- Interconnect is now PPI again

- Scary pointer math is now contained in the tasks and events
- ppi now sets the tasks and events immediately and the struct is now zero-sized
- StaticToOne is renamed to ZeroToOne
- Used DPPI tasks and events now panic when enabled twice

10 files changed, 206 insertions, 173 deletions

diff --git a/embassy-nrf/src/buffered_uarte.rs b/embassy-nrf/src/buffered_uarte.rs
index 7c9a2344e..1dc04f4f6 100644
--- a/embassy-nrf/src/buffered_uarte.rs
+++ b/embassy-nrf/src/buffered_uarte.rs
@@ -14,8 +14,8 @@ use embassy_hal_common::{low_power_wait_until, unborrow};
 
 use crate::gpio::sealed::Pin as _;
 use crate::gpio::{OptionalPin as GpioOptionalPin, Pin as GpioPin};
-use crate::interconnect::{AnyChannel, Event, OneToOneChannel, OneToTwoChannel, Ppi, Task};
 use crate::pac;
+use crate::ppi::{AnyChannel, Event, OneToOneChannel, OneToTwoChannel, Ppi, Task};
 use crate::timer::Instance as TimerInstance;
 use crate::timer::{Frequency, Timer};
 use crate::uarte::{Config, Instance as UarteInstance};
diff --git a/embassy-nrf/src/gpiote.rs b/embassy-nrf/src/gpiote.rs
index 6703bfc60..7ec072ac8 100644
--- a/embassy-nrf/src/gpiote.rs
+++ b/embassy-nrf/src/gpiote.rs
@@ -11,8 +11,8 @@ use futures::future::poll_fn;
 
 use crate::gpio::sealed::Pin as _;
 use crate::gpio::{AnyPin, Input, Output, Pin as GpioPin};
-use crate::interconnect::{Event, Task};
 use crate::pac;
+use crate::ppi::{Event, Task};
 use crate::{interrupt, peripherals};
 
