//
//    This file is part of Dire Wolf, an amateur radio packet TNC.
//
//    Copyright (C) 2011, 2013, 2014, 2015, 2016, 2017  John Langner, WB2OSZ
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 2 of the License, or
//    (at your option) any later version.
//
//    This program 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 General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with this program.  If not, see <http://www.gnu.org/licenses/>.


/*------------------------------------------------------------------
 *
 * Module:      ptt.c
 *
 * Purpose:   	Activate the output control lines for push to talk (PTT) and other purposes.
 *		
 * Description:	Traditionally this is done with the RTS signal of the serial port.
 *
 *		If we have two radio channels and only one serial port, DTR
 *		can be used for the second channel.
 *
 *		If __WIN32__ is defined, we use the Windows interface.
 *		Otherwise we use the Linux interface.
 *
 * Version 0.9:	Add ability to use GPIO pins on Linux.
 *
 * Version 1.1: Add parallel printer port for x86 Linux only.
 *
 *		This is hardcoded to use the primary motherboard parallel
 *		printer port at I/O address 0x378.  This might work with
 *		a PCI card configured to use the same address if the 
 *		motherboard does not have a built in parallel port.
 *		It won't work with a USB-to-parallel-printer-port adapter.
 *
 * Version 1.2: More than two radio channels.
 *		Generalize for additional signals besides PTT.
 *
 * Version 1.3:	HAMLIB support.
 *
 * Version 1.4:	The spare "future" indicator is now used when connected to another station.
 *
 *		Take advantage of the new 'gpio' group and new /sys/class/gpio protections in Raspbian Jessie.
 *
 *		Handle more complicated gpio node names for CubieBoard, etc.
 *
 * Version 1.5:	Ability to use GPIO pins of CM108/CM119 for PTT signal.
 *
 *
 * References:	http://www.robbayer.com/files/serial-win.pdf
 *
 *		https://www.kernel.org/doc/Documentation/gpio.txt
 *
 *---------------------------------------------------------------*/

/*
	A growing number of people have been asking about support for the DMK URI,
	RB-USB RIM, etc.

	These use a C-Media CM108/CM119 with an interesting addition, a GPIO
	pin is used to drive PTT.  Here is some related information.

	DMK URI:

		http://www.dmkeng.com/URI_Order_Page.htm
		http://dmkeng.com/images/URI%20Schematic.pdf

	RB-USB RIM:

		http://www.repeater-builder.com/products/usb-rim-lite.html
		http://www.repeater-builder.com/voip/pdf/cm119-datasheet.pdf

	RA-35:

		http://www.masterscommunications.com/products/radio-adapter/ra35.html

	DINAH:

		https://hamprojects.info/dinah/


	Homebrew versions of the same idea:

		http://images.ohnosec.org/usbfob.pdf
		http://www.qsl.net/kb9mwr/projects/voip/usbfob-119.pdf
		http://rtpdir.weebly.com/uploads/1/6/8/7/1687703/usbfob.pdf
		http://www.repeater-builder.com/projects/fob/USB-Fob-Construction.pdf

	Applications that have support for this:

		http://docs.allstarlink.org/drupal/
		http://soundmodem.sourcearchive.com/documentation/0.16-1/ptt_8c_source.html
		https://github.com/N0NB/hamlib/blob/master/src/cm108.c#L190
		http://permalink.gmane.org/gmane.linux.hams.hamlib.devel/3420

	Information about the "hidraw" device:

		http://unix.stackexchange.com/questions/85379/dev-hidraw-read-permissions
		http://www.signal11.us/oss/udev/
		http://www.signal11.us/oss/hidapi/
		https://github.com/signal11/hidapi/blob/master/libusb/hid.c
		http://stackoverflow.com/questions/899008/howto-write-to-the-gpio-pin-of-the-cm108-chip-in-linux
		https://www.kernel.org/doc/Documentation/hid/hidraw.txt
		https://github.com/torvalds/linux/blob/master/samples/hidraw/hid-example.c

	Similar chips: SSS1621, SSS1623

		https://irongarment.wordpress.com/2011/03/29/cm108-compatible-chips-with-gpio/

	Here is an attempt to add direct CM108 support.
	Seems to be hardcoded for only a single USB audio adapter.

		https://github.com/donothingloop/direwolf_cm108

	In version 1.3, we add HAMLIB support which should be able to do this in a roundabout way.
	(Linux only at this point.)

	This is documented in the User Guide, section called,
		"Hamlib PTT Example 2: Use GPIO of USB audio adapter.  (e.g. DMK URI)"

	It's rather involved and the explantion doesn't cover the case of multiple
	USB-Audio adapters.  It would be nice to have a little script which lists all
	of the USB-Audio adapters and the corresponding /dev/hidraw device.
	( We now have it.  The included "cm108" application. )
	
	In version 1.5 we have a flexible, easy to use implementation for Linux.
	Windows would be a lot of extra work because USB devices are nothing like Linux.
	We'd be starting from scratch to figure out how to do it.
*/


#include "direwolf.h"		// should be first.   This includes windows.h.

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <time.h>

#if __WIN32__
#else
#include <sys/termios.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <grp.h>
#include <dirent.h>

#ifdef USE_HAMLIB
#include <hamlib/rig.h>
#endif

#ifdef USE_CM108
#include "cm108.h"
#endif

#ifdef USE_GPIOD
#include <gpiod.h>
#endif 

/* So we can have more common code for fd. */
typedef int HANDLE;
#define INVALID_HANDLE_VALUE (-1)

#endif

#include "textcolor.h"
#include "audio.h"
#include "ptt.h"
#include "dlq.h"


#if __WIN32__

#define RTS_ON(fd) 	EscapeCommFunction(fd,SETRTS);
#define RTS_OFF(fd) 	EscapeCommFunction(fd,CLRRTS);
#define DTR_ON(fd)    	EscapeCommFunction(fd,SETDTR);
#define DTR_OFF(fd)	EscapeCommFunction(fd,CLRDTR);

#else

#define RTS_ON(fd) 	{ int stuff; ioctl (fd, TIOCMGET, &stuff); stuff |= TIOCM_RTS;  ioctl (fd, TIOCMSET, &stuff); }
#define RTS_OFF(fd) 	{ int stuff; ioctl (fd, TIOCMGET, &stuff); stuff &= ~TIOCM_RTS; ioctl (fd, TIOCMSET, &stuff); }
#define DTR_ON(fd)    	{ int stuff; ioctl (fd, TIOCMGET, &stuff); stuff |= TIOCM_DTR;  ioctl (fd, TIOCMSET, &stuff); }
#define DTR_OFF(fd)	{ int stuff; ioctl (fd, TIOCMGET, &stuff); stuff &= ~TIOCM_DTR;	ioctl (fd, TIOCMSET, &stuff); }

