5045 use atomic_{inc,dec}_* instead of atomic_add_*

[illumos-gate.git] / usr / src / uts / common / io / bscbus.c

/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * The "bscbus" driver provides access to the LOMlite2 virtual registers,
 * so that its clients (children) need not be concerned with the details
 * of the access mechanism, which in this case is implemented via a
 * packet-based protocol over a Xbus (similar to ebus) parallel link to the
 * H8 host interface registers.
 *
 * On the other hand, this driver doesn't generally know what the virtual
 * registers signify - only the clients need this information.
 */


#include <sys/note.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/debug.h>
#include <sys/errno.h>
#include <sys/file.h>

#if defined(__sparc)
#include <sys/intr.h>
#include <sys/membar.h>
#endif

#include <sys/kmem.h>
#include <sys/modctl.h>
#include <sys/note.h>
#include <sys/open.h>
#include <sys/poll.h>
#include <sys/spl.h>
#include <sys/stat.h>
#include <sys/strlog.h>
#include <sys/atomic.h>

#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/sunndi.h>

#include <sys/bscbus.h>

#if     defined(NDI_ACC_HDL_V2)

/*
 * Compiling for Solaris 10+ with access handle enhancements
 */
#define HANDLE_TYPE             ndi_acc_handle_t
#define HANDLE_ADDR(hdlp)       (hdlp->ah_addr)
#define HANDLE_FAULT(hdlp)      (hdlp->ah_fault)
#define HANDLE_MAPLEN(hdlp)     (hdlp->ah_len)
#define HANDLE_PRIVATE(hdlp)    (hdlp->ah_bus_private)

#else

/*
 * Compatibility definitions for backport to Solaris 8/9
 */
#define HANDLE_TYPE             ddi_acc_impl_t
#define HANDLE_ADDR(hdlp)       (hdlp->ahi_common.ah_addr)
#define HANDLE_FAULT(hdlp)      (hdlp->ahi_fault)
#define HANDLE_MAPLEN(hdlp)     (hdlp->ahi_common.ah_len)
#define HANDLE_PRIVATE(hdlp)    (hdlp->ahi_common.ah_bus_private)

#define ddi_driver_major(dip)   ddi_name_to_major(ddi_binding_name(dip))

#endif  /* NDI_ACC_HDL_V2 */


/*
 * Local definitions
 */
#define MYNAME                  "bscbus"
#define NOMAJOR                 (~(major_t)0)
#define DUMMY_VALUE             (~(int8_t)0)

#define BSCBUS_INST_TO_MINOR(i) (i)
#define BSCBUS_MINOR_TO_INST(m) (m)

#define BSCBUS_MAX_CHANNELS     (4)

#define BSCBUS_DUMMY_ADDRESS    ((caddr_t)0x0CADD1ED)
#define ADDR_TO_OFFSET(a, hdlp) ((caddr_t)(a) - HANDLE_ADDR(hdlp))
#define ADDR_TO_VREG(a)         ((caddr_t)(a) - BSCBUS_DUMMY_ADDRESS)
#define VREG_TO_ADDR(v)         (BSCBUS_DUMMY_ADDRESS + (v))

#ifdef DEBUG
#define BSCBUS_LOGSTATUS
#endif /* DEBUG */

#ifdef BSCBUS_LOGSTATUS
/*
 * BSC command logging routines.
 * Record the data passing to and from the BSC
 */

typedef enum {
        BSC_CMD_BUSY = 1,               /* bsc reports busy     */
        BSC_CMD_CLEARING = 2,           /* clearing bsc busy    */
        BSC_CMD_CLEARED = 3,            /* cleared bsc busy     */
        BSC_CMD_SENDING = 4,            /* sending next byte    */
        BSC_CMD_SENT = 5,               /* sending last byte    */
        BSC_CMD_PENDING = 6,            /* got sent byte ack    */
        BSC_CMD_REPLY = 7,              /* got reply byte       */
        BSC_CMD_COMPLETE = 8,           /* command complete     */
        BSC_CMD_ERROR_SEQ = 9,          /* error status         */
        BSC_CMD_ERROR_STATUS = 10,      /* error status         */
        BSC_CMD_ERROR_OFLOW = 11,       /* error status         */
        BSC_CMD_ERROR_TOUT = 12,        /* error status         */

        BSC_CMD_PROCESS = 13,           /* async intr           */
        BSC_CMD_V1INTR = 14,            /* v1 intr              */
        BSC_CMD_V1INTRUNCL = 15,        /* v1 intr unclaim      */
        BSC_CMD_DOGPAT = 17             /* watchdog pat         */
} bsc_cmd_stamp_t;

typedef struct {
        hrtime_t        bcl_now;
        int             bcl_seq;
        bsc_cmd_stamp_t bcl_cat;
        uint8_t         bcl_chno;
        uint8_t         bcl_cmdstate;
        uint8_t         bcl_status;
        uint8_t         bcl_data;
} bsc_cmd_log_t;

uint32_t        bscbus_cmd_log_size = 1024;

uint32_t        bscbus_cmd_log_flags = 0xffffffff;

#endif /* BSCBUS_LOGSTATUS */

/*
 * The following definitions are taken from the Hardware Manual for
 * the Hitachi H8S/2148 in conjunction with the hardware specification
 * for the Stiletto blade.
 *
 * Each instance of the host interface has 3 registers on the H8:
 * IDRn  - Input Data Register  - write-only for Solaris.
 *                                writes to this can be done via two
 *                                addresses - control and data.
 *                                The H8 can determine which address was
 *                                written by examining the C/D bit in
 *                                the status register.
 * ODRn  - Output Data Register - read-only for Solaris.
 *                                A read has the side effect of acknowledging
 *                                interrupts.
 * STRn  - Status Register      - read-only for Solaris.
 *
 *
 *
 * In terms of host access to this the Input and Output data registers are
 * mapped at the same address.
 */
#define H8_IDRD 0
#define H8_IDRC 1
#define H8_ODR  0
#define H8_STR  1

#define H8_STR_OBF              0x01    /* data available in ODR */
#define H8_STR_IBF              0x02    /* data for H8 in IDR */
#define H8_STR_IDRC             0x08    /* last write to IDR was to IDRC */
                                        /* 0=data, 1=command */
#define H8_STR_BUSY             0x04    /* H8 busy processing command */
#define H8_STR_TOKENPROTOCOL    0x80    /* token-passing protocol */

/*
 * Packet format ...
 */
#define BSCBUS_MASK             0xc0    /* Byte-type bits               */
#define BSCBUS_PARAM            0x00    /* Parameter byte: 0b0xxxxxxx   */
#define BSCBUS_LAST             0x80    /* Last byte of packet          */
#define BSCBUS_CMD              0x80    /* Command byte:   0b10###XWV   */
#define BSCBUS_STATUS           0xc0    /* Status  byte:   0b11###AEV   */

#define BSCBUS_SEQ              0x38    /* Sequence number bits         */
#define BSCBUS_SEQ_LSB          0x08    /* Sequence number LSB          */
#define BSCBUS_CMD_XADDR        0x04    /* Extended (2-byte) addressing */
#define BSCBUS_CMD_WRITE        0x02    /* Write command                */
#define BSCBUS_CMD_WMSB         0x01    /* Set MSB on Write             */
#define BSCBUS_CMD_READ         0x01    /* Read command                 */
#define BSCBUS_CMD_NOP          0x00    /* NOP command                  */

#define BSCBUS_STATUS_ASYNC     0x04    /* Asynchronous event pending   */
#define BSCBUS_STATUS_ERR       0x02    /* Error in command processing  */
#define BSCBUS_STATUS_MSB       0x01    /* MSB of Value read            */

#define BSCBUS_VREG_LO(x)       ((x) & ((1 << 7) - 1))
#define BSCBUS_VREG_HI(x)       ((x) >> 7)

#define BSCBUS_BUFSIZE          8

#define BSCBUS_CHANNEL_TO_OFFSET(chno)  ((chno) * 2)    /* Register offset */

/*
 * Time periods, in nanoseconds
 *
 * Note that LOMBUS_ONE_SEC and some other time
 * periods are defined in <sys/lombus.h>
 */
#define BSCBUS_CMD_POLL                 (LOMBUS_ONE_SEC)
#define BSCBUS_CMD_POLLNOINTS           (LOMBUS_ONE_SEC/20)
#define BSCBUS_HWRESET_POLL             (LOMBUS_ONE_SEC/20)
#define BSCBUS_HWRESET_TIMEOUT          (LOMBUS_ONE_SEC*2)

#define BSCBUS_DOG_PAT_POLL_LIMIT       (1000)
#define BSCBUS_DOG_PAT_POLL             (1)
#define BSCBUS_PAT_RETRY_LIMIT  5

/*
 * Local datatypes
 */
enum bscbus_cmdstate {
        BSCBUS_CMDSTATE_IDLE,           /* No transaction in progress */
        BSCBUS_CMDSTATE_BUSY,           /* Setting up command */
        BSCBUS_CMDSTATE_CLEARING,       /* Clearing firmware busy status */
        BSCBUS_CMDSTATE_SENDING,        /* Waiting to send data to f/w */
        BSCBUS_CMDSTATE_PENDING,        /* Waiting for ack from f/w */
        BSCBUS_CMDSTATE_WAITING,        /* Waiting for status from f/w */
        BSCBUS_CMDSTATE_READY,          /* Status received/command done */
        BSCBUS_CMDSTATE_ERROR           /* Command failed with error */
};

struct bscbus_channel_state {
        /* Changes to these are protected by the instance ch_mutex mutex */
        struct bscbus_state     *ssp;
        uint8_t                 *ch_regs;
        ddi_acc_handle_t        ch_handle;  /* per channel access handle */
        unsigned int            chno;
        unsigned int            map_count; /* Number of mappings to channel */
        boolean_t               map_dog;   /* channel is mapped for watchdog */

        /*
         * Flag to indicate that we've incurred a hardware fault on
         * accesses to the H8; once this is set, we fake all further
         * accesses in order not to provoke additional bus errors.
         */
        boolean_t               xio_fault;

        /*
         * Data protected by the dog_mutex: the watchdog-patting
         * protocol data (since the dog can be patted from a high-level
         * cyclic), and the interrupt-enabled flag.
         */
        kmutex_t                dog_mutex[1];
        unsigned int            pat_retry_count;
        unsigned int            pat_fail_count;

        /*
         * Serial protocol state data, protected by lo_mutex
         * (which is initialised using <lo_iblk>)
         */
        kmutex_t                lo_mutex[1];
        ddi_iblock_cookie_t     lo_iblk;
        kcondvar_t              lo_cv[1];
        int                     unclaimed_count;

        volatile enum bscbus_cmdstate cmdstate;
        clock_t                 deadline;
        clock_t                 poll_hz;
        boolean_t               interrupt_failed;
        uint8_t                 cmdbuf[BSCBUS_BUFSIZE];
        uint8_t                 *cmdp;  /* Points to last tx'd in cmdbuf */
        uint8_t                 reply[BSCBUS_BUFSIZE];
        uint8_t                 async;
        uint8_t                 index;
        uint8_t                 result;
        uint8_t                 sequence;
        uint32_t                error;
};

