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, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "hw.h"
  22 #include "i2c.h"
  23
  24 typedef struct {
  25     i2c_slave i2c;
  26     uint8_t len;
  27     uint8_t buf[2];
  28     qemu_irq pin;
  29
  30     uint8_t pointer;
  31     uint8_t config;
  32     int16_t temperature;
  33     int16_t limit[2];
  34     int faults;
  35     uint8_t alarm;
  36 } TMP105State;
  37
  38 static void tmp105_interrupt_update(TMP105State *s)
  39 {
  40     qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1));   /* POL */
  41 }
  42
  43 static void tmp105_alarm_update(TMP105State *s)
  44 {
  45     if ((s->config >> 0) & 1) {                                 /* SD */
  46         if ((s->config >> 7) & 1)                               /* OS */
  47             s->config &= ~(1 << 7);                             /* OS */
  48         else
  49             return;
  50     }
  51
  52     if ((s->config >> 1) & 1) {                                 /* TM */
  53         if (s->temperature >= s->limit[1])
  54             s->alarm = 1;
  55         else if (s->temperature < s->limit[0])
  56             s->alarm = 1;
  57     } else {
  58         if (s->temperature >= s->limit[1])
  59             s->alarm = 1;
  60         else if (s->temperature < s->limit[0])
  61             s->alarm = 0;
  62     }
  63
  64     tmp105_interrupt_update(s);
  65 }
  66
  67 /* Units are 0.001 centigrades relative to 0 C.  */
  68 void tmp105_set(i2c_slave *i2c, int temp)
  69 {
  70     TMP105State *s = (TMP105State *) i2c;
  71
  72     if (temp >= 128000 || temp < -128000) {
  73         fprintf(stderr, "%s: values is out of range (%i.%03i C)\n",
  74                         __FUNCTION__, temp / 1000, temp % 1000);
  75         exit(-1);
  76     }
  77
  78     s->temperature = ((int16_t) (temp * 0x800 / 128000)) << 4;
  79
  80     tmp105_alarm_update(s);
  81 }
  82
  83 static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
  84
  85 static void tmp105_read(TMP105State *s)
  86 {
  87     s->len = 0;
  88
  89     if ((s->config >> 1) & 1) {                                 /* TM */
  90         s->alarm = 0;
  91         tmp105_interrupt_update(s);
  92     }
  93
  94     switch (s->pointer & 3) {
  95     case 0:     /* Temperature */
  96         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
  97         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
  98                 (0xf0 << ((~s->config >> 5) & 3));              /* R */
  99         break;
 100
 101     case 1:     /* Configuration */
 102         s->buf[s->len ++] = s->config;
 103         break;
 104
 105     case 2:     /* T_LOW */
 106         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
 107         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
 108         break;
 109
 110     case 3:     /* T_HIGH */
 111         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
 112         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
 113         break;
 114     }
 115 }
 116
 117 static void tmp105_write(TMP105State *s)
 118 {
 119     switch (s->pointer & 3) {
 120     case 0:     /* Temperature */
 121         break;
 122
 123     case 1:     /* Configuration */
 124         if (s->buf[0] & ~s->config & (1 << 0))                  /* SD */
 125             printf("%s: TMP105 shutdown\n", __FUNCTION__);
 126         s->config = s->buf[0];
 127         s->faults = tmp105_faultq[(s->config >> 3) & 3];        /* F */
 128         tmp105_alarm_update(s);
 129         break;
 130
 131     case 2:     /* T_LOW */
 132     case 3:     /* T_HIGH */
 133         if (s->len >= 3)
 134             s->limit[s->pointer & 1] = (int16_t)
 135                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
 136         tmp105_alarm_update(s);
 137         break;
 138     }
 139 }
 140
 141 static int tmp105_rx(i2c_slave *i2c)
 142 {
 143     TMP105State *s = (TMP105State *) i2c;
 144
 145     if (s->len < 2)
 146         return s->buf[s->len ++];
 147     else
 148         return 0xff;
 149 }
 150
 151 static int tmp105_tx(i2c_slave *i2c, uint8_t data)
 152 {
 153     TMP105State *s = (TMP105State *) i2c;
 154
 155     if (!s->len ++)
 156         s->pointer = data;
 157     else {
 158         if (s->len <= 2)
 159             s->buf[s->len - 1] = data;
 160         tmp105_write(s);
 161     }
 162
 163     return 0;
 164 }
 165
 166 static void tmp105_event(i2c_slave *i2c, enum i2c_event event)
 167 {
 168     TMP105State *s = (TMP105State *) i2c;
 169
 170     if (event == I2C_START_RECV)
 171         tmp105_read(s);
 172
 173     s->len = 0;
 174 }
 175
 176 static void tmp105_post_save(void *opaque)
 177 {
 178     TMP105State *s = opaque;
 179     s->faults = tmp105_faultq[(s->config >> 3) & 3];            /* F */
 180 }
 181
 182 static int tmp105_post_load(void *opaque, int version_id)
 183 {
 184     TMP105State *s = opaque;
 185
 186     tmp105_interrupt_update(s);
 187     return 0;
 188 }
 189
 190 static const VMStateDescription vmstate_tmp105 = {
 191     .name = "TMP105",
 192     .version_id = 0,
 193     .minimum_version_id = 0,
 194     .minimum_version_id_old = 0,
 195     .post_save = tmp105_post_save,
 196     .post_load = tmp105_post_load,
 197     .fields      = (VMStateField []) {
 198         VMSTATE_UINT8(len, TMP105State),
 199         VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
 200         VMSTATE_UINT8(pointer, TMP105State),
 201         VMSTATE_UINT8(config, TMP105State),
 202         VMSTATE_INT16(temperature, TMP105State),
 203         VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
 204         VMSTATE_UINT8(alarm, TMP105State),
 205         VMSTATE_I2C_SLAVE(i2c, TMP105State),
 206         VMSTATE_END_OF_LIST()
 207     }
 208 };
 209
 210 static void tmp105_reset(i2c_slave *i2c)
 211 {
 212     TMP105State *s = (TMP105State *) i2c;
 213
 214     s->temperature = 0;
 215     s->pointer = 0;
 216     s->config = 0;
 217     s->faults = tmp105_faultq[(s->config >> 3) & 3];
 218     s->alarm = 0;
 219
 220     tmp105_interrupt_update(s);
 221 }
 222
 223 static int tmp105_init(i2c_slave *i2c)
 224 {
 225     TMP105State *s = FROM_I2C_SLAVE(TMP105State, i2c);
 226
 227     qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
 228
 229     tmp105_reset(&s->i2c);
 230
 231     vmstate_register(-1, &vmstate_tmp105, s);
 232     return 0;
 233 }
 234
 235 static I2CSlaveInfo tmp105_info = {
 236     .qdev.name = "tmp105",
 237     .qdev.size = sizeof(TMP105State),
 238     .init = tmp105_init,
 239     .event = tmp105_event,
 240     .recv = tmp105_rx,
 241     .send = tmp105_tx
 242 };
 243
 244 static void tmp105_register_devices(void)
 245 {
 246     i2c_register_slave(&tmp105_info);
 247 }
 248
 249 device_init(tmp105_register_devices)