Start on configuring the DAC over i2c

main/CMakeLists.txt

@@ -1,4 +1,4 @@
 idf_component_register(
-  SRCS "gay-ipod-fw.cpp" "gpio-expander.cpp" "battery.cpp" "storage.cpp"
+  SRCS "gay-ipod-fw.cpp" "dac.cpp" "gpio-expander.cpp" "battery.cpp" "storage.cpp"
   INCLUDE_DIRS "."
   REQUIRES "esp_adc_cal" "fatfs")

main/battery.h

@@ -1,5 +1,4 @@
-#ifndef BATTERY_H
+#pragma once
-#define BATTERY_H
 
 #include <stdint.h>
 
@@ -15,5 +14,3 @@ esp_err_t init_adc(void);
 uint32_t read_battery_voltage(void);
 
 } // namespace gay_ipod
-
-#endif

main/dac.cpp

@@ -0,0 +1,220 @@
+#include "dac.h"
+
+#include "esp_log.h"
+#include "assert.h"
+#include "driver/i2c.h"
+#include "gpio-expander.h"
+#include "hal/i2c_types.h"
+#include <cstdint>
+
+namespace gay_ipod {
+
+static const char* TAG = "AUDIODAC";
+
+/**
+ * Utility method for writing to a register on the PCM5122. Writes two bytes:
+ * first the address for the register that we're writing to, and then the value
+ * to write.
+ *
+ * Note this function assumes that the correct page has already been selected.
+ */
+static void set_register(i2c_cmd_handle_t handle, uint8_t reg, uint8_t val) {
+    i2c_master_write_byte(handle, reg, true);
+    i2c_master_write_byte(handle, val, true);
+}
+
+AudioDac::AudioDac(GpioExpander *gpio) {
+  this->gpio_ = gpio;
+};
+
+AudioDac::~AudioDac() {};
+
+void AudioDac::Start(SampleRate sample_rate, BitDepth bit_depth) {
+  // First check that the arguments look okay.
+
+  // Check that the bit clock (PLL input) is between 1MHz and 50MHz
+  uint32_t bckFreq = sample_rate * bit_depth * 2;
+  if (bckFreq < 1000000 || bckFreq > 50000000) {
+    return;
+  }
+
+  // 24 bits is not supported for 44.1kHz and 48kHz.
+  if ((sample_rate == SAMPLE_RATE_44_1K || sample_rate == SAMPLE_RATE_48K)
+      && bit_depth == BIT_DEPTH_24) {
+    return;
+  }
+
+  // Now do all the math required to correctly set up the internal clocks.
+  int p, j, d, r;
+  int nmac, ndac, ncp, dosr, idac;
+  if (sample_rate == SAMPLE_RATE_11_025K ||
+      sample_rate == SAMPLE_RATE_22_05K ||
+      sample_rate == SAMPLE_RATE_44_1K) {
+    //44.1kHz and derivatives.
+    //P = 1, R = 2, D = 0 for all supported combinations.
+    //Set J to have PLL clk = 90.3168 MHz
+    p = 1;
+    r = 2;
+    j = 90316800 / bckFreq / r;
+    d = 0;
+
+    //Derive clocks from the 90.3168MHz PLL
+    nmac = 2;
+    ndac = 16;
+    ncp = 4;
+    dosr = 8;
+    idac = 1024; // DSP clock / sample rate
+  } else {
+    //8kHz and multiples.
+    //PLL config for a 98.304 MHz PLL clk
+    if (bit_depth == BIT_DEPTH_24 && bckFreq > 1536000)
+      p = 3;
+    else if (bckFreq > 12288000)
+      p = 2;
+    else
+      p = 1;
+
+    r = 2;
+    j = 98304000 / (bckFreq / p) / r;
+    d = 0;
+
+    //Derive clocks from the 98.304MHz PLL
+    switch (sample_rate) {
+      case SAMPLE_RATE_16K: nmac = 6; break;
+      case SAMPLE_RATE_32K: nmac = 3; break;
+      default:              nmac = 2; break;
+    };
+
+    ndac = 16;
+    ncp = 4;
+    dosr = 384000 / sample_rate;
+    idac = 98304000 / nmac / sample_rate; // DSP clock / sample rate
+  }
+
+  // FS speed mode
+  int speedMode;
+  if (sample_rate <= SAMPLE_RATE_48K) {
+    speedMode = 0;
+  } else if (sample_rate <= SAMPLE_RATE_96K) {
+    speedMode = 1;
+  } else if (sample_rate <= SAMPLE_RATE_192K) {
+    speedMode = 2;
+  } else {
+    speedMode = 3;
+  }
+
