[PATCH v4 4/6] mtd: spi-nor: macronix: Handle ID collision b/w MX25L12805D and MX25L12835F

[Tudor Ambarus]

Macronix has a bad habbit of reusing flash IDs. While MX25L12835F supports
RDSFDP opcode, MX25L12805D does not. Given that it is unlikely that RDSFDP
will cause any problems for the old MX25L12805D, differentiate between the
two flashes by parsing SFDP.

cc: Heiko Thiery <heiko.thiery at gmail.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus at microchip.com>
Acked-by: Pratyush Yadav <p.yadav at ti.com>
---
# cat /sys/devices/platform/soc at 0/30800000.bus/30bb0000.spi/spi_master/spi0/spi0
.0/spi-nor/sfdp | xxd -p
53464450000101ff00000109300000ffc2000104600000ffffffffffffff
ffffffffffffffffffffffffffffffffffffe520f1ffffffff0744eb086b
083b04bbfeffffffffff00ffffff44eb0c200f5210d800ffffffffffffff
ffffffffffff003600279df9c06485cbffffffffffff

 drivers/mtd/spi-nor/macronix.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/macronix.c b/drivers/mtd/spi-nor/macronix.c
index 2754bbef3d2e..45c2f2c50e56 100644
--- a/drivers/mtd/spi-nor/macronix.c
+++ b/drivers/mtd/spi-nor/macronix.c
@@ -26,6 +26,24 @@ static const struct spi_nor_fixups mx25l3205d_fixups = {
 	.post_bfpt = mx25l3205d_post_bfpt_fixups,
 };
 
+static int mx25l12805d_post_bfpt_fixups(struct spi_nor *nor,
+				const struct sfdp_parameter_header *bfpt_header,
+				const struct sfdp_bfpt *bfpt)
+{
+	/*
+	 * Macronix has a bad habit of reusing flash IDs: MX25L12835F collides
+	 * with MX25L12805D. MX25L12835F defines SFDP tables, while the older
+	 * variant does not.
+	 */
+	nor->name = "mx25l12835f";
+
+	return 0;
+}
+
+static const struct spi_nor_fixups mx25l12805d_fixups = {
+	.post_bfpt = mx25l12805d_post_bfpt_fixups,
+};
+
 static int
 mx25l25635_post_bfpt_fixups(struct spi_nor *nor,
 			    const struct sfdp_parameter_header *bfpt_header,
@@ -82,8 +100,11 @@ static const struct flash_info macronix_nor_parts[] = {
 	{ "mx25u6435f",  INFO(0xc22537, 0, 64 * 1024, 128)
 		NO_SFDP_FLAGS(SECT_4K) },
 	{ "mx25l12805d", INFO(0xc22018, 0, 64 * 1024, 256)
+		/* ID collision with mx25l12835f. */
+		PARSE_SFDP
 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_4BIT_BP)
-		NO_SFDP_FLAGS(SECT_4K) },
+		NO_SFDP_FLAGS(SECT_4K)
+		.fixups = &mx25l12805d_fixups },
 	{ "mx25l12855e", INFO(0xc22618, 0, 64 * 1024, 256) },
 	{ "mx25r1635f",  INFO(0xc22815, 0, 64 * 1024,  32)
 		NO_SFDP_FLAGS(SECT_4K | SPI_NOR_DUAL_READ |
-- 
2.25.1