1 /* 2 * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com> 3 * 4 * The LM95245 is a sensor chip made by National Semiconductors. 5 * It reports up to two temperatures (its own plus an external one). 6 * Complete datasheet can be obtained from National's website at: 7 * http://www.national.com/ds.cgi/LM/LM95245.pdf 8 * 9 * This driver is based on lm95241.c 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 24 */ 25 26 #include <linux/module.h> 27 #include <linux/init.h> 28 #include <linux/slab.h> 29 #include <linux/jiffies.h> 30 #include <linux/i2c.h> 31 #include <linux/hwmon.h> 32 #include <linux/hwmon-sysfs.h> 33 #include <linux/err.h> 34 #include <linux/mutex.h> 35 #include <linux/sysfs.h> 36 37 #define DEVNAME "lm95245" 38 39 static const unsigned short normal_i2c[] = { 40 0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END }; 41 42 /* LM95245 registers */ 43 /* general registers */ 44 #define LM95245_REG_RW_CONFIG1 0x03 45 #define LM95245_REG_RW_CONVERS_RATE 0x04 46 #define LM95245_REG_W_ONE_SHOT 0x0F 47 48 /* diode configuration */ 49 #define LM95245_REG_RW_CONFIG2 0xBF 50 #define LM95245_REG_RW_REMOTE_OFFH 0x11 51 #define LM95245_REG_RW_REMOTE_OFFL 0x12 52 53 /* status registers */ 54 #define LM95245_REG_R_STATUS1 0x02 55 #define LM95245_REG_R_STATUS2 0x33 56 57 /* limit registers */ 58 #define LM95245_REG_RW_REMOTE_OS_LIMIT 0x07 59 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT 0x20 60 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT 0x19 61 #define LM95245_REG_RW_COMMON_HYSTERESIS 0x21 62 63 /* temperature signed */ 64 #define LM95245_REG_R_LOCAL_TEMPH_S 0x00 65 #define LM95245_REG_R_LOCAL_TEMPL_S 0x30 66 #define LM95245_REG_R_REMOTE_TEMPH_S 0x01 67 #define LM95245_REG_R_REMOTE_TEMPL_S 0x10 68 /* temperature unsigned */ 69 #define LM95245_REG_R_REMOTE_TEMPH_U 0x31 70 #define LM95245_REG_R_REMOTE_TEMPL_U 0x32 71 72 /* id registers */ 73 #define LM95245_REG_R_MAN_ID 0xFE 74 #define LM95245_REG_R_CHIP_ID 0xFF 75 76 /* LM95245 specific bitfields */ 77 #define CFG_STOP 0x40 78 #define CFG_REMOTE_TCRIT_MASK 0x10 79 #define CFG_REMOTE_OS_MASK 0x08 80 #define CFG_LOCAL_TCRIT_MASK 0x04 81 #define CFG_LOCAL_OS_MASK 0x02 82 83 #define CFG2_OS_A0 0x40 84 #define CFG2_DIODE_FAULT_OS 0x20 85 #define CFG2_DIODE_FAULT_TCRIT 0x10 86 #define CFG2_REMOTE_TT 0x08 87 #define CFG2_REMOTE_FILTER_DIS 0x00 88 #define CFG2_REMOTE_FILTER_EN 0x06 89 90 /* conversation rate in ms */ 91 #define RATE_CR0063 0x00 92 #define RATE_CR0364 0x01 93 #define RATE_CR1000 0x02 94 #define RATE_CR2500 0x03 95 96 #define STATUS1_DIODE_FAULT 0x04 97 #define STATUS1_RTCRIT 0x02 98 #define STATUS1_LOC 0x01 99 100 #define MANUFACTURER_ID 0x01 101 #define DEFAULT_REVISION 0xB3 102 103 static const u8 lm95245_reg_address[] = { 104 LM95245_REG_R_LOCAL_TEMPH_S, 105 LM95245_REG_R_LOCAL_TEMPL_S, 106 LM95245_REG_R_REMOTE_TEMPH_S, 107 LM95245_REG_R_REMOTE_TEMPL_S, 108 LM95245_REG_R_REMOTE_TEMPH_U, 109 LM95245_REG_R_REMOTE_TEMPL_U, 110 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT, 111 LM95245_REG_RW_REMOTE_TCRIT_LIMIT, 112 LM95245_REG_RW_COMMON_HYSTERESIS, 113 LM95245_REG_R_STATUS1, 114 }; 115 116 /* Client data (each client gets its own) */ 117 struct lm95245_data { 118 struct device *hwmon_dev; 119 struct mutex update_lock; 120 unsigned long last_updated; /* in jiffies */ 121 unsigned long interval; /* in msecs */ 122 bool valid; /* zero until following fields are valid */ 123 /* registers values */ 124 u8 regs[ARRAY_SIZE(lm95245_reg_address)]; 125 u8 config1, config2; 126 }; 127 128 /* Conversions */ 129 static int temp_from_reg_unsigned(u8 val_h, u8 val_l) 130 { 131 return