/*
 * Copyright (c) 2003 Julien Bordet <zejames@greyhats.org>
 * 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.
 * 
 * $OpenBSD: it.c,v 1.22 2007/03/22 16:55:31 deraadt Exp $
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <sys/rman.h>

#include <bus/isa/isavar.h>
#include <sys/systm.h>

#include <sys/sensors.h>

#include "itvar.h"

#if defined(ITDEBUG)
#define DPRINTF(x)              do { kprintf x; } while (0)
#else
#define DPRINTF(x)
#endif

/*
 * IT87-compatible chips can typically measure voltages up to 4.096 V.
 * To measure higher voltages the input is attenuated with (external)
 * resistors.  Negative voltages are measured using a reference
 * voltage.  So we have to convert the sensor values back to real
 * voltages by applying the appropriate resistor factor.
 */
#define RFACT_NONE      10000
#define RFACT(x, y)     (RFACT_NONE * ((x) + (y)) / (y))

int it_probe(device_t);
int it_attach(device_t);
int it_detach(device_t);
u_int8_t it_readreg(struct it_softc *, int);
void it_writereg(struct it_softc *, int, int);
void it_setup_volt(struct it_softc *, int, int);
void it_setup_temp(struct it_softc *, int, int);
void it_setup_fan(struct it_softc *, int, int);

void it_generic_stemp(struct it_softc *, struct ksensor *);
void it_generic_svolt(struct it_softc *, struct ksensor *);
void it_generic_fanrpm(struct it_softc *, struct ksensor *);

void it_refresh_sensor_data(struct it_softc *);
void it_refresh(void *);

static device_method_t it_methods[] = {
        /* Methods from the device interface */
        DEVMETHOD(device_probe,         it_probe),
        DEVMETHOD(device_attach,        it_attach),
        DEVMETHOD(device_detach,        it_detach),

        /* Terminate method list */
        DEVMETHOD_END
};

static driver_t it_driver = {
        "it",
        it_methods,
        sizeof (struct it_softc)
};

static devclass_t it_devclass;

DRIVER_MODULE(it, isa, it_driver, it_devclass, NULL, NULL);


const int it_vrfact[] = {
        RFACT_NONE,
        RFACT_NONE,
        RFACT_NONE,
        RFACT(68, 100),
        RFACT(30, 10),
        RFACT(21, 10),
        RFACT(83, 20),
        RFACT(68, 100),
        RFACT_NONE
};

int
it_probe(device_t dev)
{
        struct resource *iores;
        int iorid = 0;
        bus_space_tag_t iot;
        bus_space_handle_t ioh;
        u_int8_t cr;

        iores = bus_alloc_resource(dev, SYS_RES_IOPORT, &iorid,
            0ul, ~0ul, 8, RF_ACTIVE);
        if (iores == NULL) {
                DPRINTF(("%s: can't map i/o space\n", __func__));
                return 1;
        }
        iot = rman_get_bustag(iores);
        ioh = rman_get_bushandle(iores);

        /* Check Vendor ID */
        bus_space_write_1(iot, ioh, ITC_ADDR, ITD_CHIPID);
        cr = bus_space_read_1(iot, ioh, ITC_DATA);
        bus_release_resource(dev, SYS_RES_IOPORT, iorid, iores);
        DPRINTF(("it: vendor id 0x%x\n", cr));
        if (cr != IT_ID_IT87)
                return 1;

        return 0;
}

int
it_attach(device_t dev)
{
        struct it_softc *sc = device_get_softc(dev);
        int i;
        u_int8_t cr;

        sc->sc_dev = dev;
        sc->sc_iores = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->sc_iorid,
            0ul, ~0ul, 8, RF_ACTIVE);
        if (sc->sc_iores == NULL) {
                device_printf(dev, "can't map i/o space\n");
                return 1;
        }
        sc->sc_iot = rman_get_bustag(sc->sc_iores);
        sc->sc_ioh = rman_get_bushandle(sc->sc_iores);

        sc->numsensors = IT_NUM_SENSORS;

        it_setup_fan(sc, 0, 3);
        it_setup_volt(sc, 3, 9);
        it_setup_temp(sc, 12, 3);

        sensor_task_register(sc, it_refresh, 5);

        /* Activate monitoring */
        cr = it_readreg(sc, ITD_CONFIG);
        cr |= 0x01 | 0x08;
        it_writereg(sc, ITD_CONFIG, cr);

