mtd: spi-nand: Import Toshiba SPI-NAND support

Linux has good support for Toshiba SPI-NAND, so lets import it.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Tested-by: Luka Kovacic <luka.kovacic@sartura.hr>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/mtd/nand/spi/toshiba.c b/drivers/mtd/nand/spi/toshiba.c
new file mode 100644
index 0000000..571104a
--- /dev/null
+++ b/drivers/mtd/nand/spi/toshiba.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 exceet electronics GmbH
+ * Copyright (c) 2018 Kontron Electronics GmbH
+ *
+ * Author: Frieder Schrempf <frieder.schrempf@kontron.de>
+ */
+
+#ifndef __UBOOT__
+#include <malloc.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#endif
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_TOSHIBA		0x98
+#define TOSH_STATUS_ECC_HAS_BITFLIPS_T	(3 << 4)
+
+static SPINAND_OP_VARIANTS(read_cache_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_X4_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(true, 0, NULL, 0));
+
+static SPINAND_OP_VARIANTS(update_cache_variants,
+		SPINAND_PROG_LOAD(false, 0, NULL, 0));
+
+static int tc58cxgxsx_ooblayout_ecc(struct mtd_info *mtd, int section,
+				     struct mtd_oob_region *region)
+{
+	if (section > 0)
+		return -ERANGE;
+
+	region->offset = mtd->oobsize / 2;
+	region->length = mtd->oobsize / 2;
+
+	return 0;
+}
+
+static int tc58cxgxsx_ooblayout_free(struct mtd_info *mtd, int section,
+				      struct mtd_oob_region *region)
+{
+	if (section > 0)
+		return -ERANGE;
+
+	/* 2 bytes reserved for BBM */
+	region->offset = 2;
+	region->length = (mtd->oobsize / 2) - 2;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops tc58cxgxsx_ooblayout = {
+	.ecc = tc58cxgxsx_ooblayout_ecc,
+	.rfree = tc58cxgxsx_ooblayout_free,
+};
+
+static int tc58cxgxsx_ecc_get_status(struct spinand_device *spinand,
+				      u8 status)
+{
+	struct nand_device *nand = spinand_to_nand(spinand);
+	u8 mbf = 0;
+	struct spi_mem_op op = SPINAND_GET_FEATURE_OP(0x30, &mbf);
+
+	switch (status & STATUS_ECC_MASK) {
+	case STATUS_ECC_NO_BITFLIPS:
+		return 0;
+
+	case STATUS_ECC_UNCOR_ERROR:
+		return -EBADMSG;
+
+	case STATUS_ECC_HAS_BITFLIPS:
+	case TOSH_STATUS_ECC_HAS_BITFLIPS_T:
+		/*
+		 * Let's try to retrieve the real maximum number of bitflips
+		 * in order to avoid forcing the wear-leveling layer to move
+		 * data around if it's not necessary.
+		 */
+		if (spi_mem_exec_op(spinand->slave, &op))
+			return nand->eccreq.strength;
+
+		mbf >>= 4;
+
+		if (WARN_ON(mbf > nand->eccreq.strength || !mbf))
+			return nand->eccreq.strength;
+
+		return mbf;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static const struct spinand_info toshiba_spinand_table[] = {
+	/* 3.3V 1Gb */
+	SPINAND_INFO("TC58CVG0S3", 0xC2,
+		     NAND_MEMORG(1, 2048, 128, 64, 1024, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     0,
+		     SPINAND_ECCINFO(&tc58cxgxsx_ooblayout,
+				     tc58cxgxsx_ecc_get_status)),
+	/* 3.3V 2Gb */
+	SPINAND_INFO("TC58CVG1S3", 0xCB,
+		     NAND_MEMORG(1, 2048, 128, 64, 2048, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     0,
+		     SPINAND_ECCINFO(&tc58cxgxsx_ooblayout,
+				     tc58cxgxsx_ecc_get_status)),
+	/* 3.3V 4Gb */
+	SPINAND_INFO("TC58CVG2S0", 0xCD,
+		     NAND_MEMORG(1, 4096, 256, 64, 2048, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     0,
+		     SPINAND_ECCINFO(&tc58cxgxsx_ooblayout,
+				     tc58cxgxsx_ecc_get_status)),
+	/* 1.8V 1Gb */
+	SPINAND_INFO("TC58CYG0S3", 0xB2,
+		     NAND_MEMORG(1, 2048, 128, 64, 1024, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     0,
+		     SPINAND_ECCINFO(&tc58cxgxsx_ooblayout,
+				     tc58cxgxsx_ecc_get_status)),
+	/* 1.8V 2Gb */
+	SPINAND_INFO("TC58CYG1S3", 0xBB,
+		     NAND_MEMORG(1, 2048, 128, 64, 2048, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     0,
+		     SPINAND_ECCINFO(&tc58cxgxsx_ooblayout,
+				     tc58cxgxsx_ecc_get_status)),
+	/* 1.8V 4Gb */
+	SPINAND_INFO("TC58CYG2S0", 0xBD,
+		     NAND_MEMORG(1, 4096, 256, 64, 2048, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     0,
+		     SPINAND_ECCINFO(&tc58cxgxsx_ooblayout,
+				     tc58cxgxsx_ecc_get_status)),
+};
+
+static int toshiba_spinand_detect(struct spinand_device *spinand)
+{
+	u8 *id = spinand->id.data;
+	int ret;
+
+	/*
+	 * Toshiba SPI NAND read ID needs a dummy byte,
+	 * so the first byte in id is garbage.
+	 */
+	if (id[1] != SPINAND_MFR_TOSHIBA)
+		return 0;
+
+	ret = spinand_match_and_init(spinand, toshiba_spinand_table,
+				     ARRAY_SIZE(toshiba_spinand_table),
+				     id[2]);
+	if (ret)
+		return ret;
+
+	return 1;
+}
+
+static const struct spinand_manufacturer_ops toshiba_spinand_manuf_ops = {
+	.detect = toshiba_spinand_detect,
+};
+
+const struct spinand_manufacturer toshiba_spinand_manufacturer = {
+	.id = SPINAND_MFR_TOSHIBA,
+	.name = "Toshiba",
+	.ops = &toshiba_spinand_manuf_ops,
+};