val_h * 1000 + val_l * 1000 / 256; 132 } 133 134 static int temp_from_reg_signed(u8 val_h, u8 val_l) 135 { 136 if (val_h & 0x80) 137 return (val_h - 0x100) * 1000; 138 return temp_from_reg_unsigned(val_h, val_l); 139 } 140 141 static struct lm95245_data *lm95245_update_device(struct device *dev) 142 { 143 struct i2c_client *client = to_i2c_client(dev); 144 struct lm95245_data *data = i2c_get_clientdata(client); 145 146 mutex_lock(&data->update_lock); 147 148 if (time_after(jiffies, data->last_updated 149 + msecs_to_jiffies(data->interval)) || !data->valid) { 150 int i; 151 152 dev_dbg(&client->dev, "Updating lm95245 data.\n"); 153 for (i = 0; i < ARRAY_SIZE(lm95245_reg_address); i++) 154 data->regs[i] 155 = i2c_smbus_read_byte_data(client, 156 lm95245_reg_address[i]); 157 data->last_updated = jiffies; 158 data->valid = 1; 159 } 160 161 mutex_unlock(&data->update_lock); 162 163 return data; 164 } 165 166 static unsigned long lm95245_read_conversion_rate(struct i2c_client *client) 167 { 168 int rate; 169 unsigned long interval; 170 171 rate = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONVERS_RATE); 172 173 switch (rate) { 174 case RATE_CR0063: 175 interval = 63; 176 break; 177 case RATE_CR0364: 178 interval = 364; 179 break; 180 case RATE_CR1000: 181 interval = 1000; 182 break; 183 case RATE_CR2500: 184 default: 185 interval = 2500; 186 break; 187 } 188 189 return interval; 190 } 191 192 static unsigned long lm95245_set_conversion_rate(struct i2c_client *client, 193 unsigned long interval) 194 { 195 int rate; 196 197 if (interval <= 63) { 198 interval = 63; 199 rate = RATE_CR0063; 200 } else if (interval <= 364) { 201 interval = 364; 202 rate = RATE_CR0364; 203 } else if (interval <= 1000) { 204 interval = 1000; 205 rate = RATE_CR1000; 206 } else { 207 interval = 2500; 208 rate = RATE_CR2500; 209 } 210 211 i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONVERS_RATE, rate); 212 213 return interval; 214 } 215 216 /* Sysfs stuff */ 217 static ssize_t show_input(struct device *dev, struct device_attribute *attr, 218 char *buf) 219 { 220 struct lm95245_data *data = lm95245_update_device(dev); 221 int temp; 222 int index = to_sensor_dev_attr(attr)->index; 223 224 /* 225 * Index 0 (Local temp) is always signed 226 * Index 2 (Remote temp) has both signed and unsigned data 227 * use signed calculation for remote if signed bit is set 228 */ 229 if (index == 0 || data->regs[index] & 0x80) 230 temp = temp_from_reg_signed(data->regs[index], 231 data->regs[index + 1]); 232 else 233 temp = temp_from_reg_unsigned(data->regs[index + 2], 234 data->regs[index + 3]); 235 236 return snprintf(buf, PAGE_SIZE - 1, "%d\n", temp); 237 } 238 239 static ssize_t show_limit(struct device *dev, struct device_attribute *attr, 240 char *buf) 241 { 242 struct lm95245_data *data = lm95245_update_device(dev); 243 int index = to_sensor_dev_attr(attr)->index; 244 245 return snprintf(buf, PAGE_SIZE - 1, "%d\n", 246 data->regs[index] * 1000); 247 } 248 249 static ssize_t set_limit(struct device *dev, struct device_attribute *attr, 250 const char *buf, size_t count) 251 { 252 struct i2c_client *client = to_i2c_client(dev); 253 struct lm95245_data *data = i2c_get_clientdata(client); 254 int index = to_sensor_dev_attr(attr)->index; 255 unsigned long val; 256 257 if (kstrtoul(buf, 10, &val) < 0) 258 return -EINVAL; 259 260 val /= 1000; 261 262 val = SENSORS_LIMIT(val, 0, (index == 6 ? 