/*
 * 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.
 */


/*
 * Sample skeleton USB driver.
 * This driver provides a framework for developing USB client drivers.
 *
 * As a simplistic example, usbskel implements a data transfer by reading
 * raw configuration data, which every USB device has. It is expected that
 * the caller will issue an initial 4-byte read to get the total length of the
 * first configuration, and follow up with a second read, passing the total
 * length to read the entire configuration cloud.
 *
 * The device has four states (refer to usbai.h):
 *      USB_DEV_ONLINE: In action or ready for action.
 *      USB_DEV_DISCONNECTED: Hotplug removed, or device not present/correct on
 *              resume (CPR).
 *      USB_DEV_SUSPENDED: Device has been suspended along with the system.
 *      USB_DEV_PWRED_DOWN: Device has been powered down.  (Note that this
 *              driver supports only two power states, powered down and
 *              full power.)
 *
 * In order to avoid race conditions between driver entry points,
 * access to the device is serialized.  Race conditions are an issue in
 * particular between disconnect event callbacks, detach, power, open
 * and data transfer callbacks.  The functions usbskel_serialize/release_access
 * are implemented for this purpose.
 *
 * Mutexes should never be held when making calls into USBA or when
 * sleeping.
 *
 * pm_busy_component and pm_idle_component mark the device as busy or idle to
 * the system.  These functions are paired, and are called only from code
 * bracketed by usbskel_serialize_access and usbskel_release_access.
 *
 * NOTE: PM and CPR will be enabled at a later release of S10.
 */

#if defined(lint) && !defined(DEBUG)
#define DEBUG
#endif

#define USBDRV_MAJOR_VER        2
#define USBDRV_MINOR_VER        0

/* Uncomment to enable Power Management, when the OS PM framework is ready. */
/*
 * #ifndef USBSKEL_PM
 * #define      USBSKEL_PM
 * #endif
 */

/*
 * Uncomment to enable Check Point Resume (system suspend and resume) when the
 * OS CPR framework is ready.
 */
/*
 * #ifndef USBSKEL_CPR
 * #define      USBSKEL_CPR
 * #endif
 */

#include <sys/usb/usba.h>
#include <sys/strsun.h>
#include <sys/usb/clients/usbskel/usbskel.h>

int             usbskel_errlevel = USBSKEL_LOG_LOG;
static char     *name = "usbskl";       /* Driver name, used all over. */

/*
 * Boolean set to whether or not to dump the device's descriptor tree.
 * Can be changed with the usblog_dumptree property in a usbskel.conf file.
 */
static boolean_t        usbskel_dumptree;

/*
 * Function Prototypes
 */
static int      usbskel_attach(dev_info_t *, ddi_attach_cmd_t);
static int      usbskel_detach(dev_info_t *, ddi_detach_cmd_t);
static int      usbskel_info(dev_info_t *, ddi_info_cmd_t, void *, void **);
static int      usbskel_cleanup(dev_info_t *, usbskel_state_t *);
static int      usbskel_open(dev_t *, int, int, cred_t *);
static int      usbskel_close(dev_t, int, int, cred_t *);
static int      usbskel_read(dev_t, struct uio *uip_p, cred_t *);
static int      usbskel_strategy(struct buf *);
static void     usbskel_minphys(struct buf *);
static void     usbskel_normal_callback(usb_pipe_handle_t, usb_ctrl_req_t *);
static void     usbskel_exception_callback(usb_pipe_handle_t, usb_ctrl_req_t *);
static int      usbskel_ioctl(dev_t, int, intptr_t, int, cred_t *, int *);
static int      usbskel_disconnect_callback(dev_info_t *);
static int      usbskel_reconnect_callback(dev_info_t *);
static void     usbskel_restore_device_state(dev_info_t *, usbskel_state_t *);
static int      usbskel_cpr_suspend(dev_info_t *);
static void     usbskel_cpr_resume(dev_info_t *);
static int      usbskel_test_and_adjust_device_state(usbskel_state_t *);
static int      usbskel_open_pipes(usbskel_state_t *);
static void     usbskel_close_pipes(usbskel_state_t *);
static int      usbskel_pm_busy_component(usbskel_state_t *);
static void     usbskel_pm_idle_component(usbskel_state_t *);
static int      usbskel_power(dev_info_t *, int, int);
#ifdef USBSKEL_PM
static int      usbskel_init_power_mgmt(usbskel_state_t *);
static void     usbskel_destroy_power_mgmt(usbskel_state_t *);
#endif
static int      usbskel_serialize_access(usbskel_state_t *, boolean_t);
static void     usbskel_release_access(usbskel_state_t *);
static int      usbskel_check_same_device(usbskel_state_t *);

/*PRINTFLIKE3*/
static void     usbskel_log(usbskel_state_t *, int, char *, ...);

/* _NOTE is an advice for locklint.  Locklint checks lock use for deadlocks. */
_NOTE(SCHEME_PROTECTS_DATA("unique per call", usb_ctrl_req))
_NOTE(SCHEME_PROTECTS_DATA("unique per call", buf))

/* module loading stuff */
struct cb_ops usbskel_cb_ops = {
        usbskel_open,           /* open  */
        usbskel_close,          /* close */
        usbskel_strategy,       /* strategy */
        nulldev,                /* print */
        nulldev,                /* dump */
        usbskel_read,           /* read */
        nodev,                  /* write */
        usbskel_ioctl,          /* ioctl */
        nulldev,                /* devmap */
        nodev,                  /* mmap */
        nodev,                  /* segmap */
        nochpoll,               /* poll */
        ddi_prop_op,            /* cb_prop_op */
        NULL,                   /* streamtab  */
        D_MP
};

static struct dev_ops usbskel_ops = {
        DEVO_REV,               /* devo_rev, */
        0,                      /* refcnt  */
        usbskel_info,           /* info */
        nulldev,                /* identify */
        nulldev,                /* probe */
        usbskel_attach,         /* attach */
        usbskel_detach,         /* detach */
        nodev,                  /* reset */
        &usbskel_cb_ops,        /* driver operations */
        NULL,                   /* bus operations */
        usbskel_power,          /* power */
        ddi_quiesce_not_needed, /* devo_quiesce */
};

static struct modldrv usbskel_modldrv = {
        &mod_driverops,
        "USB skeleton driver",
        &usbskel_ops
};

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

/* local variables */

/* Soft state structures */
#define USBSKEL_INITIAL_SOFT_SPACE      1
static void *usbskel_statep;


