[PATCH 2/4] mtd: spi-nor: sfdp: read disable-quad-mode property

[Hsin-Yi Wang <hsinyi@chromium.org>]

Some flash devices, eg. gd25lq64c, enable quad mode by default after
spi_nor_parse_bfpt(). However, the systems using these flash devices may
required the quad mode to be turned off to use write protection or to
avoid a potential short issue[1].

Add a disable-quad-mode property in devicetree that system can use it to
override the quad mode status parsed from BFPT.

[1]https://www.elm-tech.com/ja/products/spi-flash-memory/gd25lq64/gd25lq64.pdf
page 13

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 drivers/mtd/spi-nor/core.c    | 5 +++++
 drivers/mtd/spi-nor/core.h    | 1 +
 drivers/mtd/spi-nor/debugfs.c | 1 +
 3 files changed, 7 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 614960c7d22cc..dcf4ff46c37ae 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2847,6 +2847,11 @@ static void spi_nor_init_flags(struct spi_nor *nor)
 	if (of_property_read_bool(np, "no-wp"))
 		nor->flags |= SNOR_F_NO_WP;
 
+	if (of_property_read_bool(np, "disable-quad-mode")) {
+		nor->flags |= SNOR_F_DISABLE_QUAD;
+		nor->params->quad_enable = NULL;
+	}
+
 	if (flags & SPI_NOR_SWP_IS_VOLATILE)
 		nor->flags |= SNOR_F_SWP_IS_VOLATILE;
 
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 9217379b9cfef..b06bd97668f3a 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -133,6 +133,7 @@ enum spi_nor_option_flags {
 	SNOR_F_RWW		= BIT(14),
 	SNOR_F_ECC		= BIT(15),
 	SNOR_F_NO_WP		= BIT(16),
+	SNOR_F_DISABLE_QUAD	= BIT(17),
 };
 
 struct spi_nor_read_command {
diff --git a/drivers/mtd/spi-nor/debugfs.c b/drivers/mtd/spi-nor/debugfs.c
index 6e163cb5b478c..c17451ae0931a 100644
--- a/drivers/mtd/spi-nor/debugfs.c
+++ b/drivers/mtd/spi-nor/debugfs.c
@@ -28,6 +28,7 @@ static const char *const snor_f_names[] = {
 	SNOR_F_NAME(RWW),
 	SNOR_F_NAME(ECC),
 	SNOR_F_NAME(NO_WP),
+	SNOR_F_NAME(DISABLE_QUAD),
 };
 #undef SNOR_F_NAME
 
-- 
2.41.0.694.ge786442a9b-goog