nrf/gpiote: new api: switch to owned structs, implement WaitForHigh/WaitForLow.

embassy-nrf/src/gpiote.rs

@@ -1,18 +1,20 @@
-use crate::fmt::{panic, *};
-use core::cell::Cell;
 use core::future::Future;
+use core::mem::ManuallyDrop;
+use core::ops::Deref;
+use core::pin::Pin;
 use core::ptr;
 use core::task::{Context, Poll};
+use embassy::gpio::{WaitForHigh, WaitForLow};
 use embassy::util::Signal;
 
-use crate::hal::gpio::{Input, Level, Output, Pin, Port};
+use crate::fmt::{panic, *};
+use crate::hal::gpio::{Input, Level, Output, Pin as GpioPin, Port};
 use crate::interrupt;
 use crate::interrupt::OwnedInterrupt;
+use crate::pac;
 use crate::pac::generic::Reg;
 use crate::pac::gpiote::_TASKS_OUT;
-#[cfg(any(feature = "52833", feature = "52840"))]
-use crate::pac::P1;
-use crate::pac::{p0 as gpio, GPIOTE, P0};
+use crate::pac::{p0 as pac_gpio, GPIOTE};
 
 #[cfg(not(feature = "51"))]
 use crate::pac::gpiote::{_TASKS_CLR, _TASKS_SET};
@@ -24,20 +26,51 @@ pub const PIN_COUNT: usize = 48;
 #[cfg(not(any(feature = "52833", feature = "52840")))]
 pub const PIN_COUNT: usize = 32;
 
-pub struct Gpiote {
-    inner: GPIOTE,
-    free_channels: Cell<u8>, // 0 = used, 1 = free. 8 bits for 8 channelself.
-    channel_signals: [Signal<()>; CHANNEL_COUNT],
-    port_signals: [Signal<()>; PIN_COUNT],
+pub trait ChannelID {
+    fn number(&self) -> usize;
 }
 
-static mut INSTANCE: *const Gpiote = ptr::null_mut();
+macro_rules! impl_channel {
+    ($ChX:ident, $n:expr) => {
+        pub struct $ChX(());
+        impl $ChX {
+            pub fn degrade(self) -> ChAny {
+                ChAny($n)
+            }
+        }
 
-pub enum PortInputPolarity {
-    High,
-    Low,
+        impl ChannelID for $ChX {
+            fn number(&self) -> usize {
+                $n
+            }
+        }
+    };
 }
 
+impl_channel!(Ch0, 0);
+impl_channel!(Ch1, 1);
+impl_channel!(Ch2, 2);
+impl_channel!(Ch3, 3);
+impl_channel!(Ch4, 4);
+impl_channel!(Ch5, 5);
+impl_channel!(Ch6, 6);
+impl_channel!(Ch7, 7);
+
+pub struct ChAny(u8);
+
+impl ChannelID for ChAny {
+    fn number(&self) -> usize {
+        self.0 as usize
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct Gpiote(());
+
+const NEW_SIGNAL: Signal<()> = Signal::new();
+static CHANNEL_SIGNALS: [Signal<()>; CHANNEL_COUNT] = [NEW_SIGNAL; CHANNEL_COUNT];
+static PORT_SIGNALS: [Signal<()>; PIN_COUNT] = [NEW_SIGNAL; PIN_COUNT];
+
 pub enum InputChannelPolarity {
     None,
     HiToLo,
@@ -58,12 +91,23 @@ pub enum NewChannelError {
     NoFreeChannels,
 }
 
+pub struct Channels {
+    pub ch0: Ch0,
+    pub ch1: Ch1,
+    pub ch2: Ch2,
+    pub ch3: Ch3,
+    pub ch4: Ch4,
+    pub ch5: Ch5,
+    pub ch6: Ch6,
+    pub ch7: Ch7,
+}
+
 impl Gpiote {
-    pub fn new(gpiote: GPIOTE, irq: interrupt::GPIOTEInterrupt) -> Self {
+    pub fn new(gpiote: GPIOTE, irq: interrupt::GPIOTEInterrupt) -> (Self, Channels) {
         #[cfg(any(feature = "52833", feature = "52840"))]
-        let ports = unsafe { &[&*P0::ptr(), &*P1::ptr()] };
+        let ports = unsafe { &[&*pac::P0::ptr(), &*pac::P1::ptr()] };
         #[cfg(not(any(feature = "52833", feature = "52840")))]
-        let ports = unsafe { &[&*P0::ptr()] };
+        let ports = unsafe { &[&*pac::P0::ptr()] };
 
         for &p in ports {
             // Enable latched detection
@@ -79,240 +123,38 @@ impl Gpiote {
         irq.unpend();
         irq.enable();
 