#define BSCBUS_TX_PENDING(csp)          ((csp)->cmdp > (csp)->cmdbuf)

/*
 * This driver's soft-state structure
 */

struct bscbus_state {
        /*
         * Configuration data, set during attach
         */
        dev_info_t              *dip;
        major_t                 majornum;
        int                     instance;

        ddi_acc_handle_t        h8_handle;
        uint8_t                 *h8_regs;

        /*
         * Parameters derived from .conf properties
         */
        uint32_t                debug;

        /*
         * Flag to indicate that we are using per channel
         * mapping of the register sets and interrupts.
         * reg set 0 is chan 0
         * reg set 1 is chan 1 ...
         *
         * Interrupts are specified in that order but later
         * channels may not have interrupts.
         */
        boolean_t               per_channel_regs;

        /*
         * channel state data, protected by ch_mutex
         * channel claim/release requests are protected by this mutex.
         */
        kmutex_t                ch_mutex[1];
        struct bscbus_channel_state     channel[BSCBUS_MAX_CHANNELS];

#ifdef BSCBUS_LOGSTATUS
        /*
         * Command logging buffer for recording transactions with the
         * BSC. This is useful for debugging failed transactions and other
         * such funnies.
         */
        bsc_cmd_log_t           *cmd_log;
        uint32_t                cmd_log_idx;
        uint32_t                cmd_log_size;
        uint32_t                cmd_log_flags;
#endif /* BSCBUS_LOGSTATUS */
};

/*
 * The auxiliary structure attached to each child
 * (the child's parent-private-data points to this).
 */
struct bscbus_child_info {
        lombus_regspec_t *rsp;
        int nregs;
};

#ifdef BSCBUS_LOGSTATUS
void bscbus_cmd_log(struct bscbus_channel_state *, bsc_cmd_stamp_t,
    uint8_t, uint8_t);
#else /* BSCBUS_LOGSTATUS */
#define bscbus_cmd_log(state, stamp, status, data)
#endif /* BSCBUS_LOGSTATUS */


/*
 * Local data
 */

static void *bscbus_statep;

static major_t bscbus_major = NOMAJOR;

static ddi_device_acc_attr_t bscbus_dev_acc_attr[1] = {
        DDI_DEVICE_ATTR_V0,
        DDI_STRUCTURE_LE_ACC,
        DDI_STRICTORDER_ACC
};


/*
 *  General utility routines ...
 */

#ifdef DEBUG
static void
bscbus_trace(struct bscbus_channel_state *csp, char code, const char *caller,
        const char *fmt, ...)
{
        char buf[256];
        char *p;
        va_list va;

        if (csp->ssp->debug & (1 << (code-'@'))) {
                p = buf;
                (void) snprintf(p, sizeof (buf) - (p - buf),
                    "%s/%s: ", MYNAME, caller);
                p += strlen(p);

                va_start(va, fmt);
                (void) vsnprintf(p, sizeof (buf) - (p - buf), fmt, va);
                va_end(va);

                buf[sizeof (buf) - 1] = '\0';
                (void) strlog(csp->ssp->majornum, csp->ssp->instance,
                    code, SL_TRACE, buf);
        }
}
#else /* DEBUG */
#define bscbus_trace
#endif /* DEBUG */

static struct bscbus_state *
bscbus_getstate(dev_info_t *dip, int instance, const char *caller)
{
        struct bscbus_state *ssp = NULL;
        dev_info_t *sdip = NULL;
        major_t dmaj = NOMAJOR;

        if (dip != NULL) {
                /*
                 * Use the instance number from the <dip>; also,
                 * check that it really corresponds to this driver
                 */
                instance = ddi_get_instance(dip);
                dmaj = ddi_driver_major(dip);
                if (bscbus_major == NOMAJOR && dmaj != NOMAJOR)
                        bscbus_major = dmaj;
                else if (dmaj != bscbus_major) {
                        cmn_err(CE_WARN,
                            "%s: major number mismatch (%d vs. %d) in %s(),"
                            "probably due to child misconfiguration",
                            MYNAME, bscbus_major, dmaj, caller);
                        instance = -1;
                }
        }

        if (instance >= 0)
                ssp = ddi_get_soft_state(bscbus_statep, instance);
        if (ssp != NULL) {
                sdip = ssp->dip;
                if (dip == NULL && sdip == NULL)
                        ssp = NULL;
                else if (dip != NULL && sdip != NULL && sdip != dip) {
                        cmn_err(CE_WARN,
                            "%s: devinfo mismatch (%p vs. %p) in %s(), "
                            "probably due to child misconfiguration",
                            MYNAME, (void *)dip, (void *)sdip, caller);
                        ssp = NULL;
                }
        }

        return (ssp);
}

/*
 * Lowest-level I/O register read/write
 */

static void
bscbus_put_reg(struct bscbus_channel_state *csp, uint_t reg, uint8_t val)
{
        if (csp->ch_handle != NULL && !csp->xio_fault) {
                ddi_put8(csp->ch_handle,
                    csp->ch_regs + reg, val);
        }
}

static uint8_t
bscbus_get_reg(struct bscbus_channel_state *csp, uint_t reg)
{
        uint8_t val;

        if (csp->ch_handle != NULL && !csp->xio_fault)
                val = ddi_get8(csp->ch_handle,
                    csp->ch_regs + reg);
        else
                val = DUMMY_VALUE;

        return (val);
}

static void
bscbus_check_fault_status(struct bscbus_channel_state *csp)
{
        csp->xio_fault =
            ddi_check_acc_handle(csp->ch_handle) != DDI_SUCCESS;
}

static boolean_t
bscbus_faulty(struct bscbus_channel_state *csp)
{
        if (!csp->xio_fault)
                bscbus_check_fault_status(csp);
        return (csp->xio_fault);
}

/*
 * Write data into h8 registers
 */
static void
bscbus_pat_dog(struct bscbus_channel_state *csp, uint8_t val)
{
        uint8_t status;
        uint32_t doglimit = BSCBUS_DOG_PAT_POLL_LIMIT;

        bscbus_trace(csp, 'W', "bscbus_pat_dog:", "");

        bscbus_cmd_log(csp, BSC_CMD_DOGPAT, 0, val);
        status = bscbus_get_reg(csp, H8_STR);
        while (status & H8_STR_IBF) {
                if (csp->pat_retry_count > BSCBUS_PAT_RETRY_LIMIT) {
                        /*
                         * Previous attempts to contact BSC have failed.
                         * Do not bother waiting for it to eat previous
                         * data.
                         * Pat anyway just in case the BSC is really alive
                         * and the IBF bit is lying.
                         */
                        bscbus_put_reg(csp, H8_IDRC, val);
                        bscbus_trace(csp, 'W', "bscbus_pat_dog:",
                            "retry count exceeded");
                        return;
                }
                if (--doglimit == 0) {
                        /* The BSC is not responding - give up */
                        csp->pat_fail_count++;
                        csp->pat_retry_count++;
                        /* Pat anyway just in case the BSC is really alive */
                        bscbus_put_reg(csp, H8_IDRC, val);
                        bscbus_trace(csp, 'W', "bscbus_pat_dog:",
                            "poll limit exceeded");
                        return;
                }
                drv_usecwait(BSCBUS_DOG_PAT_POLL);
                status = bscbus_get_reg(csp, H8_STR);
        }
        bscbus_put_reg(csp, H8_IDRC, val);
        csp->pat_retry_count = 0;
}

/*
 * State diagrams for how bscbus_process works.
 *      BSCBUS_CMDSTATE_IDLE            No transaction in progress
 *      BSCBUS_CMDSTATE_BUSY            Setting up command
 *      BSCBUS_CMDSTATE_CLEARING        Clearing firmware busy status
 *      BSCBUS_CMDSTATE_SENDING         Waiting to send data to f/w
 *      BSCBUS_CMDSTATE_PENDING         Waiting for ack from f/w
 *      BSCBUS_CMDSTATE_WAITING         Waiting for status from f/w
 *      BSCBUS_CMDSTATE_READY           Status received/command done
 *      BSCBUS_CMDSTATE_ERROR           Command failed with error
 *
 *      +----------+
 *      |          |
 *      | IDLE/BUSY|
 *      |   (0/1)  |  abnormal
 *      +----------+  state
 *          |     \   detected
 *          |      \------>------+  +----<---+
 *      bsc |                    |  |        |
 *      is  |                    V  V        |
 *     ready|                +----------+    |
 *          |                |          |    ^
 *          |                | CLEARING |    |
 *          |                |   (2)    |    |
 *          |                +----------+    |
 *          |            cleared /  | \      | more to clear
 *          |                   /   |  \-->--+
 *          |  +-------<-------/    V
 *          |  |                    |
 *          V  V                    |timeout
 *      +----------+ timeout        |
 *      |          |------>---------+--------+
 *      | SENDING  |                         |
 *      |   (3)    |------<-------+          |
 *      +----------+              |          V
 *      sent|    \ send           ^ack       |
 *      last|     \ next          |received  |
 *          |      \         +----------+    |
 *          |       \        |          |    |
 *          |        \------>| PENDING  |-->-+
 *          |                |   (4)    |    |
 *          |                +----------+    |timeout
 *          |    +---<----+                  |
 *          |    |        |                  |
 *          V    V        |                  |
 *      +----------+      |                  |
 *      |          |      |                  |
 *      | WAITING  |      ^                  |
 *      |   (5)    |      |                  |
 *      +----------+      |                  |
 *          |  | |more    |                  |
 *          |  V |required|                  |
 *      done|  | +--->----+                  |
 *          |  +--->--------------+  +---<---+
 *          |   error/timeout     |  |
 *          V                     V  V
 *      +----------+          +----------+
 *      |          |          |          |
 *      | READY    |          |  ERROR   |
 *      |   (7)    |          |   (6)    |
 *      +----------+          +----------+
 *          |                     |
 *          V                     V
 *          |                     |
 *          +------>---+---<------+
 *                     |
 *                     |
 *                   Back to
 *                    Idle
 */

