1 files changed, 77 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/nand_toshiba.c b/drivers/mtd/nand/raw/nand_toshiba.c
new file mode 100644
index 000000000..ab43f027c
--- /dev/null
+++ b/drivers/mtd/nand/raw/nand_toshiba.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2017 Free Electrons
+ * Copyright (C) 2017 NextThing Co
+ *
+ * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/mtd/rawnand.h>
+
+static void toshiba_nand_decode_id(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	nand_decode_ext_id(chip);
+
+	/*
+	 * Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
+	 * 512B page. For Toshiba SLC, we decode the 5th/6th byte as
+	 * follows:
+	 * - ID byte 6, bits[2:0]: 100b -> 43nm, 101b -> 32nm,
+	 *                         110b -> 24nm
+	 * - ID byte 5, bit[7]:    1 -> BENAND, 0 -> raw SLC
+	 */
+	if (chip->id.len >= 6 && nand_is_slc(chip) &&
+	    (chip->id.data[5] & 0x7) == 0x6 /* 24nm */ &&
+	    !(chip->id.data[4] & 0x80) /* !BENAND */)
+		mtd->oobsize = 32 * mtd->writesize >> 9;
+
+	/*
+	 * Extract ECC requirements from 6th id byte.
+	 * For Toshiba SLC, ecc requrements are as follows:
+	 *  - 43nm: 1 bit ECC for each 512Byte is required.
+	 *  - 32nm: 4 bit ECC for each 512Byte is required.
+	 *  - 24nm: 8 bit ECC for each 512Byte is required.
+	 */
+	if (chip->id.len >= 6 && nand_is_slc(chip)) {
+		chip->ecc_step_ds = 512;
+		switch (chip->id.data[5] & 0x7) {
+		case 0x4:
+			chip->ecc_strength_ds = 1;
+			break;
+		case 0x5:
+			chip->ecc_strength_ds = 4;
+			break;
+		case 0x6:
+			chip->ecc_strength_ds = 8;
+			break;
+		default:
+			WARN(1, "Could not get ECC info");
+			chip->ecc_step_ds = 0;
+			break;
+		}
+	}
+}
+
+static int toshiba_nand_init(struct nand_chip *chip)
+{
+	if (nand_is_slc(chip))
+		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
+
+	return 0;
+}
+
+const struct nand_manufacturer_ops toshiba_nand_manuf_ops = {
+	.detect = toshiba_nand_decode_id,
+	.init = toshiba_nand_init,
+};