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[netbsd-mini2440.git] / sys / arch / sparc / dev / zs.c

/*      $NetBSD: zs.c,v 1.115 2009/05/22 03:51:30 mrg Exp $     */

/*-
 * Copyright (c) 1996 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Gordon W. Ross.
 *
 * 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.
 */

/*
 * Zilog Z8530 Dual UART driver (machine-dependent part)
 *
 * Runs two serial lines per chip using slave drivers.
 * Plain tty/async lines use the zs_async slave.
 * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.115 2009/05/22 03:51:30 mrg Exp $");

#include "opt_ddb.h"
#include "opt_kgdb.h"
#include "opt_sparc_arch.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/time.h>
#include <sys/syslog.h>
#include <sys/intr.h>

#include <machine/bsd_openprom.h>
#include <machine/autoconf.h>
#include <machine/eeprom.h>
#include <machine/psl.h>
#include <machine/z8530var.h>

#include <dev/cons.h>
#include <dev/ic/z8530reg.h>

#include <sparc/sparc/vaddrs.h>
#include <sparc/sparc/auxreg.h>
#include <sparc/sparc/auxiotwo.h>
#include <sparc/dev/cons.h>
#include <dev/sun/kbd_ms_ttyvar.h>

#include "kbd.h"
#include "ms.h"
#include "wskbd.h"

/*
 * Some warts needed by z8530tty.c -
 * The default parity REALLY needs to be the same as the PROM uses,
 * or you can not see messages done with printf during boot-up...
 */
int zs_def_cflag = (CREAD | CS8 | HUPCL);

/*
 * The Sun provides a 4.9152 MHz clock to the ZS chips.
 */
#define PCLK    (9600 * 512)    /* PCLK pin input clock rate */

#define ZS_DELAY()              (CPU_ISSUN4C ? (0) : delay(2))

/* The layout of this is hardware-dependent (padding, order). */
struct zschan {
        volatile uint8_t zc_csr;        /* ctrl,status, and indirect access */
        uint8_t         zc_xxx0;
        volatile uint8_t zc_data;       /* data */
        uint8_t         zc_xxx1;
};
struct zsdevice {
        /* Yes, they are backwards. */
        struct  zschan zs_chan_b;
        struct  zschan zs_chan_a;
};

/* ZS channel used as the console device (if any) */
void *zs_conschan_get, *zs_conschan_put;

static uint8_t zs_init_reg[16] = {
        0,      /* 0: CMD (reset, etc.) */
        0,      /* 1: No interrupts yet. */
        0,      /* 2: IVECT */
        ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
        ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
        ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
        0,      /* 6: TXSYNC/SYNCLO */
        0,      /* 7: RXSYNC/SYNCHI */
        0,      /* 8: alias for data port */
        ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
        0,      /*10: Misc. TX/RX control bits */
        ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
        ((PCLK/32)/9600)-2,     /*12: BAUDLO (default=9600) */
        0,                      /*13: BAUDHI (default=9600) */
        ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
        ZSWR15_BREAK_IE,
};

/* Console ops */
static int  zscngetc(dev_t);
static void zscnputc(dev_t, int);
static void zscnpollc(dev_t, int);

struct consdev zs_consdev = {
        NULL,
        NULL,
        zscngetc,
        zscnputc,
        zscnpollc,
        NULL,
};


/****************************************************************
 * Autoconfig
 ****************************************************************/

/* Definition of the driver for autoconfig. */
static int  zs_match_mainbus(device_t, cfdata_t, void *);
static int  zs_match_obio(device_t, cfdata_t, void *);
static void zs_attach_mainbus(device_t, device_t, void *);
static void zs_attach_obio(device_t, device_t, void *);

#if defined(SUN4D)
#include <sparc/dev/bootbusvar.h>

static int  zs_match_bootbus(device_t, cfdata_t, void *);
static void zs_attach_bootbus(device_t, device_t, void *);

CFATTACH_DECL_NEW(zs_bootbus, sizeof(struct zsc_softc),
    zs_match_bootbus, zs_attach_bootbus, NULL, NULL);
#endif /* SUN4D */

static void zs_attach(struct zsc_softc *, struct zsdevice *, int);
static int  zs_print(void *, const char *name);

CFATTACH_DECL_NEW(zs_mainbus, sizeof(struct zsc_softc),
    zs_match_mainbus, zs_attach_mainbus, NULL, NULL);

