/* $NetBSD: meson_clk.c,v 1.3 2019/04/19 19:07:56 jmcneill Exp $ */

/*-
 * Copyright (c) 2017-2019 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: meson_clk.c,v 1.3 2019/04/19 19:07:56 jmcneill Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>

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

#include <dev/clk/clk_backend.h>

#include <arm/amlogic/meson_clk.h>

static void *
meson_clk_reset_acquire(device_t dev, const void *data, size_t len)
{
        struct meson_clk_softc * const sc = device_private(dev);
        struct meson_clk_reset *reset;

        if (len != 4)
                return NULL;

        const u_int reset_id = be32dec(data);

        if (reset_id >= sc->sc_nresets)
                return NULL;

        reset = &sc->sc_resets[reset_id];
        if (reset->mask == 0)
                return NULL;

        return reset;
}

static void
meson_clk_reset_release(device_t dev, void *priv)
{
}

static int
meson_clk_reset_assert(device_t dev, void *priv)
{
        struct meson_clk_softc * const sc = device_private(dev);
        struct meson_clk_reset * const reset = priv;

        CLK_LOCK(sc);
        const uint32_t val = CLK_READ(sc, reset->reg);
        CLK_WRITE(sc, reset->reg, val | reset->mask);
        CLK_UNLOCK(sc);

        return 0;
}

static int
meson_clk_reset_deassert(device_t dev, void *priv)
{
        struct meson_clk_softc * const sc = device_private(dev);
        struct meson_clk_reset * const reset = priv;

        CLK_LOCK(sc);
        const uint32_t val = CLK_READ(sc, reset->reg);
        CLK_WRITE(sc, reset->reg, val & ~reset->mask);
        CLK_UNLOCK(sc);

        return 0;
}

static const struct fdtbus_reset_controller_func meson_clk_fdtreset_funcs = {
        .acquire = meson_clk_reset_acquire,
        .release = meson_clk_reset_release,
        .reset_assert = meson_clk_reset_assert,
        .reset_deassert = meson_clk_reset_deassert,
};

static struct clk *
meson_clk_clock_decode(device_t dev, int cc_phandle, const void *data,
                       size_t len)
{
        struct meson_clk_softc * const sc = device_private(dev);
        struct meson_clk_clk *clk;

        if (len != 4)
                return NULL;

        const u_int clock_id = be32dec(data);
        if (clock_id >= sc->sc_nclks)
                return NULL;

        clk = &sc->sc_clks[clock_id];
        if (clk->type == MESON_CLK_UNKNOWN)
                return NULL;

        return &clk->base;
}

static const struct fdtbus_clock_controller_func meson_clk_fdtclock_funcs = {
        .decode = meson_clk_clock_decode,
};

static struct clk *
meson_clk_clock_get(void *priv, const char *name)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk;

        clk = meson_clk_clock_find(sc, name);
        if (clk == NULL)
                return NULL;

        return &clk->base;
}

static void
meson_clk_clock_put(void *priv, struct clk *clk)
{
}

static u_int
meson_clk_clock_get_rate(void *priv, struct clk *clkp)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk = (struct meson_clk_clk *)clkp;
        struct clk *clkp_parent;

        if (clk->get_rate)
                return clk->get_rate(sc, clk);

        clkp_parent = clk_get_parent(clkp);
        if (clkp_parent == NULL) {
                aprint_debug("%s: no parent for %s\n", __func__, clk->base.name);
                return 0;
        }

        return clk_get_rate(clkp_parent);
}

static int
meson_clk_clock_set_rate(void *priv, struct clk *clkp, u_int rate)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk = (struct meson_clk_clk *)clkp;
        struct clk *clkp_parent;

        if (clkp->flags & CLK_SET_RATE_PARENT) {
                clkp_parent = clk_get_parent(clkp);
                if (clkp_parent == NULL) {
                        aprint_debug("%s: no parent for %s\n", __func__, clk->base.name);
                        return ENXIO;
                }
                return clk_set_rate(clkp_parent, rate);
        }

        if (clk->set_rate)
                return clk->set_rate(sc, clk, rate);

        return ENXIO;
}

static u_int
meson_clk_clock_round_rate(void *priv, struct clk *clkp, u_int rate)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk = (struct meson_clk_clk *)clkp;
        struct clk *clkp_parent;

        if (clkp->flags & CLK_SET_RATE_PARENT) {
                clkp_parent = clk_get_parent(clkp);
                if (clkp_parent == NULL) {
                        aprint_debug("%s: no parent for %s\n", __func__, clk->base.name);
                        return 0;
                }
                return clk_round_rate(clkp_parent, rate);
        }

        if (clk->round_rate)
                return clk->round_rate(sc, clk, rate);

        return 0;
}

static int
meson_clk_clock_enable(void *priv, struct clk *clkp)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk = (struct meson_clk_clk *)clkp;
        struct clk *clkp_parent;
        int error = 0;

        clkp_parent = clk_get_parent(clkp);
        if (clkp_parent != NULL) {
                error = clk_enable(clkp_parent);
                if (error != 0)
                        return error;
        }

        if (clk->enable)
                error = clk->enable(sc, clk, 1);

