commonlib/device_tree.c: Add read reg property helper

Add a helper function to read the reg property from an unflattened
device tree.
It also factors out the common code into a new function called
`read_reg_prop`.

Signed-off-by: Maximilian Brune <maximilian.brune@9elements.com>
Change-Id: I7846eb8af390d709b0757262025cb819e9988699
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83457
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/commonlib/include/commonlib/device_tree.h b/src/commonlib/include/commonlib/device_tree.h
index 81377fa9df..c15d7ae5b1 100644
--- a/src/commonlib/include/commonlib/device_tree.h
+++ b/src/commonlib/include/commonlib/device_tree.h
@@ -147,6 +147,8 @@ uint32_t dt_flat_size(const struct device_tree *tree);
 /* Flatten a device tree into the buffer pointed to by dest. */
 void dt_flatten(const struct device_tree *tree, void *dest);
 void dt_print_node(const struct device_tree_node *node);
+size_t dt_read_reg_prop(struct device_tree_node *node, u32 addr_cells, u32 size_cells,
+			struct device_tree_region regions[], size_t regions_count);
 /* Read #address-cells and #size-cells properties from a node. */
 void dt_read_cell_props(const struct device_tree_node *node, u32 *addrcp,
 			u32 *sizecp);