/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 *      Serial I/O driver for Z8530 chips
 */


#include        <sys/types.h>
#include        <sys/param.h>
#include        <sys/systm.h>
#include        <sys/sysmacros.h>
#include        <sys/stropts.h>
#include        <sys/stream.h>
#include        <sys/stat.h>
#include        <sys/mkdev.h>
#include        <sys/cmn_err.h>
#include        <sys/errno.h>
#include        <sys/kmem.h>
#include        <sys/zsdev.h>
#include        <sys/debug.h>
#include        <sys/machsystm.h>

#include        <sys/conf.h>
#include        <sys/sunddi.h>
#include        <sys/errno.h>

#define  ZS_TRACING
#ifdef  ZS_TRACING
#include <sys/vtrace.h>

/*
 * Temp tracepoint definitions
 */
#define TR_FAC_ZS               51

#define TR_ZS_H_INT_START       1
#define TR_ZS_H_INT_END         2
#define TR_ZS_INT_START         3
#define TR_ZS_INT_END           4

#define TR_FAC_ZS_INT           52
#define TR_READ_START           1
#define TR_READ_END             2

#endif  /* ZSH_TRACING */

#define KIOIP           KSTAT_INTR_PTR(zs->intrstats)

#ifndef MAXZS
#define MAXZS           4
#endif
int maxzs = MAXZS;

int nzs = 0;

struct zscom *zscom;
struct zscom *zscurr;
struct zscom *zslast;
struct zs_prog *zs_prog;
char  *zssoftCAR;
int     zs_watchdog_count = 10; /* countdown to determine if tx hung */

int zs_drain_check = 15000000;          /* tunable: exit drain check time */

#ifdef ZS_DEBUG
char zs_h_log[ZS_H_LOG_MAX +10];
int zs_h_log_n = 0;
#define zs_h_log_add(c) \
        { \
                if (zs_h_log_n >= ZS_H_LOG_MAX) \
                        zs_h_log_n = 0; \
                zs_h_log[zs_h_log_n++] = c; \
                zs_h_log[zs_h_log_n] = '\0'; \
        }

#else /* NO_ZS_DEBUG */
#define zs_h_log_add(c)
#endif /* ZS_DEBUG */


/*
 * Driver data
 */

#define GETPROP(dip, str, defval) \
        ddi_getprop(DDI_DEV_T_ANY, (dip), DDI_PROP_DONTPASS, (str), (defval))

int     zs_usec_delay = 1;
int     zssoftpend;
ddi_softintr_t zs_softintr_id;
time_t  default_dtrlow = 3;     /* hold dtr low nearly this long on close */
static ddi_iblock_cookie_t zs_iblock;
static ddi_iblock_cookie_t zs_hi_iblock;
static int zs_addedsoft = 0;


/*
 * Driver information for auto-configuration stuff.
 */

static int zsprobe(dev_info_t *dev);
static int zsattach(dev_info_t *dev, ddi_attach_cmd_t cmd);
static int zsdetach(dev_info_t *dev, ddi_detach_cmd_t cmd);
void    zsopinit(struct zscom *zs, struct zsops *zso);

static void zsnull_intr(struct zscom *zs);
static int zsnull_softint(struct zscom *zs);
static int zsnull_suspend(struct zscom *zs);
static int zsnull_resume(struct zscom *zs);

struct zsops zsops_null = {
                        zsnull_intr,
                        zsnull_intr,
                        zsnull_intr,
                        zsnull_intr,
                        zsnull_softint,
                        zsnull_suspend,
                        zsnull_resume
};

extern struct streamtab asynctab;       /* default -- from zs_async.c */

uint_t zs_high_intr(caddr_t argzs);
uint_t zsintr(caddr_t intarg);

extern int zsc_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
void **result);

extern int ddi_create_internal_pathname(dev_info_t *dip, char *name,
    int spec_type, minor_t minor_num);

extern struct streamtab zsstab;
int             zssoftpend;             /* soft interrupt pending */
kmutex_t        zs_soft_lock;           /* adapt.lock,to use to protect data */
                                        /* common to sev. streams or ports   */
kmutex_t        zs_curr_lock;           /* lock protecting zscurr */

extern kcondvar_t lbolt_cv;

