Add rust wrappers around FFI bindings to provide a convenient interface for the users.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- bindings/rust/Cargo.toml | 2 + bindings/rust/src/chip.rs | 197 +++++++++++++ bindings/rust/src/edge_event.rs | 78 +++++ bindings/rust/src/event_buffer.rs | 59 ++++ bindings/rust/src/info_event.rs | 70 +++++ bindings/rust/src/lib.rs | 268 +++++++++++++++++ bindings/rust/src/line_config.rs | 431 ++++++++++++++++++++++++++++ bindings/rust/src/line_info.rs | 186 ++++++++++++ bindings/rust/src/line_request.rs | 218 ++++++++++++++ bindings/rust/src/request_config.rs | 118 ++++++++ 10 files changed, 1627 insertions(+) create mode 100644 bindings/rust/src/chip.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/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 index 62f3d52ddb0f..d57dfd65ba7d 100644 --- a/bindings/rust/Cargo.toml +++ b/bindings/rust/Cargo.toml @@ -6,6 +6,8 @@ edition = "2021" # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies] +thiserror = "1.0" +vmm-sys-util = "=0.9.0"

[build-dependencies] bindgen = "0.59.1" diff --git a/bindings/rust/src/chip.rs b/bindings/rust/src/chip.rs new file mode 100644 index 000000000000..144f5ef9c570 --- /dev/null +++ b/bindings/rust/src/chip.rs @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +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, Error, Result}; +use crate::info_event::GpiodInfoEvent; +use crate::line_config::GpiodLineConfig; +use crate::line_info::GpiodLineInfo; +use crate::line_request::GpiodLineRequest; +use crate::request_config::GpiodRequestConfig; + +/// 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 GpiodChipInternal { + chip: *mut bindings::gpiod_chip, +} + +impl GpiodChipInternal { + /// Find a GPIO chip by path. + pub(crate) fn open(path: &str) -> Result<Self> { + let chip = unsafe { bindings::gpiod_chip_open(path.as_ptr() as *const c_char) }; + if chip.is_null() { + return Err(Error::OperationFailed("GpiodChip 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 GpiodChipInternal { + /// Close the GPIO chip and release all associated resources. + fn drop(&mut self) { + unsafe { bindings::gpiod_chip_close(self.chip) } + } +} + +pub struct GpiodChip { + ichip: Arc<GpiodChipInternal>, +} + +impl GpiodChip { + /// Find a GPIO chip by path. + pub fn open(path: &str) -> Result<Self> { + Ok(Self { + ichip: Arc::new(GpiodChipInternal::open(path)?), + }) + } + + /// Get the GPIO chip name as represented in the kernel. + pub fn get_name(&self) -> Result<&str> { + // SAFETY: The string returned by libgpiod is guaranteed to live as long + // as the `struct GpiodChip`. + let name = unsafe { bindings::gpiod_chip_get_name(self.ichip.chip()) }; + if name.is_null() { + return Err(Error::NameNotFound("GPIO chip name")); + } + + unsafe { + str::from_utf8(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 fn get_label(&self) -> Result<&str> { + // SAFETY: The string returned by libgpiod is guaranteed to live as long + // as the `struct GpiodChip`. + let label = unsafe { bindings::gpiod_chip_get_label(self.ichip.chip()) }; + if label.is_null() { + return Err(Error::NameNotFound("GPIO chip label")); + } + + unsafe { + str::from_utf8(slice::from_raw_parts( + label as *const u8, + bindings::strlen(label) as usize, + )) + .map_err(Error::InvalidString) + } + } + + /// Get the path used to find this GPIO chip. + pub fn get_path(&self) -> Result<&str> { + // SAFETY: The string returned by libgpiod is guaranteed to live as long + // as the `struct GpiodChip`. + let path = unsafe { bindings::gpiod_chip_get_path(self.ichip.chip()) }; + if path.is_null() { + return Err(Error::NameNotFound("GPIO chip path")); + } + + unsafe { + str::from_utf8(slice::from_raw_parts( + path as *const u8, + bindings::strlen(path) as usize, + )) + .map_err(Error::InvalidString) + } + } + + /// Get the number of GPIO lines exposed by this chip. + pub fn get_num_lines(&self) -> u32 { + unsafe { bindings::gpiod_chip_get_num_lines(self.ichip.chip()) } + } + + /// Get the current snapshot of information about the line at given offset. + pub fn line_info(&self, offset: u32) -> Result<GpiodLineInfo> { + GpiodLineInfo::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<GpiodLineInfo> { + GpiodLineInfo::new(self.ichip.clone(), offset, true) + } + + /// Get