WIP use result<> and RAII

1 files changed, 54 insertions, 39 deletions

diff --git a/main/dac.cpp b/main/dac.cpp
index 513793db..0e34c98f 100644
--- a/main/dac.cpp
+++ b/main/dac.cpp
@@ -1,41 +1,56 @@
 #include "dac.h"
 
-#include "esp_err.h"
-#include "i2c.h"
-#include "esp_log.h"
+#include <cstdint>
+
 #include "assert.h"
 #include "driver/i2c.h"
+#include "esp_err.h"
+#include "esp_log.h"
 #include "gpio-expander.h"
 #include "hal/i2c_types.h"
-#include <cstdint>
+#include "i2c.h"
 
 namespace gay_ipod {
 
-static const char* TAG = "AUDIODAC";
-
-AudioDac::AudioDac(GpioExpander *gpio) {
-  this->gpio_ = gpio;
-};
+static const char* kTag = "AUDIODAC";
+static const uint8_t kPcm5122Address = 0x4C;
+static const uint8_t kPcm5122Timeout = 100 / portTICK_RATE_MS;
 
-AudioDac::~AudioDac() {};
+auto AudioDac::create(GpioExpander* expander)
+    -> cpp::result<std::unique_ptr<AudioDac>, Error> {
+  std::unique_ptr<AudioDac> dac = std::make_unique<AudioDac>(expander);
 
-esp_err_t AudioDac::Start() {
-  bool is_booted = WaitForPowerState([](bool booted, PowerState state){ return booted; });
+  bool is_booted = dac->WaitForPowerState(
+      [](bool booted, PowerState state) { return booted; });
   if (!is_booted) {
-    ESP_LOGE(TAG, "Timed out waiting for boot");
-    return ESP_ERR_TIMEOUT;
+    ESP_LOGE(kTag, "Timed out waiting for boot");
+    return cpp::fail(Error::FAILED_TO_BOOT);
   }
 
-  WriteRegister(Register::DE_EMPHASIS, 1 << 4);
-  WriteVolume(100);
+  dac->WriteRegister(Register::DE_EMPHASIS, 1 << 4);
+  dac->WriteVolume(100);
 
-  WaitForPowerState([](bool booted, PowerState state){
-      return state == WAIT_FOR_CP || state == RAMP_UP || state == RUN || state == STANDBY;
-  });
+  bool is_configured =
+      dac->WaitForPowerState([](bool booted, PowerState state) {
+        return state == WAIT_FOR_CP || state == RAMP_UP || state == RUN ||
+               state == STANDBY;
+      });
+  if (!is_configured) {
+    return cpp::fail(Error::FAILED_TO_CONFIGURE);
+  }
 
-  return ESP_OK;
+  return dac;
 }
 
+AudioDac::AudioDac(GpioExpander* gpio) {
+  this->gpio_ = gpio;
+};
+
+AudioDac::~AudioDac(){
+    // TODO: reset stuff like de-emphasis? Reboot the whole dac? Need to think
+    // about this.
+};
+
 void AudioDac::WriteVolume(uint8_t volume) {
   WriteRegister(Register::DIGITAL_VOLUME_L, volume);
   WriteRegister(Register::DIGITAL_VOLUME_R, volume);
@@ -45,31 +60,32 @@ std::pair<bool, AudioDac::PowerState> AudioDac::ReadPowerState() {
   uint8_t result = 0;
 
   I2CTransaction transaction;
-  transaction
-    .start()
-    .write_addr(kPCM5122Address, I2C_MASTER_WRITE)
-    .write_ack(DSP_BOOT_POWER_STATE)
-    .start()
-    .write_addr(kPCM5122Address, I2C_MASTER_READ)
-    .read(&result, I2C_MASTER_NACK)
-    .stop();
+  transaction.start()
+      .write_addr(kPcm5122Address, I2C_MASTER_WRITE)
+      .write_ack(DSP_BOOT_POWER_STATE)
+      .start()
+      .write_addr(kPcm5122Address, I2C_MASTER_READ)
+      .read(&result, I2C_MASTER_NACK)
+      .stop();
 
   ESP_ERROR_CHECK(transaction.Execute());
 
   bool is_booted = result >> 7;
-  PowerState detail = (PowerState) (result & 0b1111);
+  PowerState detail = (PowerState)(result & 0b1111);
   return std::pair(is_booted, detail);
 }
 
-bool AudioDac::WaitForPowerState(std::function<bool(bool,AudioDac::PowerState)> predicate) {
+bool AudioDac::WaitForPowerState(
+    std::function<bool(bool, AudioDac::PowerState)> predicate) {
   bool has_matched = false;
-  for (int i=0; i<10; i++) {
+  for (int i = 0; i < 10; i++) {
     std::pair<bool, PowerState> result = ReadPowerState();
     has_matched = predicate(result.first, result.second);
     if (has_matched) {
       break;
     } else {
-      ESP_LOGI(TAG, "Waiting for power state (was %d %x)", result.first, (uint8_t) result.second);
+      ESP_LOGI(kTag, "Waiting for power state (was %d %x)", result.first,
+               (uint8_t)result.second);
       vTaskDelay(pdMS_TO_TICKS(1));
     }
   }
@@ -77,14 +93,13 @@ bool AudioDac::WaitForPowerState(std::function<bool(bool,AudioDac::PowerState)>
 }
 
 void AudioDac::WriteRegister(Register reg, uint8_t val) {
-    I2CTransaction transaction;
-    transaction
-      .start()
-      .write_addr(kPCM5122Address, I2C_MASTER_WRITE)
+  I2CTransaction transaction;
+  transaction.start()
+      .write_addr(kPcm5122Address, I2C_MASTER_WRITE)
       .write_ack(reg, val)
       .stop();
-    // TODO: Retry once?
-    ESP_ERROR_CHECK(transaction.Execute());
+  // TODO: Retry once?
+  ESP_ERROR_CHECK(transaction.Execute());
 }
 
-} // namespace gay_ipod
+}  // namespace gay_ipod