/*====================================================================*
*
*   Copyright (c) 2013 Qualcomm Atheros, Inc.
*
*   All rights reserved.
*
*====================================================================*/
/*====================================================================*
 *
 *   ttysig.c - Serial Line Signal Controller;
 *
 *   This program is for Linux only;
 *
 *   Contributor(s):
 *	Nathaniel Houghton <nhoughto@qca.qualcomm.com>
 *
 *--------------------------------------------------------------------*/

/*====================================================================*
 *   kernel header files;
 *--------------------------------------------------------------------*/

#include <sys/ioctl.h>

/*====================================================================*
 *   system header files;
 *--------------------------------------------------------------------*/

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <termios.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/*====================================================================*
 *   custom header files;
 *--------------------------------------------------------------------*/

#include "../tools/getoptv.h"
#include "../tools/putoptv.h"
#include "../tools/version.h"
#include "../tools/types.h"
#include "../tools/flags.h"
#include "../tools/number.h"
#include "../tools/error.h"

/*====================================================================*
 *   custom source files;
 *--------------------------------------------------------------------*/

#ifndef MAKEFILE
#include "../tools/getoptv.c"
#include "../tools/putoptv.c"
#include "../tools/version.c"
#include "../tools/uintspec.c"
#include "../tools/todigit.c"
#include "../tools/error.c"
#endif

/*====================================================================*
 *   constants;
 *--------------------------------------------------------------------*/

#define SERIAL_PORT "/dev/ttyS0"
#define TTYSIG_SET_DTR       (1 << 0)
#define TTYSIG_SET_RTS       (1 << 1)
#define TTYSIG_READ_STATUS   (1 << 2)
#define TTYSIG_INTERACTIVE   (1 << 3)
#define TTYSIG_NOPROMPT      (1 << 4)

void set_status (int fd, int flag, int value) 

{ 
	int status; 
	if (ioctl (fd, TIOCMGET, & status) == - 1) error (1, errno, "TIOCMGET failed"); 
	if (value) status |= flag; 
	else status &= ~ flag; 
	if (ioctl (fd, TIOCMSET, & status) == - 1) error (1, errno, "TIOCMSET failed"); 
} 

void print_status (int fd) 

{ 
	int status; 
	if (ioctl (fd, TIOCMGET, & status) == - 1) error (1, errno, "TIOCMGET failed"); 
	printf ("--> DTR: %s\n", (status & TIOCM_DTR)? "+V": "-V"); 
	printf ("--> RTS: %s\n", (status & TIOCM_RTS)? "+V": "-V"); 
	printf ("<-- CTS: %s\n", (status & TIOCM_CTS)? "+V": "-V"); 
	printf ("<-- DSR: %s\n", (status & TIOCM_DSR)? "+V": "-V"); 
	printf ("<-- DCD: %s\n", (status & TIOCM_CD)? "+V": "-V"); 
	printf ("<-- RI : %s\n", (status & TIOCM_RI)? "+V": "-V"); 
} 

void comment (void) 

{ 
	int c; 
	while ((c = getchar ()) != EOF) 
	{ 
		if (c == '\n') 
		{ 
			ungetc (c, stdin); 
			break; 
		} 
	} 
} 

int number (char * buf, int * val) 

{ 
	char * p; 
	while (isspace ((unsigned char)* buf)) ++ buf;  
	if (! isdigit ((unsigned char)* buf)) 
	{ 
		error (0, 0, "\"%s\" is not a number", buf); 
		return (- 1); 
	} 
	* val = atoi (buf); 
	p = buf; 
	while (isdigit ((unsigned char)* buf)) ++ buf;  
	if (* buf != '\0') 
	{ 
		error (0, 0, "\"%s\" is not a number", p); 
		return (- 1); 
	} 
	return (0); 
} 

void interactive (int fd, flag_t flags) 