/*
 * Module-wide initialization routine.
 */
int
_init(void)
{
        int rval;

        usbskel_log(NULL, USBSKEL_LOG_LOG, "usbskel _init");

        if ((rval = ddi_soft_state_init(&usbskel_statep,
            sizeof (usbskel_state_t), USBSKEL_INITIAL_SOFT_SPACE)) != 0) {

                return (rval);
        }

        if ((rval = mod_install(&modlinkage)) != 0) {
                ddi_soft_state_fini(&usbskel_statep);
        }

        usbskel_log(NULL, USBSKEL_LOG_LOG, "usbskel _init done");

        return (rval);
}


/*
 * Module-wide tear-down routine.
 */
int
_fini(void)
{
        int rval;

        usbskel_log(NULL, USBSKEL_LOG_LOG, "usbskel _fini");
        if ((rval = mod_remove(&modlinkage)) != 0) {

                return (rval);
        }

        ddi_soft_state_fini(&usbskel_statep);
        usbskel_log(NULL, USBSKEL_LOG_LOG, "usbskel _fini done");

        return (rval);
}


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


/*
 * usbskel_info:
 *      Get minor number, soft state structure, etc.
 */
/*ARGSUSED*/
static int
usbskel_info(dev_info_t *dip, ddi_info_cmd_t infocmd,
                        void *arg, void **result)
{
        usbskel_state_t *usbskelp;
        int error = DDI_FAILURE;

        switch (infocmd) {
        case DDI_INFO_DEVT2DEVINFO:
                if ((usbskelp = ddi_get_soft_state(usbskel_statep,
                    getminor((dev_t)arg))) != NULL) {
                        *result = usbskelp->usbskel_dip;
                        if (*result != NULL) {
                                error = DDI_SUCCESS;
                        }
                } else {
                        *result = NULL;
                }
                break;
        case DDI_INFO_DEVT2INSTANCE:
                *result = (void *)(uintptr_t)getminor((dev_t)arg);
                error = DDI_SUCCESS;
                break;
        default:
                break;
        }

        return (error);
}


/*
 * usbskel_attach:
 *      Attach or resume.
 *
 *      For attach, initialize state and device, including:
 *              state variables, locks, device node
 *              device registration with system
 *              power management, hotplugging
 *      For resume, restore device and state
 */
static int
usbskel_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        int                     instance = ddi_get_instance(dip);
        char                    *devinst;
        int                     devinstlen;
        usbskel_state_t         *usbskelp = NULL;
        usb_reg_parse_lvl_t     parse_level;
        usb_ep_data_t           *ep_datap;
        int                     status;

        switch (cmd) {
        case DDI_ATTACH:
                break;

        case DDI_RESUME:
                usbskel_cpr_resume(dip);

                /*
                 * Always return success to work around enumeration failures.
                 * This works around an issue where devices which are present
                 * before a suspend and absent upon resume could cause a system
                 * panic on resume.
                 */
                return (DDI_SUCCESS);
        default:
                return (DDI_FAILURE);
        }

        if (ddi_soft_state_zalloc(usbskel_statep, instance) == DDI_SUCCESS) {
                usbskelp = ddi_get_soft_state(usbskel_statep, instance);
        }
        if (usbskelp == NULL)  {

                return (DDI_FAILURE);
        }

        usbskelp->usbskel_dip = dip;

        devinst = kmem_zalloc(USB_MAXSTRINGLEN, KM_SLEEP);
        devinstlen = snprintf(devinst, USB_MAXSTRINGLEN, "%s%d: ",
            ddi_driver_name(dip), instance);

        usbskelp->usbskel_devinst = kmem_zalloc(devinstlen + 1, KM_SLEEP);
        (void) strncpy(usbskelp->usbskel_devinst, devinst, devinstlen);
        kmem_free(devinst, USB_MAXSTRINGLEN);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "Attach: enter for attach");

        usbskel_dumptree = (ddi_prop_exists(DDI_DEV_T_ANY, dip,
            DDI_PROP_DONTPASS, "usbskel_dumptree") == 1);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "Tree will %sbe dumped",
            ((usbskel_dumptree) ? "" : "not "));

        parse_level = (usb_reg_parse_lvl_t)ddi_prop_get_int(
            DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS,
            "usbskel_parse_level", USB_PARSE_LVL_ALL);

        switch (parse_level) {
        case USB_PARSE_LVL_NONE:
                /* This driver needs a tree. */
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "parse_level requested to NOT DUMP");
                parse_level = USB_PARSE_LVL_IF;
                /*FALLTHROUGH*/
        case USB_PARSE_LVL_IF:
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "parse_level set to dump specific interface");
                break;
        case USB_PARSE_LVL_CFG:
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "parse_level set to dump specific config");
                break;
        case USB_PARSE_LVL_ALL:
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "parse_level set to dump everything");
                break;
        default:
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "attach: parse_level will default to dump everything");
                parse_level = USB_PARSE_LVL_ALL;
        }

        if ((status = usb_client_attach(dip, USBDRV_VERSION, 0)) !=
            USB_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "attach: usb_client_attach failed, error code:%d", status);
                goto fail;
        }

        if ((status = usb_get_dev_data(dip, &usbskelp->usbskel_reg, parse_level,
            0)) != USB_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "attach: usb_get_dev_data failed, error code:%d", status);
                goto fail;
        }

        if (usbskel_dumptree) {
                (void) usb_print_descr_tree(
                    usbskelp->usbskel_dip, usbskelp->usbskel_reg);
        }

        /*
         * Get the descriptor for an intr pipe at alt 0 of current interface.
         * This will be used later to open the pipe.
         */
        if ((ep_datap = usb_lookup_ep_data(dip, usbskelp->usbskel_reg,
            usbskelp->usbskel_reg->dev_curr_if, 0, 0,
            USB_EP_ATTR_INTR, USB_EP_DIR_IN)) == NULL) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "attach: Error getting intr endpoint descriptor");
                goto fail;
        }
        usbskelp->usbskel_intr_ep_descr = ep_datap->ep_descr;

        usb_free_descr_tree(dip, usbskelp->usbskel_reg);

        mutex_init(&usbskelp->usbskel_mutex, NULL, MUTEX_DRIVER,
            usbskelp->usbskel_reg->dev_iblock_cookie);

        cv_init(&usbskelp->usbskel_serial_cv, NULL, CV_DRIVER, NULL);
        usbskelp->usbskel_serial_inuse = B_FALSE;

        usbskelp->usbskel_locks_initialized = B_TRUE;

        /* create minor node */
        if (ddi_create_minor_node(dip, name, S_IFCHR, instance,
            "usb_skeleton", 0) != DDI_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "attach: Error creating minor node");
                goto fail;
        }

