/*-
 * Copyright 1998 Massachusetts Institute of Technology
 * Copyright 2001 by Thomas Moestl <tmm@FreeBSD.org>.
 * Copyright 2006 by Marius Strobl <marius@FreeBSD.org>.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. 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.
 *
 *      from: FreeBSD: src/sys/i386/i386/nexus.c,v 1.43 2001/02/09
 */

/*
 * This code implements a `root nexus' for Power ISA Architecture
 * machines.  The function of the root nexus is to serve as an
 * attachment point for both processors and buses, and to manage
 * resources which are common to all of them.  In particular,
 * this code implements the core resource managers for interrupt
 * requests and I/O memory address space.
 */

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

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

#include <machine/bus.h>
#include <machine/endian.h>
#include <machine/intr_machdep.h>
#include <machine/resource.h>

#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/openfirm.h>

static struct rman intr_rman;
static struct rman mem_rman;

static device_probe_t           nexus_probe;
static device_attach_t          nexus_attach;

static bus_get_rman_t           nexus_get_rman;
static bus_map_resource_t       nexus_map_resource;
static bus_unmap_resource_t     nexus_unmap_resource;

#ifdef SMP
static bus_bind_intr_t          nexus_bind_intr;
#endif
static bus_config_intr_t        nexus_config_intr;
static bus_setup_intr_t         nexus_setup_intr;
static bus_teardown_intr_t      nexus_teardown_intr;

static bus_get_bus_tag_t        nexus_get_bus_tag;

static ofw_bus_map_intr_t       nexus_ofw_map_intr;

static device_method_t nexus_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         nexus_probe),
        DEVMETHOD(device_attach,        nexus_attach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),

        /* Bus interface */
        DEVMETHOD(bus_add_child,        bus_generic_add_child),
        DEVMETHOD(bus_adjust_resource,  bus_generic_rman_adjust_resource),
        DEVMETHOD(bus_activate_resource, bus_generic_rman_activate_resource),
        DEVMETHOD(bus_alloc_resource,   bus_generic_rman_alloc_resource),
        DEVMETHOD(bus_deactivate_resource, bus_generic_rman_deactivate_resource),
        DEVMETHOD(bus_get_rman,         nexus_get_rman),
        DEVMETHOD(bus_map_resource,     nexus_map_resource),
        DEVMETHOD(bus_release_resource, bus_generic_rman_release_resource),
        DEVMETHOD(bus_unmap_resource,   nexus_unmap_resource),
#ifdef SMP
        DEVMETHOD(bus_bind_intr,        nexus_bind_intr),
#endif
        DEVMETHOD(bus_config_intr,      nexus_config_intr),
        DEVMETHOD(bus_setup_intr,       nexus_setup_intr),
        DEVMETHOD(bus_teardown_intr,    nexus_teardown_intr),
        DEVMETHOD(bus_get_bus_tag,      nexus_get_bus_tag),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_map_intr,     nexus_ofw_map_intr),

        DEVMETHOD_END
};

DEFINE_CLASS_0(nexus, nexus_driver, nexus_methods, 1);
EARLY_DRIVER_MODULE(nexus, root, nexus_driver, 0, 0, BUS_PASS_BUS);
MODULE_VERSION(nexus, 1);

static int
nexus_probe(device_t dev)
{
        
        device_quiet(dev);      /* suppress attach message for neatness */

        return (BUS_PROBE_DEFAULT);
}

static int
nexus_attach(device_t dev)
{

        intr_rman.rm_type = RMAN_ARRAY;
        intr_rman.rm_descr = "Interrupts";
        mem_rman.rm_type = RMAN_ARRAY;
        mem_rman.rm_descr = "I/O memory addresses";
        if (rman_init(&intr_rman) != 0 || rman_init(&mem_rman) != 0 ||
            rman_manage_region(&intr_rman, 0, ~0) != 0 ||
            rman_manage_region(&mem_rman, 0, BUS_SPACE_MAXADDR) != 0)
                panic("%s: failed to set up rmans.", __func__);

        /* Add ofwbus0. */
        device_add_child(dev, "ofwbus", 0);

        /* Now, probe children. */
        bus_identify_children(dev);
        bus_attach_children(dev);

        return (0);
}

static int
nexus_setup_intr(device_t bus __unused, device_t child, struct resource *r,
    int flags, driver_filter_t *filt, driver_intr_t *intr, void *arg,
    void **cookiep)
{
        int error, domain;

        if (r == NULL)
                panic("%s: NULL interrupt resource!", __func__);

        if (cookiep != NULL)
                *cookiep = NULL;
        if ((rman_get_flags(r) & RF_SHAREABLE) == 0)
                flags |= INTR_EXCL;

