[PATCH v2 2/2] reset: Allow reset_get_by_name() with NULL name

[Samuel Holland <samuel@sholland.org>]

This allows devm_reset_control_get(dev, NULL) to work and get the first
reset control, which is common in code ported from Linux.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

Changes in v2:
 - Move index error check inside if statement
 - Update function comment
 - Add unit test

 drivers/reset/reset-uclass.c | 12 +++++++-----
 include/reset.h              |  3 ++-
 test/dm/reset.c              |  3 +--
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/reset/reset-uclass.c b/drivers/reset/reset-uclass.c
index bcef46039c..b972faf013 100644
--- a/drivers/reset/reset-uclass.c
+++ b/drivers/reset/reset-uclass.c
@@ -147,16 +147,18 @@ int reset_get_bulk(struct udevice *dev, struct reset_ctl_bulk *bulk)
 int reset_get_by_name(struct udevice *dev, const char *name,
 		     struct reset_ctl *reset_ctl)
 {
-	int index;
+	int index = 0;
 
 	debug("%s(dev=%p, name=%s, reset_ctl=%p)\n", __func__, dev, name,
 	      reset_ctl);
 	reset_ctl->dev = NULL;
 
-	index = dev_read_stringlist_search(dev, "reset-names", name);
-	if (index < 0) {
-		debug("fdt_stringlist_search() failed: %d\n", index);
-		return index;
+	if (name) {
+		index = dev_read_stringlist_search(dev, "reset-names", name);
+		if (index < 0) {
+			debug("fdt_stringlist_search() failed: %d\n", index);
+			return index;
+		}
 	}
 
 	return reset_get_by_index(dev, index, reset_ctl);
diff --git a/include/reset.h b/include/reset.h
index 965f02e0ce..036a786d2a 100644
--- a/include/reset.h
+++ b/include/reset.h
@@ -238,7 +238,8 @@ int reset_get_bulk(struct udevice *dev, struct reset_ctl_bulk *bulk);
  *
  * @dev:	The client device.
  * @name:	The name of the reset signal to request, within the client's
- *		list of reset signals.
+ *		list of reset signals, or NULL to request the first reset
+ *		signal in the list.
  * @reset_ctl:	A pointer to a reset control struct to initialize.
  * Return: 0 if OK, or a negative error code.
  */
diff --git a/test/dm/reset.c b/test/dm/reset.c
index 9c00452336..e2d6f45623 100644
--- a/test/dm/reset.c
+++ b/test/dm/reset.c
@@ -35,8 +35,7 @@ static int dm_test_reset_base(struct unit_test_state *uts)
 
 	/* Get the same reset port in 2 different ways and compare */
 	ut_assertok(reset_get_by_index(dev, 0, &reset_method1));
-	ut_assertok(reset_get_by_index_nodev(dev_ofnode(dev), 0,
-					     &reset_method1_1));
+	ut_assertok(reset_get_by_name(dev, NULL, &reset_method1_1));
 	ut_assertok(reset_get_by_index(dev, 1, &reset_method2));
 	ut_assertok(reset_get_by_index_nodev(dev_ofnode(dev), 1,
 					     &reset_method2_1));
-- 
2.37.4