#define LPT_IO_ADDR 0x378

#endif



static struct audio_s *save_audio_config_p;	/* Save config information for later use. */

static int ptt_debug_level = 0;

void ptt_set_debug(int debug)
{
	ptt_debug_level = debug;
}


/*-------------------------------------------------------------------
 *
 * Name:	get_access_to_gpio
 *
 * Purpose:	Try to get access to the GPIO device.
 *
 * Inputs:	path		- Path to device node.
 *					/sys/class/gpio/export
 *					/sys/class/gpio/unexport
 *					/sys/class/gpio/gpio??/direction
 *					/sys/class/gpio/gpio??/value
 *
 * Description:	First see if we have access thru the usual uid/gid/mode method.
 *		If that fails, we try a hack where we use "sudo chmod ..." to open up access.
 *		That requires that sudo be configured to work without a password.
 *		That's the case for 'pi' user in Raspbian but not not be for other boards / operating systems.
 *
 * Debug:	Use the "-doo" command line option.
 *
 *------------------------------------------------------------------*/

#ifndef __WIN32__

#define MAX_GROUPS 50


static void get_access_to_gpio (const char *path)
{

	static int my_uid = -1;
	static int my_gid = -1;
	static gid_t my_groups[MAX_GROUPS];
	static int num_groups = 0;
	static int first_time = 1;

	struct stat finfo;
	int i;
	char cmd[80];
	int err;

/*
 * Does path even exist?
 */

	if (stat(path, &finfo) < 0) {
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("Can't get properties of %s.\n", path);
	  dw_printf ("This system is not configured with the GPIO user interface.\n");
	  dw_printf ("Use a different method for PTT control.\n");
	  exit (1);
	}

	if (first_time) {

	  // No need to fetch same information each time.  Cache it.
	  my_uid = geteuid();
	  my_gid = getegid();
	  num_groups = getgroups (MAX_GROUPS, my_groups);

	  if (num_groups < 0) {
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("getgroups() failed to get supplementary groups, errno=%d\n", errno);
	    num_groups = 0;
	  }
	  first_time = 0;
	}

	if (ptt_debug_level >= 2) {
	  text_color_set(DW_COLOR_DEBUG);
	  dw_printf ("%s: uid=%d, gid=%d, mode=o%o\n", path, finfo.st_uid, finfo.st_gid, finfo.st_mode);
	  dw_printf ("my uid=%d, gid=%d, supplementary groups=", my_uid, my_gid);
	  for (i = 0; i < num_groups; i++) {
	    dw_printf (" %d", my_groups[i]);
	  }
	  dw_printf ("\n");
	}

/*
 * Do we have permission to access it?
 *
 * On Debian 7 (Wheezy) we see this:
 *
 *	$ ls -l /sys/class/gpio/export
 *	--w------- 1 root root 4096 Feb 27 12:31 /sys/class/gpio/export
 *
 *
 * Only root can write to it.
 * Our work-around is change the protection so that everyone can write.
 * This requires that the current user can use sudo without a password.
 * This has been the case for the predefined "pi" user but can be a problem
 * when people add new user names.
 * Other operating systems could have different default configurations.
 *
 * A better solution is available in Debian 8 (Jessie).  The group is now "gpio"
 * so anyone in that group can now write to it.
 *
 *	$ ls -l /sys/class/gpio/export
 *	-rwxrwx--- 1 root gpio 4096 Mar  4 21:12 /sys/class/gpio/export
 *
 *
 * First see if we can access it by the usual file protection rules.
 * If not, we will try the "sudo chmod go+rw ..." hack.
 *
 */


/*
 * Do I have access?
 * We could just try to open for write but this gives us more debugging information.
 */

	if ((my_uid == finfo.st_uid) && (finfo.st_mode & S_IWUSR)) {	// user write 00200
	  if (ptt_debug_level >= 2) {
	    text_color_set(DW_COLOR_DEBUG);
	    dw_printf ("My uid matches and we have user write permission.\n");
	  }
	  return;
	}

	if ((my_gid == finfo.st_gid) && (finfo.st_mode & S_IWGRP)) {	// group write 00020
	  if (ptt_debug_level >= 2) {
	    text_color_set(DW_COLOR_DEBUG);
	    dw_printf ("My primary gid matches and we have group write permission.\n");
	  }
	  return;
	}

	for (i = 0; i < num_groups; i++) {
	  if ((my_groups[i] == finfo.st_gid) && (finfo.st_mode & S_IWGRP)) {	// group write 00020
	    if (ptt_debug_level >= 2) {
	      text_color_set(DW_COLOR_DEBUG);
	      dw_printf ("My supplemental group %d matches and we have group write permission.\n", my_groups[i]);
	    }
	    return;
	  }
	}

	if (finfo.st_mode & S_IWOTH) {	// other write 00002
	  if (ptt_debug_level >= 2) {
	    text_color_set(DW_COLOR_DEBUG);
	    dw_printf ("We have other write permission.\n");
	  }
	  return;
	}

/*
 * We don't have permission.
 * Try a hack which requires that the user be set up to use sudo without a password.
 */

	if (ptt_debug_level >= 2) {
	  text_color_set(DW_COLOR_ERROR);	// debug message but different color so it stands out.
	  dw_printf ("Trying 'sudo chmod go+rw %s' hack.\n", path);
	}

	snprintf (cmd, sizeof(cmd), "sudo chmod go+rw %s", path);
	err = system (cmd);
	(void)err;	// suppress warning about not using result.

/*
 * I don't trust status coming back from system() so we will check the mode again.
 */

	if (stat(path, &finfo) < 0) {
	  /* Unexpected because we could do it before. */
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("This system is not configured with the GPIO user interface.\n");
	  dw_printf ("Use a different method for PTT control.\n");
	  exit (1);
	}

	/* Did we succeed in changing the protection? */

	if ( (finfo.st_mode & 0266) != 0266) {
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("You don't have the necessary permission to access GPIO.\n");
	  dw_printf ("There are three different solutions: \n");
	  dw_printf (" 1. Run as root. (not recommended)\n");
	  dw_printf (" 2. If operating system has 'gpio' group, add your user id to it.\n");
	  dw_printf (" 3. Configure your user id for sudo without a password.\n");
	  dw_printf ("\n");
	  dw_printf ("Read the documentation and try -doo command line option for debugging details.\n");
	  exit (1);
	}

}

#endif



/*-------------------------------------------------------------------
 *
 * Name:	export_gpio
 *
 * Purpose:	Tell the GPIO subsystem to export a GPIO line for
 * 		us to use, and set the initial state of the GPIO.
 *
 * Inputs:	ch		- Radio Channel.
 *		ot		- Output type.
 *		invert:		- Is the GPIO active low?
 *		direction:	- 0 for input, 1 for output
 *
 * Outputs:	out_gpio_name	- in the audio configuration structure.
 *		in_gpio_name
 *
 *------------------------------------------------------------------*/

#ifndef __WIN32__


void export_gpio(int ch, int ot, int invert, int direction)
{
	HANDLE fd;
	const char gpio_export_path[] = "/sys/class/gpio/export";
	char gpio_direction_path[80];
	char gpio_value_path[80];
	char stemp[16];
	int gpio_num;
	char *gpio_name;

// Raspberry Pi was easy.  GPIO 24 has the name gpio24.
// Others, such as the Cubieboard, take a little more effort.
// The name might be gpio24_ph11 meaning connector H, pin 11.
// When we "export" GPIO number, we will store the corresponding
// device name for future use when we want to access it.

