1 /* 2 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors 3 * 4 * Copyright (c) 2010 Ericsson AB. 5 * 6 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>. 7 * 8 * JC42.4 compliant temperature sensors are typically used on memory modules. 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 23 */ 24 25 #include <linux/module.h> 26 #include <linux/init.h> 27 #include <linux/slab.h> 28 #include <linux/jiffies.h> 29 #include <linux/i2c.h> 30 #include <linux/hwmon.h> 31 #include <linux/hwmon-sysfs.h> 32 #include <linux/err.h> 33 #include <linux/mutex.h> 34 35 /* Addresses to scan */ 36 static const unsigned short normal_i2c[] = { 37 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END }; 38 39 /* JC42 registers. All registers are 16 bit. */ 40 #define JC42_REG_CAP 0x00 41 #define JC42_REG_CONFIG 0x01 42 #define JC42_REG_TEMP_UPPER 0x02 43 #define JC42_REG_TEMP_LOWER 0x03 44 #define JC42_REG_TEMP_CRITICAL 0x04 45 #define JC42_REG_TEMP 0x05 46 #define JC42_REG_MANID 0x06 47 #define JC42_REG_DEVICEID 0x07 48 49 /* Status bits in temperature register */ 50 #define JC42_ALARM_CRIT_BIT 15 51 #define JC42_ALARM_MAX_BIT 14 52 #define JC42_ALARM_MIN_BIT 13 53 54 /* Configuration register defines */ 55 #define JC42_CFG_CRIT_ONLY (1 << 2) 56 #define JC42_CFG_TCRIT_LOCK (1 << 6) 57 #define JC42_CFG_EVENT_LOCK (1 << 7) 58 #define JC42_CFG_SHUTDOWN (1 << 8) 59 #define JC42_CFG_HYST_SHIFT 9 60 #define JC42_CFG_HYST_MASK 0x03 61 62 /* Capabilities */ 63 #define JC42_CAP_RANGE (1 << 2) 64 65 /* Manufacturer IDs */ 66 #define ADT_MANID 0x11d4 /* Analog Devices */ 67 #define MAX_MANID 0x004d /* Maxim */ 68 #define IDT_MANID 0x00b3 /* IDT */ 69 #define MCP_MANID 0x0054 /* Microchip */ 70 #define NXP_MANID 0x1131 /* NXP Semiconductors */ 71 #define ONS_MANID 0x1b09 /* ON Semiconductor */ 72 #define STM_MANID 0x104a /* ST Microelectronics */ 73 74 /* Supported chips */ 75 76 /* Analog Devices */ 77 #define ADT7408_DEVID 0x0801 78 #define ADT7408_DEVID_MASK 0xffff 79 80 /* IDT */ 81 #define TS3000B3_DEVID 0x2903 /* Also matches TSE2002B3 */ 82 #define TS3000B3_DEVID_MASK 0xffff 83 84 /* Maxim */ 85 #define MAX6604_DEVID 0x3e00 86 #define MAX6604_DEVID_MASK 0xffff 87 88 /* Microchip */ 89 #define MCP98242_DEVID 0x2000 90 #define MCP98242_DEVID_MASK 0xfffc 91 92 #define MCP98243_DEVID 0x2100 93 #define MCP98243_DEVID_MASK 0xfffc 94 95 #define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */ 96 #define MCP9843_DEVID_MASK 0xfffe 97 98 /* NXP */ 99 #define SE97_DEVID 0xa200 100 #define SE97_DEVID_MASK 0xfffc 101 102 #define SE98_DEVID 0xa100 103 #define SE98_DEVID_MASK 0xfffc 104 105 /* ON Semiconductor */ 106 #define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */ 107 #define CAT6095_DEVID_MASK 0xffe0 108 109 /* ST Microelectronics */ 110 #define STTS424_DEVID 0x0101 111 #define STTS424_DEVID_MASK 0xffff 112 113 #define STTS424E_DEVID 0x0000 114 #define STTS424E_DEVID_MASK 0xfffe 115 116 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 }; 117 118 struct jc42_chips { 119 u16 manid; 120 u16 devid; 121 u16 devid_mask; 122 }; 123 124 static struct jc42_chips jc42_chips[] = { 125 { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK }, 126 { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK }, 127 { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK }, 128 { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK }, 129 { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK }, 130 { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK }, 131 { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK }, 132 { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK }, 133 { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK }, 134 { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK }, 135 { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK }, 136 }; 137 138 /* Each client has this additional data */ 139 struct jc42_data { 140 struct device *hwmon_dev; 141 struct mutex update_lock; /* protect register access */ 142 bool extended; /* true if extended range supported */ 143 bool valid; 144 unsigned long last_updated; /* In jiffies */ 145 u16 orig_config; /* original configuration */ 146 u16 config; /* current configuration */ 147 u16 temp_input; /* Temperatures */ 148 u16 temp_crit; 149 u16 temp_min; 150 u16 temp_max; 151 }; 152 153 static int jc42_probe(struct i2c_client *client, 154 const struct i2c_device_id *id); 155 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info); 156 static int jc42_remove(struct i2c_client *client); 157 static int jc42_read_value(struct i2c_client *client, u8 reg); 158 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value); 159 160 static struct jc42_data *jc42_update_device(struct device *dev); 161 162 static const struct i2c_device_id jc42_id[] = { 163 { "adt7408", 0 }, 164 { "cat94ts02", 0 }, 165 { "cat6095", 0 }, 166 { "jc42", 0 }, 167 { "max6604", 0 }, 168 { "mcp9805", 0 }, 169 { "mcp98242", 0 }, 170 { "mcp98243", 0 }, 171 { "mcp9843", 0 }, 172 { "se97", 0 }, 173 { "se97b", 0 }, 174 { "se98", 0 }, 175 { "stts424", 0 }, 176 { "tse2002b3", 0 }, 177 { "ts3000b3", 0 }, 178 { } 179 }; 180 MODULE_DEVICE_TABLE(i2c, jc42_id); 181 182 #ifdef CONFIG_PM 183 184 static int jc42_suspend(struct device *dev) 185 { 186 struct i2c_client *client = to_i2c_client(dev); 187 struct jc42_data *data = i2c_get_clientdata(client); 188 189 data->config |= JC42_CFG_SHUTDOWN; 190 jc42_write_value(client, JC42_REG_CONFIG, data->config); 191 return 0; 192 } 193 194 static int jc42_resume(struct device *dev) 195 { 196 struct i2c_client *client = to_i2c_client(dev); 197 struct jc42_data *data = i2c_get_clientdata(client); 198 199 data->config &= ~JC42_CFG_SHUTDOWN; 200 jc42_write_value(client, JC42_REG_CONFIG, data->config); 201 return 0; 202 } 203 204 static const struct dev_pm_ops jc42_dev_pm_ops = { 205 .suspend = jc42_suspend, 206 .resume = jc42_resume, 207 }; 208 209 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops) 210 #else 211 #define JC42_DEV_PM_OPS NULL 212 #endif /* CONFIG_PM */ 213 214 /* This is the driver that will be inserted */ 215 static struct i2c_driver jc42_driver = { 216 .class = I2C_CLASS_SPD, 217 .driver = { 218 .name = "jc42", 219 .pm = JC42_DEV_PM_OPS, 220 }, 221 .probe = jc42_probe, 222 .remove = jc42_remove, 223 .id_table = jc42_id, 224 .detect = jc42_detect, 225 .address_list = normal_i2c, 226 }; 227 228 #define JC42_TEMP_MIN_EXTENDED (-40000) 229 #define JC42_TEMP_MIN 0 230 #define JC42_TEMP_MAX 125000 231 232 static u16 jc42_temp_to_reg(int temp, bool extended) 233 { 234 int ntemp = SENSORS_LIMIT(temp, 235 extended ? JC42_TEMP_MIN_EXTENDED : 236 JC42_TEMP_MIN, JC42_TEMP_MAX); 237 238 /* convert from 0.001 to 0.0625 resolution */ 239 return (ntemp * 2 / 125) & 0x1fff; 240 } 241 242 static int jc42_temp_from_reg(s16 reg) 243 { 244 reg &= 0x1fff; 245 246 /* sign extend register */ 247 if (reg & 0x1000) 248 reg |= 0xf000; 249 250 /* convert from 0.0625 to 0.001 resolution */ 251 return reg * 