tmp105.c (8708B)
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/i2c/i2c.h" 23 #include "hw/irq.h" 24 #include "migration/vmstate.h" 25 #include "hw/sensor/tmp105.h" 26 #include "qapi/error.h" 27 #include "qapi/visitor.h" 28 #include "qemu/module.h" 29 30 static void tmp105_interrupt_update(TMP105State *s) 31 { 32 qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1)); /* POL */ 33 } 34 35 static void tmp105_alarm_update(TMP105State *s) 36 { 37 if ((s->config >> 0) & 1) { /* SD */ 38 if ((s->config >> 7) & 1) /* OS */ 39 s->config &= ~(1 << 7); /* OS */ 40 else 41 return; 42 } 43 44 if (s->config >> 1 & 1) { 45 /* 46 * TM == 1 : Interrupt mode. We signal Alert when the 47 * temperature rises above T_high, and expect the guest to clear 48 * it (eg by reading a device register). 49 */ 50 if (s->detect_falling) { 51 if (s->temperature < s->limit[0]) { 52 s->alarm = 1; 53 s->detect_falling = false; 54 } 55 } else { 56 if (s->temperature >= s->limit[1]) { 57 s->alarm = 1; 58 s->detect_falling = true; 59 } 60 } 61 } else { 62 /* 63 * TM == 0 : Comparator mode. We signal Alert when the temperature 64 * rises above T_high, and stop signalling it when the temperature 65 * falls below T_low. 66 */ 67 if (s->detect_falling) { 68 if (s->temperature < s->limit[0]) { 69 s->alarm = 0; 70 s->detect_falling = false; 71 } 72 } else { 73 if (s->temperature >= s->limit[1]) { 74 s->alarm = 1; 75 s->detect_falling = true; 76 } 77 } 78 } 79 80 tmp105_interrupt_update(s); 81 } 82 83 static void tmp105_get_temperature(Object *obj, Visitor *v, const char *name, 84 void *opaque, Error **errp) 85 { 86 TMP105State *s = TMP105(obj); 87 int64_t value = s->temperature * 1000 / 256; 88 89 visit_type_int(v, name, &value, errp); 90 } 91 92 /* Units are 0.001 centigrades relative to 0 C. s->temperature is 8.8 93 * fixed point, so units are 1/256 centigrades. A simple ratio will do. 94 */ 95 static void tmp105_set_temperature(Object *obj, Visitor *v, const char *name, 96 void *opaque, Error **errp) 97 { 98 TMP105State *s = TMP105(obj); 99 int64_t temp; 100 101 if (!visit_type_int(v, name, &temp, errp)) { 102 return; 103 } 104 if (temp >= 128000 || temp < -128000) { 105 error_setg(errp, "value %" PRId64 ".%03" PRIu64 " C is out of range", 106 temp / 1000, temp % 1000); 107 return; 108 } 109 110 s->temperature = (int16_t) (temp * 256 / 1000); 111 112 tmp105_alarm_update(s); 113 } 114 115 static const int tmp105_faultq[4] = { 1, 2, 4, 6 }; 116 117 static void tmp105_read(TMP105State *s) 118 { 119 s->len = 0; 120 121 if ((s->config >> 1) & 1) { /* TM */ 122 s->alarm = 0; 123 tmp105_interrupt_update(s); 124 } 125 126 switch (s->pointer & 3) { 127 case TMP105_REG_TEMPERATURE: 128 s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8); 129 s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) & 130 (0xf0 << ((~s->config >> 5) & 3)); /* R */ 131 break; 132 133 case TMP105_REG_CONFIG: 134 s->buf[s->len ++] = s->config; 135 break; 136 137 case TMP105_REG_T_LOW: 138 s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8; 139 s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0; 140 break; 141 142 case TMP105_REG_T_HIGH: 143 s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8; 144 s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0; 145 break; 146 } 147 } 148 149 static void tmp105_write(TMP105State *s) 150 { 151 switch (s->pointer & 3) { 152 case TMP105_REG_TEMPERATURE: 153 break; 154 155 case TMP105_REG_CONFIG: 156 if (s->buf[0] & ~s->config & (1 << 0)) /* SD */ 157 printf("%s: TMP105 shutdown\n", __func__); 158 s->config = s->buf[0]; 159 s->faults = tmp105_faultq[(s->config >> 3) & 3]; /* F */ 160 tmp105_alarm_update(s); 161 break; 162 163 case TMP105_REG_T_LOW: 164 case TMP105_REG_T_HIGH: 165 if (s->len >= 3) 166 s->limit[s->pointer & 1] = (int16_t) 167 ((((uint16_t) s->buf[0]) << 