 pub const CHANNEL_COUNT: usize = 8;
diff --git a/embassy-nrf/src/interconnect/dppi.rs b/embassy-nrf/src/interconnect/dppi.rs
deleted file mode 100644
index 60f19fca0..000000000
--- a/embassy-nrf/src/interconnect/dppi.rs
+++ /dev/null
@@ -1,47 +0,0 @@
-use super::{Channel, Event, Ppi, Task};
-
-const DPPI_ENABLE_BIT: u32 = 0x8000_0000;
-const DPPI_CHANNEL_MASK: u32 = 0x0000_00FF;
-const REGISTER_DPPI_CONFIG_OFFSET: usize = 0x80 / core::mem::size_of::<u32>();
-
-impl<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize>
-    Ppi<'d, C, EVENT_COUNT, TASK_COUNT>
-{
-    pub(super) fn enable_task(task: &Task, channel: &C, _index: usize) {
-        unsafe {
-            task.0
-                .as_ptr()
-                .add(REGISTER_DPPI_CONFIG_OFFSET)
-                .write_volatile(DPPI_ENABLE_BIT | (channel.number() as u32 & DPPI_CHANNEL_MASK));
-        }
-    }
-
-    pub(super) fn disable_task(task: &Task, _channel: &C, _index: usize) {
-        unsafe {
-            task.0
-                .as_ptr()
-                .add(REGISTER_DPPI_CONFIG_OFFSET)
-                .write_volatile(0);
-        }
-    }
-
-    pub(super) fn enable_event(event: &Event, channel: &C, _index: usize) {
-        unsafe {
-            event
-                .0
-                .as_ptr()
-                .add(REGISTER_DPPI_CONFIG_OFFSET)
-                .write_volatile(DPPI_ENABLE_BIT | (channel.number() as u32 & DPPI_CHANNEL_MASK));
-        }
-    }
-
-    pub(super) fn disable_event(event: &Event, _channel: &C, _index: usize) {
-        unsafe {
-            event
-                .0
-                .as_ptr()
-                .add(REGISTER_DPPI_CONFIG_OFFSET)
-                .write_volatile(0);
-        }
-    }
-}
diff --git a/embassy-nrf/src/interconnect/ppi.rs b/embassy-nrf/src/interconnect/ppi.rs
deleted file mode 100644
index 91ff811fe..000000000
--- a/embassy-nrf/src/interconnect/ppi.rs
+++ /dev/null
@@ -1,65 +0,0 @@
-use super::{Channel, Event, Ppi, Task};
-use crate::pac;
-
-impl<'d, C: Channel + 'd, const EVENT_COUNT: usize, const TASK_COUNT: usize>
-    Ppi<'d, C, EVENT_COUNT, TASK_COUNT>
-{
-    pub(super) fn enable_task(task: &Task, channel: &C, index: usize) {
-        match (index, channel.is_task_configurable()) {
-            (0, false) => Self::set_fork_task(Some(task), channel.number()), // Static channel with fork
-            (0, true) => Self::set_main_task(Some(task), channel.number()), // Configurable channel without fork
-            (1, true) => Self::set_fork_task(Some(task), channel.number()), // Configurable channel with fork
-            _ => unreachable!("{}, {}", index, channel.is_task_configurable()), // Not available with the PPI, so should not be constructable
-        }
-    }
-
-    pub(super) fn disable_task(_task: &Task, channel: &C, index: usize) {
-        match (index, channel.is_task_configurable()) {
-            (0, false) => Self::set_fork_task(None, channel.number()), // Static channel with fork
-            (0, true) => Self::set_main_task(None, channel.number()), // Configurable channel without fork
-            (1, true) => Self::set_fork_task(None, channel.number()), // Configurable channel with fork
-            _ => unreachable!(), // Not available with the PPI, so should not be constructable
-        }
-    }
-
-    pub(super) fn enable_event(event: &Event, channel: &C, _index: usize) {
-        Self::set_event(Some(event), channel.number())
-    }
-
-    pub(super) fn disable_event(_event: &Event, channel: &C, _index: usize) {
-        Self::set_event(None, channel.number())
-    }
-
-    fn set_main_task(task: Option<&Task>, channel: usize) {
-        let r = unsafe { &*pac::PPI::ptr() };
-        if let Some(task) = task {
-            r.ch[channel]
-                .tep
-                .write(|w| unsafe { w.bits(task.0.as_ptr() as u32) })
-        } else {
-            r.ch[channel].tep.write(|w| unsafe { w.bits(0) })
-        }
-    }
-
-    fn set_fork_task(task: Option<&Task>, channel: usize) {
-        let r = unsafe { &*pac::PPI::ptr() };
-        if let Some(task) = task {
-            r.fork[channel]
-                .tep
-                .write(|w| unsafe { w.bits(task.0.as_ptr() as u32) })
-        } else {
-            r.fork[channel].tep.write(|w| unsafe { w.bits(0) })
-        }
-    }
-
-    fn set_event(event: Option<&Event>, channel: usize) {
-        let r = unsafe { &*pac::PPI::ptr() };
-        if let Some(event) = event {
-            r.ch[channel]
-                .eep
-                .write(|w| unsafe { w.bits(event.0.as_ptr() as u32) })
-        } else {
-            r.ch[channel].eep.write(|w| unsafe { w.bits(0) })
-        }
-    }
-}
diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
index 39f3e4a4a..c21c4d398 100644
--- a/embassy-nrf/src/lib.rs
+++ b/embassy-nrf/src/lib.rs
@@ -31,7 +31,7 @@ pub mod gpio;
 pub mod gpiote;
 #[cfg(not(feature = "nrf9160"))]
 pub mod nvmc;
-pub mod interconnect;
+pub mod ppi;
 #[cfg(not(any(feature = "nrf52805", feature = "nrf52820")))]
 pub mod pwm;
 #[cfg(feature = "nrf52840")]
diff --git a/embassy-nrf/src/ppi/dppi.rs b/embassy-nrf/src/ppi/dppi.rs
new file mode 100644
index 000000000..083ec858a
--- /dev/null
+++ b/embassy-nrf/src/ppi/dppi.rs
@@ -0,0 +1,61 @@
+use super::{Channel, Event, Ppi, Task};
+
+const DPPI_ENABLE_BIT: u32 = 0x8000_0000;
+const DPPI_CHANNEL_MASK: u32 = 0x0000_00FF;
+
+impl<'d, C: Channel + 'd, const EVENT_COUNT: usize, const TASK_COUNT: usize>
+    Ppi<'d, C, EVENT_COUNT, TASK_COUNT>
+{
+    pub(super) fn enable_task(task: &Task, channel: &C, _index: usize) {
+        unsafe {
+            if task.subscribe_reg().read_volatile() != 0 {
+                panic!("Task is already in use");
+            }
+            task.subscribe_reg()
+                .write_volatile(DPPI_ENABLE_BIT | (channel.number() as u32 & DPPI_CHANNEL_MASK));
+        }
+    }
+
+    pub(super) fn disable_task(task: &Task, _channel: &C, _index: usize) {
+        unsafe {
+            task.subscribe_reg().write_volatile(0);
+        }
+    }
+
+    pub(super) fn enable_event(event: &Event, channel: &C, _index: usize) {
+        unsafe {
+            if event.publish_reg().read_volatile() != 0 {
+                panic!("Task is already in use");
+            }
+            event
+                .publish_reg()
+                .write_volatile(DPPI_ENABLE_BIT | (channel.number() as u32 & DPPI_CHANNEL_MASK));
+        }
+    }
+
+    pub(super) fn disable_event(event: &Event, _channel: &C, _index: usize) {
+        unsafe {
+            event.publish_reg().write_volatile(0);
+        }
+    }
+
+    /// Enables all tasks and events
+    pub(super) fn enable_all(tasks: &[Task], events: &[Event], channel: &C) {
+        for (index, task) in tasks.iter().enumerate() {
+            Self::enable_task(task, channel, index);
+        }
+        for (index, event) in events.iter().enumerate() {
+            Self::enable_event(event, channel, index);
+        }
+    }
+
+    /// Disable all tasks and events
+    pub(super) fn disable_all(&self) {
+        for (index, task) in self.tasks.iter().enumerate() {
+            Self::disable_task(task, &self.ch, index);
+        }
+        for (index, event) in self.events.iter().enumerate() {
+            Self::disable_event(event, &self.ch, index);
+        }
+    }
+}
diff --git a/embassy-nrf/src/interconnect/mod.rs b/embassy-nrf/src/ppi/mod.rs
index 8cb505bdc..ffb6af020 100644
--- a/embassy-nrf/src/interconnect/mod.rs
+++ b/embassy-nrf/src/ppi/mod.rs
@@ -28,12 +28,14 @@ mod ppi;
 
