// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.hardware.gpio;

using zx;

/// Flags for `ConfigIn`.
type GpioFlags = strict enum : uint32 {
    PULL_DOWN = 0x0;
    PULL_UP = 0x1;
    NO_PULL = 0x2;
    PULL_MASK = 0x3;
};

protocol Gpio {
    /// Configures a GPIO for input.
    ConfigIn(struct {
        flags GpioFlags;
    }) -> (struct {}) error zx.status;

    /// Configures a GPIO for output.
    ConfigOut(struct {
        initial_value uint8;
    }) -> (struct {}) error zx.status;

    /// Reads the current value of a GPIO (0 or 1).
    Read() -> (struct {
        value uint8;
    }) error zx.status;

    /// Sets the current value of the GPIO (any non-zero value maps to 1).
    Write(struct {
        value uint8;
    }) -> (struct {}) error zx.status;

    /// Sets the drive strength of the GPIO.
    /// actual_ds_ua is always >= ds_ua. If ds_ua is larger than max value, the drive strength will be set to the max value.
    /// Return error if unable to set drive strength. actual_ds_ua is not set in this case.
    SetDriveStrength(struct {
        ds_ua uint64;
    }) -> (struct {
        actual_ds_ua uint64;
    }) error zx.status;

    /// Gets the configured drive strength of the GPIO in microamps (ua).
    GetDriveStrength() -> (struct {
        result_ua uint64;
    }) error zx.status;

    /// Gets an interrupt object pertaining to a particular GPIO pin. `flags`
    /// is passed as the `options` parameter when
    /// [creating the interrupt](https://fuchsia.dev/fuchsia-src/reference/syscalls/interrupt_create).
    GetInterrupt(struct {
        flags uint32;
    }) -> (resource struct {
        irq zx.handle:INTERRUPT;
    }) error zx.status;

    /// Release the interrupt.
    ReleaseInterrupt() -> (struct {}) error zx.status;
};