Enable I2S tests on ESP32 and work around first sample issue

esp-hal/CHANGELOG.md

@@ -56,6 +56,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix I2C ending up in a state when only re-creating the peripheral makes it useable again (#2141)
 - Fix `SpiBus::transfer` transferring data twice in some cases (#2159)
 - Fixed UART freezing when using `RcFast` clock source on ESP32-C2/C3 (#2170)
+- I2S: on ESP32 and ESP32-S2 data is now output to the right (WS=1) channel first. (#2194)
 
 ### Removed
 

esp-hal/src/i2s.rs

@@ -1137,10 +1137,15 @@ mod private {
                 // Short frame synchronization
                 w.tx_short_sync().bit(false);
                 w.rx_short_sync().bit(false);
-                w.tx_msb_right().clear_bit();
-                w.rx_msb_right().clear_bit();
-                w.tx_right_first().clear_bit();
-                w.rx_right_first().clear_bit();
+                // Send MSB to the right channel to be consistent with ESP32-S3 et al.
+                w.tx_msb_right().set_bit();
+                w.rx_msb_right().set_bit();
+                // ESP32 generates two clock pulses first. If the WS is low, those first clock
+                // pulses are indistinguishable from real data, which corrupts the first few
+                // samples. So we send the right channel first (which means WS is high during
+                // the first sample) to prevent this issue.
+                w.tx_right_first().set_bit();
+                w.rx_right_first().set_bit();
                 w.tx_mono().clear_bit();
                 w.rx_mono().clear_bit();
                 w.sig_loopback().clear_bit()

hil-test/src/lib.rs

@@ -51,11 +51,9 @@ macro_rules! common_test_pins {
         cfg_if::cfg_if! {
             if #[cfg(any(esp32s2, esp32s3))] {
                 ($io.pins.gpio9, $io.pins.gpio10)
-            }
-            else if #[cfg(esp32)] {
+            } else if #[cfg(esp32)] {
                 ($io.pins.gpio26, $io.pins.gpio27)
-            }
-            else {
+            } else {
                 ($io.pins.gpio2, $io.pins.gpio3)
             }
         }

hil-test/tests/i2s.rs

@@ -3,7 +3,7 @@
 //! This test uses I2S TX to transmit known data to I2S RX (forced to slave mode
 //! with loopback mode enabled).
 
-//% CHIPS: esp32c3 esp32c6 esp32h2 esp32s2 esp32s3
+//% CHIPS: esp32 esp32c3 esp32c6 esp32h2 esp32s2 esp32s3
 //% FEATURES: generic-queue
 
 #![no_std]