/*
 * spkr.c -- device driver for console speaker
 *
 * v1.4 by Eric S. Raymond (esr@snark.thyrsus.com) Aug 1993
 * modified for FreeBSD by Andrew A. Chernov <ache@astral.msk.su>
 *
 *    $Id: spkr.c,v 1.39 1999/08/23 20:35:17 bde Exp $
 */

#include "speaker.h"

#if NSPEAKER > 0

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/buf.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <i386/isa/isa.h>
#include <i386/isa/timerreg.h>
#include <machine/clock.h>
#include <machine/speaker.h>

static	d_open_t	spkropen;
static	d_close_t	spkrclose;
static	d_write_t	spkrwrite;
static	d_ioctl_t	spkrioctl;

#define CDEV_MAJOR 26
static struct cdevsw spkr_cdevsw = {
	/* open */	spkropen,
	/* close */	spkrclose,
	/* read */	noread,
	/* write */	spkrwrite,
	/* ioctl */	spkrioctl,
	/* stop */	nostop,
	/* reset */	noreset,
	/* devtotty */	nodevtotty,
	/* poll */	nopoll,
	/* mmap */	nommap,
	/* strategy */	nostrategy,
	/* name */	"spkr",
	/* parms */	noparms,
	/* maj */	CDEV_MAJOR,
	/* dump */	nodump,
	/* psize */	nopsize,
	/* flags */	0,
	/* maxio */	0,
	/* bmaj */	-1
};

/**************** MACHINE DEPENDENT PART STARTS HERE *************************
 *
 * This section defines a function tone() which causes a tone of given
 * frequency and duration from the ISA console speaker.
 * Another function endtone() is defined to force sound off, and there is
 * also a rest() entry point to do pauses.
 *
 * Audible sound is generated using the Programmable Interval Timer (PIT) and
 * Programmable Peripheral Interface (PPI) attached to the ISA speaker. The
 * PPI controls whether sound is passed through at all; the PIT's channel 2 is
 * used to generate clicks (a square wave) of whatever frequency is desired.
 */

/*
 * PPI control values.
 * XXX should be in a header and used in clock.c.
 */
#define PPI_SPKR	0x03	/* turn these PPI bits on to pass sound */

#define SPKRPRI PSOCK
static char endtone, endrest;

static void tone __P((unsigned int thz, unsigned int ticks));
static void rest __P((int ticks));
static void playinit __P((void));
static void playtone __P((int pitch, int value, int sustain));
static int abs __P((int n));
static void playstring __P((char *cp, size_t slen));

/* emit tone of frequency thz for given number of ticks */
static void
tone(thz, ticks)
	unsigned int thz, ticks;
{
    unsigned int divisor;
    int sps;

    if (thz <= 0)
	return;

    divisor = timer_freq / thz;

#ifdef DEBUG
    (void) printf("tone: thz=%d ticks=%d\n", thz, ticks);
#endif /* DEBUG */

    /* set timer to generate clicks at given frequency in Hertz */
    sps = splclock();

    if (acquire_timer2(TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT)) {
	/* enter list of waiting procs ??? */
	splx(sps);
	return;
    }
    splx(sps);
    disable_intr();
    outb(TIMER_CNTR2, (divisor & 0xff));	/* send lo byte */
    outb(TIMER_CNTR2, (divisor >> 8));	/* send hi byte */
    enable_intr();

    /* turn the speaker on */
    outb(IO_PPI, inb(IO_PPI) | PPI_SPKR);

    /*
     * Set timeout to endtone function, then give up the timeslice.
     * This is so other processes can execute while the tone is being
     * emitted.
     */
    if (ticks > 0)
	tsleep((caddr_t)&endtone, SPKRPRI | PCATCH, "spkrtn", ticks);
    outb(IO_PPI, inb(IO_PPI) & ~PPI_SPKR);
    sps = splclock();
    release_timer2();
    splx(sps);
}

/* rest for given number of ticks */
static void
rest(ticks)
	int	ticks;
{
    /*
     * Set timeout to endrest function, then give up the timeslice.
     * This is so other processes can execute while the rest is being
     * waited out.
     */
#ifdef DEBUG
    (void) printf("rest: %d\n", ticks);
#endif /* DEBUG */
    if (ticks > 0)
	tsleep((caddr_t)&endrest, SPKRPRI | PCATCH, "spkrrs", ticks);
}