the file descriptor associated with this chip. + /// + /// The returned file descriptor must not be closed by the caller, else other methods for the + /// `struct GpiodChip` 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("GpiodChip get-fd", IoError::last())) + } else { + Ok(fd as u32) + } + } + + /// Wait for line status events on any of the watched lines exposed by this + /// chip. + pub fn info_event_wait(&self, timeout: Duration) -> Result<()> { + let ret = unsafe { + bindings::gpiod_chip_info_event_wait(self.ichip.chip(), timeout.as_nanos() as u64) + }; + + match ret { + -1 => Err(Error::OperationFailed( + "GpiodChip info-event-wait", + IoError::last(), + )), + 0 => Err(Error::OperationTimedOut), + _ => Ok(()), + } + } + + /// Read a single line status change event from this chip. If no events are + /// pending, this function will block. + pub fn info_event_read(&self) -> Result<GpiodInfoEvent> { + GpiodInfoEvent::new(&self.ichip.clone()) + } + + /// Map a GPIO line's name to its offset within the chip. + pub fn find_line(&self, name: &str) -> Result<u32> { + let ret = unsafe { + bindings::gpiod_chip_find_line(self.ichip.chip(), name.as_ptr() as *const c_char) + }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodChip find-line", + IoError::last(), + )) + } else { + Ok(ret as u32) + } + } + + /// Request a set of lines for exclusive usage. + pub fn request_lines( + &self, + rconfig: &GpiodRequestConfig, + lconfig: &GpiodLineConfig, + ) -> Result<GpiodLineRequest> { + GpiodLineRequest::new(&self.ichip.clone(), rconfig, lconfig) + } +} diff --git a/bindings/rust/src/edge_event.rs b/bindings/rust/src/edge_event.rs new file mode 100644 index 000000000000..5fe292ac69aa --- /dev/null +++ b/bindings/rust/src/edge_event.rs @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +use std::time::Duration; + +use vmm_sys_util::errno::Error as IoError; + +use super::{bindings, EdgeEvent, Error, Result}; +use crate::event_buffer::GpiodEdgeEventBuffer; + +/// Line edge events handling +/// +/// An edge event object contains information about a single line event. It +/// contains the event type, timestamp and the offset of the line on which the +/// event occurred as well as two sequential numbers (global for all lines +/// associated with the parent chip and local for this line only). +/// +/// For performance and to limit the number of memory allocations when a lot of +/// events are being read, edge events are stored in an edge-event buffer object. + +pub struct GpiodEdgeEvent { + event: *mut bindings::gpiod_edge_event, +} + +impl GpiodEdgeEvent { + /// Get an event stored in the buffer. + pub fn new(buffer: &GpiodEdgeEventBuffer, index: u64) -> Result<Self> { + let event = unsafe { bindings::gpiod_edge_event_buffer_get_event(buffer.buffer(), index) }; + if event.is_null() { + return Err(Error::OperationFailed( + "GpiodEdgeEvent buffer-get-event", + IoError::last(), + )); + } + + Ok(Self { event }) + } + + /// Get the event type. + pub fn get_event_type(&self) -> Result<EdgeEvent> { + EdgeEvent::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(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 this 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 this 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 GpiodEdgeEvent { + /// Free the edge event object and release all associated resources. + fn drop(&mut self) { + 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..fd702e91818d --- /dev/null +++ b/bindings/rust/src/event_buffer.rs @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +use vmm_sys_util::errno::Error as IoError; + +use super::{bindings, Error, Result}; +use crate::edge_event::GpiodEdgeEvent; + +/// Line edge events buffer +pub struct GpiodEdgeEventBuffer { + buffer: *mut bindings::gpiod_edge_event_buffer, +} + +impl GpiodEdgeEventBuffer { + /// 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) }; + if buffer.is_null() { + return Err(Error::OperationFailed( + "GpiodEdgeEventBuffer 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 + } + + /// Get the capacity of the event buffer. + pub fn get_capacity(&self) -> u32 { + unsafe { bindings::gpiod_edge_event_buffer_get_capacity(self.buffer) } + } + + /// Read an