	if (direction) {
	  gpio_num  = save_audio_config_p->achan[ch].octrl[ot].out_gpio_num;
	  gpio_name = save_audio_config_p->achan[ch].octrl[ot].out_gpio_name;
	}
	else {
	  gpio_num  = save_audio_config_p->achan[ch].ictrl[ot].in_gpio_num;
	  gpio_name = save_audio_config_p->achan[ch].ictrl[ot].in_gpio_name;
	}


	get_access_to_gpio (gpio_export_path);

	fd = open(gpio_export_path, O_WRONLY);
	if (fd < 0) {
	  // Not expected.  Above should have obtained permission or exited.
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("Permissions do not allow access to GPIO.\n");
	  exit (1);
	}

	snprintf (stemp, sizeof(stemp), "%d", gpio_num);
	if (write (fd, stemp, strlen(stemp)) != strlen(stemp)) {
	  int e = errno;
	  /* Ignore EBUSY error which seems to mean */
	  /* the device node already exists. */
	  if (e != EBUSY) {
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Error writing \"%s\" to %s, errno=%d\n", stemp, gpio_export_path, e);
	    dw_printf ("%s\n", strerror(e));
	    exit (1);
	  }
	}
	/* Wait for udev to adjust permissions after enabling GPIO. */
	/* https://github.com/wb2osz/direwolf/issues/176 */
	SLEEP_MS(250);
	close (fd);

/*
 *	Added in release 1.4.
 *
 *	On the RPi, the device path for GPIO number XX is simply /sys/class/gpio/gpioXX.
 *
 *	There was a report that it is different for the CubieBoard.  For instance
 *	GPIO 61 has gpio61_pi13 in the path.  This indicates connector "i" pin 13.
 *	https://github.com/cubieplayer/Cubian/wiki/GPIO-Introduction
 *
 *	For another similar single board computer, we find the same thing:
 *	https://www.olimex.com/wiki/A20-OLinuXino-LIME#GPIO_under_Linux
 *
 *	How should we deal with this?  Some possibilities:
 *
 *	(1) The user might explicitly mention the name in direwolf.conf.
 *	(2) We might be able to find the names in some system device config file.
 *	(3) Get a directory listing of /sys/class/gpio then search for a
 *		matching name.  Suppose we wanted GPIO 61.  First look for an exact
 *		match to "gpio61".  If that is not found, look for something
 *		matching the pattern "gpio61_*".
 *
 *	We are finally implementing the third choice.
 */

	struct dirent **file_list;
	int num_files;
	int i;
	int ok = 0;

	if (ptt_debug_level >= 2) {
	  text_color_set(DW_COLOR_DEBUG);
	  dw_printf ("Contents of /sys/class/gpio:\n");
	}

	num_files = scandir ("/sys/class/gpio", &file_list, NULL, alphasort);

	if (num_files < 0) {
	  // Something went wrong.  Fill in the simple expected name and keep going.

	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("ERROR! Could not get directory listing for /sys/class/gpio\n");

	  snprintf (gpio_name, MAX_GPIO_NAME_LEN, "gpio%d", gpio_num);
	  num_files = 0;
	  ok = 1;
	}
	else {

	  if (ptt_debug_level >= 2) {

	    text_color_set(DW_COLOR_DEBUG);

	    for (i = 0; i < num_files; i++) {
	      dw_printf("\t%s\n", file_list[i]->d_name);
	    }
	  }

	  // Look for exact name gpioNN

	  char lookfor[16];
	  snprintf (lookfor, sizeof(lookfor), "gpio%d", gpio_num);

	  for (i = 0; i < num_files && ! ok; i++) {
	    if (strcmp(lookfor, file_list[i]->d_name) == 0) {
	      strlcpy (gpio_name, file_list[i]->d_name, MAX_GPIO_NAME_LEN);
	      ok = 1;
	    }
	  }

	  // If not found, Look for gpioNN_*

	  snprintf (lookfor, sizeof(lookfor), "gpio%d_", gpio_num);

	  for (i = 0; i < num_files && ! ok; i++) {
	    if (strncmp(lookfor, file_list[i]->d_name, strlen(lookfor)) == 0) {
	      strlcpy (gpio_name, file_list[i]->d_name, MAX_GPIO_NAME_LEN);
	      ok = 1;
	    }
	  }

	  // Free the storage allocated by scandir().

	  for (i = 0; i < num_files; i++) {
	    free (file_list[i]);
	  }
	  free (file_list);
	}

/*
 * We should now have the corresponding node name.
 */
	if (ok) {

	  if (ptt_debug_level >= 2) {
	    text_color_set(DW_COLOR_DEBUG);
	    dw_printf ("Path for gpio number %d is /sys/class/gpio/%s\n", gpio_num, gpio_name);
	  }
	}
	else {

	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("ERROR! Could not find Path for gpio number %d.n", gpio_num);
	  exit (1);
	}

/*
 * Set output direction and initial state
 */

	snprintf (gpio_direction_path, sizeof(gpio_direction_path), "/sys/class/gpio/%s/direction", gpio_name);
	get_access_to_gpio (gpio_direction_path);

	fd = open(gpio_direction_path, O_WRONLY);
	if (fd < 0) {
	  int e = errno;
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("Error opening %s\n", stemp);
	  dw_printf ("%s\n", strerror(e));
	  exit (1);
	}

	char gpio_val[8];
	if (direction) {
	  if (invert) {
	    strlcpy (gpio_val, "high", sizeof(gpio_val));
	  }
	  else {
	    strlcpy (gpio_val, "low", sizeof(gpio_val));
	  }
	}
	else {
	  strlcpy (gpio_val, "in", sizeof(gpio_val));
	}
	if (write (fd, gpio_val, strlen(gpio_val)) != strlen(gpio_val)) {
	  int e = errno;
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("Error writing initial state to %s\n", stemp);
	  dw_printf ("%s\n", strerror(e));
	  exit (1);
	}
	close (fd);

/*
 * Make sure that we have access to 'value'.
 * Do it once here, rather than each time we want to use it.
 */

	snprintf (gpio_value_path, sizeof(gpio_value_path), "/sys/class/gpio/%s/value", gpio_name);
	get_access_to_gpio (gpio_value_path);
}

#if defined(USE_GPIOD)
int gpiod_probe(const char *chip_name, int line_number)
{
	struct gpiod_chip *chip;
	chip = gpiod_chip_open_by_name(chip_name);
	if (chip == NULL) {
		text_color_set(DW_COLOR_ERROR);
		dw_printf ("Can't open GPIOD chip %s.\n", chip_name);
		return -1;
	}

	struct gpiod_line *line;
	line = gpiod_chip_get_line(chip, line_number);
	if (line == NULL) {
		text_color_set(DW_COLOR_ERROR);
		dw_printf ("Can't get GPIOD line %d.\n", line_number);
		return -1;
	}
	if (ptt_debug_level >= 2) {
		text_color_set(DW_COLOR_DEBUG);
		dw_printf("GPIOD probe OK. Chip: %s line: %d\n", chip_name, line_number);
	}
	return 0;
}
#endif   /* USE_GPIOD */
#endif   /* not __WIN32__ */


