[PATCH v6 11/21] mtd: spi-nor-core: prepare BFPT parsing for JESD216 rev D

[Pratyush Yadav]

JESD216 rev D makes BFPT 20 DWORDs. Update the BFPT size define to
reflect that.

The check for rev A or later compared the BFPT header length with the
maximum BFPT length, BFPT_DWORD_MAX. Since BFPT_DWORD_MAX was 16, and so
was the BFPT length for both rev A and B, this check worked fine. But
now, since BFPT_DWORD_MAX is 20, it means this check will also stop BFPT
parsing for rev A or B, since their length is 16.

So, instead check for BFPT_DWORD_MAX_JESD216 to stop BFPT parsing for
the first JESD216 version, and check for BFPT_DWORD_MAX_JESD216B for the
next two versions.

Signed-off-by: Pratyush Yadav <p.yadav at ti.com>
---
 drivers/mtd/spi/spi-nor-core.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 8eead6a89b..c7a453aac9 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -77,14 +77,15 @@ struct sfdp_header {
 /* Basic Flash Parameter Table */
 
 /*
- * JESD216 rev B defines a Basic Flash Parameter Table of 16 DWORDs.
+ * JESD216 rev D defines a Basic Flash Parameter Table of 20 DWORDs.
  * They are indexed from 1 but C arrays are indexed from 0.
  */
 #define BFPT_DWORD(i)		((i) - 1)
-#define BFPT_DWORD_MAX		16
+#define BFPT_DWORD_MAX		20
 
 /* The first version of JESB216 defined only 9 DWORDs. */
 #define BFPT_DWORD_MAX_JESD216			9
+#define BFPT_DWORD_MAX_JESD216B			16
 
 /* 1st DWORD. */
 #define BFPT_DWORD1_FAST_READ_1_1_2		BIT(16)
@@ -1992,7 +1993,7 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 	}
 
 	/* Stop here if not JESD216 rev A or later. */
-	if (bfpt_header->length < BFPT_DWORD_MAX)
+	if (bfpt_header->length == BFPT_DWORD_MAX_JESD216)
 		return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt,
 						params);
 
@@ -2027,6 +2028,11 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 		return -EINVAL;
 	}
 
+	/* Stop here if JESD216 rev B. */
+	if (bfpt_header->length == BFPT_DWORD_MAX_JESD216B)
+		return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt,
+						params);
+
 	return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt, params);
 }
 
-- 
2.27.0