hw/misc/tmp105.c

   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
  30 static void tmp105_interrupt_update(TMP105State *s)
  31 {
  32     qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  33 }
  34
  35 static 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
  59 static 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  */
  71 static 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
  94 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  95
  96 static 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
 128 static 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
 152 static 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
 163 static 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
 181 static 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
 193 static 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
 203 static 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
 221 static 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
 234 static 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
 244 static void tmp105_initfn(Object *obj)
 245 {
 246     object_property_add(obj, "temperature", "int",
 247                         tmp105_get_temperature,
 248                         tmp105_set_temperature, NULL, NULL);
 249 }
 250
 251 static 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
 263 static 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
 271 static void tmp105_register_types(void)
 272 {
 273     type_register_static(&tmp105_info);
 274 }
 275
 276 type_init(tmp105_register_types)