event stored in the buffer. + pub fn get_event(&self, index: u64) -> Result<GpiodEdgeEvent> { + GpiodEdgeEvent::new(self, index) + } + + /// Get the number of events this buffers stores. + pub fn num_events(&self) -> u32 { + unsafe { bindings::gpiod_edge_event_buffer_num_events(self.buffer) } + } +} + +impl Drop for GpiodEdgeEventBuffer { + /// Free the edge event buffer and release all associated resources. + fn drop(&mut self) { + unsafe { bindings::gpiod_edge_event_buffer_free(self.buffer) }; + } +} diff --git a/bindings/rust/src/info_event.rs b/bindings/rust/src/info_event.rs new file mode 100644 index 000000000000..e0f82b31548f --- /dev/null +++ b/bindings/rust/src/info_event.rs @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +use std::convert::TryFrom; +use std::sync::Arc; +use std::time::Duration; + +use vmm_sys_util::errno::Error as IoError; + +use super::chip::GpiodChipInternal; +use super::{bindings, Error, Event, Result}; +use crate::line_info::GpiodLineInfo; + +/// 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 GpiodInfoEvent { + event: *mut bindings::gpiod_info_event, +} + +impl GpiodInfoEvent { + /// Get a single chip's line's status change event. + pub(crate) fn new(ichip: &Arc<GpiodChipInternal>) -> Result<Self> { + let event = unsafe { bindings::gpiod_chip_info_event_read(ichip.chip()) }; + if event.is_null() { + return Err(Error::OperationFailed( + "GpiodInfoEvent 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 this 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. + pub fn get_timestamp(&self) -> Duration { + Duration::from_nanos(unsafe { bindings::gpiod_info_event_get_timestamp(self.event) }) + } + + /// Get the line-info object associated with this event. + pub fn line_info(&self) -> Result<GpiodLineInfo> { + GpiodLineInfo::try_from(self) + } +} + +impl Drop for GpiodInfoEvent { + /// 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 index e69de29bb2d1..cbdef64fdb8b 100644 --- a/bindings/rust/src/lib.rs +++ b/bindings/rust/src/lib.rs @@ -0,0 +1,268 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Rust wrappers for GPIOD APIs +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +//! 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 bindings; +pub mod chip; +pub mod edge_event; +pub mod event_buffer; +pub mod info_event; +pub mod line_config; +pub mod line_info; +pub mod line_request; +pub mod 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 didn't change current direction. + AsIs, + /// Direction is input - we're reading the state of a GPIO line. + Input, + /// Direction is output - we're 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 detect 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, + } + } +} + +/// 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)), + } + } +} + +/// Edge event types. +pub enum EdgeEvent { + /// Rising edge event. + Rising, + /// Falling edge event. + Falling, +} + +impl EdgeEvent { + fn new(event: u32) -> Result<Self> { + match event { + bindings::GPIOD_EDGE_EVENT_RISING_EDGE => Ok(EdgeEvent::Rising), + bindings::GPIOD_EDGE_EVENT_FALLING_EDGE => Ok(EdgeEvent::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 { + 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")); + } + + unsafe { + str::from_utf8(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..c657902bd6f5 --- /dev/null +++ b/bindings/rust/src/line_config.rs @@ -0,0 +1,431 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +use std::time::Duration; + +use vmm_sys_util::errno::Error as IoError; + +use super::{bindings, Bias, Direction, Drive, Edge, Error, EventClock, Result}; + +/// Line configuration objects. +/// +/// The line-config object stores the configuration for lines that can be used +/// in two cases: when making a line request and when reconfiguring a set of +/// already requested lines. The mutators for the line request don't return +/// errors. If the set of options is too complex to be translated into kernel +/// uAPI structures - the error will be returned at the time of the request or +/// reconfiguration. If an invalid value was passed to any of the getters - the +/// default value will be silently used instead. Each option can be set +/// globally, for a single line offset or for multiple line