/*
 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
 * 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 unmodified, 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 ``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 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.
 *
 * $Id: pcibus.c,v 1.42 1999/05/18 20:48:43 peter Exp $
 *
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>

#include <pci/pcivar.h>
#include <pci/pcireg.h>
#include <i386/isa/pcibus.h>

#ifdef PCI_COMPAT
/* XXX this is a terrible hack, which keeps the Tekram AMD SCSI driver happy */
#define cfgmech pci_mechanism
int cfgmech;
#else
static int cfgmech;
#endif /* PCI_COMPAT */
static int devmax;

/* enable configuration space accesses and return data port address */

static int
pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
{
	int dataport = 0;

	if (bus <= PCI_BUSMAX
	    && slot < devmax
	    && func <= PCI_FUNCMAX
	    && reg <= PCI_REGMAX
	    && bytes != 3
	    && (unsigned) bytes <= 4
	    && (reg & (bytes -1)) == 0) {
		switch (cfgmech) {
		case 1:
			outl(CONF1_ADDR_PORT, (1 << 31)
			     | (bus << 16) | (slot << 11) 
			     | (func << 8) | (reg & ~0x03));
			dataport = CONF1_DATA_PORT + (reg & 0x03);
			break;
		case 2:
			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
			outb(CONF2_FORWARD_PORT, bus);
			dataport = 0xc000 | (slot << 8) | reg;
			break;
		}
	}
	return (dataport);
}

/* disable configuration space accesses */

static void
pci_cfgdisable(void)
{
	switch (cfgmech) {
	case 1:
		outl(CONF1_ADDR_PORT, 0);
		break;
	case 2:
		outb(CONF2_ENABLE_PORT, 0);
		outb(CONF2_FORWARD_PORT, 0);
		break;
	}
}

/* read configuration space register */

int
pci_cfgread(pcicfgregs *cfg, int reg, int bytes)
{
	int data = -1;
	int port;

	port = pci_cfgenable(cfg->bus, cfg->slot, cfg->func, reg, bytes);

	if (port != 0) {
		switch (bytes) {
		case 1:
			data = inb(port);
			break;
		case 2:
			data = inw(port);
			break;
		case 4:
			data = inl(port);
			break;
		}
		pci_cfgdisable();
	}
	return (data);
}

/* write configuration space register */

void
pci_cfgwrite(pcicfgregs *cfg, int reg, int data, int bytes)
{
	int port;

	port = pci_cfgenable(cfg->bus, cfg->slot, cfg->func, reg, bytes);
	if (port != 0) {
		switch (bytes) {
		case 1:
			outb(port, data);
			break;
		case 2:
			outw(port, data);
			break;
		case 4:
			outl(port, data);
			break;
		}
		pci_cfgdisable();
	}
}

/* check whether the configuration mechanism has been correct identified */

static int
pci_cfgcheck(int maxdev)
{
	u_char device;

	if (bootverbose) 
		printf("pci_cfgcheck:\tdevice ");

	for (device = 0; device < maxdev; device++) {
		unsigned id, class, header;
		if (bootverbose) 
			printf("%d ", device);

		id = inl(pci_cfgenable(0, device, 0, 0, 4));
		if (id == 0 || id == -1)
			continue;

		class = inl(pci_cfgenable(0, device, 0, 8, 4)) >> 8;
		if (bootverbose)
			printf("[class=%06x] ", class);
		if (class == 0 || (class & 0xf870ff) != 0)
			continue;

		header = inb(pci_cfgenable(0, device, 0, 14, 1));
		if (bootverbose) 
			printf("[hdr=%02x] ", header);
		if ((header & 0x7e) != 0)
			continue;

		if (bootverbose)
			printf("is there (id=%08x)\n", id);

		pci_cfgdisable();
		return (1);
	}
	if (bootverbose) 
		printf("-- nothing found\n");

	pci_cfgdisable();
	return (0);
}

static int
pci_cfgopen(void)
{
	unsigned long mode1res,oldval1;
	unsigned char mode2res,oldval2;

	oldval1 = inl(CONF1_ADDR_PORT);

	if (bootverbose) {
		printf("pci_open(1):\tmode 1 addr port (0x0cf8) is 0x%08lx\n",
		       oldval1);
	}

	if ((oldval1 & CONF1_ENABLE_MSK) == 0) {

		cfgmech = 1;
		devmax = 32;

		outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
		outb(CONF1_ADDR_PORT +3, 0);
		mode1res = inl(CONF1_ADDR_PORT);
		outl(CONF1_ADDR_PORT, oldval1);

