/*      $OpenBSD: bcm2835_temp.c,v 1.2 2021/10/24 17:52:26 mpi Exp $    */
/*
 * Copyright (c) 2018 Mark Kettenis <kettenis@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/sensors.h>

#include <machine/bus.h>
#include <machine/fdt.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/fdt.h>

/* Registers */
#define TS_TSENSCTL             0x0000
#define TS_TSENSSTAT            0x0004
#define  TS_TSENSSTAT_VALID     (1 << 10)
#define  TS_TSENSSTAT_DATA(x)   ((x) & 0x3ff)

#define HREAD4(sc, reg)                                                 \
        (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
#define HWRITE4(sc, reg, val)                                           \
        bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))

struct bcmtemp_softc {
        struct device           sc_dev;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;

        int32_t                 sc_slope;
        int32_t                 sc_offset;

        struct ksensor          sc_sensor;
        struct ksensordev       sc_sensordev;
};

int     bcmtemp_match(struct device *, void *, void *);
void    bcmtemp_attach(struct device *, struct device *, void *);

const struct cfattach   bcmtemp_ca = {
        sizeof (struct bcmtemp_softc), bcmtemp_match, bcmtemp_attach
};

struct cfdriver bcmtemp_cd = {
        NULL, "bcmtemp", DV_DULL
};

void    bcmtemp_refresh_sensors(void *);

int
bcmtemp_match(struct device *parent, void *match, void *aux)
{
        struct fdt_attach_args *faa = aux;

        return (OF_is_compatible(faa->fa_node, "brcm,bcm2836-thermal") ||
            OF_is_compatible(faa->fa_node, "brcm,bcm2837-thermal"));
}

void
bcmtemp_attach(struct device *parent, struct device *self, void *aux)
{
        struct bcmtemp_softc *sc = (struct bcmtemp_softc *)self;
        struct fdt_attach_args *faa = aux;

        if (faa->fa_nreg < 1) {
                printf(": no registers\n");
                return;
        }

        sc->sc_iot = faa->fa_iot;
        if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
            faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
                printf(": can't map registers\n");
                return;
        }

        printf("\n");

        /* XXX fetch these from /thermal-zones. */
        sc->sc_slope = -538;
        if (OF_is_compatible(faa->fa_node, "brcm,bcm2836-thermal"))
                sc->sc_offset = 407000;
        else
                sc->sc_offset = 412000;

        /* Register sensors. */
        strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
            sizeof(sc->sc_sensordev.xname));
        sc->sc_sensor.type = SENSOR_TEMP;
        sc->sc_sensor.flags = SENSOR_FINVALID;
        sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
        sensordev_install(&sc->sc_sensordev);
        sensor_task_register(sc, bcmtemp_refresh_sensors, 5);
}

void
bcmtemp_refresh_sensors(void *arg)
{
        struct bcmtemp_softc *sc = arg;
        int32_t code, temp;

        code = HREAD4(sc, TS_TSENSSTAT);
        temp = sc->sc_offset + TS_TSENSSTAT_DATA(code) * sc->sc_slope;
        sc->sc_sensor.value = 273150000 + 1000 * temp;
        if (code & TS_TSENSSTAT_VALID)
                sc->sc_sensor.flags &= ~SENSOR_FINVALID;
        else
                sc->sc_sensor.flags |= SENSOR_FINVALID;
}