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     int64_t temp;
  76
  77     if (!visit_type_int(v, name, &temp, errp)) {
  78         return;
  79     }
  80     if (temp >= 128000 || temp < -128000) {
  81         error_setg(errp, "value %" PRId64 ".%03" PRIu64 " C is out of range",
  82                    temp / 1000, temp % 1000);
  83         return;
  84     }
  85
  86     s->temperature = (int16_t) (temp * 256 / 1000);
  87
  88     tmp105_alarm_update(s);
  89 }
  90
  91 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  92
  93 static void tmp105_read(TMP105State *s)
  94 {
  95     s->len = 0;
  96
  97     if ((s->config >> 1) & 1) {                                 /* TM */
  98         s->alarm = 0;
  99         tmp105_interrupt_update(s);
 100     }
 101
 102     switch (s->pointer & 3) {
 103     case TMP105_REG_TEMPERATURE:
 104         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
 105         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
 106                 (0xf0 << ((~s->config >> 5) & 3));              /* R */
 107         break;
 108
 109     case TMP105_REG_CONFIG:
 110         s->buf[s->len ++] = s->config;
 111         break;
 112
 113     case TMP105_REG_T_LOW:
 114         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 115         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 116         break;
 117
 118     case TMP105_REG_T_HIGH:
 119         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 120         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 121         break;
 122     }
 123 }
 124
 125 static void tmp105_write(TMP105State *s)
 126 {
 127     switch (s->pointer & 3) {
 128     case TMP105_REG_TEMPERATURE:
 129         break;
 130
 131     case TMP105_REG_CONFIG:
 132         if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 133             printf("%s: TMP105 shutdown\n", __func__);
 134         s->config = s->buf[0];
 135         s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 136         tmp105_alarm_update(s);
 137         break;
 138
 139     case TMP105_REG_T_LOW:
 140     case TMP105_REG_T_HIGH:
 141         if (s->len >= 3)
 142             s->limit[s->pointer & 1] = (int16_t)
 143                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 144         tmp105_alarm_update(s);
 145         break;
 146     }
 147 }
 148
 149 static uint8_t tmp105_rx(I2CSlave *i2c)
 150 {
 151     TMP105State *s = TMP105(i2c);
 152
 153     if (s->len < 2) {
 154         return s->buf[s->len ++];
 155     } else {
 156         return 0xff;
 157     }
 158 }
 159
 160 static int tmp105_tx(I2CSlave *i2c, uint8_t data)
 161 {
 162     TMP105State *s = TMP105(i2c);
 163
 164     if (s->len == 0) {
 165         s->pointer = data;
 166         s->len++;
 167     } else {
 168         if (s->len <= 2) {
 169             s->buf[s->len - 1] = data;
 170         }
 171         s->len++;
 172         tmp105_write(s);
 173     }
 174
 175     return 0;
 176 }
 177
 178 static int tmp105_event(I2CSlave *i2c, enum i2c_event event)
 179 {
 180     TMP105State *s = TMP105(i2c);
 181
 182     if (event == I2C_START_RECV) {
 183         tmp105_read(s);
 184     }
 185
 186     s->len = 0;
 187     return 0;
 188 }
 189
 190 static int tmp105_post_load(void *opaque, int version_id)
 191 {
 192     TMP105State *s = opaque;
 193
 194     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 195
 196     tmp105_interrupt_update(s);
 197     return 0;
 198 }
 199
 200 static const VMStateDescription vmstate_tmp105 = {
 201     .name = "TMP105",
 202     .version_id = 0,
 203     .minimum_version_id = 0,
 204     .post_load = tmp105_post_load,
 205     .fields = (VMStateField[]) {
 206         VMSTATE_UINT8(len, TMP105State),
 207         VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
 208         VMSTATE_UINT8(pointer, TMP105State),
 209         VMSTATE_UINT8(config, TMP105State),
 210         VMSTATE_INT16(temperature, TMP105State),
 211         VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
 212         VMSTATE_UINT8(alarm, TMP105State),
 213         VMSTATE_I2C_SLAVE(i2c, TMP105State),
 214         VMSTATE_END_OF_LIST()
 215     }
 216 };
 217
 218 static void tmp105_reset(I2CSlave *i2c)
 219 {
 220     TMP105State *s = TMP105(i2c);
 221
 222     s->temperature = 0;
 223     s->pointer = 0;
 224     s->config = 0;
 225     s->faults = tmp105_faultq[(s->config >> 3) & 3];
 226     s->alarm = 0;
 227
 228     tmp105_interrupt_update(s);
 229 }
 230
 231 static void tmp105_realize(DeviceState *dev, Error **errp)
 232 {
 233     I2CSlave *i2c = I2C_SLAVE(dev);
 234     TMP105State *s = TMP105(i2c);
 235
 236     qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 237
 238     tmp105_reset(&s->i2c);
 239 }
 240
 241 static void tmp105_initfn(Object *obj)
 242 {
 243     object_property_add(obj, "temperature", "int",
 244                         tmp105_get_temperature,
 245                         tmp105_set_temperature, NULL, NULL);
 246 }
 247
 248 static void tmp105_class_init(ObjectClass *klass, void *data)
 249 {
 250     DeviceClass *dc = DEVICE_CLASS(klass);
 251     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 252
 253     dc->realize = tmp105_realize;
 254     k->event = tmp105_event;
 255     k->recv = tmp105_rx;
 256     k->send = tmp105_tx;
 257     dc->vmsd = &vmstate_tmp105;
 258 }
 259
 260 static const TypeInfo tmp105_info = {
 261     .name          = TYPE_TMP105,
 262     .parent        = TYPE_I2C_SLAVE,
 263     .instance_size = sizeof(TMP105State),
 264     .instance_init = tmp105_initfn,
 265     .class_init    = tmp105_class_init,
 266 };
 267
 268 static void tmp105_register_types(void)
 269 {
 270     type_register_static(&tmp105_info);
 271 }
 272
 273 type_init(tmp105_register_types)