/*      $NetBSD: weasel_pci.c,v 1.16 2016/07/07 06:55:41 msaitoh Exp $  */

/*-
 * Copyright (c) 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Herb Peyerl and Jason Thorpe.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Device driver for the control space on the Middle Digital, Inc.
 * PCI-Weasel serial console board.
 *
 * Since the other functions of the PCI-Weasel already appear in
 * PCI configuration space, we just need to hook up the watchdog
 * timer.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: weasel_pci.c,v 1.16 2016/07/07 06:55:41 msaitoh Exp $");

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

#include <sys/bus.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcidevs.h>

#include <dev/pci/weaselreg.h>

#include <dev/sysmon/sysmonvar.h>

struct weasel_softc {
        device_t sc_dev;
        bus_space_tag_t sc_st;
        bus_space_handle_t sc_sh;

        struct sysmon_wdog sc_smw;

        int sc_wdog_armed;
        int sc_wdog_period;
};

/* XXX */
extern int      sysmon_wdog_setmode(struct sysmon_wdog *, int, u_int);

static int      weasel_pci_wdog_setmode(struct sysmon_wdog *);
static int      weasel_pci_wdog_tickle(struct sysmon_wdog *);

static int      weasel_wait_response(struct weasel_softc *);
static int      weasel_issue_command(struct weasel_softc *, uint8_t cmd);

static int      weasel_pci_wdog_arm(struct weasel_softc *);
static int      weasel_pci_wdog_disarm(struct weasel_softc *);

static int      weasel_pci_wdog_query_state(struct weasel_softc *);

static int
weasel_pci_match(device_t parent, cfdata_t cf, void *aux)
{
        struct pci_attach_args *pa = aux;

        if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_MIDDLE_DIGITAL &&
            PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_MIDDLE_DIGITAL_WEASEL_CONTROL)
                return (1);

        return (0);
}

static void
weasel_pci_attach(device_t parent, device_t self, void *aux)
{
        struct weasel_softc *sc = device_private(self);
        struct pci_attach_args *pa = aux;
        struct weasel_config_block cfg;
        const char *vers, *mode;
        uint8_t v, *cp;
        uint16_t cfg_size;
        uint8_t buf[8];

        sc->sc_dev = self;

        printf(": PCI-Weasel watchdog timer\n");

        if (pci_mapreg_map(pa, PCI_MAPREG_START,
            PCI_MAPREG_TYPE_MEM|PCI_MAPREG_MEM_TYPE_32BIT, 0,
            &sc->sc_st, &sc->sc_sh, NULL, NULL) != 0) {
                aprint_error_dev(self, "unable to map device registers\n");
                return;
        }

        /* Ping the Weasel to see if it's alive. */
        if (weasel_issue_command(sc, OS_CMD_PING)) {
                aprint_error_dev(self, "Weasel didn't respond to PING\n");
                return;
        }
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
        if ((v = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD)) !=
            OS_RET_PONG) {
                aprint_error_dev(self,
                    "unexpected PING response from Weasel: 0x%02x\n", v);
                return;
        }

        /* Read the config block. */
        if (weasel_issue_command(sc, OS_CMD_SHOW_CONFIG)) {
                aprint_error_dev(self,
                    "Weasel didn't respond to SHOW_CONFIG\n");
                return;
        }
        cfg_size = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);

        if (++cfg_size != sizeof(cfg)) {
                aprint_error_dev(self,
                    "weird config block size from Weasel: 0x%03x\n", cfg_size);
                return;
        }

        for (cp = (uint8_t *) &cfg; cfg_size != 0; cfg_size--) {
                if (weasel_wait_response(sc)) {
                        aprint_error_dev(self,
                            "Weasel stopped providing config block(%d)\n",
                            cfg_size);
                        return;
                }
                *cp++ = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
                bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
        }

        switch (cfg.cfg_version) {
        case CFG_VERSION_2:
                vers="2";
                switch (cfg.enable_duart_switching) {
                case 0:
                        mode = "emulation";
                        break;
                case 1:
                        mode = "serial";
                        break;
                case 2:
                        mode = "autoswitch";
                        break;
                default:
                        mode = "unknown";
                }
                break;

        default:
                vers = mode = NULL;
        }

        if (vers != NULL)
                printf("%s: %s mode\n", device_xname(self), mode);
        else
                printf("%s: unknown config version 0x%02x\n",
                    device_xname(self), cfg.cfg_version);

