Temperature API

Cargo.toml

@@ -18,6 +18,7 @@ libtock_leds = { path = "apis/leds" }
 libtock_low_level_debug = { path = "apis/low_level_debug" }
 libtock_platform = { path = "platform" }
 libtock_runtime = { path = "runtime" }
+libtock_temperature = { path = "apis/temperature"}
 
 [profile.dev]
 panic = "abort"
@@ -38,6 +39,7 @@ members = [
     "apis/console",
     "apis/leds",
     "apis/low_level_debug",
+    "apis/temperature",
     "panic_handlers/debug_panic",
     "panic_handlers/small_panic",
     "platform",

apis/temperature/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "libtock_temperature"
+version = "0.1.0"
+authors = ["Tock Project Developers <tock-dev@googlegroups.com>"]
+license = "MIT/Apache-2.0"
+edition = "2021"
+repository = "https://www.github.com/tock/libtock-rs"
+description = "libtock temperature driver"
+
+[dependencies]
+libtock_platform = { path = "../../platform" }
+
+[dev-dependencies]
+libtock_unittest = { path = "../../unittest" }

apis/temperature/src/lib.rs

@@ -0,0 +1,81 @@
+#![no_std]
+
+use core::cell::Cell;
+use libtock_platform::{
+    share, subscribe::OneId, DefaultConfig, ErrorCode, Subscribe, Syscalls, Upcall,
+};
+
+pub struct Temperature<S: Syscalls>(S);
+
+impl<S: Syscalls> Temperature<S> {
+    /// Returns Ok() if the driver was present.This does not necessarily mean
+    /// that the driver is working.
+    pub fn exists() -> Result<(), ErrorCode> {
+        S::command(DRIVER_NUM, EXISTS, 0, 0).to_result()
+    }
+
+    /// Initiate a temperature measurement.
+    ///
+    /// This function is used both for synchronous and asynchronous readings
+    pub fn read_temperature() -> Result<(), ErrorCode> {
+        S::command(DRIVER_NUM, READ_TEMP, 0, 0).to_result()
+    }
+
+    /// Register an events listener
+    pub fn register_listener<'share, F: Fn(i32)>(
+        listener: &'share TemperatureListener<F>,
+        subscribe: share::Handle<Subscribe<'share, S, DRIVER_NUM, 0>>,
+    ) -> Result<(), ErrorCode> {
+        S::subscribe::<_, _, DefaultConfig, DRIVER_NUM, 0>(subscribe, listener)
+    }
+
+    /// Unregister the events listener
+    pub fn unregister_listener() {
+        S::unsubscribe(DRIVER_NUM, 0)
+    }
+
+    /// Initiate a synchronous temperature measurement.
+    /// Returns Ok(temperature_value) if the operation was successful
+    /// temperature_value is returned in hundreds of centigrades
+    pub fn read_temperature_sync() -> Result<i32, ErrorCode> {
+        let temperature_cell: Cell<Option<i32>> = Cell::new(None);
+        let listener = TemperatureListener(|temp_val| {
+            temperature_cell.set(Some(temp_val));
+        });
+        share::scope(|subscribe| {
+            if let Ok(()) = Self::register_listener(&listener, subscribe) {
+                if let Ok(()) = Self::read_temperature() {
+                    while temperature_cell.get() == None {
+                        S::yield_wait();
+                    }
+                }
+            }
+        });
+
+        match temperature_cell.get() {
+            None => Err(ErrorCode::Busy),
+            Some(temp_val) => Ok(temp_val),
+        }
+    }
+}
+
+pub struct TemperatureListener<F: Fn(i32)>(pub F);
+impl<F: Fn(i32)> Upcall<OneId<DRIVER_NUM, 0>> for TemperatureListener<F> {
+    fn upcall(&self, temp_val: u32, _arg1: u32, _arg2: u32) {
+        self.0(temp_val as i32)
+    }
+}
+
+#[cfg(test)]
+mod tests;
+
+// -----------------------------------------------------------------------------
+// Driver number and command IDs
+// -----------------------------------------------------------------------------
+
+const DRIVER_NUM: u32 = 0x60000;
+
+// Command IDs
+
+const EXISTS: u32 = 0;
+const READ_TEMP: u32 = 1;

