/*-
 * 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_bus.h"
#include "opt_agp.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>

#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <pci/agppriv.h>
#include <pci/agpreg.h>

#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/pmap.h>

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

struct agp_via_softc {
	struct agp_softc agp;
	u_int32_t	initial_aperture; /* aperture size at startup */
	struct agp_gatt *gatt;
	int		*regs;
};

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

static const char*
agp_via_match(device_t dev)
{
	if (pci_get_class(dev) != PCIC_BRIDGE
	    || pci_get_subclass(dev) != PCIS_BRIDGE_HOST)
		return NULL;

	if (agp_find_caps(dev) == 0)
		return NULL;

	switch (pci_get_devid(dev)) {
	case 0x03051106:
		return ("VIA 82C8363 (Apollo KT133A) host to PCI bridge");
	case 0x05011106:
		return ("VIA 8501 (Apollo MVP4) host to PCI bridge");
	case 0x05971106:
		return ("VIA 82C597 (Apollo VP3) host to PCI bridge");
	case 0x05981106:
		return ("VIA 82C598 (Apollo MVP3) host to PCI bridge");
	case 0x06051106:
		return ("VIA 82C694X (Apollo Pro 133A) host to PCI bridge");
	case 0x06911106:
		return ("VIA 82C691 (Apollo Pro) host to PCI bridge");
	case 0x31881106:
#if defined(__amd64__) || defined(AGP_AMD64_GART)
		return NULL;
#else
		return ("VIA 8385 host to PCI bridge");
#endif
	case 0x31891106:
		return ("VIA 8377 (Apollo KT400/KT400A/KT600) host to PCI bridge");
	};

	if (pci_get_vendor(dev) == 0x1106)
		return ("VIA Generic host to PCI bridge");

	return NULL;
}

static int
agp_via_probe(device_t dev)
{
	const char *desc;

	if (resource_disabled("agp", device_get_unit(dev)))
		return (ENXIO);
	desc = agp_via_match(dev);
	if (desc) {
		device_verbose(dev);
		device_set_desc(dev, desc);
		return 0;
	}

	return ENXIO;
}

static int
agp_via_attach(device_t dev)
{
	struct agp_via_softc *sc = device_get_softc(dev);
	struct agp_gatt *gatt;
	int error;
	u_int32_t agpsel;

	switch (pci_get_devid(dev)) {
#ifdef AGP_NO_AMD64_GART
	case 0x31881106:
#endif
	case 0x31891106:
		/* The newer VIA chipsets will select the AGP version based on
		 * what AGP versions the card supports.  We still have to
		 * program it using the v2 registers if it has chosen to use
		 * compatibility mode.
		 */
		agpsel = pci_read_config(dev, AGP_VIA_AGPSEL, 1);
		if ((agpsel & (1 << 1)) == 0)
			sc->regs = via_v3_regs;
		else
			sc->regs = via_v2_regs;
		break;
	default:
		sc->regs = via_v2_regs;
		break;
	}
	
	error = agp_generic_attach(dev);
	if (error)
		return error;

	sc->initial_aperture = AGP_GET_APERTURE(dev);

	for (;;) {
		gatt = agp_alloc_gatt(dev);
		if (gatt)
			break;

		/*
		 * Probably contigmalloc failure. Try reducing the
		 * aperture so that the gatt size reduces.
		 */
		if (AGP_SET_APERTURE(dev, AGP_GET_APERTURE(dev) / 2)) {
			agp_generic_detach(dev);
			return ENOMEM;
		}
	}
	sc->gatt = gatt;

	/* Install the gatt. */
	pci_write_config(dev, sc->regs[REG_ATTBASE], gatt->ag_physical | 3, 4);
	
	/* Enable the aperture. */
	pci_write_config(dev, sc->regs[REG_GARTCTRL], 0x0f, 4);

	return 0;
}

static int
agp_via_detach(device_t dev)
{
	struct agp_via_softc *sc = device_get_softc(dev);
	int error;

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

	pci_write_config(dev, sc->regs[REG_GARTCTRL], 0, 4);
	pci_write_config(dev, sc->regs[REG_ATTBASE], 0, 4);
	AGP_SET_APERTURE(dev, sc->initial_aperture);
	agp_free_gatt(sc->gatt);

	return 0;
}

static u_int32_t
agp_via_get_aperture(device_t dev)
{
	struct agp_via_softc *sc = device_get_softc(dev);
	u_int32_t apsize;

	apsize = pci_read_config(dev, sc->regs[REG_APSIZE], 1) & 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;
}

static int
agp_via_set_aperture(device_t dev, u_int32_t aperture)
{
	struct agp_via_softc *sc = device_get_softc(dev);
	u_int32_t apsize;

	/*
	 * 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;

	pci_write_config(dev, sc->regs[REG_APSIZE], apsize, 1);

	return 0;
}

static int
agp_via_bind_page(device_t dev, int offset, vm_offset_t physical)
{
	struct agp_via_softc *sc = device_get_softc(dev);

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

	sc->gatt->ag_virtual[offset >> AGP_PAGE_SHIFT] = physical;
	return 0;
}

static int
agp_via_unbind_page(device_t dev, int offset)
{
	struct agp_via_softc *sc = device_get_softc(dev);

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

	sc->gatt->ag_virtual[offset >> AGP_PAGE_SHIFT] = 0;
	return 0;
}

static void
agp_via_flush_tlb(device_t dev)
{
	struct agp_via_softc *sc = device_get_softc(dev);

	pci_write_config(dev, sc->regs[REG_GARTCTRL], 0x8f, 4);
	pci_write_config(dev, sc->regs[REG_GARTCTRL], 0x0f, 4);
}

static device_method_t agp_via_methods[] = {
	/* Device interface */
	DEVMETHOD(device_probe,		agp_via_probe),
	DEVMETHOD(device_attach,	agp_via_attach),
	DEVMETHOD(device_detach,	agp_via_detach),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
	DEVMETHOD(device_suspend,	bus_generic_suspend),
	DEVMETHOD(device_resume,	bus_generic_resume),

	/* AGP interface */
	DEVMETHOD(agp_get_aperture,	agp_via_get_aperture),
	DEVMETHOD(agp_set_aperture,	agp_via_set_aperture),
	DEVMETHOD(agp_bind_page,	agp_via_bind_page),
	DEVMETHOD(agp_unbind_page,	agp_via_unbind_page),
	DEVMETHOD(agp_flush_tlb,	agp_via_flush_tlb),
	DEVMETHOD(agp_enable,		agp_generic_enable),
	DEVMETHOD(agp_alloc_memory,	agp_generic_alloc_memory),
	DEVMETHOD(agp_free_memory,	agp_generic_free_memory),
	DEVMETHOD(agp_bind_memory,	agp_generic_bind_memory),
	DEVMETHOD(agp_unbind_memory,	agp_generic_unbind_memory),

	{ 0, 0 }
};

static driver_t agp_via_driver = {
	"agp",
	agp_via_methods,
	sizeof(struct agp_via_softc),
};

static devclass_t agp_devclass;

DRIVER_MODULE(agp_via, pci, agp_via_driver, agp_devclass, 0, 0);
MODULE_DEPEND(agp_via, agp, 1, 1, 1);
MODULE_DEPEND(agp_via, pci, 1, 1, 1);