/*
 * extensions.c:
 *	Part of the GPIO program to test, peek, poke and otherwise
 *	noodle with the GPIO hardware on the Raspberry Pi.
 *	Copyright (c) 2012-2013 Gordon Henderson
 ***********************************************************************
 * This file is part of wiringPi:
 *	https://projects.drogon.net/raspberry-pi/wiringpi/
 *
 *    wiringPi is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU Lesser General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    wiringPi is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Lesser General Public License for more details.
 *
 *    You should have received a copy of the GNU Lesser General Public License
 *    along with wiringPi.  If not, see <http://www.gnu.org/licenses/>.
 ***********************************************************************
 */


#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <ctype.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <fcntl.h>

#include <wiringPi.h>

#include <mcp23008.h>
#include <mcp23016.h>
#include <mcp23017.h>
#include <mcp23s08.h>
#include <mcp23s17.h>
#include <sr595.h>
#include <pcf8591.h>
#include <pcf8574.h>

#include "extensions.h"

extern int wiringPiDebug ;

#ifndef TRUE
#  define	TRUE	(1==1)
#  define	FALSE	(1==2)
#endif

// Local structure to hold details

struct extensionFunctionStruct
{
  const char *name ;
  int	(*function)(char *progName, int pinBase, char *params) ;
} ;


/*
 * extractInt:
 *	Check & return an integer at the given location (prefixed by a :)
 *********************************************************************************
 */

static char *extractInt (char *progName, char *p, int *num)
{
  if (*p != ':')
  {
    fprintf (stderr, "%s: colon expected\n", progName) ;
    return NULL ;
  }

  ++p ;

  if (!isdigit (*p))
  {
    fprintf (stderr, "%s: digit expected\n", progName) ;
    return NULL ;
  }

  *num = strtol (p, NULL, 0) ;
  while (isdigit (*p))
    ++p ;

  return p ;
}



/*
 * doExtensionMcp23008:
 *	MCP23008 - 8-bit I2C GPIO expansion chip
 *	mcp23002:base:i2cAddr
 *********************************************************************************
 */

static int doExtensionMcp23008 (char *progName, int pinBase, char *params)
{
  int i2c ;

  if ((params = extractInt (progName, params, &i2c)) == NULL)
    return FALSE ;

  if ((i2c < 0x03) || (i2c > 0x77))
  {
    fprintf (stderr, "%s: i2c address (0x%X) out of range\n", progName, i2c) ;
    return FALSE ;
  }

  mcp23008Setup (pinBase, i2c) ;

  return TRUE ;
}


/*
 * doExtensionMcp23016:
 *	MCP230016- 16-bit I2C GPIO expansion chip
 *	mcp23016:base:i2cAddr
 *********************************************************************************
 */

static int doExtensionMcp23016 (char *progName, int pinBase, char *params)
{
  int i2c ;

  if ((params = extractInt (progName, params, &i2c)) == NULL)
    return FALSE ;

  if ((i2c < 0x03) || (i2c > 0x77))
  {
    fprintf (stderr, "%s: i2c address (0x%X) out of range\n", progName, i2c) ;
    return FALSE ;
  }

  mcp23016Setup (pinBase, i2c) ;

  return TRUE ;
}


/*
 * doExtensionMcp23017:
 *	MCP230017- 16-bit I2C GPIO expansion chip
 *	mcp23017:base:i2cAddr
 *********************************************************************************
 */

static int doExtensionMcp23017 (char *progName, int pinBase, char *params)
{
  int i2c ;

  if ((params = extractInt (progName, params, &i2c)) == NULL)
    return FALSE ;

  if ((i2c < 0x03) || (i2c > 0x77))
  {
    fprintf (stderr, "%s: i2c address (0x%X) out of range\n", progName, i2c) ;
    return FALSE ;
  }

  mcp23017Setup (pinBase, i2c) ;

  return TRUE ;
}


/*
 * doExtensionMcp23s08:
 *	MCP23s08 - 8-bit SPI GPIO expansion chip
 *	mcp23s08:base:spi:port
 *********************************************************************************
 */

static int doExtensionMcp23s08 (char *progName, int pinBase, char *params)
{
  int spi, port ;

  if ((params = extractInt (progName, params, &spi)) == NULL)
    return FALSE ;

  if ((spi < 0) || (spi > 1))
  {
    fprintf (stderr, "%s: SPI address (%d) out of range\n", progName, spi) ;
    return FALSE ;
  }

  if ((params = extractInt (progName, params, &port)) == NULL)
    return FALSE ;

  if ((port < 0) || (port > 7))
  {
    fprintf (stderr, "%s: port address (%d) out of range\n", progName, port) ;
    return FALSE ;
  }

  mcp23s08Setup (pinBase, spi, port) ;

  return TRUE ;
}


/*
 * doExtensionMcp23s17:
 *	MCP23s17 - 16-bit SPI GPIO expansion chip
 *	mcp23s17:base:spi:port
 *********************************************************************************
 */

static int doExtensionMcp23s17 (char *progName, int pinBase, char *params)
{
  int spi, port ;

