[PATCH V4 4/8] libgpiod: Add rust wrapper crate

[Viresh Kumar <viresh.kumar@xxxxxxxxxx>]

Add rust wrapper crate, around the libpiod-sys crate added earlier, to
provide a convenient interface for the users.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
 bindings/rust/Cargo.toml            |  12 +
 bindings/rust/src/chip.rs           | 179 ++++++++++
 bindings/rust/src/chip_info.rs      |  69 ++++
 bindings/rust/src/edge_event.rs     | 105 ++++++
 bindings/rust/src/event_buffer.rs   |  88 +++++
 bindings/rust/src/info_event.rs     |  68 ++++
 bindings/rust/src/lib.rs            | 317 ++++++++++++++++++
 bindings/rust/src/line_config.rs    | 493 ++++++++++++++++++++++++++++
 bindings/rust/src/line_info.rs      | 189 +++++++++++
 bindings/rust/src/line_request.rs   | 248 ++++++++++++++
 bindings/rust/src/request_config.rs | 122 +++++++
 11 files changed, 1890 insertions(+)
 create mode 100644 bindings/rust/Cargo.toml
 create mode 100644 bindings/rust/src/chip.rs
 create mode 100644 bindings/rust/src/chip_info.rs
 create mode 100644 bindings/rust/src/edge_event.rs
 create mode 100644 bindings/rust/src/event_buffer.rs
 create mode 100644 bindings/rust/src/info_event.rs
 create mode 100644 bindings/rust/src/lib.rs
 create mode 100644 bindings/rust/src/line_config.rs
 create mode 100644 bindings/rust/src/line_info.rs
 create mode 100644 bindings/rust/src/line_request.rs
 create mode 100644 bindings/rust/src/request_config.rs

diff --git a/bindings/rust/Cargo.toml b/bindings/rust/Cargo.toml
new file mode 100644
index 000000000000..d5d81486fa2f
--- /dev/null
+++ b/bindings/rust/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "libgpiod"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+libc = ">=0.2.39"
+libgpiod-sys = { path = "libgpiod-sys" }
+thiserror = "1.0"
+vmm-sys-util = "=0.9.0"
diff --git a/bindings/rust/src/chip.rs b/bindings/rust/src/chip.rs
new file mode 100644
index 000000000000..50b5d6102f96
--- /dev/null
+++ b/bindings/rust/src/chip.rs
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use std::os::raw::c_char;
+use std::sync::Arc;
+use std::time::Duration;
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{
+    bindings, chip_info::ChipInfo, Error, InfoEvent, LineConfig, LineInfo, LineRequest,
+    RequestConfig, Result,
+};
+
+/// GPIO chip
+///
+/// A GPIO chip object is associated with an open file descriptor to the GPIO
+/// character device. It exposes basic information about the chip and allows
+/// callers to retrieve information about each line, watch lines for state
+/// changes and make line requests.
+pub(crate) struct ChipInternal {
+    chip: *mut bindings::gpiod_chip,
+}
+
+impl ChipInternal {
+    /// Find a chip by path.
+    pub(crate) fn open(path: &str) -> Result<Self> {
+        // Null-terminate the string
+        let path = path.to_owned() + "\0";
+
+        let chip = unsafe { bindings::gpiod_chip_open(path.as_ptr() as *const c_char) };
+        if chip.is_null() {
+            return Err(Error::OperationFailed("Gpio Chip open", IoError::last()));
+        }
+
+        Ok(Self { chip })
+    }
+
+    /// Private helper, Returns gpiod_chip
+    pub(crate) fn chip(&self) -> *mut bindings::gpiod_chip {
+        self.chip
+    }
+}
+
+impl Drop for ChipInternal {
+    /// Close the chip and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { bindings::gpiod_chip_close(self.chip) }
+    }
+}
+
+pub struct Chip {
+    ichip: Arc<ChipInternal>,
+    info: ChipInfo,
+}
+
+impl Chip {
+    /// Find a chip by path.
+    pub fn open(path: &str) -> Result<Self> {
+        let ichip = Arc::new(ChipInternal::open(path)?);
+        let info = ChipInfo::new(ichip.clone())?;
+
+        Ok(Self { ichip, info })
+    }
+
+    /// Get the chip name as represented in the kernel.
+    pub fn get_name(&self) -> Result<&str> {
+        self.info.name()
+    }
+
+    /// Get the chip label as represented in the kernel.
+    pub fn get_label(&self) -> Result<&str> {
+        self.info.label()
+    }
+
+    /// Get the number of GPIO lines exposed by the chip.
+    pub fn get_num_lines(&self) -> u32 {
+        self.info.num_lines()
+    }
+
+    /// Get the path used to find the chip.
+    pub fn get_path(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct Chip`.
+        let path = unsafe { bindings::gpiod_chip_get_path(self.ichip.chip()) };
+
+        // SAFETY: The string is guaranteed to be valid here.
+        str::from_utf8(unsafe {
+            slice::from_raw_parts(path as *const u8, bindings::strlen(path) as usize)
+        })
+        .map_err(Error::InvalidString)
+    }
+
+    /// Get information about the chip.
+    pub fn info(&self) -> Result<ChipInfo> {
+        ChipInfo::new(self.ichip.clone())
+    }
+
+    /// Get a snapshot of information about the line.
+    pub fn line_info(&self, offset: u32) -> Result<LineInfo> {
+        LineInfo::new(self.ichip.clone(), offset, false)
+    }
+
+    /// Get the current snapshot of information about the line at given offset
+    /// and optionally start watching it for future changes.
+    pub fn watch_line_info(&self, offset: u32) -> Result<LineInfo> {
+        LineInfo::new(self.ichip.clone(), offset, true)
+    }
+
+    /// Get the file descriptor associated with the chip.
+    ///
+    /// The returned file descriptor must not be closed by the caller, else other methods for the
+    /// `struct Chip` may fail.
+    pub fn get_fd(&self) -> Result<u32> {
+        let fd = unsafe { bindings::gpiod_chip_get_fd(self.ichip.chip()) };
+
+        if fd < 0 {
+            Err(Error::OperationFailed("Gpio Chip get-fd", IoError::last()))
+        } else {
+            Ok(fd as u32)
+        }
+    }
+
+    /// Wait for line status events on any of the watched lines on the chip.
+    pub fn wait_info_event(&self, timeout: Duration) -> Result<()> {
+        let ret = unsafe {
+            bindings::gpiod_chip_wait_info_event(self.ichip.chip(), timeout.as_nanos() as i64)
+        };
+
+        match ret {
+            -1 => Err(Error::OperationFailed(
+                "Gpio Chip info-event-wait",
+                IoError::last(),
+            )),
+            0 => Err(Error::OperationTimedOut),
+            _ => Ok(()),
+        }
+    }
+
+    /// Read a single line status change event from the chip. If no events are
+    /// pending, this function will block.
+    pub fn read_info_event(&self) -> Result<InfoEvent> {
+        InfoEvent::new(&self.ichip)
+    }
+
+    /// Map a GPIO line's name to its offset within the chip.
+    pub fn find_line(&self, name: &str) -> Result<u32> {
+        // Null-terminate the string
+        let name = name.to_owned() + "\0";
+
+        let ret = unsafe {
+            bindings::gpiod_chip_get_line_offset_from_name(
+                self.ichip.chip(),
+                name.as_ptr() as *const c_char,
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio Chip find-line",
+                IoError::last(),
+            ))
+        } else {
+            Ok(ret as u32)
+        }
+    }
+
+    /// Request a set of lines for exclusive usage.
+    pub fn request_lines(
+        &self,
+        rconfig: &RequestConfig,
+        lconfig: &LineConfig,
+    ) -> Result<LineRequest> {
+        LineRequest::new(&self.ichip, rconfig, lconfig)
+    }
+}
diff --git a/bindings/rust/src/chip_info.rs b/bindings/rust/src/chip_info.rs
new file mode 100644
index 000000000000..950368b54c6f
--- /dev/null
+++ b/bindings/rust/src/chip_info.rs
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use std::sync::Arc;
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{bindings, ChipInternal, Error, Result};
+
+/// GPIO chip Information
+pub struct ChipInfo {
+    info: *mut bindings::gpiod_chip_info,
+}
+
+impl ChipInfo {
+    /// Find a GPIO chip by path.
