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, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  */
  21
  22 #include "hw.h"
  23 #include "i2c.h"
  24
  25 typedef struct {
  26     i2c_slave i2c;
  27     int len;
  28     uint8_t buf[2];
  29     qemu_irq pin;
  30
  31     uint8_t pointer;
  32     uint8_t config;
  33     int16_t temperature;
  34     int16_t limit[2];
  35     int faults;
  36     int alarm;
  37 } TMP105State;
  38
  39 static void tmp105_interrupt_update(TMP105State *s)
  40 {
  41     qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  42 }
  43
  44 static void tmp105_alarm_update(TMP105State *s)
  45 {
  46     if ((s->config >> 0) & 1) {                                 /* SD */
  47         if ((s->config >> 7) & 1)                               /* OS */
  48             s->config &= ~(1 << 7);                             /* OS */
  49         else
  50             return;
  51     }
  52
  53     if ((s->config >> 1) & 1) {                                 /* TM */
  54         if (s->temperature >= s->limit[1])
  55             s->alarm = 1;
  56         else if (s->temperature < s->limit[0])
  57             s->alarm = 1;
  58     } else {
  59         if (s->temperature >= s->limit[1])
  60             s->alarm = 1;
  61         else if (s->temperature < s->limit[0])
  62             s->alarm = 0;
  63     }
  64
  65     tmp105_interrupt_update(s);
  66 }
  67
  68 /* Units are 0.001 centigrades relative to 0 C.  */
  69 void tmp105_set(i2c_slave *i2c, int temp)
  70 {
  71     TMP105State *s = (TMP105State *) i2c;
  72
  73     if (temp >= 128000 || temp < -128000) {
  74         fprintf(stderr, "%s: values is out of range (%i.%03i C)\n",
  75                         __FUNCTION__, temp / 1000, temp % 1000);
  76         exit(-1);
  77     }
  78
  79     s->temperature = ((int16_t) (temp * 0x800 / 128000)) << 4;
  80
  81     tmp105_alarm_update(s);
  82 }
  83
  84 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  85
  86 static void tmp105_read(TMP105State *s)
  87 {
  88     s->len = 0;
  89
  90     if ((s->config >> 1) & 1) {                                 /* TM */
  91         s->alarm = 0;
  92         tmp105_interrupt_update(s);
  93     }
  94
  95     switch (s->pointer & 3) {
  96     case 0:     /* Temperature */
  97         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
  98         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
  99                 (0xf0 << ((~s->config >> 5) & 3));              /* R */
 100         break;
 101
 102     case 1:     /* Configuration */
 103         s->buf[s->len ++] = s->config;
 104         break;
 105
 106     case 2:     /* T_LOW */
 107         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 108         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 109         break;
 110
 111     case 3:     /* T_HIGH */
 112         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 113         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 114         break;
 115     }
 116 }
 117
 118 static void tmp105_write(TMP105State *s)
 119 {
 120     switch (s->pointer & 3) {
 121     case 0:     /* Temperature */
 122         break;
 123
 124     case 1:     /* Configuration */
 125         if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 126             printf("%s: TMP105 shutdown\n", __FUNCTION__);
 127         s->config = s->buf[0];
 128         s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 129         tmp105_alarm_update(s);
 130         break;
 131
 132     case 2:     /* T_LOW */
 133     case 3:     /* T_HIGH */
 134         if (s->len >= 3)
 135             s->limit[s->pointer & 1] = (int16_t)
 136                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 137         tmp105_alarm_update(s);
 138         break;
 139     }
 140 }
 141
 142 static int tmp105_rx(i2c_slave *i2c)
 143 {
 144     TMP105State *s = (TMP105State *) i2c;
 145
 146     if (s->len < 2)
 147         return s->buf[s->len ++];
 148     else
 149         return 0xff;
 150 }
 151
 152 static int tmp105_tx(i2c_slave *i2c, uint8_t data)
 153 {
 154     TMP105State *s = (TMP105State *) i2c;
 155
 156     if (!s->len ++)
 157         s->pointer = data;
 158     else {
 159         if (s->len <= 2)
 160             s->buf[s->len - 1] = data;
 161         tmp105_write(s);
 162     }
 163
 164     return 0;
 165 }
 166
 167 static void tmp105_event(i2c_slave *i2c, enum i2c_event event)
 168 {
 169     TMP105State *s = (TMP105State *) i2c;
 170
 171     if (event == I2C_START_RECV)
 172         tmp105_read(s);
 173
 174     s->len = 0;
 175 }
 176
 177 static void tmp105_save(QEMUFile *f, void *opaque)
 178 {
 179     TMP105State *s = (TMP105State *) opaque;
 180
 181     qemu_put_byte(f, s->len);
 182     qemu_put_8s(f, &s->buf[0]);
 183     qemu_put_8s(f, &s->buf[1]);
 184
 185     qemu_put_8s(f, &s->pointer);
 186     qemu_put_8s(f, &s->config);
 187     qemu_put_sbe16s(f, &s->temperature);
 188     qemu_put_sbe16s(f, &s->limit[0]);
 189     qemu_put_sbe16s(f, &s->limit[1]);
 190     qemu_put_byte(f, s->alarm);
 191     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 192
 193     i2c_slave_save(f, &s->i2c);
 194 }
 195
 196 static int tmp105_load(QEMUFile *f, void *opaque, int version_id)
 197 {
 198     TMP105State *s = (TMP105State *) opaque;
 199
 200     s->len = qemu_get_byte(f);
 201     qemu_get_8s(f, &s->buf[0]);
 202     qemu_get_8s(f, &s->buf[1]);
 203
 204     qemu_get_8s(f, &s->pointer);
 205     qemu_get_8s(f, &s->config);
 206     qemu_get_sbe16s(f, &s->temperature);
 207     qemu_get_sbe16s(f, &s->limit[0]);
 208     qemu_get_sbe16s(f, &s->limit[1]);
 209     s->alarm = qemu_get_byte(f);
 210
 211     tmp105_interrupt_update(s);
 212
 213     i2c_slave_load(f, &s->i2c);
 214     return 0;
 215 }
 216
 217 static void tmp105_reset(i2c_slave *i2c)
 218 {
 219     TMP105State *s = (TMP105State *) 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 void tmp105_init(i2c_slave *i2c)
 231 {
 232     TMP105State *s = FROM_I2C_SLAVE(TMP105State, i2c);
 233
 234     qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 235
 236     tmp105_reset(&s->i2c);
 237
 238     register_savevm("TMP105", -1, 0, tmp105_save, tmp105_load, s);
 239 }
 240
 241 static I2CSlaveInfo tmp105_info = {
 242     .init = tmp105_init,
 243     .event = tmp105_event,
 244     .recv = tmp105_rx,
 245     .send = tmp105_tx
 246 };
 247
 248 static void tmp105_register_devices(void)
 249 {
 250     i2c_register_slave("tmp105", sizeof(TMP105State), &tmp105_info);
 251 }
 252
 253 device_init(tmp105_register_devices)