Merge pull request tock#498 from tock/example-gpio

Add GPIO example

apis/gpio/src/lib.rs

@@ -6,15 +6,15 @@ use libtock_platform::{
     share::Handle, subscribe::OneId, DefaultConfig, ErrorCode, Subscribe, Syscalls, Upcall,
 };
 
-/// The Gpio driver
+/// The GPIO driver.
 ///
 /// # Example
 /// ```ignore
-/// use libtock::Gpios;
-///
-/// // Turn on led 0
-/// let pin = Gpios::get_pin(0)?;
+/// use libtock::gpio;
 ///
+/// // Set pin to high.
+/// let pin = gpio::Gpio::get_pin(0).unwrap().make_output().unwrap();
+/// let _ = pin.set();
 /// ```
 
 #[derive(Copy, Clone, Eq, PartialEq, Debug)]

examples/gpio.rs

@@ -0,0 +1,43 @@
+//! A simple GPIO example for getting GPIO interrupts.
+//!
+//! This will configure GPIO 0 to be a rising-edge triggered interrupt and print
+//! a message when the interrupt is triggered.
+
+#![no_main]
+#![no_std]
+
+use core::fmt::Write;
+use libtock::console::Console;
+use libtock::gpio;
+use libtock::gpio::Gpio;
+use libtock::runtime::{set_main, stack_size};
+use libtock_platform::{share, Syscalls};
+use libtock_runtime::TockSyscalls;
+
+set_main! {main}
+stack_size! {0x1000}
+
+fn main() {
+    let listener = gpio::GpioInterruptListener(|gpio_index, state| {
+        writeln!(Console::writer(), "GPIO[{}]: {:?}", gpio_index, state).unwrap();
+    });
+
+    if !Gpio::count().is_ok_and(|c| c > 0) {
+        writeln!(Console::writer(), "No GPIO pins on this board.").unwrap();
+        return;
+    }
+
+    // Configure pin 0 as an input and enable rising interrupts
+    let pin = Gpio::get_pin(0).unwrap();
+    let input_pin = pin.make_input::<gpio::PullNone>().unwrap();
+    let _ = input_pin.enable_interrupts(gpio::PinInterruptEdge::Rising);
+
+    // Wait for callbacks.
+    share::scope(|subscribe| {
+        Gpio::register_listener(&listener, subscribe).unwrap();
+
+        loop {
+            TockSyscalls::yield_wait();
+        }
+    });
+}