static void
bscbus_process_sending(struct bscbus_channel_state *csp, uint8_t status)
{
        /*
         * When we get here we actually expect H8_STR_IBF to
         * be clear but we check just in case of problems.
         */
        ASSERT(BSCBUS_TX_PENDING(csp));
        if (!(status & H8_STR_IBF)) {
                bscbus_put_reg(csp, H8_IDRD, *--csp->cmdp);
                bscbus_trace(csp, 'P', "bscbus_process_sending",
                    "state %d; val $%x",
                    csp->cmdstate, *csp->cmdp);
                if (!BSCBUS_TX_PENDING(csp)) {
                        bscbus_cmd_log(csp, BSC_CMD_SENT,
                            status, *csp->cmdp);
                        /* No more pending - move to waiting state */
                        bscbus_trace(csp, 'P', "bscbus_process_sending",
                            "moving to waiting");
                        csp->cmdstate = BSCBUS_CMDSTATE_WAITING;
                        /* Extend deadline because time has moved on */
                        csp->deadline = ddi_get_lbolt() +
                            drv_usectohz(LOMBUS_CMD_TIMEOUT/1000);
                } else {
                        /* Wait for ack of this byte */
                        bscbus_cmd_log(csp, BSC_CMD_SENDING,
                            status, *csp->cmdp);
                        csp->cmdstate = BSCBUS_CMDSTATE_PENDING;
                        bscbus_trace(csp, 'P', "bscbus_process_sending",
                            "moving to pending");
                }
        }
}

static void
bscbus_process_clearing(struct bscbus_channel_state *csp,
    uint8_t status, uint8_t data)
{
        /*
         * We only enter this state if H8_STR_BUSY was set when
         * we started the transaction. We just ignore all received
         * data until we see OBF set AND BUSY cleared.
         * It is not good enough to see BUSY clear on its own
         */
        if ((status & H8_STR_OBF) && !(status & H8_STR_BUSY)) {
                bscbus_cmd_log(csp, BSC_CMD_CLEARED, status, data);
                csp->cmdstate = BSCBUS_CMDSTATE_SENDING;
                /* Throw away any data received up until now */
                bscbus_trace(csp, 'P', "bscbus_process_clearing",
                    "busy cleared");
                /*
                 * Send the next byte immediately.
                 * At this stage we should clear the OBF flag because that
                 * data has been used. IBF is still valid so do not clear that.
                 */
                status &= ~(H8_STR_OBF);
                bscbus_process_sending(csp, status);
        } else {
                if (status & H8_STR_OBF) {
                        bscbus_cmd_log(csp, BSC_CMD_CLEARING, status, data);
                }
        }
}

static void
bscbus_process_pending(struct bscbus_channel_state *csp, uint8_t status)
{
        /* We are waiting for an acknowledgement of a byte */
        if (status & H8_STR_OBF) {
                bscbus_cmd_log(csp, BSC_CMD_PENDING,
                    status, *csp->cmdp);
                bscbus_trace(csp, 'P', "bscbus_process_pending",
                    "moving to sending");
                csp->cmdstate = BSCBUS_CMDSTATE_SENDING;
                /*
                 * Send the next byte immediately.
                 * At this stage we should clear the OBF flag because that
                 * data has been used. IBF is still valid so do not clear that.
                 */
                status &= ~(H8_STR_OBF);
                bscbus_process_sending(csp, status);
        }
}

static boolean_t
bscbus_process_waiting(struct bscbus_channel_state *csp,
    uint8_t status, uint8_t data)
{
        uint8_t rcvd = 0;
        boolean_t ready = B_FALSE;
        uint8_t tmp;

        if (status & H8_STR_OBF) {
                csp->reply[rcvd = csp->index] = data;
                if (++rcvd < BSCBUS_BUFSIZE)
                        csp->index = rcvd;

                bscbus_trace(csp, 'D', "bscbus_process_waiting",
                    "rcvd %d: $%02x $%02x $%02x $%02x $%02x $%02x $%02x $%02x",
                    rcvd,
                    csp->reply[0], csp->reply[1],
                    csp->reply[2], csp->reply[3],
                    csp->reply[4], csp->reply[5],
                    csp->reply[6], csp->reply[7]);
        }

        if (rcvd == 0) {
                /*
                 * No bytes received this time through (though there
                 * might be a partial packet sitting in the buffer).
                 */
                /* EMPTY */
                ;
        } else if (rcvd >= BSCBUS_BUFSIZE) {
                /*
                 * Buffer overflow; discard the data & treat as an error
                 * (even if the last byte read did claim to terminate a
                 * packet, it can't be a valid one 'cos it's too long!)
                 */
                bscbus_cmd_log(csp, BSC_CMD_ERROR_OFLOW, status, data);
                csp->index = 0;
                csp->cmdstate = BSCBUS_CMDSTATE_ERROR;
                csp->error = LOMBUS_ERR_OFLOW;
                ready = B_TRUE;
        } else if ((data & BSCBUS_LAST) == 0) {
                /*
                 * Packet not yet complete; leave the partial packet in
                 * the buffer for later ...
                 */
                bscbus_cmd_log(csp, BSC_CMD_REPLY, status, data);
        } else if ((data & BSCBUS_MASK) != BSCBUS_STATUS) {
                /* Invalid "status" byte - maybe an echo of the command? */
                bscbus_cmd_log(csp, BSC_CMD_ERROR_STATUS, status, data);

                csp->cmdstate = BSCBUS_CMDSTATE_ERROR;
                csp->error = LOMBUS_ERR_BADSTATUS;
                ready = B_TRUE;
        } else if ((data & BSCBUS_SEQ) != csp->sequence) {
                /* Wrong sequence number!  Flag this as an error */
                bscbus_cmd_log(csp, BSC_CMD_ERROR_SEQ, status, data);

                csp->cmdstate = BSCBUS_CMDSTATE_ERROR;
                csp->error = LOMBUS_ERR_SEQUENCE;
                ready = B_TRUE;
        } else {
                /*
                 * Finally, we know that's it's a valid reply to our
                 * last command.  Update the ASYNC status, derive the
                 * reply parameter (if any), and check the ERROR bit
                 * to find out what the parameter means.
                 *
                 * Note that not all the values read/assigned here
                 * are meaningful, but it doesn't matter; the waiting
                 * thread will know which one(s) it should check.
                 */
                bscbus_cmd_log(csp, BSC_CMD_COMPLETE, status, data);
                csp->async = (data & BSCBUS_STATUS_ASYNC) ? 1 : 0;

                tmp = ((data & BSCBUS_STATUS_MSB) ? 0x80 : 0) | csp->reply[0];
                if (data & BSCBUS_STATUS_ERR) {
                        csp->cmdstate = BSCBUS_CMDSTATE_ERROR;
                        csp->error = tmp;
                } else {
                        csp->cmdstate = BSCBUS_CMDSTATE_READY;
                        csp->result = tmp;
                }
                ready = B_TRUE;
        }
        return (ready);
}

/*
 * Packet receive handler
 *
 * This routine should be called from the low-level softint,
 * or bscbus_cmd() (for polled operation), with the
 * low-level mutex already held.
 */
static void
bscbus_process(struct bscbus_channel_state *csp,
    uint8_t status, uint8_t data)
{
        boolean_t ready = B_FALSE;

        ASSERT(mutex_owned(csp->lo_mutex));

        if ((status & H8_STR_OBF) || (status & H8_STR_IBF)) {
                bscbus_trace(csp, 'D', "bscbus_process",
                    "state %d; error $%x",
                    csp->cmdstate, csp->error);
        }

        switch (csp->cmdstate) {
        case BSCBUS_CMDSTATE_CLEARING:
                bscbus_process_clearing(csp, status, data);
                break;
        case BSCBUS_CMDSTATE_SENDING:
                bscbus_process_sending(csp, status);
                break;
        case BSCBUS_CMDSTATE_PENDING:
                bscbus_process_pending(csp, status);
                break;
        case BSCBUS_CMDSTATE_WAITING:
                ready = bscbus_process_waiting(csp, status, data);
                break;
        default:
                /* Nothing to do */
                break;
        }

        /*
         * Check for timeouts - but only if the command has not yet
         * completed (ready is true when command completes in this
         * call to bscbus_process OR cmdstate is READY or ERROR if
         * this is a spurious call to bscbus_process i.e. a spurious
         * interrupt)
         */
        if (!ready &&
            ((ddi_get_lbolt() - csp->deadline) > 0) &&
            csp->cmdstate != BSCBUS_CMDSTATE_READY &&
            csp->cmdstate != BSCBUS_CMDSTATE_ERROR) {
                bscbus_trace(csp, 'P', "bscbus_process",
                    "timeout previous state %d; error $%x",
                    csp->cmdstate, csp->error);
                bscbus_cmd_log(csp, BSC_CMD_ERROR_TOUT, status, data);
                if (csp->cmdstate == BSCBUS_CMDSTATE_CLEARING) {
                        /* Move onto sending because busy might be stuck */
                        csp->cmdstate = BSCBUS_CMDSTATE_SENDING;
                        /* Extend timeout relative to original start time */
                        csp->deadline += drv_usectohz(LOMBUS_CMD_TIMEOUT/1000);
                } else if (csp->cmdstate != BSCBUS_CMDSTATE_IDLE) {
                        csp->cmdstate = BSCBUS_CMDSTATE_ERROR;
                        csp->error = LOMBUS_ERR_TIMEOUT;
                }
                ready = B_TRUE;
        }

        if ((status & H8_STR_OBF) || (status & H8_STR_IBF) || ready) {
                bscbus_trace(csp, 'D', "bscbus_process",
                    "last $%02x; state %d; error $%x; ready %d",
                    data, csp->cmdstate, csp->error, ready);
        }
        if (ready)
                cv_broadcast(csp->lo_cv);
}

static uint_t
bscbus_hwintr(caddr_t arg)
{
        struct bscbus_channel_state *csp = (void *)arg;

        uint8_t status;
        uint8_t data = 0xb0 /* Dummy value */;

        mutex_enter(csp->lo_mutex);
        /*
         * Read the registers to ensure that the interrupt is cleared.
         * Status must be read first because reading data changes the
         * status.
         * We always read the data because that clears the interrupt down.
         * This is horrible hardware semantics but we have to do it!
         */
        status = bscbus_get_reg(csp, H8_STR);
        data = bscbus_get_reg(csp, H8_ODR);
        if (!(status & H8_STR_OBF)) {
                bscbus_cmd_log(csp, BSC_CMD_V1INTRUNCL, status, data);
                csp->unclaimed_count++;
        } else {
                bscbus_cmd_log(csp, BSC_CMD_V1INTR, status, data);
        }
        if (status & H8_STR_TOKENPROTOCOL) {
                bscbus_process(csp, status, data);
                if (csp->interrupt_failed) {
                        bscbus_trace(csp, 'I', "bscbus_hwintr:",
                            "interrupt fault cleared channel %d", csp->chno);
                        csp->interrupt_failed = B_FALSE;
                        csp->poll_hz = drv_usectohz(BSCBUS_CMD_POLL / 1000);
                }
        }

        mutex_exit(csp->lo_mutex);
        return (DDI_INTR_CLAIMED);
}

void
bscbus_poll(struct bscbus_channel_state *csp)
{
        /*
         * This routine is only called if we timeout in userland
         * waiting for an interrupt. This generally means that we have
         * lost interrupt capabilities or that something has gone
         * wrong.  In this case we are allowed to access the hardware
         * and read the data register if necessary.
         * If interrupts return then recovery actions should mend us!
         */
        uint8_t status;
        uint8_t data = 0xfa; /* Dummy value */

