hw/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.h"
  23 #include "hw/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;
  60
  61     visit_type_int(v, &value, name, errp);
  62 }
  63
  64 /* Units are 0.001 centigrades relative to 0 C.  */
  65 static void tmp105_set_temperature(Object *obj, Visitor *v, void *opaque,
  66                                    const char *name, Error **errp)
  67 {
  68     TMP105State *s = TMP105(obj);
  69     int64_t temp;
  70
  71     visit_type_int(v, &temp, name, errp);
  72     if (error_is_set(errp)) {
  73         return;
  74     }
  75     if (temp >= 128000 || temp < -128000) {
  76         error_setg(errp, "value %" PRId64 ".%03" PRIu64 " °C is out of range",
  77                    temp / 1000, temp % 1000);
  78         return;
  79     }
  80
  81     s->temperature = ((int16_t) (temp * 0x800 / 128000)) << 4;
  82
  83     tmp105_alarm_update(s);
  84 }
  85
  86 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  87
  88 static void tmp105_read(TMP105State *s)
  89 {
  90     s->len = 0;
  91
  92     if ((s->config >> 1) & 1) {                                 /* TM */
  93         s->alarm = 0;
  94         tmp105_interrupt_update(s);
  95     }
  96
  97     switch (s->pointer & 3) {
  98     case TMP105_REG_TEMPERATURE:
  99         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
 100         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
 101                 (0xf0 << ((~s->config >> 5) & 3));              /* R */
 102         break;
 103
 104     case TMP105_REG_CONFIG:
 105         s->buf[s->len ++] = s->config;
 106         break;
 107
 108     case TMP105_REG_T_LOW:
 109         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 110         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 111         break;
 112
 113     case TMP105_REG_T_HIGH:
 114         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 115         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 116         break;
 117     }
 118 }
 119
 120 static void tmp105_write(TMP105State *s)
 121 {
 122     switch (s->pointer & 3) {
 123     case TMP105_REG_TEMPERATURE:
 124         break;
 125
 126     case TMP105_REG_CONFIG:
 127         if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 128             printf("%s: TMP105 shutdown\n", __FUNCTION__);
 129         s->config = s->buf[0];
 130         s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 131         tmp105_alarm_update(s);
 132         break;
 133
 134     case TMP105_REG_T_LOW:
 135     case TMP105_REG_T_HIGH:
 136         if (s->len >= 3)
 137             s->limit[s->pointer & 1] = (int16_t)
 138                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 139         tmp105_alarm_update(s);
 140         break;
 141     }
 142 }
 143
 144 static int tmp105_rx(I2CSlave *i2c)
 145 {
 146     TMP105State *s = TMP105(i2c);
 147
 148     if (s->len < 2) {
 149         return s->buf[s->len ++];
 150     } else {
 151         return 0xff;
 152     }
 153 }
 154
 155 static int tmp105_tx(I2CSlave *i2c, uint8_t data)
 156 {
 157     TMP105State *s = TMP105(i2c);
 158
 159     if (s->len == 0) {
 160         s->pointer = data;
 161         s->len++;
 162     } else {
 163         if (s->len <= 2) {
 164             s->buf[s->len - 1] = data;
 165         }
 166         s->len++;
 167         tmp105_write(s);
 168     }
 169
 170     return 0;
 171 }
 172
 173 static void tmp105_event(I2CSlave *i2c, enum i2c_event event)
 174 {
 175     TMP105State *s = TMP105(i2c);
 176
 177     if (event == I2C_START_RECV) {
 178         tmp105_read(s);
 179     }
 180
 181     s->len = 0;
 182 }
 183
 184 static int tmp105_post_load(void *opaque, int version_id)
 185 {
 186     TMP105State *s = opaque;
 187
 188     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 189
 190     tmp105_interrupt_update(s);
 191     return 0;
 192 }
 193
 194 static const VMStateDescription vmstate_tmp105 = {
 195     .name = "TMP105",
 196     .version_id = 0,
 197     .minimum_version_id = 0,
 198     .minimum_version_id_old = 0,
 199     .post_load = tmp105_post_load,
 200     .fields      = (VMStateField []) {
 201         VMSTATE_UINT8(len, TMP105State),
 202         VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
 203         VMSTATE_UINT8(pointer, TMP105State),
 204         VMSTATE_UINT8(config, TMP105State),
 205         VMSTATE_INT16(temperature, TMP105State),
 206         VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
 207         VMSTATE_UINT8(alarm, TMP105State),
 208         VMSTATE_I2C_SLAVE(i2c, TMP105State),
 209         VMSTATE_END_OF_LIST()
 210     }
 211 };
 212
 213 static void tmp105_reset(I2CSlave *i2c)
 214 {
 215     TMP105State *s = TMP105(i2c);
 216
 217     s->temperature = 0;
 218     s->pointer = 0;
 219     s->config = 0;
 220     s->faults = tmp105_faultq[(s->config >> 3) & 3];
 221     s->alarm = 0;
 222
 223     tmp105_interrupt_update(s);
 224 }
 225
 226 static int tmp105_init(I2CSlave *i2c)
 227 {
 228     TMP105State *s = TMP105(i2c);
 229
 230     qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 231
 232     tmp105_reset(&s->i2c);
 233
 234     return 0;
 235 }
 236
 237 static void tmp105_initfn(Object *obj)
 238 {
 239     object_property_add(obj, "temperature", "int",
 240                         tmp105_get_temperature,
 241                         tmp105_set_temperature, NULL, NULL, NULL);
 242 }
 243
 244 static void tmp105_class_init(ObjectClass *klass, void *data)
 245 {
 246     DeviceClass *dc = DEVICE_CLASS(klass);
 247     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 248
 249     k->init = tmp105_init;
 250     k->event = tmp105_event;
 251     k->recv = tmp105_rx;
 252     k->send = tmp105_tx;
 253     dc->vmsd = &vmstate_tmp105;
 254 }
 255
 256 static const TypeInfo tmp105_info = {
 257     .name          = TYPE_TMP105,
 258     .parent        = TYPE_I2C_SLAVE,
 259     .instance_size = sizeof(TMP105State),
 260     .instance_init = tmp105_initfn,
 261     .class_init    = tmp105_class_init,
 262 };
 263
 264 static void tmp105_register_types(void)
 265 {
 266     type_register_static(&tmp105_info);
 267 }
 268
 269 type_init(tmp105_register_types)