 pub struct Ppi<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize> {
     ch: C,
+    #[cfg(feature = "_dppi")]
     events: [Event; EVENT_COUNT],
+    #[cfg(feature = "_dppi")]
     tasks: [Task; TASK_COUNT],
     phantom: PhantomData<&'d mut C>,
 }
 
-impl<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize>
+impl<'d, C: Channel + 'd, const EVENT_COUNT: usize, const TASK_COUNT: usize>
     Ppi<'d, C, EVENT_COUNT, TASK_COUNT>
 {
     pub fn degrade(self) -> Ppi<'d, AnyChannel, EVENT_COUNT, TASK_COUNT> {
@@ -43,7 +45,9 @@ impl<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize>
                 #[cfg(feature = "_ppi")]
                 has_configurable_task: self.ch.is_task_configurable(),
             },
+            #[cfg(feature = "_dppi")]
             events: self.events,
+            #[cfg(feature = "_dppi")]
             tasks: self.tasks,
             phantom: PhantomData,
         }
@@ -62,26 +66,6 @@ impl<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize>
         r.chenclr
             .write(|w| unsafe { w.bits(1 << self.ch.number()) });
     }
-
-    /// Enables all tasks and events
-    fn enable_all(&self) {
-        for (index, task) in self.tasks.iter().enumerate() {
-            Self::enable_task(task, &self.ch, index);
-        }
-        for (index, event) in self.events.iter().enumerate() {
-            Self::enable_event(event, &self.ch, index);
-        }
-    }
-
-    /// Disable all tasks and events
-    fn disable_all(&self) {
-        for (index, task) in self.tasks.iter().enumerate() {
-            Self::disable_task(task, &self.ch, index);
-        }
-        for (index, event) in self.events.iter().enumerate() {
-            Self::disable_event(event, &self.ch, index);
-        }
-    }
 }
 
