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 "hw/hw.h"
  22 #include "hw/i2c/i2c.h"
  23 #include "tmp105.h"
  24 #include "qapi/visitor.h"
  25
  26 static void tmp105_interrupt_update(TMP105State *s)
  27 {
  28     qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  29 }
  30
  31 static void tmp105_alarm_update(TMP105State *s)
  32 {
  33     if ((s->config >> 0) & 1) {                                 /* SD */
  34         if ((s->config >> 7) & 1)                               /* OS */
  35             s->config &= ~(1 << 7);                             /* OS */
  36         else
  37             return;
  38     }
  39
  40     if ((s->config >> 1) & 1) {                                 /* TM */
  41         if (s->temperature >= s->limit[1])
  42             s->alarm = 1;
  43         else if (s->temperature < s->limit[0])
  44             s->alarm = 1;
  45     } else {
  46         if (s->temperature >= s->limit[1])
  47             s->alarm = 1;
  48         else if (s->temperature < s->limit[0])
  49             s->alarm = 0;
  50     }
  51
  52     tmp105_interrupt_update(s);
  53 }
  54
  55 static void tmp105_get_temperature(Object *obj, Visitor *v, void *opaque,
  56                                    const char *name, Error **errp)
  57 {
  58     TMP105State *s = TMP105(obj);
  59     int64_t value = s->temperature * 1000 / 256;
  60
  61     visit_type_int(v, &value, name, errp);
  62 }
  63
  64 /* Units are 0.001 centigrades relative to 0 C.  s->temperature is 8.8
  65  * fixed point, so units are 1/256 centigrades.  A simple ratio will do.
  66  */
  67 static void tmp105_set_temperature(Object *obj, Visitor *v, void *opaque,
  68                                    const char *name, Error **errp)
  69 {
  70     TMP105State *s = TMP105(obj);
  71     Error *local_err = NULL;
  72     int64_t temp;
  73
  74     visit_type_int(v, &temp, name, &local_err);
  75     if (local_err) {
  76         error_propagate(errp, local_err);
  77         return;
  78     }
  79     if (temp >= 128000 || temp < -128000) {
  80         error_setg(errp, "value %" PRId64 ".%03" PRIu64 " °C is out of range",
  81                    temp / 1000, temp % 1000);
  82         return;
  83     }
  84
  85     s->temperature = (int16_t) (temp * 256 / 1000);
  86
  87     tmp105_alarm_update(s);
  88 }
  89
  90 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  91
  92 static void tmp105_read(TMP105State *s)
  93 {
  94     s->len = 0;
  95
  96     if ((s->config >> 1) & 1) {                                 /* TM */
  97         s->alarm = 0;
  98         tmp105_interrupt_update(s);
  99     }
 100
 101     switch (s->pointer & 3) {
 102     case TMP105_REG_TEMPERATURE:
 103         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
 104         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
 105                 (0xf0 << ((~s->config >> 5) & 3));              /* R */
 106         break;
 107
 108     case TMP105_REG_CONFIG:
 109         s->buf[s->len ++] = s->config;
 110         break;
 111
 112     case TMP105_REG_T_LOW:
 113         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 114         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 115         break;
 116
 117     case TMP105_REG_T_HIGH:
 118         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 119         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 120         break;
 121     }
 122 }
 123
 124 static void tmp105_write(TMP105State *s)
 125 {
 126     switch (s->pointer & 3) {
 127     case TMP105_REG_TEMPERATURE:
 128         break;
 129
 130     case TMP105_REG_CONFIG:
 131         if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 132             printf("%s: TMP105 shutdown\n", __FUNCTION__);
 133         s->config = s->buf[0];
