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/hw.h"
  23 #include "hw/i2c/i2c.h"
  24 #include "tmp105.h"
  25 #include "qapi/error.h"
  26 #include "qapi/visitor.h"
  27 #include "qemu/module.h"
  28
  29 static void tmp105_interrupt_update(TMP105State *s)
  30 {
  31     qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  32 }
  33
  34 static void tmp105_alarm_update(TMP105State *s)
  35 {
  36     if ((s->config >> 0) & 1) {                                 /* SD */
  37         if ((s->config >> 7) & 1)                               /* OS */
  38             s->config &= ~(1 << 7);                             /* OS */
  39         else
  40             return;
  41     }
  42
  43     if ((s->config >> 1) & 1) {                                 /* TM */
  44         if (s->temperature >= s->limit[1])
  45             s->alarm = 1;
  46         else if (s->temperature < s->limit[0])
  47             s->alarm = 1;
  48     } else {
  49         if (s->temperature >= s->limit[1])
  50             s->alarm = 1;
  51         else if (s->temperature < s->limit[0])
  52             s->alarm = 0;
  53     }
  54
  55     tmp105_interrupt_update(s);
  56 }
  57
  58 static void tmp105_get_temperature(Object *obj, Visitor *v, const char *name,
  59                                    void *opaque, Error **errp)
  60 {
  61     TMP105State *s = TMP105(obj);
  62     int64_t value = s->temperature * 1000 / 256;
  63
  64     visit_type_int(v, name, &value, errp);
  65 }
  66
  67 /* Units are 0.001 centigrades relative to 0 C.  s->temperature is 8.8
  68  * fixed point, so units are 1/256 centigrades.  A simple ratio will do.
  69  */
  70 static void tmp105_set_temperature(Object *obj, Visitor *v, const char *name,
  71                                    void *opaque, Error **errp)
  72 {
  73     TMP105State *s = TMP105(obj);
  74     Error *local_err = NULL;
  75     int64_t temp;
  76
  77     visit_type_int(v, name, &temp, &local_err);
  78     if (local_err) {
  79         error_propagate(errp, local_err);
  80         return;
  81     }
  82     if (temp >= 128000 || temp < -128000) {
  83         error_setg(errp, "value %" PRId64 ".%03" PRIu64 " C is out of range",
  84                    temp / 1000, temp % 1000);
  85         return;
  86     }
  87
  88     s->temperature = (int16_t) (temp * 256 / 1000);
  89
  90     tmp105_alarm_update(s);
  91 }
  92
  93 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  94
  95 static void tmp105_read(TMP105State *s)
  96 {
  97     s->len = 0;
  98
  99     if ((s->config >> 1) & 1) {                                 /* TM */
 100         s->alarm = 0;
 101         tmp105_interrupt_update(s);
 102     }
 103
 104     switch (s->pointer & 3) {
 105     case TMP105_REG_TEMPERATURE:
 106         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
 107         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
 108                 (0xf0 << ((~s->config >> 5) & 3));              /* R */
 109         break;
 110
 111     case TMP105_REG_CONFIG:
 112         s->buf[s->len ++] = s->config;
 113         break;
 114
 115     case TMP105_REG_T_LOW:
 116         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 117         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 118         break;
 119
 120     case TMP105_REG_T_HIGH:
 121         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 122         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 123         break;
 124     }
 125 }
 126
 127 static void tmp105_write(TMP105State *s)
 128 {
 129     switch (s->pointer & 3) {
 130     case TMP105_REG_TEMPERATURE:
 131         break;
 132
 133     case TMP105_REG_CONFIG:
 134         if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 135             printf("%s: TMP105 shutdown\n", __func__);
 136         s->config = s->buf[0];