		if (bootverbose)
			printf("pci_open(1a):\tmode1res=0x%08lx (0x%08lx)\n", 
			       mode1res, CONF1_ENABLE_CHK);

		if (mode1res) {
			if (pci_cfgcheck(32)) 
				return (cfgmech);
		}

		outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
		mode1res = inl(CONF1_ADDR_PORT);
		outl(CONF1_ADDR_PORT, oldval1);

		if (bootverbose)
			printf("pci_open(1b):\tmode1res=0x%08lx (0x%08lx)\n", 
			       mode1res, CONF1_ENABLE_CHK1);

		if ((mode1res & CONF1_ENABLE_MSK1) == CONF1_ENABLE_RES1) {
			if (pci_cfgcheck(32)) 
				return (cfgmech);
		}
	}

	oldval2 = inb(CONF2_ENABLE_PORT);

	if (bootverbose) {
		printf("pci_open(2):\tmode 2 enable port (0x0cf8) is 0x%02x\n",
		       oldval2);
	}

	if ((oldval2 & 0xf0) == 0) {

		cfgmech = 2;
		devmax = 16;

		outb(CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
		mode2res = inb(CONF2_ENABLE_PORT);
		outb(CONF2_ENABLE_PORT, oldval2);

		if (bootverbose)
			printf("pci_open(2a):\tmode2res=0x%02x (0x%02x)\n", 
			       mode2res, CONF2_ENABLE_CHK);

		if (mode2res == CONF2_ENABLE_RES) {
			if (bootverbose)
				printf("pci_open(2a):\tnow trying mechanism 2\n");

			if (pci_cfgcheck(16)) 
				return (cfgmech);
		}
	}

	cfgmech = 0;
	devmax = 0;
	return (cfgmech);
}

static devclass_t	pcib_devclass;

static const char *
nexus_pcib_is_host_bridge(pcicfgregs *cfg,
			  u_int32_t id, u_int8_t class, u_int8_t subclass,
			  u_int8_t *busnum)
{
	const char *s = "Host to PCI bridge";
	static u_int8_t pxb[4];	/* hack for 450nx */

	if (class != PCIC_BRIDGE || subclass != PCIS_BRIDGE_HOST)
		return NULL;

	*busnum = 0;

	switch (id) {
	case 0x12258086:
		s = "Intel 824?? host to PCI bridge";
		/* XXX This is a guess */
		*busnum = pci_cfgread(cfg, 0x41, 1);
		break;
	case 0x71808086:
		s = "Intel 82443LX (440 LX) host to PCI bridge";
		break;
	case 0x71908086:
		s = "Intel 82443BX (440 BX) host to PCI bridge";
		break;
	case 0x71928086:
		s = "Intel 82443BX host to PCI bridge (AGP disabled)";
		break;
	case 0x71a08086:
		s = "Intel 82443GX host to PCI bridge";
		break;
	case 0x71a18086:
		s = "Intel 82443GX host to AGP bridge";
		break;
	case 0x71a28086:
		s = "Intel 82443GX host to PCI bridge (AGP disabled)";
		break;
	case 0x84c48086:
		s = "Intel 82454KX/GX (Orion) host to PCI bridge";
		*busnum = pci_cfgread(cfg, 0x4a, 1);
		break;
	case 0x84ca8086:
		/*
		 * For the 450nx chipset, there is a whole bundle of
		 * things pretending to be host bridges. The MIOC will 
		 * be seen first and isn't really a pci bridge (the
		 * actual busses are attached to the PXB's). We need to 
		 * read the registers of the MIOC to figure out the
		 * bus numbers for the PXB channels.
		 *
		 * Since the MIOC doesn't have a pci bus attached, we
		 * pretend it wasn't there.
		 */
		pxb[0] = pci_cfgread(cfg, 0xd0, 1); /* BUSNO[0] */
		pxb[1] = pci_cfgread(cfg, 0xd1, 1) + 1;	/* SUBA[0]+1 */
		pxb[2] = pci_cfgread(cfg, 0xd3, 1); /* BUSNO[1] */
		pxb[3] = pci_cfgread(cfg, 0xd4, 1) + 1;	/* SUBA[1]+1 */
		return NULL;
	case 0x84cb8086:
		switch (cfg->slot) {
		case 0x12:
			s = "Intel 82454NX PXB#0, Bus#A";
			*busnum = pxb[0];
			break;
		case 0x13:
			s = "Intel 82454NX PXB#0, Bus#B";
			*busnum = pxb[1];
			break;
		case 0x14:
			s = "Intel 82454NX PXB#1, Bus#A";
			*busnum = pxb[2];
			break;
		case 0x15:
			s = "Intel 82454NX PXB#1, Bus#B";
			*busnum = pxb[3];
			break;
		}
		break;

