/*      $OpenBSD: ipmi_i2c.c,v 1.6 2024/10/09 00:38:26 jsg Exp $        */
/*
 * Copyright (c) 2019 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 <dev/i2c/i2cvar.h>
#include <dev/ipmivar.h>

#define BMC_SA                  0x20    /* BMC/ESM3 */
#define BMC_LUN                 0

struct ipmi_i2c_softc {
        struct ipmi_softc sc;
        i2c_tag_t       sc_tag;
        i2c_addr_t      sc_addr;
        uint8_t         sc_rev;
};

void    cmn_buildmsg(struct ipmi_cmd *);
int     ssif_sendmsg(struct ipmi_cmd *);
int     ssif_recvmsg(struct ipmi_cmd *);
int     ssif_reset(struct ipmi_softc *);
int     ssif_probe(struct ipmi_softc *);

struct ipmi_if ssif_if = {
        "SSIF",
        0,
        cmn_buildmsg,
        ssif_sendmsg,
        ssif_recvmsg,
        ssif_reset,
        ssif_probe,
        IPMI_MSG_DATASND,
        IPMI_MSG_DATARCV
};

int     ipmi_i2c_match(struct device *, void *, void *);
void    ipmi_i2c_attach(struct device *, struct device *, void *);

const struct cfattach ipmi_i2c_ca = {
        sizeof(struct ipmi_i2c_softc), ipmi_i2c_match, ipmi_i2c_attach,
        NULL, ipmi_activate
};

int     ipmi_i2c_get_interface_caps(struct ipmi_i2c_softc *);
int     ipmi_i2c_get_device_id(struct ipmi_i2c_softc *);

int
ipmi_i2c_match(struct device *parent, void *match, void *aux)
{
        struct i2c_attach_args *ia = aux;

        return (strcmp(ia->ia_name, "IPI0001") == 0 ||
            strcmp(ia->ia_name, "APMC0D8A") == 0);
}

void
ipmi_i2c_attach(struct device *parent, struct device *self, void *aux)
{
        struct ipmi_i2c_softc *sc = (struct ipmi_i2c_softc *)self;
        struct i2c_attach_args *ia = aux;
        struct ipmi_attach_args iaa;

        sc->sc_tag = ia->ia_tag;
        sc->sc_addr = ia->ia_addr;
        sc->sc.sc_if = &ssif_if;

        if (ipmi_i2c_get_interface_caps(sc)) {
                printf(": can't get system interface capabilities\n");
                return;
        }

        if (ipmi_i2c_get_device_id(sc)) {
                printf(": can't get system interface capabilities\n");
                return;
        }

        memset(&iaa, 0, sizeof(iaa));
        iaa.iaa_if_type = IPMI_IF_SSIF;
        iaa.iaa_if_rev = (sc->sc_rev >> 4 | sc->sc_rev << 4);
        iaa.iaa_if_irq = -1;
        ipmi_attach_common(&sc->sc, &iaa);
}

int
ipmi_i2c_get_interface_caps(struct ipmi_i2c_softc *sc)
{
        struct ipmi_cmd c;
        uint8_t data[5];

        data[0] = 0;            /* SSIF */

        c.c_sc = &sc->sc;
        c.c_rssa = BMC_SA;
        c.c_rslun = BMC_LUN;
        c.c_netfn = APP_NETFN;
        c.c_cmd = APP_GET_SYSTEM_INTERFACE_CAPS;
        c.c_txlen = 1;
        c.c_rxlen = 0;
        c.c_maxrxlen = sizeof(data);
        c.c_data = data;
        if (ipmi_sendcmd(&c) || ipmi_recvcmd(&c))
                return EIO;

