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/* SC16IS750 interface 
 *   /////////////////////v1.0 Tedd OKANO, 18 Jul 2012, I2C I/F only, MIT License
 *   v1.1 WH, Nov 2013, Added SPI I/F and more methods, MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
 * and associated documentation files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or
 * substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef _SC16IS750_H
#define _SC16IS750_H

//Default I2C Slaveaddress
#define DEFAULT_SC16IS750_ADDR  0x9A

//Default baudrate
#define DEFAULT_BAUD_RATE       9600

#define ENABLE_BULK_TRANSFERS   0x01

//#include "Configuration.h"

#define XTAL_FREQUENCY 14745600UL // On-board crystal (New mid-2010 Version)

// See datasheet section 7.8 for configuring the
// "Programmable baud rate generator"
#define PRESCALER                  1 // Default prescaler after reset
#define BAUD_RATE_DIVISOR(baud) ((XTAL_FREQUENCY/PRESCALER)/(baud*16UL))

// See section 8.4 of the datasheet for definitions
// of bits in the Line Control Register (LCR)
#define LCR_BITS5                0x00
#define LCR_BITS6                0x01
#define LCR_BITS7                0x02
#define LCR_BITS8                0x03

#define LCR_BITS1                0x00
#define LCR_BITS2                0x04

#define LCR_NONE                 0x00
#define LCR_ODD                  0x08
#define LCR_EVEN                 0x18
#define LCR_FORCED1              0x28
#define LCR_FORCED0              0x38

#define LCR_BRK_ENA              0x40
#define LCR_BRK_DIS              0x00

#define LCR_DIV_ENA              0x80
#define LCR_DIV_DIS              0x00


// See section 8.10 of the datasheet for definitions
// of bits in the Enhanced Features Register (EFR)
#define EFR_ENABLE_CTS                (1 << 7)
#define EFR_ENABLE_RTS                (1 << 6)
#define EFR_ENABLE_ENHANCED_FUNCTIONS (1 << 4)

// See Chapter 11 of datasheet
#define SPI_READ_MODE_FLAG      0x80


/** Abstract class SC16IS750 for a converter between either SPI or I2C and a Serial port
  *
  * Supports both SPI and I2C interfaces through derived classes
  *
  * @code
  *
  * @endcode
  */
//class SC16IS750 : public Serial { //Fout, geen Serial constr met Serial(NC, NC) toegestaan...
class SC16IS750 {
    
public:

//  SC16IS750 Register definitions (shifted to align)
    enum RegisterName { 
        RHR         = 0x00 << 3,
        THR         = 0x00 << 3,
        IER         = 0x01 << 3,
        FCR         = 0x02 << 3,
        IIR         = 0x02 << 3,
        LCR         = 0x03 << 3,
        MCR         = 0x04 << 3,
        LSR         = 0x05 << 3,
        MSR         = 0x06 << 3,
        SPR         = 0x07 << 3,
        TCR         = 0x06 << 3,
        TLR         = 0x07 << 3,
        TXLVL       = 0x08 << 3,
        RXLVL       = 0x09 << 3,
        IODIR       = 0x0A << 3,
        IOSTATE     = 0x0B << 3,
        IOINTMSK    = 0x0C << 3,
        reserved    = 0x0D << 3,
        IOCTRL      = 0x0E << 3,
        EFCR        = 0x0F << 3,
        DLL         = 0x00 << 3,
        DLH         = 0x01 << 3,
        EFR         = 0x02 << 3,
        XON1        = 0x04 << 3,
        XON2        = 0x05 << 3,
        XOFF1       = 0x06 << 3,
        XOFF2       = 0x07 << 3,
    } ;


// SC16IS750 configuration register values
struct SC16IS750_cfg {
  char baudrate;
  char dataformat;  
  char flowctrl;  
  char fifoformat;    
};

/** Constructor
  *  
  */
  SC16IS750();  

/** Determine if there is a character available to read.
  *   @return 1 if there is a character available to read, 0 otherwise
  */
    int readable();

/** Determine if how many characters available to read.
  *   @return int Characters available to read
  */
    int readableCount();

/** Determine if there is space available to write a character.    
  *   @return 1 if there is a space for a character to write, 0 otherwise
  */
    int writable();

/** Determine if how much space is available to write characters.
  *   @return int Characterspace available for writing
  */
    int writableCount();
        
    char getc();  
    void putc(char value);    

    void write(const char *str);
    
/** Set baudrate of the serial port.    
  *  @param  baud integer baudrate (4800, 9600 etc)
  *  @return none
  */
    void baud(int baudrate = DEFAULT_BAUD_RATE);   