125 / 2; 252 } 253 254 /* sysfs stuff */ 255 256 /* read routines for temperature limits */ 257 #define show(value) \ 258 static ssize_t show_##value(struct device *dev, \ 259 struct device_attribute *attr, \ 260 char *buf) \ 261 { \ 262 struct jc42_data *data = jc42_update_device(dev); \ 263 if (IS_ERR(data)) \ 264 return PTR_ERR(data); \ 265 return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value)); \ 266 } 267 268 show(temp_input); 269 show(temp_crit); 270 show(temp_min); 271 show(temp_max); 272 273 /* read routines for hysteresis values */ 274 static ssize_t show_temp_crit_hyst(struct device *dev, 275 struct device_attribute *attr, char *buf) 276 { 277 struct jc42_data *data = jc42_update_device(dev); 278 int temp, hyst; 279 280 if (IS_ERR(data)) 281 return PTR_ERR(data); 282 283 temp = jc42_temp_from_reg(data->temp_crit); 284 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT) 285 & JC42_CFG_HYST_MASK]; 286 return sprintf(buf, "%d\n", temp - hyst); 287 } 288 289 static ssize_t show_temp_max_hyst(struct device *dev, 290 struct device_attribute *attr, char *buf) 291 { 292 struct jc42_data *data = jc42_update_device(dev); 293 int temp, hyst; 294 295 if (IS_ERR(data)) 296 return PTR_ERR(data); 297 298 temp = jc42_temp_from_reg(data->temp_max); 299 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT) 300 & JC42_CFG_HYST_MASK]; 301 return sprintf(buf, "%d\n", temp - hyst); 302 } 303 304 /* write routines */ 305 #define set(value, reg) \ 306 static ssize_t set_##value(struct device *dev, \ 307 struct device_attribute *attr, \ 308 const char *buf, size_t count) \ 309 { \ 310 struct i2c_client *client = to_i2c_client(dev); \ 311 struct jc42_data *data = i2c_get_clientdata(client); \ 312 int err, ret = count; \ 313 long val; \ 314 if (strict_strtol(buf, 10, &val) < 0) \ 315 return -EINVAL; \ 316 mutex_lock(&data->update_lock); \ 317 data->value = jc42_temp_to_reg(val, data->extended); \ 318 err = jc42_write_value(client, reg, data->value); \ 319 if (err < 0) \ 320 ret = err; \ 321 mutex_unlock(&data->update_lock); \ 322 return ret; \ 323 } 324 325 set(temp_min, JC42_REG_TEMP_LOWER); 326 set(temp_max, JC42_REG_TEMP_UPPER); 327 set(temp_crit, JC42_REG_TEMP_CRITICAL); 328 329 /* JC42.4 compliant chips only support four hysteresis values. 330 * Pick best choice and go from there. */ 331 static ssize_t set_temp_crit_hyst(struct device *dev, 332 struct device_attribute *attr, 333 const char *buf, size_t count) 334 { 335 struct i2c_client *client = to_i2c_client(dev); 336 struct jc42_data *data = i2c_get_clientdata(client); 337 unsigned long val; 338 int diff, hyst; 339 int err; 340 int ret = count; 341 342 if (strict_strtoul(buf, 10, &val) < 0) 343 return -EINVAL; 344 345 diff = jc42_temp_from_reg(data->temp_crit) - val; 346 hyst = 0; 347 if (diff > 0) { 348 if (diff < 2250) 349 hyst = 1; /* 1.5 degrees C */ 350 else if (diff < 4500) 351 hyst = 2; /* 3.0 degrees C */ 352 else 353 hyst = 3; /* 6.0 degrees C */ 354 } 355 356 mutex_lock(&data->update_lock); 357 data->config = (data->config 358 & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT)) 359 | (hyst << JC42_CFG_HYST_SHIFT); 360 err = jc42_write_value(client, JC42_REG_CONFIG, data->config); 361 if (err < 0) 362 ret = err; 363 mutex_unlock(&data->update_lock); 364 return ret; 365 } 366 367 static ssize_t show_alarm(struct device *dev, 368 struct device_attribute *attr, char *buf) 369 { 370 u16 bit = to_sensor_dev_attr(attr)->index; 371 struct jc42_data *data = jc42_update_device(dev); 372 u16 val; 373 374 if (IS_ERR(data)) 375 return PTR_ERR(data); 376 377 val = data->temp_input; 378 if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY)) 379 val = 0; 380 return sprintf(buf, "%u\n", (val >> bit) & 1); 381 } 382 383 static DEVICE_ATTR(temp1_input, S_IRUGO, 384 show_temp_input, NULL); 385 static DEVICE_ATTR(temp1_crit, S_IRUGO, 386 show_temp_crit, set_temp_crit); 387 static DEVICE_ATTR(temp1_min, S_IRUGO, 388 show_temp_min, set_temp_min); 389 static DEVICE_ATTR(temp1_max, S_IRUGO, 390 show_temp_max, set_temp_max); 391 392 static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO, 393 show_temp_crit_hyst, set_temp_crit_hyst); 394 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, 395 show_temp_max_hyst, NULL); 396 397 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 398 JC42_ALARM_CRIT_BIT); 399 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 400 JC42_ALARM_MIN_BIT); 401 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 402 JC42_ALARM_MAX_BIT); 403 404 static struct attribute *jc42_attributes[] = { 405 &dev_attr_temp1_input.attr, 406 &dev_attr_temp1_crit.attr, 407 &dev_attr_temp1_min.attr, 408 &dev_attr_temp1_max.attr, 409 &dev_attr_temp1_crit_hyst.attr, 410 &dev_attr_temp1_max_hyst.attr, 411 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, 412 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 413 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 414 NULL 415 }; 416 417 static mode_t jc42_attribute_mode(struct kobject *kobj, 418 struct attribute *attr, int index) 419 { 420 struct device *dev = container_of(kobj, struct device, kobj); 421 struct i2c_client *client = to_i2c_client(dev); 422 struct jc42_data *data = i2c_get_clientdata(client); 423 unsigned int config = data->config; 424 bool readonly; 425 426 if (attr == &dev_attr_temp1_crit.attr) 427 readonly = config & JC42_CFG_TCRIT_LOCK; 428 else if (attr == &dev_attr_temp1_min.attr || 429 attr == &dev_attr_temp1_max.attr) 430 readonly = config & JC42_CFG_EVENT_LOCK; 431 else if (attr == &dev_attr_temp1_crit_hyst.attr) 432 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK); 433 else 434 readonly = true; 435 436 return S_IRUGO | (readonly ? 0 : S_IWUSR); 437 } 438 439 static const struct attribute_group jc42_group = { 440 .attrs = jc42_attributes, 441 .is_visible = jc42_attribute_mode, 442 }; 443 444 /* Return 0 if detection is successful, -ENODEV otherwise */ 445 static int jc42_detect(struct i2c_client *new_client, 446 struct i2c_board_info *info) 447 { 448 struct i2c_adapter *adapter = new_client->adapter; 449 int i, config, cap, manid, devid; 450 451 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 452 I2C_FUNC_SMBUS_WORD_DATA)) 453 return -ENODEV; 454 455 cap = jc42_read_value(new_client, JC42_REG_CAP); 456 config = jc42_read_value(new_client, JC42_REG_CONFIG); 457 manid = jc42_read_value(new_client, JC42_REG_MANID); 458 devid = jc42_read_value(new_client, JC42_REG_DEVICEID); 459 460 if (cap < 0 || config < 0 || manid < 0 || devid < 0) 461 return -ENODEV; 462 463 if ((cap & 0xff00) || (config & 0xf800)) 464 return -ENODEV; 465 466 for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) { 467 struct jc42_chips *chip = &jc42_chips[i]; 468 if (manid == chip->manid && 469 (devid & chip->devid_mask) == chip->devid) { 470 strlcpy(info->type, "jc42", I2C_NAME_SIZE); 471 return 0; 472 } 473 } 474 return -ENODEV; 475 } 476 477 static int jc42_probe(struct i2c_client *new_client, 478 const struct i2c_device_id *id) 479 { 480 struct jc42_data *data; 481 int config, cap, err; 482 483 data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL); 484 if (!data) { 485 err = -ENOMEM; 486 goto exit; 487 } 488 489 i2c_set_clientdata(new_client, data); 490 mutex_init(&data->update_lock); 491 492 cap = jc42_read_value(new_client, JC42_REG_CAP); 493 if (cap < 0) { 494 err = -EINVAL; 495 goto exit_free; 496 } 497 data->extended = !!