        /* We depend here on rman_activate_resource() being idempotent. */
        error = rman_activate_resource(r);
        if (error)
                return (error);

        if (bus_get_domain(child, &domain) != 0) {
                if(bootverbose)
                        device_printf(child, "no domain found\n");
                domain = 0;
        }
        error = powerpc_setup_intr(device_get_nameunit(child),
            rman_get_start(r), filt, intr, arg, flags, cookiep, domain);

        return (error);
}

static int
nexus_teardown_intr(device_t bus __unused, device_t child __unused,
    struct resource *r, void *ih)
{
        
        if (r == NULL)
                return (EINVAL);

        return (powerpc_teardown_intr(ih));
}

static bus_space_tag_t
nexus_get_bus_tag(device_t bus __unused, device_t child __unused)
{

#if BYTE_ORDER == LITTLE_ENDIAN
        return(&bs_le_tag);
#else
        return(&bs_be_tag);
#endif
}

#ifdef SMP
static int
nexus_bind_intr(device_t bus __unused, device_t child __unused,
    struct resource *r, int cpu)
{

        return (powerpc_bind_intr(rman_get_start(r), cpu));
}
#endif

static int
nexus_config_intr(device_t dev, int irq, enum intr_trigger trig,
    enum intr_polarity pol)
{

        return (powerpc_config_intr(irq, trig, pol));
}

static int
nexus_ofw_map_intr(device_t dev, device_t child, phandle_t iparent, int icells,
    pcell_t *irq)
{
        u_int intr = MAP_IRQ(iparent, irq[0]);
        if (icells > 1)
                powerpc_fw_config_intr(intr, irq[1]);
        return (intr);
}

static struct rman *
nexus_get_rman(device_t bus, int type, u_int flags)
{
        switch (type) {
        case SYS_RES_IRQ:
                return (&intr_rman);
        case SYS_RES_MEMORY:
                return (&mem_rman);
        default:
                return (NULL);
        }
}

static int
nexus_map_resource(device_t bus, device_t child, struct resource *r,
    struct resource_map_request *argsp, struct resource_map *map)
{
        struct resource_map_request args;
        rman_res_t length, start;
        int error;

        /* Resources must be active to be mapped. */
        if (!(rman_get_flags(r) & RF_ACTIVE))
                return (ENXIO);

        /* Mappings are only supported on I/O and memory resources. */
        switch (rman_get_type(r)) {
        case SYS_RES_IOPORT:
        case SYS_RES_MEMORY:
                break;
        default:
                return (EINVAL);
        }

        resource_init_map_request(&args);
        error = resource_validate_map_request(r, argsp, &args, &start, &length);
        if (error)
                return (error);

        /*
         * If this is a memory resource, map it into the kernel.
         */
        switch (rman_get_type(r)) {
        case SYS_RES_IOPORT:
                panic("%s:%d SYS_RES_IOPORT handling not implemented", __func__, __LINE__);
                /*   XXX: untested
                map->r_bushandle = start;
                if ((rman_get_flags(r) & RF_LITTLEENDIAN) != 0)
                        map->r_bustag = &bs_le_tag;
                else
                        map->r_bustag = nexus_get_bus_tag(NULL, NULL);
                map->r_size = length;
                map->r_vaddr = NULL;
                */
                break;
        case SYS_RES_MEMORY:
                map->r_vaddr = pmap_mapdev_attr(start, length, args.memattr);
                if ((rman_get_flags(r) & RF_LITTLEENDIAN) != 0)
                        map->r_bustag = &bs_le_tag;
                else
                        map->r_bustag = &bs_be_tag;
                map->r_size = length;
                map->r_bushandle = (bus_space_handle_t)map->r_vaddr;
                break;
        }

        return (0);

}

static int
nexus_unmap_resource(device_t bus, device_t child, struct resource *r,
    struct resource_map *map)
{

        /*
         * If this is a memory resource, unmap it.
         */
        switch (rman_get_type(r)) {
        case SYS_RES_MEMORY:
                pmap_unmapdev(map->r_vaddr, map->r_size);
                /* FALLTHROUGH */
        case SYS_RES_IOPORT:
                break;
        default:
                return (EINVAL);
        }

        return (0);

}