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
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  */
  22
  23 #include "hw.h"
  24 #include "i2c.h"
  25
  26 struct tmp105_s {
  27     i2c_slave i2c;
  28     int len;
  29     uint8_t buf[2];
  30     qemu_irq pin;
  31
  32     uint8_t pointer;
  33     uint8_t config;
  34     int16_t temperature;
  35     int16_t limit[2];
  36     int faults;
  37     int alarm;
  38 };
  39
  40 static void tmp105_interrupt_update(struct tmp105_s *s)
  41 {
  42     qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  43 }
  44
  45 static void tmp105_alarm_update(struct tmp105_s *s)
  46 {
  47     if ((s->config >> 0) & 1) {                                 /* SD */
  48         if ((s->config >> 7) & 1)                               /* OS */
  49             s->config &= ~(1 << 7);                             /* OS */
  50         else
  51             return;
  52     }
  53
  54     if ((s->config >> 1) & 1) {                                 /* TM */
  55         if (s->temperature >= s->limit[1])
  56             s->alarm = 1;
  57         else if (s->temperature < s->limit[0])
  58             s->alarm = 1;
  59     } else {
  60         if (s->temperature >= s->limit[1])
  61             s->alarm = 1;
  62         else if (s->temperature < s->limit[0])
  63             s->alarm = 0;
  64     }
  65
  66     tmp105_interrupt_update(s);
  67 }
  68
  69 /* Units are 0.001 centigrades relative to 0 C.  */
  70 void tmp105_set(i2c_slave *i2c, int temp)
  71 {
  72     struct tmp105_s *s = (struct tmp105_s *) i2c;
  73
  74     if (temp >= 128000 || temp < -128000) {
  75         fprintf(stderr, "%s: values is out of range (%i.%03i C)\n",
  76                         __FUNCTION__, temp / 1000, temp % 1000);
  77         exit(-1);
  78     }
  79
  80     s->temperature = ((int16_t) (temp * 0x800 / 128000)) << 4;
  81
  82     tmp105_alarm_update(s);
  83 }
  84
  85 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  86
  87 static void tmp105_read(struct tmp105_s *s)
  88 {
  89     s->len = 0;
  90
  91     if ((s->config >> 1) & 1) {                                 /* TM */
  92         s->alarm = 0;
  93         tmp105_interrupt_update(s);
  94     }
  95
  96     switch (s->pointer & 3) {
  97     case 0:     /* Temperature */
  98         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
  99         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
 100                 (0xf0 << ((~s->config >> 5) & 3));              /* R */
 101         break;
 102
 103     case 1:     /* Configuration */
 104         s->buf[s->len ++] = s->config;
 105         break;
 106
 107     case 2:     /* T_LOW */
 108         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 109         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 110         break;
 111
 112     case 3:     /* T_HIGH */
 113         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 114         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 115         break;
 116     }
 117 }
 118
 119 static void tmp105_write(struct tmp105_s *s)
 120 {
 121     switch (s->pointer & 3) {
 122     case 0:     /* Temperature */
 123         break;
 124
 125     case 1:     /* Configuration */
 126         if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 127             printf("%s: TMP105 shutdown\n", __FUNCTION__);
 128         s->config = s->buf[0];
 129         s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 130         tmp105_alarm_update(s);
 131         break;
 132
 133     case 2:     /* T_LOW */
 134     case 3:     /* T_HIGH */
 135         if (s->len >= 3)
 136             s->limit[s->pointer & 1] = (int16_t)
 137                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 138         tmp105_alarm_update(s);
 139         break;
 140     }
 141 }
 142
 143 static int tmp105_rx(i2c_slave *i2c)
 144 {
 145     struct tmp105_s *s = (struct tmp105_s *) i2c;
 146
 147     if (s->len < 2)
 148         return s->buf[s->len ++];
 149     else
 150         return 0xff;
 151 }
 152
 153 static int tmp105_tx(i2c_slave *i2c, uint8_t data)
 154 {
 155     struct tmp105_s *s = (struct tmp105_s *) i2c;
 156
 157     if (!s->len ++)
 158         s->pointer = data;
 159     else {
 160         if (s->len <= 2)
 161             s->buf[s->len - 1] = data;
 162         tmp105_write(s);
 163     }
 164
 165     return 0;
 166 }
 167
 168 static void tmp105_event(i2c_slave *i2c, enum i2c_event event)
 169 {
 170     struct tmp105_s *s = (struct tmp105_s *) i2c;
 171
 172     if (event == I2C_START_RECV)
 173         tmp105_read(s);
 174
 175     s->len = 0;
 176 }
 177
 178 static void tmp105_save(QEMUFile *f, void *opaque)
 179 {
 180     struct tmp105_s *s = (struct tmp105_s *) opaque;
 181
 182     qemu_put_byte(f, s->len);
 183     qemu_put_8s(f, &s->buf[0]);
 184     qemu_put_8s(f, &s->buf[1]);
 185
 186     qemu_put_8s(f, &s->pointer);
 187     qemu_put_8s(f, &s->config);
 188     qemu_put_be16s(f, (uint16_t *) &s->temperature);
 189     qemu_put_be16s(f, (uint16_t *) &s->limit[0]);
 190     qemu_put_be16s(f, (uint16_t *) &s->limit[1]);
 191     qemu_put_byte(f, s->alarm);
 192     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 193
 194     i2c_slave_save(f, &s->i2c);
 195 }
 196
 197 static int tmp105_load(QEMUFile *f, void *opaque, int version_id)
 198 {
 199     struct tmp105_s *s = (struct tmp105_s *) opaque;
 200
 201     s->len = qemu_get_byte(f);
 202     qemu_get_8s(f, &s->buf[0]);
 203     qemu_get_8s(f, &s->buf[1]);
 204
 205     qemu_get_8s(f, &s->pointer);
 206     qemu_get_8s(f, &s->config);
 207     qemu_get_be16s(f, (uint16_t *) &s->temperature);
 208     qemu_get_be16s(f, (uint16_t *) &s->limit[0]);
 209     qemu_get_be16s(f, (uint16_t *) &s->limit[1]);
 210     s->alarm = qemu_get_byte(f);
 211
 212     tmp105_interrupt_update(s);
 213
 214     i2c_slave_load(f, &s->i2c);
 215     return 0;
 216 }
 217
 218 void tmp105_reset(i2c_slave *i2c)
 219 {
 220     struct tmp105_s *s = (struct tmp105_s *) 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 int tmp105_iid = 0;
 232
 233 struct i2c_slave *tmp105_init(i2c_bus *bus, qemu_irq alarm)
 234 {
 235     struct tmp105_s *s = (struct tmp105_s *)
 236             i2c_slave_init(bus, 0, sizeof(struct tmp105_s));
 237
 238     s->i2c.event = tmp105_event;
 239     s->i2c.recv = tmp105_rx;
 240     s->i2c.send = tmp105_tx;
 241     s->pin = alarm;
 242
 243     tmp105_reset(&s->i2c);
 244
 245     register_savevm("TMP105", tmp105_iid ++, 0,
 246                     tmp105_save, tmp105_load, s);
 247
 248     return &s->i2c;
 249 }