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* [PATCH V6 0/8] libgpiod: Add Rust bindings
@ 2022-09-26 11:08 Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 1/8] libgpiod: Add libgpiod-sys rust crate Viresh Kumar
                   ` (8 more replies)
  0 siblings, 9 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

Hello,

Here is another version of rust bindings for libgpiod v2.0, based of the
next/libgpiod-2.0 + the HTE patch from Bartosz [1].

Pushed here:

https://github.com/vireshk/libgpiod master

[I have pushed v5 and v4 there too, in case someone wants to look at the
changes].

V5->V6:
- Updates according to the new line-settings interface.
- New file, line_settings.rs.
- Renamed 'enum Setting' as 'SettingVal' to avoid conflicting names, as we also
  have 'struct Settings' now.
- Support for HTE clock type.
- Implement 'Eq' for public structure/enums (reported by build).
- Remove 'SettingKindMap' and 'SettingMap' as they aren't required anymore.
- Updated tests based on new interface.

V4->V5:
- Arrange as workspace with crates for libgpiod-sys, libgpiod, gpiosim.
- Use static libgpiod and libgpiosim libraries instead of rebuilding again.
- Arrange in modules instead of flattened approach.
- New enums like Setting and SettingKind and new types based on them SettingMap
  and SettingKindMap.
- New property independent helpers for line_config, like set_prop_default().
- Improved tests/examples, new example for gpiowatch.
- Add pre-built bindings for gpiosim too.
- Many other changes.

V3->V4:
- Rebased on top of new changes, and made changes accordingly.
- Added rust integration tests with gpiosim.
- Found a kernel bug with tests, sent a patch for that to LKML.

V2->V3:
- Remove naming redundancy, users just need to do this now
  use libgpiod:{Chip, Direction, LineConfig} now (Bartosz);
- Fix lifetime issues between event-buffer and edge-event modules, the event
  buffer is released after the last edge-event reference is dropped (Bartosz).
- Allow edge-event to be copied, and freed later (Bartosz).
- Add two separate rust crates, sys and wrapper (Gerard).
- Null-terminate the strings passed to libgpiod (Wedson).
- Drop unnecessary checks to validate string returned from chip:name/label/path.
- Fix SAFETY comments (Wedson).
- Drop unnecessary clone() instances (Bartosz).

V1->V2:
- Added examples (I tested everything except gpiomon.rs, didn't have right
  hardware/mock device to test).
- Build rust bindings as part of Make, update documentation.

Thanks.

--
Viresh

[1] https://lore.kernel.org/all/20220923081223.25851-1-brgl@bgdev.pl/

Viresh Kumar (8):
  libgpiod: Add libgpiod-sys rust crate
  libgpiod-sys: Add pre generated rust bindings
  libgpiod: Add rust wrapper crate
  libgpiod: Add rust examples
  libgpiod: Add gpiosim rust crate
  gpiosim: Add pre generated rust bindings
  libgpiod: Add rust tests
  libgpiod: Integrate building of rust bindings with make

 .gitignore                                    |    5 +
 README                                        |    8 +-
 TODO                                          |    8 -
 bindings/Makefile.am                          |    6 +
 bindings/rust/Cargo.toml                      |    7 +
 bindings/rust/Makefile.am                     |   18 +
 bindings/rust/gpiosim/Cargo.toml              |   18 +
 bindings/rust/gpiosim/README.md               |   11 +
 bindings/rust/gpiosim/build.rs                |   43 +
 bindings/rust/gpiosim/src/bindings.rs         |  180 +++
 bindings/rust/gpiosim/src/lib.rs              |   25 +
 bindings/rust/gpiosim/src/sim.rs              |  323 +++++
 bindings/rust/libgpiod-sys/Cargo.toml         |   15 +
 bindings/rust/libgpiod-sys/README.md          |   11 +
 bindings/rust/libgpiod-sys/build.rs           |   41 +
 bindings/rust/libgpiod-sys/src/bindings.rs    | 1173 +++++++++++++++++
 bindings/rust/libgpiod-sys/src/lib.rs         |   13 +
 bindings/rust/libgpiod/Cargo.toml             |   16 +
 bindings/rust/libgpiod/examples/gpiodetect.rs |   30 +
 bindings/rust/libgpiod/examples/gpiofind.rs   |   35 +
 bindings/rust/libgpiod/examples/gpioget.rs    |   42 +
 bindings/rust/libgpiod/examples/gpioinfo.rs   |   95 ++
 bindings/rust/libgpiod/examples/gpiomon.rs    |   73 +
 bindings/rust/libgpiod/examples/gpioset.rs    |   60 +
 bindings/rust/libgpiod/examples/gpiowatch.rs  |   54 +
 bindings/rust/libgpiod/src/chip.rs            |  253 ++++
 bindings/rust/libgpiod/src/edge_event.rs      |  102 ++
 bindings/rust/libgpiod/src/event_buffer.rs    |   90 ++
 bindings/rust/libgpiod/src/info_event.rs      |   68 +
 bindings/rust/libgpiod/src/lib.rs             |  471 +++++++
 bindings/rust/libgpiod/src/line_config.rs     |  118 ++
 bindings/rust/libgpiod/src/line_info.rs       |  180 +++
 bindings/rust/libgpiod/src/line_request.rs    |  246 ++++
 bindings/rust/libgpiod/src/line_settings.rs   |  277 ++++
 bindings/rust/libgpiod/src/request_config.rs  |   96 ++
 bindings/rust/libgpiod/tests/chip.rs          |   97 ++
 bindings/rust/libgpiod/tests/common/config.rs |  134 ++
 bindings/rust/libgpiod/tests/common/mod.rs    |   10 +
 bindings/rust/libgpiod/tests/edge_event.rs    |  294 +++++
 bindings/rust/libgpiod/tests/info_event.rs    |  125 ++
 bindings/rust/libgpiod/tests/line_config.rs   |  105 ++
 bindings/rust/libgpiod/tests/line_info.rs     |  279 ++++
 bindings/rust/libgpiod/tests/line_request.rs  |  519 ++++++++
 bindings/rust/libgpiod/tests/line_settings.rs |  226 ++++
 .../rust/libgpiod/tests/request_config.rs     |   38 +
 configure.ac                                  |   16 +
 46 files changed, 6043 insertions(+), 11 deletions(-)
 create mode 100644 bindings/rust/Cargo.toml
 create mode 100644 bindings/rust/Makefile.am
 create mode 100644 bindings/rust/gpiosim/Cargo.toml
 create mode 100644 bindings/rust/gpiosim/README.md
 create mode 100644 bindings/rust/gpiosim/build.rs
 create mode 100644 bindings/rust/gpiosim/src/bindings.rs
 create mode 100644 bindings/rust/gpiosim/src/lib.rs
 create mode 100644 bindings/rust/gpiosim/src/sim.rs
 create mode 100644 bindings/rust/libgpiod-sys/Cargo.toml
 create mode 100644 bindings/rust/libgpiod-sys/README.md
 create mode 100644 bindings/rust/libgpiod-sys/build.rs
 create mode 100644 bindings/rust/libgpiod-sys/src/bindings.rs
 create mode 100644 bindings/rust/libgpiod-sys/src/lib.rs
 create mode 100644 bindings/rust/libgpiod/Cargo.toml
 create mode 100644 bindings/rust/libgpiod/examples/gpiodetect.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpiofind.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpioget.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpioinfo.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpiomon.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpioset.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpiowatch.rs
 create mode 100644 bindings/rust/libgpiod/src/chip.rs
 create mode 100644 bindings/rust/libgpiod/src/edge_event.rs
 create mode 100644 bindings/rust/libgpiod/src/event_buffer.rs
 create mode 100644 bindings/rust/libgpiod/src/info_event.rs
 create mode 100644 bindings/rust/libgpiod/src/lib.rs
 create mode 100644 bindings/rust/libgpiod/src/line_config.rs
 create mode 100644 bindings/rust/libgpiod/src/line_info.rs
 create mode 100644 bindings/rust/libgpiod/src/line_request.rs
 create mode 100644 bindings/rust/libgpiod/src/line_settings.rs
 create mode 100644 bindings/rust/libgpiod/src/request_config.rs
 create mode 100644 bindings/rust/libgpiod/tests/chip.rs
 create mode 100644 bindings/rust/libgpiod/tests/common/config.rs
 create mode 100644 bindings/rust/libgpiod/tests/common/mod.rs
 create mode 100644 bindings/rust/libgpiod/tests/edge_event.rs
 create mode 100644 bindings/rust/libgpiod/tests/info_event.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_config.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_info.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_request.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_settings.rs
 create mode 100644 bindings/rust/libgpiod/tests/request_config.rs

-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply	[flat|nested] 37+ messages in thread

* [PATCH V6 1/8] libgpiod: Add libgpiod-sys rust crate
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 2/8] libgpiod-sys: Add pre generated rust bindings Viresh Kumar
                   ` (7 subsequent siblings)
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

This adds libgpiod-sys rust crate, which provides FFI (foreign function
interface) bindings for libgpiod APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 .gitignore                            |  5 ++++
 bindings/rust/Cargo.toml              |  5 ++++
 bindings/rust/libgpiod-sys/Cargo.toml | 15 ++++++++++
 bindings/rust/libgpiod-sys/build.rs   | 41 +++++++++++++++++++++++++++
 bindings/rust/libgpiod-sys/src/lib.rs | 13 +++++++++
 5 files changed, 79 insertions(+)
 create mode 100644 bindings/rust/Cargo.toml
 create mode 100644 bindings/rust/libgpiod-sys/Cargo.toml
 create mode 100644 bindings/rust/libgpiod-sys/build.rs
 create mode 100644 bindings/rust/libgpiod-sys/src/lib.rs

diff --git a/.gitignore b/.gitignore
index 6c08415b390d..9f2fcf440c5d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,3 +35,8 @@ stamp-h1
 # profiling
 *.gcda
 *.gcno
+
+# Added by cargo
+
+target
+Cargo.lock
diff --git a/bindings/rust/Cargo.toml b/bindings/rust/Cargo.toml
new file mode 100644
index 000000000000..d0b3a3c88ff1
--- /dev/null
+++ b/bindings/rust/Cargo.toml
@@ -0,0 +1,5 @@
+[workspace]
+
+members = [
+    "libgpiod-sys",
+]
diff --git a/bindings/rust/libgpiod-sys/Cargo.toml b/bindings/rust/libgpiod-sys/Cargo.toml
new file mode 100644
index 000000000000..77f82719d269
--- /dev/null
+++ b/bindings/rust/libgpiod-sys/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "libgpiod-sys"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[features]
+generate = [ "bindgen" ]
+
+[build-dependencies]
+bindgen = { version = "0.59.1", optional = true }
+cc = "1.0.46"
diff --git a/bindings/rust/libgpiod-sys/build.rs b/bindings/rust/libgpiod-sys/build.rs
new file mode 100644
index 000000000000..98863686c7af
--- /dev/null
+++ b/bindings/rust/libgpiod-sys/build.rs
@@ -0,0 +1,41 @@
+#[cfg(feature = "generate")]
+extern crate bindgen;
+#[cfg(feature = "generate")]
+use std::env;
+#[cfg(feature = "generate")]
+use std::path::PathBuf;
+
+#[cfg(feature = "generate")]
+fn generate_bindings() {
+    // Tell cargo to invalidate the built crate whenever following files change
+    println!("cargo:rerun-if-changed=../../../include/gpiod.h");
+
+    // The bindgen::Builder is the main entry point
+    // to bindgen, and lets you build up options for
+    // the resulting bindings.
+    let bindings = bindgen::Builder::default()
+        // The input header we would like to generate
+        // bindings for.
+        .header("../../../include/gpiod.h")
+        // Tell cargo to invalidate the built crate whenever any of the
+        // included header files changed.
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks))
+        // Finish the builder and generate the bindings.
+        .generate()
+        // Unwrap the Result and panic on failure.
+        .expect("Unable to generate bindings");
+
+    // Write the bindings to the $OUT_DIR/bindings.rs file.
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    bindings
+        .write_to_file(out_path.join("bindings.rs"))
+        .expect("Couldn't write bindings!");
+}
+
+fn main() {
+    #[cfg(feature = "generate")]
+    generate_bindings();
+
+    println!("cargo:rustc-link-search=./../../lib/.libs/");
+    println!("cargo:rustc-link-lib=static=gpiod");
+}
diff --git a/bindings/rust/libgpiod-sys/src/lib.rs b/bindings/rust/libgpiod-sys/src/lib.rs
new file mode 100644
index 000000000000..1ca355b5f5ac
--- /dev/null
+++ b/bindings/rust/libgpiod-sys/src/lib.rs
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#[allow(non_camel_case_types, non_upper_case_globals)]
+#[cfg_attr(test, allow(deref_nullptr, non_snake_case))]
+
+mod bindings_raw {
+    #[cfg(feature = "generate")]
+    include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
+
+    #[cfg(not(feature = "generate"))]
+    include!("bindings.rs");
+}
+pub use bindings_raw::*;
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* [PATCH V6 2/8] libgpiod-sys: Add pre generated rust bindings
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 1/8] libgpiod: Add libgpiod-sys rust crate Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 3/8] libgpiod: Add rust wrapper crate Viresh Kumar
                   ` (6 subsequent siblings)
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

This adds a copy of pre generated bindings and adds the suggested way of
updating those in README.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 bindings/rust/libgpiod-sys/README.md       |   11 +
 bindings/rust/libgpiod-sys/src/bindings.rs | 1173 ++++++++++++++++++++
 2 files changed, 1184 insertions(+)
 create mode 100644 bindings/rust/libgpiod-sys/README.md
 create mode 100644 bindings/rust/libgpiod-sys/src/bindings.rs