+    pub(crate) fn new(chip: Arc<ChipInternal>) -> Result<Self> {
+        let info = unsafe { bindings::gpiod_chip_get_info(chip.chip()) };
+        if info.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio Chip get info",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self { info })
+    }
+
+    /// Get the GPIO chip name as represented in the kernel.
+    pub(crate) fn name(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct Chip`.
+        let name = unsafe { bindings::gpiod_chip_info_get_name(self.info) };
+
+        // SAFETY: The string is guaranteed to be valid here.
+        str::from_utf8(unsafe {
+            slice::from_raw_parts(name as *const u8, bindings::strlen(name) as usize)
+        })
+        .map_err(Error::InvalidString)
+    }
+
+    /// Get the GPIO chip label as represented in the kernel.
+    pub(crate) fn label(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct Chip`.
+        let label = unsafe { bindings::gpiod_chip_info_get_label(self.info) };
+
+        // SAFETY: The string is guaranteed to be valid here.
+        str::from_utf8(unsafe {
+            slice::from_raw_parts(label as *const u8, bindings::strlen(label) as usize)
+        })
+        .map_err(Error::InvalidString)
+    }
+
+    /// Get the number of GPIO lines exposed by the chip.
+    pub(crate) fn num_lines(&self) -> u32 {
+        unsafe { bindings::gpiod_chip_info_get_num_lines(self.info) as u32 }
+    }
+}
+
+impl Drop for ChipInfo {
+    /// Close the GPIO chip info and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { bindings::gpiod_chip_info_free(self.info) }
+    }
+}
diff --git a/bindings/rust/src/edge_event.rs b/bindings/rust/src/edge_event.rs
new file mode 100644
index 000000000000..89bda58709d2
--- /dev/null
+++ b/bindings/rust/src/edge_event.rs
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use std::sync::Arc;
+use std::time::Duration;
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{bindings, EdgeEventBufferInternal, Error, LineEdgeEvent, Result};
+
+/// Line edge events handling
+///
+/// An edge event object contains information about a single line edge event.
+/// It contains the event type, timestamp and the offset of the line on which
+/// the event occurred as well as two sequence numbers (global for all lines
+/// in the associated request and local for this line only).
+///
+/// Edge events are stored into an edge-event buffer object to improve
+/// performance and to limit the number of memory allocations when a large
+/// number of events are being read.
+
+pub struct EdgeEvent {
+    ibuffer: Option<Arc<EdgeEventBufferInternal>>,
+    event: *mut bindings::gpiod_edge_event,
+}
+
+impl EdgeEvent {
+    /// Get an event stored in the buffer.
+    pub(crate) fn new(
+        ibuffer: &Arc<EdgeEventBufferInternal>,
+        index: u64,
+        copy: bool,
+    ) -> Result<Self> {
+        let event = unsafe { bindings::gpiod_edge_event_buffer_get_event(ibuffer.buffer(), index) };
+        if event.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio EdgeEvent buffer-get-event",
+                IoError::last(),
+            ));
+        }
+
+        if copy {
+            let event = unsafe { bindings::gpiod_edge_event_copy(event) };
+            if event.is_null() {
+                return Err(Error::OperationFailed(
+                    "Gpio EdgeEvent copy",
+                    IoError::last(),
+                ));
+            }
+
+            Ok(Self {
+                ibuffer: None,
+                event,
+            })
+        } else {
+            Ok(Self {
+                ibuffer: Some(ibuffer.clone()),
+                event,
+            })
+        }
+    }
+
+    /// Get the event type.
+    pub fn get_event_type(&self) -> Result<LineEdgeEvent> {
+        LineEdgeEvent::new(unsafe { bindings::gpiod_edge_event_get_event_type(self.event) } as u32)
+    }
+
+    /// Get the timestamp of the event.
+    pub fn get_timestamp(&self) -> Duration {
+        Duration::from_nanos(unsafe { bindings::gpiod_edge_event_get_timestamp_ns(self.event) })
+    }
+
+    /// Get the offset of the line on which the event was triggered.
+    pub fn get_line_offset(&self) -> u32 {
+        unsafe { bindings::gpiod_edge_event_get_line_offset(self.event) }
+    }
+
+    /// Get the global sequence number of the event.
+    ///
+    /// Returns sequence number of the event relative to all lines in the
+    /// associated line request.
+    pub fn get_global_seqno(&self) -> u64 {
+        unsafe { bindings::gpiod_edge_event_get_global_seqno(self.event) }
+    }
+
+    /// Get the event sequence number specific to concerned line.
+    ///
+    /// Returns sequence number of the event relative to the line within the
+    /// lifetime of the associated line request.
+    pub fn get_line_seqno(&self) -> u64 {
+        unsafe { bindings::gpiod_edge_event_get_line_seqno(self.event) }
+    }
+}
+
+impl Drop for EdgeEvent {
+    /// Free the edge event.
+    fn drop(&mut self) {
+        // Free the event only if a copy is made
+        if self.ibuffer.is_none() {
+            unsafe { bindings::gpiod_edge_event_free(self.event) };
+        }
+    }
+}
diff --git a/bindings/rust/src/event_buffer.rs b/bindings/rust/src/event_buffer.rs
new file mode 100644
index 000000000000..bb568a80e09c
--- /dev/null
+++ b/bindings/rust/src/event_buffer.rs
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use std::os::raw::c_ulong;
+use std::sync::Arc;
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{bindings, EdgeEvent, Error, Result};
+
+/// Line edge events buffer
+pub(crate) struct EdgeEventBufferInternal {
+    buffer: *mut bindings::gpiod_edge_event_buffer,
+}
+
+impl EdgeEventBufferInternal {
+    /// Create a new edge event buffer.
+    ///
+    /// If capacity equals 0, it will be set to a default value of 64. If
+    /// capacity is larger than 1024, it will be limited to 1024.
+    pub fn new(capacity: u32) -> Result<Self> {
+        let buffer = unsafe { bindings::gpiod_edge_event_buffer_new(capacity as c_ulong) };
+        if buffer.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio EdgeEventBuffer new",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self { buffer })
+    }
+
+    /// Private helper, Returns gpiod_edge_event_buffer
+    pub(crate) fn buffer(&self) -> *mut bindings::gpiod_edge_event_buffer {
+        self.buffer
+    }
+}
+
+impl Drop for EdgeEventBufferInternal {
+    /// Free the edge event buffer and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { bindings::gpiod_edge_event_buffer_free(self.buffer) };
+    }
+}
+
+/// Line edge events buffer
+pub struct EdgeEventBuffer {
+    ibuffer: Arc<EdgeEventBufferInternal>,
+}
+
+impl EdgeEventBuffer {
+    /// Create a new edge event buffer.
+    ///
+    /// If capacity equals 0, it will be set to a default value of 64. If
+    /// capacity is larger than 1024, it will be limited to 1024.
+    pub fn new(capacity: u32) -> Result<Self> {
+        Ok(Self {
+            ibuffer: Arc::new(EdgeEventBufferInternal::new(capacity)?),
+        })
+    }
+
+    /// Private helper, Returns gpiod_edge_event_buffer
+    pub(crate) fn buffer(&self) -> *mut bindings::gpiod_edge_event_buffer {
+        self.ibuffer.buffer()
+    }
+
+    /// Get the capacity of the event buffer.
+    pub fn get_capacity(&self) -> u32 {
+        unsafe { bindings::gpiod_edge_event_buffer_get_capacity(self.buffer()) as u32 }
+    }
+
+    /// Read an event stored in the buffer.
