/* $NetBSD: tmp121.c,v 1.7 2022/01/19 05:21:44 thorpej Exp $ */

/*-
* Copyright (c) 2006 Urbana-Champaign Independent Media Center.
* Copyright (c) 2006 Garrett D'Amore.
* All rights reserved.
*
* Portions of this code were written by Garrett D'Amore for the
* Champaign-Urbana Community Wireless Network Project.
*
* 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.
* 3. All advertising materials mentioning features or use of this
*    software must display the following acknowledgements:
*      This product includes software developed by the Urbana-Champaign
*      Independent Media Center.
*      This product includes software developed by Garrett D'Amore.
* 4. Urbana-Champaign Independent Media Center's name and Garrett
*    D'Amore's name may not be used to endorse or promote products
*    derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE URBANA-CHAMPAIGN INDEPENDENT
* MEDIA CENTER AND GARRETT D'AMORE ``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 URBANA-CHAMPAIGN INDEPENDENT
* MEDIA CENTER OR GARRETT D'AMORE 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>
__KERNEL_RCSID(0, "$NetBSD: tmp121.c,v 1.7 2022/01/19 05:21:44 thorpej Exp $");

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

#include <dev/sysmon/sysmonvar.h>

#include <dev/spi/spivar.h>

struct tmp121temp_softc {
       struct spi_handle *sc_sh;

       struct sysmon_envsys *sc_sme;
       envsys_data_t sc_sensor;
};

static int      tmp121temp_match(device_t, cfdata_t, void *);
static void     tmp121temp_attach(device_t, device_t, void *);

static void     tmp121temp_refresh(struct sysmon_envsys *, envsys_data_t *);

CFATTACH_DECL_NEW(tmp121temp, sizeof(struct tmp121temp_softc),
   tmp121temp_match, tmp121temp_attach, NULL, NULL);

static int
tmp121temp_match(device_t parent, cfdata_t cf, void *aux)
{
       return 1;
}

static void
tmp121temp_attach(device_t parent, device_t self, void *aux)
{
       struct tmp121temp_softc *sc = device_private(self);
       struct spi_attach_args *sa = aux;
       int error;

       aprint_naive(": Temperature Sensor\n");
       aprint_normal(": TI TMP121 Temperature Sensor\n");

       /* configure for 10MHz */
       error = spi_configure(self, sa->sa_handle, SPI_MODE_0, 1000000);
       if (error) {
               return;
       }

       sc->sc_sh = sa->sa_handle;

       sc->sc_sme = sysmon_envsys_create();
       sc->sc_sensor.units = ENVSYS_STEMP;
       sc->sc_sensor.state = ENVSYS_SINVALID;
       strlcpy(sc->sc_sensor.desc, device_xname(self),
           sizeof(sc->sc_sensor.desc));
       if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
               sysmon_envsys_destroy(sc->sc_sme);
               return;
       }

       sc->sc_sme->sme_name = device_xname(self);
       sc->sc_sme->sme_refresh = tmp121temp_refresh;
       sc->sc_sme->sme_cookie = sc;

       if (sysmon_envsys_register(sc->sc_sme)) {
               aprint_error_dev(self, "unable to register with sysmon\n");
               sysmon_envsys_destroy(sc->sc_sme);
       }
}

static void
tmp121temp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
       struct tmp121temp_softc *sc = sme->sme_cookie;
       uint16_t                reg;
       int16_t                 sreg;
       int                     val;

       if (spi_recv(sc->sc_sh, 2, (uint8_t *)&reg) != 0) {
               edata->state = ENVSYS_SINVALID;
               return;
       }

       sreg = (int16_t)be16toh(reg);

       /*
        * convert to uK:
        *
        * TMP121 bits:
        * D15          : sign bit
        * D14-D3       : data (D14 is MSB)
        * D2-D0        : zero
        *
        * The data is represented in units of 0.0625 deg C.
        */
       sreg >>= 3;
       val = sreg * 62500 + 273150000;

       edata->value_cur = val;
       edata->state = ENVSYS_SVALID;
}