RMT: changelog and migration guide

Author: wisp3rwind

esp-hal/CHANGELOG.md

@@ -8,14 +8,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- All public RMT types now derive `Debug`. (#4302)
 
 
 ### Changed
 
 - `work_queue` is no longer public (#4357)
 - UART memory is now powered down when the driver is no longer in use. (#4354)
+- `rmt::SingleShotTxTransaction` has been renamed to `rmt::TxTransaction`. (#4302)
+- `rmt::ChannelCreator::configure_tx` and `rmt::ChannelCreator::configure_rx` now take the configuration by reference (#4302)
 
 ### Fixed
+- RMT: All blocking methods now return the channel on failure (#4302)
+- RMT: the `place_rmt_driver_in_ram` option now also places the async interrupt handler in RAM (#4302)
 
 
 ### Removed

esp-hal/MIGRATING-1.0.0-rc.1.md

@@ -1 +1,31 @@
 # Migration Guide from 1.0.0-rc.1 to {{currentVersion}}
+
+## RMT Changes
+
+Several details of the driver structs and their methods have changed:
+
+- `SingleShotTxTransaction` has been renamed to `TxTransaction`.
+- All `Channel` and `ChannelCreator` methods that take their arguments (channels and pins) by value now return them on failure; this might require changed to error handling. Changed methods are
+    - `ChannelCreator<'_, _, _>::configure_tx` and `ChannelCreator<'_, _, _>::configure_rx`,
+    - `Channel<'_, Blocking, Tx>::transmit`,
+    - `Channel<'_, Blocking, Tx>::transmit_continuously`,
+    - `Channel<'_, Blocking, Rx>::receive`.
+- The `ChannelCreator::configure_tx` and `ChannelCreator::configure_rx` methods now take the configuration by reference.
+
+```diff
+-let mut tx = rmt.channel0.configure_tx(tx_pin, TxChannelConfig::default());
+-let mut rx = rmt.channel2.configure_rx(rx_pin, RxChannelConfig::default());
++let mut tx = rmt.channel0.configure_tx(tx_pin, &TxChannelConfig::default());
++let mut rx = rmt.channel2.configure_rx(rx_pin, &RxChannelConfig::default());
+
+-let tx_transaction: SingleShotTxTransaction<'_, PulseCode> = tx.transmit(&data)?;
++let tx_transaction: TxTransaction<'_, PulseCode> = match tx.transmit(&data) {
++    Ok(t) => t,
++    Err((e, channel)) => {
++        // Now, the `channel` is not lost permanently, but can continue to be used
++        // (e.g. to retry configuration with different parameters)
++        e?
++    }
++};
+```
+