offsets. +pub struct GpiodLineConfig { + config: *mut bindings::gpiod_line_config, +} + +impl GpiodLineConfig { + /// 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( + "GpiodLineConfig 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 this 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 direction for all lines. + pub fn set_direction(&mut self, direction: Direction) { + unsafe { + bindings::gpiod_line_config_set_direction( + self.config, + direction.gpiod_direction() as i32, + ) + } + } + + /// Set the direction for a single line at given offset. + pub fn set_direction_offset(&mut self, direction: Direction, offset: u32) { + unsafe { + bindings::gpiod_line_config_set_direction_offset( + self.config, + direction.gpiod_direction() as i32, + offset, + ) + } + } + + /// Set the direction for a subset of lines. + pub fn set_direction_subset(&mut self, direction: Direction, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_direction_subset( + self.config, + direction.gpiod_direction() as i32, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Get the direction of a given line. + /// + /// If an offset is used for which no config was provided, the function will + /// return the global default value. + pub fn get_direction(&mut self, offset: u32) -> Result<Direction> { + Direction::new( + unsafe { bindings::gpiod_line_config_get_direction(self.config, offset) } as u32, + ) + } + + /// Set the edge event detection for all lines. + pub fn set_edge_detection(&mut self, edge: Edge) { + unsafe { + bindings::gpiod_line_config_set_edge_detection(self.config, edge.gpiod_edge() as i32) + } + } + + /// Set the edge event detection for a single line at given offset. + pub fn set_edge_detection_offset(&mut self, edge: Edge, offset: u32) { + unsafe { + bindings::gpiod_line_config_set_edge_detection_offset( + self.config, + edge.gpiod_edge() as i32, + offset, + ) + } + } + + /// Set the edge event detection for a subset of lines. + pub fn set_edge_detection_subset(&mut self, edge: Edge, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_edge_detection_subset( + self.config, + edge.gpiod_edge() as i32, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Get the edge event detection setting for a given line. + /// + /// Returns edge event detection setting that would have been used for given + /// offset if the config object was used in a request at the time of the + /// call. If an offset is used for which no config was provided, the + /// function will return the global default value. + pub fn get_edge_detection(&mut self, offset: u32) -> Result<Edge> { + Edge::new( + unsafe { bindings::gpiod_line_config_get_edge_detection(self.config, offset) } as u32, + ) + } + + /// Set the bias of all lines. + pub fn set_bias(&mut self, bias: Bias) { + unsafe { bindings::gpiod_line_config_set_bias(self.config, bias.gpiod_bias() as i32) } + } + + /// Set the bias for a single line at given offset. + pub fn set_bias_offset(&mut self, bias: Bias, offset: u32) { + unsafe { + bindings::gpiod_line_config_set_bias_offset( + self.config, + bias.gpiod_bias() as i32, + offset, + ) + } + } + + /// Set the bias for a subset of lines. + pub fn set_bias_subset(&mut self, bias: Bias, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_bias_subset( + self.config, + bias.gpiod_bias() as i32, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Get the bias setting for a given line. + /// + /// Returns Bias setting that would have been used for given offset if the + /// config object was used in a request at the time of the call. If an + /// offset is used for which no config was provided, the function will + /// return the global default value. + pub fn get_bias(&mut self, offset: u32) -> Result<Bias> { + Bias::new(unsafe { bindings::gpiod_line_config_get_bias(self.config, offset) } as u32) + } + + /// Set the drive of all lines. + pub fn set_drive(&mut self, drive: Drive) { + unsafe { bindings::gpiod_line_config_set_drive(self.config, drive.gpiod_drive() as i32) } + } + + /// Set the drive for a single line at given offset. + pub fn set_drive_offset(&mut self, drive: Drive, offset: u32) { + unsafe { + bindings::gpiod_line_config_set_drive_offset( + self.config, + drive.gpiod_drive() as i32, + offset, + ) + } + } + + /// Set