text: /*
   * Author: Sergey Kiselev <sergey.kiselev@intel.com>
   * Copyright (c) 2017 Sergey Kiselev
   * Based on the apa102 driver writen by Yannick Adam <yannick.adam@gmail.com>
   *
   * 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 <cstring>
  #include <iostream>
  #include <stdexcept>
  #include <stdlib.h>
  #include <unistd.h>
  
  #include "p9813.hpp"
  
  using namespace upm;
  
  P9813::P9813(uint16_t ledCount, uint16_t clkPin, uint16_t dataPin, bool batchMode)
          : m_leds(ledCount), m_clkGpio(clkPin), m_dataGpio(dataPin), m_batchMode(batchMode)
  {
      mraa::Result res = mraa::SUCCESS;
  
      // Set GPIO pins to output direction
      res = m_clkGpio.dir(mraa::DIR_OUT);
      if (res != mraa::SUCCESS) {
          throw std::invalid_argument(std::string(__FUNCTION__) +
                                      ": GPIO failed to set direction");
      }
      res = m_dataGpio.dir(mraa::DIR_OUT);
      if (res != mraa::SUCCESS) {
          throw std::invalid_argument(std::string(__FUNCTION__) +
                                      ": GPIO failed to set direction");
      }
  }
  
  void
  P9813::setLed(uint16_t ledIdx, uint8_t r, uint8_t g, uint8_t b)
  {
      setLeds(ledIdx, ledIdx, r, g, b);
  }
  
  void
  P9813::setAllLeds(uint8_t r, uint8_t g, uint8_t b)
  {
      setLeds(0, m_leds.size() - 1, r, g, b);
  }
  
  void
  P9813::setLeds(uint16_t startIdx, uint16_t endIdx, uint8_t r, uint8_t g, uint8_t b)
  {
      for (uint16_t i = startIdx; i <= endIdx; i++) {
  	m_leds[i].red = r;
  	m_leds[i].green = g;
  	m_leds[i].blue = b;
      }
  
      if (!m_batchMode) {
          pushState();
      }
  }
  
  void
  P9813::setLeds(uint16_t startIdx, uint16_t endIdx, std::vector<RgbColor> colors)
  {
      for (uint16_t i = startIdx, j = 0; i <= endIdx; i++) {
  	m_leds[i].red = colors[j].red;
  	m_leds[i].green = colors[j].green;
  	m_leds[i].blue = colors[j].blue;
      }
  
      if (!m_batchMode) {
          pushState();
      }
  }
  
  void
  P9813::pushState(void)
  {
      // Begin data frame
      sendByte(0x00);
      sendByte(0x00);
      sendByte(0x00);
      sendByte(0x00);
  
      for (uint16_t i = 0; i < m_leds.size(); i++) {
  	uint8_t red = m_leds[i].red;
          uint8_t green = m_leds[i].green;
          uint8_t blue = m_leds[i].blue;
          // The first byte is 11 followed by inverted bits 7 and 6 of blue, green, and red
          uint8_t byte0 = 0xFF;
          byte0 ^= (blue >> 2) & 0x30; // XOR bits 4-5
          byte0 ^= (green >> 4) & 0x0C; // XOR bits 2-3
          byte0 ^= (red >> 6) & 0x03; // XOR bits 0-1
  	sendByte(byte0);
          sendByte(blue);
          sendByte(green);
          sendByte(red);
      }
  
      // End data frame
      sendByte(0x00);
      sendByte(0x00);
      sendByte(0x00);
      sendByte(0x00);
  }
  
  /*
   * **************
   *  private area
   * **************
  */
  
  void
  P9813::sendByte(uint8_t data)
  {
      for (uint16_t i = 0; i < 8; i++) {
          // Write the data bit
          m_dataGpio.write((data & 0x80) >> 7);
  	// Pulse the clock
          m_clkGpio.write(1);
          usleep(20);
          m_clkGpio.write(0);
          usleep(20);
  
  	// Shift to the next data bit
          data <<= 1;
      }
  }
  