-        Self {
-            inner: gpiote,
-            free_channels: Cell::new(0xFF), // all 8 channels free
-            channel_signals: [
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-            ],
-            // This is just horrible
-            #[cfg(any(feature = "52833", feature = "52840"))]
-            port_signals: [
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-            ],
-            #[cfg(not(any(feature = "52833", feature = "52840")))]
-            port_signals: [
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-                Signal::new(),
-            ],
-        }
-    }
-
-    fn allocate_channel(&self) -> Result<u8, NewChannelError> {
-        interrupt::free(|_| {
-            let chs = self.free_channels.get();
-            let index = chs.trailing_zeros() as usize;
-            if index == 8 {
-                return Err(NewChannelError::NoFreeChannels);
-            }
-            self.free_channels.set(chs & !(1 << index));
-            Ok(index as u8)
-        })
-    }
-
-    fn free_channel(&self, index: u8) {
-        interrupt::free(|_| {
-            self.inner.config[index as usize].write(|w| w.mode().disabled());
-            self.inner.intenclr.write(|w| unsafe { w.bits(1 << index) });
-
-            self.free_channels
-                .set(self.free_channels.get() | 1 << index);
-            trace!("freed ch {:?}", index);
-        })
-    }
-
-    pub fn wait_port_input<'a, T>(
-        &'a self,
-        pin: &'a Pin<Input<T>>,
-        polarity: PortInputPolarity,
-    ) -> PortInputFuture<'a, T> {
-        interrupt::free(|_| {
-            unsafe { INSTANCE = self };
-            PortInputFuture {
-                gpiote: self,
-                pin,
-                polarity,
-            }
-        })
-    }
-
-    pub fn new_input_channel<'a, T>(
-        &'a self,
-        pin: Pin<Input<T>>,
-        polarity: InputChannelPolarity,
-    ) -> Result<InputChannel<'a, T>, NewChannelError> {
-        interrupt::free(|_| {
-            unsafe { INSTANCE = self };
-            let index = self.allocate_channel()?;
-            trace!("allocated in ch {:?}", index as u8);
-
-            self.inner.config[index as usize].write(|w| {
-                match polarity {
-                    InputChannelPolarity::HiToLo => w.mode().event().polarity().hi_to_lo(),
-                    InputChannelPolarity::LoToHi => w.mode().event().polarity().lo_to_hi(),
-                    InputChannelPolarity::None => w.mode().event().polarity().none(),
-                    InputChannelPolarity::Toggle => w.mode().event().polarity().toggle(),
-                };
-                #[cfg(any(feature = "52833", feature = "52840"))]
-                w.port().bit(match pin.port() {
-                    Port::Port0 => false,
-                    Port::Port1 => true,
-                });
-                unsafe { w.psel().bits(pin.pin()) }
-            });
-
-            // Enable interrupt
-            self.inner.intenset.write(|w| unsafe { w.bits(1 << index) });
-
-            Ok(InputChannel {
-                gpiote: self,
-                index,
-                pin,
-            })
-        })
-    }
-
-    pub fn new_output_channel<'a, T>(
-        &'a self,
-        pin: Pin<Output<T>>,
-        level: Level,
-        polarity: OutputChannelPolarity,
-    ) -> Result<OutputChannel<'a>, NewChannelError> {
-        interrupt::free(|_| {
-            unsafe { INSTANCE = self };
-            let index = self.allocate_channel()?;
-            trace!("allocated out ch {:?}", index);
-
-            self.inner.config[index as usize].write(|w| {
-                w.mode().task();
-                match level {
-                    Level::High => w.outinit().high(),
-                    Level::Low => w.outinit().low(),
-                };
-                match polarity {
-                    OutputChannelPolarity::Set => w.polarity().lo_to_hi(),
-                    OutputChannelPolarity::Clear => w.polarity().hi_to_lo(),
-                    OutputChannelPolarity::Toggle => w.polarity().toggle(),
-                };
-                #[cfg(any(feature = "52833", feature = "52840"))]
-                w.port().bit(match pin.port() {
-                    Port::Port0 => false,
-                    Port::Port1 => true,
-                });
-                unsafe { w.psel().bits(pin.pin()) }
-            });
-
-            // Enable interrupt
-            self.inner.intenset.write(|w| unsafe { w.bits(1 << index) });
-
-            Ok(OutputChannel {
-                gpiote: self,
-                index,
-            })
-        })
+        (
+            Self(()),
+            Channels {
+                ch0: Ch0(()),
+                ch1: Ch1(()),
+                ch2: Ch2(()),
+                ch3: Ch3(()),
+                ch4: Ch4(()),
+                ch5: Ch5(()),
+                ch6: Ch6(()),
+                ch7: Ch7(()),
+            },
+        )
     }
 