/*
 * curently the only spin lock level 12 for all ocasions
 */

#define ZSS_CONF_FLAG   (D_NEW | D_MP)

static  struct cb_ops cb_zs_ops = {
        nulldev,                /* cb_open */
        nulldev,                /* cb_close */
        nodev,                  /* cb_strategy */
        nodev,                  /* cb_print */
        nodev,                  /* cb_dump */
        nodev,                  /* cb_read */
        nodev,                  /* cb_write */
        nodev,                  /* cb_ioctl */
        nodev,                  /* cb_devmap */
        nodev,                  /* cb_mmap */
        nodev,                  /* cb_segmap */
        nochpoll,               /* cb_chpoll */
        ddi_prop_op,            /* cb_prop_op */
        &asynctab,              /* cb_stream */
        (int)(ZSS_CONF_FLAG)    /* cb_flag */
};

struct dev_ops zs_ops = {
        DEVO_REV,               /* devo_rev */
        0,                      /* devo_refcnt */
        zsc_info,               /* devo_getinfo */
        nulldev,                /* devo_identify */
        zsprobe,                /* devo_probe */
        zsattach,               /* devo_attach */
        zsdetach,               /* devo_detach */
        nodev,                  /* devo_reset */
        &cb_zs_ops,             /* devo_cb_ops */
        (struct bus_ops *)NULL, /* devo_bus_ops */
        ddi_power,              /* devo_power */
        ddi_quiesce_not_supported,      /* devo_quiesce */
};


/*
 * This is the loadable module wrapper.
 */

#include <sys/modctl.h>

/*
 * Module linkage information for the kernel.
 */

extern struct mod_ops mod_driverops;

static struct modldrv modldrv = {
                &mod_driverops, /* Type of module.  This one is a driver */
                "Z8530 serial driver",
                &zs_ops,        /* driver ops */
};

static struct modlinkage modlinkage = {
                        MODREV_1, (void *)&modldrv, NULL
};

int
_init(void)
{
        return (mod_install(&modlinkage));
}

int
_fini(void)
{
        return (EBUSY);
}

int
_info(struct modinfo *modinfop)
{
        return (mod_info(&modlinkage, modinfop));
}

static int
zsprobe(dev_info_t *dev)
{
        struct zscc_device *zsaddr;
        int     rval;
        auto char       c;

        rval = DDI_PROBE_FAILURE;

        /*
         * temporarily map in  registers
         */
        if (ddi_map_regs(dev, 0, (caddr_t *)&zsaddr, 0, 0)) {
                cmn_err(CE_WARN, "zsprobe: unable to map registers");
                return (rval);
        }

        /*
         * NON-DDI Compliant call
         */
        mon_clock_stop();

        /*
         * get in sync with the chip
         */

        if (ddi_peek8(dev, (char *)&zsaddr->zscc_control, &c) != DDI_SUCCESS) {
                goto out;
        }
        drv_usecwait(2);

        /*
         * The traditional test for the presence of an 8530 has been to write
         * a 15 (octal 017) to its control register address, then read it back.
         * A Z8530 will respond to this with the contents of Read-Register 15.
         * If this address were memory, or something else, we would expect to
         * see the 15 again.  Normally, the contents of RR15 will be entirely
         * different.  A Z8530 does not use the D0 and D2 bits of register 15,
         * so they should equal zero.  Compatable chips should do the same.
         * Beware of "enhanced" SCC's that do not guarantee this.
         */
        if (ddi_poke8(dev, (char *)&zsaddr->zscc_control, '\017')
            != DDI_SUCCESS) {
                goto out;
        }
        drv_usecwait(2);
        if (ddi_peek8(dev, (char *)&zsaddr->zscc_control, &c) != DDI_SUCCESS) {
                goto out;
        }
        drv_usecwait(2);
        if (c & 5) {
                goto out;
        }

        rval = DDI_PROBE_SUCCESS;

out:
        /*
         * NON-DDI Compliant call
         */
        mon_clock_start();

        ddi_unmap_regs(dev, 0, (caddr_t *)&zsaddr, 0, 0);
        return (rval);
}

/*ARGSUSED*/
static int
zsattach(dev_info_t *dev, ddi_attach_cmd_t cmd)
{
        struct zscom    *zs;
        int             loops, i;
        uint_t          s;
        int             rtsdtr_bits = 0;
        char                    softcd;
        uchar_t rr;
        short                   speed[2];
        int                     current_chip = ddi_get_instance(dev);
        struct zscc_device      *tmpzs;         /* for mapping purposes */
        char name[16];
        int keyboard_prop;

        switch (cmd) {
        case DDI_ATTACH:
                break;

        case DDI_RESUME:
                zs = &zscom[current_chip*2];
                /*
                 * Try to resume first channel
                 */
                if (!zs->zs_resume || (zs->zs_resume)(zs) != DDI_SUCCESS)
                        return (DDI_FAILURE);
                /*
                 * And the second channel
                 */
                zs++;
                if (!zs->zs_resume || (zs->zs_resume)(zs) != DDI_SUCCESS) {
                        zs--;
                        if (!zs->zs_suspend ||
                            (zs->zs_suspend)(zs) != DDI_SUCCESS)
                                cmn_err(CE_WARN,
                                    "zs: inconsistent suspend/resume state");
                        return (DDI_FAILURE);
                }
                return (DDI_SUCCESS);

