1 /* 2 * lm95241.c - Part of lm_sensors, Linux kernel modules for hardware 3 * monitoring 4 * Copyright (C) 2008 Davide Rizzo <elpa-rizzo@gmail.com> 5 * 6 * Based on the max1619 driver. The LM95241 is a sensor chip made by National 7 * Semiconductors. 8 * It reports up to three temperatures (its own plus up to 9 * two external ones). Complete datasheet can be 10 * obtained from National's website at: 11 * http://www.national.com/ds.cgi/LM/LM95241.pdf 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; either version 2 of the License, or 16 * (at your option) any later version. 17 * 18 * This program is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 * GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with this program; if not, write to the Free Software 25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 26 */ 27 28 #include <linux/module.h> 29 #include <linux/init.h> 30 #include <linux/slab.h> 31 #include <linux/jiffies.h> 32 #include <linux/i2c.h> 33 #include <linux/hwmon.h> 34 #include <linux/hwmon-sysfs.h> 35 #include <linux/err.h> 36 #include <linux/mutex.h> 37 #include <linux/sysfs.h> 38 39 static const unsigned short normal_i2c[] = { 40 0x19, 0x2a, 0x2b, I2C_CLIENT_END}; 41 42 /* Insmod parameters */ 43 I2C_CLIENT_INSMOD_1(lm95241); 44 45 /* LM95241 registers */ 46 #define LM95241_REG_R_MAN_ID 0xFE 47 #define LM95241_REG_R_CHIP_ID 0xFF 48 #define LM95241_REG_R_STATUS 0x02 49 #define LM95241_REG_RW_CONFIG 0x03 50 #define LM95241_REG_RW_REM_FILTER 0x06 51 #define LM95241_REG_RW_TRUTHERM 0x07 52 #define LM95241_REG_W_ONE_SHOT 0x0F 53 #define LM95241_REG_R_LOCAL_TEMPH 0x10 54 #define LM95241_REG_R_REMOTE1_TEMPH 0x11 55 #define LM95241_REG_R_REMOTE2_TEMPH 0x12 56 #define LM95241_REG_R_LOCAL_TEMPL 0x20 57 #define LM95241_REG_R_REMOTE1_TEMPL 0x21 58 #define LM95241_REG_R_REMOTE2_TEMPL 0x22 59 #define LM95241_REG_RW_REMOTE_MODEL 0x30 60 61 /* LM95241 specific bitfields */ 62 #define CFG_STOP 0x40 63 #define CFG_CR0076 0x00 64 #define CFG_CR0182 0x10 65 #define CFG_CR1000 0x20 66 #define CFG_CR2700 0x30 67 #define R1MS_SHIFT 0 68 #define R2MS_SHIFT 2 69 #define R1MS_MASK (0x01 << (R1MS_SHIFT)) 70 #define R2MS_MASK (0x01 << (R2MS_SHIFT)) 71 #define R1DF_SHIFT 1 72 #define R2DF_SHIFT 2 73 #define R1DF_MASK (0x01 << (R1DF_SHIFT)) 74 #define R2DF_MASK (0x01 << (R2DF_SHIFT)) 75 #define R1FE_MASK 0x01 76 #define R2FE_MASK 0x05 77 #define TT1_SHIFT 0 78 #define TT2_SHIFT 4 79 #define TT_OFF 0 80 #define TT_ON 1 81 #define TT_MASK 7 82 #define MANUFACTURER_ID 0x01 83 #define DEFAULT_REVISION 0xA4 84 85 /* Conversions and various macros */ 86 #define TEMP_FROM_REG(val_h, val_l) (((val_h) & 0x80 ? (val_h) - 0x100 : \ 87 (val_h)) * 1000 + (val_l) * 1000 / 256) 88 89 /* Functions declaration */ 90 static void lm95241_init_client(struct i2c_client *client); 91 static struct lm95241_data *lm95241_update_device(struct device *dev); 92 93 /* Client data (each client gets its own) */ 94 struct lm95241_data { 95 struct device *hwmon_dev; 96 struct mutex update_lock; 97 unsigned long last_updated, rate; /* in jiffies */ 98 char valid; /* zero until following fields are valid */ 99 /* registers values */ 100 u8 local_h, local_l; /* local */ 101 u8 remote1_h, remote1_l; /* remote1 */ 102 u8 remote2_h, remote2_l; /* remote2 */ 103 u8 config, model, trutherm; 104 }; 105 106 /* Sysfs stuff */ 107 #define show_temp(value) \ 108 static ssize_t show_##value(struct device *dev, \ 109 struct device_attribute *attr, char *buf) \ 110 { \ 111 struct lm95241_data *data = lm95241_update_device(dev); \ 112 snprintf(buf, PAGE_SIZE - 1, "%d\n", \ 113 TEMP_FROM_REG(data->value##_h, data->value##_l)); \ 114 return strlen(buf); \ 115 } 116 show_temp(local); 117 show_temp(remote1); 118 show_temp(remote2); 119 120 