  if ((params = extractInt (progName, params, &spi)) == NULL)
    return FALSE ;

  if ((spi < 0) || (spi > 1))
  {
    fprintf (stderr, "%s: SPI address (%d) out of range\n", progName, spi) ;
    return FALSE ;
  }

  if ((params = extractInt (progName, params, &port)) == NULL)
    return FALSE ;

  if ((port < 0) || (port > 7))
  {
    fprintf (stderr, "%s: port address (%d) out of range\n", progName, port) ;
    return FALSE ;
  }

  mcp23s17Setup (pinBase, spi, port) ;

  return TRUE ;
}


/*
 * doExtensionSr595:
 *	Shift Register 74x595
 *	sr595:base:pins:data:clock:latch
 *********************************************************************************
 */

static int doExtensionSr595 (char *progName, int pinBase, char *params)
{
  int pins, data, clock, latch ;

// Extract pins

  if ((params = extractInt (progName, params, &pins)) == NULL)
    return FALSE ;

  if ((pins < 8) || (pins > 32))
  {
    fprintf (stderr, "%s: pin count (%d) out of range - 8-32 expected.\n", progName, pins) ;
    return FALSE ;
  }

  if ((params = extractInt (progName, params, &data)) == NULL)
    return FALSE ;

  if ((params = extractInt (progName, params, &clock)) == NULL)
    return FALSE ;

  if ((params = extractInt (progName, params, &latch)) == NULL)
    return FALSE ;

  sr595Setup (pinBase, pins, data, clock, latch) ;

  return TRUE ;
}


/*
 * doExtensionPcf8574:
 *	Digital IO (Crude!)
 *	pcf8574:base:i2cAddr
 *********************************************************************************
 */

static int doExtensionPcf8574 (char *progName, int pinBase, char *params)
{
  int i2c ;

  if ((params = extractInt (progName, params, &i2c)) == NULL)
    return FALSE ;

  if ((i2c < 0x03) || (i2c > 0x77))
  {
    fprintf (stderr, "%s: i2c address (0x%X) out of range\n", progName, i2c) ;
    return FALSE ;
  }

  pcf8574Setup (pinBase, i2c) ;

  return TRUE ;
}


/*
 * doExtensionPcf8591:
 *	Analog IO
 *	pcf8591:base:i2cAddr
 *********************************************************************************
 */

static int doExtensionPcf8591 (char *progName, int pinBase, char *params)
{
  int i2c ;

  if ((params = extractInt (progName, params, &i2c)) == NULL)
    return FALSE ;

  if ((i2c < 0x03) || (i2c > 0x77))
  {
    fprintf (stderr, "%s: i2c address (0x%X) out of range\n", progName, i2c) ;
    return FALSE ;
  }

  pcf8591Setup (pinBase, i2c) ;

  return TRUE ;
}


/*
 * Function list
 *********************************************************************************
 */

struct extensionFunctionStruct extensionFunctions [] = 
{
  { "mcp23008",		&doExtensionMcp23008 	},
  { "mcp23016",		&doExtensionMcp23016 	},
  { "mcp23017",		&doExtensionMcp23017 	},
  { "mcp23s08",		&doExtensionMcp23s08 	},
  { "mcp23s17",		&doExtensionMcp23s17 	},
  { "sr595",		&doExtensionSr595	},
  { "pcf8574",		&doExtensionPcf8574	},
  { "pcf8591",		&doExtensionPcf8591	},
  { NULL,		NULL		 	},
} ;


/*
 * doExtension:
 *	Load in a wiringPi extension
 *********************************************************************************
 */

int doExtension (char *progName, char *extensionData)
{
  char *p ;
  char *extension = extensionData ;
  struct extensionFunctionStruct *extensionFn ;
  int pinBase = 0 ;

// Get the extension extension name by finding the first colon

  p = extension ;
  while (*p != ':')
  {
    if (!*p)	// ran out of characters
    {
      fprintf (stderr, "%s: extension name not terminated by a colon\n", progName) ;
      return FALSE ;
    }
    ++p ;
  }

  *p++ = 0 ;

  if (!isdigit (*p))
  {
    fprintf (stderr, "%s: pinBase number expected after extension name\n", progName) ;
    return FALSE ;
  }

  while (isdigit (*p))
  {
    if (pinBase > 1000000000)
    {
      fprintf (stderr, "%s: pinBase too large\n", progName) ;
      return FALSE ;
    }

    pinBase = pinBase * 10 + (*p - '0') ;
    ++p ;
  }

  if (pinBase < 64)
  {
    fprintf (stderr, "%s: pinBase (%d) too small. Minimum is 64.\n", progName, pinBase) ;
    return FALSE ;
  }

// Search for extensions:

  for (extensionFn = extensionFunctions ; extensionFn->name != NULL ; ++extensionFn)
  {
    if (strcmp (extensionFn->name, extension) == 0)
      return extensionFn->function (progName, pinBase, p) ;
  }

  fprintf (stderr, "%s: extension %s not found\n", progName, extension) ;
  return FALSE ;
}