        /* Put online before PM init as can get power managed afterward. */
        usbskelp->usbskel_dev_state = USB_DEV_ONLINE;

#ifdef USBSKEL_PM
        /* initialize power management */
        if (usbskel_init_power_mgmt(usbskelp) != USB_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "attach: Could not initialize power mgmt");
        }
#endif

        if (usb_register_hotplug_cbs(dip, usbskel_disconnect_callback,
            usbskel_reconnect_callback) != USB_SUCCESS) {

                goto fail;
        }

        /* Report device */
        ddi_report_dev(dip);

        return (DDI_SUCCESS);

fail:
        if (usbskelp) {
                (void) usbskel_cleanup(dip, usbskelp);
        }

        return (DDI_FAILURE);
}


/*
 * usbskel_detach:
 *      detach or suspend driver instance
 *
 * Note: in detach, only contention threads is from pm and disconnnect.
 */
static int
usbskel_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        int             instance = ddi_get_instance(dip);
        usbskel_state_t *usbskelp =
            ddi_get_soft_state(usbskel_statep, instance);
        int             rval = DDI_FAILURE;

        switch (cmd) {
        case DDI_DETACH:
                mutex_enter(&usbskelp->usbskel_mutex);
                ASSERT((usbskelp->usbskel_drv_state & USBSKEL_OPEN) == 0);
                mutex_exit(&usbskelp->usbskel_mutex);

                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "Detach: enter for detach");

                rval = usbskel_cleanup(dip, usbskelp);

                break;
        case DDI_SUSPEND:
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "Detach: enter for suspend");

                rval = usbskel_cpr_suspend(dip);
        default:

                break;
        }

        return ((rval == USB_SUCCESS) ? DDI_SUCCESS : DDI_FAILURE);
}


/*
 * usbskel_cleanup:
 *      clean up the driver state for detach
 */
static int
usbskel_cleanup(dev_info_t *dip, usbskel_state_t *usbskelp)
{
        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "Cleanup: enter");

        if (usbskelp->usbskel_locks_initialized) {

                /* This must be done 1st to prevent more events from coming. */
                usb_unregister_hotplug_cbs(dip);

                /*
                 * At this point, no new activity can be initiated. The driver
                 * has disabled hotplug callbacks. The Solaris framework has
                 * disabled new opens on a device being detached, and does not
                 * allow detaching an open device.
                 *
                 * The following ensures that all driver activity has drained.
                 */
                mutex_enter(&usbskelp->usbskel_mutex);
                (void) usbskel_serialize_access(usbskelp, USBSKEL_SER_NOSIG);
                usbskel_release_access(usbskelp);
                mutex_exit(&usbskelp->usbskel_mutex);

#ifdef USBSKEL_PM
                /* All device activity has died down. */
                usbskel_destroy_power_mgmt(usbskelp);
#endif

                /* start dismantling */
                ddi_remove_minor_node(dip, NULL);

                cv_destroy(&usbskelp->usbskel_serial_cv);
                mutex_destroy(&usbskelp->usbskel_mutex);
        }

        usb_client_detach(dip, usbskelp->usbskel_reg);

        if (usbskelp->usbskel_devinst != NULL) {
                kmem_free(usbskelp->usbskel_devinst,
                    strlen(usbskelp->usbskel_devinst) + 1);
        }

        ddi_soft_state_free(usbskel_statep, ddi_get_instance(dip));
        ddi_prop_remove_all(dip);

        return (USB_SUCCESS);
}


/*ARGSUSED*/
static int
usbskel_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
{
        usbskel_state_t *usbskelp =
            ddi_get_soft_state(usbskel_statep, getminor(*devp));
        int rval = 0;

        if (usbskelp == NULL) {

                return (ENXIO);
        }

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "open: enter");

        /*
         * Keep it simple: one client at a time.
         * Exclusive open only
         */
        mutex_enter(&usbskelp->usbskel_mutex);
        if ((usbskelp->usbskel_drv_state & USBSKEL_OPEN) != 0) {
                mutex_exit(&usbskelp->usbskel_mutex);

                return (EBUSY);
        }
        usbskelp->usbskel_drv_state |= USBSKEL_OPEN;

        /*
         * This is in place so that a disconnect or CPR doesn't interfere with
         * pipe opens.
         */
        if (usbskel_serialize_access(usbskelp, USBSKEL_SER_SIG) == 0) {
                usbskelp->usbskel_drv_state &= ~USBSKEL_OPEN;
                mutex_exit(&usbskelp->usbskel_mutex);

                return (EINTR);
        }

        mutex_exit(&usbskelp->usbskel_mutex);
        if (usbskel_pm_busy_component(usbskelp) != DDI_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "open: Error raising power");
                rval = EIO;
                goto done;
        }
        mutex_enter(&usbskelp->usbskel_mutex);

        /* Fail if device is no longer ready. */
        if (usbskelp->usbskel_dev_state != USB_DEV_ONLINE) {
                mutex_exit(&usbskelp->usbskel_mutex);
                rval = EIO;
                goto done;
        }

        mutex_exit(&usbskelp->usbskel_mutex);
        if (usbskel_open_pipes(usbskelp) != USB_SUCCESS) {
                rval = EIO;
                goto done;
        }

        /* Device specific initialization goes here. */

done:
        if (rval != 0) {
                mutex_enter(&usbskelp->usbskel_mutex);
                usbskelp->usbskel_drv_state &= ~USBSKEL_OPEN;

                usbskel_release_access(usbskelp);
                mutex_exit(&usbskelp->usbskel_mutex);

                usbskel_pm_idle_component(usbskelp);
        } else {

                /* Device is idle until it is used. */
                mutex_enter(&usbskelp->usbskel_mutex);
                usbskel_release_access(usbskelp);
                mutex_exit(&usbskelp->usbskel_mutex);
        }

        return (rval);
}


/*ARGSUSED*/
static int
usbskel_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
{
        usbskel_state_t *usbskelp =
            ddi_get_soft_state(usbskel_statep, getminor(dev));

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "close: enter");

        mutex_enter(&usbskelp->usbskel_mutex);
        (void) usbskel_serialize_access(usbskelp, USBSKEL_SER_NOSIG);
        mutex_exit(&usbskelp->usbskel_mutex);

        /* Perform device session cleanup here. */

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "close: cleaning up...");