/*-------------------------------------------------------------------
 *
 * Name:        ptt_init
 *
 * Purpose:    	Open serial port(s) used for PTT signals and set to proper state.
 *
 * Inputs:	audio_config_p		- Structure with communication parameters.
 *
 *		    for each channel we have:
 *
 *			ptt_method	Method for PTT signal. 
 *					PTT_METHOD_NONE - not configured.  Could be using VOX. 
 *					PTT_METHOD_SERIAL - serial (com) port. 
 *					PTT_METHOD_GPIO - general purpose I/O (sysfs). 
 *					PTT_METHOD_GPIOD - general purpose I/O (libgpiod). 
 *					PTT_METHOD_LPT - Parallel printer port. 
 *                  			PTT_METHOD_HAMLIB - HAMLib rig control.
 *					PTT_METHOD_CM108 - GPIO pins of CM108 etc. USB Audio.
 *			
 *			ptt_device	Name of serial port device.  
 *					 e.g. COM1 or /dev/ttyS0. 
 *					 HAMLIB can also use hostaddr:port.
 *					 Like /dev/hidraw1 for CM108.
 *			
 *			ptt_line	RTS or DTR when using serial port. 
 *			
 *			out_gpio_num	GPIO number.  Only used for Linux. 
 *					 Valid only when ptt_method is PTT_METHOD_GPIO. 
 *					
 *			ptt_lpt_bit	Bit number for parallel printer port.  
 *					 Bit 0 = pin 2, ..., bit 7 = pin 9. 
 *					 Valid only when ptt_method is PTT_METHOD_LPT. 
 *			
 *			ptt_invert	Invert the signal.  
 *					 Normally higher voltage means transmit or LED on. 
 *
 *			ptt_model	Only for HAMLIB.
 *					2 to communicate with rigctld.
 *					>= 3 for specific radio model.
 *					-1 guess at what is out there.  (AUTO option in config file.)
 *
 * Outputs:	Remember required information for future use.
 *
 * Description:	
 *
 *--------------------------------------------------------------------*/




static HANDLE ptt_fd[MAX_CHANS][NUM_OCTYPES];	
					/* Serial port handle or fd.  */
					/* Could be the same for two channels */	
					/* if using both RTS and DTR. */
#if USE_HAMLIB
static RIG *rig[MAX_CHANS][NUM_OCTYPES];
#endif

static char otnames[NUM_OCTYPES][8];

void ptt_init (struct audio_s *audio_config_p)
{
	int ch;
	HANDLE fd = INVALID_HANDLE_VALUE;
#if __WIN32__
#else
	int using_gpio;
#endif

#if DEBUG
	text_color_set(DW_COLOR_DEBUG);
	dw_printf ("ptt_init ( ... )\n");
#endif

	save_audio_config_p = audio_config_p;

	strlcpy (otnames[OCTYPE_PTT], "PTT", sizeof(otnames[OCTYPE_PTT]));
	strlcpy (otnames[OCTYPE_DCD], "DCD", sizeof(otnames[OCTYPE_DCD]));
	strlcpy (otnames[OCTYPE_CON], "CON", sizeof(otnames[OCTYPE_CON]));


	for (ch = 0; ch < MAX_CHANS; ch++) {
	  int ot;

	  for (ot = 0; ot < NUM_OCTYPES; ot++) {

	    ptt_fd[ch][ot] = INVALID_HANDLE_VALUE;
#if USE_HAMLIB
	    rig[ch][ot] = NULL;
#endif
	    if (ptt_debug_level >= 2) {

	      text_color_set(DW_COLOR_DEBUG);
              dw_printf ("ch=%d, %s method=%d, device=%s, line=%d, name=%s, gpio=%d, lpt_bit=%d, invert=%d\n",
		ch,
		otnames[ot],
		audio_config_p->achan[ch].octrl[ot].ptt_method, 
		audio_config_p->achan[ch].octrl[ot].ptt_device,
		audio_config_p->achan[ch].octrl[ot].ptt_line,
		audio_config_p->achan[ch].octrl[ot].out_gpio_name,
		audio_config_p->achan[ch].octrl[ot].out_gpio_num,
		audio_config_p->achan[ch].octrl[ot].ptt_lpt_bit,
		audio_config_p->achan[ch].octrl[ot].ptt_invert);
	    }
	  }
	}

/*
 * Set up serial ports.
 */

	for (ch = 0; ch < MAX_CHANS; ch++) {

	  if (audio_config_p->achan[ch].medium == MEDIUM_RADIO) {
	    int ot;

	    for (ot = 0; ot < NUM_OCTYPES; ot++) {

	      if (audio_config_p->achan[ch].octrl[ot].ptt_method == PTT_METHOD_SERIAL) {

#if __WIN32__
#else
	        /* Translate Windows device name into Linux name. */
	        /* COM1 -> /dev/ttyS0, etc. */

	        if (strncasecmp(audio_config_p->achan[ch].octrl[ot].ptt_device, "COM", 3) == 0) {
	          int n = atoi (audio_config_p->achan[ch].octrl[ot].ptt_device + 3);
	          text_color_set(DW_COLOR_INFO);
	          dw_printf ("Converted %s device '%s'", audio_config_p->achan[ch].octrl[ot].ptt_device, otnames[ot]);
	          if (n < 1) n = 1;
	          snprintf (audio_config_p->achan[ch].octrl[ot].ptt_device, sizeof(audio_config_p->achan[ch].octrl[ot].ptt_device), "/dev/ttyS%d", n-1);
	          dw_printf (" to Linux equivalent '%s'\n", audio_config_p->achan[ch].octrl[ot].ptt_device);
	        }
#endif
	        /* Can't open the same device more than once so we */
	        /* need more logic to look for the case of multiple radio */
	        /* channels using different pins of the same COM port. */

	        /* Did some earlier channel use the same device name? */

	        int same_device_used = 0;
	        int j, k;

	        for (j = ch; j >= 0; j--) {
	          if (audio_config_p->achan[j].medium == MEDIUM_RADIO) {
		    for (k = ((j==ch) ? (ot - 1) : (NUM_OCTYPES-1)); k >= 0; k--) {
	              if (strcmp(audio_config_p->achan[ch].octrl[ot].ptt_device,audio_config_p->achan[j].octrl[k].ptt_device) == 0) {
	                fd = ptt_fd[j][k];
	                same_device_used = 1;
	              }
	            }
	          }
	        }

	        if ( ! same_device_used) {
	
#if __WIN32__
	          char bettername[50];
	          // Bug fix in release 1.1 - Need to munge name for COM10 and up.
	          // http://support.microsoft.com/kb/115831

	          strlcpy (bettername, audio_config_p->achan[ch].octrl[ot].ptt_device, sizeof(bettername));
	          if (strncasecmp(bettername, "COM", 3) == 0) {
	            int n;
	            n = atoi(bettername+3);
	            if (n >= 10) {
	              strlcpy (bettername, "\\\\.\\", sizeof(bettername));
	              strlcat (bettername, audio_config_p->achan[ch].octrl[ot].ptt_device, sizeof(bettername));
	            }
	          }
	          fd = CreateFile(bettername,
			GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
#else