        default:
                return (DDI_FAILURE);
        }

        if (zscom == NULL) {
                mutex_init(&zs_soft_lock, NULL, MUTEX_DRIVER, (void *)ZS_PL);
                mutex_init(&zs_curr_lock, NULL, MUTEX_DRIVER, (void *)ZS_PL_HI);
                zscom = kmem_zalloc(maxzs * sizeof (struct zscom), KM_SLEEP);
                zs_prog = kmem_zalloc(maxzs * sizeof (struct zs_prog),
                    KM_SLEEP);
                zssoftCAR = kmem_zalloc(maxzs, KM_SLEEP);
                /* don't set nzs until arrays are allocated */
                membar_producer();
                nzs = maxzs;
                zscurr = &zscom[(current_chip*2) + 1];
                zslast = &zscom[current_chip*2];
                i = GETPROP(dev, "zs-usec-delay", 0);
                zs_usec_delay = (i <= 0) ? 1 : i;
        }

        if (2 * current_chip >=  maxzs) {
                cmn_err(CE_WARN,
                    "zs: unable to allocate resources for  chip %d.",
                    current_chip);
                cmn_err(CE_WARN, "Change zs:maxzs in /etc/system");
                return (DDI_FAILURE);
        }
        zs = &zscom[current_chip*2];

        /*
         * map in the device registers
         */
        if (ddi_map_regs(dev, 0, (caddr_t *)&zs->zs_addr, 0, 0)) {
                cmn_err(CE_WARN, "zs%d: unable to map registers\n",
                    current_chip);
                return (DDI_FAILURE);
        }

        tmpzs = zs->zs_addr;

        /*
         * Non-DDI compliant Sun-Ness specfic call(s)
         */

        /*
         * Stop the monitor's polling interrupt.
         *
         * I know that this is not exactly obvious. On all sunmon PROM
         * machines, the PROM has can have a high level periodic clock
         * interrupt going at this time. It uses this periodic interrupt
         * to poll the console tty or kbd uart to check for things like
         * BREAK or L1-A (abort). While we're probing this device out we
         * have to shut that off so the PROM won't get confused by what
         * we're doing to the zs. This has caused some pretty funny bugs
         * in its time.
         *
         * For OPENPROM machines, the prom  takes level12 interrupts directly,
         * but we call this routine anyway (I forget why).
         */
        mon_clock_stop();

        /*
         * Go critical to keep uart from urking.
         */
        s = ddi_enter_critical();

        /*
         * We are about to issue a full reset to this chip.
         * First, now that interrupts are blocked, we will delay up to a
         * half-second, checking both channels for any stray activity.
         * Next we will preserve the time constants from both channels,
         * so that they can be restored after the reset.  This is especially
         * important for the console device.  Finally, do the reset and
         * follow it with an extended recovery while the chip settles down.
         */
        for (loops = 0; loops++ <= 500; DELAY(1000)) {
                SCC_READA(1, rr);
                if ((rr & ZSRR1_ALL_SENT) == 0) continue;
                SCC_READB(1, rr);
                if ((rr & ZSRR1_ALL_SENT) == 0) continue;
                SCC_READA(0, rr);
                if ((rr & ZSRR0_TX_READY) == 0) continue;
                SCC_READB(0, rr);
                if ((rr & ZSRR0_TX_READY) != 0) break;
        }

        SCC_READA(12, speed[0]);
        SCC_READA(13, rr);
        speed[0] |= rr << 8;
        SCC_READB(12, speed[1]);
        SCC_READB(13, rr);
        speed[1] |= rr << 8;

        SCC_WRITE(9, ZSWR9_RESET_WORLD);
        DELAY(10);

        /*
         * Set up the other components of the zscom structs for this chip.
         */
        for (i = 0; i < 2; i++) {
                /*
                 * Property for ignoring DCD.
                 * We switch between 'a' and 'b' ports for this device.
                 */
                static char prop[] = "port-a-ignore-cd";