diff --git a/bindings/rust/libgpiod-sys/README.md b/bindings/rust/libgpiod-sys/README.md
new file mode 100644
index 000000000000..ecf75b31c41e
--- /dev/null
+++ b/bindings/rust/libgpiod-sys/README.md
@@ -0,0 +1,11 @@
+# Generated libgpiod-sys Rust FFI bindings
+Automatically generated Rust FFI bindings via
+	[bindgen](https://github.com/rust-lang/rust-bindgen).
+
+## Updating bindings
+1. Clone the source from
+	<https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/>
+2. run `cd libgpiod/bindings/rust/libgpiod-sys/`
+2. run `cargo build --features generate`
+3. Copy the bindings 'cp ../target/debug/build/libgpiod-sys-###/out/bindings.rs src/bindings.rs'
+4. Commit changes in `src/bindings.rs`
diff --git a/bindings/rust/libgpiod-sys/src/bindings.rs b/bindings/rust/libgpiod-sys/src/bindings.rs
new file mode 100644
index 000000000000..fc2ffa02c3c4
--- /dev/null
+++ b/bindings/rust/libgpiod-sys/src/bindings.rs
@@ -0,0 +1,1173 @@
+/* automatically generated by rust-bindgen 0.59.2 */
+
+pub const true_: u32 = 1;
+pub const false_: u32 = 0;
+pub const __bool_true_false_are_defined: u32 = 1;
+pub const _STDINT_H: u32 = 1;
+pub const _FEATURES_H: u32 = 1;
+pub const _DEFAULT_SOURCE: u32 = 1;
+pub const __GLIBC_USE_ISOC2X: u32 = 0;
+pub const __USE_ISOC11: u32 = 1;
+pub const __USE_ISOC99: u32 = 1;
+pub const __USE_ISOC95: u32 = 1;
+pub const __USE_POSIX_IMPLICITLY: u32 = 1;
+pub const _POSIX_SOURCE: u32 = 1;
+pub const _POSIX_C_SOURCE: u32 = 200809;
+pub const __USE_POSIX: u32 = 1;
+pub const __USE_POSIX2: u32 = 1;
+pub const __USE_POSIX199309: u32 = 1;
+pub const __USE_POSIX199506: u32 = 1;
+pub const __USE_XOPEN2K: u32 = 1;
+pub const __USE_XOPEN2K8: u32 = 1;
+pub const _ATFILE_SOURCE: u32 = 1;
+pub const __USE_MISC: u32 = 1;
+pub const __USE_ATFILE: u32 = 1;
+pub const __USE_FORTIFY_LEVEL: u32 = 0;
+pub const __GLIBC_USE_DEPRECATED_GETS: u32 = 0;
+pub const __GLIBC_USE_DEPRECATED_SCANF: u32 = 0;
+pub const _STDC_PREDEF_H: u32 = 1;
+pub const __STDC_IEC_559__: u32 = 1;
+pub const __STDC_IEC_559_COMPLEX__: u32 = 1;
+pub const __STDC_ISO_10646__: u32 = 201706;
+pub const __GNU_LIBRARY__: u32 = 6;
+pub const __GLIBC__: u32 = 2;
+pub const __GLIBC_MINOR__: u32 = 31;
+pub const _SYS_CDEFS_H: u32 = 1;
+pub const __glibc_c99_flexarr_available: u32 = 1;
+pub const __WORDSIZE: u32 = 64;
+pub const __WORDSIZE_TIME64_COMPAT32: u32 = 1;
+pub const __SYSCALL_WORDSIZE: u32 = 64;
+pub const __LONG_DOUBLE_USES_FLOAT128: u32 = 0;
+pub const __HAVE_GENERIC_SELECTION: u32 = 1;
+pub const __GLIBC_USE_LIB_EXT2: u32 = 0;
+pub const __GLIBC_USE_IEC_60559_BFP_EXT: u32 = 0;
+pub const __GLIBC_USE_IEC_60559_BFP_EXT_C2X: u32 = 0;
+pub const __GLIBC_USE_IEC_60559_FUNCS_EXT: u32 = 0;
+pub const __GLIBC_USE_IEC_60559_FUNCS_EXT_C2X: u32 = 0;
+pub const __GLIBC_USE_IEC_60559_TYPES_EXT: u32 = 0;
+pub const _BITS_TYPES_H: u32 = 1;
+pub const __TIMESIZE: u32 = 64;
+pub const _BITS_TYPESIZES_H: u32 = 1;
+pub const __OFF_T_MATCHES_OFF64_T: u32 = 1;
+pub const __INO_T_MATCHES_INO64_T: u32 = 1;
+pub const __RLIM_T_MATCHES_RLIM64_T: u32 = 1;
+pub const __STATFS_MATCHES_STATFS64: u32 = 1;
+pub const __FD_SETSIZE: u32 = 1024;
+pub const _BITS_TIME64_H: u32 = 1;
+pub const _BITS_WCHAR_H: u32 = 1;
+pub const _BITS_STDINT_INTN_H: u32 = 1;
+pub const _BITS_STDINT_UINTN_H: u32 = 1;
+pub const INT8_MIN: i32 = -128;
+pub const INT16_MIN: i32 = -32768;
+pub const INT32_MIN: i32 = -2147483648;
+pub const INT8_MAX: u32 = 127;
+pub const INT16_MAX: u32 = 32767;
+pub const INT32_MAX: u32 = 2147483647;
+pub const UINT8_MAX: u32 = 255;
+pub const UINT16_MAX: u32 = 65535;
+pub const UINT32_MAX: u32 = 4294967295;
+pub const INT_LEAST8_MIN: i32 = -128;
+pub const INT_LEAST16_MIN: i32 = -32768;
+pub const INT_LEAST32_MIN: i32 = -2147483648;
+pub const INT_LEAST8_MAX: u32 = 127;
+pub const INT_LEAST16_MAX: u32 = 32767;
+pub const INT_LEAST32_MAX: u32 = 2147483647;
+pub const UINT_LEAST8_MAX: u32 = 255;
+pub const UINT_LEAST16_MAX: u32 = 65535;
+pub const UINT_LEAST32_MAX: u32 = 4294967295;
+pub const INT_FAST8_MIN: i32 = -128;
+pub const INT_FAST16_MIN: i64 = -9223372036854775808;
+pub const INT_FAST32_MIN: i64 = -9223372036854775808;
+pub const INT_FAST8_MAX: u32 = 127;
+pub const INT_FAST16_MAX: u64 = 9223372036854775807;
+pub const INT_FAST32_MAX: u64 = 9223372036854775807;
+pub const UINT_FAST8_MAX: u32 = 255;
+pub const UINT_FAST16_MAX: i32 = -1;
+pub const UINT_FAST32_MAX: i32 = -1;
+pub const INTPTR_MIN: i64 = -9223372036854775808;
+pub const INTPTR_MAX: u64 = 9223372036854775807;
+pub const UINTPTR_MAX: i32 = -1;
+pub const PTRDIFF_MIN: i64 = -9223372036854775808;
+pub const PTRDIFF_MAX: u64 = 9223372036854775807;
+pub const SIG_ATOMIC_MIN: i32 = -2147483648;
+pub const SIG_ATOMIC_MAX: u32 = 2147483647;
+pub const SIZE_MAX: i32 = -1;
+pub const WINT_MIN: u32 = 0;
+pub const WINT_MAX: u32 = 4294967295;
+pub type size_t = ::std::os::raw::c_ulong;
+pub type wchar_t = ::std::os::raw::c_int;
+#[repr(C)]
+#[repr(align(16))]
+#[derive(Debug, Copy, Clone)]
+pub struct max_align_t {
+    pub __clang_max_align_nonce1: ::std::os::raw::c_longlong,
+    pub __bindgen_padding_0: u64,
+    pub __clang_max_align_nonce2: u128,
+}
+#[test]
+fn bindgen_test_layout_max_align_t() {
+    assert_eq!(
+        ::std::mem::size_of::<max_align_t>(),
+        32usize,
+        concat!("Size of: ", stringify!(max_align_t))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<max_align_t>(),
+        16usize,
+        concat!("Alignment of ", stringify!(max_align_t))
+    );
+    assert_eq!(
+        unsafe {
+            &(*(::std::ptr::null::<max_align_t>())).__clang_max_align_nonce1 as *const _ as usize
+        },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(max_align_t),
+            "::",
+            stringify!(__clang_max_align_nonce1)
+        )
+    );
+    assert_eq!(
+        unsafe {
+            &(*(::std::ptr::null::<max_align_t>())).__clang_max_align_nonce2 as *const _ as usize
+        },
+        16usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(max_align_t),
+            "::",
+            stringify!(__clang_max_align_nonce2)
+        )
+    );
+}
+pub type __u_char = ::std::os::raw::c_uchar;
+pub type __u_short = ::std::os::raw::c_ushort;
+pub type __u_int = ::std::os::raw::c_uint;
+pub type __u_long = ::std::os::raw::c_ulong;
+pub type __int8_t = ::std::os::raw::c_schar;
+pub type __uint8_t = ::std::os::raw::c_uchar;
+pub type __int16_t = ::std::os::raw::c_short;
+pub type __uint16_t = ::std::os::raw::c_ushort;
+pub type __int32_t = ::std::os::raw::c_int;
+pub type __uint32_t = ::std::os::raw::c_uint;
+pub type __int64_t = ::std::os::raw::c_long;
+pub type __uint64_t = ::std::os::raw::c_ulong;
+pub type __int_least8_t = __int8_t;
+pub type __uint_least8_t = __uint8_t;
+pub type __int_least16_t = __int16_t;
+pub type __uint_least16_t = __uint16_t;
+pub type __int_least32_t = __int32_t;
+pub type __uint_least32_t = __uint32_t;
+pub type __int_least64_t = __int64_t;
+pub type __uint_least64_t = __uint64_t;
+pub type __quad_t = ::std::os::raw::c_long;
+pub type __u_quad_t = ::std::os::raw::c_ulong;
+pub type __intmax_t = ::std::os::raw::c_long;
+pub type __uintmax_t = ::std::os::raw::c_ulong;
+pub type __dev_t = ::std::os::raw::c_ulong;
+pub type __uid_t = ::std::os::raw::c_uint;
+pub type __gid_t = ::std::os::raw::c_uint;
+pub type __ino_t = ::std::os::raw::c_ulong;
+pub type __ino64_t = ::std::os::raw::c_ulong;
+pub type __mode_t = ::std::os::raw::c_uint;
+pub type __nlink_t = ::std::os::raw::c_ulong;
+pub type __off_t = ::std::os::raw::c_long;
+pub type __off64_t = ::std::os::raw::c_long;
+pub type __pid_t = ::std::os::raw::c_int;
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct __fsid_t {
+    pub __val: [::std::os::raw::c_int; 2usize],
+}
+#[test]
+fn bindgen_test_layout___fsid_t() {
+    assert_eq!(
+        ::std::mem::size_of::<__fsid_t>(),
+        8usize,
+        concat!("Size of: ", stringify!(__fsid_t))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<__fsid_t>(),
+        4usize,
+        concat!("Alignment of ", stringify!(__fsid_t))
+    );
+    assert_eq!(
+        unsafe { &(*(::std::ptr::null::<__fsid_t>())).__val as *const _ as usize },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(__fsid_t),
+            "::",
+            stringify!(__val)
+        )
+    );
+}
+pub type __clock_t = ::std::os::raw::c_long;
+pub type __rlim_t = ::std::os::raw::c_ulong;
+pub type __rlim64_t = ::std::os::raw::c_ulong;
+pub type __id_t = ::std::os::raw::c_uint;
+pub type __time_t = ::std::os::raw::c_long;
+pub type __useconds_t = ::std::os::raw::c_uint;
+pub type __suseconds_t = ::std::os::raw::c_long;
+pub type __daddr_t = ::std::os::raw::c_int;
+pub type __key_t = ::std::os::raw::c_int;
+pub type __clockid_t = ::std::os::raw::c_int;
+pub type __timer_t = *mut ::std::os::raw::c_void;
+pub type __blksize_t = ::std::os::raw::c_long;
+pub type __blkcnt_t = ::std::os::raw::c_long;
+pub type __blkcnt64_t = ::std::os::raw::c_long;
+pub type __fsblkcnt_t = ::std::os::raw::c_ulong;
+pub type __fsblkcnt64_t = ::std::os::raw::c_ulong;
+pub type __fsfilcnt_t = ::std::os::raw::c_ulong;
+pub type __fsfilcnt64_t = ::std::os::raw::c_ulong;
+pub type __fsword_t = ::std::os::raw::c_long;
+pub type __ssize_t = ::std::os::raw::c_long;
+pub type __syscall_slong_t = ::std::os::raw::c_long;
+pub type __syscall_ulong_t = ::std::os::raw::c_ulong;
+pub type __loff_t = __off64_t;
+pub type __caddr_t = *mut ::std::os::raw::c_char;
+pub type __intptr_t = ::std::os::raw::c_long;
+pub type __socklen_t = ::std::os::raw::c_uint;
+pub type __sig_atomic_t = ::std::os::raw::c_int;
+pub type int_least8_t = __int_least8_t;
+pub type int_least16_t = __int_least16_t;
+pub type int_least32_t = __int_least32_t;
+pub type int_least64_t = __int_least64_t;
+pub type uint_least8_t = __uint_least8_t;
+pub type uint_least16_t = __uint_least16_t;
+pub type uint_least32_t = __uint_least32_t;
+pub type uint_least64_t = __uint_least64_t;
+pub type int_fast8_t = ::std::os::raw::c_schar;
+pub type int_fast16_t = ::std::os::raw::c_long;
+pub type int_fast32_t = ::std::os::raw::c_long;
+pub type int_fast64_t = ::std::os::raw::c_long;
+pub type uint_fast8_t = ::std::os::raw::c_uchar;
+pub type uint_fast16_t = ::std::os::raw::c_ulong;
+pub type uint_fast32_t = ::std::os::raw::c_ulong;
+pub type uint_fast64_t = ::std::os::raw::c_ulong;
+pub type intmax_t = __intmax_t;
+pub type uintmax_t = __uintmax_t;
+#[doc = " @mainpage libgpiod public API"]
+#[doc = ""]
+#[doc = " This is the complete documentation of the public API made available to"]
+#[doc = " users of libgpiod."]
+#[doc = ""]
+#[doc = " <p>The API is logically split into several parts such as: GPIO chip & line"]
+#[doc = " operators, GPIO events handling etc."]
+#[doc = ""]
+#[doc = " <p>General note on error handling: all functions exported by libgpiod that"]
+#[doc = " can fail, set errno to one of the error values defined in errno.h upon"]
+#[doc = " failure. The way of notifying the caller that an error occurred varies"]
+#[doc = " between functions, but in general a function that returns an int, returns -1"]
+#[doc = " on error, while a function returning a pointer indicates an error condition"]
+#[doc = " by returning a NULL pointer. It's not practical to list all possible error"]
+#[doc = " codes for every function as they propagate errors from the underlying libc"]
+#[doc = " functions."]
+#[doc = ""]
+#[doc = " <p>In general libgpiod functions are not NULL-aware and it's expected that"]
+#[doc = " users pass valid pointers to objects as arguments. An exception to this rule"]
+#[doc = " are the functions that free/close/release resources - which work when passed"]
+#[doc = " a NULL-pointer as argument. Other exceptions are documented."]
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_chip {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_chip_info {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_line_info {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_line_settings {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_line_config {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_request_config {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_line_request {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_info_event {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_edge_event {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiod_edge_event_buffer {
+    _unused: [u8; 0],
+}
+extern "C" {
+    #[doc = " @brief Open a chip by path."]
+    #[doc = " @param path Path to the gpiochip device file."]
+    #[doc = " @return GPIO chip request or NULL if an error occurred."]
+    pub fn gpiod_chip_open(path: *const ::std::os::raw::c_char) -> *mut gpiod_chip;
+}
+extern "C" {
+    #[doc = " @brief Close the chip and release all associated resources."]
+    #[doc = " @param chip Chip to close."]
+    pub fn gpiod_chip_close(chip: *mut gpiod_chip);
+}
+extern "C" {
+    #[doc = " @brief Get information about the chip."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @return New GPIO chip info object or NULL if an error occurred. The returned"]
+    #[doc = "         object must be freed by the caller using ::gpiod_chip_info_free."]
+    pub fn gpiod_chip_get_info(chip: *mut gpiod_chip) -> *mut gpiod_chip_info;
+}
+extern "C" {
+    #[doc = " @brief Get the path used to open the chip."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @return Path to the file passed as argument to ::gpiod_chip_open."]
+    pub fn gpiod_chip_get_path(chip: *mut gpiod_chip) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    #[doc = " @brief Get a snapshot of information about a line."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @param offset The offset of the GPIO line."]
+    #[doc = " @return New GPIO line info object or NULL if an error occurred. The returned"]
+    #[doc = "\t   object must be freed by the caller using ::gpiod_line_info_free."]
+    pub fn gpiod_chip_get_line_info(
+        chip: *mut gpiod_chip,
+        offset: ::std::os::raw::c_uint,
+    ) -> *mut gpiod_line_info;
+}
+extern "C" {
+    #[doc = " @brief Get a snapshot of the status of a line and start watching it for"]
+    #[doc = "\t  future changes."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @param offset The offset of the GPIO line."]
+    #[doc = " @return New GPIO line info object or NULL if an error occurred. The returned"]
+    #[doc = "\t   object must be freed by the caller using ::gpiod_line_info_free."]
+    #[doc = " @note Line status does not include the line value.  To monitor the line"]
+    #[doc = "\t value the line must be requested as an input with edge detection set."]
+    pub fn gpiod_chip_watch_line_info(
+        chip: *mut gpiod_chip,
+        offset: ::std::os::raw::c_uint,
+    ) -> *mut gpiod_line_info;
+}
+extern "C" {
+    #[doc = " @brief Stop watching a line for status changes."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @param offset The offset of the line to stop watching."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_chip_unwatch_line_info(
+        chip: *mut gpiod_chip,
+        offset: ::std::os::raw::c_uint,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the file descriptor associated with the chip."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @return File descriptor number for the chip."]
+    #[doc = "\t   This function never fails."]
+    #[doc = "\t   The returned file descriptor must not be closed by the caller."]
+    #[doc = "\t   Call ::gpiod_chip_close to close the file descriptor."]
+    pub fn gpiod_chip_get_fd(chip: *mut gpiod_chip) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Wait for line status change events on any of the watched lines"]
+    #[doc = "\t  on the chip."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @param timeout_ns Wait time limit in nanoseconds. If set to 0, the function"]
+    #[doc = "\t\t     returns immediatelly. If set to a negative number, the"]
+    #[doc = "\t\t     function blocks indefinitely until an event becomes"]
+    #[doc = "\t\t     available."]
+    #[doc = " @return 0 if wait timed out, -1 if an error occurred, 1 if an event is"]
+    #[doc = "\t   pending."]
+    pub fn gpiod_chip_wait_info_event(
+        chip: *mut gpiod_chip,
+        timeout_ns: i64,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Read a single line status change event from the chip."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @return Newly read watch event object or NULL on error. The event must be"]
+    #[doc = "\t   freed by the caller using ::gpiod_info_event_free."]
+    #[doc = " @note If no events are pending, this function will block."]
+    pub fn gpiod_chip_read_info_event(chip: *mut gpiod_chip) -> *mut gpiod_info_event;
+}
+extern "C" {
+    #[doc = " @brief Map a line's name to its offset within the chip."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @param name Name of the GPIO line to map."]
+    #[doc = " @return Offset of the line within the chip or -1 on error."]
+    #[doc = " @note If a line with given name is not exposed by the chip, the function"]
+    #[doc = "       sets errno to ENOENT."]
+    pub fn gpiod_chip_get_line_offset_from_name(
+        chip: *mut gpiod_chip,
+        name: *const ::std::os::raw::c_char,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Request a set of lines for exclusive usage."]
+    #[doc = " @param chip GPIO chip object."]
+    #[doc = " @param req_cfg Request config object. Can be NULL for default settings."]
+    #[doc = " @param line_cfg Line config object."]
+    #[doc = " @return New line request object or NULL if an error occurred. The request"]
+    #[doc = "\t   must be released by the caller using ::gpiod_line_request_release."]
+    pub fn gpiod_chip_request_lines(
+        chip: *mut gpiod_chip,
+        req_cfg: *mut gpiod_request_config,
+        line_cfg: *mut gpiod_line_config,
+    ) -> *mut gpiod_line_request;
+}
+extern "C" {
+    #[doc = " @brief Free a chip info object and release all associated resources."]
+    #[doc = " @param info GPIO chip info object to free."]
+    pub fn gpiod_chip_info_free(info: *mut gpiod_chip_info);
+}
+extern "C" {
+    #[doc = " @brief Get the name of the chip as represented in the kernel."]
+    #[doc = " @param info GPIO chip info object."]
+    #[doc = " @return Pointer to a human-readable string containing the chip name."]
+    pub fn gpiod_chip_info_get_name(info: *mut gpiod_chip_info) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    #[doc = " @brief Get the label of the chip as represented in the kernel."]
+    #[doc = " @param info GPIO chip info object."]
+    #[doc = " @return Pointer to a human-readable string containing the chip label."]
+    pub fn gpiod_chip_info_get_label(info: *mut gpiod_chip_info) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    #[doc = " @brief Get the number of lines exposed by the chip."]
+    #[doc = " @param info GPIO chip info object."]
+    #[doc = " @return Number of GPIO lines."]
+    pub fn gpiod_chip_info_get_num_lines(info: *mut gpiod_chip_info) -> size_t;
+}
+pub const GPIOD_LINE_VALUE_INACTIVE: ::std::os::raw::c_uint = 0;
+pub const GPIOD_LINE_VALUE_ACTIVE: ::std::os::raw::c_uint = 1;
+#[doc = " @brief Logical line state."]
+pub type _bindgen_ty_1 = ::std::os::raw::c_uint;
+pub const GPIOD_LINE_DIRECTION_AS_IS: ::std::os::raw::c_uint = 1;
+pub const GPIOD_LINE_DIRECTION_INPUT: ::std::os::raw::c_uint = 2;
+pub const GPIOD_LINE_DIRECTION_OUTPUT: ::std::os::raw::c_uint = 3;
+#[doc = " @brief Direction settings."]
+pub type _bindgen_ty_2 = ::std::os::raw::c_uint;
+pub const GPIOD_LINE_EDGE_NONE: ::std::os::raw::c_uint = 1;
+pub const GPIOD_LINE_EDGE_RISING: ::std::os::raw::c_uint = 2;
+pub const GPIOD_LINE_EDGE_FALLING: ::std::os::raw::c_uint = 3;
+pub const GPIOD_LINE_EDGE_BOTH: ::std::os::raw::c_uint = 4;
+#[doc = " @brief Edge detection settings."]
+pub type _bindgen_ty_3 = ::std::os::raw::c_uint;
+pub const GPIOD_LINE_BIAS_AS_IS: ::std::os::raw::c_uint = 1;
+pub const GPIOD_LINE_BIAS_UNKNOWN: ::std::os::raw::c_uint = 2;
+pub const GPIOD_LINE_BIAS_DISABLED: ::std::os::raw::c_uint = 3;
+pub const GPIOD_LINE_BIAS_PULL_UP: ::std::os::raw::c_uint = 4;
+pub const GPIOD_LINE_BIAS_PULL_DOWN: ::std::os::raw::c_uint = 5;
+#[doc = " @brief Internal bias settings."]
+pub type _bindgen_ty_4 = ::std::os::raw::c_uint;
+pub const GPIOD_LINE_DRIVE_PUSH_PULL: ::std::os::raw::c_uint = 1;
+pub const GPIOD_LINE_DRIVE_OPEN_DRAIN: ::std::os::raw::c_uint = 2;
+pub const GPIOD_LINE_DRIVE_OPEN_SOURCE: ::std::os::raw::c_uint = 3;
+#[doc = " @brief Drive settings."]
+pub type _bindgen_ty_5 = ::std::os::raw::c_uint;
+pub const GPIOD_LINE_EVENT_CLOCK_MONOTONIC: ::std::os::raw::c_uint = 1;
+pub const GPIOD_LINE_EVENT_CLOCK_REALTIME: ::std::os::raw::c_uint = 2;
+pub const GPIOD_LINE_EVENT_CLOCK_HTE: ::std::os::raw::c_uint = 3;
+#[doc = " @brief Event clock settings."]
+pub type _bindgen_ty_6 = ::std::os::raw::c_uint;
+extern "C" {
+    #[doc = " @brief Free a line info object and release all associated resources."]
+    #[doc = " @param info GPIO line info object to free."]
+    pub fn gpiod_line_info_free(info: *mut gpiod_line_info);
+}
+extern "C" {
+    #[doc = " @brief Copy a line info object."]
+    #[doc = " @param info Line info to copy."]
+    #[doc = " @return Copy of the line info or NULL on error. The returned object must"]
+    #[doc = "\t   be freed by the caller using :gpiod_line_info_free."]
+    pub fn gpiod_line_info_copy(info: *mut gpiod_line_info) -> *mut gpiod_line_info;
+}
+extern "C" {
+    #[doc = " @brief Get the offset of the line."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Offset of the line within the parent chip."]
+    #[doc = ""]
+    #[doc = " The offset uniquely identifies the line on the chip."]
+    #[doc = " The combination of the chip and offset uniquely identifies the line within"]
+    #[doc = " the system."]
+    pub fn gpiod_line_info_get_offset(info: *mut gpiod_line_info) -> ::std::os::raw::c_uint;
+}
+extern "C" {
+    #[doc = " @brief Get the name of the line."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Name of the GPIO line as it is represented in the kernel."]
+    #[doc = "\t   This function returns a pointer to a null-terminated string"]
+    #[doc = "\t   or NULL if the line is unnamed."]
+    pub fn gpiod_line_info_get_name(info: *mut gpiod_line_info) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    #[doc = " @brief Check if the line is in use."]
+    #[doc = " @param info GPIO line object."]
+    #[doc = " @return True if the line is in use, false otherwise."]
+    #[doc = ""]
+    #[doc = " The exact reason a line is busy cannot be determined from user space."]
+    #[doc = " It may have been requested by another process or hogged by the kernel."]
+    #[doc = " It only matters that the line is used and can't be requested until"]
+    #[doc = " released by the existing consumer."]
+    pub fn gpiod_line_info_is_used(info: *mut gpiod_line_info) -> bool;
+}
+extern "C" {
+    #[doc = " @brief Get the name of the consumer of the line."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Name of the GPIO consumer as it is represented in the kernel."]
+    #[doc = "\t   This function returns a pointer to a null-terminated string"]
+    #[doc = "\t   or NULL if the consumer name is not set."]
+    pub fn gpiod_line_info_get_consumer(
+        info: *mut gpiod_line_info,
+    ) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    #[doc = " @brief Get the direction setting of the line."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Returns ::GPIOD_LINE_DIRECTION_INPUT or"]
+    #[doc = "\t   ::GPIOD_LINE_DIRECTION_OUTPUT."]
+    pub fn gpiod_line_info_get_direction(info: *mut gpiod_line_info) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the edge detection setting of the line."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Returns ::GPIOD_LINE_EDGE_NONE, ::GPIOD_LINE_EDGE_RISING,"]
+    #[doc = "\t   ::GPIOD_LINE_EDGE_FALLING or ::GPIOD_LINE_EDGE_BOTH."]
+    pub fn gpiod_line_info_get_edge_detection(info: *mut gpiod_line_info) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the bias setting of the line."]
+    #[doc = " @param info GPIO line object."]
+    #[doc = " @return Returns ::GPIOD_LINE_BIAS_PULL_UP, ::GPIOD_LINE_BIAS_PULL_DOWN,"]
+    #[doc = "\t   ::GPIOD_LINE_BIAS_DISABLED or ::GPIOD_LINE_BIAS_UNKNOWN."]
+    pub fn gpiod_line_info_get_bias(info: *mut gpiod_line_info) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the drive setting of the line."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Returns ::GPIOD_LINE_DRIVE_PUSH_PULL, ::GPIOD_LINE_DRIVE_OPEN_DRAIN"]
+    #[doc = "\t   or ::GPIOD_LINE_DRIVE_OPEN_SOURCE."]
+    pub fn gpiod_line_info_get_drive(info: *mut gpiod_line_info) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Check if the logical value of the line is inverted compared to the"]
+    #[doc = "\t  physical."]
+    #[doc = " @param info GPIO line object."]
+    #[doc = " @return True if the line is \"active-low\", false otherwise."]
+    pub fn gpiod_line_info_is_active_low(info: *mut gpiod_line_info) -> bool;
+}
+extern "C" {
+    #[doc = " @brief Check if the line is debounced (either by hardware or by the kernel"]
+    #[doc = "\t  software debouncer)."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return True if the line is debounced, false otherwise."]
+    pub fn gpiod_line_info_is_debounced(info: *mut gpiod_line_info) -> bool;
+}
+extern "C" {
+    #[doc = " @brief Get the debounce period of the line, in microseconds."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Debounce period in microseconds."]
+    #[doc = "\t   0 if the line is not debounced."]
+    pub fn gpiod_line_info_get_debounce_period_us(
+        info: *mut gpiod_line_info,
+    ) -> ::std::os::raw::c_ulong;
+}
+extern "C" {
+    #[doc = " @brief Get the event clock setting used for edge event timestamps for the"]
+    #[doc = "\t  line."]
+    #[doc = " @param info GPIO line info object."]
+    #[doc = " @return Returns ::GPIOD_LINE_EVENT_CLOCK_MONOTONIC or"]
+    #[doc = "\t   ::GPIOD_LINE_EVENT_CLOCK_REALTIME."]
+    pub fn gpiod_line_info_get_event_clock(info: *mut gpiod_line_info) -> ::std::os::raw::c_int;
+}
+pub const GPIOD_INFO_EVENT_LINE_REQUESTED: ::std::os::raw::c_uint = 1;
+pub const GPIOD_INFO_EVENT_LINE_RELEASED: ::std::os::raw::c_uint = 2;
+pub const GPIOD_INFO_EVENT_LINE_CONFIG_CHANGED: ::std::os::raw::c_uint = 3;
+#[doc = " @brief Line status change event types."]
+pub type _bindgen_ty_7 = ::std::os::raw::c_uint;
+extern "C" {
+    #[doc = " @brief Free the info event object and release all associated resources."]
+    #[doc = " @param event Info event to free."]
+    pub fn gpiod_info_event_free(event: *mut gpiod_info_event);
+}
+extern "C" {
+    #[doc = " @brief Get the event type of the status change event."]
+    #[doc = " @param event Line status watch event."]
+    #[doc = " @return One of ::GPIOD_INFO_EVENT_LINE_REQUESTED,"]
+    #[doc = "\t   ::GPIOD_INFO_EVENT_LINE_RELEASED or"]
+    #[doc = "\t   ::GPIOD_INFO_EVENT_LINE_CONFIG_CHANGED."]
+    pub fn gpiod_info_event_get_event_type(event: *mut gpiod_info_event) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the timestamp of the event."]
+    #[doc = " @param event Line status watch event."]
+    #[doc = " @return Timestamp in nanoseconds, read from the monotonic clock."]
+    pub fn gpiod_info_event_get_timestamp_ns(event: *mut gpiod_info_event) -> u64;
+}
+extern "C" {
+    #[doc = " @brief Get the snapshot of line-info associated with the event."]
+    #[doc = " @param event Line info event object."]
+    #[doc = " @return Returns a pointer to the line-info object associated with the event"]
+    #[doc = "\t   whose lifetime is tied to the event object. It must not be freed by"]
+    #[doc = "\t   the caller."]
+    pub fn gpiod_info_event_get_line_info(event: *mut gpiod_info_event) -> *mut gpiod_line_info;
+}
+extern "C" {
+    #[doc = " @brief Create a new line settings object."]
+    #[doc = " @return New line settings object or NULL on error."]
+    pub fn gpiod_line_settings_new() -> *mut gpiod_line_settings;
+}
+extern "C" {
+    #[doc = " @brief Free the line settings object and release all associated resources."]
+    #[doc = " @param settings Line settings object."]
+    pub fn gpiod_line_settings_free(settings: *mut gpiod_line_settings);
+}
+extern "C" {
+    #[doc = " @brief Reset the line settings object to its default values."]
+    #[doc = " @param settings Line settings object."]
+    pub fn gpiod_line_settings_reset(settings: *mut gpiod_line_settings);
+}
+extern "C" {
+    #[doc = " @brief Copy the line settings object."]
+    #[doc = " @param settings Line settings object to copy."]
+    #[doc = " @return New line settings object that must be freed using"]
+    #[doc = "         ::gpiod_line_settings_free or NULL on failure."]
+    pub fn gpiod_line_settings_copy(settings: *mut gpiod_line_settings)
+        -> *mut gpiod_line_settings;
+}
+extern "C" {
+    #[doc = " @brief Set direction."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param direction New direction."]
+    #[doc = " @return 0 on success, -1 on error."]
+    pub fn gpiod_line_settings_set_direction(
+        settings: *mut gpiod_line_settings,
+        direction: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get direction."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return Current direction."]
+    pub fn gpiod_line_settings_get_direction(
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set edge detection."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param edge New edge detection setting."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_settings_set_edge_detection(
+        settings: *mut gpiod_line_settings,
+        edge: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get edge detection."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return Current edge detection setting."]
+    pub fn gpiod_line_settings_get_edge_detection(
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set bias."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param bias New bias."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_settings_set_bias(
+        settings: *mut gpiod_line_settings,
+        bias: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get bias."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return Current bias setting."]
+    pub fn gpiod_line_settings_get_bias(
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set drive."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param drive New drive setting."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_settings_set_drive(
+        settings: *mut gpiod_line_settings,
+        drive: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get drive."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return Current drive setting."]
+    pub fn gpiod_line_settings_get_drive(
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set active-low setting."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param active_low New active-low setting."]
+    pub fn gpiod_line_settings_set_active_low(settings: *mut gpiod_line_settings, active_low: bool);
+}
+extern "C" {
+    #[doc = " @brief Get active-low setting."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return True if active-low is enabled, false otherwise."]
+    pub fn gpiod_line_settings_get_active_low(settings: *mut gpiod_line_settings) -> bool;
+}
+extern "C" {
+    #[doc = " @brief Set debounce period."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param period New debounce period in microseconds."]
+    pub fn gpiod_line_settings_set_debounce_period_us(
+        settings: *mut gpiod_line_settings,
+        period: ::std::os::raw::c_ulong,
+    );
+}
+extern "C" {
+    #[doc = " @brief Get debounce period."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return Current debounce period in microseconds."]
+    pub fn gpiod_line_settings_get_debounce_period_us(
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_ulong;
+}
+extern "C" {
+    #[doc = " @brief Set event clock."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param event_clock New event clock."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_settings_set_event_clock(
+        settings: *mut gpiod_line_settings,
+        event_clock: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get event clock setting."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return Current event clock setting."]
+    pub fn gpiod_line_settings_get_event_clock(
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set the output value."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @param value New output value."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_settings_set_output_value(
+        settings: *mut gpiod_line_settings,
+        value: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the output value."]
+    #[doc = " @param settings Line settings object."]
+    #[doc = " @return Current output value."]
+    pub fn gpiod_line_settings_get_output_value(
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Create a new line config object."]
+    #[doc = " @return New line config object or NULL on error."]
+    pub fn gpiod_line_config_new() -> *mut gpiod_line_config;
+}
+extern "C" {
+    #[doc = " @brief Free the line config object and release all associated resources."]
+    #[doc = " @param config Line config object to free."]
+    pub fn gpiod_line_config_free(config: *mut gpiod_line_config);
+}
+extern "C" {
+    #[doc = " @brief Reset the line config object."]
+    #[doc = " @param config Line config object to free."]
+    #[doc = ""]
+    #[doc = " Resets the entire configuration stored in the object. This is useful if"]
+    #[doc = " the user wants to reuse the object without reallocating it."]
+    pub fn gpiod_line_config_reset(config: *mut gpiod_line_config);
+}
+extern "C" {
+    #[doc = " @brief Add line settings for a set of offsets."]
+    #[doc = " @param config Line config object."]
+    #[doc = " @param offsets Array of offsets for which to apply the settings."]
+    #[doc = " @param num_offsets Number of offsets stored in the offsets array."]
+    #[doc = " @param settings Line settings to apply."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_config_add_line_settings(
+        config: *mut gpiod_line_config,
+        offsets: *const ::std::os::raw::c_uint,
+        num_offsets: size_t,
+        settings: *mut gpiod_line_settings,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get line settings for offset."]
+    #[doc = " @param config Line config object."]
+    #[doc = " @param offset Offset for which to get line settings."]
+    #[doc = " @return New line settings object (must be freed by the caller) or NULL on"]
+    #[doc = "         error."]
+    pub fn gpiod_line_config_get_line_settings(
+        config: *mut gpiod_line_config,
+        offset: ::std::os::raw::c_uint,
+    ) -> *mut gpiod_line_settings;
+}
+extern "C" {
+    #[doc = " @brief Get configured offsets."]
+    #[doc = " @param config Line config object."]
+    #[doc = " @param num_offsets Pointer to a variable in which the number of line offsets"]
+    #[doc = "                    will be stored."]
+    #[doc = " @param offsets Pointer to a pointer which will be set to point to an array"]
+    #[doc = "                containing the configured offsets. The array will be allocated"]
+    #[doc = "                using malloc() and must be freed using free()."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_config_get_offsets(
+        config: *mut gpiod_line_config,
+        num_offsets: *mut size_t,
+        offsets: *mut *mut ::std::os::raw::c_uint,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Create a new request config object."]
+    #[doc = " @return New request config object or NULL on error."]
+    pub fn gpiod_request_config_new() -> *mut gpiod_request_config;
+}
+extern "C" {
+    #[doc = " @brief Free the request config object and release all associated resources."]
+    #[doc = " @param config Line config object."]
+    pub fn gpiod_request_config_free(config: *mut gpiod_request_config);
+}
+extern "C" {
+    #[doc = " @brief Set the consumer name for the request."]
+    #[doc = " @param config Request config object."]
+    #[doc = " @param consumer Consumer name."]
+    #[doc = " @note If the consumer string is too long, it will be truncated to the max"]
+    #[doc = "       accepted length."]
+    pub fn gpiod_request_config_set_consumer(
+        config: *mut gpiod_request_config,
+        consumer: *const ::std::os::raw::c_char,
+    );
+}
+extern "C" {
+    #[doc = " @brief Get the consumer name configured in the request config."]
+    #[doc = " @param config Request config object."]
+    #[doc = " @return Consumer name stored in the request config."]
+    pub fn gpiod_request_config_get_consumer(
+        config: *mut gpiod_request_config,
+    ) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    #[doc = " @brief Set the size of the kernel event buffer for the request."]
+    #[doc = " @param config Request config object."]
+    #[doc = " @param event_buffer_size New event buffer size."]
+    #[doc = " @note The kernel may adjust the value if it's too high. If set to 0, the"]
+    #[doc = "       default value will be used."]
+    #[doc = " @note The kernel buffer is distinct from and independent of the user space"]
+    #[doc = "\t buffer (::gpiod_edge_event_buffer_new)."]
+    pub fn gpiod_request_config_set_event_buffer_size(
+        config: *mut gpiod_request_config,
+        event_buffer_size: size_t,
+    );
+}
+extern "C" {
+    #[doc = " @brief Get the edge event buffer size for the request config."]
+    #[doc = " @param config Request config object."]
+    #[doc = " @return Edge event buffer size setting from the request config."]
+    pub fn gpiod_request_config_get_event_buffer_size(config: *mut gpiod_request_config) -> size_t;
+}
+extern "C" {
+    #[doc = " @brief Release the requested lines and free all associated resources."]
+    #[doc = " @param request Line request object to release."]
+    pub fn gpiod_line_request_release(request: *mut gpiod_line_request);
+}
+extern "C" {
+    #[doc = " @brief Get the number of lines in the request."]
+    #[doc = " @param request Line request object."]
+    #[doc = " @return Number of requested lines."]
+    pub fn gpiod_line_request_get_num_lines(request: *mut gpiod_line_request) -> size_t;
+}
+extern "C" {
+    #[doc = " @brief Get the offsets of the lines in the request."]
+    #[doc = " @param request Line request object."]
+    #[doc = " @param offsets Array to store offsets. Must be sized to hold the number of"]
+    #[doc = "\t\t  lines returned by ::gpiod_line_request_get_num_lines."]
+    pub fn gpiod_line_request_get_offsets(
+        request: *mut gpiod_line_request,
+        offsets: *mut ::std::os::raw::c_uint,
+    );
+}
+extern "C" {
+    #[doc = " @brief Get the value of a single requested line."]
+    #[doc = " @param request Line request object."]
+    #[doc = " @param offset The offset of the line of which the value should be read."]
+    #[doc = " @return Returns 1 or 0 on success and -1 on error."]
+    pub fn gpiod_line_request_get_value(
+        request: *mut gpiod_line_request,
+        offset: ::std::os::raw::c_uint,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the values of a subset of requested lines."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @param num_values Number of lines for which to read values."]
+    #[doc = " @param offsets Array of offsets identifying the subset of requested lines"]
+    #[doc = "\t\t  from which to read values."]
+    #[doc = " @param values Array in which the values will be stored.  Must be sized"]
+    #[doc = "\t\t to hold \\p num_values entries.  Each value is associated with the"]
+    #[doc = "\t\t line identified by the corresponding entry in \\p offsets."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_request_get_values_subset(
+        request: *mut gpiod_line_request,
+        num_values: size_t,
+        offsets: *const ::std::os::raw::c_uint,
+        values: *mut ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the values of all requested lines."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @param values Array in which the values will be stored. Must be sized to"]
+    #[doc = "\t\t hold the number of lines returned by"]
+    #[doc = "\t\t ::gpiod_line_request_get_num_lines."]
+    #[doc = "\t\t Each value is associated with the line identified by the"]
+    #[doc = "\t\t corresponding entry in the offset array returned by"]
+    #[doc = "\t\t ::gpiod_line_request_get_offsets."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_request_get_values(
+        request: *mut gpiod_line_request,
+        values: *mut ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set the value of a single requested line."]
+    #[doc = " @param request Line request object."]
+    #[doc = " @param offset The offset of the line for which the value should be set."]
+    #[doc = " @param value Value to set."]
+    pub fn gpiod_line_request_set_value(
+        request: *mut gpiod_line_request,
+        offset: ::std::os::raw::c_uint,
+        value: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set the values of a subset of requested lines."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @param num_values Number of lines for which to set values."]
+    #[doc = " @param offsets Array of offsets, containing the number of entries specified"]
+    #[doc = "\t\t  by \\p num_values, identifying the requested lines for"]
+    #[doc = "\t\t  which to set values."]
+    #[doc = " @param values Array of values to set, containing the number of entries"]
+    #[doc = "\t\t specified by \\p num_values.  Each value is associated with the"]
+    #[doc = "\t\t line identified by the corresponding entry in \\p offsets."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    pub fn gpiod_line_request_set_values_subset(
+        request: *mut gpiod_line_request,
+        num_values: size_t,
+        offsets: *const ::std::os::raw::c_uint,
+        values: *const ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Set the values of all lines associated with a request."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @param values Array containing the values to set. Must be sized to"]
+    #[doc = "\t\t contain the number of lines returned by"]
+    #[doc = "\t\t ::gpiod_line_request_get_num_lines."]
+    #[doc = "\t\t Each value is associated with the line identified by the"]
+    #[doc = "\t\t corresponding entry in the offset array returned by"]
+    #[doc = "\t\t ::gpiod_line_request_get_offsets."]
+    pub fn gpiod_line_request_set_values(
+        request: *mut gpiod_line_request,
+        values: *const ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Update the configuration of lines associated with a line request."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @param config New line config to apply."]
+    #[doc = " @return 0 on success, -1 on failure."]
+    #[doc = " @note The new line configuration completely replaces the old."]
+    #[doc = " @note Any requested lines without overrides are configured to the requested"]
+    #[doc = "\t defaults."]
+    #[doc = " @note Any configured overrides for lines that have not been requested"]
+    #[doc = "\t are silently ignored."]
+    pub fn gpiod_line_request_reconfigure_lines(
+        request: *mut gpiod_line_request,
+        config: *mut gpiod_line_config,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the file descriptor associated with a line request."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @return The file descriptor associated with the request."]
+    #[doc = "\t   This function never fails."]
+    #[doc = "\t   The returned file descriptor must not be closed by the caller."]
+    #[doc = "\t   Call ::gpiod_line_request_release to close the file."]
+    pub fn gpiod_line_request_get_fd(request: *mut gpiod_line_request) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Wait for edge events on any of the requested lines."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @param timeout_ns Wait time limit in nanoseconds. If set to 0, the function"]
+    #[doc = "\t\t     returns immediatelly. If set to a negative number, the"]
+    #[doc = "\t\t     function blocks indefinitely until an event becomes"]
+    #[doc = "\t\t     available."]
+    #[doc = " @return 0 if wait timed out, -1 if an error occurred, 1 if an event is"]
+    #[doc = "\t   pending."]
+    #[doc = "q"]
+    #[doc = " Lines must have edge detection set for edge events to be emitted."]
+    #[doc = " By default edge detection is disabled."]
+    pub fn gpiod_line_request_wait_edge_event(
+        request: *mut gpiod_line_request,
+        timeout_ns: i64,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Read a number of edge events from a line request."]
+    #[doc = " @param request GPIO line request."]
+    #[doc = " @param buffer Edge event buffer, sized to hold at least \\p max_events."]
+    #[doc = " @param max_events Maximum number of events to read."]
+    #[doc = " @return On success returns the number of events read from the file"]
+    #[doc = "\t   descriptor, on failure return -1."]
+    #[doc = " @note This function will block if no event was queued for the line request."]
+    #[doc = " @note Any exising events in the buffer are overwritten.  This is not an"]
+    #[doc = "       append operation."]
+    pub fn gpiod_line_request_read_edge_event(
+        request: *mut gpiod_line_request,
+        buffer: *mut gpiod_edge_event_buffer,
+        max_events: size_t,
+    ) -> ::std::os::raw::c_int;
+}
+pub const GPIOD_EDGE_EVENT_RISING_EDGE: ::std::os::raw::c_uint = 1;
+pub const GPIOD_EDGE_EVENT_FALLING_EDGE: ::std::os::raw::c_uint = 2;
+#[doc = " @brief Event types."]
+pub type _bindgen_ty_8 = ::std::os::raw::c_uint;
+extern "C" {
+    #[doc = " @brief Free the edge event object."]
+    #[doc = " @param event Edge event object to free."]
+    pub fn gpiod_edge_event_free(event: *mut gpiod_edge_event);
+}
+extern "C" {
+    #[doc = " @brief Copy the edge event object."]
+    #[doc = " @param event Edge event to copy."]
+    #[doc = " @return Copy of the edge event or NULL on error. The returned object must"]
+    #[doc = "\t   be freed by the caller using ::gpiod_edge_event_free."]
+    pub fn gpiod_edge_event_copy(event: *mut gpiod_edge_event) -> *mut gpiod_edge_event;
+}
+extern "C" {
+    #[doc = " @brief Get the event type."]
+    #[doc = " @param event GPIO edge event."]
+    #[doc = " @return The event type (::GPIOD_EDGE_EVENT_RISING_EDGE or"]
+    #[doc = "\t   ::GPIOD_EDGE_EVENT_FALLING_EDGE)."]
+    pub fn gpiod_edge_event_get_event_type(event: *mut gpiod_edge_event) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    #[doc = " @brief Get the timestamp of the event."]
+    #[doc = " @param event GPIO edge event."]
+    #[doc = " @return Timestamp in nanoseconds."]
+    #[doc = " @note The source clock for the timestamp depends on the event_clock"]
+    #[doc = "\t setting for the line."]
+    pub fn gpiod_edge_event_get_timestamp_ns(event: *mut gpiod_edge_event) -> u64;
+}
+extern "C" {
+    #[doc = " @brief Get the offset of the line which triggered the event."]
+    #[doc = " @param event GPIO edge event."]
+    #[doc = " @return Line offset."]
+    pub fn gpiod_edge_event_get_line_offset(event: *mut gpiod_edge_event)
+        -> ::std::os::raw::c_uint;
+}
+extern "C" {
+    #[doc = " @brief Get the global sequence number of the event."]
+    #[doc = " @param event GPIO edge event."]
+    #[doc = " @return Sequence number of the event in the series of events for all lines"]
+    #[doc = "\t   in the associated line request."]
+    pub fn gpiod_edge_event_get_global_seqno(
+        event: *mut gpiod_edge_event,
+    ) -> ::std::os::raw::c_ulong;
+}
+extern "C" {
+    #[doc = " @brief Get the event sequence number specific to the line."]
+    #[doc = " @param event GPIO edge event."]
+    #[doc = " @return Sequence number of the event in the series of events only for this"]
+    #[doc = "\t   line within the lifetime of the associated line request."]
+    pub fn gpiod_edge_event_get_line_seqno(event: *mut gpiod_edge_event)
+        -> ::std::os::raw::c_ulong;
+}
+extern "C" {
+    #[doc = " @brief Create a new edge event buffer."]
+    #[doc = " @param capacity Number of events the buffer can store (min = 1, max = 1024)."]
+    #[doc = " @return New edge event buffer or NULL on error."]
+    #[doc = " @note If capacity equals 0, it will be set to a default value of 64. If"]
+    #[doc = "\t capacity is larger than 1024, it will be limited to 1024."]
+    #[doc = " @note The user space buffer is independent of the kernel buffer"]
+    #[doc = "\t (::gpiod_request_config_set_event_buffer_size).  As the user space"]
+    #[doc = "\t buffer is filled from the kernel buffer, there is no benefit making"]
+    #[doc = "\t the user space buffer larger than the kernel buffer."]
+    #[doc = "\t The default kernel buffer size for each request is 16*num_lines."]
+    pub fn gpiod_edge_event_buffer_new(capacity: size_t) -> *mut gpiod_edge_event_buffer;
+}
+extern "C" {
+    #[doc = " @brief Get the capacity (the max number of events that can be stored) of"]
+    #[doc = "\t  the event buffer."]
+    #[doc = " @param buffer Edge event buffer."]
+    #[doc = " @return The capacity of the buffer."]
+    pub fn gpiod_edge_event_buffer_get_capacity(buffer: *mut gpiod_edge_event_buffer) -> size_t;
+}
+extern "C" {
+    #[doc = " @brief Free the edge event buffer and release all associated resources."]
+    #[doc = " @param buffer Edge event buffer to free."]
+    pub fn gpiod_edge_event_buffer_free(buffer: *mut gpiod_edge_event_buffer);
+}
+extern "C" {
+    #[doc = " @brief Get an event stored in the buffer."]
+    #[doc = " @param buffer Edge event buffer."]
+    #[doc = " @param index Index of the event in the buffer."]
+    #[doc = " @return Pointer to an event stored in the buffer. The lifetime of the"]
+    #[doc = "\t   event is tied to the buffer object. Users must not free the event"]
+    #[doc = "\t   returned by this function."]
+    pub fn gpiod_edge_event_buffer_get_event(
+        buffer: *mut gpiod_edge_event_buffer,
+        index: ::std::os::raw::c_ulong,
+    ) -> *mut gpiod_edge_event;
+}
+extern "C" {
+    #[doc = " @brief Get the number of events a buffer has stored."]
+    #[doc = " @param buffer Edge event buffer."]
+    #[doc = " @return Number of events stored in the buffer."]
+    pub fn gpiod_edge_event_buffer_get_num_events(buffer: *mut gpiod_edge_event_buffer) -> size_t;
+}
+extern "C" {
+    #[doc = " @brief Check if the file pointed to by path is a GPIO chip character device."]
+    #[doc = " @param path Path to check."]
+    #[doc = " @return True if the file exists and is either a GPIO chip character device"]
+    #[doc = "\t   or a symbolic link to one."]
+    pub fn gpiod_is_gpiochip_device(path: *const ::std::os::raw::c_char) -> bool;
+}
+extern "C" {
+    #[doc = " @brief Get the API version of the library as a human-readable string."]
+    #[doc = " @return Human-readable string containing the library version."]
+    pub fn gpiod_version_string() -> *const ::std::os::raw::c_char;
+}
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 1/8] libgpiod: Add libgpiod-sys rust crate Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 2/8] libgpiod-sys: Add pre generated rust bindings Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 13:29   ` Bartosz Golaszewski
  2022-09-26 11:08 ` [PATCH V6 4/8] libgpiod: Add rust examples Viresh Kumar
                   ` (5 subsequent siblings)
  8 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

