From 1a50e3612de9187857f55ee14a573f7f8e7d4ebc Mon Sep 17 00:00:00 2001
From: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Date: Tue, 3 Dec 2024 11:46:50 +0900
Subject: [PATCH] mtd: spinand: Add support for SkyHigh S35ML-3 family

SkyHigh S35ML01G300, S35ML01G301, S35ML02G300, and S35ML04G300 are 1Gb,
2Gb, and 4Gb SLC SPI NAND flash family. This family of devices has
on-die ECC which parity bits are stored to hidden area. In this family
the on-die ECC cannot be disabled so raw access needs to be prevented.

Link: https://www.skyhighmemory.com/download/SPI_S35ML01_04G3_002_19205.pdf?v=P
Co-developed-by: KR Kim <kr.kim@skyhighmemory.com>
Signed-off-by: KR Kim <kr.kim@skyhighmemory.com>
Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/spi/Makefile  |   2 +-
 drivers/mtd/nand/spi/core.c    |   1 +
 drivers/mtd/nand/spi/skyhigh.c | 147 +++++++++++++++++++++++++++++++++
 include/linux/mtd/spinand.h    |   1 +
 4 files changed, 150 insertions(+), 1 deletion(-)
 create mode 100644 drivers/mtd/nand/spi/skyhigh.c

--- a/drivers/mtd/nand/spi/Makefile
+++ b/drivers/mtd/nand/spi/Makefile
@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 spinand-objs := core.o alliancememory.o ato.o esmt.o fmsh.o foresee.o gigadevice.o macronix.o
-spinand-objs += micron.o paragon.o toshiba.o winbond.o xtx.o
+spinand-objs += micron.o paragon.o skyhigh.o toshiba.o winbond.o xtx.o
 obj-$(CONFIG_MTD_SPI_NAND) += spinand.o
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1183,6 +1183,7 @@ static const struct spinand_manufacturer
 	&macronix_spinand_manufacturer,
 	&micron_spinand_manufacturer,
 	&paragon_spinand_manufacturer,
+	&skyhigh_spinand_manufacturer,
 	&toshiba_spinand_manufacturer,
 	&winbond_spinand_manufacturer,
 	&xtx_spinand_manufacturer,
--- /dev/null
+++ b/drivers/mtd/nand/spi/skyhigh.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 SkyHigh Memory Limited
+ *
+ * Author: Takahiro Kuwano <takahiro.kuwano@infineon.com>
+ * Co-Author: KR Kim <kr.kim@skyhighmemory.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_SKYHIGH			0x01
+#define SKYHIGH_STATUS_ECC_1TO2_BITFLIPS	(1 << 4)
+#define SKYHIGH_STATUS_ECC_3TO6_BITFLIPS	(2 << 4)
+#define SKYHIGH_STATUS_ECC_UNCOR_ERROR		(3 << 4)
+#define SKYHIGH_CONFIG_PROTECT_EN		BIT(1)
+
+static SPINAND_OP_VARIANTS(read_cache_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_QUADIO_OP(0, 4, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_X4_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_DUALIO_OP(0, 2, 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 skyhigh_spinand_ooblayout_ecc(struct mtd_info *mtd, int section,
+					 struct mtd_oob_region *region)
+{
+	/* ECC bytes are stored in hidden area. */
+	return -ERANGE;
+}
+
+static int skyhigh_spinand_ooblayout_free(struct mtd_info *mtd, int section,
+					  struct mtd_oob_region *region)
+{
+	if (section)
+		return -ERANGE;
+
+	/* ECC bytes are stored in hidden area. Reserve 2 bytes for the BBM. */
+	region->offset = 2;
+	region->length = mtd->oobsize - 2;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops skyhigh_spinand_ooblayout = {
+	.ecc = skyhigh_spinand_ooblayout_ecc,
+	.free = skyhigh_spinand_ooblayout_free,
+};
+
+static int skyhigh_spinand_ecc_get_status(struct spinand_device *spinand,
+					  u8 status)
+{
+	switch (status & STATUS_ECC_MASK) {
+	case STATUS_ECC_NO_BITFLIPS:
+		return 0;
+
+	case SKYHIGH_STATUS_ECC_UNCOR_ERROR:
+		return -EBADMSG;
+
+	case SKYHIGH_STATUS_ECC_1TO2_BITFLIPS:
+		return 2;
+
+	case SKYHIGH_STATUS_ECC_3TO6_BITFLIPS:
+		return 6;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static const struct spinand_info skyhigh_spinand_table[] = {
+	SPINAND_INFO("S35ML01G301",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x15),
+		     NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
+		     NAND_ECCREQ(6, 32),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_NO_RAW_ACCESS,
+		     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
+				     skyhigh_spinand_ecc_get_status)),
+	SPINAND_INFO("S35ML01G300",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x14),
+		     NAND_MEMORG(1, 2048, 128, 64, 1024, 20, 1, 1, 1),
+		     NAND_ECCREQ(6, 32),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_NO_RAW_ACCESS,
+		     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
+				     skyhigh_spinand_ecc_get_status)),
+	SPINAND_INFO("S35ML02G300",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x25),
+		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 2, 1, 1),
+		     NAND_ECCREQ(6, 32),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_NO_RAW_ACCESS,
+		     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
+				     skyhigh_spinand_ecc_get_status)),
+	SPINAND_INFO("S35ML04G300",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x35),
+		     NAND_MEMORG(1, 2048, 128, 64, 4096, 80, 2, 1, 1),
+		     NAND_ECCREQ(6, 32),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_NO_RAW_ACCESS,
+		     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
+				     skyhigh_spinand_ecc_get_status)),
+};
+
+static int skyhigh_spinand_init(struct spinand_device *spinand)
+{
+	/*
+	 * Config_Protect_En (bit 1 in Block Lock register) must be set to 1
+	 * before writing other bits. Do it here before core unlocks all blocks
+	 * by writing block protection bits.
+	 */
+	return spinand_write_reg_op(spinand, REG_BLOCK_LOCK,
+				    SKYHIGH_CONFIG_PROTECT_EN);
+}
+
+static const struct spinand_manufacturer_ops skyhigh_spinand_manuf_ops = {
+	.init = skyhigh_spinand_init,
+};
+
+const struct spinand_manufacturer skyhigh_spinand_manufacturer = {
+	.id = SPINAND_MFR_SKYHIGH,
+	.name = "SkyHigh",
+	.chips = skyhigh_spinand_table,
+	.nchips = ARRAY_SIZE(skyhigh_spinand_table),
+	.ops = &skyhigh_spinand_manuf_ops,
+};
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -269,6 +269,7 @@ extern const struct spinand_manufacturer
 extern const struct spinand_manufacturer macronix_spinand_manufacturer;
 extern const struct spinand_manufacturer micron_spinand_manufacturer;
 extern const struct spinand_manufacturer paragon_spinand_manufacturer;
+extern const struct spinand_manufacturer skyhigh_spinand_manufacturer;
 extern const struct spinand_manufacturer toshiba_spinand_manufacturer;
 extern const struct spinand_manufacturer winbond_spinand_manufacturer;
 extern const struct spinand_manufacturer xtx_spinand_manufacturer;
