sys/dev/sysmon/sysmon_envsys.c

root/sys/dev/sysmon/sysmon_envsys.c
/*      $NetBSD: sysmon_envsys.c,v 1.151 2022/05/20 21:31:24 andvar Exp $       */

/*-
 * Copyright (c) 2007, 2008 Juan Romero Pardines.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*-
 * Copyright (c) 2000 Zembu Labs, Inc.
 * All rights reserved.
 *
 * Author: Jason R. Thorpe <thorpej@zembu.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Zembu Labs, Inc.
 * 4. Neither the name of Zembu Labs nor the names of its employees may
 *    be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ZEMBU LABS, INC. ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAR-
 * RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS-
 * CLAIMED.  IN NO EVENT SHALL ZEMBU LABS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Environmental sensor framework for sysmon, exported to userland
 * with proplib(3).
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sysmon_envsys.c,v 1.151 2022/05/20 21:31:24 andvar Exp $");

#include <sys/param.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mutex.h>
#include <sys/kmem.h>
#include <sys/rndsource.h>
#include <sys/module.h>
#include <sys/once.h>

#include <dev/sysmon/sysmonvar.h>
#include <dev/sysmon/sysmon_envsysvar.h>
#include <dev/sysmon/sysmon_taskq.h>

kmutex_t sme_global_mtx;

prop_dictionary_t sme_propd;

struct sysmon_envsys_lh sysmon_envsys_list;

static uint32_t sysmon_envsys_next_sensor_index;
static struct sysmon_envsys *sysmon_envsys_find_40(u_int);

static void sysmon_envsys_destroy_plist(prop_array_t);
static void sme_remove_userprops(void);
static int sme_add_property_dictionary(struct sysmon_envsys *, prop_array_t,
                                       prop_dictionary_t);
static sme_event_drv_t * sme_add_sensor_dictionary(struct sysmon_envsys *,
        prop_array_t, prop_dictionary_t, envsys_data_t *);
static void sme_initial_refresh(void *);
static uint32_t sme_get_max_value(struct sysmon_envsys *,
     bool (*)(const envsys_data_t*), bool);

MODULE(MODULE_CLASS_DRIVER, sysmon_envsys, "sysmon,sysmon_taskq,sysmon_power");

static struct sysmon_opvec sysmon_envsys_opvec = {
        sysmonopen_envsys, sysmonclose_envsys, sysmonioctl_envsys,
        NULL, NULL, NULL
};

ONCE_DECL(once_envsys);

static int
sme_preinit(void)
{

        LIST_INIT(&sysmon_envsys_list);
        mutex_init(&sme_global_mtx, MUTEX_DEFAULT, IPL_NONE);
        sme_propd = prop_dictionary_create();

        return 0;
}

/*
 * sysmon_envsys_init:
 *
 *      + Initialize global mutex, dictionary and the linked list.
 */
int
sysmon_envsys_init(void)
{
        int error;

        (void)RUN_ONCE(&once_envsys, sme_preinit);

        error = sysmon_attach_minor(SYSMON_MINOR_ENVSYS, &sysmon_envsys_opvec);

        return error;
}

int
sysmon_envsys_fini(void)
{
        int error;

        if ( ! LIST_EMPTY(&sysmon_envsys_list))
                error = EBUSY;
        else
                error = sysmon_attach_minor(SYSMON_MINOR_ENVSYS, NULL);

        if (error == 0)
                mutex_destroy(&sme_global_mtx);

        // XXX: prop_dictionary ???

        return error;
}

/*
 * sysmonopen_envsys:
 *
 *      + Open the system monitor device.
 */
int
sysmonopen_envsys(dev_t dev, int flag, int mode, struct lwp *l)
{
        return 0;
}

/*
 * sysmonclose_envsys:
 *
 *      + Close the system monitor device.
 */
int
sysmonclose_envsys(dev_t dev, int flag, int mode, struct lwp *l)
{
        return 0;
}

/*
 * sysmonioctl_envsys:
 *
 *      + Perform a sysmon envsys control request.
 */
int
sysmonioctl_envsys(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        struct sysmon_envsys *sme = NULL;
        int error = 0;
        u_int oidx;

        switch (cmd) {
        /*
         * To update the global dictionary with latest data from devices.
         */
        case ENVSYS_GETDICTIONARY:
            {
                struct plistref *plist = (struct plistref *)data;

                /*
                 * Update dictionaries on all sysmon envsys devices
                 * registered.
                 */
                mutex_enter(&sme_global_mtx);
                LIST_FOREACH(sme, &sysmon_envsys_list, sme_list) {
                        sysmon_envsys_acquire(sme, false);
                        error = sme_update_dictionary(sme);
                        if (error) {
                                DPRINTF(("%s: sme_update_dictionary, "
                                    "error=%d\n", __func__, error));
                                sysmon_envsys_release(sme, false);
                                mutex_exit(&sme_global_mtx);
                                return error;
                        }
                        sysmon_envsys_release(sme, false);
                }
                mutex_exit(&sme_global_mtx);
                /*
                 * Copy global dictionary to userland.
                 */
                error = prop_dictionary_copyout_ioctl(plist, cmd, sme_propd);
                break;
            }
        /*
         * To set properties on multiple devices.
         */
        case ENVSYS_SETDICTIONARY:
            {
                const struct plistref *plist = (const struct plistref *)data;
                prop_dictionary_t udict;
                prop_object_iterator_t iter, iter2;
                prop_object_t obj, obj2;
                prop_array_t array_u, array_k;
                const char *devname = NULL;

                if ((flag & FWRITE) == 0)
                        return EPERM;

                /*
                 * Get dictionary from userland.
                 */
                error = prop_dictionary_copyin_ioctl(plist, cmd, &udict);
                if (error) {
                        DPRINTF(("%s: copyin_ioctl error=%d\n",
                            __func__, error));
                        break;
                }

                iter = prop_dictionary_iterator(udict);
                if (!iter) {
                        prop_object_release(udict);
                        return ENOMEM;
                }

                /*
                 * Iterate over the userland dictionary and process
                 * the list of devices.
                 */
                while ((obj = prop_object_iterator_next(iter))) {
                        array_u = prop_dictionary_get_keysym(udict, obj);
                        if (prop_object_type(array_u) != PROP_TYPE_ARRAY) {
                                prop_object_iterator_release(iter);
                                prop_object_release(udict);
                                return EINVAL;
                        }

                        devname = prop_dictionary_keysym_value(obj);
                        DPRINTF(("%s: processing the '%s' array requests\n",
                            __func__, devname));

                        /*
                         * find the correct sme device.
                         */
                        sme = sysmon_envsys_find(devname);
                        if (!sme) {
                                DPRINTF(("%s: NULL sme\n", __func__));
                                prop_object_iterator_release(iter);
                                prop_object_release(udict);
                                return EINVAL;
                        }

                        /*
                         * Find the correct array object with the string
                         * supplied by the userland dictionary.
                         */
                        array_k = prop_dictionary_get(sme_propd, devname);
                        if (prop_object_type(array_k) != PROP_TYPE_ARRAY) {
                                DPRINTF(("%s: array device failed\n",
                                    __func__));
                                sysmon_envsys_release(sme, false);
                                prop_object_iterator_release(iter);
                                prop_object_release(udict);
                                return EINVAL;
                        }

                        iter2 = prop_array_iterator(array_u);
                        if (!iter2) {
                                sysmon_envsys_release(sme, false);
                                prop_object_iterator_release(iter);
                                prop_object_release(udict);
                                return ENOMEM;
                        }

                        /*
                         * Iterate over the array of dictionaries to
                         * process the list of sensors and properties.
                         */
                        while ((obj2 = prop_object_iterator_next(iter2))) {
                                /*
                                 * do the real work now.
                                 */
                                error = sme_userset_dictionary(sme,
                                                               obj2,
                                                               array_k);
                                if (error) {
                                        sysmon_envsys_release(sme, false);
                                        prop_object_iterator_release(iter2);
                                        prop_object_iterator_release(iter);
                                        prop_object_release(udict);
                                        return error;
                                }
                        }