static ssize_t show_rate(struct device *dev, struct device_attribute *attr, 121 char *buf) 122 { 123 struct lm95241_data *data = lm95241_update_device(dev); 124 125 snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->rate / HZ); 126 return strlen(buf); 127 } 128 129 static ssize_t set_rate(struct device *dev, struct device_attribute *attr, 130 const char *buf, size_t count) 131 { 132 struct i2c_client *client = to_i2c_client(dev); 133 struct lm95241_data *data = i2c_get_clientdata(client); 134 135 strict_strtol(buf, 10, &data->rate); 136 data->rate = data->rate * HZ / 1000; 137 138 return count; 139 } 140 141 #define show_type(flag) \ 142 static ssize_t show_type##flag(struct device *dev, \ 143 struct device_attribute *attr, char *buf) \ 144 { \ 145 struct i2c_client *client = to_i2c_client(dev); \ 146 struct lm95241_data *data = i2c_get_clientdata(client); \ 147 \ 148 snprintf(buf, PAGE_SIZE - 1, \ 149 data->model & R##flag##MS_MASK ? "1\n" : "2\n"); \ 150 return strlen(buf); \ 151 } 152 show_type(1); 153 show_type(2); 154 155 #define show_min(flag) \ 156 static ssize_t show_min##flag(struct device *dev, \ 157 struct device_attribute *attr, char *buf) \ 158 { \ 159 struct i2c_client *client = to_i2c_client(dev); \ 160 struct lm95241_data *data = i2c_get_clientdata(client); \ 161 \ 162 snprintf(buf, PAGE_SIZE - 1, \ 163 data->config & R##flag##DF_MASK ? \ 164 "-127000\n" : "0\n"); \ 165 return strlen(buf); \ 166 } 167 show_min(1); 168 show_min(2); 169 170 #define show_max(flag) \ 171 static ssize_t show_max##flag(struct device *dev, \ 172 struct device_attribute *attr, char *buf) \ 173 { \ 174 struct i2c_client *client = to_i2c_client(dev); \ 175 struct lm95241_data *data = i2c_get_clientdata(client); \ 176 \ 177 snprintf(buf, PAGE_SIZE - 1, \ 178 data->config & R##flag##DF_MASK ? \ 179 "127000\n" : "255000\n"); \ 180 return strlen(buf); \ 181 } 182 show_max(1); 183 show_max(2); 184 185 #define set_type(flag) \ 186 static ssize_t set_type##flag(struct device *dev, \ 187 struct device_attribute *attr, \ 188 const char *buf, size_t count) \ 189 { \ 190 struct i2c_client *client = to_i2c_client(dev); \ 191 struct lm95241_data *data = i2c_get_clientdata(client); \ 192 \ 193 long val; \ 194 strict_strtol(buf, 10, &val); \ 195 \ 196 if ((val == 1) || (val == 2)) { \ 197 \ 198 mutex_lock(&data->update_lock); \ 199 \ 200 data->trutherm &= ~(TT_MASK << TT##flag##_SHIFT); \ 201 if (val == 1) { \ 202 data->model |= R##flag##MS_MASK; \ 203 data->trutherm |= (TT_ON << TT##flag##_SHIFT); \ 204 } \ 205 else { \ 206 data->model &= ~R##flag##MS_MASK; \ 207 data->trutherm |= (TT_OFF << TT##flag##_SHIFT); \ 208 } \ 209 \ 210 data->valid = 0; \ 211 \ 212 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, \ 213 data->model); \ 214 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, \ 215 data->trutherm); \ 216 \ 217 mutex_unlock(&data->update_lock); \ 218 \ 219 } \ 220 return count; \ 221 } 222 set_type(1); 223 set_type(2); 224 225 #define set_min(flag) \ 226 static ssize_t set_min##flag(struct device *dev, \ 227 struct device_attribute *devattr, const char *buf, size_t count) \ 228 { \ 229 struct i2c_client *client = to_i2c_client(dev); \ 230 struct lm95241_data *data = i2c_get_clientdata(client); \ 231 \ 232 long val; \ 233 strict_strtol(buf, 10, &val); \ 234 \ 235 mutex_lock(&data->update_lock); \ 236 \ 237 if (val < 0) \ 238 data->config |= R##flag##DF_MASK; \ 239 else \ 240 data->config &= ~R##flag##DF_MASK; \ 241 \ 242 data->valid = 0; \ 243 \ 244 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \ 245 data->config); \ 246 \ 247 mutex_unlock(&data->update_lock); \ 248 \ 249 return count; \ 250 } 251 set_min(1); 252 set_min(2); 253 254 #define set_max(flag) \ 255 static ssize_t set_max##flag(struct