/**************** PLAY STRING INTERPRETER BEGINS HERE **********************
 *
 * Play string interpretation is modelled on IBM BASIC 2.0's PLAY statement;
 * M[LNS] are missing; the ~ synonym and the _ slur mark and the octave-
 * tracking facility are added.
 * Requires tone(), rest(), and endtone(). String play is not interruptible
 * except possibly at physical block boundaries.
 */

typedef int	bool;
#define TRUE	1
#define FALSE	0

#define toupper(c)	((c) - ' ' * (((c) >= 'a') && ((c) <= 'z')))
#define isdigit(c)	(((c) >= '0') && ((c) <= '9'))
#define dtoi(c)		((c) - '0')

static int octave;	/* currently selected octave */
static int whole;	/* whole-note time at current tempo, in ticks */
static int value;	/* whole divisor for note time, quarter note = 1 */
static int fill;	/* controls spacing of notes */
static bool octtrack;	/* octave-tracking on? */
static bool octprefix;	/* override current octave-tracking state? */

/*
 * Magic number avoidance...
 */
#define SECS_PER_MIN	60	/* seconds per minute */
#define WHOLE_NOTE	4	/* quarter notes per whole note */
#define MIN_VALUE	64	/* the most we can divide a note by */
#define DFLT_VALUE	4	/* default value (quarter-note) */
#define FILLTIME	8	/* for articulation, break note in parts */
#define STACCATO	6	/* 6/8 = 3/4 of note is filled */
#define NORMAL		7	/* 7/8ths of note interval is filled */
#define LEGATO		8	/* all of note interval is filled */
#define DFLT_OCTAVE	4	/* default octave */
#define MIN_TEMPO	32	/* minimum tempo */
#define DFLT_TEMPO	120	/* default tempo */
#define MAX_TEMPO	255	/* max tempo */
#define NUM_MULT	3	/* numerator of dot multiplier */
#define DENOM_MULT	2	/* denominator of dot multiplier */

/* letter to half-tone:  A   B  C  D  E  F  G */
static int notetab[8] = {9, 11, 0, 2, 4, 5, 7};

/*
 * This is the American Standard A440 Equal-Tempered scale with frequencies
 * rounded to nearest integer. Thank Goddess for the good ol' CRC Handbook...
 * our octave 0 is standard octave 2.
 */
#define OCTAVE_NOTES	12	/* semitones per octave */
static int pitchtab[] =
{
/*        C     C#    D     D#    E     F     F#    G     G#    A     A#    B*/
/* 0 */   65,   69,   73,   78,   82,   87,   93,   98,  103,  110,  117,  123,
/* 1 */  131,  139,  147,  156,  165,  175,  185,  196,  208,  220,  233,  247,
/* 2 */  262,  277,  294,  311,  330,  349,  370,  392,  415,  440,  466,  494,
/* 3 */  523,  554,  587,  622,  659,  698,  740,  784,  831,  880,  932,  988,
/* 4 */ 1047, 1109, 1175, 1245, 1319, 1397, 1480, 1568, 1661, 1760, 1865, 1975,
/* 5 */ 2093, 2217, 2349, 2489, 2637, 2794, 2960, 3136, 3322, 3520, 3729, 3951,
/* 6 */ 4186, 4435, 4698, 4978, 5274, 5588, 5920, 6272, 6644, 7040, 7459, 7902,
};

static void
playinit()
{
    octave = DFLT_OCTAVE;
    whole = (hz * SECS_PER_MIN * WHOLE_NOTE) / DFLT_TEMPO;
    fill = NORMAL;
    value = DFLT_VALUE;
    octtrack = FALSE;
    octprefix = TRUE;	/* act as though there was an initial O(n) */
}

/* play tone of proper duration for current rhythm signature */
static void
playtone(pitch, value, sustain)
	int	pitch, value, sustain;
{
    register int	sound, silence, snum = 1, sdenom = 1;

    /* this weirdness avoids floating-point arithmetic */
    for (; sustain; sustain--)
    {
	/* See the BUGS section in the man page for discussion */
	snum *= NUM_MULT;
	sdenom *= DENOM_MULT;
    }

    if (value == 0 || sdenom == 0)
	return;

    if (pitch == -1)
	rest(whole * snum / (value * sdenom));
    else
    {
	sound = (whole * snum) / (value * sdenom)
		- (whole * (FILLTIME - fill)) / (value * FILLTIME);
	silence = whole * (FILLTIME-fill) * snum / (FILLTIME * value * sdenom);