        /*
         * USBA automatically flushes/resets active non-default pipes
         * when they are closed.  We can't reset default pipe, but we
         * can wait for all requests on it from this dip to drain.
         */
        (void) usb_pipe_drain_reqs(usbskelp->usbskel_dip,
            usbskelp->usbskel_reg->dev_default_ph, 0,
            USB_FLAGS_SLEEP, NULL, 0);

        mutex_enter(&usbskelp->usbskel_mutex);
        usbskel_close_pipes(usbskelp);

        usbskelp->usbskel_drv_state &= ~USBSKEL_OPEN;

        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        usbskel_pm_idle_component(usbskelp);

        return (0);
}


/*ARGSUSED*/
static int
usbskel_read(dev_t dev, struct uio *uio_p, cred_t *cred_p)
{
        usbskel_state_t *usbskelp =
            ddi_get_soft_state(usbskel_statep, getminor(dev));

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "read enter");

        return (physio(usbskel_strategy, NULL, dev, B_READ,
            usbskel_minphys, uio_p));
}


/*
 * strategy:
 *      Called through physio to setup and start the transfer.
 */
static int
usbskel_strategy(struct buf *bp)
{
        usbskel_state_t *usbskelp = ddi_get_soft_state(usbskel_statep,
            getminor(bp->b_edev));
        usb_pipe_handle_t pipe = usbskelp->usbskel_reg->dev_default_ph;
        usb_ctrl_req_t  *request;
        int status;

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "strategy enter");

        /*
         * Initialize residual count here in case transfer doesn't even get
         * started.
         */
        bp->b_resid = bp->b_bcount;

        /* Needed as this is a character driver. */
        if (bp->b_flags & (B_PHYS | B_PAGEIO)) {
                bp_mapin(bp);
        }

        mutex_enter(&usbskelp->usbskel_mutex);
        (void) usbskel_serialize_access(usbskelp, USBSKEL_SER_NOSIG);

        /* Make sure device has not been disconnected. */
        if (usbskelp->usbskel_dev_state != USB_DEV_ONLINE) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_strategy: device can't be accessed");
                mutex_exit(&usbskelp->usbskel_mutex);
                goto fail;
        }
        mutex_exit(&usbskelp->usbskel_mutex);

        /*
         * Since every device has raw configuration data, set up a control
         * transfer to read the raw configuration data. In a production driver
         * a read would probably be done on a pipe other than the default pipe,
         * and would be reading data streamed by the device.
         */

        /* Allocate and initialize the request. */
        if ((bp->b_private = request = usb_alloc_ctrl_req(
            usbskelp->usbskel_dip, bp->b_bcount, USB_FLAGS_SLEEP)) ==
            NULL) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_read: Error allocating request");
                goto fail;
        }

        request->ctrl_bmRequestType =
            USB_DEV_REQ_DEV_TO_HOST | USB_DEV_REQ_TYPE_STANDARD |
            USB_DEV_REQ_RCPT_DEV;
        request->ctrl_bRequest = USB_REQ_GET_DESCR;

        /* For now, return only the first configuration. */
        request->ctrl_wValue = USB_DESCR_TYPE_SETUP_CFG | 0;
        request->ctrl_wIndex = 0;
        request->ctrl_wLength = bp->b_bcount;
        request->ctrl_timeout = 3;

        /* Autoclearing automatically set on default pipe. */
        request->ctrl_attributes = USB_ATTRS_SHORT_XFER_OK;

        request->ctrl_cb = usbskel_normal_callback;
        request->ctrl_exc_cb = usbskel_exception_callback;

        /* Hook the req to the bp, so callback knows where to put the data. */
        /* Now both bp and request know about each other. */
        request->ctrl_client_private = (usb_opaque_t)bp;

        /*
         * Issue the request asynchronously.  Physio will block waiting for an
         * "interrupt" which comes as a callback.  The callback calls biodone
         * to release physio from its wait.
         */
        if ((status = usb_pipe_ctrl_xfer(pipe, request, USB_FLAGS_NOSLEEP)) !=
            USB_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_strategy: can't start transfer: status: %d",
                    status);
                goto fail;
        }

        /*
         * Normally, usbskel_release_access() and usbskel_pm_idle_component
         * is called in callback handler.
         */

        return (0);

fail:
        mutex_enter(&usbskelp->usbskel_mutex);
        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        bioerror(bp, EIO);
        biodone(bp);

        return (0);
}


static void
usbskel_minphys(struct buf *bp)
{
        /* the config cloud is limited to 64k */
        if (bp->b_bcount > USBSKEL_REQUEST_SIZE) {
                bp->b_bcount = USBSKEL_REQUEST_SIZE;
        }
        minphys(bp);
}


/*
 * usbskel_normal_callback:
 *      Completion handler for successful transfer.
 *              Copy data from mblk returned by USBA, into
 *              buffer passed by physio, to get it back to user.
 *              Idle device
 *              update counts, etc.
 *              release request.
 *              signal completion via biodone
 */
/*ARGSUSED*/
static void
usbskel_normal_callback(usb_pipe_handle_t pipe, usb_ctrl_req_t *request)
{
        struct buf *bp          = (struct buf *)request->ctrl_client_private;
        usbskel_state_t *usbskelp = ddi_get_soft_state(usbskel_statep,
            getminor(bp->b_edev));
        mblk_t *data            = request->ctrl_data;
        int amt_transferred     = MBLKL(data);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "normal callback enter");

        ASSERT((request->ctrl_cb_flags & USB_CB_INTR_CONTEXT) == 0);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "at entry, b_bcount = %lu, b_resid = %lu, trans = %d", bp->b_bcount,
            bp->b_resid, amt_transferred);

        mutex_enter(&usbskelp->usbskel_mutex);
        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        /* Copy data out of mblk, into buffer. */
        if (amt_transferred) {
                bcopy(data->b_rptr, bp->b_un.b_addr, amt_transferred);
        }

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "normal callback: transferring %d bytes from 0x%p to 0x%p",
            amt_transferred, (void *)data, (void *)(bp->b_un.b_addr));

        /* Unhook. */
        bp->b_private = NULL;
        request->ctrl_client_private = NULL;

        /* Free request. */
        usb_free_ctrl_req(request);

        /* Finish up. */
        bp->b_resid = bp->b_bcount - amt_transferred;

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "at exit, b_bcount = %lu, b_resid = %lu, trans = %d", bp->b_bcount,
            bp->b_resid, amt_transferred);

        biodone(bp);
}


/*
 * usbskel_exception_callback:
 *      Completion handler for an erred transfer.
 *              Copy data from mblk returned by USBA, if any, into
 *              buffer passed by physio, to get it back to user.
 *              Idle device
 *              update counts, etc.
 *              release request.
 *              signal completion via biodone
 */
/*ARGSUSED*/
static void
usbskel_exception_callback(usb_pipe_handle_t pipe, usb_ctrl_req_t *request)
{
        struct buf *bp = (struct buf *)request->ctrl_client_private;
        usbskel_state_t *usbskelp = ddi_get_soft_state(usbskel_statep,
            getminor(bp->b_edev));
        mblk_t  *data = request->ctrl_data;
        int     amt_transferred = (data ? MBLKL(data) : 0);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "at except cb entry, b_bcount = %lu, b_resid = %lu, trans = %d",
            bp->b_bcount, bp->b_resid, amt_transferred);

