hw/misc/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/hw.h"
  29 #include "hw/i2c/i2c.h"
  30 #include "qapi/error.h"
  31 #include "qapi/visitor.h"
  32
  33 /* Manufacturer / Device ID's */
  34 #define TMP421_MANUFACTURER_ID          0x55
  35 #define TMP421_DEVICE_ID                0x21
  36 #define TMP422_DEVICE_ID                0x22
  37 #define TMP423_DEVICE_ID                0x23
  38
  39 typedef struct DeviceInfo {
  40     int model;
  41     const char *name;
  42 } DeviceInfo;
  43
  44 static const DeviceInfo devices[] = {
  45     { TMP421_DEVICE_ID, "tmp421" },
  46     { TMP422_DEVICE_ID, "tmp422" },
  47     { TMP423_DEVICE_ID, "tmp423" },
  48 };
  49
  50 typedef struct TMP421State {
  51     /*< private >*/
  52     I2CSlave i2c;
  53     /*< public >*/
  54
  55     int16_t temperature[4];
  56
  57     uint8_t status;
  58     uint8_t config[2];
  59     uint8_t rate;
  60
  61     uint8_t len;
  62     uint8_t buf[2];
  63     uint8_t pointer;
  64
  65 } TMP421State;
  66
  67 typedef struct TMP421Class {
  68     I2CSlaveClass parent_class;
  69     DeviceInfo *dev;
  70 } TMP421Class;
  71
  72 #define TYPE_TMP421 "tmp421-generic"
  73 #define TMP421(obj) OBJECT_CHECK(TMP421State, (obj), TYPE_TMP421)
  74
  75 #define TMP421_CLASS(klass) \
  76      OBJECT_CLASS_CHECK(TMP421Class, (klass), TYPE_TMP421)
  77 #define TMP421_GET_CLASS(obj) \
  78      OBJECT_GET_CLASS(TMP421Class, (obj), TYPE_TMP421)
  79
  80 /* the TMP421 registers */
  81 #define TMP421_STATUS_REG               0x08
  82 #define    TMP421_STATUS_BUSY             (1 << 7)
  83 #define TMP421_CONFIG_REG_1             0x09
  84 #define    TMP421_CONFIG_RANGE            (1 << 2)
  85 #define    TMP421_CONFIG_SHUTDOWN         (1 << 6)
  86 #define TMP421_CONFIG_REG_2             0x0A
  87 #define    TMP421_CONFIG_RC               (1 << 2)
  88 #define    TMP421_CONFIG_LEN              (1 << 3)
  89 #define    TMP421_CONFIG_REN              (1 << 4)
  90 #define    TMP421_CONFIG_REN2             (1 << 5)
  91 #define    TMP421_CONFIG_REN3             (1 << 6)
  92
  93 #define TMP421_CONVERSION_RATE_REG      0x0B
  94 #define TMP421_ONE_SHOT                 0x0F
  95
  96 #define TMP421_RESET                    0xFC
  97 #define TMP421_MANUFACTURER_ID_REG      0xFE
  98 #define TMP421_DEVICE_ID_REG            0xFF
  99
 100 #define TMP421_TEMP_MSB0                0x00
 101 #define TMP421_TEMP_MSB1                0x01
 102 #define TMP421_TEMP_MSB2                0x02
 103 #define TMP421_TEMP_MSB3                0x03
 104 #define TMP421_TEMP_LSB0                0x10
 105 #define TMP421_TEMP_LSB1                0x11
 106 #define TMP421_TEMP_LSB2                0x12
 107 #define TMP421_TEMP_LSB3                0x13
 108
 109 static const int32_t mins[2] = { -40000, -55000 };
 110 static const int32_t maxs[2] = { 127000, 150000 };
 111
 112 static void tmp421_get_temperature(Object *obj, Visitor *v, const char *name,
 113                                    void *opaque, Error **errp)
 114 {
 115     TMP421State *s = TMP421(obj);
 116     bool ext_range = (s->config[0] & TMP421_CONFIG_RANGE);
 117     int offset = ext_range * 64 * 256;
 118     int64_t value;
 119     int tempid;
 120
 121     if (sscanf(name, "temperature%d", &tempid) != 1) {
 122         error_setg(errp, "error reading %s: %m", name);
 123         return;
 124     }
 125
 126     if (tempid >= 4 || tempid < 0) {
 127         error_setg(errp, "error reading %s", name);
 128         return;
 129     }
 130
 131     value = ((s->temperature[tempid] - offset) * 1000 + 128) / 256;
 132
 133     visit_type_int(v, name, &value, errp);
 134 }
 135
 136 /* Units are 0.001 centigrades relative to 0 C.  s->temperature is 8.8
 137  * fixed point, so units are 1/256 centigrades.  A simple ratio will do.