+    pub fn get_event(&self, index: u64) -> Result<EdgeEvent> {
+        EdgeEvent::new(&self.ibuffer, index, false)
+    }
+
+    /// Make copy of an edge event stored in the buffer.
+    pub fn get_event_copy(&self, index: u64) -> Result<EdgeEvent> {
+        EdgeEvent::new(&self.ibuffer, index, true)
+    }
+
+    /// Get the number of events the buffers stores.
+    pub fn get_num_events(&self) -> u32 {
+        unsafe { bindings::gpiod_edge_event_buffer_get_num_events(self.buffer()) as u32 }
+    }
+}
diff --git a/bindings/rust/src/info_event.rs b/bindings/rust/src/info_event.rs
new file mode 100644
index 000000000000..ffba23f350be
--- /dev/null
+++ b/bindings/rust/src/info_event.rs
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use std::convert::TryFrom;
+use std::sync::Arc;
+use std::time::Duration;
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{bindings, ChipInternal, Error, Event, LineInfo, Result};
+
+/// Line status watch events
+///
+/// Accessors for the info event objects allowing to monitor changes in GPIO
+/// line state.
+///
+/// Callers can be notified about changes in line's state using the interfaces
+/// exposed by GPIO chips. Each info event contains information about the event
+/// itself (timestamp, type) as well as a snapshot of line's state in the form
+/// of a line-info object.
+
+pub struct InfoEvent {
+    event: *mut bindings::gpiod_info_event,
+}
+
+impl InfoEvent {
+    /// Get a single chip's line's status change event.
+    pub(crate) fn new(ichip: &Arc<ChipInternal>) -> Result<Self> {
+        let event = unsafe { bindings::gpiod_chip_read_info_event(ichip.chip()) };
+        if event.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio InfoEvent event-read",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self { event })
+    }
+
+    /// Private helper, Returns gpiod_info_event
+    pub(crate) fn event(&self) -> *mut bindings::gpiod_info_event {
+        self.event
+    }
+
+    /// Get the event type of the status change event.
+    pub fn get_event_type(&self) -> Result<Event> {
+        Event::new(unsafe { bindings::gpiod_info_event_get_event_type(self.event) } as u32)
+    }
+
+    /// Get the timestamp of the event, read from the monotonic clock.
+    pub fn get_timestamp(&self) -> Duration {
+        Duration::from_nanos(unsafe { bindings::gpiod_info_event_get_timestamp_ns(self.event) })
+    }
+
+    /// Get the line-info object associated with the event.
+    pub fn line_info(&self) -> Result<LineInfo> {
+        LineInfo::try_from(self)
+    }
+}
+
+impl Drop for InfoEvent {
+    /// Free the info event object and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { bindings::gpiod_info_event_free(self.event) }
+    }
+}
diff --git a/bindings/rust/src/lib.rs b/bindings/rust/src/lib.rs
new file mode 100644
index 000000000000..2f2ac515d353
--- /dev/null
+++ b/bindings/rust/src/lib.rs
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Rust wrappers for GPIOD APIs
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+//! libgpiod public API
+//!
+//! This is the complete documentation of the public Rust API made available to
+//! users of libgpiod.
+//!
+//! The API is logically split into several parts such as: GPIO chip & line
+//! operators, GPIO events handling etc.
+
+mod chip;
+mod chip_info;
+mod edge_event;
+mod event_buffer;
+mod info_event;
+mod line_config;
+mod line_info;
+mod line_request;
+mod request_config;
+
+use libgpiod_sys as bindings;
+
+pub use crate::chip::*;
+pub use crate::edge_event::*;
+pub use crate::event_buffer::*;
+pub use crate::info_event::*;
+pub use crate::line_config::*;
+pub use crate::line_info::*;
+pub use crate::line_request::*;
+pub use crate::request_config::*;
+
+use std::os::raw::c_char;
+use std::{slice, str};
+
+use thiserror::Error as ThisError;
+use vmm_sys_util::errno::Error as IoError;
+
+/// Result of libgpiod operations
+pub type Result<T> = std::result::Result<T, Error>;
+
+/// Error codes for libgpiod operations
+#[derive(Copy, Clone, Debug, PartialEq, ThisError)]
+pub enum Error {
+    #[error("Failed to find {0}")]
+    NameNotFound(&'static str),
+    #[error("Invalid String: {0:?}")]
+    InvalidString(str::Utf8Error),
+    #[error("Invalid {0} value: {1}")]
+    InvalidValue(&'static str, u32),
+    #[error("Operation {0} Failed: {1}")]
+    OperationFailed(&'static str, IoError),
+    #[error("Operation Timed-out")]
+    OperationTimedOut,
+}
+
+/// Direction settings.
+pub enum Direction {
+    /// Request the line(s), but don't change direction.
+    AsIs,
+    /// Direction is input - for reading the value of an externally driven GPIO line.
+    Input,
+    /// Direction is output - for driving the GPIO line.
+    Output,
+}
+
+impl Direction {
+    fn new(dir: u32) -> Result<Self> {
+        match dir {
+            bindings::GPIOD_LINE_DIRECTION_AS_IS => Ok(Direction::AsIs),
+            bindings::GPIOD_LINE_DIRECTION_INPUT => Ok(Direction::Input),
+            bindings::GPIOD_LINE_DIRECTION_OUTPUT => Ok(Direction::Output),
+            _ => Err(Error::InvalidValue("direction", dir)),
+        }
+    }
+
+    fn gpiod_direction(&self) -> u32 {
+        match self {
+            Direction::AsIs => bindings::GPIOD_LINE_DIRECTION_AS_IS,
+            Direction::Input => bindings::GPIOD_LINE_DIRECTION_INPUT,
+            Direction::Output => bindings::GPIOD_LINE_DIRECTION_OUTPUT,
+        }
+    }
+}
+
+/// Internal bias settings.
+pub enum Bias {
+    /// Don't change the bias setting when applying line config.
+    AsIs,
+    /// The internal bias state is unknown.
+    Unknown,
+    /// The internal bias is disabled.
+    Disabled,
+    /// The internal pull-up bias is enabled.
+    PullUp,
+    /// The internal pull-down bias is enabled.
+    PullDown,
+}
+
+impl Bias {
+    fn new(bias: u32) -> Result<Self> {
+        match bias {
+            bindings::GPIOD_LINE_BIAS_AS_IS => Ok(Bias::AsIs),
+            bindings::GPIOD_LINE_BIAS_UNKNOWN => Ok(Bias::Unknown),
+            bindings::GPIOD_LINE_BIAS_DISABLED => Ok(Bias::Disabled),
+            bindings::GPIOD_LINE_BIAS_PULL_UP => Ok(Bias::PullUp),
+            bindings::GPIOD_LINE_BIAS_PULL_DOWN => Ok(Bias::PullDown),
+            _ => Err(Error::InvalidValue("bias", bias)),
+        }
+    }
+
+    fn gpiod_bias(&self) -> u32 {
+        match self {
+            Bias::AsIs => bindings::GPIOD_LINE_BIAS_AS_IS,
+            Bias::Unknown => bindings::GPIOD_LINE_BIAS_UNKNOWN,
+            Bias::Disabled => bindings::GPIOD_LINE_BIAS_DISABLED,
+            Bias::PullUp => bindings::GPIOD_LINE_BIAS_PULL_UP,
+            Bias::PullDown => bindings::GPIOD_LINE_BIAS_PULL_DOWN,
+        }
+    }
+}
+
+/// Drive settings.
+pub enum Drive {
+    /// Drive setting is push-pull.
+    PushPull,
+    /// Line output is open-drain.
+    OpenDrain,
+    /// Line output is open-source.
