qemu/hw/misc/tmp421.c
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   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#include "qemu/module.h"
  33
  34/* Manufacturer / Device ID's */
  35#define TMP421_MANUFACTURER_ID          0x55
  36#define TMP421_DEVICE_ID                0x21
  37#define TMP422_DEVICE_ID                0x22
  38#define TMP423_DEVICE_ID                0x23
  39
  40typedef struct DeviceInfo {
  41    int model;
  42    const char *name;
  43} DeviceInfo;
  44
  45static const DeviceInfo devices[] = {
  46    { TMP421_DEVICE_ID, "tmp421" },
  47    { TMP422_DEVICE_ID, "tmp422" },
  48    { TMP423_DEVICE_ID, "tmp423" },
  49};
  50
  51typedef struct TMP421State {
  52    /*< private >*/
  53    I2CSlave i2c;
  54    /*< public >*/
  55
  56    int16_t temperature[4];
  57
  58    uint8_t status;
  59    uint8_t config[2];
  60    uint8_t rate;
  61
  62    uint8_t len;
  63    uint8_t buf[2];
  64    uint8_t pointer;
  65
  66} TMP421State;
  67
  68typedef struct TMP421Class {
  69    I2CSlaveClass parent_class;
  70    DeviceInfo *dev;
  71} TMP421Class;
  72
  73#define TYPE_TMP421 "tmp421-generic"
  74#define TMP421(obj) OBJECT_CHECK(TMP421State, (obj), TYPE_TMP421)
  75
  76#define TMP421_CLASS(klass) \
  77     OBJECT_CLASS_CHECK(TMP421Class, (klass), TYPE_TMP421)
  78#define TMP421_GET_CLASS(obj) \
  79     OBJECT_GET_CLASS(TMP421Class, (obj), TYPE_TMP421)
  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
 110static const int32_t mins[2] = { -40000, -55000 };
 111static const int32_t maxs[2] = { 127000, 150000 };
 112
 113static 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: %m", name);
 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 */
 140static void tmp421_set_temperature(Object *obj, Visitor *v, const char *name,
 141                                   void *opaque, Error **errp)
 142{
 143    TMP421State *s = TMP421(obj);
 144    Error *local_err = NULL;
 145    int64_t temp;
 146    bool ext_range = (s->config[0] & TMP421_CONFIG_RANGE);
 147    int offset = ext_range * 64 * 256;
 148    int tempid;
 149
 150    visit_type_int(v, name, &temp, &local_err);
 151    if (local_err) {
 152        error_propagate(errp, local_err);
 153        return;
 154    }
 155
 156    if (temp >= maxs[ext_range] || temp < mins[ext_range]) {
 157        error_setg(errp, "value %" PRId64 ".%03" PRIu64 " C is out of range",
 158                   temp / 1000, temp % 1000);
 159        return;
 160    }
 161
 162    if (sscanf(name, "temperature%d", &tempid) != 1) {
 163        error_setg(errp, "error reading %s: %m", name);
 164        return;
 165    }
 166
 167    if (tempid >= 4 || tempid < 0) {
 168        error_setg(errp, "error reading %s", name);
 169        return;
 170    }
 171
 172    s->temperature[tempid] = (int16_t) ((temp * 256 - 128) / 1000) + offset;
 173}
 174
 175static void tmp421_read(TMP421State *s)
 176{
 177    TMP421Class *sc = TMP421_GET_CLASS(s);
 178
 179    s->len = 0;
 180
 181    switch (s->pointer) {
 182    case TMP421_MANUFACTURER_ID_REG:
 183        s->buf[s->len++] = TMP421_MANUFACTURER_ID;
 184        break;
 185    case TMP421_DEVICE_ID_REG:
 186        s->buf[s->len++] = sc->dev->model;
 187        break;
 188    case TMP421_CONFIG_REG_1:
 189        s->buf[s->len++] = s->config[0];
 190        break;
 191    case TMP421_CONFIG_REG_2:
 192        s->buf[s->len++] = s->config[1];
 193        break;
 194    case TMP421_CONVERSION_RATE_REG:
 195        s->buf[s->len++] = s->rate;
 196        break;
 197    case TMP421_STATUS_REG:
 198        s->buf[s->len++] = s->status;
 199        break;
 200
 201        /* FIXME: check for channel enablement in config registers */
 202    case TMP421_TEMP_MSB0:
 203        s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 8);
 204        s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 0) & 0xf0;
 205        break;
 206    case TMP421_TEMP_MSB1:
 207        s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 8);
 208        s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 0) & 0xf0;
 209        break;
 210    case TMP421_TEMP_MSB2:
 211        s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 8);
 212        s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 0) & 0xf0;
 213        break;
 214    case TMP421_TEMP_MSB3:
 215        s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 8);
 216        s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 0) & 0xf0;
 217        break;
 218    case TMP421_TEMP_LSB0:
 219        s->buf[s->len++] = (((uint16_t) s->temperature[0]) >> 0) & 0xf0;
 220        break;
 221    case TMP421_TEMP_LSB1:
 222        s->buf[s->len++] = (((uint16_t) s->temperature[1]) >> 0) & 0xf0;
 223        break;
 224    case TMP421_TEMP_LSB2:
 225        s->buf[s->len++] = (((uint16_t) s->temperature[2]) >> 0) & 0xf0;
 226        break;
 227    case TMP421_TEMP_LSB3:
 228        s->buf[s->len++] = (((uint16_t) s->temperature[3]) >> 0) & 0xf0;
 229        break;
 230    }
 231}
