/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2018-2021 Emmanuel Vadot <manu@FreeBSD.org>
 *
 * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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/param.h>
#include <sys/bus.h>
#include <sys/systm.h>
#include <sys/clock.h>

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

#include <dev/regulator/regulator.h>

#include <dev/iicbus/pmic/rockchip/rk8xx.h>

#include "regdev_if.h"

static int rk8xx_regnode_status(struct regnode *regnode, int *status);
static int rk8xx_regnode_set_voltage(struct regnode *regnode, int min_uvolt,
    int max_uvolt, int *udelay);
static int rk8xx_regnode_get_voltage(struct regnode *regnode, int *uvolt);

/* #define      dprintf(sc, format, arg...)     device_printf(sc->base_dev, "%s: " format, __func__, arg) */
#define dprintf(sc, format, arg...) (sc = sc)

static int
rk8xx_regnode_init(struct regnode *regnode)
{
        struct rk8xx_reg_sc *sc;
        struct regnode_std_param *param;
        int rv, udelay, uvolt, status;

        sc = regnode_get_softc(regnode);
        dprintf(sc, "Regulator %s init called\n", sc->def->name);
        param = regnode_get_stdparam(regnode);
        if (param->min_uvolt == 0)
                return (0);

        /* Check that the regulator is preset to the correct voltage */
        rv  = rk8xx_regnode_get_voltage(regnode, &uvolt);
        if (rv != 0)
                return(rv);

        if (uvolt >= param->min_uvolt && uvolt <= param->max_uvolt)
                return(0);
        /* 
         * Set the regulator at the correct voltage if it is not enabled.
         * Do not enable it, this is will be done either by a
         * consumer or by regnode_set_constraint if boot_on is true
         */
        rv = rk8xx_regnode_status(regnode, &status);
        if (rv != 0 || status == REGULATOR_STATUS_ENABLED)
                return (rv);

        rv = rk8xx_regnode_set_voltage(regnode, param->min_uvolt,
            param->max_uvolt, &udelay);
        if (udelay != 0)
                DELAY(udelay);

        return (rv);
}

static int
rk8xx_regnode_enable(struct regnode *regnode, bool enable, int *udelay)
{
        struct rk8xx_reg_sc *sc;
        uint8_t val;

        sc = regnode_get_softc(regnode);

        dprintf(sc, "%sabling regulator %s\n",
            enable ? "En" : "Dis",
            sc->def->name);
        rk8xx_read(sc->base_dev, sc->def->enable_reg, &val, 1);
        if (enable)
                val |= sc->def->enable_mask;
        else
                val &= ~sc->def->enable_mask;
        rk8xx_write(sc->base_dev, sc->def->enable_reg, &val, 1);

        *udelay = 0;

        return (0);
}

static void
rk8xx_regnode_reg_to_voltage(struct rk8xx_reg_sc *sc, uint8_t val, int *uv)
{
        struct rk8xx_softc *sc1;

        sc1 = device_get_softc(sc->base_dev);
        if (sc1->type == RK809 || sc1->type == RK817) {
                if (sc->def->voltage_step2) {
                        int change;

                        change =
                            ((sc->def->voltage_min2 - sc->def->voltage_min) /
                            sc->def->voltage_step);
                        if (val > change) {
                                if (val < sc->def->voltage_nstep) {
                                        *uv = sc->def->voltage_min2 +
                                            (val - change) *
                                            sc->def->voltage_step2;
                                } else
                                        *uv = sc->def->voltage_max2;
                                return;
                        }
                }
                if (val < sc->def->voltage_nstep)
                        *uv = sc->def->voltage_min + val * sc->def->voltage_step;
                else
                        *uv = sc->def->voltage_max;

        } else {
                if (val < sc->def->voltage_nstep)
                        *uv = sc->def->voltage_min + val * sc->def->voltage_step;
                else
                        *uv = sc->def->voltage_min +
                            (sc->def->voltage_nstep * sc->def->voltage_step);
        }
}

static int
rk8xx_regnode_voltage_to_reg(struct rk8xx_reg_sc *sc, int min_uvolt,
    int max_uvolt, uint8_t *val)
{
        uint8_t nval;
        int nstep, uvolt;
        struct rk8xx_softc *sc1;

        sc1 = device_get_softc(sc->base_dev);
        nval = 0;
        uvolt = sc->def->voltage_min;

        for (nstep = 0; nstep < sc->def->voltage_nstep && uvolt < min_uvolt;
             nstep++) {
                ++nval;
                if (sc1->type == RK809 || sc1->type == RK817) {
                        if (sc->def->voltage_step2) {
                                if (uvolt < sc->def->voltage_min2)
                                        uvolt += sc->def->voltage_step;
                                else
                                        uvolt += sc->def->voltage_step2;
                        } else
                                uvolt += sc->def->voltage_step;
                } else
                        uvolt += sc->def->voltage_step;
        }
        if (uvolt > max_uvolt)
                return (EINVAL);

        *val = nval;
        return (0);
}

static int
rk8xx_regnode_status(struct regnode *regnode, int *status)
{
        struct rk8xx_reg_sc *sc;
        uint8_t val;

        sc = regnode_get_softc(regnode);