+    OpenSource,
+}
+
+impl Drive {
+    fn new(drive: u32) -> Result<Self> {
+        match drive {
+            bindings::GPIOD_LINE_DRIVE_PUSH_PULL => Ok(Drive::PushPull),
+            bindings::GPIOD_LINE_DRIVE_OPEN_DRAIN => Ok(Drive::OpenDrain),
+            bindings::GPIOD_LINE_DRIVE_OPEN_SOURCE => Ok(Drive::OpenSource),
+            _ => Err(Error::InvalidValue("drive", drive)),
+        }
+    }
+
+    fn gpiod_drive(&self) -> u32 {
+        match self {
+            Drive::PushPull => bindings::GPIOD_LINE_DRIVE_PUSH_PULL,
+            Drive::OpenDrain => bindings::GPIOD_LINE_DRIVE_OPEN_DRAIN,
+            Drive::OpenSource => bindings::GPIOD_LINE_DRIVE_OPEN_SOURCE,
+        }
+    }
+}
+
+/// Edge detection settings.
+pub enum Edge {
+    /// Line edge detection is disabled.
+    None,
+    /// Line detects rising edge events.
+    Rising,
+    /// Line detects falling edge events.
+    Falling,
+    /// Line detects both rising and falling edge events.
+    Both,
+}
+
+impl Edge {
+    fn new(edge: u32) -> Result<Self> {
+        match edge {
+            bindings::GPIOD_LINE_EDGE_NONE => Ok(Edge::None),
+            bindings::GPIOD_LINE_EDGE_RISING => Ok(Edge::Rising),
+            bindings::GPIOD_LINE_EDGE_FALLING => Ok(Edge::Falling),
+            bindings::GPIOD_LINE_EDGE_BOTH => Ok(Edge::Both),
+            _ => Err(Error::InvalidValue("edge", edge)),
+        }
+    }
+
+    fn gpiod_edge(&self) -> u32 {
+        match self {
+            Edge::None => bindings::GPIOD_LINE_EDGE_NONE,
+            Edge::Rising => bindings::GPIOD_LINE_EDGE_RISING,
+            Edge::Falling => bindings::GPIOD_LINE_EDGE_FALLING,
+            Edge::Both => bindings::GPIOD_LINE_EDGE_BOTH,
+        }
+    }
+}
+
+/// Line config settings.
+pub enum Config {
+    /// Line direction.
+    Direction,
+    /// Edge detection.
+    EdgeDetection,
+    /// Bias.
+    Bias,
+    /// Drive.
+    Drive,
+    /// Active-low setting.
+    ActiveLow,
+    /// Debounce period.
+    DebouncePeriodUs,
+    /// Event clock type.
+    EventClock,
+    /// Output value.
+    OutputValue,
+}
+
+impl Config {
+    fn new(config: u32) -> Result<Self> {
+        match config {
+            bindings::GPIOD_LINE_CONFIG_PROP_DIRECTION => Ok(Config::Direction),
+            bindings::GPIOD_LINE_CONFIG_PROP_EDGE_DETECTION => Ok(Config::EdgeDetection),
+            bindings::GPIOD_LINE_CONFIG_PROP_BIAS => Ok(Config::Bias),
+            bindings::GPIOD_LINE_CONFIG_PROP_DRIVE => Ok(Config::Drive),
+            bindings::GPIOD_LINE_CONFIG_PROP_ACTIVE_LOW => Ok(Config::ActiveLow),
+            bindings::GPIOD_LINE_CONFIG_PROP_DEBOUNCE_PERIOD_US => Ok(Config::DebouncePeriodUs),
+            bindings::GPIOD_LINE_CONFIG_PROP_EVENT_CLOCK => Ok(Config::EventClock),
+            bindings::GPIOD_LINE_CONFIG_PROP_OUTPUT_VALUE => Ok(Config::OutputValue),
+            _ => Err(Error::InvalidValue("config", config)),
+        }
+    }
+}
+
+/// Event clock settings.
+pub enum EventClock {
+    /// Line uses the monotonic clock for edge event timestamps.
+    Monotonic,
+    /// Line uses the realtime clock for edge event timestamps.
+    Realtime,
+}
+
+impl EventClock {
+    fn new(clock: u32) -> Result<Self> {
+        match clock {
+            bindings::GPIOD_LINE_EVENT_CLOCK_MONOTONIC => Ok(EventClock::Monotonic),
+            bindings::GPIOD_LINE_EVENT_CLOCK_REALTIME => Ok(EventClock::Realtime),
+            _ => Err(Error::InvalidValue("event clock", clock)),
+        }
+    }
+
+    fn gpiod_clock(&self) -> u32 {
+        match self {
+            EventClock::Monotonic => bindings::GPIOD_LINE_EVENT_CLOCK_MONOTONIC,
+            EventClock::Realtime => bindings::GPIOD_LINE_EVENT_CLOCK_REALTIME,
+        }
+    }
+}
+
+/// Line status change event types.
+pub enum Event {
+    /// Line has been requested.
+    LineRequested,
+    /// Previously requested line has been released.
+    LineReleased,
+    /// Line configuration has changed.
+    LineConfigChanged,
+}
+
+impl Event {
+    fn new(event: u32) -> Result<Self> {
+        match event {
+            bindings::GPIOD_INFO_EVENT_LINE_REQUESTED => Ok(Event::LineRequested),
+            bindings::GPIOD_INFO_EVENT_LINE_RELEASED => Ok(Event::LineReleased),
+            bindings::GPIOD_INFO_EVENT_LINE_CONFIG_CHANGED => Ok(Event::LineConfigChanged),
+            _ => Err(Error::InvalidValue("event", event)),
+        }
+    }
+}
+
+#[derive(Copy, Clone)]
+/// Edge event types.
+pub enum LineEdgeEvent {
+    /// Rising edge event.
+    Rising,
+    /// Falling edge event.
+    Falling,
+}
+
+impl LineEdgeEvent {
+    fn new(event: u32) -> Result<Self> {
+        match event {
+            bindings::GPIOD_EDGE_EVENT_RISING_EDGE => Ok(LineEdgeEvent::Rising),
+            bindings::GPIOD_EDGE_EVENT_FALLING_EDGE => Ok(LineEdgeEvent::Falling),
+            _ => Err(Error::InvalidValue("edge event", event)),
+        }
+    }
+}
+
+/// Various libgpiod-related functions.
+
+/// Check if the file pointed to by path is a GPIO chip character device.
+///
+/// Returns true if the file exists and is a GPIO chip character device or a
+/// symbolic link to it.
+pub fn gpiod_is_gpiochip_device(path: &str) -> bool {
+    // Null-terminate the string
+    let path = path.to_owned() + "\0";
+
+    unsafe { bindings::gpiod_is_gpiochip_device(path.as_ptr() as *const c_char) }
+}
+
+/// Get the API version of the library as a human-readable string.
+pub fn gpiod_version_string() -> Result<&'static str> {
+    // SAFETY: The string returned by libgpiod is guaranteed to live forever.
+    let version = unsafe { bindings::gpiod_version_string() };
+
+    if version.is_null() {
+        return Err(Error::NameNotFound("GPIO library version"));
+    }
+
+    // SAFETY: The string is guaranteed to be valid here.
+    str::from_utf8(unsafe {
+        slice::from_raw_parts(version as *const u8, bindings::strlen(version) as usize)
+    })
+    .map_err(Error::InvalidString)
+}
diff --git a/bindings/rust/src/line_config.rs b/bindings/rust/src/line_config.rs
new file mode 100644
index 000000000000..0fc8d0b736a3
--- /dev/null
+++ b/bindings/rust/src/line_config.rs
@@ -0,0 +1,493 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use libc::EINVAL;
+use std::os::raw::c_ulong;
+use std::time::Duration;
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{bindings, Bias, Config, Direction, Drive, Edge, Error, EventClock, Result};
+
+/// Line configuration objects.
+///
+/// The line-config object contains the configuration for lines that can be
+/// used in two cases:
+///  - when making a line request
+///  - when reconfiguring a set of already requested lines.
+///
+/// A new line-config object is instantiated with a set of sane defaults
+/// for all supported configuration settings. Those defaults can be modified by
+/// the caller. Default values can be overridden by applying different values
+/// for specific lines. When making a request or reconfiguring an existing one,
+/// the overridden settings for specific lines take precedence. For lines
+/// without an override the requested default settings are used.