CFATTACH_DECL_NEW(zs_obio, sizeof(struct zsc_softc),
    zs_match_obio, zs_attach_obio, NULL, NULL);

extern struct cfdriver zs_cd;

/* softintr(9) cookie, shared by all instances of this driver */
static void *zs_sicookie;

/* Interrupt handlers. */
static int zshard(void *);
static void zssoft(void *);

static int zs_get_speed(struct zs_chanstate *);

/* Console device support */
static int zs_console_flags(int, int, int);

/* Power management hooks */
int  zs_enable(struct zs_chanstate *);
void zs_disable(struct zs_chanstate *);


/* XXX from dev/ic/z8530tty.c */
extern struct tty *zstty_get_tty_from_dev(struct device *);

/*
 * Is the zs chip present?
 */
static int
zs_match_mainbus(device_t parent, cfdata_t cf, void *aux)
{
        struct mainbus_attach_args *ma = aux;

        if (strcmp(cf->cf_name, ma->ma_name) != 0)
                return (0);

        return (1);
}

static int
zs_match_obio(device_t parent, cfdata_t cf, void *aux)
{
        union obio_attach_args *uoba = aux;
        struct obio4_attach_args *oba;

        if (uoba->uoba_isobio4 == 0) {
                struct sbus_attach_args *sa = &uoba->uoba_sbus;

                if (strcmp(cf->cf_name, sa->sa_name) != 0)
                        return (0);

                return (1);
        }

        oba = &uoba->uoba_oba4;
        return (bus_space_probe(oba->oba_bustag, oba->oba_paddr,
                                1, 0, 0, NULL, NULL));
}

#if defined(SUN4D)
static int
zs_match_bootbus(device_t parent, cfdata_t cf, void *aux)
{
        struct bootbus_attach_args *baa = aux;

        return (strcmp(cf->cf_name, baa->ba_name) == 0);
}
#endif /* SUN4D */

static void
zs_attach_mainbus(device_t parent, device_t self, void *aux)
{
        struct zsc_softc *zsc = device_private(self);
        struct mainbus_attach_args *ma = aux;

        zsc->zsc_dev = self;
        zsc->zsc_bustag = ma->ma_bustag;
        zsc->zsc_dmatag = ma->ma_dmatag;
        zsc->zsc_promunit = prom_getpropint(ma->ma_node, "slave", -2);
        zsc->zsc_node = ma->ma_node;

        /*
         * For machines with zs on mainbus (all sun4c models), we expect
         * the device registers to be mapped by the PROM.
         */
        zs_attach(zsc, ma->ma_promvaddr, ma->ma_pri);
}

static void
zs_attach_obio(device_t parent, device_t self, void *aux)
{
        struct zsc_softc *zsc = device_private(self);
        union obio_attach_args *uoba = aux;

        zsc->zsc_dev = self;

        if (uoba->uoba_isobio4 == 0) {
                struct sbus_attach_args *sa = &uoba->uoba_sbus;
                void *va;
                struct zs_chanstate *cs;
                int channel;

                if (sa->sa_nintr == 0) {
                        aprint_error(": no interrupt lines\n");
                        return;
                }

                /*
                 * Some sun4m models (Javastations) may not map the zs device.
                 */
                if (sa->sa_npromvaddrs > 0)
                        va = (void *)sa->sa_promvaddr;
                else {
                        bus_space_handle_t bh;

                        if (sbus_bus_map(sa->sa_bustag,
                                         sa->sa_slot,
                                         sa->sa_offset,
                                         sa->sa_size,
                                         BUS_SPACE_MAP_LINEAR, &bh) != 0) {
                                aprint_error(": cannot map zs registers\n");
                                return;
                        }
                        va = (void *)bh;
                }

                /*
                 * Check if power state can be set, e.g. Tadpole 3GX
                 */
                if (prom_getpropint(sa->sa_node, "pwr-on-auxio2", 0)) {
                        aprint_normal(": powered via auxio2");
                        for (channel = 0; channel < 2; channel++) {
                                cs = &zsc->zsc_cs_store[channel];
                                cs->enable = zs_enable;
                                cs->disable = zs_disable;
                        }
                }

                zsc->zsc_bustag = sa->sa_bustag;
                zsc->zsc_dmatag = sa->sa_dmatag;
                zsc->zsc_promunit = prom_getpropint(sa->sa_node, "slave", -2);
                zsc->zsc_node = sa->sa_node;
                zs_attach(zsc, va, sa->sa_pri);
        } else {
                struct obio4_attach_args *oba = &uoba->uoba_oba4;
                bus_space_handle_t bh;
                bus_addr_t paddr = oba->oba_paddr;