the drive for a subset of lines. + pub fn set_drive_subset(&mut self, drive: Drive, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_drive_subset( + self.config, + drive.gpiod_drive() as i32, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Get the drive setting for a given line. + /// + /// Returns drive setting that would have been used for given offset if the + /// config object was used in a request at the time of the call. If an + /// offset is used for which no config was provided, the function will + /// return the global default value. + pub fn get_drive(&mut self, offset: u32) -> Result<Drive> { + Drive::new(unsafe { bindings::gpiod_line_config_get_drive(self.config, offset) } as u32) + } + + /// Set all lines as active-low. + pub fn set_active_low(&mut self) { + unsafe { bindings::gpiod_line_config_set_active_low(self.config) } + } + + /// Set a single line as active-low. + pub fn set_active_low_offset(&mut self, offset: u32) { + unsafe { bindings::gpiod_line_config_set_active_low_offset(self.config, offset) } + } + + /// Set a subset of lines as active-low. + pub fn set_active_low_subset(&mut self, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_active_low_subset( + self.config, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Check if the line at given offset was configured as active-low. + /// + /// Returns active-low setting that would have been used for given offset if + /// the config object was used in a request at the time of the call. If an + /// offset is used for which no config was provided, the function will + /// return the global default value. + pub fn is_active_low(&mut self, offset: u32) -> bool { + unsafe { bindings::gpiod_line_config_is_active_low(self.config, offset) } + } + + /// Set all lines as active-high. + pub fn set_active_high(&mut self) { + unsafe { bindings::gpiod_line_config_set_active_high(self.config) } + } + + /// Set a single line as active-high. + pub fn set_active_high_offset(&mut self, offset: u32) { + unsafe { bindings::gpiod_line_config_set_active_high_offset(self.config, offset) } + } + + /// Set a subset of lines as active-high. + pub fn set_active_high_subset(&mut self, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_active_high_subset( + self.config, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Set the debounce period for all lines, disables debouncing if 0. + pub fn set_debounce_period_us(&mut self, period: Duration) { + unsafe { + bindings::gpiod_line_config_set_debounce_period_us( + self.config, + period.as_micros() as u64, + ) + } + } + + /// Set the debounce period for a single line at given offset, disables + /// debouncing if 0. + pub fn set_debounce_period_us_offset(&mut self, period: Duration, offset: u32) { + unsafe { + bindings::gpiod_line_config_set_debounce_period_us_offset( + self.config, + period.as_micros() as u64, + offset, + ) + } + } + + /// Set the debounce period for a subset of lines, disables debouncing if + /// `period` is 0. + pub fn set_debounce_period_us_subset(&mut self, period: Duration, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_debounce_period_us_subset( + self.config, + period.as_micros() as u64, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Get the debounce period for a given line. + /// + /// Returns debounce period that would have been used for given offset if + /// the config object was used in a request at the time of the call. If an + /// offset is used for which no config was provided, the function will + /// return the global default value. + pub fn get_debounce_period_us(&mut self, offset: u32) -> Result<Duration> { + Ok(Duration::from_micros(unsafe { + bindings::gpiod_line_config_get_debounce_us_period(self.config, offset) + })) + } + + /// Set the event clock for all lines. + pub fn set_event_clock(&mut self, clock: EventClock) { + unsafe { + bindings::gpiod_line_config_set_event_clock(self.config, clock.gpiod_clock() as i32) + } + } + + /// Set the event clock for a single line at given offset. + pub fn set_event_clock_offset(&mut self, clock: EventClock, offset: u32) { + unsafe { + bindings::gpiod_line_config_set_event_clock_offset( + self.config, + clock.gpiod_clock() as i32, + offset, + ) + } + } + + /// Set the event clock for a subset of lines. + pub