        ASSERT((request->ctrl_cb_flags & USB_CB_INTR_CONTEXT) == 0);

        mutex_enter(&usbskelp->usbskel_mutex);
        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        /* Copy data, if any,  out of mblk, into buffer. */
        if (amt_transferred) {
                bcopy(data, bp->b_un.b_addr, amt_transferred);
        }
        bp->b_resid = bp->b_bcount - amt_transferred;

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "exception cb: req = 0x%p, cr = %d\n\t cb_flags = 0x%x "
            "data = 0x%p, amt xfered = %d", (void *)request,
            request->ctrl_completion_reason, request->ctrl_cb_flags,
            (void *)(request->ctrl_data), amt_transferred);

        /* Unhook */
        bp->b_private = NULL;
        request->ctrl_client_private = NULL;

        /* Free request. */
        usb_free_ctrl_req(request);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "at except cb exit, b_bcount = %lu, b_resid = %lu, trans = %d",
            bp->b_bcount, bp->b_resid, amt_transferred);

        bioerror(bp, EIO);
        biodone(bp);
}


/*
 * XXX Empty ioctl for now.
 */
/*ARGSUSED*/
static int
usbskel_ioctl(dev_t dev, int cmd, intptr_t arg,
                int mode, cred_t *cred_p, int *rval_p)
{
        usbskel_state_t *usbskelp =
            ddi_get_soft_state(usbskel_statep, getminor(dev));

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "ioctl enter");

        return (ENOTTY);
}


/*
 * usbskel_disconnect_callback:
 *      Called when device hotplug-removed.
 *              Close pipes. (This does not attempt to contact device.)
 *              Set state to DISCONNECTED
 */
static int
usbskel_disconnect_callback(dev_info_t *dip)
{
        int instance = ddi_get_instance(dip);
        usbskel_state_t *usbskelp =
            ddi_get_soft_state(usbskel_statep, instance);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "disconnect: enter");

        mutex_enter(&usbskelp->usbskel_mutex);
        (void) usbskel_serialize_access(usbskelp, USBSKEL_SER_NOSIG);

        /*
         * Save any state of device or IO in progress required by
         * usbskel_restore_device_state for proper device "thawing" later.
         */
        usbskelp->usbskel_dev_state = USB_DEV_DISCONNECTED;

        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        return (USB_SUCCESS);
}


/*
 * usbskel_reconnect_callback:
 *      Called with device hotplug-inserted
 *              Restore state
 */
static int
usbskel_reconnect_callback(dev_info_t *dip)
{
        int instance = ddi_get_instance(dip);
        usbskel_state_t *usbskelp =
            ddi_get_soft_state(usbskel_statep, instance);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "reconnect: enter");

        mutex_enter(&usbskelp->usbskel_mutex);
        (void) usbskel_serialize_access(usbskelp, USBSKEL_SER_NOSIG);
        usbskel_restore_device_state(dip, usbskelp);
        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        return (USB_SUCCESS);
}


/*
 * usbskel_restore_device_state:
 *      Called during hotplug-reconnect and resume.
 *              reenable power management
 *              Verify the device is the same as before the disconnect/suspend.
 *              Restore device state
 *              Thaw any IO which was frozen.
 *              Quiesce device.  (Other routines will activate if thawed IO.)
 *              Set device online.
 *              Leave device disconnected if there are problems.
 */
static void
usbskel_restore_device_state(dev_info_t *dip, usbskel_state_t *usbskelp)
{
        int rval;

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "usbskel_restore_device_state: enter");

        ASSERT(mutex_owned(&usbskelp->usbskel_mutex));

        ASSERT((usbskelp->usbskel_dev_state == USB_DEV_DISCONNECTED) ||
            (usbskelp->usbskel_dev_state == USB_DEV_SUSPENDED));

        mutex_exit(&usbskelp->usbskel_mutex);

        if (usbskel_pm_busy_component(usbskelp) != DDI_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_restore_device_state: Error raising power");

                goto fail;
        }

        /* Check if we are talking to the same device */
        if (usbskel_check_same_device(usbskelp) != USB_SUCCESS) {

                goto fail;
        }

        mutex_enter(&usbskelp->usbskel_mutex);
        if ((rval = usbskel_test_and_adjust_device_state(usbskelp)) !=
            USB_SUCCESS) {
                mutex_exit(&usbskelp->usbskel_mutex);
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_restore_device_state: "
                    "Error adjusting device: rval = %d", rval);

                goto fail;
        }
        usbskelp->usbskel_dev_state = USB_DEV_ONLINE;
        mutex_exit(&usbskelp->usbskel_mutex);

        if (usbskelp->usbskel_pm) {

                /* Failure here means device disappeared again. */
                if (usb_handle_remote_wakeup(dip, USB_REMOTE_WAKEUP_ENABLE) !=
                    USB_SUCCESS) {
                        usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                            "device may or may not be accessible. "
                            "Please verify reconnection");
                }
                usbskel_pm_idle_component(usbskelp);
        }


        mutex_enter(&usbskelp->usbskel_mutex);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "usbskel_restore_device_state: end");

        return;

fail:
        /* change the device state from suspended to disconnected */
        mutex_enter(&usbskelp->usbskel_mutex);
        usbskelp->usbskel_dev_state = USB_DEV_DISCONNECTED;
        mutex_exit(&usbskelp->usbskel_mutex);

        usbskel_pm_idle_component(usbskelp);
        mutex_enter(&usbskelp->usbskel_mutex);
}


/*
 * usbskel_cpr_suspend:
 *      Clean up device.
 *      Wait for any IO to finish, then close pipes.
 *      Quiesce device.
 */
static int
usbskel_cpr_suspend(dev_info_t *dip)
{
        int             instance = ddi_get_instance(dip);
        usbskel_state_t *usbskelp = ddi_get_soft_state(usbskel_statep,
            instance);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "suspend enter");

