libasync, libboard_zynq: add block_async glue, make GlobalTimer sharable

Cargo.lock

@@ -38,6 +38,7 @@ dependencies = [
 name = "experiments"
 version = "0.0.0"
 dependencies = [
+ "embedded-hal 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libasync 0.0.0",
  "libboard_zynq 0.0.0",
  "libcortex_a9 0.0.0",
@@ -50,8 +51,10 @@ dependencies = [
 name = "libasync"
 version = "0.0.0"
 dependencies = [
+ "embedded-hal 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libboard_zynq 0.0.0",
  "libcortex_a9 0.0.0",
+ "nb 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "smoltcp 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

experiments/Cargo.toml

@@ -12,6 +12,7 @@ default = ["target_zc706"]
 
 [dependencies]
 log = "0.4"
+embedded-hal = "0.2"
 libregister = { path = "../libregister" }
 libcortex_a9 = { path = "../libcortex_a9" }
 libboard_zynq = { path = "../libboard_zynq" }

experiments/src/main.rs

@@ -6,6 +6,8 @@ extern crate alloc;
 use core::{mem::transmute, task::Poll};
 use alloc::{borrow::ToOwned, collections::BTreeMap, format};
 use log::info;
+use embedded_hal::timer::CountDown;
+use libregister::RegisterR;
 use libcortex_a9::{mutex::Mutex, sync_channel::{self, sync_channel}};
 use libboard_zynq::{
     print, println,
@@ -18,12 +20,13 @@ use libboard_zynq::{
         socket::SocketSet,
         socket::{TcpSocket, TcpSocketBuffer},
     },
+    time::Milliseconds,
 };
 use libsupport_zynq::{
     ram, alloc::{vec, vec::Vec},
     boot,
 };
-use libasync::{smoltcp::{Sockets, TcpStream}, task};
+use libasync::{delay, smoltcp::{Sockets, TcpStream}, task};
 
 mod ps7_init;
 
@@ -39,10 +42,7 @@ pub fn main_core0() {
     libsupport_zynq::logger::init().unwrap();
     log::set_max_level(log::LevelFilter::Trace);
 
-    {
-        use libregister::RegisterR;
-        info!("Boot mode: {:?}", zynq::slcr::RegisterBlock::new().boot_mode.read().boot_mode_pins());
-    }
+    info!("Boot mode: {:?}", zynq::slcr::RegisterBlock::new().boot_mode.read().boot_mode_pins());
 
     #[cfg(feature = "target_zc706")]
     const CPU_FREQ: u32 = 800_000_000;
@@ -72,6 +72,8 @@ pub fn main_core0() {
     }
     let mut flash = flash.stop();
 
+    let timer = libboard_zynq::timer::GlobalTimer::new();
+
     let mut ddr = zynq::ddr::DdrRam::new();
     #[cfg(not(feature = "target_zc706"))]
     ddr.memtest();
@@ -262,10 +264,16 @@ pub fn main_core0() {
         }
     });
 
-    let mut time = 0u32;
+    let mut countdown = timer.countdown();
+    task::spawn(async move {
+        loop {
+            delay(&mut countdown, Milliseconds(1000)).await;
+            println!("time: {} ms", timer.get_time().0);
+        }
+    });
+
     Sockets::run(&mut iface, || {
-        time += 1;
-        Instant::from_millis(time)
+        Instant::from_millis(timer.get_time().0 as i64)
     })
 }
 

libasync/Cargo.toml

@@ -8,6 +8,8 @@ edition = "2018"
 [dependencies]
 #futures = { version = "0.3", default-features = false }
 pin-utils = "0.1.0-alpha.4"
+embedded-hal = "0.2"
+nb = "0.1"
 libcortex_a9 = { path = "../libcortex_a9" }
 
 [dependencies.smoltcp]

libasync/src/lib.rs

@@ -4,5 +4,33 @@ extern crate alloc;
 
 pub mod task;
 pub mod executor;
+mod delay;
+pub use delay::delay;
 
 pub mod smoltcp;
+
+/// Reexport for macro use
+pub use nb;
+
+/// The `nb` crate's `block!` macro adapted for async fns
+///
+/// Call `.await` on the result!
+#[macro_export]
+macro_rules! block_async {
+    ($e:expr) => {
+        async {
+            loop {
+                #[allow(unreachable_patterns)]
+                match $e {
+                    Err($crate::nb::Error::Other(e)) => {
+                        #[allow(unreachable_code)]
+                        break Err(e)
+                    },
+                    Err($crate::nb::Error::WouldBlock) =>
+                        $crate::task::r#yield().await,
+                    Ok(x) => break Ok(x),
+                }
+            }
+        }
+    }
+}

libboard_zynq/src/time.rs

@@ -1,2 +1,10 @@
 #[derive(Debug, Clone, PartialEq, PartialOrd)]
 pub struct Milliseconds(pub u64);
+
+impl core::ops::Add for Milliseconds {
+    type Output = Self;
+
+    fn add(self, rhs: Self) -> Self::Output {
+        Milliseconds(self.0 + rhs.0)
+    }
+}

libboard_zynq/src/timer/global.rs

@@ -7,32 +7,34 @@ use crate::{
 };
 
 /// "uptime"
+#[derive(Clone, Copy)]
 pub struct GlobalTimer {
-    regs: &'static mut mpcore::RegisterBlock,
+    regs: &'static mpcore::RegisterBlock,
 }
 
 impl GlobalTimer {
     pub fn new() -> GlobalTimer {
-        let regs = mpcore::RegisterBlock::new();
+        let mut regs = mpcore::RegisterBlock::new();
+        Self::reset(&mut regs);
         GlobalTimer { regs }
     }
 
-    pub fn reset(&mut self) {
+    fn reset(regs: &mut mpcore::RegisterBlock) {
         // Disable
-        self.regs.global_timer_control.write(
+        regs.global_timer_control.write(
             mpcore::GlobalTimerControl::zeroed()
         );
 
         // Reset counters
-        self.regs.global_timer_counter0.write(
+        regs.global_timer_counter0.write(
             mpcore::ValueRegister::zeroed()
         );
-        self.regs.global_timer_counter1.write(
+        regs.global_timer_counter1.write(
             mpcore::ValueRegister::zeroed()
         );
 
         // Start
-        self.regs.global_timer_control.write(
+        regs.global_timer_control.write(
             mpcore::GlobalTimerControl::zeroed()
                 // maximum prescaler is still enough for millisecond
                 // precision while overflowing after centuries.
@@ -68,23 +70,23 @@ impl GlobalTimer {
     /// `embedded_hal::timer::CountDown`
     pub fn countdown(&self) -> CountDown {
         CountDown {
-            timer: &self,
+            timer: self.clone(),
             timeout: Milliseconds(0),
         }
     }
 }
 
 #[derive(Clone)]
-pub struct CountDown<'a> {
-    timer: &'a GlobalTimer,
+pub struct CountDown {
+    timer: GlobalTimer,
     timeout: Milliseconds,
 }
 
-impl embedded_hal::timer::CountDown for CountDown<'_> {
+impl embedded_hal::timer::CountDown for CountDown {
     type Time = Milliseconds;
 
     fn start<T: Into<Self::Time>>(&mut self, count: T) {
-        self.timeout = count.into();
+        self.timeout = self.timer.get_time() + count.into();
     }
 
     fn wait(&mut self) -> nb::Result<(), Void> {