feat(fdt-wrappers): add function to find or add a sudnode
This change adds a new utility function - `fdtw_find_or_add_subnode`
to find a subnode. If the subnode is not present, the function adds
it in the flattened device tree.
Signed-off-by: Ruchika Gupta <ruchika.gupta@linaro.org>
Change-Id: Idf3ceddc57761ac015763d4a8b004877bcad766a
diff --git a/common/fdt_wrappers.c b/common/fdt_wrappers.c
index 2a9673f..1b065b1 100644
--- a/common/fdt_wrappers.c
+++ b/common/fdt_wrappers.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2022, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -618,3 +618,24 @@
return ret;
}
+
+/*
+ * Find a given node in device tree. If not present, add it.
+ * Returns offset of node found/added on success, and < 0 on error.
+ */
+int fdtw_find_or_add_subnode(void *fdt, int parentoffset, const char *name)
+{
+ int offset;
+
+ offset = fdt_subnode_offset(fdt, parentoffset, name);
+
+ if (offset == -FDT_ERR_NOTFOUND) {
+ offset = fdt_add_subnode(fdt, parentoffset, name);
+ }
+
+ if (offset < 0) {
+ ERROR("%s: %s: %s\n", __func__, name, fdt_strerror(offset));
+ }
+
+ return offset;
+}
diff --git a/include/common/fdt_wrappers.h b/include/common/fdt_wrappers.h
index 9c7180c..2929fc2 100644
--- a/include/common/fdt_wrappers.h
+++ b/include/common/fdt_wrappers.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2022, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -44,6 +44,8 @@
int fdtw_for_each_cpu(const void *fdt,
int (*callback)(const void *dtb, int node, uintptr_t mpidr));
+int fdtw_find_or_add_subnode(void *fdt, int parentoffset, const char *name);
+
static inline uint32_t fdt_blob_size(const void *dtb)
{
const uint32_t *dtb_header = dtb;