127 : 255)); 263 264 mutex_lock(&data->update_lock); 265 266 data->valid = 0; 267 268 i2c_smbus_write_byte_data(client, lm95245_reg_address[index], val); 269 270 mutex_unlock(&data->update_lock); 271 272 return count; 273 } 274 275 static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr, 276 const char *buf, size_t count) 277 { 278 struct i2c_client *client = to_i2c_client(dev); 279 struct lm95245_data *data = i2c_get_clientdata(client); 280 unsigned long val; 281 282 if (kstrtoul(buf, 10, &val) < 0) 283 return -EINVAL; 284 285 val /= 1000; 286 287 val = SENSORS_LIMIT(val, 0, 31); 288 289 mutex_lock(&data->update_lock); 290 291 data->valid = 0; 292 293 /* shared crit hysteresis */ 294 i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS, 295 val); 296 297 mutex_unlock(&data->update_lock); 298 299 return count; 300 } 301 302 static ssize_t show_type(struct device *dev, struct device_attribute *attr, 303 char *buf) 304 { 305 struct i2c_client *client = to_i2c_client(dev); 306 struct lm95245_data *data = i2c_get_clientdata(client); 307 308 return snprintf(buf, PAGE_SIZE - 1, 309 data->config2 & CFG2_REMOTE_TT ? "1\n" : "2\n"); 310 } 311 312 static ssize_t set_type(struct device *dev, struct device_attribute *attr, 313 const char *buf, size_t count) 314 { 315 struct i2c_client *client = to_i2c_client(dev); 316 struct lm95245_data *data = i2c_get_clientdata(client); 317 unsigned long val; 318 319 if (kstrtoul(buf, 10, &val) < 0) 320 return -EINVAL; 321 if (val != 1 && val != 2) 322 return -EINVAL; 323 324 mutex_lock(&data->update_lock); 325 326 if (val == 1) 327 data->config2 |= CFG2_REMOTE_TT; 328 else 329 data->config2 &= ~CFG2_REMOTE_TT; 330 331 data->valid = 0; 332 333 i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2, 334 data->config2); 335 336 mutex_unlock(&data->update_lock); 337 338 return count; 339 } 340 341 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, 342 char *buf) 343 { 344 struct lm95245_data *data = lm95245_update_device(dev); 345 int index = to_sensor_dev_attr(attr)->index; 346 347 return snprintf(buf, PAGE_SIZE - 1, "%d\n", 348 !!(data->regs[9] & index)); 349 } 350 351 static ssize_t show_interval(struct device *dev, struct device_attribute *attr, 352 char *buf) 353 { 354 struct lm95245_data *data = lm95245_update_device(dev); 355 356 return snprintf(buf, PAGE_SIZE - 1, "%lu\n", data->interval); 357 } 358 359 static ssize_t set_interval(struct device *dev, struct device_attribute *attr, 360 const char *buf, size_t count) 361 { 362 struct i2c_client *client = to_i2c_client(dev); 363 struct lm95245_data *data = i2c_get_clientdata(client); 364 unsigned long val; 365 366 if (kstrtoul(buf, 10, &val) < 0) 367 return -EINVAL; 368 369 mutex_lock(&data->update_lock); 370 371 data->interval = lm95245_set_conversion_rate(client, val); 372 373 mutex_unlock(&data->update_lock); 374 375 return count; 376 } 377 378 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0); 379 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit, 380 set_limit, 6); 381 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_limit, 382 set_crit_hyst, 8); 383 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 384 STATUS1_LOC); 385 386 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2); 387 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit, 388 set_limit, 7); 389 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_limit, 390 set_crit_hyst, 8); 391 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 392 STATUS1_RTCRIT); 393 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, 394 set_type, 0); 395 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 396 STATUS1_DIODE_FAULT); 397 398 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval, 399 set_interval); 400 401 static struct attribute *lm95245_attributes[] = { 402 &sensor_dev_attr_temp1_input.dev_attr.attr, 