qemu/hw/misc/tmp105.c
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   1/*
   2 * Texas Instruments TMP105 temperature sensor.
   3 *
   4 * Copyright (C) 2008 Nokia Corporation
   5 * Written by Andrzej Zaborowski <andrew@openedhand.com>
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License as
   9 * published by the Free Software Foundation; either version 2 or
  10 * (at your option) version 3 of the License.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License along
  18 * with this program; if not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21#include "qemu/osdep.h"
  22#include "hw/i2c/i2c.h"
  23#include "hw/irq.h"
  24#include "migration/vmstate.h"
  25#include "tmp105.h"
  26#include "qapi/error.h"
  27#include "qapi/visitor.h"
  28#include "qemu/module.h"
  29
  30static void tmp105_interrupt_update(TMP105State *s)
  31{
  32    qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  33}
  34
  35static void tmp105_alarm_update(TMP105State *s)
  36{
  37    if ((s->config >> 0) & 1) {                                 /* SD */
  38        if ((s->config >> 7) & 1)                               /* OS */
  39            s->config &= ~(1 << 7);                             /* OS */
  40        else
  41            return;
  42    }
  43
  44    if ((s->config >> 1) & 1) {                                 /* TM */
  45        if (s->temperature >= s->limit[1])
  46            s->alarm = 1;
  47        else if (s->temperature < s->limit[0])
  48            s->alarm = 1;
  49    } else {
  50        if (s->temperature >= s->limit[1])
  51            s->alarm = 1;
  52        else if (s->temperature < s->limit[0])
  53            s->alarm = 0;
  54    }
  55
  56    tmp105_interrupt_update(s);
  57}
  58
  59static void tmp105_get_temperature(Object *obj, Visitor *v, const char *name,
  60                                   void *opaque, Error **errp)
  61{
  62    TMP105State *s = TMP105(obj);
  63    int64_t value = s->temperature * 1000 / 256;
  64
  65    visit_type_int(v, name, &value, errp);
  66}
  67
  68/* Units are 0.001 centigrades relative to 0 C.  s->temperature is 8.8
  69 * fixed point, so units are 1/256 centigrades.  A simple ratio will do.
  70 */
  71static void tmp105_set_temperature(Object *obj, Visitor *v, const char *name,
  72                                   void *opaque, Error **errp)
  73{
  74    TMP105State *s = TMP105(obj);
  75    Error *local_err = NULL;
  76    int64_t temp;
  77
  78    visit_type_int(v, name, &temp, &local_err);
  79    if (local_err) {
  80        error_propagate(errp, local_err);
  81        return;
  82    }
  83    if (temp >= 128000 || temp < -128000) {
  84        error_setg(errp, "value %" PRId64 ".%03" PRIu64 " C is out of range",
  85                   temp / 1000, temp % 1000);
  86        return;
  87    }
  88
  89    s->temperature = (int16_t) (temp * 256 / 1000);
  90
  91    tmp105_alarm_update(s);
  92}
  93
  94static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  95
  96static void tmp105_read(TMP105State *s)
  97{
  98    s->len = 0;
  99
 100    if ((s->config >> 1) & 1) {                                 /* TM */
 101        s->alarm = 0;
 102        tmp105_interrupt_update(s);
 103    }
 104
 105    switch (s->pointer & 3) {
 106    case TMP105_REG_TEMPERATURE:
 107        s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
 108        s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
 109                (0xf0 << ((~s->config >> 5) & 3));              /* R */
 110        break;
 111
 112    case TMP105_REG_CONFIG:
 113        s->buf[s->len ++] = s->config;
 114        break;
 115
 116    case TMP105_REG_T_LOW:
 117        s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 118        s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 119        break;
 120
 121    case TMP105_REG_T_HIGH:
 122        s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 123        s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 124        break;
 125    }
 126}
 127
 128static void tmp105_write(TMP105State *s)
