dm: Provide a function to scan child FDT nodes

At present only root nodes in the device tree are scanned for devices.
But some devices can have children. For example a SPI bus may have
several children for each of its chip selects.

Add a function which scans subnodes and binds devices for each one. This
can be used for the root node scan also, so change it.

A device can call this function in its bind() or probe() methods to bind
its children.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 18 insertions, 15 deletions

diff --git a/drivers/core/root.c b/drivers/core/root.c
index 60597563d6..4f9c7e708a 100644
--- a/drivers/core/root.c
+++ b/drivers/core/root.c
@@ -80,29 +80,32 @@ int dm_scan_platdata(bool pre_reloc_only)
 }
 
 #ifdef CONFIG_OF_CONTROL
-int dm_scan_fdt(const void *blob, bool pre_reloc_only)
+int dm_scan_fdt_node(struct udevice *parent, const void *blob, int offset,
+		     bool pre_reloc_only)
 {
-	int offset = 0;
 	int ret = 0, err;
-	int depth = 0;
-
-	do {
-		offset = fdt_next_node(blob, offset, &depth);
-		if (offset > 0 && depth == 1) {
-			if (pre_reloc_only &&
-			    !fdt_getprop(blob, offset, "u-boot,dm-pre-reloc", NULL))
-				continue;
-			err = lists_bind_fdt(gd->dm_root, blob, offset);
-			if (err && !ret)
-				ret = err;
-		}
-	} while (offset > 0);
+
+	for (offset = fdt_first_subnode(blob, offset);
+	     offset > 0;
+	     offset = fdt_next_subnode(blob, offset)) {
+		if (pre_reloc_only &&
+		    !fdt_getprop(blob, offset, "u-boot,dm-pre-reloc", NULL))
+			continue;
+		err = lists_bind_fdt(parent, blob, offset);
+		if (err && !ret)
+			ret = err;
+	}
 
 	if (ret)
 		dm_warn("Some drivers failed to bind\n");
 
 	return ret;
 }
+
+int dm_scan_fdt(const void *blob, bool pre_reloc_only)
+{
+	return dm_scan_fdt_node(gd->dm_root, blob, 0, pre_reloc_only);
+}
 #endif
 
 int dm_init_and_scan(bool pre_reloc_only)