403 &sensor_dev_attr_temp1_crit.dev_attr.attr, 404 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, 405 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, 406 &sensor_dev_attr_temp2_input.dev_attr.attr, 407 &sensor_dev_attr_temp2_crit.dev_attr.attr, 408 &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr, 409 &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr, 410 &sensor_dev_attr_temp2_type.dev_attr.attr, 411 &sensor_dev_attr_temp2_fault.dev_attr.attr, 412 &dev_attr_update_interval.attr, 413 NULL 414 }; 415 416 static const struct attribute_group lm95245_group = { 417 .attrs = lm95245_attributes, 418 }; 419 420 /* Return 0 if detection is successful, -ENODEV otherwise */ 421 static int lm95245_detect(struct i2c_client *new_client, 422 struct i2c_board_info *info) 423 { 424 struct i2c_adapter *adapter = new_client->adapter; 425 426 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 427 return -ENODEV; 428 429 if (i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID) 430 != MANUFACTURER_ID 431 || i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID) 432 != DEFAULT_REVISION) 433 return -ENODEV; 434 435 strlcpy(info->type, DEVNAME, I2C_NAME_SIZE); 436 return 0; 437 } 438 439 static void lm95245_init_client(struct i2c_client *client) 440 { 441 struct lm95245_data *data = i2c_get_clientdata(client); 442 443 data->valid = 0; 444 data->interval = lm95245_read_conversion_rate(client); 445 446 data->config1 = i2c_smbus_read_byte_data(client, 447 LM95245_REG_RW_CONFIG1); 448 data->config2 = i2c_smbus_read_byte_data(client, 449 LM95245_REG_RW_CONFIG2); 450 451 if (data->config1 & CFG_STOP) { 452 /* Clear the standby bit */ 453 data->config1 &= ~CFG_STOP; 454 i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1, 455 data->config1); 456 } 457 } 458 459 static int lm95245_probe(struct i2c_client *new_client, 460 const struct i2c_device_id *id) 461 { 462 struct lm95245_data *data; 463 int err; 464 465 data = kzalloc(sizeof(struct lm95245_data), GFP_KERNEL); 466 if (!data) { 467 err = -ENOMEM; 468 goto exit; 469 } 470 471 i2c_set_clientdata(new_client, data); 472 mutex_init(&data->update_lock); 473 474 /* Initialize the LM95245 chip */ 475 lm95245_init_client(new_client); 476 477 /* Register sysfs hooks */ 478 err = sysfs_create_group(&new_client->dev.kobj, &lm95245_group); 479 if (err) 480 goto exit_free; 481 482 data->hwmon_dev = hwmon_device_register(&new_client->dev); 483 if (IS_ERR(data->hwmon_dev)) { 484 err = PTR_ERR(data->hwmon_dev); 485 goto exit_remove_files; 486 } 487 488 return 0; 489 490 exit_remove_files: 491 sysfs_remove_group(&new_client->dev.kobj, &lm95245_group); 492 exit_free: 493 kfree(data); 494 exit: 495 return err; 496 } 497 498 static int lm95245_remove(struct i2c_client *client) 499 { 500 struct lm95245_data *data = i2c_get_clientdata(client); 501 502 hwmon_device_unregister(data->hwmon_dev); 503 sysfs_remove_group(&client->dev.kobj, &lm95245_group); 504 505 kfree(data); 506 return 0; 507 } 508 509 /* Driver data (common to all clients) */ 510 static const struct i2c_device_id lm95245_id[] = { 511 { DEVNAME, 0 }, 512 { } 513 }; 514 MODULE_DEVICE_TABLE(i2c, lm95245_id); 515 516 static struct i2c_driver lm95245_driver = { 517 .class = I2C_CLASS_HWMON, 518 .driver = { 519 .name = DEVNAME, 520 }, 521 .probe = lm95245_probe, 522 .remove = lm95245_remove, 523 .id_table = lm95245_id, 524 .detect = lm95245_detect, 525 .address_list = normal_i2c, 526 }; 527 528 module_i2c_driver(lm95245_driver); 529 530 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); 531 MODULE_DESCRIPTION("LM95245 sensor driver"); 532 MODULE_LICENSE("GPL"); 533