		  /* O_NONBLOCK added in version 0.9. */
		  /* Was hanging with some USB-serial adapters. */
		  /* https://bugs.launchpad.net/ubuntu/+source/linux/+bug/661321/comments/12 */

	          fd = open (audio_config_p->achan[ch].octrl[ot].ptt_device, O_RDONLY | O_NONBLOCK);
#endif
                }

	        if (fd != INVALID_HANDLE_VALUE) {
	          ptt_fd[ch][ot] = fd;
	        }
	        else {
#if __WIN32__
#else
	          int e = errno;
#endif
	          text_color_set(DW_COLOR_ERROR);
	          dw_printf ("ERROR can't open device %s for channel %d PTT control.\n",
			audio_config_p->achan[ch].octrl[ot].ptt_device, ch);
#if __WIN32__
#else
	          dw_printf ("%s\n", strerror(e));
#endif
	          /* Don't try using it later if device open failed. */

	          audio_config_p->achan[ch].octrl[ot].ptt_method = PTT_METHOD_NONE;
	        }

/*
 * Set initial state off.
 * ptt_set will invert output signal if appropriate.
 */	  
	        ptt_set (ot, ch, 0);

	      }    /* if serial method. */
	    }	 /* for each output type. */
	  }    /* if channel valid. */
	}    /* For each channel. */


/* 
 * Set up GPIO - for Linux only.
 */

#if __WIN32__
#else

/*
 * Does any of them use GPIO?
 */

	using_gpio = 0;
	for (ch=0; ch<MAX_CHANS; ch++) {
	  if (save_audio_config_p->achan[ch].medium == MEDIUM_RADIO) {
	    int ot;
	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (audio_config_p->achan[ch].octrl[ot].ptt_method == PTT_METHOD_GPIO) {
	        using_gpio = 1;
	      }
	    }
	    for (ot = 0; ot < NUM_ICTYPES; ot++) {
	      if (audio_config_p->achan[ch].ictrl[ot].method == PTT_METHOD_GPIO) {
	        using_gpio = 1;
	      }
	    }
	  }
	}

	if (using_gpio) {
	  get_access_to_gpio ("/sys/class/gpio/export");
	}
#if defined(USE_GPIOD)
    // GPIOD
	for (ch = 0; ch < MAX_CHANS; ch++) {
	  if (save_audio_config_p->achan[ch].medium == MEDIUM_RADIO) {
	    for (int ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (audio_config_p->achan[ch].octrl[ot].ptt_method == PTT_METHOD_GPIOD) {
	        const char *chip_name = audio_config_p->achan[ch].octrl[ot].out_gpio_name;
	        int line_number = audio_config_p->achan[ch].octrl[ot].out_gpio_num;
	        int rc = gpiod_probe(chip_name, line_number);
	        if (rc < 0) {
	          text_color_set(DW_COLOR_ERROR);
	          dw_printf ("Disable PTT for channel %d\n", ch);
	          audio_config_p->achan[ch].octrl[ot].ptt_method = PTT_METHOD_NONE;
	        } else {
	          // Set initial state off ptt_set will invert output signal if appropriate.
	          ptt_set (ot, ch, 0);
	        }
	      }
	    }
	  }
	}
#endif /* USE_GPIOD */
/*
 * We should now be able to create the device nodes for 
 * the pins we want to use.
 */
	    
	for (ch = 0; ch < MAX_CHANS; ch++) {
	  if (save_audio_config_p->achan[ch].medium == MEDIUM_RADIO) {

	    int ot;	// output control type, PTT, DCD, CON, ...
	    int it;	// input control type

	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (audio_config_p->achan[ch].octrl[ot].ptt_method == PTT_METHOD_GPIO) {
	        export_gpio(ch, ot, audio_config_p->achan[ch].octrl[ot].ptt_invert, 1);
	      }
	    }
	    for (it = 0; it < NUM_ICTYPES; it++) {
	      if (audio_config_p->achan[ch].ictrl[it].method == PTT_METHOD_GPIO) {
	        export_gpio(ch, it, audio_config_p->achan[ch].ictrl[it].invert, 0);
	      }
	    }
	  }
	}
#endif



/*
 * Set up parallel printer port.
 * 
 * Restrictions:
 * 	Only the primary printer port.
 * 	For x86 Linux only.
 */

#if  ( defined(__i386__) || defined(__x86_64__) ) && ( defined(__linux__) || defined(__unix__) )

	for (ch = 0; ch < MAX_CHANS; ch++) {
	  if (save_audio_config_p->achan[ch].medium == MEDIUM_RADIO) {
	    int ot;
	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (audio_config_p->achan[ch].octrl[ot].ptt_method == PTT_METHOD_LPT) {

	        /* Can't open the same device more than once so we */
	        /* need more logic to look for the case of mutiple radio */
	        /* channels using different pins of the LPT port. */

	        /* Did some earlier channel use the same ptt device name? */

	        int same_device_used = 0;
	        int j, k;
	
	        for (j = ch; j >= 0; j--) {
	          if (audio_config_p->achan[j].medium == MEDIUM_RADIO) {
		    for (k = ((j==ch) ? (ot - 1) : (NUM_OCTYPES-1)); k >= 0; k--) {
	              if (strcmp(audio_config_p->achan[ch].octrl[ot].ptt_device,audio_config_p->achan[j].octrl[k].ptt_device) == 0) {
	                fd = ptt_fd[j][k];
	                same_device_used = 1;
	              }
	            }
	          }
	        }

	        if ( ! same_device_used) {
	          fd = open ("/dev/port", O_RDWR | O_NDELAY);
	        }

	        if (fd != INVALID_HANDLE_VALUE) {
	          ptt_fd[ch][ot] = fd;
	        }
	        else {

	          int e = errno;

	          text_color_set(DW_COLOR_ERROR);
	          dw_printf ("ERROR - Can't open /dev/port for parallel printer port PTT control.\n");
	          dw_printf ("%s\n", strerror(e));
	          dw_printf ("You probably don't have adequate permissions to access I/O ports.\n");
	          dw_printf ("Either run direwolf as root or change these permissions:\n");
	          dw_printf ("  sudo chmod go+rw /dev/port\n");
	          dw_printf ("  sudo setcap cap_sys_rawio=ep `which direwolf`\n");

	          /* Don't try using it later if device open failed. */

	          audio_config_p->achan[ch].octrl[ot].ptt_method = PTT_METHOD_NONE;
	        }
	    

/*
 * Set initial state off.
 * ptt_set will invert output signal if appropriate.
 */	  
	        ptt_set (ot, ch, 0);

	      }       /* if parallel printer port method. */
	    }       /* for each output type */
	  }       /* if valid channel. */
	}	/* For each channel. */



#endif /* x86 Linux */

#ifdef USE_HAMLIB
	for (ch = 0; ch < MAX_CHANS; ch++) {
	  if (save_audio_config_p->achan[ch].medium == MEDIUM_RADIO) {
	    int ot;
	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (audio_config_p->achan[ch].octrl[ot].ptt_method == PTT_METHOD_HAMLIB) {
	        if (ot == OCTYPE_PTT) {

