[PATCH v3 1/2] mtd: spi-nor: Add support for MX25L12833F and MX25L12845G

[Cheng Ming Lin <linchengming884@gmail.com>]

From: Cheng Ming Lin <chengminglin@mxic.com.tw>

Add support for Macronix MX25L12833F and MX25L12845G SPI NOR flashes.
These parts share the same JEDEC ID (0xc2, 0x20, 0x18) as the legacy
MX25L12805D.

The newer flashes support SFDP and 1-4-4 Page Program in 3-byte address
mode, but this 4PP capability is not defined in their SFDP tables.
Conversely, the legacy MX25L12805D lacks SFDP support entirely and does
not support 4PP.

To safely enable 4PP for the newer flashes without breaking the legacy
part, introduce a post_sfdp fixup. Since the legacy MX25L12805D does
not support SFDP, it falls back to static parameters and will never
execute the post_sfdp hook. The newer flashes will successfully parse
the SFDP, trigger the hook, and safely append the SNOR_HWCAPS_PP_1_4_4
capability.

Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>
---
 drivers/mtd/spi-nor/macronix.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/macronix.c b/drivers/mtd/spi-nor/macronix.c
index e97f5cbd9..1adb79832 100644
--- a/drivers/mtd/spi-nor/macronix.c
+++ b/drivers/mtd/spi-nor/macronix.c
@@ -83,6 +83,25 @@ mx25l3255e_late_init_fixups(struct spi_nor *nor)
 	return 0;
 }
 
+static int
+mx25l12805d_4pp3b_post_sfdp_fixups(struct spi_nor *nor)
+{
+	struct spi_nor_flash_parameter *params = nor->params;
+
+	/*
+	 * JEDEC ID 0xc22018 is shared by MX25L12805D (no SFDP, no 4PP) and
+	 * MX25L12833F/MX25L12845G (support SFDP and 4PP in 3-byte mode).
+	 * The legacy 05D lacks SFDP and will not execute this hook. For
+	 * the newer flashes, 3-byte 1-4-4 PP is not defined in SFDP, so
+	 * we safely enable it here.
+	 */
+	params->hwcaps.mask |= SNOR_HWCAPS_PP_1_4_4;
+	spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP_1_4_4],
+				SPINOR_OP_PP_1_4_4, SNOR_PROTO_1_4_4);
+
+	return 0;
+}
+
 static const struct spi_nor_fixups mx25l25635_fixups = {
 	.post_bfpt = mx25l25635_post_bfpt_fixups,
 	.post_sfdp = macronix_qpp4b_post_sfdp_fixups,
@@ -96,6 +115,10 @@ static const struct spi_nor_fixups mx25l3255e_fixups = {
 	.late_init = mx25l3255e_late_init_fixups,
 };
 
+static const struct spi_nor_fixups mx25l12805d_4pp3b_fixups = {
+	.post_sfdp = mx25l12805d_4pp3b_post_sfdp_fixups,
+};
+
 static const struct flash_info macronix_nor_parts[] = {
 	{
 		.id = SNOR_ID(0xc2, 0x20, 0x10),
@@ -130,9 +153,10 @@ static const struct flash_info macronix_nor_parts[] = {
 		.size = SZ_8M,
 		.no_sfdp_flags = SECT_4K,
 	}, {
-		/* MX25L12805D */
+		/* MX25L12805D, MX25L12833F, MX25L12845G */
 		.id = SNOR_ID(0xc2, 0x20, 0x18),
 		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_4BIT_BP,
+		.fixups = &mx25l12805d_4pp3b_fixups,
 	}, {
 		/* MX25L25635E, MX25L25645G */
 		.id = SNOR_ID(0xc2, 0x20, 0x19),
-- 
2.25.1