        ASSERT(mutex_owned(csp->lo_mutex));

        /* Should look for data to receive */
        status = bscbus_get_reg(csp, H8_STR);
        if (status & H8_STR_OBF) {
                /* There is data available */
                data = bscbus_get_reg(csp, H8_ODR);
                bscbus_cmd_log(csp, BSC_CMD_PROCESS, status, data);
        }
        bscbus_process(csp, status, data);
}

/*
 * Serial protocol
 *
 * This routine builds a command and sets it in progress.
 */
static uint8_t
bscbus_cmd(HANDLE_TYPE *hdlp, ptrdiff_t vreg, uint_t val, uint_t cmd)
{
        struct bscbus_channel_state *csp;
        clock_t start;
        uint8_t status;

        /*
         * First of all, wait for the interface to be available.
         *
         * NOTE: we blow through all the mutex/cv/state checking and
         * preempt any command in progress if the system is panicking!
         */
        csp = HANDLE_PRIVATE(hdlp);
        mutex_enter(csp->lo_mutex);
        while (csp->cmdstate != BSCBUS_CMDSTATE_IDLE && !ddi_in_panic())
                cv_wait(csp->lo_cv, csp->lo_mutex);

        csp->cmdstate = BSCBUS_CMDSTATE_BUSY;
        csp->sequence = (csp->sequence + BSCBUS_SEQ_LSB) & BSCBUS_SEQ;

        /*
         * We have exclusive ownership, so assemble the command (backwards):
         *
         * [byte 0]     Command:        modified by XADDR and/or WMSB bits
         * [Optional] Parameter:        Value to write (low 7 bits)
         * [Optional] Parameter:        Register number (high 7 bits)
         * [Optional] Parameter:        Register number (low 7 bits)
         */
        csp->cmdp = &csp->cmdbuf[0];
        *csp->cmdp++ = BSCBUS_CMD | csp->sequence | cmd;
        switch (cmd) {
        case BSCBUS_CMD_WRITE:
                *csp->cmdp++ = val & 0x7f;
                if (val >= 0x80)
                        csp->cmdbuf[0] |= BSCBUS_CMD_WMSB;
                /*FALLTHRU*/
        case BSCBUS_CMD_READ:
                if (BSCBUS_VREG_HI(vreg) != 0) {
                        *csp->cmdp++ = BSCBUS_VREG_HI(vreg);
                        csp->cmdbuf[0] |= BSCBUS_CMD_XADDR;
                }
                *csp->cmdp++ = BSCBUS_VREG_LO(vreg);
                /*FALLTHRU*/
        case BSCBUS_CMD_NOP:
                break;
        }

        /*
         * Check and update the H8 h/w fault status before accessing
         * the chip registers.  If there's a (new or previous) fault,
         * we'll run through the protocol but won't really touch the
         * hardware and all commands will timeout.  If a previously
         * discovered fault has now gone away (!), then we can (try to)
         * proceed with the new command (probably a probe).
         */
        bscbus_check_fault_status(csp);

        /*
         * Prepare for the command (to be processed by the interrupt
         * handler and/or polling loop below), and wait for a response
         * or timeout.
         */
        start = ddi_get_lbolt();
        csp->deadline = start + drv_usectohz(LOMBUS_CMD_TIMEOUT/1000);
        csp->error = 0;
        csp->index = 0;
        csp->result = DUMMY_VALUE;

        status = bscbus_get_reg(csp, H8_STR);
        if (status & H8_STR_BUSY) {
                bscbus_cmd_log(csp, BSC_CMD_BUSY, status, 0xfd);
                /*
                 * Must ensure that the busy state has cleared before
                 * sending the command
                 */
                csp->cmdstate = BSCBUS_CMDSTATE_CLEARING;
                bscbus_trace(csp, 'P', "bscbus_cmd",
                    "h8 reporting status (%x) busy - clearing", status);
        } else {
                /* It is clear to send the command immediately */
                csp->cmdstate = BSCBUS_CMDSTATE_SENDING;
                bscbus_trace(csp, 'P', "bscbus_cmd",
                    "sending first byte of command, status %x", status);
                bscbus_poll(csp);
        }

        csp->poll_hz = drv_usectohz(
            (csp->interrupt_failed ?
            BSCBUS_CMD_POLLNOINTS : BSCBUS_CMD_POLL) / 1000);

        while ((csp->cmdstate != BSCBUS_CMDSTATE_READY) &&
            (csp->cmdstate != BSCBUS_CMDSTATE_ERROR)) {
                ASSERT(csp->cmdstate != BSCBUS_CMDSTATE_IDLE);

                if ((cv_reltimedwait(csp->lo_cv, csp->lo_mutex,
                    csp->poll_hz, TR_CLOCK_TICK) == -1) &&
                    csp->cmdstate != BSCBUS_CMDSTATE_READY &&
                    csp->cmdstate != BSCBUS_CMDSTATE_ERROR) {
                        if (!csp->interrupt_failed) {
                                bscbus_trace(csp, 'I', "bscbus_cmd:",
                                    "interrupt_failed channel %d", csp->chno);
                                csp->interrupt_failed = B_TRUE;
                                csp->poll_hz = drv_usectohz(
                                    BSCBUS_CMD_POLLNOINTS / 1000);
                        }
                        bscbus_poll(csp);
                }
        }

        /*
         * The return value may not be meaningful but retrieve it anyway
         */
        val = csp->result;
        if (bscbus_faulty(csp)) {
                val = DUMMY_VALUE;
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_SIOHW;
        } else if (csp->cmdstate != BSCBUS_CMDSTATE_READY) {
                /*
                 * Some problem here ... transfer the error code from
                 * the per-instance state to the per-handle fault flag.
                 * The error code shouldn't be zero!
                 */
                if (csp->error != 0)
                        HANDLE_FAULT(hdlp) = csp->error;
                else
                        HANDLE_FAULT(hdlp) = LOMBUS_ERR_BADERRCODE;
        }

        /*
         * All done now!
         */
        csp->index = 0;
        csp->cmdstate = BSCBUS_CMDSTATE_IDLE;
        cv_broadcast(csp->lo_cv);
        mutex_exit(csp->lo_mutex);

        return (val);
}

/*
 * Space 0 - LOM virtual register access
 * Only 8-bit accesses are supported.
 */
static uint8_t
bscbus_vreg_get8(HANDLE_TYPE *hdlp, uint8_t *addr)
{
        ptrdiff_t offset;

        /*
         * Check the offset that the caller has added to the base address
         * against the length of the mapping originally requested.
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        if (offset < 0 || offset >= HANDLE_MAPLEN(hdlp)) {
                /*
                 * Invalid access - flag a fault and return a dummy value
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_NUM;
                return (DUMMY_VALUE);
        }

        /*
         * Derive the virtual register number and run the command
         */
        return (bscbus_cmd(hdlp, ADDR_TO_VREG(addr), 0, BSCBUS_CMD_READ));
}

static void
bscbus_vreg_put8(HANDLE_TYPE *hdlp, uint8_t *addr, uint8_t val)
{
        ptrdiff_t offset;

        /*
         * Check the offset that the caller has added to the base address
         * against the length of the mapping originally requested.
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        if (offset < 0 || offset >= HANDLE_MAPLEN(hdlp)) {
                /*
                 * Invalid access - flag a fault and return
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_NUM;
                return;
        }

        /*
         * Derive the virtual register number and run the command
         */
        (void) bscbus_cmd(hdlp, ADDR_TO_VREG(addr), val, BSCBUS_CMD_WRITE);
}

static void
bscbus_vreg_rep_get8(HANDLE_TYPE *hdlp, uint8_t *host_addr,
        uint8_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                *host_addr++ = bscbus_vreg_get8(hdlp, dev_addr);
}

static void
bscbus_vreg_rep_put8(HANDLE_TYPE *hdlp, uint8_t *host_addr,
        uint8_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                bscbus_vreg_put8(hdlp, dev_addr, *host_addr++);
}


/*
 * Space 1 - LOM watchdog pat register access
 * Only 8-bit accesses are supported.
 *
 * Reads have no effect and return 0.
 *
 * Multi-byte reads (using ddi_rep_get8(9F)) are a fairly inefficient
 * way of zeroing the destination area ;-) and still won't pat the dog.
 *
 * Multi-byte writes (using ddi_rep_put8(9F)) will almost certainly
 * only count as a single pat, no matter how many bytes the caller
 * says to write, as the inter-pat time is VERY long compared with
 * the time it will take to read the memory source area.
 */

static uint8_t
bscbus_pat_get8(HANDLE_TYPE *hdlp, uint8_t *addr)
{
        ptrdiff_t offset;

        /*
         * Check the offset that the caller has added to the base address
         * against the length of the mapping originally requested.
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        if (offset < 0 || offset >= HANDLE_MAPLEN(hdlp)) {
                /*
                 * Invalid access - flag a fault and return a dummy value
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_NUM;
                return (DUMMY_VALUE);
        }

        return (0);
}

static void
bscbus_pat_put8(HANDLE_TYPE *hdlp, uint8_t *addr, uint8_t val)
{
        struct bscbus_channel_state *csp;
        ptrdiff_t offset;

        /*
         * Check the offset that the caller has added to the base address
         * against the length of the mapping originally requested.
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        if (offset < 0 || offset >= HANDLE_MAPLEN(hdlp)) {
                /*
                 * Invalid access - flag a fault and return
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_NUM;
                return;
        }

        csp = HANDLE_PRIVATE(hdlp);
        mutex_enter(csp->dog_mutex);
        bscbus_pat_dog(csp, val);
        mutex_exit(csp->dog_mutex);
}

static void
bscbus_pat_rep_get8(HANDLE_TYPE *hdlp, uint8_t *host_addr,
        uint8_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                *host_addr++ = bscbus_pat_get8(hdlp, dev_addr);
}

static void
bscbus_pat_rep_put8(HANDLE_TYPE *hdlp, uint8_t *host_addr,
        uint8_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                bscbus_pat_put8(hdlp, dev_addr, *host_addr++);
}


/*
 * Space 2 - LOM async event flag register access
 * Only 16-bit accesses are supported.
 */
static uint16_t
bscbus_event_get16(HANDLE_TYPE *hdlp, uint16_t *addr)
{
        struct bscbus_channel_state *csp;
        ptrdiff_t offset;

        /*
         * Check the offset that the caller has added to the base address
         * against the length of the mapping orignally requested.
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        if (offset < 0 || (offset%2) != 0 || offset >= HANDLE_MAPLEN(hdlp)) {
                /*
                 * Invalid access - flag a fault and return a dummy value
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_NUM;
                return (DUMMY_VALUE);
        }

