xref: /openbmc/qemu/hw/sensor/tmp421.c (revision 43709a0c)
1 /*
2  * Texas Instruments TMP421 temperature sensor.
3  *
4  * Copyright (c) 2016 IBM Corporation.
5  *
6  * Largely inspired by :
7  *
8  * Texas Instruments TMP105 temperature sensor.
9  *
10  * Copyright (C) 2008 Nokia Corporation
11  * Written by Andrzej Zaborowski <andrew@openedhand.com>
12  *
13  * This program is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License as
15  * published by the Free Software Foundation; either version 2 or
16  * (at your option) version 3 of the License.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License along
24  * with this program; if not, see <http://www.gnu.org/licenses/>.
25  */
26 
27 #include "qemu/osdep.h"
28 #include "hw/i2c/i2c.h"
29 #include "migration/vmstate.h"
30 #include "qapi/error.h"
31 #include "qapi/visitor.h"
32 #include "qemu/module.h"
33 #include "qom/object.h"
34 
35 /* Manufacturer / Device ID's */
36 #define TMP421_MANUFACTURER_ID          0x55
37 #define TMP421_DEVICE_ID                0x21
38 #define TMP422_DEVICE_ID                0x22
39 #define TMP423_DEVICE_ID                0x23
40 
41 typedef struct DeviceInfo {
42     int model;
43     const char *name;
44 } DeviceInfo;
45 
46 static const DeviceInfo devices[] = {
47     { TMP421_DEVICE_ID, "tmp421" },
48     { TMP422_DEVICE_ID, "tmp422" },
49     { TMP423_DEVICE_ID, "tmp423" },
50 };
51 
52 struct TMP421State {
53     /*< private >*/
54     I2CSlave i2c;
55     /*< public >*/
56 
57     int16_t temperature[4];
58 
59     uint8_t status;
60     uint8_t config[2];
61     uint8_t rate;
62 
63     uint8_t len;
64     uint8_t buf[2];
65     uint8_t pointer;
66 
67 };
68 
69 struct TMP421Class {
70     I2CSlaveClass parent_class;
71     DeviceInfo *dev;
72 };
73 
74 #define TYPE_TMP421 "tmp421-generic"
75 OBJECT_DECLARE_TYPE(TMP421State, TMP421Class, TMP421)
76 
77 
78 /* the TMP421 registers */
79 #define TMP421_STATUS_REG               0x08
80 #define    TMP421_STATUS_BUSY             (1 << 7)
81 #define TMP421_CONFIG_REG_1             0x09
82 #define    TMP421_CONFIG_RANGE            (1 << 2)
83 #define    TMP421_CONFIG_SHUTDOWN         (1 << 6)
84 #define TMP421_CONFIG_REG_2             0x0A
85 #define    TMP421_CONFIG_RC               (1 << 2)
86 #define    TMP421_CONFIG_LEN              (1 << 3)
87 #define    TMP421_CONFIG_REN              (1 << 4)
88 #define    TMP421_CONFIG_REN2             (1 << 5)
89 #define    TMP421_CONFIG_REN3             (1 << 6)
90 
91 #define TMP421_CONVERSION_RATE_REG      0x0B
92 #define TMP421_ONE_SHOT                 0x0F
93 
94 #define TMP421_RESET                    0xFC
95 #define TMP421_MANUFACTURER_ID_REG      0xFE
96 #define TMP421_DEVICE_ID_REG            0xFF
97 
98 #define TMP421_TEMP_MSB0                0x00
99 #define TMP421_TEMP_MSB1                0x01
100 #define TMP421_TEMP_MSB2                0x02
101 #define TMP421_TEMP_MSB3                0x03
102 #define TMP421_TEMP_LSB0                0x10
103 #define TMP421_TEMP_LSB1                0x11
104 #define TMP421_TEMP_LSB2                0x12
105 #define TMP421_TEMP_LSB3                0x13
106 
107 static const int32_t mins[2] = { -40000, -55000 };
108 static const int32_t maxs[2] = { 127000, 150000 };
109 
110 static void tmp421_get_temperature(Object *obj, Visitor *v, const char *name,
111                                    void *opaque, Error **errp)
112 {
113     TMP421State *s = TMP421(obj);
114     bool ext_range = (s->config[0] & TMP421_CONFIG_RANGE);
115     int offset = ext_range * 64 * 256;
116     int64_t value;
117     int tempid;
118 
119     if (sscanf(name, "temperature%d", &tempid) != 1) {
120         error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
121         return;
122     }
123 
124     if (tempid >= 4 || tempid < 0) {
125         error_setg(errp, "error reading %s", name);
126         return;
127     }
128 
129     value = ((s->temperature[tempid] - offset) * 1000 + 128) / 256;
130 
131     visit_type_int(v, name, &value, errp);
132 }
133 
134 /* Units are 0.001 centigrades relative to 0 C.  s->temperature is 8.8
135  * fixed point, so units are 1/256 centigrades.  A simple ratio will do.
