mtd: spinand: Add support for ATO25D1GA

Add support for the ATO25D1GA SPI NAND flash.

Datasheet:
- https://atta.szlcsc.com/upload/public/pdf/source/20191212/C469320_04599D67B03B078044EB65FF5AEDDDE9.pdf

Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220604113250.4745-1-aidanmacdonald.0x0@gmail.com

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 xtx.o
+spinand-objs := core.o ato.o gigadevice.o macronix.o micron.o paragon.o toshiba.o winbond.o xtx.o
 obj-$(CONFIG_MTD_SPI_NAND) += spinand.o

drivers/mtd/nand/spi/ato.c

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Aidan MacDonald
+ *
+ * Author: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+
+#define SPINAND_MFR_ATO		0x9b
+
+
+static SPINAND_OP_VARIANTS(read_cache_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_X4_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 ato25d1ga_ooblayout_ecc(struct mtd_info *mtd, int section,
+				   struct mtd_oob_region *region)
+{
+	if (section > 3)
+		return -ERANGE;
+
+	region->offset = (16 * section) + 8;
+	region->length = 8;
+	return 0;
+}
+
+static int ato25d1ga_ooblayout_free(struct mtd_info *mtd, int section,
+				   struct mtd_oob_region *region)
+{
+	if (section > 3)
+		return -ERANGE;
+
+	if (section) {
+		region->offset = (16 * section);
+		region->length = 8;
+	} else {
+		/* first byte of section 0 is reserved for the BBM */
+		region->offset = 1;
+		region->length = 7;
+	}
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops ato25d1ga_ooblayout = {
+	.ecc = ato25d1ga_ooblayout_ecc,
+	.free = ato25d1ga_ooblayout_free,
+};
+
+
+static const struct spinand_info ato_spinand_table[] = {
+	SPINAND_INFO("ATO25D1GA",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_ADDR, 0x12),
+		     NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
+		     NAND_ECCREQ(1, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&ato25d1ga_ooblayout, NULL)),
+};
+
+static const struct spinand_manufacturer_ops ato_spinand_manuf_ops = {
+};
+
+const struct spinand_manufacturer ato_spinand_manufacturer = {
+	.id = SPINAND_MFR_ATO,
+	.name = "ATO",
+	.chips = ato_spinand_table,
+	.nchips = ARRAY_SIZE(ato_spinand_table),
+	.ops = &ato_spinand_manuf_ops,
+};

drivers/mtd/nand/spi/core.c

@@ -927,6 +927,7 @@ static const struct nand_ops spinand_ops = {
 };
 
 static const struct spinand_manufacturer *spinand_manufacturers[] = {
+	&ato_spinand_manufacturer,
 	&gigadevice_spinand_manufacturer,
 	&macronix_spinand_manufacturer,
 	&micron_spinand_manufacturer,

include/linux/mtd/spinand.h

@@ -260,6 +260,7 @@ struct spinand_manufacturer {
 };
 
 /* SPI NAND manufacturers */
+extern const struct spinand_manufacturer ato_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;