/*      $OpenBSD: rkiovd.c,v 1.1 2023/04/01 08:39:05 kettenis Exp $     */
/*
 * Copyright (c) 2023 Mark Kettenis <kettenis@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <machine/intr.h>
#include <machine/bus.h>
#include <machine/fdt.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_misc.h>
#include <dev/ofw/ofw_regulator.h>
#include <dev/ofw/fdt.h>

#define RK3568_PMU_GRF_IO_VSEL0         0x0140
#define RK3568_PMU_GRF_IO_VSEL1         0x0144
#define RK3568_PMU_GRF_IO_VSEL2         0x0148

#define RKIOVD_MAX_DOMAINS      9

const char *rkiovd_rk3568_domains[] = {
        "pmuio1-supply",
        "pmuio2-supply",
        "vccio1-supply",
        "vccio2-supply",
        "vccio3-supply",
        "vccio4-supply",
        "vccio5-supply",
        "vccio6-supply",
        "vccio7-supply",
        NULL
};

struct rkiovd_domain {
        struct rkiovd_softc     *rd_sc;
        int                     rd_idx;
        struct regulator_notifier rd_rn;
};

struct rkiovd_softc {
        struct device           sc_dv;
        struct regmap           *sc_rm;
        struct rkiovd_domain    sc_rd[RKIOVD_MAX_DOMAINS];
};

int     rkiovd_match(struct device *, void *, void *);
void    rkiovd_attach(struct device *, struct device *, void *);

const struct cfattach rkiovd_ca = {
        sizeof (struct rkiovd_softc), rkiovd_match, rkiovd_attach
};

struct cfdriver rkiovd_cd = {
        NULL, "rkiovd", DV_DULL
};

void    rkiovd_rk3568_notify(void *, uint32_t);

int
rkiovd_match(struct device *parent, void *match, void *aux)
{
        struct fdt_attach_args *faa = aux;

        return OF_is_compatible(faa->fa_node,
            "rockchip,rk3568-pmu-io-voltage-domain");
}

void
rkiovd_attach(struct device *parent, struct device *self, void *aux)
{
        struct rkiovd_softc *sc = (struct rkiovd_softc *)self;
        struct fdt_attach_args *faa = aux;
        int idx;

        printf("\n");

        sc->sc_rm = regmap_bynode(OF_parent(faa->fa_node));
        if (sc->sc_rm == NULL)
                return;

        for (idx = 0; rkiovd_rk3568_domains[idx]; idx++) {
                struct rkiovd_domain *rd = &sc->sc_rd[idx];
                char *name = (char *)rkiovd_rk3568_domains[idx];
                uint32_t phandle;

                phandle = OF_getpropint(faa->fa_node, name, 0);
                if (phandle == 0)
                        continue;

                rd->rd_sc = sc;
                rd->rd_idx = idx;
                rd->rd_rn.rn_phandle = phandle;
                rd->rd_rn.rn_cookie = rd;
                rd->rd_rn.rn_notify = rkiovd_rk3568_notify;
                regulator_notify(&rd->rd_rn);
        }
}

void
rkiovd_rk3568_notify(void *cookie, uint32_t voltage)
{
        struct rkiovd_domain *rd = cookie;
        struct rkiovd_softc *sc = rd->rd_sc;
        uint32_t current_voltage;
        uint32_t vsel0, vsel1;
        int bit;

        /*
         * If the new voltage is higher than the current voltage we
         * need to configure the I/O voltage domain before changing
         * the voltage.  If the new voltage is lower we need to
         * configure the domain after changing the voltage.  Using the
         * maximum of the new and current voltage makes sure this is
         * always the case.
         */
        current_voltage = regulator_get_voltage(rd->rd_rn.rn_phandle);
        if (voltage < current_voltage)
                voltage = current_voltage;

        switch (rd->rd_idx) {
        case 1:                 /* PMUIO2 */
                if (voltage > 1980000) {
                        vsel0 = (1 << 1) << 16 | (0 << 1);
                        vsel1 = (1 << 5) << 16 | (1 << 5);
                } else {
                        vsel0 = (1 << 1) << 16 | (1 << 1);
                        vsel1 = (1 << 5) << 16 | (0 << 5);
                }
                regmap_write_4(sc->sc_rm, RK3568_PMU_GRF_IO_VSEL2, vsel0);
                regmap_write_4(sc->sc_rm, RK3568_PMU_GRF_IO_VSEL2, vsel1);
                break;
        case 2:                 /* VCCIO1 */
        case 4:                 /* VCCIO3 */
        case 5:                 /* VCCIO4 */
        case 6:                 /* VCCIO5 */
        case 7:                 /* VCCIO6 */
        case 8:                 /* VCCIO7 */
                bit = rd->rd_idx - 1;
                if (voltage > 1980000) {
                        vsel0 = (1 << bit) << 16 | (0 << bit);
                        vsel1 = (1 << bit) << 16 | (1 << bit);
                } else {
                        vsel0 = (1 << bit) << 16 | (1 << bit);
                        vsel1 = (1 << bit) << 16 | (0 << bit);
                }
                regmap_write_4(sc->sc_rm, RK3568_PMU_GRF_IO_VSEL0, vsel0);
                regmap_write_4(sc->sc_rm, RK3568_PMU_GRF_IO_VSEL1, vsel1);
                break;
        case 0:                 /* PMUIO1 */
        case 3:                 /* VCCIO2 */
                /* Ignore */
                break;
        }
}