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freebsd-nq/sys/i386/isa/spkr.c
David Greenman 9714de6a38 Check for 0 before dividing by it. Patch from Paul Traina, modified 
slightly by me.
1995-05-05 06:15:11 +00:00

554 lines
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/*
* 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 1.12 1995/03/16 18:12:05 bde Exp $
*/
#include "speaker.h"
#if NSPEAKER > 0
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <i386/isa/isa.h>
#include <i386/isa/timerreg.h>
#include <machine/clock.h>
#include <machine/speaker.h>
/**************** MACHINE DEPENDENT PART STARTS HERE *************************
*
* This section defines a function tone() which causes a tone of given
* frequency and duration from the 80x86's 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 80x86's 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.
*/
/*
* PIT and PPI port addresses and control values
*
* Most of the magic is hidden in the TIMER_PREP value, which selects PIT
* channel 2, frequency LSB first, square-wave mode and binary encoding.
* The encoding is as follows:
*
* +----------+----------+---------------+-----+
* | 1 0 | 1 1 | 0 1 1 | 0 |
* | SC1 SC0 | RW1 RW0 | M2 M1 M0 | BCD |
* +----------+----------+---------------+-----+
* Counter Write Mode 3 Binary
* Channel 2 LSB first, (Square Wave) Encoding
* MSB second
*/
#define PPI_SPKR 0x03 /* turn these PPI bits on to pass sound */
#define PIT_MODE 0xB6 /* set timer mode for sound generation */
/*
* Magic numbers for timer control.
*/
#define TIMER_CLK 1193180L /* corresponds to 18.2 MHz tick rate */
#define SPKRPRI PSOCK
static char endtone, endrest;
static void tone(thz, ticks)
/* emit tone of frequency thz for given number of ticks */
unsigned int thz, ticks;
{
unsigned int divisor;
int sps;
if (thz <= 0)
return;
divisor = TIMER_CLK / 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 = spltty();
if (acquire_timer2(PIT_MODE)) {
/* enter list of waiting procs ??? */
return;
}
outb(TIMER_CNTR2, (divisor & 0xff)); /* send lo byte */
outb(TIMER_CNTR2, (divisor >> 8)); /* send hi byte */
splx(sps);
/* 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);
release_timer2();
}
static void rest(ticks)
/* rest for given number of 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) */
}
static void playtone(pitch, value, sustain)
/* play tone of proper duration for current rhythm signature */
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);
}
static void playstring(cp, slen)
/* interpret and play an item from a notation string */
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)
dev_t dev;
{
#ifdef DEBUG
(void) printf("spkropen: entering with dev = %x\n", 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)
dev_t dev;
struct uio *uio;
{
#ifdef DEBUG
printf("spkrwrite: entering with dev = %x, count = %d\n",
dev, uio->uio_resid);
#endif /* DEBUG */
if (minor(dev) != 0)
return(ENXIO);
else if (uio->uio_resid > DEV_BSIZE) /* prevent system crashes */
return(E2BIG);
else
{
unsigned n;
char *cp;
int error;
n = uio->uio_resid;
cp = spkr_inbuf->b_un.b_addr;
if (!(error = uiomove(cp, n, uio)))
playstring(cp, n);
return(error);
}
}
int spkrclose(dev)
dev_t dev;
{
#ifdef DEBUG
(void) printf("spkrclose: entering with dev = %x\n", 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)
dev_t dev;
int cmd;
caddr_t cmdarg;
{
#ifdef DEBUG
(void) printf("spkrioctl: entering with dev = %x, cmd = %x\n");
#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);
}
#endif /* NSPEAKER > 0 */
/* spkr.c ends here */
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