8) | s->buf[1]); 168 tmp105_alarm_update(s); 169 break; 170 } 171 } 172 173 static uint8_t tmp105_rx(I2CSlave *i2c) 174 { 175 TMP105State *s = TMP105(i2c); 176 177 if (s->len < 2) { 178 return s->buf[s->len ++]; 179 } else { 180 return 0xff; 181 } 182 } 183 184 static int tmp105_tx(I2CSlave *i2c, uint8_t data) 185 { 186 TMP105State *s = TMP105(i2c); 187 188 if (s->len == 0) { 189 s->pointer = data; 190 s->len++; 191 } else { 192 if (s->len <= 2) { 193 s->buf[s->len - 1] = data; 194 } 195 s->len++; 196 tmp105_write(s); 197 } 198 199 return 0; 200 } 201 202 static int tmp105_event(I2CSlave *i2c, enum i2c_event event) 203 { 204 TMP105State *s = TMP105(i2c); 205 206 if (event == I2C_START_RECV) { 207 tmp105_read(s); 208 } 209 210 s->len = 0; 211 return 0; 212 } 213 214 static int tmp105_post_load(void *opaque, int version_id) 215 { 216 TMP105State *s = opaque; 217 218 s->faults = tmp105_faultq[(s->config >> 3) & 3]; /* F */ 219 220 tmp105_interrupt_update(s); 221 return 0; 222 } 223 224 static bool detect_falling_needed(void *opaque) 225 { 226 TMP105State *s = opaque; 227 228 /* 229 * We only need to migrate the detect_falling bool if it's set; 230 * for migration from older machines we assume that it is false 231 * (ie temperature is not out of range). 232 */ 233 return s->detect_falling; 234 } 235 236 static const VMStateDescription vmstate_tmp105_detect_falling = { 237 .name = "TMP105/detect-falling", 238 .version_id = 1, 239 .minimum_version_id = 1, 240 .needed = detect_falling_needed, 241 .fields = (VMStateField[]) { 242 VMSTATE_BOOL(detect_falling, TMP105State), 243 VMSTATE_END_OF_LIST() 244 } 245 }; 246 247 static const VMStateDescription vmstate_tmp105 = { 248 .name = "TMP105", 249 .version_id = 0, 250 .minimum_version_id = 0, 251 .post_load = tmp105_post_load, 252 .fields = (VMStateField[]) { 253 VMSTATE_UINT8(len, TMP105State), 254 VMSTATE_UINT8_ARRAY(buf, TMP105State, 2), 255 VMSTATE_UINT8(pointer, TMP105State), 256 VMSTATE_UINT8(config, TMP105State), 257 VMSTATE_INT16(temperature, TMP105State), 258 VMSTATE_INT16_ARRAY(limit, TMP105State, 2), 259 VMSTATE_UINT8(alarm, TMP105State), 260 VMSTATE_I2C_SLAVE(i2c, TMP105State), 261 VMSTATE_END_OF_LIST() 262 }, 263 .subsections = (const VMStateDescription*[]) { 264 &vmstate_tmp105_detect_falling, 265 NULL 266 } 267 }; 268 269 static void tmp105_reset(I2CSlave *i2c) 270 { 271 TMP105State *s = TMP105(i2c); 272 273 s->temperature = 0; 274 s->pointer = 0; 275 s->config = 0; 276 s->faults = tmp105_faultq[(s->config >> 3) & 3]; 277 s->alarm = 0; 278 s->detect_falling = false; 279 280 s->limit[0] = 0x4b00; /* T_LOW, 75 degrees C */ 281 s->limit[1] = 0x5000; /* T_HIGH, 80 degrees C */ 282 283 tmp105_interrupt_update(s); 284 } 285 286 static void tmp105_realize(DeviceState *dev, Error **errp) 287 { 288 I2CSlave *i2c = I2C_SLAVE(dev); 289 TMP105State *s = TMP105(i2c); 290 291 qdev_init_gpio_out(&i2c->qdev, &s->pin, 1); 292 293 tmp105_reset(&s->i2c); 294 } 295 296 static void tmp105_initfn(Object *obj) 297 { 298 object_property_add(obj, "temperature", "int", 299 tmp105_get_temperature, 300 tmp105_set_temperature, NULL, NULL); 301 } 302 303 static void tmp105_class_init(ObjectClass *klass, void *data) 304 { 305 DeviceClass *dc = DEVICE_CLASS(klass); 306 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 307 308 dc->realize = tmp105_realize; 309 k->event = tmp105_event; 310 k->recv = tmp105_rx; 311 k->send = tmp105_tx; 312 dc->vmsd = &vmstate_tmp105; 313 } 314 315 static const TypeInfo tmp105_info = { 316 .name = TYPE_TMP105, 317 .parent = TYPE_I2C_SLAVE, 318 .instance_size = sizeof(TMP105State), 319 .instance_init = tmp105_initfn, 320 .class_init = tmp105_class_init, 321 }; 322 323 static void tmp105_register_types(void) 324 { 325 type_register_static(&tmp105_info); 326 } 327 328 type_init(tmp105_register_types)