        /* Check SSIF version number. */
        if ((data[1] & 0x7) != 0)
                return EINVAL;
        /* Check input and output message sizes. */
        if (data[2] < 32 || data[3] < 32)
                return EINVAL;

        return 0;
}

int
ipmi_i2c_get_device_id(struct ipmi_i2c_softc *sc)
{
        struct ipmi_cmd c;
        uint8_t data[16];

        c.c_sc = &sc->sc;
        c.c_rssa = BMC_SA;
        c.c_rslun = BMC_LUN;
        c.c_netfn = APP_NETFN;
        c.c_cmd = APP_GET_DEVICE_ID;
        c.c_txlen = 0;
        c.c_rxlen = 0;
        c.c_maxrxlen = sizeof(data);
        c.c_data = data;
        if (ipmi_sendcmd(&c) || ipmi_recvcmd(&c))
                return EIO;

        sc->sc_rev = data[4];
        return 0;
}

int
ssif_sendmsg(struct ipmi_cmd *c)
{
        struct ipmi_i2c_softc *sc = (struct ipmi_i2c_softc *)c->c_sc;
        uint8_t *buf = sc->sc.sc_buf;
        uint8_t cmd[2];
        int error, retry;

        /* We only support single-part writes. */
        if (c->c_txlen > 32)
                return -1;

        iic_acquire_bus(sc->sc_tag, 0);

        cmd[0] = 2;
        cmd[1] = c->c_txlen;
        for (retry = 0; retry < 5; retry++) {
                error = iic_exec(sc->sc_tag, I2C_OP_WRITE_BLOCK,
                    sc->sc_addr, cmd, sizeof(cmd), buf, c->c_txlen, 0);
                if (!error)
                        break;
        }

        iic_release_bus(sc->sc_tag, 0);

        return (error ? -1 : 0);
}

int
ssif_recvmsg(struct ipmi_cmd *c)
{
        struct ipmi_i2c_softc *sc = (struct ipmi_i2c_softc *)c->c_sc;
        uint8_t buf[33];
        uint8_t cmd[1];
        uint8_t len;
        int error, retry;
        int blkno = 0;

        iic_acquire_bus(sc->sc_tag, 0);

        cmd[0] = 3;
        for (retry = 0; retry < 250; retry++) {
                memset(buf, 0, sizeof(buf));
                error = iic_exec(sc->sc_tag, I2C_OP_READ_BLOCK,
                    sc->sc_addr, cmd, sizeof(cmd), buf, sizeof(buf), 0);
                if (error)
                        continue;

                if (buf[0] < 1 || buf[0] > 32) {
                        error = EIO;
                        goto release;
                }

                if (buf[0] == 32 && buf[1] == 0x00 && buf[2] == 0x01) {
                        /* Multi-part read start. */
                        c->c_rxlen = MIN(30, c->c_maxrxlen);
                        memcpy(sc->sc.sc_buf, &buf[3], c->c_rxlen);
                        break;
                } else {
                        /* Single-part read. */
                        c->c_rxlen = MIN(buf[0], c->c_maxrxlen);
                        memcpy(sc->sc.sc_buf, &buf[1], c->c_rxlen);
                        goto release;
                }
        }
        if (retry == 250)
                goto release;

        cmd[0] = 9;
        while (buf[1] != 0xff && c->c_rxlen < c->c_maxrxlen) {
                memset(buf, 0, sizeof(buf));
                error = iic_exec(sc->sc_tag, I2C_OP_READ_BLOCK,
                    sc->sc_addr, cmd, sizeof(cmd), buf, sizeof(buf), 0);
                if (error)
                        goto release;

                if (buf[0] < 1 || buf[0] > 32) {
                        error = EIO;
                        goto release;
                }

                if (buf[0] == 32 && buf[1] == blkno) {
                        /* Multi-part read middle. */
                        len = MIN(31, c->c_maxrxlen - c->c_rxlen);
                        memcpy(&sc->sc.sc_buf[c->c_rxlen], &buf[2], len);
                } else if (buf[1] == 0xff) {
                        /* Multi-part read end. */
                        len = MIN(buf[0] - 1, c->c_maxrxlen - c->c_rxlen);
                        memcpy(&sc->sc.sc_buf[c->c_rxlen], &buf[2], len);
                } else {
                        error = EIO;
                        goto release;
                }
                c->c_rxlen += len;
                blkno++;
        }

release:
        iic_release_bus(sc->sc_tag, 0);

        return (error ? -1 : 0);
}

int
ssif_reset(struct ipmi_softc *sc)
{
        return -1;
}

int
ssif_probe(struct ipmi_softc *sc)
{
        return 0;
}