                /*
                 * As for zs on mainbus, we require a PROM mapping.
                 */
                if (bus_space_map(oba->oba_bustag,
                                  paddr,
                                  sizeof(struct zsdevice),
                                  BUS_SPACE_MAP_LINEAR | OBIO_BUS_MAP_USE_ROM,
                                  &bh) != 0) {
                        aprint_error(": cannot map zs registers\n");
                        return;
                }
                zsc->zsc_bustag = oba->oba_bustag;
                zsc->zsc_dmatag = oba->oba_dmatag;
                /*
                 * Find prom unit by physical address
                 * We're just comparing the address (not the iospace) here
                 */
                paddr = BUS_ADDR_PADDR(paddr);
                if (cpuinfo.cpu_type == CPUTYP_4_100)
                        /*
                         * On the sun4/100, the top-most 4 bits are zero
                         * on obio addresses; force them to 1's for the
                         * sake of the comparison here.
                         */
                        paddr |= 0xf0000000;
                zsc->zsc_promunit =
                        (paddr == 0xf1000000) ? 0 :
                        (paddr == 0xf0000000) ? 1 :
                        (paddr == 0xe0000000) ? 2 : -2;

                zs_attach(zsc, (void *)bh, oba->oba_pri);
        }
}

#if defined(SUN4D)
static void
zs_attach_bootbus(device_t parent, device_t self, void *aux)
{
        struct zsc_softc *zsc = device_private(self);
        struct bootbus_attach_args *baa = aux;
        void *va;

        zsc->zsc_dev = self;

        if (baa->ba_nintr == 0) {
                aprint_error(": no interrupt lines\n");
                return;
        }

        if (baa->ba_npromvaddrs > 0)
                va = (void *) baa->ba_promvaddrs;
        else {
                bus_space_handle_t bh;

                if (bus_space_map(baa->ba_bustag,
                    BUS_ADDR(baa->ba_slot, baa->ba_offset),
                    baa->ba_size, BUS_SPACE_MAP_LINEAR, &bh) != 0) {
                        aprint_error(": cannot map zs registers\n");
                        return;
                }
                va = (void *) bh;
        }

        zsc->zsc_bustag = baa->ba_bustag;
        zsc->zsc_promunit = prom_getpropint(baa->ba_node, "slave", -2);
        zsc->zsc_node = baa->ba_node;
        zs_attach(zsc, va, baa->ba_intr[0].oi_pri);
}
#endif /* SUN4D */

/*
 * Attach a found zs.
 *
 * USE ROM PROPERTIES port-a-ignore-cd AND port-b-ignore-cd FOR
 * SOFT CARRIER, AND keyboard PROPERTY FOR KEYBOARD/MOUSE?
 */
static void
zs_attach(struct zsc_softc *zsc, struct zsdevice *zsd, int pri)
{
        struct zsc_attach_args zsc_args;
        struct zs_chanstate *cs;
        int channel;
        static int didintr, prevpri;
#if (NKBD > 0) || (NMS > 0)
        int ch0_is_cons = 0;
#endif

        memset(&zsc_args, 0, sizeof zsc_args);
        if (zsd == NULL) {
                aprint_error(": configuration incomplete\n");
                return;
        }

        if (!didintr) {
                zs_sicookie = softint_establish(SOFTINT_SERIAL, zssoft, NULL);
                if (zs_sicookie == NULL) {
                        aprint_error(": cannot establish soft int handler\n");
                        return;
                }
        }
        aprint_normal(" softpri %d\n", IPL_SOFTSERIAL);

        /*
         * Initialize software state for each channel.
         */
        for (channel = 0; channel < 2; channel++) {
                struct zschan *zc;
                struct device *child;
                int hwflags;

                zsc_args.channel = channel;
                zsc_args.hwflags = 0;
                cs = &zsc->zsc_cs_store[channel];
                zsc->zsc_cs[channel] = cs;

                zs_lock_init(cs);
                cs->cs_channel = channel;
                cs->cs_private = NULL;
                cs->cs_ops = &zsops_null;
                cs->cs_brg_clk = PCLK / 16;

                zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;

                hwflags = zs_console_flags(zsc->zsc_promunit,
                                                    zsc->zsc_node,
                                                    channel);