        /*
         * Return the value of the asynchronous-event-pending flag
         * as passed back by the LOM at the end of the last command.
         */
        csp = HANDLE_PRIVATE(hdlp);
        return (csp->async);
}

static void
bscbus_event_put16(HANDLE_TYPE *hdlp, uint16_t *addr, uint16_t val)
{
        ptrdiff_t offset;

        _NOTE(ARGUNUSED(val))

        /*
         * Check the offset that the caller has added to the base address
         * against the length of the mapping originally requested.
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        if (offset < 0 || (offset%2) != 0 || offset >= HANDLE_MAPLEN(hdlp)) {
                /*
                 * Invalid access - flag a fault and return
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_NUM;
                return;
        }

        /*
         * The user can't overwrite the asynchronous-event-pending flag!
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_RO;
}

static void
bscbus_event_rep_get16(HANDLE_TYPE *hdlp, uint16_t *host_addr,
        uint16_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                *host_addr++ = bscbus_event_get16(hdlp, dev_addr);
}

static void
bscbus_event_rep_put16(HANDLE_TYPE *hdlp, uint16_t *host_addr,
        uint16_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                bscbus_event_put16(hdlp, dev_addr, *host_addr++);
}


/*
 * All spaces - access handle fault information
 * Only 32-bit accesses are supported.
 */
static uint32_t
bscbus_meta_get32(HANDLE_TYPE *hdlp, uint32_t *addr)
{
        struct bscbus_channel_state *csp;
        ptrdiff_t offset;

        /*
         * Derive the offset that the caller has added to the base
         * address originally returned, and use it to determine
         * which meta-register is to be accessed ...
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        switch (offset) {
        case LOMBUS_FAULT_REG:
                /*
                 * This meta-register provides a code for the most
                 * recent virtual register access fault, if any.
                 */
                return (HANDLE_FAULT(hdlp));

        case LOMBUS_PROBE_REG:
                /*
                 * Reading this meta-register clears any existing fault
                 * (at the virtual, not the hardware access layer), then
                 * runs a NOP command and returns the fault code from that.
                 */
                HANDLE_FAULT(hdlp) = 0;
                (void) bscbus_cmd(hdlp, 0, 0, BSCBUS_CMD_NOP);
                return (HANDLE_FAULT(hdlp));

        case LOMBUS_ASYNC_REG:
                /*
                 * Obsolescent - but still supported for backwards
                 * compatibility.  This is an alias for the newer
                 * LOMBUS_EVENT_REG, but doesn't require a separate
                 * "reg" entry and ddi_regs_map_setup() call.
                 *
                 * It returns the value of the asynchronous-event-pending
                 * flag as passed back by the BSC at the end of the last
                 * completed command.
                 */
                csp = HANDLE_PRIVATE(hdlp);
                return (csp->async);

        default:
                /*
                 * Invalid access - flag a fault and return a dummy value
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
                return (DUMMY_VALUE);
        }
}

static void
bscbus_meta_put32(HANDLE_TYPE *hdlp, uint32_t *addr, uint32_t val)
{
        ptrdiff_t offset;

        /*
         * Derive the offset that the caller has added to the base
         * address originally returned, and use it to determine
         * which meta-register is to be accessed ...
         */
        offset = ADDR_TO_OFFSET(addr, hdlp);
        switch (offset) {
        case LOMBUS_FAULT_REG:
                /*
                 * This meta-register contains a code for the most
                 * recent virtual register access fault, if any.
                 * It can be cleared simply by writing 0 to it.
                 */
                HANDLE_FAULT(hdlp) = val;
                return;

        case LOMBUS_PROBE_REG:
                /*
                 * Writing this meta-register clears any existing fault
                 * (at the virtual, not the hardware acess layer), then
                 * runs a NOP command.  The caller can check the fault
                 * code later if required.
                 */
                HANDLE_FAULT(hdlp) = 0;
                (void) bscbus_cmd(hdlp, 0, 0, BSCBUS_CMD_NOP);
                return;

        default:
                /*
                 * Invalid access - flag a fault
                 */
                HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
                return;
        }
}

static void
bscbus_meta_rep_get32(HANDLE_TYPE *hdlp, uint32_t *host_addr,
        uint32_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                *host_addr++ = bscbus_meta_get32(hdlp, dev_addr);
}

static void
bscbus_meta_rep_put32(HANDLE_TYPE *hdlp, uint32_t *host_addr,
        uint32_t *dev_addr, size_t repcount, uint_t flags)
{
        size_t inc;

        inc = (flags & DDI_DEV_AUTOINCR) ? 1 : 0;
        for (; repcount--; dev_addr += inc)
                bscbus_meta_put32(hdlp, dev_addr, *host_addr++);
}


/*
 * Finally, some dummy functions for all unsupported access
 * space/size/mode combinations ...
 */
static uint8_t
bscbus_no_get8(HANDLE_TYPE *hdlp, uint8_t *addr)
{
        _NOTE(ARGUNUSED(addr))

        /*
         * Invalid access - flag a fault and return a dummy value
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
        return (DUMMY_VALUE);
}

static void
bscbus_no_put8(HANDLE_TYPE *hdlp, uint8_t *addr, uint8_t val)
{
        _NOTE(ARGUNUSED(addr, val))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static void
bscbus_no_rep_get8(HANDLE_TYPE *hdlp, uint8_t *host_addr,
                uint8_t *dev_addr, size_t repcount, uint_t flags)
{
        _NOTE(ARGUNUSED(host_addr, dev_addr, repcount, flags))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static void
bscbus_no_rep_put8(HANDLE_TYPE *hdlp, uint8_t *host_addr,
        uint8_t *dev_addr, size_t repcount, uint_t flags)
{
        _NOTE(ARGUNUSED(host_addr, dev_addr, repcount, flags))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static uint16_t
bscbus_no_get16(HANDLE_TYPE *hdlp, uint16_t *addr)
{
        _NOTE(ARGUNUSED(addr))

        /*
         * Invalid access - flag a fault and return a dummy value
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
        return (DUMMY_VALUE);
}

static void
bscbus_no_put16(HANDLE_TYPE *hdlp, uint16_t *addr, uint16_t val)
{
        _NOTE(ARGUNUSED(addr, val))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static void
bscbus_no_rep_get16(HANDLE_TYPE *hdlp, uint16_t *host_addr,
                uint16_t *dev_addr, size_t repcount, uint_t flags)
{
        _NOTE(ARGUNUSED(host_addr, dev_addr, repcount, flags))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static void
bscbus_no_rep_put16(HANDLE_TYPE *hdlp, uint16_t *host_addr,
        uint16_t *dev_addr, size_t repcount, uint_t flags)
{
        _NOTE(ARGUNUSED(host_addr, dev_addr, repcount, flags))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static uint64_t
bscbus_no_get64(HANDLE_TYPE *hdlp, uint64_t *addr)
{
        _NOTE(ARGUNUSED(addr))

        /*
         * Invalid access - flag a fault and return a dummy value
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
        return (DUMMY_VALUE);
}

static void
bscbus_no_put64(HANDLE_TYPE *hdlp, uint64_t *addr, uint64_t val)
{
        _NOTE(ARGUNUSED(addr, val))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static void
bscbus_no_rep_get64(HANDLE_TYPE *hdlp, uint64_t *host_addr,
        uint64_t *dev_addr, size_t repcount, uint_t flags)
{
        _NOTE(ARGUNUSED(host_addr, dev_addr, repcount, flags))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static void
bscbus_no_rep_put64(HANDLE_TYPE *hdlp, uint64_t *host_addr,
        uint64_t *dev_addr, size_t repcount, uint_t flags)
{
        _NOTE(ARGUNUSED(host_addr, dev_addr, repcount, flags))

        /*
         * Invalid access - flag a fault
         */
        HANDLE_FAULT(hdlp) = LOMBUS_ERR_REG_SIZE;
}

static int
bscbus_acc_fault_check(HANDLE_TYPE *hdlp)
{
        return (HANDLE_FAULT(hdlp) != 0);
}

/*
 * Hardware setup - ensure that there are no pending transactions and
 * hence no pending interrupts. We do this be ensuring that the BSC is
 * not reporting a busy condition and that it does not have any data
 * pending in its output buffer.
 * This is important because if we have pending interrupts at attach
 * time Solaris will hang due to bugs in ddi_get_iblock_cookie.
 */
static void
bscbus_hw_reset(struct bscbus_channel_state *csp)
{
        int64_t timeout;
        uint8_t status;

        if (csp->map_count == 0) {
                /* No-one using this instance - no need to reset hardware */
                return;
        }

        bscbus_trace(csp, 'R', "bscbus_hw_reset",
            "resetting channel %d", csp->chno);

        status = bscbus_get_reg(csp, H8_STR);
        if (status & H8_STR_BUSY) {
                /*
                 * Give the h8 time to complete a reply.
                 * In practice we should never worry about this
                 * because whenever we get here it will have been
                 * long enough for the h8 to complete a reply
                 */
                bscbus_cmd_log(csp, BSC_CMD_BUSY, status, 0);
                bscbus_trace(csp, 'R', "bscbus_hw_reset",
                    "h8 reporting status (%x) busy - waiting", status);
                if (ddi_in_panic()) {
                        drv_usecwait(BSCBUS_HWRESET_POLL/1000);
                } else {
                        delay(drv_usectohz(BSCBUS_HWRESET_POLL/1000));
                }
        }
        /* Reply should be completed by now. Try to clear busy status */
        status = bscbus_get_reg(csp, H8_STR);
        if (status & (H8_STR_BUSY | H8_STR_OBF)) {
                bscbus_trace(csp, 'R', "bscbus_hw_reset",
                    "clearing busy status for channel %d", csp->chno);

                for (timeout = BSCBUS_HWRESET_TIMEOUT;
                    (timeout > 0);
                    timeout -= BSCBUS_HWRESET_POLL) {
                        if (status & H8_STR_OBF) {
                                (void) bscbus_get_reg(csp, H8_ODR);
                                if (!(status & H8_STR_BUSY)) {
                                        /* We are done */
                                        break;
                                }
                        }
                        if (ddi_in_panic()) {
                                drv_usecwait(BSCBUS_HWRESET_POLL/1000);
                        } else {
                                delay(drv_usectohz(BSCBUS_HWRESET_POLL/1000));
                        }
                        status = bscbus_get_reg(csp, H8_STR);
                }
                if (timeout <= 0) {
                        cmn_err(CE_WARN, "bscbus_hw_reset: timed out "
                            "clearing busy status");
                }
        }
        /*
         * We read ODR just in case there is a pending interrupt with
         * no data. This is potentially dangerous because we could get
         * out of sync due to race conditions BUT at this point the
         * channel should be idle so it is safe.
         */
        (void) bscbus_get_reg(csp, H8_ODR);
}

