[PATCH v2] arm64: dts: rockchip: Add overlay for the PCIe slot on RK3576 EVB1

[PATCH v2] arm64: dts: rockchip: Add overlay for the PCIe slot on RK3576 EVB1

[Alexey Charkov]

Rockchip RK3576 EVB1 has an onboard PCIe slot (PCIe 2.1, x4 mechanically,
x1 electrically), but it shares pins and PHY with the only USB3 Type-A
port.

There is a physical switch next to the slot to transfer respective pins
connection from the USB3 port to the PCIe slot, but apart from flipping
the switch one must also disable the USB3 host controller to prevent it
from claiming the PHY before the PCIe slot can become usable.

Add an overlay to disable the USB3 host port and instead enable the
PCIe slot, along with its pin configs. The physical switch must still be
flipped to the "ON - PCIe1" position for this to work.

Signed-off-by: Alexey Charkov <alchark@gmail.com>
---
Changes in v2:
- Added the standalone .dtbo Makefile target forgotten in v1
- Link to v1: https://lore.kernel.org/r/20251201-evb1-pcie1-v1-1-c62bba5c1167@gmail.com
---
 arch/arm64/boot/dts/rockchip/Makefile              |  5 ++++
 .../boot/dts/rockchip/rk3576-evb1-v10-pcie1.dtso   | 31 ++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/Makefile b/arch/arm64/boot/dts/rockchip/Makefile
index ad684e3831bc..ecd2dd365e97 100644
--- a/arch/arm64/boot/dts/rockchip/Makefile
+++ b/arch/arm64/boot/dts/rockchip/Makefile
@@ -153,6 +153,7 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-wolfvision-pf5-io-expander.dtbo
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-armsom-sige5.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-armsom-sige5-v1.2-wifibt.dtbo
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-evb1-v10.dtb
+dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-evb1-v10-pcie1.dtbo
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-luckfox-omni3576.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-nanopi-m5.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-roc-pc.dtb
@@ -252,6 +253,10 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-armsom-sige5-v1.2-wifibt.dtb
 rk3576-armsom-sige5-v1.2-wifibt-dtbs := rk3576-armsom-sige5.dtb \
 	rk3576-armsom-sige5-v1.2-wifibt.dtbo
 
+dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-evb1-v10-pcie1.dtb
+rk3576-evb1-v10-pcie1-dtbs := rk3576-evb1-v10.dtb \
+	rk3576-evb1-v10-pcie1.dtbo
+
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-edgeble-neu6a-wifi.dtb
 rk3588-edgeble-neu6a-wifi-dtbs := rk3588-edgeble-neu6a-io.dtb \
 	rk3588-edgeble-neu6a-wifi.dtbo
diff --git a/arch/arm64/boot/dts/rockchip/rk3576-evb1-v10-pcie1.dtso b/arch/arm64/boot/dts/rockchip/rk3576-evb1-v10-pcie1.dtso
new file mode 100644
index 000000000000..dccf4a5debdb
--- /dev/null
+++ b/arch/arm64/boot/dts/rockchip/rk3576-evb1-v10-pcie1.dtso
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * DT-overlay to enable the onboard PCIe x1 slot, which shares pins and the PHY
+ * with the USB3 host port.
+ * To use the PCIe slot, apply this overlay and flip the Dial_Switch_1 right
+ * next to the PCIe slot to low state (labeled "ON - PCIe1"). USB3 host port
+ * will be unusable (not even in 2.0 mode)
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/pinctrl/rockchip.h>
+
+&pcie1 {
+	pinctrl-0 = <&pcie1m0_pins &pcie1_rst>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&pinctrl {
+	pcie1 {
+		pcie1_rst: pcie1-rst {
+			rockchip,pins = <4 RK_PC4 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
+};
+
+&usb_drd1_dwc3 {
+	status = "disabled";
+};

---
base-commit: 7d0a66e4bb9081d75c82ec4957c50034cb0ea449
change-id: 20251128-evb1-pcie1-ade389a4d590

Best regards,
-- 
Alexey Charkov <alchark@gmail.com>

Re: [PATCH v2] arm64: dts: rockchip: Add overlay for the PCIe slot on RK3576 EVB1

[Heiko Stuebner]

On Tue, 02 Dec 2025 13:54:31 +0400, Alexey Charkov wrote:
> Rockchip RK3576 EVB1 has an onboard PCIe slot (PCIe 2.1, x4 mechanically,
> x1 electrically), but it shares pins and PHY with the only USB3 Type-A
> port.
> 
> There is a physical switch next to the slot to transfer respective pins
> connection from the USB3 port to the PCIe slot, but apart from flipping
> the switch one must also disable the USB3 host controller to prevent it
> from claiming the PHY before the PCIe slot can become usable.
> 
> [...]

Applied, thanks!

[1/1] arm64: dts: rockchip: Add overlay for the PCIe slot on RK3576 EVB1
      commit: 47b5d3697f6b9f53a0db30a99656a2f8f919e246

Best regards,
-- 
Heiko Stuebner <heiko@sntech.de>