/*-
 * Copyright (c) 2019 Emmanuel Vadot <manu@FreeBSD.org>
 *
 * Copyright (c) 2020 Oskar Holmlund <oskar.holmlund@ohdata.se>
 *
 * 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.
 */
/* Based on sys/arm/ti/ti_sysc.c */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/lock.h>
#include <sys/mutex.h>

#include <machine/bus.h>
#include <machine/resource.h>

#include <dev/fdt/simplebus.h>

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

#include "syscon_if.h"
#include <dev/syscon/syscon.h>
#include "clkdev_if.h"

#include <arm/ti/ti_cpuid.h>

#if 0
#define DPRINTF(dev, msg...) device_printf(dev, msg)
#else
#define DPRINTF(dev, msg...)
#endif

MALLOC_DECLARE(M_SYSCON);

struct ti_scm_syscon_softc {
        struct simplebus_softc  sc_simplebus;
        device_t                dev;
        struct syscon *         syscon;
        struct resource *       res[1];
        bus_space_tag_t         bst;
        bus_space_handle_t      bsh;
        struct mtx              mtx;
};

static struct resource_spec ti_scm_syscon_res_spec[] = {
        { SYS_RES_MEMORY, 0, RF_ACTIVE | RF_SHAREABLE },
        { -1, 0 }
};

/* Device */
static struct ofw_compat_data compat_data[] = {
        { "syscon",     1 },
        { NULL,         0 }
};

/* --- dev/extres/syscon syscon_method_t interface --- */
static int
ti_scm_syscon_write_4(struct syscon *syscon, bus_size_t offset, uint32_t val)
{
        struct ti_scm_syscon_softc *sc;

        sc = device_get_softc(syscon->pdev);
        DPRINTF(sc->dev, "offset=%lx write %x\n", offset, val);
        mtx_lock(&sc->mtx);
        bus_space_write_4(sc->bst, sc->bsh, offset, val);
        mtx_unlock(&sc->mtx);
        return (0);
}

static uint32_t
ti_scm_syscon_read_4(struct syscon *syscon, bus_size_t offset)
{
        struct ti_scm_syscon_softc *sc;
        uint32_t val;

        sc = device_get_softc(syscon->pdev);

        mtx_lock(&sc->mtx);
        val = bus_space_read_4(sc->bst, sc->bsh, offset);
        mtx_unlock(&sc->mtx);
        DPRINTF(sc->dev, "offset=%lx Read %x\n", offset, val);
        return (val);
}
static int
ti_scm_syscon_modify_4(struct syscon *syscon, bus_size_t offset, uint32_t clr, uint32_t set)
{
        struct ti_scm_syscon_softc *sc;
        uint32_t reg;

        sc = device_get_softc(syscon->pdev);

        mtx_lock(&sc->mtx);
        reg = bus_space_read_4(sc->bst, sc->bsh, offset);
        reg &= ~clr;
        reg |= set;
        bus_space_write_4(sc->bst, sc->bsh, offset, reg);
        mtx_unlock(&sc->mtx);
        DPRINTF(sc->dev, "offset=%lx reg: %x (clr %x set %x)\n", offset, reg, clr, set);

        return (0);
}

static syscon_method_t ti_scm_syscon_reg_methods[] = {
        SYSCONMETHOD(syscon_read_4,     ti_scm_syscon_read_4),
        SYSCONMETHOD(syscon_write_4,    ti_scm_syscon_write_4),
        SYSCONMETHOD(syscon_modify_4,   ti_scm_syscon_modify_4),

        SYSCONMETHOD_END
};

DEFINE_CLASS_1(ti_scm_syscon_reg, ti_scm_syscon_reg_class, ti_scm_syscon_reg_methods,
    0, syscon_class);

/* device interface */
static int
ti_scm_syscon_probe(device_t dev)
{
        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (!ti_soc_is_supported())
                return (ENXIO);

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

        device_set_desc(dev, "TI OMAP Control Module Syscon");
        return(BUS_PROBE_DEFAULT);
}

static int
ti_scm_syscon_attach(device_t dev)
{
        struct ti_scm_syscon_softc *sc;
        phandle_t node, child;

