1 // Copyright (c) 2018 The rust-gpio-cdev Project Developers.
2 //
3 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6 // option. This file may not be copied, modified, or distributed
7 // except according to those terms.
8
9 use gpio_cdev::{Chip, LineRequestFlags};
10 use quicli::prelude::*;
11 use structopt::StructOpt;
12
13 #[derive(Debug, StructOpt)]
14 struct Cli {
15 /// The gpiochip device (e.g. /dev/gpiochip0)
16 chip: String,
17 /// The offset of the GPIO line for the provided chip
18 line: u32,
19 /// The value to write
20 value: u8,
21 }
22
do_main(args: Cli) -> std::result::Result<(), gpio_cdev::Error>23 fn do_main(args: Cli) -> std::result::Result<(), gpio_cdev::Error> {
24 let mut chip = Chip::new(args.chip)?;
25
26 // NOTE: we set the default value to the desired state so
27 // setting it separately is not required. The LineHandle
28 // instance that is returned by request must be owned by a
29 // variable for the duration of the time that the line will
30 // be used. If the instance is not assigned to a variable,
31 // then the LineHandle will be immediately dropped after
32 // request returns and the pin will appear to do nothing.
33 let _handle =
34 chip.get_line(args.line)?
35 .request(LineRequestFlags::OUTPUT, args.value, "driveoutput")?;
36
37 println!("Output being driven... Enter to exit");
38 let mut buf = String::new();
39 ::std::io::stdin().read_line(&mut buf)?;
40
41 Ok(())
42 }
43
main() -> CliResult44 fn main() -> CliResult {
45 let args = Cli::from_args();
46 do_main(args).or_else(|e| {
47 error!("{:?}", e);
48 Ok(())
49 })
50 }
51