+///
+/// For every setting there are two mutators (one setting the default and one
+/// for the per-line override), two getters (one for reading the global
+/// default and one for retrieving the effective value for the line),
+/// a function for testing if a setting is overridden for the line
+/// and finally a function for clearing the overrides (per line).
+///
+/// The mutators don't return errors. If the set of options is too complex to
+/// be translated into kernel uAPI structures then an error will be returned at
+/// the time of the request or reconfiguration. If an invalid value was passed
+/// to any of the mutators then the default value will be silently used instead.
+///
+/// Operating on lines in struct LineConfig has no immediate effect on real
+/// GPIOs, it only manipulates the config object in memory.  Those changes are
+/// only applied to the hardware at the time of the request or reconfiguration.
+///
+/// Overrides for lines that don't end up being requested are silently ignored
+/// both in LineRequest::new() as well as in LineRequest::reconfigure_lines().
+///
+/// In cases where all requested lines are using the one configuration, the
+/// line overrides can be entirely ignored when preparing the configuration.
+
+pub struct LineConfig {
+    config: *mut bindings::gpiod_line_config,
+}
+
+impl LineConfig {
+    /// Create a new line config object.
+    pub fn new() -> Result<Self> {
+        let config = unsafe { bindings::gpiod_line_config_new() };
+
+        if config.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio LineConfig new",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self { config })
+    }
+
+    /// Private helper, Returns gpiod_line_config
+    pub(crate) fn config(&self) -> *mut bindings::gpiod_line_config {
+        self.config
+    }
+
+    /// Resets the entire configuration stored in the object. This is useful if
+    /// the user wants to reuse the object without reallocating it.
+    pub fn reset(&mut self) {
+        unsafe { bindings::gpiod_line_config_reset(self.config) }
+    }
+
+    /// Set the default line direction.
+    pub fn set_direction_default(&mut self, direction: Direction) {
+        unsafe {
+            bindings::gpiod_line_config_set_direction_default(
+                self.config,
+                direction.gpiod_direction() as i32,
+            )
+        }
+    }
+
+    /// Set the direction for a line.
+    pub fn set_direction_override(&mut self, direction: Direction, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_direction_override(
+                self.config,
+                direction.gpiod_direction() as i32,
+                offset,
+            )
+        }
+    }
+
+    /// Clear the direction for a line.
+    pub fn clear_direction_override(&mut self, offset: u32) {
+        unsafe { bindings::gpiod_line_config_clear_direction_override(self.config, offset) }
+    }
+
+    /// Check if the direction is overridden for a line.
+    pub fn direction_is_overridden(&self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_direction_is_overridden(self.config, offset) }
+    }
+
+    /// Get the default direction setting.
+    pub fn get_direction_default(&self) -> Result<Direction> {
+        Direction::new(
+            unsafe { bindings::gpiod_line_config_get_direction_default(self.config) } as u32,
+        )
+    }
+
+    /// Get the direction of a given line.
+    ///
+    /// Direction setting for the line if the config object were used in a request.
+    pub fn get_direction_offset(&self, offset: u32) -> Result<Direction> {
+        Direction::new(unsafe {
+            bindings::gpiod_line_config_get_direction_offset(self.config, offset)
+        } as u32)
+    }
+
+    /// Set the default edge event detection setting.
+    pub fn set_edge_detection_default(&mut self, edge: Edge) {
+        unsafe {
+            bindings::gpiod_line_config_set_edge_detection_default(
+                self.config,
+                edge.gpiod_edge() as i32,
+            )
+        }
+    }
+
+    /// Set the edge event detection for a single line.
+    pub fn set_edge_detection_override(&mut self, edge: Edge, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_edge_detection_override(
+                self.config,
+                edge.gpiod_edge() as i32,
+                offset,
+            )
+        }
+    }
+
+    /// Clear the edge event detection for a single line.
+    pub fn clear_edge_detection_override(&mut self, offset: u32) {
+        unsafe { bindings::gpiod_line_config_clear_edge_detection_override(self.config, offset) }
+    }
+
+    /// Check if the edge event detection is overridden for a line.
+    pub fn edge_detection_is_overridden(&self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_edge_detection_is_overridden(self.config, offset) }
+    }
+
+    /// Get the default edge event detection setting.
+    pub fn get_edge_detection_default(&self) -> Result<Edge> {
+        Edge::new(
+            unsafe { bindings::gpiod_line_config_get_edge_detection_default(self.config) } as u32,
+        )
+    }
+
+    /// Get the edge event detection setting for a given line.
+    ///
+    /// Edge event detection setting for the line if the config object were used in a request.
+    pub fn get_edge_detection_offset(&self, offset: u32) -> Result<Edge> {
+        Edge::new(unsafe {
+            bindings::gpiod_line_config_get_edge_detection_offset(self.config, offset)
+        } as u32)
+    }
+
+    /// Set the default bias setting.
+    pub fn set_bias_default(&mut self, bias: Bias) {
+        unsafe {
+            bindings::gpiod_line_config_set_bias_default(self.config, bias.gpiod_bias() as i32)
+        }
+    }
+
+    /// Set the bias for a single line.
+    pub fn set_bias_override(&mut self, bias: Bias, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_bias_override(
+                self.config,
+                bias.gpiod_bias() as i32,
+                offset,
+            )
+        }
+    }
+
+    /// Clear the bias for a single line.
+    pub fn clear_bias_override(&mut self, offset: u32) {
+        unsafe { bindings::gpiod_line_config_clear_bias_override(self.config, offset) }
+    }
+
+    /// Check if the bias is overridden for a line.
+    pub fn bias_is_overridden(&self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_bias_is_overridden(self.config, offset) }
+    }
+
+    /// Get the default bias setting.
+    pub fn get_bias_default(&self) -> Result<Bias> {
+        Bias::new(unsafe { bindings::gpiod_line_config_get_bias_default(self.config) } as u32)
+    }
+
+    /// Get the bias setting for a given line.
+    ///
+    /// Bias setting used for the line if the config object were used in a request.
+    pub fn get_bias_offset(&self, offset: u32) -> Result<Bias> {
+        Bias::new(
+            unsafe { bindings::gpiod_line_config_get_bias_offset(self.config, offset) } as u32,
+        )
+    }
+
+    /// Set the default drive setting.
+    pub fn set_drive_default(&mut self, drive: Drive) {
+        unsafe {
+            bindings::gpiod_line_config_set_drive_default(self.config, drive.gpiod_drive() as i32)
+        }
+    }
+
+    /// Set the drive for a single line.
+    pub fn set_drive_override(&mut self, drive: Drive, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_drive_override(
+                self.config,
+                drive.gpiod_drive() as i32,
+                offset,
+            )
+        }
+    }
+
+    /// clear the drive for a single line.
+    pub fn clear_drive_override(&mut self, offset: u32) {
+        unsafe { bindings::gpiod_line_config_clear_drive_override(self.config, offset) }
+    }
+
+    /// Check if the drive is overridden for a line.
+    pub fn drive_is_overridden(&self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_drive_is_overridden(self.config, offset) }
+    }
+
+    /// Get the default drive setting.
+    pub fn get_drive_default(&self) -> Result<Drive> {
+        Drive::new(unsafe { bindings::gpiod_line_config_get_drive_default(self.config) } as u32)
+    }
+
+    /// Get the drive setting for a given line.
+    ///
+    /// The offset of the line for which to read the drive setting. Drive setting for the line if
+    /// the config object were used in a request.
+    pub fn get_drive_offset(&self, offset: u32) -> Result<Drive> {
+        Drive::new(
+            unsafe { bindings::gpiod_line_config_get_drive_offset(self.config, offset) } as u32,
+        )
+    }
+
+    /// Set default active-low setting.
+    pub fn set_active_low_default(&mut self, active_low: bool) {
+        unsafe { bindings::gpiod_line_config_set_active_low_default(self.config, active_low) }
+    }
+
+    /// Set active-low setting for a single line.