                /*
                 * For this channel, set the hardware address, allocate the
                 * high-level mutex, and update the zscurr pointer.
                 * The high-level lock is shared by both channels because
                 * 8530 register addressing is non-atomic and asymetrical.
                 * Multiple threads crossing paths during this operation
                 * could trash the chip, and thus, possibly the system console.
                 */
                if (i == 0) {           /* port A */
                        zs->zs_addr = (struct zscc_device *)
                            ((uintptr_t)tmpzs | ZSOFF);
                        (zs+1)->zs_excl_hi = zs->zs_excl_hi = &zs_curr_lock;
                } else {                /* port B */
                        zs++;
                        zs->zs_addr = (struct zscc_device *)
                            ((uintptr_t)tmpzs & ~ZSOFF);
                        zscurr = zs;
                }
                zs->zs_unit = current_chip * 2 + i;
                zs->zs_dip = dev;
                zs->zs_excl = kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
                mutex_init(zs->zs_excl, NULL, MUTEX_DRIVER, (void *)ZS_PL);
                zs->zs_ocexcl = kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
                mutex_init(zs->zs_ocexcl, NULL, MUTEX_DRIVER, (void *)ZS_PL);

                zsopinit(zs, &zsops_null);

                prop[5] = 'a' + i;
                softcd = GETPROP((dev_info_t *)(dev), prop, 0);
                zssoftCAR[zs->zs_unit] = softcd;
                if (softcd)
                        rtsdtr_bits = ZSWR5_RTS | ZSWR5_DTR;

                keyboard_prop = GETPROP((dev_info_t *)(zs->zs_dip),
                    "keyboard", 0);

                mutex_enter(&zs_curr_lock);

                /*
                 * Set up the default asynch modes
                 * so the monitor will still work
                 */
                SCC_WRITE(4, ZSWR4_PARITY_EVEN | ZSWR4_1_STOP | ZSWR4_X16_CLK);
                SCC_WRITE(3, ZSWR3_RX_8);
                SCC_WRITE(11, ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD);
                SCC_WRITE(12, (speed[i] & 0xff));
                SCC_WRITE(13, (speed[i] >> 8) & 0xff);
                SCC_WRITE(14, ZSWR14_BAUD_FROM_PCLK);
                SCC_WRITE(3, ZSWR3_RX_8 | ZSWR3_RX_ENABLE);
                SCC_WRITE(5, ZSWR5_TX_ENABLE | ZSWR5_TX_8 | rtsdtr_bits);
                SCC_WRITE(14, ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK);

                /*
                 * The SYNC pin on the second SCC (keyboard & mouse) may not
                 * be connected and noise creates transitions on this line.
                 * This floods the system with interrupts, unless the
                 * Sync/Hunt Interrupt Enable is cleared.  So write
                 * register 15 with everything we need but that one.
                 */
                if (keyboard_prop) {
                        SCC_WRITE(15, ZSR15_BREAK | ZSR15_TX_UNDER |
                            ZSR15_CTS | ZSR15_CD);
                }

                SCC_WRITE0(ZSWR0_RESET_ERRORS);
                SCC_WRITE0(ZSWR0_RESET_STATUS);
                mutex_exit(&zs_curr_lock);

                zs->zs_dtrlow = gethrestime_sec() - default_dtrlow;
                cv_init(&zs->zs_flags_cv, NULL, CV_DEFAULT, NULL);
                zsa_init(zs);
        }

        mutex_enter(&zs_curr_lock);
        SCC_WRITE(9, ZSWR9_MASTER_IE | ZSWR9_VECTOR_INCL_STAT);
        DELAY(4000);
        mutex_exit(&zs_curr_lock);

        /*
         * Two levels of interrupt - chip interrupts at a high level (12),
         * (which is seen below as zs_high_intr), and then as a secondary
         * stage soft interrupt as seen in zsintr below.
         *
         * Because zs_high_intr does a window save, as well as calls to
         * other functions, we cannot install it as a "fast" interrupt
         * that would execute right out of the trap window.  Too bad...
         */
        if (ddi_add_intr(dev, (uint_t)0, &zs_hi_iblock,
            (ddi_idevice_cookie_t *)0, zs_high_intr,
            (caddr_t)0) != DDI_SUCCESS) {
                cmn_err(CE_PANIC, "cannot set high level zs interrupt");
                /*NOTREACHED*/
        }

        if (zs_addedsoft == 0) {
                if (ddi_add_softintr(dev, DDI_SOFTINT_HIGH, &zs_softintr_id,
                    &zs_iblock, (ddi_idevice_cookie_t *)0,
                    zsintr, (caddr_t)0) != DDI_SUCCESS) {
                        cmn_err(CE_PANIC,
                            "cannot set second stage zs interrupt");
                        /*NOTREACHED*/
                }

                zs_addedsoft++; /* we only need one zsintr! */
        }

        if (zs > zslast)
                zslast = zs;

        (void) ddi_exit_critical(s);

        /*
         * Non-DDI compliant Sun-Ness specific call
         */
        mon_clock_start();      /* re-enable monitor's polling interrupt */

        if (!GETPROP(zs->zs_dip, "keyboard", 0)) {
                static char *serial_line = DDI_NT_SERIAL_MB;
                static char *dial_out = DDI_NT_SERIAL_MB_DO;

