/*	$OpenBSD: agp_via.c,v 1.10 2008/11/09 22:47:54 oga Exp $	*/
/*	$NetBSD: agp_via.c,v 1.2 2001/09/15 00:25:00 thorpej Exp $	*/

/*-
 * Copyright (c) 2000 Doug Rabson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	$FreeBSD: src/sys/pci/agp_via.c,v 1.3 2001/07/05 21:28:47 jhb Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/agpio.h>

#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcidevs.h>
#include <dev/pci/vga_pcivar.h>
#include <dev/pci/agpvar.h>
#include <dev/pci/agpreg.h>

#include <machine/bus.h>

void	agp_via_attach(struct device *, struct device *, void *);
int	agp_via_probe(struct device *, void *, void *);
bus_size_t agp_via_get_aperture(void *);
int	agp_via_set_aperture(void *, bus_size_t);
int	agp_via_bind_page(void *, off_t, bus_addr_t);
int	agp_via_unbind_page(void *, off_t);
void	agp_via_flush_tlb(void *);

const struct agp_methods agp_via_methods = {
	agp_via_get_aperture,
	agp_via_bind_page,
	agp_via_unbind_page,
	agp_via_flush_tlb,
};

struct agp_via_softc {
	struct device		 dev;
	struct agp_softc	*agpdev;
	struct agp_gatt		*gatt;
	int			*regs;
	pci_chipset_tag_t	 vsc_pc;
	pcitag_t		 vsc_tag;
	bus_size_t		 initial_aperture;
};

struct cfattach viaagp_ca = {
        sizeof(struct agp_via_softc), agp_via_probe, agp_via_attach
};

struct cfdriver viaagp_cd = {
	NULL, "viaagp", DV_DULL
};

#define REG_GARTCTRL	0
#define REG_APSIZE	1
#define REG_ATTBASE	2

int via_v2_regs[] =
	{ AGP_VIA_GARTCTRL, AGP_VIA_APSIZE, AGP_VIA_ATTBASE };
int via_v3_regs[] =
	{ AGP3_VIA_GARTCTRL, AGP3_VIA_APSIZE, AGP3_VIA_ATTBASE };

int
agp_via_probe(struct device *parent, void *match, void *aux)
{
	struct agp_attach_args	*aa = aux;
	struct pci_attach_args	*pa = aa->aa_pa;

	/* Must be a pchb don't attach to iommu-style agp devs */
	if (agpbus_probe(aa) == 1 &&
	    PCI_VENDOR(pa->pa_id) == PCI_VENDOR_VIATECH &&
	    PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_VIATECH_K8M800_0 &&
	    PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_VIATECH_K8T890_0 &&
	    PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_VIATECH_K8HTB_0 &&
	    PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_VIATECH_K8HTB)
		return (1);
	return (0);
}

void
agp_via_attach(struct device *parent, struct device *self, void *aux)
{
	struct agp_via_softc	*asc = (struct agp_via_softc *)self;
	struct agp_attach_args	*aa = aux;
	struct pci_attach_args	*pa = aa->aa_pa;
	struct agp_gatt		*gatt;
	pcireg_t		 agpsel, capval;

	asc->vsc_pc = pa->pa_pc;
	asc->vsc_tag = pa->pa_tag;
	pci_get_capability(pa->pa_pc, pa->pa_tag, PCI_CAP_AGP, NULL, &capval);

	if (AGP_CAPID_GET_MAJOR(capval) >= 3) {
		agpsel = pci_conf_read(pa->pa_pc, pa->pa_tag, AGP_VIA_AGPSEL);
		if ((agpsel & (1 << 1)) == 0) {
			asc->regs = via_v3_regs;
			printf("v3, ");
		} else {
			asc->regs = via_v2_regs;
			printf("v2 compat mode, ");
		}
	} else {
		asc->regs = via_v2_regs;
		printf("v2, ");
	}


	asc->initial_aperture = agp_via_get_aperture(asc);

	for (;;) {
		bus_size_t size = agp_via_get_aperture(asc);
		gatt = agp_alloc_gatt(pa->pa_dmat, size);
		if (gatt != NULL)
			break;