 129{
 130    switch (s->pointer & 3) {
 131    case TMP105_REG_TEMPERATURE:
 132        break;
 133
 134    case TMP105_REG_CONFIG:
 135        if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 136            printf("%s: TMP105 shutdown\n", __func__);
 137        s->config = s->buf[0];
 138        s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 139        tmp105_alarm_update(s);
 140        break;
 141
 142    case TMP105_REG_T_LOW:
 143    case TMP105_REG_T_HIGH:
 144        if (s->len >= 3)
 145            s->limit[s->pointer & 1] = (int16_t)
 146                    ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 147        tmp105_alarm_update(s);
 148        break;
 149    }
 150}
 151
 152static uint8_t tmp105_rx(I2CSlave *i2c)
 153{
 154    TMP105State *s = TMP105(i2c);
 155
 156    if (s->len < 2) {
 157        return s->buf[s->len ++];
 158    } else {
 159        return 0xff;
 160    }
 161}
 162
 163static int tmp105_tx(I2CSlave *i2c, uint8_t data)
 164{
 165    TMP105State *s = TMP105(i2c);
 166
 167    if (s->len == 0) {
 168        s->pointer = data;
 169        s->len++;
 170    } else {
 171        if (s->len <= 2) {
 172            s->buf[s->len - 1] = data;
 173        }
 174        s->len++;
 175        tmp105_write(s);
 176    }
 177
 178    return 0;
 179}
 180
 181static int tmp105_event(I2CSlave *i2c, enum i2c_event event)
 182{
 183    TMP105State *s = TMP105(i2c);
 184
 185    if (event == I2C_START_RECV) {
 186        tmp105_read(s);
 187    }
 188
 189    s->len = 0;
 190    return 0;
 191}
 192
 193static int tmp105_post_load(void *opaque, int version_id)
 194{
 195    TMP105State *s = opaque;
 196
 197    s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 198
 199    tmp105_interrupt_update(s);
 200    return 0;
 201}
 202
 203static const VMStateDescription vmstate_tmp105 = {
 204    .name = "TMP105",
 205    .version_id = 0,
 206    .minimum_version_id = 0,
 207    .post_load = tmp105_post_load,
 208    .fields = (VMStateField[]) {
 209        VMSTATE_UINT8(len, TMP105State),
 210        VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
 211        VMSTATE_UINT8(pointer, TMP105State),
 212        VMSTATE_UINT8(config, TMP105State),
 213        VMSTATE_INT16(temperature, TMP105State),
 214        VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
 215        VMSTATE_UINT8(alarm, TMP105State),
 216        VMSTATE_I2C_SLAVE(i2c, TMP105State),
 217        VMSTATE_END_OF_LIST()
 218    }
 219};
 220
 221static void tmp105_reset(I2CSlave *i2c)
 222{
 223    TMP105State *s = TMP105(i2c);
 224
 225    s->temperature = 0;
 226    s->pointer = 0;
 227    s->config = 0;
 228    s->faults = tmp105_faultq[(s->config >> 3) & 3];
 229    s->alarm = 0;
 230
 231    tmp105_interrupt_update(s);
 232}
 233
 234static void tmp105_realize(DeviceState *dev, Error **errp)
 235{
 236    I2CSlave *i2c = I2C_SLAVE(dev);
 237    TMP105State *s = TMP105(i2c);
 238
 239    qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 240
 241    tmp105_reset(&s->i2c);
 242}
 243
 244static void tmp105_initfn(Object *obj)
 245{
 246    object_property_add(obj, "temperature", "int",
 247                        tmp105_get_temperature,
 248                        tmp105_set_temperature, NULL, NULL, NULL);
 249}
 250
 251static void tmp105_class_init(ObjectClass *klass, void *data)
 252{
 253    DeviceClass *dc = DEVICE_CLASS(klass);
 254    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 255
 256    dc->realize = tmp105_realize;
 257    k->event = tmp105_event;
 258    k->recv = tmp105_rx;
 259    k->send = tmp105_tx;
 260    dc->vmsd = &vmstate_tmp105;
 261}
 262
 263static const TypeInfo tmp105_info = {
 264    .name          = TYPE_TMP105,
 265    .parent        = TYPE_I2C_SLAVE,
 266    .instance_size = sizeof(TMP105State),
 267    .instance_init = tmp105_initfn,
 268    .class_init    = tmp105_class_init,
 269};
 270
 271static void tmp105_register_types(void)
 272{
 273    type_register_static(&tmp105_info);
 274}
 275
 276type_init(tmp105_register_types)
 277