/*	$NetBSD: isadma.c,v 1.12 2011/03/06 14:58:43 tsutsui Exp $	*/
/*	$OpenBSD: isadma.c,v 1.2 1996/11/23 21:45:34 kstailey Exp $	*/
/*	NetBSD: isadma.c,v 1.19 1996/04/29 20:03:26 christos Exp 	*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: isadma.c,v 1.12 2011/03/06 14:58:43 tsutsui Exp $");

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

#include <uvm/uvm_extern.h>

#include <machine/pio.h>

#include <dev/isa/isareg.h>
#include <dev/isa/isavar.h>
#include <dev/isa/isadmavar.h>
#include <arch/arc/isa/isadmareg.h> /*XXX*/

struct dma_info {
	int flags;
	int active;
	void *addr;
	bus_size_t nbytes;
	struct isadma_seg phys[1];
};

static struct isadma_softc *isadma_sc;	/*XXX ugly */
static struct dma_info dma_info[8];
static uint8_t dma_finished;

/* high byte of address is stored in this port for i-th dma channel */
static int dmapageport[2][4] = {
	{0x87, 0x83, 0x81, 0x82},
	{0x8f, 0x8b, 0x89, 0x8a}
};

static uint8_t dmamode[4] = {
	DMA37MD_READ | DMA37MD_SINGLE,
	DMA37MD_WRITE | DMA37MD_SINGLE,
	DMA37MD_READ | DMA37MD_LOOP,
	DMA37MD_WRITE | DMA37MD_LOOP
};

static int isadmamatch(device_t, cfdata_t, void *);
static void isadmaattach(device_t, device_t, void *);

struct isadma_softc {
	device_t sc_dev;
	bus_space_tag_t sc_iot;
	bus_space_handle_t sc_ioh1;
	bus_space_handle_t sc_ioh2;
}

CFATTACH_DECL_NEW(isadma, sizeof(struct isadma_softc),
    isadmamatch, isadmaattach, NULL, NULL);

struct cfdriver isadma_cd = {
	NULL, "isadma", DV_DULL, 1
};

static int
isadmamatch(device_t parent, cfdata_t cf, void *aux)
{
	struct isa_attach_args *ia = aux;

	/* Sure we exist */
	ia->ia_iosize = 0;
	return 1;
}

static void
isadmaattach(device_t parent, device_t self, void *aux)
{
	struct isadma_softc *sc = device_private(self);
	struct isa_attach_args *ia = aux;
	bus_space_tag_t iot;
	bus_space_handle_t ioh;

	sc->sc_dev = self;

	aprint_normal("\n");

	iot = sc->sc_iot = ia->ia_iot;
	if (bus_space_map(iot, IO_DMA1, DMA_NREGS, 0, &ioh))
		panic("%s: couldn't map I/O ports", __func__);
	sc->sc_ioh1 = ioh;
	if (bus_space_map(iot, IO_DMA2, DMA_NREGS*2, 0, &ioh))
		panic("%s: couldn't map I/O ports", __func__);
	sc->sc_ioh2 = ioh;
	isadma_sc = sc;
}

/*
 * isadma_cascade(): program 8237 DMA controller channel to accept
 * external dma control by a board.
 */
void
isadma_cascade(int chan)
{
	struct isadma_softc *sc = isadma_sc;
	bus_space_tag_t iot = sc->sc_iot;

#ifdef ISADMA_DEBUG
	if (chan < 0 || chan > 7)
		panic("%s: impossible request", __func__);
#endif

	/* set dma channel mode, and set dma channel mode */
	if ((chan & 4) == 0) {
		bus_space_write_1(iot, sc->sc_ioh1, DMA1_MODE,
		    chan | DMA37MD_CASCADE);
		bus_space_write_1(iot, sc->sc_ioh1, DMA1_SMSK, chan);
	} else {
		chan &= 3;

		bus_space_write_1(iot, sc->sc_ioh2, DMA2_MODE,
		    chan | DMA37MD_CASCADE);
		bus_space_write_1(iot, sc->sc_ioh2, DMA2_SMSK, chan);
	}
}

/*
 * isadma_start(): program 8237 DMA controller channel, avoid page alignment
 * problems by using a bounce buffer.
 */
void
isadma_start(void *addr, bus_size_t nbytes, int chan, int flags)
{
	struct dma_info *di;
	int waport;
	int mflags;
	struct isadma_softc *sc = isadma_sc;
	bus_space_tag_t iot = sc->sc_iot;
	bus_space_handle_t ioh;