	          /* For "AUTO" model, try to guess what is out there. */

	          if (audio_config_p->achan[ch].octrl[ot].ptt_model == -1) {
	            hamlib_port_t hport;

	            memset (&hport, 0, sizeof(hport));
	            strlcpy (hport.pathname, audio_config_p->achan[ch].octrl[ot].ptt_device, sizeof(hport.pathname));
	            rig_load_all_backends();
                    audio_config_p->achan[ch].octrl[ot].ptt_model = rig_probe(&hport);

	            if (audio_config_p->achan[ch].octrl[ot].ptt_model == RIG_MODEL_NONE) {
	              text_color_set(DW_COLOR_ERROR);
	              dw_printf ("Hamlib Error: Couldn't guess rig model number for AUTO option.  Run \"rigctl --list\" for a list of model numbers.\n");
	              continue;
	            }

	            text_color_set(DW_COLOR_INFO);
	            dw_printf ("Hamlib AUTO option detected rig model %d.  Run \"rigctl --list\" for a list of model numbers.\n",
							audio_config_p->achan[ch].octrl[ot].ptt_model);
	          }

	          rig[ch][ot] = rig_init(audio_config_p->achan[ch].octrl[ot].ptt_model);
	          if (rig[ch][ot] == NULL) {
	            text_color_set(DW_COLOR_ERROR);
	            dw_printf ("Hamlib error: Unknown rig model %d.  Run \"rigctl --list\" for a list of model numbers.\n",
	                          audio_config_p->achan[ch].octrl[ot].ptt_model);
	            continue;
	          }

	          strlcpy (rig[ch][ot]->state.rigport.pathname, audio_config_p->achan[ch].octrl[ot].ptt_device, sizeof(rig[ch][ot]->state.rigport.pathname));
	          int err = rig_open(rig[ch][ot]);
	          if (err != RIG_OK) {
	            text_color_set(DW_COLOR_ERROR);
	            dw_printf ("Hamlib Rig open error %d: %s\n", err, rigerror(err));
	            rig_cleanup (rig[ch][ot]);
	            rig[ch][ot] = NULL;
	            continue;
	          }

       		  /* Successful.  Later code should check for rig[ch][ot] not NULL. */
	        }
	        else {
                  text_color_set(DW_COLOR_ERROR);
                  dw_printf ("HAMLIB can only be used for PTT.  Not DCD or other output.\n");
	        }
	      }
	    }
	  }
	}

#endif

/*
 * Confirm what is going on with CM108 GPIO output.
 * Could use some error checking for overlap.
 */

#if USE_CM108

	for (ch = 0; ch < MAX_CHANS; ch++) {

	  if (audio_config_p->achan[ch].medium == MEDIUM_RADIO) {
	    int ot;
	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (audio_config_p->achan[ch].octrl[ot].ptt_method == PTT_METHOD_CM108) {
	        text_color_set(DW_COLOR_INFO);
	        dw_printf ("Using %s GPIO %d for channel %d %s control.\n",
			audio_config_p->achan[ch].octrl[ot].ptt_device,
			audio_config_p->achan[ch].octrl[ot].out_gpio_num,
			ch,
			otnames[ot]);
	      }
	    }
	  }
	}

#endif


/* Why doesn't it transmit?  Probably forgot to specify PTT option. */

	for (ch=0; ch<MAX_CHANS; ch++) {
	  if (audio_config_p->achan[ch].medium == MEDIUM_RADIO) {
	    if(audio_config_p->achan[ch].octrl[OCTYPE_PTT].ptt_method == PTT_METHOD_NONE) {
	      text_color_set(DW_COLOR_INFO);
	      dw_printf ("Note: PTT not configured for channel %d. (Ignore this if using VOX.)\n", ch);
	    }
	  }
	}

} /* end ptt_init */


/*-------------------------------------------------------------------
 *
 * Name:        ptt_set
 *
 * Purpose:    	Turn output control line on or off.
 *		Originally this was just for PTT, hence the name.
 *		Now that it is more general purpose, it should
 *		probably be renamed something like octrl_set.
 *
 * Inputs:	ot		- Output control type:
 *				   OCTYPE_PTT, OCTYPE_DCD, OCTYPE_FUTURE
 *
 *		chan		- channel, 0 .. (number of channels)-1
 *
 *		ptt_signal	- 1 for transmit, 0 for receive.
 *
 *
 * Assumption:	ptt_init was called first.
 *
 * Description:	Set the RTS or DTR line or GPIO pin.
 *		More positive output corresponds to 1 unless invert is set.
 *
 *--------------------------------------------------------------------*/


void ptt_set (int ot, int chan, int ptt_signal)
{

	int ptt = ptt_signal;
	int ptt2 = ptt_signal;

	assert (ot >= 0 && ot < NUM_OCTYPES);
	assert (chan >= 0 && chan < MAX_CHANS);

	if (ptt_debug_level >= 1) {
	  text_color_set(DW_COLOR_DEBUG);
	  dw_printf ("%s %d = %d\n", otnames[ot], chan, ptt_signal);
	}

	assert (chan >= 0 && chan < MAX_CHANS);

	if (   save_audio_config_p->achan[chan].medium != MEDIUM_RADIO) {
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("Internal error, ptt_set ( %s, %d, %d ), did not expect invalid channel.\n", otnames[ot], chan, ptt);
	  return;
	}

/*
 * The data link state machine has an interest in activity on the radio channel.
 * This is a very convenient place to get that information.
 */

#ifndef TEST
	dlq_channel_busy (chan, ot, ptt_signal);
#endif

/* 
 * Inverted output? 
 */

	if (save_audio_config_p->achan[chan].octrl[ot].ptt_invert) {
	  ptt = ! ptt;
	}
	if (save_audio_config_p->achan[chan].octrl[ot].ptt_invert2) {
	  ptt2 = ! ptt2;
	}

/*
 * Using serial port?
 */
	if (save_audio_config_p->achan[chan].octrl[ot].ptt_method == PTT_METHOD_SERIAL && 
		ptt_fd[chan][ot] != INVALID_HANDLE_VALUE) {

	  if (save_audio_config_p->achan[chan].octrl[ot].ptt_line == PTT_LINE_RTS) {

	    if (ptt) {
	      RTS_ON(ptt_fd[chan][ot]);
	    }
	    else {
	      RTS_OFF(ptt_fd[chan][ot]);
	    }
	  }
	  else if (save_audio_config_p->achan[chan].octrl[ot].ptt_line == PTT_LINE_DTR) {

	    if (ptt) {
	      DTR_ON(ptt_fd[chan][ot]);
	    }
	    else {
	      DTR_OFF(ptt_fd[chan][ot]);
	    }
	  }

/* 
 * Second serial port control line?  Typically driven with opposite phase but could be in phase.
 */

	  if (save_audio_config_p->achan[chan].octrl[ot].ptt_line2 == PTT_LINE_RTS) {

	    if (ptt2) {
	      RTS_ON(ptt_fd[chan][ot]);
	    }
	    else {
	      RTS_OFF(ptt_fd[chan][ot]);
	    }
	  }
	  else if (save_audio_config_p->achan[chan].octrl[ot].ptt_line2 == PTT_LINE_DTR) {

	    if (ptt2) {
	      DTR_ON(ptt_fd[chan][ot]);
	    }
	    else {
	      DTR_OFF(ptt_fd[chan][ot]);
	    }
	  }
	  /* else neither one */

