commit 9285d5053fb1cb419655a4411f985965e3838ab2
author Tejas Bhumkar <tejas.arvind.bhumkar@amd.com> Fri Oct 20 10:36:22 2023 +0530
committer Michal Simek <michal.simek@amd.com> Tue Nov 07 13:47:09 2023 +0100
tree e77dee394e43cb980276342f67ef5270a058da4c
parent 78974fb28f91cdf3bdeeddb5706b32d806948c89

arm64: zynqmp: Disable Tri-state for MIO38 Pin

gpio38 is used in SOM's kv260 to reset the Ethernet PHY.
At present, HW reset is not working properly as Tri-state 
is enabled for MIO38, causing inappropriate PHY register reads.

Disabled Tri-state for MIO38 to make HW reset work.

Tri-state disable :
ZynqMP> md 0xFF180208 2
ff180208: 00bfe7a3 00000540

Tri-state enable :
ZynqMP> md 0xFF180208 2
ff180208: 00bfe7e3 00000540

Signed-off-by: Tejas Bhumkar <tejas.arvind.bhumkar@amd.com>
Link: https://lore.kernel.org/r/20231020050622.972750-1-tejas.arvind.bhumkar@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>

arch/arm/dts/zynqmp-sck-kv-g-revA.dtso

diff --git a/arch/arm/dts/zynqmp-sck-kv-g-revA.dtso b/arch/arm/dts/zynqmp-sck-kv-g-revA.dtso
index 22e7d68..c4f1da9 100644
--- a/arch/arm/dts/zynqmp-sck-kv-g-revA.dtso
+++ b/arch/arm/dts/zynqmp-sck-kv-g-revA.dtso
@@ -190,6 +190,25 @@
 &pinctrl0 {
 	status = "okay";
 
+	pinctrl_gpio0_default: gpio0-default {
+                conf {
+                        groups = "gpio0_38_grp";
+                        bias-pull-up;
+                        power-source = <IO_STANDARD_LVCMOS18>;
+                };
+
+                mux {
+                        groups = "gpio0_38_grp";
+                        function = "gpio0";
+                };
+
+                conf-tx {
+                        pins = "MIO38";
+                        bias-disable;
+                        output-enable;
+                };
+        };
+
 	pinctrl_uart1_default: uart1-default {
 		conf {
 			groups = "uart1_9_grp";
@@ -345,6 +364,12 @@
 	};
 };
 
+&gpio {
+        status = "okay";
+        pinctrl-names = "default";
+        pinctrl-0 = <&pinctrl_gpio0_default>;
+};
+
 &uart1 {
 	status = "okay";
 	pinctrl-names = "default";

arch/arm/dts/zynqmp-sck-kv-g-revB.dtso

diff --git a/arch/arm/dts/zynqmp-sck-kv-g-revB.dtso b/arch/arm/dts/zynqmp-sck-kv-g-revB.dtso
index eadc256..6c5e0e5 100644
--- a/arch/arm/dts/zynqmp-sck-kv-g-revB.dtso
+++ b/arch/arm/dts/zynqmp-sck-kv-g-revB.dtso
@@ -178,6 +178,25 @@
 &pinctrl0 {
 	status = "okay";
 
+	pinctrl_gpio0_default: gpio0-default {
+		conf {
+			groups = "gpio0_38_grp";
+			bias-pull-up;
+			power-source = <IO_STANDARD_LVCMOS18>;
+		};
+
+		mux {
+			groups = "gpio0_38_grp";
+			function = "gpio0";
+		};
+
+		conf-tx {
+			pins = "MIO38";
+			bias-disable;
+			output-enable;
+		};
+	};
+
 	pinctrl_uart1_default: uart1-default {
 		conf {
 			groups = "uart1_9_grp";
@@ -333,6 +352,12 @@
 	};
 };
 
+&gpio {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_gpio0_default>;
+};
+
 &uart1 {
 	status = "okay";
 	pinctrl-names = "default";