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@linaro.org>
---
 bindings/rust/Cargo.toml                     |   1 +
 bindings/rust/libgpiod/Cargo.toml            |  13 +
 bindings/rust/libgpiod/src/chip.rs           | 253 ++++++++++
 bindings/rust/libgpiod/src/edge_event.rs     | 102 ++++
 bindings/rust/libgpiod/src/event_buffer.rs   |  90 ++++
 bindings/rust/libgpiod/src/info_event.rs     |  68 +++
 bindings/rust/libgpiod/src/lib.rs            | 471 +++++++++++++++++++
 bindings/rust/libgpiod/src/line_config.rs    | 118 +++++
 bindings/rust/libgpiod/src/line_info.rs      | 180 +++++++
 bindings/rust/libgpiod/src/line_request.rs   | 246 ++++++++++
 bindings/rust/libgpiod/src/line_settings.rs  | 277 +++++++++++
 bindings/rust/libgpiod/src/request_config.rs |  96 ++++
 12 files changed, 1915 insertions(+)
 create mode 100644 bindings/rust/libgpiod/Cargo.toml
 create mode 100644 bindings/rust/libgpiod/src/chip.rs
 create mode 100644 bindings/rust/libgpiod/src/edge_event.rs
 create mode 100644 bindings/rust/libgpiod/src/event_buffer.rs
 create mode 100644 bindings/rust/libgpiod/src/info_event.rs
 create mode 100644 bindings/rust/libgpiod/src/lib.rs
 create mode 100644 bindings/rust/libgpiod/src/line_config.rs
 create mode 100644 bindings/rust/libgpiod/src/line_info.rs
 create mode 100644 bindings/rust/libgpiod/src/line_request.rs
 create mode 100644 bindings/rust/libgpiod/src/line_settings.rs
 create mode 100644 bindings/rust/libgpiod/src/request_config.rs

diff --git a/bindings/rust/Cargo.toml b/bindings/rust/Cargo.toml
index d0b3a3c88ff1..1e57ef2c0002 100644
--- a/bindings/rust/Cargo.toml
+++ b/bindings/rust/Cargo.toml
@@ -2,4 +2,5 @@
 
 members = [
     "libgpiod-sys",
+    "libgpiod"
 ]
diff --git a/bindings/rust/libgpiod/Cargo.toml b/bindings/rust/libgpiod/Cargo.toml
new file mode 100644
index 000000000000..f25242abb153
--- /dev/null
+++ b/bindings/rust/libgpiod/Cargo.toml
@@ -0,0 +1,13 @@
+[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]
+intmap = "2.0.0"
+libc = ">=0.2.39"
+libgpiod-sys = { path = "../libgpiod-sys" }
+thiserror = "1.0"
+vmm-sys-util = "=0.10.0"
diff --git a/bindings/rust/libgpiod/src/chip.rs b/bindings/rust/libgpiod/src/chip.rs
new file mode 100644
index 000000000000..4f52c3f141f4
--- /dev/null
+++ b/bindings/rust/libgpiod/src/chip.rs
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use libc::strlen;
+use std::os::raw::c_char;
+use std::path::Path;
+use std::sync::Arc;
+use std::time::Duration;
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{gpiod, info, line, request, Error, Offset, OperationType, Result};
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub(crate) struct Internal {
+    chip: *mut gpiod::gpiod_chip,
+}
+
+impl Internal {
+    /// Find a chip by path.
+    pub(crate) fn open<P: AsRef<Path>>(path: &P) -> Result<Self> {
+        // Null-terminate the string
+        let path = path.as_ref().to_string_lossy() + "\0";
+
+        let chip = unsafe { gpiod::gpiod_chip_open(path.as_ptr() as *const c_char) };
+        if chip.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::ChipOpen,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { chip })
+    }
+
+    /// Private helper, Returns gpiod_chip
+    pub(crate) fn chip(&self) -> *mut gpiod::gpiod_chip {
+        self.chip
+    }
+}
+
+impl Drop for Internal {
+    /// Close the chip and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_chip_close(self.chip) }
+    }
+}
+
+/// 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.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Chip {
+    ichip: Arc<Internal>,
+    info: Info,
+}
+
+unsafe impl Send for Chip {}
+unsafe impl Sync for Chip {}
+
+impl Chip {
+    /// Find a chip by path.
+    pub fn open<P: AsRef<Path>>(path: &P) -> Result<Self> {
+        let ichip = Arc::new(Internal::open(path)?);
+        let info = Info::new(ichip.clone())?;
+
+        Ok(Self { ichip, info })
+    }
+
+    /// Get the chip name as represented in the kernel.
+    pub fn name(&self) -> Result<&str> {
+        self.info.name()
+    }
+
+    /// Get the chip label as represented in the kernel.
+    pub fn label(&self) -> Result<&str> {
+        self.info.label()
+    }
+
+    /// Get the number of GPIO lines exposed by the chip.
+    pub fn num_lines(&self) -> usize {
+        self.info.num_lines()
+    }
+
+    /// Get the path used to find the chip.
+    pub fn path(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct Chip`.
+        let path = unsafe { gpiod::gpiod_chip_get_path(self.ichip.chip()) };
+
+        // SAFETY: The string is guaranteed to be valid here by the C API.
+        str::from_utf8(unsafe { slice::from_raw_parts(path as *const u8, strlen(path) as usize) })
+            .map_err(Error::StringNotUtf8)
+    }
+
+    /// Get information about the chip.
+    pub fn info(&self) -> Result<Info> {
+        Info::new(self.ichip.clone())
+    }
+
+    /// Get a snapshot of information about the line.
+    pub fn line_info(&self, offset: Offset) -> Result<line::Info> {
+        line::Info::new(self.ichip.clone(), offset)
+    }
+
+    /// Get the current snapshot of information about the line at given offset and start watching
+    /// it for future changes.
+    pub fn watch_line_info(&self, offset: Offset) -> Result<line::Info> {
+        line::Info::new_watch(self.ichip.clone(), offset)
+    }
+
+    /// Stop watching a line
+    pub fn unwatch(&self, offset: Offset) {
+        unsafe {
+            gpiod::gpiod_chip_unwatch_line_info(self.ichip.chip(), offset);
+        }
+    }
+
+    /// 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 fd(&self) -> Result<u32> {
+        let fd = unsafe { gpiod::gpiod_chip_get_fd(self.ichip.chip()) };
+
+        if fd < 0 {
+            Err(Error::OperationFailed(
+                OperationType::ChipGetFd,
+                Errno::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: Option<Duration>) -> Result<bool> {
+        let timeout = match timeout {
+            Some(x) => x.as_nanos() as i64,
+            // Block indefinitely
+            None => -1,
+        };
+
+        let ret = unsafe { gpiod::gpiod_chip_wait_info_event(self.ichip.chip(), timeout) };
+
+        match ret {
+            -1 => Err(Error::OperationFailed(
+                OperationType::ChipWaitInfoEvent,
+                Errno::last(),
+            )),
+            0 => Ok(false),
+            _ => Ok(true),
+        }
+    }
+
+    /// 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<info::Event> {
+        info::Event::new(&self.ichip)
+    }
+
+    /// Map a GPIO line's name to its offset within the chip.
+    pub fn line_offset_from_name(&self, name: &str) -> Result<Offset> {
+        // Null-terminate the string
+        let name = name.to_owned() + "\0";
+
+        let ret = unsafe {
+            gpiod::gpiod_chip_get_line_offset_from_name(
+                self.ichip.chip(),
+                name.as_ptr() as *const c_char,
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::ChipGetLine,
+                Errno::last(),
+            ))
+        } else {
+            Ok(ret as u32)
+        }
+    }
+
+    /// Request a set of lines for exclusive usage.
+    pub fn request_lines(
+        &self,
+        rconfig: &request::Config,
+        lconfig: &line::Config,
+    ) -> Result<line::Request> {
+        line::Request::new(&self.ichip, rconfig, lconfig)
+    }
+}
+
+/// GPIO chip Information
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Info {
+    info: *mut gpiod::gpiod_chip_info,
+}
+
+impl Info {
+    /// Find a GPIO chip by path.
+    pub(crate) fn new(chip: Arc<Internal>) -> Result<Self> {
+        let info = unsafe { gpiod::gpiod_chip_get_info(chip.chip()) };
+        if info.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::ChipInfoGet,
+                Errno::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 { gpiod::gpiod_chip_info_get_name(self.info) };
+
+        // SAFETY: The string is guaranteed to be valid here by the C API.
+        str::from_utf8(unsafe { slice::from_raw_parts(name as *const u8, strlen(name) as usize) })
+            .map_err(Error::StringNotUtf8)
+    }
+
+    /// 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 { gpiod::gpiod_chip_info_get_label(self.info) };
+
+        // SAFETY: The string is guaranteed to be valid here by the C API.
+        str::from_utf8(unsafe { slice::from_raw_parts(label as *const u8, strlen(label) as usize) })
+            .map_err(Error::StringNotUtf8)
+    }
+
+    /// Get the number of GPIO lines exposed by the chip.
+    pub(crate) fn num_lines(&self) -> usize {
+        unsafe { gpiod::gpiod_chip_info_get_num_lines(self.info) as usize }
+    }
+}
+
+impl Drop for Info {
+    /// Close the GPIO chip info and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_chip_info_free(self.info) }
+    }
+}
diff --git a/bindings/rust/libgpiod/src/edge_event.rs b/bindings/rust/libgpiod/src/edge_event.rs
new file mode 100644
index 000000000000..ce583916a2e3
--- /dev/null
+++ b/bindings/rust/libgpiod/src/edge_event.rs
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 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 Errno;
+
+use super::{edge::event::BufferInternal, gpiod, EdgeKind, Error, Offset, OperationType, 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.
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Event {
+    ibuffer: Option<Arc<BufferInternal>>,
+    event: *mut gpiod::gpiod_edge_event,
+}
+
+impl Event {
+    /// Get an event stored in the buffer.
+    pub(crate) fn new(ibuffer: &Arc<BufferInternal>, index: u64) -> Result<Self> {
+        let event = unsafe { gpiod::gpiod_edge_event_buffer_get_event(ibuffer.buffer(), index) };
+        if event.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::EdgeEventBufferGetEvent,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self {
+            ibuffer: Some(ibuffer.clone()),
+            event,
+        })
+    }
+
+    pub fn event_clone(&self) -> Result<Self> {
+        let event = unsafe { gpiod::gpiod_edge_event_copy(self.event) };
+        if event.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::EdgeEventCopy,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self {
+            ibuffer: None,
+            event,
+        })
+    }
+
+    /// Get the event type.
+    pub fn event_type(&self) -> Result<EdgeKind> {
+        EdgeKind::new(unsafe { gpiod::gpiod_edge_event_get_event_type(self.event) } as u32)
+    }
+
+    /// Get the timestamp of the event.
+    pub fn timestamp(&self) -> Duration {
+        Duration::from_nanos(unsafe { gpiod::gpiod_edge_event_get_timestamp_ns(self.event) })
+    }
+
+    /// Get the offset of the line on which the event was triggered.
+    pub fn line_offset(&self) -> Offset {
+        unsafe { gpiod::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 global_seqno(&self) -> u64 {
+        unsafe { gpiod::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 line_seqno(&self) -> u64 {
+        unsafe { gpiod::gpiod_edge_event_get_line_seqno(self.event) }
+    }
+}
+
+impl Drop for Event {
+    /// Free the edge event.
+    fn drop(&mut self) {
+        // Free the event only if a copy is made
+        if self.ibuffer.is_none() {
+            unsafe { gpiod::gpiod_edge_event_free(self.event) };
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/src/event_buffer.rs b/bindings/rust/libgpiod/src/event_buffer.rs
new file mode 100644
index 000000000000..e272e7aa9e9d
--- /dev/null
+++ b/bindings/rust/libgpiod/src/event_buffer.rs
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use std::os::raw::c_ulong;
+use std::sync::Arc;
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{edge, gpiod, Error, OperationType, Result};
+
+/// Line edge events buffer
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub(crate) struct BufferInternal {
+    buffer: *mut gpiod::gpiod_edge_event_buffer,
+}
+
+impl BufferInternal {
+    /// 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: usize) -> Result<Self> {
+        let buffer = unsafe { gpiod::gpiod_edge_event_buffer_new(capacity as c_ulong) };
+        if buffer.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::EdgeEventBufferNew,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { buffer })
+    }
+
+    /// Private helper, Returns gpiod_edge_event_buffer
+    pub(crate) fn buffer(&self) -> *mut gpiod::gpiod_edge_event_buffer {
+        self.buffer
+    }
+}
+
+impl Drop for BufferInternal {
+    /// Free the edge event buffer and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_edge_event_buffer_free(self.buffer) };
+    }
+}
+
+/// Line edge events buffer
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Buffer {
+    ibuffer: Arc<BufferInternal>,
+}
+
+impl Buffer {
+    /// 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: usize) -> Result<Self> {
+        Ok(Self {
+            ibuffer: Arc::new(BufferInternal::new(capacity)?),
+        })
+    }
+
+    /// Private helper, Returns gpiod_edge_event_buffer
+    pub(crate) fn buffer(&self) -> *mut gpiod::gpiod_edge_event_buffer {
+        self.ibuffer.buffer()
+    }
+
+    /// Get the capacity of the event buffer.
+    pub fn capacity(&self) -> usize {
+        unsafe { gpiod::gpiod_edge_event_buffer_get_capacity(self.buffer()) as usize }
+    }
+
+    /// Read an event stored in the buffer.
+    pub fn event(&self, index: u64) -> Result<edge::Event> {
+        edge::Event::new(&self.ibuffer, index)
+    }
+
+    /// Get the number of events the buffer contains.
+    pub fn len(&self) -> usize {
+        unsafe { gpiod::gpiod_edge_event_buffer_get_num_events(self.buffer()) as usize }
+    }
+
+    /// Check if buffer is empty.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+}
diff --git a/bindings/rust/libgpiod/src/info_event.rs b/bindings/rust/libgpiod/src/info_event.rs
new file mode 100644
index 000000000000..d8be87df6679
--- /dev/null
+++ b/bindings/rust/libgpiod/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@linaro.org>
+
+use std::sync::Arc;
+use std::time::Duration;
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{chip, gpiod, line, Error, InfoChangeKind, OperationType, 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.
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Event {
+    event: *mut gpiod::gpiod_info_event,
+}
+
+impl Event {
+    /// Get a single chip's line's status change event.
+    pub(crate) fn new(ichip: &Arc<chip::Internal>) -> Result<Self> {
+        let event = unsafe { gpiod::gpiod_chip_read_info_event(ichip.chip()) };
+        if event.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::ChipReadInfoEvent,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { event })
+    }
+
+    /// Private helper, Returns gpiod_info_event
+    pub(crate) fn event(&self) -> *mut gpiod::gpiod_info_event {
+        self.event
+    }
+
+    /// Get the event type of the status change event.
+    pub fn event_type(&self) -> Result<InfoChangeKind> {
+        InfoChangeKind::new(unsafe { gpiod::gpiod_info_event_get_event_type(self.event) } as u32)
+    }
+
+    /// Get the timestamp of the event, read from the monotonic clock.
+    pub fn timestamp(&self) -> Duration {
+        Duration::from_nanos(unsafe { gpiod::gpiod_info_event_get_timestamp_ns(self.event) })
+    }
+
+    /// Get the line-info object associated with the event.
+    pub fn line_info(&self) -> Result<line::Info> {
+        line::Info::new_from_event(self)
+    }
+}
+
+impl Drop for Event {
+    /// Free the info event object and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_info_event_free(self.event) }
+    }
+}
diff --git a/bindings/rust/libgpiod/src/lib.rs b/bindings/rust/libgpiod/src/lib.rs
new file mode 100644
index 000000000000..c5d974a9f4ea
--- /dev/null
+++ b/bindings/rust/libgpiod/src/lib.rs
@@ -0,0 +1,471 @@
+// 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@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.
+
+/// GPIO chip related definitions.
+pub mod chip;
+
+mod edge_event;
+mod event_buffer;
+
+/// GPIO chip edge event related definitions.
+pub mod edge {
+    pub use crate::edge_event::*;
+
+    /// GPIO chip edge event buffer related definitions.
+    pub mod event {
+        pub use crate::event_buffer::*;
+    }
+}
+
+mod info_event;
+
+/// GPIO chip info event related definitions.
+pub mod info {
+    pub use crate::info_event::*;
+}
+
+mod line_config;
+mod line_info;
+mod line_request;
+mod line_settings;
+
+/// GPIO chip line related definitions.
+pub mod line {
+    pub use crate::line_config::*;
+    pub use crate::line_info::*;
+    pub use crate::line_request::*;
+    pub use crate::line_settings::*;
+}
+
+mod request_config;
+
+/// GPIO chip request related definitions.
+pub mod request {
+    pub use crate::request_config::*;
+}
+
+use libgpiod_sys as gpiod;
+
+use intmap::IntMap;
+use libc::strlen;
+use std::fs;
+use std::os::raw::c_char;
+use std::path::Path;
+use std::time::Duration;
+use std::{fmt, slice, str};
+
+use thiserror::Error as ThisError;
+use vmm_sys_util::errno::Error as Errno;
+
+/// Operation types, used with OperationFailed() Error.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum OperationType {
+    ChipOpen,
+    ChipGetFd,
+    ChipWaitInfoEvent,
+    ChipGetLine,
+    ChipGetLineInfo,
+    ChipInfoGet,
+    ChipReadInfoEvent,
+    ChipWatchLineInfo,
+    EdgeEventBufferGetEvent,
+    EdgeEventCopy,
+    EdgeEventBufferNew,
+    InfoEventGetLineInfo,
+    LineConfigNew,
+    LineConfigAddSettings,
+    LineConfigGetOffsets,
+    LineConfigGetSetting,
+    LineRequest,
+    LineRequestReconfigLines,
+    LineRequestGetVal,
+    LineRequestGetValSubset,
+    LineRequestSetVal,
+    LineRequestSetValSubset,
+    LineRequestReadEdgeEvent,
+    LineRequestWaitEdgeEvent,
+    LineSettingsNew,
+    LineSettingsCopy,
+    LineSettingsGetOutVal,
+    LineSettingsSetDirection,
+    LineSettingsSetEdgeDetection,
+    LineSettingsSetBias,
+    LineSettingsSetDrive,
+    LineSettingsSetActiveLow,
+    LineSettingsSetDebouncePeriod,
+    LineSettingsSetEventClock,
+    LineSettingsSetOutputValue,
+    RequestConfigNew,
+    RequestConfigGetConsumer,
+    SimBankGetVal,
+    SimBankNew,
+    SimBankSetLabel,
+    SimBankSetNumLines,
+    SimBankSetLineName,
+    SimBankSetPull,
+    SimBankHogLine,
+    SimCtxNew,
+    SimDevNew,
+    SimDevEnable,
+    SimDevDisable,
+}
+
+impl fmt::Display for OperationType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+/// 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 get {0}")]
+    NullString(&'static str),
+    #[error("String not utf8: {0:?}")]
+    StringNotUtf8(str::Utf8Error),
+    #[error("Invalid enum {0} value: {1}")]
+    InvalidEnumValue(&'static str, u32),
+    #[error("Operation {0} Failed: {1}")]
+    OperationFailed(OperationType, Errno),
+    #[error("Invalid Arguments")]
+    InvalidArguments,
+    #[error("Std Io Error")]
+    IoError,
+}
+
+/// Value settings.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Value {
+    /// Active
+    Active,
+    /// Inactive
+    InActive,
+}
+
+/// Maps offset to Value.
+pub type ValueMap = IntMap<Value>;
+
+impl Value {
+    pub fn new(val: i32) -> Result<Self> {
+        match val {
+            0 => Ok(Value::InActive),
+            1 => Ok(Value::Active),
+            _ => Err(Error::InvalidEnumValue("Value", val as u32)),
+        }
+    }
+
+    fn value(&self) -> i32 {
+        match self {
+            Value::Active => 1,
+            Value::InActive => 0,
+        }
+    }
+}
+
+/// Offset type.
+pub type Offset = u32;
+
+/// Direction settings.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+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 {
+            gpiod::GPIOD_LINE_DIRECTION_AS_IS => Ok(Direction::AsIs),
+            gpiod::GPIOD_LINE_DIRECTION_INPUT => Ok(Direction::Input),
+            gpiod::GPIOD_LINE_DIRECTION_OUTPUT => Ok(Direction::Output),
+            _ => Err(Error::InvalidEnumValue("Direction", dir)),
+        }
+    }
+
+    fn gpiod_direction(&self) -> u32 {
+        match self {
+            Direction::AsIs => gpiod::GPIOD_LINE_DIRECTION_AS_IS,
+            Direction::Input => gpiod::GPIOD_LINE_DIRECTION_INPUT,
+            Direction::Output => gpiod::GPIOD_LINE_DIRECTION_OUTPUT,
+        }
+    }
+}
+
+/// Internal bias settings.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Bias {
+    /// 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<Option<Self>> {
+        match bias {
+            gpiod::GPIOD_LINE_BIAS_UNKNOWN => Ok(None),
+            gpiod::GPIOD_LINE_BIAS_AS_IS => Ok(None),
+            gpiod::GPIOD_LINE_BIAS_DISABLED => Ok(Some(Bias::Disabled)),
+            gpiod::GPIOD_LINE_BIAS_PULL_UP => Ok(Some(Bias::PullUp)),
+            gpiod::GPIOD_LINE_BIAS_PULL_DOWN => Ok(Some(Bias::PullDown)),
+            _ => Err(Error::InvalidEnumValue("Bias", bias)),
+        }
+    }
+
+    fn gpiod_bias(bias: Option<Bias>) -> u32 {
+        match bias {
+            None => gpiod::GPIOD_LINE_BIAS_AS_IS,
+            Some(bias) => match bias {
+                Bias::Disabled => gpiod::GPIOD_LINE_BIAS_DISABLED,
+                Bias::PullUp => gpiod::GPIOD_LINE_BIAS_PULL_UP,
+                Bias::PullDown => gpiod::GPIOD_LINE_BIAS_PULL_DOWN,
+            },
+        }
+    }
+}
+
+/// Drive settings.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+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 {
+            gpiod::GPIOD_LINE_DRIVE_PUSH_PULL => Ok(Drive::PushPull),
+            gpiod::GPIOD_LINE_DRIVE_OPEN_DRAIN => Ok(Drive::OpenDrain),
+            gpiod::GPIOD_LINE_DRIVE_OPEN_SOURCE => Ok(Drive::OpenSource),
+            _ => Err(Error::InvalidEnumValue("Drive", drive)),
+        }
+    }
+
+    fn gpiod_drive(&self) -> u32 {
+        match self {
+            Drive::PushPull => gpiod::GPIOD_LINE_DRIVE_PUSH_PULL,
+            Drive::OpenDrain => gpiod::GPIOD_LINE_DRIVE_OPEN_DRAIN,
+            Drive::OpenSource => gpiod::GPIOD_LINE_DRIVE_OPEN_SOURCE,
+        }
+    }
+}
+
+/// Edge detection settings.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Edge {
+    /// 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<Option<Self>> {
+        match edge {
+            gpiod::GPIOD_LINE_EDGE_NONE => Ok(None),
+            gpiod::GPIOD_LINE_EDGE_RISING => Ok(Some(Edge::Rising)),
+            gpiod::GPIOD_LINE_EDGE_FALLING => Ok(Some(Edge::Falling)),
+            gpiod::GPIOD_LINE_EDGE_BOTH => Ok(Some(Edge::Both)),
+            _ => Err(Error::InvalidEnumValue("Edge", edge)),
+        }
+    }
+
+    fn gpiod_edge(edge: Option<Edge>) -> u32 {
+        match edge {
+            None => gpiod::GPIOD_LINE_EDGE_NONE,
+            Some(edge) => match edge {
+                Edge::Rising => gpiod::GPIOD_LINE_EDGE_RISING,
+                Edge::Falling => gpiod::GPIOD_LINE_EDGE_FALLING,
+                Edge::Both => gpiod::GPIOD_LINE_EDGE_BOTH,
+            },
+        }
+    }
+}
+
+/// Line setting kind.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum SettingKind {
+    /// Line direction.
+    Direction,
+    /// Bias.
+    Bias,
+    /// Drive.
+    Drive,
+    /// Edge detection.
+    EdgeDetection,
+    /// Active-low setting.
+    ActiveLow,
+    /// Debounce period.
+    DebouncePeriod,
+    /// Event clock type.
+    EventClock,
+    /// Output value.
+    OutputValue,
+}
+
+/// Line settings.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum SettingVal {
+    /// Line direction.
+    Direction(Direction),
+    /// Bias.
+    Bias(Option<Bias>),
+    /// Drive.
+    Drive(Drive),
+    /// Edge detection.
+    EdgeDetection(Option<Edge>),
+    /// Active-low setting.
+    ActiveLow(bool),
+    /// Debounce period.
+    DebouncePeriod(Duration),
+    /// Event clock type.
+    EventClock(EventClock),
+    /// Output value.
+    OutputValue(Value),
+}
+
+impl fmt::Display for SettingVal {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+/// Event clock settings.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum EventClock {
+    /// Line uses the monotonic clock for edge event timestamps.
+    Monotonic,
+    /// Line uses the realtime clock for edge event timestamps.
+    Realtime,
+    /// Line uses the hardware timestamp engine clock for edge event timestamps.
+    HTE,
+}
+
+impl EventClock {
+    fn new(clock: u32) -> Result<Self> {
+        match clock {
+            gpiod::GPIOD_LINE_EVENT_CLOCK_MONOTONIC => Ok(EventClock::Monotonic),
+            gpiod::GPIOD_LINE_EVENT_CLOCK_REALTIME => Ok(EventClock::Realtime),
+            gpiod::GPIOD_LINE_EVENT_CLOCK_HTE => Ok(EventClock::HTE),
+            _ => Err(Error::InvalidEnumValue("Eventclock", clock)),
+        }
+    }
+
+    fn gpiod_clock(&self) -> u32 {
+        match self {
+            EventClock::Monotonic => gpiod::GPIOD_LINE_EVENT_CLOCK_MONOTONIC,
+            EventClock::Realtime => gpiod::GPIOD_LINE_EVENT_CLOCK_REALTIME,
+            EventClock::HTE => gpiod::GPIOD_LINE_EVENT_CLOCK_HTE,
+        }
+    }
+}
+
+/// Line status change event types.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum InfoChangeKind {
+    /// Line has been requested.
+    LineRequested,
+    /// Previously requested line has been released.
+    LineReleased,
+    /// Line configuration has changed.
+    LineConfigChanged,
+}
+
+impl InfoChangeKind {
+    fn new(kind: u32) -> Result<Self> {
+        match kind {
+            gpiod::GPIOD_INFO_EVENT_LINE_REQUESTED => Ok(InfoChangeKind::LineRequested),
+            gpiod::GPIOD_INFO_EVENT_LINE_RELEASED => Ok(InfoChangeKind::LineReleased),
+            gpiod::GPIOD_INFO_EVENT_LINE_CONFIG_CHANGED => Ok(InfoChangeKind::LineConfigChanged),
+            _ => Err(Error::InvalidEnumValue("InfoChangeKind", kind)),
+        }
+    }
+}
+
+/// Edge event types.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum EdgeKind {
+    /// Rising edge event.
+    Rising,
+    /// Falling edge event.
+    Falling,
+}
+
+impl EdgeKind {
+    fn new(kind: u32) -> Result<Self> {
+        match kind {
+            gpiod::GPIOD_EDGE_EVENT_RISING_EDGE => Ok(EdgeKind::Rising),
+            gpiod::GPIOD_EDGE_EVENT_FALLING_EDGE => Ok(EdgeKind::Falling),
+            _ => Err(Error::InvalidEnumValue("EdgeEvent", kind)),
+        }
+    }
+}
+
+/// 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 is_gpiochip_device<P: AsRef<Path>>(path: &P) -> bool {
+    // Null-terminate the string
+    let path = path.as_ref().to_string_lossy() + "\0";
+
+    unsafe { gpiod::gpiod_is_gpiochip_device(path.as_ptr() as *const c_char) }
+}
+
+/// Iterator for GPIO devices.
+pub fn gpiochip_devices<P: AsRef<Path>>(path: &P) -> Result<Vec<chip::Chip>> {
+    let mut chips = Vec::new();
+
+    for entry in fs::read_dir(path).map_err(|_| Error::IoError)?.flatten() {
+        let path = entry.path();
+
+        if is_gpiochip_device(&path) {
+            chips.push(chip::Chip::open(&path)?);
+        }
+    }
+
+    Ok(chips)
+}
+
+/// Get the API version of the library as a human-readable string.
+pub fn version_string() -> Result<&'static str> {
+    // SAFETY: The string returned by libgpiod is guaranteed to live forever.
+    let version = unsafe { gpiod::gpiod_version_string() };
+
+    if version.is_null() {
+        return Err(Error::NullString("GPIO library version"));
+    }
+
+    // SAFETY: The string is guaranteed to be valid here by the C API.
+    str::from_utf8(unsafe { slice::from_raw_parts(version as *const u8, strlen(version) as usize) })
+        .map_err(Error::StringNotUtf8)
+}
diff --git a/bindings/rust/libgpiod/src/line_config.rs b/bindings/rust/libgpiod/src/line_config.rs
new file mode 100644
index 000000000000..ea25452fd1d6
--- /dev/null
+++ b/bindings/rust/libgpiod/src/line_config.rs
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use std::os::raw::c_ulong;
+use std::slice::from_raw_parts;
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{gpiod, line::Settings, Error, Offset, OperationType, 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 empty. Using it in a request will lead to an
+/// error. In order to a line-config to become useful, it needs to be assigned
+/// at least one offset-to-settings mapping by calling
+/// ::gpiod_line_config_add_line_settings.
+///
+/// When calling ::gpiod_chip_request_lines, the library will request all
+/// offsets that were assigned settings in the order that they were assigned.
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Config {
+    config: *mut gpiod::gpiod_line_config,
+}
+
+impl Config {
+    /// Create a new line config object.
+    pub fn new() -> Result<Self> {
+        let config = unsafe { gpiod::gpiod_line_config_new() };
+
+        if config.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::LineConfigNew,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { config })
+    }
+
+    /// Private helper, Returns gpiod_line_config
+    pub(crate) fn config(&self) -> *mut gpiod::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 { gpiod::gpiod_line_config_reset(self.config) }
+    }
+
+    /// Add line settings for a set of offsets.
+    pub fn add_line_settings(&self, offsets: &[Offset], settings: Settings) -> Result<()> {
+        let ret = unsafe {
+            gpiod::gpiod_line_config_add_line_settings(
+                self.config,
+                offsets.as_ptr(),
+                offsets.len() as c_ulong,
+                settings.settings(),
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineConfigAddSettings,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get line settings for offset.
+    pub fn line_settings(&self, offset: Offset) -> Result<Settings> {
+        let settings = unsafe { gpiod::gpiod_line_config_get_line_settings(self.config, offset) };
+
+        if settings.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::LineConfigGetSetting,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Settings::new_with_settings(settings))
+    }
+
+    /// Get configured offsets.
+    pub fn offsets(&self) -> Result<Vec<Offset>> {
+        let mut num: u64 = 0;
+        let mut offsets: *mut Offset = std::ptr::null_mut();
+
+        let ret =
+            unsafe { gpiod::gpiod_line_config_get_offsets(self.config, &mut num, &mut offsets) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineConfigGetOffsets,
+                Errno::last(),
+            ))
+        } else {
+            Ok(unsafe { from_raw_parts(offsets as *const Offset, num as usize).to_vec() })
+        }
+    }
+}
+
+impl Drop for Config {
+    /// Free the line config object and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_line_config_free(self.config) }
+    }
+}
diff --git a/bindings/rust/libgpiod/src/line_info.rs b/bindings/rust/libgpiod/src/line_info.rs
new file mode 100644
index 000000000000..9db51fc30efd
--- /dev/null
+++ b/bindings/rust/libgpiod/src/line_info.rs
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use libc::strlen;
+use std::sync::Arc;
+use std::time::Duration;
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{
+    chip, gpiod, info, Bias, Direction, Drive, Edge, Error, EventClock, Offset, OperationType,
+    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.
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Info {
+    info: *mut gpiod::gpiod_line_info,
+    info_event: bool,
+}
+
+impl Info {
+    /// Get a snapshot of information about the line and optionally start watching it for changes.
+    pub(crate) fn new(ichip: Arc<chip::Internal>, offset: Offset) -> Result<Self> {
+        let info = unsafe { gpiod::gpiod_chip_get_line_info(ichip.chip(), offset) };
+
+        if info.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::ChipGetLineInfo,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self {
+            info,
+            info_event: false,
+        })
+    }
+
+    pub(crate) fn new_watch(ichip: Arc<chip::Internal>, offset: Offset) -> Result<Self> {
+        let info = unsafe { gpiod::gpiod_chip_watch_line_info(ichip.chip(), offset) };
+
+        if info.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::ChipWatchLineInfo,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self {
+            info,
+            info_event: false,
+        })
+    }
+
+    /// Get the Line info object associated with an event.
+    pub(crate) fn new_from_event(event: &info::Event) -> Result<Self> {
+        let info = unsafe { gpiod::gpiod_info_event_get_line_info(event.event()) };
+
+        if info.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::InfoEventGetLineInfo,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self {
+            info,
+            info_event: true,
+        })
+    }
+
+    /// 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 offset(&self) -> Offset {
+        unsafe { gpiod::gpiod_line_info_get_offset(self.info) }
+    }
+
+    /// Get GPIO line's name.
+    pub fn name(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct Info`.
+        let name = unsafe { gpiod::gpiod_line_info_get_name(self.info) };
+        if name.is_null() {
+            return Err(Error::NullString("GPIO line's name"));
+        }
+
+        // SAFETY: The string is guaranteed to be valid here by the C API.
+        str::from_utf8(unsafe { slice::from_raw_parts(name as *const u8, strlen(name) as usize) })
+            .map_err(Error::StringNotUtf8)
+    }
+
+    /// 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 { gpiod::gpiod_line_info_is_used(self.info) }
+    }
+
+    /// Get the GPIO line's consumer name.
+    pub fn consumer(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct Info`.
+        let name = unsafe { gpiod::gpiod_line_info_get_consumer(self.info) };
+        if name.is_null() {
+            return Err(Error::NullString("GPIO line's consumer name"));
+        }
+
+        // SAFETY: The string is guaranteed to be valid here by the C API.
+        str::from_utf8(unsafe { slice::from_raw_parts(name as *const u8, strlen(name) as usize) })
+            .map_err(Error::StringNotUtf8)
+    }
+
+    /// Get the GPIO line's direction.
+    pub fn direction(&self) -> Result<Direction> {
+        Direction::new(unsafe { gpiod::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 { gpiod::gpiod_line_info_is_active_low(self.info) }
+    }
+
+    /// Get the GPIO line's bias setting.
+    pub fn bias(&self) -> Result<Option<Bias>> {
+        Bias::new(unsafe { gpiod::gpiod_line_info_get_bias(self.info) } as u32)
+    }
+
+    /// Get the GPIO line's drive setting.
+    pub fn drive(&self) -> Result<Drive> {
+        Drive::new(unsafe { gpiod::gpiod_line_info_get_drive(self.info) } as u32)
+    }
+
+    /// Get the current edge detection setting of the line.
+    pub fn edge_detection(&self) -> Result<Option<Edge>> {
+        Edge::new(unsafe { gpiod::gpiod_line_info_get_edge_detection(self.info) } as u32)
+    }
+
+    /// Get the current event clock setting used for edge event timestamps.
+    pub fn event_clock(&self) -> Result<EventClock> {
+        EventClock::new(unsafe { gpiod::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 { gpiod::gpiod_line_info_is_debounced(self.info) }
+    }
+
+    /// Get the debounce period of the line.
+    pub fn debounce_period(&self) -> Duration {
+        Duration::from_micros(unsafe { gpiod::gpiod_line_info_get_debounce_period_us(self.info) })
+    }
+}
+
+impl Drop for Info {
+    fn drop(&mut self) {
+        // We must not free the Line info object created from `struct info::Event` by calling
+        // libgpiod API.
+        if !self.info_event {
+            unsafe { gpiod::gpiod_line_info_free(self.info) }
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/src/line_request.rs b/bindings/rust/libgpiod/src/line_request.rs
new file mode 100644
index 000000000000..617efaa34d58
--- /dev/null
+++ b/bindings/rust/libgpiod/src/line_request.rs
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use libc::EINVAL;
+use std::os::raw::c_ulong;
+use std::sync::Arc;
+use std::time::Duration;
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{
+    chip, edge, gpiod, line, request, Error, Offset, OperationType, Result, Value, ValueMap,
+};
+
+/// Line request operations
+///
+/// Allows interaction with a set of requested lines.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Request {
+    request: *mut gpiod::gpiod_line_request,
+}
+
+impl Request {
+    /// Request a set of lines for exclusive usage.
+    pub(crate) fn new(
+        ichip: &Arc<chip::Internal>,
+        rconfig: &request::Config,
+        lconfig: &line::Config,
+    ) -> Result<Self> {
+        let request = unsafe {
+            gpiod::gpiod_chip_request_lines(ichip.chip(), rconfig.config(), lconfig.config())
+        };
+
+        if request.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::LineRequest,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { request })
+    }
+
+    /// Get the number of lines in the request.
+    pub fn num_lines(&self) -> usize {
+        unsafe { gpiod::gpiod_line_request_get_num_lines(self.request) as usize }
+    }
+
+    /// Get the offsets of lines in the request.
+    pub fn offsets(&self) -> Vec<Offset> {
+        let mut offsets = vec![0; self.num_lines() as usize];
+
+        unsafe { gpiod::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 value(&self, offset: Offset) -> Result<Value> {
+        let value = unsafe { gpiod::gpiod_line_request_get_value(self.request, offset) };
+
+        if value != 0 && value != 1 {
+            Err(Error::OperationFailed(
+                OperationType::LineRequestGetVal,
+                Errno::last(),
+            ))
+        } else {
+            Value::new(value)
+        }
+    }
+
+    /// Get values of a subset of lines associated with the request.
+    pub fn values_subset(&self, offsets: &[Offset]) -> Result<ValueMap> {
+        let mut values = vec![0; offsets.len()];
+
+        let ret = unsafe {
+            gpiod::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(
+                OperationType::LineRequestGetValSubset,
+                Errno::last(),
+            ))
+        } else {
+            let mut map = ValueMap::new();
+
+            for (i, val) in values.iter().enumerate() {
+                map.insert(offsets[i].into(), Value::new(*val)?);
+            }
+
+            Ok(map)
+        }
+    }
+
+    /// Get values of all lines associated with the request.
+    pub fn values(&self) -> Result<ValueMap> {
+        self.values_subset(&self.offsets())
+    }
+
+    /// Set the value of a single line associated with the request.
+    pub fn set_value(&self, offset: Offset, value: Value) -> Result<()> {
+        let ret =
+            unsafe { gpiod::gpiod_line_request_set_value(self.request, offset, value.value()) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineRequestSetVal,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get values of a subset of lines associated with the request.
+    pub fn set_values_subset(&self, map: ValueMap) -> Result<()> {
+        let mut offsets = Vec::new();
+        let mut values = Vec::new();
+
+        for (offset, value) in map {
+            offsets.push(offset as u32);
+            values.push(value.value());
+        }
+
+        let ret = unsafe {
+            gpiod::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(
+                OperationType::LineRequestSetValSubset,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get values of all lines associated with the request.
+    pub fn set_values(&self, values: &[Value]) -> Result<()> {
+        if values.len() != self.num_lines() as usize {
+            return Err(Error::OperationFailed(
+                OperationType::LineRequestSetVal,
+                Errno::new(EINVAL),
+            ));
+        }
+
+        let mut new_values = Vec::new();
+        for value in values {
+            new_values.push(value.value());
+        }
+
+        let ret =
+            unsafe { gpiod::gpiod_line_request_set_values(self.request, new_values.as_ptr()) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineRequestSetVal,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Update the configuration of lines associated with the line request.
+    pub fn reconfigure_lines(&self, lconfig: &line::Config) -> Result<()> {
+        let ret =
+            unsafe { gpiod::gpiod_line_request_reconfigure_lines(self.request, lconfig.config()) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineRequestReconfigLines,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the file descriptor associated with the line request.
+    pub fn fd(&self) -> u32 {
+        unsafe { gpiod::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: Option<Duration>) -> Result<bool> {
+        let timeout = match timeout {
+            Some(x) => x.as_nanos() as i64,
+            // Block indefinitely
+            None => -1,
+        };
+
+        let ret = unsafe { gpiod::gpiod_line_request_wait_edge_event(self.request, timeout) };
+
+        match ret {
+            -1 => Err(Error::OperationFailed(
+                OperationType::LineRequestWaitEdgeEvent,
+                Errno::last(),
+            )),
+            0 => Ok(false),
+            _ => Ok(true),
+        }
+    }
+
+    /// 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_events(&self, buffer: &edge::event::Buffer) -> Result<u32> {
+        let ret = unsafe {
+            gpiod::gpiod_line_request_read_edge_event(
+                self.request,
+                buffer.buffer(),
+                buffer.capacity() as u64,
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineRequestReadEdgeEvent,
+                Errno::last(),
+            ))
+        } else {
+            Ok(ret as u32)
+        }
+    }
+}
+
+impl Drop for Request {
+    /// Release the requested lines and free all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_line_request_release(self.request) }
+    }
+}
diff --git a/bindings/rust/libgpiod/src/line_settings.rs b/bindings/rust/libgpiod/src/line_settings.rs
new file mode 100644
index 000000000000..2c3090132ea5
--- /dev/null
+++ b/bindings/rust/libgpiod/src/line_settings.rs
@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use std::time::Duration;
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{
+    gpiod, Bias, Direction, Drive, Edge, Error, EventClock, OperationType, Result, SettingKind,
+    SettingVal, Value,
+};
+
+/// Line settings objects.
+///
+/// Line settings object contains a set of line properties that can be used
+/// when requesting lines or reconfiguring an existing request.
+///
+/// Mutators in general can only fail if the new property value is invalid. The
+/// return values can be safely ignored - the object remains valid even after
+/// a mutator fails and simply uses the sane default appropriate for given
+/// property.
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Settings {
+    settings: *mut gpiod::gpiod_line_settings,
+}
+
+impl Settings {
+    /// Create a new line settings object.
+    pub fn new() -> Result<Self> {
+        let settings = unsafe { gpiod::gpiod_line_settings_new() };
+
+        if settings.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::LineSettingsNew,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { settings })
+    }
+
+    pub fn new_with_settings(settings: *mut gpiod::gpiod_line_settings) -> Self {
+        Self { settings }
+    }
+
+    /// Private helper, Returns gpiod_line_settings
+    pub(crate) fn settings(&self) -> *mut gpiod::gpiod_line_settings {
+        self.settings
+    }
+
+    /// Resets the line settings object to its default values.
+    pub fn reset(&mut self) {
+        unsafe { gpiod::gpiod_line_settings_reset(self.settings) }
+    }
+
+    /// Makes copy of the settings object.
+    pub fn settings_clone(&self) -> Result<Self> {
+        let settings = unsafe { gpiod::gpiod_line_settings_copy(self.settings) };
+        if settings.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::LineSettingsCopy,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { settings })
+    }
+
+    /// Set line prop setting.
+    pub fn set_prop(&mut self, values: &[SettingVal]) -> Result<()> {
+        for value in values {
+            match value {
+                SettingVal::Direction(val) => self.set_direction(*val)?,
+                SettingVal::EdgeDetection(val) => self.set_edge_detection(*val)?,
+                SettingVal::Bias(val) => self.set_bias(*val)?,
+                SettingVal::Drive(val) => self.set_drive(*val)?,
+                SettingVal::ActiveLow(val) => self.set_active_low(*val),
+                SettingVal::DebouncePeriod(val) => self.set_debounce_period(*val),
+                SettingVal::EventClock(val) => self.set_event_clock(*val)?,
+                SettingVal::OutputValue(val) => self.set_output_value(*val)?,
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Get the line prop setting.
+    pub fn prop(&self, property: SettingKind) -> Result<SettingVal> {
+        Ok(match property {
+            SettingKind::Direction => SettingVal::Direction(self.direction()?),
+            SettingKind::EdgeDetection => SettingVal::EdgeDetection(self.edge_detection()?),
+            SettingKind::Bias => SettingVal::Bias(self.bias()?),
+            SettingKind::Drive => SettingVal::Drive(self.drive()?),
+            SettingKind::ActiveLow => SettingVal::ActiveLow(self.active_low()),
+            SettingKind::DebouncePeriod => SettingVal::DebouncePeriod(self.debounce_period()?),
+            SettingKind::EventClock => SettingVal::EventClock(self.event_clock()?),
+            SettingKind::OutputValue => SettingVal::OutputValue(self.output_value()?),
+        })
+    }
+
+    /// Set the line direction.
+    fn set_direction(&mut self, direction: Direction) -> Result<()> {
+        let ret = unsafe {
+            gpiod::gpiod_line_settings_set_direction(
+                self.settings,
+                direction.gpiod_direction() as i32,
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineSettingsSetDirection,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the direction setting.
+    fn direction(&self) -> Result<Direction> {
+        Direction::new(unsafe { gpiod::gpiod_line_settings_get_direction(self.settings) } as u32)
+    }
+
+    /// Set the edge event detection setting.
+    fn set_edge_detection(&mut self, edge: Option<Edge>) -> Result<()> {
+        let ret = unsafe {
+            gpiod::gpiod_line_settings_set_edge_detection(
+                self.settings,
+                Edge::gpiod_edge(edge) as i32,
+            )
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineSettingsSetEdgeDetection,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the edge event detection setting.
+    fn edge_detection(&self) -> Result<Option<Edge>> {
+        Edge::new(unsafe { gpiod::gpiod_line_settings_get_edge_detection(self.settings) } as u32)
+    }
+
+    /// Set the bias setting.
+    fn set_bias(&mut self, bias: Option<Bias>) -> Result<()> {
+        let ret = unsafe {
+            gpiod::gpiod_line_settings_set_bias(self.settings, Bias::gpiod_bias(bias) as i32)
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineSettingsSetBias,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the bias setting.
+    fn bias(&self) -> Result<Option<Bias>> {
+        Bias::new(unsafe { gpiod::gpiod_line_settings_get_bias(self.settings) } as u32)
+    }
+
+    /// Set the drive setting.
+    fn set_drive(&mut self, drive: Drive) -> Result<()> {
+        let ret = unsafe {
+            gpiod::gpiod_line_settings_set_drive(self.settings, drive.gpiod_drive() as i32)
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineSettingsSetDrive,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the drive setting.
+    fn drive(&self) -> Result<Drive> {
+        Drive::new(unsafe { gpiod::gpiod_line_settings_get_drive(self.settings) } as u32)
+    }
+
+    /// Set active-low setting.
+    fn set_active_low(&mut self, active_low: bool) {
+        unsafe { gpiod::gpiod_line_settings_set_active_low(self.settings, active_low) }
+    }
+
+    /// Check the active-low setting.
+    fn active_low(&self) -> bool {
+        unsafe { gpiod::gpiod_line_settings_get_active_low(self.settings) }
+    }
+
+    /// Set the debounce period setting.
+    fn set_debounce_period(&mut self, period: Duration) {
+        unsafe {
+            gpiod::gpiod_line_settings_set_debounce_period_us(
+                self.settings,
+                period.as_micros() as u64,
+            )
+        }
+    }
+
+    /// Get the debounce period.
+    fn debounce_period(&self) -> Result<Duration> {
+        Ok(Duration::from_micros(unsafe {
+            gpiod::gpiod_line_settings_get_debounce_period_us(self.settings)
+        }))
+    }
+
+    /// Set the event clock setting.
+    fn set_event_clock(&mut self, clock: EventClock) -> Result<()> {
+        let ret = unsafe {
+            gpiod::gpiod_line_settings_set_event_clock(self.settings, clock.gpiod_clock() as i32)
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineSettingsSetEventClock,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the event clock setting.
+    fn event_clock(&self) -> Result<EventClock> {
+        EventClock::new(unsafe { gpiod::gpiod_line_settings_get_event_clock(self.settings) } as u32)
+    }
+
+    /// Set the output value setting.
+    fn set_output_value(&mut self, value: Value) -> Result<()> {
+        let ret =
+            unsafe { gpiod::gpiod_line_settings_set_output_value(self.settings, value.value()) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::LineSettingsSetOutputValue,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Get the output value, 0 or 1.
+    fn output_value(&self) -> Result<Value> {
+        let value = unsafe { gpiod::gpiod_line_settings_get_output_value(self.settings) };
+
+        if value != 0 && value != 1 {
+            Err(Error::OperationFailed(
+                OperationType::LineSettingsGetOutVal,
+                Errno::last(),
+            ))
+        } else {
+            Value::new(value)
+        }
+    }
+}
+
+impl Drop for Settings {
+    /// Free the line settings object and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_line_settings_free(self.settings) }
+    }
+}
diff --git a/bindings/rust/libgpiod/src/request_config.rs b/bindings/rust/libgpiod/src/request_config.rs
new file mode 100644
index 000000000000..760d9c755c86
--- /dev/null
+++ b/bindings/rust/libgpiod/src/request_config.rs
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use libc::strlen;
+use std::os::raw::{c_char, c_ulong};
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as Errno;
+
+use super::{gpiod, Error, OperationType, 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. The mutators don't return error values. If the
+/// values are invalid, in general they are silently adjusted to acceptable
+/// ranges.
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Config {
+    config: *mut gpiod::gpiod_request_config,
+}
+
+impl Config {
+    /// Create a new request config object.
+    pub fn new() -> Result<Self> {
+        let config = unsafe { gpiod::gpiod_request_config_new() };
+        if config.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::RequestConfigNew,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { config })
+    }
+
+    /// Private helper, Returns gpiod_request_config
+    pub(crate) fn config(&self) -> *mut gpiod::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 {
+            gpiod::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 consumer(&self) -> Result<&str> {
+        // SAFETY: The string returned by libgpiod is guaranteed to live as long
+        // as the `struct Config`.
+        let consumer = unsafe { gpiod::gpiod_request_config_get_consumer(self.config) };
+        if consumer.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::RequestConfigGetConsumer,
+                Errno::last(),
+            ));
+        }
+
+        // SAFETY: The string is guaranteed to be valid here by the C API.
+        str::from_utf8(unsafe {
+            slice::from_raw_parts(consumer as *const u8, strlen(consumer) as usize)
+        })
+        .map_err(Error::StringNotUtf8)
+    }
+
+    /// Set the size of the kernel event buffer for the request.
+    pub fn set_event_buffer_size(&self, size: usize) {
+        unsafe { gpiod::gpiod_request_config_set_event_buffer_size(self.config, size as c_ulong) }
+    }
+
+    /// Get the edge event buffer size setting for the request config.
+    pub fn event_buffer_size(&self) -> usize {
+        unsafe { gpiod::gpiod_request_config_get_event_buffer_size(self.config) as usize }
+    }
+}
+
+impl Drop for Config {
+    /// Free the request config object and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_request_config_free(self.config) }
+    }
+}
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* [PATCH V6 4/8] libgpiod: Add rust examples
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
                   ` (2 preceding siblings ...)
  2022-09-26 11:08 ` [PATCH V6 3/8] libgpiod: Add rust wrapper crate Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 5/8] libgpiod: Add gpiosim rust crate Viresh Kumar
                   ` (4 subsequent siblings)
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

