/*-
 * Copyright (C) 2018 Justin Hibbits
 *
 * 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 TOOLS GMBH 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.
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/endian.h>

#include <vm/vm.h>
#include <vm/pmap.h>

#include <machine/bus.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include "opal.h"

struct opal_sensor_softc {
        device_t         sc_dev;
        struct mtx       sc_mtx;
        uint32_t         sc_handle;
        uint32_t         sc_min_handle;
        uint32_t         sc_max_handle;
        char            *sc_label;
        int              sc_type;
};

#define SENSOR_LOCK(_sc)                mtx_lock(&(_sc)->sc_mtx)
#define SENSOR_UNLOCK(_sc)              mtx_unlock(&(_sc)->sc_mtx)
#define SENSOR_LOCK_INIT(_sc) \
        mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
            "opal-sensor", MTX_DEF)

/*
 * A bit confusing, maybe.  There are two types of nodes with compatible strings
 * of "ibm,opal-sensor".  One hangs off /ibm,opal/, named "sensors", the other
 * hangs off of this node.  For newbus attachments, we have one node (opalsens)
 * attach from opal0, and the others (opal_sensor) attach from opalsens.  These
 * are the real sensors.
 */
enum opal_sensor_type {
        OPAL_SENSOR_TEMP        = 0,    /* From OPAL: degC */
        OPAL_SENSOR_FAN         = 1,    /* From OPAL: RPM */
        OPAL_SENSOR_POWER       = 2,    /* From OPAL: W */
        OPAL_SENSOR_IN          = 3,    /* From OPAL: mV */
        OPAL_SENSOR_ENERGY      = 4,    /* From OPAL: uJ */
        OPAL_SENSOR_CURR        = 5,    /* From OPAL: mA */
        OPAL_SENSOR_MAX
};

/* This must be kept sorted with the enum above. */
const char *opal_sensor_types[] = {
        "temp",
        "fan",
        "power",
        "in",
        "energy",
        "curr"
};

/*
 * Retrieve the raw value from OPAL.  This will be cooked by the sysctl handler.
 */
static int
opal_sensor_get_val(struct opal_sensor_softc *sc, uint32_t key, uint64_t *val)
{
        struct opal_msg msg;
        uint32_t val32;
        int rv, token;

        token = opal_alloc_async_token();
        SENSOR_LOCK(sc);
        rv = opal_call(OPAL_SENSOR_READ, key, token, vtophys(&val32));

        if (rv == OPAL_ASYNC_COMPLETION) {
                /* Sleep a little to let things settle. */
                DELAY(100);
                bzero(&msg, sizeof(msg));
                rv = opal_wait_completion(&msg, sizeof(msg), token);

                if (rv == OPAL_SUCCESS)
                        val32 = msg.params[0];
        }
        SENSOR_UNLOCK(sc);

        if (rv == OPAL_SUCCESS)
                *val = be32toh(val32);
        else
                rv = EIO;

        opal_free_async_token(token);
        return (rv);
}

static int
opal_sensor_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct opal_sensor_softc *sc;
        int error, result;
        uint32_t sensor;
        uint64_t sensval;

        sc = arg1;
        sensor = arg2;

        error = opal_sensor_get_val(sc, sensor, &sensval);

        if (error)
                return (error);

        result = sensval;

        switch (sc->sc_type) {
        case OPAL_SENSOR_TEMP:
                result = result * 10 + 2731; /* Convert to K */
                break;
        case OPAL_SENSOR_POWER:
                result = result * 1000; /* Convert to mW */
                break;
        }

        error = sysctl_handle_int(oidp, &result, 0, req);

        return (error);
}

static int
opal_sensor_probe(device_t dev)
{
        if (!ofw_bus_is_compatible(dev, "ibm,opal-sensor"))
                return (ENXIO);

        device_set_desc(dev, "OPAL sensor");
        return (BUS_PROBE_GENERIC);
}

static int
opal_sensor_attach(device_t dev)
{
        struct opal_sensor_softc *sc;
        struct sysctl_ctx_list *ctx;
        struct sysctl_oid *tree;
        char            type[8];
        phandle_t       node;
        cell_t          sensor_id;
        int             i;

        sc = device_get_softc(dev);
        sc->sc_dev = dev;

        node = ofw_bus_get_node(dev);

        if (OF_getencprop(node, "sensor-data", &sensor_id, sizeof(sensor_id)) < 0) {
                device_printf(dev, "Missing sensor ID\n");
                return (ENXIO);
        }
        if (OF_getprop(node, "sensor-type", type, sizeof(type)) < 0) {
                device_printf(dev, "Missing sensor type\n");
                return (ENXIO);
        }

