xref: /netbsd-src/sys/dev/i2c/lm75.c (revision d20841bb642898112fe68f0ad3f7b26dddf56f07)
1 /*	$NetBSD: lm75.c,v 1.1 2003/09/30 00:35:31 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/device.h>
41 #include <sys/kernel.h>
42 
43 #include <dev/sysmon/sysmonvar.h>
44 
45 #include <dev/i2c/i2cvar.h>
46 #include <dev/i2c/lm75reg.h>
47 
48 struct lmtemp_softc {
49 	struct device sc_dev;
50 	i2c_tag_t sc_tag;
51 	int sc_address;
52 
53 	struct envsys_tre_data sc_sensor[1];
54 	struct envsys_basic_info sc_info[1];
55 
56 	struct sysmon_envsys sc_sysmon;
57 };
58 
59 static int  lmtemp_match(struct device *, struct cfdata *, void *);
60 static void lmtemp_attach(struct device *, struct device *, void *);
61 
62 CFATTACH_DECL(lmtemp, sizeof(struct lmtemp_softc),
63 	lmtemp_match, lmtemp_attach, NULL, NULL);
64 
65 static int	lmtemp_gtredata(struct sysmon_envsys *,
66 				struct envsys_tre_data *);
67 static int	lmtemp_streinfo(struct sysmon_envsys *,
68 				struct envsys_basic_info *);
69 
70 static const struct envsys_range lmtemp_ranges[] = {
71 	{ 0, 1,		ENVSYS_STEMP },
72 	{ 1, 0,		-1 },
73 };
74 
75 static int lmtemp_config_write(struct lmtemp_softc *, uint8_t);
76 
77 static int
78 lmtemp_match(struct device *parent, struct cfdata *cf, void *aux)
79 {
80 	struct i2c_attach_args *ia = aux;
81 
82 	if ((ia->ia_addr & LM75_ADDRMASK) == LM75_ADDR)
83 		return (1);
84 
85 	return (0);
86 }
87 
88 static void
89 lmtemp_attach(struct device *parent, struct device *self, void *aux)
90 {
91 	struct lmtemp_softc *sc = (struct lmtemp_softc *)self;
92 	struct i2c_attach_args *ia = aux;
93 	int ptype;
94 
95 	sc->sc_tag = ia->ia_tag;
96 	sc->sc_address = ia->ia_addr;
97 
98 	aprint_naive(": Temperature Sensor\n");
99 	aprint_normal(": LM75 Temperature Sensor\n");
100 
101 	/* Set the configuration of the LM75 to defaults. */
102 	iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
103 	if (lmtemp_config_write(sc, 0) != 0) {
104 		aprint_error("%s: unable to write config register\n",
105 		    sc->sc_dev.dv_xname);
106 		iic_release_bus(sc->sc_tag, I2C_F_POLL);
107 		return;
108 	}
109 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
110 
111 	/* Initialize sensor data. */
112 	sc->sc_sensor[0].sensor = sc->sc_info[0].sensor = 0;
113 	sc->sc_sensor[0].validflags = ENVSYS_FVALID;
114 	sc->sc_info[0].validflags = ENVSYS_FVALID;
115 	sc->sc_sensor[0].warnflags = ENVSYS_WARN_OK;
116 
117 	sc->sc_sensor[0].units = sc->sc_info[0].units = ENVSYS_STEMP;
118 	if (prop_get(dev_propdb, &sc->sc_dev, "description",
119 		     sc->sc_info[0].desc, sizeof(sc->sc_info[0].desc),
120 		     &ptype) < 1 ||
121 	    ptype != PROP_STRING)
122 		strcpy(sc->sc_info[0].desc, sc->sc_dev.dv_xname);
123 
124 	/* Hook info system monitor. */
125 	sc->sc_sysmon.sme_ranges = lmtemp_ranges;
126 	sc->sc_sysmon.sme_sensor_info = sc->sc_info;
127 	sc->sc_sysmon.sme_sensor_data = sc->sc_sensor;
128 	sc->sc_sysmon.sme_cookie = sc;
129 