+  // Set correct I2S config
+  uint8_t i2s_format = 0;
+  switch (bit_depth) {
+    case BIT_DEPTH_16: i2s_format = 0x00; break;
+    case BIT_DEPTH_24: i2s_format = 0x02; break;
+    case BIT_DEPTH_32: i2s_format = 0x03; break;
+  };
+
+  // We've calculated all of our data. Now assemble the big list of registers
+  // that we need to configure.
+  i2c_cmd_handle_t handle = i2c_cmd_link_create();
+  if (handle == NULL) {
+    return;
+  }
+
+  i2c_master_start(handle);
+  i2c_master_write_byte(handle, (kPCM5122Address << 1 | I2C_MASTER_WRITE), true);
+
+  // All our registers are on the first page.
+  set_register(handle, Register::PAGE_SELECT, 0);
+
+  // Disable clock autoset and ignore SCK detection
+  set_register(handle, Register::IGNORE_ERRORS, 0x1A);
+  // Set PLL clock source to BCK
+  set_register(handle, Register::PLL_CLOCK_SOURCE, 0x10);
+  // Set DAC clock source to PLL output
+  set_register(handle, Register::DAC_CLOCK_SOURCE, 0x10);
+
+  // Configure PLL
+  set_register(handle, Register::PLL_P, p - 1);
+  set_register(handle, Register::PLL_J, j);
+  set_register(handle, Register::PLL_D_MSB, (d >> 8) & 0x3F);
+  set_register(handle, Register::PLL_D_LSB, d & 0xFF);
+  set_register(handle, Register::PLL_R, r - 1);
+
+  // Clock dividers
+  set_register(handle, Register::DSP_CLOCK_DIV, nmac - 1);
+  set_register(handle, Register::DAC_CLOCK_DIV, ndac - 1);
+  set_register(handle, Register::NCP_CLOCK_DIV, ncp - 1);
+  set_register(handle, Register::OSR_CLOCK_DIV, dosr - 1);
+
+  // IDAC (nb of DSP clock cycles per sample)
+  set_register(handle, Register::IDAC_MSB, (idac >> 8) & 0xFF);
+  set_register(handle, Register::IDAC_LSB, idac & 0xFF);
+
+  set_register(handle, Register::FS_SPEED_MODE, speedMode);
+  set_register(handle, Register::I2S_FORMAT, i2s_format);
+
+  i2c_master_stop(handle);
+
+  // TODO: Handle this gracefully.
+  ESP_ERROR_CHECK(i2c_master_cmd_begin(I2C_NUM_0, handle, 50));
+
+  i2c_cmd_link_delete(handle);
+
+  vTaskDelay(pdMS_TO_TICKS(10));
+
+  // TODO: Handle this gracefully.
+  assert(ReadPowerState() == 0x05);
+}
+
+uint8_t AudioDac::ReadPowerState() {
+  i2c_cmd_handle_t handle = i2c_cmd_link_create();
+  if (handle == NULL) {
+    return 0;
+  }
+
+  uint8_t result = 0;
+
+  i2c_master_start(handle);
+  i2c_master_write_byte(handle, (kPCM5122Address << 1 | I2C_MASTER_WRITE), true);
+  i2c_master_write_byte(handle, DSP_BOOT_POWER_STATE, true);
+  i2c_master_start(handle);
+  i2c_master_read_byte(handle, &result, I2C_MASTER_NACK);
+  i2c_master_stop(handle);
+
+  ESP_ERROR_CHECK(i2c_master_cmd_begin(I2C_NUM_0, handle, 50));
+
+  i2c_cmd_link_delete(handle);
+
+  return result;
+}
+
+void AudioDac::WriteVolume(uint8_t volume) {
+  i2c_cmd_handle_t handle = i2c_cmd_link_create();
+  if (handle == NULL) {
+    return;
+  }
+
+  i2c_master_start(handle);
+  i2c_master_write_byte(handle, (kPCM5122Address << 1 | I2C_MASTER_WRITE), true);
+
+  set_register(handle, Register::DIGITAL_VOLUME_L, volume);
+  set_register(handle, Register::DIGITAL_VOLUME_R, volume);
+
+  i2c_master_stop(handle);
+
+  i2c_master_cmd_begin(I2C_NUM_0, handle, 50);
+
+  i2c_cmd_link_delete(handle);
+}
+
+void AudioDac::WritePowerMode(PowerMode mode) {
+  switch (mode) {
+    case ON:
+    case STANDBY:
+      // TODO: enable power switch.
+      break;
+    case OFF:
+      // TODO: disable power switch.
+      break;
+  }
+}
+
+} // namespace gay_ipod