#if NWSKBD == 0 
                /* Not using wscons console, so always set console flags.*/
                zsc_args.hwflags = hwflags;
                if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE) {
                        zsc_args.hwflags |= ZS_HWFLAG_USE_CONSDEV;
                        zsc_args.consdev = &zs_consdev;
                }
#else
                /* If we are unit 1, then this is the "real" console.
                 * Remember this in order to set up the keyboard and
                 * mouse line disciplines for SUN4 machines below.
                 * Also, don't set the console flags, otherwise we
                 * tell zstty_attach() to attach as console.
                 */
                if (zsc->zsc_promunit == 1) {
                        if ((hwflags & ZS_HWFLAG_CONSOLE_INPUT) != 0 &&
                            !channel) {
#if (NKBD > 0) || (NMS > 0)
                                ch0_is_cons = 1;
#endif
                        }
                } else {
                        zsc_args.hwflags = hwflags;
                }
#endif
                if ((zsc_args.hwflags & ZS_HWFLAG_CONSOLE_INPUT) != 0) {
                        zs_conschan_get = zc;
                }
                if ((zsc_args.hwflags & ZS_HWFLAG_CONSOLE_OUTPUT) != 0) {
                        zs_conschan_put = zc;
                }
                /* Childs need to set cn_dev, etc */

                cs->cs_reg_csr  = &zc->zc_csr;
                cs->cs_reg_data = &zc->zc_data;

                memcpy(cs->cs_creg, zs_init_reg, 16);
                memcpy(cs->cs_preg, zs_init_reg, 16);

                /* XXX: Consult PROM properties for this?! */
                cs->cs_defspeed = zs_get_speed(cs);
                cs->cs_defcflag = zs_def_cflag;

                /* Make these correspond to cs_defcflag (-crtscts) */
                cs->cs_rr0_dcd = ZSRR0_DCD;
                cs->cs_rr0_cts = 0;
                cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
                cs->cs_wr5_rts = 0;

                /*
                 * Clear the master interrupt enable.
                 * The INTENA is common to both channels,
                 * so just do it on the A channel.
                 */
                if (channel == 0) {
                        zs_write_reg(cs, 9, 0);
                }

                /*
                 * Look for a child driver for this channel.
                 * The child attach will setup the hardware.
                 */

                child = config_found(zsc->zsc_dev, &zsc_args, zs_print);
                if (child == NULL) {
                        /* No sub-driver.  Just reset it. */
                        uint8_t reset = (channel == 0) ?
                                ZSWR9_A_RESET : ZSWR9_B_RESET;
                        zs_lock_chan(cs);
                        zs_write_reg(cs,  9, reset);
                        zs_unlock_chan(cs);
                }
#if (NKBD > 0) || (NMS > 0)
                /*
                 * If this was a zstty it has a keyboard
                 * property on it we need to attach the
                 * sunkbd and sunms line disciplines.
                 * There are no properties on SUN4 machines.
                 * For them, check if we have set the
                 * ch0_is_cons variable above.
                 */
                if ((child != NULL) &&
                    (device_is_a(child, "zstty")) && (
                    (CPU_ISSUN4 && ch0_is_cons) || (!CPU_ISSUN4 &&
                    (prom_getproplen(zsc->zsc_node, "keyboard") == 0))))
                {
                        struct kbd_ms_tty_attach_args kma;
                        struct tty *tp = zstty_get_tty_from_dev(child);
                        kma.kmta_tp = tp;
                        kma.kmta_dev = tp->t_dev;
                        kma.kmta_consdev = zsc_args.consdev;

                        /* Attach 'em if we got 'em. */
#if (NKBD > 0)
                        if (channel == 0) {
                                kma.kmta_name = "keyboard";
                                config_found(child, &kma, NULL);
                        }
#endif
#if (NMS > 0)
                        if (channel == 1) {
                                kma.kmta_name = "mouse";
                                config_found(child, &kma, NULL);
                        }
#endif
                }
#endif
        }