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

        if (bus_alloc_resources(dev, ti_scm_syscon_res_spec, sc->res)) {
                device_printf(sc->dev, "Cant allocate resources\n");
                return (ENXIO);
        }

        sc->dev = dev;
        sc->bst = rman_get_bustag(sc->res[0]);
        sc->bsh = rman_get_bushandle(sc->res[0]);

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

        /* dev/extres/syscon interface */
        sc->syscon = syscon_create_ofw_node(dev, &ti_scm_syscon_reg_class, node);
        if (sc->syscon == NULL) {
                device_printf(dev, "Failed to create/register syscon\n");
                return (ENXIO);
        }

        simplebus_init(sc->dev, node);

        bus_identify_children(sc->dev);
        for (child = OF_child(node); child != 0; child = OF_peer(child)) {
                simplebus_add_device(sc->dev, child, 0, NULL, -1, NULL);
        }

        bus_attach_children(sc->dev);
        return (0);
}

/* syscon interface */
static int
ti_scm_syscon_get_handle(device_t dev, struct syscon **syscon)
{
        struct ti_scm_syscon_softc *sc;

        sc = device_get_softc(dev);
        *syscon = sc->syscon;
        if (*syscon == NULL)
                return (ENODEV);
        return (0);
}

/* clkdev interface */
static int
ti_scm_syscon_clk_write_4(device_t dev, bus_addr_t addr, uint32_t val)
{
        struct ti_scm_syscon_softc *sc;

        sc = device_get_softc(dev);
        DPRINTF(sc->dev, "offset=%lx write %x\n", addr, val);
        bus_space_write_4(sc->bst, sc->bsh, addr, val);
        return (0);
}

static int
ti_scm_syscon_clk_read_4(device_t dev, bus_addr_t addr, uint32_t *val)
{
        struct ti_scm_syscon_softc *sc;

        sc = device_get_softc(dev);

        *val = bus_space_read_4(sc->bst, sc->bsh, addr);
        DPRINTF(sc->dev, "offset=%lx Read %x\n", addr, *val);
        return (0);
}

static int
ti_scm_syscon_clk_modify_4(device_t dev, bus_addr_t addr, uint32_t clr, uint32_t set)
{
        struct ti_scm_syscon_softc *sc;
        uint32_t reg;

        sc = device_get_softc(dev);

        reg = bus_space_read_4(sc->bst, sc->bsh, addr);
        reg &= ~clr;
        reg |= set;
        bus_space_write_4(sc->bst, sc->bsh, addr, reg);
        DPRINTF(sc->dev, "offset=%lx reg: %x (clr %x set %x)\n", addr, reg, clr, set);

        return (0);
}

static void
ti_scm_syscon_clk_device_lock(device_t dev)
{
        struct ti_scm_syscon_softc *sc;

        sc = device_get_softc(dev);
        mtx_lock(&sc->mtx);
}

static void
ti_scm_syscon_clk_device_unlock(device_t dev)
{
        struct ti_scm_syscon_softc *sc;
        sc = device_get_softc(dev);
        mtx_unlock(&sc->mtx);
}

static device_method_t ti_scm_syscon_methods[] = {
        DEVMETHOD(device_probe,         ti_scm_syscon_probe),
        DEVMETHOD(device_attach,        ti_scm_syscon_attach),

        /* syscon interface */
        DEVMETHOD(syscon_get_handle,    ti_scm_syscon_get_handle),

        /* clkdev interface */
        DEVMETHOD(clkdev_write_4,       ti_scm_syscon_clk_write_4),
        DEVMETHOD(clkdev_read_4,        ti_scm_syscon_clk_read_4),
        DEVMETHOD(clkdev_modify_4,      ti_scm_syscon_clk_modify_4),
        DEVMETHOD(clkdev_device_lock,   ti_scm_syscon_clk_device_lock),
        DEVMETHOD(clkdev_device_unlock, ti_scm_syscon_clk_device_unlock),

        DEVMETHOD_END
};

DEFINE_CLASS_1(ti_scm_syscon, ti_scm_syscon_driver, ti_scm_syscon_methods,
    sizeof(struct ti_scm_syscon_softc), simplebus_driver);

EARLY_DRIVER_MODULE(ti_scm_syscon, simplebus, ti_scm_syscon_driver, 0, 0,
    BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
MODULE_VERSION(ti_scm_syscon, 1);
MODULE_DEPEND(ti_scm_syscon, ti_scm, 1, 1, 1);