main/dac.h

@@ -0,0 +1,96 @@
+#pragma once
+
+#include "gpio-expander.h"
+#include <stdint.h>
+
+namespace gay_ipod {
+
+  static const uint8_t kPCM5122Address = 0x4C;
+
+/**
+ * PCM5122PWR
+ *
+ * Heavily inspired from the Arduino library here:
+ * https://github.com/tommag/PCM51xx_Arduino/
+ */
+class AudioDac {
+  public:
+    AudioDac(GpioExpander *gpio);
+    ~AudioDac();
+
+    /** Supported sample rates */
+    enum SampleRate {
+      SAMPLE_RATE_8K        = 8000,
+      SAMPLE_RATE_11_025K   = 11025,
+      SAMPLE_RATE_16K       = 16000,
+      SAMPLE_RATE_22_05K    = 22050,
+      SAMPLE_RATE_32K       = 32000,
+      SAMPLE_RATE_44_1K     = 44100,
+      SAMPLE_RATE_48K       = 48000,
+      SAMPLE_RATE_96K       = 96000,
+      SAMPLE_RATE_192K      = 192000,
+      SAMPLE_RATE_384K      = 384000
+    };
+
+    enum BitDepth {
+      BIT_DEPTH_16        = 16,
+      BIT_DEPTH_24        = 24,
+      BIT_DEPTH_32        = 32,
+    };
+
+    /**
+     * Performs initial configuration of the DAC and sets it to begin expecting
+     * I2S audio data.
+     */
+    void Start(SampleRate sample_rate, BitDepth bit_depth);
+
+    /**
+     * Sets the volume on a scale from 0 (loudest) to 254 (quietest). A value of
+     * 255 engages the soft mute function.
+     */
+    void WriteVolume(uint8_t volume);
+
+    enum PowerMode {
+      ON = 0,
+      STANDBY = 0x10,
+      OFF = 0x01,
+    };
+
+    void WritePowerMode(PowerMode state);
+
+    // Not copyable or movable.
+    // TODO: maybe this could be movable?
+    AudioDac(const AudioDac&) = delete;
+    AudioDac& operator=(const AudioDac&) = delete;
+
+  private:
+    GpioExpander *gpio_;
+    PowerMode last_power_state_ = PowerMode::OFF;
+
+    enum Register {
+      PAGE_SELECT	    = 0, 
+      IGNORE_ERRORS	    = 37,
+      PLL_CLOCK_SOURCE	    = 13,
+      DAC_CLOCK_SOURCE	    = 14,
+      PLL_P		    = 20,
+      PLL_J		    = 21,
+      PLL_D_MSB		    = 22,
+      PLL_D_LSB		    = 23,
+      PLL_R		    = 24,
+      DSP_CLOCK_DIV	    = 27,
+      DAC_CLOCK_DIV	    = 14,
+      NCP_CLOCK_DIV	    = 29,
+      OSR_CLOCK_DIV	    = 30,
+      IDAC_MSB		    = 35,
+      IDAC_LSB		    = 36,
+      FS_SPEED_MODE	    = 34,
+      I2S_FORMAT	    = 40,
+      DIGITAL_VOLUME_L	    = 61,
+      DIGITAL_VOLUME_R	    = 62,
+      DSP_BOOT_POWER_STATE  = 118,
+    };
+
+    uint8_t ReadPowerState();
+};
+
+} // namespace gay_ipod