                /*
                 * Export names for channel a or b consconfig match...
                 * The names exported to the filesystem include the
                 * designated tty'a' type name and may not match the PROM
                 * pathname.
                 * Note the special name "obp-console-name" used in these calls.
                 * This keeps the ports and devlinks programs from seeing these
                 * names. (But allows ddi_pathname_to_dev_t to see them.)
                 * We don't need to do this if the instance number is zero,
                 * because we'll create them below, in this case.
                 */

                if (ddi_get_instance(dev) != 0)  {

                        /*
                         * Select a node type unused by ddi/devfs
                         */
                        static char *obp_type = "obp-console-name";

                        (void) strcpy(name, "a");
                        if (ddi_create_minor_node(dev, name, S_IFCHR,
                            ddi_get_instance(dev) * 2,
                            obp_type, 0) == DDI_FAILURE) {
                                ddi_remove_minor_node(dev, NULL);
                                return (DDI_FAILURE);
                        }
                        (void) strcpy(name, "b");
                        if (ddi_create_minor_node(dev, name, S_IFCHR,
                            (ddi_get_instance(dev) * 2) + 1,
                            obp_type, 0) == DDI_FAILURE) {
                                ddi_remove_minor_node(dev, NULL);
                                return (DDI_FAILURE);
                        }
                }

                /*
                 * Export normal device names...
                 */
                (void) sprintf(name, "%c", (ddi_get_instance(dev) + 'a'));
                if (ddi_create_minor_node(dev, name, S_IFCHR,
                    ddi_get_instance(dev) * 2,
                    serial_line, 0) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }
                (void) sprintf(name, "%c", (ddi_get_instance(dev) + 'b'));
                if (ddi_create_minor_node(dev, name, S_IFCHR,
                    (ddi_get_instance(dev) * 2) + 1,
                    serial_line, 0) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }
                (void) sprintf(name, "%c,cu", (ddi_get_instance(dev) + 'a'));
                if (ddi_create_minor_node(dev, name, S_IFCHR,
                    (ddi_get_instance(dev) * 2) | OUTLINE,
                    dial_out, 0) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }
                (void) sprintf(name, "%c,cu", (ddi_get_instance(dev) + 'b'));
                if (ddi_create_minor_node(dev, name, S_IFCHR,
                    ((ddi_get_instance(dev)  * 2) + 1) | OUTLINE,
                    dial_out, 0) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }
        } else {

                /*
                 * Create keyboard and mouse nodes which devfs doesn't see
                 */

                /*
                 * This set of minor nodes is for use with the consconfig_dacf
                 * module for the sun4u platforms.  (See PSARC/1998/212)
                 */
                if (ddi_create_internal_pathname(dev, "keyboard", S_IFCHR,
                    ddi_get_instance(dev) * 2) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }

                if (ddi_create_internal_pathname(dev, "mouse", S_IFCHR,
                    (ddi_get_instance(dev) * 2) + 1) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }

                /*
                 * These minor nodes are for use with pre-sun4u platforms.
                 * Either one set or the other will be opened by consconfig.
                 */
                (void) strcpy(name, "a");
                if (ddi_create_internal_pathname(dev, name, S_IFCHR,
                    ddi_get_instance(dev) * 2) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }

                (void) strcpy(name, "b");
                if (ddi_create_internal_pathname(dev, name, S_IFCHR,
                    (ddi_get_instance(dev) * 2) + 1) == DDI_FAILURE) {
                        ddi_remove_minor_node(dev, NULL);
                        return (DDI_FAILURE);
                }

        }

        ddi_report_dev(dev);
        /*
         * Initialize power management bookkeeping; components are
         * created idle.
         */
        if (pm_create_components(dev, 3) == DDI_SUCCESS) {
                (void) pm_busy_component(dev, 0);
                pm_set_normal_power(dev, 0, 1);
                pm_set_normal_power(dev, 1, 1);
                pm_set_normal_power(dev, 2, 1);
        } else {
                return (DDI_FAILURE);
        }