+    pub fn set_active_low_override(&mut self, active_low: bool, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_active_low_override(self.config, active_low, offset)
+        }
+    }
+
+    /// Clear a single line's active-low setting.
+    pub fn clear_active_low_override(&mut self, offset: u32) {
+        unsafe { bindings::gpiod_line_config_clear_active_low_override(self.config, offset) }
+    }
+
+    /// Check if the active-low is overridden for a line.
+    pub fn active_low_is_overridden(&mut self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_active_low_is_overridden(self.config, offset) }
+    }
+
+    /// Check the default active-low setting.
+    pub fn get_active_low_default(&self) -> bool {
+        unsafe { bindings::gpiod_line_config_get_active_low_default(self.config) }
+    }
+
+    /// Check the active-low setting of a line.
+    ///
+    /// Active-low setting for the line if the config object were used in a request.
+    pub fn get_active_low_offset(&self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_get_active_low_offset(self.config, offset) }
+    }
+
+    /// Set the deafult debounce period setting.
+    pub fn set_debounce_period_default(&mut self, period: Duration) {
+        unsafe {
+            bindings::gpiod_line_config_set_debounce_period_us_default(
+                self.config,
+                period.as_micros() as u64,
+            )
+        }
+    }
+
+    /// Set the debounce period for a single line.
+    pub fn set_debounce_period_override(&mut self, period: Duration, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_debounce_period_us_override(
+                self.config,
+                period.as_micros() as u64,
+                offset,
+            )
+        }
+    }
+
+    /// Clear the debounce period for a single line.
+    pub fn clear_debounce_period_override(&mut self, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_clear_debounce_period_us_override(self.config, offset)
+        }
+    }
+
+    /// Check if the debounce period setting is overridden.
+    pub fn debounce_period_is_overridden(&self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_debounce_period_us_is_overridden(self.config, offset) }
+    }
+
+    /// Get the default debounce period.
+    pub fn get_debounce_period_default(&self) -> Result<Duration> {
+        Ok(Duration::from_micros(unsafe {
+            bindings::gpiod_line_config_get_debounce_period_us_default(self.config)
+        }))
+    }
+
+    /// Get the debounce period for a given line.
+    ///
+    /// Debounce period for the line if the config object were used in a request, 0 if debouncing
+    /// is disabled.
+    pub fn get_debounce_period_offset(&self, offset: u32) -> Result<Duration> {
+        Ok(Duration::from_micros(unsafe {
+            bindings::gpiod_line_config_get_debounce_period_us_offset(self.config, offset)
+        }))
+    }
+
+    /// Set the default event clock setting.
+    pub fn set_event_clock_default(&mut self, clock: EventClock) {
+        unsafe {
+            bindings::gpiod_line_config_set_event_clock_default(
+                self.config,
+                clock.gpiod_clock() as i32,
+            )
+        }
+    }
+
+    /// Set the event clock for a single line.
+    pub fn set_event_clock_override(&mut self, clock: EventClock, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_event_clock_override(
+                self.config,
+                clock.gpiod_clock() as i32,
+                offset,
+            )
+        }
+    }
+
+    /// Clear the event clock for a single line.
+    pub fn clear_event_clock_override(&mut self, offset: u32) {
+        unsafe { bindings::gpiod_line_config_clear_event_clock_override(self.config, offset) }
+    }
+
+    /// Check if the event clock is overridden for a line.
+    pub fn event_clock_is_overridden(&mut self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_event_clock_is_overridden(self.config, offset) }
+    }
+
+    /// Get the default event clock setting.
+    pub fn get_event_clock_default(&self) -> Result<EventClock> {
+        EventClock::new(
+            unsafe { bindings::gpiod_line_config_get_event_clock_default(self.config) } as u32,
+        )
+    }
+
+    /// Get the event clock setting for a given line.
+    ///
+    /// Event clock setting for the line if the config object were used in a request.
+    pub fn get_event_clock_offset(&self, offset: u32) -> Result<EventClock> {
+        EventClock::new(unsafe {
+            bindings::gpiod_line_config_get_event_clock_offset(self.config, offset)
+        } as u32)
+    }
+
+    /// Set the default output value setting.
+    pub fn set_output_value_default(&mut self, value: u32) {
+        unsafe { bindings::gpiod_line_config_set_output_value_default(self.config, value as i32) }
+    }
+
+    /// Set the output value for a line.
+    pub fn set_output_value_override(&mut self, value: u32, offset: u32) {
+        unsafe {
+            bindings::gpiod_line_config_set_output_value_override(self.config, value as i32, offset)
+        }
+    }
+
+    /// Set the output values for a set of lines.
+    pub fn set_output_values(&mut self, offsets: &[u32], values: &[i32]) -> Result<()> {
+        if offsets.len() != values.len() {
+            return Err(Error::OperationFailed(
+                "Gpio LineConfig array size mismatch",
+                IoError::new(EINVAL),
+            ));
+        }
+
+        unsafe {
+            bindings::gpiod_line_config_set_output_values(
+                self.config,
+                values.len() as c_ulong,
+                offsets.as_ptr(),
+                values.as_ptr(),
+            );
+        }
+
+        Ok(())
+    }
+
+    /// Clear the output value for a line.
+    pub fn clear_output_value_override(&mut self, offset: u32) {
+        unsafe { bindings::gpiod_line_config_clear_output_value_override(self.config, offset) }
+    }
+
+    /// Check if the output value is overridden for a line.
+    pub fn output_value_is_overridden(&self, offset: u32) -> bool {
+        unsafe { bindings::gpiod_line_config_output_value_is_overridden(self.config, offset) }
+    }
+
+    /// Get the default output value, 0 or 1.
+    pub fn get_output_value_default(&self) -> Result<u32> {
+        let value = unsafe { bindings::gpiod_line_config_get_output_value_default(self.config) };
+
+        if value != 0 && value != 1 {
+            Err(Error::OperationFailed(
+                "Gpio LineConfig get-output-value",
+                IoError::last(),
+            ))
+        } else {
+            Ok(value as u32)
+        }
+    }
+
+    /// Get the output value configured for a given line, 0 or 1.
+    pub fn get_output_value_offset(&self, offset: u32) -> Result<u32> {
+        let value =
+            unsafe { bindings::gpiod_line_config_get_output_value_offset(self.config, offset) };
+
+        if value != 0 && value != 1 {
+            Err(Error::OperationFailed(
+                "Gpio LineConfig get-output-value",
+                IoError::last(),
+            ))
+        } else {
+            Ok(value as u32)
+        }
+    }
+
+    /// Get the list of overridden offsets and the corresponding types of overridden settings.
+    pub fn get_overrides(&self) -> Result<Vec<(u32, Config)>> {
+        let num = unsafe { bindings::gpiod_line_config_get_num_overrides(self.config) } as usize;
+        if num == 0 {
+            return Ok(Vec::new());
+        }
+
+        let mut overrides = Vec::new();
+        let mut offset = vec![0_u32; num];
+        let mut props = vec![0_i32; num];
+
+        unsafe {
+            bindings::gpiod_line_config_get_overrides(
+                self.config,
+                offset.as_mut_ptr(),
+                props.as_mut_ptr(),
+            )
+        };
+
+        for i in 0..num {
+            overrides.push((offset[i], Config::new(props[i] as u32)?));
+        }
+
+        Ok(overrides)
+    }
+}
+
+impl Drop for LineConfig {
+    /// Free the line config object and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { bindings::gpiod_line_config_free(self.config) }
+    }
+}
diff --git a/bindings/rust/src/line_info.rs b/bindings/rust/src/line_info.rs
new file mode 100644
index 000000000000..70b6bd6a84bb
--- /dev/null
+++ b/bindings/rust/src/line_info.rs
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use std::convert::TryFrom;
+use std::sync::Arc;
+use std::time::Duration;
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{
+    bindings, Bias, ChipInternal, Direction, Drive, Edge, Error, EventClock, InfoEvent, Result,
+};
+
+/// Line info
+///
+/// Exposes functions for retrieving kernel information about both requested and
+/// free lines.  Line info object contains an immutable snapshot of a line's status.
