[PATCH] mtd: nand: spi: Support GigaDevice GD5F1GQ5UExxG

[Reto Schneider]

From: Reto Schneider <reto.schneider at husqvarnagroup.com>

The relevant changes to the already existing GD5F1GQ4UExxG support has
been determined by consulting the GigaDevice product change notice
AN-0392-10, version 1.0 from November 30, 2020.

As the overlaps are huge, variable names have been generalized
accordingly.

Apart form the lowered ECC strength (4 instead of 8 bits per 512 bytes),
the new device ID, and the extra quad IO dummy byte, no changes had to
be taken into account.

New hardware features are not supported, namely:
 - Power on reset
 - Unique ID
 - Double transfer rate (DTR)
 - Parameter page
 - Random data quad IO

The inverted semantic of the "driver strength" register bits, defaulting
to 100% instead of 50% for the Q5 devices, got ignored as the driver has
never touched them anyway.

The no longer supported "read from cache during block erase"
functionality I do not know how to reflect.

Implementation has been tested on MediaTek MT7688 based GARDENA smart
Gateways using both, GigaDevice GD5F1GQ5UEYIG and GD5F1GQ4UBYIG.

Signed-off-by: Reto Schneider <reto.schneider at husqvarnagroup.com>
---
 drivers/mtd/nand/spi/gigadevice.c | 69 +++++++++++++++++++++++++++----
 1 file changed, 60 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/spi/gigadevice.c b/drivers/mtd/nand/spi/gigadevice.c
index 33c67403c4aa..1dd1c5898093 100644
--- a/drivers/mtd/nand/spi/gigadevice.c
+++ b/drivers/mtd/nand/spi/gigadevice.c
@@ -13,7 +13,10 @@
 #define GD5FXGQ4XA_STATUS_ECC_1_7_BITFLIPS	(1 << 4)
 #define GD5FXGQ4XA_STATUS_ECC_8_BITFLIPS	(3 << 4)
 
-#define GD5FXGQ4UEXXG_REG_STATUS2		0xf0
+#define GD5FXGQ5XE_STATUS_ECC_1_4_BITFLIPS	(1 << 4)
+#define GD5FXGQ5XE_STATUS_ECC_4_BITFLIPS	(3 << 4)
+
+#define GD5FXGQXXEXXG_REG_STATUS2		0xf0
 
 #define GD5FXGQ4UXFXXG_STATUS_ECC_MASK		(7 << 4)
 #define GD5FXGQ4UXFXXG_STATUS_ECC_NO_BITFLIPS	(0 << 4)
@@ -102,7 +105,7 @@ static int gd5fxgq4xa_ecc_get_status(struct spinand_device *spinand,
 	return -EINVAL;
 }
 
-static int gd5fxgq4_variant2_ooblayout_ecc(struct mtd_info *mtd, int section,
+static int gd5fxgqx_variant2_ooblayout_ecc(struct mtd_info *mtd, int section,
 				       struct mtd_oob_region *region)
 {
 	if (section)
@@ -114,7 +117,7 @@ static int gd5fxgq4_variant2_ooblayout_ecc(struct mtd_info *mtd, int section,
 	return 0;
 }
 
-static int gd5fxgq4_variant2_ooblayout_free(struct mtd_info *mtd, int section,
+static int gd5fxgqx_variant2_ooblayout_free(struct mtd_info *mtd, int section,
 					struct mtd_oob_region *region)
 {
 	if (section)
@@ -127,9 +130,10 @@ static int gd5fxgq4_variant2_ooblayout_free(struct mtd_info *mtd, int section,
 	return 0;
 }
 