        /*
         * Now safe to install interrupt handlers.  Note the arguments
         * to the interrupt handlers aren't used.  Note, we only do this
         * once since both SCCs interrupt at the same level and vector.
         */
        if (!didintr) {
                didintr = 1;
                prevpri = pri;
                bus_intr_establish(zsc->zsc_bustag, pri, IPL_SERIAL,
                                   zshard, NULL);
        } else if (pri != prevpri)
                panic("broken zs interrupt scheme");

        evcnt_attach_dynamic(&zsc->zsc_intrcnt, EVCNT_TYPE_INTR, NULL,
            device_xname(zsc->zsc_dev), "intr");

        /*
         * Set the master interrupt enable and interrupt vector.
         * (common to both channels, do it on A)
         */
        cs = zsc->zsc_cs[0];
        zs_lock_chan(cs);
        /* interrupt vector */
        zs_write_reg(cs, 2, zs_init_reg[2]);
        /* master interrupt control (enable) */
        zs_write_reg(cs, 9, zs_init_reg[9]);
        zs_unlock_chan(cs);

#if 0
        /*
         * XXX: L1A hack - We would like to be able to break into
         * the debugger during the rest of autoconfiguration, so
         * lower interrupts just enough to let zs interrupts in.
         * This is done after both zs devices are attached.
         */
        if (zsc->zsc_promunit == 1) {
                aprint_debug("zs1: enabling zs interrupts\n");
                (void)splfd(); /* XXX: splzs - 1 */
        }
#endif

}

static int
zs_print(void *aux, const char *name)
{
        struct zsc_attach_args *args = aux;

        if (name != NULL)
                aprint_normal("%s: ", name);

        if (args->channel != -1)
                aprint_normal(" channel %d", args->channel);

        return (UNCONF);
}

static volatile int zssoftpending;

/*
 * Our ZS chips all share a common, autovectored interrupt,
 * so we have to look at all of them on each interrupt.
 */
static int
zshard(void *arg)
{
        struct zsc_softc *zsc;
        int unit, rr3, rval, softreq;

        rval = softreq = 0;
        for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
                struct zs_chanstate *cs;

                zsc = device_lookup_private(&zs_cd, unit);
                if (zsc == NULL)
                        continue;
                rr3 = zsc_intr_hard(zsc);
                /* Count up the interrupts. */
                if (rr3) {
                        rval |= rr3;
                        zsc->zsc_intrcnt.ev_count++;
                }
                if ((cs = zsc->zsc_cs[0]) != NULL)
                        softreq |= cs->cs_softreq;
                if ((cs = zsc->zsc_cs[1]) != NULL)
                        softreq |= cs->cs_softreq;
        }

        /* We are at splzs here, so no need to lock. */
        if (softreq && (zssoftpending == 0)) {
                zssoftpending = 1;
                softint_schedule(zs_sicookie);
        }
        return (rval);
}

/*
 * Similar scheme as for zshard (look at all of them)
 */
static void
zssoft(void *arg)
{
        struct zsc_softc *zsc;
        int unit;

        /* This is not the only ISR on this IPL. */
        if (zssoftpending == 0)
                return;

        /*
         * The soft intr. bit will be set by zshard only if
         * the variable zssoftpending is zero.  The order of
         * these next two statements prevents our clearing
         * the soft intr bit just after zshard has set it.
         */
        /* ienab_bic(IE_ZSSOFT); */
        zssoftpending = 0;

#if 0 /* not yet */
        /* Make sure we call the tty layer with tty_lock held. */
        mutex_spin_enter(&tty_lock);
#endif
        for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
                zsc = device_lookup_private(&zs_cd, unit);
                if (zsc == NULL)
                        continue;
                (void)zsc_intr_soft(zsc);
        }
#if 0 /* not yet */
        mutex_spin_exit(&tty_lock);
#endif
}


/*
 * Compute the current baud rate given a ZS channel.
 */
static int
zs_get_speed(struct zs_chanstate *cs)
{
        int tconst;

        tconst = zs_read_reg(cs, 12);
        tconst |= zs_read_reg(cs, 13) << 8;
        return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
}

/*
 * MD functions for setting the baud rate and control modes.
 * bps - in bits per second
 */
int
zs_set_speed(struct zs_chanstate *cs, int bps)
{
        int tconst, real_bps;

        if (bps == 0)
                return (0);

#ifdef  DIAGNOSTIC
        if (cs->cs_brg_clk == 0)
                panic("zs_set_speed");
#endif

        tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
        if (tconst < 0)
                return (EINVAL);

        /* Convert back to make sure we can do it. */
        real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);

