Optionally type-erased GPIO drivers (#2075)

* Remove type erased gpio structs

* Implement Peripheral for ErasedPin

* Simpler type erasing, accept ErasedPin in pin drivers, remove type erased drivers

* Reformulate pin drivers using Flex

* Erase gpio types by default

* Accept any pin in AnyPin

* Add changelog and migration guide

* Fix tests and examples

* Undo rename of clone_unchecked

esp-hal/CHANGELOG.md

@@ -11,13 +11,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Implement `embedded-hal` output pin traits for `DummyPin` (#2019)
 - Added `esp_hal::init` to simplify HAL initialisation (#1970, #1999)
+- Added GpioPin::degrade to create ErasePins easily. Same for AnyPin by accident. (#2075)
+- Added missing functions to `Flex`: `unlisten`, `is_interrupt_set`, `wakeup_enable`, `wait_for_high`, `wait_for_low`, `wait_for_rising_edge`, `wait_for_falling_edge`, `wait_for_any_edge`. (#2075)
+- `Flex` now implements `Wait`. (#2075)
 - Added sleep and wakeup support for esp32c2 (#1922)
 
 ### Changed
 - Make saving and restoring SHA digest state an explicit operation (#2049)
 
 - `Delay::new()` is now a `const` function (#1999)
 - You can now create an `AnyPin` out of an `ErasedPin`. (#2072)
+- `Input`, `Output`, `OutputOpenDrain` and `Flex` are now type-erased by default. Use the new `new_typed` constructor to keep using the ZST pin types. (#2075)
 
 ### Fixed
 - SHA driver can now be safely used in multiple contexts concurrently (#2049)

esp-hal/MIGRATING-0.20.md

@@ -41,3 +41,13 @@ Instead of manually grabbing peripherals and setting up clocks, you should now c
  - The `GpioN` type aliasses are no longer available. You can use `GpioPin<N>` instead.
  - The `AnyInputOnlyPin` has been removed. Replace any use with `AnyPin`.
  - The `NoPinType` has been removed. You can use `DummyPin` in its place.
+
+### Type-erased GPIO drivers
+
+You no longer have to spell out the GPIO pin type for `Input`, `Output`, `OutputOpenDrain` or `Flex`.
+However, if you want to, you can keep using their typed form!
+
+```rust
+let pin = Input::new(io.gpio0); // pin will have the type `Input<'some>` (or `Input<'some, ErasedPin>` if you want to be explicit about it)
+let pin = Input::new_typed(io.gpio0); // pin will have the type `Input<'some, GpioPin<0>>`
+```

esp-hal/src/gpio/any_pin.rs

@@ -13,9 +13,12 @@ pub struct AnyPin<'d> {
 impl<'d> AnyPin<'d> {
     /// Create wrapper for the given pin.
     #[inline]
-    pub fn new<P: CreateErasedPin>(pin: impl crate::peripheral::Peripheral<P = P> + 'd) -> Self {
+    pub fn new<P>(pin: impl crate::peripheral::Peripheral<P = P> + 'd) -> Self
+    where
+        P: Pin,
+    {
         crate::into_ref!(pin);
-        let pin = pin.erased_pin(private::Internal);
+        let pin = pin.degrade_internal(private::Internal);
 
         Self {
             pin,
@@ -27,11 +30,12 @@ impl<'d> AnyPin<'d> {
     /// Create wrapper for the given pin. The peripheral signal will be
     /// inverted.
     #[inline]
-    pub fn new_inverted<P: OutputPin + InputPin + CreateErasedPin>(
-        pin: impl crate::peripheral::Peripheral<P = P> + 'd,
-    ) -> Self {
+    pub fn new_inverted<P>(pin: impl crate::peripheral::Peripheral<P = P> + 'd) -> Self
+    where
+        P: Pin,
+    {
         crate::into_ref!(pin);
-        let pin = pin.erased_pin(private::Internal);
+        let pin = pin.degrade_internal(private::Internal);
 
         Self {
             pin,
@@ -59,6 +63,7 @@ impl<'d> Pin for AnyPin<'d> {
     delegate::delegate! {
         to self.pin {
             fn number(&self, _internal: private::Internal) -> u8;
+            fn degrade_internal(&self, _internal: private::Internal) -> ErasedPin;
             fn sleep_mode(&mut self, on: bool, _internal: private::Internal);
             fn set_alternate_function(&mut self, alternate: AlternateFunction, _internal: private::Internal);
             fn is_listening(&self, _internal: private::Internal) -> bool;

esp-hal/src/gpio/dummy_pin.rs

@@ -32,6 +32,10 @@ impl Pin for DummyPin {
         panic!("DummyPin not supported here!");
     }
 
+    fn degrade_internal(&self, _: private::Internal) -> ErasedPin {
+        panic!("Can not type erase the DummyPin!");
+    }
+
     fn sleep_mode(&mut self, _on: bool, _: private::Internal) {}
 
     fn set_alternate_function(&mut self, _alternate: AlternateFunction, _: private::Internal) {}