#include	"u.h"#include	"../port/lib.h"#include	"mem.h"#include	"dat.h"#include	"fns.h"#include	"../port/error.h"#include	"devtab.h" #include	"io.h"#include	"ureg.h" #define	NPORT		(sizeof audiodir/sizeof(Dirtab))#define	CSR		(*(ulong*)SOUNDOUTDMA)#define	DMA1B		(*(ulong*)SOUNDOUTBASE)#define	DMA1L		(*(ulong*)SOUNDOUTLIMIT)#define	DMA2B		(*(ulong*)SOUNDOUTCHAINBASE)#define	DMA2L		(*(ulong*)SOUNDOUTCHAINLIMIT)#define	MONCMD		(*(ulong*)MONCSR)#define	MONDAT		(*(ulong*)KMSDATA) enum{	Qdir		= 0,	Qaudio,	Qvolume, 	Sempty		= 0,	Sfilling,	Sfull,	Scurrent,	Schained, 	Outcint		= 1<<27,	Outrw		= 1<<26,	/* always 0 */	Outchain	= 1<<25,	Outenable	= 1<<24, 	Outinitbuff	= 1<<21,	Outcreset	= 1<<20,	Outclrcint	= 1<<19,	Outwr		= 1<<18,	/* 0 = read */	Outsetchain	= 1<<17,	Outsetenable	= 1<<16, 	Bufsize		= 8*1024,	Nbuf		= 10,}; Dirtabaudiodir[] ={	"audio",	{Qaudio},		0,	0600,	"volume",	{Qvolume},		0,	0600,}; typedef struct	Buf	Buf;struct	Buf{	uchar*	virt;	ulong	phys;	ulong	age;	int	state;};static	struct{	Rendez	vous;	int	bufinit;	/* boolean if buffers allocated */	int	open;		/* boolean if open */	int	curcount;	/* how much data in current buffer */	int	active;		/* boolean dma running */	int	intr;		/* boolean an interrupt has happened */	ulong	agegen;		/* incremented for age in buffers */	int	volume;		/* volume set */	int	c4cmd;		/* various modes, ie mute */	char	place[20];	Buf	buf[Nbuf];} audio; /* * send a command to the * monitor sub-system. * SoundOutEnable is left on. */static	voidmonxmit(int cmd, long data){ 	/*	 * this routine suffers from usual	 * NEXT copious documentation.	 * 1.	other (which?) MONCMD bits/modes	 *	are not preserved across call.	 * 2.	the delays are arbitrary.	 * 3.	the use of bit9 and bit31 are	 *	mystical.	 */	MONCMD = (1<<9) | cmd;	delay(1);	MONDAT = data;	delay(1);	MONCMD = (1<<31)|(1<<9);} /* * get a word from the write argument * and return the number of bytes consumed. */static	intgetcmd(char *a, long n){	char *p, *ep;	int m, c; 	p = audio.place;	ep = p + sizeof(audio.place) - 1;	m = 0;	while(m < n) {		c = *a++;		m++;		if(c == ' ' || c == '\n')			continue;		*p++ = c;		break;	}	while(m < n) {		c = *a++;		m++;		if(c == ' ' || c == '\n')			break;		if(p < ep)			*p++ = c;	}	*p = 0;	return m;} /* * find the oldest buffer of * a certain type. this should * probably be done in link lists, * but there arent too many buffers * and locking is a pain. */static	Buf*getbuf(int state){	Buf *b, *p, *eb; 	b = &audio.buf[0];	eb = b + Nbuf;	while(b < eb) {		if(b->state == state) {			if(state != Sfull)				return b;			p = b;			for(b++; b<eb; b++)				if(b->state == state)					if(b->age < p->age)						p = b;			return p;		}		b++;	}	return 0;} /* * if audio is stopped, * start it up again. */static	voidpokeaudio(void){	Buf *b1, *b2; 	if(audio.active == 0) {		/*		 * precaution, return active buffers		 */		while(b1 = getbuf(Scurrent))			b1->state = Sfull;		while(b1 = getbuf(Schained))			b1->state = Sfull; 		/*		 * start up audio with the		 * two oldest full buffers.		 * if there is not two,		 * dont start.		 */		b1 = getbuf(Sfull);		if(b1 == 0)			return;		b1->state = Scurrent; 		b2 = getbuf(Sfull);		if(b2 == 0) {			b1->state = Sfull;			return;		}		b2->state = Schained; 		audio.active = 1;		CSR = 0;		CSR = Outcreset|Outinitbuff;		DMA1L = b1->phys+Bufsize;		DMA1B = b1->phys;		DMA2L = b2->phys+Bufsize;		DMA2B = b2->phys;		CSR = Outsetenable|Outsetchain;	}} voidaudiodmaintr(void){	long csr;	Buf *b; 	csr = CSR;	audio.intr = 1; 	b = getbuf(Scurrent);	if(b)		b->state = Sempty;	b = getbuf(Schained); 	/*	 * we took the last interrupt	 * without a chain.	 * just shut down.	 */	if((csr & Outenable) == 0) {		if(b)			b->state = Sfull;		CSR = Outcreset | Outclrcint;		audio.active = 0;		wakeup(&audio.vous);		return;	} 	/*	 * we have another full buffer,	 * chain it on the end.	 */	if(b)		b->state = Scurrent;	b = getbuf(Sfull);	if(b) {		b->state = Schained;		DMA2L = b->phys+Bufsize;		DMA2B = b->phys;		CSR = Outsetchain | Outclrcint;		wakeup(&audio.vous);		return;	} 	/*	 * there is no full buffer,	 * just clear the interrupt	 * and let the last buffer go out	 */	CSR = Outclrcint;	wakeup(&audio.vous);} static intanybuf(void *p){	USED(p);	return audio.intr;} /* * wait for some output to get * empty buffers back. */static voidwaitaudio(void){ 	audio.intr = 0;	pokeaudio();	tsleep(&audio.vous, anybuf, 0, 10*1000);	if(audio.intr == 0) {		print("audio timeout\n");		audio.active = 0;		pokeaudio();	}} static voidbufinit(void){	int i;	ulong l, p;	Buf *b; 	b = &audio.buf[0];	for(i=0; i<Nbuf; i++,b++) {		p = (ulong)xspanalloc(Bufsize, BY2PG, 0);		b->virt = (uchar*)kmappa(p);		b->phys = (ulong)p;		for(l = BY2PG; l < Bufsize; l += BY2PG)			kmappa(p+l);	}} voidaudioreset(void){} voidaudioinit(void){} Chan*audioattach(char *param){	return devattach('h', param);} Chan*audioclone(Chan *c, Chan *nc){	return devclone(c, nc);} intaudiowalk(Chan *c, char *name){	return devwalk(c, name, audiodir, NPORT, devgen);} voidaudiostat(Chan *c, char *db){	devstat(c, db, audiodir, NPORT, devgen);} Chan*audioopen(Chan *c, int omode){	int i;	Buf *b; 	switch(c->qid.path & ~CHDIR) {	default:		error(Eperm);		break; 	case Qdir:	case Qvolume:		break; 	case Qaudio:		if(audio.open)			error(Einuse); 		if(audio.bufinit == 0) {			/* sound out enable, analog out enable */			monxmit(0x0f, 0);			bufinit();			audio.bufinit = 1;		}		b = &audio.buf[0];		for(i=0; i<Nbuf; i++,b++) {			b->state = Sempty;			b->age = i;		}		audio.agegen = Nbuf;		audio.curcount = 0;		audio.open = 1;		break;	}	c = devopen(c, omode, audiodir, NPORT, devgen);	c->mode = openmode(omode);	c->flag |= COPEN;	c->offset = 0; 	return c;} voidaudiocreate(Chan *c, char *name, int omode, ulong perm){	USED(c);	USED(name);	USED(omode);	USED(perm); 	error(Eperm);} voidaudioclose(Chan *c){ 	switch(c->qid.path & ~CHDIR) {	default:		error(Eperm);		break; 	case Qdir:	case Qvolume:		break; 	case Qaudio:		while(audio.active)			waitaudio();		CSR = 0;		CSR = Outcreset|Outinitbuff;		audio.open = 0;		break;	}} longaudioread(Chan *c, char *a, long n, ulong offset){ 	USED(offset); 	switch(c->qid.path & ~CHDIR) {	default:		error(Eperm);		break; 	case Qdir:		return devdirread(c, a, n, audiodir, NPORT, devgen); 	case Qaudio:	case Qvolume:		break;	}	return 0;} longaudiowrite(Chan *c, char *a, long n, ulong offset){	long m, bytes;	Buf *b; 	USED(offset); 	bytes = 0;	switch(c->qid.path & ~CHDIR) {	default:		error(Eperm);		break; 	case Qvolume:		for(;;) {			m = getcmd(a, n);			if(m <= 0)				break;			a += m;			bytes += m;			n -= m; 			/*			 * a number is volume			 */			if(audio.place[0] >= '0' && audio.place[0] <= '9') {				m = strtoul(audio.place, 0, 10);				audio.volume = m;	/* goes up to 11! */				m *= 3;				if(m < 0)					m = 0;				if(m > 31)					m = 31;				monxmit(0xc2, (0xdf-m)<<24);				continue;			} 			/*			 * c4 command operands			 *	[|un][mute|dec]			 */			if(strcmp(audio.place, "mute") == 0) {				audio.c4cmd |= (1<<4);				goto doc4;			}			if(strcmp(audio.place, "unmute") == 0) {				audio.c4cmd &= ~(1<<4);				goto doc4;			}			if(strcmp(audio.place, "dec") == 0) {				audio.c4cmd |= (1<<3);				goto doc4;			}			if(strcmp(audio.place, "undec") == 0) {				audio.c4cmd &= ~(1<<3);			doc4:				monxmit(0xc4, audio.c4cmd<<24);				continue;			}

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