        /*
         * Fetch sw version.
         */
        if (weasel_issue_command(sc, OS_CMD_QUERY_SW_VER)) {
                aprint_error_dev(self,
                    "didn't reply to software version query.\n");
        }
        else {
                v = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
                bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
                if (v>7)
                        printf("%s: weird length for version string(%d).\n",
                            device_xname(self), v);
                memset(buf, 0, sizeof(buf));
                for (cp = buf; v != 0; v--) {
                        if (weasel_wait_response(sc)) {
                                printf("%s: Weasel stopped providing version\n",
                                    device_xname(self));
                        }
                        *cp++ = bus_space_read_1(sc->sc_st, sc->sc_sh,
                            WEASEL_DATA_RD);
                        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS,
                            0);
                }
                printf("%s: sw: %s", device_xname(self), buf);
        }
        /*
         * Fetch logic version.
         */
        if (weasel_issue_command(sc, OS_CMD_QUERY_L_VER)) {
                aprint_normal("\n");
                aprint_error_dev(self,
                    "didn't reply to logic version query.\n");
        }
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
        v = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
        printf(" logic: %03d", v);
        /*
         * Fetch vga bios version.
         */
        if (weasel_issue_command(sc, OS_CMD_QUERY_VB_VER)) {
                aprint_normal("\n");
                aprint_error_dev(self,
                    "didn't reply to vga bios version query.\n");
        }
        v = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
        printf(" vga bios: %d.%d", (v>>4), (v&0x0f));
        /*
         * Fetch hw version.
         */
        if (weasel_issue_command(sc, OS_CMD_QUERY_HW_VER)) {
                aprint_normal("\n");
                aprint_error_dev(self,
                    "didn't reply to hardware version query.\n");
        }
        v = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
        printf(" hw: %d.%d", (v>>4), (v&0x0f));

        printf("\n%s: break passthrough %s", device_xname(self),
            cfg.break_passthru ? "enabled" : "disabled");

        if ((sc->sc_wdog_armed = weasel_pci_wdog_query_state(sc)) == -1)
                sc->sc_wdog_armed = 0;

        /* Weasel is big-endian */
        sc->sc_wdog_period = be16toh(cfg.wdt_msec) / 1000;

        printf(", watchdog timer %d sec.\n", sc->sc_wdog_period);
        sc->sc_smw.smw_name = "weasel";
        sc->sc_smw.smw_cookie = sc;
        sc->sc_smw.smw_setmode = weasel_pci_wdog_setmode;
        sc->sc_smw.smw_tickle = weasel_pci_wdog_tickle;
        sc->sc_smw.smw_period = sc->sc_wdog_period;

        if (sysmon_wdog_register(&sc->sc_smw) != 0)
                aprint_error_dev(self, "unable to register PC-Weasel watchdog "
                    "with sysmon\n");
}

CFATTACH_DECL_NEW(weasel_pci, sizeof(struct weasel_softc),
    weasel_pci_match, weasel_pci_attach, NULL, NULL);

static int
weasel_wait_response(struct weasel_softc *sc)
{
        int i;

        for (i = 10000; i ; i--) {
                delay(100);
                if (bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS) ==
                    OS_WS_HOST_READ)
                        return(0);
        }
        return (1);
}

static int
weasel_issue_command(struct weasel_softc *sc, uint8_t cmd)
{
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_WR, cmd);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_HOST_STATUS,
            OS_HS_WEASEL_READ);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
        return (weasel_wait_response(sc));
}

static int
weasel_pci_wdog_setmode(struct sysmon_wdog *smw)
{
        struct weasel_softc *sc = smw->smw_cookie;
        int error = 0;