     unsafe fn on_irq(_ctx: *mut ()) {
-        let s = &(*INSTANCE);
+        let g = &*GPIOTE::ptr();
 
         for i in 0..8 {
-            if s.inner.events_in[i].read().bits() != 0 {
-                s.inner.events_in[i].write(|w| w);
-                s.channel_signals[i].signal(());
+            if g.events_in[i].read().bits() != 0 {
+                g.events_in[i].write(|w| w);
+                CHANNEL_SIGNALS[i].signal(());
             }
         }
 
-        if s.inner.events_port.read().bits() != 0 {
-            s.inner.events_port.write(|w| w);
+        if g.events_port.read().bits() != 0 {
+            g.events_port.write(|w| w);
 
             #[cfg(any(feature = "52833", feature = "52840"))]
-            let ports = &[&*P0::ptr(), &*P1::ptr()];
+            let ports = &[&*pac::P0::ptr(), &*pac::P1::ptr()];
             #[cfg(not(any(feature = "52833", feature = "52840")))]
-            let ports = &[&*P0::ptr()];
+            let ports = &[&*pac::P0::ptr()];
 
             let mut work = true;
             while work {
@@ -322,7 +164,7 @@ impl Gpiote {
                         work = true;
                         p.pin_cnf[pin as usize].modify(|_, w| w.sense().disabled());
                         p.latch.write(|w| w.bits(1 << pin));
-                        s.port_signals[port * 32 + pin as usize].signal(());
+                        PORT_SIGNALS[port * 32 + pin as usize].signal(());
                     }
                 }
             }
@@ -330,32 +172,7 @@ impl Gpiote {
     }
 }
 
-pub struct PortInputFuture<'a, T> {
-    gpiote: &'a Gpiote,
-    pin: &'a Pin<Input<T>>,
-    polarity: PortInputPolarity,
-}
-
-impl<'a, T> Drop for PortInputFuture<'a, T> {
-    fn drop(&mut self) {
-        pin_conf(&self.pin).modify(|_, w| w.sense().disabled());
-        self.gpiote.port_signals[pin_num(&self.pin)].reset();
-    }
-}
-
-impl<'a, T> Future for PortInputFuture<'a, T> {
-    type Output = ();
-
-    fn poll(self: core::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        pin_conf(&self.pin).modify(|_, w| match self.polarity {
-            PortInputPolarity::Low => w.sense().low(),
-            PortInputPolarity::High => w.sense().high(),
-        });
-        self.gpiote.port_signals[pin_num(&self.pin)].poll_wait(cx)
-    }
-}
-
-fn pin_num<T>(pin: &Pin<T>) -> usize {
+fn pin_num<T>(pin: &GpioPin<T>) -> usize {
     let port = match pin.port() {
         Port::Port0 => 0,
         #[cfg(any(feature = "52833", feature = "52840"))]
@@ -365,86 +182,189 @@ fn pin_num<T>(pin: &Pin<T>) -> usize {
     port + pin.pin() as usize
 }
 
-fn pin_block<T>(pin: &Pin<T>) -> &gpio::RegisterBlock {
+fn pin_block<T>(pin: &GpioPin<T>) -> &pac_gpio::RegisterBlock {
     let ptr = match pin.port() {
-        Port::Port0 => P0::ptr(),
+        Port::Port0 => pac::P0::ptr(),
         #[cfg(any(feature = "52833", feature = "52840"))]
-        Port::Port1 => P1::ptr(),
+        Port::Port1 => pac::P1::ptr(),
     };
 
     unsafe { &*ptr }
 }
 
-fn pin_conf<T>(pin: &Pin<T>) -> &gpio::PIN_CNF {
+fn pin_conf<T>(pin: &GpioPin<T>) -> &pac_gpio::PIN_CNF {
     &pin_block(pin).pin_cnf[pin.pin() as usize]
 }
 
-pub struct InputChannel<'a, T> {
-    gpiote: &'a Gpiote,
-    pin: Pin<Input<T>>,
-    index: u8,
+pub struct InputChannel<C: ChannelID, T> {
+    ch: C,
+    pin: GpioPin<Input<T>>,
 }
 
