[PATCH 1/3] mtd: spi-nor: Make write support optional

[Sascha Hauer]

Write support is optional with the CONFIG_MTD_WRITE option. Bail out
early in the write functions to save some binary space.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/mtd/spi-nor/spi-nor.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 350b82a6be..bd748ff5b4 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -470,6 +470,9 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 	uint32_t rem;
 	int ret;
 
+	if (!IS_ENABLED(CONFIG_MTD_WRITE))
+		return -ENOSYS;
+
 	dev_dbg(nor->dev, "at 0x%llx, len %lld\n", (long long)instr->addr,
 			(long long)instr->len);
 
@@ -928,6 +931,9 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 	size_t actual;
 	int ret;
 
+	if (!IS_ENABLED(CONFIG_MTD_WRITE))
+		return -ENOSYS;
+
 	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
 
 	ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_WRITE);
@@ -1000,6 +1006,9 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	size_t retval;
 	int ret;
 
+	if (!IS_ENABLED(CONFIG_MTD_WRITE))
+		return -ENOSYS;
+
 	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
 
 	ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_WRITE);
-- 
2.20.1