bringup r8 muting

1 files changed, 15 insertions, 3 deletions

diff --git a/src/drivers/i2s_dac.cpp b/src/drivers/i2s_dac.cpp
index 4d29f917..e206bd7a 100644
--- a/src/drivers/i2s_dac.cpp
+++ b/src/drivers/i2s_dac.cpp
@@ -88,13 +88,21 @@ I2SDac::I2SDac(IGpios& gpio, i2s_chan_handle_t i2s_handle)
                                                        I2S_SLOT_MODE_STEREO)) {
   clock_config_.clk_src = I2S_CLK_SRC_APLL;
 
+  // The amplifier's power rails ramp unevenly, with the negative rail coming
+  // up ~5ms after the positive rail. Ensure that headphone output is muted
+  // during this to avoid a loud pop during power up.
+  gpio_.WriteSync(IGpios::Pin::kAmplifierMute, true);
+  vTaskDelay(pdMS_TO_TICKS(1));
+
   gpio_.WriteSync(IGpios::Pin::kAmplifierEnable, true);
 
   // Reset all registers back to their default values.
   wm8523::WriteRegister(wm8523::Register::kReset, 1);
+
+  // Wait for DAC reset + analog rails ramp.
   vTaskDelay(pdMS_TO_TICKS(10));
-  wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b0);
 
+  wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b0);
   // Use zero-cross detection for volume changes.
   wm8523::WriteRegister(wm8523::Register::kDacCtrl, 0b10000);
 }
@@ -103,6 +111,8 @@ I2SDac::~I2SDac() {
   Stop();
   i2s_del_channel(i2s_handle_);
 
+  gpio_.WriteSync(IGpios::Pin::kAmplifierMute, true);
+  vTaskDelay(pdMS_TO_TICKS(1));
   gpio_.WriteSync(IGpios::Pin::kAmplifierEnable, false);
 }
 
@@ -119,11 +129,13 @@ auto I2SDac::Stop() -> void {
 
 auto I2SDac::SetPaused(bool paused) -> void {
   if (paused) {
-    gpio_.WriteSync(IGpios::Pin::kAmplifierUnmute, false);
+    gpio_.WriteSync(IGpios::Pin::kAmplifierUnmuteLegacy, false);
+    gpio_.WriteSync(IGpios::Pin::kAmplifierMute, true);
     set_channel(false);
   } else {
     set_channel(true);
-    gpio_.WriteSync(IGpios::Pin::kAmplifierUnmute, true);
+    gpio_.WriteSync(IGpios::Pin::kAmplifierUnmuteLegacy, true);
+    gpio_.WriteSync(IGpios::Pin::kAmplifierMute, false);
   }
 }