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