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

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

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

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

    /// Sets the current value of the GPIO (any non-zero value maps to 1).
    Write(uint8 value) -> () 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(uint64 ds_ua) -> (uint64 actual_ds_ua) error zx.status;
};