	}

/*
 * Using GPIO? 
 */

#if __WIN32__
#else

	if (save_audio_config_p->achan[chan].octrl[ot].ptt_method == PTT_METHOD_GPIO) {
	  int fd;
	  char gpio_value_path[80];
	  char stemp[16];

	  snprintf (gpio_value_path, sizeof(gpio_value_path), "/sys/class/gpio/%s/value", save_audio_config_p->achan[chan].octrl[ot].out_gpio_name);

	  fd = open(gpio_value_path, O_WRONLY);
	  if (fd < 0) {
	    int e = errno;
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Error opening %s to set %s signal.\n", stemp, otnames[ot]);
	    dw_printf ("%s\n", strerror(e));
	    return;
	  }

	  snprintf (stemp, sizeof(stemp), "%d", ptt);

	  if (write (fd, stemp, 1) != 1) {
	    int e = errno;
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Error setting GPIO %d for %s\n", save_audio_config_p->achan[chan].octrl[ot].out_gpio_num, otnames[ot]);
	    dw_printf ("%s\n", strerror(e));
	  }
	  close (fd);

	}

#if defined(USE_GPIOD)
	if (save_audio_config_p->achan[chan].octrl[ot].ptt_method == PTT_METHOD_GPIOD) {
		const char *chip = save_audio_config_p->achan[chan].octrl[ot].out_gpio_name;
		int line = save_audio_config_p->achan[chan].octrl[ot].out_gpio_num;
		int rc = gpiod_ctxless_set_value(chip, line, ptt, false, "direwolf", NULL, NULL);
		if (ptt_debug_level >= 1) {
			text_color_set(DW_COLOR_DEBUG);
			dw_printf("PTT_METHOD_GPIOD chip: %s line: %d ptt: %d  rc: %d\n", chip, line, ptt, rc);
		}
	}
#endif /* USE_GPIOD */
#endif
	
/*
 * Using parallel printer port?
 */

#if  ( defined(__i386__) || defined(__x86_64__) ) && ( defined(__linux__) || defined(__unix__) )

	if (save_audio_config_p->achan[chan].octrl[ot].ptt_method == PTT_METHOD_LPT && 
		ptt_fd[chan][ot] != INVALID_HANDLE_VALUE) {

	  char lpt_data;
	  //ssize_t n;		

	  lseek (ptt_fd[chan][ot], (off_t)LPT_IO_ADDR, SEEK_SET);
	  if (read (ptt_fd[chan][ot], &lpt_data, (size_t)1) != 1) {
	    int e = errno;
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Error reading current state of LPT for channel %d %s\n", chan, otnames[ot]);
	    dw_printf ("%s\n", strerror(e));
	  }

	  if (ptt) {
	    lpt_data |= ( 1 << save_audio_config_p->achan[chan].octrl[ot].ptt_lpt_bit );
	  }
	  else {
	    lpt_data &= ~ ( 1 << save_audio_config_p->achan[chan].octrl[ot].ptt_lpt_bit );
	  }

	  lseek (ptt_fd[chan][ot], (off_t)LPT_IO_ADDR, SEEK_SET);
	  if (write (ptt_fd[chan][ot], &lpt_data, (size_t)1) != 1) {
	    int e = errno;
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Error writing to LPT for channel %d %s\n", chan, otnames[ot]);
	    dw_printf ("%s\n", strerror(e));
	  }
	}

#endif /* x86 Linux */

#ifdef USE_HAMLIB
/*
 * Using hamlib?
 */

	if (save_audio_config_p->achan[chan].octrl[ot].ptt_method == PTT_METHOD_HAMLIB) {

	  if (rig[chan][ot] != NULL) {

	    int retcode = rig_set_ptt(rig[chan][ot], RIG_VFO_CURR, ptt ? RIG_PTT_ON : RIG_PTT_OFF);

	    if (retcode != RIG_OK) {
	      text_color_set(DW_COLOR_ERROR);
	      dw_printf ("Hamlib Error: rig_set_ptt command for channel %d %s\n", chan, otnames[ot]);
	      dw_printf ("%s\n", rigerror(retcode));
	    }
	  }
	  else {
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Hamlib: Can't use rig_set_ptt for channel %d %s because rig_open failed.\n", chan, otnames[ot]);
	  }
	}
#endif

/*
 * Using CM108 USB Audio adapter GPIO?
 */

#ifdef USE_CM108

	if (save_audio_config_p->achan[chan].octrl[ot].ptt_method == PTT_METHOD_CM108) {

	  if (cm108_set_gpio_pin (save_audio_config_p->achan[chan].octrl[ot].ptt_device,
				save_audio_config_p->achan[chan].octrl[ot].out_gpio_num, ptt) != 0) {
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("ERROR:  %s for channel %d has failed.  See User Guide for troubleshooting tips.\n", otnames[ot], chan);
	  }
	}
#endif

} /* end ptt_set */

/*-------------------------------------------------------------------
 *
 * Name:	get_input
 *
 * Purpose:	Read the value of an input line
 *
 * Inputs:	it	- Input type (ICTYPE_TCINH supported so far)
 * 		chan	- Audio channel number
 * 
 * Outputs:	0 = inactive, 1 = active, -1 = error
 *
 * ------------------------------------------------------------------*/

int get_input (int it, int chan)
{
	assert (it >= 0 && it < NUM_ICTYPES);
	assert (chan >= 0 && chan < MAX_CHANS);

	if (   save_audio_config_p->achan[chan].medium != MEDIUM_RADIO) {
	  text_color_set(DW_COLOR_ERROR);
	  dw_printf ("Internal error, get_input ( %d, %d ), did not expect invalid channel.\n", it, chan);
	  return -1;
	}
	
#if __WIN32__
#else
	if (save_audio_config_p->achan[chan].ictrl[it].method == PTT_METHOD_GPIO) {
	  int fd;
	  char gpio_value_path[80];

	  snprintf (gpio_value_path, sizeof(gpio_value_path), "/sys/class/gpio/%s/value", save_audio_config_p->achan[chan].ictrl[it].in_gpio_name);

	  get_access_to_gpio (gpio_value_path);

	  fd = open(gpio_value_path, O_RDONLY);
	  if (fd < 0) {
	    int e = errno;
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Error opening %s to check input.\n", gpio_value_path);
	    dw_printf ("%s\n", strerror(e));
	    return -1;
	  }

	  char vtemp[2];
	  if (read (fd, vtemp, 1) != 1) {
	    int e = errno;
	    text_color_set(DW_COLOR_ERROR);
	    dw_printf ("Error getting GPIO %d value\n", save_audio_config_p->achan[chan].ictrl[it].in_gpio_num);
	    dw_printf ("%s\n", strerror(e));
	  }
	  close (fd);

	  vtemp[1] = '\0';
	  if (atoi(vtemp) != save_audio_config_p->achan[chan].ictrl[it].invert) {
	    return 1;
	  }
	  else {
	    return 0;
	  }
	}
#endif

	return -1;	/* Method was none, or something went wrong */
}

/*-------------------------------------------------------------------
 *
 * Name:        ptt_term
 *
 * Purpose:    	Make sure PTT and others are turned off when we exit.
 *
 * Inputs:	none
 *
 * Description:	
 *
 *--------------------------------------------------------------------*/

void ptt_term (void)
{
	int n;

	for (n = 0; n < MAX_CHANS; n++) {
	  if (save_audio_config_p->achan[n].medium == MEDIUM_RADIO) {
	    int ot;
	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      ptt_set (ot, n, 0);
	    }
	  }
	}

	for (n = 0; n < MAX_CHANS; n++) {
	  if (save_audio_config_p->achan[n].medium == MEDIUM_RADIO) {
	    int ot;
	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (ptt_fd[n][ot] != INVALID_HANDLE_VALUE) {
#if __WIN32__
	        CloseHandle (ptt_fd[n][ot]);
#else
	        close(ptt_fd[n][ot]);
#endif
	        ptt_fd[n][ot] = INVALID_HANDLE_VALUE;
	      }
	    }
	  }
	}