apis/temperature/src/tests.rs

@@ -0,0 +1,81 @@
+use core::cell::Cell;
+use libtock_platform::{share, ErrorCode, Syscalls, YieldNoWaitReturn};
+use libtock_unittest::fake;
+
+type Temperature = super::Temperature<fake::Syscalls>;
+
+#[test]
+fn no_driver() {
+    let _kernel = fake::Kernel::new();
+    assert_eq!(Temperature::exists(), Err(ErrorCode::NoDevice));
+}
+
+#[test]
+fn driver_check() {
+    let kernel = fake::Kernel::new();
+    let driver = fake::Temperature::new();
+    kernel.add_driver(&driver);
+
+    assert_eq!(Temperature::exists(), Ok(()));
+}
+
+#[test]
+fn read_temperature() {
+    let kernel = fake::Kernel::new();
+    let driver = fake::Temperature::new();
+    kernel.add_driver(&driver);
+
+    assert_eq!(Temperature::read_temperature(), Ok(()));
+    assert!(driver.is_busy());
+
+    assert_eq!(Temperature::read_temperature(), Err(ErrorCode::Busy));
+    assert_eq!(Temperature::read_temperature_sync(), Err(ErrorCode::Busy));
+}
+
+#[test]
+fn register_unregister_listener() {
+    let kernel = fake::Kernel::new();
+    let driver = fake::Temperature::new();
+    kernel.add_driver(&driver);
+
+    let temperature_cell: Cell<Option<i32>> = Cell::new(None);
+    let listener = crate::TemperatureListener(|temp_val| {
+        temperature_cell.set(Some(temp_val));
+    });
+    share::scope(|subscribe| {
+        assert_eq!(Temperature::read_temperature(), Ok(()));
+        driver.set_value(100);
+        assert_eq!(fake::Syscalls::yield_no_wait(), YieldNoWaitReturn::NoUpcall);
+
+        assert_eq!(Temperature::register_listener(&listener, subscribe), Ok(()));
+        assert_eq!(Temperature::read_temperature(), Ok(()));
+        driver.set_value(100);
+        assert_eq!(fake::Syscalls::yield_no_wait(), YieldNoWaitReturn::Upcall);
+        assert_eq!(temperature_cell.get(), Some(100));
+
+        Temperature::unregister_listener();
+        assert_eq!(Temperature::read_temperature(), Ok(()));
+        driver.set_value(100);
+        assert_eq!(fake::Syscalls::yield_no_wait(), YieldNoWaitReturn::NoUpcall);
+    });
+}
+
+#[test]
+fn read_temperature_sync() {
+    let kernel = fake::Kernel::new();
+    let driver = fake::Temperature::new();
+    kernel.add_driver(&driver);
+
+    driver.set_value_sync(1000);
+    assert_eq!(Temperature::read_temperature_sync(), Ok(1000));
+}
+
+#[test]
+fn negative_value() {
+    let kernel = fake::Kernel::new();
+    let driver = fake::Temperature::new();
+    kernel.add_driver(&driver);
+
+    driver.set_value_sync(-1000);
+    assert_eq!(Temperature::read_temperature_sync(), Ok(-1000));
+}

examples/temperature.rs

@@ -0,0 +1,52 @@
+//! A simple libtock-rs example. Checks for temperature driver
+//! and samples the sensor every 2 seconds.
+
+#![no_main]
+#![no_std]
+
+use core::fmt::Write;
+use libtock::console::Console;
+
+use libtock::alarm::{Alarm, Milliseconds};
+use libtock::runtime::{set_main, stack_size};
+use libtock::temperature::Temperature;
+
+set_main! {main}
+stack_size! {0x200}
+
+fn main() {
+    match Temperature::exists() {
+        Ok(()) => writeln!(Console::writer(), "temperature driver available").unwrap(),
+        Err(_) => {
+            writeln!(Console::writer(), "temperature driver unavailable").unwrap();
+            return;
+        }
+    }
+
+    loop {
+        match Temperature::read_temperature_sync() {
+            Ok(temp_val) => {
+                if temp_val >= 0 {
+                    writeln!(
+                        Console::writer(),
+                        "Temperature: {}.{}*C\n",
+                        temp_val / 100,
+                        temp_val % 100
+                    )
+                    .unwrap()
+                } else {
+                    writeln!(
+                        Console::writer(),
+                        "Temperature: -{}.{}*C\n",
+                        (0 - temp_val) / 100,
+                        (0 - temp_val) % 100
+                    )
+                    .unwrap()
+                }
+            }
+            Err(_) => writeln!(Console::writer(), "error while reading temperature",).unwrap(),
+        }
+
+        Alarm::sleep_for(Milliseconds(2000)).unwrap();
+    }
+}