                        sysmon_envsys_release(sme, false);
                        prop_object_iterator_release(iter2);
                }

                prop_object_iterator_release(iter);
                prop_object_release(udict);
                break;
            }
        /*
         * To remove all properties from all devices registered.
         */
        case ENVSYS_REMOVEPROPS:
            {
                const struct plistref *plist = (const struct plistref *)data;
                prop_dictionary_t udict;
                prop_object_t obj;

                if ((flag & FWRITE) == 0)
                        return EPERM;

                error = prop_dictionary_copyin_ioctl(plist, cmd, &udict);
                if (error) {
                        DPRINTF(("%s: copyin_ioctl error=%d\n",
                            __func__, error));
                        break;
                }

                obj = prop_dictionary_get(udict, "envsys-remove-props");
                if (!obj || !prop_bool_true(obj)) {
                        DPRINTF(("%s: invalid 'envsys-remove-props'\n",
                             __func__));
                        return EINVAL;
                }

                prop_object_release(udict);
                sme_remove_userprops();

                break;
            }
        /*
         * Compatibility ioctls with the old interface, only implemented
         * ENVSYS_GTREDATA and ENVSYS_GTREINFO; enough to make old
         * applications work.
         */
        case ENVSYS_GTREDATA:
            {
                struct envsys_tre_data *tred = (void *)data;
                envsys_data_t *edata = NULL;
                bool found = false;

                tred->validflags = 0;

                sme = sysmon_envsys_find_40(tred->sensor);
                if (!sme)
                        break;

                oidx = tred->sensor;
                tred->sensor = SME_SENSOR_IDX(sme, tred->sensor);

                DPRINTFOBJ(("%s: sensor=%d oidx=%d dev=%s nsensors=%d\n",
                    __func__, tred->sensor, oidx, sme->sme_name,
                    sme->sme_nsensors));

                TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                        if (edata->sensor == tred->sensor) {
                                found = true;
                                break;
                        }
                }

                if (!found) {
                        sysmon_envsys_release(sme, false);
                        error = ENODEV;
                        break;
                }

                if (tred->sensor < sme->sme_nsensors) {
                        if ((sme->sme_flags & SME_POLL_ONLY) == 0) {
                                mutex_enter(&sme->sme_mtx);
                                sysmon_envsys_refresh_sensor(sme, edata);
                                mutex_exit(&sme->sme_mtx);
                        }

                        /*
                         * copy required values to the old interface.
                         */
                        tred->sensor = edata->sensor;
                        tred->cur.data_us = edata->value_cur;
                        tred->cur.data_s = edata->value_cur;
                        tred->max.data_us = edata->value_max;
                        tred->max.data_s = edata->value_max;
                        tred->min.data_us = edata->value_min;
                        tred->min.data_s = edata->value_min;
                        tred->avg.data_us = 0;
                        tred->avg.data_s = 0;
                        if (edata->units == ENVSYS_BATTERY_CHARGE)
                                tred->units = ENVSYS_INDICATOR;
                        else
                                tred->units = edata->units;

                        tred->validflags |= ENVSYS_FVALID;
                        tred->validflags |= ENVSYS_FCURVALID;

                        if (edata->flags & ENVSYS_FPERCENT) {
                                tred->validflags |= ENVSYS_FMAXVALID;
                                tred->validflags |= ENVSYS_FFRACVALID;
                        }

                        if (edata->state == ENVSYS_SINVALID) {
                                tred->validflags &= ~ENVSYS_FCURVALID;
                                tred->cur.data_us = tred->cur.data_s = 0;
                        }

                        DPRINTFOBJ(("%s: sensor=%s tred->cur.data_s=%d\n",
                            __func__, edata->desc, tred->cur.data_s));
                        DPRINTFOBJ(("%s: tred->validflags=%d tred->units=%d"
                            " tred->sensor=%d\n", __func__, tred->validflags,
                            tred->units, tred->sensor));
                }
                tred->sensor = oidx;
                sysmon_envsys_release(sme, false);

                break;
            }
        case ENVSYS_GTREINFO:
            {
                struct envsys_basic_info *binfo = (void *)data;
                envsys_data_t *edata = NULL;
                bool found = false;

                binfo->validflags = 0;

                sme = sysmon_envsys_find_40(binfo->sensor);
                if (!sme)
                        break;

                oidx = binfo->sensor;
                binfo->sensor = SME_SENSOR_IDX(sme, binfo->sensor);

                TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                        if (edata->sensor == binfo->sensor) {
                                found = true;
                                break;
                        }
                }

                if (!found) {
                        sysmon_envsys_release(sme, false);
                        error = ENODEV;
                        break;
                }

                binfo->validflags |= ENVSYS_FVALID;

                if (binfo->sensor < sme->sme_nsensors) {
                        if (edata->units == ENVSYS_BATTERY_CHARGE)
                                binfo->units = ENVSYS_INDICATOR;
                        else
                                binfo->units = edata->units;

                        /*
                         * previously, the ACPI sensor names included the
                         * device name. Include that in compatibility code.
                         */
                        if (strncmp(sme->sme_name, "acpi", 4) == 0)
                                (void)snprintf(binfo->desc, sizeof(binfo->desc),
                                    "%s %s", sme->sme_name, edata->desc);
                        else
                                (void)strlcpy(binfo->desc, edata->desc,
                                    sizeof(binfo->desc));
                }

                DPRINTFOBJ(("%s: binfo->units=%d binfo->validflags=%d\n",
                    __func__, binfo->units, binfo->validflags));
                DPRINTFOBJ(("%s: binfo->desc=%s binfo->sensor=%d\n",
                    __func__, binfo->desc, binfo->sensor));

                binfo->sensor = oidx;
                sysmon_envsys_release(sme, false);

                break;
            }
        default:
                error = ENOTTY;
                break;
        }

        return error;
}

/*
 * sysmon_envsys_create:
 *
 *      + Allocates a new sysmon_envsys object and initializes the
 *        stuff for sensors and events.
 */
struct sysmon_envsys *
sysmon_envsys_create(void)
{
        struct sysmon_envsys *sme;

        CTASSERT(SME_CALLOUT_INVALID == 0);

        sme = kmem_zalloc(sizeof(*sme), KM_SLEEP);
        TAILQ_INIT(&sme->sme_sensors_list);
        LIST_INIT(&sme->sme_events_list);
        mutex_init(&sme->sme_mtx, MUTEX_DEFAULT, IPL_NONE);
        mutex_init(&sme->sme_work_mtx, MUTEX_DEFAULT, IPL_SOFTCLOCK);
        cv_init(&sme->sme_condvar, "sme_wait");

        return sme;
}

/*
 * sysmon_envsys_destroy:
 *
 *      + Removes all sensors from the tail queue, destroys the callout
 *        and frees the sysmon_envsys object.
 */
void
sysmon_envsys_destroy(struct sysmon_envsys *sme)
{
        envsys_data_t *edata;

        KASSERT(sme != NULL);

        while (!TAILQ_EMPTY(&sme->sme_sensors_list)) {
                edata = TAILQ_FIRST(&sme->sme_sensors_list);
                TAILQ_REMOVE(&sme->sme_sensors_list, edata, sensors_head);
        }
        mutex_destroy(&sme->sme_mtx);
        mutex_destroy(&sme->sme_work_mtx);
        cv_destroy(&sme->sme_condvar);
        kmem_free(sme, sizeof(*sme));
}

/*
 * sysmon_envsys_sensor_attach:
 *
 *      + Attaches a sensor into a sysmon_envsys device checking that units
 *        is set to a valid type and description is unique and not empty.
 */
int
sysmon_envsys_sensor_attach(struct sysmon_envsys *sme, envsys_data_t *edata)
{
        const struct sme_descr_entry *sdt_units;
        envsys_data_t *oedata;

        KASSERT(sme != NULL || edata != NULL);