 impl<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize> Drop
@@ -93,19 +77,23 @@ impl<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize> Drop
     }
 }
 
-impl<'d, C: StaticToOneChannel> Ppi<'d, C, 0, 1> {
+impl<'d, C: ZeroToOneChannel> Ppi<'d, C, 0, 1> {
     pub fn new_static_to_one(ch: impl Unborrow<Target = C> + 'd, task: Task) -> Self {
         unborrow!(ch);
 
-        let s = Self {
+        let events = [];
+        let tasks = [task];
+
+        Self::enable_all(&tasks, &events, &ch);
+
+        Self {
             ch,
-            events: [],
-            tasks: [task],
+            #[cfg(feature = "_dppi")]
+            events,
+            #[cfg(feature = "_dppi")]
+            tasks,
             phantom: PhantomData,
-        };
-
-        s.enable_all();
-        s
+        }
     }
 }
 
@@ -113,15 +101,19 @@ impl<'d, C: OneToOneChannel> Ppi<'d, C, 1, 1> {
     pub fn new_one_to_one(ch: impl Unborrow<Target = C> + 'd, event: Event, task: Task) -> Self {
         unborrow!(ch);
 
-        let s = Self {
+        let events = [event];
+        let tasks = [task];
+
+        Self::enable_all(&tasks, &events, &ch);
+
+        Self {
             ch,
-            events: [event],
-            tasks: [task],
+            #[cfg(feature = "_dppi")]
+            events,
+            #[cfg(feature = "_dppi")]
+            tasks,
             phantom: PhantomData,
-        };
-
-        s.enable_all();
-        s
+        }
     }
 }
 
@@ -134,15 +126,19 @@ impl<'d, C: OneToTwoChannel> Ppi<'d, C, 1, 2> {
     ) -> Self {
         unborrow!(ch);
 
-        let s = Self {
+        let events = [event];
+        let tasks = [task1, task2];
+
+        Self::enable_all(&tasks, &events, &ch);
+
+        Self {
             ch,
-            events: [event],
-            tasks: [task1, task2],
+            #[cfg(feature = "_dppi")]
+            events,
+            #[cfg(feature = "_dppi")]
+            tasks,
             phantom: PhantomData,
-        };
-
-        s.enable_all();
-        s
+        }
     }
 }
 
@@ -156,18 +152,21 @@ impl<'d, C: ManyToManyChannel, const EVENT_COUNT: usize, const TASK_COUNT: usize
     ) -> Self {
         unborrow!(ch);
 
-        let s = Self {
+        Self::enable_all(&tasks, &events, &ch);
+
+        Self {
             ch,
+            #[cfg(feature = "_dppi")]
             events,
+            #[cfg(feature = "_dppi")]
             tasks,
             phantom: PhantomData,
-        };
-
-        s.enable_all();
-        s
+        }
     }
 }
 
+const REGISTER_DPPI_CONFIG_OFFSET: usize = 0x80 / core::mem::size_of::<u32>();
+
 /// Represents a task that a peripheral can do.
 /// When a task is subscribed to a PPI channel it will run when the channel is triggered by
 /// a published event.
@@ -179,6 +178,10 @@ impl Task {
     pub(crate) fn from_reg<T>(reg: &T) -> Self {
         Self(unsafe { NonNull::new_unchecked(reg as *const _ as *mut _) })
     }
+
+    pub fn subscribe_reg(&self) -> *mut u32 {
+        unsafe { self.0.as_ptr().add(REGISTER_DPPI_CONFIG_OFFSET) }
+    }
 }
 