Add examples for the usage of the rust bindings, quite similar to the
ones in cxx bindings.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 bindings/rust/libgpiod/examples/gpiodetect.rs | 30 ++++++
 bindings/rust/libgpiod/examples/gpiofind.rs   | 35 +++++++
 bindings/rust/libgpiod/examples/gpioget.rs    | 42 ++++++++
 bindings/rust/libgpiod/examples/gpioinfo.rs   | 95 +++++++++++++++++++
 bindings/rust/libgpiod/examples/gpiomon.rs    | 73 ++++++++++++++
 bindings/rust/libgpiod/examples/gpioset.rs    | 60 ++++++++++++
 bindings/rust/libgpiod/examples/gpiowatch.rs  | 54 +++++++++++
 7 files changed, 389 insertions(+)
 create mode 100644 bindings/rust/libgpiod/examples/gpiodetect.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpiofind.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpioget.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpioinfo.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpiomon.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpioset.rs
 create mode 100644 bindings/rust/libgpiod/examples/gpiowatch.rs

diff --git a/bindings/rust/libgpiod/examples/gpiodetect.rs b/bindings/rust/libgpiod/examples/gpiodetect.rs
new file mode 100644
index 000000000000..f24ac72e2d48
--- /dev/null
+++ b/bindings/rust/libgpiod/examples/gpiodetect.rs
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+//
+// Simplified Rust implementation of gpiodetect tool.
+
+use std::env;
+use std::path::Path;
+
+use libgpiod::{gpiochip_devices, Error, Result};
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() > 1 {
+        println!("Usage: {}", args[0]);
+        return Err(Error::InvalidArguments);
+    }
+
+    for chip in gpiochip_devices(&Path::new("/dev"))? {
+        println!(
+            "{} [{}] ({})",
+            chip.name()?,
+            chip.label()?,
+            chip.num_lines(),
+        );
+    }
+
+    Ok(())
+}
diff --git a/bindings/rust/libgpiod/examples/gpiofind.rs b/bindings/rust/libgpiod/examples/gpiofind.rs
new file mode 100644
index 000000000000..07e886bc3896
--- /dev/null
+++ b/bindings/rust/libgpiod/examples/gpiofind.rs
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+//
+// Simplified Rust implementation of gpiofind tool.
+
+use std::env;
+use std::path::Path;
+
+use libgpiod::{gpiochip_devices, Error, Result};
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() != 2 {
+        println!("Usage: {} <line-name>", args[0]);
+        return Err(Error::InvalidArguments);
+    }
+
+    for chip in gpiochip_devices(&Path::new("/dev"))? {
+        let offset = chip.line_offset_from_name(&args[1]);
+        if offset.is_ok() {
+            println!(
+                "Line {} found: Chip: {}, offset: {}",
+                args[1],
+                chip.name()?,
+                offset?
+            );
+            return Ok(());
+        }
+    }
+
+    println!("Failed to find line: {}", args[1]);
+    Ok(())
+}
diff --git a/bindings/rust/libgpiod/examples/gpioget.rs b/bindings/rust/libgpiod/examples/gpioget.rs
new file mode 100644
index 000000000000..f4c111987d96
--- /dev/null
+++ b/bindings/rust/libgpiod/examples/gpioget.rs
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+//
+// Simplified Rust implementation of gpioget tool.
+
+use std::env;
+
+use libgpiod::{chip::Chip, line, request, Direction, Error, Offset, Result, SettingVal};
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() < 3 {
+        println!("Usage: {} <chip> <line_offset0> ...", args[0]);
+        return Err(Error::InvalidArguments);
+    }
+
+    let mut lsettings = line::Settings::new()?;
+    let lconfig = line::Config::new()?;
+    let mut offsets = Vec::<Offset>::new();
+
+    for arg in &args[2..] {
+        let offset = arg.parse::<Offset>().map_err(|_| Error::InvalidArguments)?;
+        offsets.push(offset);
+    }
+
+    lsettings.set_prop(&[SettingVal::Direction(Direction::Input)])?;
+    lconfig.add_line_settings(&offsets, lsettings)?;
+
+    let path = format!("/dev/gpiochip{}", args[1]);
+    let chip = Chip::open(&path)?;
+
+    let rconfig = request::Config::new()?;
+    rconfig.set_consumer(&args[0]);
+
+    let request = chip.request_lines(&rconfig, &lconfig)?;
+    let map = request.values()?;
+
+    println!("{:?}", map);
+    Ok(())
+}
diff --git a/bindings/rust/libgpiod/examples/gpioinfo.rs b/bindings/rust/libgpiod/examples/gpioinfo.rs
new file mode 100644
index 000000000000..8b9fcb000f63
--- /dev/null
+++ b/bindings/rust/libgpiod/examples/gpioinfo.rs
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+//
+// Simplified Rust implementation of gpioinfo tool.
+
+use std::env;
+use std::path::Path;
+
+use libgpiod::{
+    chip::Chip, gpiochip_devices, is_gpiochip_device, Direction, Error, Offset, Result,
+};
+
+fn line_info(chip: &Chip, offset: Offset) -> Result<()> {
+    let info = chip.line_info(offset)?;
+    let off = info.offset();
+
+    let name = match info.name() {
+        Ok(name) => name,
+        _ => "unused",
+    };
+
+    let consumer = match info.consumer() {
+        Ok(name) => name,
+        _ => "unnamed",
+    };
+
+    let low = if info.is_active_low() {
+        "active-low"
+    } else {
+        "active-high"
+    };
+
+    let dir = match info.direction()? {
+        Direction::AsIs => "None",
+        Direction::Input => "Input",
+        Direction::Output => "Output",
+    };
+
+    println!(
+        "\tline {:>3}\
+              \t{:>10}\
+              \t{:>10}\
+              \t{:>6}\
+              \t{:>14}",
+        off, name, consumer, dir, low
+    );
+
+    Ok(())
+}
+
+fn chip_info(chip: &Chip) -> Result<()> {
+    let ngpio = chip.num_lines();
+
+    println!("GPIO Chip name: {}", chip.name()?);
+    println!("\tlabel: {}", chip.label()?);
+    println!("\tpath: {}", chip.path()?);
+    println!("\tngpio: {}\n", ngpio);
+
+    println!("\tLine information:");
+
+    for offset in 0..ngpio {
+        line_info(chip, offset as Offset)?;
+    }
+    println!("\n");
+
+    Ok(())
+}
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() > 2 {
+        println!("Usage: {}", args[0]);
+        return Err(Error::InvalidArguments);
+    }
+
+    if args.len() == 1 {
+        for chip in gpiochip_devices(&Path::new("/dev"))? {
+            chip_info(&chip)?;
+        }
+    } else {
+        let index = args[1]
+            .parse::<u32>()
+            .map_err(|_| Error::InvalidArguments)?;
+        let path = format!("/dev/gpiochip{}", index);
+        if is_gpiochip_device(&path) {
+            let chip = Chip::open(&path)?;
+
+            chip_info(&chip)?;
+        }
+    }
+
+    Ok(())
+}
diff --git a/bindings/rust/libgpiod/examples/gpiomon.rs b/bindings/rust/libgpiod/examples/gpiomon.rs
new file mode 100644
index 000000000000..bf01b5717963
--- /dev/null
+++ b/bindings/rust/libgpiod/examples/gpiomon.rs
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+//
+// Simplified Rust implementation of the gpiomon tool.
+
+use std::env;
+
+use libgpiod::{
+    chip::Chip, edge, line, request, Edge, EdgeKind, Error, Offset, Result, SettingVal,
+};
+
+fn usage(name: &str) {
+    println!("Usage: {} <chip> <offset0> ...", name);
+}
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() < 3 {
+        usage(&args[0]);
+        return Err(Error::InvalidArguments);
+    }
+
+    let mut lsettings = line::Settings::new()?;
+    let lconfig = line::Config::new()?;
+    let mut offsets = Vec::<Offset>::new();
+
+    for arg in &args[2..] {
+        let offset = arg.parse::<Offset>().map_err(|_| Error::InvalidArguments)?;
+        offsets.push(offset);
+    }
+
+    lsettings.set_prop(&[SettingVal::EdgeDetection(Some(Edge::Both))])?;
+    lconfig.add_line_settings(&offsets, lsettings)?;
+
+    let path = format!("/dev/gpiochip{}", args[1]);
+    let chip = Chip::open(&path)?;
+
+    let rconfig = request::Config::new()?;
+
+    let buffer = edge::event::Buffer::new(1)?;
+    let request = chip.request_lines(&rconfig, &lconfig)?;
+
+    loop {
+        match request.wait_edge_event(None) {
+            Err(x) => {
+                println!("{:?}", x);
+                return Err(Error::InvalidArguments);
+            }
+
+            Ok(false) => {
+                // This shouldn't happen as the call is blocking.
+                panic!();
+            }
+            Ok(true) => (),
+        }
+
+        let count = request.read_edge_events(&buffer)?;
+        if count == 1 {
+            let event = buffer.event(0)?;
+            println!(
+                "line: {} type: {}, time: {:?}",
+                event.line_offset(),
+                match event.event_type()? {
+                    EdgeKind::Rising => "Rising",
+                    EdgeKind::Falling => "Falling",
+                },
+                event.timestamp()
+            );
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/examples/gpioset.rs b/bindings/rust/libgpiod/examples/gpioset.rs
new file mode 100644
index 000000000000..56ed241ce9de
--- /dev/null
+++ b/bindings/rust/libgpiod/examples/gpioset.rs
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+//
+// Simplified Rust implementation of the gpioset tool.
+
+use std::env;
+use std::io::{stdin, Read};
+
+use libgpiod::{chip::Chip, line, request, Direction, Error, Offset, Result, SettingVal, Value};
+
+fn usage(name: &str) {
+    println!("Usage: {} <chip> <line_offset0>=<value0> ...", name);
+}
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() < 3 {
+        usage(&args[0]);
+        return Err(Error::InvalidArguments);
+    }
+
+    let lconfig = line::Config::new()?;
+
+    for arg in &args[2..] {
+        let pair: Vec<&str> = arg.split('=').collect();
+        if pair.len() != 2 {
+            usage(&args[0]);
+            return Err(Error::InvalidArguments);
+        }
+
+        let offset = pair[0]
+            .parse::<Offset>()
+            .map_err(|_| Error::InvalidArguments)?;
+        let value = pair[1]
+            .parse::<i32>()
+            .map_err(|_| Error::InvalidArguments)?;
+
+        let mut lsettings = line::Settings::new()?;
+        lsettings.set_prop(&[
+            SettingVal::Direction(Direction::Output),
+            SettingVal::OutputValue(Value::new(value)?),
+        ])?;
+        lconfig.add_line_settings(&[offset], lsettings)?;
+    }
+
+    let path = format!("/dev/gpiochip{}", args[1]);
+    let chip = Chip::open(&path)?;
+
+    let rconfig = request::Config::new()?;
+    rconfig.set_consumer(&args[0]);
+
+    chip.request_lines(&rconfig, &lconfig)?;
+
+    // Wait for keypress, let user verify line status.
+    stdin().read_exact(&mut [0u8]).unwrap();
+
+    Ok(())
+}
diff --git a/bindings/rust/libgpiod/examples/gpiowatch.rs b/bindings/rust/libgpiod/examples/gpiowatch.rs
new file mode 100644
index 000000000000..030168ba9788
--- /dev/null
+++ b/bindings/rust/libgpiod/examples/gpiowatch.rs
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+//
+// Simplified Rust implementation of the gpiowatch tool.
+
+use std::env;
+
+use libgpiod::{chip::Chip, Error, Offset, Result};
+
+fn usage(name: &str) {
+    println!("Usage: {} <chip> <offset0> ...", name);
+}
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() < 2 {
+        usage(&args[0]);
+        return Err(Error::InvalidArguments);
+    }
+
+    let path = format!("/dev/gpiochip{}", args[1]);
+    let offset = args[2]
+        .parse::<Offset>()
+        .map_err(|_| Error::InvalidArguments)?;
+
+    let chip = Chip::open(&path)?;
+    let _info = chip.watch_line_info(offset)?;
+
+    match chip.wait_info_event(None) {
+        Err(x) => {
+            println!("{:?}", x);
+            return Err(Error::InvalidArguments);
+        }
+
+        Ok(false) => {
+            // This shouldn't happen as the call is blocking.
+            panic!();
+        }
+        Ok(true) => (),
+    }
+
+    let event = chip.read_info_event()?;
+    println!(
+        "line: {} type: {:?}, time: {:?}",
+        offset,
+        event.event_type()?,
+        event.timestamp()
+    );
+
+    chip.unwatch(offset);
+    Ok(())
+}
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* [PATCH V6 5/8] libgpiod: Add gpiosim rust crate
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
                   ` (3 preceding siblings ...)
  2022-09-26 11:08 ` [PATCH V6 4/8] libgpiod: Add rust examples Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 6/8] gpiosim: Add pre generated rust bindings Viresh Kumar
                   ` (3 subsequent siblings)
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

This adds gpiosim rust crate, which provides helpers to emulate GPIO
chips.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 bindings/rust/Cargo.toml         |   3 +-
 bindings/rust/gpiosim/Cargo.toml |  18 ++
 bindings/rust/gpiosim/build.rs   |  43 ++++
 bindings/rust/gpiosim/src/lib.rs |  25 +++
 bindings/rust/gpiosim/src/sim.rs | 323 +++++++++++++++++++++++++++++++
 5 files changed, 411 insertions(+), 1 deletion(-)
 create mode 100644 bindings/rust/gpiosim/Cargo.toml
 create mode 100644 bindings/rust/gpiosim/build.rs
 create mode 100644 bindings/rust/gpiosim/src/lib.rs
 create mode 100644 bindings/rust/gpiosim/src/sim.rs

diff --git a/bindings/rust/Cargo.toml b/bindings/rust/Cargo.toml
index 1e57ef2c0002..8721bc610b86 100644
--- a/bindings/rust/Cargo.toml
+++ b/bindings/rust/Cargo.toml
@@ -2,5 +2,6 @@
 
 members = [
     "libgpiod-sys",
-    "libgpiod"
+    "libgpiod",
+    "gpiosim"
 ]
diff --git a/bindings/rust/gpiosim/Cargo.toml b/bindings/rust/gpiosim/Cargo.toml
new file mode 100644
index 000000000000..d6b4cc34339b
--- /dev/null
+++ b/bindings/rust/gpiosim/Cargo.toml
@@ -0,0 +1,18 @@
+[package]
+name = "gpiosim"
+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 = { path = "../libgpiod" }
+vmm-sys-util = "=0.10.0"
+
+[features]
+generate = [ "bindgen" ]
+
+[build-dependencies]
+bindgen = { version = "0.59.1", optional = true }
+cc = "1.0.46"
diff --git a/bindings/rust/gpiosim/build.rs b/bindings/rust/gpiosim/build.rs
new file mode 100644
index 000000000000..460fb8c092c3
--- /dev/null
+++ b/bindings/rust/gpiosim/build.rs
@@ -0,0 +1,43 @@
+#[cfg(feature = "generate")]
+extern crate bindgen;
+#[cfg(feature = "generate")]
+use std::env;
+#[cfg(feature = "generate")]
+use std::path::PathBuf;
+
+#[cfg(feature = "generate")]
+fn generate_bindings() {
+    // Tell cargo to invalidate the built crate whenever following files change
+    println!("cargo:rerun-if-changed=../../../tests/gpiosim/gpiosim.h");
+
+    // The bindgen::Builder is the main entry point
+    // to bindgen, and lets you build up options for
+    // the resulting bindings.
+    let bindings = bindgen::Builder::default()
+        // The input header we would like to generate
+        // bindings for.
+        .header("../../../tests/gpiosim/gpiosim.h")
+        // Tell cargo to invalidate the built crate whenever any of the
+        // included header files changed.
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks))
+        // Finish the builder and generate the bindings.
+        .generate()
+        // Unwrap the Result and panic on failure.
+        .expect("Unable to generate bindings");
+
+    // Write the bindings to the $OUT_DIR/bindings.rs file.
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    bindings
+        .write_to_file(out_path.join("bindings.rs"))
+        .expect("Couldn't write bindings!");
+}
+
+fn main() {
+    #[cfg(feature = "generate")]
+    generate_bindings();
+
+    println!("cargo:rustc-link-lib=kmod");
+    println!("cargo:rustc-link-lib=mount");
+    println!("cargo:rustc-link-search=./../../tests/gpiosim/.libs/");
+    println!("cargo:rustc-link-lib=static=gpiosim");
+}
diff --git a/bindings/rust/gpiosim/src/lib.rs b/bindings/rust/gpiosim/src/lib.rs
new file mode 100644
index 000000000000..94d0ddb38e0f
--- /dev/null
+++ b/bindings/rust/gpiosim/src/lib.rs
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#[allow(non_camel_case_types, non_upper_case_globals)]
+#[cfg_attr(test, allow(deref_nullptr, non_snake_case))]
+#[allow(dead_code)]
+mod bindings_raw {
+    #[cfg(feature = "generate")]
+    include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
+
+    #[cfg(not(feature = "generate"))]
+    include!("bindings.rs");
+}
+
+use bindings_raw::*;
+
+pub use bindings_raw::{
+    GPIOSIM_HOG_DIR_INPUT, GPIOSIM_HOG_DIR_OUTPUT_HIGH, GPIOSIM_HOG_DIR_OUTPUT_LOW,
+    GPIOSIM_PULL_DOWN, GPIOSIM_PULL_UP, GPIOSIM_VALUE_ACTIVE, GPIOSIM_VALUE_INACTIVE,
+};
+
+#[allow(dead_code)]
+mod sim;
+
+#[allow(unused_imports)]
+pub use sim::*;
diff --git a/bindings/rust/gpiosim/src/sim.rs b/bindings/rust/gpiosim/src/sim.rs
new file mode 100644
index 000000000000..50977ea54ebb
--- /dev/null
+++ b/bindings/rust/gpiosim/src/sim.rs
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use libc::strlen;
+use std::os::raw::c_char;
+use std::path::PathBuf;
+use std::{slice, str};
+
+use vmm_sys_util::errno::Error as Errno;
+
+use libgpiod::{Error, Offset, OperationType, Result};
+
+use crate::*;
+
+/// Sim Ctx
+#[derive(Debug)]
+struct SimCtx {
+    ctx: *mut gpiosim_ctx,
+}
+
+unsafe impl Send for SimCtx {}
+unsafe impl Sync for SimCtx {}
+
+impl SimCtx {
+    fn new() -> Result<Self> {
+        let ctx = unsafe { gpiosim_ctx_new() };
+        if ctx.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::SimCtxNew,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { ctx })
+    }
+
+    fn ctx(&self) -> *mut gpiosim_ctx {
+        self.ctx
+    }
+}
+
+impl Drop for SimCtx {
+    fn drop(&mut self) {
+        unsafe { gpiosim_ctx_unref(self.ctx) }
+    }
+}
+
+/// Sim Dev
+#[derive(Debug)]
+struct SimDev {
+    dev: *mut gpiosim_dev,
+}
+
+unsafe impl Send for SimDev {}
+unsafe impl Sync for SimDev {}
+
+impl SimDev {
+    fn new(ctx: &SimCtx) -> Result<Self> {
+        let dev = unsafe { gpiosim_dev_new(ctx.ctx()) };
+        if dev.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::SimDevNew,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { dev })
+    }
+
+    fn dev(&self) -> *mut gpiosim_dev {
+        self.dev
+    }
+
+    fn enable(&self) -> Result<()> {
+        let ret = unsafe { gpiosim_dev_enable(self.dev) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimDevEnable,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    fn disable(&self) -> Result<()> {
+        let ret = unsafe { gpiosim_dev_disable(self.dev) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimDevDisable,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl Drop for SimDev {
+    fn drop(&mut self) {
+        unsafe { gpiosim_dev_unref(self.dev) }
+    }
+}
+
+/// Sim Bank
+#[derive(Debug)]
+struct SimBank {
+    bank: *mut gpiosim_bank,
+}
+
+unsafe impl Send for SimBank {}
+unsafe impl Sync for SimBank {}
+
+impl SimBank {
+    fn new(dev: &SimDev) -> Result<Self> {
+        let bank = unsafe { gpiosim_bank_new(dev.dev()) };
+        if bank.is_null() {
+            return Err(Error::OperationFailed(
+                OperationType::SimBankNew,
+                Errno::last(),
+            ));
+        }
+
+        Ok(Self { bank })
+    }
+
+    fn chip_name(&self) -> Result<&str> {
+        // SAFETY: The string returned by gpiosim is guaranteed to live as long
+        // as the `struct SimBank`.
+        let name = unsafe { gpiosim_bank_get_chip_name(self.bank) };
+
+        // SAFETY: The string is guaranteed to be valid here.
+        str::from_utf8(unsafe { slice::from_raw_parts(name as *const u8, strlen(name) as usize) })
+            .map_err(Error::StringNotUtf8)
+    }
+
+    fn dev_path(&self) -> Result<PathBuf> {
+        // SAFETY: The string returned by gpiosim is guaranteed to live as long
+        // as the `struct SimBank`.
+        let path = unsafe { gpiosim_bank_get_dev_path(self.bank) };
+
+        // SAFETY: The string is guaranteed to be valid here.
+        let path = str::from_utf8(unsafe {
+            slice::from_raw_parts(path as *const u8, strlen(path) as usize)
+        })
+        .map_err(Error::StringNotUtf8)?;
+
+        Ok(PathBuf::from(path))
+    }
+
+    fn val(&self, offset: Offset) -> Result<u32> {
+        let ret = unsafe { gpiosim_bank_get_value(self.bank, offset) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimBankGetVal,
+                Errno::last(),
+            ))
+        } else {
+            Ok(ret as u32)
+        }
+    }
+
+    fn set_label(&self, label: &str) -> Result<()> {
+        // Null-terminate the string
+        let label = label.to_owned() + "\0";
+
+        let ret = unsafe { gpiosim_bank_set_label(self.bank, label.as_ptr() as *const c_char) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimBankSetLabel,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    fn set_num_lines(&self, num: u64) -> Result<()> {
+        let ret = unsafe { gpiosim_bank_set_num_lines(self.bank, num) };
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimBankSetNumLines,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    fn set_line_name(&self, offset: Offset, name: &str) -> Result<()> {
+        // Null-terminate the string
+        let name = name.to_owned() + "\0";
+
+        let ret = unsafe {
+            gpiosim_bank_set_line_name(self.bank, offset, name.as_ptr() as *const c_char)
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimBankSetLineName,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    fn set_pull(&self, offset: Offset, pull: i32) -> Result<()> {
+        let ret = unsafe { gpiosim_bank_set_pull(self.bank, offset, pull) };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimBankSetPull,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    fn hog_line(&self, offset: Offset, name: &str, dir: i32) -> Result<()> {
+        // Null-terminate the string
+        let name = name.to_owned() + "\0";
+
+        let ret = unsafe {
+            gpiosim_bank_hog_line(self.bank, offset, name.as_ptr() as *const c_char, dir)
+        };
+
+        if ret == -1 {
+            Err(Error::OperationFailed(
+                OperationType::SimBankHogLine,
+                Errno::last(),
+            ))
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl Drop for SimBank {
+    fn drop(&mut self) {
+        unsafe { gpiosim_bank_unref(self.bank) }
+    }
+}
+
+/// GPIO SIM
+#[derive(Debug)]
+pub struct Sim {
+    ctx: SimCtx,
+    dev: SimDev,
+    bank: SimBank,
+}
+
+unsafe impl Send for Sim {}
+unsafe impl Sync for Sim {}
+
+impl Sim {
+    pub fn new(ngpio: Option<u64>, label: Option<&str>, enable: bool) -> Result<Self> {
+        let ctx = SimCtx::new()?;
+        let dev = SimDev::new(&ctx)?;
+        let bank = SimBank::new(&dev)?;
+
+        if let Some(ngpio) = ngpio {
+            bank.set_num_lines(ngpio)?;
+        }
+
+        if let Some(label) = label {
+            bank.set_label(label)?;
+        }
+
+        if enable {
+            dev.enable()?;
+        }
+
+        Ok(Self { ctx, dev, bank })
+    }
+
+    pub fn chip_name(&self) -> &str {
+        self.bank.chip_name().unwrap()
+    }
+
+    pub fn dev_path(&self) -> PathBuf {
+        self.bank.dev_path().unwrap()
+    }
+
+    pub fn val(&self, offset: Offset) -> Result<u32> {
+        self.bank.val(offset)
+    }
+
+    pub fn set_label(&self, label: &str) -> Result<()> {
+        self.bank.set_label(label)
+    }
+
+    pub fn set_num_lines(&self, num: u64) -> Result<()> {
+        self.bank.set_num_lines(num)
+    }
+
+    pub fn set_line_name(&self, offset: Offset, name: &str) -> Result<()> {
+        self.bank.set_line_name(offset, name)
+    }
+
+    pub fn set_pull(&self, offset: Offset, pull: i32) -> Result<()> {
+        self.bank.set_pull(offset, pull)
+    }
+
+    pub fn hog_line(&self, offset: Offset, name: &str, dir: i32) -> Result<()> {
+        self.bank.hog_line(offset, name, dir)
+    }
+
+    pub fn enable(&self) -> Result<()> {
+        self.dev.enable()
+    }
+
+    pub fn disable(&self) -> Result<()> {
+        self.dev.disable()
+    }
+}
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* [PATCH V6 6/8] gpiosim: Add pre generated rust bindings
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
                   ` (4 preceding siblings ...)
  2022-09-26 11:08 ` [PATCH V6 5/8] libgpiod: Add gpiosim rust crate Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 7/8] libgpiod: Add rust tests Viresh Kumar
                   ` (2 subsequent siblings)
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