 134         s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 135         tmp105_alarm_update(s);
 136         break;
 137
 138     case TMP105_REG_T_LOW:
 139     case TMP105_REG_T_HIGH:
 140         if (s->len >= 3)
 141             s->limit[s->pointer & 1] = (int16_t)
 142                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 143         tmp105_alarm_update(s);
 144         break;
 145     }
 146 }
 147
 148 static int tmp105_rx(I2CSlave *i2c)
 149 {
 150     TMP105State *s = TMP105(i2c);
 151
 152     if (s->len < 2) {
 153         return s->buf[s->len ++];
 154     } else {
 155         return 0xff;
 156     }
 157 }
 158
 159 static int tmp105_tx(I2CSlave *i2c, uint8_t data)
 160 {
 161     TMP105State *s = TMP105(i2c);
 162
 163     if (s->len == 0) {
 164         s->pointer = data;
 165         s->len++;
 166     } else {
 167         if (s->len <= 2) {
 168             s->buf[s->len - 1] = data;
 169         }
 170         s->len++;
 171         tmp105_write(s);
 172     }
 173
 174     return 0;
 175 }
 176
 177 static void tmp105_event(I2CSlave *i2c, enum i2c_event event)
 178 {
 179     TMP105State *s = TMP105(i2c);
 180
 181     if (event == I2C_START_RECV) {
 182         tmp105_read(s);
 183     }
 184
 185     s->len = 0;
 186 }
 187
 188 static int tmp105_post_load(void *opaque, int version_id)
 189 {
 190     TMP105State *s = opaque;
 191
 192     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 193
 194     tmp105_interrupt_update(s);
 195     return 0;
 196 }
 197
 198 static const VMStateDescription vmstate_tmp105 = {
 199     .name = "TMP105",
 200     .version_id = 0,
 201     .minimum_version_id = 0,
 202     .post_load = tmp105_post_load,
 203     .fields = (VMStateField[]) {
 204         VMSTATE_UINT8(len, TMP105State),
 205         VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
 206         VMSTATE_UINT8(pointer, TMP105State),
 207         VMSTATE_UINT8(config, TMP105State),
 208         VMSTATE_INT16(temperature, TMP105State),
 209         VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
 210         VMSTATE_UINT8(alarm, TMP105State),
 211         VMSTATE_I2C_SLAVE(i2c, TMP105State),
 212         VMSTATE_END_OF_LIST()
 213     }
 214 };
 215
 216 static void tmp105_reset(I2CSlave *i2c)
 217 {
 218     TMP105State *s = TMP105(i2c);
 219
 220     s->temperature = 0;
 221     s->pointer = 0;
 222     s->config = 0;
 223     s->faults = tmp105_faultq[(s->config >> 3) & 3];
 224     s->alarm = 0;
 225
 226     tmp105_interrupt_update(s);
 227 }
 228
 229 static int tmp105_init(I2CSlave *i2c)
 230 {
 231     TMP105State *s = TMP105(i2c);
 232
 233     qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 234
 235     tmp105_reset(&s->i2c);
 236
 237     return 0;
 238 }
 239
 240 static void tmp105_initfn(Object *obj)
 241 {
 242     object_property_add(obj, "temperature", "int",
 243                         tmp105_get_temperature,
 244                         tmp105_set_temperature, NULL, NULL, NULL);
 245 }
 246
 247 static void tmp105_class_init(ObjectClass *klass, void *data)
 248 {
 249     DeviceClass *dc = DEVICE_CLASS(klass);
 250     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 251
 252     k->init = tmp105_init;
 253     k->event = tmp105_event;
 254     k->recv = tmp105_rx;
 255     k->send = tmp105_tx;
 256     dc->vmsd = &vmstate_tmp105;
 257 }
 258
 259 static const TypeInfo tmp105_info = {
 260     .name          = TYPE_TMP105,
 261     .parent        = TYPE_I2C_SLAVE,
 262     .instance_size = sizeof(TMP105State),
 263     .instance_init = tmp105_initfn,
 264     .class_init    = tmp105_class_init,
 265 };
 266
 267 static void tmp105_register_types(void)
 268 {
 269     type_register_static(&tmp105_info);
 270 }
 271
 272 type_init(tmp105_register_types)