arm64: renesas: Add R-Car S4 Starter Kit support
Add support for the R-Car S4 Starter Kit with R8A779F4 SoC support.
This implementation natively uses OF_UPSTREAM to pull in most recent
DT. The defconfig is derived from S4 Spider, with reduced UART baud
rate to 921600 Bdps. The DT alias to rswitch is removed as the alias
should point to rswitch ports, not to rswitch itself, see [1].
[1] https://lore.kernel.org/linux-arm-kernel/20250118111344.361617-5-marek.vasut+renesas@mailbox.org/
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/arch/arm/dts/r8a779f4-s4sk-u-boot.dtsi b/arch/arm/dts/r8a779f4-s4sk-u-boot.dtsi
new file mode 100644
index 0000000..c2c743b
--- /dev/null
+++ b/arch/arm/dts/r8a779f4-s4sk-u-boot.dtsi
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree Source extras for U-Boot for the S4SK board
+ *
+ * Copyright (C) 2024-2025 Renesas Electronics Corp.
+ */
+
+#include "r8a779f0-u-boot.dtsi"
+
+/ {
+ aliases {
+ spi0 = &rpc;
+ /delete-property/ ethernet0;
+ };
+};
+
+&pfc {
+ qspi0_pins: qspi0 {
+ groups = "qspi0_ctrl", "qspi0_data4";
+ function = "qspi0";
+ };
+};
+
+&rpc {
+ pinctrl-0 = <&qspi0_pins>;
+ pinctrl-names = "default";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+ spi-max-frequency = <40000000>;
+ status = "okay";
+
+ spi-flash@0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "s25fs512s", "jedec,spi-nor";
+ reg = <0>;
+ spi-tx-bus-width = <1>;
+ spi-rx-bus-width = <1>;
+ spi-max-frequency = <40000000>;
+ };
+};
diff --git a/arch/arm/mach-renesas/Kconfig.rcar4 b/arch/arm/mach-renesas/Kconfig.rcar4
index c2812fd..c42bb97 100644
--- a/arch/arm/mach-renesas/Kconfig.rcar4
+++ b/arch/arm/mach-renesas/Kconfig.rcar4
@@ -54,6 +54,12 @@
help
Support for Renesas R-Car Gen4 Spider platform
+config TARGET_S4SK
+ bool "S4SK board"
+ imply R8A779F0
+ help
+ Support for Renesas R-Car Gen4 S4SK platform
+
config TARGET_WHITEHAWK
bool "White Hawk board"
imply R8A779G0
@@ -70,6 +76,7 @@
source "board/renesas/falcon/Kconfig"
source "board/renesas/spider/Kconfig"
+source "board/renesas/s4sk/Kconfig"
source "board/renesas/whitehawk/Kconfig"
source "board/renesas/grayhawk/Kconfig"