/*	$NetBSD: isadma.c,v 1.12 1995/04/17 12:09:11 cgd Exp $	*/

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/file.h>
#include <sys/buf.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/uio.h>

#include <vm/vm.h>

#include <machine/pio.h>

#include <dev/isa/isareg.h>
#include <dev/isa/isadmavar.h>
#include <dev/isa/isadmareg.h>

struct dma_info {
	int flags;
	caddr_t addr;
	vm_size_t nbytes;
	struct isadma_seg phys[1];
};

static struct dma_info dma_info[8];

/* high byte of address is stored in this port for i-th dma channel */
static int dmapageport[8] =
	{ 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };

/*
 * isadma_cascade(): program 8237 DMA controller channel to accept
 * external dma control by a board.
 */
void
isadma_cascade(chan)
	int chan;
{

#ifdef DIAGNOSTIC
	if (chan < 0 || chan > 7)
		panic("isadma_cascade: impossible request"); 
#endif

	/* set dma channel mode, and set dma channel mode */
	if ((chan & 4) == 0) {
		outb(DMA1_MODE, DMA37MD_CASCADE | chan);
		outb(DMA1_SMSK, chan);
	} else {
		outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
		outb(DMA2_SMSK, chan & 3);
	}
}

/*
 * isadma_start(): program 8237 DMA controller channel, avoid page alignment
 * problems by using a bounce buffer.
 */
void
isadma_start(addr, nbytes, chan, flags)
	caddr_t addr;
	vm_size_t nbytes;
	int chan;
	int flags;
{
	struct dma_info *di;
	int waport;
	int mflags;
	vm_size_t size;

#ifdef DIAGNOSTIC
	if (chan < 0 || chan > 7 ||
	    ((flags & ISADMA_START_READ) == 0) == ((flags & ISADMA_START_WRITE) == 0) ||
	    ((chan & 4) ? (nbytes >= (1<<17) || nbytes & 1 || (u_int)addr & 1) :
	    (nbytes >= (1<<16))))
		panic("isadma_start: impossible request"); 
#endif

	di = dma_info+chan;
	if (di->flags != 0) {
		log(LOG_ERR,"isadma_start: old request active on %d\n",chan);
		isadma_abort(chan);
	}

	di->flags = flags;
	di->addr = addr;
	di->nbytes = nbytes;

	mflags = ISADMA_MAP_WAITOK | ISADMA_MAP_BOUNCE | ISADMA_MAP_CONTIG;
	mflags |= (chan & 4) ? ISADMA_MAP_16BIT : ISADMA_MAP_8BIT;

	if (isadma_map(addr, nbytes, di->phys, mflags) != 1)
		panic("isadma_start: cannot map");

	if ((flags & ISADMA_START_READ) == 0)
		isadma_copytobuf(addr, nbytes, 1, di->phys);

	if ((chan & 4) == 0) {
		/*
		 * Program one of DMA channels 0..3.  These are
		 * byte mode channels.
		 */
		/* set dma channel mode, and reset address ff */
		if (flags & ISADMA_START_READ)
			outb(DMA1_MODE, chan | DMA37MD_SINGLE | DMA37MD_WRITE);
		else
			outb(DMA1_MODE, chan | DMA37MD_SINGLE | DMA37MD_READ);
		outb(DMA1_FFC, 0);

		/* send start address */
		waport =  DMA1_CHN(chan);
		outb(waport, di->phys[0].addr);
		outb(waport, di->phys[0].addr>>8);
		outb(dmapageport[chan], di->phys[0].addr>>16);

		/* send count */
		outb(waport + 1, --nbytes);
		outb(waport + 1, nbytes>>8);

		/* unmask channel */
		outb(DMA1_SMSK, chan | DMA37SM_CLEAR);
	} else {
		/*
		 * Program one of DMA channels 4..7.  These are
		 * word mode channels.
		 */
		/* set dma channel mode, and reset address ff */
		if (flags & ISADMA_START_READ)
			outb(DMA2_MODE, (chan & 3) | DMA37MD_SINGLE | DMA37MD_WRITE);
		else
			outb(DMA2_MODE, (chan & 3) | DMA37MD_SINGLE | DMA37MD_READ);
		outb(DMA2_FFC, 0);

		/* send start address */
		waport = DMA2_CHN(chan & 3);
		outb(waport, di->phys[0].addr>>1);
		outb(waport, di->phys[0].addr>>9);
		outb(dmapageport[chan], di->phys[0].addr>>16);

		/* send count */
		nbytes >>= 1;
		outb(waport + 2, --nbytes);
		outb(waport + 2, nbytes>>8);

		/* unmask channel */
		outb(DMA2_SMSK, (chan & 3) | DMA37SM_CLEAR);
	}
}

void
isadma_abort(chan)
	int chan;
{
	struct dma_info *di;

#ifdef DIAGNOSTIC
	if (chan < 0 || chan > 7)
		panic("isadma_abort: impossible request");
#endif

	di = dma_info+chan;
	if (di->flags == 0) {
		log(LOG_ERR,"isadma_abort: no request active on %d\n",chan);
		return;
	}

	/* mask channel */
	if ((chan & 4) == 0)
		outb(DMA1_SMSK, DMA37SM_SET | chan);
	else
		outb(DMA2_SMSK, DMA37SM_SET | (chan & 3));

	isadma_unmap(di->addr, di->nbytes, 1, di->phys);
	di->flags = 0;
}

void
isadma_done(chan)
	int chan;
{
	struct dma_info *di;
	u_char tc;

#ifdef DIAGNOSTIC
	if (chan < 0 || chan > 7)
		panic("isadma_done: impossible request");
#endif

	di = dma_info+chan;
	if (di->flags == 0) {
		log(LOG_ERR,"isadma_done: no request active on %d\n",chan);
		return;
	}

	/* check that the terminal count was reached */
	if ((chan & 4) == 0)
		tc = inb(DMA1_SR) & (1 << chan);
	else
		tc = inb(DMA2_SR) & (1 << (chan & 3));
	if (tc == 0)
		/* XXX probably should panic or something */
		log(LOG_ERR, "dma channel %d not finished\n", chan);

	/* mask channel */
	if ((chan & 4) == 0)
		outb(DMA1_SMSK, DMA37SM_SET | chan);
	else
		outb(DMA2_SMSK, DMA37SM_SET | (chan & 3));

	if (di->flags & ISADMA_START_READ)
		isadma_copyfrombuf(di->addr, di->nbytes, 1, di->phys);

	isadma_unmap(di->addr, di->nbytes, 1, di->phys);
	di->flags = 0;
}