/*      $OpenBSD: aplspmi.c,v 1.3 2025/09/30 14:29:54 kettenis Exp $    */
/*
 * Copyright (c) 2021 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/bus.h>
#include <machine/fdt.h>

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

#include <dev/fdt/spmivar.h>

#define SPMI_STAT               0x00
#define  SPMI_STAT_RXEMPTY              (1 << 24)
#define  SPMI_STAT_TXEMPTY              (1 << 8)
#define SPMI_CMD                0x04
#define  SPMI_CMD_ADDR(x)               ((x) << 16)
#define  SPMI_CMD_LAST                  (1 << 15)
#define  SPMI_CMD_SID(x)                ((x) << 8)
#define SPMI_RESP               0x08
#define SPMI_INTEN(i)           (0x20 + (i) * 4)
#define SPMI_INTSTAT(i)         (0x60 + (i) * 4)

#define HREAD4(sc, reg)                                                 \
        (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
#define HWRITE4(sc, reg, val)                                           \
        bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))

struct aplspmi_softc {
        struct device           sc_dev;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;

        struct spmi_controller  sc_tag;
};

int     aplspmi_match(struct device *, void *, void *);
void    aplspmi_attach(struct device *, struct device *, void *);

const struct cfattach   aplspmi_ca = {
        sizeof (struct aplspmi_softc), aplspmi_match, aplspmi_attach
};

struct cfdriver aplspmi_cd = {
        NULL, "aplspmi", DV_DULL
};

int     aplspmi_print(void *, const char *);
int     aplspmi_cmd_read(void *, uint8_t, uint8_t, uint16_t, void *, size_t);
int     aplspmi_cmd_write(void *, uint8_t, uint8_t, uint16_t,
            const void *, size_t);

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

        return OF_is_compatible(faa->fa_node, "apple,spmi") ||
            OF_is_compatible(faa->fa_node, "apple,t8103-spmi");
}

void
aplspmi_attach(struct device *parent, struct device *self, void *aux)
{
        struct aplspmi_softc *sc = (struct aplspmi_softc *)self;
        struct fdt_attach_args *faa = aux;
        struct spmi_attach_args sa;
        char name[32];
        uint32_t reg[2];
        int node;

        if (faa->fa_nreg < 1) {
                printf(": no registers\n");
                return;
        }

        sc->sc_iot = faa->fa_iot;
        if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
            faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
                printf(": can't map registers\n");
                return;
        }

        printf("\n");

        sc->sc_tag.sc_cookie = sc;
        sc->sc_tag.sc_cmd_read = aplspmi_cmd_read;
        sc->sc_tag.sc_cmd_write = aplspmi_cmd_write;

        for (node = OF_child(faa->fa_node); node; node = OF_peer(node)) {
                if (OF_getpropintarray(node, "reg", reg,
                    sizeof(reg)) != sizeof(reg))
                        continue;

                memset(name, 0, sizeof(name));
                if (OF_getprop(node, "compatible", name, sizeof(name)) == -1)
                        continue;
                if (name[0] == '\0')
                        continue;

                memset(&sa, 0, sizeof(sa));
                sa.sa_tag = &sc->sc_tag;
                sa.sa_sid = reg[0];
                sa.sa_name = name;
                sa.sa_node = node;
                config_found(self, &sa, aplspmi_print);
        }
}

int
aplspmi_print(void *aux, const char *pnp)
{
        struct spmi_attach_args *sa = aux;

        if (pnp != NULL)
                printf("\"%s\" at %s", sa->sa_name, pnp);
        printf(" sid 0x%x", sa->sa_sid);

        return UNCONF;
}

int
aplspmi_read_resp(struct aplspmi_softc *sc, uint32_t *resp)
{
        int retry;

        for (retry = 1000; retry > 0; retry--) {
                if ((HREAD4(sc, SPMI_STAT) & SPMI_STAT_RXEMPTY) == 0)
                        break;
                delay(1);
        }
        if (retry == 0)
                return ETIMEDOUT;

        *resp = HREAD4(sc, SPMI_RESP);
        return 0;
}

int
aplspmi_cmd_read(void *cookie, uint8_t sid, uint8_t cmd, uint16_t addr,
    void *buf, size_t len)
{
        struct aplspmi_softc *sc = cookie;
        uint8_t *cbuf = buf;
        uint32_t resp;
        int error;

        if (len == 0 || len > 8)
                return EINVAL;

        HWRITE4(sc, SPMI_CMD, SPMI_CMD_SID(sid) | cmd | SPMI_CMD_ADDR(addr) |
            (len - 1) | SPMI_CMD_LAST);

        error = aplspmi_read_resp(sc, &resp);
        if (error)
                return error;

        while (len > 0) {
                error = aplspmi_read_resp(sc, &resp);
                if (error)
                        return error;
                memcpy(cbuf, &resp, MIN(len, 4));
                cbuf += MIN(len, 4);
                len -= MIN(len, 4);
        }

        return 0;
}

int
aplspmi_cmd_write(void *cookie, uint8_t sid, uint8_t cmd, uint16_t addr,
    const void *buf, size_t len)
{
        struct aplspmi_softc *sc = cookie;
        const uint8_t *cbuf = buf;
        uint32_t data, resp;

        if (len == 0 || len > 8)
                return EINVAL;

        HWRITE4(sc, SPMI_CMD, SPMI_CMD_SID(sid) | cmd | SPMI_CMD_ADDR(addr) |
            (len - 1) | SPMI_CMD_LAST);

        while (len > 0) {
                memcpy(&data, cbuf, MIN(len, 4));
                HWRITE4(sc, SPMI_CMD, data);
                cbuf += MIN(len, 4);
                len -= MIN(len, 4);
        }

        return aplspmi_read_resp(sc, &resp);
}