This new helper routine returns the node path of a device
referred to by its node name and compat string.
Signed-off-by: Eric Auger <eric.au...@linaro.org>
---
v1 -> v2:
- move doc comment in header file
- do not use a fixed size buffer
- break on errors in while loop
- use strcmp instead of strncmp
RFC -> v1:
- improve error handling according to Alex' comments
---
device_tree.c | 37 +++++++++++++++++++++++++++++++++++++
include/sysemu/device_tree.h | 14 ++++++++++++++
2 files changed, 51 insertions(+)
diff --git a/device_tree.c b/device_tree.c
index b262c2d..8441e01 100644
--- a/device_tree.c
+++ b/device_tree.c
@@ -231,6 +231,43 @@ static int findnode_nofail(void *fdt, const char
*node_path)
return offset;
}
+int qemu_fdt_node_path(void *fdt, const char *name, char *compat,
+ char **node_path)
+{
+ int offset, len, ret;
+ const char *iter_name;
+ unsigned int path_len = 16;
+ char *path;
+
+ *node_path = NULL;
+ offset = fdt_node_offset_by_compatible(fdt, -1, compat);
+
+ while (offset >= 0) {
+ iter_name = fdt_get_name(fdt, offset, &len);
+ if (!iter_name) {
+ offset = len;
+ break;
+ }
+ if (!strcmp(iter_name, name)) {
+ goto found;
+ }
+ offset = fdt_node_offset_by_compatible(fdt, offset, compat);
+ }
+ return offset;
+
+found:
+ path = g_malloc(path_len);
+ while ((ret = fdt_get_path(fdt, offset, path, path_len))
+ == -FDT_ERR_NOSPACE) {
+ path_len += 16;
+ path = g_realloc(path, path_len);
+ }
+ if (!ret) {
+ *node_path = path;
+ }
+ return ret;
+}
+
int qemu_fdt_setprop(void *fdt, const char *node_path,
const char *property, const void *val, int size)
{
diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h
index fdf25a4..269cb1c 100644
--- a/include/sysemu/device_tree.h
+++ b/include/sysemu/device_tree.h
@@ -20,6 +20,20 @@ void *load_device_tree(const char *filename_path, int
*sizep);
void *load_device_tree_from_sysfs(void);
#endif
+/**
+ * qemu_fdt_node_path: return the node path of a device, given its
+ * node name and its compat string
+ * @fdt: pointer to the dt blob
+ * @name: device node name
+ * @compat: compatibility string of the device
+ * @node_path: returned node path
+ *
+ * upon success, the path is output at node_path address
+ * returns 0 on success, < 0 on failure
+ */
+int qemu_fdt_node_path(void *fdt, const char *name, char *compat,
+ char **node_path);
+
int qemu_fdt_setprop(void *fdt, const char *node_path,
const char *property, const void *val, int size);
int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
--
1.9.1