        /* XXX - Allow some tolerance here? */
        if (real_bps != bps)
                return (EINVAL);

        cs->cs_preg[12] = tconst;
        cs->cs_preg[13] = tconst >> 8;

        /* Caller will stuff the pending registers. */
        return (0);
}

int
zs_set_modes(struct zs_chanstate *cs, int cflag)
{

        /*
         * Output hardware flow control on the chip is horrendous:
         * if carrier detect drops, the receiver is disabled, and if
         * CTS drops, the transmitter is stoped IN MID CHARACTER!
         * Therefore, NEVER set the HFC bit, and instead use the
         * status interrupt to detect CTS changes.
         */
        zs_lock_chan(cs);
        cs->cs_rr0_pps = 0;
        if ((cflag & (CLOCAL | MDMBUF)) != 0) {
                cs->cs_rr0_dcd = 0;
                if ((cflag & MDMBUF) == 0)
                        cs->cs_rr0_pps = ZSRR0_DCD;
        } else
                cs->cs_rr0_dcd = ZSRR0_DCD;
        if ((cflag & CRTSCTS) != 0) {
                cs->cs_wr5_dtr = ZSWR5_DTR;
                cs->cs_wr5_rts = ZSWR5_RTS;
                cs->cs_rr0_cts = ZSRR0_CTS;
        } else if ((cflag & CDTRCTS) != 0) {
                cs->cs_wr5_dtr = 0;
                cs->cs_wr5_rts = ZSWR5_DTR;
                cs->cs_rr0_cts = ZSRR0_CTS;
        } else if ((cflag & MDMBUF) != 0) {
                cs->cs_wr5_dtr = 0;
                cs->cs_wr5_rts = ZSWR5_DTR;
                cs->cs_rr0_cts = ZSRR0_DCD;
        } else {
                cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
                cs->cs_wr5_rts = 0;
                cs->cs_rr0_cts = 0;
        }
        zs_unlock_chan(cs);

        /* Caller will stuff the pending registers. */
        return (0);
}


/*
 * Read or write the chip with suitable delays.
 */

uint8_t
zs_read_reg(struct zs_chanstate *cs, uint8_t reg)
{
        uint8_t val;

        *cs->cs_reg_csr = reg;
        ZS_DELAY();
        val = *cs->cs_reg_csr;
        ZS_DELAY();
        return (val);
}

void
zs_write_reg(struct zs_chanstate *cs, uint8_t reg, uint8_t val)
{

        *cs->cs_reg_csr = reg;
        ZS_DELAY();
        *cs->cs_reg_csr = val;
        ZS_DELAY();
}

uint8_t
zs_read_csr(struct zs_chanstate *cs)
{
        uint8_t val;

        val = *cs->cs_reg_csr;
        ZS_DELAY();
        return (val);
}

void
zs_write_csr(struct zs_chanstate *cs, uint8_t val)
{

        *cs->cs_reg_csr = val;
        ZS_DELAY();
}

uint8_t
zs_read_data(struct zs_chanstate *cs)
{
        uint8_t val;

        val = *cs->cs_reg_data;
        ZS_DELAY();
        return (val);
}

void
zs_write_data(struct zs_chanstate *cs, uint8_t val)
{

        *cs->cs_reg_data = val;
        ZS_DELAY();
}

/****************************************************************
 * Console support functions (Sun specific!)
 * Note: this code is allowed to know about the layout of
 * the chip registers, and uses that to keep things simple.
 * XXX - I think I like the mvme167 code better. -gwr
 ****************************************************************/

/*
 * Handle user request to enter kernel debugger.
 */
void
zs_abort(struct zs_chanstate *cs)
{
        struct zschan *zc = zs_conschan_get;
        int rr0;

        /* Wait for end of break to avoid PROM abort. */
        /* XXX - Limit the wait? */
        do {
                rr0 = zc->zc_csr;
                ZS_DELAY();
        } while (rr0 & ZSRR0_BREAK);

#if defined(KGDB)
        zskgdb(cs);
#elif defined(DDB)
        Debugger();
#else
        printf("stopping on keyboard abort\n");
        callrom();
#endif
}

int  zs_getc(void *);
void zs_putc(void *, int);

/*
 * Polled input char.
 */
int
zs_getc(void *arg)
{
        struct zschan *zc = arg;
        int s, c, rr0;
        u_int omid;