        /*
         * Find the correct units for this sensor.
         */
        sdt_units = sme_find_table_entry(SME_DESC_UNITS, edata->units);
        if (sdt_units == NULL || sdt_units->type == -1)
                return EINVAL;

        /*
         * Check that description is not empty or duplicate.
         */
        if (strlen(edata->desc) == 0)
                return EINVAL;

        mutex_enter(&sme->sme_mtx);
        sysmon_envsys_acquire(sme, true);
        TAILQ_FOREACH(oedata, &sme->sme_sensors_list, sensors_head) {
                if (strcmp(oedata->desc, edata->desc) == 0) {
                        sysmon_envsys_release(sme, true);
                        mutex_exit(&sme->sme_mtx);
                        return EEXIST;
                }
        }
        /*
         * Ok, the sensor has been added into the device queue.
         */
        TAILQ_INSERT_TAIL(&sme->sme_sensors_list, edata, sensors_head);

        /*
         * Give the sensor an index position.
         */
        edata->sensor = sme->sme_nsensors;
        sme->sme_nsensors++;
        sysmon_envsys_release(sme, true);
        mutex_exit(&sme->sme_mtx);

        DPRINTF(("%s: attached #%d (%s), units=%d (%s)\n",
            __func__, edata->sensor, edata->desc,
            sdt_units->type, sdt_units->desc));

        return 0;
}

/*
 * sysmon_envsys_sensor_detach:
 *
 *      + Detachs a sensor from a sysmon_envsys device and decrements the
 *        sensors count on success.
 */
int
sysmon_envsys_sensor_detach(struct sysmon_envsys *sme, envsys_data_t *edata)
{
        envsys_data_t *oedata;
        bool found = false;
        bool destroy = false;

        KASSERT(sme != NULL || edata != NULL);

        /*
         * Check the sensor is already on the list.
         */
        mutex_enter(&sme->sme_mtx);
        sysmon_envsys_acquire(sme, true);
        TAILQ_FOREACH(oedata, &sme->sme_sensors_list, sensors_head) {
                if (oedata->sensor == edata->sensor) {
                        found = true;
                        break;
                }
        }

        if (!found) {
                sysmon_envsys_release(sme, true);
                mutex_exit(&sme->sme_mtx);
                return EINVAL;
        }

        /*
         * remove it, unhook from rnd(4), and decrement the sensors count.
         */
        if (oedata->flags & ENVSYS_FHAS_ENTROPY)
                rnd_detach_source(&oedata->rnd_src);
        sme_event_unregister_sensor(sme, edata);
        mutex_enter(&sme->sme_work_mtx);
        if (LIST_EMPTY(&sme->sme_events_list)) {
                if (sme->sme_callout_state == SME_CALLOUT_READY)
                        sme_events_halt_callout(sme);
                destroy = true;
        }
        mutex_exit(&sme->sme_work_mtx);
        TAILQ_REMOVE(&sme->sme_sensors_list, edata, sensors_head);
        sme->sme_nsensors--;
        sysmon_envsys_release(sme, true);
        mutex_exit(&sme->sme_mtx);

        if (destroy)
                sme_events_destroy(sme);

        return 0;
}


/*
 * sysmon_envsys_register:
 *
 *      + Register a sysmon envsys device.
 *      + Create array of dictionaries for a device.
 */
int
sysmon_envsys_register(struct sysmon_envsys *sme)
{
        struct sme_evdrv {
                SLIST_ENTRY(sme_evdrv) evdrv_head;
                sme_event_drv_t *evdrv;
        };
        SLIST_HEAD(, sme_evdrv) sme_evdrv_list;
        struct sme_evdrv *evdv = NULL;
        struct sysmon_envsys *lsme;
        prop_array_t array = NULL;
        prop_dictionary_t dict, dict2;
        envsys_data_t *edata = NULL;
        sme_event_drv_t *this_evdrv;
        int nevent;
        int error = 0;
        char rnd_name[sizeof(edata->rnd_src.name)];

        KASSERT(sme != NULL);
        KASSERT(sme->sme_name != NULL);

        (void)RUN_ONCE(&once_envsys, sme_preinit);

        /*
         * Check if requested sysmon_envsys device is valid
         * and does not exist already in the list.
         */
        mutex_enter(&sme_global_mtx);
        LIST_FOREACH(lsme, &sysmon_envsys_list, sme_list) {
               if (strcmp(lsme->sme_name, sme->sme_name) == 0) {
                        mutex_exit(&sme_global_mtx);
                        return EEXIST;
               }
        }
        mutex_exit(&sme_global_mtx);

        /*
         * sanity check: if SME_DISABLE_REFRESH is not set,
         * the sme_refresh function callback must be non NULL.
         */
        if ((sme->sme_flags & SME_DISABLE_REFRESH) == 0)
                if (!sme->sme_refresh)
                        return EINVAL;

        /*
         * If the list of sensors is empty, there's no point to continue...
         */
        if (TAILQ_EMPTY(&sme->sme_sensors_list)) {
                DPRINTF(("%s: sensors list empty for %s\n", __func__,
                    sme->sme_name));
                return ENOTSUP;
        }

        /*
         * Initialize the singly linked list for driver events.
         */
        SLIST_INIT(&sme_evdrv_list);

        array = prop_array_create();
        if (!array)
                return ENOMEM;

        /*
         * Iterate over all sensors and create a dictionary per sensor.
         * We must respect the order in which the sensors were added.
         */
        TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                dict = prop_dictionary_create();
                if (!dict) {
                        error = ENOMEM;
                        goto out2;
                }

                /*
                 * Create all objects in sensor's dictionary.
                 */
                this_evdrv = sme_add_sensor_dictionary(sme, array,
                                                       dict, edata);
                if (this_evdrv) {
                        evdv = kmem_zalloc(sizeof(*evdv), KM_SLEEP);
                        evdv->evdrv = this_evdrv;
                        SLIST_INSERT_HEAD(&sme_evdrv_list, evdv, evdrv_head);
                }
        }

        /*
         * If the array does not contain any object (sensor), there's
         * no need to attach the driver.
         */
        if (prop_array_count(array) == 0) {
                error = EINVAL;
                DPRINTF(("%s: empty array for '%s'\n", __func__,
                    sme->sme_name));
                goto out;
        }

        /*
         * Add the dictionary for the global properties of this device.
         */
        dict2 = prop_dictionary_create();
        if (!dict2) {
                error = ENOMEM;
                goto out;
        }

        error = sme_add_property_dictionary(sme, array, dict2);
        if (error) {
                prop_object_release(dict2);
                goto out;
        }

        /*
         * Add the array into the global dictionary for the driver.
         *
         * <dict>
         *      <key>foo0</key>
         *      <array>
         *              ...
         */
        mutex_enter(&sme_global_mtx);
        if (!prop_dictionary_set(sme_propd, sme->sme_name, array)) {
                error = EINVAL;
                mutex_exit(&sme_global_mtx);
                DPRINTF(("%s: prop_dictionary_set for '%s'\n", __func__,
                    sme->sme_name));
                goto out;
        }

        /*
         * Add the device into the list.
         */
        LIST_INSERT_HEAD(&sysmon_envsys_list, sme, sme_list);
        sme->sme_fsensor = sysmon_envsys_next_sensor_index;
        sysmon_envsys_next_sensor_index += sme->sme_nsensors;
        mutex_exit(&sme_global_mtx);

out:
        /*
         * No errors?  Make an initial data refresh if was requested,
         * then register the events that were set in the driver.  Do
         * the refresh first in case it is needed to establish the
         * limits or max_value needed by some events.
         */
        if (error == 0) {
                nevent = 0;

                /*
                 * Hook the sensor into rnd(4) entropy pool if requested
                 */
                TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                        if (edata->flags & ENVSYS_FHAS_ENTROPY) {
                                uint32_t rnd_type, rnd_flag = 0;
                                size_t n;
                                int tail = 1;