main/gay-ipod-fw.cpp

@@ -2,6 +2,7 @@
 #include <dirent.h>
 
 #include "battery.h"
+#include "dac.h"
 #include "driver/adc.h"
 #include "driver/gpio.h"
 #include "driver/i2c.h"
@@ -101,17 +102,28 @@ extern "C" void app_main(void)
   ESP_LOGI(TAG, "Init ADC");
   ESP_ERROR_CHECK(gay_ipod::init_adc());
 
-  ESP_LOGI(TAG, "Everything looks good! Waiting a mo for debugger.");
+  ESP_LOGI(TAG, "Init SD card");
-  vTaskDelay(pdMS_TO_TICKS(2500));
-
-  ESP_LOGI(TAG, "Trying to init SD card");
   gay_ipod::SdStorage storage(&expander);
-
   gay_ipod::SdStorage::Error err = storage.Acquire();
   if (err != gay_ipod::SdStorage::Error::OK) {
     ESP_LOGE(TAG, "Failed to acquire storage!");
     return;
   }
+
+  ESP_LOGI(TAG, "Everything looks good! Waiting a mo for debugger.");
+  vTaskDelay(pdMS_TO_TICKS(1500));
+
+  /*
+   * TODO: not working :(
+  ESP_LOGI(TAG, "Trying to init DAC");
+  gay_ipod::AudioDac dac(&expander);
+  dac.Start(
+	gay_ipod::AudioDac::SAMPLE_RATE_44_1K,
+	gay_ipod::AudioDac::BIT_DEPTH_16);
+
+  vTaskDelay(pdMS_TO_TICKS(1000));
+  */
+
   ESP_LOGI(TAG, "Looks okay? Let's list some files!");
   vTaskDelay(pdMS_TO_TICKS(1000));
 

main/gpio-expander.cpp

@@ -48,16 +48,16 @@ esp_err_t GpioExpander::Read() {
   return ret;
 }
 
-bool GpioExpander::charge_power_ok(void) {
+bool GpioExpander::charge_power_ok(void) const {
   // Active-low.
   return (input_a_ & (1 << 4)) == 0;
 }
 
-bool GpioExpander::headphone_detect(void) {
+bool GpioExpander::headphone_detect(void) const {
   return (input_b_ & (1 << 0));
 }
 
-uint8_t GpioExpander::key_states(void) {
+uint8_t GpioExpander::key_states(void) const {
   return input_b_ & 0b00111111;
 }
 

main/gpio-expander.h

@@ -1,5 +1,4 @@
-#ifndef GPIO_EXPANDER_H
+#pragma once
-#define GPIO_EXPANDER_H
 
 #include <stdint.h>
 
@@ -23,9 +22,9 @@ class GpioExpander {
     esp_err_t Write(void);
     esp_err_t Read(void);
 
-    bool charge_power_ok(void);
+    bool charge_power_ok(void) const;
-    bool headphone_detect(void);
+    bool headphone_detect(void) const;
-    uint8_t key_states(void);
+    uint8_t key_states(void) const;
 
     enum SdMuxController {
       ESP,
@@ -71,5 +70,3 @@ class GpioExpander {
 };
 
 } // namespace gay_ipod
-
-#endif

main/storage.h

@@ -1,5 +1,4 @@
-#ifndef STORAGE_H
+#pragma once
-#define STORAGE_H
 
 #include "driver/sdmmc_types.h"
 #include "driver/sdspi_host.h"
@@ -58,5 +57,3 @@ class SdStorage {
 };
 
 } // namespace gay_ipod
-
-#endif