/* $NetBSD: imx_ccm.c,v 1.1 2020/12/23 14:42:38 skrll Exp $ */

/*-
 * Copyright (c) 2020 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: imx_ccm.c,v 1.1 2020/12/23 14:42:38 skrll Exp $");

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

#include <dev/fdt/fdtvar.h>

#include <dev/clk/clk_backend.h>

#include <arm/nxp/imx_ccm.h>

static struct clk *
imx_ccm_clock_decode(device_t dev, int cc_phandle, const void *data, size_t len)
{
        struct imx_ccm_softc * const sc = device_private(dev);
        struct imx_ccm_clk *clk;

        if (len != 4)
                return NULL;

        const u_int clock_id = be32dec(data);

        for (int i = 0; i < sc->sc_nclks; i++) {
                clk = &sc->sc_clks[i];
                if (clk->id == clock_id)
                        return &clk->base;
        }

        return NULL;
}

static const struct fdtbus_clock_controller_func imx_ccm_fdtclock_funcs = {
        .decode = imx_ccm_clock_decode,
};

static struct clk *
imx_ccm_clock_get(void *priv, const char *name)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk;

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

        return &clk->base;
}

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

static u_int
imx_ccm_clock_get_rate(void *priv, struct clk *clkp)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk = (struct imx_ccm_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
imx_ccm_clock_set_rate(void *priv, struct clk *clkp, u_int rate)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk = (struct imx_ccm_clk *)clkp;
        struct clk *clkp_parent;

        if (clkp->flags & CLK_SET_RATE_PARENT) {
                clkp_parent = clk_get_parent(clkp);
                if (clkp_parent == NULL) {
                        aprint_error("%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
imx_ccm_clock_round_rate(void *priv, struct clk *clkp, u_int rate)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk = (struct imx_ccm_clk *)clkp;
        struct clk *clkp_parent;

        if (clkp->flags & CLK_SET_RATE_PARENT) {
                clkp_parent = clk_get_parent(clkp);
                if (clkp_parent == NULL) {
                        aprint_error("%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
imx_ccm_clock_enable(void *priv, struct clk *clkp)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk = (struct imx_ccm_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
imx_ccm_clock_disable(void *priv, struct clk *clkp)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk = (struct imx_ccm_clk *)clkp;
        int error = EINVAL;

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

        return error;
}

static int
imx_ccm_clock_set_parent(void *priv, struct clk *clkp,
    struct clk *clkp_parent)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk = (struct imx_ccm_clk *)clkp;

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

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

static struct clk *
imx_ccm_clock_get_parent(void *priv, struct clk *clkp)
{
        struct imx_ccm_softc * const sc = priv;
        struct imx_ccm_clk *clk = (struct imx_ccm_clk *)clkp;
        struct imx_ccm_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 = imx_ccm_clock_find(sc, parent);
        if (clk_parent != NULL)
                return &clk_parent->base;

        /* No parent in this domain, try FDT */
        return fdtbus_clock_byname(parent);
}

const struct clk_funcs imx_ccm_clock_funcs = {
        .get = imx_ccm_clock_get,
        .put = imx_ccm_clock_put,
        .get_rate = imx_ccm_clock_get_rate,
        .set_rate = imx_ccm_clock_set_rate,
        .round_rate = imx_ccm_clock_round_rate,
        .enable = imx_ccm_clock_enable,
        .disable = imx_ccm_clock_disable,
        .set_parent = imx_ccm_clock_set_parent,
        .get_parent = imx_ccm_clock_get_parent,
};

struct imx_ccm_clk *
imx_ccm_clock_find(struct imx_ccm_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;
}

int
imx_ccm_attach(struct imx_ccm_softc *sc)
{
        bus_addr_t addr;
        bus_size_t size;
        int i;

        if (fdtbus_get_reg(sc->sc_phandle, 0, &addr, &size) != 0) {
                aprint_error(": couldn't get registers\n");
                return ENXIO;
        }
        if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh[0]) != 0) {
                aprint_error(": couldn't map registers\n");
                return ENXIO;
        }

        sc->sc_clkdom.name = device_xname(sc->sc_dev);
        sc->sc_clkdom.funcs = &imx_ccm_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);
        }

        fdtbus_register_clock_controller(sc->sc_dev, sc->sc_phandle,
            &imx_ccm_fdtclock_funcs);

        return 0;
}

void
imx_ccm_print(struct imx_ccm_softc *sc)
{
        struct imx_ccm_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 == IMX_CCM_UNKNOWN)
                        continue;

                clkp_parent = clk_get_parent(&clk->base);

                switch (clk->type) {
                case IMX_CCM_EXTCLK:            type = "extclk"; break;
                case IMX_CCM_GATE:              type = "gate"; break;
                case IMX_CCM_COMPOSITE:         type = "comp"; break;
                case IMX_CCM_PLL:               type = "pll"; break;
                case IMX_CCM_FIXED:             type = "fixed"; break;
                case IMX_CCM_FIXED_FACTOR:      type = "fixed-factor"; break;
                case IMX_CCM_MUX:               type = "mux"; break;
                case IMX_CCM_DIV:               type = "div"; break;
                default:                        type = "???"; break;
                }

                aprint_debug_dev(sc->sc_dev,
                    "%3d %-14s %2s %-14s %-7s ",
                    clk->id,
                    clk->base.name,
                    clkp_parent ? "<-" : "",
                    clkp_parent ? clkp_parent->name : "",
                    type);
                aprint_debug("%10d Hz\n", clk_get_rate(&clk->base));
        }
}