 137         s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 138         tmp105_alarm_update(s);
 139         break;
 140
 141     case TMP105_REG_T_LOW:
 142     case TMP105_REG_T_HIGH:
 143         if (s->len >= 3)
 144             s->limit[s->pointer & 1] = (int16_t)
 145                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 146         tmp105_alarm_update(s);
 147         break;
 148     }
 149 }
 150
 151 static uint8_t tmp105_rx(I2CSlave *i2c)
 152 {
 153     TMP105State *s = TMP105(i2c);
 154
 155     if (s->len < 2) {
 156         return s->buf[s->len ++];
 157     } else {
 158         return 0xff;
 159     }
 160 }
 161
 162 static int tmp105_tx(I2CSlave *i2c, uint8_t data)
 163 {
 164     TMP105State *s = TMP105(i2c);
 165
 166     if (s->len == 0) {
 167         s->pointer = data;
 168         s->len++;
 169     } else {
 170         if (s->len <= 2) {
 171             s->buf[s->len - 1] = data;
 172         }
 173         s->len++;
 174         tmp105_write(s);
 175     }
 176
 177     return 0;
 178 }
 179
 180 static int tmp105_event(I2CSlave *i2c, enum i2c_event event)
 181 {
 182     TMP105State *s = TMP105(i2c);
 183
 184     if (event == I2C_START_RECV) {
 185         tmp105_read(s);
 186     }
 187
 188     s->len = 0;
 189     return 0;
 190 }
 191
 192 static int tmp105_post_load(void *opaque, int version_id)
 193 {
 194     TMP105State *s = opaque;
 195
 196     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 197
 198     tmp105_interrupt_update(s);
 199     return 0;
 200 }
 201
 202 static const VMStateDescription vmstate_tmp105 = {
 203     .name = "TMP105",
 204     .version_id = 0,
 205     .minimum_version_id = 0,
 206     .post_load = tmp105_post_load,
 207     .fields = (VMStateField[]) {
 208         VMSTATE_UINT8(len, TMP105State),
 209         VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
 210         VMSTATE_UINT8(pointer, TMP105State),
 211         VMSTATE_UINT8(config, TMP105State),
 212         VMSTATE_INT16(temperature, TMP105State),
 213         VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
 214         VMSTATE_UINT8(alarm, TMP105State),
 215         VMSTATE_I2C_SLAVE(i2c, TMP105State),
 216         VMSTATE_END_OF_LIST()
 217     }
 218 };
 219
 220 static void tmp105_reset(I2CSlave *i2c)
 221 {
 222     TMP105State *s = TMP105(i2c);
 223
 224     s->temperature = 0;
 225     s->pointer = 0;
 226     s->config = 0;
 227     s->faults = tmp105_faultq[(s->config >> 3) & 3];
 228     s->alarm = 0;
 229
 230     tmp105_interrupt_update(s);
 231 }
 232
 233 static void tmp105_realize(DeviceState *dev, Error **errp)
 234 {
 235     I2CSlave *i2c = I2C_SLAVE(dev);
 236     TMP105State *s = TMP105(i2c);
 237
 238     qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 239
 240     tmp105_reset(&s->i2c);
 241 }
 242
 243 static void tmp105_initfn(Object *obj)
 244 {
 245     object_property_add(obj, "temperature", "int",
 246                         tmp105_get_temperature,
 247                         tmp105_set_temperature, NULL, NULL, NULL);
 248 }
 249
 250 static void tmp105_class_init(ObjectClass *klass, void *data)
 251 {
 252     DeviceClass *dc = DEVICE_CLASS(klass);
 253     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 254
 255     dc->realize = tmp105_realize;
 256     k->event = tmp105_event;
 257     k->recv = tmp105_rx;
 258     k->send = tmp105_tx;
 259     dc->vmsd = &vmstate_tmp105;
 260 }
 261
 262 static const TypeInfo tmp105_info = {
 263     .name          = TYPE_TMP105,
 264     .parent        = TYPE_I2C_SLAVE,
 265     .instance_size = sizeof(TMP105State),
 266     .instance_init = tmp105_initfn,
 267     .class_init    = tmp105_class_init,
 268 };
 269
 270 static void tmp105_register_types(void)
 271 {
 272     type_register_static(&tmp105_info);
 273 }
 274
 275 type_init(tmp105_register_types)