/*
 * $Id: plat_linux.c,v 1.7 1999/03/07 08:36:40 dirk Exp $
 *
 * This file is part of WorkMan, the civilized CD player library
 * (c) 1991-1997 by Steven Grimm (original author)
 * (c) by Dirk Försterling (current 'author' = maintainer)
 * The maintainer can be contacted by his e-mail address:
 * milliByte@DeathsDoor.com 
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *
 * Linux-specific drive control routines.  Very similar to the Sun module.
 */

#ifdef linux
/* Id for ident command */
static char plat_linux_id[] = "$Id: plat_linux.c,v 1.7 1999/03/07 08:36:40 dirk Exp $";

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <malloc.h>
#include <string.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include "include/wm_config.h"

#if defined(BSD_MOUNTTEST)
  #include <mntent.h>
#else
  /*
   * this is for glibc 2.x which defines ust structure in
   * ustat.h not stat.h
   */
  #ifdef __GLIBC__
    #include <sys/ustat.h>
  #endif
#endif

#include <sys/time.h>
#include <sys/ioctl.h>
#include <linux/cdrom.h>

#include "include/wm_cdda.h"
#include "include/wm_struct.h"
#include "include/wm_platform.h"
#include "include/wm_cdrom.h"
#include "include/wm_scsi.h"
#include "include/wm_helpers.h"

#ifdef OSS_SUPPORT
#include <linux/soundcard.h>
#define CD_CHANNEL SOUND_MIXER_CD
#endif

#define max(a,b) ((a) > (b) ? (a) : (b))

#define WM_MSG_CLASS WM_MSG_CLASS_PLATFORM
 
#ifdef LINUX_SCSI_PASSTHROUGH
/* this is from <scsi/scsi_ioctl.h> */
# define SCSI_IOCTL_SEND_COMMAND 1
#endif

int	min_volume = 0;
int	max_volume = 255;

#ifdef OSS_SUPPORT
int mixer;
char mixer_dev_name[20] = "/dev/mixer";
#endif
extern char	*cd_device, *cddaslave_path;

int	cdda_slave = -1;

/*
 * Wait for an acknowledgement from the CDDA slave.
 */
static int
get_ack(int fd)
{
#if defined(BUILD_CDDA) && defined(WMCDDA_DONE) /* { */
	struct cdda_block	blk;

	do
		if (read(fd, &blk, sizeof(blk)) <= 0)
			return (0);
	while (blk.status != WMCDDA_ACK);
#endif /* } */

	return (1);
} /* get_ack() */

/*--------------------------------------------------------*
 * Initialize the drive.  A no-op for the generic driver.
 *--------------------------------------------------------*/
int
gen_init( struct wm_drive *d )
{
#ifdef OSS_SUPPORT
/*
 * Open and use the mixer device to set volume
 */
	if( ( mixer = open( mixer_dev_name, O_RDWR, 0 ) ) == -1 )
	  {
	  	perror( mixer_dev_name );
	  	exit( -1 );
	  }
#endif
	return (0);
} /* gen_init() */

/*
 * Try to initialize the CDDA slave.  Returns 0 on error.
 */
int
cdda_init( struct wm_drive *d )
{
#if defined(BUILD_CDDA) && defined(WMCDDA_DONE) /* { */
	int	slavefds[2];

	if (cdda_slave > -1)
		return (1);

	fprintf( stderr, "slave okay\n" );

	if (socketpair(AF_UNIX, SOCK_STREAM, 0, slavefds))
	{
		perror("socketpair");
		return (0);
	}

	fprintf( stderr, "going to fork\n" );
	switch (fork()) {
	case 0:
		close(slavefds[0]);
		dup2(slavefds[1], 1);
		dup2(slavefds[1], 0);
		close(slavefds[1]);
		close(d->fd);
		/* Try the default path first. */
		execl(cddaslave_path, cddaslave_path, cd_device, NULL);
		/* Search $PATH if that didn't work. */
		execlp("cddaslave", "cddaslave", cd_device, NULL);
		perror(cddaslave_path);
		exit(1);

	case -1:
		close(slavefds[0]);
		close(slavefds[1]);
		perror("fork");
		return (0);
	}

	close(slavefds[1]);
	cdda_slave = slavefds[0];

	if (!get_ack(cdda_slave))
	{
		fprintf( stderr, "get_ack failed\n" );
		cdda_slave = -1;
/*		codec_start(); */
		return (0);
	}

	return (1);