                                snprintf(rnd_name, sizeof(rnd_name), "%s-%s",
                                    sme->sme_name, edata->desc);
                                n = strlen(rnd_name);
                                /*
                                 * 1) Remove trailing white space(s).
                                 * 2) If space exist, replace it with '-'
                                 */
                                while (--n) {
                                        if (rnd_name[n] == ' ') {
                                                if (tail != 0)
                                                        rnd_name[n] = '\0';
                                                else
                                                        rnd_name[n] = '-';
                                        } else
                                                tail = 0;
                                }
                                rnd_flag |= RND_FLAG_COLLECT_TIME;
                                rnd_flag |= RND_FLAG_ESTIMATE_TIME;

                                switch (edata->units) {
                                    case ENVSYS_STEMP:
                                    case ENVSYS_SFANRPM:
                                    case ENVSYS_INTEGER:
                                        rnd_type = RND_TYPE_ENV;
                                        rnd_flag |= RND_FLAG_COLLECT_VALUE;
                                        rnd_flag |= RND_FLAG_ESTIMATE_VALUE;
                                        break;
                                    case ENVSYS_SVOLTS_AC:
                                    case ENVSYS_SVOLTS_DC:
                                    case ENVSYS_SOHMS:
                                    case ENVSYS_SWATTS:
                                    case ENVSYS_SAMPS:
                                    case ENVSYS_SWATTHOUR:
                                    case ENVSYS_SAMPHOUR:
                                        rnd_type = RND_TYPE_POWER;
                                        rnd_flag |= RND_FLAG_COLLECT_VALUE;
                                        rnd_flag |= RND_FLAG_ESTIMATE_VALUE;
                                        break;
                                    default:
                                        rnd_type = RND_TYPE_UNKNOWN;
                                        break;
                                }
                                rnd_attach_source(&edata->rnd_src, rnd_name,
                                    rnd_type, rnd_flag);
                        }
                }

                if (sme->sme_flags & SME_INIT_REFRESH) {
                        sysmon_task_queue_sched(0, sme_initial_refresh, sme);
                        DPRINTF(("%s: scheduled initial refresh for '%s'\n",
                                __func__, sme->sme_name));
                }
                SLIST_FOREACH(evdv, &sme_evdrv_list, evdrv_head) {
                        sysmon_task_queue_sched(0,
                            sme_event_drvadd, evdv->evdrv);
                        nevent++;
                }
                DPRINTF(("%s: driver '%s' registered (nsens=%d nevent=%d)\n",
                    __func__, sme->sme_name, sme->sme_nsensors, nevent));
        }

out2:
        while (!SLIST_EMPTY(&sme_evdrv_list)) {
                evdv = SLIST_FIRST(&sme_evdrv_list);
                SLIST_REMOVE_HEAD(&sme_evdrv_list, evdrv_head);
                kmem_free(evdv, sizeof(*evdv));
        }
        if (!error)
                return 0;

        /*
         * Ugh... something wasn't right; unregister all events and sensors
         * previously assigned and destroy the array with all its objects.
         */
        DPRINTF(("%s: failed to register '%s' (%d)\n", __func__,
            sme->sme_name, error));

        sme_event_unregister_all(sme);
        while (!TAILQ_EMPTY(&sme->sme_sensors_list)) {
                edata = TAILQ_FIRST(&sme->sme_sensors_list);
                TAILQ_REMOVE(&sme->sme_sensors_list, edata, sensors_head);
        }
        sysmon_envsys_destroy_plist(array);
        return error;
}

/*
 * sysmon_envsys_destroy_plist:
 *
 *      + Remove all objects from the array of dictionaries that is
 *        created in a sysmon envsys device.
 */
static void
sysmon_envsys_destroy_plist(prop_array_t array)
{
        prop_object_iterator_t iter, iter2;
        prop_dictionary_t dict;
        prop_object_t obj;

        KASSERT(array != NULL);
        KASSERT(prop_object_type(array) == PROP_TYPE_ARRAY);

        DPRINTFOBJ(("%s: objects in array=%d\n", __func__,
            prop_array_count(array)));

        iter = prop_array_iterator(array);
        if (!iter)
                return;

        while ((dict = prop_object_iterator_next(iter))) {
                KASSERT(prop_object_type(dict) == PROP_TYPE_DICTIONARY);
                iter2 = prop_dictionary_iterator(dict);
                if (!iter2)
                        goto out;
                DPRINTFOBJ(("%s: iterating over dictionary\n", __func__));
                while ((obj = prop_object_iterator_next(iter2)) != NULL) {
                        DPRINTFOBJ(("%s: obj=%s\n", __func__,
                            prop_dictionary_keysym_value(obj)));
                        prop_dictionary_remove(dict,
                            prop_dictionary_keysym_value(obj));
                        prop_object_iterator_reset(iter2);
                }
                prop_object_iterator_release(iter2);
                DPRINTFOBJ(("%s: objects in dictionary:%d\n",
                    __func__, prop_dictionary_count(dict)));
                prop_object_release(dict);
        }

out:
        prop_object_iterator_release(iter);
        prop_object_release(array);
}

/*
 * sysmon_envsys_unregister:
 *
 *      + Unregister a sysmon envsys device.
 */
void
sysmon_envsys_unregister(struct sysmon_envsys *sme)
{
        prop_array_t array;
        struct sysmon_envsys *osme;
        envsys_data_t *edata;

        KASSERT(sme != NULL);

        /*
         * Decrement global sensors counter and the first_sensor index
         * for remaining devices in the list (only used for compatibility
         * with previous API), and remove the device from the list.
         */
        mutex_enter(&sme_global_mtx);
        sysmon_envsys_next_sensor_index -= sme->sme_nsensors;
        LIST_FOREACH(osme, &sysmon_envsys_list, sme_list) {
                if (osme->sme_fsensor >= sme->sme_fsensor)
                        osme->sme_fsensor -= sme->sme_nsensors;
        }
        LIST_REMOVE(sme, sme_list);
        mutex_exit(&sme_global_mtx);

        while ((edata = TAILQ_FIRST(&sme->sme_sensors_list)) != NULL) {
                sysmon_envsys_sensor_detach(sme, edata);
        }

        /*
         * Unregister all events associated with device.
         */
        sme_event_unregister_all(sme);

        /*
         * Remove the device (and all its objects) from the global dictionary.
         */
        array = prop_dictionary_get(sme_propd, sme->sme_name);
        if (array && prop_object_type(array) == PROP_TYPE_ARRAY) {
                mutex_enter(&sme_global_mtx);
                prop_dictionary_remove(sme_propd, sme->sme_name);
                mutex_exit(&sme_global_mtx);
                sysmon_envsys_destroy_plist(array);
        }
        /*
         * And finally destroy the sysmon_envsys object.
         */
        sysmon_envsys_destroy(sme);
}

/*
 * sysmon_envsys_find:
 *
 *      + Find a sysmon envsys device and mark it as busy
 *        once it's available.
 */
struct sysmon_envsys *
sysmon_envsys_find(const char *name)
{
        struct sysmon_envsys *sme;

        mutex_enter(&sme_global_mtx);
        LIST_FOREACH(sme, &sysmon_envsys_list, sme_list) {
                if (strcmp(sme->sme_name, name) == 0) {
                        sysmon_envsys_acquire(sme, false);
                        break;
                }
        }
        mutex_exit(&sme_global_mtx);

        return sme;
}

/*
 * Compatibility function with the old API.
 */
struct sysmon_envsys *
sysmon_envsys_find_40(u_int idx)
{
        struct sysmon_envsys *sme;

        mutex_enter(&sme_global_mtx);
        LIST_FOREACH(sme, &sysmon_envsys_list, sme_list) {
                if (idx >= sme->sme_fsensor &&
                    idx < (sme->sme_fsensor + sme->sme_nsensors)) {
                        sysmon_envsys_acquire(sme, false);
                        break;
                }
        }
        mutex_exit(&sme_global_mtx);

        return sme;
}

/*
 * sysmon_envsys_acquire:
 *
 *      + Wait until a sysmon envsys device is available and mark
 *        it as busy.
 */
void
sysmon_envsys_acquire(struct sysmon_envsys *sme, bool locked)
{
        KASSERT(sme != NULL);

        if (locked) {
                while (sme->sme_flags & SME_FLAG_BUSY)
                        cv_wait(&sme->sme_condvar, &sme->sme_mtx);
                sme->sme_flags |= SME_FLAG_BUSY;
        } else {
                mutex_enter(&sme->sme_mtx);
                while (sme->sme_flags & SME_FLAG_BUSY)
                        cv_wait(&sme->sme_condvar, &sme->sme_mtx);
                sme->sme_flags |= SME_FLAG_BUSY;
                mutex_exit(&sme->sme_mtx);
        }
}

