soft_i2c_slave_states.h

// ---------------------------------------------
//           This file is part of
//      _  _   __    _   _    __    __
//     ( \/ ) /__\  ( )_( )  /__\  (  )
//      \  / /(__)\  ) _ (  /(__)\  )(__
//      (__)(__)(__)(_) (_)(__)(__)(____)
//
//     Yet Another HW Abstraction Library
//      Copyright (C) Andreas Terstegge
//      BSD Licensed (see file LICENSE)
//
// ---------------------------------------------
//
//  This class is used by the soft_i2c_slave driver.
//  It implements all necessary states for the state
//  machine, which processes the SDA and SCL line
//  changes. The state pattern (GoF) is used!
 
#ifndef _SOFT_I2C_SLAVE_STATES_H_
#define _SOFT_I2C_SLAVE_STATES_H_
 
#include <cstdint>
 
class soft_i2c_slave;
 
namespace I2C
{
 
class STATE {
public:
    STATE(soft_i2c_slave & c) : _context(c) {}
 
    virtual void enter() { }
    virtual void leave() { }
 
    void start();
    void stop();
    virtual void high()  { }
    virtual void low()   { }
    virtual void scl_falling() { }
 
    virtual ~STATE() { }
 
protected:
    soft_i2c_slave & _context;
};
 
class IDLE : public STATE {
public:
    IDLE(soft_i2c_slave & c) :  STATE(c) {}
    void enter() override;
};
 
class READ_ADDR : public STATE {
public:
    READ_ADDR(soft_i2c_slave & c) :  STATE(c), _data(0), _bit_mask(0) {}
    void enter() override;
    void high()  override;
    void low()   override;
    void scl_falling() override;
private:
    uint8_t _data;
    int     _bit_mask;
};
 
class WRITE_ACK : public STATE {
public:
    WRITE_ACK(soft_i2c_slave & c) :  STATE(c) {}
    void enter() override;
    void scl_falling() override;
};
 
class READ_DATA : public STATE {
public:
    READ_DATA(soft_i2c_slave & c) :  STATE(c), _data(0), _bit_mask(0) {}
    void enter() override;
    void high()  override;
    void low()   override;
    void scl_falling() override;
private:
    uint8_t   _data;
    int       _bit_mask;
};
 
class WRITE_DATA : public STATE {
public:
    WRITE_DATA(soft_i2c_slave & c) :  STATE(c), _data(0), _bit_mask(0) {}
    void enter() override;
    void scl_falling() override;
private:
    uint8_t   _data;
    int       _bit_mask;
};
 
class READ_ACK : public STATE {
public:
    READ_ACK(soft_i2c_slave & c) :  STATE(c) {}
    void high()  override;
    void low()   override;
    void scl_falling() override;
};
 
} // namespace I2C
 
#endif // _SOFT_I2C_SLAVE_STATES_H_