-impl<'a, T> Drop for InputChannel<'a, T> {
+impl<C: ChannelID, T> Drop for InputChannel<C, T> {
     fn drop(&mut self) {
-        self.gpiote.free_channel(self.index);
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+        g.config[index].write(|w| w.mode().disabled());
+        g.intenclr.write(|w| unsafe { w.bits(1 << index) });
     }
 }
 
-impl<'a, T> InputChannel<'a, T> {
-    pub async fn wait(&self) {
-        self.gpiote.channel_signals[self.index as usize]
-            .wait()
-            .await;
+impl<C: ChannelID, T> InputChannel<C, T> {
+    pub fn new(
+        _gpiote: Gpiote,
+        ch: C,
+        pin: GpioPin<Input<T>>,
+        polarity: InputChannelPolarity,
+    ) -> Self {
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = ch.number();
+
+        g.config[index].write(|w| {
+            match polarity {
+                InputChannelPolarity::HiToLo => w.mode().event().polarity().hi_to_lo(),
+                InputChannelPolarity::LoToHi => w.mode().event().polarity().lo_to_hi(),
+                InputChannelPolarity::None => w.mode().event().polarity().none(),
+                InputChannelPolarity::Toggle => w.mode().event().polarity().toggle(),
+            };
+            #[cfg(any(feature = "52833", feature = "52840"))]
+            w.port().bit(match pin.port() {
+                Port::Port0 => false,
+                Port::Port1 => true,
+            });
+            unsafe { w.psel().bits(pin.pin()) }
+        });
+
+        CHANNEL_SIGNALS[index].reset();
+
+        // Enable interrupt
+        g.intenset.write(|w| unsafe { w.bits(1 << index) });
+
+        InputChannel { ch, pin }
     }
 
-    pub fn pin(&self) -> &Pin<Input<T>> {
+    pub fn free(self) -> (C, GpioPin<Input<T>>) {
+        let m = ManuallyDrop::new(self);
+        let ch = unsafe { ptr::read(&m.ch) };
+        let pin = unsafe { ptr::read(&m.pin) };
+        (ch, pin)
+    }
+
+    pub async fn wait(&self) {
+        let index = self.ch.number();
+        CHANNEL_SIGNALS[index].wait().await;
+    }
+
+    pub fn pin(&self) -> &GpioPin<Input<T>> {
         &self.pin
     }
 }
 
-pub struct OutputChannel<'a> {
-    gpiote: &'a Gpiote,
-    index: u8,
+pub struct OutputChannel<C: ChannelID, T> {
+    ch: C,
+    pin: GpioPin<Output<T>>,
 }
 
-impl<'a> Drop for OutputChannel<'a> {
+impl<C: ChannelID, T> Drop for OutputChannel<C, T> {
     fn drop(&mut self) {
-        self.gpiote.free_channel(self.index);
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+        g.config[index].write(|w| w.mode().disabled());
+        g.intenclr.write(|w| unsafe { w.bits(1 << index) });
     }
 }
 
-impl<'a> OutputChannel<'a> {
+impl<C: ChannelID, T> OutputChannel<C, T> {
+    pub fn new(
+        _gpiote: Gpiote,
+        ch: C,
+        pin: GpioPin<Output<T>>,
+        level: Level,
+        polarity: OutputChannelPolarity,
+    ) -> Self {
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = ch.number();
+
+        g.config[index].write(|w| {
+            w.mode().task();
+            match level {
+                Level::High => w.outinit().high(),
+                Level::Low => w.outinit().low(),
+            };
+            match polarity {
+                OutputChannelPolarity::Set => w.polarity().lo_to_hi(),
+                OutputChannelPolarity::Clear => w.polarity().hi_to_lo(),
+                OutputChannelPolarity::Toggle => w.polarity().toggle(),
+            };
+            #[cfg(any(feature = "52833", feature = "52840"))]
+            w.port().bit(match pin.port() {
+                Port::Port0 => false,
+                Port::Port1 => true,
+            });
+            unsafe { w.psel().bits(pin.pin()) }
+        });
+
+        // Enable interrupt
+        g.intenset.write(|w| unsafe { w.bits(1 << index) });
+
+        OutputChannel { ch, pin }
+    }
+
+    pub fn free(self) -> (C, GpioPin<Output<T>>) {
+        let m = ManuallyDrop::new(self);
+        let ch = unsafe { ptr::read(&m.ch) };
+        let pin = unsafe { ptr::read(&m.pin) };
+        (ch, pin)
+    }
+
     /// Triggers `task out` (as configured with task_out_polarity, defaults to Toggle).
     pub fn out(&self) {
-        self.gpiote.inner.tasks_out[self.index as usize].write(|w| unsafe { w.bits(1) });
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+
+        g.tasks_out[index].write(|w| unsafe { w.bits(1) });
     }
     /// Triggers `task set` (set associated pin high).
     #[cfg(not(feature = "51"))]
     pub fn set(&self) {
-        self.gpiote.inner.tasks_set[self.index as usize].write(|w| unsafe { w.bits(1) });
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+
+        g.tasks_set[index].write(|w| unsafe { w.bits(1) });
     }
     /// Triggers `task clear` (set associated pin low).
     #[cfg(not(feature = "51"))]
     pub fn clear(&self) {
-        self.gpiote.inner.tasks_clr[self.index as usize].write(|w| unsafe { w.bits(1) });
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+
+        g.tasks_clr[index].write(|w| unsafe { w.bits(1) });
     }
 
