/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2021 Alstom Group.
 * Copyright (c) 2021 Semihalf.
 *
 * 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/cdefs.h>
#include "opt_platform.h"

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/ctype.h>
#include <sys/kernel.h>
#include <sys/libkern.h>
#include <sys/sysctl.h>

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

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

#define BIT(x)                                  (1UL << (x))

/* register map */
#define TMP461_LOCAL_TEMP_REG_MSB               0x0
#define TMP461_LOCAL_TEMP_REG_LSB               0x15
#define TMP461_GLOBAL_TEMP_REG_MSB              0x1
#define TMP461_GLOBAL_TEMP_REG_LSB              0x10
#define TMP461_STATUS_REG                       0x2
#define TMP461_STATUS_REG_TEMP_LOCAL            BIT(2)
#define TMP461_CONFIG_REG_R                     0x3
#define TMP461_CONFIG_REG_W                     0x9
#define TMP461_CONFIG_REG_TEMP_RANGE_BIT        BIT(2)
#define TMP461_CONFIG_REG_STANDBY_BIT           BIT(6)
#define TMP461_CONVERSION_RATE_REG              0x4
#define TMP461_ONESHOT_REG                      0xF
#define TMP461_EXTENDED_TEMP_MODIFIER           64

/* 28.4 fixed point representation of 273.15f */
#define TMP461_C_TO_K_FIX                       4370

#define TMP461_SENSOR_MAX_CONV_TIME             16000000
#define TMP461_LOCAL_MEASURE                    0
#define TMP461_REMOTE_MEASURE                   1

/* flags */
#define TMP461_LOCAL_TEMP_DOUBLE_REG            BIT(0)
#define TMP461_REMOTE_TEMP_DOUBLE_REG           BIT(1)

static int tmp461_probe(device_t dev);
static int tmp461_attach(device_t dev);
static int tmp461_read_1(device_t dev, uint8_t reg, uint8_t *data);
static int tmp461_write_1(device_t dev, uint8_t reg, uint8_t data);
static int tmp461_read_temperature(device_t dev, int32_t *temperature, bool mode);
static int tmp461_detach(device_t dev);
static int tmp461_sensor_sysctl(SYSCTL_HANDLER_ARGS);

static device_method_t tmp461_methods[] = {
        DEVMETHOD(device_probe,         tmp461_probe),
        DEVMETHOD(device_attach,        tmp461_attach),
        DEVMETHOD(device_detach,        tmp461_detach),

        DEVMETHOD_END
};

struct tmp461_softc {
        struct mtx              mtx;
        uint8_t                 conf;
};

static driver_t tmp461_driver = {
        "tmp461_dev",
        tmp461_methods,
        sizeof(struct tmp461_softc)
};

struct tmp461_data {
        const char      *compat;
        const char      *desc;
        uint8_t         flags;
};

static struct tmp461_data sensor_list[] = {
        {"adt7461", "ADT7461 Thernal Sensor Information",
            TMP461_REMOTE_TEMP_DOUBLE_REG},
        {"tmp461", "TMP461 Thernal Sensor Information",
            TMP461_LOCAL_TEMP_DOUBLE_REG | TMP461_REMOTE_TEMP_DOUBLE_REG}
};

static struct ofw_compat_data tmp461_compat_data[] = {
        {"adi,adt7461",         (uintptr_t)&sensor_list[0]},
        {"ti,tmp461",           (uintptr_t)&sensor_list[1]},
        {NULL,                  0}
};

DRIVER_MODULE(tmp461, iicbus, tmp461_driver, 0, 0);
IICBUS_FDT_PNP_INFO(tmp461_compat_data);

static int
tmp461_attach(device_t dev)
{
        struct sysctl_oid *sensor_root_oid;
        struct tmp461_data *compat_data;
        struct sysctl_ctx_list *ctx;
        struct tmp461_softc *sc;
        uint8_t data;

        sc = device_get_softc(dev);
        compat_data = (struct tmp461_data *)
            ofw_bus_search_compatible(dev, tmp461_compat_data)->ocd_data;
        sc->conf = compat_data->flags;
        ctx = device_get_sysctl_ctx(dev);

        mtx_init(&sc->mtx, "tmp461 temperature", "temperature", MTX_DEF);

        sensor_root_oid = SYSCTL_ADD_NODE(ctx, SYSCTL_STATIC_CHILDREN(_hw),
            OID_AUTO, "temperature", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
            "Thermal Sensor Information");
        if (sensor_root_oid == NULL)
                return (ENXIO);

        SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(sensor_root_oid), OID_AUTO,
            "local_sensor", CTLTYPE_INT | CTLFLAG_RD, dev,
            TMP461_LOCAL_MEASURE, tmp461_sensor_sysctl,
            "IK1", compat_data->desc);