        *status = 0;
        rk8xx_read(sc->base_dev, sc->def->enable_reg, &val, 1);
        if (val & sc->def->enable_mask)
                *status = REGULATOR_STATUS_ENABLED;

        return (0);
}

static int
rk8xx_regnode_set_voltage(struct regnode *regnode, int min_uvolt,
    int max_uvolt, int *udelay)
{
        struct rk8xx_reg_sc *sc;
        uint8_t val, old;
        int uvolt;
        struct rk8xx_softc *sc1;

        sc = regnode_get_softc(regnode);
        sc1 = device_get_softc(sc->base_dev);

        if (!sc->def->voltage_step)
                return (ENXIO);

        dprintf(sc, "Setting %s to %d<->%d uvolts\n",
            sc->def->name,
            min_uvolt,
            max_uvolt);
        rk8xx_read(sc->base_dev, sc->def->voltage_reg, &val, 1);
        old = val;
        if (rk8xx_regnode_voltage_to_reg(sc, min_uvolt, max_uvolt, &val) != 0)
                return (ERANGE);

        if (sc1->type == RK809 || sc1->type == RK817)
                val |= (old &= ~sc->def->voltage_mask);

        rk8xx_write(sc->base_dev, sc->def->voltage_reg, &val, 1);

        rk8xx_read(sc->base_dev, sc->def->voltage_reg, &val, 1);

        *udelay = 0;

        rk8xx_regnode_reg_to_voltage(sc, val, &uvolt);
        dprintf(sc, "Regulator %s set to %d uvolt\n",
          sc->def->name,
          uvolt);

        return (0);
}

static int
rk8xx_regnode_get_voltage(struct regnode *regnode, int *uvolt)
{
        struct rk8xx_reg_sc *sc;
        uint8_t val;

        sc = regnode_get_softc(regnode);

        if (sc->def->voltage_min ==  sc->def->voltage_max) {
                *uvolt = sc->def->voltage_min;
                return (0);
        }

        if (!sc->def->voltage_step)
                return (ENXIO);

        rk8xx_read(sc->base_dev, sc->def->voltage_reg, &val, 1);
        rk8xx_regnode_reg_to_voltage(sc, val & sc->def->voltage_mask, uvolt);

        dprintf(sc, "Regulator %s is at %d uvolt\n",
          sc->def->name,
          *uvolt);

        return (0);
}

static regnode_method_t rk8xx_regnode_methods[] = {
        /* Regulator interface */
        REGNODEMETHOD(regnode_init,             rk8xx_regnode_init),
        REGNODEMETHOD(regnode_enable,           rk8xx_regnode_enable),
        REGNODEMETHOD(regnode_status,           rk8xx_regnode_status),
        REGNODEMETHOD(regnode_set_voltage,      rk8xx_regnode_set_voltage),
        REGNODEMETHOD(regnode_get_voltage,      rk8xx_regnode_get_voltage),
        REGNODEMETHOD(regnode_check_voltage,    regnode_method_check_voltage),
        REGNODEMETHOD_END
};
DEFINE_CLASS_1(rk8xx_regnode, rk8xx_regnode_class, rk8xx_regnode_methods,
    sizeof(struct rk8xx_reg_sc), regnode_class);

static struct rk8xx_reg_sc *
rk8xx_reg_attach(device_t dev, phandle_t node,
    struct rk8xx_regdef *def)
{
        struct rk8xx_reg_sc *reg_sc;
        struct regnode_init_def initdef;
        struct regnode *regnode;

        memset(&initdef, 0, sizeof(initdef));
        if (regulator_parse_ofw_stdparam(dev, node, &initdef) != 0) {
                device_printf(dev, "cannot create regulator\n");
                return (NULL);
        }
        if (initdef.std_param.min_uvolt == 0)
                initdef.std_param.min_uvolt = def->voltage_min;
        if (initdef.std_param.max_uvolt == 0)
                initdef.std_param.max_uvolt = def->voltage_max;
        initdef.id = def->id;
        initdef.ofw_node = node;

        regnode = regnode_create(dev, &rk8xx_regnode_class, &initdef);
        if (regnode == NULL) {
                device_printf(dev, "cannot create regulator\n");
                return (NULL);
        }

        reg_sc = regnode_get_softc(regnode);
        reg_sc->regnode = regnode;
        reg_sc->base_dev = dev;
        reg_sc->def = def;
        reg_sc->xref = OF_xref_from_node(node);
        reg_sc->param = regnode_get_stdparam(regnode);

        regnode_register(regnode);

        return (reg_sc);
}

void
rk8xx_attach_regulators(struct rk8xx_softc *sc)
{
        struct rk8xx_reg_sc *reg;
        struct reg_list *regp;
        phandle_t rnode, child;
        int i;

        TAILQ_INIT(&sc->regs);

        rnode = ofw_bus_find_child(ofw_bus_get_node(sc->dev), "regulators");
        if (rnode > 0) {
                for (i = 0; i < sc->nregs; i++) {
                        child = ofw_bus_find_child(rnode,
                            sc->regdefs[i].name);
                        if (child == 0)
                                continue;
                        if (OF_hasprop(child, "regulator-name") != 1)
                                continue;
                        reg = rk8xx_reg_attach(sc->dev, child, &sc->regdefs[i]);
                        if (reg == NULL) {
                                device_printf(sc->dev,
                                    "cannot attach regulator %s\n",
                                    sc->regdefs[i].name);
                                continue;
                        }
                        regp = malloc(sizeof(*regp), M_DEVBUF, M_WAITOK | M_ZERO);
                        regp->reg = reg;
                        TAILQ_INSERT_TAIL(&sc->regs, regp, next);
                        if (bootverbose)
                                device_printf(sc->dev, "Regulator %s attached\n",
                                    sc->regdefs[i].name);
                }
        }
}

int
rk8xx_map(device_t dev, phandle_t xref, int ncells,
    pcell_t *cells, intptr_t *id)
{
        struct rk8xx_softc *sc;
        struct reg_list *regp;

        sc = device_get_softc(dev);

        TAILQ_FOREACH(regp, &sc->regs, next) {
                if (regp->reg->xref == xref) {
                        *id = regp->reg->def->id;
                        return (0);
                }
        }

        return (ERANGE);
}