// Copyright 2018 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`.
const GPIO_PULL_DOWN uint32 = 0x0;
const GPIO_PULL_UP uint32 = 0x1;
const GPIO_NO_PULL uint32 = 0x2;
const GPIO_PULL_MASK uint32 = 0x3;

/// Values for `SetPolarity`.
type GpioPolarity = strict enum : uint32 {
    LOW = 0x0;
    HIGH = 0x1;
};

@transport("Banjo")
@banjo_layout("ddk-protocol")
protocol Gpio {
    /// Configures a GPIO for input.
    ConfigIn(struct {
        flags uint32;
    }) -> (struct {
        s zx.status;
    });
    /// Configures a GPIO for output.
    ConfigOut(struct {
        initial_value uint8;
    }) -> (struct {
        s zx.status;
    });
    /// Configures the GPIO pin for an alternate function (I2C, SPI, etc)
    /// the interpretation of "function" is platform dependent.
    SetAltFunction(struct {
        function uint64;
    }) -> (struct {
        s zx.status;
    });
    /// Reads the current value of a GPIO (0 or 1).
    Read() -> (struct {
        s zx.status;
        value uint8;
    });
    /// Sets the current value of the GPIO (any non-zero value maps to 1).
    Write(struct {
        value uint8;
    }) -> (struct {
        s zx.status;
    });
    /// Gets an interrupt object pertaining to a particular GPIO pin.
    GetInterrupt(struct {
        flags uint32;
    }) -> (resource struct {
        s zx.status;
        irq zx.handle:INTERRUPT;
    });
    /// Release the interrupt.
    ReleaseInterrupt() -> (struct {
        s zx.status;
    });
    /// Set GPIO polarity.
    SetPolarity(struct {
        polarity GpioPolarity;
    }) -> (struct {
        s zx.status;
    });
    /// Set GPIO drive strength.
    SetDriveStrength(struct {
        ds_ua uint64;
    }) -> (struct {
        s zx.status;
        actual_ds_ua uint64;
    });
    /// Get GPIO drive strength.
    GetDriveStrength() -> (struct {
        s zx.status;
        value uint64;
    });
};