arm64: tegra: Add configuration for PCIe C5 sideband signals

Add support to configure PCIe C5's sideband signals PERST# and CLKREQ#
as output and bi-directional signals respectively which unlike other
PCIe controllers sideband signals are not configured by default.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>

arch/arm64/boot/dts/nvidia/tegra194.dtsi

@@ -3,8 +3,9 @@
 #include <dt-bindings/gpio/tegra194-gpio.h>
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/mailbox/tegra186-hsp.h>
-#include <dt-bindings/reset/tegra194-reset.h>
+#include <dt-bindings/pinctrl/pinctrl-tegra.h>
 #include <dt-bindings/power/tegra194-powergate.h>
+#include <dt-bindings/reset/tegra194-reset.h>
 #include <dt-bindings/thermal/tegra194-bpmp-thermal.h>
 
 / {
@@ -130,6 +131,38 @@ agic: interrupt-controller@2a40000 {
 			};
 		};
 
+		pinmux: pinmux@2430000 {
+			compatible = "nvidia,tegra194-pinmux";
+			reg = <0x2430000 0x17000
+			       0xc300000 0x4000>;
+
+			status = "okay";
+
+			pex_rst_c5_out_state: pex_rst_c5_out {
+				pex_rst {
+					nvidia,pins = "pex_l5_rst_n_pgg1";
+					nvidia,schmitt = <TEGRA_PIN_DISABLE>;
+					nvidia,lpdr = <TEGRA_PIN_ENABLE>;
+					nvidia,enable-input = <TEGRA_PIN_DISABLE>;
+					nvidia,io-high-voltage = <TEGRA_PIN_ENABLE>;
+					nvidia,tristate = <TEGRA_PIN_DISABLE>;
+					nvidia,pull = <TEGRA_PIN_PULL_NONE>;
+				};
+			};
+
+			clkreq_c5_bi_dir_state: clkreq_c5_bi_dir {
+				clkreq {
+					nvidia,pins = "pex_l5_clkreq_n_pgg0";
+					nvidia,schmitt = <TEGRA_PIN_DISABLE>;
+					nvidia,lpdr = <TEGRA_PIN_ENABLE>;
+					nvidia,enable-input = <TEGRA_PIN_ENABLE>;
+					nvidia,io-high-voltage = <TEGRA_PIN_ENABLE>;
+					nvidia,tristate = <TEGRA_PIN_DISABLE>;
+					nvidia,pull = <TEGRA_PIN_PULL_NONE>;
+				};
+			};
+		};
+
 		uarta: serial@3100000 {
 			compatible = "nvidia,tegra194-uart", "nvidia,tegra20-uart";
 			reg = <0x03100000 0x40>;
@@ -1365,6 +1398,9 @@ pcie@141a0000 {
 		num-viewport = <8>;
 		linux,pci-domain = <5>;
 
+		pinctrl-names = "default";
+		pinctrl-0 = <&pex_rst_c5_out_state>, <&clkreq_c5_bi_dir_state>;
+
 		clocks = <&bpmp TEGRA194_CLK_PEX1_CORE_5>,
 			<&bpmp TEGRA194_CLK_PEX1_CORE_5M>;
 		clock-names = "core", "core_m";