fn set_event_clock_subset(&mut self, clock: EventClock, offsets: &mut Vec<u32>) { + unsafe { + bindings::gpiod_line_config_set_event_clock_subset( + self.config, + clock.gpiod_clock() as i32, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Set the output value for a single offset. + pub fn set_output_value(&mut self, offset: u32, value: u32) { + unsafe { bindings::gpiod_line_config_set_output_value(self.config, offset, value as i32) } + } + + /// Set the output values for a set of offsets. + pub fn set_output_values(&mut self, offsets: &mut Vec<u32>, values: &mut Vec<i32>) { + unsafe { + bindings::gpiod_line_config_set_output_values( + self.config, + values.len() as u32, + offsets.as_mut_ptr(), + values.as_mut_ptr(), + ) + } + } + + /// Get the number of lines for which the config object stores values. + pub fn num_output_values(&mut self) -> u32 { + unsafe { bindings::gpiod_line_config_num_output_values(self.config) } + } + + /// Get the output value configured for a given line, 0 or 1. + pub fn get_output_value(&mut self, offset: u32) -> Result<u32> { + let value = unsafe { bindings::gpiod_line_config_get_output_value(self.config, offset) }; + + if value != 0 && value != 1 { + Err(Error::OperationFailed( + "GpiodLineConfig get-output-value", + IoError::last(), + )) + } else { + Ok(value as u32) + } + } + + /// Get the output value mapping (offset, value) at given index. + /// + /// This function together with `get_num_output()` allows to iterate over + /// all output value mappings currently held by this object. + pub fn get_output_value_index(&mut self, index: u32) -> Result<(u32, u32)> { + let mut offset: u32 = 0; + let mut value: i32 = 0; + + let ret = unsafe { + bindings::gpiod_line_config_get_output_value_index( + self.config, + index, + &mut offset, + &mut value, + ) + }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodLineConfig get-output-value-index", + IoError::last(), + )) + } else { + Ok((offset, !!(value as u32))) + } + } + + /// Get all output value mappings stored in this config object. + /// + /// Each offset in the offsets vector corresponds to the value in the values + /// array at the same index. + pub fn get_output_values(&mut self) -> Result<(Vec<u32>, Vec<i32>)> { + let count = self.num_output_values() as usize; + let mut offset: Vec<u32> = vec![0; count]; + let mut value: Vec<i32> = vec![0; count]; + + unsafe { + bindings::gpiod_line_config_get_output_values( + self.config, + offset.as_mut_ptr(), + value.as_mut_ptr(), + ) + }; + + Ok((offset, value)) + } +} + +impl Drop for GpiodLineConfig { + /// 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..8d8097de9a60 --- /dev/null +++ b/bindings/rust/src/line_info.rs @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +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::chip::GpiodChipInternal; +use super::{bindings, Bias, Direction, Drive, Edge, Error, EventClock, Result}; +use crate::info_event::GpiodInfoEvent; + +/// Line info +/// +/// Exposes functions for retrieving kernel information about both requested and +/// free lines. Line info object contains an immutable snapshot of the line's +/// state at the time when it was created. +pub struct GpiodLineInfo { + info: *mut bindings::gpiod_line_info, + ichip: Option<Arc<GpiodChipInternal>>, + free: bool, +} + +impl GpiodLineInfo { + /// Get the current snapshot of information about the line at given offset + /// and optionally start watching it for changes. + pub(crate) fn new(ichip: Arc<GpiodChipInternal>, 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( + "GpiodLineInfo 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. + pub fn get_offset(&mut 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 GpiodLineInfo`. + let name = unsafe { bindings::gpiod_line_info_get_name(self.info) }; + if name.is_null() { + return Err(Error::NameNotFound("GPIO line's name")); + } + + unsafe { + str::from_utf8(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(&mut 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 GpiodLineInfo`. + let name = unsafe { bindings::gpiod_line_info_get_consumer(self.info) }; + if name.is_null() { + return Err(Error::NameNotFound("GPIO line's consumer name")); + } + + unsafe { + str::from_utf8(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 