--- /dev/null
+From a43b844cb40bf1b783055fdc81b7f991e21e7e76 Mon Sep 17 00:00:00 2001
+From: Chuanhong Guo <gch981213@gmail.com>
+Date: Wed, 13 Apr 2022 11:58:17 +0800
+Subject: [PATCH] mtd: spinand: add support for ESMT F50x1G41LB
+
+This patch adds support for ESMT F50L1G41LB and F50D1G41LB.
+It seems that ESMT likes to use random JEDEC ID from other vendors.
+Their 1G chips uses 0xc8 from GigaDevice and 2G/4G chips uses 0x2c from
+Micron. For this reason, the ESMT entry is named esmt_c8 with explicit
+JEDEC ID in variable name.
+
+Datasheets:
+https://www.esmt.com.tw/upload/pdf/ESMT/datasheets/F50L1G41LB(2M).pdf
+https://www.esmt.com.tw/upload/pdf/ESMT/datasheets/F50D1G41LB(2M).pdf
+
+Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
+---
+ drivers/mtd/nand/spi/Makefile | 2 +-
+ drivers/mtd/nand/spi/core.c | 1 +
+ drivers/mtd/nand/spi/esmt.c | 89 +++++++++++++++++++++++++++++++++++
+ include/linux/mtd/spinand.h | 1 +
+ 4 files changed, 92 insertions(+), 1 deletion(-)
+ create mode 100644 drivers/mtd/nand/spi/esmt.c
+
+--- a/drivers/mtd/nand/spi/Makefile
++++ b/drivers/mtd/nand/spi/Makefile
+@@ -1,3 +1,3 @@
+ # SPDX-License-Identifier: GPL-2.0
+-spinand-objs := core.o gigadevice.o macronix.o micron.o paragon.o toshiba.o winbond.o xtx.o
++spinand-objs := core.o esmt.o gigadevice.o macronix.o 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
+@@ -896,6 +896,7 @@ static const struct nand_ops spinand_ops
+ };
+
+ static const struct spinand_manufacturer *spinand_manufacturers[] = {
++ &esmt_c8_spinand_manufacturer,
+ &gigadevice_spinand_manufacturer,
+ ¯onix_spinand_manufacturer,
+ µn_spinand_manufacturer,
+--- /dev/null
++++ b/drivers/mtd/nand/spi/esmt.c
+@@ -0,0 +1,89 @@
++// SPDX-License-Identifier: GPL-2.0
++/*
++ * Author:
++ * Chuanhong Guo <gch981213@gmail.com>
++ */
++
++#include <linux/device.h>
++#include <linux/kernel.h>
++#include <linux/mtd/spinand.h>
++
++/* ESMT uses GigaDevice 0xc8 JECDEC ID on some SPI NANDs */
++#define SPINAND_MFR_ESMT_C8 0xc8
++
++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 f50l1g41lb_ooblayout_ecc(struct mtd_info *mtd, int section,
++ struct mtd_oob_region *region)
++{
++ if (section > 3)
++ return -ERANGE;
++
++ region->offset = 16 * section + 8;
++ region->length = 8;
++
++ return 0;
++}
++
++static int f50l1g41lb_ooblayout_free(struct mtd_info *mtd, int section,
++ struct mtd_oob_region *region)
++{
++ if (section > 3)
++ return -ERANGE;
++
++ region->offset = 16 * section + 2;
++ region->length = 6;
++
++ return 0;
++}
++
++static const struct mtd_ooblayout_ops f50l1g41lb_ooblayout = {
++ .ecc = f50l1g41lb_ooblayout_ecc,
++ .free = f50l1g41lb_ooblayout_free,
++};
++
++static const struct spinand_info esmt_c8_spinand_table[] = {
++ SPINAND_INFO("F50L1G41LB",
++ SPINAND_ID(SPINAND_READID_METHOD_OPCODE_ADDR, 0x01),
++ 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),
++ 0,
++ SPINAND_ECCINFO(&f50l1g41lb_ooblayout, NULL)),
++ SPINAND_INFO("F50D1G41LB",
++ SPINAND_ID(SPINAND_READID_METHOD_OPCODE_ADDR, 0x11),
++ 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),
++ 0,
++ SPINAND_ECCINFO(&f50l1g41lb_ooblayout, NULL)),
++};
++
++static const struct spinand_manufacturer_ops esmt_spinand_manuf_ops = {
++};
++
++const struct spinand_manufacturer esmt_c8_spinand_manufacturer = {
++ .id = SPINAND_MFR_ESMT_C8,
++ .name = "ESMT",
++ .chips = esmt_c8_spinand_table,
++ .nchips = ARRAY_SIZE(esmt_c8_spinand_table),
++ .ops = &esmt_spinand_manuf_ops,
++};
+--- a/include/linux/mtd/spinand.h
++++ b/include/linux/mtd/spinand.h
+@@ -260,6 +260,7 @@ struct spinand_manufacturer {
+ };
+
+ /* SPI NAND manufacturers */
++extern const struct spinand_manufacturer esmt_c8_spinand_manufacturer;
+ extern const struct spinand_manufacturer gigadevice_spinand_manufacturer;
+ extern const struct spinand_manufacturer macronix_spinand_manufacturer;
+ extern const struct spinand_manufacturer micron_spinand_manufacturer;