(cap & JC42_CAP_RANGE); 498 499 config = jc42_read_value(new_client, JC42_REG_CONFIG); 500 if (config < 0) { 501 err = -EINVAL; 502 goto exit_free; 503 } 504 data->orig_config = config; 505 if (config & JC42_CFG_SHUTDOWN) { 506 config &= ~JC42_CFG_SHUTDOWN; 507 jc42_write_value(new_client, JC42_REG_CONFIG, config); 508 } 509 data->config = config; 510 511 /* Register sysfs hooks */ 512 err = sysfs_create_group(&new_client->dev.kobj, &jc42_group); 513 if (err) 514 goto exit_free; 515 516 data->hwmon_dev = hwmon_device_register(&new_client->dev); 517 if (IS_ERR(data->hwmon_dev)) { 518 err = PTR_ERR(data->hwmon_dev); 519 goto exit_remove; 520 } 521 522 return 0; 523 524 exit_remove: 525 sysfs_remove_group(&new_client->dev.kobj, &jc42_group); 526 exit_free: 527 kfree(data); 528 exit: 529 return err; 530 } 531 532 static int jc42_remove(struct i2c_client *client) 533 { 534 struct jc42_data *data = i2c_get_clientdata(client); 535 hwmon_device_unregister(data->hwmon_dev); 536 sysfs_remove_group(&client->dev.kobj, &jc42_group); 537 if (data->config != data->orig_config) 538 jc42_write_value(client, JC42_REG_CONFIG, data->orig_config); 539 kfree(data); 540 return 0; 541 } 542 543 /* All registers are word-sized. */ 544 static int jc42_read_value(struct i2c_client *client, u8 reg) 545 { 546 int ret = i2c_smbus_read_word_data(client, reg); 547 if (ret < 0) 548 return ret; 549 return swab16(ret); 550 } 551 552 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value) 553 { 554 return i2c_smbus_write_word_data(client, reg, swab16(value)); 555 } 556 557 static struct jc42_data *jc42_update_device(struct device *dev) 558 { 559 struct i2c_client *client = to_i2c_client(dev); 560 struct jc42_data *data = i2c_get_clientdata(client); 561 struct jc42_data *ret = data; 562 int val; 563 564 mutex_lock(&data->update_lock); 565 566 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 567 val = jc42_read_value(client, JC42_REG_TEMP); 568 if (val < 0) { 569 ret = ERR_PTR(val); 570 goto abort; 571 } 572 data->temp_input = val; 573 574 val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL); 575 if (val < 0) { 576 ret = ERR_PTR(val); 577 goto abort; 578 } 579 data->temp_crit = val; 580 581 val = jc42_read_value(client, JC42_REG_TEMP_LOWER); 582 if (val < 0) { 583 ret = ERR_PTR(val); 584 goto abort; 585 } 586 data->temp_min = val; 587 588 val = jc42_read_value(client, JC42_REG_TEMP_UPPER); 589 if (val < 0) { 590 ret = ERR_PTR(val); 591 goto abort; 592 } 593 data->temp_max = val; 594 595 data->last_updated = jiffies; 596 data->valid = true; 597 } 598 abort: 599 mutex_unlock(&data->update_lock); 600 return ret; 601 } 602 603 static int __init sensors_jc42_init(void) 604 { 605 return i2c_add_driver(&jc42_driver); 606 } 607 608 static void __exit sensors_jc42_exit(void) 609 { 610 i2c_del_driver(&jc42_driver); 611 } 612 613 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>"); 614 MODULE_DESCRIPTION("JC42 driver"); 615 MODULE_LICENSE("GPL"); 616 617 module_init(sensors_jc42_init); 618 module_exit(sensors_jc42_exit); 619