#else /* BUILD_CDDA } { */
	/*
	 * If we're not building CDDA support, don't even bother trying.
	 */
	return (0);
#endif
} /* cdda_init()  */

/*
 * Turn off the CDDA slave.
 */
void
cdda_kill( struct wm_drive *d )
{
	if (cdda_slave > -1)
	{
		write(cdda_slave, "Q", 1);
		get_ack(cdda_slave);
		wait(NULL);
		cdda_slave = -1;
/*		codec_start(); */
	}
} /* cdda_kill() */

/*-------------------------------------*
 * Get the number of tracks on the CD.
 *-------------------------------------*/
int
gen_get_trackcount(struct wm_drive *d, int *tracks)
{
	struct cdrom_tochdr	hdr;

	if (ioctl(d->fd, CDROMREADTOCHDR, &hdr))
		return (-1);
	
	*tracks = hdr.cdth_trk1;
	return (0);
} 

/*---------------------------------------------------------*
 * Get the start time and mode (data or audio) of a track.
 *---------------------------------------------------------*/
int
gen_get_trackinfo(struct wm_drive *d, int track, int *data, int *startframe)
{
	struct cdrom_tocentry	entry;

	entry.cdte_track = track;
	entry.cdte_format = CDROM_MSF;

	if (ioctl(d->fd, CDROMREADTOCENTRY, &entry))
		return (-1);
	
	*startframe =	entry.cdte_addr.msf.minute * 60 * 75 +
			entry.cdte_addr.msf.second * 75 +
			entry.cdte_addr.msf.frame;
	*data = entry.cdte_ctrl & CDROM_DATA_TRACK ? 1 : 0;
	
	return (0);
}

/*-------------------------------------*
 * Get the number of frames on the CD.
 *-------------------------------------*/
int
gen_get_cdlen(struct wm_drive *d, int *frames)
{
	int		tmp;

	return (gen_get_trackinfo(d, CDROM_LEADOUT, &tmp, frames));
}


/* Alarm signal handler. 
static void do_nothing(int x) { x++; }
*/

/*--------------------------------------------------------------------------*
 * Get the current status of the drive: the current play mode, the absolute
 * position from start of disc (in frames), and the current track and index
 * numbers if the CD is playing or paused.
 *--------------------------------------------------------------------------*/
int
gen_get_drive_status( struct wm_drive *d, enum wm_cd_modes oldmode,
                      enum wm_cd_modes *mode, int *pos, int *track, int *index )
{
	struct cdrom_subchnl		sc;

#ifdef SBPCD_HACK
	static int prevpos = 0;
#endif
	
	/* If we can't get status, the CD is ejected, so default to that. */
	*mode = WM_CDM_EJECTED;

	/* Is the device open? */
	if (d->fd < 0)
	{
		switch (wmcd_open(d))
		{

			case -1:	/* error */
				return (-1);

			case 1:		/* retry */
				return (0);
		}
	}

	sc.cdsc_format = CDROM_MSF;

	if (ioctl(d->fd, CDROMSUBCHNL, &sc))
		return (0);

	switch (sc.cdsc_audiostatus) {
	case CDROM_AUDIO_PLAY:
		*mode = WM_CDM_PLAYING;
		*track = sc.cdsc_trk;
		*index = sc.cdsc_ind;
		*pos = sc.cdsc_absaddr.msf.minute * 60 * 75 +
			sc.cdsc_absaddr.msf.second * 75 +
			sc.cdsc_absaddr.msf.frame;
#ifdef SBPCD_HACK
		if( *pos < prevpos )
                  {
                    if( (prevpos - *pos) < 75 )
                    {
                      *mode = WM_CDM_TRACK_DONE;
                    }
                  }
                  
