[PATCH 2/2] mtd: spi-nor: spansion: Add a helper for ECC related initialization

[tkuw584924 at gmail.com]

From: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>

JFFS2 supports write buffer mode for ECC'd NOR flash such like SEMPER
flash family (s26hl/s25hs/s28hl/s28hs). To activate it,
MTD_BIT_WRITEABLE needs to be unset in mtd->flags.

In existing late_init() functions for SEMPER flash family,
params->writesize is set to 16 to avoid multiple programs in 16-byte ECC
data unit.

This patch adds a common cypress_nor_ecc_init() helper that takes care
for those ECC related initialization.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
---
 drivers/mtd/spi-nor/spansion.c | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
index 1678b7b2e9f7..9539968c4a6d 100644
--- a/drivers/mtd/spi-nor/spansion.c
+++ b/drivers/mtd/spi-nor/spansion.c
@@ -219,6 +219,22 @@ static int cypress_nor_set_page_size(struct spi_nor *nor)
 	return 0;
 }
 
+static void cypress_nor_ecc_init(struct spi_nor *nor)
+{
+	/*
+	 * Programming is supported only in 16-byte ECC data unit granularity.
+	 * Byte-programming, bit-walking, or multiple program operations to the
+	 * same ECC data unit without an erase are not allowed.
+	 */
+	nor->params->writesize = 16;
+
+	/*
+	 * Unset MTD_BIT_WRITEABLE to activate JFFS2 write buffer for ECC'd NOR
+	 * flash.
+	 */
+	nor->mtd.flags = MTD_CAP_NORFLASH & ~MTD_BIT_WRITEABLE;
+}
+
 static int
 s25fs256t_post_bfpt_fixup(struct spi_nor *nor,
 			  const struct sfdp_parameter_header *bfpt_header,
@@ -260,13 +276,7 @@ static void s25fs256t_post_sfdp_fixup(struct spi_nor *nor)
 
 static void s25fs256t_late_init(struct spi_nor *nor)
 {
-	/*
-	 * Programming is supported only in 16-byte ECC data unit granularity.
-	 * Byte-programming, bit-walking, or multiple program operations to the
-	 * same ECC data unit without an erase are not allowed. See chapter
-	 * 5.3.1 and 5.6 in the datasheet.
-	 */
-	nor->params->writesize = 16;
+	cypress_nor_ecc_init(nor);
 }
 
 static struct spi_nor_fixups s25fs256t_fixups = {
@@ -312,13 +322,10 @@ static void s25hx_t_post_sfdp_fixup(struct spi_nor *nor)
 
 static void s25hx_t_late_init(struct spi_nor *nor)
 {
-	struct spi_nor_flash_parameter *params = nor->params;
-
 	/* Fast Read 4B requires mode cycles */
-	params->reads[SNOR_CMD_READ_FAST].num_mode_clocks = 8;
+	nor->params->reads[SNOR_CMD_READ_FAST].num_mode_clocks = 8;
 
-	/* The writesize should be ECC data unit size */
-	params->writesize = 16;
+	cypress_nor_ecc_init(nor);
 }
 
 static struct spi_nor_fixups s25hx_t_fixups = {
@@ -381,7 +388,7 @@ static int s28hx_t_post_bfpt_fixup(struct spi_nor *nor,
 static void s28hx_t_late_init(struct spi_nor *nor)
 {
 	nor->params->octal_dtr_enable = cypress_nor_octal_dtr_enable;
-	nor->params->writesize = 16;
+	cypress_nor_ecc_init(nor);
 }
 
 static const struct spi_nor_fixups s28hx_t_fixups = {
-- 
2.34.1