/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2022 Semihalf.
 *
 * 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 ``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/systm.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>

#include <machine/bus.h>

#include <dev/fdt/simplebus.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/clk/clk.h>
#include <dev/clk/clk_gate.h>

#include "clkdev_if.h"

#define ARMADA38X_GATECLK_MAXREG 0

static struct resource_spec armada38x_gateclk_specs[] = {
        { SYS_RES_MEMORY,       0,      RF_ACTIVE },
        { -1, 0 }
};

#define RD4(_sc, addr)          bus_read_4(_sc->res, addr)
#define WR4(_sc, addr, val)     bus_write_4(_sc->res, addr, val)

struct armada38x_gateclk_softc
{
        struct resource *res;
        struct clkdom   *clkdom;
        struct mtx      mtx;
        const char*     parent;
};

static struct clk_gate_def gateclk_nodes[] =
{
        {
                .clkdef = {
                        .name = "gateclk-audio",
                        .id = 0,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 0,
        },
        {
                .clkdef = {
                        .name = "gateclk-eth2",
                        .id = 2,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 2,
        },
        {
                .clkdef = {
                        .name = "gateclk-eth1",
                        .id = 3,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 3,
        },
        {
                .clkdef = {
                        .name = "gateclk-eth0",
                        .id = 4,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 4,
        },
        {
                .clkdef = {
                        .name = "gateclk-mdio",
                        .id = 4,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 4,
        },
        {
                .clkdef = {
                        .name = "gateclk-usb3h0",
                        .id = 9,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 9,
        },
        {
                .clkdef = {
                        .name = "gateclk-usb3h1",
                        .id = 10,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 10,
        },
        {
                .clkdef = {
                        .name = "gateclk-bm",
                        .id = 13,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 13,
        },
        {
                .clkdef = {
                        .name = "gateclk-crypto0z",
                        .id = 14,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 14,
        },
        {
                .clkdef = {
                        .name = "gateclk-sata0",
                        .id = 15,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 15,
        },
        {
                .clkdef = {
                        .name = "gateclk-crypto1z",
                        .id = 16,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 16,
        },
        {
                .clkdef = {
                        .name = "gateclk-sdio",
                        .id = 17,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 17,
        },
        {
                .clkdef = {
                        .name = "gateclk-usb2",
                        .id = 18,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 18,
        },
        {
                .clkdef = {
                        .name = "gateclk-crypto1",
                        .id = 21,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 21,
        },
        {
                .clkdef = {
                        .name = "gateclk-xor0",
                        .id = 22,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 22,
        },
        {
                .clkdef = {
                        .name = "gateclk-crypto0",
                        .id = 23,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 23,
        },
        {
                .clkdef = {
                        .name = "gateclk-xor1",
                        .id = 28,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 28,
        },
        {
                .clkdef = {
                        .name = "gateclk-sata1",
                        .id = 30,
                        .parent_cnt = 1,
                        .flags = 0,
                },
                .shift = 30,
        }
};

static int armada38x_gateclk_probe(device_t dev);
static int armada38x_gateclk_attach(device_t dev);

static int
armada38x_gateclk_write_4(device_t dev, bus_addr_t addr, uint32_t val)
{
        struct armada38x_gateclk_softc *sc = device_get_softc(dev);

        if (addr > ARMADA38X_GATECLK_MAXREG)
                return (EINVAL);

        WR4(sc, addr, val);
        return (0);
}

static int
armada38x_gateclk_read_4(device_t dev, bus_addr_t addr, uint32_t *val)
{
        struct armada38x_gateclk_softc *sc = device_get_softc(dev);

        if (addr > ARMADA38X_GATECLK_MAXREG)
                return (EINVAL);

        *val = RD4(sc, addr);
        return (0);
}

static int
armada38x_gateclk_modify_4(device_t dev, bus_addr_t addr, uint32_t clr,
    uint32_t set)
{
        struct armada38x_gateclk_softc *sc = device_get_softc(dev);
        uint32_t reg;

        if (addr > ARMADA38X_GATECLK_MAXREG)
                return (EINVAL);

        reg = RD4(sc, addr);
        reg &= ~clr;
        reg |= set;
        WR4(sc, addr, reg);

        return (0);
}

static void
armada38x_gateclk_device_lock(device_t dev)
{
        struct armada38x_gateclk_softc *sc = device_get_softc(dev);

        mtx_lock(&sc->mtx);
}

static void
armada38x_gateclk_device_unlock(device_t dev)
{
        struct armada38x_gateclk_softc *sc = device_get_softc(dev);

        mtx_unlock(&sc->mtx);
}

static device_method_t armada38x_gateclk_methods[] = {
        DEVMETHOD(device_probe,         armada38x_gateclk_probe),
        DEVMETHOD(device_attach,        armada38x_gateclk_attach),

        /* clkdev interface */
        DEVMETHOD(clkdev_write_4,       armada38x_gateclk_write_4),
        DEVMETHOD(clkdev_read_4,        armada38x_gateclk_read_4),
        DEVMETHOD(clkdev_modify_4,      armada38x_gateclk_modify_4),
        DEVMETHOD(clkdev_device_lock,   armada38x_gateclk_device_lock),
        DEVMETHOD(clkdev_device_unlock, armada38x_gateclk_device_unlock),

        DEVMETHOD_END
};

static driver_t armada38x_gateclk_driver = {
        "armada38x_gateclk",
        armada38x_gateclk_methods,
        sizeof(struct armada38x_gateclk_softc),
};

EARLY_DRIVER_MODULE(armada38x_gateclk, simplebus, armada38x_gateclk_driver, 0, 0,
        BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE + 1);

static int
armada38x_gateclk_probe(device_t dev)
{

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

        if(!ofw_bus_is_compatible(dev, "marvell,armada-380-gating-clock"))
                return (ENXIO);

        device_set_desc(dev, "ARMADA38X gateclk");

        return (BUS_PROBE_DEFAULT);
}

static int
armada38x_gateclk_attach(device_t dev)
{
        struct armada38x_gateclk_softc *sc;
        struct clk_gate_def *defp;
        phandle_t node;
        int i, error;
        clk_t clock;

        sc = device_get_softc(dev);
        node = ofw_bus_get_node(dev);

        if (bus_alloc_resources(dev, armada38x_gateclk_specs, &sc->res) != 0) {
                device_printf(dev, "Cannot allocate resources.\n");
                return (ENXIO);
        }

        mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);

        sc->clkdom = clkdom_create(dev);
        if (sc->clkdom == NULL) {
                device_printf(dev, "Cannot create clock domain.\n");
                return (ENXIO);
        }

        error = clk_get_by_ofw_index(dev, node, 0, &clock);
        if (error > 0)
                return (error);

        sc->parent = clk_get_name(clock);

        for (i = 0; i < nitems(gateclk_nodes); ++i) {
                /* Fill clk_gate fields. */
                defp = &gateclk_nodes[i];
                defp->clkdef.parent_names = &sc->parent;
                defp->offset = 0;
                defp->mask = 0x1;
                defp->on_value = 1;
                defp->off_value = 0;

                error = clknode_gate_register(sc->clkdom, defp);
                if (error != 0) {
                        device_printf(dev, "Cannot create gate nodes\n");
                        return (error);
                }
        }

        if (clkdom_finit(sc->clkdom) != 0)
                panic("Cannot finalize clock domain initialization.\n");

        return (0);
}