This adds a copy of pre generated bindings and adds the suggested way of
updating those in README.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 bindings/rust/gpiosim/README.md       |  11 ++
 bindings/rust/gpiosim/src/bindings.rs | 180 ++++++++++++++++++++++++++
 2 files changed, 191 insertions(+)
 create mode 100644 bindings/rust/gpiosim/README.md
 create mode 100644 bindings/rust/gpiosim/src/bindings.rs

diff --git a/bindings/rust/gpiosim/README.md b/bindings/rust/gpiosim/README.md
new file mode 100644
index 000000000000..acb84543dbdc
--- /dev/null
+++ b/bindings/rust/gpiosim/README.md
@@ -0,0 +1,11 @@
+# Generated gpiosim Rust FFI bindings
+Automatically generated Rust FFI bindings via
+	[bindgen](https://github.com/rust-lang/rust-bindgen).
+
+## Updating bindings
+1. Clone the source from
+	<https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/>
+2. run `cd libgpiod/bindings/rust/gpiosim/`
+2. run `cargo build --features generate`
+3. Copy the bindings 'cp ../target/debug/build/gpiosim-###/out/bindings.rs src/bindings.rs'
+4. Commit changes in `src/bindings.rs`
diff --git a/bindings/rust/gpiosim/src/bindings.rs b/bindings/rust/gpiosim/src/bindings.rs
new file mode 100644
index 000000000000..bac347f1aab9
--- /dev/null
+++ b/bindings/rust/gpiosim/src/bindings.rs
@@ -0,0 +1,180 @@
+/* automatically generated by rust-bindgen 0.59.2 */
+
+pub const true_: u32 = 1;
+pub const false_: u32 = 0;
+pub const __bool_true_false_are_defined: u32 = 1;
+pub type size_t = ::std::os::raw::c_ulong;
+pub type wchar_t = ::std::os::raw::c_int;
+#[repr(C)]
+#[repr(align(16))]
+#[derive(Debug, Copy, Clone)]
+pub struct max_align_t {
+    pub __clang_max_align_nonce1: ::std::os::raw::c_longlong,
+    pub __bindgen_padding_0: u64,
+    pub __clang_max_align_nonce2: u128,
+}
+#[test]
+fn bindgen_test_layout_max_align_t() {
+    assert_eq!(
+        ::std::mem::size_of::<max_align_t>(),
+        32usize,
+        concat!("Size of: ", stringify!(max_align_t))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<max_align_t>(),
+        16usize,
+        concat!("Alignment of ", stringify!(max_align_t))
+    );
+    assert_eq!(
+        unsafe {
+            &(*(::std::ptr::null::<max_align_t>())).__clang_max_align_nonce1 as *const _ as usize
+        },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(max_align_t),
+            "::",
+            stringify!(__clang_max_align_nonce1)
+        )
+    );
+    assert_eq!(
+        unsafe {
+            &(*(::std::ptr::null::<max_align_t>())).__clang_max_align_nonce2 as *const _ as usize
+        },
+        16usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(max_align_t),
+            "::",
+            stringify!(__clang_max_align_nonce2)
+        )
+    );
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiosim_ctx {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiosim_dev {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct gpiosim_bank {
+    _unused: [u8; 0],
+}
+pub const GPIOSIM_VALUE_INACTIVE: ::std::os::raw::c_uint = 0;
+pub const GPIOSIM_VALUE_ACTIVE: ::std::os::raw::c_uint = 1;
+pub type _bindgen_ty_1 = ::std::os::raw::c_uint;
+pub const GPIOSIM_PULL_DOWN: ::std::os::raw::c_uint = 1;
+pub const GPIOSIM_PULL_UP: ::std::os::raw::c_uint = 2;
+pub type _bindgen_ty_2 = ::std::os::raw::c_uint;
+pub const GPIOSIM_HOG_DIR_INPUT: ::std::os::raw::c_uint = 1;
+pub const GPIOSIM_HOG_DIR_OUTPUT_HIGH: ::std::os::raw::c_uint = 2;
+pub const GPIOSIM_HOG_DIR_OUTPUT_LOW: ::std::os::raw::c_uint = 3;
+pub type _bindgen_ty_3 = ::std::os::raw::c_uint;
+extern "C" {
+    pub fn gpiosim_ctx_new() -> *mut gpiosim_ctx;
+}
+extern "C" {
+    pub fn gpiosim_ctx_ref(ctx: *mut gpiosim_ctx) -> *mut gpiosim_ctx;
+}
+extern "C" {
+    pub fn gpiosim_ctx_unref(ctx: *mut gpiosim_ctx);
+}
+extern "C" {
+    pub fn gpiosim_dev_new(ctx: *mut gpiosim_ctx) -> *mut gpiosim_dev;
+}
+extern "C" {
+    pub fn gpiosim_dev_ref(dev: *mut gpiosim_dev) -> *mut gpiosim_dev;
+}
+extern "C" {
+    pub fn gpiosim_dev_unref(dev: *mut gpiosim_dev);
+}
+extern "C" {
+    pub fn gpiosim_dev_get_ctx(dev: *mut gpiosim_dev) -> *mut gpiosim_ctx;
+}
+extern "C" {
+    pub fn gpiosim_dev_get_name(dev: *mut gpiosim_dev) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    pub fn gpiosim_dev_enable(dev: *mut gpiosim_dev) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_dev_disable(dev: *mut gpiosim_dev) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_dev_is_live(dev: *mut gpiosim_dev) -> bool;
+}
+extern "C" {
+    pub fn gpiosim_bank_new(dev: *mut gpiosim_dev) -> *mut gpiosim_bank;
+}
+extern "C" {
+    pub fn gpiosim_bank_ref(bank: *mut gpiosim_bank) -> *mut gpiosim_bank;
+}
+extern "C" {
+    pub fn gpiosim_bank_unref(bank: *mut gpiosim_bank);
+}
+extern "C" {
+    pub fn gpiosim_bank_get_dev(bank: *mut gpiosim_bank) -> *mut gpiosim_dev;
+}
+extern "C" {
+    pub fn gpiosim_bank_get_chip_name(bank: *mut gpiosim_bank) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    pub fn gpiosim_bank_get_dev_path(bank: *mut gpiosim_bank) -> *const ::std::os::raw::c_char;
+}
+extern "C" {
+    pub fn gpiosim_bank_set_label(
+        bank: *mut gpiosim_bank,
+        label: *const ::std::os::raw::c_char,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_bank_set_num_lines(
+        bank: *mut gpiosim_bank,
+        num_lines: size_t,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_bank_set_line_name(
+        bank: *mut gpiosim_bank,
+        offset: ::std::os::raw::c_uint,
+        name: *const ::std::os::raw::c_char,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_bank_hog_line(
+        bank: *mut gpiosim_bank,
+        offset: ::std::os::raw::c_uint,
+        name: *const ::std::os::raw::c_char,
+        direction: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_bank_clear_hog(
+        bank: *mut gpiosim_bank,
+        offset: ::std::os::raw::c_uint,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_bank_get_value(
+        bank: *mut gpiosim_bank,
+        offset: ::std::os::raw::c_uint,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_bank_get_pull(
+        bank: *mut gpiosim_bank,
+        offset: ::std::os::raw::c_uint,
+    ) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn gpiosim_bank_set_pull(
+        bank: *mut gpiosim_bank,
+        offset: ::std::os::raw::c_uint,
+        pull: ::std::os::raw::c_int,
+    ) -> ::std::os::raw::c_int;
+}
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* [PATCH V6 7/8] libgpiod: Add rust tests
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
                   ` (5 preceding siblings ...)
  2022-09-26 11:08 ` [PATCH V6 6/8] gpiosim: Add pre generated rust bindings Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 11:08 ` [PATCH V6 8/8] libgpiod: Integrate building of rust bindings with make Viresh Kumar
  2022-09-26 15:57 ` [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

Add tests for the rust bindings, quite similar to the ones in cxx
bindings.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 bindings/rust/libgpiod/Cargo.toml             |   3 +
 bindings/rust/libgpiod/tests/chip.rs          |  97 ++++
 bindings/rust/libgpiod/tests/common/config.rs | 134 +++++
 bindings/rust/libgpiod/tests/common/mod.rs    |  10 +
 bindings/rust/libgpiod/tests/edge_event.rs    | 294 ++++++++++
 bindings/rust/libgpiod/tests/info_event.rs    | 125 +++++
 bindings/rust/libgpiod/tests/line_config.rs   | 105 ++++
 bindings/rust/libgpiod/tests/line_info.rs     | 279 ++++++++++
 bindings/rust/libgpiod/tests/line_request.rs  | 519 ++++++++++++++++++
 bindings/rust/libgpiod/tests/line_settings.rs | 226 ++++++++
 .../rust/libgpiod/tests/request_config.rs     |  38 ++
 11 files changed, 1830 insertions(+)
 create mode 100644 bindings/rust/libgpiod/tests/chip.rs
 create mode 100644 bindings/rust/libgpiod/tests/common/config.rs
 create mode 100644 bindings/rust/libgpiod/tests/common/mod.rs
 create mode 100644 bindings/rust/libgpiod/tests/edge_event.rs
 create mode 100644 bindings/rust/libgpiod/tests/info_event.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_config.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_info.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_request.rs
 create mode 100644 bindings/rust/libgpiod/tests/line_settings.rs
 create mode 100644 bindings/rust/libgpiod/tests/request_config.rs