#ifdef DEBUG
	(void) printf("playtone: pitch %d for %d ticks, rest for %d ticks\n",
			pitch, sound, silence);
#endif /* DEBUG */

	tone(pitchtab[pitch], sound);
	if (fill != LEGATO)
	    rest(silence);
    }
}

static int
abs(n)
	int n;
{
    if (n < 0)
	return(-n);
    else
	return(n);
}

/* interpret and play an item from a notation string */
static void
playstring(cp, slen)
	char	*cp;
	size_t	slen;
{
    int		pitch, oldfill, lastpitch = OCTAVE_NOTES * DFLT_OCTAVE;

#define GETNUM(cp, v)	for(v=0; isdigit(cp[1]) && slen > 0; ) \
				{v = v * 10 + (*++cp - '0'); slen--;}
    for (; slen--; cp++)
    {
	int		sustain, timeval, tempo;
	register char	c = toupper(*cp);

#ifdef DEBUG
	(void) printf("playstring: %c (%x)\n", c, c);
#endif /* DEBUG */

	switch (c)
	{
	case 'A':  case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':

	    /* compute pitch */
	    pitch = notetab[c - 'A'] + octave * OCTAVE_NOTES;

	    /* this may be followed by an accidental sign */
	    if (cp[1] == '#' || cp[1] == '+')
	    {
		++pitch;
		++cp;
		slen--;
	    }
	    else if (cp[1] == '-')
	    {
		--pitch;
		++cp;
		slen--;
	    }

	    /*
	     * If octave-tracking mode is on, and there has been no octave-
	     * setting prefix, find the version of the current letter note
	     * closest to the last regardless of octave.
	     */
	    if (octtrack && !octprefix)
	    {
		if (abs(pitch-lastpitch) > abs(pitch+OCTAVE_NOTES-lastpitch))
		{
		    ++octave;
		    pitch += OCTAVE_NOTES;
		}

		if (abs(pitch-lastpitch) > abs((pitch-OCTAVE_NOTES)-lastpitch))
		{
		    --octave;
		    pitch -= OCTAVE_NOTES;
		}
	    }
	    octprefix = FALSE;
	    lastpitch = pitch;

	    /* ...which may in turn be followed by an override time value */
	    GETNUM(cp, timeval);
	    if (timeval <= 0 || timeval > MIN_VALUE)
		timeval = value;

	    /* ...and/or sustain dots */
	    for (sustain = 0; cp[1] == '.'; cp++)
	    {
		slen--;
		sustain++;
	    }

	    /* ...and/or a slur mark */
	    oldfill = fill;
	    if (cp[1] == '_')
	    {
		fill = LEGATO;
		++cp;
		slen--;
	    }

	    /* time to emit the actual tone */
	    playtone(pitch, timeval, sustain);

	    fill = oldfill;
	    break;

	case 'O':
	    if (cp[1] == 'N' || cp[1] == 'n')
	    {
		octprefix = octtrack = FALSE;
		++cp;
		slen--;
	    }
	    else if (cp[1] == 'L' || cp[1] == 'l')
	    {
		octtrack = TRUE;
		++cp;
		slen--;
	    }
	    else
	    {
		GETNUM(cp, octave);
		if (octave >= sizeof(pitchtab) / sizeof(pitchtab[0]) / OCTAVE_NOTES)
		    octave = DFLT_OCTAVE;
		octprefix = TRUE;
	    }
	    break;

	case '>':
	    if (octave < sizeof(pitchtab) / sizeof(pitchtab[0]) / OCTAVE_NOTES - 1)
		octave++;
	    octprefix = TRUE;
	    break;

	case '<':
	    if (octave > 0)
		octave--;
	    octprefix = TRUE;
	    break;

	case 'N':
	    GETNUM(cp, pitch);
	    for (sustain = 0; cp[1] == '.'; cp++)
	    {
		slen--;
		sustain++;
	    }
	    oldfill = fill;
	    if (cp[1] == '_')
	    {
		fill = LEGATO;
		++cp;
		slen--;
	    }
	    playtone(pitch - 1, value, sustain);
	    fill = oldfill;
	    break;

	case 'L':
	    GETNUM(cp, value);
	    if (value <= 0 || value > MIN_VALUE)
		value = DFLT_VALUE;
	    break;

	case 'P':
	case '~':
	    /* this may be followed by an override time value */
	    GETNUM(cp, timeval);
	    if (timeval <= 0 || timeval > MIN_VALUE)
		timeval = value;
	    for (sustain = 0; cp[1] == '.'; cp++)
	    {
		slen--;
		sustain++;
	    }
	    playtone(-1, timeval, sustain);
	    break;