		/*
		 * Probably failed to alloc congigious memory. Try reducing the
		 * aperture so that the gatt size reduces.
		 */
		if (agp_via_set_aperture(asc, size / 2)) {
			printf("can't set aperture size\n");
			return;
		}
	}
	asc->gatt = gatt;

	if (asc->regs == via_v2_regs) {
		/* Install the gatt. */
		pci_conf_write(pa->pa_pc, pa->pa_tag, asc->regs[REG_ATTBASE],
		    gatt->ag_physical | 3);
		/* Enable the aperture. */
		pci_conf_write(pa->pa_pc, pa->pa_tag, asc->regs[REG_GARTCTRL],
		    0x0000000f);
	} else {
		pcireg_t gartctrl;
		/* Install the gatt. */
		pci_conf_write(pa->pa_pc, pa->pa_tag, asc->regs[REG_ATTBASE],
		    gatt->ag_physical);
		/* Enable the aperture. */
		gartctrl = pci_conf_read(pa->pa_pc, pa->pa_tag,
		    asc->regs[REG_ATTBASE]);
		pci_conf_write(pa->pa_pc, pa->pa_tag, asc->regs[REG_GARTCTRL],
		    gartctrl | (3 << 7));
	}
	asc->agpdev = (struct agp_softc *)agp_attach_bus(pa, &agp_via_methods,
	    AGP_APBASE, PCI_MAPREG_TYPE_MEM, &asc->dev);

	return;
}

#if 0
int
agp_via_detach(struct agp_softc *sc)
{
	struct agp_via_softc *asc = sc->sc_chipc;
	int error;

	error = agp_generic_detach(sc);
	if (error)
		return (error);

	pci_conf_write(sc->as_pc, sc->as_tag, asc->regs[REG_GARTCTRL], 0);
	pci_conf_write(sc->as_pc, sc->as_tag, asc->regs[REG_ATTBASE], 0);
	AGP_SET_APERTURE(sc, asc->initial_aperture);
	agp_free_gatt(sc, asc->gatt);

	return (0);
}
#endif

bus_size_t
agp_via_get_aperture(void *sc)
{
	struct agp_via_softc	*vsc = sc;
	bus_size_t		 apsize;

	apsize = pci_conf_read(vsc->vsc_pc, vsc->vsc_tag, 
	    vsc->regs[REG_APSIZE]) & 0x1f;

	/*
	 * The size is determined by the number of low bits of
	 * register APBASE which are forced to zero. The low 20 bits
	 * are always forced to zero and each zero bit in the apsize
	 * field just read forces the corresponding bit in the 27:20
	 * to be zero. We calculate the aperture size accordingly.
	 */
	return ((((apsize ^ 0xff) << 20) | ((1 << 20) - 1)) + 1);
}

int
agp_via_set_aperture(void *sc, bus_size_t aperture)
{
	struct agp_via_softc	*vsc = sc;
	bus_size_t		 apsize;
	pcireg_t		 reg;

	/*
	 * Reverse the magic from get_aperture.
	 */
	apsize = ((aperture - 1) >> 20) ^ 0xff;

	/*
	 * Double check for sanity.
	 */
	if ((((apsize ^ 0xff) << 20) | ((1 << 20) - 1)) + 1 != aperture)
		return (EINVAL);

	reg = pci_conf_read(vsc->vsc_pc, vsc->vsc_tag, vsc->regs[REG_APSIZE]);
	reg &= ~0xff;
	reg |= apsize;
	pci_conf_write(vsc->vsc_pc, vsc->vsc_tag, vsc->regs[REG_APSIZE], reg);

	return (0);
}

int
agp_via_bind_page(void *sc, off_t offset, bus_addr_t physical)
{
	struct agp_via_softc *vsc = sc;

	if (offset < 0 || offset >= (vsc->gatt->ag_entries << AGP_PAGE_SHIFT))
		return (EINVAL);

	vsc->gatt->ag_virtual[offset >> AGP_PAGE_SHIFT] = physical;
	return (0);
}

int
agp_via_unbind_page(void *sc, off_t offset)
{
	struct agp_via_softc *vsc = sc;

	if (offset < 0 || offset >= (vsc->gatt->ag_entries << AGP_PAGE_SHIFT))
		return (EINVAL);

	vsc->gatt->ag_virtual[offset >> AGP_PAGE_SHIFT] = 0;
	return (0);
}

void
agp_via_flush_tlb(void *sc)
{
	struct agp_via_softc *vsc = sc;
	pcireg_t gartctrl;

	if (vsc->regs == via_v2_regs) {
		pci_conf_write(vsc->vsc_pc, vsc->vsc_tag,
		    vsc->regs[REG_GARTCTRL], 0x8f);
		pci_conf_write(vsc->vsc_pc, vsc->vsc_tag,
		    vsc->regs[REG_GARTCTRL], 0x0f);
	} else {
		gartctrl = pci_conf_read(vsc->vsc_pc, vsc->vsc_tag,
		    vsc->regs[REG_GARTCTRL]);
		pci_conf_write(vsc->vsc_pc, vsc->vsc_tag,
		    vsc->regs[REG_GARTCTRL], gartctrl & ~(1 << 7));
		pci_conf_write(vsc->vsc_pc, vsc->vsc_tag,
		    vsc->regs[REG_GARTCTRL], gartctrl);
	}
}