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 */ 36static 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_SHUTDOWN (1 << 8) 57#define JC42_CFG_HYST_SHIFT 9 58#define JC42_CFG_HYST_MASK 0x03 59 60/* Capabilities */ 61#define JC42_CAP_RANGE (1 << 2) 62 63/* Manufacturer IDs */ 64#define ADT_MANID 0x11d4 /* Analog Devices */ 65#define MAX_MANID 0x004d /* Maxim */ 66#define IDT_MANID 0x00b3 /* IDT */ 67#define MCP_MANID 0x0054 /* Microchip */ 68#define NXP_MANID 0x1131 /* NXP Semiconductors */ 69#define ONS_MANID 0x1b09 /* ON Semiconductor */ 70#define STM_MANID 0x104a /* ST Microelectronics */ 71 72/* Supported chips */ 73 74/* Analog Devices */ 75#define ADT7408_DEVID 0x0801 76#define ADT7408_DEVID_MASK 0xffff 77 78/* IDT */ 79#define TS3000B3_DEVID 0x2903 /* Also matches TSE2002B3 */ 80#define TS3000B3_DEVID_MASK 0xffff 81 82/* Maxim */ 83#define MAX6604_DEVID 0x3e00 84#define MAX6604_DEVID_MASK 0xffff 85 86/* Microchip */ 87#define MCP98242_DEVID 0x2000 88#define MCP98242_DEVID_MASK 0xfffc 89 90#define MCP98243_DEVID 0x2100 91#define MCP98243_DEVID_MASK 0xfffc 92 93#define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */ 94#define MCP9843_DEVID_MASK 0xfffe 95 96/* NXP */ 97#define SE97_DEVID 0xa200 98#define SE97_DEVID_MASK 0xfffc 99 100#define SE98_DEVID 0xa100 101#define SE98_DEVID_MASK 0xfffc 102 103/* ON Semiconductor */ 104#define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */ 105#define CAT6095_DEVID_MASK 0xffe0 106 107/* ST Microelectronics */ 108#define STTS424_DEVID 0x0101 109#define STTS424_DEVID_MASK 0xffff 110 111#define STTS424E_DEVID 0x0000 112#define STTS424E_DEVID_MASK 0xfffe 113 114static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 }; 115 116struct jc42_chips { 117 u16 manid; 118 u16 devid; 119 u16 devid_mask; 120}; 121 122static struct jc42_chips jc42_chips[] = { 123 { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK }, 124 { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK }, 125 { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK }, 126 { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK }, 127 { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK }, 128 { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK }, 129 { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK }, 130 { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK }, 131 { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK }, 132 { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK }, 133 { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK }, 134}; 135 136/* Each client has this additional data */ 137struct jc42_data { 138 struct device *hwmon_dev; 139 struct mutex update_lock; /* protect register access */ 140 bool extended; /* true if extended range supported */ 141 bool valid; 142 unsigned long last_updated; /* In jiffies */ 143 u16 orig_config; /* original configuration */ 144 u16 config; /* current configuration */ 145 u16 temp_input; /* Temperatures */ 146 u16 temp_crit; 147 u16 temp_min; 148 u16 temp_max; 149}; 150 151static int jc42_probe(struct i2c_client *client, 152 const struct i2c_device_id *id); 153static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info); 154static int jc42_remove(struct i2c_client *client); 155static int jc42_read_value(struct i2c_client *client, u8 reg); 156static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value); 157 158static struct jc42_data *jc42_update_device(struct device *dev); 159 160static const struct i2c_device_id jc42_id[] = { 161 { "adt7408", 0 }, 162 { "cat94ts02", 0 }, 163 { "cat6095", 0 }, 164 { "jc42", 0 }, 165 { "max6604", 0 }, 166 { "mcp9805", 0 }, 167 { "mcp98242", 0 }, 168 { "mcp98243", 0 }, 169 { "mcp9843", 0 }, 170 { "se97", 0 }, 171 { "se97b", 0 }, 172 { "se98", 0 }, 173 { "stts424", 0 }, 174 { "tse2002b3", 0 }, 175 { "ts3000b3", 0 }, 176 { } 177}; 178MODULE_DEVICE_TABLE(i2c, jc42_id); 179 180#ifdef CONFIG_PM 181 182static int jc42_suspend(struct device *dev) 183{ 184 struct i2c_client *client = to_i2c_client(dev); 185 struct jc42_data *data = i2c_get_clientdata(client); 186 187 data->config |= JC42_CFG_SHUTDOWN; 188 jc42_write_value(client, JC42_REG_CONFIG, data->config); 189 return 0; 190} 191 192static int jc42_resume(struct device *dev) 193{ 194 struct i2c_client *client = to_i2c_client(dev); 195 struct jc42_data *data = i2c_get_clientdata(client); 196 197 data->config &= ~JC42_CFG_SHUTDOWN; 198 jc42_write_value(client, JC42_REG_CONFIG, data->config); 199 return 0; 200} 201 202static const struct dev_pm_ops jc42_dev_pm_ops = { 203 .suspend = jc42_suspend, 204 .resume = jc42_resume, 205}; 206 207#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops) 208#else 209#define JC42_DEV_PM_OPS NULL 210#endif /* CONFIG_PM */ 211 212/* This is the driver that will be inserted */ 213static struct i2c_driver jc42_driver = { 214 .class = I2C_CLASS_HWMON, 215 .driver = { 216 .name = "jc42", 217 .pm = JC42_DEV_PM_OPS, 218 }, 219 .probe = jc42_probe, 220 .remove = jc42_remove, 221 .id_table = jc42_id, 222 .detect = jc42_detect, 223 .address_list = normal_i2c, 224}; 225 226#define JC42_TEMP_MIN_EXTENDED (-40000) 227#define JC42_TEMP_MIN 0 228#define JC42_TEMP_MAX 125000 229 230static u16 jc42_temp_to_reg(int temp, bool extended) 231{ 232 int ntemp = SENSORS_LIMIT(temp, 233 extended ? JC42_TEMP_MIN_EXTENDED : 234 JC42_TEMP_MIN, JC42_TEMP_MAX); 235 236 /* convert from 0.001 to 0.0625 resolution */ 237 return (ntemp * 2 / 125) & 0x1fff; 238} 239 240static int jc42_temp_from_reg(s16 reg) 241{ 242 reg &= 0x1fff; 243 244 /* sign extend register */ 245 if (reg & 0x1000) 246 reg |= 0xf000; 247 248 /* convert from 0.0625 to 0.001 resolution */ 249 return reg * 125 / 2; 250} 251 252/* sysfs stuff */ 253 254/* read routines for temperature limits */ 255#define show(value) \ 256static ssize_t show_##value(struct device *dev, \ 257 struct device_attribute *attr, \ 258 char *buf) \ 259{ \ 260 struct jc42_data *data = jc42_update_device(dev); \ 261 if (IS_ERR(data)) \ 262 return PTR_ERR(data); \ 263 return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value)); \ 264} 265 266show(temp_input); 267show(temp_crit); 268show(temp_min); 269show(temp_max); 270 271/* read routines for hysteresis values */ 272static ssize_t show_temp_crit_hyst(struct device *dev, 273 struct device_attribute *attr, char *buf) 274{ 275 struct jc42_data *data = jc42_update_device(dev); 276 int temp, hyst; 277 278 if (IS_ERR(data)) 279 return PTR_ERR(data); 280 281 temp = jc42_temp_from_reg(data->temp_crit); 282 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT) 283 & JC42_CFG_HYST_MASK]; 284 return sprintf(buf, "%d\n", temp - hyst); 285} 286 287static ssize_t show_temp_max_hyst(struct device *dev, 288 struct device_attribute *attr, char *buf) 289{ 290 struct jc42_data *data = jc42_update_device(dev); 291 int temp, hyst; 292 293 if (IS_ERR(data)) 294 return PTR_ERR(data); 295 296 temp = jc42_temp_from_reg(data->temp_max); 297 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT) 298 & JC42_CFG_HYST_MASK]; 299 return sprintf(buf, "%d\n", temp - hyst); 300} 301 302/* write routines */ 303#define set(value, reg) \ 304static ssize_t set_##value(struct device *dev, \ 305 struct device_attribute *attr, \ 306 const char *buf, size_t count) \ 307{ \ 308 struct i2c_client *client = to_i2c_client(dev); \ 309 struct jc42_data *data = i2c_get_clientdata(client); \ 310 int err, ret = count; \ 311 long val; \ 312 if (strict_strtol(buf, 10, &val) < 0) \ 313 return -EINVAL; \ 314 mutex_lock(&data->update_lock); \ 315 data->value = jc42_temp_to_reg(val, data->extended); \ 316 err = jc42_write_value(client, reg, data->value); \ 317 if (err < 0) \ 318 ret = err; \ 319 mutex_unlock(&data->update_lock); \ 320 return ret; \ 321} 322 323set(temp_min, JC42_REG_TEMP_LOWER); 324set(temp_max, JC42_REG_TEMP_UPPER); 325set(temp_crit, JC42_REG_TEMP_CRITICAL); 326 327/* JC42.4 compliant chips only support four hysteresis values. 