/* $NetBSD: syscon.c,v 1.5 2021/01/27 03:10:21 thorpej Exp $ */

/*-
 * Copyright (c) 2018 Jared McNeill <jmcneill@invisible.ca>
 * 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 ``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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: syscon.c,v 1.5 2021/01/27 03:10:21 thorpej Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/kmem.h>
#include <sys/gpio.h>

#include <dev/fdt/fdtvar.h>
#include <dev/fdt/syscon.h>

struct syscon_softc {
        device_t                sc_dev;
        bus_space_tag_t         sc_bst;
        bus_space_handle_t      sc_bsh;
        kmutex_t                sc_lock;

        struct syscon           sc_syscon;
};

static int      syscon_match(device_t, cfdata_t, void *);
static void     syscon_attach(device_t, device_t, void *);

static const struct device_compatible_entry compat_data[] = {
        { .compat = "syscon" },
        { .compat = "simple-mfd" },
        DEVICE_COMPAT_EOL
};

CFATTACH_DECL_NEW(syscon, sizeof(struct syscon_softc),
        syscon_match, syscon_attach, NULL, NULL);

static void
syscon_generic_lock(void *priv)
{
        struct syscon_softc * const sc = priv;

        mutex_enter(&sc->sc_lock);
}

static void
syscon_generic_unlock(void *priv)
{
        struct syscon_softc * const sc = priv;

        mutex_exit(&sc->sc_lock);
}

static uint32_t
syscon_generic_read_4(void *priv, bus_size_t reg)
{
        struct syscon_softc * const sc = priv;

        KASSERT(mutex_owned(&sc->sc_lock));

        return bus_space_read_4(sc->sc_bst, sc->sc_bsh, reg);
}

static void
syscon_generic_write_4(void *priv, bus_size_t reg, uint32_t val)
{
        struct syscon_softc * const sc = priv;

        KASSERT(mutex_owned(&sc->sc_lock));

        bus_space_write_4(sc->sc_bst, sc->sc_bsh, reg, val);
}

static int
syscon_match(device_t parent, cfdata_t cf, void *aux)
{
        struct fdt_attach_args * const faa = aux;

        return of_compatible_match(faa->faa_phandle, compat_data);
}

static void
syscon_attach(device_t parent, device_t self, void *aux)
{
        struct syscon_softc * const sc = device_private(self);
        struct fdt_attach_args * const faa = aux;
        const int phandle = faa->faa_phandle;
        bus_addr_t addr;
        bus_size_t size;
        int child;

        if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
                aprint_error(": couldn't get registers\n");
                return;
        }

        sc->sc_dev = self;
        sc->sc_bst = faa->faa_bst;
        if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
                aprint_error(": couldn't map registers\n");
                return;
        }
        mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
        sc->sc_syscon.priv = sc;
        sc->sc_syscon.lock = syscon_generic_lock;
        sc->sc_syscon.unlock = syscon_generic_unlock;
        sc->sc_syscon.read_4 = syscon_generic_read_4;
        sc->sc_syscon.write_4 = syscon_generic_write_4;

        aprint_naive("\n");
        aprint_normal(": System Controller Registers\n");

        fdtbus_register_syscon(self, phandle, &sc->sc_syscon);

        fdt_add_bus(self, phandle, faa);

        child = of_find_firstchild_byname(phandle, "clocks");
        if (child > 0)
                fdt_add_bus(self, child, faa);
}