mtd: spinand: add support for ESMT F50x1G41LB

Adaptation of Linux commit d74c36480a67

This patch adds support for ESMT F50L1G41LB and F50D1G41LB.
It seems that ESMT likes to use random JEDEC ID from other vendors.
Their 1G chips uses 0xc8 from GigaDevice and 2G/4G chips uses 0x2c from
Micron. For this reason, the ESMT entry is named esmt_c8 with explicit
JEDEC ID in variable name.

Datasheets:
https://www.esmt.com.tw/upload/pdf/ESMT/datasheets/F50L1G41LB(2M).pdf
https://www.esmt.com.tw/upload/pdf/ESMT/datasheets/F50D1G41LB(2M).pdf

Signed-off-by: Igor Prusov <ivprusov@salutedevices.com>
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Signed-off-by: Martin Kurbanov <mmkurbanov@sberdevices.ru>
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Tested-by: Martin Kurbanov <mmkurbanov@sberdevices.ru>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/mtd/nand/spi/esmt.c b/drivers/mtd/nand/spi/esmt.c
new file mode 100644
index 0000000..7e07b26
--- /dev/null
+++ b/drivers/mtd/nand/spi/esmt.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author:
+ *	Chuanhong Guo <gch981213@gmail.com> - the main driver logic
+ *	Martin Kurbanov <mmkurbanov@sberdevices.ru> - OOB layout
+ */
+
+#ifndef __UBOOT__
+#include <linux/device.h>
+#include <linux/kernel.h>
+#endif
+#include <linux/mtd/spinand.h>
+
+/* ESMT uses GigaDevice 0xc8 JECDEC ID on some SPI NANDs */
+#define SPINAND_MFR_ESMT_C8			0xc8
+
+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_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));
+
+/*
+ * OOB spare area map (64 bytes)
+ *
+ * Bad Block Markers
+ * filled by HW and kernel                 Reserved
+ *   |                 +-----------------------+-----------------------+
+ *   |                 |                       |                       |
+ *   |                 |    OOB free data Area |non ECC protected      |
+ *   |   +-------------|-----+-----------------|-----+-----------------|-----+
+ *   |   |             |     |                 |     |                 |     |
+ * +-|---|----------+--|-----|--------------+--|-----|--------------+--|-----|--------------+
+ * | |   | section0 |  |     |    section1  |  |     |    section2  |  |     |    section3  |
+ * +-v-+-v-+---+----+--v--+--v--+-----+-----+--v--+--v--+-----+-----+--v--+--v--+-----+-----+
+ * |   |   |   |    |     |     |     |     |     |     |     |     |     |     |     |     |
+ * |0:1|2:3|4:7|8:15|16:17|18:19|20:23|24:31|32:33|34:35|36:39|40:47|48:49|50:51|52:55|56:63|
+ * |   |   |   |    |     |     |     |     |     |     |     |     |     |     |     |     |
+ * +---+---+-^-+--^-+-----+-----+--^--+--^--+-----+-----+--^--+--^--+-----+-----+--^--+--^--+
+ *           |    |                |     |                 |     |                 |     |
+ *           |    +----------------|-----+-----------------|-----+-----------------|-----+
+ *           |             ECC Area|(Main + Spare) - filled|by ESMT NAND HW        |
+ *           |                     |                       |                       |
+ *           +---------------------+-----------------------+-----------------------+
+ *                         OOB ECC protected Area - not used due to
+ *                         partial programming from some filesystems
+ *                             (like JFFS2 with cleanmarkers)
+ */
+
+#define ESMT_OOB_SECTION_COUNT			4
+#define ESMT_OOB_SECTION_SIZE(nand) \
+	(nanddev_per_page_oobsize(nand) / ESMT_OOB_SECTION_COUNT)
+#define ESMT_OOB_FREE_SIZE(nand) \
+	(ESMT_OOB_SECTION_SIZE(nand) / 2)
+#define ESMT_OOB_ECC_SIZE(nand) \
+	(ESMT_OOB_SECTION_SIZE(nand) - ESMT_OOB_FREE_SIZE(nand))
+#define ESMT_OOB_BBM_SIZE			2
+
+static int f50l1g41lb_ooblayout_ecc(struct mtd_info *mtd, int section,
+				    struct mtd_oob_region *region)
+{
+	struct nand_device *nand = mtd_to_nanddev(mtd);
+
+	if (section >= ESMT_OOB_SECTION_COUNT)
+		return -ERANGE;
+
+	region->offset = section * ESMT_OOB_SECTION_SIZE(nand) +
+			 ESMT_OOB_FREE_SIZE(nand);
+	region->length = ESMT_OOB_ECC_SIZE(nand);
+
+	return 0;
+}
+
+static int f50l1g41lb_ooblayout_free(struct mtd_info *mtd, int section,
+				     struct mtd_oob_region *region)
+{
+	struct nand_device *nand = mtd_to_nanddev(mtd);
+
+	if (section >= ESMT_OOB_SECTION_COUNT)
+		return -ERANGE;
+
+	/*
+	 * Reserve space for bad blocks markers (section0) and
+	 * reserved bytes (sections 1-3)
+	 */
+	region->offset = section * ESMT_OOB_SECTION_SIZE(nand) + 2;
+
+	/* Use only 2 non-protected ECC bytes per each OOB section */
+	region->length = 2;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops f50l1g41lb_ooblayout = {
+	.ecc = f50l1g41lb_ooblayout_ecc,
+	.rfree = f50l1g41lb_ooblayout_free,
+};
+
+static const struct spinand_info esmt_c8_spinand_table[] = {
+	SPINAND_INFO("F50L1G41LB",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_ADDR, 0x01),
+		     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),
+		     0,
+		     SPINAND_ECCINFO(&f50l1g41lb_ooblayout, NULL)),
+	SPINAND_INFO("F50D1G41LB",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_ADDR, 0x11),
+		     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),
+		     0,
+		     SPINAND_ECCINFO(&f50l1g41lb_ooblayout, NULL)),
+};
+
+static const struct spinand_manufacturer_ops esmt_spinand_manuf_ops = {
+};
+
+const struct spinand_manufacturer esmt_c8_spinand_manufacturer = {
+	.id = SPINAND_MFR_ESMT_C8,
+	.name = "ESMT",
+	.chips = esmt_c8_spinand_table,
+	.nchips = ARRAY_SIZE(esmt_c8_spinand_table),
+	.ops = &esmt_spinand_manuf_ops,
+};