 138  */
 139 static void tmp421_set_temperature(Object *obj, Visitor *v, const char *name,
 140                                    void *opaque, Error **errp)
 141 {
 142     TMP421State *s = TMP421(obj);
 143     Error *local_err = NULL;
 144     int64_t temp;
 145     bool ext_range = (s->config[0] & TMP421_CONFIG_RANGE);
 146     int offset = ext_range * 64 * 256;
 147     int tempid;
 148
 149     visit_type_int(v, name, &temp, &local_err);
 150     if (local_err) {
 151         error_propagate(errp, local_err);
 152         return;
 153     }
 154
 155     if (temp >= maxs[ext_range] || temp < mins[ext_range]) {
 156         error_setg(errp, "value %" PRId64 ".%03" PRIu64 " °C is out of range",
 157                    temp / 1000, temp % 1000);
 158         return;
 159     }
 160
 161     if (sscanf(name, "temperature%d", &tempid) != 1) {
 162         error_setg(errp, "error reading %s: %m", name);
 163         return;
 164     }
 165
 166     if (tempid >= 4 || tempid < 0) {
 167         error_setg(errp, "error reading %s", name);
 168         return;
 169     }
 170
 171     s->temperature[tempid] = (int16_t) ((temp * 256 - 128) / 1000) + offset;
 172 }
 173
 174 static void tmp421_read(TMP421State *s)
 175 {
 176     TMP421Class *sc = TMP421_GET_CLASS(s);
 177
 178     s->len = 0;
 179
 180     switch (s->pointer) {
 181     case TMP421_MANUFACTURER_ID_REG:
 182         s->buf[s->len++] = TMP421_MANUFACTURER_ID;
 183         break;
 184     case TMP421_DEVICE_ID_REG:
 185         s->buf[s->len++] = sc->dev->model;
 186         break;
 187     case TMP421_CONFIG_REG_1:
 188         s->buf[s->len++] = s->config[0];
 189         break;
 190     case TMP421_CONFIG_REG_2:
 191         s->buf[s->len++] = s->config[1];
 192         break;
 193     case TMP421_CONVERSION_RATE_REG:
 194         s->buf[s->len++] = s->rate;
 195         break;
 196     case TMP421_STATUS_REG:
 197         s->buf[s->len++] = s->status;
 198         break;
 199
 200         /* FIXME: check for channel enablement in config registers */
 201     case TMP421_TEMP_MSB0:
 202         s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 8);
 203         s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 0) & 0xf0;
 204         break;
 205     case TMP421_TEMP_MSB1:
 206         s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 8);
 207         s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 0) & 0xf0;
 208         break;
 209     case TMP421_TEMP_MSB2:
 210         s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 8);
 211         s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 0) & 0xf0;
 212         break;
 213     case TMP421_TEMP_MSB3:
 214         s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 8);
 215         s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 0) & 0xf0;
 216         break;
 217     case TMP421_TEMP_LSB0:
 218         s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 0) & 0xf0;
 219         break;
 220     case TMP421_TEMP_LSB1:
 221         s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 0) & 0xf0;
 222         break;
 223     case TMP421_TEMP_LSB2:
 224         s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 0) & 0xf0;
 225         break;
 226     case TMP421_TEMP_LSB3:
 227         s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 0) & 0xf0;
 228         break;
 229     }
 230 }
 231
 232 static void tmp421_reset(I2CSlave *i2c);
 233
 234 static void tmp421_write(TMP421State *s)
 235 {
 236     switch (s->pointer) {
 237     case TMP421_CONVERSION_RATE_REG:
 238         s->rate = s->buf[0];
 239         break;
 240     case TMP421_CONFIG_REG_1:
 241         s->config[0] = s->buf[0];
 242         break;
 243     case TMP421_CONFIG_REG_2:
 244         s->config[1] = s->buf[0];
 245         break;
 246     case TMP421_RESET:
 247         tmp421_reset(I2C_SLAVE(s));
 248         break;
 249     }
 250 }
 251
 252 static int tmp421_rx(I2CSlave *i2c)
 253 {
 254     TMP421State *s = TMP421(i2c);
 255
 256     if (s->len < 2) {
 257         return s->buf[s->len++];
 258     } else {
 259         return 0xff;
 260     }
 261 }
 262
 263 static int tmp421_tx(I2CSlave *i2c, uint8_t data)
 264 {
 265     TMP421State *s = TMP421(i2c);
 266
 267     if (s->len == 0) {
