[Minios-devel] [UNIKRAFT PATCH 8/8] lib/fdt: Add two macros to list iterate all compatible nodes

[Wei Chen <wei.chen@xxxxxxx>]

Sometimes, we will list all compatible nodes from device tree to
do a probe work like bus-probe. For examplem, we will iterate all
virtio-mmio devices' node to bind correct virtio device drivers.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
 lib/fdt/include/libfdt.h | 58 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/lib/fdt/include/libfdt.h b/lib/fdt/include/libfdt.h
index 74507fc..5797838 100644
--- a/lib/fdt/include/libfdt.h
+++ b/lib/fdt/include/libfdt.h
@@ -213,6 +213,64 @@ int fdt_next_subnode(const void *fdt, int offset);
             node >= 0;                                 \
             node = fdt_next_subnode(fdt, node))
 
+/**
+ * fdt_for_each_compatible_node - iterate over all compatible nodes
+ *
+ * @node:      node (int, lvalue)
+ * @fdt:       FDT blob (const void *)
+ * @compatible:        a 'compatible' string to match against
+ *
+ * This is actually a wrapper around a for loop and would be used like so:
+ *
+ *     fdt_for_each_compatible_node(node, fdt, compatible) {
+ *             Use node
+ *             ...
+ *     }
+ *
+ *     if ((node < 0) && (node != -FDT_ERR_NOT_FOUND)) {
+ *             Error handling
+ *     }
+ *
+ * Note that this is implemented as a macro and @node is used as
+ * iterator in the loop. The parent variable be constant or even a
+ * literal.
+ *
+ */
+#define fdt_for_each_compatible_node(node, fdt, compatible)            \
+       for (node = fdt_node_offset_by_compatible(fdt, -1, compatible); \
+            node >= 0;                                                 \
+            node = fdt_node_offset_by_compatible(fdt, node, compatible))
+
+/**
+ * fdt_for_each_matching_node - iterate over all match nodes
+ *
+ * @node:      node (int, lvalue)
+ * @fdt:       FDT blob (const void *)
+ * @compatible:        a list of 'compatible' strings to match against
+ *
+ * This is actually a wrapper around a for loop and would be used like so:
+ *
+ *     fdt_for_each_matching_node(node, fdt, compatible_list, size) {
+ *             Use node
+ *             ...
+ *     }
+ *
+ *     if ((node < 0) && (node != -FDT_ERR_NOT_FOUND)) {
+ *             Error handling
+ *     }
+ *
+ * Note that this is implemented as a macro and @node is used as
+ * iterator in the loop. The parent variable be constant or even a
+ * literal.
+ *
+ */
+#define fdt_for_each_matching_node(node, fdt, compatibles, size)       \
+       for (node = fdt_node_offset_by_compatible_list(fdt, -1,         \
+                                               compatibles, size);     \
+            node >= 0;                                                 \
+            node = fdt_node_offset_by_compatible_list(fdt, node,       \
+                                               compatibles, size))
+
 /**********************************************************************/
 /* General functions                                                  */
 /**********************************************************************/
-- 
2.17.1


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