[PATCH v2] arm64: dts: renesas: spider: Add overlay for PCIe ch0 endpoint mode

[Koichiro Den]

PCIe channel 0 on the R-Car S4-8 Spider board can work either as a Root
Complex (the default) or as an Endpoint. Add an overlay that disables
the RC node and enables the EP node, to let it work in EP mode.

Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
---
Changes in v2:
  - Polish the header (Marek)
  - Link to v1: https://lore.kernel.org/r/20261022082113.3163666-1-den@xxxxxxxxxxxxx/

 arch/arm64/boot/dts/renesas/Makefile          |  3 +++
 .../dts/renesas/r8a779f0-spider-pcie0-ep.dtso | 21 +++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 arch/arm64/boot/dts/renesas/r8a779f0-spider-pcie0-ep.dtso

diff --git a/arch/arm64/boot/dts/renesas/Makefile b/arch/arm64/boot/dts/renesas/Makefile
index c6f3718cd19f..2b0012118287 100644
--- a/arch/arm64/boot/dts/renesas/Makefile
+++ b/arch/arm64/boot/dts/renesas/Makefile
@@ -86,6 +86,9 @@ dtb-$(CONFIG_ARCH_R8A77995) += r8a77995-draak-panel-aa104xd12.dtb
 dtb-$(CONFIG_ARCH_R8A779A0) += r8a779a0-falcon.dtb
 
 dtb-$(CONFIG_ARCH_R8A779F0) += r8a779f0-spider.dtb
+dtb-$(CONFIG_ARCH_R8A779F0) += r8a779f0-spider-pcie0-ep.dtbo
+r8a779f0-spider-pcie0-ep-dtbs := r8a779f0-spider.dtb r8a779f0-spider-pcie0-ep.dtbo
+dtb-$(CONFIG_ARCH_R8A779F0) += r8a779f0-spider-pcie0-ep.dtb
 dtb-$(CONFIG_ARCH_R8A779F0) += r8a779f4-s4sk.dtb
 
 dtb-$(CONFIG_ARCH_R8A779G0) += r8a779g0-white-hawk.dtb
diff --git a/arch/arm64/boot/dts/renesas/r8a779f0-spider-pcie0-ep.dtso b/arch/arm64/boot/dts/renesas/r8a779f0-spider-pcie0-ep.dtso
new file mode 100644
index 000000000000..cdfc898e44f6
--- /dev/null
+++ b/arch/arm64/boot/dts/renesas/r8a779f0-spider-pcie0-ep.dtso
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * DT Overlay for enabling PCIe channel 0 in Endpoint Configuration with the
+ * R-Car S4-8 Spider board.
+ *
+ * Copyright (C) 2026 Renesas Electronics Corp.
+ *
+ * For example, follow the standard configfs steps for pci-epf-test documented
+ * in Documentation/PCI/endpoint/pci-test-howto.rst to set the endpoint up.
+ */
+
+/dts-v1/;
+/plugin/;
+
+&pciec0 {
+	status = "disabled";
+};
+
+&pciec0_ep {
+	status = "okay";
+};

base-commit: d99e991749f3b12a3a8b23224725dbc1ca15f6bf
-- 
2.54.0