328 * Pick best choice and go from there. */ 329static ssize_t set_temp_crit_hyst(struct device *dev, 330 struct device_attribute *attr, 331 const char *buf, size_t count) 332{ 333 struct i2c_client *client = to_i2c_client(dev); 334 struct jc42_data *data = i2c_get_clientdata(client); 335 long val; 336 int diff, hyst; 337 int err; 338 int ret = count; 339 340 if (strict_strtoul(buf, 10, &val) < 0) 341 return -EINVAL; 342 343 diff = jc42_temp_from_reg(data->temp_crit) - val; 344 hyst = 0; 345 if (diff > 0) { 346 if (diff < 2250) 347 hyst = 1; /* 1.5 degrees C */ 348 else if (diff < 4500) 349 hyst = 2; /* 3.0 degrees C */ 350 else 351 hyst = 3; /* 6.0 degrees C */ 352 } 353 354 mutex_lock(&data->update_lock); 355 data->config = (data->config 356 & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT)) 357 | (hyst << JC42_CFG_HYST_SHIFT); 358 err = jc42_write_value(client, JC42_REG_CONFIG, data->config); 359 if (err < 0) 360 ret = err; 361 mutex_unlock(&data->update_lock); 362 return ret; 363} 364 365static ssize_t show_alarm(struct device *dev, 366 struct device_attribute *attr, char *buf) 367{ 368 u16 bit = to_sensor_dev_attr(attr)->index; 369 struct jc42_data *data = jc42_update_device(dev); 370 u16 val; 371 372 if (IS_ERR(data)) 373 return PTR_ERR(data); 374 375 val = data->temp_input; 376 if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY)) 377 val = 0; 378 return sprintf(buf, "%u\n", (val >> bit) & 1); 379} 380 381static DEVICE_ATTR(temp1_input, S_IRUGO, 382 show_temp_input, NULL); 383static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, 384 show_temp_crit, set_temp_crit); 385static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, 386 show_temp_min, set_temp_min); 387static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, 388 show_temp_max, set_temp_max); 389 390static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, 391 show_temp_crit_hyst, set_temp_crit_hyst); 392static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, 393 show_temp_max_hyst, NULL); 394 395static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 396 JC42_ALARM_CRIT_BIT); 397static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 398 JC42_ALARM_MIN_BIT); 399static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 400 JC42_ALARM_MAX_BIT); 401 402static struct attribute *jc42_attributes[] = { 403 &dev_attr_temp1_input.attr, 404 &dev_attr_temp1_crit.attr, 405 &dev_attr_temp1_min.attr, 406 &dev_attr_temp1_max.attr, 407 &dev_attr_temp1_crit_hyst.attr, 408 &dev_attr_temp1_max_hyst.attr, 409 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, 410 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 411 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 412 NULL 413}; 414 415static const struct attribute_group jc42_group = { 416 .attrs = jc42_attributes, 417}; 418 419/* Return 0 if detection is successful, -ENODEV otherwise */ 420static int jc42_detect(struct i2c_client *new_client, 421 struct i2c_board_info *info) 422{ 423 struct i2c_adapter *adapter = new_client->adapter; 424 int i, config, cap, manid, devid; 425 426 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 427 I2C_FUNC_SMBUS_WORD_DATA)) 428 return -ENODEV; 429 430 cap = jc42_read_value(new_client, JC42_REG_CAP); 431 config = jc42_read_value(new_client, JC42_REG_CONFIG); 432 manid = jc42_read_value(new_client, JC42_REG_MANID); 433 devid = jc42_read_value(new_client, JC42_REG_DEVICEID); 434 435 if (cap < 0 || config < 0 || manid < 0 || devid < 0) 436 return -ENODEV; 437 438 if ((cap & 0xff00) || (config & 0xf800)) 439 return -ENODEV; 440 441 for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) { 442 struct jc42_chips *chip = &jc42_chips[i]; 443 if (manid == chip->manid && 444 (devid & chip->devid_mask) == chip->devid) { 445 strlcpy(info->type, "jc42", I2C_NAME_SIZE); 446 return 0; 447 } 448 } 449 return -ENODEV; 450} 451 452static int jc42_probe(struct i2c_client *new_client, 453 const struct i2c_device_id *id) 454{ 455 struct jc42_data *data; 456 int config, cap, err; 457 458 data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL); 459 if (!data) { 460 err = -ENOMEM; 461 goto exit; 462 } 463 464 i2c_set_clientdata(new_client, data); 465 mutex_init(&data->update_lock); 466 467 cap = jc42_read_value(new_client, JC42_REG_CAP); 468 if (cap < 0) { 469 err = -EINVAL; 470 goto exit_free; 471 } 472 data->extended = !!(cap & JC42_CAP_RANGE); 473 474 config = jc42_read_value(new_client, JC42_REG_CONFIG); 475 if (config < 0) { 476 err = -EINVAL; 477 goto exit_free; 478 } 479 data->orig_config = config; 480 if (config & JC42_CFG_SHUTDOWN) { 481 config &= ~JC42_CFG_SHUTDOWN; 482 jc42_write_value(new_client, JC42_REG_CONFIG, config); 483 } 484 data->config = config; 485 486 /* Register sysfs hooks */ 487 err = sysfs_create_group(&new_client->dev.kobj, &jc42_group); 488 if (err) 489 goto exit_free; 490 491 data->hwmon_dev = hwmon_device_register(&new_client->dev); 492 if (IS_ERR(data->hwmon_dev)) { 493 err = PTR_ERR(data->hwmon_dev); 494 goto exit_remove; 495 } 496 497 return 0; 498 499exit_remove: 500 sysfs_remove_group(&new_client->dev.kobj, &jc42_group); 501exit_free: 502 kfree(data); 503exit: 504 return err; 505} 506 507static int jc42_remove(struct i2c_client *client) 508{ 509 struct jc42_data *data = i2c_get_clientdata(client); 510 hwmon_device_unregister(data->hwmon_dev); 511 sysfs_remove_group(&client->dev.kobj, &jc42_group); 512 if (data->config != data->orig_config) 513 jc42_write_value(client, JC42_REG_CONFIG, data->orig_config); 514 kfree(data); 515 return 0; 516} 517 518/* All registers are word-sized. */ 519static int jc42_read_value(struct i2c_client *client, u8 reg) 520{ 521 int ret = i2c_smbus_read_word_data(client, reg); 522 if (ret < 0) 523 return ret; 524 return swab16(ret); 525} 526 527static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value) 528{ 529 return i2c_smbus_write_word_data(client, reg, swab16(value)); 530} 531 532static struct jc42_data *jc42_update_device(struct device *dev) 533{ 534 struct i2c_client *client = to_i2c_client(dev); 535 struct jc42_data *data = i2c_get_clientdata(client); 536 struct jc42_data *ret = data; 537 int val; 538 539 mutex_lock(&data->update_lock); 540 541 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 542 val = jc42_read_value(client, JC42_REG_TEMP); 543 if (val < 0) { 544 ret = ERR_PTR(val); 545 goto abort; 546 } 547 data->temp_input = val; 548 549 val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL); 550 if (val < 0) { 551 ret = ERR_PTR(val); 552 goto abort; 553 } 554 data->temp_crit = val; 555 556 val = jc42_read_value(client, JC42_REG_TEMP_LOWER); 557 if (val < 0) { 558 ret = ERR_PTR(val); 559 goto abort; 560 } 561 data->temp_min = val; 562 563 val = jc42_read_value(client, JC42_REG_TEMP_UPPER); 564 if (val < 0) { 565 ret = ERR_PTR(val); 566 goto abort; 567 } 568 data->temp_max = val; 569 570 data->last_updated = jiffies; 571 data->valid = true; 572 } 573abort: 574 mutex_unlock(&data->update_lock); 575 return ret; 576} 577 578static int __init sensors_jc42_init(void) 579{ 580 return i2c_add_driver(&jc42_driver); 581} 582 583static void __exit sensors_jc42_exit(void) 584{ 585 i2c_del_driver(&jc42_driver); 586} 587 588MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>"); 589MODULE_DESCRIPTION("JC42 driver"); 590MODULE_LICENSE("GPL"); 591 592module_init(sensors_jc42_init); 593module_exit(sensors_jc42_exit); 594