/*************************************************************************//**
 * @file dmdif_ssd2119_ebi.c
 * @brief Dot matrix display interface using EBI
 * @author Energy Micro AS
 ******************************************************************************
 * @section License
 * <b>(C) Copyright 2012 Energy Micro AS, http://www.energymicro.com</b>
 ******************************************************************************
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 * 4. The source and compiled code may only be used on Energy Micro "EFM32"
 *    microcontrollers and "EFR4" radios.
 *
 * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
 * obligation to support this Software. Energy Micro AS is providing the
 * Software "AS IS", with no express or implied warranties of any kind,
 * including, but not limited to, any implied warranties of merchantability
 * or fitness for any particular purpose or warranties against infringement
 * of any proprietary rights of a third party.
 *
 * Energy Micro AS will not be liable for any consequential, incidental, or
 * special damages, or any other relief, or for any claim by any third party,
 * arising from your use of this Software.
 *
 *****************************************************************************/

#include <stdint.h>
#include "dmd_ssd2119_registers.h"
#include "dmd_ssd2119.h"
#include "dmdif_ssd2119_ebi.h"
#include "dvk.h"

/* Local function prototypes */
static EMSTATUS setNextReg(uint8_t reg);

static volatile uint16_t *command_register;
static volatile uint16_t *data_register;

/**************************************************************************//**
*  @brief
*  Initializes the data interface to the LCD controller SSD2119
*
*
*  @param cmdRegAddr
*  The address in memory where data to the command register in the display
*  controller are written
*  @param dataRegAddr
*  The address in memory where data to the data register in the display
*  controller are written
*
*  @return
*  DMD_OK on success, otherwise error code
******************************************************************************/
EMSTATUS DMDIF_init(uint32_t cmdRegAddr, uint32_t dataRegAddr)
{
  command_register = (volatile uint16_t*) cmdRegAddr;
  data_register    = (volatile uint16_t*) dataRegAddr;

  return DMD_OK;
}

/**************************************************************************//**
*  @brief
*  Writes a value to a control register in the LCD controller
*
*  @param reg
*  The register that will be written to
*  @param data
*  The value to write to the register
*
*  @return
*  DMD_OK on success, otherwise error code
******************************************************************************/
EMSTATUS DMDIF_writeReg(uint8_t reg, uint16_t data)
{
  setNextReg(reg);

  *data_register = data;

  return DMD_OK;
}

/**************************************************************************//**
*  @brief
*  Reads the device code of the LCD controller
*  DOESN'T WORK
*
*  @return
*  The device code of the LCD controller
******************************************************************************/
uint16_t DMDIF_readDeviceCode(void)
{
  uint16_t deviceCode;

  /* Reading from the oscillation control register gives the device code */
  setNextReg(DMD_SSD2119_DEVICE_CODE_READ);

  deviceCode    = *data_register;

  return deviceCode;
}

/**************************************************************************//**
*  @brief
*  Sends the data access command to the LCD controller to prepare for one or more
*  writes or reads using the DMDIF_writeData() and DMDIF_readData()
*
*  @return
*  DMD_OK on success, otherwise error code
******************************************************************************/
EMSTATUS DMDIF_prepareDataAccess(void)
{
  setNextReg(DMD_SSD2119_ACCESS_DATA);

  return DMD_OK;
}

/**************************************************************************//**
*  @brief
*  Writes one pixel to the LCD controller. DMDIF_prepareDataAccess() needs to be
*  called before writing data using this function.
*
*  @param data
*  The color value of the pixel to be written in 18bpp format
*
*  @return
*  DMD_OK on success, otherwise error code
******************************************************************************/
EMSTATUS DMDIF_writeData(uint32_t data)
{
  *data_register = (data & 0x0000FFFF);

  return DMD_OK;
}


/**************************************************************************//**
*  @brief
*  Writes one pixel to the LCD controller. DMDIF_prepareDataAccess() needs to be
*  called before writing data using this function.
*
*  @param data
*  The color value of the pixel to be written in 18bpp format
*
*  @return
*  DMD_OK on success, otherwise error code
******************************************************************************/
EMSTATUS DMDIF_writeDataRepeated( uint32_t data, int len ){

   uint16_t pixelData;
   int i;

   /* Write bits [8:0] of the pixel data to bits [8:0] on the output lines */
   pixelData = data & 0x0000FFFF;

   for (i=0; i<len; i++) {
      *data_register = pixelData;
   }

   return DMD_OK;

}


/**************************************************************************//**
*  @brief
*  Writes one pixel to the LCD controller. DMDIF_prepareDataAccess() needs to be
*  called before writing data using this function.
*
*  @param a
*  The upper 9 bits of color value of the pixel to be written in 18bpp format
*
*  @param b
*  The low 9 bits of color value of the pixel to be written in 18bpp format
*
*  @return
*  DMD_OK on success, otherwise error code
******************************************************************************/
EMSTATUS DMDIF_writeDataConverted( uint16_t a, uint16_t b ){

   uint16_t pixel;

   pixel  = b >> 1;
   pixel |= (a << 8) & 0xFF00;

   *data_register = pixel;

   return DMD_OK;

}


/**************************************************************************//**
*  @brief
*  Reads a byte of data from the memory of the LCD controller.
*  DMDIF_prepareDataAccess() needs to be called before using this function.
*  DOESN'T WORK
*
*  @return
*  18bpp value of pixel
******************************************************************************/
uint32_t DMDIF_readData(void)
{
  uint32_t data;

  data = *data_register;

  return data;
}

/**************************************************************************//**
*  \brief
*  Sets the register in the LCD controller to write commands to
*
*  \param reg
*  The next register in the LCD controller to write to
*
*  @return
*  DMD_OK on success, otherwise error code
******************************************************************************/
static EMSTATUS setNextReg(uint8_t reg)
{
  uint16_t data;

  data = reg & 0xff;
  /* Write the register address to bits [8:1] in the index register */
  *command_register = data;

  return DMD_OK;
}