regulator: core: Don't allow to get regulator until all couples resolved

Don't allow to get regulator until all of its couples resolved because
consumer will get EPERM and coupling shall be transparent for the drivers.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

drivers/regulator/core.c

@@ -1747,6 +1747,16 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 		return regulator;
 	}
 
+	mutex_lock(&regulator_list_mutex);
+	ret = (rdev->coupling_desc.n_resolved != rdev->coupling_desc.n_coupled);
+	mutex_unlock(&regulator_list_mutex);
+
+	if (ret != 0) {
+		regulator = ERR_PTR(-EPROBE_DEFER);
+		put_device(&rdev->dev);
+		return regulator;
+	}
+
 	ret = regulator_resolve_supply(rdev);
 	if (ret < 0) {
 		regulator = ERR_PTR(ret);