{ 
	char buf [32]; 
	int i, 
	c; 
	int value; 
	char * p; 
	for (; ; ) 
	{ 
		if (! _anyset (flags, TTYSIG_NOPROMPT)) 
		{ 
			printf ("command (D #, R #, e, r, s, q): "); 
			fflush (stdout); 
		} 
		i = 0; 
		while ((c = getchar ()) != EOF) 
		{ 
			if (c == '#') 
			{ 
				comment (); 
				continue; 
			} 
			if (c == '\n') break; 
			if (i == sizeof (buf) - 1) error (1, 0, "input too large"); 
			buf [i++] = c; 
		} 
		if (c == EOF) return; 
		if (i == 0) continue; 
		buf [i] = '\0'; 
		switch (buf [0]) 
		{ 
		case 'D': 
			if (number (buf +  1, & value)) break; 
			set_status (fd, TIOCM_DTR, value); 
			break; 
		case 'e': 
			p = buf +  1; 
			if (* p == ' ') ++ p; 
			printf ("%s\n", p); 
			fflush (stdout); 
			break; 
		case 'R': 
			if (number (buf +  1, & value)) break; 
			set_status (fd, TIOCM_RTS, value); 
			break; 
		case 'r': 
			print_status (fd); 
			break; 
		case 's': 
			if (number (buf +  1, & value)) break; 
			sleep (value); 
			break; 
		case 'q': 
		case 'Q': 
			return; 
			break; 
		case '\0': 
			break; 
		default: 
			error (0, 0, "invalid command"); 
		} 
	} 
} 

int main (int argc, char const ** argv) 

{ 
	int fd; 
	static char const * optv [] = 
	{ 
		"s:D:IR:rqv", 
		"[ttysig script filename]", 
		"Serial Line Signal Controller", 
		"D n\tset DTR (0 = -V, 1 = +V) at startup", 
		"I\tInteractive mode", 
		"R n\tset RTS (0 = -V, 1 = +V) at startup", 
		"r\tread current RTS/DTR values at startup", 
		"s f\tserial port is (f) [" SERIAL_PORT "]", 
		"q\tquiet mode", 
		"v\tverbose mode", 
		(char const *) (0)
	}; 
	signed c; 
	optind = 1; 
	flag_t flags = 0; 
	uint8_t dtr_value; 
	uint8_t rts_value; 
	char * device = SERIAL_PORT; 
	int input = - 1; 
	while (~ (c = getoptv (argc, argv, optv))) 
	{ 
		switch ((char) (c)) 
		{ 
		case 'D': 
			dtr_value = uintspec (optarg, 0, 1); 
			_setbits (flags, TTYSIG_SET_DTR); 
			break; 
		case 'I': 
			_setbits (flags, TTYSIG_INTERACTIVE); 
			break; 
		case 'R': 
			rts_value = uintspec (optarg, 0, 1); 
			_setbits (flags, TTYSIG_SET_RTS); 
			break; 
		case 'r': 
			_setbits (flags, TTYSIG_READ_STATUS); 
			break; 
		case 's': 
			device = optarg; 
			break; 
		default: 
			break; 
		} 
	} 
	argc -= optind; 
	argv += optind; 
	if (argc == 1) 
	{ 
		input = open (* argv, O_RDONLY); 
		if (input == - 1) error (1, errno, "%s", * argv); 
		if (dup2 (input, STDIN_FILENO) == - 1) error (1, errno, "%s", * argv); 
		_setbits (flags, TTYSIG_INTERACTIVE | TTYSIG_NOPROMPT); 
	} 
	else if (argc > 0) error (1, 0, "Invalid arguments"); 
	fd = open (device, O_RDONLY); 
	if (fd == - 1) error (1, errno, "could not open %s", device); 
	if (_anyset (flags, TTYSIG_SET_DTR)) set_status (fd, TIOCM_DTR, dtr_value); 
	if (_anyset (flags, TTYSIG_SET_RTS)) set_status (fd, TIOCM_RTS, rts_value); 
	if (_anyset (flags, TTYSIG_READ_STATUS)) print_status (fd); 
	if (_anyset (flags, TTYSIG_INTERACTIVE)) interactive (fd, flags); 
	close (fd); 
	return (0); 
}