diff --git a/bindings/rust/libgpiod/Cargo.toml b/bindings/rust/libgpiod/Cargo.toml
index f25242abb153..8abcaacdee67 100644
--- a/bindings/rust/libgpiod/Cargo.toml
+++ b/bindings/rust/libgpiod/Cargo.toml
@@ -11,3 +11,6 @@ libc = ">=0.2.39"
 libgpiod-sys = { path = "../libgpiod-sys" }
 thiserror = "1.0"
 vmm-sys-util = "=0.10.0"
+
+[dev-dependencies]
+gpiosim = { path = "../gpiosim" }
diff --git a/bindings/rust/libgpiod/tests/chip.rs b/bindings/rust/libgpiod/tests/chip.rs
new file mode 100644
index 000000000000..ce592331b5e8
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/chip.rs
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+mod common;
+
+mod chip {
+    use libc::{ENODEV, ENOENT, ENOTTY};
+    use std::path::PathBuf;
+
+    use vmm_sys_util::errno::Error as Errno;
+
+    use gpiosim::Sim;
+    use libgpiod::{chip::Chip, Error as ChipError, OperationType};
+
+    mod open {
+        use super::*;
+
+        #[test]
+        fn nonexistent_file() {
+            assert_eq!(
+                Chip::open(&PathBuf::from("/dev/nonexistent")).unwrap_err(),
+                ChipError::OperationFailed(OperationType::ChipOpen, Errno::new(ENOENT))
+            );
+        }
+
+        #[test]
+        fn no_dev_file() {
+            assert_eq!(
+                Chip::open(&PathBuf::from("/tmp")).unwrap_err(),
+                ChipError::OperationFailed(OperationType::ChipOpen, Errno::new(ENOTTY))
+            );
+        }
+
+        #[test]
+        fn non_gpio_char_dev_file() {
+            assert_eq!(
+                Chip::open(&PathBuf::from("/dev/null")).unwrap_err(),
+                ChipError::OperationFailed(OperationType::ChipOpen, Errno::new(ENODEV))
+            );
+        }
+
+        #[test]
+        fn gpiosim_file() {
+            let sim = Sim::new(None, None, true).unwrap();
+            assert!(Chip::open(&sim.dev_path()).is_ok());
+        }
+    }
+
+    mod verify {
+        use super::*;
+        const NGPIO: u64 = 16;
+        const LABEL: &str = "foobar";
+
+        #[test]
+        fn basic_helpers() {
+            let sim = Sim::new(Some(NGPIO), Some(LABEL), true).unwrap();
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+
+            assert_eq!(chip.label().unwrap(), LABEL);
+            assert_eq!(chip.name().unwrap(), sim.chip_name());
+            assert_eq!(chip.path().unwrap(), sim.dev_path().to_str().unwrap());
+            assert_eq!(chip.num_lines(), NGPIO as usize);
+            assert!(chip.fd().is_ok());
+        }
+
+        #[test]
+        fn find_line() {
+            let sim = Sim::new(Some(NGPIO), None, false).unwrap();
+            sim.set_line_name(0, "zero").unwrap();
+            sim.set_line_name(2, "two").unwrap();
+            sim.set_line_name(3, "three").unwrap();
+            sim.set_line_name(5, "five").unwrap();
+            sim.set_line_name(10, "ten").unwrap();
+            sim.set_line_name(11, "ten").unwrap();
+            sim.enable().unwrap();
+
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+
+            // Success case
+            assert_eq!(chip.line_offset_from_name("zero").unwrap(), 0);
+            assert_eq!(chip.line_offset_from_name("two").unwrap(), 2);
+            assert_eq!(chip.line_offset_from_name("three").unwrap(), 3);
+            assert_eq!(chip.line_offset_from_name("five").unwrap(), 5);
+
+            // Success with duplicate names, should return first entry
+            assert_eq!(chip.line_offset_from_name("ten").unwrap(), 10);
+
+            // Failure
+            assert_eq!(
+                chip.line_offset_from_name("nonexistent").unwrap_err(),
+                ChipError::OperationFailed(OperationType::ChipGetLine, Errno::new(ENOENT))
+            );
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/common/config.rs b/bindings/rust/libgpiod/tests/common/config.rs
new file mode 100644
index 000000000000..ef4285067ebf
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/common/config.rs
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+use std::sync::Arc;
+use std::time::Duration;
+
+use gpiosim::Sim;
+use libgpiod::{
+    chip::Chip, line, request, Bias, Direction, Drive, Edge, EventClock, Offset, Result,
+    SettingVal, Value,
+};
+
+pub(crate) struct TestConfig {
+    sim: Arc<Sim>,
+    chip: Option<Chip>,
+    request: Option<line::Request>,
+    rconfig: request::Config,
+    lconfig: line::Config,
+    lsettings: Option<line::Settings>,
+}
+
+impl TestConfig {
+    pub(crate) fn new(ngpio: u64) -> Result<Self> {
+        Ok(Self {
+            sim: Arc::new(Sim::new(Some(ngpio), None, true)?),
+            chip: None,
+            request: None,
+            rconfig: request::Config::new().unwrap(),
+            lconfig: line::Config::new().unwrap(),
+            lsettings: Some(line::Settings::new().unwrap()),
+        })
+    }
+
+    pub(crate) fn set_pull(&self, offsets: &[Offset], pulls: &[u32]) {
+        for i in 0..pulls.len() {
+            self.sim.set_pull(offsets[i], pulls[i] as i32).unwrap();
+        }
+    }
+
+    pub(crate) fn rconfig_set_consumer(&self, consumer: &str) {
+        self.rconfig.set_consumer(consumer);
+    }
+
+    pub(crate) fn lconfig_val(&mut self, dir: Option<Direction>, val: Option<Value>) {
+        let mut settings = Vec::new();
+
+        if let Some(dir) = dir {
+            settings.push(SettingVal::Direction(dir));
+        }
+
+        if let Some(val) = val {
+            settings.push(SettingVal::OutputValue(val));
+        }
+
+        if !settings.is_empty() {
+            self.lsettings().set_prop(&settings).unwrap();
+        }
+    }
+
+    pub(crate) fn lconfig_bias(&mut self, dir: Direction, bias: Option<Bias>) {
+        let settings = vec![SettingVal::Direction(dir), SettingVal::Bias(bias)];
+        self.lsettings().set_prop(&settings).unwrap();
+    }
+
+    pub(crate) fn lconfig_clock(&mut self, clock: EventClock) {
+        let settings = vec![SettingVal::EventClock(clock)];
+        self.lsettings().set_prop(&settings).unwrap();
+    }
+
+    pub(crate) fn lconfig_debounce(&mut self, duration: Duration) {
+        let settings = vec![
+            SettingVal::Direction(Direction::Input),
+            SettingVal::DebouncePeriod(duration),
+        ];
+        self.lsettings().set_prop(&settings).unwrap();
+    }
+
+    pub(crate) fn lconfig_drive(&mut self, dir: Direction, drive: Drive) {
+        let settings = vec![SettingVal::Direction(dir), SettingVal::Drive(drive)];
+        self.lsettings().set_prop(&settings).unwrap();
+    }
+
+    pub(crate) fn lconfig_edge(&mut self, dir: Option<Direction>, edge: Option<Edge>) {
+        let mut settings = Vec::new();
+
+        if let Some(dir) = dir {
+            settings.push(SettingVal::Direction(dir));
+        }
+
+        settings.push(SettingVal::EdgeDetection(edge));
+        self.lsettings().set_prop(&settings).unwrap();
+    }
+
+    pub(crate) fn lconfig_add_settings(&mut self, offsets: &[Offset]) {
+        self.lconfig
+            .add_line_settings(offsets, self.lsettings.take().unwrap())
+            .unwrap()
+    }
+
+    pub(crate) fn request_lines(&mut self) -> Result<()> {
+        let chip = Chip::open(&self.sim.dev_path())?;
+
+        self.request = Some(chip.request_lines(&self.rconfig, &self.lconfig)?);
+        self.chip = Some(chip);
+
+        Ok(())
+    }
+
+    pub(crate) fn sim(&self) -> Arc<Sim> {
+        self.sim.clone()
+    }
+
+    pub(crate) fn chip(&self) -> &Chip {
+        self.chip.as_ref().unwrap()
+    }
+
+    pub(crate) fn lsettings(&mut self) -> &mut line::Settings {
+        self.lsettings.as_mut().unwrap()
+    }
+
+    pub(crate) fn request(&self) -> &line::Request {
+        self.request.as_ref().unwrap()
+    }
+}
+
+impl Drop for TestConfig {
+    fn drop(&mut self) {
+        // Explicit freeing is important to make sure "request" get freed
+        // before "sim" and "chip".
+        self.request = None;
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/common/mod.rs b/bindings/rust/libgpiod/tests/common/mod.rs
new file mode 100644
index 000000000000..8904f7121b4c
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/common/mod.rs
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+#[allow(dead_code)]
+mod config;
+
+#[allow(unused_imports)]
+pub(crate) use config::*;
diff --git a/bindings/rust/libgpiod/tests/edge_event.rs b/bindings/rust/libgpiod/tests/edge_event.rs
new file mode 100644
index 000000000000..29f7a66ed979
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/edge_event.rs
@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+mod common;
+
+mod edge_event {
+    use std::sync::Arc;
+    use std::thread::{sleep, spawn};
+    use std::time::Duration;
+
+    use crate::common::*;
+    use gpiosim::Sim;
+    use gpiosim::{GPIOSIM_PULL_DOWN, GPIOSIM_PULL_UP};
+    use libgpiod::{edge, Edge, EdgeKind, Offset};
+
+    const NGPIO: u64 = 8;
+
+    mod buffer_capacity {
+        use super::*;
+
+        #[test]
+        fn default_capacity() {
+            assert_eq!(edge::event::Buffer::new(0).unwrap().capacity(), 64);
+        }
+
+        #[test]
+        fn user_defined_capacity() {
+            assert_eq!(edge::event::Buffer::new(123).unwrap().capacity(), 123);
+        }
+
+        #[test]
+        fn max_capacity() {
+            assert_eq!(edge::event::Buffer::new(1024 * 2).unwrap().capacity(), 1024);
+        }
+    }
+
+    mod trigger {
+        use super::*;
+
+        // Helpers to generate events
+        fn trigger_falling_and_rising_edge(sim: Arc<Sim>, offset: Offset) {
+            spawn(move || {
+                sleep(Duration::from_millis(30));
+                sim.set_pull(offset, GPIOSIM_PULL_UP as i32).unwrap();
+
+                sleep(Duration::from_millis(30));
+                sim.set_pull(offset, GPIOSIM_PULL_DOWN as i32).unwrap();
+            });
+        }
+
+        fn trigger_rising_edge_events_on_two_offsets(sim: Arc<Sim>, offset: [Offset; 2]) {
+            spawn(move || {
+                sleep(Duration::from_millis(30));
+                sim.set_pull(offset[0], GPIOSIM_PULL_UP as i32).unwrap();
+
+                sleep(Duration::from_millis(30));
+                sim.set_pull(offset[1], GPIOSIM_PULL_UP as i32).unwrap();
+            });
+        }
+
+        fn trigger_multiple_events(sim: Arc<Sim>, offset: Offset) {
+            sim.set_pull(offset, GPIOSIM_PULL_UP as i32).unwrap();
+            sleep(Duration::from_millis(10));
+
+            sim.set_pull(offset, GPIOSIM_PULL_DOWN as i32).unwrap();
+            sleep(Duration::from_millis(10));
+
+            sim.set_pull(offset, GPIOSIM_PULL_UP as i32).unwrap();
+            sleep(Duration::from_millis(10));
+        }
+
+        #[test]
+        fn both_edges() {
+            const GPIO: Offset = 2;
+            let buf = edge::event::Buffer::new(0).unwrap();
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(None, Some(Edge::Both));
+            config.lconfig_add_settings(&[GPIO]);
+            config.request_lines().unwrap();
+
+            // Generate events
+            trigger_falling_and_rising_edge(config.sim(), GPIO);
+
+            // Rising event
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 1);
+            assert_eq!(buf.len(), 1);
+
+            let event = buf.event(0).unwrap();
+            let ts_rising = event.timestamp();
+            assert_eq!(event.event_type().unwrap(), EdgeKind::Rising);
+            assert_eq!(event.line_offset(), GPIO);
+
+            // Falling event
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 1);
+            assert_eq!(buf.len(), 1);
+
+            let event = buf.event(0).unwrap();
+            let ts_falling = event.timestamp();
+            assert_eq!(event.event_type().unwrap(), EdgeKind::Falling);
+            assert_eq!(event.line_offset(), GPIO);
+
+            // No events available
+            assert!(!config
+                .request()
+                .wait_edge_event(Some(Duration::from_millis(100)))
+                .unwrap());
+
+            assert!(ts_falling > ts_rising);
+        }
+
+        #[test]
+        fn rising_edge() {
+            const GPIO: Offset = 6;
+            let buf = edge::event::Buffer::new(0).unwrap();
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(None, Some(Edge::Rising));
+            config.lconfig_add_settings(&[GPIO]);
+            config.request_lines().unwrap();
+
+            // Generate events
+            trigger_falling_and_rising_edge(config.sim(), GPIO);
+
+            // Rising event
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 1);
+            assert_eq!(buf.len(), 1);
+
+            let event = buf.event(0).unwrap();
+            assert_eq!(event.event_type().unwrap(), EdgeKind::Rising);
+            assert_eq!(event.line_offset(), GPIO);
+
+            // No events available
+            assert!(!config
+                .request()
+                .wait_edge_event(Some(Duration::from_millis(100)))
+                .unwrap());
+        }
+
+        #[test]
+        fn falling_edge() {
+            const GPIO: Offset = 7;
+            let buf = edge::event::Buffer::new(0).unwrap();
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(None, Some(Edge::Falling));
+            config.lconfig_add_settings(&[GPIO]);
+            config.request_lines().unwrap();
+
+            // Generate events
+            trigger_falling_and_rising_edge(config.sim(), GPIO);
+
+            // Falling event
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 1);
+            assert_eq!(buf.len(), 1);
+
+            let event = buf.event(0).unwrap();
+            assert_eq!(event.event_type().unwrap(), EdgeKind::Falling);
+            assert_eq!(event.line_offset(), GPIO);
+
+            // No events available
+            assert!(!config
+                .request()
+                .wait_edge_event(Some(Duration::from_millis(100)))
+                .unwrap());
+        }
+
+        #[test]
+        fn edge_sequence() {
+            const GPIO: [u32; 2] = [0, 1];
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(None, Some(Edge::Both));
+            config.lconfig_add_settings(&GPIO);
+            config.request_lines().unwrap();
+
+            // Generate events
+            trigger_rising_edge_events_on_two_offsets(config.sim(), GPIO);
+
+            // Rising event GPIO 0
+            let buf = edge::event::Buffer::new(0).unwrap();
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 1);
+            assert_eq!(buf.len(), 1);
+
+            let event = buf.event(0).unwrap();
+            assert_eq!(event.event_type().unwrap(), EdgeKind::Rising);
+            assert_eq!(event.line_offset(), GPIO[0]);
+            assert_eq!(event.global_seqno(), 1);
+            assert_eq!(event.line_seqno(), 1);
+
+            // Rising event GPIO 1
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 1);
+            assert_eq!(buf.len(), 1);
+
+            let event = buf.event(0).unwrap();
+            assert_eq!(event.event_type().unwrap(), EdgeKind::Rising);
+            assert_eq!(event.line_offset(), GPIO[1]);
+            assert_eq!(event.global_seqno(), 2);
+            assert_eq!(event.line_seqno(), 1);
+
+            // No events available
+            assert!(!config
+                .request()
+                .wait_edge_event(Some(Duration::from_millis(100)))
+                .unwrap());
+        }
+
+        #[test]
+        fn multiple_events() {
+            const GPIO: Offset = 1;
+            let buf = edge::event::Buffer::new(0).unwrap();
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(None, Some(Edge::Both));
+            config.lconfig_add_settings(&[GPIO]);
+            config.request_lines().unwrap();
+
+            // Generate events
+            trigger_multiple_events(config.sim(), GPIO);
+
+            // Read multiple events
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 3);
+            assert_eq!(buf.len(), 3);
+
+            let mut global_seqno = 1;
+            let mut line_seqno = 1;
+
+            // Verify sequence number of events
+            for i in 0..3 {
+                let event = buf.event(i).unwrap();
+                assert_eq!(event.line_offset(), GPIO);
+                assert_eq!(event.global_seqno(), global_seqno);
+                assert_eq!(event.line_seqno(), line_seqno);
+
+                global_seqno += 1;
+                line_seqno += 1;
+            }
+        }
+
+        #[test]
+        fn over_capacity() {
+            const GPIO: Offset = 2;
+            let buf = edge::event::Buffer::new(2).unwrap();
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(None, Some(Edge::Both));
+            config.lconfig_add_settings(&[GPIO]);
+            config.request_lines().unwrap();
+
+            // Generate events
+            trigger_multiple_events(config.sim(), GPIO);
+
+            // Read multiple events
+            assert!(config
+                .request()
+                .wait_edge_event(Some(Duration::from_secs(1)))
+                .unwrap());
+
+            assert_eq!(config.request().read_edge_events(&buf).unwrap(), 2);
+            assert_eq!(buf.len(), 2);
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/info_event.rs b/bindings/rust/libgpiod/tests/info_event.rs
new file mode 100644
index 000000000000..8c342992d74e
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/info_event.rs
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+mod common;
+
+mod info_event {
+    use libc::EINVAL;
+    use std::sync::Arc;
+    use std::thread::{sleep, spawn};
+    use std::time::Duration;
+
+    use vmm_sys_util::errno::Error as Errno;
+
+    use gpiosim::Sim;
+    use libgpiod::{
+        chip::Chip, line, request, Direction, Error as ChipError, InfoChangeKind, Offset,
+        OperationType, SettingVal,
+    };
+
+    fn request_reconfigure_line(chip: Arc<Chip>) {
+        spawn(move || {
+            sleep(Duration::from_millis(10));
+
+            let lconfig1 = line::Config::new().unwrap();
+            let lsettings = line::Settings::new().unwrap();
+            lconfig1.add_line_settings(&[7], lsettings).unwrap();
+            let rconfig = request::Config::new().unwrap();
+
+            let request = chip.request_lines(&rconfig, &lconfig1).unwrap();
+
+            sleep(Duration::from_millis(10));
+
+            let lconfig2 = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[SettingVal::Direction(Direction::Output)])
+                .unwrap();
+            lconfig2.add_line_settings(&[7], lsettings).unwrap();
+
+            request.reconfigure_lines(&lconfig2).unwrap();
+
+            sleep(Duration::from_millis(10));
+        });
+    }
+
+    mod watch {
+        use super::*;
+        const NGPIO: u64 = 8;
+        const GPIO: Offset = 7;
+
+        #[test]
+        fn line_info() {
+            let sim = Sim::new(Some(NGPIO), None, true).unwrap();
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+
+            assert_eq!(
+                chip.watch_line_info(NGPIO as u32).unwrap_err(),
+                ChipError::OperationFailed(OperationType::ChipWatchLineInfo, Errno::new(EINVAL))
+            );
+
+            let info = chip.watch_line_info(GPIO).unwrap();
+            assert_eq!(info.offset(), GPIO);
+
+            // No events available
+            assert!(!chip
+                .wait_info_event(Some(Duration::from_millis(100)))
+                .unwrap());
+        }
+
+        #[test]
+        fn reconfigure() {
+            let sim = Sim::new(Some(NGPIO), None, true).unwrap();
+            let chip = Arc::new(Chip::open(&sim.dev_path()).unwrap());
+            let info = chip.watch_line_info(GPIO).unwrap();
+
+            assert_eq!(info.direction().unwrap(), Direction::Input);
+
+            // Generate events
+            request_reconfigure_line(chip.clone());
+
+            // Line requested event
+            assert!(chip.wait_info_event(Some(Duration::from_secs(1))).unwrap());
+            let event = chip.read_info_event().unwrap();
+            let ts_req = event.timestamp();
+
+            assert_eq!(event.event_type().unwrap(), InfoChangeKind::LineRequested);
+            assert_eq!(
+                event.line_info().unwrap().direction().unwrap(),
+                Direction::Input
+            );
+
+            // Line changed event
+            assert!(chip.wait_info_event(Some(Duration::from_secs(1))).unwrap());
+            let event = chip.read_info_event().unwrap();
+            let ts_rec = event.timestamp();
+
+            assert_eq!(
+                event.event_type().unwrap(),
+                InfoChangeKind::LineConfigChanged
+            );
+            assert_eq!(
+                event.line_info().unwrap().direction().unwrap(),
+                Direction::Output
+            );
+
+            // Line released event
+            assert!(chip.wait_info_event(Some(Duration::from_secs(1))).unwrap());
+            let event = chip.read_info_event().unwrap();
+            let ts_rel = event.timestamp();
+
+            assert_eq!(event.event_type().unwrap(), InfoChangeKind::LineReleased);
+
+            // No events available
+            assert!(!chip
+                .wait_info_event(Some(Duration::from_millis(100)))
+                .unwrap());
+
+            // Check timestamps are really monotonic.
+            assert!(ts_rel > ts_rec);
+            assert!(ts_rec > ts_req);
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/line_config.rs b/bindings/rust/libgpiod/tests/line_config.rs
new file mode 100644
index 000000000000..e65cd1d23f9b
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/line_config.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@linaro.org>
+
+mod common;
+
+mod line_config {
+    use libgpiod::{
+        line, Bias, Direction, Drive, Edge, EventClock, SettingKind, SettingVal, Value,
+    };
+
+    #[test]
+    fn settings() {
+        let mut lsettings1 = line::Settings::new().unwrap();
+        lsettings1
+            .set_prop(&[SettingVal::Direction(Direction::Input)])
+            .unwrap();
+        lsettings1
+            .set_prop(&[SettingVal::EdgeDetection(Some(Edge::Both))])
+            .unwrap();
+        lsettings1
+            .set_prop(&[SettingVal::Bias(Some(Bias::PullDown))])
+            .unwrap();
+        lsettings1
+            .set_prop(&[SettingVal::Drive(Drive::PushPull)])
+            .unwrap();
+
+        let mut lsettings2 = line::Settings::new().unwrap();
+        lsettings2
+            .set_prop(&[SettingVal::Direction(Direction::Output)])
+            .unwrap();
+        lsettings2.set_prop(&[SettingVal::ActiveLow(true)]).unwrap();
+        lsettings2
+            .set_prop(&[SettingVal::EventClock(EventClock::Realtime)])
+            .unwrap();
+        lsettings2
+            .set_prop(&[SettingVal::OutputValue(Value::Active)])
+            .unwrap();
+
+        // Add settings for multiple lines
+        let lconfig = line::Config::new().unwrap();
+        lconfig.add_line_settings(&[0, 1, 2], lsettings1).unwrap();
+        lconfig.add_line_settings(&[4, 5], lsettings2).unwrap();
+
+        // Retrieve settings
+        let lsettings = lconfig.line_settings(1).unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Direction).unwrap(),
+            SettingVal::Direction(Direction::Input)
+        );
+        assert_eq!(
+            lsettings.prop(SettingKind::EdgeDetection).unwrap(),
+            SettingVal::EdgeDetection(Some(Edge::Both))
+        );
+        assert_eq!(
+            lsettings.prop(SettingKind::Bias).unwrap(),
+            SettingVal::Bias(Some(Bias::PullDown))
+        );
+        assert_eq!(
+            lsettings.prop(SettingKind::Drive).unwrap(),
+            SettingVal::Drive(Drive::PushPull)
+        );
+
+        let lsettings = lconfig.line_settings(5).unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Direction).unwrap(),
+            SettingVal::Direction(Direction::Output)
+        );
+        assert_eq!(
+            lsettings.prop(SettingKind::ActiveLow).unwrap(),
+            SettingVal::ActiveLow(true)
+        );
+        assert_eq!(
+            lsettings.prop(SettingKind::EventClock).unwrap(),
+            SettingVal::EventClock(EventClock::Realtime)
+        );
+        assert_eq!(
+            lsettings.prop(SettingKind::OutputValue).unwrap(),
+            SettingVal::OutputValue(Value::Active)
+        );
+    }
+
+    #[test]
+    fn offsets() {
+        let mut lsettings1 = line::Settings::new().unwrap();
+        lsettings1
+            .set_prop(&[SettingVal::Direction(Direction::Input)])
+            .unwrap();
+
+        let mut lsettings2 = line::Settings::new().unwrap();
+        lsettings2
+            .set_prop(&[SettingVal::EventClock(EventClock::Realtime)])
+            .unwrap();
+
+        // Add settings for multiple lines
+        let lconfig = line::Config::new().unwrap();
+        lconfig.add_line_settings(&[0, 1, 2], lsettings1).unwrap();
+        lconfig.add_line_settings(&[4, 5], lsettings2).unwrap();
+
+        // Verify offsets
+        let offsets = lconfig.offsets().unwrap();
+        assert_eq!(offsets, [0, 1, 2, 4, 5]);
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/line_info.rs b/bindings/rust/libgpiod/tests/line_info.rs
new file mode 100644
index 000000000000..22edeb4da263
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/line_info.rs
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+mod common;
+
+mod line_info {
+    use libc::EINVAL;
+    use std::time::Duration;
+
+    use vmm_sys_util::errno::Error as Errno;
+
+    use crate::common::*;
+    use gpiosim::Sim;
+    use gpiosim::{GPIOSIM_HOG_DIR_INPUT, GPIOSIM_HOG_DIR_OUTPUT_HIGH, GPIOSIM_HOG_DIR_OUTPUT_LOW};
+    use libgpiod::{
+        chip::Chip, Bias, Direction, Drive, Edge, Error as ChipError, EventClock, OperationType,
+    };
+
+    const NGPIO: u64 = 8;
+
+    mod properties {
+        use super::*;
+
+        #[test]
+        fn default() {
+            let sim = Sim::new(Some(NGPIO), None, false).unwrap();
+            sim.set_line_name(4, "four").unwrap();
+            sim.hog_line(4, "hog4", GPIOSIM_HOG_DIR_OUTPUT_LOW as i32)
+                .unwrap();
+            sim.enable().unwrap();
+
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+
+            let info4 = chip.line_info(4).unwrap();
+            assert_eq!(info4.offset(), 4);
+            assert_eq!(info4.name().unwrap(), "four");
+            assert!(info4.is_used());
+            assert_eq!(info4.consumer().unwrap(), "hog4");
+            assert_eq!(info4.direction().unwrap(), Direction::Output);
+            assert!(!info4.is_active_low());
+            assert_eq!(info4.bias().unwrap(), None);
+            assert_eq!(info4.drive().unwrap(), Drive::PushPull);
+            assert_eq!(info4.edge_detection().unwrap(), None);
+            assert_eq!(info4.event_clock().unwrap(), EventClock::Monotonic);
+            assert!(!info4.is_debounced());
+            assert_eq!(info4.debounce_period(), Duration::from_millis(0));
+
+            assert_eq!(
+                chip.line_info(NGPIO as u32).unwrap_err(),
+                ChipError::OperationFailed(OperationType::ChipGetLineInfo, Errno::new(EINVAL))
+            );
+        }
+
+        #[test]
+        fn name_and_offset() {
+            let sim = Sim::new(Some(NGPIO), None, false).unwrap();
+
+            // Line 0 has no name
+            for i in 1..NGPIO {
+                sim.set_line_name(i as u32, &i.to_string()).unwrap();
+            }
+            sim.enable().unwrap();
+
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+            let info = chip.line_info(0).unwrap();
+
+            assert_eq!(info.offset(), 0);
+            assert_eq!(
+                info.name().unwrap_err(),
+                ChipError::NullString("GPIO line's name")
+            );
+
+            for i in 1..NGPIO {
+                let info = chip.line_info(i as u32).unwrap();
+
+                assert_eq!(info.offset(), i as u32);
+                assert_eq!(info.name().unwrap(), &i.to_string());
+            }
+        }
+
+        #[test]
+        fn is_used() {
+            let sim = Sim::new(Some(NGPIO), None, false).unwrap();
+            sim.hog_line(0, "hog", GPIOSIM_HOG_DIR_OUTPUT_HIGH as i32)
+                .unwrap();
+            sim.enable().unwrap();
+
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+
+            let info = chip.line_info(0).unwrap();
+            assert!(info.is_used());
+
+            let info = chip.line_info(1).unwrap();
+            assert!(!info.is_used());
+        }
+
+        #[test]
+        fn consumer() {
+            let sim = Sim::new(Some(NGPIO), None, false).unwrap();
+            sim.hog_line(0, "hog", GPIOSIM_HOG_DIR_OUTPUT_HIGH as i32)
+                .unwrap();
+            sim.enable().unwrap();
+
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+
+            let info = chip.line_info(0).unwrap();
+            assert_eq!(info.consumer().unwrap(), "hog");
+
+            let info = chip.line_info(1).unwrap();
+            assert_eq!(
+                info.consumer().unwrap_err(),
+                ChipError::NullString("GPIO line's consumer name")
+            );
+        }
+
+        #[test]
+        fn direction() {
+            let sim = Sim::new(Some(NGPIO), None, false).unwrap();
+            sim.hog_line(0, "hog", GPIOSIM_HOG_DIR_INPUT as i32)
+                .unwrap();
+            sim.hog_line(1, "hog", GPIOSIM_HOG_DIR_OUTPUT_HIGH as i32)
+                .unwrap();
+            sim.hog_line(2, "hog", GPIOSIM_HOG_DIR_OUTPUT_LOW as i32)
+                .unwrap();
+            sim.enable().unwrap();
+
+            let chip = Chip::open(&sim.dev_path()).unwrap();
+
+            let info = chip.line_info(0).unwrap();
+            assert_eq!(info.direction().unwrap(), Direction::Input);
+
+            let info = chip.line_info(1).unwrap();
+            assert_eq!(info.direction().unwrap(), Direction::Output);
+
+            let info = chip.line_info(2).unwrap();
+            assert_eq!(info.direction().unwrap(), Direction::Output);
+        }
+
+        #[test]
+        fn bias() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), None);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_bias(Direction::Input, Some(Bias::PullUp));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), Some(Bias::PullUp));
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_bias(Direction::Input, Some(Bias::PullDown));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), Some(Bias::PullDown));
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_bias(Direction::Input, Some(Bias::Disabled));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), Some(Bias::Disabled));
+        }
+
+        #[test]
+        fn drive() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::PushPull);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_drive(Direction::Input, Drive::PushPull);
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::PushPull);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_drive(Direction::Output, Drive::OpenDrain);
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::OpenDrain);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_drive(Direction::Output, Drive::OpenSource);
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::OpenSource);
+        }
+
+        #[test]
+        fn edge() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), None);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(Some(Direction::Input), Some(Edge::Both));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), Some(Edge::Both));
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(Some(Direction::Input), Some(Edge::Rising));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), Some(Edge::Rising));
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(Some(Direction::Input), Some(Edge::Falling));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), Some(Edge::Falling));
+        }
+
+        #[test]
+        fn clock() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::Monotonic);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_clock(EventClock::Monotonic);
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::Monotonic);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_clock(EventClock::Realtime);
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::Realtime);
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_clock(EventClock::HTE);
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::HTE);
+        }
+
+        #[test]
+        fn debounce() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert!(!info.is_debounced());
+            assert_eq!(info.debounce_period(), Duration::from_millis(0));
+
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_debounce(Duration::from_millis(100));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert!(info.is_debounced());
+            assert_eq!(info.debounce_period(), Duration::from_millis(100));
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/line_request.rs b/bindings/rust/libgpiod/tests/line_request.rs
new file mode 100644
index 000000000000..e933fe7cb74a
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/line_request.rs
@@ -0,0 +1,519 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+mod common;
+
+mod line_request {
+    use libc::{E2BIG, EINVAL};
+    use std::time::Duration;
+
+    use vmm_sys_util::errno::Error as Errno;
+
+    use crate::common::*;
+    use gpiosim::{
+        GPIOSIM_PULL_DOWN, GPIOSIM_PULL_UP, GPIOSIM_VALUE_ACTIVE, GPIOSIM_VALUE_INACTIVE,
+    };
+    use libgpiod::{
+        line, Bias, Direction, Drive, Edge, Error as ChipError, EventClock, Offset, OperationType,
+        SettingVal, Value, ValueMap,
+    };
+
+    const NGPIO: u64 = 8;
+
+    mod invalid_arguments {
+        use super::*;
+
+        #[test]
+        fn no_offsets() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+
+            assert_eq!(
+                config.request_lines().unwrap_err(),
+                ChipError::OperationFailed(OperationType::LineRequest, Errno::new(EINVAL))
+            );
+        }
+
+        #[test]
+        fn out_of_bound_offsets() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[2, 0, 8, 4]);
+
+            assert_eq!(
+                config.request_lines().unwrap_err(),
+                ChipError::OperationFailed(OperationType::LineRequest, Errno::new(EINVAL))
+            );
+        }
+
+        #[test]
+        fn dir_out_edge_failure() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(Some(Direction::Output), Some(Edge::Both));
+            config.lconfig_add_settings(&[0]);
+
+            assert_eq!(
+                config.request_lines().unwrap_err(),
+                ChipError::OperationFailed(OperationType::LineRequest, Errno::new(EINVAL))
+            );
+        }
+    }
+
+    mod verify {
+        use super::*;
+
+        #[test]
+        fn custom_consumer() {
+            const GPIO: Offset = 2;
+            const CONSUMER: &str = "foobar";
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.rconfig_set_consumer(CONSUMER);
+            config.lconfig_add_settings(&[GPIO]);
+            config.request_lines().unwrap();
+
+            let info = config.chip().line_info(GPIO).unwrap();
+
+            assert!(info.is_used());
+            assert_eq!(info.consumer().unwrap(), CONSUMER);
+        }
+
+        #[test]
+        fn empty_consumer() {
+            const GPIO: Offset = 2;
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[GPIO]);
+            config.request_lines().unwrap();
+
+            let info = config.chip().line_info(GPIO).unwrap();
+
+            assert!(info.is_used());
+            assert_eq!(info.consumer().unwrap(), "?");
+        }
+
+        #[test]
+        fn read_values() {
+            let offsets = [7, 1, 0, 6, 2];
+            let pulls = [
+                GPIOSIM_PULL_UP,
+                GPIOSIM_PULL_UP,
+                GPIOSIM_PULL_DOWN,
+                GPIOSIM_PULL_UP,
+                GPIOSIM_PULL_DOWN,
+            ];
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.set_pull(&offsets, &pulls);
+            config.lconfig_val(Some(Direction::Input), None);
+            config.lconfig_add_settings(&offsets);
+            config.request_lines().unwrap();
+
+            let request = config.request();
+
+            // Single values read properly
+            assert_eq!(request.value(7).unwrap(), Value::Active);
+
+            // Values read properly
+            let map = request.values().unwrap();
+            for i in 0..offsets.len() {
+                assert_eq!(
+                    *map.get(offsets[i].into()).unwrap(),
+                    match pulls[i] {
+                        GPIOSIM_PULL_DOWN => Value::InActive,
+                        _ => Value::Active,
+                    }
+                );
+            }
+
+            // Subset of values read properly
+            let map = request.values_subset(&[2, 0, 6]).unwrap();
+            assert_eq!(*map.get(2).unwrap(), Value::InActive);
+            assert_eq!(*map.get(0).unwrap(), Value::InActive);
+            assert_eq!(*map.get(6).unwrap(), Value::Active);
+
+            // Value read properly after reconfigure
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings.set_prop(&[SettingVal::ActiveLow(true)]).unwrap();
+            let lconfig = line::Config::new().unwrap();
+            lconfig.add_line_settings(&offsets, lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            assert_eq!(request.value(7).unwrap(), Value::InActive);
+        }
+
+        #[test]
+        fn set_output_values() {
+            let offsets = [0, 1, 3, 4];
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_val(Some(Direction::Output), Some(Value::Active));
+            config.lconfig_add_settings(&offsets);
+            config.request_lines().unwrap();
+
+            assert_eq!(config.sim().val(0).unwrap(), GPIOSIM_VALUE_ACTIVE);
+            assert_eq!(config.sim().val(1).unwrap(), GPIOSIM_VALUE_ACTIVE);
+            assert_eq!(config.sim().val(3).unwrap(), GPIOSIM_VALUE_ACTIVE);
+            assert_eq!(config.sim().val(4).unwrap(), GPIOSIM_VALUE_ACTIVE);
+
+            // Default
+            assert_eq!(config.sim().val(2).unwrap(), GPIOSIM_VALUE_INACTIVE);
+        }
+
+        #[test]
+        fn update_output_values() {
+            let offsets = [0, 1, 3, 4];
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_val(Some(Direction::Output), Some(Value::InActive));
+            config.lconfig_add_settings(&offsets);
+            config.request_lines().unwrap();
+            let request = config.request();
+
+            // Set single value
+            request.set_value(1, Value::Active).unwrap();
+            assert_eq!(config.sim().val(0).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(1).unwrap(), GPIOSIM_VALUE_ACTIVE);
+            assert_eq!(config.sim().val(3).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(4).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            request.set_value(1, Value::InActive).unwrap();
+            assert_eq!(config.sim().val(1).unwrap(), GPIOSIM_VALUE_INACTIVE);
+
+            // Set values of subset
+            let mut map = ValueMap::new();
+            map.insert(4, Value::Active);
+            map.insert(3, Value::Active);
+            request.set_values_subset(map).unwrap();
+            assert_eq!(config.sim().val(0).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(1).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(3).unwrap(), GPIOSIM_VALUE_ACTIVE);
+            assert_eq!(config.sim().val(4).unwrap(), GPIOSIM_VALUE_ACTIVE);
+
+            let mut map = ValueMap::new();
+            map.insert(4, Value::InActive);
+            map.insert(3, Value::InActive);
+            request.set_values_subset(map).unwrap();
+            assert_eq!(config.sim().val(3).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(4).unwrap(), GPIOSIM_VALUE_INACTIVE);
+
+            // Set all values
+            request
+                .set_values(&[
+                    Value::Active,
+                    Value::InActive,
+                    Value::Active,
+                    Value::InActive,
+                ])
+                .unwrap();
+            assert_eq!(config.sim().val(0).unwrap(), GPIOSIM_VALUE_ACTIVE);
+            assert_eq!(config.sim().val(1).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(3).unwrap(), GPIOSIM_VALUE_ACTIVE);
+            assert_eq!(config.sim().val(4).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            request
+                .set_values(&[
+                    Value::InActive,
+                    Value::InActive,
+                    Value::InActive,
+                    Value::InActive,
+                ])
+                .unwrap();
+            assert_eq!(config.sim().val(0).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(1).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(3).unwrap(), GPIOSIM_VALUE_INACTIVE);
+            assert_eq!(config.sim().val(4).unwrap(), GPIOSIM_VALUE_INACTIVE);
+        }
+
+        #[test]
+        fn set_bias() {
+            let offsets = [3];
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_bias(Direction::Input, Some(Bias::PullUp));
+            config.lconfig_add_settings(&offsets);
+            config.request_lines().unwrap();
+            config.request();
+
+            // Set single value
+            assert_eq!(config.sim().val(3).unwrap(), GPIOSIM_VALUE_ACTIVE);
+        }
+
+        #[test]
+        fn no_events() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_edge(None, Some(Edge::Both));
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+
+            // No events available
+            assert!(!config
+                .request()
+                .wait_edge_event(Some(Duration::from_millis(100)))
+                .unwrap());
+        }
+    }
+
+    mod reconfigure {
+        use super::*;
+
+        #[test]
+        fn e2big() {
+            let offsets = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+            let mut config = TestConfig::new(16).unwrap();
+            config.lconfig_add_settings(&offsets);
+            config.request_lines().unwrap();
+
+            let request = config.request();
+
+            // Reconfigure
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[SettingVal::Direction(Direction::Input)])
+                .unwrap();
+            let lconfig = line::Config::new().unwrap();
+
+            // The uAPI config has only 10 attribute slots, this should pass.
+            for offset in offsets {
+                lsettings
+                    .set_prop(&[SettingVal::DebouncePeriod(Duration::from_millis(
+                        (100 + offset).into(),
+                    ))])
+                    .unwrap();
+                lconfig
+                    .add_line_settings(&[offset as Offset], lsettings.settings_clone().unwrap())
+                    .unwrap();
+            }
+
+            assert!(request.reconfigure_lines(&lconfig).is_ok());
+
+            // The uAPI config has only 10 attribute slots, and this is the 11th entry.
+            // This should fail with E2BIG.
+            lsettings
+                .set_prop(&[SettingVal::DebouncePeriod(Duration::from_millis(100 + 11))])
+                .unwrap();
+            lconfig.add_line_settings(&[11], lsettings).unwrap();
+
+            assert_eq!(
+                request.reconfigure_lines(&lconfig).unwrap_err(),
+                ChipError::OperationFailed(
+                    OperationType::LineRequestReconfigLines,
+                    Errno::new(E2BIG),
+                )
+            );
+        }
+
+        #[test]
+        fn bias() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), None);
+
+            let request = config.request();
+
+            // Reconfigure
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::Bias(Some(Bias::PullUp)),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), Some(Bias::PullUp));
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::Bias(Some(Bias::PullDown)),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), Some(Bias::PullDown));
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::Bias(Some(Bias::Disabled)),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.bias().unwrap(), Some(Bias::Disabled));
+        }
+
+        #[test]
+        fn drive() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::PushPull);
+
+            let request = config.request();
+
+            // Reconfigure
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::Drive(Drive::PushPull),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::PushPull);
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Output),
+                    SettingVal::Drive(Drive::OpenDrain),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::OpenDrain);
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Output),
+                    SettingVal::Drive(Drive::OpenSource),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.drive().unwrap(), Drive::OpenSource);
+        }
+
+        #[test]
+        fn edge() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), None);
+
+            let request = config.request();
+
+            // Reconfigure
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::EdgeDetection(Some(Edge::Both)),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), Some(Edge::Both));
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::EdgeDetection(Some(Edge::Rising)),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), Some(Edge::Rising));
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::EdgeDetection(Some(Edge::Falling)),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.edge_detection().unwrap(), Some(Edge::Falling));
+        }
+
+        #[test]
+        fn event_clock() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::Monotonic);
+
+            let request = config.request();
+
+            // Reconfigure
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[SettingVal::EventClock(EventClock::Monotonic)])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::Monotonic);
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[SettingVal::EventClock(EventClock::Realtime)])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::Realtime);
+
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[SettingVal::EventClock(EventClock::HTE)])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert_eq!(info.event_clock().unwrap(), EventClock::HTE);
+        }
+
+        #[test]
+        fn debounce() {
+            let mut config = TestConfig::new(NGPIO).unwrap();
+            config.lconfig_add_settings(&[0]);
+            config.request_lines().unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert!(!info.is_debounced());
+            assert_eq!(info.debounce_period(), Duration::from_millis(0));
+
+            let request = config.request();
+
+            // Reconfigure
+            let lconfig = line::Config::new().unwrap();
+            let mut lsettings = line::Settings::new().unwrap();
+            lsettings
+                .set_prop(&[
+                    SettingVal::Direction(Direction::Input),
+                    SettingVal::DebouncePeriod(Duration::from_millis(100)),
+                ])
+                .unwrap();
+            lconfig.add_line_settings(&[0], lsettings).unwrap();
+            request.reconfigure_lines(&lconfig).unwrap();
+            let info = config.chip().line_info(0).unwrap();
+            assert!(info.is_debounced());
+            assert_eq!(info.debounce_period(), Duration::from_millis(100));
+        }
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/line_settings.rs b/bindings/rust/libgpiod/tests/line_settings.rs
new file mode 100644
index 000000000000..3f84bf328ab7
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/line_settings.rs
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+mod common;
+
+mod line_settings {
+    use std::time::Duration;
+
+    use libgpiod::{
+        line, Bias, Direction, Drive, Edge, EventClock, SettingKind, SettingVal, Value,
+    };
+
+    #[test]
+    fn direction() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Direction).unwrap(),
+            SettingVal::Direction(Direction::AsIs)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::Direction(Direction::Input)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Direction).unwrap(),
+            SettingVal::Direction(Direction::Input)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::Direction(Direction::Output)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Direction).unwrap(),
+            SettingVal::Direction(Direction::Output)
+        );
+    }
+
+    #[test]
+    fn edge_detection() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EdgeDetection).unwrap(),
+            SettingVal::EdgeDetection(None)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::EdgeDetection(Some(Edge::Both))])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EdgeDetection).unwrap(),
+            SettingVal::EdgeDetection(Some(Edge::Both))
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::EdgeDetection(Some(Edge::Rising))])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EdgeDetection).unwrap(),
+            SettingVal::EdgeDetection(Some(Edge::Rising))
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::EdgeDetection(Some(Edge::Falling))])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EdgeDetection).unwrap(),
+            SettingVal::EdgeDetection(Some(Edge::Falling))
+        );
+    }
+
+    #[test]
+    fn bias() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Bias).unwrap(),
+            SettingVal::Bias(None)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::Bias(Some(Bias::PullDown))])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Bias).unwrap(),
+            SettingVal::Bias(Some(Bias::PullDown))
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::Bias(Some(Bias::PullUp))])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Bias).unwrap(),
+            SettingVal::Bias(Some(Bias::PullUp))
+        );
+    }
+
+    #[test]
+    fn drive() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Drive).unwrap(),
+            SettingVal::Drive(Drive::PushPull)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::Drive(Drive::PushPull)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Drive).unwrap(),
+            SettingVal::Drive(Drive::PushPull)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::Drive(Drive::OpenDrain)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Drive).unwrap(),
+            SettingVal::Drive(Drive::OpenDrain)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::Drive(Drive::OpenSource)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::Drive).unwrap(),
+            SettingVal::Drive(Drive::OpenSource)
+        );
+    }
+
+    #[test]
+    fn active_low() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::ActiveLow).unwrap(),
+            SettingVal::ActiveLow(false)
+        );
+
+        lsettings.set_prop(&[SettingVal::ActiveLow(true)]).unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::ActiveLow).unwrap(),
+            SettingVal::ActiveLow(true)
+        );
+
+        lsettings.set_prop(&[SettingVal::ActiveLow(false)]).unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::ActiveLow).unwrap(),
+            SettingVal::ActiveLow(false)
+        );
+    }
+
+    #[test]
+    fn debounce_period() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::DebouncePeriod).unwrap(),
+            SettingVal::DebouncePeriod(Duration::from_millis(0))
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::DebouncePeriod(Duration::from_millis(5))])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::DebouncePeriod).unwrap(),
+            SettingVal::DebouncePeriod(Duration::from_millis(5))
+        );
+    }
+
+    #[test]
+    fn event_clock() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EventClock).unwrap(),
+            SettingVal::EventClock(EventClock::Monotonic)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::EventClock(EventClock::Realtime)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EventClock).unwrap(),
+            SettingVal::EventClock(EventClock::Realtime)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::EventClock(EventClock::HTE)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EventClock).unwrap(),
+            SettingVal::EventClock(EventClock::HTE)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::EventClock(EventClock::Monotonic)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::EventClock).unwrap(),
+            SettingVal::EventClock(EventClock::Monotonic)
+        );
+    }
+
+    #[test]
+    fn output_value() {
+        let mut lsettings = line::Settings::new().unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::OutputValue).unwrap(),
+            SettingVal::OutputValue(Value::InActive)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::OutputValue(Value::Active)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::OutputValue).unwrap(),
+            SettingVal::OutputValue(Value::Active)
+        );
+
+        lsettings
+            .set_prop(&[SettingVal::OutputValue(Value::InActive)])
+            .unwrap();
+        assert_eq!(
+            lsettings.prop(SettingKind::OutputValue).unwrap(),
+            SettingVal::OutputValue(Value::InActive)
+        );
+    }
+}
diff --git a/bindings/rust/libgpiod/tests/request_config.rs b/bindings/rust/libgpiod/tests/request_config.rs
new file mode 100644
index 000000000000..d9892ee99101
--- /dev/null
+++ b/bindings/rust/libgpiod/tests/request_config.rs
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+//
+// Copyright 2022 Linaro Ltd. All Rights Reserved.
+//     Viresh Kumar <viresh.kumar@linaro.org>
+
+mod common;
+
+mod request_config {
+    use vmm_sys_util::errno::Error as Errno;
+
+    use libgpiod::{request, Error as ChipError, OperationType};
+
+    mod verify {
+        use super::*;
+
+        #[test]
+        fn default() {
+            let rconfig = request::Config::new().unwrap();
+
+            assert_eq!(rconfig.event_buffer_size(), 0);
+            assert_eq!(
+                rconfig.consumer().unwrap_err(),
+                ChipError::OperationFailed(OperationType::RequestConfigGetConsumer, Errno::new(0))
+            );
+        }
+
+        #[test]
+        fn initialized() {
+            const CONSUMER: &str = "foobar";
+            let rconfig = request::Config::new().unwrap();
+            rconfig.set_consumer(CONSUMER);
+            rconfig.set_event_buffer_size(64);
+
+            assert_eq!(rconfig.event_buffer_size(), 64);
+            assert_eq!(rconfig.consumer().unwrap(), CONSUMER);
+        }
+    }
+}
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* [PATCH V6 8/8] libgpiod: Integrate building of rust bindings with make
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
                   ` (6 preceding siblings ...)
  2022-09-26 11:08 ` [PATCH V6 7/8] libgpiod: Add rust tests Viresh Kumar
@ 2022-09-26 11:08 ` Viresh Kumar
  2022-09-26 15:57 ` [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 11:08 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Viresh Kumar, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

Lets make build rust bindings as well.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 README                    |  8 +++++---
 TODO                      |  8 --------
 bindings/Makefile.am      |  6 ++++++
 bindings/rust/Makefile.am | 18 ++++++++++++++++++
 configure.ac              | 16 ++++++++++++++++
 5 files changed, 45 insertions(+), 11 deletions(-)
 create mode 100644 bindings/rust/Makefile.am

diff --git a/README b/README
index 814a0f161fd2..68b5d69f9b66 100644
--- a/README
+++ b/README
@@ -119,9 +119,9 @@ TOOLS
 BINDINGS
 --------
 
-High-level, object-oriented bindings for C++ and python3 are provided. They
-can be enabled by passing --enable-bindings-cxx and --enable-bindings-python
-arguments respectively to configure.
+High-level, object-oriented bindings for C++, python3 and Rust are provided.
+They can be enabled by passing --enable-bindings-cxx, --enable-bindings-python
+and --enable-bindings-rust arguments respectively to configure.
 
 C++ bindings require C++11 support and autoconf-archive collection if building
 from git.
@@ -132,6 +132,8 @@ the PYTHON_CPPFLAGS and PYTHON_LIBS variables in order to point the build
 system to the correct locations. During native builds, the configure script
 can auto-detect the location of the development files.
 
+Rust bindings require cargo support.
+
 TESTING
 -------
 
diff --git a/TODO b/TODO
index 8bb4d8f3ad56..cf4fd7b4a962 100644
--- a/TODO
+++ b/TODO
@@ -28,14 +28,6 @@ and is partially functional.
 
 ----------
 
-* implement rust bindings
-
-With Rust gaining popularity as a low-level system's language and the
-possibility of it making its way into the linux kernel, it's probably time to
-provide Rust bindings to libgpiod as part of the project.
-
-----------
-
 * implement a simple daemon for controlling GPIOs in C together with a client
   program
 
diff --git a/bindings/Makefile.am b/bindings/Makefile.am
index 8f8c762f254f..004ae23dbc58 100644
--- a/bindings/Makefile.am
+++ b/bindings/Makefile.am
@@ -14,3 +14,9 @@ if WITH_BINDINGS_PYTHON
 SUBDIRS += python
 
 endif
+
+if WITH_BINDINGS_RUST
+
+SUBDIRS += rust
+
+endif
diff --git a/bindings/rust/Makefile.am b/bindings/rust/Makefile.am
new file mode 100644
index 000000000000..79a52bc691ae
--- /dev/null
+++ b/bindings/rust/Makefile.am
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# SPDX-FileCopyrightText: 2022 Viresh Kumar <viresh.kumar@linaro.org>
+
+command = cargo build --release --lib
+
+if WITH_TESTS
+command += --tests
+endif
+
+if WITH_EXAMPLES
+command += --examples
+endif
+
+all:
+	$(command)
+
+clean:
+	cargo clean
diff --git a/configure.ac b/configure.ac
index 6ac1d8ed8a40..37cfdb3644f7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -212,6 +212,21 @@ then
 		[AC_SUBST(PYTHON_LIBS, [`$PYTHON-config --libs`])])
 fi
 
+AC_ARG_ENABLE([bindings-rust],
+	[AS_HELP_STRING([--enable-bindings-rust],[enable rust bindings [default=no]])],
+	[if test "x$enableval" = xyes; then with_bindings_rust=true; fi],
+	[with_bindings_rust=false])
+AM_CONDITIONAL([WITH_BINDINGS_RUST], [test "x$with_bindings_rust" = xtrue])
+
+if test "x$with_bindings_rust" = xtrue
+then
+	AC_CHECK_PROG([has_cargo], [cargo], [true], [false])
+	if test "x$has_cargo" = xfalse
+	then
+		AC_MSG_ERROR([cargo not found - needed for rust bindings])
+	fi
+fi
+
 AC_CHECK_PROG([has_doxygen], [doxygen], [true], [false])
 AM_CONDITIONAL([HAS_DOXYGEN], [test "x$has_doxygen" = xtrue])
 if test "x$has_doxygen" = xfalse
@@ -246,6 +261,7 @@ AC_CONFIG_FILES([Makefile
 		 bindings/python/Makefile
 		 bindings/python/examples/Makefile
 		 bindings/python/tests/Makefile
+		 bindings/rust/Makefile
 		 man/Makefile])
 
 AC_OUTPUT
-- 
2.31.1.272.g89b43f80a514


^ permalink raw reply related	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-26 11:08 ` [PATCH V6 3/8] libgpiod: Add rust wrapper crate Viresh Kumar
@ 2022-09-26 13:29   ` Bartosz Golaszewski
  2022-09-26 15:26     ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-09-26 13:29 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Wedson Almeida Filho, Alex Bennée,
	stratos-dev, Gerard Ryan

On Mon, Sep 26, 2022 at 1:08 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> 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@linaro.org>
> ---

Hey Viresh!

Thanks for being patient with me. :)

I obviously cannot give a comprehensive review of Rust code as you
know it much better than I do but there's one thing that bothers me at
first glance. Please see below.

[snip]

> diff --git a/bindings/rust/libgpiod/src/event_buffer.rs b/bindings/rust/libgpiod/src/event_buffer.rs
> new file mode 100644
> index 000000000000..e272e7aa9e9d
> --- /dev/null
> +++ b/bindings/rust/libgpiod/src/event_buffer.rs
> @@ -0,0 +1,90 @@
> +// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
> +//
> +// Copyright 2022 Linaro Ltd. All Rights Reserved.
> +//     Viresh Kumar <viresh.kumar@linaro.org>
> +
> +use std::os::raw::c_ulong;
> +use std::sync::Arc;
> +
> +use vmm_sys_util::errno::Error as Errno;
> +
> +use super::{edge, gpiod, Error, OperationType, Result};
> +
> +/// Line edge events buffer
> +#[derive(Clone, Debug, Eq, PartialEq)]
> +pub(crate) struct BufferInternal {
> +    buffer: *mut gpiod::gpiod_edge_event_buffer,
> +}
> +
> +impl BufferInternal {
> +    /// 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: usize) -> Result<Self> {
> +        let buffer = unsafe { gpiod::gpiod_edge_event_buffer_new(capacity as c_ulong) };
> +        if buffer.is_null() {
> +            return Err(Error::OperationFailed(
> +                OperationType::EdgeEventBufferNew,
> +                Errno::last(),
> +            ));
> +        }
> +
> +        Ok(Self { buffer })
> +    }
> +
> +    /// Private helper, Returns gpiod_edge_event_buffer
> +    pub(crate) fn buffer(&self) -> *mut gpiod::gpiod_edge_event_buffer {
> +        self.buffer
> +    }
> +}
> +
> +impl Drop for BufferInternal {
> +    /// Free the edge event buffer and release all associated resources.
> +    fn drop(&mut self) {
> +        unsafe { gpiod::gpiod_edge_event_buffer_free(self.buffer) };
> +    }
> +}
> +
> +/// Line edge events buffer
> +#[derive(Clone, Debug, Eq, PartialEq)]
> +pub struct Buffer {
> +    ibuffer: Arc<BufferInternal>,
> +}
> +
> +impl Buffer {
> +    /// 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: usize) -> Result<Self> {
> +        Ok(Self {
> +            ibuffer: Arc::new(BufferInternal::new(capacity)?),
> +        })
> +    }
> +
> +    /// Private helper, Returns gpiod_edge_event_buffer
> +    pub(crate) fn buffer(&self) -> *mut gpiod::gpiod_edge_event_buffer {
> +        self.ibuffer.buffer()
> +    }
> +
> +    /// Get the capacity of the event buffer.
> +    pub fn capacity(&self) -> usize {
> +        unsafe { gpiod::gpiod_edge_event_buffer_get_capacity(self.buffer()) as usize }
> +    }
> +
> +    /// Read an event stored in the buffer.
> +    pub fn event(&self, index: u64) -> Result<edge::Event> {
> +        edge::Event::new(&self.ibuffer, index)
> +    }

In Event's new() you call gpiod_edge_event_buffer_get_event() which
returns a pointer to an event stored inside the buffer. There's also
the event_clone() function that calls gpiod_edge_event_copy() but I
don't see it called anywhere. Should users pay attention to the
lifetime of the buffer storing the event? Because IMO if the buffer
goes out of scope, the program will crash attempting to access the
event.

In C++ the events in the buffer can only be accessed as const
edge_event& so it's clear we're only holding a reference to an object
existing somewhere else. Internally, the object stored in the buffer
doesn't copy the edge event, only holds a C pointer to the event
structure in struct gpiod_edge_event_buffer. Only upon calling
edge_event& edge_event::operator=(const edge_event& other) will we
trigger a copy.

This way doing `for (const auto& event: buffer)` allows us to iterate
over events without doing any additional allocations.

Can we reproduce that behavior in Rust? For instance, the above
function could return a borrowed reference and then we could have some
interface to trigger the copy? Maybe do an implicit copy like in C++?
I don't know if that's possible though.

Bartosz

> +
> +    /// Get the number of events the buffer contains.
> +    pub fn len(&self) -> usize {
> +        unsafe { gpiod::gpiod_edge_event_buffer_get_num_events(self.buffer()) as usize }
> +    }
> +
> +    /// Check if buffer is empty.
> +    pub fn is_empty(&self) -> bool {
> +        self.len() == 0
> +    }
> +}

[snip]

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-26 13:29   ` Bartosz Golaszewski
@ 2022-09-26 15:26     ` Viresh Kumar
  2022-09-27 13:18       ` Bartosz Golaszewski
  0 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 15:26 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

Hi Bartosz,

On Mon, 26 Sept 2022 at 18:59, Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> Thanks for being patient with me. :)

I should thank you for being patient with me :)

> > +    /// Read an event stored in the buffer.
> > +    pub fn event(&self, index: u64) -> Result<edge::Event> {
> > +        edge::Event::new(&self.ibuffer, index)
> > +    }
>
> In Event's new() you call gpiod_edge_event_buffer_get_event() which
> returns a pointer to an event stored inside the buffer. There's also
> the event_clone() function that calls gpiod_edge_event_copy() but I
> don't see it called anywhere.

