regmap: add regmap_update_bits() helper

Add the regmap_update_bits() to simply the read/modify/write of registers
in a single command. The function is taken from Linux regmap
implementation.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
index fabcc5f53a..8e5c3bcf61 100644
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -132,3 +132,17 @@ int regmap_write(struct regmap *map, uint offset, uint val)
 
 	return 0;
 }
+
+int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val)
+{
+	uint reg;
+	int ret;
+
+	ret = regmap_read(map, offset, &reg);
+	if (ret)
+		return ret;
+
+	reg &= ~mask;
+
+	return regmap_write(map, offset, reg | val);
+}