/*
 * sysmon_envsys_release:
 *
 *      + Unmark a sysmon envsys device as busy, and notify
 *        waiters.
 */
void
sysmon_envsys_release(struct sysmon_envsys *sme, bool locked)
{
        KASSERT(sme != NULL);

        if (locked) {
                sme->sme_flags &= ~SME_FLAG_BUSY;
                cv_broadcast(&sme->sme_condvar);
        } else {
                mutex_enter(&sme->sme_mtx);
                sme->sme_flags &= ~SME_FLAG_BUSY;
                cv_broadcast(&sme->sme_condvar);
                mutex_exit(&sme->sme_mtx);
        }
}

/*
 * sme_initial_refresh:
 *
 *      + Do an initial refresh of the sensors in a device just after
 *        interrupts are enabled in the autoconf(9) process.
 *
 */
static void
sme_initial_refresh(void *arg)
{
        struct sysmon_envsys *sme = arg;
        envsys_data_t *edata;

        mutex_enter(&sme->sme_mtx);
        sysmon_envsys_acquire(sme, true);
        TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head)
                sysmon_envsys_refresh_sensor(sme, edata);
        sysmon_envsys_release(sme, true);
        mutex_exit(&sme->sme_mtx);
}

/*
 * sme_sensor_dictionary_get:
 *
 *      + Returns a dictionary of a device specified by its index
 *        position.
 */
prop_dictionary_t
sme_sensor_dictionary_get(prop_array_t array, const char *index)
{
        prop_object_iterator_t iter;
        prop_dictionary_t dict;
        prop_object_t obj;

        KASSERT(array != NULL || index != NULL);

        iter = prop_array_iterator(array);
        if (!iter)
                return NULL;

        while ((dict = prop_object_iterator_next(iter))) {
                obj = prop_dictionary_get(dict, "index");
                if (prop_string_equals_string(obj, index))
                        break;
        }

        prop_object_iterator_release(iter);
        return dict;
}

/*
 * sme_remove_userprops:
 *
 *      + Remove all properties from all devices that were set by
 *        the ENVSYS_SETDICTIONARY ioctl.
 */
static void
sme_remove_userprops(void)
{
        struct sysmon_envsys *sme;
        prop_array_t array;
        prop_dictionary_t sdict;
        envsys_data_t *edata = NULL;
        char tmp[ENVSYS_DESCLEN];
        char rnd_name[sizeof(edata->rnd_src.name)];
        sysmon_envsys_lim_t lims;
        const struct sme_descr_entry *sdt_units;
        uint32_t props;
        int ptype;

        mutex_enter(&sme_global_mtx);
        LIST_FOREACH(sme, &sysmon_envsys_list, sme_list) {
                sysmon_envsys_acquire(sme, false);
                array = prop_dictionary_get(sme_propd, sme->sme_name);

                TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                        (void)snprintf(tmp, sizeof(tmp), "sensor%d",
                                       edata->sensor);
                        sdict = sme_sensor_dictionary_get(array, tmp);
                        KASSERT(sdict != NULL);

                        ptype = 0;
                        if (edata->upropset & PROP_BATTCAP) {
                                prop_dictionary_remove(sdict,
                                    "critical-capacity");
                                ptype = PENVSYS_EVENT_CAPACITY;
                        }

                        if (edata->upropset & PROP_BATTWARN) {
                                prop_dictionary_remove(sdict,
                                    "warning-capacity");
                                ptype = PENVSYS_EVENT_CAPACITY;
                        }

                        if (edata->upropset & PROP_BATTHIGH) {
                                prop_dictionary_remove(sdict,
                                    "high-capacity");
                                ptype = PENVSYS_EVENT_CAPACITY;
                        }

                        if (edata->upropset & PROP_BATTMAX) {
                                prop_dictionary_remove(sdict,
                                    "maximum-capacity");
                                ptype = PENVSYS_EVENT_CAPACITY;
                        }
                        if (edata->upropset & PROP_WARNMAX) {
                                prop_dictionary_remove(sdict, "warning-max");
                                ptype = PENVSYS_EVENT_LIMITS;
                        }

                        if (edata->upropset & PROP_WARNMIN) {
                                prop_dictionary_remove(sdict, "warning-min");
                                ptype = PENVSYS_EVENT_LIMITS;
                        }

                        if (edata->upropset & PROP_CRITMAX) {
                                prop_dictionary_remove(sdict, "critical-max");
                                ptype = PENVSYS_EVENT_LIMITS;
                        }

                        if (edata->upropset & PROP_CRITMIN) {
                                prop_dictionary_remove(sdict, "critical-min");
                                ptype = PENVSYS_EVENT_LIMITS;
                        }
                        if (edata->upropset & PROP_RFACT) {
                                (void)sme_sensor_upint32(sdict, "rfact", 0);
                                edata->rfact = 0;
                        }

                        if (edata->upropset & PROP_DESC)
                                (void)sme_sensor_upstring(sdict,
                                    "description", edata->desc);

                        if (ptype == 0)
                                continue;

                        /*
                         * If there were any limit values removed, we
                         * need to revert to initial limits.
                         *
                         * First, tell the driver that we need it to
                         * restore any h/w limits which may have been
                         * changed to stored, boot-time values.
                         */
                        if (sme->sme_set_limits) {
                                DPRINTF(("%s: reset limits for %s %s\n",
                                        __func__, sme->sme_name, edata->desc));
                                (*sme->sme_set_limits)(sme, edata, NULL, NULL);
                        }

                        /*
                         * Next, we need to retrieve those initial limits.
                         */
                        props = 0;
                        edata->upropset &= ~PROP_LIMITS;
                        if (sme->sme_get_limits) {
                                DPRINTF(("%s: retrieve limits for %s %s\n",
                                        __func__, sme->sme_name, edata->desc));
                                lims = edata->limits;
                                (*sme->sme_get_limits)(sme, edata, &lims,
                                                       &props);
                        }

                        /*
                         * If the sensor is providing entropy data,
                         * get rid of the rndsrc;  we'll provide a new
                         * one shortly.
                         */
                        if (edata->flags & ENVSYS_FHAS_ENTROPY)
                                rnd_detach_source(&edata->rnd_src);

                        /*
                         * Remove the old limits event, if any
                         */
                        sme_event_unregister(sme, edata->desc,
                            PENVSYS_EVENT_LIMITS);

                        /*
                         * Create and install a new event (which will
                         * update the dictionary) with the correct
                         * units.
                         */
                        sdt_units = sme_find_table_entry(SME_DESC_UNITS,
                            edata->units);

                        if (props & PROP_LIMITS) {
                                DPRINTF(("%s: install limits for %s %s\n",
                                        __func__, sme->sme_name, edata->desc));

                                sme_event_register(sdict, edata, sme,
                                    &lims, props, PENVSYS_EVENT_LIMITS,
                                    sdt_units->crittype);
                        }

                        /* Finally, if the sensor provides entropy,
                         * create an additional event entry and attach
                         * the rndsrc
                         */
                        if (edata->flags & ENVSYS_FHAS_ENTROPY) {
                                sme_event_register(sdict, edata, sme,
                                    &lims, props, PENVSYS_EVENT_NULL,
                                    sdt_units->crittype);
                                snprintf(rnd_name, sizeof(rnd_name), "%s-%s",
                                    sme->sme_name, edata->desc);
                                rnd_attach_source(&edata->rnd_src, rnd_name,
                                    RND_TYPE_ENV, RND_FLAG_COLLECT_VALUE|
                                                  RND_FLAG_COLLECT_TIME|
                                                  RND_FLAG_ESTIMATE_VALUE|
                                                  RND_FLAG_ESTIMATE_TIME);
                        }
                }

