HardwareI2C_RPI.h

#pragma once
/*
  HardwareI2C_RPI.h 
  Copyright (c) 2025 Phil Schatzmann. All right reserved.
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef USE_RPI
 
#include <fcntl.h>   // for O_RDWR
#include <unistd.h>  // for open(), close(), etc.
#include <vector>
#include "api/HardwareI2C.h"
#include "ArduinoLogger.h"
 
namespace arduino {
 
class HardwareI2C_RPI : public HardwareI2C {
 public:
  HardwareI2C_RPI(const char* device = "/dev/i2c-1") {
    i2c_device = device;
  }
  ~HardwareI2C_RPI() {
    end();
  }
  void begin() override;
  void begin(uint8_t address) override;
  void end() override;
  void setClock(uint32_t freq) override;
  void beginTransmission(uint8_t address) override;
  uint8_t endTransmission(bool stopBit) override;
  uint8_t endTransmission(void) { return endTransmission(true);};
  size_t requestFrom(uint8_t address, size_t len, bool stopBit) override;
  size_t requestFrom(uint8_t address, size_t len) override;
  void onReceive(void (*)(int)) override;
  void onRequest(void (*)(void)) override;
  size_t write(uint8_t) override;
  size_t write(const uint8_t*, size_t) override;
  int available() override;
  int read() override;
  int peek() override;
  void flush() override { fsync(i2c_fd);}
 
  operator bool() { return is_open; }
 
 private:
  int i2c_fd = -1;
  uint8_t current_address = 0;
  uint32_t i2c_clock = 100000;  // default 100kHz
  std::vector<uint8_t> i2c_rx_buffer;
  std::vector<uint8_t> i2c_tx_buffer;
  int i2c_rx_pos = 0;
  const char* i2c_device;
  bool is_open = false;
};
 
}  // namespace arduino
 
#endif