     /// Returns reference to task_out endpoint for PPI.
     pub fn task_out(&self) -> &Reg<u32, _TASKS_OUT> {
-        &self.gpiote.inner.tasks_out[self.index as usize]
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+
+        &g.tasks_out[index]
     }
 
     /// Returns reference to task_clr endpoint for PPI.
     #[cfg(not(feature = "51"))]
     pub fn task_clr(&self) -> &Reg<u32, _TASKS_CLR> {
-        &self.gpiote.inner.tasks_clr[self.index as usize]
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+
+        &g.tasks_clr[index]
     }
 
     /// Returns reference to task_set endpoint for PPI.
     #[cfg(not(feature = "51"))]
     pub fn task_set(&self) -> &Reg<u32, _TASKS_SET> {
-        &self.gpiote.inner.tasks_set[self.index as usize]
+        let g = unsafe { &*GPIOTE::ptr() };
+        let index = self.ch.number();
+
+        &g.tasks_set[index]
     }
 }
 
@@ -463,3 +383,73 @@ impl Iterator for BitIter {
         }
     }
 }
+
+pub struct GpiotePin<T> {
+    pin: GpioPin<Input<T>>,
+}
+
+impl<T> Unpin for GpiotePin<T> {}
+
+impl<T> GpiotePin<T> {
+    pub fn new(_gpiote: Gpiote, pin: GpioPin<Input<T>>) -> Self {
+        Self { pin }
+    }
+}
+
+impl<T: 'static> WaitForHigh for GpiotePin<T> {
+    type Future<'a> = PortInputFuture<'a, T>;
+
+    fn wait_for_high<'a>(self: Pin<&'a mut Self>) -> Self::Future<'a> {
+        PortInputFuture {
+            pin: &self.get_mut().pin,
+            polarity: PortInputPolarity::High,
+        }
+    }
+}
+
+impl<T: 'static> WaitForLow for GpiotePin<T> {
+    type Future<'a> = PortInputFuture<'a, T>;
+
+    fn wait_for_low<'a>(self: Pin<&'a mut Self>) -> Self::Future<'a> {
+        PortInputFuture {
+            pin: &self.get_mut().pin,
+            polarity: PortInputPolarity::Low,
+        }
+    }
+}
+
+impl<T> Deref for GpiotePin<T> {
+    type Target = GpioPin<Input<T>>;
+    fn deref(&self) -> &Self::Target {
+        &self.pin
+    }
+}
+
+enum PortInputPolarity {
+    High,
+    Low,
+}
+
+pub struct PortInputFuture<'a, T> {
+    pin: &'a GpioPin<Input<T>>,
+    polarity: PortInputPolarity,
+}
+
+impl<'a, T> Drop for PortInputFuture<'a, T> {
+    fn drop(&mut self) {
+        pin_conf(&self.pin).modify(|_, w| w.sense().disabled());
+        PORT_SIGNALS[pin_num(&self.pin)].reset();
+    }
+}
+
+impl<'a, T> Future for PortInputFuture<'a, T> {
+    type Output = ();
+
+    fn poll(self: core::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        pin_conf(&self.pin).modify(|_, w| match self.polarity {
+            PortInputPolarity::Low => w.sense().low(),
+            PortInputPolarity::High => w.sense().high(),
+        });
+        PORT_SIGNALS[pin_num(&self.pin)].poll_wait(cx)
+    }
+}