                /*
                 * Restore default timeout value.
                 */
                mutex_enter(&sme->sme_work_mtx);
                sme->sme_events_timeout = SME_EVENTS_DEFTIMEOUT;
                sme_schedule_callout(sme);
                mutex_exit(&sme->sme_work_mtx);

                sysmon_envsys_release(sme, false);
        }
        mutex_exit(&sme_global_mtx);
}

/*
 * sme_add_property_dictionary:
 *
 *      + Add global properties into a device.
 */
static int
sme_add_property_dictionary(struct sysmon_envsys *sme, prop_array_t array,
                            prop_dictionary_t dict)
{
        prop_dictionary_t pdict;
        uint64_t timo;
        const char *class;
        int error = 0;

        pdict = prop_dictionary_create();
        if (!pdict)
                return EINVAL;

        /*
         * Add the 'refresh-timeout' and 'dev-class' objects into the
         * 'device-properties' dictionary.
         *
         *      ...
         *      <dict>
         *              <key>device-properties</key>
         *              <dict>
         *                      <key>refresh-timeout</key>
         *                      <integer>120</integer<
         *                      <key>device-class</key>
         *                      <string>class_name</string>
         *              </dict>
         *      </dict>
         *      ...
         *
         */
        mutex_enter(&sme->sme_work_mtx);
        if (sme->sme_events_timeout == 0) {
                sme->sme_events_timeout = SME_EVENTS_DEFTIMEOUT;
                sme_schedule_callout(sme);
        }
        timo = sme->sme_events_timeout;
        mutex_exit(&sme->sme_work_mtx);

        if (!prop_dictionary_set_uint64(pdict, "refresh-timeout", timo)) {
                error = EINVAL;
                goto out;
        }
        if (sme->sme_class == SME_CLASS_BATTERY)
                class = "battery";
        else if (sme->sme_class == SME_CLASS_ACADAPTER)
                class = "ac-adapter";
        else
                class = "other";
        if (!prop_dictionary_set_string_nocopy(pdict, "device-class", class)) {
                error = EINVAL;
                goto out;
        }

        if (!prop_dictionary_set(dict, "device-properties", pdict)) {
                error = EINVAL;
                goto out;
        }

        /*
         * Add the device dictionary into the sysmon envsys array.
         */
        if (!prop_array_add(array, dict))
                error = EINVAL;

out:
        prop_object_release(pdict);
        return error;
}

/*
 * sme_add_sensor_dictionary:
 *
 *      + Adds the sensor objects into the dictionary and returns a pointer
 *        to a sme_event_drv_t object if a monitoring flag was set
 *        (or NULL otherwise).
 */
static sme_event_drv_t *
sme_add_sensor_dictionary(struct sysmon_envsys *sme, prop_array_t array,
                          prop_dictionary_t dict, envsys_data_t *edata)
{
        const struct sme_descr_entry *sdt;
        int error;
        sme_event_drv_t *sme_evdrv_t = NULL;
        char indexstr[ENVSYS_DESCLEN];
        bool mon_supported, allow_rfact;

        /*
         * Add the index sensor string.
         *
         *              ...
         *              <key>index</eyr
         *              <string>sensor0</string>
         *              ...
         */
        (void)snprintf(indexstr, sizeof(indexstr), "sensor%d", edata->sensor);
        if (sme_sensor_upstring(dict, "index", indexstr))
                goto bad;

        /*
         *              ...
         *              <key>description</key>
         *              <string>blah blah</string>
         *              ...
         */
        if (sme_sensor_upstring(dict, "description", edata->desc))
                goto bad;

        /*
         * Add the monitoring boolean object:
         *
         *              ...
         *              <key>monitoring-supported</key>
         *              <true/>
         *              ...
         *
         * always false on Battery {capacity,charge}, Drive and Indicator types.
         * They cannot be monitored.
         *
         */
        if ((edata->flags & ENVSYS_FMONNOTSUPP) ||
            (edata->units == ENVSYS_INDICATOR) ||
            (edata->units == ENVSYS_DRIVE) ||
            (edata->units == ENVSYS_BATTERY_CAPACITY) ||
            (edata->units == ENVSYS_BATTERY_CHARGE))
                mon_supported = false;
        else
                mon_supported = true;
        if (sme_sensor_upbool(dict, "monitoring-supported", mon_supported))
                goto out;

        /*
         * Add the allow-rfact boolean object, true if
         * ENVSYS_FCHANGERFACT is set, false otherwise.
         *
         *              ...
         *              <key>allow-rfact</key>
         *              <true/>
         *              ...
         */
        if (edata->units == ENVSYS_SVOLTS_DC ||
            edata->units == ENVSYS_SVOLTS_AC) {
                if (edata->flags & ENVSYS_FCHANGERFACT)
                        allow_rfact = true;
                else
                        allow_rfact = false;
                if (sme_sensor_upbool(dict, "allow-rfact", allow_rfact))
                        goto out;
        }

        error = sme_update_sensor_dictionary(dict, edata,
                        (edata->state == ENVSYS_SVALID));
        if (error < 0)
                goto bad;
        else if (error)
                goto out;

        /*
         *      ...
         * </dict>
         *
         * Add the dictionary into the array.
         *
         */
        if (!prop_array_add(array, dict)) {
                DPRINTF(("%s: prop_array_add\n", __func__));
                goto bad;
        }

        /*
         * Register new event(s) if any monitoring flag was set or if
         * the sensor provides entropy for rnd(4).
         */
        if (edata->flags & (ENVSYS_FMONANY | ENVSYS_FHAS_ENTROPY)) {
                sme_evdrv_t = kmem_zalloc(sizeof(*sme_evdrv_t), KM_SLEEP);
                sme_evdrv_t->sed_sdict = dict;
                sme_evdrv_t->sed_edata = edata;
                sme_evdrv_t->sed_sme = sme;
                sdt = sme_find_table_entry(SME_DESC_UNITS, edata->units);
                sme_evdrv_t->sed_powertype = sdt->crittype;
        }

out:
        return sme_evdrv_t;

bad:
        prop_object_release(dict);
        return NULL;
}

/*
 * Find the maximum of all currently reported values.
 * The provided callback decides whether a sensor is part of the
 * maximum calculation (by returning true) or ignored (callback
 * returns false). Example usage: callback selects temperature
 * sensors in a given thermal zone, the function calculates the
 * maximum currently reported temperature in this zone.
 * If the parameter "refresh" is true, new values will be acquired
 * from the hardware, if not, the last reported value will be used.
 */
uint32_t
sysmon_envsys_get_max_value(bool (*predicate)(const envsys_data_t*),
        bool refresh)
{
        struct sysmon_envsys *sme;
        uint32_t maxv, v;

        maxv = 0;
        mutex_enter(&sme_global_mtx);
        LIST_FOREACH(sme, &sysmon_envsys_list, sme_list) {
                sysmon_envsys_acquire(sme, false);
                v = sme_get_max_value(sme, predicate, refresh);
                sysmon_envsys_release(sme, false);
                if (v > maxv)
                        maxv = v;
        }
        mutex_exit(&sme_global_mtx);
        return maxv;
}

static uint32_t
sme_get_max_value(struct sysmon_envsys *sme,
    bool (*predicate)(const envsys_data_t*),
    bool refresh)
{
        envsys_data_t *edata;
        uint32_t maxv, v;

        /*
         * Iterate over all sensors that match the predicate
         */
        maxv = 0;
        TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                if (!(*predicate)(edata))
                        continue;

                /*
                 * refresh sensor data
                 */
                mutex_enter(&sme->sme_mtx);
                sysmon_envsys_refresh_sensor(sme, edata);
                mutex_exit(&sme->sme_mtx);

                v = edata->value_cur;
                if (v > maxv)
                        maxv = v;