 268         /* first byte is the register pointer for a read or write
 269          * operation */
 270         s->pointer = data;
 271         s->len++;
 272     } else if (s->len == 1) {
 273         /* second byte is the data to write. The device only supports
 274          * one byte writes */
 275         s->buf[0] = data;
 276         tmp421_write(s);
 277     }
 278
 279     return 0;
 280 }
 281
 282 static int tmp421_event(I2CSlave *i2c, enum i2c_event event)
 283 {
 284     TMP421State *s = TMP421(i2c);
 285
 286     if (event == I2C_START_RECV) {
 287         tmp421_read(s);
 288     }
 289
 290     s->len = 0;
 291     return 0;
 292 }
 293
 294 static const VMStateDescription vmstate_tmp421 = {
 295     .name = "TMP421",
 296     .version_id = 0,
 297     .minimum_version_id = 0,
 298     .fields = (VMStateField[]) {
 299         VMSTATE_UINT8(len, TMP421State),
 300         VMSTATE_UINT8_ARRAY(buf, TMP421State, 2),
 301         VMSTATE_UINT8(pointer, TMP421State),
 302         VMSTATE_UINT8_ARRAY(config, TMP421State, 2),
 303         VMSTATE_UINT8(status, TMP421State),
 304         VMSTATE_UINT8(rate, TMP421State),
 305         VMSTATE_INT16_ARRAY(temperature, TMP421State, 4),
 306         VMSTATE_I2C_SLAVE(i2c, TMP421State),
 307         VMSTATE_END_OF_LIST()
 308     }
 309 };
 310
 311 static void tmp421_reset(I2CSlave *i2c)
 312 {
 313     TMP421State *s = TMP421(i2c);
 314     TMP421Class *sc = TMP421_GET_CLASS(s);
 315
 316     memset(s->temperature, 0, sizeof(s->temperature));
 317     s->pointer = 0;
 318
 319     s->config[0] = 0; /* TMP421_CONFIG_RANGE */
 320
 321      /* resistance correction and channel enablement */
 322     switch (sc->dev->model) {
 323     case TMP421_DEVICE_ID:
 324         s->config[1] = 0x1c;
 325         break;
 326     case TMP422_DEVICE_ID:
 327         s->config[1] = 0x3c;
 328         break;
 329     case TMP423_DEVICE_ID:
 330         s->config[1] = 0x7c;
 331         break;
 332     }
 333
 334     s->rate = 0x7;       /* 8Hz */
 335     s->status = 0;
 336 }
 337
 338 static void tmp421_realize(DeviceState *dev, Error **errp)
 339 {
 340     TMP421State *s = TMP421(dev);
 341
 342     tmp421_reset(&s->i2c);
 343 }
 344
 345 static void tmp421_initfn(Object *obj)
 346 {
 347     object_property_add(obj, "temperature0", "int",
 348                         tmp421_get_temperature,
 349                         tmp421_set_temperature, NULL, NULL, NULL);
 350     object_property_add(obj, "temperature1", "int",
 351                         tmp421_get_temperature,
 352                         tmp421_set_temperature, NULL, NULL, NULL);
 353     object_property_add(obj, "temperature2", "int",
 354                         tmp421_get_temperature,
 355                         tmp421_set_temperature, NULL, NULL, NULL);
 356     object_property_add(obj, "temperature3", "int",
 357                         tmp421_get_temperature,
 358                         tmp421_set_temperature, NULL, NULL, NULL);
 359 }
 360
 361 static void tmp421_class_init(ObjectClass *klass, void *data)
 362 {
 363     DeviceClass *dc = DEVICE_CLASS(klass);
 364     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 365     TMP421Class *sc = TMP421_CLASS(klass);
 366
 367     dc->realize = tmp421_realize;
 368     k->event = tmp421_event;
 369     k->recv = tmp421_rx;
 370     k->send = tmp421_tx;
 371     dc->vmsd = &vmstate_tmp421;
 372     sc->dev = (DeviceInfo *) data;
 373 }
 374
 375 static const TypeInfo tmp421_info = {
 376     .name          = TYPE_TMP421,
 377     .parent        = TYPE_I2C_SLAVE,
 378     .instance_size = sizeof(TMP421State),
 379     .class_size    = sizeof(TMP421Class),
 380     .instance_init = tmp421_initfn,
 381     .abstract      = true,
 382 };
 383
 384 static void tmp421_register_types(void)
 385 {
 386     int i;
 387
 388     type_register_static(&tmp421_info);
 389     for (i = 0; i < ARRAY_SIZE(devices); ++i) {
 390         TypeInfo ti = {
 391             .name       = devices[i].name,
 392             .parent     = TYPE_TMP421,
 393             .class_init = tmp421_class_init,
 394             .class_data = (void *) &devices[i],
 395         };
 396         type_register(&ti);
 397     }
 398 }
 399
 400 type_init(tmp421_register_types)