/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
 * 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.
 */

/*
 * Vybrid Family Direct Memory Access Multiplexer (DMAMUX)
 * Chapter 22, Vybrid Reference Manual, Rev. 5, 07/2013
 */

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

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

#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>

#include <arm/freescale/vybrid/vf_common.h>
#include <arm/freescale/vybrid/vf_dmamux.h>

#define DMAMUX_CHCFG(n)         (0x1 * n)       /* Channels 0-15 Cfg Reg */
#define CHCFG_ENBL              (1 << 7)        /* Channel Enable */
#define CHCFG_TRIG              (1 << 6)        /* Channel Trigger Enable */
#define CHCFG_SOURCE_MASK       0x3f            /* Channel Source (Slot) */
#define CHCFG_SOURCE_SHIFT      0

struct dmamux_softc {
        struct resource         *res[4];
        bus_space_tag_t         bst[4];
        bus_space_handle_t      bsh[4];
};

struct dmamux_softc *dmamux_sc;

static struct resource_spec dmamux_spec[] = {
        { SYS_RES_MEMORY,       0,      RF_ACTIVE }, /* DMAMUX0 */
        { SYS_RES_MEMORY,       1,      RF_ACTIVE }, /* DMAMUX1 */
        { SYS_RES_MEMORY,       2,      RF_ACTIVE }, /* DMAMUX2 */
        { SYS_RES_MEMORY,       3,      RF_ACTIVE }, /* DMAMUX3 */
        { -1, 0 }
};

static int
dmamux_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (!ofw_bus_is_compatible(dev, "fsl,mvf600-dmamux"))
                return (ENXIO);

        device_set_desc(dev, "Vybrid Family Direct Memory Access Multiplexer");
        return (BUS_PROBE_DEFAULT);
}

int
dmamux_configure(int mux, int source, int channel, int enable)
{
        struct dmamux_softc *sc;
        int reg;

        sc = dmamux_sc;

        MUX_WRITE1(sc, mux, DMAMUX_CHCFG(channel), 0x0);

        reg = 0;
        if (enable)
                reg |= (CHCFG_ENBL);

        reg &= ~(CHCFG_SOURCE_MASK << CHCFG_SOURCE_SHIFT);
        reg |= (source << CHCFG_SOURCE_SHIFT);

        MUX_WRITE1(sc, mux, DMAMUX_CHCFG(channel), reg);

        return (0);
}

static int
dmamux_attach(device_t dev)
{
        struct dmamux_softc *sc;
        int i;

        sc = device_get_softc(dev);

        if (bus_alloc_resources(dev, dmamux_spec, sc->res)) {
                device_printf(dev, "could not allocate resources\n");
                return (ENXIO);
        }

        /* Memory interface */
        for (i = 0; i < 4; i++) {
                sc->bst[i] = rman_get_bustag(sc->res[i]);
                sc->bsh[i] = rman_get_bushandle(sc->res[i]);
        }

        dmamux_sc = sc;

        return (0);
}

static device_method_t dmamux_methods[] = {
        DEVMETHOD(device_probe,         dmamux_probe),
        DEVMETHOD(device_attach,        dmamux_attach),
        { 0, 0 }
};

static driver_t dmamux_driver = {
        "dmamux",
        dmamux_methods,
        sizeof(struct dmamux_softc),
};

DRIVER_MODULE(dmamux, simplebus, dmamux_driver, 0, 0);