-static const struct mtd_ooblayout_ops gd5fxgq4_variant2_ooblayout = {
-	.ecc = gd5fxgq4_variant2_ooblayout_ecc,
-	.free = gd5fxgq4_variant2_ooblayout_free,
+/* Valid for Q4/Q5 and Q6 (untested) devices */
+static const struct mtd_ooblayout_ops gd5fxgqx_variant2_ooblayout = {
+	.ecc = gd5fxgqx_variant2_ooblayout_ecc,
+	.free = gd5fxgqx_variant2_ooblayout_free,
 };
 
 static int gd5fxgq4xc_ooblayout_256_ecc(struct mtd_info *mtd, int section,
@@ -165,7 +169,7 @@ static int gd5fxgq4uexxg_ecc_get_status(struct spinand_device *spinand,
 					u8 status)
 {
 	u8 status2;
-	struct spi_mem_op op = SPINAND_GET_FEATURE_OP(GD5FXGQ4UEXXG_REG_STATUS2,
+	struct spi_mem_op op = SPINAND_GET_FEATURE_OP(GD5FXGQXXEXXG_REG_STATUS2,
 						      &status2);
 	int ret;
 
@@ -203,6 +207,43 @@ static int gd5fxgq4uexxg_ecc_get_status(struct spinand_device *spinand,
 	return -EINVAL;
 }
 
+static int gd5fxgq5xexxg_ecc_get_status(struct spinand_device *spinand,
+					u8 status)
+{
+	u8 status2;
+	struct spi_mem_op op = SPINAND_GET_FEATURE_OP(GD5FXGQXXEXXG_REG_STATUS2,
+						      &status2);
+	int ret;
+
+	switch (status & STATUS_ECC_MASK) {
+	case STATUS_ECC_NO_BITFLIPS:
+		return 0;
+
+	case GD5FXGQ5XE_STATUS_ECC_1_4_BITFLIPS:
+		/*
+		 * Read status2 register to determine a more fine grained
+		 * bit error status
+		 */
+		ret = spi_mem_exec_op(spinand->spimem, &op);
+		if (ret)
+			return ret;
+
+		/*
+		 * 1 ... 4 bits are flipped (and corrected)
+		 */
+		/* bits sorted this way (1...0): ECCSE1, ECCSE0 */
+		return ((status2 & STATUS_ECC_MASK) >> 4) + 1;
+
+	case STATUS_ECC_UNCOR_ERROR:
+		return -EBADMSG;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
 static int gd5fxgq4ufxxg_ecc_get_status(struct spinand_device *spinand,
 					u8 status)
 {
@@ -282,7 +323,7 @@ static const struct spinand_info gigadevice_spinand_table[] = {
 					      &write_cache_variants,
 					      &update_cache_variants),
 		     SPINAND_HAS_QE_BIT,
-		     SPINAND_ECCINFO(&gd5fxgq4_variant2_ooblayout,
+		     SPINAND_ECCINFO(&gd5fxgqx_variant2_ooblayout,
 				     gd5fxgq4uexxg_ecc_get_status)),
 	SPINAND_INFO("GD5F1GQ4UFxxG",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE, 0xb1, 0x48),
@@ -292,8 +333,18 @@ static const struct spinand_info gigadevice_spinand_table[] = {
 					      &write_cache_variants,
 					      &update_cache_variants),
 		     SPINAND_HAS_QE_BIT,
-		     SPINAND_ECCINFO(&gd5fxgq4_variant2_ooblayout,
+		     SPINAND_ECCINFO(&gd5fxgqx_variant2_ooblayout,
 				     gd5fxgq4ufxxg_ecc_get_status)),
+	SPINAND_INFO("GD5F1GQ5UExxG",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x51),
+		     NAND_MEMORG(1, 2048, 128, 64, 1024, 20, 1, 1, 1),
+		     NAND_ECCREQ(4, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&gd5fxgqx_variant2_ooblayout,
+				     gd5fxgq5xexxg_ecc_get_status)),
 };
 
 static const struct spinand_manufacturer_ops gigadevice_spinand_manuf_ops = {

base-commit: 92bf22614b21a2706f4993b278017e437f7785b3
-- 
2.29.2