esp32.h

 
#pragma once
 
#include <stdbool.h>
#include <stdint.h>
 
#include <esp_intr_alloc.h>
#include <esp_timer.h>
#include <driver/gpio.h>
 
#include <joybus/bus.h>

#define JOYBUS_ESP32(bus) ((struct joybus_esp32 *)(bus))
 
// Private implementation details - do not access directly
struct joybus_esp32_data {
  // Bus state
  uint8_t state;
 
  // GPIO configuration
  gpio_num_t gpio;
 
  // RMT channel assignment
  uint8_t rmt_tx_ch;
  uint8_t rmt_rx_ch;
  uint8_t rmt_rx_mem_ch;
 
  // RMT interrupt
  intr_handle_t rmt_intr;
 
  // Pre-encoded TX symbols
  uint32_t sym_one;
  uint32_t sym_zero;
  uint32_t sym_stop;
 
  // TARGET_REPLY_FLOOR_NS in CPU cycles, resolved once at enable
  uint32_t reply_floor_cycles;
 
  // RX/TX state
  uint8_t *read_buf;
  uint8_t read_len;
  uint8_t read_count;
  uint8_t rx_skip;
  const uint8_t *write_buf;
  uint8_t write_len;
  uint8_t write_count;
 
  // One-shot timer for inter-transfer gap scheduling
  esp_timer_handle_t transfer_start_timer;
 
  // Transfer state
  joybus_transfer_cb done_callback;
  void *done_user_data;
  int64_t last_transfer_us;
};

struct joybus_esp32 {
  struct joybus base;
  struct joybus_esp32_data data;
};

struct joybus_esp32_config {
  gpio_num_t gpio;

  uint32_t freq;

  uint8_t rmt_tx_ch;

  uint8_t rmt_rx_ch;
};

static inline struct joybus_esp32_config joybus_esp32_config_default(gpio_num_t gpio)
{
  return (struct joybus_esp32_config){
    .gpio      = gpio,
    .freq      = JOYBUS_FREQ_NOMINAL,
    .rmt_tx_ch = 0,
    .rmt_rx_ch = 0,
  };
}

int joybus_esp32_init(struct joybus_esp32 *esp32_bus, struct joybus_esp32_config config);