136  */
137 static void tmp421_set_temperature(Object *obj, Visitor *v, const char *name,
138                                    void *opaque, Error **errp)
139 {
140     TMP421State *s = TMP421(obj);
141     int64_t temp;
142     bool ext_range = (s->config[0] & TMP421_CONFIG_RANGE);
143     int offset = ext_range * 64 * 256;
144     int tempid;
145 
146     if (!visit_type_int(v, name, &temp, errp)) {
147         return;
148     }
149 
150     if (temp >= maxs[ext_range] || temp < mins[ext_range]) {
151         error_setg(errp, "value %" PRId64 ".%03" PRIu64 " C is out of range",
152                    temp / 1000, temp % 1000);
153         return;
154     }
155 
156     if (sscanf(name, "temperature%d", &tempid) != 1) {
157         error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
158         return;
159     }
160 
161     if (tempid >= 4 || tempid < 0) {
162         error_setg(errp, "error reading %s", name);
163         return;
164     }
165 
166     s->temperature[tempid] = (int16_t) ((temp * 256 - 128) / 1000) + offset;
167 }
168 
169 static void tmp421_read(TMP421State *s)
170 {
171     TMP421Class *sc = TMP421_GET_CLASS(s);
172 
173     s->len = 0;
174 
175     switch (s->pointer) {
176     case TMP421_MANUFACTURER_ID_REG:
177         s->buf[s->len++] = TMP421_MANUFACTURER_ID;
178         break;
179     case TMP421_DEVICE_ID_REG:
180         s->buf[s->len++] = sc->dev->model;
181         break;
182     case TMP421_CONFIG_REG_1:
183         s->buf[s->len++] = s->config[0];
184         break;
185     case TMP421_CONFIG_REG_2:
186         s->buf[s->len++] = s->config[1];
187         break;
188     case TMP421_CONVERSION_RATE_REG:
189         s->buf[s->len++] = s->rate;
190         break;
191     case TMP421_STATUS_REG:
192         s->buf[s->len++] = s->status;
193         break;
194 
195         /* FIXME: check for channel enablement in config registers */
196     case TMP421_TEMP_MSB0:
197         s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 8);
198         s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 0) & 0xf0;
199         break;
200     case TMP421_TEMP_MSB1:
201         s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 8);
202         s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 0) & 0xf0;
203         break;
204     case TMP421_TEMP_MSB2:
205         s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 8);
206         s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 0) & 0xf0;
207         break;
208     case TMP421_TEMP_MSB3:
209         s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 8);
210         s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 0) & 0xf0;
211         break;
212     case TMP421_TEMP_LSB0:
213         s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 0) & 0xf0;
214         break;
215     case TMP421_TEMP_LSB1:
216         s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 0) & 0xf0;
217         break;
218     case TMP421_TEMP_LSB2:
219         s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 0) & 0xf0;
220         break;
221     case TMP421_TEMP_LSB3:
222         s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 0) & 0xf0;
223         break;
224     }
225 }
226 
227 static void tmp421_reset(I2CSlave *i2c);
228 
229 static void tmp421_write(TMP421State *s)
230 {
231     switch (s->pointer) {
232     case TMP421_CONVERSION_RATE_REG:
233         s->rate = s->buf[0];
234         break;
235     case TMP421_CONFIG_REG_1:
236         s->config[0] = s->buf[0];
237         break;
238     case TMP421_CONFIG_REG_2:
239         s->config[1] = s->buf[0];
240         break;
241     case TMP421_RESET:
242         tmp421_reset(I2C_SLAVE(s));
243         break;
244     }
245 }
246 
247 static uint8_t tmp421_rx(I2CSlave *i2c)
248 {
249     TMP421State *s = TMP421(i2c);
250 
251     if (s->len < 2) {
252         return s->buf[s->len++];
253     } else {
254         return 0xff;
255     }
256 }
257 
258 static int tmp421_tx(I2CSlave *i2c, uint8_t data)
259 {
260     TMP421State *s = TMP421(i2c);
261 
262     if (s->len == 0) {
