1 /* $OpenBSD: lm75.c,v 1.15 2007/03/22 16:55:31 deraadt Exp $ */
2 /* $NetBSD: lm75.c,v 1.1 2003/09/30 00:35:31 thorpej Exp $ */
3 /*
4 * Copyright (c) 2006 Theo de Raadt <deraadt@openbsd.org>
5 * Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 /*
21 * National Semiconductor LM75/LM77 temperature sensor.
22 */
23
24 #include <sys/param.h>
25 #include <sys/systm.h>
26 #include <sys/device.h>
27 #include <sys/kernel.h>
28 #include <sys/sensors.h>
29
30 #include <dev/i2c/i2cvar.h>
31
32 #define LM_MODEL_LM75 1
33 #define LM_MODEL_LM77 2
34 #define LM_MODEL_DS1775 3
35 #define LM_MODEL_LM75A 4
36
37 #define LM_POLLTIME 3 /* 3s */
38
39 #define LM75_REG_TEMP 0x00
40 #define LM75_REG_CONFIG 0x01
41 #define LM75_CONFIG_SHUTDOWN 0x01
42 #define LM75_CONFIG_CMPINT 0x02
43 #define LM75_CONFIG_OSPOLARITY 0x04
44 #define LM75_CONFIG_FAULT_QUEUE_MASK 0x18
45 #define LM75_CONFIG_FAULT_QUEUE_1 (0 << 3)
46 #define LM75_CONFIG_FAULT_QUEUE_2 (1 << 3)
47 #define LM75_CONFIG_FAULT_QUEUE_4 (2 << 3)
48 #define LM75_CONFIG_FAULT_QUEUE_6 (3 << 3)
49 #define LM77_CONFIG_INTPOLARITY 0x08
50 #define LM77_CONFIG_FAULT_QUEUE_4 0x10
51 #define DS1755_CONFIG_RESOLUTION(i) (9 + (((i) >> 5) & 3))
52 #define LM75_REG_THYST_SET_POINT 0x02
53 #define LM75_REG_TOS_SET_POINT 0x03
54 #define LM77_REG_TLOW 0x04
55 #define LM77_REG_THIGH 0x05
56
57 struct lmtemp_softc {
58 struct device sc_dev;
59 i2c_tag_t sc_tag;
60 int sc_addr;
61 int sc_model;
62 int sc_bits;
63
64 struct ksensor sc_sensor;
65 struct ksensordev sc_sensordev;
66 };
67
68 int lmtemp_match(struct device *, void *, void *);
69 void lmtemp_attach(struct device *, struct device *, void *);
70
71 struct cfattach lmtemp_ca = {
72 sizeof(struct lmtemp_softc),
73 lmtemp_match,
74 lmtemp_attach
75 };
76
77 struct cfdriver lmtemp_cd = {
78 NULL, "lmtemp", DV_DULL
79 };
80
81 /*
82 * Temperature on the LM75 is represented by a 9-bit two's complement
83 * integer in steps of 0.5C. The following examples are taken from
84 * the LM75 data sheet:
85 *
86 * +125C 0 1111 1010 0x0fa
87 * +25C 0 0011 0010 0x032
88 * +0.5C 0 0000 0001 0x001
89 * 0C 0 0000 0000 0x000
90 * -0.5C 1 1111 1111 0x1ff
91 * -25C 1 1100 1110 0x1ce
92 * -55C 1 1001 0010 0x192
93 *
94 * Temperature on the LM75A is represented by an 11-bit two's complement
95 * integer in steps of 0.125C. The LM75A can be treated like an LM75 if
96 * the extra precision is not required. The following examples are
97 * taken from the LM75A data sheet:
98 *
99 * +127.000C 011 1111 1000 0x3f8
100 * +126.875C 011 1111 0111 0x3f7
101 * +126.125C 011 1111 0001 0x3f1
102 * +125.000C 011 1110 1000 0x3e8
103 * +25.000C 000 1100 1000 0x0c8
104 * +0.125C 000 0000 0001 0x001
105 * 0C 000 0000 0000 0x000
106 * -0.125C 111 1111 1111 0x7ff
107 * -25.000C 111 0011 1000 0x738
108 * -54.875C 110 0100 1001 0x649
109 * -55.000C 110 0100 1000 0x648
110 *
111 * Temperature on the LM77 is represented by a 10-bit two's complement
112 * integer in steps of 0.5C:
113 *
114 * +130C 01 0000 0100 0x104
115 * +125C 00 1111 1010 0x0fa
116 * +25C 00 0011 0010 0x032
117 * +0.5C 00 0000 0001 0x001
118 * 0C 00 0000 0000 0x000
119 * -0.5C 11 1111 1111 0x3ff
120 * -25C 11 1100 1110 0x3ce
121 * -55C 11 1001 0010 0x392
122 *
123 * LM75 temperature word:
124 *
125 * MSB Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 X X X X X X X
126 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
127 *
128 *
129 * LM75A temperature word:
130 *
131 * MSB Bit9 Bit8 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 X X X X X
