Peripheral interconnect redo, vol 2 (split()) (#2418)

* Replace peripheral connection conversions with split

* Constrain Flex conversions

esp-hal/CHANGELOG.md

@@ -26,6 +26,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `DmaDescriptor` is now `Send` (#2456)
 - `into_async` and `into_blocking` functions for most peripherals (#2430)
 - API mode type parameter (currently always `Blocking`) to `master::Spi` and `slave::Spi` (#2430)
+- `gpio::{GpioPin, AnyPin, Flex, Output, OutputOpenDrain}::split()` to obtain peripheral interconnect signals. (#2418)
+- `gpio::Input::{split(), into_peripheral_output()}` when used with output pins. (#2418)
+- `gpio::Output::peripheral_input()` (#2418)
 
 ### Changed
 
@@ -42,6 +45,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - SPI interrupt listening is now only available in Blocking mode. The `set_interrupt_handler` is available via `InterruptConfigurable` (#2442)
 - Allow users to create DMA `Preparation`s (#2455) 
 - The `rmt::asynch::RxChannelAsync` and `rmt::asynch::TxChannelAsync` traits have been moved to `rmt` (#2430)
+- Calling `AnyPin::output_signals` on an input-only pin (ESP32 GPIO 34-39) will now result in a panic. (#2418)
 
 ### Fixed
 

esp-hal/MIGRATING-0.21.md

@@ -194,7 +194,8 @@ You can now listen/unlisten multiple interrupt bits at once:
 -uart0.listen_at_cmd();
 -uart0.listen_rx_fifo_full();
 +uart0.listen(UartInterrupt::AtCmd | UartConterrupt::RxFifoFull);
-```˛
+```
+
 ## Circular DMA transfer's `available` returns `Result<usize, DmaError>` now
 
 In case of any error you should drop the transfer and restart it.
@@ -211,3 +212,21 @@ In case of any error you should drop the transfer and restart it.
 +            },
 +        };
 ```
+
+## Removed `peripheral_input` and `into_peripheral_output` from GPIO pin types
+
+Creating peripheral interconnect signals now consume the GPIO pin used for the connection.
+
+The previous signal function have been replaced by `split`. This change affects the following APIs:
+
+- `GpioPin`
+- `AnyPin`
+
+```diff
+-let input_signal = gpioN.peripheral_input();
+-let output_signal = gpioN.into_peripheral_output();
++let (input_signal, output_signal) = gpioN.split();
+```
+
+`into_peripheral_output`, `split` (for output pins only) and `peripheral_input` have been added to
+the GPIO drivers (`Input`, `Output`, `OutputOpenDrain` and `Flex`) instead.

esp-hal/src/gpio/interconnect.rs

@@ -54,9 +54,6 @@ impl PeripheralOutput for OutputConnection {}
 
 /// A configurable input signal between a peripheral and a GPIO pin.
 ///
-/// Obtained by calling [`super::GpioPin::peripheral_input()`],
-/// [`super::Flex::peripheral_input()`] or [`super::Input::peripheral_input()`].
-///
 /// Multiple input signals can be connected to one pin.
 pub struct InputSignal {
     pin: AnyPin,
@@ -188,10 +185,6 @@ impl InputSignal {
 
 /// A configurable output signal between a peripheral and a GPIO pin.
 ///
-/// Obtained by calling [`super::GpioPin::into_peripheral_output()`],
-/// [`super::Flex::into_peripheral_output()`] or
-/// [`super::Output::into_peripheral_output()`].
-///
 /// Multiple pins can be connected to one output signal.
 pub struct OutputSignal {
     pin: AnyPin,
@@ -441,9 +434,9 @@ where
     P: InputPin,
 {
     fn from(input: P) -> Self {
-        Self(InputConnectionInner::Input(
-            input.degrade().peripheral_input(),
-        ))
+        Self(InputConnectionInner::Input(InputSignal::new(
+            input.degrade(),
+        )))
     }
 }
 
@@ -534,9 +527,9 @@ where
     P: OutputPin,
 {
     fn from(input: P) -> Self {
-        Self(OutputConnectionInner::Output(
-            input.degrade().into_peripheral_output(),
-        ))
+        Self(OutputConnectionInner::Output(OutputSignal::new(
+            input.degrade(),
+        )))
     }
 }