+///
+/// The line info contains all the publicly available information about a
+/// line, which does not include the line value.  The line must be requested
+/// to access the line value.
+
+pub struct LineInfo {
+    info: *mut bindings::gpiod_line_info,
+    ichip: Option<Arc<ChipInternal>>,
+    free: bool,
+}
+
+impl LineInfo {
+    /// Get a snapshot of information about the line and optionally start watching it for changes.
+    pub(crate) fn new(ichip: Arc<ChipInternal>, offset: u32, watch: bool) -> Result<Self> {
+        let info = if watch {
+            unsafe { bindings::gpiod_chip_watch_line_info(ichip.chip(), offset) }
+        } else {
+            unsafe { bindings::gpiod_chip_get_line_info(ichip.chip(), offset) }
+        };
+
+        if info.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio LineInfo line-info",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self {
+            info,
+            ichip: if watch { Some(ichip) } else { None },
+            free: watch,
+        })
+    }
+
+    /// Stop watching the line
+    pub fn unwatch(&mut self) {
+        if let Some(ichip) = &self.ichip {
+            unsafe {
+                bindings::gpiod_chip_unwatch_line_info(ichip.chip(), self.get_offset());
+            }
+            self.ichip = None;
+        }
+    }
+
+    /// Get the offset of the line within the GPIO chip.
+    ///
+    /// The offset uniquely identifies the line on the chip. The combination of the chip and offset
+    /// uniquely identifies the line within the system.
+
+    pub fn get_offset(&self) -> u32 {
+        unsafe { bindings::gpiod_line_info_get_offset(self.info) }
+    }
+
+    /// Get GPIO line's name.
+    pub fn get_name(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct LineInfo`.
+        let name = unsafe { bindings::gpiod_line_info_get_name(self.info) };
+        if name.is_null() {
+            return Err(Error::NameNotFound("GPIO line's name"));
+        }
+
+        // SAFETY: The string is guaranteed to be valid here.
+        str::from_utf8(unsafe {
+            slice::from_raw_parts(name as *const u8, bindings::strlen(name) as usize)
+        })
+        .map_err(Error::InvalidString)
+    }
+
+    /// Returns True if the line is in use, false otherwise.
+    ///
+    /// The user space can't know exactly why a line is busy. It may have been
+    /// requested by another process or hogged by the kernel. It only matters that
+    /// the line is used and we can't request it.
+    pub fn is_used(&self) -> bool {
+        unsafe { bindings::gpiod_line_info_is_used(self.info) }
+    }
+
+    /// Get the GPIO line's consumer name.
+    pub fn get_consumer(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct LineInfo`.
+        let name = unsafe { bindings::gpiod_line_info_get_consumer(self.info) };
+        if name.is_null() {
+            return Err(Error::NameNotFound("GPIO line's consumer name"));
+        }
+
+        // SAFETY: The string is guaranteed to be valid here.
+        str::from_utf8(unsafe {
+            slice::from_raw_parts(name as *const u8, bindings::strlen(name) as usize)
+        })
+        .map_err(Error::InvalidString)
+    }
+
+    /// Get the GPIO line's direction.
+    pub fn get_direction(&self) -> Result<Direction> {
+        Direction::new(unsafe { bindings::gpiod_line_info_get_direction(self.info) } as u32)
+    }
+
+    /// Returns true if the line is "active-low", false otherwise.
+    pub fn is_active_low(&self) -> bool {
+        unsafe { bindings::gpiod_line_info_is_active_low(self.info) }
+    }
+
+    /// Get the GPIO line's bias setting.
+    pub fn get_bias(&self) -> Result<Bias> {
+        Bias::new(unsafe { bindings::gpiod_line_info_get_bias(self.info) } as u32)
+    }
+
+    /// Get the GPIO line's drive setting.
+    pub fn get_drive(&self) -> Result<Drive> {
+        Drive::new(unsafe { bindings::gpiod_line_info_get_drive(self.info) } as u32)
+    }
+
+    /// Get the current edge detection setting of the line.
+    pub fn get_edge_detection(&self) -> Result<Edge> {
+        Edge::new(unsafe { bindings::gpiod_line_info_get_edge_detection(self.info) } as u32)
+    }
+
+    /// Get the current event clock setting used for edge event timestamps.
+    pub fn get_event_clock(&self) -> Result<EventClock> {
+        EventClock::new(unsafe { bindings::gpiod_line_info_get_event_clock(self.info) } as u32)
+    }
+
+    /// Returns true if the line is debounced (either by hardware or by the
+    /// kernel software debouncer), false otherwise.
+    pub fn is_debounced(&self) -> bool {
+        unsafe { bindings::gpiod_line_info_is_debounced(self.info) }
+    }
+
+    /// Get the debounce period of the line.
+    pub fn get_debounce_period(&self) -> Duration {
+        Duration::from_micros(unsafe {
+            bindings::gpiod_line_info_get_debounce_period_us(self.info)
+        })
+    }
+}
+
+impl TryFrom<&InfoEvent> for LineInfo {
+    type Error = Error;
+
+    /// Get the Line info object associated with a event.
+    fn try_from(event: &InfoEvent) -> Result<Self> {
+        let info = unsafe { bindings::gpiod_info_event_get_line_info(event.event()) };
+        if info.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio LineInfo try-from",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self {
+            info,
+            ichip: None,
+            free: false,
+        })
+    }
+}
+
+impl Drop for LineInfo {
+    fn drop(&mut self) {
+        // We must not free the Line info object created from `struct InfoEvent` by calling
+        // libgpiod API.
+        if self.free {
+            self.unwatch();
+            unsafe { bindings::gpiod_line_info_free(self.info) }
+        }
+    }
+}
diff --git a/bindings/rust/src/line_request.rs b/bindings/rust/src/line_request.rs
new file mode 100644
index 000000000000..bb338e72671d
--- /dev/null
+++ b/bindings/rust/src/line_request.rs
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use libc::EINVAL;
+use std::os::raw::c_ulong;
+use std::sync::Arc;
+use std::time::Duration;
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{bindings, ChipInternal, EdgeEventBuffer, Error, LineConfig, RequestConfig, Result};
+
+/// Line request operations
+///
+/// Allows interaction with a set of requested lines.
+pub struct LineRequest {
+    request: *mut bindings::gpiod_line_request,
+}
+
+impl LineRequest {
+    /// Request a set of lines for exclusive usage.
+    pub(crate) fn new(
+        ichip: &Arc<ChipInternal>,
+        rconfig: &RequestConfig,
+        lconfig: &LineConfig,
+    ) -> Result<Self> {
+        let request = unsafe {
+            bindings::gpiod_chip_request_lines(ichip.chip(), rconfig.config(), lconfig.config())
+        };
+
+        if request.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio LineRequest request-lines",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self { request })
+    }
+
+    /// Get the number of lines in the request.
+    pub fn get_num_lines(&self) -> u32 {
+        unsafe { bindings::gpiod_line_request_get_num_lines(self.request) as u32 }
+    }
+
+    /// Get the offsets of lines in the request.
+    pub fn get_offsets(&self) -> Vec<u32> {
+        let mut offsets = vec![0; self.get_num_lines() as usize];
+
+        unsafe { bindings::gpiod_line_request_get_offsets(self.request, offsets.as_mut_ptr()) };
+        offsets
+    }
+
+    /// Get the value (0 or 1) of a single line associated with the request.
+    pub fn get_value(&self, offset: u32) -> Result<u32> {
+        let value = unsafe { bindings::gpiod_line_request_get_value(self.request, offset) };
+
+        if value != 0 && value != 1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest get-value",
+                IoError::last(),
+            ))
+        } else {
+            Ok(value as u32)
+        }
+    }
+
+    /// Get values of a subset of lines associated with the request.
