/* $NetBSD: ti_prcm.c,v 1.5 2025/12/16 12:20:23 skrll Exp $ */

/*-
 * Copyright (c) 2017 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: ti_prcm.c,v 1.5 2025/12/16 12:20:23 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>

#define TI_PRCM_PRIVATE
#include <arm/ti/ti_prcm.h>

static struct ti_prcm_softc *prcm_softc = NULL;

static struct clk *
ti_prcm_clock_get(void *priv, const char *name)
{
        struct ti_prcm_softc * const sc = priv;
        struct ti_prcm_clk *clk;

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

        return &clk->base;
}

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

static u_int
ti_prcm_clock_get_rate(void *priv, struct clk *clkp)
{
        struct ti_prcm_softc * const sc = priv;
        struct ti_prcm_clk *clk = (struct ti_prcm_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_error("%s: no parent for %s\n", __func__, clk->base.name);
                return 0;
        }

        return clk_get_rate(clkp_parent);
}

static int
ti_prcm_clock_set_rate(void *priv, struct clk *clkp, u_int rate)
{
        struct ti_prcm_softc * const sc = priv;
        struct ti_prcm_clk *clk = (struct ti_prcm_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 int
ti_prcm_clock_enable(void *priv, struct clk *clkp)
{
        struct ti_prcm_softc * const sc = priv;
        struct ti_prcm_clk *clk = (struct ti_prcm_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
ti_prcm_clock_disable(void *priv, struct clk *clkp)
{
        struct ti_prcm_softc * const sc = priv;
        struct ti_prcm_clk *clk = (struct ti_prcm_clk *)clkp;
        int error = EINVAL;

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

        return error;
}

static int
ti_prcm_clock_set_parent(void *priv, struct clk *clkp,
    struct clk *clkp_parent)
{
        struct ti_prcm_softc * const sc = priv;
        struct ti_prcm_clk *clk = (struct ti_prcm_clk *)clkp;

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

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

static struct clk *
ti_prcm_clock_get_parent(void *priv, struct clk *clkp)
{
        struct ti_prcm_softc * const sc = priv;
        struct ti_prcm_clk *clk = (struct ti_prcm_clk *)clkp;
        struct ti_prcm_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 = ti_prcm_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 ti_prcm_clock_funcs = {
        .get = ti_prcm_clock_get,
        .put = ti_prcm_clock_put,
        .get_rate = ti_prcm_clock_get_rate,
        .set_rate = ti_prcm_clock_set_rate,
        .enable = ti_prcm_clock_enable,
        .disable = ti_prcm_clock_disable,
        .set_parent = ti_prcm_clock_set_parent,
        .get_parent = ti_prcm_clock_get_parent,
};

struct ti_prcm_clk *
ti_prcm_clock_find(struct ti_prcm_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
ti_prcm_attach(struct ti_prcm_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) {
                aprint_error(": couldn't map registers\n");
                return ENXIO;
        }

        sc->sc_clkdom.funcs = &ti_prcm_clock_funcs;
        sc->sc_clkdom.priv = sc;
        for (i = 0; i < sc->sc_nclks; i++)
                sc->sc_clks[i].base.domain = &sc->sc_clkdom;

        if (prcm_softc == NULL)
                prcm_softc = sc;

        return 0;
}

struct clk *
ti_prcm_get_hwmod(const int phandle, u_int index)
{
        struct ti_prcm_clk *tc;
        const char *hwmods, *p;
        int len, resid, hwmod_phandle;
        u_int n;

        KASSERTMSG(prcm_softc != NULL, "prcm driver not attached");

        /* If this node does not have a ti,hwmods property, try the parent */
        hwmod_phandle = of_hasprop(phandle, "ti,hwmods") ? phandle : OF_parent(phandle);

        /* Lookup clock by "ti,hwmods" name (old method) */
        hwmods = fdtbus_get_prop(hwmod_phandle, "ti,hwmods", &len);
        if (len > 0) {
                p = hwmods;
                for (n = 0, resid = len; resid > 0; n++) {
                        if (n == index) {
                                tc = ti_prcm_clock_find(prcm_softc, p);
                                if (tc == NULL) {
                                        aprint_error_dev(prcm_softc->sc_dev,
                                            "no hwmod with name '%s'\n", p);
                                        return NULL;
                                }
                                KASSERT(tc->type == TI_PRCM_HWMOD);
                                return &tc->base;
                        }
                        resid -= strlen(p);
                        p += strlen(p) + 1;
                }
        }

        /* Find clock resource */
        return fdtbus_clock_get_index(hwmod_phandle, index);
}

int
ti_prcm_enable_hwmod(const int phandle, u_int index)
{
        struct clk *clk;

        clk = ti_prcm_get_hwmod(phandle, index);
        if (clk == NULL)
                return ENOENT;

        return clk_enable(clk);
}