[PATCH v2] mtd: spinand: Add support for Etron EM73D044VCx

[Bert Vermeulen <bert@biot.com>]

This adds a new vendor Etron, and support for a 2Gb chip.

The datasheet is available at
https://www.etron.com/cn/products/EM73%5B8%5DC%5BD_E_F%5DVC%20SPI%20NAND%20Flash_Promotion_Rev%201_00A.pdf

Signed-off-by: Bert Vermeulen <bert@biot.com>
---
v2:
- Made ooblayout_free/_ecc depend on chip-specific parameters, instead of
  hardcoded to this 2Gb chip only
- Fixed manufacturer ordering
- Fixed minor formatting issues as reported
- Removed debug comment

 drivers/mtd/nand/spi/Makefile |   2 +-
 drivers/mtd/nand/spi/core.c   |   1 +
 drivers/mtd/nand/spi/etron.c  | 104 ++++++++++++++++++++++++++++++++++
 include/linux/mtd/spinand.h   |   1 +
 4 files changed, 107 insertions(+), 1 deletion(-)
 create mode 100644 drivers/mtd/nand/spi/etron.c

diff --git a/drivers/mtd/nand/spi/Makefile b/drivers/mtd/nand/spi/Makefile
index 9662b9c1d5a9..cc3c4e046ea9 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 etron.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 446ba8d43fbc..2cbf25b8caa2 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -894,6 +894,7 @@ static const struct nand_ops spinand_ops = {
 };
 
 static const struct spinand_manufacturer *spinand_manufacturers[] = {
+	&etron_spinand_manufacturer,
 	&gigadevice_spinand_manufacturer,
 	&macronix_spinand_manufacturer,
 	&micron_spinand_manufacturer,
diff --git a/drivers/mtd/nand/spi/etron.c b/drivers/mtd/nand/spi/etron.c
new file mode 100644
index 000000000000..1a92b9cf3043
--- /dev/null
+++ b/drivers/mtd/nand/spi/etron.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_ETRON			0xd5
+
+static SPINAND_OP_VARIANTS(read_cache_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_QUADIO_OP(0, 1, 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 etron_oob_spare(struct mtd_info *mtd)
+{
+	if (mtd->size < 0x10000000)
+		return mtd->oobsize / 2;
+	else
+		return mtd->oobsize / 2 + mtd->oobsize / 16;
+}
+
+static int etron_ooblayout_ecc(struct mtd_info *mtd, int section,
+					struct mtd_oob_region *oobregion)
+{
+	if (section)
+		return -ERANGE;
+
+	oobregion->offset = etron_oob_spare(mtd);
+	oobregion->length = mtd->oobsize - oobregion->offset;
+
+	return 0;
+}
+
+static int etron_ooblayout_free(struct mtd_info *mtd, int section,
+			   struct mtd_oob_region *oobregion)
+{
+	if (section)
+		return -ERANGE;
+
+	oobregion->offset = 2;
+	oobregion->length = etron_oob_spare(mtd) - 2;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops etron_ooblayout = {
+	.ecc = etron_ooblayout_ecc,
+	.free = etron_ooblayout_free,
+};
+
+static int etron_ecc_get_status(struct spinand_device *spinand, u8 status)
+{
+	switch (status & STATUS_ECC_MASK) {
+	case STATUS_ECC_NO_BITFLIPS:
+		return 0;
+
+	case STATUS_ECC_HAS_BITFLIPS:
+		/* Between 1-7 bitflips were corrected */
+		return 7;
+
+	case STATUS_ECC_MASK:
+		/* Maximum bitflips were corrected */
+		return 8;
+
+	case STATUS_ECC_UNCOR_ERROR:
+		return -EBADMSG;
+	}
+
+	return -EINVAL;
+}
+
+static const struct spinand_info etron_spinand_table[] = {
+	SPINAND_INFO("EM73D044VCx",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_ADDR, 0x1f),
+		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&etron_ooblayout, etron_ecc_get_status)),
+};
+
+static const struct spinand_manufacturer_ops etron_spinand_manuf_ops = {
+};
+
+const struct spinand_manufacturer etron_spinand_manufacturer = {
+	.id = SPINAND_MFR_ETRON,
+	.name = "Etron",
+	.chips = etron_spinand_table,
+	.nchips = ARRAY_SIZE(etron_spinand_table),
+	.ops = &etron_spinand_manuf_ops,
+};
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 6988956b8492..d7c0a0439652 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 etron_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;
-- 
2.25.1