        /* Serialize to prevent races with detach, open, device access. */
        mutex_enter(&usbskelp->usbskel_mutex);
        (void) usbskel_serialize_access(usbskelp, USBSKEL_SER_NOSIG);
        mutex_exit(&usbskelp->usbskel_mutex);

        if (usbskel_pm_busy_component(usbskelp) != DDI_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "suspend: Error raising power");
                usbskel_pm_idle_component(usbskelp);

                return (USB_FAILURE);
        }

        mutex_enter(&usbskelp->usbskel_mutex);

        /*
         * Set dev_state to suspended so other driver threads don't start any
         * new I/O.  In a real driver, there may be draining of requests done
         * afterwards, and we don't want the draining to compete with new
         * requests being queued.
         */

        /* Don't suspend if the device is open. */
        if ((usbskelp->usbskel_drv_state & USBSKEL_OPEN) != 0) {
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "suspend: Device is open.  Can't suspend");

                usbskel_release_access(usbskelp);
                mutex_exit(&usbskelp->usbskel_mutex);

                usbskel_pm_idle_component(usbskelp);

                return (USB_FAILURE);
        }

        /* Access device here to clean it up. */

        usbskelp->usbskel_dev_state = USB_DEV_SUSPENDED;

        /*
         * Save any state of device required by usbskel_restore_device_state
         * for proper device "thawing" later.
         */

        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        usbskel_pm_idle_component(usbskelp);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "suspend: success");

        return (USB_SUCCESS);
}


/*
 * usbskel_cpr_resume:
 *
 *      usbskel_restore_device_state marks success by putting device back online
 */
static void
usbskel_cpr_resume(dev_info_t *dip)
{
        int             instance = ddi_get_instance(dip);
        usbskel_state_t *usbskelp = ddi_get_soft_state(usbskel_statep,
            instance);

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "resume: enter");

        /*
         * NOTE: A pm_raise_power in usbskel_restore_device_state will bring
         * the power-up state of device into synch with the system.
         */
        mutex_enter(&usbskelp->usbskel_mutex);
        usbskel_restore_device_state(dip, usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);
}


/*
 * usbskel_test_and_adjust_device_state:
 *      Place any device-specific initialization or sanity verification here.
 */
static int
usbskel_test_and_adjust_device_state(usbskel_state_t *usbskelp)
{
        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "test and adjust enter");

        return (USB_SUCCESS);
}


/*
 * usbskel_open_pipes:
 *      Open any pipes other than default pipe.
 *      Mutex is assumed to be held.
 */
static int
usbskel_open_pipes(usbskel_state_t *usbskelp)
{

        int                     rval = USB_SUCCESS;
        usb_pipe_policy_t       pipe_policy;
        usb_pipe_handle_t       pipe_handle;

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "open_pipes enter");

        bzero(&pipe_policy, sizeof (pipe_policy));

        /*
         * Allow that pipes can support at least two asynchronous operations
         * going on simultaneously.  Operations include asynchronous callbacks,
         * resets, closures.
         */
        pipe_policy.pp_max_async_reqs = 2;

        if ((rval = usb_pipe_open(usbskelp->usbskel_dip,
            &usbskelp->usbskel_intr_ep_descr, &pipe_policy,
            USB_FLAGS_SLEEP, &pipe_handle)) != USB_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_open_pipes: Error opening intr pipe: status = %d",
                    rval);
                rval = USB_FAILURE;
        }
        mutex_enter(&usbskelp->usbskel_mutex);
        usbskelp->usbskel_intr_ph = pipe_handle;
        mutex_exit(&usbskelp->usbskel_mutex);

        /*
         * At this point, polling could be started on the pipe by making an
         * asynchronous input request on the pipe.  Allocate a request by
         * calling usb_alloc_intr_req(9F) with a zero length, initialize
         * attributes with USB_ATTRS_SHORT_XFER_OK | USB_ATTRS_AUTOCLEARING,
         * initialize length to be packetsize of the endpoint, specify the
         * callbacks.  Pass this request to usb_pipe_intr_xfer to start polling.
         * Call usb_pipe_stop_intr_polling(9F) to stop polling.
         */

        return (rval);
}


/*
 * usbskel_close_pipes:
 *      Close pipes. Mutex is assumed to be held.
 */
/*ARGSUSED*/
static void
usbskel_close_pipes(usbskel_state_t *usbskelp)
{
        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "close_pipes enter");

        if (usbskelp->usbskel_intr_ph) {
                usb_pipe_handle_t       pipe_handle = usbskelp->usbskel_intr_ph;
                usbskelp->usbskel_intr_ph = NULL;
                mutex_exit(&usbskelp->usbskel_mutex);

                usb_pipe_close(usbskelp->usbskel_dip, pipe_handle,
                    USB_FLAGS_SLEEP, NULL, 0);

                mutex_enter(&usbskelp->usbskel_mutex);
        }
}

static int
usbskel_pm_busy_component(usbskel_state_t *usbskelp)
{
        int rval = DDI_SUCCESS;

        mutex_enter(&usbskelp->usbskel_mutex);
        if (usbskelp->usbskel_pm != NULL) {
                usbskelp->usbskel_pm->usbskel_pm_busy++;
                mutex_exit(&usbskelp->usbskel_mutex);
                if (pm_busy_component(usbskelp->usbskel_dip, 0) ==
                    DDI_SUCCESS) {
                        (void) pm_raise_power(
                            usbskelp->usbskel_dip, 0, USB_DEV_OS_FULL_PWR);
                        mutex_enter(&usbskelp->usbskel_mutex);
                } else {
                        mutex_enter(&usbskelp->usbskel_mutex);
                        usbskelp->usbskel_pm->usbskel_pm_busy--;
                        rval = DDI_FAILURE;
                }
        }
        mutex_exit(&usbskelp->usbskel_mutex);

        return (rval);
}

static void
usbskel_pm_idle_component(usbskel_state_t *usbskelp)
{
        mutex_enter(&usbskelp->usbskel_mutex);
        if (usbskelp->usbskel_pm != NULL) {
                mutex_exit(&usbskelp->usbskel_mutex);
                if (pm_idle_component(usbskelp->usbskel_dip, 0) ==
                    DDI_SUCCESS) {
                        mutex_enter(&usbskelp->usbskel_mutex);
                        ASSERT(usbskelp->usbskel_pm->usbskel_pm_busy > 0);
                        usbskelp->usbskel_pm->usbskel_pm_busy--;
                        mutex_exit(&usbskelp->usbskel_mutex);
                }
                mutex_enter(&usbskelp->usbskel_mutex);
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "usbskel_pm_idle_component: %d",
                    usbskelp->usbskel_pm->usbskel_pm_busy);
        }
        mutex_exit(&usbskelp->usbskel_mutex);
}

