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tmp121.c revision 1.4.36.1 
      1 /* $NetBSD: tmp121.c,v 1.4.36.1 2011/06/23 14:20:08 cherry Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2006 Urbana-Champaign Independent Media Center.
      5  * Copyright (c) 2006 Garrett D'Amore.
      6  * All rights reserved.
      7  *
      8  * Portions of this code were written by Garrett D'Amore for the
      9  * Champaign-Urbana Community Wireless Network Project.
     10  *
     11  * Redistribution and use in source and binary forms, with or
     12  * without modification, are permitted provided that the following
     13  * conditions are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above
     17  *    copyright notice, this list of conditions and the following
     18  *    disclaimer in the documentation and/or other materials provided
     19  *    with the distribution.
     20  * 3. All advertising materials mentioning features or use of this
     21  *    software must display the following acknowledgements:
     22  *      This product includes software developed by the Urbana-Champaign
     23  *      Independent Media Center.
     24  *	This product includes software developed by Garrett D'Amore.
     25  * 4. Urbana-Champaign Independent Media Center's name and Garrett
     26  *    D'Amore's name may not be used to endorse or promote products
     27  *    derived from this software without specific prior written permission.
     28  *
     29  * THIS SOFTWARE IS PROVIDED BY THE URBANA-CHAMPAIGN INDEPENDENT
     30  * MEDIA CENTER AND GARRETT D'AMORE ``AS IS'' AND ANY EXPRESS OR
     31  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     32  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE URBANA-CHAMPAIGN INDEPENDENT
     34  * MEDIA CENTER OR GARRETT D'AMORE BE LIABLE FOR ANY DIRECT, INDIRECT,
     35  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     36  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     37  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
     38  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     40  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     41  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     42  */
     43 
     44 #include <sys/cdefs.h>
     45 __KERNEL_RCSID(0, "$NetBSD: tmp121.c,v 1.4.36.1 2011/06/23 14:20:08 cherry Exp $");
     46 
     47 #include <sys/param.h>
     48 #include <sys/systm.h>
     49 #include <sys/device.h>
     50 #include <sys/kernel.h>
     51 
     52 #include <dev/sysmon/sysmonvar.h>
     53 
     54 #include <dev/spi/spivar.h>
     55 
     56 struct tmp121temp_softc {
     57 	struct spi_handle *sc_sh;
     58 
     59 	struct sysmon_envsys *sc_sme;
     60 	envsys_data_t sc_sensor;
     61 };
     62 
     63 static int	tmp121temp_match(device_t, cfdata_t, void *);
     64 static void	tmp121temp_attach(device_t, device_t, void *);
     65 
     66 static void	tmp121temp_refresh(struct sysmon_envsys *, envsys_data_t *);
     67 
     68 CFATTACH_DECL_NEW(tmp121temp, sizeof(struct tmp121temp_softc),
     69     tmp121temp_match, tmp121temp_attach, NULL, NULL);
     70 
     71 static int
     72 tmp121temp_match(device_t parent, cfdata_t cf, void *aux)
     73 {
     74 	struct spi_attach_args *sa = aux;
     75 
     76 	/* configure for 10MHz */
     77 	if (spi_configure(sa->sa_handle, SPI_MODE_0, 1000000))
     78 		return 0;
     79 
     80 	return 1;
     81 }
     82 
     83 static void
     84 tmp121temp_attach(device_t parent, device_t self, void *aux)
     85 {
     86 	struct tmp121temp_softc *sc = device_private(self);
     87 	struct spi_attach_args *sa = aux;
     88 
     89 	aprint_naive(": Temperature Sensor\n");
     90 	aprint_normal(": TI TMP121 Temperature Sensor\n");
     91 
     92 	sc->sc_sh = sa->sa_handle;
     93 
     94 	sc->sc_sme = sysmon_envsys_create();
     95 	sc->sc_sensor.units = ENVSYS_STEMP;
     96 	sc->sc_sensor.state = ENVSYS_SINVALID;
     97 	strlcpy(sc->sc_sensor.desc, device_xname(self),
     98 	    sizeof(sc->sc_sensor.desc));
     99 	if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
    100 		sysmon_envsys_destroy(sc->sc_sme);
    101 		return;
    102 	}
    103 
    104 	sc->sc_sme->sme_name = device_xname(self);
    105 	sc->sc_sme->sme_refresh = tmp121temp_refresh;
    106 	sc->sc_sme->sme_cookie = sc;
    107 
    108 	if (sysmon_envsys_register(sc->sc_sme)) {
    109 		aprint_error_dev(self, "unable to register with sysmon\n");
    110 		sysmon_envsys_destroy(sc->sc_sme);
    111 	}
    112 }
    113 
    114 static void
    115 tmp121temp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
    116 {
    117 	struct tmp121temp_softc *sc = sme->sme_cookie;
    118 	uint16_t		reg;
    119 	int16_t			sreg;
    120 	int			val;
    121 
    122 	if (spi_recv(sc->sc_sh, 2, (uint8_t *)&reg) != 0) {
    123 		edata->state = ENVSYS_SINVALID;
    124 		return;
    125 	}
    126 
    127 	sreg = (int16_t)be16toh(reg);
    128 
    129 	/*
    130 	 * convert to uK:
    131 	 *
    132 	 * TMP121 bits:
    133 	 * D15		: sign bit
    134 	 * D14-D3	: data (D14 is MSB)
    135 	 * D2-D0	: zero
    136 	 *
    137 	 * The data is represented in units of 0.0625 deg C.
    138 	 */
    139 	sreg >>= 3;
    140 	val = sreg * 62500 + 273150000;
    141 
    142 	edata->value_cur = val;
    143 	edata->state = ENVSYS_SVALID;
    144 }
    145