        /* get status register */
        if (tmp461_read_1(dev, TMP461_STATUS_REG, &data) != 0)
                return (ENXIO);

        if (!(data & TMP461_STATUS_REG_TEMP_LOCAL))
                SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(sensor_root_oid), OID_AUTO,
                    "remote_sensor", CTLTYPE_INT | CTLFLAG_RD, dev,
                    TMP461_REMOTE_MEASURE, tmp461_sensor_sysctl,
                    "IK1", compat_data->desc);

        /* set standby mode */
        if (tmp461_read_1(dev, TMP461_CONFIG_REG_R, &data) != 0)
                return (ENXIO);

        data |= TMP461_CONFIG_REG_STANDBY_BIT;
        if (tmp461_write_1(dev, TMP461_CONFIG_REG_W, data) != 0)
                return (ENXIO);

        return (0);
}

static int
tmp461_probe(device_t dev)
{
        struct tmp461_data *compat_data;

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        compat_data = (struct tmp461_data *)
            ofw_bus_search_compatible(dev, tmp461_compat_data)->ocd_data;
        if (!compat_data)
                return (ENXIO);

        device_set_desc(dev, compat_data->compat);

        return (BUS_PROBE_GENERIC);
}

static int
tmp461_detach(device_t dev)
{
        struct tmp461_softc *sc;

        sc = device_get_softc(dev);
        mtx_destroy(&sc->mtx);

        return (0);
}

static int
tmp461_read_1(device_t dev, uint8_t reg, uint8_t *data)
{
        int error;

        error = iicdev_readfrom(dev, reg, (void *) data, 1, IIC_DONTWAIT);
        if (error != 0)
                device_printf(dev, "Failed to read from device\n");

        return (error);
}

static int
tmp461_write_1(device_t dev, uint8_t reg, uint8_t data)
{
        int error;

        error = iicdev_writeto(dev, reg, (void *) &data, 1, IIC_DONTWAIT);
        if (error != 0)
                device_printf(dev, "Failed to write to device\n");

        return (error);
}

static int
tmp461_read_temperature(device_t dev, int32_t *temperature, bool remote_measure)
{
        uint8_t data, offset, reg;
        struct tmp461_softc *sc;
        int error;

        sc = device_get_softc(dev);

        mtx_lock(&sc->mtx);

        error = tmp461_read_1(dev, TMP461_CONVERSION_RATE_REG, &data);
        if (error != 0)
                goto fail;

        /* trigger sample*/
        error = tmp461_write_1(dev, TMP461_ONESHOT_REG, 0xFF);
        if (error != 0)
                goto fail;

        /* wait for conversion time */
        DELAY(TMP461_SENSOR_MAX_CONV_TIME/(1UL<<data));

        /* read config register offset */
        error = tmp461_read_1(dev, TMP461_CONFIG_REG_R, &data);
        if (error != 0)
                goto fail;

        offset = (data & TMP461_CONFIG_REG_TEMP_RANGE_BIT ?
            TMP461_EXTENDED_TEMP_MODIFIER : 0);

        reg = remote_measure ?
            TMP461_GLOBAL_TEMP_REG_MSB : TMP461_LOCAL_TEMP_REG_MSB;

        /* read temeperature value*/
        error = tmp461_read_1(dev, reg, &data);
        if (error != 0)
                goto fail;

        data -= offset;
        *temperature = signed_extend32(data, 0, 8) << 4;

        if (remote_measure) {
                if (sc->conf & TMP461_REMOTE_TEMP_DOUBLE_REG) {
                        error = tmp461_read_1(dev,
                            TMP461_GLOBAL_TEMP_REG_LSB, &data);
                        if (error != 0)
                                goto fail;

                        *temperature |= data >> 4;
                }
        } else {
                if (sc->conf & TMP461_LOCAL_TEMP_DOUBLE_REG) {
                        error = tmp461_read_1(dev,
                            TMP461_LOCAL_TEMP_REG_LSB, &data);
                        if (error != 0)
                                goto fail;

                        *temperature |= data >> 4;
                }
        }
        *temperature = (((*temperature + TMP461_C_TO_K_FIX) * 10) >> 4);

fail:
        mtx_unlock(&sc->mtx);
        return (error);
}

static int
tmp461_sensor_sysctl(SYSCTL_HANDLER_ARGS)
{
        int32_t temperature;
        device_t dev;
        int error;
        bool mode;

        dev = arg1;
        mode = arg2;

        error = tmp461_read_temperature(dev, &temperature, mode);
        if (error != 0)
                return (error);

        return (sysctl_handle_int(oidp, &temperature, 0, req));
}