/*
 * usbskel_power :
 *      Power entry point, the workhorse behind pm_raise_power, pm_lower_power,
 *      usb_req_raise_power and usb_req_lower_power.
 */
/* ARGSUSED */
static int
usbskel_power(dev_info_t *dip, int comp, int level)
{
        usbskel_state_t *usbskelp;
        usbskel_power_t *pm;
        int     rval = USB_FAILURE;

        usbskelp = ddi_get_soft_state(usbskel_statep, ddi_get_instance(dip));

        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
            "usbskel_power: enter: level = %d", level);

        mutex_enter(&usbskelp->usbskel_mutex);
        (void) usbskel_serialize_access(usbskelp, USBSKEL_SER_NOSIG);


        /*
         * If we are disconnected/suspended, return success. Note that if we
         * return failure, bringing down the system will hang when
         * PM tries to power up all devices
         */
        if ((usbskelp->usbskel_dev_state == USB_DEV_DISCONNECTED) ||
            (usbskelp->usbskel_dev_state == USB_DEV_SUSPENDED)) {

                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "usbskel_power: disconnected/suspended "
                    "dev_state=%d", usbskelp->usbskel_dev_state);
                rval = USB_SUCCESS;

                goto done;
        }

        if (usbskelp->usbskel_pm == NULL) {

                goto done;
        }

        pm = usbskelp->usbskel_pm;

        /* Check if we are transitioning to a legal power level */
        if (USB_DEV_PWRSTATE_OK(pm->usbskel_pwr_states, level)) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_power: illegal power level = %d "
                    "pwr_states: %x", level, pm->usbskel_pwr_states);

                goto done;
        }

        switch (level) {
        case USB_DEV_OS_PWR_OFF :
                /* fail attempt to go to low power if busy */
                if (pm->usbskel_pm_busy) {

                        goto done;
                }
                if (usbskelp->usbskel_dev_state == USB_DEV_ONLINE) {
                        usbskelp->usbskel_dev_state = USB_DEV_PWRED_DOWN;
                        usbskelp->usbskel_pm->usbskel_current_power =
                            USB_DEV_OS_PWR_OFF;
                } else {
                        rval = USB_SUCCESS;
                }
                break;

        case USB_DEV_OS_FULL_PWR :
                /*
                 * PM framework tries to put us in full power during system
                 * shutdown.
                 */
                usbskelp->usbskel_dev_state = USB_DEV_ONLINE;
                usbskelp->usbskel_pm->usbskel_current_power =
                    USB_DEV_OS_FULL_PWR;
                break;

        /* Levels 1 and 2 are not supported by this driver to keep it simple. */
        default:
                usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                    "usbskel_power: power level %d not supported", level);
                break;
        }
done:
        usbskel_release_access(usbskelp);
        mutex_exit(&usbskelp->usbskel_mutex);

        return ((rval == USB_SUCCESS) ? DDI_SUCCESS : DDI_FAILURE);
}


#ifdef USBSKEL_PM
/*
 * usbskel_init_power_mgmt:
 *      Initialize power management and remote wakeup functionality.
 *      No mutex is necessary in this function as it's called only by attach.
 */
static int
usbskel_init_power_mgmt(usbskel_state_t *usbskelp)
{
        int             rval = USB_FAILURE;

        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "init_power_mgmt enter");

        /*
         * If remote wakeup is not available you may not want to do
         * power management.
         */
        if (usb_handle_remote_wakeup(usbskelp->usbskel_dip,
            USB_REMOTE_WAKEUP_ENABLE) == USB_SUCCESS) {
                usbskel_power_t *usbskelpm;
                uint_t          pwr_states;

                /* Allocate the state structure */
                usbskelpm = kmem_zalloc(sizeof (usbskel_power_t), KM_SLEEP);
                usbskelp->usbskel_pm = usbskelpm;
                usbskelpm->usbskel_state = usbskelp;
                usbskelpm->usbskel_pm_capabilities = 0;
                usbskelpm->usbskel_current_power = USB_DEV_OS_FULL_PWR;

                if ((rval = usb_create_pm_components(
                    usbskelp->usbskel_dip, &pwr_states)) == USB_SUCCESS) {

                        usbskel_log(usbskelp, USBSKEL_LOG_LOG,
                            "usbskel_init_power_mgmt: created PM components");

                        usbskelpm->usbskel_pwr_states =
                            (uint8_t)pwr_states;
                        (void) pm_raise_power(
                            usbskelp->usbskel_dip, 0, USB_DEV_OS_FULL_PWR);
                } else {
                        usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                            "usbskel_init_power_mgmt: create_pm_compts failed");
                }
        } else {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_init_power_mgmt: failure enabling remote wakeup");
        }
        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "usbskel_init_power_mgmt: end");

        return (rval);
}


/*
 * usbskel_destroy_power_mgmt:
 *      Shut down and destroy power management and remote wakeup functionality.
 */
static void
usbskel_destroy_power_mgmt(usbskel_state_t *usbskelp)
{
        usbskel_log(usbskelp, USBSKEL_LOG_LOG, "destroy_power_mgmt enter");

        ASSERT(!mutex_owned(&usbskelp->usbskel_mutex));

        if (usbskelp->usbskel_pm) {
                (void) usbskel_pm_busy_component(usbskelp);

                mutex_enter(&usbskelp->usbskel_mutex);
                if (usbskelp->usbskel_dev_state != USB_DEV_DISCONNECTED) {
                        int rval;

                        mutex_exit(&usbskelp->usbskel_mutex);

                        if ((rval = usb_handle_remote_wakeup(
                            usbskelp->usbskel_dip,
                            USB_REMOTE_WAKEUP_DISABLE)) !=
                            USB_SUCCESS) {
                                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                                    "usbskel_destroy_power_mgmt: "
                                    "Error disabling rmt wakeup: rval = %d",
                                    rval);
                        }
                } else {
                        mutex_exit(&usbskelp->usbskel_mutex);
                }

                /*
                 * Since remote wakeup is disabled now,
                 * no one can raise power
                 * and get to device once power is lowered here.
                 */
                pm_lower_power(usbskelp->usbskel_dip, 0, USB_DEV_OS_PWR_OFF);
                usbskel_pm_idle_component(usbskelp);
                kmem_free(usbskelp->usbskel_pm, sizeof (usbskel_power_t));
                usbskelp->usbskel_pm = NULL;
        }
}
#endif


