mtd: Fallback to ->_read/write_oob() when ->_read/write() is missing
Some MTD sublayers/drivers are implementing ->_read/write_oob() and
provide dummy wrappers for their ->_read/write() implementations.
Let the core handle this case instead of duplicating the logic.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Tested-by: Ladislav Michl <ladis@linux-mips.org>
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 642c35d..d7ab091 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1058,7 +1058,20 @@ int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
* representing the maximum number of bitflips that were corrected on
* any one ecc region (if applicable; zero otherwise).
*/
- ret_code = mtd->_read(mtd, from, len, retlen, buf);
+ if (mtd->_read) {
+ ret_code = mtd->_read(mtd, from, len, retlen, buf);
+ } else if (mtd->_read_oob) {
+ struct mtd_oob_ops ops = {
+ .len = len,
+ .datbuf = buf,
+ };
+
+ ret_code = mtd->_read_oob(mtd, from, &ops);
+ *retlen = ops.retlen;
+ } else {
+ return -ENOTSUPP;
+ }
+
if (unlikely(ret_code < 0))
return ret_code;
if (mtd->ecc_strength == 0)
@@ -1073,11 +1086,25 @@ int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
*retlen = 0;
if (to < 0 || to >= mtd->size || len > mtd->size - to)
return -EINVAL;
- if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
+ if ((!mtd->_write && !mtd->_write_oob) ||
+ !(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (!len)
return 0;
ledtrig_mtd_activity();
+
+ if (!mtd->_write) {
+ struct mtd_oob_ops ops = {
+ .len = len,
+ .datbuf = (u8 *)buf,
+ };
+ int ret;
+
+ ret = mtd->_write_oob(mtd, to, &ops);
+ *retlen = ops.retlen;
+ return ret;
+ }
+
return mtd->_write(mtd, to, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_write);
