rp2xxx.h

 
#pragma once
 
#include <hardware/irq.h>
#include <hardware/pio.h>
#include <hardware/timer.h>
 
#include <joybus/bus.h>

#define JOYBUS_RP2XXX(bus) ((struct joybus_rp2xxx *)(bus))
 
struct joybus_rp2xxx;
 
// Private implementation details - do not access directly
struct joybus_rp2xxx_data {
  // Bus state
  uint8_t state;
 
  // GPIO configuration
  uint gpio;
 
  // PIO instance and state machine
  PIO pio;
  uint pio_sm;
  bool pio_configured;
 
  // DMA configuration
  uint dma_chan_tx;
  uint dma_chan_rx;
 
  // RX/TX state
  uint8_t *read_buf;
  uint8_t read_len;
  uint8_t read_count;
  uint8_t *write_buf;
  uint8_t write_len;
  // Hardware alarm the timeouts run on, shared with any other bus on it
  timer_hw_t *timer;
  uint alarm_num;
  struct joybus_rp2xxx *alarm_next;
 
  // How the PIO and alarm handlers reach their vectors
  void (*set_irq_handler)(uint irq_num, irq_handler_t handler);
 
  // What this bus is waiting for, if anything
  uint64_t alarm_target_us;
  void (*alarm_callback)(void *user_data);
 
  // Transfer state
  joybus_transfer_cb done_callback;
  void *done_user_data;
  uint64_t last_transfer_us;
};

struct joybus_rp2xxx {
  struct joybus base;
  struct joybus_rp2xxx_data data;
};

struct joybus_rp2xxx_config {
  uint8_t gpio;

  PIO pio;

  timer_hw_t *timer;

  uint alarm_num;

  uint32_t freq;

  void (*set_irq_handler)(uint irq_num, irq_handler_t handler);
};

static inline void joybus_rp2xxx_set_irq_handler_sdk(uint irq_num, irq_handler_t handler)
{
  irq_set_exclusive_handler(irq_num, handler);
  irq_set_enabled(irq_num, true);
}

static inline struct joybus_rp2xxx_config joybus_rp2xxx_config_default(uint8_t gpio)
{
  return (struct joybus_rp2xxx_config){
    .gpio            = gpio,
    .pio             = pio0,
    .timer           = PICO_DEFAULT_TIMER_INSTANCE(),
    .alarm_num       = 0,
    .freq            = JOYBUS_FREQ_NOMINAL,
    .set_irq_handler = joybus_rp2xxx_set_irq_handler_sdk,
  };
}

int joybus_rp2xxx_init(struct joybus_rp2xxx *rp2xxx_bus, struct joybus_rp2xxx_config config);