From a81b96356191be59f91b7fa641a97f78d0d1cd25 Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Wed, 1 Sep 2021 23:54:26 +0200
Subject: [PATCH 1/2] nrf/saadc: don't use wake_on_interrupt.

---
 embassy-nrf/src/saadc.rs | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/embassy-nrf/src/saadc.rs b/embassy-nrf/src/saadc.rs
index 7bc38f1d..bc7f3471 100644
--- a/embassy-nrf/src/saadc.rs
+++ b/embassy-nrf/src/saadc.rs
@@ -2,17 +2,14 @@ use core::future::Future;
 use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
-use embassy::util::{wake_on_interrupt, Unborrow};
+use embassy::interrupt::InterruptExt;
+use embassy::util::{AtomicWaker, Unborrow};
 use embassy_hal_common::unborrow;
 use futures::future::poll_fn;
 
 use crate::interrupt;
 use crate::{pac, peripherals};
 
-#[cfg(feature = "9160")]
-use pac::{saadc_ns as saadc, SAADC_NS as SAADC};
-
-#[cfg(not(feature = "9160"))]
 use pac::{saadc, SAADC};
 
 pub use saadc::{
@@ -31,10 +28,11 @@ pub enum Error {}
 
 /// One-shot saadc. Continuous sample mode TODO.
 pub struct OneShot<'d> {
-    irq: interrupt::SAADC,
     phantom: PhantomData<&'d mut peripherals::SAADC>,
 }
 
+static WAKER: AtomicWaker = AtomicWaker::new();
+
 /// Used to configure the SAADC peripheral.
 ///
 /// See the `Default` impl for suitable default values.
@@ -108,18 +106,30 @@ impl<'d> OneShot<'d> {
         // Disable all events interrupts
         r.intenclr.write(|w| unsafe { w.bits(0x003F_FFFF) });
 
+        irq.set_handler(Self::on_interrupt);
+        irq.unpend();
+        irq.enable();
+
         Self {
-            irq,
             phantom: PhantomData,
         }
     }
 
-    fn regs(&self) -> &saadc::RegisterBlock {
+    fn on_interrupt(_ctx: *mut ()) {
+        let r = Self::regs();
+
+        if r.events_end.read().bits() != 0 {
+            r.intenclr.write(|w| w.end().clear());
+            WAKER.wake();
+        }
+    }
+
+    fn regs() -> &'static saadc::RegisterBlock {
         unsafe { &*SAADC::ptr() }
     }
 
     async fn sample_inner(&mut self, pin: PositiveChannel) -> i16 {
-        let r = self.regs();
+        let r = Self::regs();
 
         // Set positive channel
         r.ch[0].pselp.write(|w| w.pselp().variant(pin));
@@ -144,15 +154,15 @@ impl<'d> OneShot<'d> {
 
         // Wait for 'end' event.
         poll_fn(|cx| {
-            let r = self.regs();
+            let r = Self::regs();
+
+            WAKER.register(cx.waker());
 
             if r.events_end.read().bits() != 0 {
                 r.events_end.reset();
                 return Poll::Ready(());
             }
 
-            wake_on_interrupt(&mut self.irq, cx.waker());
-
             Poll::Pending
         })
         .await;
@@ -164,7 +174,7 @@ impl<'d> OneShot<'d> {
 
 impl<'d> Drop for OneShot<'d> {
     fn drop(&mut self) {
-        let r = self.regs();
+        let r = Self::regs();
         r.enable.write(|w| w.enable().disabled());
     }
 }

From 6b158ba94aa096619e218f0302eec35baeebaf12 Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Wed, 1 Sep 2021 23:55:20 +0200
Subject: [PATCH 2/2] nrf/saadc: add example

---
 examples/nrf/src/bin/saadc.rs | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 examples/nrf/src/bin/saadc.rs

diff --git a/examples/nrf/src/bin/saadc.rs b/examples/nrf/src/bin/saadc.rs
new file mode 100644
index 00000000..f96cf290
--- /dev/null
+++ b/examples/nrf/src/bin/saadc.rs
@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_nrf::saadc::{Config, OneShot, Sample};
+use embassy_nrf::{interrupt, Peripherals};
+use example_common::*;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, mut p: Peripherals) {
+    let config = Config::default();
+    let mut saadc = OneShot::new(p.SAADC, interrupt::take!(SAADC), config);
+
+    loop {
+        let sample = saadc.sample(&mut p.P0_02).await;
+        info!("sample: {=i16}", sample);
+        Timer::after(Duration::from_millis(100)).await;
+    }
+}