mtd: spinand: rework detect procedure for different READ_ID operation

Currently there are 3 different variants of read_id implementation:
1. opcode only. Found in GD5FxGQ4xF.
2. opcode + 1 addr byte. Found in GD5GxGQ4xA/E
3. opcode + 1 dummy byte. Found in other currently supported chips.

Original implementation was for variant 1 and let detect function
of chips with variant 2 and 3 to ignore the first byte. This isn't
robust:

1. For chips of variant 2, if SPI master doesn't keep MOSI low
during read, chip will get a random id offset, and the entire id
buffer will shift by that offset, causing detect failure.

2. For chips of variant 1, if it happens to get a devid that equals
to manufacture id of variant 2 or 3 chips, it'll get incorrectly
detected.

This patch reworks detect procedure to address problems above. New
logic do detection for all variants separatedly, in 1-2-3 order.
Since all current detect methods do exactly the same id matching
procedure, unify them into core.c and remove detect method from
manufacture_ops.

Tested on GD5F1GQ4UAYIG and W25N01GVZEIG.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200208074439.146296-1-gch981213@gmail.com

1 files changed, 4 insertions, 22 deletions

diff --git a/drivers/mtd/nand/spi/micron.c b/drivers/mtd/nand/spi/micron.c
index 7d7b1f7fcf71..f56f81325e10 100644
--- a/drivers/mtd/nand/spi/micron.c
+++ b/drivers/mtd/nand/spi/micron.c
@@ -91,7 +91,8 @@ static int mt29f2g01abagd_ecc_get_status(struct spinand_device *spinand,
 }
 
 static const struct spinand_info micron_spinand_table[] = {
-	SPINAND_INFO("MT29F2G01ABAGD", 0x24,
+	SPINAND_INFO("MT29F2G01ABAGD",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x24),
 		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 2, 1, 1),
 		     NAND_ECCREQ(8, 512),
 		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
@@ -102,32 +103,13 @@ static const struct spinand_info micron_spinand_table[] = {
 				     mt29f2g01abagd_ecc_get_status)),
 };
 
-static int micron_spinand_detect(struct spinand_device *spinand)
-{
-	u8 *id = spinand->id.data;
-	int ret;
-
-	/*
-	 * Micron SPI NAND read ID need a dummy byte,
-	 * so the first byte in raw_id is dummy.
-	 */
-	if (id[1] != SPINAND_MFR_MICRON)
-		return 0;
-
-	ret = spinand_match_and_init(spinand, micron_spinand_table,
-				     ARRAY_SIZE(micron_spinand_table), id[2]);
-	if (ret)
-		return ret;
-
-	return 1;
-}
-
 static const struct spinand_manufacturer_ops micron_spinand_manuf_ops = {
-	.detect = micron_spinand_detect,
 };
 
 const struct spinand_manufacturer micron_spinand_manufacturer = {
 	.id = SPINAND_MFR_MICRON,
 	.name = "Micron",
+	.chips = micron_spinand_table,
+	.nchips = ARRAY_SIZE(micron_spinand_table),
 	.ops = &micron_spinand_manuf_ops,
 };