#ifdef USE_HAMLIB

	for (n = 0; n < MAX_CHANS; n++) {
	  if (save_audio_config_p->achan[n].medium == MEDIUM_RADIO) {
	    int ot;
	    for (ot = 0; ot < NUM_OCTYPES; ot++) {
	      if (rig[n][ot] != NULL) {

	        rig_close(rig[n][ot]);
	        rig_cleanup(rig[n][ot]);
	        rig[n][ot] = NULL;
	      }
	    }
	  }
	}
#endif
}




/*
 * Quick stand-alone test for above.
 *
 *     gcc -DTEST -o ptest ptt.c textcolor.o misc.a ; ./ptest
 *
 * TODO:  Retest this, add CM108 GPIO to test.
 */


#if TEST

int main ()
{
	struct audio_s my_audio_config;
	int n;
	int chan;

	memset (&my_audio_config, 0, sizeof(my_audio_config));

	my_audio_config.adev[0].num_channels = 2;

	my_audio_config.achan[0].medium = MEDIUM_RADIO;
	my_audio_config.achan[0].octrl[OCTYPE_PTT].ptt_method = PTT_METHOD_SERIAL;
// TODO: device should be command line argument.
	strlcpy (my_audio_config.achan[0].octrl[OCTYPE_PTT].ptt_device, "COM3", sizeof(my_audio_config.achan[0].octrl[OCTYPE_PTT].ptt_device));
	//strlcpy (my_audio_config.achan[0].octrl[OCTYPE_PTT].ptt_device, "/dev/ttyUSB0", sizeof(my_audio_config.achan[0].octrl[OCTYPE_PTT].ptt_device));
	my_audio_config.achan[0].octrl[OCTYPE_PTT].ptt_line = PTT_LINE_RTS;

	my_audio_config.achan[1].medium = MEDIUM_RADIO;
	my_audio_config.achan[1].octrl[OCTYPE_PTT].ptt_method = PTT_METHOD_SERIAL;
	strlcpy (my_audio_config.achan[1].octrl[OCTYPE_PTT].ptt_device, "COM3", sizeof(my_audio_config.achan[1].octrl[OCTYPE_PTT].ptt_device));
	//strlcpy (my_audio_config.achan[1].octrl[OCTYPE_PTT].ptt_device, "/dev/ttyUSB0", sizeof(my_audio_config.achan[1].octrl[OCTYPE_PTT].ptt_device));
	my_audio_config.achan[1].octrl[OCTYPE_PTT].ptt_line = PTT_LINE_DTR;


/* initialize - both off */

	ptt_init (&my_audio_config);

	SLEEP_SEC(2);

/* flash each a few times. */

	dw_printf ("turn on RTS a few times...\n");

	chan = 0;
	for (n=0; n<3; n++) {
	  ptt_set (OCTYPE_PTT, chan, 1);
	  SLEEP_SEC(1);
	  ptt_set (OCTYPE_PTT, chan, 0);
	  SLEEP_SEC(1);
	}

	dw_printf ("turn on DTR a few times...\n");

	chan = 1;
	for (n=0; n<3; n++) {
	  ptt_set (OCTYPE_PTT, chan, 1);
	  SLEEP_SEC(1);
	  ptt_set (OCTYPE_PTT, chan, 0);
	  SLEEP_SEC(1);
	}

	ptt_term();

/* Same thing again but invert RTS. */

	my_audio_config.achan[0].octrl[OCTYPE_PTT].ptt_invert = 1;

	ptt_init (&my_audio_config);

	SLEEP_SEC(2);

	dw_printf ("INVERTED -  RTS a few times...\n");

	chan = 0;
	for (n=0; n<3; n++) {
	  ptt_set (OCTYPE_PTT, chan, 1);
	  SLEEP_SEC(1);
	  ptt_set (OCTYPE_PTT, chan, 0);
	  SLEEP_SEC(1);
	}

	dw_printf ("turn on DTR a few times...\n");

	chan = 1;
	for (n=0; n<3; n++) {
	  ptt_set (OCTYPE_PTT, chan, 1);
	  SLEEP_SEC(1);
	  ptt_set (OCTYPE_PTT, chan, 0);
	  SLEEP_SEC(1);
	}

	ptt_term ();


/* Test GPIO */

#if __arm__

	memset (&my_audio_config, 0, sizeof(my_audio_config));
	my_audio_config.adev[0].num_channels = 1;
	my_audio_config.achan[0].medium = MEDIUM_RADIO;
	my_audio_config.adev[0].octrl[OCTYPE_PTT].ptt_method = PTT_METHOD_GPIO;
	my_audio_config.adev[0].octrl[OCTYPE_PTT].out_gpio_num = 25;

	dw_printf ("Try GPIO %d a few times...\n", my_audio_config.out_gpio_num[0]);

	ptt_init (&my_audio_config);

	SLEEP_SEC(2);
	chan = 0;
	for (n=0; n<3; n++) {
	  ptt_set (OCTYPE_PTT, chan, 1);
	  SLEEP_SEC(1);
	  ptt_set (OCTYPE_PTT, chan, 0);
	  SLEEP_SEC(1);
	}

	ptt_term ();
#endif



/* Parallel printer port. */

#if  ( defined(__i386__) || defined(__x86_64__) ) && ( defined(__linux__) || defined(__unix__) )

	// TODO

#if 0
	memset (&my_audio_config, 0, sizeof(my_audio_config));
	my_audio_config.num_channels = 2;
	my_audio_config.achan[0].medium = MEDIUM_RADIO;
	my_audio_config.adev[0].octrl[OCTYPE_PTT].ptt_method = PTT_METHOD_LPT;
	my_audio_config.adev[0].octrl[OCTYPE_PTT].ptt_lpt_bit = 0;
	my_audio_config.achan[1].medium = MEDIUM_RADIO;
	my_audio_config.adev[1].octrl[OCTYPE_PTT].ptt_method = PTT_METHOD_LPT;
	my_audio_config.adev[1].octrl[OCTYPE_PTT].ptt_lpt_bit = 1;

	dw_printf ("Try LPT bits 0 & 1 a few times...\n");

	ptt_init (&my_audio_config);

	for (n=0; n<8; n++) {
	  ptt_set (OCTYPE_PTT, 0, n & 1);
	  ptt_set (OCTYPE_PTT, 1, (n>>1) & 1);
	  SLEEP_SEC(1);
	}

	ptt_term ();	
#endif

#endif

	return(0);
}

#endif  /* TEST */

/* end ptt.c */