device *dev, \ 256 struct device_attribute *devattr, const char *buf, size_t count) \ 257 { \ 258 struct i2c_client *client = to_i2c_client(dev); \ 259 struct lm95241_data *data = i2c_get_clientdata(client); \ 260 \ 261 long val; \ 262 strict_strtol(buf, 10, &val); \ 263 \ 264 mutex_lock(&data->update_lock); \ 265 \ 266 if (val <= 127000) \ 267 data->config |= R##flag##DF_MASK; \ 268 else \ 269 data->config &= ~R##flag##DF_MASK; \ 270 \ 271 data->valid = 0; \ 272 \ 273 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \ 274 data->config); \ 275 \ 276 mutex_unlock(&data->update_lock); \ 277 \ 278 return count; \ 279 } 280 set_max(1); 281 set_max(2); 282 283 static DEVICE_ATTR(temp1_input, S_IRUGO, show_local, NULL); 284 static DEVICE_ATTR(temp2_input, S_IRUGO, show_remote1, NULL); 285 static DEVICE_ATTR(temp3_input, S_IRUGO, show_remote2, NULL); 286 static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type1, set_type1); 287 static DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type2, set_type2); 288 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min1, set_min1); 289 static DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min2, set_min2); 290 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max1, set_max1); 291 static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max2, set_max2); 292 static DEVICE_ATTR(rate, S_IWUSR | S_IRUGO, show_rate, set_rate); 293 294 static struct attribute *lm95241_attributes[] = { 295 &dev_attr_temp1_input.attr, 296 &dev_attr_temp2_input.attr, 297 &dev_attr_temp3_input.attr, 298 &dev_attr_temp2_type.attr, 299 &dev_attr_temp3_type.attr, 300 &dev_attr_temp2_min.attr, 301 &dev_attr_temp3_min.attr, 302 &dev_attr_temp2_max.attr, 303 &dev_attr_temp3_max.attr, 304 &dev_attr_rate.attr, 305 NULL 306 }; 307 308 static const struct attribute_group lm95241_group = { 309 .attrs = lm95241_attributes, 310 }; 311 312 /* Return 0 if detection is successful, -ENODEV otherwise */ 313 static int lm95241_detect(struct i2c_client *new_client, int kind, 314 struct i2c_board_info *info) 315 { 316 struct i2c_adapter *adapter = new_client->adapter; 317 int address = new_client->addr; 318 const char *name = ""; 319 320 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 321 return -ENODEV; 322 323 /* 324 * Now we do the remaining detection. A negative kind means that 325 * the driver was loaded with no force parameter (default), so we 326 * must both detect and identify the chip. A zero kind means that 327 * the driver was loaded with the force parameter, the detection 328 * step shall be skipped. A positive kind means that the driver 329 * was loaded with the force parameter and a given kind of chip is 330 * requested, so both the detection and the identification steps 331 * are skipped. 332 */ 333 if (kind < 0) { /* detection */ 334 if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID) 335 != MANUFACTURER_ID) 336 || (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID) 337 < DEFAULT_REVISION)) { 338 dev_dbg(&adapter->dev, 339 "LM95241 detection failed at 0x%02x.\n", 340 address); 341 return -ENODEV; 342 } 343 } 344 345 if (kind <= 0) { /* identification */ 346 if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID) 347 == MANUFACTURER_ID) 348 && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID) 349 >= DEFAULT_REVISION)) { 350 351 kind = lm95241; 352 353 if (kind <= 0) { /* identification failed */ 354 dev_info(&adapter->dev, "Unsupported chip\n"); 355 return -ENODEV; 356 } 357 } 358 } 359 360 /* Fill the i2c board info */ 361 if (kind == lm95241) 362 name = "lm95241"; 363 strlcpy(info->type, name, I2C_NAME_SIZE); 364 return 0; 365 } 366 367 static int lm95241_probe(struct i2c_client *new_client, 368 const struct i2c_device_id *id) 369 { 370 struct lm95241_data *data; 371 int err; 372 373 data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL); 374 if (!data) { 375 err = -ENOMEM; 376 goto exit; 377 } 378 379 i2c_set_clientdata(new_client, data); 380 mutex_init(&data->update_lock); 381 382 /* Initialize the LM95241 chip */ 383 lm95241_init_client(new_client); 384 385 /* Register sysfs hooks */ 386 err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group); 387 if (err) 388 goto exit_free; 389 390 data->hwmon_dev = hwmon_device_register(&new_client->dev); 391 if (IS_ERR(data->hwmon_dev)) { 392 err = PTR_ERR(data->hwmon_dev); 393 goto exit_remove_files; 394 } 395 396 return 0; 397 398 exit_remove_files: 399 sysfs_remove_group(&new_client->dev.kobj, &lm95241_group); 400 exit_free: 401 kfree(data); 402 exit: 403 return err; 404 } 405 406 static void lm95241_init_client(struct i2c_client *client) 407 { 408 struct lm95241_data *data = i2c_get_clientdata(client); 409 410 data->rate = HZ; /* 1 sec default */ 411 data->valid = 0; 412 data->config = CFG_CR0076; 413 data->model = 0; 414 data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT); 415 416 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, 417 data->config); 418 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER, 419 R1FE_MASK | R2FE_MASK); 420 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, 421 data->trutherm); 422 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, 423 data->model); 424 } 425 426 static int lm95241_remove(struct i2c_client *client) 427 { 428 struct lm95241_data *data = i2c_get_clientdata(client); 429 430 hwmon_device_unregister(data->hwmon_dev); 431 sysfs_remove_group(&client->dev.kobj, &lm95241_group); 432 433 i2c_set_clientdata(client, NULL); 434 kfree(data); 435 return 0; 436 } 437 438 static struct lm95241_data *lm95241_update_device(struct device *dev) 439 { 440 struct i2c_client *client = to_i2c_client(dev); 441 struct lm95241_data *data = i2c_get_clientdata(client); 442 443 mutex_lock(&data->update_lock); 444 445 if (time_after(jiffies, data->last_updated + data->rate) || 446 !data->valid) { 447 dev_dbg(&client->dev, "Updating lm95241 data.\n"); 448 data->local_h = 449 i2c_smbus_read_byte_data(client, 450 LM95241_REG_R_LOCAL_TEMPH); 451 data->local_l = 452 i2c_smbus_read_byte_data(client, 453 LM95241_REG_R_LOCAL_TEMPL); 454 data->remote1_h = 455 i2c_smbus_read_byte_data(client, 456 LM95241_REG_R_REMOTE1_TEMPH); 457 data->remote1_l = 458 i2c_smbus_read_byte_data(client, 459 LM95241_REG_R_REMOTE1_TEMPL); 460 data->remote2_h = 461 i2c_smbus_read_byte_data(client, 462 LM95241_REG_R_REMOTE2_TEMPH); 463 data->remote2_l = 464 i2c_smbus_read_byte_data(client, 465 LM95241_REG_R_REMOTE2_TEMPL); 466 data->last_updated = jiffies; 467 data->valid = 1; 468 } 469 470 mutex_unlock(&data->update_lock); 471 472 return data; 473 } 474 475 /* Driver data (common to all clients) */ 476 static const struct i2c_device_id lm95241_id[] = { 477 { "lm95241", lm95241 }, 478 { } 479 }; 480 MODULE_DEVICE_TABLE(i2c, lm95241_id); 481 482 static struct i2c_driver lm95241_driver = { 483 .class = I2C_CLASS_HWMON, 484 .driver = { 485 .name = "lm95241", 486 }, 487 .probe = lm95241_probe, 488 .remove = lm95241_remove, 489 .id_table = lm95241_id, 490 .detect = lm95241_detect, 491 .address_data = &addr_data, 492 }; 493 494 static int __init sensors_lm95241_init(void) 495 { 496 return i2c_add_driver(&lm95241_driver); 497 } 498 499 static void __exit sensors_lm95241_exit(void) 500 { 501 i2c_del_driver(&lm95241_driver); 502 } 503 504 MODULE_AUTHOR("Davide Rizzo <elpa-rizzo@gmail.com>"); 505 MODULE_DESCRIPTION("LM95241 sensor driver"); 506 MODULE_LICENSE("GPL"); 507 508 module_init(sensors_lm95241_init); 509 module_exit(sensors_lm95241_exit); 510