1/* $NetBSD: tmp121.c,v 1.4 2008/04/04 10:13:59 xtraeme 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 2008/04/04 10:13:59 xtraeme 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
56struct tmp121temp_softc {
57	struct spi_handle *sc_sh;
58
59	struct sysmon_envsys *sc_sme;
60	envsys_data_t sc_sensor;
61};
62
63static int	tmp121temp_match(device_t, cfdata_t, void *);
64static void	tmp121temp_attach(device_t, device_t, void *);
65
66static void	tmp121temp_refresh(struct sysmon_envsys *, envsys_data_t *);
67
68CFATTACH_DECL_NEW(tmp121temp, sizeof(struct tmp121temp_softc),
69    tmp121temp_match, tmp121temp_attach, NULL, NULL);
70
71static int
72tmp121temp_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
83static void
84tmp121temp_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
114static void
115tmp121temp_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