dm: uclass: Add uclass_next_device_err() to return a valid device

Similarly to uclass_first_device_err(), add uclass_next_device_err()
which returns an error if there are no next devices in that uclass.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/core/uclass.c

@@ -562,6 +562,19 @@ int uclass_next_device(struct udevice **devp)
 	return uclass_get_device_tail(dev, ret, devp);
 }
 
+int uclass_next_device_err(struct udevice **devp)
+{
+	int ret;
+
+	ret = uclass_next_device(devp);
+	if (ret)
+		return ret;
+	else if (!*devp)
+		return -ENODEV;
+
+	return 0;
+}
+
 int uclass_first_device_check(enum uclass_id id, struct udevice **devp)
 {
 	int ret;

include/dm/uclass.h

@@ -307,6 +307,18 @@ int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
  */
 int uclass_next_device(struct udevice **devp);
 
+/**
+ * uclass_next_device_err() - Get the next device in a uclass
+ *
+ * The device returned is probed if necessary, and ready for use
+ *
+ * @devp: On entry, pointer to device to lookup. On exit, returns pointer
+ * to the next device in the uclass if no error occurred, or -ENODEV if
+ * there is no next device.
+ * @return 0 if found, -ENODEV if not found, other -ve on error
+ */
+int uclass_next_device_err(struct udevice **devp);
+
 /**
  * uclass_first_device_check() - Get the first device in a uclass
  *