#ifdef ISADMA_DEBUG
	if (chan < 0 || chan > 7 ||
	    (((flags & DMAMODE_READ) != 0) + ((flags & DMAMODE_WRITE) != 0) +
	    ((flags & DMAMODE_LOOP) != 0) != 1) ||
	    ((chan & 4) ? (nbytes >= (1<<17) || nbytes & 1 || (u_int)addr & 1) :
	    (nbytes >= (1<<16))))
		panic("%s: impossible request", __func__);
#endif

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

	di->flags = flags;
	di->active = 1;
	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("%s: cannot map", __func__);

	/* XXX Will this do what we want with DMAMODE_LOOP?  */
	if ((flags & DMAMODE_READ) == 0)
		isadma_copytobuf(addr, nbytes, 1, di->phys);

	dma_finished &= ~(1 << chan);

	if ((chan & 4) == 0) {
		ioh = sc->sc_ioh1;
		/*
		 * Program one of DMA channels 0..3.  These are
		 * byte mode channels.
		 */
		/* set dma channel mode, and reset address ff */
		bus_space_write_1(iot, ioh, DMA1_MODE, chan | dmamode[flags]);
		bus_space_write_1(iot, ioh, DMA1_FFC, 0);

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

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

		/* unmask channel */
		bus_space_write_1(iot, ioh, DMA1_SMSK, chan | DMA37SM_CLEAR);
	} else {
		ioh = sc->sc_ioh2;
		/*
		 * Program one of DMA channels 4..7.  These are
		 * word mode channels.
		 */
		/* set dma channel mode, and reset address ff */
		bus_space_write_1(iot, ioh, DMA2_MODE,
		    (chan & 3) | dmamode[flags]);
		bus_space_write_1(iot, ioh, DMA2_FFC, 0);

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

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

		/* unmask channel */
		bus_space_write_1(iot, ioh, DMA2_SMSK,
		    (chan & 3) | DMA37SM_CLEAR);
	}
}

void
isadma_abort(int chan)
{
	struct dma_info *di;
	struct isadma_softc *sc = isadma_sc;
	bus_space_tag_t iot = sc->sc_iot;

#ifdef ISADMA_DEBUG
	if (chan < 0 || chan > 7)
		panic("%s: impossible request", __func__);
#endif

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

	/* mask channel */
	if ((chan & 4) == 0)
		bus_space_write_1(iot, sc->sc_ioh1, DMA1_SMSK,
		    DMA37SM_SET | chan);
	else
		bus_space_write_1(iot, sc->sc_ioh2, DMA2_SMSK,
		    DMA37SM_SET | (chan & 3));

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

int
isadma_finished(int chan)
{
	struct isadma_softc *sc = isadma_sc;
	bus_space_tag_t iot = sc->sc_iot;

#ifdef ISADMA_DEBUG
	if (chan < 0 || chan > 7)
		panic("%s: impossible request", __func__);
#endif

	/* check that the terminal count was reached */
	if ((chan & 4) == 0)
		dma_finished |=
		    bus_space_read_1(iot, sc->sc_ioh1, DMA1_SR) & 0x0f;
	else
		dma_finished |=
		    (bus_space_read_1(iot, sc->sc_ioh2, DMA2_SR) & 0x0f) << 4;

	return (dma_finished & (1 << chan)) != 0;
}

void
isadma_done(int chan)
{
	struct dma_info *di;
	u_char tc;
	struct isadma_softc *sc = isadma_sc;
	bus_space_tag_t iot = sc->sc_iot;

#ifdef DIAGNOSTIC
	if (chan < 0 || chan > 7)
		panic("%s: impossible request", __func__);
#endif

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

	/* check that the terminal count was reached */
	if ((chan & 4) == 0)
		tc = bus_space_read_1(iot, sc->sc_ioh1, DMA1_SR) & (1 << chan);
	else
		tc = bus_space_read_1(iot, sc->sc_ioh2, 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)
		bus_space_write_1(iot, sc->sc_ioh1, DMA1_SMSK,
		    DMA37SM_SET | chan);
	else
		bus_space_write_1(iot, sc->sc_ioh2, DMA2_SMSK,
		    DMA37SM_SET | (chan & 3));

	/* XXX Will this do what we want with DMAMODE_LOOP?  */
	if (di->flags & DMAMODE_READ)
		isadma_copyfrombuf(di->addr, di->nbytes, 1, di->phys);

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