write: add gpio write support

Signed-off-by: Paul Osborne <[email protected]>

Author: posborne

src/commands/gpio_write.rs

@@ -0,0 +1,26 @@
+// Copyright (C) 2016, The gpio-utils Authors
+
+use options::GpioWriteOptions;
+use config::GpioConfig;
+use std::process::exit;
+use sysfs_gpio::Direction;
+
+pub fn main(config: &GpioConfig, opts: &GpioWriteOptions) {
+    let pin_config = match config.get_pin(&opts.pin[..]) {
+        Some(pin) => pin,
+        None => {
+            println!("Unable to find config entry for pin '{}'", opts.pin);
+            exit(1);
+        }
+    };
+
+    let pin = pin_config.get_pin();
+    pin.set_direction(Direction::Out).unwrap_or_else(|e| {
+        println!("Error setting GPIO direction: {:?}", e);
+        exit(1)
+    });
+    pin.set_value(opts.value).unwrap_or_else(|e| {
+        println!("There was an error writing to the gpio: {:?}", e);
+        exit(1);
+    });
+}

src/commands/mod.rs

@@ -3,3 +3,4 @@
 pub mod gpio_read;
 pub mod gpio_export;
 pub mod gpio_exportall;
+pub mod gpio_write;

src/main.rs

@@ -11,6 +11,7 @@ use clap::{Arg, App, SubCommand, AppSettings};
 use gpio_utils::options::*;
 use gpio_utils::commands::*;
 use gpio_utils::config::{self, GpioConfig};
+use std::process::exit;
 
 fn main() {
     env_logger::init().unwrap();
@@ -51,6 +52,10 @@ fn main() {
                     .arg(Arg::with_name("pin")
                          .help("The pin name (or number)")
                          .index(1)
+                         .required(true))
+                    .arg(Arg::with_name("value")
+                         .help("Value to write to pin (0|1)")
+                         .index(2)
                          .required(true)))
 
         // gpio export
@@ -128,7 +133,21 @@ fn main() {
             gpio_read::main(&cfg, &read_options);
         }
         ("poll", Some(_)) => {}
-        ("write", Some(_)) => {}
+        ("write", Some(m)) => {
+            let write_options = GpioWriteOptions {
+                gpio_opts: gpio_options,
+                pin: String::from(m.value_of("pin").unwrap()),
+                value: match m.value_of("value").unwrap().parse::<u8>() {
+                    Ok(value) => value,
+                    Err(_) => {
+                        println!("Provided value {:?} is not valid",
+                                 m.value_of("value").unwrap());
+                        exit(1);
+                    }
+                },
+            };
+            gpio_write::main(&cfg, &write_options);
+        }
         ("export", Some(m)) => {
             let export_options = GpioExportOptions {
                 gpio_opts: gpio_options,
@@ -138,7 +157,6 @@ fn main() {
                     None => None,
                 },
             };
-
             gpio_export::main(&cfg, &export_options);
         }
         ("export-all", Some(m)) => {
@@ -149,7 +167,6 @@ fn main() {
                     None => None,
                 },
             };
-
             gpio_exportall::main(&cfg, &exportall_options);
         }
         ("unexport", Some(_)) => {}

src/options.rs

@@ -15,6 +15,7 @@ pub struct GpioReadOptions {
 pub struct GpioWriteOptions {
     pub gpio_opts: GpioOptions,
     pub pin: String,
+    pub value: u8,
 }
 
 #[derive(Debug)]