+    pub fn get_values_subset(&self, offsets: &[u32], values: &mut Vec<i32>) -> Result<()> {
+        if offsets.len() != values.len() {
+            return Err(Error::OperationFailed(
+                "Gpio LineRequest array size mismatch",
+                IoError::new(EINVAL),
+            ));
+        }
+
+        let ret = unsafe {
+            bindings::gpiod_line_request_get_values_subset(
+                self.request,
+                offsets.len() as c_ulong,
+                offsets.as_ptr(),
+                values.as_mut_ptr(),
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest get-values-subset",
+                IoError::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get values of all lines associated with the request.
+    pub fn get_values(&self, values: &mut Vec<i32>) -> Result<()> {
+        if values.len() != self.get_num_lines() as usize {
+            return Err(Error::OperationFailed(
+                "Gpio LineRequest array size mismatch",
+                IoError::new(EINVAL),
+            ));
+        }
+
+        let ret =
+            unsafe { bindings::gpiod_line_request_get_values(self.request, values.as_mut_ptr()) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest get-values",
+                IoError::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Set the value of a single line associated with the request.
+    pub fn set_value(&self, offset: u32, value: i32) -> Result<()> {
+        let ret = unsafe { bindings::gpiod_line_request_set_value(self.request, offset, !!value) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest set-value",
+                IoError::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get values of a subset of lines associated with the request.
+    pub fn set_values_subset(&self, offsets: &[u32], values: &[i32]) -> Result<()> {
+        if offsets.len() != values.len() {
+            return Err(Error::OperationFailed(
+                "Gpio LineRequest array size mismatch",
+                IoError::new(EINVAL),
+            ));
+        }
+
+        let ret = unsafe {
+            bindings::gpiod_line_request_set_values_subset(
+                self.request,
+                offsets.len() as c_ulong,
+                offsets.as_ptr(),
+                values.as_ptr(),
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest set-values-subset",
+                IoError::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get values of all lines associated with the request.
+    pub fn set_values(&self, values: &[i32]) -> Result<()> {
+        if values.len() != self.get_num_lines() as usize {
+            return Err(Error::OperationFailed(
+                "Gpio LineRequest array size mismatch",
+                IoError::new(EINVAL),
+            ));
+        }
+
+        let ret = unsafe { bindings::gpiod_line_request_set_values(self.request, values.as_ptr()) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest set-values",
+                IoError::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Update the configuration of lines associated with the line request.
+    pub fn reconfigure_lines(&self, lconfig: &LineConfig) -> Result<()> {
+        let ret = unsafe {
+            bindings::gpiod_line_request_reconfigure_lines(self.request, lconfig.config())
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest reconfigure-lines",
+                IoError::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the file descriptor associated with the line request.
+    pub fn get_fd(&self) -> u32 {
+        unsafe { bindings::gpiod_line_request_get_fd(self.request) as u32 }
+    }
+
+    /// Wait for edge events on any of the lines associated with the request.
+    pub fn wait_edge_event(&self, timeout: Duration) -> Result<()> {
+        let ret = unsafe {
+            bindings::gpiod_line_request_wait_edge_event(self.request, timeout.as_nanos() as i64)
+        };
+
+        match ret {
+            -1 => Err(Error::OperationFailed(
+                "Gpio LineRequest edge-event-wait",
+                IoError::last(),
+            )),
+            0 => Err(Error::OperationTimedOut),
+            _ => Ok(()),
+        }
+    }
+
+    /// Get a number of edge events from a line request.
+    ///
+    /// This function will block if no event was queued for the line.
+    pub fn read_edge_event(&self, buffer: &EdgeEventBuffer, max_events: u32) -> Result<u32> {
+        let ret = unsafe {
+            bindings::gpiod_line_request_read_edge_event(
+                self.request,
+                buffer.buffer(),
+                max_events as c_ulong,
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                "Gpio LineRequest edge-event-read",
+                IoError::last(),
+            ))
+        } else {
+            Ok(ret as u32)
+        }
+    }
+}
+
+impl Drop for LineRequest {
+    /// Release the requested lines and free all associated resources.
+    fn drop(&mut self) {
+        unsafe { bindings::gpiod_line_request_release(self.request) }
+    }
+}
diff --git a/bindings/rust/src/request_config.rs b/bindings/rust/src/request_config.rs
new file mode 100644
index 000000000000..3e667d28cc1f
--- /dev/null
+++ b/bindings/rust/src/request_config.rs
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
+
+use std::os::raw::{c_char, c_ulong};
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as IoError;
+
+use super::{bindings, Error, Result};
+
+/// Request configuration objects
+///
+/// Request config objects are used to pass a set of options to the kernel at
+/// the time of the line request. Similarly to the line-config - the mutators
+/// don't return error values. If the values are invalid, in general they are
+/// silently adjusted to acceptable ranges.
+
+pub struct RequestConfig {
+    config: *mut bindings::gpiod_request_config,
+}
+
+impl RequestConfig {
+    /// Create a new request config object.
+    pub fn new() -> Result<Self> {
+        let config = unsafe { bindings::gpiod_request_config_new() };
+        if config.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio RequestConfig new",
+                IoError::last(),
+            ));
+        }
+
+        Ok(Self { config })
+    }
+
+    /// Private helper, Returns gpiod_request_config
+    pub(crate) fn config(&self) -> *mut bindings::gpiod_request_config {
+        self.config
+    }
+
+    /// Set the consumer name for the request.
+    ///
+    /// If the consumer string is too long, it will be truncated to the max
+    /// accepted length.
+    pub fn set_consumer(&self, consumer: &str) {
+        // Null-terminate the string
+        let consumer = consumer.to_owned() + "\0";
+
+        unsafe {
+            bindings::gpiod_request_config_set_consumer(
+                self.config,
+                consumer.as_ptr() as *const c_char,
+            )
+        }
+    }
+
+    /// Get the consumer name configured in the request config.
+    pub fn get_consumer(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct RequestConfig`.
+        let consumer = unsafe { bindings::gpiod_request_config_get_consumer(self.config) };
+        if consumer.is_null() {
+            return Err(Error::OperationFailed(
+                "Gpio RequestConfig get-consumer",
+                IoError::last(),
+            ));
+        }
+
+        // SAFETY: The string is guaranteed to be valid here.
+        str::from_utf8(unsafe {
+            slice::from_raw_parts(consumer as *const u8, bindings::strlen(consumer) as usize)
+        })
+        .map_err(Error::InvalidString)
+    }
+
+    /// Set the offsets of the lines to be requested.
+    ///
+    /// If too many offsets were specified, the offsets above the limit accepted
+    /// by the kernel (64 lines) are silently dropped.
+    pub fn set_offsets(&self, offsets: &[u32]) {
+        unsafe {
+            bindings::gpiod_request_config_set_offsets(
+                self.config,
+                offsets.len() as c_ulong,
+                offsets.as_ptr(),
+            )
+        }
+    }
+
+    /// Get the offsets of lines in the request config.
+    pub fn get_offsets(&self) -> Vec<u32> {
+        let num = unsafe { bindings::gpiod_request_config_get_num_offsets(self.config) };
+        let mut offsets = vec![0; num as usize];
+
+        unsafe { bindings::gpiod_request_config_get_offsets(self.config, offsets.as_mut_ptr()) };
+        offsets
+    }
+
+    /// Set the size of the kernel event buffer for the request.
+    ///
+    /// The kernel may adjust the value if it's too high. If set to 0, the
+    /// default value will be used.
+    pub fn set_event_buffer_size(&self, size: u32) {
+        unsafe {
+            bindings::gpiod_request_config_set_event_buffer_size(self.config, size as c_ulong)
+        }
+    }
+
+    /// Get the edge event buffer size for the request config.
+    pub fn get_event_buffer_size(&self) -> u32 {
+        unsafe { bindings::gpiod_request_config_get_event_buffer_size(self.config) as u32 }
+    }
+}
+
+impl Drop for RequestConfig {
+    /// Free the request config object and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { bindings::gpiod_request_config_free(self.config) }
+    }
+}
-- 
2.31.1.272.g89b43f80a514