        /* Initialize sensors */
        strlcpy(sc->sensordev.xname, device_get_nameunit(sc->sc_dev),
            sizeof(sc->sensordev.xname));
        for (i = 0; i < sc->numsensors; ++i)
                sensor_attach(&sc->sensordev, &sc->sensors[i]);
        sensordev_install(&sc->sensordev);

        return 0;
}

int
it_detach(device_t dev)
{
        struct it_softc *sc = device_get_softc(dev);
        int error;

        sensordev_deinstall(&sc->sensordev);
        sensor_task_unregister(sc);

        error = bus_release_resource(dev, SYS_RES_IOPORT, sc->sc_iorid,
            sc->sc_iores);
        if (error)
                return error;

        return 0;
}

u_int8_t
it_readreg(struct it_softc *sc, int reg)
{
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, ITC_ADDR, reg);
        return (bus_space_read_1(sc->sc_iot, sc->sc_ioh, ITC_DATA));
}

void
it_writereg(struct it_softc *sc, int reg, int val)
{
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, ITC_ADDR, reg);
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, ITC_DATA, val);
}

void
it_setup_volt(struct it_softc *sc, int start, int n)
{
        int i;

        for (i = 0; i < n; ++i) {
                sc->sensors[start + i].type = SENSOR_VOLTS_DC;
        }

        ksnprintf(sc->sensors[start + 0].desc, sizeof(sc->sensors[0].desc),
            "VCORE_A");
        ksnprintf(sc->sensors[start + 1].desc, sizeof(sc->sensors[1].desc),
            "VCORE_B");
        ksnprintf(sc->sensors[start + 2].desc, sizeof(sc->sensors[2].desc),
            "+3.3V");
        ksnprintf(sc->sensors[start + 3].desc, sizeof(sc->sensors[3].desc),
            "+5V");
        ksnprintf(sc->sensors[start + 4].desc, sizeof(sc->sensors[4].desc),
            "+12V");
        ksnprintf(sc->sensors[start + 5].desc, sizeof(sc->sensors[5].desc),
            "Unused");
        ksnprintf(sc->sensors[start + 6].desc, sizeof(sc->sensors[6].desc),
            "-12V");
        ksnprintf(sc->sensors[start + 7].desc, sizeof(sc->sensors[7].desc),
            "+5VSB");
        ksnprintf(sc->sensors[start + 8].desc, sizeof(sc->sensors[8].desc),
            "VBAT");
}

void
it_setup_temp(struct it_softc *sc, int start, int n)
{
        int i;

        for (i = 0; i < n; ++i)
                sc->sensors[start + i].type = SENSOR_TEMP;
}

void
it_setup_fan(struct it_softc *sc, int start, int n)
{
        int i;

        for (i = 0; i < n; ++i)
                sc->sensors[start + i].type = SENSOR_FANRPM;
}

void
it_generic_stemp(struct it_softc *sc, struct ksensor *sensors)
{
        int i, sdata;

        for (i = 0; i < 3; i++) {
                sdata = it_readreg(sc, ITD_SENSORTEMPBASE + i);
                /* Convert temperature to Fahrenheit degres */
                sensors[i].value = sdata * 1000000 + 273150000;
        }
}

void
it_generic_svolt(struct it_softc *sc, struct ksensor *sensors)
{
        int i, sdata;

        for (i = 0; i < 9; i++) {
                sdata = it_readreg(sc, ITD_SENSORVOLTBASE + i);
                DPRINTF(("sdata[volt%d] 0x%x\n", i, sdata));
                /* voltage returned as (mV >> 4) */
                sensors[i].value = (sdata << 4);
                /* these two values are negative and formula is different */
                if (i == 5 || i == 6)
                        sensors[i].value = ((sdata << 4) - IT_VREF);
                /* rfact is (factor * 10^4) */
                sensors[i].value *= it_vrfact[i];
                /* division by 10 gets us back to uVDC */
                sensors[i].value /= 10;
                if (i == 5 || i == 6)
                        sensors[i].value += IT_VREF * 1000;
        }
}

void
it_generic_fanrpm(struct it_softc *sc, struct ksensor *sensors)
{
        int i, sdata, divisor, odivisor, ndivisor;

        odivisor = ndivisor = divisor = it_readreg(sc, ITD_FAN);
        for (i = 0; i < 3; i++, divisor >>= 3) {
                sensors[i].flags &= ~SENSOR_FINVALID;
                if ((sdata = it_readreg(sc, ITD_SENSORFANBASE + i)) == 0xff) {
                        sensors[i].flags |= SENSOR_FINVALID;
                        if (i == 2)
                                ndivisor ^= 0x40;
                        else {
                                ndivisor &= ~(7 << (i * 3));
                                ndivisor |= ((divisor + 1) & 7) << (i * 3);
                        }
                } else if (sdata == 0) {
                        sensors[i].value = 0;
                } else {
                        if (i == 2)
                                divisor = divisor & 1 ? 3 : 1;
                        sensors[i].value = 1350000 / (sdata << (divisor & 7));
                }
        }
        if (ndivisor != odivisor)
                it_writereg(sc, ITD_FAN, ndivisor);
}

/*
 * pre:  last read occurred >= 1.5 seconds ago
 * post: sensors[] current data are the latest from the chip
 */
void
it_refresh_sensor_data(struct it_softc *sc)
{
        /* Refresh our stored data for every sensor */
        it_generic_stemp(sc, &sc->sensors[12]);
        it_generic_svolt(sc, &sc->sensors[3]);
        it_generic_fanrpm(sc, &sc->sensors[0]);
}

void
it_refresh(void *arg)
{
        struct it_softc *sc = (struct it_softc *)arg;

        it_refresh_sensor_data(sc);
}