        (void) sprintf(name, "zsc%d", current_chip);
        zs->intrstats = kstat_create("zs", current_chip, name, "controller",
            KSTAT_TYPE_INTR, 1, KSTAT_FLAG_PERSISTENT);
        if (zs->intrstats) {
                kstat_install(zs->intrstats);
        }

        return (DDI_SUCCESS);
}

static int
zsdetach(dev_info_t *dev, ddi_detach_cmd_t cmd)
{
        struct zscom *zs;
        int     current_chip = ddi_get_instance(dev);

        switch (cmd) {
        case DDI_DETACH:
                return (DDI_FAILURE);

        case DDI_SUSPEND:
                zs = &zscom[current_chip*2];
                /*
                 * Try to suspend first channel
                 */
                if (!zs->zs_suspend || (zs->zs_suspend)(zs) != DDI_SUCCESS)
                        return (DDI_FAILURE);
                /*
                 * And the second channel
                 */
                zs++;
                if (!zs->zs_suspend || (zs->zs_suspend)(zs) != DDI_SUCCESS) {
                        zs--;
                        if (!zs->zs_resume ||
                            (zs->zs_resume)(zs) != DDI_SUCCESS)
                                cmn_err(CE_WARN,
                                    "zs: inconsistent suspend/resume state");
                        return (DDI_FAILURE);
                }
                return (DDI_SUCCESS);

        default:
                return (DDI_FAILURE);
        }
}

/*
 * SCC High Level Interrupt Handler
 *
 * This routine fields the level 12 interrupts generated by the 8530 chips.
 * When the SCC interrupts the conditions that triggered it are available
 * for reference in Read Register 3 of the A channel (RR3A).  We process
 * all the pending interrupts before returning.  The maximum interrupts
 * that will be processed before returning is set to 6, which is twice
 * the size of RX-FIFO.
 * We keep a pointer to the B side of the most recently interrupting chip
 * in zscurr.
 */

/*
 * 'argzs' actually 'struct zscom *argzs'
 */

#define ZSRR3_INT_PENDING (ZSRR3_IP_B_STAT | ZSRR3_IP_B_TX | ZSRR3_IP_B_RX |\
                        ZSRR3_IP_A_STAT | ZSRR3_IP_A_TX | ZSRR3_IP_A_RX)

#define ZSRR1_ANY_ERRORS (ZSRR1_PE | ZSRR1_DO | ZSRR1_FE | ZSRR1_RXEOF)
#define ZS_HIGH_INTR_LOOPLIMIT 6

/*ARGSUSED*/
uint_t
zs_high_intr(caddr_t argzs)
{
        struct zscom    *zs;
        uchar_t stat, isource, count;
        int             unit;

        TRACE_0(TR_FAC_ZS, TR_ZS_H_INT_START, "zs_h_int start");
        mutex_enter(&zs_curr_lock);
        zs = zscurr;                            /* Points at Channel B */

        ZSNEXTPOLL(zs, zscurr);

        SCC_READA(3, isource);
start_zs_h:
        count = ZS_HIGH_INTR_LOOPLIMIT;
        while ((isource & ZSRR3_INT_PENDING) && (count--)) {
                if (isource & ZSRR3_IP_B_STAT)
                        (zs->zs_xsint)(zs);
                else {
                        if (isource & ZSRR3_IP_B_TX)
                                (zs->zs_txint)(zs);
                        if (isource & ZSRR3_IP_B_RX) {
                                SCC_READ(1, stat);
                                if (stat & ZSRR1_ANY_ERRORS)
                                        (zs->zs_srint)(zs);
                                else if ((SCC_READ0()) & ZSRR0_RX_READY)
                                        (zs->zs_rxint)(zs);
                        }
                }

                zs -= 1;
                if (isource & ZSRR3_IP_A_STAT)
                        (zs->zs_xsint)(zs);
                else {
                        if (isource & ZSRR3_IP_A_TX)
                                (zs->zs_txint)(zs);
                        if (isource & ZSRR3_IP_A_RX) {
                                SCC_READ(1, stat);
                                if (stat & ZSRR1_ANY_ERRORS)
                                        (zs->zs_srint)(zs);
                                else if ((SCC_READ0()) & ZSRR0_RX_READY)
                                        (zs->zs_rxint)(zs);
                        }
                }

                zs = zscurr;
                SCC_READA(3, isource);
        }

        if (count == ZS_HIGH_INTR_LOOPLIMIT) {
                unit = (nzs >> 1) - 1;
                while (unit--) {
                        zs += 2;        /* Always Channel B */
                        if (zs > zslast)
                                zs = &zscom[1];
                        if (!zs->zs_ops)
                                continue;
                        SCC_READA(3, isource);
                        if (isource & ZSRR3_INT_PENDING) {
                                zscurr = zs;    /* update zscurr and */
                                goto start_zs_h;
                        }
                }
                if (zs->intrstats) {
                        KIOIP->intrs[KSTAT_INTR_HARD]++;
                }
                mutex_exit(&zs_curr_lock);
                TRACE_0(TR_FAC_ZS, TR_ZS_H_INT_END, "zs_h_int end");
                return (DDI_INTR_UNCLAIMED);    /* Must not be for us. */
        }
        if (zs->intrstats) {
                KIOIP->intrs[KSTAT_INTR_HARD]++;
        }
        mutex_exit(&zs_curr_lock);      /* we're done with zscurr */
        TRACE_0(TR_FAC_ZS, TR_ZS_H_INT_END, "zs_h_int end");
        return (DDI_INTR_CLAIMED);
}

