/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2019 Axiado Corporation.
 * All rights reserved.
 *
 * This software was developed in part by Philip Paeps under contract for
 * Axiado Corporation.
 *
 * 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rman.h>

#include <dev/clk/clk.h>

#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>

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

#include "iicbus_if.h"
#include "iicoc.h"

static struct ofw_compat_data compat_data[] = {
        { "opencores,i2c-ocores",       1 },
        { "sifive,fu740-c000-i2c",      1 },
        { "sifive,fu540-c000-i2c",      1 },
        { "sifive,i2c0",                1 },
        { NULL,                         0 }
};

static struct resource_spec iicoc_spec[] = {
        { SYS_RES_MEMORY, 0, RF_ACTIVE },
        RESOURCE_SPEC_END
};

static phandle_t
iicoc_get_node(device_t bus, device_t dev)
{

        /* Share controller node with iicbus device. */
        return (ofw_bus_get_node(bus));
}

static int
iicoc_attach(device_t dev)
{
        struct iicoc_softc *sc;
        phandle_t node;
        clk_t clock;
        uint64_t clockfreq;
        int error;

        sc = device_get_softc(dev);
        sc->dev = dev;

        mtx_init(&sc->sc_mtx, "iicoc", "iicoc", MTX_DEF);

        error = bus_alloc_resources(dev, iicoc_spec, &sc->mem_res);
        if (error) {
                device_printf(dev, "Could not allocate bus resource.\n");
                goto fail;
        }

        node = ofw_bus_get_node(dev);
        sc->reg_shift = 0;
        OF_getencprop(node, "reg-shift", &sc->reg_shift,
            sizeof(sc->reg_shift));

        error = clk_get_by_ofw_index(dev, 0, 0, &clock);
        if (error) {
                device_printf(dev, "Couldn't get clock\n");
                goto fail;
        }
        error = clk_enable(clock);
        if (error) {
                device_printf(dev, "Couldn't enable clock\n");
                goto fail1;
        }
        error = clk_get_freq(clock, &clockfreq);
        if (error) {
                device_printf(dev, "Couldn't get clock frequency\n");
                goto fail1;
        }
        if (clockfreq > UINT_MAX) {
                device_printf(dev, "Unsupported clock frequency\n");
                goto fail1;
        }
        sc->clockfreq = (u_int)clockfreq;
        sc->i2cfreq = XLP_I2C_FREQ;
        iicoc_init(dev);

        sc->iicbus = device_add_child(dev, "iicbus", DEVICE_UNIT_ANY);
        if (sc->iicbus == NULL) {
                device_printf(dev, "Could not allocate iicbus instance.\n");
                error = ENXIO;
                goto fail1;
        }

        /* Probe and attach the iicbus when interrupts are available. */
        bus_delayed_attach_children(dev);

        return (0);

fail1:
        clk_disable(clock);

fail:
        bus_release_resources(dev, iicoc_spec, &sc->mem_res);
        mtx_destroy(&sc->sc_mtx);
        return (error);
}

static int
iicoc_probe(device_t dev)
{

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

        if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
                return (ENXIO);

        device_set_desc(dev, "OpenCores I2C master controller");

        return (BUS_PROBE_DEFAULT);
}

static device_method_t iicoc_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe, iicoc_probe),
        DEVMETHOD(device_attach, iicoc_attach),

        /* ofw interface */
        DEVMETHOD(ofw_bus_get_node, iicoc_get_node),

        /* iicbus interface */
        DEVMETHOD(iicbus_callback, iicbus_null_callback),
        DEVMETHOD(iicbus_repeated_start, iicoc_iicbus_repeated_start),
        DEVMETHOD(iicbus_start, iicoc_iicbus_start),
        DEVMETHOD(iicbus_stop, iicoc_iicbus_stop),
        DEVMETHOD(iicbus_reset, iicoc_iicbus_reset),
        DEVMETHOD(iicbus_write, iicoc_iicbus_write),
        DEVMETHOD(iicbus_read, iicoc_iicbus_read),
        DEVMETHOD(iicbus_transfer, iicbus_transfer_gen),

        DEVMETHOD_END
};

static driver_t iicoc_driver = {
        "iicoc",
        iicoc_methods,
        sizeof(struct iicoc_softc),
};

SIMPLEBUS_PNP_INFO(compat_data);
DRIVER_MODULE(iicoc, simplebus, iicoc_driver, 0, 0);
DRIVER_MODULE(ofw_iicbus, iicoc, ofw_iicbus_driver, 0, 0);
MODULE_DEPEND(iicoc, iicbus, 1, 1, 1);
MODULE_DEPEND(iicoc, ofw_iicbus, 1, 1, 1);