[PATCH v7 4/5] mtd: nand: spi: Add initial support for Micron MT29F2G01ABAGD

[Boris Brezillon <boris.brezillon@bootlin.com>]

From: Peter Pan <peterpandong@micron.com>

Add a basic driver for Micron SPI NANDs. Only one device is supported
right now, but the driver will be extended to support more devices
afterwards.

Signed-off-by: Peter Pan <peterpandong@micron.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
---
 drivers/mtd/nand/spi/Makefile |   2 +-
 drivers/mtd/nand/spi/core.c   |  17 ++++++
 drivers/mtd/nand/spi/micron.c | 133 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/spinand.h   |   3 +
 4 files changed, 154 insertions(+), 1 deletion(-)
 create mode 100644 drivers/mtd/nand/spi/micron.c

diff --git a/drivers/mtd/nand/spi/Makefile b/drivers/mtd/nand/spi/Makefile
index feb79a1d1b46..79a1f1e79221 100644
--- a/drivers/mtd/nand/spi/Makefile
+++ b/drivers/mtd/nand/spi/Makefile
@@ -1,2 +1,2 @@
-spinand-objs := core.o
+spinand-objs := core.o micron.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 faad9bc93775..a4b8906d7084 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -767,8 +767,25 @@ static const struct nand_ops spinand_ops = {
 	.isbad = spinand_isbad,
 };
 
+static const struct spinand_manufacturer *spinand_manufacturers[] = {
+	&micron_spinand_manufacturer,
+};
+
 static int spinand_manufacturer_detect(struct spinand_device *spinand)
 {
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(spinand_manufacturers); i++) {
+		ret = spinand_manufacturers[i]->ops->detect(spinand);
+		if (ret > 0) {
+			spinand->manufacturer = spinand_manufacturers[i];
+			return 0;
+		} else if (ret < 0) {
+			return ret;
+		}
+	}
+
 	return -ENOTSUPP;
 }
 
diff --git a/drivers/mtd/nand/spi/micron.c b/drivers/mtd/nand/spi/micron.c
new file mode 100644
index 000000000000..9c4381d6847b
--- /dev/null
+++ b/drivers/mtd/nand/spi/micron.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016-2017 Micron Technology, Inc.
+ *
+ * Authors:
+ *	Peter Pan <peterpandong@micron.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_MICRON		0x2c
+
+#define MICRON_STATUS_ECC_MASK		GENMASK(7, 4)
+#define MICRON_STATUS_ECC_NO_BITFLIPS	(0 << 4)
+#define MICRON_STATUS_ECC_1TO3_BITFLIPS	(1 << 4)
+#define MICRON_STATUS_ECC_4TO6_BITFLIPS	(3 << 4)
+#define MICRON_STATUS_ECC_7TO8_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 mt29f2g01abagd_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 mt29f2g01abagd_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 const struct mtd_ooblayout_ops mt29f2g01abagd_ooblayout = {
+	.ecc = mt29f2g01abagd_ooblayout_ecc,
+	.free = mt29f2g01abagd_ooblayout_free,
+};
+
+static int mt29f2g01abagd_ecc_get_status(struct spinand_device *spinand,
+					 u8 status)
+{
+	switch (status & MICRON_STATUS_ECC_MASK) {
+	case STATUS_ECC_NO_BITFLIPS:
+		return 0;
+
+	case STATUS_ECC_UNCOR_ERROR:
+		return -EBADMSG;
+
+	case MICRON_STATUS_ECC_1TO3_BITFLIPS:
+		return 3;
+
+	case MICRON_STATUS_ECC_4TO6_BITFLIPS:
+		return 6;
+
+	case MICRON_STATUS_ECC_7TO8_BITFLIPS:
+		return 8;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static const struct spinand_info micron_spinand_table[] = {
+	SPINAND_INFO("MT29F2G01ABAGD", 0x24,
+		     NAND_MEMORG(1, 2048, 128, 64, 2048, 2, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     0,
+		     SPINAND_ECCINFO(&mt29f2g01abagd_ooblayout,
+				     mt29f2g01abagd_ecc_get_status)),
+};
+
+static int micron_spinand_detect(struct spinand_device *spinand)
+{
+	u8 *id = spinand->id.data;
+	int ret;
+
+	/*
+	 * Micron SPI NAND read ID need a dummy byte,
+	 * so the first byte in raw_id is dummy.
+	 */
+	if (id[1] != SPINAND_MFR_MICRON)
+		return 0;
+
+	ret = spinand_match_and_init(spinand, micron_spinand_table,
+				     ARRAY_SIZE(micron_spinand_table), id[2]);
+	if (ret)
+		return ret;
+
+	return 1;
+}
+
+static const struct spinand_manufacturer_ops micron_spinand_manuf_ops = {
+	.detect = micron_spinand_detect,
+};
+
+const struct spinand_manufacturer micron_spinand_manufacturer = {
+	.id = SPINAND_MFR_MICRON,
+	.name = "Micron",
+	.ops = &micron_spinand_manuf_ops,
+};
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 17a4584c0017..11a18c1993e8 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -192,6 +192,9 @@ struct spinand_manufacturer {
 	const struct spinand_manufacturer_ops *ops;
 };
 
+/* SPI NAND manufacturers */
+extern const struct spinand_manufacturer micron_spinand_manufacturer;
+
 /**
  * struct spinand_op_variants - SPI NAND operation variants
  * @ops: the list of variants for a given operation
-- 
2.14.1