/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Andreas Tobler
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/callout.h>
#include <sys/conf.h>
#include <sys/cpu.h>
#include <sys/ctype.h>
#include <sys/kernel.h>
#include <sys/reboot.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <sys/limits.h>

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

#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <powerpc/powermac/powermac_thermal.h>

/* Drivebay sensor: LM75/DS1775. */
#define DS1775_TEMP         0x0

/* Regular bus attachment functions */
static int  ds1775_probe(device_t);
static int  ds1775_attach(device_t);

struct ds1775_softc {
        struct pmac_therm       sc_sensor;
        device_t                sc_dev;
        struct intr_config_hook enum_hook;
        uint32_t                sc_addr;
};

/* Utility functions */
static int  ds1775_sensor_read(struct ds1775_softc *sc);
static int  ds1775_sensor_sysctl(SYSCTL_HANDLER_ARGS);
static void ds1775_start(void *xdev);
static int  ds1775_read_2(device_t dev, uint32_t addr, uint8_t reg,
                          uint16_t *data);

static device_method_t  ds1775_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ds1775_probe),
        DEVMETHOD(device_attach,        ds1775_attach),
        DEVMETHOD_END
};

static driver_t ds1775_driver = {
        "ds1775",
        ds1775_methods,
        sizeof(struct ds1775_softc)
};

DRIVER_MODULE(ds1775, iicbus, ds1775_driver, 0, 0);

static int
ds1775_read_2(device_t dev, uint32_t addr, uint8_t reg, uint16_t *data)
{
        uint8_t buf[4];
        int err, try = 0;

        struct iic_msg msg[2] = {
            { addr, IIC_M_WR | IIC_M_NOSTOP, 1, &reg },
            { addr, IIC_M_RD, 2, buf },
        };

        for (;;)
        {
                err = iicbus_transfer(dev, msg, nitems(msg));
                if (err != 0)
                        goto retry;

                *data = *((uint16_t*)buf);
                return (0);
        retry:
                if (++try > 5) {
                        device_printf(dev, "iicbus read failed\n");
                        return (-1);
                }
                pause("ds1775_read_2", hz);
        }
}

static int
ds1775_probe(device_t dev)
{
        const char  *name, *compatible;
        struct ds1775_softc *sc;

        name = ofw_bus_get_name(dev);
        compatible = ofw_bus_get_compat(dev);

        if (!name)
                return (ENXIO);

        if (strcmp(name, "temp-monitor") != 0 ||
            (strcmp(compatible, "ds1775") != 0 &&
             strcmp(compatible, "lm75") != 0))
                return (ENXIO);

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

        device_set_desc(dev, "Temp-Monitor DS1775");

        return (0);
}

static int
ds1775_attach(device_t dev)
{
        struct ds1775_softc *sc;

        sc = device_get_softc(dev);

        sc->enum_hook.ich_func = ds1775_start;
        sc->enum_hook.ich_arg = dev;

        /* We have to wait until interrupts are enabled. I2C read and write
         * only works if the interrupts are available.
         * The unin/i2c is controlled by the htpic on unin. But this is not
         * the master. The openpic on mac-io is controlling the htpic.
         * This one gets attached after the mac-io probing and then the
         * interrupts will be available.
         */

        if (config_intrhook_establish(&sc->enum_hook) != 0)
                return (ENOMEM);

        return (0);
}

static void
ds1775_start(void *xdev)
{
        phandle_t child;
        struct ds1775_softc *sc;
        struct sysctl_oid *oid, *sensroot_oid;
        struct sysctl_ctx_list *ctx;
        ssize_t plen;
        int i;
        char sysctl_name[40], sysctl_desc[40];

        device_t dev = (device_t)xdev;

        sc = device_get_softc(dev);

        child = ofw_bus_get_node(dev);

        ctx = device_get_sysctl_ctx(dev);
        sensroot_oid = SYSCTL_ADD_NODE(ctx,
            SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "sensor",
            CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "DS1775 Sensor Information");

        if (OF_getprop(child, "hwsensor-zone", &sc->sc_sensor.zone,
                       sizeof(int)) < 0)
                sc->sc_sensor.zone = 0;

        plen = OF_getprop(child, "hwsensor-location", sc->sc_sensor.name,
                          sizeof(sc->sc_sensor.name));

        if (plen == -1) {
                strcpy(sysctl_name, "sensor");
        } else {
                for (i = 0; i < strlen(sc->sc_sensor.name); i++) {
                        sysctl_name[i] = tolower(sc->sc_sensor.name[i]);
                        if (isspace(sysctl_name[i]))
                                sysctl_name[i] = '_';
                }
                sysctl_name[i] = 0;
        }

        /* Make up target temperatures. These are low, for the drive bay. */
        if (sc->sc_sensor.zone == 0) {
                sc->sc_sensor.target_temp = 500 + ZERO_C_TO_K;
                sc->sc_sensor.max_temp = 600 + ZERO_C_TO_K;
        }
        else {
                sc->sc_sensor.target_temp = 300 + ZERO_C_TO_K;
                sc->sc_sensor.max_temp = 600 + ZERO_C_TO_K;
        }

        sc->sc_sensor.read =
            (int (*)(struct pmac_therm *sc))(ds1775_sensor_read);
        pmac_thermal_sensor_register(&sc->sc_sensor);

        sprintf(sysctl_desc,"%s %s", sc->sc_sensor.name, "(C)");
        oid = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(sensroot_oid),
            OID_AUTO, sysctl_name, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
            "Sensor Information");
        SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "temp",
                        CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev,
                        0, ds1775_sensor_sysctl, "IK", sysctl_desc);

        config_intrhook_disestablish(&sc->enum_hook);
}

static int
ds1775_sensor_read(struct ds1775_softc *sc)
{
        uint16_t buf[2];
        uint16_t read;
        int err;

        err = ds1775_read_2(sc->sc_dev, sc->sc_addr, DS1775_TEMP, buf);
        if (err < 0)
                return (-1);

        read = *((int16_t *)buf);

        /* The default mode of the ADC is 9 bit, the resolution is 0.5 C per
           bit. The temperature is in tenth kelvin.
        */
        return (((int16_t)(read) >> 7) * 5 + ZERO_C_TO_K);
}

static int
ds1775_sensor_sysctl(SYSCTL_HANDLER_ARGS)
{
        device_t dev;
        struct ds1775_softc *sc;
        int error;
        int temp;

        dev = arg1;
        sc = device_get_softc(dev);

        temp = ds1775_sensor_read(sc);
        if (temp < 0)
                return (EIO);

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

        return (error);
}