[RFC PATCH v1 6/6] mtd: spi-nor: introduce support for displaying deprecation message

[Michael Walle <mwalle@kernel.org>]

SPI-NOR will automatically detect the attached flash device most of the
time. We cannot easily find out if boards are using a given flash.
Therefore, introduce a (temporary) flag to display a message on boot if
support for a given flash device is scheduled to be removed in the
future.

Signed-off-by: Michael Walle <mwalle@kernel.org>
---
 drivers/mtd/spi-nor/core.c | 12 ++++++++++++
 drivers/mtd/spi-nor/core.h |  1 +
 2 files changed, 13 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 58d310427d35..a294eef2e34a 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3312,6 +3312,7 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor,
 						       const char *name)
 {
 	const struct flash_info *jinfo = NULL, *info = NULL;
+	const char *deprecated = NULL;
 
 	if (name)
 		info = spi_nor_match_name(nor, name);
@@ -3326,6 +3327,17 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor,
 			return jinfo;
 	}
 
+	if (info && (info->flags & SPI_NOR_DEPRECATED))
+		deprecated = info->name;
+	else if (jinfo && (jinfo->flags & SPI_NOR_DEPRECATED))
+		deprecated = jinfo->name;
+
+	if (deprecated)
+		pr_warn("Your board or device tree is using a SPI NOR flash (%s) with\n"
+			"deprecated driver support. It will be removed in future kernel\n"
+			"version. If you feel this shouldn't be the case, please contact\n"
+			"us at linux-mtd@lists.infradead.org\n", deprecated);
+
 	/*
 	 * If caller has specified name of flash model that can normally be
 	 * detected using JEDEC, let's verify it.
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 8552e31b1b07..0317d8e253f4 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -524,6 +524,7 @@ struct flash_info {
 #define SPI_NOR_NO_ERASE		BIT(6)
 #define SPI_NOR_QUAD_PP			BIT(8)
 #define SPI_NOR_RWW			BIT(9)
+#define SPI_NOR_DEPRECATED		BIT(15)
 
 	u8 no_sfdp_flags;
 #define SPI_NOR_SKIP_SFDP		BIT(0)
-- 
2.39.2