src/lib.rs

@@ -28,3 +28,8 @@ pub mod low_level_debug {
     pub type LowLevelDebug = lldb::LowLevelDebug<super::runtime::TockSyscalls>;
     pub use lldb::AlertCode;
 }
+
+pub mod temperature {
+    use libtock_temperature as temperature;
+    pub type Temperature = temperature::Temperature<super::runtime::TockSyscalls>;
+}

unittest/src/fake/mod.rs

@@ -18,6 +18,7 @@ mod leds;
 mod low_level_debug;
 mod syscall_driver;
 mod syscalls;
+mod temperature;
 
 pub use alarm::Alarm;
 pub use buttons::Buttons;
@@ -28,6 +29,7 @@ pub use leds::Leds;
 pub use low_level_debug::{LowLevelDebug, Message};
 pub use syscall_driver::SyscallDriver;
 pub use syscalls::Syscalls;
+pub use temperature::Temperature;
 
 #[cfg(test)]
 mod kernel_tests;

unittest/src/fake/temperature/mod.rs

@@ -0,0 +1,85 @@
+//! Fake implementation of the Temperature API, documented here:
+//! https://github.com/tock/tock/blob/master/doc/syscalls/60000_ambient_temperature.md
+//!
+//! Like the real API, `Temperature` controls a fake temperature sensor. It provides
+//! a function `set_value` used to immediately call an upcall with a temperature value read by the sensor
+//! and a function 'set_value_sync' used to call the upcall when the read command is received.
+
+use crate::{DriverInfo, DriverShareRef};
+use libtock_platform::{CommandReturn, ErrorCode};
+use std::cell::Cell;
+
+// The `upcall_on_command` field is set to Some(value) if an upcall(with value as its argument) should be called when read command is received,
+// or None otherwise. It was needed for testing `read_sync` library function which simulates a synchronous temperature read,
+// because it was impossible to schedule an upcall during the `synchronous` read in other ways.
+pub struct Temperature {
+    busy: Cell<bool>,
+    upcall_on_command: Cell<Option<i32>>,
+    share_ref: DriverShareRef,
+}
+
+impl Temperature {
+    pub fn new() -> std::rc::Rc<Temperature> {
+        std::rc::Rc::new(Temperature {
+            busy: Cell::new(false),
+            upcall_on_command: Cell::new(None),
+            share_ref: Default::default(),
+        })
+    }
+
+    pub fn is_busy(&self) -> bool {
+        self.busy.get()
+    }
+    pub fn set_value(&self, value: i32) {
+        if self.busy.get() {
+            self.share_ref
+                .schedule_upcall(0, (value as u32, 0, 0))
+                .expect("Unable to schedule upcall");
+            self.busy.set(false);
+        }
+    }
+    pub fn set_value_sync(&self, value: i32) {
+        self.upcall_on_command.set(Some(value));
+    }
+}
+
+impl crate::fake::SyscallDriver for Temperature {
+    fn info(&self) -> DriverInfo {
+        DriverInfo::new(DRIVER_NUM).upcall_count(1)
+    }
+
+    fn register(&self, share_ref: DriverShareRef) {
+        self.share_ref.replace(share_ref);
+    }
+
+    fn command(&self, command_id: u32, _argument0: u32, _argument1: u32) -> CommandReturn {
+        match command_id {
+            EXISTS => crate::command_return::success(),
+
+            READ_TEMP => {
+                if self.busy.get() {
+                    return crate::command_return::failure(ErrorCode::Busy);
+                }
+                self.busy.set(true);
+                if let Some(val) = self.upcall_on_command.take() {
+                    self.set_value(val);
+                }
+                crate::command_return::success()
+            }
+            _ => crate::command_return::failure(ErrorCode::NoSupport),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests;
+// -----------------------------------------------------------------------------
+// Driver number and command IDs
+// -----------------------------------------------------------------------------
+
+const DRIVER_NUM: u32 = 0x60000;
+
+// Command IDs
+
+const EXISTS: u32 = 0;
+const READ_TEMP: u32 = 1;