regmap: Implement writable register checks
This is mainly intended to be used by devices which can dynamically
block register writes at runtime, for other devices there is usually
limited value.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 7d4dc11..e57f10f 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -211,6 +211,13 @@
void *buf;
int ret = -ENOTSUPP;
size_t len;
+ int i;
+
+ /* Check for unwritable registers before we start */
+ if (map->writeable_reg)
+ for (i = 0; i < val_len / map->format.val_bytes; i++)
+ if (!map->writeable_reg(map->dev, reg + i))
+ return -EINVAL;
map->format.format_reg(map->work_buf, reg);