 /// # Safety
@@ -196,6 +199,10 @@ impl Event {
     pub(crate) fn from_reg<T>(reg: &T) -> Self {
         Self(unsafe { NonNull::new_unchecked(reg as *const _ as *mut _) })
     }
+
+    pub fn publish_reg(&self) -> *mut u32 {
+        unsafe { self.0.as_ptr().add(REGISTER_DPPI_CONFIG_OFFSET) }
+    }
 }
 
 /// # Safety
@@ -218,8 +225,8 @@ pub trait Channel: sealed::Channel + Unborrow<Target = Self> + Sized {
     fn is_task_configurable(&self) -> bool;
 }
 
-pub trait StaticToOneChannel: Channel {}
-pub trait OneToOneChannel: StaticToOneChannel {}
+pub trait ZeroToOneChannel: Channel {}
+pub trait OneToOneChannel: ZeroToOneChannel {}
 pub trait OneToTwoChannel: OneToOneChannel {}
 pub trait ManyToManyChannel: OneToTwoChannel {}
 
@@ -250,8 +257,8 @@ impl Channel for AnyChannel {
 
 macro_rules! impl_ppi_channel {
     ($type:ident, $number:expr, $has_configurable_task:expr) => {
-        impl crate::interconnect::sealed::Channel for peripherals::$type {}
-        impl crate::interconnect::Channel for peripherals::$type {
+        impl crate::ppi::sealed::Channel for peripherals::$type {}
+        impl crate::ppi::Channel for peripherals::$type {
             fn number(&self) -> usize {
                 $number
             }
@@ -267,19 +274,19 @@ macro_rules! impl_ppi_channel {
     };
     ($type:ident, $number:expr, $has_configurable_task:expr, 0, 1) => {
         impl_ppi_channel!($type, $number, $has_configurable_task, 0, 0);
-        impl crate::interconnect::StaticToOneChannel for peripherals::$type {}
+        impl crate::ppi::ZeroToOneChannel for peripherals::$type {}
     };
     ($type:ident, $number:expr, $has_configurable_task:expr, 1, 1) => {
         impl_ppi_channel!($type, $number, $has_configurable_task, 0, 1);
-        impl crate::interconnect::OneToOneChannel for peripherals::$type {}
+        impl crate::ppi::OneToOneChannel for peripherals::$type {}
     };
     ($type:ident, $number:expr, $has_configurable_task:expr, 1, 2) => {
         impl_ppi_channel!($type, $number, $has_configurable_task, 1, 1);
-        impl crate::interconnect::OneToTwoChannel for peripherals::$type {}
+        impl crate::ppi::OneToTwoChannel for peripherals::$type {}
     };
     ($type:ident, $number:expr, $has_configurable_task:expr, many, many) => {
         impl_ppi_channel!($type, $number, $has_configurable_task, 1, 2);
-        impl crate::interconnect::ManyToManyChannel for peripherals::$type {}
+        impl crate::ppi::ManyToManyChannel for peripherals::$type {}
     };
 }
 
