1 files changed, 97 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/of_helpers.c b/arch/powerpc/platforms/pseries/of_helpers.c
new file mode 100644
index 000000000..23241c71e
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/of_helpers.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/string.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <asm/prom.h>
+
+#include "of_helpers.h"
+
+/**
+ * pseries_of_derive_parent - basically like dirname(1)
+ * @path:  the full_name of a node to be added to the tree
+ *
+ * Returns the node which should be the parent of the node
+ * described by path.  E.g., for path = "/foo/bar", returns
+ * the node with full_name = "/foo".
+ */
+struct device_node *pseries_of_derive_parent(const char *path)
+{
+	struct device_node *parent;
+	char *parent_path = "/";
+	const char *tail;
+
+	/* We do not want the trailing '/' character */
+	tail = kbasename(path) - 1;
+
+	/* reject if path is "/" */
+	if (!strcmp(path, "/"))
+		return ERR_PTR(-EINVAL);
+
+	if (tail > path) {
+		parent_path = kstrndup(path, tail - path, GFP_KERNEL);
+		if (!parent_path)
+			return ERR_PTR(-ENOMEM);
+	}
+	parent = of_find_node_by_path(parent_path);
+	if (strcmp(parent_path, "/"))
+		kfree(parent_path);
+	return parent ? parent : ERR_PTR(-EINVAL);
+}
+
+
+/* Helper Routines to convert between drc_index to cpu numbers */
+
+int of_read_drc_info_cell(struct property **prop, const __be32 **curval,
+			struct of_drc_info *data)
+{
+	const char *p = (char *)(*curval);
+	const __be32 *p2;
+
+	if (!data)
+		return -EINVAL;
+
+	/* Get drc-type:encode-string */
+	data->drc_type = (char *)p;
+	p = of_prop_next_string(*prop, p);
+	if (!p)
+		return -EINVAL;
+
+	/* Get drc-name-prefix:encode-string */
+	data->drc_name_prefix = (char *)p;
+	p = of_prop_next_string(*prop, p);
+	if (!p)
+		return -EINVAL;
+
+	/* Get drc-index-start:encode-int */
+	p2 = (const __be32 *)p;
+	data->drc_index_start = be32_to_cpu(*p2);
+
+	/* Get drc-name-suffix-start:encode-int */
+	p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start);
+	if (!p2)
+		return -EINVAL;
+
+	/* Get number-sequential-elements:encode-int */
+	p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems);
+	if (!p2)
+		return -EINVAL;
+
+	/* Get sequential-increment:encode-int */
+	p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc);
+	if (!p2)
+		return -EINVAL;
+
+	/* Get drc-power-domain:encode-int */
+	p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain);
+	if (!p2)
+		return -EINVAL;
+
+	/* Should now know end of current entry */
+	(*curval) = (void *)(++p2);
+	data->last_drc_index = data->drc_index_start +
+		((data->num_sequential_elems - 1) * data->sequential_inc);
+
+	return 0;
+}
+EXPORT_SYMBOL(of_read_drc_info_cell);