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/* mbed PT6961 Library, for Princeton PT6961 LED controller
 * Copyright (c) 2015, v01: WH, Initial version
 *
 * 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.
 */
#include "mbed.h" 
#include "PT6961.h"

/** Constructor for class for driving Princeton PT6961 LED controller with SPI bus interface device. 
 *  @brief Supports 6 Digits or 12 Segments or 7 Digits of 11 Segments. Also supports a scanned keyboard of upto 30 keys.
 *   
 *  @param  PinName mosi, miso, sclk, cs SPI bus pins
 *  @param  Mode selects either 6 Digits of 12 Segments or 7 Digits of 11 Segments (default) 
*/
PT6961::PT6961(PinName mosi, PinName miso, PinName sclk, PinName cs, Mode mode) : _spi(mosi,miso,sclk), _cs(cs), _mode(mode) {

  _init();
}

/** Init the SPI interface and the controller
  * @param  none
  * @return none
  */ 
void PT6961::_init(){
  
//init SPI
  _cs=1;
  _spi.format(8,3); //PT6961 uses mode 3 (Clock High on Idle, Data latched on second (=rising) edge)
  _spi.frequency(500000);   

//init controller  
  _writeCmd(PT6961_MODE_SET_CMD, _mode);                                               // Mode set command 

  _display = PT6961_DSP_ON;
  _bright  = PT6961_BRT_DEF; 
  _writeCmd(PT6961_DSP_CTRL_CMD, _display | _bright );                                 // Display control cmd, display on/off, brightness   
  
  _writeCmd(PT6961_DATA_SET_CMD, PT6961_DATA_WR | PT6961_ADDR_INC | PT6961_MODE_NORM); // Data set cmd, normal mode, auto incr, write data  
}   


/** Clear the screen and locate to 0
 */  
void PT6961::cls() {
  
  _cs=0;
  wait_us(1);    
  _spi.write(_flip(PT6961_ADDR_SET_CMD | 0x00)); // Address set cmd, 0
      
  for (int cnt=0; cnt<PT6961_DISPLAY_MEM; cnt++) {
    _spi.write(0x00); // data 
  }
  
  wait_us(1);
  _cs=1;      
}  

/** Set Brightness
  *
  * @param  char brightness (3 significant bits, valid range 0..7 (1/16 .. 14/14 dutycycle)  
  * @return none
  */
void PT6961::setBrightness(char brightness){

  _bright = brightness & PT6961_BRT_MSK; // mask invalid bits
  
  _writeCmd(PT6961_DSP_CTRL_CMD, _display | _bright );  // Display control cmd, display on/off, brightness  
}

/** Set the Display mode On/off
  *
  * @param bool display mode
  */
void PT6961::setDisplay(bool on) {
  
  if (on) {
    _display = PT6961_DSP_ON;
  }
  else {
   _display = PT6961_DSP_OFF;
  }
  
  _writeCmd(PT6961_DSP_CTRL_CMD, _display | _bright );  // Display control cmd, display on/off, brightness   
}

/** Write databyte to PT6961
  *  @param  int address display memory location to write byte
  *  @param  char data byte written at given address
  *  @return none
  */ 
void PT6961::writeData(int address, char data) {
  _cs=0;
  wait_us(1);    
  _spi.write(_flip(PT6961_ADDR_SET_CMD | (address & PT6961_ADDR_MSK))); // Set Address cmd
      
  _spi.write(_flip(data)); // data 
  
  wait_us(1);
  _cs=1;             
}

/** Write Display datablock to PT6961
  *  @param  DisplayData_t data Array of PT6961_DISPLAY_MEM (=14) bytes for displaydata (starting at address 0)
  *  @param  length number bytes to write (valide range 0..PT6961_DISPLAY_MEM (=14), starting at address 0)     
  *  @return none
  */ 
void PT6961::writeData(DisplayData_t data, int length) {
  _cs=0;
  wait_us(1);    
  _spi.write(_flip(PT6961_ADDR_SET_CMD | 0x00)); // Set Address at 0
      
// sanity check
  if (length < 0) {length = 0;}
  if (length > PT6961_DISPLAY_MEM) {length = PT6961_DISPLAY_MEM;}

//  for (int idx=0; idx<PT6961_DISPLAY_MEM; idx++) {  
  for (int idx=0; idx<length; idx++) {    
    _spi.write(_flip(data[idx])); // data 
  }
  
  wait_us(1);
  _cs=1;             
}


/** Read keydata block from PT6961
  *  @param  *keydata Ptr to Array of PT6961_KEY_MEM (=5) bytes for keydata
  *  @return bool keypress True when at least one key was pressed
  *
  * Note: Due to the hardware configuration the PT6961 key matrix scanner will detect multiple keys pressed at same time,
  *       but this may also result in some spurious keys being set in keypress data array.
  *       It may be best to ignore all keys in those situations. That option is implemented in this method depending on #define setting.  
  */ 
bool PT6961::getKeys(KeyData_t *keydata) {
  int keypress = 0;
  char data;

  // Read keys
  _cs=0;
  wait_us(1);    
  
  // Enable Key Read mode
  _spi.write(_flip(PT6961_DATA_SET_CMD | PT6961_KEY_RD | PT6961_ADDR_INC | PT6961_MODE_NORM)); // Data set cmd, normal mode, auto incr, read data

  for (int idx=0; idx < PT6961_KEY_MEM; idx++) {
    data = _flip(_spi.write(0xFF));    // read keys and correct bitorder

    if (data != 0) {  // Check for any pressed key
      for (int bit=0; bit < PT6961_KEY_BITS; bit++) {
        if (data & (1 << bit)) {keypress++;} // Test all significant bits
      }
    }  

    (*keydata)[idx] = data;            // Store keydata after correcting bitorder
  }

  wait_us(1);
  _cs=1;    

  // Restore Data Write mode
  _writeCmd(PT6961_DATA_SET_CMD, PT6961_DATA_WR | PT6961_ADDR_INC | PT6961_MODE_NORM); // Data set cmd, normal mode, auto incr, write data  
      
#if(1)
// Dismiss multiple keypresses at same time
  return (keypress == 1);    
#else
// Allow multiple keypress and accept possible spurious keys
  return (keypress > 0);
#endif  
}
    

/** Helper to reverse all command or databits. The PT6961 expects LSB first, whereas SPI is MSB first
  *  @param  char data
  *  @return bitreversed data
  */ 
char PT6961::_flip(char data) {
 char value=0;
  
 if (data & 0x01) {value |= 0x80;} ;  
 if (data & 0x02) {value |= 0x40;} ;
 if (data & 0x04) {value |= 0x20;} ;
 if (data & 0x08) {value |= 0x10;} ;
 if (data & 0x10) {value |= 0x08;} ;
 if (data & 0x20) {value |= 0x04;} ;
 if (data & 0x40) {value |= 0x02;} ;
 if (data & 0x80) {value |= 0x01;} ;
 return value;       
}


/** Write command and parameter to PT6961
  *  @param  int cmd Command byte
  *  &Param  int data Parameters for command
  *  @return none
  */  
void PT6961::_writeCmd(int cmd, int data){
    
  _cs=0;
  wait_us(1);    
//  _spi.write(_flip( (cmd & 0xF0) | (data & 0x0F)));  
  _spi.write(_flip( (cmd & PT6961_CMD_MSK) | (data & ~PT6961_CMD_MSK)));   
 
  wait_us(1);
  _cs=1;          
}