        }

        return maxv;
}

/*
 * sme_update_dictionary:
 *
 *      + Update per-sensor dictionaries with new values if there were
 *        changes, otherwise the object in dictionary is untouched.
 */
int
sme_update_dictionary(struct sysmon_envsys *sme)
{
        envsys_data_t *edata;
        prop_object_t array, dict, obj, obj2;
        uint64_t timo;
        int error = 0;

        /*
         * Retrieve the array of dictionaries in device.
         */
        array = prop_dictionary_get(sme_propd, sme->sme_name);
        if (prop_object_type(array) != PROP_TYPE_ARRAY) {
                DPRINTF(("%s: not an array (%s)\n", __func__, sme->sme_name));
                return EINVAL;
        }

        /*
         * Get the last dictionary on the array, this contains the
         * 'device-properties' sub-dictionary.
         */
        obj = prop_array_get(array, prop_array_count(array) - 1);
        if (!obj || prop_object_type(obj) != PROP_TYPE_DICTIONARY) {
                DPRINTF(("%s: not a device-properties dictionary\n", __func__));
                return EINVAL;
        }

        obj2 = prop_dictionary_get(obj, "device-properties");
        if (!obj2)
                return EINVAL;

        /*
         * Update the 'refresh-timeout' property.
         */
        mutex_enter(&sme->sme_work_mtx);
        timo = sme->sme_events_timeout;
        mutex_exit(&sme->sme_work_mtx);
        if (!prop_dictionary_set_uint64(obj2, "refresh-timeout", timo))
                return EINVAL;

        /*
         * - iterate over all sensors.
         * - fetch new data.
         * - check if data in dictionary is different than new data.
         * - update dictionary if there were changes.
         */
        DPRINTF(("%s: updating '%s' with nsensors=%d\n", __func__,
            sme->sme_name, sme->sme_nsensors));

        /*
         * Don't bother with locking when traversing the queue,
         * the device is already marked as busy; if a sensor
         * is going to be removed or added it will have to wait.
         */
        TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                /*
                 * refresh sensor data via sme_envsys_refresh_sensor
                 */
                mutex_enter(&sme->sme_mtx);
                sysmon_envsys_refresh_sensor(sme, edata);
                mutex_exit(&sme->sme_mtx);

                /*
                 * retrieve sensor's dictionary.
                 */
                dict = prop_array_get(array, edata->sensor);
                if (prop_object_type(dict) != PROP_TYPE_DICTIONARY) {
                        DPRINTF(("%s: not a dictionary (%d:%s)\n",
                            __func__, edata->sensor, sme->sme_name));
                        return EINVAL;
                }

                /*
                 * update sensor's state.
                 */
                error = sme_update_sensor_dictionary(dict, edata, true);

                if (error)
                        break;
        }

        return error;
}

int
sme_update_sensor_dictionary(prop_object_t dict, envsys_data_t *edata,
        bool value_update)
{
        const struct sme_descr_entry *sdt;
        int error = 0;

        sdt = sme_find_table_entry(SME_DESC_STATES, edata->state);
        if (sdt == NULL) {
                printf("sme_update_sensor_dictionary: cannot update sensor %d "
                    "state %d unknown\n", edata->sensor, edata->state);
                return EINVAL;
        }

        DPRINTFOBJ(("%s: sensor #%d type=%d (%s) flags=%d\n", __func__,
            edata->sensor, sdt->type, sdt->desc, edata->flags));

        error = sme_sensor_upstring(dict, "state", sdt->desc);
        if (error)
                return (-error);

        /*
         * update sensor's type.
         */
        sdt = sme_find_table_entry(SME_DESC_UNITS, edata->units);
        if (sdt == NULL)
                return EINVAL;

        DPRINTFOBJ(("%s: sensor #%d units=%d (%s)\n", __func__, edata->sensor,
            sdt->type, sdt->desc));

        error = sme_sensor_upstring(dict, "type", sdt->desc);
        if (error)
                return (-error);

        if (value_update) {
                /*
                 * update sensor's current value.
                 */
                error = sme_sensor_upint32(dict, "cur-value", edata->value_cur);
                if (error)
                        return error;
        }

        /*
         * Battery charge and Indicator types do not
         * need the remaining objects, so skip them.
         */
        if (edata->units == ENVSYS_INDICATOR ||
            edata->units == ENVSYS_BATTERY_CHARGE)
                return error;

        /*
         * update sensor flags.
         */
        if (edata->flags & ENVSYS_FPERCENT) {
                error = sme_sensor_upbool(dict, "want-percentage", true);
                if (error)
                        return error;
        }

        if (value_update) {
                /*
                 * update sensor's {max,min}-value.
                 */
                if (edata->flags & ENVSYS_FVALID_MAX) {
                        error = sme_sensor_upint32(dict, "max-value",
                                                   edata->value_max);
                        if (error)
                                return error;
                }

                if (edata->flags & ENVSYS_FVALID_MIN) {
                        error = sme_sensor_upint32(dict, "min-value",
                                                   edata->value_min);
                        if (error)
                                return error;
                }

                /*
                 * update 'rpms' only for ENVSYS_SFANRPM sensors.
                 */
                if (edata->units == ENVSYS_SFANRPM) {
                        error = sme_sensor_upuint32(dict, "rpms", edata->rpms);
                        if (error)
                                return error;
                }

                /*
                 * update 'rfact' only for ENVSYS_SVOLTS_[AD]C sensors.
                 */
                if (edata->units == ENVSYS_SVOLTS_AC ||
                    edata->units == ENVSYS_SVOLTS_DC) {
                        error = sme_sensor_upint32(dict, "rfact", edata->rfact);
                        if (error)
                                return error;
                }
        }

        /*
         * update 'drive-state' only for ENVSYS_DRIVE sensors.
         */
        if (edata->units == ENVSYS_DRIVE) {
                sdt = sme_find_table_entry(SME_DESC_DRIVE_STATES,
                                           edata->value_cur);
                if (sdt == NULL)
                        return EINVAL;
                error = sme_sensor_upstring(dict, "drive-state", sdt->desc);
                if (error)
                        return error;
        }

        /*
         * update 'battery-capacity' only for ENVSYS_BATTERY_CAPACITY
         * sensors.
         */
        if (edata->units == ENVSYS_BATTERY_CAPACITY) {
                sdt = sme_find_table_entry(SME_DESC_BATTERY_CAPACITY,
                    edata->value_cur);
                if (sdt == NULL)
                        return EINVAL;
                error = sme_sensor_upstring(dict, "battery-capacity",
                                            sdt->desc);
                if (error)
                        return error;
        }

        return error;
}

/*
 * sme_userset_dictionary:
 *
 *      + Parse the userland dictionary and run the appropriate tasks
 *        that were specified.
 */
int
sme_userset_dictionary(struct sysmon_envsys *sme, prop_dictionary_t udict,
                       prop_array_t array)
{
        const struct sme_descr_entry *sdt;
        envsys_data_t *edata;
        prop_dictionary_t dict, tdict = NULL;
        prop_object_t obj, obj1, obj2, tobj = NULL;
        uint32_t props;
        uint64_t refresh_timo = 0;
        sysmon_envsys_lim_t lims;
        int i, error = 0;
        const char *blah;
        bool targetfound = false;

        /*
         * The user wanted to change the refresh timeout value for this
         * device.
         *
         * Get the 'device-properties' object from the userland dictionary.
         */
        obj = prop_dictionary_get(udict, "device-properties");
        if (obj && prop_object_type(obj) == PROP_TYPE_DICTIONARY) {
                /*
                 * Get the 'refresh-timeout' property for this device.
                 */
                obj1 = prop_dictionary_get(obj, "refresh-timeout");
                if (obj1 && prop_object_type(obj1) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        refresh_timo =
                            prop_number_unsigned_value(obj1);
                        if (refresh_timo < 1)
                                error = EINVAL;
                        else {
                                mutex_enter(&sme->sme_work_mtx);
                                if (sme->sme_events_timeout != refresh_timo) {
                                        sme->sme_events_timeout = refresh_timo;
                                        sme_schedule_callout(sme);
                                }
                                mutex_exit(&sme->sme_work_mtx);
                        }
                }
                return error;

