/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
 * Copyright (c) 2013 The FreeBSD Foundation
 * All rights reserved.
 *
 * Portions of this software were developed by Oleksandr Rybalko
 * under sponsorship from the FreeBSD Foundation.
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/libkern.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>

#include <dev/fdt/fdt_common.h>
#include <dev/spibus/spi.h>
#include <dev/spibus/spibusvar.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/openfirm.h>

#include "spibus_if.h"

struct ofw_spibus_devinfo {
        struct spibus_ivar      opd_dinfo;
        struct ofw_bus_devinfo  opd_obdinfo;
};

/* Methods */
static device_probe_t ofw_spibus_probe;
static device_attach_t ofw_spibus_attach;
static device_t ofw_spibus_add_child(device_t dev, u_int order,
    const char *name, int unit);
static const struct ofw_bus_devinfo *ofw_spibus_get_devinfo(device_t bus,
    device_t dev);

static int
ofw_spibus_probe(device_t dev)
{

        if (ofw_bus_get_node(dev) == -1)
                return (ENXIO);
        device_set_desc(dev, "OFW SPI bus");

        return (BUS_PROBE_DEFAULT + 1);
}

static int
ofw_spibus_attach(device_t dev)
{
        struct spibus_softc *sc = device_get_softc(dev);
        struct ofw_spibus_devinfo *dinfo;
        phandle_t child;
        pcell_t clock, paddr;
        device_t childdev;
        uint32_t mode = SPIBUS_MODE_NONE;

        sc->dev = dev;

        bus_identify_children(dev);
        bus_enumerate_hinted_children(dev);

        /*
         * Attach those children represented in the device tree.
         */
        for (child = OF_child(ofw_bus_get_node(dev)); child != 0;
            child = OF_peer(child)) {
                /*
                 * Try to get the CS number first from the spi-chipselect
                 * property, then try the reg property.
                 */
                if (OF_getencprop(child, "spi-chipselect", &paddr,
                    sizeof(paddr)) == -1) {
                        if (OF_getencprop(child, "reg", &paddr,
                            sizeof(paddr)) == -1)
                                continue;
                }

                /*
                 * Try to get the cpol/cpha mode
                 */
                if (OF_hasprop(child, "spi-cpol"))
                        mode = SPIBUS_MODE_CPOL;
                if (OF_hasprop(child, "spi-cpha")) {
                        if (mode == SPIBUS_MODE_CPOL)
                                mode = SPIBUS_MODE_CPOL_CPHA;
                        else
                                mode = SPIBUS_MODE_CPHA;
                }

                /*
                 * Try to get the CS polarity
                 */
                if (OF_hasprop(child, "spi-cs-high"))
                        paddr |= SPIBUS_CS_HIGH;

                /*
                 * Get the maximum clock frequency for device, zero means
                 * use the default bus speed.
                 *
                 * XXX Note that the current (2018-04-07) dts bindings say that
                 * spi-max-frequency is a required property (but says nothing of
                 * how to interpret a value of zero).
                 */
                if (OF_getencprop(child, "spi-max-frequency", &clock,
                    sizeof(clock)) == -1)
                        clock = 0;

                /*
                 * Now set up the SPI and OFW bus layer devinfo and add it
                 * to the bus.
                 */
                dinfo = malloc(sizeof(struct ofw_spibus_devinfo), M_DEVBUF,
                    M_NOWAIT | M_ZERO);
                if (dinfo == NULL)
                        continue;
                dinfo->opd_dinfo.cs = paddr;
                dinfo->opd_dinfo.clock = clock;
                dinfo->opd_dinfo.mode = mode;
                if (ofw_bus_gen_setup_devinfo(&dinfo->opd_obdinfo, child) !=
                    0) {
                        free(dinfo, M_DEVBUF);
                        continue;
                }
                childdev = device_add_child(dev, NULL, DEVICE_UNIT_ANY);

                resource_list_init(&dinfo->opd_dinfo.rl);
                ofw_bus_intr_to_rl(childdev, child,
                    &dinfo->opd_dinfo.rl, NULL);
                device_set_ivars(childdev, dinfo);
        }

        bus_attach_children(dev);
        return (0);
}

static device_t
ofw_spibus_add_child(device_t dev, u_int order, const char *name, int unit)
{
        device_t child;
        struct ofw_spibus_devinfo *devi;

        child = device_add_child_ordered(dev, order, name, unit);
        if (child == NULL)
                return (child);
        devi = malloc(sizeof(struct ofw_spibus_devinfo), M_DEVBUF,
            M_NOWAIT | M_ZERO);
        if (devi == NULL) {
                device_delete_child(dev, child);
                return (0);
        }

        /*
         * NULL all the OFW-related parts of the ivars for non-OFW
         * children.
         */
        devi->opd_obdinfo.obd_node = -1;
        devi->opd_obdinfo.obd_name = NULL;
        devi->opd_obdinfo.obd_compat = NULL;
        devi->opd_obdinfo.obd_type = NULL;
        devi->opd_obdinfo.obd_model = NULL;

        device_set_ivars(child, devi);

        return (child);
}

static void
ofw_spibus_child_deleted(device_t dev, device_t child)
{
        free(device_get_ivars(child), M_DEVBUF);
}

static const struct ofw_bus_devinfo *
ofw_spibus_get_devinfo(device_t bus, device_t dev)
{
        struct ofw_spibus_devinfo *dinfo;

        dinfo = device_get_ivars(dev);
        return (&dinfo->opd_obdinfo);
}

static struct resource_list *
ofw_spibus_get_resource_list(device_t bus __unused, device_t child)
{
        struct spibus_ivar *devi;
        
        devi = SPIBUS_IVAR(child);
        return (&devi->rl);
}

static device_method_t ofw_spibus_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ofw_spibus_probe),
        DEVMETHOD(device_attach,        ofw_spibus_attach),

        /* Bus interface */
        DEVMETHOD(bus_child_pnpinfo,    ofw_bus_gen_child_pnpinfo),
        DEVMETHOD(bus_add_child,        ofw_spibus_add_child),
        DEVMETHOD(bus_child_deleted,    ofw_spibus_child_deleted),
        DEVMETHOD(bus_get_resource_list, ofw_spibus_get_resource_list),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_get_devinfo,  ofw_spibus_get_devinfo),
        DEVMETHOD(ofw_bus_get_compat,   ofw_bus_gen_get_compat),
        DEVMETHOD(ofw_bus_get_model,    ofw_bus_gen_get_model),
        DEVMETHOD(ofw_bus_get_name,     ofw_bus_gen_get_name),
        DEVMETHOD(ofw_bus_get_node,     ofw_bus_gen_get_node),
        DEVMETHOD(ofw_bus_get_type,     ofw_bus_gen_get_type),

        DEVMETHOD_END
};

DEFINE_CLASS_1(spibus, ofw_spibus_driver, ofw_spibus_methods,
    sizeof(struct spibus_softc), spibus_driver);
DRIVER_MODULE(ofw_spibus, spi, ofw_spibus_driver, 0, 0);
MODULE_VERSION(ofw_spibus, 1);
MODULE_DEPEND(ofw_spibus, spibus, 1, 1, 1);