130 	sc->sc_sysmon.sme_gtredata = lmtemp_gtredata;
131 	sc->sc_sysmon.sme_streinfo = lmtemp_streinfo;
132 
133 	sc->sc_sysmon.sme_nsensors = 1;
134 	sc->sc_sysmon.sme_envsys_version = 1000;
135 
136 	if (sysmon_envsys_register(&sc->sc_sysmon))
137 		aprint_error("%s: unable to register with sysmon\n",
138 		    sc->sc_dev.dv_xname);
139 }
140 
141 static int
142 lmtemp_config_write(struct lmtemp_softc *sc, uint8_t val)
143 {
144 	uint8_t cmdbuf[2];
145 
146 	cmdbuf[0] = LM75_REG_CONFIG;
147 	cmdbuf[1] = val;
148 
149 	return (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
150 	    sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, I2C_F_POLL));
151 }
152 
153 static int
154 lmtemp_temp_read(struct lmtemp_softc *sc, uint8_t which, uint32_t *valp)
155 {
156 	int error, neg, temp;
157 	uint32_t val;
158 	uint8_t cmdbuf[1];
159 	uint8_t buf[LM75_TEMP_LEN];
160 
161 	cmdbuf[0] = which;
162 
163 	error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
164 	    sc->sc_address, cmdbuf, 1, buf, LM75_TEMP_LEN, 0);
165 	if (error)
166 		return (error);
167 
168 	if (buf[0] & 1) {
169 		/* Below 0C */
170 		temp = ~buf[1] + 1;
171 		neg = 1;
172 	} else {
173 		temp = buf[1];
174 		neg = 0;
175 	}
176 
177 	/* Temp is given in 1/2 deg. C, we convert to uK. */
178 	val = ((neg ? -temp : temp) / 2) * 1000000 + 273150000;
179 	if (temp & 1) {
180 		if (neg)
181 			val -= 500000;
182 		else
183 			val += 500000;
184 	}
185 	*valp = val;
186 
187 	return (0);
188 }
189 
190 static void
191 lmtemp_refresh_sensor_data(struct lmtemp_softc *sc)
192 {
193 	uint32_t val;
194 	int error;
195 
196 	error = lmtemp_temp_read(sc, LM75_REG_TEMP, &val);
197 	if (error) {
198 #if 0
199 		printf("%s: unable to read temperature, error = %d\n",
200 		    sc->sc_dev.dv_xname, error);
201 #endif
202 		sc->sc_sensor[0].validflags &= ~ENVSYS_FCURVALID;
203 		return;
204 	}
205 
206 	sc->sc_sensor[0].cur.data_us = val;
207 	sc->sc_sensor[0].validflags |= ENVSYS_FCURVALID;
208 }
209 
210 static int
211 lmtemp_gtredata(struct sysmon_envsys *sme, struct envsys_tre_data *tred)
212 {
213 	struct lmtemp_softc *sc = sme->sme_cookie;
214 
215 	iic_acquire_bus(sc->sc_tag, 0);	/* also locks our instance */
216 
217 	lmtemp_refresh_sensor_data(sc);
218 	*tred = sc->sc_sensor[tred->sensor];
219 
220 	iic_release_bus(sc->sc_tag, 0);	/* also unlocks our instance */
221 
222 	return (0);
223 }
224 
225 static int
226 lmtemp_streinfo(struct sysmon_envsys *sme, struct envsys_basic_info *binfo)
227 {
228 	struct lmtemp_softc *sc = sme->sme_cookie;
229 
230 	iic_acquire_bus(sc->sc_tag, 0);	/* also locks our instance */
231 
232 	memcpy(sc->sc_info[binfo->sensor].desc, binfo->desc,
233 	    sizeof(sc->sc_info[binfo->sensor].desc));
234 	sc->sc_info[binfo->sensor].desc[
235 	    sizeof(sc->sc_info[binfo->sensor].desc) - 1] = '\0';
236 
237 	iic_release_bus(sc->sc_tag, 0);	/* also unlocks our instance */
238 
239 	binfo->validflags = ENVSYS_FVALID;
240 
241 	return (0);
242 }
243