 232
 233static void tmp421_reset(I2CSlave *i2c);
 234
 235static void tmp421_write(TMP421State *s)
 236{
 237    switch (s->pointer) {
 238    case TMP421_CONVERSION_RATE_REG:
 239        s->rate = s->buf[0];
 240        break;
 241    case TMP421_CONFIG_REG_1:
 242        s->config[0] = s->buf[0];
 243        break;
 244    case TMP421_CONFIG_REG_2:
 245        s->config[1] = s->buf[0];
 246        break;
 247    case TMP421_RESET:
 248        tmp421_reset(I2C_SLAVE(s));
 249        break;
 250    }
 251}
 252
 253static uint8_t tmp421_rx(I2CSlave *i2c)
 254{
 255    TMP421State *s = TMP421(i2c);
 256
 257    if (s->len < 2) {
 258        return s->buf[s->len++];
 259    } else {
 260        return 0xff;
 261    }
 262}
 263
 264static int tmp421_tx(I2CSlave *i2c, uint8_t data)
 265{
 266    TMP421State *s = TMP421(i2c);
 267
 268    if (s->len == 0) {
 269        /* first byte is the register pointer for a read or write
 270         * operation */
 271        s->pointer = data;
 272        s->len++;
 273    } else if (s->len == 1) {
 274        /* second byte is the data to write. The device only supports
 275         * one byte writes */
 276        s->buf[0] = data;
 277        tmp421_write(s);
 278    }
 279
 280    return 0;
 281}
 282
 283static int tmp421_event(I2CSlave *i2c, enum i2c_event event)
 284{
 285    TMP421State *s = TMP421(i2c);
 286
 287    if (event == I2C_START_RECV) {
 288        tmp421_read(s);
 289    }
 290
 291    s->len = 0;
 292    return 0;
 293}
 294
 295static const VMStateDescription vmstate_tmp421 = {
 296    .name = "TMP421",
 297    .version_id = 0,
 298    .minimum_version_id = 0,
 299    .fields = (VMStateField[]) {
 300        VMSTATE_UINT8(len, TMP421State),
 301        VMSTATE_UINT8_ARRAY(buf, TMP421State, 2),
 302        VMSTATE_UINT8(pointer, TMP421State),
 303        VMSTATE_UINT8_ARRAY(config, TMP421State, 2),
 304        VMSTATE_UINT8(status, TMP421State),
 305        VMSTATE_UINT8(rate, TMP421State),
 306        VMSTATE_INT16_ARRAY(temperature, TMP421State, 4),
 307        VMSTATE_I2C_SLAVE(i2c, TMP421State),
 308        VMSTATE_END_OF_LIST()
 309    }
 310};
 311
 312static void tmp421_reset(I2CSlave *i2c)
 313{
 314    TMP421State *s = TMP421(i2c);
 315    TMP421Class *sc = TMP421_GET_CLASS(s);
 316
 317    memset(s->temperature, 0, sizeof(s->temperature));
 318    s->pointer = 0;
 319
 320    s->config[0] = 0; /* TMP421_CONFIG_RANGE */
 321
 322     /* resistance correction and channel enablement */
 323    switch (sc->dev->model) {
 324    case TMP421_DEVICE_ID:
 325        s->config[1] = 0x1c;
 326        break;
 327    case TMP422_DEVICE_ID:
 328        s->config[1] = 0x3c;
 329        break;
 330    case TMP423_DEVICE_ID:
 331        s->config[1] = 0x7c;
 332        break;
 333    }
 334
 335    s->rate = 0x7;       /* 8Hz */
 336    s->status = 0;
 337}
 338
 339static void tmp421_realize(DeviceState *dev, Error **errp)
 340{
 341    TMP421State *s = TMP421(dev);
 342
 343    tmp421_reset(&s->i2c);
 344}
 345
 346static void tmp421_initfn(Object *obj)
 347{
 348    object_property_add(obj, "temperature0", "int",
 349                        tmp421_get_temperature,
 350                        tmp421_set_temperature, NULL, NULL, NULL);
 351    object_property_add(obj, "temperature1", "int",
 352                        tmp421_get_temperature,
 353                        tmp421_set_temperature, NULL, NULL, NULL);
 354    object_property_add(obj, "temperature2", "int",
 355                        tmp421_get_temperature,
 356                        tmp421_set_temperature, NULL, NULL, NULL);
 357    object_property_add(obj, "temperature3", "int",
 358                        tmp421_get_temperature,
 359                        tmp421_set_temperature, NULL, NULL, NULL);
 360}
 361
 362static void tmp421_class_init(ObjectClass *klass, void *data)
 363{
 364    DeviceClass *dc = DEVICE_CLASS(klass);
 365    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 366    TMP421Class *sc = TMP421_CLASS(klass);
 367
 368    dc->realize = tmp421_realize;
 369    k->event = tmp421_event;
 370    k->recv = tmp421_rx;
 371    k->send = tmp421_tx;
 372    dc->vmsd = &vmstate_tmp421;
 373    sc->dev = (DeviceInfo *) data;
 374}
 375
 376static const TypeInfo tmp421_info = {
 377    .name          = TYPE_TMP421,
 378    .parent        = TYPE_I2C_SLAVE,
 379    .instance_size = sizeof(TMP421State),
 380    .class_size    = sizeof(TMP421Class),
 381    .instance_init = tmp421_initfn,
 382    .abstract      = true,
 383};
 384
 385static void tmp421_register_types(void)
 386{
 387    int i;
 388
 389    type_register_static(&tmp421_info);
 390    for (i = 0; i < ARRAY_SIZE(devices); ++i) {
 391        TypeInfo ti = {
 392            .name       = devices[i].name,
 393            .parent     = TYPE_TMP421,
 394            .class_init = tmp421_class_init,
 395            .class_data = (void *) &devices[i],
 396        };
 397        type_register(&ti);
 398    }
 399}
 400
 401type_init(tmp421_register_types)
 402