/** Set the transmission format used by the serial port.   
  *   @param bits      The number of bits in a word (5-8; default = 8)
  *   @param parity    The parity used (Serial::None, Serial::Odd, Serial::Even, Serial::Forced1, Serial::Forced0; default = Serial::None)
  *   @param stop_bits The number of stop bits (1 or 2; default = 1) 
  */
    void format(int bits=8, Serial::Parity parity=Serial::None, int stop_bits=1);

/**
  * Check that UART is connected and operational.
  *   @param  none
  *   @return bool true when connected, false otherwise
  */
  bool connected();

         
#if ENABLE_BULK_TRANSFERS
    void write(const uint8_t *buffer, size_t size);
#else
 //   using Print::write;
#endif
    void flush();

//required for Stream
    int peek() {return 0;};

    // These are specific to the SPI UART
    void ioSetDirection(unsigned char bits);
   void ioSetState(unsigned char bits);

/** Write value to internal register.
  * Pure virtual, must be declared in derived class.   
  *   @param register_address  The address of the Register (enum RegisterName)
  *   @param data              The 8bit value to write
  *   @return none 
  */
   virtual void writeRegister (RegisterName register_address, char data ) =0;

/** Read value from internal register.
  * Pure virtual, must be declared in derived class.   
  *   @param register_address  The address of the Register (enum RegisterName)
  *   @return char             The 8bit value read from the register
  */
   virtual char readRegister (RegisterName register_address ) =0;

protected:
//protected is accessible to derived classes, but not to external users

SC16IS750_cfg _config;

private:
//private is not accessible to derived classes, nor external users
    void init();
};



/** Class SC16IS750_SPI for a converter between SPI and a Serial port
 *
 * @code
 * #include "mbed.h"
 * #include "SC16IS750.h"
 *
 * SPI spi(PTD2, PTD3, PTD1); //MOSI, MISO, SCK
 * SC16IS750_SPI serial_spi(&spi, PTD0);
 * 
 * Serial pc(USBTX,USBRX);
 *
 * int main() {
 *   pc.printf("\nHello World!\n");
 *
 *   while(1) { 
 *     serial_spi.ioSetState(0x00);
 *     wait(0.5);
 *     pc.putc('*');                
 *   }
 * }
 *
 * @endcode
 */
class SC16IS750_SPI : public SC16IS750 {
public:

/** Create a SC16IS750_SPI object using a specified SPI bus and CS
  *
  * @param SPI &spi the SPI port to connect to 
  * @param cs  the Pin of the CS
  */  
  SC16IS750_SPI(SPI *spi, PinName cs);

/** Write value to internal register.
  *   @param register_address  The address of the Register (enum RegisterName)
  *   @param data              The 8bit value to write
  *   @return none 
  */
  virtual void writeRegister(SC16IS750::RegisterName registerAddress, char data);

/** Read value from internal register.
  *   @param register_address  The address of the Register (enum RegisterName)
  *   @return char             The 8bit value read from the register
  */
  virtual char readRegister(SC16IS750::RegisterName registerAddress);

protected:
//protected is accessible to derived classes, but not to external users


private:
  SPI *_spi;          //SPI bus reference
  DigitalOut _cs;     //CS of SPI device

};



/** Class SC16IS750_I2C for a converter between I2C and a Serial port
 *
 * @code
 * #include "mbed.h"
 * #include "SC16IS750.h"
 *
 * I2C i2c(PTE0, PTE1);       //SDA, SCL
 * SC16IS750_I2C serial_i2c(&i2c, DEFAULT_SC16IS750_ADDR);
 *
 * Serial pc(USBTX,USBRX);
 *
 * int main() {
 *   pc.printf("\nHello World!\n");
 *
 *   while(1) { 
 *     serial_i2c.ioSetState(0x00);
 *     wait(0.5);
 *     pc.putc('*');                
 *   }
 * }
 *
 * @endcode
 */
class SC16IS750_I2C : public SC16IS750 {
public:

/** Create a SC16IS750_I2C object using a specified I2C bus and slaveaddress
  *
  * @param I2C &i2c the I2C port to connect to 
  * @param char deviceAddress the address of the SC16IS750
  */  
  SC16IS750_I2C(I2C *i2c, uint8_t deviceAddress = DEFAULT_SC16IS750_ADDR);

/** Write value to internal register.
  *   @param register_address  The address of the Register (enum RegisterName)
  *   @param data              The 8bit value to write
  *   @return none 
  */
  virtual void writeRegister(SC16IS750::RegisterName register_address, char data );

/** Read value from internal register.
  *   @param register_address  The address of the Register (enum RegisterName)
  *   @return char             The 8bit value read from the register
  */
  virtual char readRegister(SC16IS750::RegisterName register_address );

protected:
//protected is accessible to derived classes, but not to external users


private:
  I2C *_i2c;                    //I2C bus reference
  uint8_t _slaveAddress;        //I2C Slave address of device
    
};


#endif  //  _SC16IS750_H