[PATCH v3 1/8] of/fdt: Consolidate duplicate code into helper functions

[Yuntao Wang <yuntao.wang@linux.dev>]

Currently, there are many pieces of nearly identical code scattered across
different places. Consolidate the duplicate code into helper functions to
improve maintainability and reduce the likelihood of errors.

Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
---
 drivers/of/fdt.c       | 41 +++++++++++++++++++++++++++++++++++++++++
 include/linux/of_fdt.h |  9 +++++++++
 2 files changed, 50 insertions(+)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 0edd639898a6..0c18bdefbbee 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -625,6 +625,47 @@ const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 	return fdt_getprop(initial_boot_params, node, name, size);
 }
 
+const __be32 *__init of_flat_dt_get_addr_size_prop(unsigned long node,
+						   const char *name,
+						   int *entries)
+{
+	const __be32 *prop;
+	int len, elen = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+
+	prop = of_get_flat_dt_prop(node, name, &len);
+	if (!prop || len % elen) {
+		*entries = 0;
+		return NULL;
+	}
+
+	*entries = len / elen;
+	return prop;
+}
+
+bool __init of_flat_dt_get_addr_size(unsigned long node, const char *name,
+				     u64 *addr, u64 *size)
+{
+	const __be32 *prop;
+	int entries;
+
+	prop = of_flat_dt_get_addr_size_prop(node, name, &entries);
+	if (!prop || entries != 1)
+		return false;
+
+	of_flat_dt_read_addr_size(prop, 0, addr, size);
+	return true;
+}
+
+void __init of_flat_dt_read_addr_size(const __be32 *prop, int entry_index,
+				      u64 *addr, u64 *size)
+{
+	int entry_cells = dt_root_addr_cells + dt_root_size_cells;
+	prop += entry_cells * entry_index;
+
+	*addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	*size = dt_mem_next_cell(dt_root_size_cells, &prop);
+}
+
 /**
  * of_fdt_is_compatible - Return true if given node from the given blob has
  * compat in its compatible list
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index b8d6c0c20876..51dadbaa3d63 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -55,6 +55,15 @@ extern int of_get_flat_dt_subnode_by_name(unsigned long node,
 					  const char *uname);
 extern const void *of_get_flat_dt_prop(unsigned long node, const char *name,
 				       int *size);
+
+extern const __be32 *of_flat_dt_get_addr_size_prop(unsigned long node,
+						   const char *name,
+						   int *entries);
+extern bool of_flat_dt_get_addr_size(unsigned long node, const char *name,
+				     u64 *addr, u64 *size);
+extern void of_flat_dt_read_addr_size(const __be32 *prop, int entry_index,
+				      u64 *addr, u64 *size);
+
 extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
 extern unsigned long of_get_flat_dt_root(void);
 extern uint32_t of_get_flat_dt_phandle(unsigned long node);
-- 
2.51.0