/*
 * usbskel_serialize_access:
 *    Get the serial synchronization object before returning.
 *
 * Arguments:
 *    usbskelp - Pointer to usbskel state structure
 *    waitsig - Set to:
 *      USBSKEL_SER_SIG - to wait such that a signal can interrupt
 *      USBSKEL_SER_NOSIG - to wait such that a signal cannot interrupt
 */
static int
usbskel_serialize_access(usbskel_state_t *usbskelp, boolean_t waitsig)
{
        int rval = 1;

        ASSERT(mutex_owned(&usbskelp->usbskel_mutex));

        while (usbskelp->usbskel_serial_inuse) {
                if (waitsig == USBSKEL_SER_SIG) {
                        rval = cv_wait_sig(&usbskelp->usbskel_serial_cv,
                            &usbskelp->usbskel_mutex);
                } else {
                        cv_wait(&usbskelp->usbskel_serial_cv,
                            &usbskelp->usbskel_mutex);
                }
        }
        usbskelp->usbskel_serial_inuse = B_TRUE;

        return (rval);
}


/*
 * usbskel_release_access:
 *    Release the serial synchronization object.
 */
static void
usbskel_release_access(usbskel_state_t *usbskelp)
{
        ASSERT(mutex_owned(&usbskelp->usbskel_mutex));
        usbskelp->usbskel_serial_inuse = B_FALSE;
        cv_broadcast(&usbskelp->usbskel_serial_cv);
}


/*
 * usbskel_check_same_device:
 *      Check if the device connected to the port is the same as
 *      the previous device that was in the port.  The previous device is
 *      represented by the dip on record for the port.  Print a message
 *      if the device is different.  Can block.
 *
 * return values:
 *      USB_SUCCESS:            same device
 *      USB_INVALID_VERSION     not same device
 *      USB_FAILURE:            Failure processing request
 */
static int
usbskel_check_same_device(usbskel_state_t *usbskelp)
{
        usb_dev_descr_t         *orig_usb_dev_descr;
        usb_dev_descr_t         usb_dev_descr;
        mblk_t                  *pdata = NULL;
        int                     rval;
        char                    *buf;
        usb_cr_t                completion_reason;
        usb_cb_flags_t          cb_flags;
        boolean_t               match = B_TRUE;

        usb_ctrl_setup_t        setup = {
            USB_DEV_REQ_DEV_TO_HOST | USB_DEV_REQ_TYPE_STANDARD |
                USB_DEV_REQ_RCPT_DEV,
            USB_REQ_GET_DESCR,          /* bRequest */
            USB_DESCR_TYPE_SETUP_DEV,   /* wValue */
            0,                          /* wIndex */
            USB_DEV_DESCR_SIZE,         /* wLength */
            0                           /* request attributes */
        };

        ASSERT(!mutex_owned(&usbskelp->usbskel_mutex));

        orig_usb_dev_descr = usbskelp->usbskel_reg->dev_descr;

        /* get the "new" device descriptor */
        rval = usb_pipe_ctrl_xfer_wait(usbskelp->usbskel_reg->dev_default_ph,
            &setup, &pdata, &completion_reason, &cb_flags, USB_FLAGS_SLEEP);

        if (rval != USB_SUCCESS) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "usbskel_check_same_device: "
                    "getting device descriptor failed "
                    "rval=%d, cr=%d, cb=0x%x\n",
                    rval, completion_reason, cb_flags);
                freemsg(pdata);

                return (USB_FAILURE);
        }

        ASSERT(pdata != NULL);

        (void) usb_parse_data("2cs4c3s4c", pdata->b_rptr,
            MBLKL(pdata), &usb_dev_descr,
            sizeof (usb_dev_descr_t));

        freemsg(pdata);
        pdata = NULL;

        /* Always check the device descriptor length. */
        if (usb_dev_descr.bLength != USB_DEV_DESCR_SIZE) {
                match = B_FALSE;

        /* Always check the device descriptor. */
        } else if (bcmp(orig_usb_dev_descr,
            (char *)&usb_dev_descr, USB_DEV_DESCR_SIZE) != 0) {
                match = B_FALSE;
        }

        /* if requested & this device has a serial number check and compare */
        if ((match == B_TRUE) &&
            (usbskelp->usbskel_reg->dev_serial != NULL)) {
                buf = kmem_alloc(USB_MAXSTRINGLEN, KM_SLEEP);
                if (usb_get_string_descr(usbskelp->usbskel_dip, USB_LANG_ID,
                    usb_dev_descr.iSerialNumber, buf,
                    USB_MAXSTRINGLEN) == USB_SUCCESS) {
                        match =
                            (strcmp(buf,
                            usbskelp->usbskel_reg->dev_serial) == 0);
                }
                kmem_free(buf, USB_MAXSTRINGLEN);
        }

        if (match == B_FALSE) {
                usbskel_log(usbskelp, USBSKEL_LOG_CONSOLE,
                    "Device is not identical to the "
                    "previous one this port.\n"
                    "Please disconnect and reconnect");

                return (USB_INVALID_VERSION);
        }

        return (USB_SUCCESS);
}

/*
 * usbskel_log:
 *     Switchable logging to logfile and screen.
 *
 * Arguments:
 *     usbskelp: usbskel state pointer.
 *         if NULL, driver name and instance won't print with the message
 *     msglevel:
 *         if USBSKEL_LOG_LOG, goes only to logfile.
 *              (usbskel_errlevel must be set to USBSKEL_LOG_LOG too.)
 *         if USBSKEL_LOG_CONSOLE, goes to both logfile and screen
 *              (usbskel_errlevel can be either value for this to work.)
 *     cmn_err_level: error level passed to cmn_err(9F)
 *     format and args: as you would call cmn_err, except without special
 *         first routing character.
 *
 * Do not call this in an interrupt context, since kmem_alloc can sleep.
 */
static void
usbskel_log(usbskel_state_t *usbskelp, int msglevel, char *formatarg, ...)
{
        va_list ap;

        if (msglevel <= usbskel_errlevel) {
                char *format;
                int formatlen = strlen(formatarg) + 2;  /* '!' and NULL char */
                int devinst_start = 0;

                /* Allocate extra room if driver name and instance is present */
                if (usbskelp != NULL) {
                        formatlen += strlen(usbskelp->usbskel_devinst);
                }

                format = kmem_zalloc(formatlen, KM_SLEEP);

                if (msglevel == USBSKEL_LOG_LOG) {
                        format[0] = '!';
                        devinst_start = 1;
                }

                if (usbskelp != NULL) {
                        (void) strcpy(&format[devinst_start],
                            usbskelp->usbskel_devinst);
                }

                va_start(ap, formatarg);
                (void) strcat(format, formatarg);
                vcmn_err(CE_CONT, format, ap);
                va_end(ap);

                kmem_free(format, formatlen);
        }
}