/*      $NetBSD: ofw_pci_subr.c,v 1.3 2022/01/22 11:49:18 thorpej Exp $ */

/*-
* Copyright (c) 2021 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__KERNEL_RCSID(0, "$NetBSD: ofw_pci_subr.c,v 1.3 2022/01/22 11:49:18 thorpej Exp $");

#include <sys/types.h>
#include <sys/device.h>
#include <sys/endian.h>
#include <sys/errno.h>

#include <dev/pci/pcivar.h>
#include <dev/pci/pci_calls.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_pci.h>

static int
ofw_pci_bus_get_child_devhandle(device_t dev, devhandle_t call_handle, void *v)
{
       struct pci_bus_get_child_devhandle_args *args = v;
       int phandle = devhandle_to_of(call_handle);
       struct ofw_pci_register opr;
       int d, f, len;
       uint32_t phys_hi;

       /*
        * No need to compare the bus number; we are searching
        * only direct children of the specified node.  Skipping
        * the bus number comparison allows us to dodge a slight
        * difference between the OpenFirmware and FDT PCI bindings
        * as it relates to PCI-PCI bridges.
        */

       pci_decompose_tag(args->pc, args->tag, NULL, &d, &f);

       for (phandle = OF_child(phandle); phandle != 0;
            phandle = OF_peer(phandle)) {
               len = OF_getprop(phandle, "reg", &opr, sizeof(opr));
               if (len < sizeof(opr)) {
                       continue;
               }

               phys_hi = be32toh(opr.phys_hi);

               if (d != OFW_PCI_PHYS_HI_DEVICE(phys_hi) ||
                   f != OFW_PCI_PHYS_HI_FUNCTION(phys_hi)) {
                       continue;
               }

               /* Found it! */
               args->devhandle = devhandle_from_of(call_handle, phandle);
               return 0;
       }

       return ENODEV;
}
OF_DEVICE_CALL_REGISTER(PCI_BUS_GET_CHILD_DEVHANDLE_STR,
                       ofw_pci_bus_get_child_devhandle)