WIP sketch out init sequence

main/CMakeLists.txt

@@ -1,7 +1,7 @@
 idf_component_register(
   SRCS
   "gay-ipod-fw.cpp" "dac.cpp" "gpio-expander.cpp" "battery.cpp"
-  "storage.cpp" "i2c.cpp" "playback.cpp"
+  "storage.cpp" "i2c.cpp" "playback.cpp" "display.cpp"
   INCLUDE_DIRS "."
   REQUIRES
   "esp_adc_cal" "fatfs" "audio_pipeline" "audio_stream" "result" "lvgl")

main/display.cpp

@@ -0,0 +1,63 @@
+#include "display.hpp"
+#include <cstdint>
+#include "driver/gpio.h"
+#include "driver/spi_master.h"
+#include "hal/gpio_types.h"
+#include "hal/spi_types.h"
+
+namespace gay_ipod {
+
+static const gpio_num_t kCommandOrDataPin = GPIO_NUM_21;
+static const gpio_num_t kLedPin = GPIO_NUM_22;
+
+static const uint8_t kDisplayWidth = 128;
+static const uint8_t kDisplayHeight = 160;
+
+auto Display::create(GpioExpander* expander)
+    -> cpp::result<std::unique_ptr<Display>, Error> {
+  // First, set up our GPIOs
+#define SPI_QUADWP_IO (GPIO_NUM_22)
+#define SPI_QUADHD_IO (GPIO_NUM_21)
+  gpio_config_t gpio_cfg = {
+    .intr_type = GPIO_INTR_DISABLE,
+    .mode = GPIO_MODE_OUTPUT,
+    .pin_bit_mask = (1 << GPIO_OUTPUT_22) | (1 << GPIO_OUTPUT_21),
+    .pull_down_en = 0,
+    .pull_up_en = 0,
+  }
+  gpio_config(&gpio_cfg);
+
+  gpio_set_level(kLedPin, 1);
+  gpio_set_level(kCommandOrDataPin, 1);
+
+  // Next, init the SPI device
+  auto lock = expander->AcquireSpiBus(GpioExpander::DISPLAY);
+  spi_device_interface_config_t spi_cfg = {
+    .command_bits = 0, // Unused
+    .address_bits = 0, // Unused
+    .dummy_bits = 0,
+    .mode = 0,
+    .duty_cycle_pos = 0, // Unused
+    .cs_ena_pretrans = 0,
+    .cs_ena_posttrans = 0,
+    .clock_speed_hz = 32000000,
+    .input_delay_ns = 0,
+    .spics_io_num = -1,
+    .flags = 0,
+    .queue_size = 0,
+    .pre_cb = NULL,
+    .post_cb = NULL,
+  };
+  spi_device_handle_t handle;
+  spi_bus_add_device(VSPI_HOST, &spi_cfg, &handle);
+
+  // Now we reset the display into a known state, then configure it
+  // https://github.com/adafruit/Adafruit-ST7735-Library/blob/master/Adafruit_ST77xx.cpp
+  // https://github.com/adafruit/Adafruit-ST7735-Library/blob/master/Adafruit_ST7735.cpp
+  // commonInit with Rcmd1
+  // displayInit with Rcmd2green
+  // displayInit with Rcmd3
+  // setRotation
+}
+
+} // namespace gay_ipod

main/display.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+#include "gpio-expander.hpp"
+
+namespace gay_ipod {
+
+/*
+ * Display driver for LVGL.
+ */
+class Display {
+  public:
+    enum Error {};
+    static auto create(GpioExpander* expander)
+	-> cpp::result<std::unique_ptr<Display>, Error>;
+
+    Display(GpioExpander *gpio);
+    ~Display();
+
+    void WriteData();
+
+  private:
+    GpioExpander *gpio_;
+};
+
+} // namespace gay_ipod

main/gay-ipod-fw.cpp

@@ -21,6 +21,7 @@
 #include "esp_log.h"
 #include "hal/gpio_types.h"
 #include "hal/spi_types.h"
+#include "lvgl/lvgl.h"
 
 #define I2C_SDA_IO (GPIO_NUM_2)
 #define I2C_SCL_IO (GPIO_NUM_4)
@@ -63,8 +64,8 @@ esp_err_t init_spi(void) {
       .mosi_io_num = SPI_SDO_IO,
       .miso_io_num = SPI_SDI_IO,
       .sclk_io_num = SPI_SCLK_IO,
-      .quadwp_io_num = SPI_QUADWP_IO,
-      .quadhd_io_num = SPI_QUADHD_IO,
+      .quadwp_io_num = -1, //SPI_QUADWP_IO,
+      .quadhd_io_num = -1, //SPI_QUADHD_IO,
 
       // Unused
       .data4_io_num = -1,
@@ -125,11 +126,6 @@ extern "C" void app_main(void) {
   ESP_LOGI(TAG, "Everything looks good! Waiting a mo for debugger.");
   vTaskDelay(pdMS_TO_TICKS(1500));
 
-  playback->Play("/sdcard/test.mp3");
-  playback->set_volume(100);
-
-  playback->ProcessEvents();
-
   ESP_LOGI(TAG, "Time to deinit.");
 
   ESP_LOGI(TAG, "Hooray!");

main/gpio-expander.cpp

@@ -71,6 +71,7 @@ bool GpioExpander::get_input(Pin pin) const {
 }
 
 GpioExpander::SpiLock GpioExpander::AcquireSpiBus(ChipSelect cs) {
+  // TODO: also spi_device_acquire_bus?
   return SpiLock(*this, cs);
 }