/*
 * Handle a second-stage interrupt.
 */
/*ARGSUSED*/
uint_t
zsintr(caddr_t intarg)
{
        struct zscom *zs;
        int    rv;

        /*
         * Test and clear soft interrupt.
         */
        TRACE_0(TR_FAC_ZS, TR_ZS_INT_START,
            "zs_int start");

        mutex_enter(&zs_curr_lock);
        rv = zssoftpend;
        if (rv != 0) {
                zssoftpend = 0;
        }
        mutex_exit(&zs_curr_lock);

        if (rv) {
                for (zs = &zscom[0]; zs <= zslast; zs++) {
                        if (zs->zs_flags & ZS_NEEDSOFT) {
                                zs->zs_flags &= ~ZS_NEEDSOFT;
                                (void) (*zs->zs_ops->zsop_softint)(zs);
                                if (zs->intrstats) {
                                        KIOIP->intrs[KSTAT_INTR_SOFT]++;
                                }
                        }
                }
        }
        TRACE_0(TR_FAC_ZS, TR_ZS_INT_END,
            "zs_int end");
        return (rv);
}

void
setzssoft(void)
{
        ddi_trigger_softintr(zs_softintr_id);
}

/*
 * Install a new ops vector into low level vector routine addresses
 */
void
zsopinit(struct zscom *zs, struct zsops *zso)
{
        zs->zs_txint    = zso->zsop_txint;
        zs->zs_xsint    = zso->zsop_xsint;
        zs->zs_rxint    = zso->zsop_rxint;
        zs->zs_srint    = zso->zsop_srint;
        zs->zs_suspend  = zso->zsop_suspend;
        zs->zs_resume   = zso->zsop_resume;
        zs->zs_ops      = zso;
        zs->zs_flags    = 0;
}

/*
 * Set or get the modem control status.
 *
 * This routine relies on the fact that the bits of interest in RR0 (CD and
 * CTS) do not overlap the bits of interest in WR5 (RTS and DTR).  Thus, they
 * can be combined into a single 'int' without harm.
 */
int
zsmctl(struct zscom *zs, int bits, int how)
{
        int mbits, obits;
        time_t now, held;

        ASSERT(mutex_owned(zs->zs_excl_hi));
        ASSERT(mutex_owned(zs->zs_excl));

again:
        mbits = zs->zs_wreg[5] & (ZSWR5_RTS|ZSWR5_DTR);
        SCC_WRITE0(ZSWR0_RESET_STATUS);
        mbits |= SCC_READ0() & (ZSRR0_CD|ZSRR0_CTS);
        ZSDELAY();
        obits = mbits;

        switch (how) {

        case DMSET:
                mbits = bits;
                break;

        case DMBIS:
                mbits |= bits;
                break;

        case DMBIC:
                mbits &= ~bits;
                break;

        case DMGET:
                return (mbits);
        }

        now = gethrestime_sec();
        held = now - zs->zs_dtrlow;

        /*
         * if DTR is going low, stash current time away
         */
        if (~mbits & obits & ZSWR5_DTR)
                zs->zs_dtrlow = now;

        /*
         * if DTR is going high, sleep until it has been low a bit
         */
        if ((mbits & ~obits & ZSWR5_DTR) && (held < default_dtrlow)) {
                mutex_exit(zs->zs_excl_hi);
                cv_wait(&lbolt_cv, zs->zs_excl);
                if (zs->zs_suspended)
                        (void) ddi_dev_is_needed(zs->zs_dip, 0, 1);
                mutex_enter(zs->zs_excl_hi);
                goto again;
        }

        zs->zs_wreg[5] &= ~(ZSWR5_RTS|ZSWR5_DTR);
        SCC_BIS(5, mbits & (ZSWR5_RTS|ZSWR5_DTR));
        return (mbits);
}

/*
 * Program the Z8530 registers.
 */
void
zs_program(struct zs_prog *zspp)
{
        struct zscom *zs = zspp->zs;
        int     loops;
        uchar_t c;
        uchar_t wr10 = 0, wr14 = 0;

        ASSERT(mutex_owned(zs->zs_excl));
        ASSERT(mutex_owned(zs->zs_excl_hi));