		/* SiS -- vendor 0x1039 */
	case 0x04961039:
		s = "SiS 85c496";
		break;
	case 0x04061039:
		s = "SiS 85c501";
		break;
	case 0x06011039:
		s = "SiS 85c601";
		break;
	case 0x55911039:
		s = "SiS 5591 host to PCI bridge";
		break;
	case 0x00011039:
		s = "SiS 5591 host to AGP bridge";
		break;
	
		/* VLSI -- vendor 0x1004 */
	case 0x00051004:
		s = "VLSI 82C592 Host to PCI bridge";
		break;

		/* XXX Here is MVP3, I got the datasheet but NO M/B to test it  */
		/* totally. Please let me know if anything wrong.            -F */
		/* XXX need info on the MVP3 -- any takers? */
	case 0x05981106:
		s = "VIA 82C598MVP (Apollo MVP3) host bridge";
		break;

		/* AcerLabs -- vendor 0x10b9 */
		/* Funny : The datasheet told me vendor id is "10b8",sub-vendor */
		/* id is '10b9" but the register always shows "10b9". -Foxfair  */
	case 0x154110b9:
		s = "AcerLabs M1541 (Aladdin-V) PCI host bridge";
		break;

		/* OPTi -- vendor 0x1045 */
	case 0xc8221045:
		s = "OPTi 82C822 host to PCI Bridge";
		break;

	/* Ross (?) -- vendor 0x1166 */
	case 0x00051166:
		s = "Ross (?) host to PCI bridge";
		/* just guessing the secondary bus register number ... */
		*busnum = pci_cfgread(cfg, 0x45, 1);
		break;
	}

	return s;
}

/*
 * Scan the first pci bus for host-pci bridges and add pcib instances
 * to the nexus for each bridge.
 */
static void
nexus_pcib_identify(driver_t *driver, device_t parent)
{
	pcicfgregs probe;

	probe.hose = 0;
	probe.bus = 0;

	pci_cfgopen();
	for (probe.slot = 0; probe.slot <= PCI_SLOTMAX; probe.slot++) {
		int pcifunchigh = 0;
		for (probe.func = 0;
		     probe.func <= pcifunchigh;
		     probe.func++) {
			/*
			 * Read the IDs and class from the device.
			 */
			u_int32_t id;
			u_int8_t class, subclass, busnum;
			device_t child;
			const char *s;

			id = pci_cfgread(&probe, PCIR_DEVVENDOR, 4);
			if (id == -1)
				continue;
			class = pci_cfgread(&probe, PCIR_CLASS, 1);
			subclass = pci_cfgread(&probe, PCIR_SUBCLASS, 1);

			s = nexus_pcib_is_host_bridge(&probe, id,
						      class, subclass,
						      &busnum);
			if (s) {
				child = BUS_ADD_CHILD(parent, 0,
						      "pcib", busnum);
				device_set_desc(child, s);
			}
		}
	}
	
}

static int
nexus_pcib_probe(device_t dev)
{
	if (pci_cfgopen() != 0) {
		device_add_child(dev, "pci", device_get_unit(dev), 0);
		return 0;
	}
	return ENXIO;
}

static device_method_t nexus_pcib_methods[] = {
	/* Device interface */
	DEVMETHOD(device_identify,	nexus_pcib_identify),
	DEVMETHOD(device_probe,		nexus_pcib_probe),
	DEVMETHOD(device_attach,	bus_generic_attach),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
	DEVMETHOD(device_suspend,	bus_generic_suspend),
	DEVMETHOD(device_resume,	bus_generic_resume),

	/* Bus interface */
	DEVMETHOD(bus_print_child,	bus_generic_print_child),
	DEVMETHOD(bus_alloc_resource,	bus_generic_alloc_resource),
	DEVMETHOD(bus_release_resource,	bus_generic_release_resource),
	DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
	DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),

	{ 0, 0 }
};

static driver_t nexus_pcib_driver = {
	"pcib",
	nexus_pcib_methods,
	1,
};

DRIVER_MODULE(pcib, nexus, nexus_pcib_driver, pcib_devclass, 0, 0);