implement a parallel interface for esp32 using the i2s peripheral (#2348)

* i2s_parallel for esp32 - partially working

* i2s_parallel for esp32 - works sync 16bit (still WIP)

* i2s_parallel - add 8-bit

* i2s_parallel - naive async implementation

* i2s_parallel - clippy

* add examples (mainly for testing now and we can reduce these before merge)

* set tx_wrx2 in 8 bit mode or it updates on half clocks!

* adjust clock config (still really a hack)

* better clock calculation/configuration

* no need to reset dma or interrupts in start, the DMA DmaTxBuf handles that

* seems to need a short delay during tx_reset

* use 20 clocks instead of 1us

* 1us delay between dma start and tx_start (like idf)

* changelog & documentation

* remove debugging functions

* no need for option in example

* make async example actually use async & remove Option

* implement Drop for I2sParallelTransfer

* fix signal offset comment for I2S0

* small cleanup in i2s_parallel examples

* added a note re I2S0 not supporting true 8bit

* update doc & fmt

* instace functions take &self

* fmt

* if run at 240MHz (CPU) delay needs to be bigger

* wait for fifo on start and fixes for 240MHz

* update for esp-hal-changes

* fmt

---------

Co-authored-by: Dániel Buga <[email protected]>

Author: liebman

esp-hal/CHANGELOG.md

@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `Spi::half_duplex_read` and `Spi::half_duplex_write` (#2373)
 - `Cpu::COUNT` and `Cpu::current()` (#2411)
 - `UartInterrupt` and related functions (#2406)
+- I2S Parallel output driver for esp32. (#2348)
 - Add an option to configure `WDT` action (#2330)
 
 ### Changed