        sc->sc_type = -1;
        for (i = 0; i < OPAL_SENSOR_MAX; i++) {
                if (strcmp(type, opal_sensor_types[i]) == 0) {
                        sc->sc_type = i;
                        break;
                }
        }
        if (sc->sc_type == -1) {
                device_printf(dev, "Unknown sensor type '%s'\n", type);
                return (ENXIO);
        }

        ctx = device_get_sysctl_ctx(dev);
        tree = device_get_sysctl_tree(dev);

        sc->sc_handle = sensor_id;
        SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
            "sensor", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, sc,
            sensor_id, opal_sensor_sysctl,
            (sc->sc_type == OPAL_SENSOR_TEMP) ? "IK" : "I", "current value");

        SYSCTL_ADD_STRING(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "type",
            CTLFLAG_RD, __DECONST(char *, opal_sensor_types[sc->sc_type]),
            0, "");

        OF_getprop_alloc(node, "label", (void **)&sc->sc_label);
        SYSCTL_ADD_STRING(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "label",
            CTLFLAG_RD, sc->sc_label, 0, "");

        if (OF_getencprop(node, "sensor-data-min",
            &sensor_id, sizeof(sensor_id)) > 0) {
                sc->sc_min_handle = sensor_id;
                SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                    "sensor_min", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
                    sc, sensor_id, opal_sensor_sysctl,
                    (sc->sc_type == OPAL_SENSOR_TEMP) ? "IK" : "I",
                    "minimum value");
        }

        if (OF_getencprop(node, "sensor-data-max",
            &sensor_id, sizeof(sensor_id)) > 0) {
                sc->sc_max_handle = sensor_id;
                SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                    "sensor_max", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
                    sc, sensor_id, opal_sensor_sysctl,
                    (sc->sc_type == OPAL_SENSOR_TEMP) ? "IK" : "I",
                    "maximum value");
        }

        SENSOR_LOCK_INIT(sc);

        return (0);
}

static device_method_t opal_sensor_methods[] = {
        DEVMETHOD(device_probe,         opal_sensor_probe),
        DEVMETHOD(device_attach,        opal_sensor_attach),

        DEVMETHOD_END
};

static driver_t opal_sensor_driver = {
        "opal_sensor",
        opal_sensor_methods,
        sizeof(struct opal_sensor_softc)
};

DRIVER_MODULE(opal_sensor, opalsens, opal_sensor_driver, NULL, NULL);

static int
opalsens_probe(device_t dev)
{

        if (!ofw_bus_is_compatible(dev, "ibm,opal-sensor"))
                return (ENXIO);

        device_set_desc(dev, "OPAL Sensors");
        return (BUS_PROBE_GENERIC);
}

static int 
opalsens_attach(device_t dev)
{
        phandle_t child;
        device_t cdev;
        struct ofw_bus_devinfo *dinfo;

        for (child = OF_child(ofw_bus_get_node(dev)); child != 0;
            child = OF_peer(child)) {
                dinfo = malloc(sizeof(*dinfo), M_DEVBUF, M_WAITOK | M_ZERO);
                if (ofw_bus_gen_setup_devinfo(dinfo, child) != 0) {
                        free(dinfo, M_DEVBUF);
                        continue;
                }
                cdev = device_add_child(dev, NULL, DEVICE_UNIT_ANY);
                if (cdev == NULL) {
                        device_printf(dev, "<%s>: device_add_child failed\n",
                            dinfo->obd_name);
                        ofw_bus_gen_destroy_devinfo(dinfo);
                        free(dinfo, M_DEVBUF);
                        continue;
                }
                device_set_ivars(cdev, dinfo);
        }

        bus_attach_children(dev);
        return (0);
}

static const struct ofw_bus_devinfo *
opalsens_get_devinfo(device_t dev, device_t child)
{
        return (device_get_ivars(child));
}

static device_method_t opalsens_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         opalsens_probe),
        DEVMETHOD(device_attach,        opalsens_attach),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_get_devinfo,  opalsens_get_devinfo),
        DEVMETHOD(ofw_bus_get_compat,   ofw_bus_gen_get_compat),
        DEVMETHOD(ofw_bus_get_model,    ofw_bus_gen_get_model),
        DEVMETHOD(ofw_bus_get_name,     ofw_bus_gen_get_name),
        DEVMETHOD(ofw_bus_get_node,     ofw_bus_gen_get_node),
        DEVMETHOD(ofw_bus_get_type,     ofw_bus_gen_get_type),

        DEVMETHOD_END
};

static driver_t opalsens_driver = {
        "opalsens",
        opalsens_methods,
        0
};

DRIVER_MODULE(opalsens, opal, opalsens_driver, NULL, NULL);