I thought that is required if the user is concerned that the buffer will
be overwritten by a new event, hence make a copy. Is that
understanding correct? I didn't use it here for that reason, but it can
be useful to the user expecting a lot of events.

> Should users pay attention to the
> lifetime of the buffer storing the event?

No.

> Because IMO if the buffer
> goes out of scope, the program will crash attempting to access the
> event.

This is where Rust's memory safety comes in. If you see the design of
the 'structure Event', it saves a reference to the 'struct BufferInternal'.
The drop() implementation of BufferInternal calls:
gpiod_edge_event_buffer_free(), but it won't get called unless all the
references to it have gone out of scope. So untill the time user is still
using any of the events, the buffer won't get freed. So we will never
have invalid reference issue here.

> In C++ the events in the buffer can only be accessed as const
> edge_event& so it's clear we're only holding a reference to an object
> existing somewhere else. Internally, the object stored in the buffer
> doesn't copy the edge event, only holds a C pointer to the event
> structure in struct gpiod_edge_event_buffer. Only upon calling
> edge_event& edge_event::operator=(const edge_event& other) will we
> trigger a copy.
>
> This way doing `for (const auto& event: buffer)` allows us to iterate
> over events without doing any additional allocations.
>
> Can we reproduce that behavior in Rust? For instance, the above
> function could return a borrowed reference and then we could have some
> interface to trigger the copy? Maybe do an implicit copy like in C++?
> I don't know if that's possible though.

So here in Rust, you clone() normally to make a copy, but the
standard clone() declaration can't have an error returned and so I had
to name it event_clone().

--
Viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 0/8] libgpiod: Add Rust bindings
  2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
                   ` (7 preceding siblings ...)
  2022-09-26 11:08 ` [PATCH V6 8/8] libgpiod: Integrate building of rust bindings with make Viresh Kumar
@ 2022-09-26 15:57 ` Viresh Kumar
  8 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-09-26 15:57 UTC (permalink / raw)
  To: Linus Walleij, Bartosz Golaszewski
  Cc: Vincent Guittot, linux-gpio, Kent Gibson, Miguel Ojeda,
	Wedson Almeida Filho, Alex Bennée, stratos-dev, Gerard Ryan

On 26-09-22, 16:38, Viresh Kumar wrote:
> Hello,
> 
> Here is another version of rust bindings for libgpiod v2.0, based of the
> next/libgpiod-2.0 + the HTE patch from Bartosz [1].
> 
> Pushed here:
> 
> https://github.com/vireshk/libgpiod master

Pushed current version as v6, master is used for something else currently.

-- 
viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-26 15:26     ` Viresh Kumar
@ 2022-09-27 13:18       ` Bartosz Golaszewski
  2022-09-27 13:57         ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-09-27 13:18 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Mon, Sep 26, 2022 at 5:27 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> Hi Bartosz,
>
> On Mon, 26 Sept 2022 at 18:59, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>
> > Thanks for being patient with me. :)
>
> I should thank you for being patient with me :)
>
> > > +    /// Read an event stored in the buffer.
> > > +    pub fn event(&self, index: u64) -> Result<edge::Event> {
> > > +        edge::Event::new(&self.ibuffer, index)
> > > +    }
> >
> > In Event's new() you call gpiod_edge_event_buffer_get_event() which
> > returns a pointer to an event stored inside the buffer. There's also
> > the event_clone() function that calls gpiod_edge_event_copy() but I
> > don't see it called anywhere.
>
> I thought that is required if the user is concerned that the buffer will
> be overwritten by a new event, hence make a copy. Is that
> understanding correct? I didn't use it here for that reason, but it can
> be useful to the user expecting a lot of events.
>

Yes, that's one of the use-cases. Copy an event from a buffer before
reading more into it.

> > Should users pay attention to the
> > lifetime of the buffer storing the event?
>
> No.
>
> > Because IMO if the buffer
> > goes out of scope, the program will crash attempting to access the
> > event.
>
> This is where Rust's memory safety comes in. If you see the design of
> the 'structure Event', it saves a reference to the 'struct BufferInternal'.
> The drop() implementation of BufferInternal calls:
> gpiod_edge_event_buffer_free(), but it won't get called unless all the
> references to it have gone out of scope. So untill the time user is still
> using any of the events, the buffer won't get freed. So we will never
> have invalid reference issue here.

You've got to help me out here, just looking at the code doesn't make
things clear for me.

Am I right to understand that each Event holds a reference to the
BufferInternal object and it will only be destroyed when the last
event is dropped? If we read new events into the buffer, does that
create a new BufferInternal? Is that efficient? Aren't we allocating
memory for each new BufferInternal at every read?

>
> > In C++ the events in the buffer can only be accessed as const
> > edge_event& so it's clear we're only holding a reference to an object
> > existing somewhere else. Internally, the object stored in the buffer
> > doesn't copy the edge event, only holds a C pointer to the event
> > structure in struct gpiod_edge_event_buffer. Only upon calling
> > edge_event& edge_event::operator=(const edge_event& other) will we
> > trigger a copy.
> >
> > This way doing `for (const auto& event: buffer)` allows us to iterate
> > over events without doing any additional allocations.
> >
> > Can we reproduce that behavior in Rust? For instance, the above
> > function could return a borrowed reference and then we could have some
> > interface to trigger the copy? Maybe do an implicit copy like in C++?
> > I don't know if that's possible though.
>
> So here in Rust, you clone() normally to make a copy, but the
> standard clone() declaration can't have an error returned and so I had
> to name it event_clone().
>

Bart

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-27 13:18       ` Bartosz Golaszewski
@ 2022-09-27 13:57         ` Viresh Kumar
  2022-09-27 15:25           ` Bartosz Golaszewski
  0 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-09-27 13:57 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Tue, 27 Sept 2022 at 18:48, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> On Mon, Sep 26, 2022 at 5:27 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:

> > This is where Rust's memory safety comes in. If you see the design of
> > the 'structure Event', it saves a reference to the 'struct BufferInternal'.
> > The drop() implementation of BufferInternal calls:
> > gpiod_edge_event_buffer_free(), but it won't get called unless all the
> > references to it have gone out of scope. So untill the time user is still
> > using any of the events, the buffer won't get freed. So we will never
> > have invalid reference issue here.
>
> You've got to help me out here, just looking at the code doesn't make
> things clear for me.

Just to clarify, Buffer is just a wrapper over BufferInternal, you can think
of them as the same entity for simplicity.

> Am I right to understand that each Event holds a reference to the
> BufferInternal object and it will only be destroyed when the last
> event is dropped?

Yes. But the buffer variable itself too holds a reference to the Buffer.
Even if all the events are dropped, the buffer won't get free unless the
buffer variable gets dropped too.

> If we read new events into the buffer, does that
> create a new BufferInternal?

No. It uses the existing buffer only, that we created using Buffer::new().

> Is that efficient? Aren't we allocating
> memory for each new BufferInternal at every read?

No, we reuse the same buffer for all the reads.

If you see the gpiomon.rs example, it shows how this is being done.
The buffer (and internal buffer too) is created only once in line 42:

let buffer = edge::event::Buffer::new(1)?;

This allocates the memory for buffer only once, after that we continue
reading from the same buffer.

The BufferInternal structure is enclosed within an Arc<> instance, which is
"Atomically Reference Counted", very much like kref_get/put in kernel.

Unless the last reference is dropped, it stays.

Hope I was able to clarify this here.

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-27 13:57         ` Viresh Kumar
@ 2022-09-27 15:25           ` Bartosz Golaszewski
  2022-09-28 11:10             ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-09-27 15:25 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Tue, Sep 27, 2022 at 3:57 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On Tue, 27 Sept 2022 at 18:48, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> > On Mon, Sep 26, 2022 at 5:27 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> > > This is where Rust's memory safety comes in. If you see the design of
> > > the 'structure Event', it saves a reference to the 'struct BufferInternal'.
> > > The drop() implementation of BufferInternal calls:
> > > gpiod_edge_event_buffer_free(), but it won't get called unless all the
> > > references to it have gone out of scope. So untill the time user is still
> > > using any of the events, the buffer won't get freed. So we will never
> > > have invalid reference issue here.
> >
> > You've got to help me out here, just looking at the code doesn't make
> > things clear for me.
>
> Just to clarify, Buffer is just a wrapper over BufferInternal, you can think
> of them as the same entity for simplicity.
>
> > Am I right to understand that each Event holds a reference to the
> > BufferInternal object and it will only be destroyed when the last
> > event is dropped?
>
> Yes. But the buffer variable itself too holds a reference to the Buffer.
> Even if all the events are dropped, the buffer won't get free unless the
> buffer variable gets dropped too.
>
> > If we read new events into the buffer, does that
> > create a new BufferInternal?
>
> No. It uses the existing buffer only, that we created using Buffer::new().
>

So what happens if I do this:

let buf = edge::event::Buffer::new(10)?;
let request = chip.request_lines(&rconfig, &lconfig)?;
let count = request.read_edge_events(&buffer)?;
let event = buffer.event(0);
let count = request.read_edge_events(&buffer)?;
println!("line: {}", event.line_offset());

?

> > Is that efficient? Aren't we allocating
> > memory for each new BufferInternal at every read?
>
> No, we reuse the same buffer for all the reads.
>
> If you see the gpiomon.rs example, it shows how this is being done.
> The buffer (and internal buffer too) is created only once in line 42:
>
> let buffer = edge::event::Buffer::new(1)?;
>
> This allocates the memory for buffer only once, after that we continue
> reading from the same buffer.
>
> The BufferInternal structure is enclosed within an Arc<> instance, which is
> "Atomically Reference Counted", very much like kref_get/put in kernel.
>
> Unless the last reference is dropped, it stays.
>
> Hope I was able to clarify this here.

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-27 15:25           ` Bartosz Golaszewski
@ 2022-09-28 11:10             ` Viresh Kumar
  2022-09-28 12:20               ` Bartosz Golaszewski
  0 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-09-28 11:10 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

Here is what happens at each call for easier understanding:

On 27-09-22, 17:25, Bartosz Golaszewski wrote:
> So what happens if I do this:
> 
> let buf = edge::event::Buffer::new(10)?;

buf1 = gpiod_edge_event_buffer_new()

> let request = chip.request_lines(&rconfig, &lconfig)?;

gpiod_chip_request_lines()

> let count = request.read_edge_events(&buffer)?;

gpiod_line_request_read_edge_event(buf1)

> let event = buffer.event(0);

event1 = gpiod_edge_event_buffer_get_event(buf1, 0)

> let count = request.read_edge_events(&buffer)?;

gpiod_line_request_read_edge_event(buf1)

> println!("line: {}", event.line_offset());

gpiod_edge_event_get_line_offset(event1)


We will allocate a single buffer (buf1) and the event (event1) will be a
reference onto its first event entry in the buffer. It will print offset value
from the second read_edge_events() here instead of first, as it was just a
reference to the first event. And for such a use case, the user should do

event = buffer.event(0).event_clone();

-- 
viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-28 11:10             ` Viresh Kumar
@ 2022-09-28 12:20               ` Bartosz Golaszewski
  2022-09-28 15:17                 ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-09-28 12:20 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Wed, Sep 28, 2022 at 1:10 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> Here is what happens at each call for easier understanding:
>
> On 27-09-22, 17:25, Bartosz Golaszewski wrote:
> > So what happens if I do this:
> >
> > let buf = edge::event::Buffer::new(10)?;
>
> buf1 = gpiod_edge_event_buffer_new()
>
> > let request = chip.request_lines(&rconfig, &lconfig)?;
>
> gpiod_chip_request_lines()
>
> > let count = request.read_edge_events(&buffer)?;
>
> gpiod_line_request_read_edge_event(buf1)
>
> > let event = buffer.event(0);
>
> event1 = gpiod_edge_event_buffer_get_event(buf1, 0)
>
> > let count = request.read_edge_events(&buffer)?;
>
> gpiod_line_request_read_edge_event(buf1)
>
> > println!("line: {}", event.line_offset());
>
> gpiod_edge_event_get_line_offset(event1)
>
>
> We will allocate a single buffer (buf1) and the event (event1) will be a
> reference onto its first event entry in the buffer. It will print offset value
> from the second read_edge_events() here instead of first, as it was just a
> reference to the first event. And for such a use case, the user should do
>
> event = buffer.event(0).event_clone();
>
> --
> viresh

Ok, so this is not correct. The doc for
gpiod_edge_event_buffer_get_event() says:

 * @return Pointer to an event stored in the buffer. The lifetime of the
 *   event is tied to the buffer object. Users must not free the event
 *   returned by this function.

We make no guarantees that the address returned by
gpiod_edge_event_buffer_get_event() will still be valid after a call
to gpiod_line_request_read_edge_event(). In fact the doc for the
latter says:

 * @note Any exising events in the buffer are overwritten.  This is not an
 *       append operation.

So we're being clear that after a call to
gpiod_line_request_read_edge_event(), all previously returned edge
event pointers are invalid unless the objects to which they point were
explicitly copied.

Current implementation does indeed work like what you describe but
that behavior is not "contractually" guaranteed and can change even
between minor releases.

In C++ if you do:

const edge_event& ev = buffer.get_event(0);
request.read_edge_event(buffer);
std::cout << ev << std::endl;

You risk a segfault.

My understanding is that Rust should not allow a crash in this
situation by design.

Bart

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-28 12:20               ` Bartosz Golaszewski
@ 2022-09-28 15:17                 ` Viresh Kumar
  2022-09-28 17:54                   ` Bartosz Golaszewski
  0 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-09-28 15:17 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On 28-09-22, 14:20, Bartosz Golaszewski wrote:
> Ok, so this is not correct. The doc for
> gpiod_edge_event_buffer_get_event() says:
> 
>  * @return Pointer to an event stored in the buffer. The lifetime of the
>  *   event is tied to the buffer object. Users must not free the event
>  *   returned by this function.
> 
> We make no guarantees that the address returned by
> gpiod_edge_event_buffer_get_event() will still be valid after a call
> to gpiod_line_request_read_edge_event(). In fact the doc for the
> latter says:
> 
>  * @note Any exising events in the buffer are overwritten.  This is not an
>  *       append operation.
> 
> So we're being clear that after a call to
> gpiod_line_request_read_edge_event(), all previously returned edge
> event pointers are invalid unless the objects to which they point were
> explicitly copied.
> 
> Current implementation does indeed work like what you describe but
> that behavior is not "contractually" guaranteed and can change even
> between minor releases.
> 
> In C++ if you do:
> 
> const edge_event& ev = buffer.get_event(0);
> request.read_edge_event(buffer);
> std::cout << ev << std::endl;
> 
> You risk a segfault.
> 
> My understanding is that Rust should not allow a crash in this
> situation by design.

Hmm, so what exactly do we want to do here then ?

- Don't allow events to be referenced ? i.e. make event_clone() the default
  behavior ?

- Don't allow read_edge_event() to be called twice for a buffer ? that will be
  inefficient though.

- Somehow guarantee that reference to all the events are dropped before issuing
  read_edge_event() again, else make it fail ? I am not sure how straight
  forward that can be though.

-- 
viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-28 15:17                 ` Viresh Kumar
@ 2022-09-28 17:54                   ` Bartosz Golaszewski
  2022-09-29  6:54                     ` Viresh Kumar
  2022-09-29 13:55                     ` Miguel Ojeda
  0 siblings, 2 replies; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-09-28 17:54 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Wed, Sep 28, 2022 at 5:17 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 28-09-22, 14:20, Bartosz Golaszewski wrote:
> > Ok, so this is not correct. The doc for
> > gpiod_edge_event_buffer_get_event() says:
> >
> >  * @return Pointer to an event stored in the buffer. The lifetime of the
> >  *   event is tied to the buffer object. Users must not free the event
> >  *   returned by this function.
> >
> > We make no guarantees that the address returned by
> > gpiod_edge_event_buffer_get_event() will still be valid after a call
> > to gpiod_line_request_read_edge_event(). In fact the doc for the
> > latter says:
> >
> >  * @note Any exising events in the buffer are overwritten.  This is not an
> >  *       append operation.
> >
> > So we're being clear that after a call to
> > gpiod_line_request_read_edge_event(), all previously returned edge
> > event pointers are invalid unless the objects to which they point were
> > explicitly copied.
> >
> > Current implementation does indeed work like what you describe but
> > that behavior is not "contractually" guaranteed and can change even
> > between minor releases.
> >
> > In C++ if you do:
> >
> > const edge_event& ev = buffer.get_event(0);
> > request.read_edge_event(buffer);
> > std::cout << ev << std::endl;
> >
> > You risk a segfault.
> >
> > My understanding is that Rust should not allow a crash in this
> > situation by design.
>
> Hmm, so what exactly do we want to do here then ?
>
> - Don't allow events to be referenced ? i.e. make event_clone() the default
>   behavior ?
>

God no, that would be wasteful.

> - Don't allow read_edge_event() to be called twice for a buffer ? that will be
>   inefficient though.
>

Not good either.

> - Somehow guarantee that reference to all the events are dropped before issuing
>   read_edge_event() again, else make it fail ? I am not sure how straight
>   forward that can be though.

In C++ the preferred way is to do buffer.get_event(0) which will
return a constant reference. If you store that reference as const
edge_event& ev = buffer.get_event(0) and reuse it after rereading into
that buffer and the program crashes - that's on you. In most cases you
should just do buffer.get_event(0).line_offset() etc. If you do:

edge_event event = buffer.get_event(0);

You'll copy the event and it will survive the overwriting of the buffer.

I'm a Rust beginner but my understanding is that the whole idea of the
language design is to *not* allow a situation where the program can
crash. It should be detected at build-time. We must not rely on
"contracts" defined by documentation.

Is there a way to invalidate a reference in Rust? Have a small (cheap)
object in the buffer which the event references and which would get
dropped when reading into the buffer?

Bart

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-28 17:54                   ` Bartosz Golaszewski
@ 2022-09-29  6:54                     ` Viresh Kumar
  2022-09-29  7:37                       ` Bartosz Golaszewski
  2022-09-29 13:55                     ` Miguel Ojeda
  1 sibling, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-09-29  6:54 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On 28-09-22, 19:54, Bartosz Golaszewski wrote:
> On Wed, Sep 28, 2022 at 5:17 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > Hmm, so what exactly do we want to do here then ?
> >
> > - Don't allow events to be referenced ? i.e. make event_clone() the default
> >   behavior ?
> >
> 
> God no, that would be wasteful.
> 
> > - Don't allow read_edge_event() to be called twice for a buffer ? that will be
> >   inefficient though.
> >
> 
> Not good either.

As I expected for both of them :)

> > - Somehow guarantee that reference to all the events are dropped before issuing
> >   read_edge_event() again, else make it fail ? I am not sure how straight
> >   forward that can be though.
> 
> In C++ the preferred way is to do buffer.get_event(0) which will
> return a constant reference. If you store that reference as const
> edge_event& ev = buffer.get_event(0) and reuse it after rereading into
> that buffer and the program crashes - that's on you. In most cases you
> should just do buffer.get_event(0).line_offset() etc. If you do:
> 
> edge_event event = buffer.get_event(0);
> 
> You'll copy the event and it will survive the overwriting of the buffer.

Right, same happens here.

> I'm a Rust beginner but my understanding is that the whole idea of the
> language design is to *not* allow a situation where the program can
> crash. It should be detected at build-time. We must not rely on
> "contracts" defined by documentation.

If everything was written in Rust, then this problem won't occur for sure. But
in this case part of the code is available via FFI (foreign function interface)
and they guarantees are a bit limited there and depend on what the FFI
guarantees.

> Is there a way to invalidate a reference in Rust? Have a small (cheap)
> object in the buffer which the event references and which would get
> dropped when reading into the buffer?

I am not sure. There are locks, but then they have a cost.

Miguel, any suggestions ?

Bartosz, just as an FYI I am out on vacation until end of next week and won't
have access to a workstation. I can still reply via Gmail (html) from my phone
though.

-- 
viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-29  6:54                     ` Viresh Kumar
@ 2022-09-29  7:37                       ` Bartosz Golaszewski
  2022-09-29  8:58                         ` Viresh Kumar
  2022-09-29 11:43                         ` Kent Gibson
  0 siblings, 2 replies; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-09-29  7:37 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Thu, Sep 29, 2022 at 8:54 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 28-09-22, 19:54, Bartosz Golaszewski wrote:
> > On Wed, Sep 28, 2022 at 5:17 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > > Hmm, so what exactly do we want to do here then ?
> > >
> > > - Don't allow events to be referenced ? i.e. make event_clone() the default
> > >   behavior ?
> > >
> >
> > God no, that would be wasteful.
> >
> > > - Don't allow read_edge_event() to be called twice for a buffer ? that will be
> > >   inefficient though.
> > >
> >
> > Not good either.
>
> As I expected for both of them :)
>
> > > - Somehow guarantee that reference to all the events are dropped before issuing
> > >   read_edge_event() again, else make it fail ? I am not sure how straight
> > >   forward that can be though.
> >
> > In C++ the preferred way is to do buffer.get_event(0) which will
> > return a constant reference. If you store that reference as const
> > edge_event& ev = buffer.get_event(0) and reuse it after rereading into
> > that buffer and the program crashes - that's on you. In most cases you
> > should just do buffer.get_event(0).line_offset() etc. If you do:
> >
> > edge_event event = buffer.get_event(0);
> >
> > You'll copy the event and it will survive the overwriting of the buffer.
>
> Right, same happens here.
>
> > I'm a Rust beginner but my understanding is that the whole idea of the
> > language design is to *not* allow a situation where the program can
> > crash. It should be detected at build-time. We must not rely on
> > "contracts" defined by documentation.
>
> If everything was written in Rust, then this problem won't occur for sure. But
> in this case part of the code is available via FFI (foreign function interface)
> and they guarantees are a bit limited there and depend on what the FFI
> guarantees.
>
> > Is there a way to invalidate a reference in Rust? Have a small (cheap)
> > object in the buffer which the event references and which would get
> > dropped when reading into the buffer?
>
> I am not sure. There are locks, but then they have a cost.
>

I'm not talking about locking, this should be left to the user of the module.

Can we force-drop an object still referenced by other objects in Rust?
This is what I had in mind - a small, dummy, cheap object inside the
buffer that's created when reading into the buffer. Each even would
reference it and then Rust would not allow us to drop it as long as
there are references to it. Does it make sense? Is that possible?

> Miguel, any suggestions ?
>
> Bartosz, just as an FYI I am out on vacation until end of next week and won't
> have access to a workstation. I can still reply via Gmail (html) from my phone
> though.
>

Nah, just take the time off and rest. BTW, I'm starting at linaro next week. :)

Bart

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-29  7:37                       ` Bartosz Golaszewski
@ 2022-09-29  8:58                         ` Viresh Kumar
  2022-09-29 11:16                           ` Bartosz Golaszewski
  2022-09-29 11:43                         ` Kent Gibson
  1 sibling, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-09-29  8:58 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Thu, 29 Sept 2022 at 13:07, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> I'm not talking about locking, this should be left to the user of the module.

Yeah, I get that.

> Can we force-drop an object still referenced by other objects in Rust?

No, AFAICT.

We can call drop(x) on an object, but as long as an reference to
it is out there, we won't end up calling the actualy drop() routine
for the object.

> This is what I had in mind - a small, dummy, cheap object inside the
> buffer that's created when reading into the buffer. Each even would
> reference it and then Rust would not allow us to drop it as long as
> there are references to it. Does it make sense? Is that possible?

I don't think so.

> Nah, just take the time off and rest. BTW, I'm starting at linaro next week. :)

Excellent, welcome buddy :)

--
Viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-29  8:58                         ` Viresh Kumar
@ 2022-09-29 11:16                           ` Bartosz Golaszewski
  0 siblings, 0 replies; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-09-29 11:16 UTC (permalink / raw)
  To: Viresh Kumar, Miguel Ojeda
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Alex Bennée, stratos-dev, Gerard Ryan

On Thu, Sep 29, 2022 at 10:58 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On Thu, 29 Sept 2022 at 13:07, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> > I'm not talking about locking, this should be left to the user of the module.
>
> Yeah, I get that.
>
> > Can we force-drop an object still referenced by other objects in Rust?
>
> No, AFAICT.
>
> We can call drop(x) on an object, but as long as an reference to
> it is out there, we won't end up calling the actualy drop() routine
> for the object.
>
> > This is what I had in mind - a small, dummy, cheap object inside the
> > buffer that's created when reading into the buffer. Each even would
> > reference it and then Rust would not allow us to drop it as long as
> > there are references to it. Does it make sense? Is that possible?
>
> I don't think so.

Miguel: Could you give us advice on how to proceed with this?

Bart

>
> > Nah, just take the time off and rest. BTW, I'm starting at linaro next week. :)
>
> Excellent, welcome buddy :)
>
> --
> Viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-29  7:37                       ` Bartosz Golaszewski
  2022-09-29  8:58                         ` Viresh Kumar
@ 2022-09-29 11:43                         ` Kent Gibson
  1 sibling, 0 replies; 37+ messages in thread
From: Kent Gibson @ 2022-09-29 11:43 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Viresh Kumar, Linus Walleij, Vincent Guittot, linux-gpio,
	Miguel Ojeda, Alex Bennée, stratos-dev, Gerard Ryan

On Thu, Sep 29, 2022 at 09:37:40AM +0200, Bartosz Golaszewski wrote:
> On Thu, Sep 29, 2022 at 8:54 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> >
> > On 28-09-22, 19:54, Bartosz Golaszewski wrote:
> > > On Wed, Sep 28, 2022 at 5:17 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > > > Hmm, so what exactly do we want to do here then ?
> > > >
> > > > - Don't allow events to be referenced ? i.e. make event_clone() the default
> > > >   behavior ?
> > > >
> > >
> > > God no, that would be wasteful.
> > >
> > > > - Don't allow read_edge_event() to be called twice for a buffer ? that will be
> > > >   inefficient though.
> > > >
> > >
> > > Not good either.
> >
> > As I expected for both of them :)
> >
> > > > - Somehow guarantee that reference to all the events are dropped before issuing
> > > >   read_edge_event() again, else make it fail ? I am not sure how straight
> > > >   forward that can be though.
> > >
> > > In C++ the preferred way is to do buffer.get_event(0) which will
> > > return a constant reference. If you store that reference as const
> > > edge_event& ev = buffer.get_event(0) and reuse it after rereading into
> > > that buffer and the program crashes - that's on you. In most cases you
> > > should just do buffer.get_event(0).line_offset() etc. If you do:
> > >
> > > edge_event event = buffer.get_event(0);
> > >
> > > You'll copy the event and it will survive the overwriting of the buffer.
> >
> > Right, same happens here.
> >
> > > I'm a Rust beginner but my understanding is that the whole idea of the
> > > language design is to *not* allow a situation where the program can
> > > crash. It should be detected at build-time. We must not rely on
> > > "contracts" defined by documentation.
> >
> > If everything was written in Rust, then this problem won't occur for sure. But
> > in this case part of the code is available via FFI (foreign function interface)
> > and they guarantees are a bit limited there and depend on what the FFI
> > guarantees.
> >
> > > Is there a way to invalidate a reference in Rust? Have a small (cheap)
> > > object in the buffer which the event references and which would get
> > > dropped when reading into the buffer?
> >
> > I am not sure. There are locks, but then they have a cost.
> >
> 
> I'm not talking about locking, this should be left to the user of the module.
> 
> Can we force-drop an object still referenced by other objects in Rust?
> This is what I had in mind - a small, dummy, cheap object inside the
> buffer that's created when reading into the buffer. Each even would
> reference it and then Rust would not allow us to drop it as long as
> there are references to it. Does it make sense? Is that possible?
> 

No, Rust will explicitly prevent you from dropping referenced objects.

But is this the sort of thing you mean:

use std::process::ExitCode;

#[derive(Clone)]
struct Event {
    pub id: u8
}

struct Events {
    b: Vec<Event>
}

impl Events {
    pub fn get(&self, idx: usize) -> Option<&Event> {
        self.b.get(idx)
    }
}

struct Buffer {
    count: u8,
    events: Option<Events>,
}

impl Buffer {
    
    pub fn read(&mut self) -> Result<&Events, ()> {
        self.count += 1;
        self.events = Some(Events{b: vec![Event{id: self.count}]});
        self.events.as_ref().ok_or(())
    }
}

fn main() -> Result<ExitCode, ()>{
    let mut b = Buffer{count: 0, events:None};
    let mut ee = b.read()?;
    let e = ee.get(0);
    println!("{:?}", e.unwrap().id);
    let cloned_e = e.unwrap().clone();
    drop(e); // <-- comment out to try to create a dangling event reference
    ee = b.read()?;
    let e = ee.get(0); // <-- comment out to try to create a dangling event reference
    println!("{:?}", cloned_e.id);
    println!("{:?}", e.unwrap().id);
    Ok(ExitCode::from(42))
}

That is a skeletal proof of concept - the small, dummy, cheap object is
the Vec in Events.  Is that cheap enough? You might be able to replace
that with something cheaper, but Events needs to be able to pull an
Event reference from somewhere (from the borrow checker's PoV) so it
made this demo simpler.

Comment out the two lines to try to carry e across the buffer read().
The compiler will not allow it, as e already borrows from b.

In an actual implementation Event would wrap the C event, and Events.get()
would get the event pointer for the Event and return that as a reference.
The Event clone would call into C, rather than being derived as it is here.

Key points:  Buffer has to own the Events snapshot that is returned by
reference by read().  The return by reference creates a borrow on the
Buffer.  The read() requires a &mut to prevent the Buffer being read
while there are any borrows outstanding.
The Events returns individual events by reference to create a borrow on
the Events to prevent it (and the Buffer) being dropped or modified.
The Event clone returns a concrete event that does not have a borrow of
the Events or Buffer.

There may well be better ways to do this, and you would really want to
do some benchmarking to compare it with the immediate clone option - it
may well be worse, but hopefully it at least demonstrates the semantics
you are after.

Cheers,
Kent.

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-28 17:54                   ` Bartosz Golaszewski
  2022-09-29  6:54                     ` Viresh Kumar
@ 2022-09-29 13:55                     ` Miguel Ojeda
  2022-10-11  4:16                       ` Viresh Kumar
  1 sibling, 1 reply; 37+ messages in thread
From: Miguel Ojeda @ 2022-09-29 13:55 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Viresh Kumar, Linus Walleij, Vincent Guittot, linux-gpio,
	Kent Gibson, Alex Bennée, stratos-dev, Gerard Ryan

On Wed, Sep 28, 2022 at 7:54 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>
> I'm a Rust beginner but my understanding is that the whole idea of the
> language design is to *not* allow a situation where the program can
> crash. It should be detected at build-time. We must not rely on

More precisely, it needs to avoid UB (which is defined similarly as in
C++, and of course UB may lead to a crash if one is lucky).

> Is there a way to invalidate a reference in Rust? Have a small (cheap)
> object in the buffer which the event references and which would get
> dropped when reading into the buffer?

From your C++ example above:

    const edge_event& ev = buffer.get_event(0);
    request.read_edge_event(buffer);
    std::cout << ev << std::endl;

It looks like a container whose elements get invalidated, so
`read_edge_event` could require an exclusive reference to `buffer` in
Rust, that way you cannot keep borrows to its elements like `ev` if
you want to call it. But of course this requires tying the lifetime of
the events to that of the buffer.

Cheers,
Miguel

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-09-29 13:55                     ` Miguel Ojeda
@ 2022-10-11  4:16                       ` Viresh Kumar
  2022-10-11  4:25                         ` Kent Gibson
  2022-10-13  6:12                         ` Viresh Kumar
  0 siblings, 2 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-10-11  4:16 UTC (permalink / raw)
  To: Bartosz Golaszewski, Miguel Ojeda
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Alex Bennée, stratos-dev, Gerard Ryan

On 29-09-22, 15:55, Miguel Ojeda wrote:
> It looks like a container whose elements get invalidated, so
> `read_edge_event` could require an exclusive reference to `buffer` in
> Rust, that way you cannot keep borrows to its elements like `ev` if
> you want to call it. But of course this requires tying the lifetime of
> the events to that of the buffer.

What about the below code changes on top of V6 ?

Changes:
- Removed BufferInternal.
- Event contains a reference to the Buffer now, with lifetime.
- read_edge_event() expects a mutable reference to buffer, to make it
  exclusive, i.e. disallow any previous Event references to exist at
  compilation itself.

diff --git a/bindings/rust/libgpiod/src/edge_event.rs b/bindings/rust/libgpiod/src/edge_event.rs
index ce583916a2e3..f5426459d779 100644
--- a/bindings/rust/libgpiod/src/edge_event.rs
+++ b/bindings/rust/libgpiod/src/edge_event.rs
@@ -3,12 +3,11 @@
 // Copyright 2022 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 Errno;
 
-use super::{edge::event::BufferInternal, gpiod, EdgeKind, Error, Offset, OperationType, Result};
+use super::{edge::event::Buffer, gpiod, EdgeKind, Error, Offset, OperationType, Result};
 
 /// Line edge events handling
 ///
@@ -22,15 +21,15 @@ use super::{edge::event::BufferInternal, gpiod, EdgeKind, Error, Offset, Operati
 /// number of events are being read.
 