                prevpos = *pos;
#endif
		break;

	case CDROM_AUDIO_PAUSED:
	case CDROM_AUDIO_NO_STATUS:
	case CDROM_AUDIO_INVALID: /**/
		if (oldmode == WM_CDM_PLAYING || oldmode == WM_CDM_PAUSED)
		{
			*mode = WM_CDM_PAUSED;
			*track = sc.cdsc_trk;
			*index = sc.cdsc_ind;
			*pos = sc.cdsc_absaddr.msf.minute * 60 * 75 +
				sc.cdsc_absaddr.msf.second * 75 +
				sc.cdsc_absaddr.msf.frame;
		}
		else
			*mode = WM_CDM_STOPPED;
		break;

	case CDROM_AUDIO_COMPLETED:
		*mode = WM_CDM_TRACK_DONE; /* waiting for next track. */
		break;

	default:
		*mode = WM_CDM_UNKNOWN;
		break;
	}

	return (0);
}

/*------------------------------------------------------------------------*
 * scale_volume(vol, max)
 *
 * Return a volume value suitable for passing to the CD-ROM drive.  "vol"
 * is a volume slider setting; "max" is the slider's maximum value.
 * This is not used if sound card support is enabled.
 *
 *------------------------------------------------------------------------*/
#ifndef OSS_SUPPORT
static int
scale_volume( int vol, int max )
{
#ifdef CURVED_VOLUME
        return ((max * max - (max - vol) * (max - vol)) *
                        (max_volume - min_volume) / (max * max) + min_volume);                        
#else
        return ((vol * (max_volume - min_volume)) / max + min_volume);
#endif        
} /* scale_volume() */
#endif

/*---------------------------------------------------------------------*
 * Set the volume level for the left and right channels.  Their values
 * range from 0 to 100.
 *---------------------------------------------------------------------*/
int
gen_set_volume( struct wm_drive *d, int left, int right )
{
#ifndef OSS_SUPPORT
	struct	cdrom_volctrl v;
#endif
	int	vol;

#ifdef OSS_SUPPORT

	left = left < 0 ? 0 : left > 100 ? 100 : left;
	right = right < 0 ? : right > 100 ? 100 : right;

	vol = ( 0x007f & left ) | ( 0x7f00 & ( right << 8 ) );
	if( ioctl( mixer, MIXER_WRITE( CD_CHANNEL ), &vol ) == -1 )
	  {
	  	perror( "MIXER_WRITE" );
	  	return ( -1 );
	  }
	return ( 0 );  
#else

/* Adjust the volume to make up for the CD-ROM drive's weirdness. */
	left = scale_volume(left, 100);
	right = scale_volume(right, 100);

	v.channel0 = v.channel2 = left < 0 ? 0 : left > 255 ? 255 : left;
	v.channel1 = v.channel3 = right < 0 ? 0 : right > 255 ? 255 : right;
	
	return (ioctl(d->fd, CDROMVOLCTRL, &v));
# endif	
}

/*---------------*
 * Pause the CD.
 *---------------*/
int
gen_pause(d)
	struct wm_drive	*d;
{
	return (ioctl(d->fd, CDROMPAUSE));
}

/*-------------------------------------------------*
 * Resume playing the CD (assuming it was paused.)
 *-------------------------------------------------*/
int
gen_resume(struct wm_drive *d)
{
	return (ioctl(d->fd, CDROMRESUME));
}

/*--------------*
 * Stop the CD.
 *--------------*/
int
gen_stop(struct wm_drive *d)
{
	return (ioctl(d->fd, CDROMSTOP));
}