        return error;
}

static int
meson_clk_clock_disable(void *priv, struct clk *clkp)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk = (struct meson_clk_clk *)clkp;
        int error = EINVAL;

        if (clk->enable)
                error = clk->enable(sc, clk, 0);

        return error;
}

static int
meson_clk_clock_set_parent(void *priv, struct clk *clkp,
    struct clk *clkp_parent)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk = (struct meson_clk_clk *)clkp;

        if (clk->set_parent == NULL)
                return EINVAL;

        return clk->set_parent(sc, clk, clkp_parent->name);
}

static struct clk *
meson_clk_clock_get_parent(void *priv, struct clk *clkp)
{
        struct meson_clk_softc * const sc = priv;
        struct meson_clk_clk *clk = (struct meson_clk_clk *)clkp;
        struct meson_clk_clk *clk_parent;
        const char *parent;

        if (clk->get_parent == NULL)
                return NULL;

        parent = clk->get_parent(sc, clk);
        if (parent == NULL)
                return NULL;

        clk_parent = meson_clk_clock_find(sc, parent);
        if (clk_parent != NULL)
                return &clk_parent->base;

        /* No parent in this domain, try FDT */
        return fdtbus_clock_get(sc->sc_phandle, parent);
}

static const struct clk_funcs meson_clk_clock_funcs = {
        .get = meson_clk_clock_get,
        .put = meson_clk_clock_put,
        .get_rate = meson_clk_clock_get_rate,
        .set_rate = meson_clk_clock_set_rate,
        .round_rate = meson_clk_clock_round_rate,
        .enable = meson_clk_clock_enable,
        .disable = meson_clk_clock_disable,
        .set_parent = meson_clk_clock_set_parent,
        .get_parent = meson_clk_clock_get_parent,
};

struct meson_clk_clk *
meson_clk_clock_find(struct meson_clk_softc *sc, const char *name)
{
        for (int i = 0; i < sc->sc_nclks; i++) {
                if (sc->sc_clks[i].base.name == NULL)
                        continue;
                if (strcmp(sc->sc_clks[i].base.name, name) == 0)
                        return &sc->sc_clks[i];
        }

        return NULL;
}

void
meson_clk_attach(struct meson_clk_softc *sc)
{
        int i;

        sc->sc_clkdom.name = device_xname(sc->sc_dev);
        sc->sc_clkdom.funcs = &meson_clk_clock_funcs;
        sc->sc_clkdom.priv = sc;
        for (i = 0; i < sc->sc_nclks; i++) {
                sc->sc_clks[i].base.domain = &sc->sc_clkdom;
                clk_attach(&sc->sc_clks[i].base);
        }

        if (sc->sc_nclks > 0)
                fdtbus_register_clock_controller(sc->sc_dev, sc->sc_phandle,
                    &meson_clk_fdtclock_funcs);

        if (sc->sc_nresets > 0)
                fdtbus_register_reset_controller(sc->sc_dev, sc->sc_phandle,
                    &meson_clk_fdtreset_funcs);
}

void
meson_clk_print(struct meson_clk_softc *sc)
{
        struct meson_clk_clk *clk;
        struct clk *clkp_parent;
        const char *type;
        int i;

        for (i = 0; i < sc->sc_nclks; i++) {
                clk = &sc->sc_clks[i];
                if (clk->type == MESON_CLK_UNKNOWN)
                        continue;

                clkp_parent = clk_get_parent(&clk->base);

                switch (clk->type) {
                case MESON_CLK_FIXED:           type = "fixed"; break;
                case MESON_CLK_GATE:            type = "gate"; break;
                case MESON_CLK_MPLL:            type = "mpll"; break;
                case MESON_CLK_PLL:             type = "pll"; break;
                case MESON_CLK_DIV:             type = "div"; break;
                case MESON_CLK_FIXED_FACTOR:    type = "fixed-factor"; break;
                case MESON_CLK_MUX:             type = "mux"; break;
                default:                        type = "???"; break;
                }

                aprint_debug_dev(sc->sc_dev,
                    "%3d %-12s %2s %-12s %-7s ",
                    i,
                    clk->base.name,
                    clkp_parent ? "<-" : "",
                    clkp_parent ? clkp_parent->name : "",
                    type);
                aprint_debug("%10u Hz\n", clk_get_rate(&clk->base));
        }
}

void
meson_clk_lock(struct meson_clk_softc *sc)
{
        if (sc->sc_syscon != NULL)
                syscon_lock(sc->sc_syscon);
}

void
meson_clk_unlock(struct meson_clk_softc *sc)
{
        if (sc->sc_syscon != NULL)
                syscon_unlock(sc->sc_syscon);
}

uint32_t
meson_clk_read(struct meson_clk_softc *sc, bus_size_t reg)
{
        if (sc->sc_syscon != NULL)
                return syscon_read_4(sc->sc_syscon, reg);
        else
                return bus_space_read_4(sc->sc_bst, sc->sc_bsh, reg);
}

void
meson_clk_write(struct meson_clk_softc *sc, bus_size_t reg, uint32_t val)
{
        if (sc->sc_syscon != NULL)
                syscon_write_4(sc->sc_syscon, reg, val);
        else
                bus_space_write_4(sc->sc_bst, sc->sc_bsh, reg, val);
}