diff --git a/embassy-nrf/src/ppi/ppi.rs b/embassy-nrf/src/ppi/ppi.rs
new file mode 100644
index 000000000..67d2086c3
--- /dev/null
+++ b/embassy-nrf/src/ppi/ppi.rs
@@ -0,0 +1,77 @@
+use super::{Channel, Event, Ppi, Task};
+use crate::pac;
+
+impl<'d, C: Channel + 'd, const EVENT_COUNT: usize, const TASK_COUNT: usize>
+    Ppi<'d, C, EVENT_COUNT, TASK_COUNT>
+{
+    fn set_main_task(task: Option<&Task>, channel: usize) {
+        let r = unsafe { &*pac::PPI::ptr() };
+        if let Some(task) = task {
+            r.ch[channel]
+                .tep
+                .write(|w| unsafe { w.bits(task.0.as_ptr() as u32) })
+        } else {
+            r.ch[channel].tep.write(|w| unsafe { w.bits(0) })
+        }
+    }
+
+    fn set_fork_task(task: Option<&Task>, channel: usize) {
+        let r = unsafe { &*pac::PPI::ptr() };
+        if let Some(task) = task {
+            r.fork[channel]
+                .tep
+                .write(|w| unsafe { w.bits(task.0.as_ptr() as u32) })
+        } else {
+            r.fork[channel].tep.write(|w| unsafe { w.bits(0) })
+        }
+    }
+
+    fn set_event(event: Option<&Event>, channel: usize) {
+        let r = unsafe { &*pac::PPI::ptr() };
+        if let Some(event) = event {
+            r.ch[channel]
+                .eep
+                .write(|w| unsafe { w.bits(event.0.as_ptr() as u32) })
+        } else {
+            r.ch[channel].eep.write(|w| unsafe { w.bits(0) })
+        }
+    }
+
+    /// Enables all tasks and events
+    pub(super) fn enable_all(tasks: &[Task], events: &[Event], channel: &C) {
+        // One configurable task, no fork
+        if channel.is_task_configurable() && TASK_COUNT == 1 {
+            Self::set_main_task(Some(&tasks[0]), channel.number());
+        }
+
+        // One configurable task, as fork
+        if !channel.is_task_configurable() && TASK_COUNT == 1 {
+            Self::set_fork_task(Some(&tasks[0]), channel.number());
+        }
+
+        // Two configurable tasks (main + fork)
+        if TASK_COUNT == 2 {
+            Self::set_main_task(Some(&tasks[0]), channel.number());
+            Self::set_fork_task(Some(&tasks[1]), channel.number());
+        }
+
+        if EVENT_COUNT == 1 {
+            Self::set_event(Some(&events[0]), channel.number());
+        }
+    }
+
+    /// Disable all tasks and events
+    pub(super) fn disable_all(&self) {
+        if self.ch.is_task_configurable() {
+            Self::set_main_task(None, self.ch.number());
+        }
+
+        if TASK_COUNT == 1 && !self.ch.is_task_configurable() || TASK_COUNT == 2 {
+            Self::set_fork_task(None, self.ch.number());
+        }
+
+        if EVENT_COUNT == 1 {
+            Self::set_event(None, self.ch.number());
+        }
+    }
+}
diff --git a/embassy-nrf/src/timer.rs b/embassy-nrf/src/timer.rs
index 27f8e715e..9173338b6 100644
--- a/embassy-nrf/src/timer.rs
+++ b/embassy-nrf/src/timer.rs
@@ -11,8 +11,8 @@ use embassy_hal_common::drop::OnDrop;
 use embassy_hal_common::unborrow;
 use futures::future::poll_fn;
 
-use crate::interconnect::{Event, Task};
 use crate::pac;
+use crate::ppi::{Event, Task};
 
 pub(crate) mod sealed {
 
diff --git a/embassy-nrf/src/uarte.rs b/embassy-nrf/src/uarte.rs
index 17e60ce22..36cf65d89 100644
--- a/embassy-nrf/src/uarte.rs
+++ b/embassy-nrf/src/uarte.rs
@@ -16,9 +16,9 @@ use futures::future::poll_fn;
 use crate::chip::EASY_DMA_SIZE;
 use crate::gpio::sealed::Pin as _;
 use crate::gpio::{self, OptionalPin as GpioOptionalPin, Pin as GpioPin};
-use crate::interconnect::{AnyChannel, Event, OneToOneChannel, OneToTwoChannel, Ppi, Task};
 use crate::interrupt::Interrupt;
 use crate::pac;
+use crate::ppi::{AnyChannel, Event, OneToOneChannel, OneToTwoChannel, Ppi, Task};
 use crate::timer::Instance as TimerInstance;
 use crate::timer::{Frequency, Timer};