	case 'T':
	    GETNUM(cp, tempo);
	    if (tempo < MIN_TEMPO || tempo > MAX_TEMPO)
		tempo = DFLT_TEMPO;
	    whole = (hz * SECS_PER_MIN * WHOLE_NOTE) / tempo;
	    break;

	case 'M':
	    if (cp[1] == 'N' || cp[1] == 'n')
	    {
		fill = NORMAL;
		++cp;
		slen--;
	    }
	    else if (cp[1] == 'L' || cp[1] == 'l')
	    {
		fill = LEGATO;
		++cp;
		slen--;
	    }
	    else if (cp[1] == 'S' || cp[1] == 's')
	    {
		fill = STACCATO;
		++cp;
		slen--;
	    }
	    break;
	}
    }
}

/******************* UNIX DRIVER HOOKS BEGIN HERE **************************
 *
 * This section implements driver hooks to run playstring() and the tone(),
 * endtone(), and rest() functions defined above.
 */

static int spkr_active = FALSE; /* exclusion flag */
static struct buf *spkr_inbuf;  /* incoming buf */

int
spkropen(dev, flags, fmt, p)
	dev_t		dev;
	int		flags;
	int		fmt;
	struct proc	*p;
{
#ifdef DEBUG
    (void) printf("spkropen: entering with dev = %s\n", devtoname(dev));
#endif /* DEBUG */

    if (minor(dev) != 0)
	return(ENXIO);
    else if (spkr_active)
	return(EBUSY);
    else
    {
#ifdef DEBUG
	(void) printf("spkropen: about to perform play initialization\n");
#endif /* DEBUG */
	playinit();
	spkr_inbuf = geteblk(DEV_BSIZE);
	spkr_active = TRUE;
	return(0);
    }
}

int
spkrwrite(dev, uio, ioflag)
	dev_t		dev;
	struct uio	*uio;
	int		ioflag;
{
#ifdef DEBUG
    printf("spkrwrite: entering with dev = %s, count = %d\n",
		devtoname(dev), uio->uio_resid);
#endif /* DEBUG */

    if (minor(dev) != 0)
	return(ENXIO);
    else if (uio->uio_resid > (DEV_BSIZE - 1))     /* prevent system crashes */
	return(E2BIG);
    else
    {
	unsigned n;
	char *cp;
	int error;

	n = uio->uio_resid;
	cp = spkr_inbuf->b_data;
	error = uiomove(cp, n, uio);
	if (!error) {
		cp[n] = '\0';
		playstring(cp, n);
	}
	return(error);
    }
}

int
spkrclose(dev, flags, fmt, p)
	dev_t		dev;
	int		flags;
	int		fmt;
	struct proc	*p;
{
#ifdef DEBUG
    (void) printf("spkrclose: entering with dev = %s\n", devtoname(dev));
#endif /* DEBUG */

    if (minor(dev) != 0)
	return(ENXIO);
    else
    {
	wakeup((caddr_t)&endtone);
	wakeup((caddr_t)&endrest);
	brelse(spkr_inbuf);
	spkr_active = FALSE;
	return(0);
    }
}

int
spkrioctl(dev, cmd, cmdarg, flags, p)
	dev_t		dev;
	unsigned long	cmd;
	caddr_t		cmdarg;
	int		flags;
	struct proc	*p;
{
#ifdef DEBUG
    (void) printf("spkrioctl: entering with dev = %s, cmd = %lx\n",
    	devtoname(dev), cmd);
#endif /* DEBUG */

    if (minor(dev) != 0)
	return(ENXIO);
    else if (cmd == SPKRTONE)
    {
	tone_t	*tp = (tone_t *)cmdarg;

	if (tp->frequency == 0)
	    rest(tp->duration);
	else
	    tone(tp->frequency, tp->duration);
	return 0;
    }
    else if (cmd == SPKRTUNE)
    {
	tone_t  *tp = (tone_t *)(*(caddr_t *)cmdarg);
	tone_t ttp;
	int error;

	for (; ; tp++) {
	    error = copyin(tp, &ttp, sizeof(tone_t));
	    if (error)
		    return(error);
	    if (ttp.duration == 0)
		    break;
	    if (ttp.frequency == 0)
		 rest(ttp.duration);
	    else
		 tone(ttp.frequency, ttp.duration);
	}
	return(0);
    }
    return(EINVAL);
}

static void
spkr_drvinit(void *unused)
{
	make_dev(&spkr_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "speaker");
}

SYSINIT(spkrdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,spkr_drvinit,NULL)


#endif  /* NSPEAKER > 0 */
/* spkr.c ends here */