 #[derive(Debug, Eq, PartialEq)]
-pub struct Event {
-    ibuffer: Option<Arc<BufferInternal>>,
+pub struct Event<'b> {
+    buffer: Option<&'b Buffer>,
     event: *mut gpiod::gpiod_edge_event,
 }
 
-impl Event {
+impl<'b> Event<'b> {
     /// Get an event stored in the buffer.
-    pub(crate) fn new(ibuffer: &Arc<BufferInternal>, index: u64) -> Result<Self> {
-        let event = unsafe { gpiod::gpiod_edge_event_buffer_get_event(ibuffer.buffer(), index) };
+    pub(crate) fn new(buffer: &'b Buffer, index: u64) -> Result<Self> {
+        let event = unsafe { gpiod::gpiod_edge_event_buffer_get_event(buffer.buffer(), index) };
         if event.is_null() {
             return Err(Error::OperationFailed(
                 OperationType::EdgeEventBufferGetEvent,
@@ -39,7 +38,7 @@ impl Event {
         }
 
         Ok(Self {
-            ibuffer: Some(ibuffer.clone()),
+            buffer: Some(buffer),
             event,
         })
     }
@@ -54,7 +53,7 @@ impl Event {
         }
 
         Ok(Self {
-            ibuffer: None,
+            buffer: None,
             event,
         })
     }
@@ -91,11 +90,11 @@ impl Event {
     }
 }
 
-impl Drop for Event {
+impl<'b> Drop for Event<'b> {
     /// Free the edge event.
     fn drop(&mut self) {
         // Free the event only if a copy is made
-        if self.ibuffer.is_none() {
+        if self.buffer.is_none() {
             unsafe { gpiod::gpiod_edge_event_free(self.event) };
         }
     }
diff --git a/bindings/rust/libgpiod/src/event_buffer.rs b/bindings/rust/libgpiod/src/event_buffer.rs
index e272e7aa9e9d..11c8b5e1d7c9 100644
--- a/bindings/rust/libgpiod/src/event_buffer.rs
+++ b/bindings/rust/libgpiod/src/event_buffer.rs
@@ -4,7 +4,6 @@
 //     Viresh Kumar <viresh.kumar@linaro.org>
 
 use std::os::raw::c_ulong;
-use std::sync::Arc;
 
 use vmm_sys_util::errno::Error as Errno;
 
@@ -12,11 +11,11 @@ use super::{edge, gpiod, Error, OperationType, Result};
 
 /// Line edge events buffer
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub(crate) struct BufferInternal {
+pub struct Buffer {
     buffer: *mut gpiod::gpiod_edge_event_buffer,
 }
 
-impl BufferInternal {
+impl Buffer {
     /// Create a new edge event buffer.
     ///
     /// If capacity equals 0, it will be set to a default value of 64. If
@@ -37,36 +36,6 @@ impl BufferInternal {
     pub(crate) fn buffer(&self) -> *mut gpiod::gpiod_edge_event_buffer {
         self.buffer
     }
-}
-
-impl Drop for BufferInternal {
-    /// Free the edge event buffer and release all associated resources.
-    fn drop(&mut self) {
-        unsafe { gpiod::gpiod_edge_event_buffer_free(self.buffer) };
-    }
-}
-
-/// Line edge events buffer
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Buffer {
-    ibuffer: Arc<BufferInternal>,
-}
-
-impl Buffer {
-    /// 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: usize) -> Result<Self> {
-        Ok(Self {
-            ibuffer: Arc::new(BufferInternal::new(capacity)?),
-        })
-    }
-
-    /// Private helper, Returns gpiod_edge_event_buffer
-    pub(crate) fn buffer(&self) -> *mut gpiod::gpiod_edge_event_buffer {
-        self.ibuffer.buffer()
-    }
 
     /// Get the capacity of the event buffer.
     pub fn capacity(&self) -> usize {
@@ -75,7 +44,7 @@ impl Buffer {
 
     /// Read an event stored in the buffer.
     pub fn event(&self, index: u64) -> Result<edge::Event> {
-        edge::Event::new(&self.ibuffer, index)
+        edge::Event::new(self, index)
     }
 
     /// Get the number of events the buffer contains.
@@ -88,3 +57,10 @@ impl Buffer {
         self.len() == 0
     }
 }
+
+impl Drop for Buffer {
+    /// Free the edge event buffer and release all associated resources.
+    fn drop(&mut self) {
+        unsafe { gpiod::gpiod_edge_event_buffer_free(self.buffer) };
+    }
+}
diff --git a/bindings/rust/libgpiod/src/line_request.rs b/bindings/rust/libgpiod/src/line_request.rs
index 617efaa34d58..e4ff951aef29 100644
--- a/bindings/rust/libgpiod/src/line_request.rs
+++ b/bindings/rust/libgpiod/src/line_request.rs
@@ -218,7 +218,7 @@ impl Request {
     /// 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_events(&self, buffer: &edge::event::Buffer) -> Result<u32> {
+    pub fn read_edge_events(&self, buffer: &mut edge::event::Buffer) -> Result<u32> {
         let ret = unsafe {
             gpiod::gpiod_line_request_read_edge_event(
                 self.request,


And here is an example where we get compilation error on the commented
line:

fn main() -> Result<()> {
    let mut lsettings = line::Settings::new()?;
    let lconfig = line::Config::new()?;
    let offsets = vec![1, 2];

    lsettings.set_prop(&[SettingVal::EdgeDetection(Some(Edge::Both))])?;
    lconfig.add_line_settings(&offsets, lsettings)?;

    let path = "/dev/gpiochip0".to_string();
    let chip = Chip::open(&path)?;

    let rconfig = request::Config::new()?;

    let mut buffer = edge::event::Buffer::new(2)?;
    let request = chip.request_lines(&rconfig, &lconfig)?;

    loop {
        match request.wait_edge_event(None) {
            Err(x) => {
                println!("{:?}", x);
                return Err(Error::InvalidArguments);
            }

            Ok(false) => {
                // This shouldn't happen as the call is blocking.
                panic!();
            }
            Ok(true) => (),
        }

        request.read_edge_events(&mut buffer)?;
        let event0 = buffer.event(0)?;
        let event1 = buffer.event(1)?;

        println!("{:?}", (event0.line_offset(), event1.line_offset()));
        drop(event0);

        // This fails to compile
        // request.read_edge_events(&mut buffer)?;

        drop(event1);
        // This compiles fine
        request.read_edge_events(&mut buffer)?;
    }
}

-- 
viresh

^ permalink raw reply related	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-11  4:16                       ` Viresh Kumar
@ 2022-10-11  4:25                         ` Kent Gibson
  2022-10-11  4:37                           ` Viresh Kumar
  2022-10-13  6:12                         ` Viresh Kumar
  1 sibling, 1 reply; 37+ messages in thread
From: Kent Gibson @ 2022-10-11  4:25 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Bartosz Golaszewski, Miguel Ojeda, Linus Walleij,
	Vincent Guittot, linux-gpio, Alex Bennée, stratos-dev,
	Gerard Ryan

On Tue, Oct 11, 2022 at 09:46:51AM +0530, Viresh Kumar wrote:
> On 29-09-22, 15:55, Miguel Ojeda wrote:
> > It looks like a container whose elements get invalidated, so
> > `read_edge_event` could require an exclusive reference to `buffer` in
> > Rust, that way you cannot keep borrows to its elements like `ev` if
> > you want to call it. But of course this requires tying the lifetime of
> > the events to that of the buffer.
> 
> What about the below code changes on top of V6 ?
> 

Can you clone the event to detach it from the buffer?
Or are you now forced to drop the event before reading more?

Cheers,
Kent.

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-11  4:25                         ` Kent Gibson
@ 2022-10-11  4:37                           ` Viresh Kumar
  2022-10-11  4:46                             ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-10-11  4:37 UTC (permalink / raw)
  To: Kent Gibson
  Cc: Bartosz Golaszewski, Miguel Ojeda, Linus Walleij,
	Vincent Guittot, linux-gpio, Alex Bennée, stratos-dev,
	Gerard Ryan

On 11-10-22, 12:25, Kent Gibson wrote:
> On Tue, Oct 11, 2022 at 09:46:51AM +0530, Viresh Kumar wrote:
> > On 29-09-22, 15:55, Miguel Ojeda wrote:
> > > It looks like a container whose elements get invalidated, so
> > > `read_edge_event` could require an exclusive reference to `buffer` in
> > > Rust, that way you cannot keep borrows to its elements like `ev` if
> > > you want to call it. But of course this requires tying the lifetime of
> > > the events to that of the buffer.
> > 
> > What about the below code changes on top of V6 ?
> > 
> 
> Can you clone the event to detach it from the buffer?

I thought we can always do:

event.event_clone() to get a copy, which won't have a reference to the
Buffer. This is how it is defined:

    pub fn event_clone(&self) -> Result<Self> {
        let event = unsafe { gpiod::gpiod_edge_event_copy(self.event) };
        if event.is_null() {
            return Err(Error::OperationFailed(
                OperationType::EdgeEventCopy,
                Errno::last(),
            ));
        }

        Ok(Self {
            buffer: None,
            event,
        })
    }

But when I try to do this in the earlier example:

@@ -40,10 +40,12 @@ fn main() -> Result<()> {
         let event1 = buffer.event(1)?;

         println!("{:?}", (event0.line_offset(), event1.line_offset()));
+        let event0_copy = event0.event_clone()?;
         drop(event0);
         // This fails to compile
         // request.read_edge_events(&mut buffer)?;
         drop(event1);
         request.read_edge_events(&mut buffer)?;
+        drop(event0_copy);
     }
 }

compilation fails :(

error[E0502]: cannot borrow `buffer` as mutable because it is also borrowed as immutable
  --> libgpiod/examples/gpiobufferevent.rs:48:34
   |
39 |         let event0 = buffer.event(0)?;
   |                      --------------- immutable borrow occurs here
...
48 |         request.read_edge_events(&mut buffer)?;
   |                                  ^^^^^^^^^^^ mutable borrow occurs here
49 |         drop(event0_copy);
   |              ----------- immutable borrow later used here


And I am not sure why, as the reference isn't used anymore in this
case to the event0.

-- 
viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-11  4:37                           ` Viresh Kumar
@ 2022-10-11  4:46                             ` Viresh Kumar
  0 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-10-11  4:46 UTC (permalink / raw)
  To: Kent Gibson
  Cc: Bartosz Golaszewski, Miguel Ojeda, Linus Walleij,
	Vincent Guittot, linux-gpio, Alex Bennée, stratos-dev,
	Gerard Ryan

On 11-10-22, 10:07, Viresh Kumar wrote:
> And I am not sure why, as the reference isn't used anymore in this
> case to the event0.

This works though:

diff --git a/bindings/rust/libgpiod/examples/gpiobufferevent.rs b/bindings/rust/libgpiod/examples/gpiobufferevent.rs
index 613a800584e3..e16a1a39b22c 100644
--- a/bindings/rust/libgpiod/examples/gpiobufferevent.rs
+++ b/bindings/rust/libgpiod/examples/gpiobufferevent.rs
@@ -40,10 +40,12 @@ fn main() -> Result<()> {
         let event1 = buffer.event(1)?;

         println!("{:?}", (event0.line_offset(), event1.line_offset()));
+        let event0_copy = edge::Event::event_clone(&event0)?;
         drop(event0);
         // This fails to compile
         // request.read_edge_events(&mut buffer)?;
         drop(event1);
         request.read_edge_events(&mut buffer)?;
+        drop(event0_copy);
     }
 }
diff --git a/bindings/rust/libgpiod/src/edge_event.rs b/bindings/rust/libgpiod/src/edge_event.rs
index f5426459d779..12c0fd73f778 100644
--- a/bindings/rust/libgpiod/src/edge_event.rs
+++ b/bindings/rust/libgpiod/src/edge_event.rs
@@ -43,8 +43,8 @@ impl<'b> Event<'b> {
         })
     }

-    pub fn event_clone(&self) -> Result<Self> {
-        let event = unsafe { gpiod::gpiod_edge_event_copy(self.event) };
+    pub fn event_clone(event: &Event) -> Result<Self> {
+        let event = unsafe { gpiod::gpiod_edge_event_copy(event.event) };
         if event.is_null() {
             return Err(Error::OperationFailed(
                 OperationType::EdgeEventCopy,


-- 
viresh

^ permalink raw reply related	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-11  4:16                       ` Viresh Kumar
  2022-10-11  4:25                         ` Kent Gibson
@ 2022-10-13  6:12                         ` Viresh Kumar
  2022-10-14  9:45                           ` Bartosz Golaszewski
  1 sibling, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-10-13  6:12 UTC (permalink / raw)
  To: Bartosz Golaszewski, Miguel Ojeda
  Cc: Linus Walleij, Vincent Guittot, linux-gpio, Kent Gibson,
	Alex Bennée, stratos-dev, Gerard Ryan

On 11-10-22, 09:46, Viresh Kumar wrote:
> What about the below code changes on top of V6 ?
> 
> Changes:
> - Removed BufferInternal.
> - Event contains a reference to the Buffer now, with lifetime.
> - read_edge_event() expects a mutable reference to buffer, to make it
>   exclusive, i.e. disallow any previous Event references to exist at
>   compilation itself.

Bartosz, should I send a V7 now with these changes ? I hope everything
is settled ?

-- 
viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-13  6:12                         ` Viresh Kumar
@ 2022-10-14  9:45                           ` Bartosz Golaszewski
  2022-10-14  9:57                             ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-10-14  9:45 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Miguel Ojeda, Linus Walleij, Vincent Guittot, linux-gpio,
	Kent Gibson, Alex Bennée, stratos-dev, Gerard Ryan

On Thu, Oct 13, 2022 at 8:12 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 11-10-22, 09:46, Viresh Kumar wrote:
> > What about the below code changes on top of V6 ?
> >
> > Changes:
> > - Removed BufferInternal.
> > - Event contains a reference to the Buffer now, with lifetime.
> > - read_edge_event() expects a mutable reference to buffer, to make it
> >   exclusive, i.e. disallow any previous Event references to exist at
> >   compilation itself.
>
> Bartosz, should I send a V7 now with these changes ? I hope everything
> is settled ?
>

Maybe also add chained mutators everywhere? To be able to do
settings.set_direction().set_edge() etc.?

And I would still love a thorough API review from someone who actually
knows rust too. :(

But I will play some more with v7 so do send it.

Bartosz

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-14  9:45                           ` Bartosz Golaszewski
@ 2022-10-14  9:57                             ` Viresh Kumar
  2022-10-14 14:25                               ` Bartosz Golaszewski
  0 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-10-14  9:57 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Miguel Ojeda, Linus Walleij, Vincent Guittot, linux-gpio,
	Kent Gibson, Alex Bennée, stratos-dev, Gerard Ryan

On 14-10-22, 11:45, Bartosz Golaszewski wrote:
> Maybe also add chained mutators everywhere? To be able to do
> settings.set_direction().set_edge() etc.?

Based on Kent's suggestion earlier, what I have implemented is
set_prop(), to which one can pass all settings and it will apply them
in a loop.

    pub fn set_prop(&mut self, values: &[SettingVal]) -> Result<()> {
        for value in values {
            match value {
                SettingVal::Direction(val) => self.set_direction(*val)?,
                SettingVal::EdgeDetection(val) => self.set_edge_detection(*val)?,
                SettingVal::Bias(val) => self.set_bias(*val)?,
                SettingVal::Drive(val) => self.set_drive(*val)?,
                SettingVal::ActiveLow(val) => self.set_active_low(*val),
                SettingVal::DebouncePeriod(val) => self.set_debounce_period(*val),
                SettingVal::EventClock(val) => self.set_event_clock(*val)?,
                SettingVal::OutputValue(val) => self.set_output_value(*val)?,
            }
        }

        Ok(())
    }

I think that replaces the need of nested ones ? And if we want to add
those later, we can always come back and add them. But I am not sure
it would be required.

> And I would still love a thorough API review from someone who actually
> knows rust too. :(

Well, Kent did a very good job earlier. I am not sure if he has extra
cycles to review this once again, though not a lot has changed since
last time.

> But I will play some more with v7 so do send it.

Great.

-- 
viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-14  9:57                             ` Viresh Kumar
@ 2022-10-14 14:25                               ` Bartosz Golaszewski
  2022-10-14 16:06                                 ` Kent Gibson
  0 siblings, 1 reply; 37+ messages in thread
From: Bartosz Golaszewski @ 2022-10-14 14:25 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Miguel Ojeda, Linus Walleij, Vincent Guittot, linux-gpio,
	Kent Gibson, Alex Bennée, stratos-dev, Gerard Ryan

On Fri, Oct 14, 2022 at 11:57 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 14-10-22, 11:45, Bartosz Golaszewski wrote:
> > Maybe also add chained mutators everywhere? To be able to do
> > settings.set_direction().set_edge() etc.?
>
> Based on Kent's suggestion earlier, what I have implemented is
> set_prop(), to which one can pass all settings and it will apply them
> in a loop.
>
>     pub fn set_prop(&mut self, values: &[SettingVal]) -> Result<()> {
>         for value in values {
>             match value {
>                 SettingVal::Direction(val) => self.set_direction(*val)?,
>                 SettingVal::EdgeDetection(val) => self.set_edge_detection(*val)?,
>                 SettingVal::Bias(val) => self.set_bias(*val)?,
>                 SettingVal::Drive(val) => self.set_drive(*val)?,
>                 SettingVal::ActiveLow(val) => self.set_active_low(*val),
>                 SettingVal::DebouncePeriod(val) => self.set_debounce_period(*val),
>                 SettingVal::EventClock(val) => self.set_event_clock(*val)?,
>                 SettingVal::OutputValue(val) => self.set_output_value(*val)?,
>             }
>         }
>
>         Ok(())
>     }
>
> I think that replaces the need of nested ones ? And if we want to add
> those later, we can always come back and add them. But I am not sure
> it would be required.
>

I cannot find Kent's comment on that - what was the reasoning behind this?

> > And I would still love a thorough API review from someone who actually
> > knows rust too. :(
>
> Well, Kent did a very good job earlier. I am not sure if he has extra
> cycles to review this once again, though not a lot has changed since
> last time.
>

Yeah sorry Kent, I forgot we're at v6 already and you did review the
previous iterations. :)

Bart

> > But I will play some more with v7 so do send it.
>
> Great.
>
> --
> viresh

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-14 14:25                               ` Bartosz Golaszewski
@ 2022-10-14 16:06                                 ` Kent Gibson
  2022-10-17 11:26                                   ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Kent Gibson @ 2022-10-14 16:06 UTC (permalink / raw)
  To: Bartosz Golaszewski
  Cc: Viresh Kumar, Miguel Ojeda, Linus Walleij, Vincent Guittot,
	linux-gpio, Alex Bennée, stratos-dev, Gerard Ryan

On Fri, Oct 14, 2022 at 04:25:31PM +0200, Bartosz Golaszewski wrote:
> On Fri, Oct 14, 2022 at 11:57 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> >
> > On 14-10-22, 11:45, Bartosz Golaszewski wrote:
> > > Maybe also add chained mutators everywhere? To be able to do
> > > settings.set_direction().set_edge() etc.?
> >
> > Based on Kent's suggestion earlier, what I have implemented is
> > set_prop(), to which one can pass all settings and it will apply them
> > in a loop.
> >
> >     pub fn set_prop(&mut self, values: &[SettingVal]) -> Result<()> {
> >         for value in values {
> >             match value {
> >                 SettingVal::Direction(val) => self.set_direction(*val)?,
> >                 SettingVal::EdgeDetection(val) => self.set_edge_detection(*val)?,
> >                 SettingVal::Bias(val) => self.set_bias(*val)?,
> >                 SettingVal::Drive(val) => self.set_drive(*val)?,
> >                 SettingVal::ActiveLow(val) => self.set_active_low(*val),
> >                 SettingVal::DebouncePeriod(val) => self.set_debounce_period(*val),
> >                 SettingVal::EventClock(val) => self.set_event_clock(*val)?,
> >                 SettingVal::OutputValue(val) => self.set_output_value(*val)?,
> >             }
> >         }
> >
> >         Ok(())
> >     }
> >
> > I think that replaces the need of nested ones ? And if we want to add
> > those later, we can always come back and add them. But I am not sure
> > it would be required.
> >
> 
> I cannot find Kent's comment on that - what was the reasoning behind this?
> 

The comment was:

    Add a Setting enum that has a variant for each setting.
    Then you only need 3 mutators total.
    And the user can define configs as a list of Settings.
    So perhaps the mutators should accept &[Setting].
    And &[offsets] rather than just offset.

    Similarly, gets can be consolidated into:

      get_prop_offset(self, offset, SettingKind) -> Result<Setting>

    and
      get_prop_default(self, SettingKind) -> Result<Setting>

    (simplified signatures)


Prior to the line_settings change there was a veritable forest of
mutators, so the idea was to consolidate them where possible, cos in Rust
you can.  But behind the scenes the implementation is just fanning them
out again, so I'm not sure I see the benefit if that is the case.

If the mutators for each field still exist they may as well be pub.

And they should return Result<&mut Self> so they can be chained, as you
suggest.

Wrt the values param (which I would prefer was called props), the idea
was that the config could be built and passed around as pure Rust
objects.  The set_prop() applied that list to the C line config, at the
time using one of the default/offset/subset mutators.  So it decoupled
the settings from the scope they were to be applied to.  Not such an
issue now - the scope is always line.
Might still be useful, might not.

> > > And I would still love a thorough API review from someone who actually
> > > knows rust too. :(
> >
> > Well, Kent did a very good job earlier. I am not sure if he has extra
> > cycles to review this once again, though not a lot has changed since
> > last time.
> >
> 
> Yeah sorry Kent, I forgot we're at v6 already and you did review the
> previous iterations. :)
> 

My review was of v4.  Things have changed a bit since then.
And I agree with your original point - it would be good to get a review
from someone that actually uses Rust in anger - I only toy with it.

Cheers,
Kent.

^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-14 16:06                                 ` Kent Gibson
@ 2022-10-17 11:26                                   ` Viresh Kumar
  2022-10-17 11:34                                     ` Kent Gibson
  0 siblings, 1 reply; 37+ messages in thread
From: Viresh Kumar @ 2022-10-17 11:26 UTC (permalink / raw)
  To: Kent Gibson
  Cc: Bartosz Golaszewski, Miguel Ojeda, Linus Walleij,
	Vincent Guittot, linux-gpio, Alex Bennée, stratos-dev,
	Gerard Ryan

On 15-10-22, 00:06, Kent Gibson wrote:
> If the mutators for each field still exist they may as well be pub.
> 
> And they should return Result<&mut Self> so they can be chained, as you
> suggest.
> 
> Wrt the values param (which I would prefer was called props)

Is this fine now ? Rebased over v7.

diff --git a/bindings/rust/libgpiod/src/line_settings.rs b/bindings/rust/libgpiod/src/line_settings.rs
index 2c3090132ea5..be50b5b41c5a 100644
--- a/bindings/rust/libgpiod/src/line_settings.rs
+++ b/bindings/rust/libgpiod/src/line_settings.rs
@@ -70,18 +70,18 @@ impl Settings {
     }

     /// Set line prop setting.
-    pub fn set_prop(&mut self, values: &[SettingVal]) -> Result<()> {
-        for value in values {
-            match value {
-                SettingVal::Direction(val) => self.set_direction(*val)?,
-                SettingVal::EdgeDetection(val) => self.set_edge_detection(*val)?,
-                SettingVal::Bias(val) => self.set_bias(*val)?,
-                SettingVal::Drive(val) => self.set_drive(*val)?,
-                SettingVal::ActiveLow(val) => self.set_active_low(*val),
-                SettingVal::DebouncePeriod(val) => self.set_debounce_period(*val),
-                SettingVal::EventClock(val) => self.set_event_clock(*val)?,
-                SettingVal::OutputValue(val) => self.set_output_value(*val)?,
-            }
+    pub fn set_prop(&mut self, props: &[SettingVal]) -> Result<()> {
+        for property in props {
+            match property {
+                SettingVal::Direction(prop) => self.set_direction(*prop)?,
+                SettingVal::EdgeDetection(prop) => self.set_edge_detection(*prop)?,
+                SettingVal::Bias(prop) => self.set_bias(*prop)?,
+                SettingVal::Drive(prop) => self.set_drive(*prop)?,
+                SettingVal::ActiveLow(prop) => self.set_active_low(*prop),
+                SettingVal::DebouncePeriod(prop) => self.set_debounce_period(*prop),
+                SettingVal::EventClock(prop) => self.set_event_clock(*prop)?,
+                SettingVal::OutputValue(prop) => self.set_output_value(*prop)?,
+            };
         }

         Ok(())
@@ -102,7 +102,7 @@ impl Settings {
     }

     /// Set the line direction.
-    fn set_direction(&mut self, direction: Direction) -> Result<()> {
+    pub fn set_direction(&mut self, direction: Direction) -> Result<&mut Self> {
         let ret = unsafe {
             gpiod::gpiod_line_settings_set_direction(
                 self.settings,
@@ -116,17 +116,17 @@ impl Settings {
                 Errno::last(),
             ))
         } else {
-            Ok(())
+            Ok(self)
         }
     }

     /// Get the direction setting.
-    fn direction(&self) -> Result<Direction> {
+    pub fn direction(&self) -> Result<Direction> {
         Direction::new(unsafe { gpiod::gpiod_line_settings_get_direction(self.settings) } as u32)
     }

     /// Set the edge event detection setting.
-    fn set_edge_detection(&mut self, edge: Option<Edge>) -> Result<()> {
+    pub fn set_edge_detection(&mut self, edge: Option<Edge>) -> Result<&mut Self> {
         let ret = unsafe {
             gpiod::gpiod_line_settings_set_edge_detection(
                 self.settings,
@@ -140,17 +140,17 @@ impl Settings {
                 Errno::last(),
             ))
         } else {
-            Ok(())
+            Ok(self)
         }
     }

     /// Get the edge event detection setting.
-    fn edge_detection(&self) -> Result<Option<Edge>> {
+    pub fn edge_detection(&self) -> Result<Option<Edge>> {
         Edge::new(unsafe { gpiod::gpiod_line_settings_get_edge_detection(self.settings) } as u32)
     }

     /// Set the bias setting.
-    fn set_bias(&mut self, bias: Option<Bias>) -> Result<()> {
+    pub fn set_bias(&mut self, bias: Option<Bias>) -> Result<&mut Self> {
         let ret = unsafe {
             gpiod::gpiod_line_settings_set_bias(self.settings, Bias::gpiod_bias(bias) as i32)
         };
@@ -161,17 +161,17 @@ impl Settings {
                 Errno::last(),
             ))
         } else {
-            Ok(())
+            Ok(self)
         }
     }

     /// Get the bias setting.
-    fn bias(&self) -> Result<Option<Bias>> {
+    pub fn bias(&self) -> Result<Option<Bias>> {
         Bias::new(unsafe { gpiod::gpiod_line_settings_get_bias(self.settings) } as u32)
     }

     /// Set the drive setting.
-    fn set_drive(&mut self, drive: Drive) -> Result<()> {
+    pub fn set_drive(&mut self, drive: Drive) -> Result<&mut Self> {
         let ret = unsafe {
             gpiod::gpiod_line_settings_set_drive(self.settings, drive.gpiod_drive() as i32)
         };
@@ -182,44 +182,49 @@ impl Settings {
                 Errno::last(),
             ))
         } else {
-            Ok(())
+            Ok(self)
         }
     }

     /// Get the drive setting.
-    fn drive(&self) -> Result<Drive> {
+    pub fn drive(&self) -> Result<Drive> {
         Drive::new(unsafe { gpiod::gpiod_line_settings_get_drive(self.settings) } as u32)
     }

     /// Set active-low setting.
-    fn set_active_low(&mut self, active_low: bool) {
-        unsafe { gpiod::gpiod_line_settings_set_active_low(self.settings, active_low) }
+    pub fn set_active_low(&mut self, active_low: bool) -> &mut Self {
+        unsafe {
+            gpiod::gpiod_line_settings_set_active_low(self.settings, active_low);
+        }
+        self
     }

     /// Check the active-low setting.
-    fn active_low(&self) -> bool {
+    pub fn active_low(&self) -> bool {
         unsafe { gpiod::gpiod_line_settings_get_active_low(self.settings) }
     }

     /// Set the debounce period setting.
-    fn set_debounce_period(&mut self, period: Duration) {
+    pub fn set_debounce_period(&mut self, period: Duration) -> &mut Self {
         unsafe {
             gpiod::gpiod_line_settings_set_debounce_period_us(
                 self.settings,
                 period.as_micros() as u64,
-            )
+            );
         }
+
+        self
     }

     /// Get the debounce period.
-    fn debounce_period(&self) -> Result<Duration> {
+    pub fn debounce_period(&self) -> Result<Duration> {
         Ok(Duration::from_micros(unsafe {
             gpiod::gpiod_line_settings_get_debounce_period_us(self.settings)
         }))
     }

     /// Set the event clock setting.
-    fn set_event_clock(&mut self, clock: EventClock) -> Result<()> {
+    pub fn set_event_clock(&mut self, clock: EventClock) -> Result<&mut Self> {
         let ret = unsafe {
             gpiod::gpiod_line_settings_set_event_clock(self.settings, clock.gpiod_clock() as i32)
         };
@@ -230,17 +235,17 @@ impl Settings {
                 Errno::last(),
             ))
         } else {
-            Ok(())
+            Ok(self)
         }
     }

     /// Get the event clock setting.
-    fn event_clock(&self) -> Result<EventClock> {
+    pub fn event_clock(&self) -> Result<EventClock> {
         EventClock::new(unsafe { gpiod::gpiod_line_settings_get_event_clock(self.settings) } as u32)
     }

     /// Set the output value setting.
-    fn set_output_value(&mut self, value: Value) -> Result<()> {
+    pub fn set_output_value(&mut self, value: Value) -> Result<&mut Self> {
         let ret =
             unsafe { gpiod::gpiod_line_settings_set_output_value(self.settings, value.value()) };

@@ -250,12 +255,12 @@ impl Settings {
                 Errno::last(),
             ))
         } else {
-            Ok(())
+            Ok(self)
         }
     }

     /// Get the output value, 0 or 1.
-    fn output_value(&self) -> Result<Value> {
+    pub fn output_value(&self) -> Result<Value> {
         let value = unsafe { gpiod::gpiod_line_settings_get_output_value(self.settings) };

         if value != 0 && value != 1 {

-- 
viresh

^ permalink raw reply related	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-17 11:26                                   ` Viresh Kumar
@ 2022-10-17 11:34                                     ` Kent Gibson
  2022-10-17 11:37                                       ` Viresh Kumar
  0 siblings, 1 reply; 37+ messages in thread
From: Kent Gibson @ 2022-10-17 11:34 UTC (permalink / raw)
  To: Viresh Kumar
  Cc: Bartosz Golaszewski, Miguel Ojeda, Linus Walleij,
	Vincent Guittot, linux-gpio, Alex Bennée, stratos-dev,
	Gerard Ryan

On Mon, Oct 17, 2022 at 04:56:25PM +0530, Viresh Kumar wrote:
> On 15-10-22, 00:06, Kent Gibson wrote:
> > If the mutators for each field still exist they may as well be pub.
> > 
> > And they should return Result<&mut Self> so they can be chained, as you
> > suggest.
> > 
> > Wrt the values param (which I would prefer was called props)
> 
> Is this fine now ? Rebased over v7.
> 
> diff --git a/bindings/rust/libgpiod/src/line_settings.rs b/bindings/rust/libgpiod/src/line_settings.rs
> index 2c3090132ea5..be50b5b41c5a 100644
> --- a/bindings/rust/libgpiod/src/line_settings.rs
> +++ b/bindings/rust/libgpiod/src/line_settings.rs
> @@ -70,18 +70,18 @@ impl Settings {
>      }
> 
>      /// Set line prop setting.
> -    pub fn set_prop(&mut self, values: &[SettingVal]) -> Result<()> {
> -        for value in values {
> -            match value {
> -                SettingVal::Direction(val) => self.set_direction(*val)?,
> -                SettingVal::EdgeDetection(val) => self.set_edge_detection(*val)?,
> -                SettingVal::Bias(val) => self.set_bias(*val)?,
> -                SettingVal::Drive(val) => self.set_drive(*val)?,
> -                SettingVal::ActiveLow(val) => self.set_active_low(*val),
> -                SettingVal::DebouncePeriod(val) => self.set_debounce_period(*val),
> -                SettingVal::EventClock(val) => self.set_event_clock(*val)?,
> -                SettingVal::OutputValue(val) => self.set_output_value(*val)?,
> -            }
> +    pub fn set_prop(&mut self, props: &[SettingVal]) -> Result<()> {
                                                                  ^   
                                                        also &mut Self

Apart from that, yeah that is what I had in mind, as also noted in my
forthcoming v7 review.

Cheers,
Kent.


^ permalink raw reply	[flat|nested] 37+ messages in thread

* Re: [PATCH V6 3/8] libgpiod: Add rust wrapper crate
  2022-10-17 11:34                                     ` Kent Gibson
@ 2022-10-17 11:37                                       ` Viresh Kumar
  0 siblings, 0 replies; 37+ messages in thread
From: Viresh Kumar @ 2022-10-17 11:37 UTC (permalink / raw)
  To: Kent Gibson
  Cc: Bartosz Golaszewski, Miguel Ojeda, Linus Walleij,
	Vincent Guittot, linux-gpio, Alex Bennée, stratos-dev,
	Gerard Ryan

On 17-10-22, 19:34, Kent Gibson wrote:
> > +    pub fn set_prop(&mut self, props: &[SettingVal]) -> Result<()> {
>                                                                   ^   
>                                                         also &mut Self
> 
> Apart from that, yeah that is what I had in mind, as also noted in my
> forthcoming v7 review.

Ahh yes.

diff --git a/bindings/rust/libgpiod/src/line_settings.rs b/bindings/rust/libgpiod/src/line_settings.rs
index be50b5b41c5a..92e8928517f7 100644
--- a/bindings/rust/libgpiod/src/line_settings.rs
+++ b/bindings/rust/libgpiod/src/line_settings.rs
@@ -70,7 +70,7 @@ impl Settings {
     }

     /// Set line prop setting.
-    pub fn set_prop(&mut self, props: &[SettingVal]) -> Result<()> {
+    pub fn set_prop(&mut self, props: &[SettingVal]) -> Result<&mut Self> {
         for property in props {
             match property {
                 SettingVal::Direction(prop) => self.set_direction(*prop)?,
@@ -84,7 +84,7 @@ impl Settings {
             };
         }

-        Ok(())
+        Ok(self)
     }

     /// Get the line prop setting.

-- 
viresh

^ permalink raw reply related	[flat|nested] 37+ messages in thread

end of thread, other threads:[~2022-10-17 11:37 UTC | newest]

Thread overview: 37+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-09-26 11:08 [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 1/8] libgpiod: Add libgpiod-sys rust crate Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 2/8] libgpiod-sys: Add pre generated rust bindings Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 3/8] libgpiod: Add rust wrapper crate Viresh Kumar
2022-09-26 13:29   ` Bartosz Golaszewski
2022-09-26 15:26     ` Viresh Kumar
2022-09-27 13:18       ` Bartosz Golaszewski
2022-09-27 13:57         ` Viresh Kumar
2022-09-27 15:25           ` Bartosz Golaszewski
2022-09-28 11:10             ` Viresh Kumar
2022-09-28 12:20               ` Bartosz Golaszewski
2022-09-28 15:17                 ` Viresh Kumar
2022-09-28 17:54                   ` Bartosz Golaszewski
2022-09-29  6:54                     ` Viresh Kumar
2022-09-29  7:37                       ` Bartosz Golaszewski
2022-09-29  8:58                         ` Viresh Kumar
2022-09-29 11:16                           ` Bartosz Golaszewski
2022-09-29 11:43                         ` Kent Gibson
2022-09-29 13:55                     ` Miguel Ojeda
2022-10-11  4:16                       ` Viresh Kumar
2022-10-11  4:25                         ` Kent Gibson
2022-10-11  4:37                           ` Viresh Kumar
2022-10-11  4:46                             ` Viresh Kumar
2022-10-13  6:12                         ` Viresh Kumar
2022-10-14  9:45                           ` Bartosz Golaszewski
2022-10-14  9:57                             ` Viresh Kumar
2022-10-14 14:25                               ` Bartosz Golaszewski
2022-10-14 16:06                                 ` Kent Gibson
2022-10-17 11:26                                   ` Viresh Kumar
2022-10-17 11:34                                     ` Kent Gibson
2022-10-17 11:37                                       ` Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 4/8] libgpiod: Add rust examples Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 5/8] libgpiod: Add gpiosim rust crate Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 6/8] gpiosim: Add pre generated rust bindings Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 7/8] libgpiod: Add rust tests Viresh Kumar
2022-09-26 11:08 ` [PATCH V6 8/8] libgpiod: Integrate building of rust bindings with make Viresh Kumar
2022-09-26 15:57 ` [PATCH V6 0/8] libgpiod: Add Rust bindings Viresh Kumar

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