text: /****************************************************************************
   * drivers/lcd/ssd1306_spi.c
   *
   *   Copyright (C) 2015 Alan Carvalho de Assis. All rights reserved.
   *   Author: Alan Carvalho de Assis <acassis@gmail.com>
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <unistd.h>
  #include <errno.h>
  #include <debug.h>
  
  #include <nuttx/kmalloc.h>
  #include <nuttx/lcd/ssd1306.h>
  #include <nuttx/spi/spi.h>
  #include "ssd1306.h"
  
  #if defined(CONFIG_LCD_SSD1306) && defined(CONFIG_LCD_SSD1306_SPI)
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: ssd1306_configspi
   *
   * Description:
   *
   ****************************************************************************/
  
  void ssd1306_configspi(FAR struct spi_dev_s *spi)
  {
    lcdinfo("Mode: %d Bits: 8 Frequency: %d\n",
            CONFIG_SSD1306_SPIMODE, CONFIG_SSD1306_FREQUENCY);
  
    /* Configure SPI for the SSD1306 */
  
    SPI_SETMODE(spi, CONFIG_SSD1306_SPIMODE);
    SPI_SETBITS(spi, 8);
    (void)SPI_HWFEATURES(spi, 0);
    (void)SPI_SETFREQUENCY(spi, CONFIG_SSD1306_FREQUENCY);
  }
  
  /****************************************************************************
   * Name: ssd1306_sendbyte
   *
   * Description:
   *   Write a value to an 8-bit value to SSD1306
   *
   ****************************************************************************/
  
  int ssd1306_sendbyte(FAR struct ssd1306_dev_s *priv, uint8_t regval)
  {
  #ifdef CONFIG_LCD_SSD1306_REGDEBUG
    _err("->0x%02x\n", regval);
  #endif
  
    /* Send byte value to display */
  
    (void)SPI_SEND(priv->spi, regval);
    return OK;
  }
  
  /****************************************************************************
   * Name: ssd1306_sendblk
   *
   * Description:
   *   Write an array of bytes to SSD1306
   *
   ****************************************************************************/
  
  int ssd1306_sendblk(FAR struct ssd1306_dev_s *priv, uint8_t *data, uint8_t len)
  {
    /* Send byte value to display */
  
    (void)SPI_SNDBLOCK(priv->spi, data, len);
    return OK;
  }
  
  /****************************************************************************
   * Name: ssd1306_select
   *
   * Description:
   *   Enable/Disable SSD1306 SPI CS
   *
   ****************************************************************************/
  
  void ssd1306_select(FAR struct ssd1306_dev_s *priv, bool cs)
  {
    /* If we are selecting the device */
  
    if (cs == true)
      {
        /* If SPI bus is shared then lock and configure it */
  
        (void)SPI_LOCK(priv->spi, true);
        ssd1306_configspi(priv->spi);
      }
  
    /* Select/deselect SPI device */
  
    SPI_SELECT(priv->spi, SPIDEV_DISPLAY(0), cs);
  
    /* If we are deselecting the device */
  
    if (cs == false)
      {
        /* Unlock bus */
  
        (void)SPI_LOCK(priv->spi, false);
      }
  }
  
  /****************************************************************************
   * Name: ssd1306_cmddata
   *
   * Description:
   *   Select Command/Data mode for SSD1306
   *
   ****************************************************************************/
  
  void ssd1306_cmddata(FAR struct ssd1306_dev_s *priv, bool cmd)
  {
    /* Select command transfer */
  
    SPI_CMDDATA(priv->spi, SPIDEV_DISPLAY(0), cmd);
  }
  #endif /* CONFIG_LCD_SSD1306 && CONFIG_LCD_SSD1306_SPI */
  