bus.h

 
#pragma once
 
#include <stdint.h>
 
#include <joybus/target.h>
 
struct joybus;

#define JOYBUS_FREQ_GCC                 250000

#define JOYBUS_FREQ_WAVEBIRD            225000

#define JOYBUS_FREQ_CONSOLE             200000

#define JOYBUS_BLOCK_SIZE               64

#define JOYBUS_INTER_TRANSFER_DELAY_US  20

#define JOYBUS_REPLY_TIMEOUT_US         100

#define JOYBUS(bus) ((struct joybus *)(bus))

typedef void (*joybus_transfer_cb_t)(struct joybus *bus, int result, void *user_data);
 
// API for a Joybus backend - internal use only
struct joybus_api {
  int (*enable)(struct joybus *bus);
  int (*disable)(struct joybus *bus);
  int (*transfer)(struct joybus *bus, const uint8_t *write_buf, uint8_t write_len, uint8_t *read_buf, uint8_t read_len,
                  joybus_transfer_cb_t callback, void *user_data);
  int (*target_register)(struct joybus *bus, struct joybus_target *target);
  int (*target_unregister)(struct joybus *bus, struct joybus_target *target);
};

struct joybus {
  const struct joybus_api *api;
 
  struct joybus_target *target;
  uint8_t command_buffer[JOYBUS_BLOCK_SIZE];
};

static inline int joybus_enable(struct joybus *bus)
{
  return bus->api->enable(bus);
}

static inline int joybus_disable(struct joybus *bus)
{
  return bus->api->disable(bus);
}

static inline int joybus_transfer(struct joybus *bus, const uint8_t *write_buf, uint8_t write_len, uint8_t *read_buf,
                                  uint8_t read_len, joybus_transfer_cb_t callback, void *user_data)
{
  return bus->api->transfer(bus, write_buf, write_len, read_buf, read_len, callback, user_data);
}

static inline int joybus_target_register(struct joybus *bus, struct joybus_target *target)
{
  return bus->api->target_register(bus, target);
}

static inline int joybus_target_unregister(struct joybus *bus, struct joybus_target *target)
{
  return bus->api->target_unregister(bus, target);
}