/*      $OpenBSD: ds1631.c,v 1.13 2022/04/06 18:59:28 naddy Exp $       */

/*
 * Copyright (c) 2005 Theo de Raadt
 *
 * 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 <dev/i2c/i2cvar.h>

/* Maxim ds 1631 registers */
#define DS1631_START            0x51
#define DS1624_START            0xee
#define DS1631_TEMP             0xaa
#define DS1631_CONTROL          0xac
#define  DS1631_CONTROL_DONE    0x80
#define  DS1631_CONTROL_1SHOT   0x01

/* Sensors */
#define MAXDS_TEMP              0
#define MAXDS_NUM_SENSORS       1

struct maxds_softc {
        struct device   sc_dev;
        i2c_tag_t       sc_tag;
        i2c_addr_t      sc_addr;

        struct ksensor  sc_sensor[MAXDS_NUM_SENSORS];
        struct ksensordev sc_sensordev;
};

int     maxds_match(struct device *, void *, void *);
void    maxds_attach(struct device *, struct device *, void *);
void    maxds_refresh(void *);

const struct cfattach maxds_ca = {
        sizeof(struct maxds_softc), maxds_match, maxds_attach
};

struct cfdriver maxds_cd = {
        NULL, "maxds", DV_DULL
};

int
maxds_match(struct device *parent, void *match, void *aux)
{
        struct i2c_attach_args *ia = aux;

        if (strcmp(ia->ia_name, "ds1631") == 0 ||
            strcmp(ia->ia_name, "ds1624") == 0 ||
            strcmp(ia->ia_name, "ds1721") == 0)
                return (1);
        return (0);
}

void
maxds_attach(struct device *parent, struct device *self, void *aux)
{
        struct maxds_softc *sc = (struct maxds_softc *)self;
        struct i2c_attach_args *ia = aux;
        u_int8_t cmd, data;
        int i;

        printf(": %s", ia->ia_name);

        sc->sc_tag = ia->ia_tag;
        sc->sc_addr = ia->ia_addr;

        iic_acquire_bus(sc->sc_tag, 0);

        cmd = DS1631_CONTROL;
        if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0) == 0) {
                if (data & DS1631_CONTROL_1SHOT) {
                        /*
                         * 1-Shot mode would require us to write every refresh
                         * which is stupid.  Put us into continuous mode.
                         */
                        data &= ~DS1631_CONTROL_1SHOT;

                        (void) iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
                            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0);
                        //delay(10 * 1000);
                        printf(", continuous");
                        goto dostart;
                }
                if (data & DS1631_CONTROL_DONE) {
dostart:
                        cmd = DS1631_START;
                        if (strcmp(ia->ia_name, "ds1624") == 0)
                                cmd = DS1624_START;
                        (void) iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
                            sc->sc_addr, &cmd, sizeof cmd, NULL, 0, 0);
                        printf(", starting");
                }
        } else {
                iic_release_bus(sc->sc_tag, 0);
                printf(", fails to respond\n");
                return;
        }

        iic_release_bus(sc->sc_tag, 0);

        /* Initialize sensor data. */
        strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
            sizeof(sc->sc_sensordev.xname));

        sc->sc_sensor[MAXDS_TEMP].type = SENSOR_TEMP;
        strlcpy(sc->sc_sensor[MAXDS_TEMP].desc, "Internal",
            sizeof(sc->sc_sensor[MAXDS_TEMP].desc));

        if (sensor_task_register(sc, maxds_refresh, 5) == NULL) {
                printf(", unable to register update task\n");
                return;
        }

        for (i = 0; i < MAXDS_NUM_SENSORS; i++)
                sensor_attach(&sc->sc_sensordev, &sc->sc_sensor[i]);
        sensordev_install(&sc->sc_sensordev);

        printf("\n");
}

void
maxds_refresh(void *arg)
{
        struct maxds_softc *sc = arg;
        u_int8_t cmd;
        u_int16_t data;

        iic_acquire_bus(sc->sc_tag, 0);

        cmd = DS1631_TEMP;
        if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0) == 0) {
                sc->sc_sensor[MAXDS_TEMP].value = 273150000 +
                    (int)(betoh16(data)) / 8 * 31250;
                sc->sc_sensor[MAXDS_TEMP].flags &= ~SENSOR_FINVALID;
        } else
                sc->sc_sensor[MAXDS_TEMP].flags |= SENSOR_FINVALID;

        iic_release_bus(sc->sc_tag, 0);
}