stm32: Remove OptionalPin

The idea behind OptionalPin has a few problems:

- you need to impl the signal traits for NoPin which is a bit weird https://github.com/embassy-rs/embassy/blob/master/embassy-stm32/src/dcmi.rs#L413-L416
- you can pass any combination of set/unset pins, which needs checking at runtime  https://github.com/embassy-rs/embassy/blob/master/embassy-stm32/src/dcmi.rs#L130

The replacement is to do multiple `new` constructors for each combination of pins you want to take.

embassy-stm32/src/pwm/mod.rs

@@ -248,31 +248,6 @@ crate::pac::interrupts! {
     };
 }
 
-#[allow(unused)]
-macro_rules! impl_pwm_nopin {
-    ($inst:ident) => {
-        impl_no_pin!($inst, Channel1Pin);
-        impl_no_pin!($inst, Channel1ComplementaryPin);
-        impl_no_pin!($inst, Channel2Pin);
-        impl_no_pin!($inst, Channel2ComplementaryPin);
-        impl_no_pin!($inst, Channel3Pin);
-        impl_no_pin!($inst, Channel3ComplementaryPin);
-        impl_no_pin!($inst, Channel4Pin);
-        impl_no_pin!($inst, Channel4ComplementaryPin);
-        impl_no_pin!($inst, ExternalTriggerPin);
-        impl_no_pin!($inst, BreakInputPin);
-        impl_no_pin!($inst, BreakInputComparator1Pin);
-        impl_no_pin!($inst, BreakInputComparator2Pin);
-        impl_no_pin!($inst, BreakInput2Pin);
-        impl_no_pin!($inst, BreakInput2Comparator1Pin);
-        impl_no_pin!($inst, BreakInput2Comparator2Pin);
-    };
-}
-
-crate::pac::peripherals!(
-    (timer, $inst:ident) => { impl_pwm_nopin!($inst); };
-);
-
 crate::pac::peripheral_pins!(
     ($inst:ident, timer, $block:ident, $pin:ident, CH1, $af:expr) => {
         impl_pin!($inst, Channel1Pin, $pin, $af);

embassy-stm32/src/pwm/pins.rs

@@ -1,4 +1,4 @@
-use crate::gpio::OptionalPin;
+use crate::gpio::Pin;
 
 #[cfg(feature = "unstable-pac")]
 pub mod low_level {
@@ -6,118 +6,106 @@ pub mod low_level {
 }
 
 pub(crate) mod sealed {
-    use crate::gpio::sealed::OptionalPin;
+    use crate::gpio::sealed::Pin;
 
-    pub trait Channel1Pin<Timer>: OptionalPin {
+    pub trait Channel1Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait Channel1ComplementaryPin<Timer>: OptionalPin {
+    pub trait Channel1ComplementaryPin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
 
-    pub trait Channel2Pin<Timer>: OptionalPin {
+    pub trait Channel2Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait Channel2ComplementaryPin<Timer>: OptionalPin {
+    pub trait Channel2ComplementaryPin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
 
-    pub trait Channel3Pin<Timer>: OptionalPin {
+    pub trait Channel3Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait Channel3ComplementaryPin<Timer>: OptionalPin {
+    pub trait Channel3ComplementaryPin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
 
-    pub trait Channel4Pin<Timer>: OptionalPin {
+    pub trait Channel4Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait Channel4ComplementaryPin<Timer>: OptionalPin {
+    pub trait Channel4ComplementaryPin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
 
-    pub trait ExternalTriggerPin<Timer>: OptionalPin {
+    pub trait ExternalTriggerPin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
 
-    pub trait BreakInputPin<Timer>: OptionalPin {
+    pub trait BreakInputPin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait BreakInputComparator1Pin<Timer>: OptionalPin {
+    pub trait BreakInputComparator1Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait BreakInputComparator2Pin<Timer>: OptionalPin {
+    pub trait BreakInputComparator2Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
 
-    pub trait BreakInput2Pin<Timer>: OptionalPin {
+    pub trait BreakInput2Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait BreakInput2Comparator1Pin<Timer>: OptionalPin {
+    pub trait BreakInput2Comparator1Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
-    pub trait BreakInput2Comparator2Pin<Timer>: OptionalPin {
+    pub trait BreakInput2Comparator2Pin<Timer>: Pin {
         unsafe fn configure(&mut self);
     }
 }
-pub trait Channel1Pin<Timer>: sealed::Channel1Pin<Timer> + OptionalPin + 'static {}
+pub trait Channel1Pin<Timer>: sealed::Channel1Pin<Timer> + Pin + 'static {}
 pub trait Channel1ComplementaryPin<Timer>:
-    sealed::Channel1ComplementaryPin<Timer> + OptionalPin + 'static
+    sealed::Channel1ComplementaryPin<Timer> + Pin + 'static
 {
 }
 
 pub trait Channel2Pin<Timer>: sealed::Channel2Pin<Timer> + 'static {}
 pub trait Channel2ComplementaryPin<Timer>:
-    sealed::Channel2ComplementaryPin<Timer> + OptionalPin + 'static
+    sealed::Channel2ComplementaryPin<Timer> + Pin + 'static
 {
 }
 
 pub trait Channel3Pin<Timer>: sealed::Channel3Pin<Timer> + 'static {}
 pub trait Channel3ComplementaryPin<Timer>:
-    sealed::Channel3ComplementaryPin<Timer> + OptionalPin + 'static
+    sealed::Channel3ComplementaryPin<Timer> + Pin + 'static
 {
 }
 
 pub trait Channel4Pin<Timer>: sealed::Channel4Pin<Timer> + 'static {}
 pub trait Channel4ComplementaryPin<Timer>:
-    sealed::Channel4ComplementaryPin<Timer> + OptionalPin + 'static
+    sealed::Channel4ComplementaryPin<Timer> + Pin + 'static
 {
 }
 
