regulator: da9121: Prevent current limit change when enabled

Prevent changing current limit when enabled as a precaution against
possibile instability due to tight integration with switching cycle

Signed-off-by: Adam Ward <Adam.Ward.opensource@diasemi.com>
Link: https://lore.kernel.org/r/52ee682476004a1736c1e0293358987319c1c415.1638223185.git.Adam.Ward.opensource@diasemi.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/da9121-regulator.c

@@ -253,6 +253,11 @@ static int da9121_set_current_limit(struct regulator_dev *rdev,
 		goto error;
 	}
 
+	if (rdev->desc->ops->is_enabled(rdev)) {
+		ret = -EBUSY;
+		goto error;
+	}
+
 	ret = da9121_ceiling_selector(rdev, min_ua, max_ua, &sel);
 	if (ret < 0)
 		goto error;