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/visitor.h"
  26
  27 static void tmp105_interrupt_update(TMP105State *s)
  28 {
  29     qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  30 }
  31
  32 static void tmp105_alarm_update(TMP105State *s)
  33 {
  34     if ((s->config >> 0) & 1) {                                 /* SD */
  35         if ((s->config >> 7) & 1)                               /* OS */
  36             s->config &= ~(1 << 7);                             /* OS */
  37         else
  38             return;
  39     }
  40
  41     if ((s->config >> 1) & 1) {                                 /* TM */
  42         if (s->temperature >= s->limit[1])
  43             s->alarm = 1;
  44         else if (s->temperature < s->limit[0])
  45             s->alarm = 1;
  46     } else {
  47         if (s->temperature >= s->limit[1])
  48             s->alarm = 1;
  49         else if (s->temperature < s->limit[0])
  50             s->alarm = 0;
  51     }
  52
  53     tmp105_interrupt_update(s);
  54 }
  55
  56 static void tmp105_get_temperature(Object *obj, Visitor *v, void *opaque,
  57                                    const char *name, Error **errp)
  58 {
  59     TMP105State *s = TMP105(obj);
  60     int64_t value = s->temperature * 1000 / 256;
  61
  62     visit_type_int(v, &value, name, errp);
  63 }
  64
  65 /* Units are 0.001 centigrades relative to 0 C.  s->temperature is 8.8
  66  * fixed point, so units are 1/256 centigrades.  A simple ratio will do.
  67  */
  68 static void tmp105_set_temperature(Object *obj, Visitor *v, void *opaque,
  69                                    const char *name, Error **errp)
  70 {
  71     TMP105State *s = TMP105(obj);
  72     Error *local_err = NULL;
  73     int64_t temp;
  74
  75     visit_type_int(v, &temp, name, &local_err);
  76     if (local_err) {
  77         error_propagate(errp, local_err);
  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", __FUNCTION__);
 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 int 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 void 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 }
 188
 189 static int tmp105_post_load(void *opaque, int version_id)
 190 {
 191     TMP105State *s = opaque;
 192
 193     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 194
 195     tmp105_interrupt_update(s);
 196     return 0;
 197 }
 198
 199 static const VMStateDescription vmstate_tmp105 = {
 200     .name = "TMP105",
 201     .version_id = 0,
 202     .minimum_version_id = 0,
 203     .post_load = tmp105_post_load,
 204     .fields = (VMStateField[]) {
 205         VMSTATE_UINT8(len, TMP105State),
 206         VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
 207         VMSTATE_UINT8(pointer, TMP105State),
 208         VMSTATE_UINT8(config, TMP105State),
 209         VMSTATE_INT16(temperature, TMP105State),
 210         VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
 211         VMSTATE_UINT8(alarm, TMP105State),
 212         VMSTATE_I2C_SLAVE(i2c, TMP105State),
 213         VMSTATE_END_OF_LIST()
 214     }
 215 };
 216
 217 static void tmp105_reset(I2CSlave *i2c)
 218 {
 219     TMP105State *s = TMP105(i2c);
 220
 221     s->temperature = 0;
 222     s->pointer = 0;
 223     s->config = 0;
 224     s->faults = tmp105_faultq[(s->config >> 3) & 3];
 225     s->alarm = 0;
 226
 227     tmp105_interrupt_update(s);
 228 }
 229
 230 static int tmp105_init(I2CSlave *i2c)
 231 {
 232     TMP105State *s = TMP105(i2c);
 233
 234     qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 235
 236     tmp105_reset(&s->i2c);
 237
 238     return 0;
 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, 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     k->init = tmp105_init;
 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)