/*
 * Higher-level setup & teardown
 */

static void
bscbus_offline(struct bscbus_state *ssp)
{
        if (ssp->h8_handle != NULL)
                ddi_regs_map_free(&ssp->h8_handle);
        ssp->h8_handle = NULL;
        ssp->h8_regs = NULL;
}

static int
bscbus_online(struct bscbus_state *ssp)
{
        ddi_acc_handle_t h;
        caddr_t p;
        int nregs;
        int err;

        ssp->h8_handle = NULL;
        ssp->h8_regs = (void *)NULL;
        ssp->per_channel_regs = B_FALSE;

        if (ddi_dev_nregs(ssp->dip, &nregs) != DDI_SUCCESS)
                nregs = 0;

        switch (nregs) {
        case 1:
                /*
                 *  regset 0 represents the H8 interface registers
                 */
                err = ddi_regs_map_setup(ssp->dip, 0, &p, 0, 0,
                    bscbus_dev_acc_attr, &h);
                if (err != DDI_SUCCESS)
                        return (EIO);

                ssp->h8_handle = h;
                ssp->h8_regs = (void *)p;
                break;

        case 0:
                /*
                 *  If no registers are defined, succeed vacuously;
                 *  commands will be accepted, but we fake the accesses.
                 */
                break;

        default:
                /*
                 * Remember that we are using the new register scheme.
                 * reg set 0 is chan 0
                 * reg set 1 is chan 1 ...
                 * Interrupts are specified in that order but later
                 * channels may not have interrupts.
                 * We map the regs later on a per channel basis.
                 */
                ssp->per_channel_regs = B_TRUE;
                break;
        }
        return (0);
}

static int
bscbus_claim_channel(struct bscbus_channel_state *csp, boolean_t map_dog)
{
        int err;

        mutex_enter(csp->ssp->ch_mutex);
        csp->map_count++;
        bscbus_trace(csp, 'C', "bscbus_claim_channel",
            "claim channel for channel %d, count %d",
            csp->chno, csp->map_count);

        if (csp->map_count == 1) {
                /* No-one is using this channel - initialise it */
                bscbus_trace(csp, 'C', "bscbus_claim_channel",
                    "initialise channel %d, count %d",
                    csp->chno, csp->map_count);

                mutex_init(csp->dog_mutex, NULL, MUTEX_DRIVER,
                    (void *)(uintptr_t)__ipltospl(SPL7 - 1));
                csp->map_dog = map_dog;
                csp->interrupt_failed = B_FALSE;
                csp->cmdstate = BSCBUS_CMDSTATE_IDLE;
                csp->pat_retry_count = 0;
                csp->pat_fail_count = 0;

                /* Map appropriate register set for this channel */
                if (csp->ssp->per_channel_regs == B_TRUE) {
                        ddi_acc_handle_t h;
                        caddr_t p;

                        err = ddi_regs_map_setup(csp->ssp->dip, csp->chno,
                            &p, 0, 0, bscbus_dev_acc_attr, &h);

                        if (err != DDI_SUCCESS) {
                                goto failed1;
                        }

                        csp->ch_handle = h;
                        csp->ch_regs = (void *)p;

                        bscbus_trace(csp, 'C', "bscbus_claim_channel",
                            "mapped chno=%d ch_handle=%d ch_regs=%p",
                            csp->chno, h, p);
                } else {
                        /*
                         * if using the old reg property scheme use the
                         * common mapping.
                         */
                        csp->ch_handle = csp->ssp->h8_handle;
                        csp->ch_regs =
                            csp->ssp->h8_regs +
                            BSCBUS_CHANNEL_TO_OFFSET(csp->chno);
                }

                /* Ensure no interrupts pending prior to getting iblk cookie */
                bscbus_hw_reset(csp);

                if (csp->map_dog == 1) {
                        /*
                         * we don't want lo_mutex to be initialised
                         * with an iblock cookie if we are the wdog,
                         * because we don't use interrupts.
                         */
                        mutex_init(csp->lo_mutex, NULL,
                            MUTEX_DRIVER, NULL);
                        cv_init(csp->lo_cv, NULL,
                            CV_DRIVER, NULL);
                        csp->unclaimed_count = 0;
                } else {
                        int ninterrupts;

                        /*
                         * check that there is an interrupt for this
                         * this channel. If we fail to setup interrupts we
                         * must unmap the registers and fail.
                         */
                        err = ddi_dev_nintrs(csp->ssp->dip, &ninterrupts);

                        if (err != DDI_SUCCESS) {
                                ninterrupts = 0;
                        }

                        if (ninterrupts <= csp->chno) {
                                cmn_err(CE_WARN,
                                    "no interrupt available for "
                                    "bscbus channel %d", csp->chno);
                                goto failed2;
                        }

                        if (ddi_intr_hilevel(csp->ssp->dip, csp->chno) != 0) {
                                cmn_err(CE_WARN,
                                    "bscbus interrupts are high "
                                    "level - channel not usable.");
                                goto failed2;
                        } else {
                                err = ddi_get_iblock_cookie(csp->ssp->dip,
                                    csp->chno, &csp->lo_iblk);
                                if (err != DDI_SUCCESS) {
                                        goto failed2;
                                }

                                mutex_init(csp->lo_mutex, NULL,
                                    MUTEX_DRIVER, csp->lo_iblk);
                                cv_init(csp->lo_cv, NULL,
                                    CV_DRIVER, NULL);
                                csp->unclaimed_count = 0;

                                err = ddi_add_intr(csp->ssp->dip, csp->chno,
                                    &csp->lo_iblk, NULL,
                                    bscbus_hwintr, (caddr_t)csp);
                                if (err != DDI_SUCCESS) {
                                        cv_destroy(csp->lo_cv);
                                        mutex_destroy(csp->lo_mutex);
                                        goto failed2;
                                }
                        }
                }
                /*
                 * The channel is now live and may
                 * receive interrupts
                 */
        } else if (csp->map_dog != map_dog) {
                bscbus_trace(csp, 'C', "bscbus_claim_channel",
                    "request conflicts with previous mapping. old %x, new %x.",
                    csp->map_dog, map_dog);
                goto failed1;
        }
        mutex_exit(csp->ssp->ch_mutex);
        return (1);

failed2:
        /* unmap regs for failed channel */
        if (csp->ssp->per_channel_regs == B_TRUE) {
                ddi_regs_map_free(&csp->ch_handle);
        }
        csp->ch_handle = NULL;
        csp->ch_regs = (void *)NULL;
failed1:
        csp->map_count--;
        mutex_exit(csp->ssp->ch_mutex);
        return (0);
}

static void
bscbus_release_channel(struct bscbus_channel_state *csp)
{
        mutex_enter(csp->ssp->ch_mutex);
        if (csp->map_count == 1) {
                /* No-one is now using this channel - shutdown channel */
                bscbus_trace(csp, 'C', "bscbus_release_channel",
                    "shutdown channel %d, count %d",
                    csp->chno, csp->map_count);

                if (csp->map_dog == 0) {
                        ASSERT(!ddi_intr_hilevel(csp->ssp->dip, csp->chno));
                        ddi_remove_intr(csp->ssp->dip, csp->chno, csp->lo_iblk);
                }
                cv_destroy(csp->lo_cv);
                mutex_destroy(csp->lo_mutex);
                mutex_destroy(csp->dog_mutex);
                bscbus_hw_reset(csp);

                /* unmap registers if using the new register scheme */
                if (csp->ssp->per_channel_regs == B_TRUE) {
                        ddi_regs_map_free(&csp->ch_handle);
                }
                csp->ch_handle = NULL;
                csp->ch_regs = (void *)NULL;
        }
        csp->map_count--;
        bscbus_trace(csp, 'C', "bscbus_release_channel",
            "release channel %d, count %d",
            csp->chno, csp->map_count);
        mutex_exit(csp->ssp->ch_mutex);
}


/*
 *  Nexus routines
 */

#if     defined(NDI_ACC_HDL_V2)

static const ndi_acc_fns_t bscbus_vreg_acc_fns = {
        NDI_ACC_FNS_CURRENT,
        NDI_ACC_FNS_V1,

        bscbus_vreg_get8,
        bscbus_vreg_put8,
        bscbus_vreg_rep_get8,
        bscbus_vreg_rep_put8,

        bscbus_no_get16,
        bscbus_no_put16,
        bscbus_no_rep_get16,
        bscbus_no_rep_put16,

        bscbus_meta_get32,
        bscbus_meta_put32,
        bscbus_meta_rep_get32,
        bscbus_meta_rep_put32,

        bscbus_no_get64,
        bscbus_no_put64,
        bscbus_no_rep_get64,
        bscbus_no_rep_put64,

        bscbus_acc_fault_check
};

static const ndi_acc_fns_t bscbus_pat_acc_fns = {
        NDI_ACC_FNS_CURRENT,
        NDI_ACC_FNS_V1,

        bscbus_pat_get8,
        bscbus_pat_put8,
        bscbus_pat_rep_get8,
        bscbus_pat_rep_put8,

        bscbus_no_get16,
        bscbus_no_put16,
        bscbus_no_rep_get16,
        bscbus_no_rep_put16,

        bscbus_meta_get32,
        bscbus_meta_put32,
        bscbus_meta_rep_get32,
        bscbus_meta_rep_put32,

        bscbus_no_get64,
        bscbus_no_put64,
        bscbus_no_rep_get64,
        bscbus_no_rep_put64,

        bscbus_acc_fault_check
};

static const ndi_acc_fns_t bscbus_event_acc_fns = {
        NDI_ACC_FNS_CURRENT,
        NDI_ACC_FNS_V1,

        bscbus_no_get8,
        bscbus_no_put8,
        bscbus_no_rep_get8,
        bscbus_no_rep_put8,

        bscbus_event_get16,
        bscbus_event_put16,
        bscbus_event_rep_get16,
        bscbus_event_rep_put16,

        bscbus_meta_get32,
        bscbus_meta_put32,
        bscbus_meta_rep_get32,
        bscbus_meta_rep_put32,

        bscbus_no_get64,
        bscbus_no_put64,
        bscbus_no_rep_get64,
        bscbus_no_rep_put64,

        bscbus_acc_fault_check
};

static int
bscbus_map_handle(struct bscbus_channel_state *csp, ddi_map_op_t op,
        int space, caddr_t vaddr, off_t len,
        ndi_acc_handle_t *hdlp, caddr_t *addrp)
{
        switch (op) {
        default:
                return (DDI_ME_UNIMPLEMENTED);

        case DDI_MO_MAP_LOCKED:
                if (bscbus_claim_channel(csp,
                    (space == LOMBUS_PAT_SPACE)) == 0) {
                        return (DDI_ME_GENERIC);
                }

                switch (space) {
                default:
                        return (DDI_ME_REGSPEC_RANGE);

                case LOMBUS_VREG_SPACE:
                        ndi_set_acc_fns(hdlp, &bscbus_vreg_acc_fns);
                        break;

                case LOMBUS_PAT_SPACE:
                        ndi_set_acc_fns(hdlp, &bscbus_pat_acc_fns);
                        break;

                case LOMBUS_EVENT_SPACE:
                        ndi_set_acc_fns(hdlp, &bscbus_event_acc_fns);
                        break;
                }
                hdlp->ah_addr = *addrp = vaddr;
                hdlp->ah_len = len;
                hdlp->ah_bus_private = csp;
                return (DDI_SUCCESS);

        case DDI_MO_UNMAP:
                *addrp = NULL;
                hdlp->ah_bus_private = NULL;
                bscbus_release_channel(csp);
                return (DDI_SUCCESS);
        }
}

