dm: uclass: Add uclass_foreach_dev_probe

Add uclass_foreach_dev_probe() which iterates through
devices of a given uclass. Devices are probed if necessary
and are ready to use.

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

include/dm/uclass.h

@@ -393,4 +393,20 @@ int uclass_resolve_seq(struct udevice *dev);
 #define uclass_foreach_dev_safe(pos, next, uc)	\
 	list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)
 
+/**
+ * uclass_foreach_dev_probe() - Helper function to iteration through devices
+ * of given uclass
+ *
+ * This creates a for() loop which works through the available devices in
+ * a uclass in order from start to end. Devices are probed if necessary,
+ * and ready for use.
+ *
+ * @id: Uclass ID
+ * @dev: struct udevice * to hold the current device. Set to NULL when there
+ * are no more devices.
+ */
+#define uclass_foreach_dev_probe(id, dev)	\
+	for (int _ret = uclass_first_device_err(id, &dev); !_ret && dev; \
+	     _ret = uclass_next_device_err(&dev))
+
 #endif