/*------------------------------------------------------------*
 * Play the CD from one position to another (both in frames.)
 *------------------------------------------------------------*/
int
gen_play(struct wm_drive *d, int start, int end)
{
	struct cdrom_msf		msf;

	msf.cdmsf_min0 = start / (60*75);
	msf.cdmsf_sec0 = (start % (60*75)) / 75;
	msf.cdmsf_frame0 = start % 75;
	msf.cdmsf_min1 = end / (60*75);
	msf.cdmsf_sec1 = (end % (60*75)) / 75;
	msf.cdmsf_frame1 = end % 75;

#ifndef FAST_IDE
	if (ioctl(d->fd, CDROMSTART))
		return (-1);
#endif		
	if (ioctl(d->fd, CDROMPLAYMSF, &msf))
		return (-2);
	
	return (0);
}

/*----------------------------------------*
 * Eject the current CD, if there is one.
 *----------------------------------------*/
int
gen_eject(struct wm_drive *d)
{
	struct stat	stbuf;
#if !defined(BSD_MOUNTTEST)
	struct ustat	ust;
#else
	struct mntent *mnt;
	FILE *fp;
#endif
	
	if (fstat(d->fd, &stbuf) != 0)
		return (-2);

	/* Is this a mounted filesystem? */
#if !defined(BSD_MOUNTTEST)
	if (ustat(stbuf.st_rdev, &ust) == 0)
		return (-3);
#else
	/*
         * This is the same test as in the WorkBone interface.
         * I should eliminate it there, because there is no need
         * for it in the UI
	 */ 
	/* check if drive is mounted (from Mark Buckaway's cdplayer code) */
	/* Changed it again (look at XPLAYCD from ????                    */
	/* It's better to check the device name rather than one device is */
	/* mounted as iso9660. That prevents "no playing" if you have more*/
	/* than one CD-ROM, and one of them is mounted, but it's not the  */
	/* audio CD                                              -dirk    */
	if ((fp = setmntent (MOUNTED, "r")) == NULL)
	{
		fprintf (stderr, "Could not open %s: %s\n", MOUNTED, strerror (errno));
		return(-3);
	}
	while ((mnt = getmntent (fp)) != NULL)
	{
		if (strcmp (mnt->mnt_fsname, cd_device) == 0)
		{
			fputs ("CDROM already mounted (according to mtab). Operation aborted.\n", stderr);
			endmntent (fp);
			return(-3);
		}
    	}
	endmntent (fp);
#endif /* BSD_MOUNTTEST */

	if (ioctl(d->fd, CDROMEJECT))
		return (-1);
/*------------------
 * Things in "foobar_one" are left over from 1.4b3
 * I put them here for further observation. In 1.4b3, however,
 * that workaround didn't help at least for /dev/sbpcd
 * (The tray closed just after ejecting because re-opening the
 * device causes the tray to close)
 *------------------*/
#ifdef foobar_one 
extern int intermittent_dev
        /*
	 * Some drives (drivers?) won't recognize a new CD if we leave the
         * device open.
         */
	if (intermittent_dev)
	{
		close(d->fd);
		d->fd = -1;
	}			  
#endif
	
	return (0);
} /* gen_eject() */

/*----------------------------------------*
 * Close the CD tray
 *----------------------------------------*/

int gen_closetray(struct wm_drive *d)
{
#ifdef CAN_CLOSE
#ifdef CDROMCLOSETRAY
	wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "CDROMCLOSETRAY closing tray...\n");
	if (ioctl(d->fd, CDROMCLOSETRAY))
		return (-1);
#else
	wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "wmcd_reopen() closing tray...\n");
	if(!close(d->fd))
	{
		d->fd=-1;
		return(wmcd_reopen(d));
	} else {
		return(-1);
	}
#endif /* CDROMCLOSETRAY */
#else /* CAN_CLOSE */
	/* Always succeed if the drive can't close. */
	return(0);
#endif /* CAN_CLOSE */
} /* gen_closetray() */

