dt-binding: Add gpio.h header

Add gpio.h header for dt-bindings.

Bug 4078385

Change-Id: Id478947d89f3fb327ee84dbf2dfd6403b0cde6bf
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/device/hardware/nvidia/t23x-public-dts/+/2892546
Reviewed-on: https://git-master.nvidia.com/r/c/device/hardware/nvidia/tegra-public-dts/+/3168927
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>

include/kernel/gpio/gpio.h

@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This header provides constants for most GPIO bindings.
+ *
+ * Most GPIO bindings include a flags cell as part of the GPIO specifier.
+ * In most cases, the format of the flags cell uses the standard values
+ * defined in this header.
+ */
+
+#ifndef _DT_BINDINGS_GPIO_GPIO_H
+#define _DT_BINDINGS_GPIO_GPIO_H
+
+/* Bit 0 express polarity */
+#define GPIO_ACTIVE_HIGH 0
+#define GPIO_ACTIVE_LOW 1
+
+/* Bit 1 express single-endedness */
+#define GPIO_PUSH_PULL 0
+#define GPIO_SINGLE_ENDED 2
+
+/* Bit 2 express Open drain or open source */
+#define GPIO_LINE_OPEN_SOURCE 0
+#define GPIO_LINE_OPEN_DRAIN 4
+
+/*
+ * Open Drain/Collector is the combination of single-ended open drain interface.
+ * Open Source/Emitter is the combination of single-ended open source interface.
+ */
+#define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_DRAIN)
+#define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_SOURCE)
+
+/* Bit 3 express GPIO suspend/resume and reset persistence */
+#define GPIO_PERSISTENT 0
+#define GPIO_TRANSITORY 8
+
+/* Bit 4 express pull up */
+#define GPIO_PULL_UP 16
+
+/* Bit 5 express pull down */
+#define GPIO_PULL_DOWN 32
+
+/* Bit 6 express pull disable */
+#define GPIO_PULL_DISABLE 64
+
+#endif