#else

static int
bscbus_map_handle(struct bscbus_channel_state *csp, ddi_map_op_t op,
        int space, caddr_t vaddr, off_t len,
        ddi_acc_hdl_t *hdlp, caddr_t *addrp)
{
        ddi_acc_impl_t *aip = hdlp->ah_platform_private;

        switch (op) {
        default:
                return (DDI_ME_UNIMPLEMENTED);

        case DDI_MO_MAP_LOCKED:
                if (bscbus_claim_channel(csp,
                    (space == LOMBUS_PAT_SPACE)) == 0) {
                        return (DDI_ME_GENERIC);
                }

                switch (space) {
                default:
                        return (DDI_ME_REGSPEC_RANGE);

                case LOMBUS_VREG_SPACE:
                        aip->ahi_get8 = bscbus_vreg_get8;
                        aip->ahi_put8 = bscbus_vreg_put8;
                        aip->ahi_rep_get8 = bscbus_vreg_rep_get8;
                        aip->ahi_rep_put8 = bscbus_vreg_rep_put8;

                        aip->ahi_get16 = bscbus_no_get16;
                        aip->ahi_put16 = bscbus_no_put16;
                        aip->ahi_rep_get16 = bscbus_no_rep_get16;
                        aip->ahi_rep_put16 = bscbus_no_rep_put16;

                        aip->ahi_get32 = bscbus_meta_get32;
                        aip->ahi_put32 = bscbus_meta_put32;
                        aip->ahi_rep_get32 = bscbus_meta_rep_get32;
                        aip->ahi_rep_put32 = bscbus_meta_rep_put32;

                        aip->ahi_get64 = bscbus_no_get64;
                        aip->ahi_put64 = bscbus_no_put64;
                        aip->ahi_rep_get64 = bscbus_no_rep_get64;
                        aip->ahi_rep_put64 = bscbus_no_rep_put64;

                        aip->ahi_fault_check = bscbus_acc_fault_check;
                        break;

                case LOMBUS_PAT_SPACE:
                        aip->ahi_get8 = bscbus_pat_get8;
                        aip->ahi_put8 = bscbus_pat_put8;
                        aip->ahi_rep_get8 = bscbus_pat_rep_get8;
                        aip->ahi_rep_put8 = bscbus_pat_rep_put8;

                        aip->ahi_get16 = bscbus_no_get16;
                        aip->ahi_put16 = bscbus_no_put16;
                        aip->ahi_rep_get16 = bscbus_no_rep_get16;
                        aip->ahi_rep_put16 = bscbus_no_rep_put16;

                        aip->ahi_get32 = bscbus_meta_get32;
                        aip->ahi_put32 = bscbus_meta_put32;
                        aip->ahi_rep_get32 = bscbus_meta_rep_get32;
                        aip->ahi_rep_put32 = bscbus_meta_rep_put32;

                        aip->ahi_get64 = bscbus_no_get64;
                        aip->ahi_put64 = bscbus_no_put64;
                        aip->ahi_rep_get64 = bscbus_no_rep_get64;
                        aip->ahi_rep_put64 = bscbus_no_rep_put64;

                        aip->ahi_fault_check = bscbus_acc_fault_check;
                        break;

                case LOMBUS_EVENT_SPACE:
                        aip->ahi_get8 = bscbus_no_get8;
                        aip->ahi_put8 = bscbus_no_put8;
                        aip->ahi_rep_get8 = bscbus_no_rep_get8;
                        aip->ahi_rep_put8 = bscbus_no_rep_put8;

                        aip->ahi_get16 = bscbus_event_get16;
                        aip->ahi_put16 = bscbus_event_put16;
                        aip->ahi_rep_get16 = bscbus_event_rep_get16;
                        aip->ahi_rep_put16 = bscbus_event_rep_put16;

                        aip->ahi_get32 = bscbus_meta_get32;
                        aip->ahi_put32 = bscbus_meta_put32;
                        aip->ahi_rep_get32 = bscbus_meta_rep_get32;
                        aip->ahi_rep_put32 = bscbus_meta_rep_put32;

                        aip->ahi_get64 = bscbus_no_get64;
                        aip->ahi_put64 = bscbus_no_put64;
                        aip->ahi_rep_get64 = bscbus_no_rep_get64;
                        aip->ahi_rep_put64 = bscbus_no_rep_put64;

                        aip->ahi_fault_check = bscbus_acc_fault_check;
                        break;
                }
                hdlp->ah_addr = *addrp = vaddr;
                hdlp->ah_len = len;
                hdlp->ah_bus_private = csp;
                return (DDI_SUCCESS);

        case DDI_MO_UNMAP:
                *addrp = NULL;
                hdlp->ah_bus_private = NULL;
                bscbus_release_channel(csp);
                return (DDI_SUCCESS);
        }
}

#endif  /* NDI_ACC_HDL_V2 */

static int
bscbus_map(dev_info_t *dip, dev_info_t *rdip, ddi_map_req_t *mp,
        off_t off, off_t len, caddr_t *addrp)
{
        struct bscbus_child_info *lcip;
        struct bscbus_state *ssp;
        lombus_regspec_t *rsp;

        if ((ssp = bscbus_getstate(dip, -1, "bscbus_map")) == NULL)
                return (DDI_FAILURE);   /* this "can't happen" */

        /*
         * Validate mapping request ...
         */

        if (mp->map_flags != DDI_MF_KERNEL_MAPPING)
                return (DDI_ME_UNSUPPORTED);
        if (mp->map_handlep == NULL)
                return (DDI_ME_UNSUPPORTED);
        if (mp->map_type != DDI_MT_RNUMBER)
                return (DDI_ME_UNIMPLEMENTED);
        if ((lcip = ddi_get_parent_data(rdip)) == NULL)
                return (DDI_ME_INVAL);
        if ((rsp = lcip->rsp) == NULL)
                return (DDI_ME_INVAL);
        if (mp->map_obj.rnumber >= lcip->nregs)
                return (DDI_ME_RNUMBER_RANGE);
        rsp += mp->map_obj.rnumber;
        if (off < 0 || off >= rsp->lombus_size)
                return (DDI_ME_INVAL);
        if (len == 0)
                len = rsp->lombus_size-off;
        if (len < 0)
                return (DDI_ME_INVAL);
        if (off+len < 0 || off+len > rsp->lombus_size)
                return (DDI_ME_INVAL);

        return (bscbus_map_handle(
            &ssp->channel[LOMBUS_SPACE_TO_CHANNEL(rsp->lombus_space)],
            mp->map_op, LOMBUS_SPACE_TO_REGSET(rsp->lombus_space),
            VREG_TO_ADDR(rsp->lombus_base+off), len, mp->map_handlep, addrp));
}


static int
bscbus_ctlops(dev_info_t *dip, dev_info_t *rdip, ddi_ctl_enum_t op,
        void *arg, void *result)
{
        struct bscbus_child_info *lcip;
        lombus_regspec_t *rsp;
        dev_info_t *cdip;
        char addr[32];
        uint_t nregs;
        uint_t rnum;
        int *regs;
        int limit;
        int err;
        int i;

        if (bscbus_getstate(dip, -1, "bscbus_ctlops") == NULL)
                return (DDI_FAILURE);   /* this "can't happen" */

        switch (op) {
        default:
                break;

        case DDI_CTLOPS_INITCHILD:
                /*
                 * First, look up and validate the "reg" property.
                 *
                 * It must be a non-empty integer array containing a set
                 * of triples.  Once we've verified that, we can treat it
                 * as an array of type lombus_regspec_t[], which defines
                 * the meaning of the elements of each triple:
                 * +  the first element of each triple must be a valid space
                 * +  the second and third elements (base, size) of each
                 *      triple must define a valid subrange of that space
                 * If it passes all the tests, we save it away for future
                 * reference in the child's parent-private-data field.
                 */
                cdip = arg;
                err = ddi_prop_lookup_int_array(DDI_DEV_T_ANY, cdip,
                    DDI_PROP_DONTPASS, "reg", &regs, &nregs);
                if (err != DDI_PROP_SUCCESS)
                        return (DDI_FAILURE);

                err = (nregs <= 0 || (nregs % LOMBUS_REGSPEC_SIZE) != 0);
                nregs /= LOMBUS_REGSPEC_SIZE;
                rsp = (lombus_regspec_t *)regs;
                for (i = 0; i < nregs && !err; ++i) {
                        switch (LOMBUS_SPACE_TO_REGSET(rsp[i].lombus_space)) {
                        default:
                                limit = 0;
                                err = 1;
                                cmn_err(CE_WARN,
                                    "child(%p): unknown reg space %d",
                                    (void *)cdip, rsp[i].lombus_space);
                                break;

                        case LOMBUS_VREG_SPACE:
                                limit = LOMBUS_MAX_REG+1;
                                break;

                        case LOMBUS_PAT_SPACE:
                                limit = LOMBUS_PAT_REG+1;
                                break;

                        case LOMBUS_EVENT_SPACE:
                                limit = LOMBUS_EVENT_REG+1;
                                break;
                        }

                        err |= (rsp[i].lombus_base < 0);
                        err |= (rsp[i].lombus_base >= limit);

                        if (rsp[i].lombus_size == 0)
                                rsp[i].lombus_size = limit-rsp[i].lombus_base;

                        err |= (rsp[i].lombus_size < 0);
                        err |= (rsp[i].lombus_base+rsp[i].lombus_size < 0);
                        err |= (rsp[i].lombus_base+rsp[i].lombus_size > limit);

                        err |= (rsp[i].lombus_base+rsp[i].lombus_size > limit);

                }

                if (err) {
                        ddi_prop_free(regs);
                        return (DDI_FAILURE);
                }

                lcip = kmem_zalloc(sizeof (*lcip), KM_SLEEP);
                lcip->nregs = nregs;
                lcip->rsp = rsp;
                ddi_set_parent_data(cdip, lcip);