        /* Temporarily direct interrupts at ourselves */
        s = splhigh();
        omid = setitr(cpuinfo.mid);

        /* Wait for a character to arrive. */
        do {
                rr0 = zc->zc_csr;
                ZS_DELAY();
        } while ((rr0 & ZSRR0_RX_READY) == 0);

        c = zc->zc_data;
        ZS_DELAY();
        setitr(omid);
        splx(s);

        /*
         * This is used by the kd driver to read scan codes,
         * so don't translate '\r' ==> '\n' here...
         */
        return (c);
}

/*
 * Polled output char.
 */
void
zs_putc(void *arg, int c)
{
        struct zschan *zc = arg;
        int s, rr0;
        u_int omid;

        /* Temporarily direct interrupts at ourselves */
        s = splhigh();
        omid = setitr(cpuinfo.mid);

        /* Wait for transmitter to become ready. */
        do {
                rr0 = zc->zc_csr;
                ZS_DELAY();
        } while ((rr0 & ZSRR0_TX_READY) == 0);

        /*
         * Send the next character.
         * Now you'd think that this could be followed by a ZS_DELAY()
         * just like all the other chip accesses, but it turns out that
         * the `transmit-ready' interrupt isn't de-asserted until
         * some period of time after the register write completes
         * (more than a couple instructions).  So to avoid stray
         * interrupts we put in the 2us delay regardless of CPU model.
         */
        zc->zc_data = c;
        delay(2);

        setitr(omid);
        splx(s);
}

/*****************************************************************/
/*
 * Polled console input putchar.
 */
static int
zscngetc(dev_t dev)
{

        return (zs_getc(zs_conschan_get));
}

/*
 * Polled console output putchar.
 */
static void
zscnputc(dev_t dev, int c)
{

        zs_putc(zs_conschan_put, c);
}

static void
zscnpollc(dev_t dev, int on)
{

        /* No action needed */
}

static int
zs_console_flags(int promunit, int node, int channel)
{
        int cookie, flags = 0;

        switch (prom_version()) {
        case PROM_OLDMON:
        case PROM_OBP_V0:
                /*
                 * Use `promunit' and `channel' to derive the PROM
                 * stdio handles that correspond to this device.
                 */
                if (promunit == 0)
                        cookie = PROMDEV_TTYA + channel;
                else if (promunit == 1 && channel == 0)
                        cookie = PROMDEV_KBD;
                else
                        cookie = -1;

                if (cookie == prom_stdin())
                        flags |= ZS_HWFLAG_CONSOLE_INPUT;

                /*
                 * Prevent the keyboard from matching the output device
                 * (note that PROMDEV_KBD == PROMDEV_SCREEN == 0!).
                 */
                if (cookie != PROMDEV_KBD && cookie == prom_stdout())
                        flags |= ZS_HWFLAG_CONSOLE_OUTPUT;

                break;

        case PROM_OBP_V2:
        case PROM_OBP_V3:
        case PROM_OPENFIRM:

                /*
                 * Match the nodes and device arguments prepared by
                 * consinit() against our device node and channel.
                 * (The device argument is the part of the OBP path
                 * following the colon, as in `/obio/zs@0,100000:a')
                 */

                /* Default to channel 0 if there are no explicit prom args */
                cookie = 0;

                if (node == prom_stdin_node) {
                        if (prom_stdin_args[0] != '\0')
                                /* Translate (a,b) -> (0,1) */
                                cookie = prom_stdin_args[0] - 'a';

                        if (channel == cookie)
                                flags |= ZS_HWFLAG_CONSOLE_INPUT;
                }

                if (node == prom_stdout_node) {
                        if (prom_stdout_args[0] != '\0')
                                /* Translate (a,b) -> (0,1) */
                                cookie = prom_stdout_args[0] - 'a';

                        if (channel == cookie)
                                flags |= ZS_HWFLAG_CONSOLE_OUTPUT;
                }

                break;

        default:
                break;
        }

        return (flags);
}

/*
 * Power management hooks for zsopen() and zsclose().
 * We use them to power on/off the ports, if necessary.
 */
int
zs_enable(struct zs_chanstate *cs)
{

        auxiotwoserialendis (ZS_ENABLE);
        cs->enabled = 1;
        return(0);
}

void
zs_disable(struct zs_chanstate *cs)
{

        auxiotwoserialendis (ZS_DISABLE);
        cs->enabled = 0;
}