hw/sensor/tmp421.c

   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 = (const 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)