From 909a5fe2e513ef91129a29ccdd8772824879383c Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Thu, 27 Apr 2023 02:12:49 +0200
Subject: rp/pio: split irqs from state machines

we can only have one active waiter for any given irq at any given time.
allowing waits for irqs on state machines bypasses this limitation and
causes lost events for all but the latest waiter for a given irq.
splitting this out also allows us to signal from state machines to other
parts of the application without monopolizing state machine access for
the irq wait, as would be necessary to make irq waiting sound.
---
 examples/rp/src/bin/pio_async.rs   | 9 +++++----
 examples/rp/src/bin/pio_hd44780.rs | 7 +++++--
 2 files changed, 10 insertions(+), 6 deletions(-)

(limited to 'examples')

diff --git a/examples/rp/src/bin/pio_async.rs b/examples/rp/src/bin/pio_async.rs
index 11b290869..3d76a7d7b 100644
--- a/examples/rp/src/bin/pio_async.rs
+++ b/examples/rp/src/bin/pio_async.rs
@@ -4,7 +4,7 @@
 use defmt::info;
 use embassy_executor::Spawner;
 use embassy_rp::peripherals::PIO0;
-use embassy_rp::pio::{Pio, PioCommon, PioPin, PioStateMachine, ShiftDirection};
+use embassy_rp::pio::{Pio, PioCommon, PioIrq, PioPin, PioStateMachine, ShiftDirection};
 use embassy_rp::pio_instr_util;
 use embassy_rp::relocate::RelocatedProgram;
 use {defmt_rtt as _, panic_probe as _};
@@ -99,10 +99,10 @@ fn setup_pio_task_sm2(pio: &mut PioCommon<PIO0>, sm: &mut PioStateMachine<PIO0,
 }
 
 #[embassy_executor::task]
-async fn pio_task_sm2(mut sm: PioStateMachine<'static, PIO0, 2>) {
+async fn pio_task_sm2(mut irq: PioIrq<'static, PIO0, 3>, mut sm: PioStateMachine<'static, PIO0, 2>) {
     sm.set_enable(true);
     loop {
-        sm.wait_irq(3).await;
+        irq.wait().await;
         info!("IRQ trigged");
     }
 }
@@ -114,6 +114,7 @@ async fn main(spawner: Spawner) {
 
     let Pio {
         mut common,
+        irq3,
         mut sm0,
         mut sm1,
         mut sm2,
@@ -125,5 +126,5 @@ async fn main(spawner: Spawner) {
     setup_pio_task_sm2(&mut common, &mut sm2);
     spawner.spawn(pio_task_sm0(sm0)).unwrap();
     spawner.spawn(pio_task_sm1(sm1)).unwrap();
-    spawner.spawn(pio_task_sm2(sm2)).unwrap();
+    spawner.spawn(pio_task_sm2(irq3, sm2)).unwrap();
 }
diff --git a/examples/rp/src/bin/pio_hd44780.rs b/examples/rp/src/bin/pio_hd44780.rs
index bc51d43c4..7c1d7acfe 100644
--- a/examples/rp/src/bin/pio_hd44780.rs
+++ b/examples/rp/src/bin/pio_hd44780.rs
@@ -85,7 +85,10 @@ impl<'l> HD44780<'l> {
 
         let db7pin = db7.pin();
         let Pio {
-            mut common, mut sm0, ..
+            mut common,
+            mut irq0,
+            mut sm0,
+            ..
         } = Pio::new(pio);
 
         // takes command words (<wait:24> <command:4> <0:4>)
@@ -145,7 +148,7 @@ impl<'l> HD44780<'l> {
         sm0.push_tx((50 << 8) | 0x20);
         sm0.push_tx(0b1100_0000);
 
-        sm0.wait_irq(0).await;
+        irq0.wait().await;
         sm0.set_enable(false);
 
         // takes command sequences (<rs:1> <count:7>, data...)
-- 
cgit