From 530fd15e66a2c89c0dcd6edd1b2a318958c349a4 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Tue, 15 Nov 2022 13:25:58 +1100
Subject: WIP audio play and pause

---
 src/drivers/i2s_audio_output.cpp | 92 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 src/drivers/i2s_audio_output.cpp

(limited to 'src/drivers/i2s_audio_output.cpp')

diff --git a/src/drivers/i2s_audio_output.cpp b/src/drivers/i2s_audio_output.cpp
new file mode 100644
index 00000000..6b231f0e
--- /dev/null
+++ b/src/drivers/i2s_audio_output.cpp
@@ -0,0 +1,92 @@
+#include "i2s_audio_output.hpp"
+#include <algorithm>
+#include "audio_output.hpp"
+#include "gpio-expander.hpp"
+
+static const i2s_port_t kI2SPort = I2S_NUM_0;
+
+namespace drivers {
+
+auto I2SAudioOutput::create(GpioExpander *expander)
+    -> cpp::result<std::unique_ptr<I2SAudioOutput>, Error> {
+
+  // First, we need to perform initial configuration of the DAC chip.
+  auto dac_result = drivers::AudioDac::create(expander);
+  if (dac_result.has_error()) {
+    ESP_LOGE(TAG, "failed to init dac: %d", dac_result.error());
+    return cpp::fail(DAC_CONFIG);
+  }
+  std::unique_ptr<AudioDac> dac = std::move(dac_result.value());
+
+  // Soft mute immediately, in order to minimise any clicks and pops caused by
+  // the initial output element and pipeline configuration.
+  dac->WriteVolume(255);
+
+  i2s_stream_cfg_t i2s_stream_config = i2s_stream_cfg_t{
+      .type = AUDIO_STREAM_WRITER,
+      .i2s_config =
+          {
+              // static_cast bc esp-adf uses enums incorrectly
+              .mode = static_cast<i2s_mode_t>(I2S_MODE_MASTER | I2S_MODE_TX),
+              .sample_rate = 44100,
+              .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
+              .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
+              .communication_format = I2S_COMM_FORMAT_STAND_I2S,
+              .intr_alloc_flags = ESP_INTR_FLAG_LOWMED,
+              .dma_buf_count = 8,
+              .dma_buf_len = 64,
+              .use_apll = false,
+              .tx_desc_auto_clear = false,
+              .fixed_mclk = 0,
+              .mclk_multiple = I2S_MCLK_MULTIPLE_DEFAULT,
+              .bits_per_chan = I2S_BITS_PER_CHAN_DEFAULT,
+          },
+      .i2s_port = kI2SPort,
+      .use_alc = false,
+      .volume = 0,  // Does nothing; use AudioDac to change this.
+      .out_rb_size = I2S_STREAM_RINGBUFFER_SIZE,
+      .task_stack = I2S_STREAM_TASK_STACK,
+      .task_core = I2S_STREAM_TASK_CORE,
+      .task_prio = I2S_STREAM_TASK_PRIO,
+      .stack_in_ext = false,
+      .multi_out_num = 0,
+      .uninstall_drv = true,
+      .need_expand = false,
+      .expand_src_bits = I2S_BITS_PER_SAMPLE_16BIT,
+  };
+  i2s_stream_writer = i2s_stream_init(&i2s_stream_config);
+  if (i2s_stream_writer == NULL) {
+    return cpp::fail(Error::STREAM_INIT);
+  }
+
+  // NOTE: i2s_stream_init does some additional setup that hardcodes MCK as
+  // GPIO0. This happens to work fine for us, but be careful if changing.
+  i2s_pin_config_t pin_config = {.mck_io_num = GPIO_NUM_0,
+                                 .bck_io_num = GPIO_NUM_26,
+                                 .ws_io_num = GPIO_NUM_27,
+                                 .data_out_num = GPIO_NUM_5,
+                                 .data_in_num = I2S_PIN_NO_CHANGE};
+  if (esp_err_t err = i2s_set_pin(kI2SPort, &pin_config) != ESP_OK) {
+    ESP_LOGE(kTag, "failed to configure i2s pins %x", err);
+    return cpp::fail(Error::I2S_CONFIG);
+  }
+
+  return std::make_unique<I2SAudioOutput>(dac, i2s_stream_writer);
+}
+
+I2SAudioOutput(std::unique<AudioDac> dac, audio_element_handle_t element) : IAudioOutput(element), dac_(dac) {}
+~I2SAudioOutput() {
+  // TODO: power down the DAC.
+}
+
+auto I2SAudioOutput::SetVolume(uint8_t volume) -> void {
+  dac_->WriteVolume(255);
+}
+
+auto I2SAudioOutput::Configure(audio_element_info_t info) -> void {
+      audio_element_setinfo(element_, &music_info);
+      i2s_stream_set_clk(element_, music_info.sample_rates,
+                         music_info.bits, music_info.channels);
+}
+
+}
-- 
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