                (void) snprintf(addr, sizeof (addr),
                    "%x,%x", rsp[0].lombus_space, rsp[0].lombus_base);
                ddi_set_name_addr(cdip, addr);

                return (DDI_SUCCESS);

        case DDI_CTLOPS_UNINITCHILD:
                cdip = arg;
                ddi_set_name_addr(cdip, NULL);
                lcip = ddi_get_parent_data(cdip);
                ddi_set_parent_data(cdip, NULL);
                ddi_prop_free(lcip->rsp);
                kmem_free(lcip, sizeof (*lcip));
                return (DDI_SUCCESS);

        case DDI_CTLOPS_REPORTDEV:
                if (rdip == NULL)
                        return (DDI_FAILURE);

                cmn_err(CE_CONT, "?BSC device: %s@%s, %s#%d\n",
                    ddi_node_name(rdip), ddi_get_name_addr(rdip),
                    ddi_driver_name(dip), ddi_get_instance(dip));

                return (DDI_SUCCESS);

        case DDI_CTLOPS_REGSIZE:
                if ((lcip = ddi_get_parent_data(rdip)) == NULL)
                        return (DDI_FAILURE);
                if ((rnum = *(uint_t *)arg) >= lcip->nregs)
                        return (DDI_FAILURE);
                *(off_t *)result = lcip->rsp[rnum].lombus_size;
                return (DDI_SUCCESS);

        case DDI_CTLOPS_NREGS:
                if ((lcip = ddi_get_parent_data(rdip)) == NULL)
                        return (DDI_FAILURE);
                *(int *)result = lcip->nregs;
                return (DDI_SUCCESS);
        }

        return (ddi_ctlops(dip, rdip, op, arg, result));
}


/*
 * This nexus does not support passing interrupts to leaf drivers, so
 * all the intrspec-related operations just fail as cleanly as possible.
 */

/*ARGSUSED*/
static int
bscbus_intr_op(dev_info_t *dip, dev_info_t *rdip, ddi_intr_op_t op,
    ddi_intr_handle_impl_t *hdlp, void *result)
{
#if defined(__sparc)
        return (i_ddi_intr_ops(dip, rdip, op, hdlp, result));
#else
        _NOTE(ARGUNUSED(dip, rdip, op, hdlp, result))
        return (DDI_FAILURE);
#endif
}

/*
 *  Clean up on detach or failure of attach
 */
static int
bscbus_unattach(struct bscbus_state *ssp, int instance)
{
        int chno;

        if (ssp != NULL) {
                for (chno = 0; chno < BSCBUS_MAX_CHANNELS; chno++) {
                        ASSERT(ssp->channel[chno].map_count == 0);
                }
                bscbus_offline(ssp);
                ddi_set_driver_private(ssp->dip, NULL);
                mutex_destroy(ssp->ch_mutex);
        }
#ifdef BSCBUS_LOGSTATUS
        if (ssp->cmd_log_size != 0) {
                kmem_free(ssp->cmd_log,
                    ssp->cmd_log_size * sizeof (bsc_cmd_log_t));
        }
#endif /* BSCBUS_LOGSTATUS */


        ddi_soft_state_free(bscbus_statep, instance);
        return (DDI_FAILURE);
}

/*
 *  Autoconfiguration routines
 */

static int
bscbus_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        struct bscbus_state *ssp = NULL;
        int chno;
        int instance;
        int err;

        switch (cmd) {
        default:
                return (DDI_FAILURE);

        case DDI_ATTACH:
                break;
        }

        /*
         *  Allocate the soft-state structure
         */
        instance = ddi_get_instance(dip);
        if (ddi_soft_state_zalloc(bscbus_statep, instance) != DDI_SUCCESS)
                return (DDI_FAILURE);
        if ((ssp = bscbus_getstate(dip, instance, "bscbus_attach")) == NULL)
                return (bscbus_unattach(ssp, instance));
        ddi_set_driver_private(dip, ssp);

        /*
         *  Initialise devinfo-related fields
         */
        ssp->dip = dip;
        ssp->majornum = ddi_driver_major(dip);
        ssp->instance = instance;

        /*
         *  Set various options from .conf properties
         */
        ssp->debug = ddi_prop_get_int(DDI_DEV_T_ANY, dip,
            DDI_PROP_DONTPASS, "debug", 0);

        mutex_init(ssp->ch_mutex, NULL, MUTEX_DRIVER, NULL);

#ifdef BSCBUS_LOGSTATUS
        ssp->cmd_log_size = bscbus_cmd_log_size;
        if (ssp->cmd_log_size != 0) {
                ssp->cmd_log_idx = 0;
                ssp->cmd_log = kmem_zalloc(ssp->cmd_log_size *
                    sizeof (bsc_cmd_log_t), KM_SLEEP);
        }
#endif /* BSCBUS_LOGSTATUS */

        /*
         *  Online the hardware ...
         */
        err = bscbus_online(ssp);
        if (err != 0)
                return (bscbus_unattach(ssp, instance));

        for (chno = 0; chno < BSCBUS_MAX_CHANNELS; chno++) {
                struct bscbus_channel_state *csp = &ssp->channel[chno];

                /*
                 * Initialise state
                 * The hardware/interrupts are setup at map time to
                 * avoid claiming hardware that OBP is using
                 */
                csp->ssp = ssp;
                csp->chno = chno;
                csp->map_count = 0;
                csp->map_dog = B_FALSE;
        }

        /*
         *  All done, report success
         */
        ddi_report_dev(dip);
        return (DDI_SUCCESS);
}

static int
bscbus_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        struct bscbus_state *ssp;
        int instance;

        switch (cmd) {
        default:
                return (DDI_FAILURE);

        case DDI_DETACH:
                break;
        }

        instance = ddi_get_instance(dip);
        if ((ssp = bscbus_getstate(dip, instance, "bscbus_detach")) == NULL)
                return (DDI_FAILURE);   /* this "can't happen" */

        (void) bscbus_unattach(ssp, instance);
        return (DDI_SUCCESS);
}

static int
bscbus_reset(dev_info_t *dip, ddi_reset_cmd_t cmd)
{
        struct bscbus_state *ssp;
        int chno;

        _NOTE(ARGUNUSED(cmd))

        if ((ssp = bscbus_getstate(dip, -1, "bscbus_reset")) == NULL)
                return (DDI_FAILURE);

        for (chno = 0; chno < BSCBUS_MAX_CHANNELS; chno++) {
                bscbus_hw_reset(&ssp->channel[chno]);
        }
        return (DDI_SUCCESS);
}


/*
 * System interface structures
 */

static struct cb_ops bscbus_cb_ops =
{
        nodev,                  /* b/c open     */
        nodev,                  /* b/c close    */
        nodev,                  /* b   strategy */
        nodev,                  /* b   print    */
        nodev,                  /* b   dump     */
        nodev,                  /* c   read     */
        nodev,                  /* c   write    */
        nodev,                  /* c   ioctl    */
        nodev,                  /* c   devmap   */
        nodev,                  /* c   mmap     */
        nodev,                  /* c   segmap   */
        nochpoll,               /* c   poll     */
        ddi_prop_op,            /* b/c prop_op  */
        NULL,                   /* c   streamtab */
        D_MP | D_NEW            /* b/c flags    */
};

static struct bus_ops bscbus_bus_ops =
{
        BUSO_REV,                       /* revision             */
        bscbus_map,                     /* bus_map              */
        0,                              /* get_intrspec         */
        0,                              /* add_intrspec         */
        0,                              /* remove_intrspec      */
        i_ddi_map_fault,                /* map_fault            */
        ddi_no_dma_map,                 /* dma_map              */
        ddi_no_dma_allochdl,            /* allocate DMA handle  */
        ddi_no_dma_freehdl,             /* free DMA handle      */
        ddi_no_dma_bindhdl,             /* bind DMA handle      */
        ddi_no_dma_unbindhdl,           /* unbind DMA handle    */
        ddi_no_dma_flush,               /* flush DMA            */
        ddi_no_dma_win,                 /* move DMA window      */
        ddi_no_dma_mctl,                /* generic DMA control  */
        bscbus_ctlops,                  /* generic control      */
        ddi_bus_prop_op,                /* prop_op              */
        ndi_busop_get_eventcookie,      /* get_eventcookie      */
        ndi_busop_add_eventcall,        /* add_eventcall        */
        ndi_busop_remove_eventcall,     /* remove_eventcall     */
        ndi_post_event,                 /* post_event           */
        0,                              /* interrupt control    */
        0,                              /* bus_config           */
        0,                              /* bus_unconfig         */
        0,                              /* bus_fm_init          */
        0,                              /* bus_fm_fini          */
        0,                              /* bus_fm_access_enter  */
        0,                              /* bus_fm_access_exit   */
        0,                              /* bus_power            */
        bscbus_intr_op                  /* bus_intr_op          */
};

static struct dev_ops bscbus_dev_ops =
{
        DEVO_REV,
        0,                              /* refcount             */
        ddi_no_info,                    /* getinfo              */
        nulldev,                        /* identify             */
        nulldev,                        /* probe                */
        bscbus_attach,                  /* attach               */
        bscbus_detach,                  /* detach               */
        bscbus_reset,                   /* reset                */
        &bscbus_cb_ops,                 /* driver operations    */
        &bscbus_bus_ops,                /* bus operations       */
        NULL,                           /* power                */
        ddi_quiesce_not_needed,                 /* quiesce              */
};

static struct modldrv modldrv =
{
        &mod_driverops,
        "bscbus driver",
        &bscbus_dev_ops
};

static struct modlinkage modlinkage =
{
        MODREV_1,
        {
                &modldrv,
                NULL
        }
};


/*
 *  Dynamic loader interface code
 */

int
_init(void)
{
        int err;

        err = ddi_soft_state_init(&bscbus_statep,
            sizeof (struct bscbus_state), 0);
        if (err == DDI_SUCCESS)
                if ((err = mod_install(&modlinkage)) != DDI_SUCCESS) {
                        ddi_soft_state_fini(&bscbus_statep);
                }

        return (err);
}

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

int
_fini(void)
{
        int err;

        if ((err = mod_remove(&modlinkage)) == DDI_SUCCESS) {
                ddi_soft_state_fini(&bscbus_statep);
                bscbus_major = NOMAJOR;
        }

        return (err);
}

#ifdef BSCBUS_LOGSTATUS
void bscbus_cmd_log(struct bscbus_channel_state *csp, bsc_cmd_stamp_t cat,
    uint8_t status, uint8_t data)
{
        int idx;
        bsc_cmd_log_t *logp;
        struct bscbus_state *ssp;

        if ((csp) == NULL)
                return;
        if ((ssp = (csp)->ssp) == NULL)
                return;
        if (ssp->cmd_log_size == 0)
                return;
        if ((bscbus_cmd_log_flags & (1 << cat)) == 0)
                return;
        idx = atomic_inc_32_nv(&ssp->cmd_log_idx);
        logp = &ssp->cmd_log[idx % ssp->cmd_log_size];
        logp->bcl_seq = idx;
        logp->bcl_cat = cat;
        logp->bcl_now = gethrtime();
        logp->bcl_chno = csp->chno;
        logp->bcl_cmdstate = csp->cmdstate;
        logp->bcl_status = status;
        logp->bcl_data = data;
}
#endif /* BSCBUS_LOGSTATUS */