-pub trait ExternalTriggerPin<Timer>:
-    sealed::ExternalTriggerPin<Timer> + OptionalPin + 'static
-{
-}
+pub trait ExternalTriggerPin<Timer>: sealed::ExternalTriggerPin<Timer> + Pin + 'static {}
 
-pub trait BreakInputPin<Timer>: sealed::BreakInputPin<Timer> + OptionalPin + 'static {}
+pub trait BreakInputPin<Timer>: sealed::BreakInputPin<Timer> + Pin + 'static {}
 pub trait BreakInputComparator1Pin<Timer>:
-    sealed::BreakInputComparator1Pin<Timer> + OptionalPin + 'static
+    sealed::BreakInputComparator1Pin<Timer> + Pin + 'static
 {
 }
 pub trait BreakInputComparator2Pin<Timer>:
-    sealed::BreakInputComparator2Pin<Timer> + OptionalPin + 'static
+    sealed::BreakInputComparator2Pin<Timer> + Pin + 'static
 {
 }
 
-pub trait BreakInput2Pin<Timer>: sealed::BreakInput2Pin<Timer> + OptionalPin + 'static {}
+pub trait BreakInput2Pin<Timer>: sealed::BreakInput2Pin<Timer> + Pin + 'static {}
 pub trait BreakInput2Comparator1Pin<Timer>:
-    sealed::BreakInput2Comparator1Pin<Timer> + OptionalPin + 'static
+    sealed::BreakInput2Comparator1Pin<Timer> + Pin + 'static
 {
 }
 pub trait BreakInput2Comparator2Pin<Timer>:
-    sealed::BreakInput2Comparator2Pin<Timer> + OptionalPin + 'static
+    sealed::BreakInput2Comparator2Pin<Timer> + Pin + 'static
 {
 }
 
-macro_rules! impl_no_pin {
-    ($timer:ident, $signal:ident) => {
-        impl crate::pwm::pins::sealed::$signal<crate::peripherals::$timer> for crate::gpio::NoPin {
-            unsafe fn configure(&mut self) {}
-        }
-        impl crate::pwm::pins::$signal<crate::peripherals::$timer> for crate::gpio::NoPin {}
-    };
-}
-
 #[allow(unused)]
 macro_rules! impl_pin {
     ($timer:ident, $signal:ident, $pin:ident, $af:expr) => {

embassy-stm32/src/pwm/simple_pwm.rs

@@ -12,7 +12,46 @@ pub struct SimplePwm<'d, T> {
 }
 
 impl<'d, T: CaptureCompareCapable16bitInstance> SimplePwm<'d, T> {
-    pub fn new<F: Into<Hertz>>(
+    pub fn new_1ch<F: Into<Hertz>>(
+        tim: impl Unborrow<Target = T> + 'd,
+        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
+        freq: F,
+    ) -> Self {
+        unborrow!(ch1);
+        Self::new_inner(tim, freq, move || unsafe {
+            ch1.configure();
+        })
+    }
+
+    pub fn new_2ch<F: Into<Hertz>>(
+        tim: impl Unborrow<Target = T> + 'd,
+        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
+        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
+        freq: F,
+    ) -> Self {
+        unborrow!(ch1, ch2);
+        Self::new_inner(tim, freq, move || unsafe {
+            ch1.configure();
+            ch2.configure();
+        })
+    }
+
+    pub fn new_3ch<F: Into<Hertz>>(
+        tim: impl Unborrow<Target = T> + 'd,
+        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
+        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
+        ch3: impl Unborrow<Target = impl Channel3Pin<T>> + 'd,
+        freq: F,
+    ) -> Self {
+        unborrow!(ch1, ch2, ch3);
+        Self::new_inner(tim, freq, move || unsafe {
+            ch1.configure();
+            ch2.configure();
+            ch3.configure();
+        })
+    }
+
+    pub fn new_4ch<F: Into<Hertz>>(
         tim: impl Unborrow<Target = T> + 'd,
         ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
         ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
@@ -20,17 +59,26 @@ impl<'d, T: CaptureCompareCapable16bitInstance> SimplePwm<'d, T> {
         ch4: impl Unborrow<Target = impl Channel4Pin<T>> + 'd,
         freq: F,
     ) -> Self {
-        unborrow!(tim, ch1, ch2, ch3, ch4);
-
-        T::enable();
-        <T as crate::rcc::sealed::RccPeripheral>::reset();
-
-        unsafe {
+        unborrow!(ch1, ch2, ch3, ch4);
+        Self::new_inner(tim, freq, move || unsafe {
             ch1.configure();
             ch2.configure();
             ch3.configure();
             ch4.configure();
-        }
+        })
+    }
+
+    fn new_inner<F: Into<Hertz>>(
+        tim: impl Unborrow<Target = T> + 'd,
+        freq: F,
+        configure_pins: impl FnOnce(),
+    ) -> Self {
+        unborrow!(tim);
+
+        T::enable();
+        <T as crate::rcc::sealed::RccPeripheral>::reset();
+
+        configure_pins();
 
         let mut this = Self {
             inner: tim,