[PATCH] mtd: spinand: add support for ESMT F50x1G41LB

[Chuanhong Guo]

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 at gmail.com>
---
 drivers/mtd/nand/spi/Makefile |  2 +-
 drivers/mtd/nand/spi/core.c   |  1 +
 drivers/mtd/nand/spi/esmt.c   | 96 +++++++++++++++++++++++++++++++++++
 include/linux/mtd/spinand.h   |  1 +
 4 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 drivers/mtd/nand/spi/esmt.c

diff --git a/drivers/mtd/nand/spi/Makefile b/drivers/mtd/nand/spi/Makefile
index 9662b9c1d5a9..7e3ab8a9aec7 100644
--- 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
+spinand-objs := core.o esmt.o gigadevice.o macronix.o micron.o paragon.o toshiba.o winbond.o
 obj-$(CONFIG_MTD_SPI_NAND) += spinand.o
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index ff8336870bc0..6c5d79ec3501 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -927,6 +927,7 @@ static const struct nand_ops spinand_ops = {
 };
 
 static const struct spinand_manufacturer *spinand_manufacturers[] = {
+	&esmt_c8_spinand_manufacturer,
 	&gigadevice_spinand_manufacturer,
 	&macronix_spinand_manufacturer,
 	&micron_spinand_manufacturer,
diff --git a/drivers/mtd/nand/spi/esmt.c b/drivers/mtd/nand/spi/esmt.c
new file mode 100644
index 000000000000..79836c05f259
--- /dev/null
+++ b/drivers/mtd/nand/spi/esmt.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author:
+ *	Chuanhong Guo <gch981213 at 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
+
+#define F50L2G41XA_ECC_STATUS_MASK		GENMASK(6, 4)
+#define F50L2G41XA_STATUS_ECC_1_3_BITFLIPS	(1 << 4)
+#define F50L2G41XA_STATUS_ECC_4_6_BITFLIPS	(3 << 4)
+#define F50L2G41XA_STATUS_ECC_7_8_BITFLIPS	(5 << 4)
+
+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, 0x7f,
+				0x7f, 0x7f),
+		     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, 0x7f,
+				0x7f, 0x7f),
+		     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,
+};
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 3aa28240a77f..e19a1554a1e9 100644
--- 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;
-- 
2.35.1