of/address: Add of_property_read_reg() helper

Add a helper, of_property_read_reg(), to read "reg" entries untranslated
address and size. This function is intended mainly for cases with an
untranslatable "reg" address (i.e. not MMIO). There's also a few
translatable cases such as address cells containing a bus chip-select
number.

Link: https://lore.kernel.org/r/20230328-dt-address-helpers-v1-5-e2456c3e77ab@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index eaeb58065acc..e73ecbef977b 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -1134,6 +1134,27 @@ static void __init of_unittest_bus_3cell_ranges(void)
 	of_node_put(np);
 }
 
+static void __init of_unittest_reg(void)
+{
+	struct device_node *np;
+	int ret;
+	u64 addr, size;
+
+	np = of_find_node_by_path("/testcase-data/address-tests/bus@80000000/device@1000");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	ret = of_property_read_reg(np, 0, &addr, &size);
+	unittest(!ret, "of_property_read_reg(%pOF) returned error %d\n",
+		np, ret);
+	unittest(addr == 0x1000, "of_property_read_reg(%pOF) untranslated address (%llx) incorrect\n",
+		np, addr);
+
+	of_node_put(np);
+}
+
 static void __init of_unittest_parse_interrupts(void)
 {
 	struct device_node *np;
@@ -3772,6 +3793,7 @@ static int __init of_unittest(void)
 	of_unittest_pci_dma_ranges();
 	of_unittest_bus_ranges();
 	of_unittest_bus_3cell_ranges();
+	of_unittest_reg();
 	of_unittest_match_node();
 	of_unittest_platform_populate();
 	of_unittest_overlay();