263         /* first byte is the register pointer for a read or write
264          * operation */
265         s->pointer = data;
266         s->len++;
267     } else if (s->len == 1) {
268         /* second byte is the data to write. The device only supports
269          * one byte writes */
270         s->buf[0] = data;
271         tmp421_write(s);
272     }
273 
274     return 0;
275 }
276 
277 static int tmp421_event(I2CSlave *i2c, enum i2c_event event)
278 {
279     TMP421State *s = TMP421(i2c);
280 
281     if (event == I2C_START_RECV) {
282         tmp421_read(s);
283     }
284 
285     s->len = 0;
286     return 0;
287 }
288 
289 static const VMStateDescription vmstate_tmp421 = {
290     .name = "TMP421",
291     .version_id = 0,
292     .minimum_version_id = 0,
293     .fields = (VMStateField[]) {
294         VMSTATE_UINT8(len, TMP421State),
295         VMSTATE_UINT8_ARRAY(buf, TMP421State, 2),
296         VMSTATE_UINT8(pointer, TMP421State),
297         VMSTATE_UINT8_ARRAY(config, TMP421State, 2),
298         VMSTATE_UINT8(status, TMP421State),
299         VMSTATE_UINT8(rate, TMP421State),
300         VMSTATE_INT16_ARRAY(temperature, TMP421State, 4),
301         VMSTATE_I2C_SLAVE(i2c, TMP421State),
302         VMSTATE_END_OF_LIST()
303     }
304 };
305 
306 static void tmp421_reset(I2CSlave *i2c)
307 {
308     TMP421State *s = TMP421(i2c);
309     TMP421Class *sc = TMP421_GET_CLASS(s);
310 
311     memset(s->temperature, 0, sizeof(s->temperature));
312     s->pointer = 0;
313 
314     s->config[0] = 0; /* TMP421_CONFIG_RANGE */
315 
316      /* resistance correction and channel enablement */
317     switch (sc->dev->model) {
318     case TMP421_DEVICE_ID:
319         s->config[1] = 0x1c;
320         break;
321     case TMP422_DEVICE_ID:
322         s->config[1] = 0x3c;
323         break;
324     case TMP423_DEVICE_ID:
325         s->config[1] = 0x7c;
326         break;
327     }
328 
329     s->rate = 0x7;       /* 8Hz */
330     s->status = 0;
331 }
332 
333 static void tmp421_realize(DeviceState *dev, Error **errp)
334 {
335     TMP421State *s = TMP421(dev);
336 
337     tmp421_reset(&s->i2c);
338 }
339 
340 static void tmp421_class_init(ObjectClass *klass, void *data)
341 {
342     DeviceClass *dc = DEVICE_CLASS(klass);
343     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
344     TMP421Class *sc = TMP421_CLASS(klass);
345 
346     dc->realize = tmp421_realize;
347     k->event = tmp421_event;
348     k->recv = tmp421_rx;
349     k->send = tmp421_tx;
350     dc->vmsd = &vmstate_tmp421;
351     sc->dev = (DeviceInfo *) data;
352 
353     object_class_property_add(klass, "temperature0", "int",
354                               tmp421_get_temperature,
355                               tmp421_set_temperature, NULL, NULL);
356     object_class_property_add(klass, "temperature1", "int",
357                               tmp421_get_temperature,
358                               tmp421_set_temperature, NULL, NULL);
359     object_class_property_add(klass, "temperature2", "int",
360                               tmp421_get_temperature,
361                               tmp421_set_temperature, NULL, NULL);
362     object_class_property_add(klass, "temperature3", "int",
363                               tmp421_get_temperature,
364                               tmp421_set_temperature, NULL, NULL);
365 }
366 
367 static const TypeInfo tmp421_info = {
368     .name          = TYPE_TMP421,
369     .parent        = TYPE_I2C_SLAVE,
370     .instance_size = sizeof(TMP421State),
371     .class_size    = sizeof(TMP421Class),
372     .abstract      = true,
373 };
374 
375 static void tmp421_register_types(void)
376 {
377     int i;
378 
379     type_register_static(&tmp421_info);
380     for (i = 0; i < ARRAY_SIZE(devices); ++i) {
381         TypeInfo ti = {
382             .name       = devices[i].name,
383             .parent     = TYPE_TMP421,
384             .class_init = tmp421_class_init,
385             .class_data = (void *) &devices[i],
386         };
387         type_register(&ti);
388     }
389 }
390 
391 type_init(tmp421_register_types)
392