this line is "active-low", false otherwise. + pub fn is_active_low(&mut 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 this 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(&mut self) -> bool { + unsafe { bindings::gpiod_line_info_is_debounced(self.info) } + } + + /// Get the current debounce period. + pub fn get_debounce_period_us(&mut self) -> Duration { + Duration::from_micros(unsafe { + bindings::gpiod_line_info_get_debounce_period_us(self.info) + }) + } +} + +impl TryFrom<&GpiodInfoEvent> for GpiodLineInfo { + type Error = Error; + + /// Get the Line info object associated with a event. + fn try_from(event: &GpiodInfoEvent) -> Result<Self> { + let info = unsafe { bindings::gpiod_info_event_get_line_info(event.event()) }; + if info.is_null() { + return Err(Error::OperationFailed( + "GpiodLineInfo try-from", + IoError::last(), + )); + } + + Ok(Self { + info, + ichip: None, + free: false, + }) + } +} + +impl Drop for GpiodLineInfo { + fn drop(&mut self) { + // We must not free the Line info object created from `struct GpiodInfoEvent` 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..547c00ce8278 --- /dev/null +++ b/bindings/rust/src/line_request.rs @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +use std::sync::Arc; +use std::time::Duration; + +use vmm_sys_util::errno::Error as IoError; + +use super::{bindings, chip::GpiodChipInternal, Error, Result}; +use crate::event_buffer::GpiodEdgeEventBuffer; +use crate::line_config::GpiodLineConfig; +use crate::request_config::GpiodRequestConfig; + +/// Line request operations +/// +/// Allows interaction with a set of requested lines. +pub struct GpiodLineRequest { + request: *mut bindings::gpiod_line_request, +} + +impl GpiodLineRequest { + /// Request a set of lines for exclusive usage. + pub(crate) fn new( + ichip: &Arc<GpiodChipInternal>, + rconfig: &GpiodRequestConfig, + lconfig: &GpiodLineConfig, + ) -> Result<Self> { + let request = unsafe { + bindings::gpiod_chip_request_lines(ichip.chip(), rconfig.config(), lconfig.config()) + }; + + if request.is_null() { + return Err(Error::OperationFailed( + "GpiodLineRequest request-lines", + IoError::last(), + )); + } + + Ok(Self { request }) + } + + /// Get the number of lines in this request. + pub fn get_num_lines(&self) -> u32 { + unsafe { bindings::gpiod_line_request_get_num_lines(self.request) } + } + + /// Get the offsets of lines in this 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 values of all lines associated with this request. + pub fn get_values(&self, values: &mut Vec<i32>) -> Result<()> { + let ret = + unsafe { bindings::gpiod_line_request_get_values(self.request, values.as_mut_ptr()) }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodLineRequest get-values", + IoError::last(), + )) + } else { + Ok(()) + } + } + + /// Get the value (0 or 1) of a single line associated with this 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( + "GpiodLineRequest get-value", + IoError::last(), + )) + } else { + Ok(value as u32) + } + } + + /// Get values of a subset of lines associated with this request. + pub fn get_values_subset(&self, offsets: &mut Vec<u32>, values: &mut Vec<i32>) -> Result<()> { + let ret = unsafe { + bindings::gpiod_line_request_get_values_subset( + self.request, + offsets.len() as u32, + offsets.as_mut_ptr(), + values.as_mut_ptr(), + ) + }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodLineRequest get-values-subset", + IoError::last(), + )) + } else { + Ok(()) + } + } + + /// Get values of all lines associated with this request. + pub fn set_values(&self, values: &mut Vec<i32>) -> Result<()> { + let ret = + unsafe { bindings::gpiod_line_request_set_values(self.request, values.as_mut_ptr()) }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodLineRequest set-values", + IoError::last(), + )) + } else { + Ok(()) + } + } + + /// Set the value of a single line associated with this 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( + "GpiodLineRequest set-value", + IoError::last(), + )) + } else { + Ok(()) + } + } + + /// Get values of a subset of lines associated with this request. + pub fn set_values_subset(&self, offsets: &mut Vec<u32>, values: &mut Vec<i32>) -> Result<()> { + let ret = unsafe { + bindings::gpiod_line_request_set_values_subset( + self.request, + offsets.len() as u32, + offsets.as_mut_ptr(), + values.as_mut_ptr(), + ) + }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodLineRequest set-values-subset", + IoError::last(), + )) + } else { + Ok(()) + } + } + + /// Update the configuration of lines associated with this line request. + pub fn reconfigure_lines(&self, lconfig: &GpiodLineConfig) -> Result<()> { + let ret = unsafe { + bindings::gpiod_line_request_reconfigure_lines(self.request, lconfig.config()) + }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodLineRequest reconfigure-lines", + IoError::last(), + )) + } else { + Ok(()) + } + } + + /// Get the file descriptor associated with this 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 this request. + pub fn edge_event_wait(&self, timeout: Duration) -> Result<()> { + let ret = unsafe { + bindings::gpiod_line_request_edge_event_wait(self.request, timeout.as_nanos() as u64) + }; + + match ret { + -1 => Err(Error::OperationFailed( + "GpiodLineRequest 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 this line. + pub fn edge_event_read(&self, buffer: &GpiodEdgeEventBuffer, max_events: u32) -> Result<u32> { + let ret = unsafe { + bindings::gpiod_line_request_edge_event_read(self.request, buffer.buffer(), max_events) + }; + + if ret == -1 { + Err(Error::OperationFailed( + "GpiodLineRequest edge-event-read", + IoError::last(), + )) + } else { + Ok(ret as u32) + } + } +} + +impl Drop for GpiodLineRequest { + /// 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..a2f1ad37c8ce --- /dev/null +++ b/bindings/rust/src/request_config.rs @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause +// +// Copyright 2021 Linaro Ltd. All Rights Reserved. +// Viresh Kumar viresh.kumar@linaro.org + +use std::os::raw::c_char; +use std::{slice, str}; + +use vmm_sys_util::errno::Error as IoError; + +use super::{bindings, Error, Result}; + +/// Request configuration objects +/// +/// Request config object is 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 GpiodRequestConfig { + config: *mut bindings::gpiod_request_config, +} + +impl GpiodRequestConfig { + /// 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( + "GpiodRequestConfig 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 string. + /// + /// If the consumer string is too long, it will be truncated to the max + /// accepted length. + pub fn set_consumer(&self, consumer: &str) { + unsafe { + bindings::gpiod_request_config_set_consumer( + self.config, + consumer.as_ptr() as *const c_char, + ) + } + } + + /// Get the consumer string. + pub fn get_consumer(&self) -> Result<&str> { + // SAFETY: The string returned by libgpiod is guaranteed to live as long + // as the `struct GpiodRequestConfig`. + let consumer = unsafe { bindings::gpiod_request_config_get_consumer(self.config) }; + if consumer.is_null() { + return Err(Error::OperationFailed( + "GpiodRequestConfig get-consumer", + IoError::last(), + )); + } + + unsafe { + str::from_utf8(slice::from_raw_parts( + consumer as *const u8, + bindings::strlen(consumer) as usize, + )) + .map_err(Error::InvalidString) + } + } + + /// Set line offsets for this request. + /// + /// 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: &mut Vec<u32>) { + unsafe { + bindings::gpiod_request_config_set_offsets( + self.config, + offsets.len() as u32, + offsets.as_mut_ptr(), + ) + } + } + + /// Get the offsets of lines in this request config. + pub fn get_num_offsets(&self) -> Vec<u32> { + let num = unsafe { bindings::gpiod_request_config_get_num_offsets(self.config) }; + let mut offsets = vec![0, num]; + + unsafe { bindings::gpiod_request_config_get_offsets(self.config, offsets.as_mut_ptr()) }; + offsets + } + + /// Set the size of the kernel event buffer. + /// + /// 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) } + } + + /// Get the edge event buffer size from this request config. + pub fn get_event_buffer_size(&self) -> u32 { + unsafe { bindings::gpiod_request_config_get_event_buffer_size(self.config) } + } +} + +impl Drop for GpiodRequestConfig { + /// Free the request config object and release all associated resources. + fn drop(&mut self) { + unsafe { bindings::gpiod_request_config_free(self.config) } + } +}