/*--------------------------------*
 * Keep the CD open all the time.
 * disabled, analogous to 1.4b3
 *--------------------------------*
void
keep_cd_open( void )
{
	int	fd;
	struct flock	fl;
	extern	end;


	for (fd = 0; fd < 256; fd++)
		close(fd);

	if (fork())
		exit(0);

	if ((fd = open("/tmp/cd.lock", O_RDWR | O_CREAT, 0666)) < 0)
		exit(0);
	fl.l_type = F_WRLCK;
	fl.l_whence = 0;
	fl.l_start = 0;
	fl.l_len = 0;
	if (fcntl(fd, F_SETLK, &fl) < 0)
		exit(0);

	if (open(cd_device, 0) >= 0)
	{
		brk(&end);
		pause();
	}

	exit(0);
}
*/

/*---------------------------------------------------------------------*
 * Read the initial volume from the drive, if available.  Each channel
 * ranges from 0 to 100, with -1 indicating data not available.
 *---------------------------------------------------------------------*/
int
gen_get_volume( struct wm_drive *d, int *left, int *right )
{
#if defined(BUILD_CDDA) && defined(WMCDDA_DONE) /* { */
	struct cdda_block	blk;

	if (cdda_slave > -1)
	{
		write(cdda_slave, "G", 1);
		get_ack(cdda_slave);
		read(cdda_slave, &blk, sizeof(blk));

		*left = *right = (blk.volume * 100 + 254) / 255;

		if (blk.balance < 110)
			*right = (((blk.volume * blk.balance + 127) / 128) *
				  100 + 254) / 255;
		else if (blk.balance > 146)
			*left = (((blk.volume * (255 - blk.balance) +
				   127) / 128) * 100 + 254) / 255;

		return (0);
	}
#else /* } */
#ifdef OSS_SUPPORT
	int vol;

	if( ioctl( mixer, MIXER_READ( CD_CHANNEL ), &vol ) == -1 )
	  {
	  	perror( "MIXER_READ" );
	  	*left = *right = -1;
	  }
	*right = 0x007f & ( vol >> 8 );
	*left = 0x007f & vol;  

#else
	/* Suns, HPs, Linux, NEWS can't read the volume; oh well */
	*left = *right = -1;

#endif
#endif
	return (0);
}

#ifdef BUILD_CDDA /* { */

/*
 * Tell the CDDA slave to set the play direction.
 */
void
gen_set_direction( int newdir )
{
	unsigned char	buf[2];

	if (cdda_slave > -1)
	{
		buf[0] = 'd';
		buf[1] = newdir;
		write(cdda_slave, buf, 2);
		get_ack(cdda_slave);
	}
}

/*
 * Tell the CDDA slave to set the play speed.
 */
void
gen_set_speed( int speed )
{
	unsigned char	buf[2];

	if (cdda_slave > -1)
	{
		buf[0] = 's';
		buf[1] = speed;
		write(cdda_slave, buf, 2);
		get_ack(cdda_slave);
	}
}

/*
 * Tell the CDDA slave to set the loudness level.
 */
void
gen_set_loudness( int loud )
{
	unsigned char	buf[2];

	if (cdda_slave > -1)
	{
		buf[0] = 'L';
		buf[1] = loud;
		write(cdda_slave, buf, 2);
		get_ack(cdda_slave);
	}
}

/*
 * Tell the CDDA slave to start (or stop) saving to a file.
 */
void
gen_save( char *filename )
{
	int	len;

	if (filename == NULL || filename[0] == '\0')
		len = 0;
	else
		len = strlen(filename);
	write(cdda_slave, "F", 1);
	write(cdda_slave, &len, sizeof(len));
	if (len)
		write(cdda_slave, filename, len);
	get_ack(cdda_slave);
}

#endif /* BUILD_CDDA } */

/*---------------------------------------------*
 * Send an arbitrary SCSI command to a device.
 *---------------------------------------------*/
int
wm_scsi( struct wm_drive *d, unsigned char *cdb, int cdblen,
	 void *retbuf, int retbuflen, int getreply )
{
#ifdef LINUX_SCSI_PASSTHROUGH

        char *cmd;
	int cmdsize;

	cmdsize = 2 * sizeof(int);
	if (retbuf)
	  {
	    if (getreply) cmdsize += max(cdblen, retbuflen);
	    else cmdsize += (cdblen + retbuflen);
	  }
	else cmdsize += cdblen;
	  
	cmd = malloc(cmdsize);
	if (cmd == NULL)
	  return (-1);

