/*
 *
 *	IRBOX, an Ivy driver for infra-red remote controls
 *
 *	Copyright 1998-1999 
 *	Centre d'Etudes de la Navigation Aerienne
 *
 *	Device driver
 *
 *	Authors: Francois-Regis Colin <fcolin@cenatoulouse.dgac.fr>
 *		Yann Malichecq
 *		Stephane Chatty <chatty@cenatoulouse.dgac.fr>
 *
 *
 *	$Id$
 *
 *	Please refer to file version.h for the
 *	copyright notice regarding this software
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/errno.h>
#include <sys/param.h>
#include <termio.h>
#include <sys/ioctl.h>

#include "irdev.h"


#define CHECKEDWRITE(fd , buff , len ) \
	if (write( fd, buff, len) != len) { perror("IR write"); return -1; }

#define NBITS 8
#define SET(n, p)   ((p)[(n)/NBITS] |= ((unsigned)1 << ((n) % NBITS)))
#define CLR(n, p)   ((p)[(n)/NBITS] &= ~((unsigned)1 << ((n) % NBITS)))
#define ISSET(n, p) ((p)[(n)/NBITS] & ((unsigned)1 << ((n) % NBITS)))

struct ir_state {
	int fd;
	IrEvtCallback	callback;
	IrFailCallback	fail_callback;
	IrTimerSetter		set_timeout;
	IrTimerCanceller	cancel_timeout;

	/* state machine stuff */
	char			 state;
	unsigned char 			 value[6];

	void	*checkinit_id;

	/* misc. std. driver stuff */
	unsigned char initialized;/* true if data structures are set */
				/* and init sequence has been sent to */
				/* device */
	unsigned char ready;	/* true if we've received confirmation */
				/* of the init sequence from the device */
	unsigned char errorCount;/* count of bad messages for recovery */
};
 

static int IrInitDevice (IrState*);


int
IrInit (IrState *ir,  IrEvtCallback cb, IrFailCallback f, IrTimerSetter st, IrTimerCanceller ct)
{
	ir->callback = cb;
	ir->fail_callback = f;
	ir->set_timeout = st;
	ir->cancel_timeout = ct;
	return IrInitDevice (ir);
}



static void
IrCheckInit (void * id, IrState *ir, int delta)
{
	if ((!ir->ready) && (ir->checkinit_id)) {
		if (ir->errorCount++<5) {
			IrInitDevice (ir);
			return;
		} else {
			/* pas de reponse, on abandonne */
			if (ir->fail_callback)
				(*ir->fail_callback)(ir);
		}
	}
	ir->checkinit_id= 0;
	return;
}


#define SPEED B9600

/* ARGSUSED */
static int
IrInitDevice (IrState *ir)
{
	unsigned char dcmd[2];
	struct termios terms;

	/*initialisation du port serie */
	if (tcgetattr (ir->fd, &terms) == -1) {
		perror ( "Cant get device configuration for IR box");
		return 0;
	}

	/* change the modes */
    	cfmakeraw (&terms);
	terms.c_lflag = 0;

	if (cfsetospeed (&terms, SPEED) < 0 ) {
		perror ("Can't set ouput speed for IR box");
		return 0;
	}

	if (cfsetispeed (&terms, SPEED) < 0 ) {
		perror ("Can't set input speed for IR box");
		return 0;
	}

	if (tcsetattr (ir->fd, TCSANOW, &terms) < 0)
	{
		perror ("Can't change device configuration for IR box");
		return 0;
	}

	/* discard all unread or unwritten data */
       	tcflush (ir->fd, TCIOFLUSH );

#ifdef DEBUG	
	fprintf (stderr, "IR box initialization in progress.....\n");
#endif
	dcmd[0] = 'I';
	dcmd[1] = 'R';
	CHECKEDWRITE(ir->fd, dcmd, sizeof(dcmd));
	
	ir->initialized= 1;
	if (ir->set_timeout)
		ir->checkinit_id = (*ir->set_timeout)(IrCheckInit, 1000, ir);
	return 1;
}




static void
IrSetup (IrState *ir)
{
	ir->ready=1;
	if (ir->cancel_timeout)
		(*ir->cancel_timeout)(ir->checkinit_id);
	
	ir->errorCount= 0;
	return;
}


static void
IrDecodeInit (IrState *ir, char ch)
{
	/* on doit attendre les caracteres "OK" */
	switch (ir->state) {
	case 0:
		if ( ch == 'O' ) 
			ir->state++;
		break;
	case 1:
		if ( ch == 'K' ) {
			ir->state = 0;
#ifdef DEBUG
			fprintf (stderr,"IR box initialized OK.\n");
#endif
			IrSetup (ir);
			ir->errorCount = 0;
		} else {
			fprintf (stderr, "unexpected char %d from IR box\n", ch);
			if (ir->errorCount++ > 5) {
				 /* try to reinitialize */
				fprintf (stderr,"Reinitializing IR box\n");

				IrInitDevice (ir);
			}
		}
		break;
	default:
		fprintf (stderr,"Impossible state %d in ir_intr.\n", ir->state);
		ir->state = 0;
		break;
	}
}


static void
IrDecodeFrame (IrState *ir, char ch)
{
	ir->value[(int)(ir->state++)] = ch;

	/* fin de trame de 6 caracteres */
	if (ir->state == 6) {
#ifdef DEBUG
		fprintf (stdout, "%.3d %.3d %.3d %.3d %.3d %.3d\n", ir->value[0], ir->value[1],ir->value[2],ir->value[3],ir->value[4],ir->value[5]);
#endif
		if (ir->callback)
			(*ir->callback)(ir, ir->value );
		ir->state = 0;
	}		
}

void
IrIntr (IrState *ir)
{
	unsigned char buf[128];
	unsigned char *str;
	int len; 
	register unsigned char ch;
#ifdef DEBUG_RECEIVE
	int i;
#endif
	if ((len = read(ir->fd, buf, sizeof(buf))) < 0)
		return;
#ifdef DEBUG_RECEIVE
	fprintf (stderr, "received %d bytes from device \n",len);
	for ( i = 0; i < len ; i ++ )
			fprintf(stderr, "0x%02x ",buf[i]);
	fprintf(stderr, "\n");
#endif
	str = buf;
	while (len > 0) {
		ch = *str++;
		if (!ir->ready) /* on doit attendre les caracteres OK */
			IrDecodeInit (ir,ch);
		else /* on doit attendre la fin de la trame ( 6 car ) */
			IrDecodeFrame (ir, ch);
		len--;
	}
	return;
}

/* ARGSUSED */
IrState*
IrOpen (const char *name )
{
	register IrState *ir;

	if ( !(ir = (IrState *)malloc(sizeof *ir)))
		return NULL;
	/* Set defaults -- totally arbitrary, my choice */
	memset( ir, 0, sizeof *ir ) ;

	if ((ir->fd = open(name, O_RDWR/*|O_NONBLOCK*/)) < 0) {
		fprintf(stderr, "Couldn't open %s\n", name); 
		free( ir );
		return NULL; 

	}

		
	ir->initialized = 1;
	ir->errorCount = 0;
	ir->state = 0;
	
	
	return ir;
}

/* ARGSUSED */
void
IrClose (IrState *ir)
{
	if (ir->checkinit_id) {
		if (ir->cancel_timeout )
			(*ir->cancel_timeout)( ir->checkinit_id );
		ir->checkinit_id= 0;
	}
	free (ir);
}

int
IrGetFd (IrState *ir)
{	
	return ir->fd;
}