[Stratos-dev] Re: [PATCH V7 4/8] libgpiod: Add rust examples

On Fri, Oct 14, 2022 at 04:17:21PM +0530, Viresh Kumar wrote:

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

Add an example that exercises the event buffer, demonstrating that its is not possible to read new events while the previous set are still in use.

I added something along those lines, based on gpiomon, in my mods branch mentioned in patch 3.

If multi-threading is supported, perhaps some examples demonstrating that as well. Even if there are tests that already cover it - major features should have explicit examples, not require rooting around through the test suite.

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)])?;

This is an example of where

lsettings.set_direction(Direction::Input)?;

would be simpler and clearer.

Cheers, Kent.