132 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
133 *
134 *
135 * LM77 temperature word:
136 *
137 * Sign Sign Sign Sign MSB Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Status bits
138 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
139 */
140
141 int lmtemp_temp_read(struct lmtemp_softc *, uint8_t, int *);
142 void lmtemp_refresh_sensor_data(void *);
143
144 int
145 lmtemp_match(struct device *parent, void *match, void *aux)
146 {
147 struct i2c_attach_args *ia = aux;
148
149 if (strcmp(ia->ia_name, "lm75") == 0 ||
150 strcmp(ia->ia_name, "lm77") == 0 ||
151 strcmp(ia->ia_name, "ds1775") == 0 ||
152 strcmp(ia->ia_name, "lm75a") == 0)
153 return (1);
154 return (0);
155 }
156
157 void
158 lmtemp_attach(struct device *parent, struct device *self, void *aux)
159 {
160 struct lmtemp_softc *sc = (struct lmtemp_softc *)self;
161 struct i2c_attach_args *ia = aux;
162 u_int8_t cmd, data;
163
164 sc->sc_tag = ia->ia_tag;
165 sc->sc_addr = ia->ia_addr;
166
167 printf(": %s", ia->ia_name);
168
169 /* If in SHUTDOWN mode, wake it up */
170 iic_acquire_bus(sc->sc_tag, 0);
171 cmd = LM75_REG_CONFIG;
172 if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
173 sc->sc_addr, &cmd, 1, &data, 1, 0)) {
174 iic_release_bus(sc->sc_tag, 0);
175 return;
176 }
177 if (data & LM75_CONFIG_SHUTDOWN) {
178 data &= ~LM75_CONFIG_SHUTDOWN;
179 if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
180 sc->sc_addr, &cmd, 1, &data, 1, 0)) {
181 printf(", cannot wake up\n");
182 iic_release_bus(sc->sc_tag, 0);
183 return;
184 }
185 printf(", woken up");
186 }
187 iic_release_bus(sc->sc_tag, 0);
188
189 sc->sc_model = LM_MODEL_LM75;
190 sc->sc_bits = 9;
191 if (strcmp(ia->ia_name, "lm77") == 0) {
192 sc->sc_model = LM_MODEL_LM77;
193 sc->sc_bits = 13;
194 } else if (strcmp(ia->ia_name, "ds1775") == 0) {
195 sc->sc_model = LM_MODEL_DS1775;
196 sc->sc_bits = 9;
197 //sc->sc_bits = DS1755_CONFIG_RESOLUTION(data);
198 } else if (strcmp(ia->ia_name, "lm75a") == 0) {
199 /* For simplicity's sake, treat the LM75A as an LM75 */
200 sc->sc_model = LM_MODEL_LM75A;
201 sc->sc_bits = 9;
202 }
203
204 printf("\n");
205
206 /* Initialize sensor data */
207 strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
208 sizeof(sc->sc_sensordev.xname));
209 sc->sc_sensor.type = SENSOR_TEMP;
210
211 /* Hook into the hw.sensors sysctl */
212 sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
213 sensordev_install(&sc->sc_sensordev);
214
215
216 sensor_task_register(sc, lmtemp_refresh_sensor_data, LM_POLLTIME);
217 }
218
219 int
220 lmtemp_temp_read(struct lmtemp_softc *sc, uint8_t which, int *valp)
221 {
222 u_int8_t cmd, buf[2];
223 int error;
224
225 cmd = which;
226 error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
227 sc->sc_addr, &cmd, 1, buf, 2, 0);
228 if (error)
229 return (error);
230
231 /* Some chips return transient 0's.. we try next time */
232 if (buf[0] == 0x00 && buf[1] == 0x00)
233 return (1);
234
235 /* convert to half-degrees C */
236 *valp = ((buf[0] << 8) | buf[1]) / (1 << (16 - sc->sc_bits));
237 return (0);
238 }
239
240 void
241 lmtemp_refresh_sensor_data(void *aux)
242 {
243 struct lmtemp_softc *sc = aux;
244 int val;
245 int error;
246
247 error = lmtemp_temp_read(sc, LM75_REG_TEMP, &val);
248 if (error) {
249 #if 0
250 printf("%s: unable to read temperature, error = %d\n",
251 sc->sc_dev.dv_xname, error);
252 #endif
253 sc->sc_sensor.flags |= SENSOR_FINVALID;
254 return;
255 }
256
257 sc->sc_sensor.value = val * 500000 + 273150000;
258 sc->sc_sensor.flags &= ~SENSOR_FINVALID;
259 }