        } else if (!obj) {
                /*
                 * Get sensor's index from userland dictionary.
                 */
                obj = prop_dictionary_get(udict, "index");
                if (!obj)
                        return EINVAL;
                if (prop_object_type(obj) != PROP_TYPE_STRING) {
                        DPRINTF(("%s: 'index' not a string\n", __func__));
                        return EINVAL;
                }
        } else
                return EINVAL;

        /*
         * Don't bother with locking when traversing the queue,
         * the device is already marked as busy; if a sensor
         * is going to be removed or added it will have to wait.
         */
        TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
                /*
                 * Get a dictionary and check if it's our sensor by checking
                 * at its index position.
                 */
                dict = prop_array_get(array, edata->sensor);
                obj1 = prop_dictionary_get(dict, "index");

                /*
                 * is it our sensor?
                 */
                if (!prop_string_equals(obj1, obj))
                        continue;

                props = 0;

                /*
                 * Check if a new description operation was
                 * requested by the user and set new description.
                 */
                obj2 = prop_dictionary_get(udict, "description");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_STRING) {
                        targetfound = true;
                        blah = prop_string_value(obj2);

                        /*
                         * Check for duplicate description.
                         */
                        for (i = 0; i < sme->sme_nsensors; i++) {
                                if (i == edata->sensor)
                                        continue;
                                tdict = prop_array_get(array, i);
                                tobj =
                                    prop_dictionary_get(tdict, "description");
                                if (prop_string_equals(obj2, tobj)) {
                                        error = EEXIST;
                                        goto out;
                                }
                        }

                        /*
                         * Update the object in dictionary.
                         */
                        mutex_enter(&sme->sme_mtx);
                        error = sme_sensor_upstring(dict,
                                                    "description",
                                                    blah);
                        if (error) {
                                mutex_exit(&sme->sme_mtx);
                                goto out;
                        }

                        DPRINTF(("%s: sensor%d changed desc to: %s\n",
                            __func__, edata->sensor, blah));
                        edata->upropset |= PROP_DESC;
                        mutex_exit(&sme->sme_mtx);
                }

                /*
                 * did the user want to change the rfact?
                 */
                obj2 = prop_dictionary_get(udict, "rfact");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        if (edata->flags & ENVSYS_FCHANGERFACT) {
                                mutex_enter(&sme->sme_mtx);
                                edata->rfact = prop_number_signed_value(obj2);
                                edata->upropset |= PROP_RFACT;
                                mutex_exit(&sme->sme_mtx);
                                DPRINTF(("%s: sensor%d changed rfact to %d\n",
                                    __func__, edata->sensor, edata->rfact));
                        } else {
                                error = ENOTSUP;
                                goto out;
                        }
                }

                sdt = sme_find_table_entry(SME_DESC_UNITS, edata->units);

                /*
                 * did the user want to set a critical capacity event?
                 */
                obj2 = prop_dictionary_get(udict, "critical-capacity");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_critmin = prop_number_signed_value(obj2);
                        props |= PROP_BATTCAP;
                }

                /*
                 * did the user want to set a warning capacity event?
                 */
                obj2 = prop_dictionary_get(udict, "warning-capacity");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_warnmin = prop_number_signed_value(obj2);
                        props |= PROP_BATTWARN;
                }

                /*
                 * did the user want to set a high capacity event?
                 */
                obj2 = prop_dictionary_get(udict, "high-capacity");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_warnmin = prop_number_signed_value(obj2);
                        props |= PROP_BATTHIGH;
                }

                /*
                 * did the user want to set a maximum capacity event?
                 */
                obj2 = prop_dictionary_get(udict, "maximum-capacity");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_warnmin = prop_number_signed_value(obj2);
                        props |= PROP_BATTMAX;
                }

                /*
                 * did the user want to set a critical max event?
                 */
                obj2 = prop_dictionary_get(udict, "critical-max");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_critmax = prop_number_signed_value(obj2);
                        props |= PROP_CRITMAX;
                }

                /*
                 * did the user want to set a warning max event?
                 */
                obj2 = prop_dictionary_get(udict, "warning-max");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_warnmax = prop_number_signed_value(obj2);
                        props |= PROP_WARNMAX;
                }

                /*
                 * did the user want to set a critical min event?
                 */
                obj2 = prop_dictionary_get(udict, "critical-min");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_critmin = prop_number_signed_value(obj2);
                        props |= PROP_CRITMIN;
                }

                /*
                 * did the user want to set a warning min event?
                 */
                obj2 = prop_dictionary_get(udict, "warning-min");
                if (obj2 && prop_object_type(obj2) == PROP_TYPE_NUMBER) {
                        targetfound = true;
                        lims.sel_warnmin = prop_number_signed_value(obj2);
                        props |= PROP_WARNMIN;
                }

                if (props && (edata->flags & ENVSYS_FMONNOTSUPP) != 0) {
                        error = ENOTSUP;
                        goto out;
                }
                if (props || (edata->flags & ENVSYS_FHAS_ENTROPY) != 0) {
                        error = sme_event_register(dict, edata, sme, &lims,
                                        props,
                                        (edata->flags & ENVSYS_FPERCENT)?
                                                PENVSYS_EVENT_CAPACITY:
                                                PENVSYS_EVENT_LIMITS,
                                        sdt->crittype);
                        if (error == EEXIST)
                                error = 0;
                        if (error)
                                goto out;
                }

                /*
                 * All objects in dictionary were processed.
                 */
                break;
        }

out:
        /*
         * invalid target? return the error.
         */
        if (!targetfound)
                error = EINVAL;

        return error;
}

/*
 * + sysmon_envsys_foreach_sensor
 *
 *      Walk through the devices' sensor lists and execute the callback.
 *      If the callback returns false, the remainder of the current
 *      device's sensors are skipped.
 */
void
sysmon_envsys_foreach_sensor(sysmon_envsys_callback_t func, void *arg,
                             bool refresh)
{
        struct sysmon_envsys *sme;
        envsys_data_t *sensor;

        mutex_enter(&sme_global_mtx);
        LIST_FOREACH(sme, &sysmon_envsys_list, sme_list) {

                sysmon_envsys_acquire(sme, false);
                TAILQ_FOREACH(sensor, &sme->sme_sensors_list, sensors_head) {
                        if (refresh) {
                                mutex_enter(&sme->sme_mtx);
                                sysmon_envsys_refresh_sensor(sme, sensor);
                                mutex_exit(&sme->sme_mtx);
                        }
                        if (!(*func)(sme, sensor, arg))
                                break;
                }
                sysmon_envsys_release(sme, false);
        }
        mutex_exit(&sme_global_mtx);
}

/*
 * Call the sensor's refresh function, and collect/stir entropy
 */
void
sysmon_envsys_refresh_sensor(struct sysmon_envsys *sme, envsys_data_t *edata)
{

        if ((sme->sme_flags & SME_DISABLE_REFRESH) == 0)
                (*sme->sme_refresh)(sme, edata);

        if (edata->flags & ENVSYS_FHAS_ENTROPY &&
            edata->state != ENVSYS_SINVALID &&
            edata->value_prev != edata->value_cur)
                rnd_add_uint32(&edata->rnd_src, edata->value_cur);
        edata->value_prev = edata->value_cur;
}

static int
sysmon_envsys_modcmd(modcmd_t cmd, void *arg)
{
        int ret;

        switch (cmd) {
        case MODULE_CMD_INIT:
                ret = sysmon_envsys_init();
                break;
        case MODULE_CMD_FINI:
                ret = sysmon_envsys_fini();
                break;
        case MODULE_CMD_STAT:
        default:
                ret = ENOTTY;
        }

        return ret;
}