[PATCH v2] mtd: spinand: Add support for AllianceMemory AS5F34G04SND

[Mario Kicherer]

Add support for AllianceMemory AS5F34G04SND SPI NAND flash

Datasheet:
- https://www.alliancememory.com/wp-content/uploads/pdf/flash/AllianceMemory_SPI_NAND_Flash_July2020_Rev1.0.pdf

Signed-off-by: Mario Kicherer <dev at kicherer.org>
Reviewed-by: Dhruva Gole <d-gole at ti.com>
---
Changes since v1:
 - added missing email recipients, sorry for the noise!

 drivers/mtd/nand/spi/Makefile         |   2 +-
 drivers/mtd/nand/spi/alliancememory.c | 119 ++++++++++++++++++++++++++
 drivers/mtd/nand/spi/core.c           |   1 +
 include/linux/mtd/spinand.h           |   1 +
 4 files changed, 122 insertions(+), 1 deletion(-)
 create mode 100644 drivers/mtd/nand/spi/alliancememory.c

diff --git a/drivers/mtd/nand/spi/Makefile b/drivers/mtd/nand/spi/Makefile
index b520fe634041..4ec973b8b6bf 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 ato.o gigadevice.o macronix.o micron.o paragon.o toshiba.o winbond.o xtx.o
+spinand-objs := core.o alliancememory.o ato.o gigadevice.o macronix.o micron.o paragon.o toshiba.o winbond.o xtx.o
 obj-$(CONFIG_MTD_SPI_NAND) += spinand.o
diff --git a/drivers/mtd/nand/spi/alliancememory.c b/drivers/mtd/nand/spi/alliancememory.c
new file mode 100644
index 000000000000..7f4b90befd27
--- /dev/null
+++ b/drivers/mtd/nand/spi/alliancememory.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Mario Kicherer <dev at kicherer.org>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_ALLIANCEMEMORY	0x52
+
+#define AM_STATUS_ECC_BITMASK		(3 << 4)
+
+#define AM_STATUS_ECC_NONE_DETECTED	(0 << 4)
+#define AM_STATUS_ECC_1_CORRECTED	(1 << 4)
+#define AM_STATUS_ECC_1_DETECTED	(2 << 4)
+#define AM_STATUS_ECC_MAX_CORRECTED	(3 << 4)
+
+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 as5f34g04snd_ooblayout_ecc(struct mtd_info *mtd, int section,
+				      struct mtd_oob_region *region)
+{
+	if (section > 3)
+		return -ERANGE;
+
+	region->offset = 0x48;
+	region->length = 0x38;
+
+	return 0;
+}
+
+static int as5f34g04snd_ooblayout_free(struct mtd_info *mtd, int section,
+				       struct mtd_oob_region *region)
+{
+	if (section)
+		return -ERANGE;
+
+	/*
+	 * It is unclear how many bytes are used for the bad block marker. We
+	 * reserve one byte here.
+	 */
+
+	region->offset = 1;
+	region->length = 0x48 - 1;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops as5f34g04snd_ooblayout = {
+	.ecc = as5f34g04snd_ooblayout_ecc,
+	.free = as5f34g04snd_ooblayout_free,
+};
+
+static int am_ecc_get_status(struct spinand_device *spinand, u8 status)
+{
+	switch (status & AM_STATUS_ECC_BITMASK) {
+	case AM_STATUS_ECC_NONE_DETECTED:
+		return 0;
+
+	case AM_STATUS_ECC_1_CORRECTED:
+		return 1;
+
+	case AM_STATUS_ECC_MAX_CORRECTED:
+		return 8;
+
+	case AM_STATUS_ECC_1_DETECTED:
+		return -EBADMSG;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static const struct spinand_info alliancememory_spinand_table[] = {
+	SPINAND_INFO("AS5F34G04SND",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x2f),
+		     NAND_MEMORG(1, 2048, 128, 64, 4096, 80, 1, 1, 1),
+		     NAND_ECCREQ(4, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&as5f34g04snd_ooblayout,
+				     am_ecc_get_status)),
+};
+
+static int alliancememory_spinand_init(struct spinand_device *spinand)
+{
+	return 0;
+}
+
+static const struct spinand_manufacturer_ops alliancememory_spinand_manuf_ops = {
+	.init = alliancememory_spinand_init,
+};
+
+const struct spinand_manufacturer alliancememory_spinand_manufacturer = {
+	.id = SPINAND_MFR_ALLIANCEMEMORY,
+	.name = "AllianceMemory",
+	.chips = alliancememory_spinand_table,
+	.nchips = ARRAY_SIZE(alliancememory_spinand_table),
+	.ops = &alliancememory_spinand_manuf_ops,
+};
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index dacd9c0e8b20..638391f77d8c 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -937,6 +937,7 @@ static const struct nand_ops spinand_ops = {
 };
 
 static const struct spinand_manufacturer *spinand_manufacturers[] = {
+	&alliancememory_spinand_manufacturer,
 	&ato_spinand_manufacturer,
 	&gigadevice_spinand_manufacturer,
 	&macronix_spinand_manufacturer,
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 6d3392a7edc6..01be9f0f008a 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 alliancememory_spinand_manufacturer;
 extern const struct spinand_manufacturer ato_spinand_manufacturer;
 extern const struct spinand_manufacturer gigadevice_spinand_manufacturer;
 extern const struct spinand_manufacturer macronix_spinand_manufacturer;
-- 
2.34.1