[PATCH v1 1/3] mtd: rawnand: nand_base: support for 'NAND_IS_BOOT_MEDIUM' flag

[Arseniy Krasnov]

Based on Linux kernel:
commit f922bd798bb9 ("mtd: rawnand: add an option to specify NAND chip as a boot device")

Allow to define a NAND chip as a boot device. This can be helpful
for the selection of the ECC algorithm and strength in case the boot
ROM supports only a subset of controller provided options.

Signed-off-by: Arseniy Krasnov <avkrasnov at salutedevices.com>
---
 drivers/mtd/nand/raw/nand_base.c | 3 +++
 include/linux/mtd/rawnand.h      | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index c40a0f23d7..ed605b4af5 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -4458,6 +4458,9 @@ static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip, ofnode nod
 	if (ret == 16)
 		chip->options |= NAND_BUSWIDTH_16;
 
+	if (ofnode_read_bool(node, "nand-is-boot-medium"))
+		chip->options |= NAND_IS_BOOT_MEDIUM;
+
 	if (ofnode_read_bool(node, "nand-on-flash-bbt"))
 		chip->bbt_options |= NAND_BBT_USE_FLASH;
 
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index fb002ae641..4eb880d8fb 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -218,6 +218,12 @@ enum nand_ecc_algo {
 /* Device needs 3rd row address cycle */
 #define NAND_ROW_ADDR_3		0x00004000
 
+/*
+ * Whether the NAND chip is a boot medium. Drivers might use this information
+ * to select ECC algorithms supported by the boot ROM or similar restrictions.
+ */
+#define NAND_IS_BOOT_MEDIUM	0x00400000
+
 /* Options valid for Samsung large page devices */
 #define NAND_SAMSUNG_LP_OPTIONS NAND_CACHEPRG
 
-- 
2.35.0