	((int*)cmd)[0] = cdblen + ((retbuf && !getreply) ? retbuflen : 0);
	((int*)cmd)[1] = ((retbuf && getreply) ? retbuflen : 0);

	memcpy(cmd + 2*sizeof(int), cdb, cdblen);
	if (retbuf && !getreply)
	  memcpy(cmd + 2*sizeof(int) + cdblen, retbuf, retbuflen);
	
	if (ioctl(d->fd, SCSI_IOCTL_SEND_COMMAND, cmd))
	  {
	    wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "%s: ioctl() failure\n", __FILE__);
	    wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "command buffer is:\n");
	    wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "%02x %02x %02x %02x %02x %02x\n",
	            cmd[0],  cmd[1],  cmd[2],  cmd[3],  cmd[4],  cmd[5]);
	    free(cmd);
	    return (-1);
	  }
	
	if (retbuf && getreply)
	  memcpy(retbuf, cmd + 2*sizeof(int), retbuflen);

	free(cmd);
	return 0;

#else /* Linux SCSI passthrough*/
	return (-1);
#endif
}

/*---------------------------------------------------------------------------*
 * Open the CD device and figure out what kind of drive is attached.
 *---------------------------------------------------------------------------*/
int
wmcd_open( struct wm_drive *d )
{
	int		fd;
	static int	warned = 0;
	int		retval = 0;
	char vendor[32], model[32], rev[32];
 
	if (cd_device == NULL)
		cd_device = DEFAULT_CD_DEVICE;

	if (d->fd >= 0)		/* Device already open? */
	{
		wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "wmcd_open(): [device is open (fd=%d)]\n", d->fd);
		return (0);
	}
	
	d->fd = open(cd_device, O_RDONLY | O_NONBLOCK);
	if (d->fd < 0)
	{
		if (errno == EACCES)
		{
			if (!warned)
			{
				fprintf(stderr,
		"As root, please run\n\nchmod 666 %s\n\n%s\n", cd_device,
		"to give yourself permission to access the CD-ROM device.");
				warned++;
			}
		}
/* Hack proposed by Carey Evans, introduced by Debian maintainer :
 * treat EIO like ENXIO since some Linux drives do never return ENXIO
 */
		else if ((errno != ENXIO) && (errno != EIO))
		{
			perror(cd_device);
			exit(1);
		}

		/* No CD in drive. */
		retval = 1;
	}

	if (warned)
	{
		warned = 0;
		fprintf(stderr, "Thank you.\n");
	}

	/* Now fill in the relevant parts of the wm_drive structure. */
	fd = d->fd;

#ifdef LINUX_SCSI_PASSTHROUGH
	/* Can we figure out the drive type? */
	wm_scsi_get_drive_type(d, vendor, model, rev);
#endif
	*d = *(find_drive_struct(vendor, model, rev));	
	wm_drive_settype(vendor, model, rev);

	d->fd = fd;
	(d->init)(d);
	return retval;
} /* wmcd_open() */

/*
 * Re-Open the device if it is open.
 */
int
wmcd_reopen( struct wm_drive *d )
{
	int status;

	do {
        	wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "wmcd_reopen ");
		if (d->fd >= 0)		/* Device really open? */
		{
        	      wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "closes the device and ");
		      status = close( d->fd );   /* close it! */
		      /* we know, that the file is closed, do we? */
        	      d->fd = -1;
		}
		wm_susleep( 1000 );
        	wm_lib_message(WM_MSG_LEVEL_DEBUG|WM_MSG_CLASS, "calls wmcd_open()\n");
		status = wmcd_open( d ); /* open it as usual */
		wm_susleep( 1000 );
	} while ( status != 0 );
        return status;
} /* wmcd_reopen() */

#endif /* linux */