        if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
                error = weasel_pci_wdog_disarm(sc);
        } else {
                if (smw->smw_period == WDOG_PERIOD_DEFAULT)
                        smw->smw_period = sc->sc_wdog_period;
                else if (smw->smw_period != sc->sc_wdog_period) {
                        /* Can't change the period on the Weasel. */
                        return (EINVAL);
                }
                error = weasel_pci_wdog_arm(sc);
                weasel_pci_wdog_tickle(smw);
        }

        return (error);
}

static int
weasel_pci_wdog_tickle(struct sysmon_wdog *smw)
{
        struct weasel_softc *sc = smw->smw_cookie;
        u_int8_t reg;
        int x;
        int s;
        int error = 0;

        s = splhigh();
        /*
         * first we tickle the watchdog
         */
        reg = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_CHALLENGE);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_RESPONSE, ~reg);

        /*
         * then we check to make sure the weasel is still armed. If someone
         * has rebooted the weasel for whatever reason (firmware update),
         * then the watchdog timer would no longer be armed and we'd be
         * servicing nothing. Let the user know that the machine is no
         * longer being monitored by the weasel.
         */
        if((x = weasel_pci_wdog_query_state(sc)) == -1)
                error = EIO;
        if (x == 1) {
                error = 0;
        } else {
                printf("%s: Watchdog timer disabled on PC/Weasel! Disarming wdog.\n",
                        device_xname(sc->sc_dev));
                sc->sc_wdog_armed = 0;
                sysmon_wdog_setmode(smw, WDOG_MODE_DISARMED, 0);
                error = 1;
        }
        splx(s);

        return (error);
}

static int
weasel_pci_wdog_arm(struct weasel_softc *sc)
{
        int x;
        int s;
        int error = 0;

        s = splhigh();
        if (weasel_issue_command(sc, OS_CMD_WDT_ENABLE)) {
                printf("%s: no reply to watchdog enable. Check Weasel \"Allow Watchdog\" setting.\n",
                        device_xname(sc->sc_dev));
                error = EIO;
        }
        (void)bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);

        /*
         * Ensure that the Weasel thinks it's in the same mode we want it to
         * be in.   EIO if not.
         */
        x = weasel_pci_wdog_query_state(sc);
        switch (x) {
                case -1:
                        error = EIO;
                        break;
                case 0:
                        sc->sc_wdog_armed = 0;
                        error = EIO;
                        break;
                case 1:
                        sc->sc_wdog_armed = 1;
                        error = 0;
                        break;
        }

        splx(s);
        return(error);
}


static int
weasel_pci_wdog_disarm(struct weasel_softc *sc)
{
        int x;
        int s;
        int error = 0;

        s = splhigh();

        if (weasel_issue_command(sc, OS_CMD_WDT_DISABLE)) {
                printf("%s: didn't reply to watchdog disable.\n",
                        device_xname(sc->sc_dev));
                error = EIO;
        }
        (void)bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);

        /*
         * Ensure that the Weasel thinks it's in the same mode we want it to
         * be in.   EIO if not.
         */
        x = weasel_pci_wdog_query_state(sc);
        switch (x) {
                case -1:
                        error = EIO;
                        break;
                case 0:
                        sc->sc_wdog_armed = 0;
                        error = 0;
                        break;
                case 1:
                        sc->sc_wdog_armed = 1;
                        error = EIO;
                        break;
        }

        splx(s);
        return(error);
}

static int
weasel_pci_wdog_query_state(struct weasel_softc *sc)
{

        u_int8_t v;

        if (weasel_issue_command(sc, OS_CMD_WDT_QUERY)) {
                printf("%s: didn't reply to watchdog state query.\n",
                        device_xname(sc->sc_dev));
                bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
                return(-1);
        }
        v = bus_space_read_1(sc->sc_st, sc->sc_sh, WEASEL_DATA_RD);
        bus_space_write_1(sc->sc_st, sc->sc_sh, WEASEL_STATUS, 0);
        return(v);
}