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