        /*
         * There are some special cases to account for before reprogramming.
         * We might be transmitting, so delay 100,000 usec (worst case at 110
         * baud) for this to finish, then disable the receiver until later,
         * reset the External Status Change latches and the error bits, and
         * drain the receive FIFO.
         * XXX: Doing any kind of reset (WR9) here causes trouble!
         */
        if (zspp->flags & ZSP_SYNC) {
                SCC_WRITE(7, SDLCFLAG);
                wr10 = ZSWR10_PRESET_ONES;
                if (zspp->flags & ZSP_NRZI)
                        wr10 |= ZSWR10_NRZI;
                SCC_WRITE(10, wr10);
        } else {
                for (loops = 1000; loops > 0; --loops) {
                        SCC_READ(1, c);
                        if (c & ZSRR1_ALL_SENT)
                                break;
                        DELAY(100);
                }
                SCC_WRITE(3, 0);
                SCC_WRITE0(ZSWR0_RESET_STATUS);
                SCC_WRITE0(ZSWR0_RESET_ERRORS);
                c = SCC_READDATA();             /* Empty the FIFO */
                c = SCC_READDATA();
                c = SCC_READDATA();
        }

        /*
         * Programming the SCC is done in three phases.
         * Phase one sets operating modes:
         */
        SCC_WRITE(4, zspp->wr4);
        SCC_WRITE(11, zspp->wr11);
        SCC_WRITE(12, zspp->wr12);
        SCC_WRITE(13, zspp->wr13);
        if (zspp->flags & ZSP_PLL) {
                SCC_WRITE(14, ZSWR14_DPLL_SRC_BAUD);
                SCC_WRITE(14, ZSWR14_DPLL_NRZI);
        } else
                SCC_WRITE(14, ZSWR14_DPLL_DISABLE);

        /*
         * Phase two enables special hardware functions:
         */
        wr14 = ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA;
        if (zspp->flags & ZSP_LOOP)
                wr14 |= ZSWR14_LOCAL_LOOPBACK;
        if (zspp->flags & ZSP_ECHO)
                wr14 |= ZSWR14_AUTO_ECHO;
        SCC_WRITE(14, wr14);
        SCC_WRITE(3, zspp->wr3);
        SCC_WRITE(5, zspp->wr5);

        SCC_WRITE0(ZSWR0_RESET_TXCRC);

        if (zspp->flags & ZSP_PARITY_SPECIAL) {
                SCC_WRITE(1, ZSWR1_PARITY_SPECIAL);
        } else {
                SCC_WRITE(1, 0);
        }

        /*
         * Phase three enables interrupt sources:
         */
        SCC_WRITE(15, zspp->wr15);
        SCC_WRITE0(ZSWR0_RESET_STATUS);
        SCC_WRITE0(ZSWR0_RESET_ERRORS);
        SCC_BIS(1, ZSWR1_INIT);
}

static void
zsnull_intr(struct zscom *zs)
{
        short   c;

        SCC_WRITE0(ZSWR0_RESET_TXINT);
        SCC_WRITE0(ZSWR0_RESET_STATUS);
        c = SCC_READDATA();
        ZSDELAY();
#ifdef lint
        c = c;
#endif /* lint */
        SCC_WRITE0(ZSWR0_RESET_ERRORS);
}

static int
zsnull_softint(struct zscom *zs)
{
        cmn_err(CE_WARN, "zs%d: unexpected soft int\n", zs->zs_unit);
        return (0);
}

/*
 * These will be called on suspend/resume for un-opened zs ports.
 */
static int
zsnull_suspend(struct zscom *zs)
{
        struct zs_prog  *zspp = &zs_prog[zs->zs_unit];

        /*
         * Get a copy of the current registers
         */
        mutex_enter(zs->zs_excl);
        mutex_enter(zs->zs_excl_hi);
        zspp->zs = zs;
        zspp->flags = 0;
        zspp->wr3 = zs->zs_wreg[3];
        zspp->wr4 = zs->zs_wreg[4];
        zspp->wr5 = zs->zs_wreg[5];
        zspp->wr11 = zs->zs_wreg[11];
        zspp->wr12 = zs->zs_wreg[12];
        zspp->wr13 = zs->zs_wreg[13];
        zspp->wr15 = zs->zs_wreg[15];
        mutex_exit(zs->zs_excl_hi);
        mutex_exit(zs->zs_excl);

        return (DDI_SUCCESS);
}

static int
zsnull_resume(struct zscom *zs)
{
        struct zs_prog  *zspp = &zs_prog[zs->zs_unit];

        /*
         * Restore registers
         */
        mutex_enter(zs->zs_excl);
        mutex_enter(zs->zs_excl_hi);
        zs_program(zspp);
        SCC_WRITE(9, ZSWR9_MASTER_IE);
        DELAY(4000);
        mutex_exit(zs->zs_excl_hi);
        mutex_exit(zs->zs_excl);
        return (DDI_SUCCESS);
}