region->offset = 2;
+	region->length = 62;
+
+	return 0;
+}
+
+static int fm25g01b_ecc_get_status(struct spinand_device *spinand,
+				   u8 status)
+{
+	switch (status & FM25G01B_STATUS_ECC_MASK) {
+	case FM25G01B_STATUS_ECC_NO_BITFLIPS:
+		return 0;
+
+	case FM25G01B_STATUS_ECC_1_3_BITFLIPS:
+		return 3;
+
+	case FM25G01B_STATUS_ECC_4_BITFLIPS:
+		return 4;
+
+	case FM25G01B_STATUS_ECC_5_BITFLIPS:
+		return 5;
+
+	case FM25G01B_STATUS_ECC_6_BITFLIPS:
+		return 6;
+
+	case FM25G01B_STATUS_ECC_7_BITFLIPS:
+		return 7;
+
+	case FM25G01B_STATUS_ECC_8_BITFLIPS:
+		return 8;
+
+	case FM25G01B_STATUS_ECC_UNCOR_ERROR:
+		return -EBADMSG;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
 static int fm25s01a_ooblayout_ecc(struct mtd_info *mtd, int section,
 				  struct mtd_oob_region *region)
 {
@@ -102,6 +173,11 @@ static int fm25s01bi3_ooblayout_free(str
 	return 0;
 }
 
+static const struct mtd_ooblayout_ops fm25g01b_ooblayout = {
+	.ecc = fm25g01b_ooblayout_ecc,
+	.free = fm25g01b_ooblayout_free,
+};
+
 static const struct mtd_ooblayout_ops fm25s01a_ooblayout = {
 	.ecc = fm25s01a_ooblayout_ecc,
 	.free = fm25s01a_ooblayout_free,
@@ -113,6 +189,26 @@ static const struct mtd_ooblayout_ops fm
 };
 
 static const struct spinand_info fmsh_spinand_table[] = {
+	SPINAND_INFO("FM25G01B",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xd1),
+		     NAND_MEMORG(1, 2048, 128, 64, 1024, 21, 1, 1, 1),
+		     NAND_ECCREQ(8, 528),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&fm25g01b_ooblayout,
+				     fm25g01b_ecc_get_status)),
+	SPINAND_INFO("FM25G02B",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xd2),
+		     NAND_MEMORG(1, 2048, 128, 64, 2048, 41, 1, 1, 1),
+		     NAND_ECCREQ(8, 528),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&fm25g01b_ooblayout,
+				     fm25g01b_ecc_get_status)),
 	SPINAND_INFO("FM25S01A",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xE4),
 		     NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
