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 /* LM95241 registers */ 43 #define LM95241_REG_R_MAN_ID 0xFE 44 #define LM95241_REG_R_CHIP_ID 0xFF 45 #define LM95241_REG_R_STATUS 0x02 46 #define LM95241_REG_RW_CONFIG 0x03 47 #define LM95241_REG_RW_REM_FILTER 0x06 48 #define LM95241_REG_RW_TRUTHERM 0x07 49 #define LM95241_REG_W_ONE_SHOT 0x0F 50 #define LM95241_REG_R_LOCAL_TEMPH 0x10 51 #define LM95241_REG_R_REMOTE1_TEMPH 0x11 52 #define LM95241_REG_R_REMOTE2_TEMPH 0x12 53 #define LM95241_REG_R_LOCAL_TEMPL 0x20 54 #define LM95241_REG_R_REMOTE1_TEMPL 0x21 55 #define LM95241_REG_R_REMOTE2_TEMPL 0x22 56 #define LM95241_REG_RW_REMOTE_MODEL 0x30 57 58 /* LM95241 specific bitfields */ 59 #define CFG_STOP 0x40 60 #define CFG_CR0076 0x00 61 #define CFG_CR0182 0x10 62 #define CFG_CR1000 0x20 63 #define CFG_CR2700 0x30 64 #define R1MS_SHIFT 0 65 #define R2MS_SHIFT 2 66 #define R1MS_MASK (0x01 << (R1MS_SHIFT)) 67 #define R2MS_MASK (0x01 << (R2MS_SHIFT)) 68 #define R1DF_SHIFT 1 69 #define R2DF_SHIFT 2 70 #define R1DF_MASK (0x01 << (R1DF_SHIFT)) 71 #define R2DF_MASK (0x01 << (R2DF_SHIFT)) 72 #define R1FE_MASK 0x01 73 #define R2FE_MASK 0x05 74 #define TT1_SHIFT 0 75 #define TT2_SHIFT 4 76 #define TT_OFF 0 77 #define TT_ON 1 78 #define TT_MASK 7 79 #define MANUFACTURER_ID 0x01 80 #define DEFAULT_REVISION 0xA4 81 82 /* Conversions and various macros */ 83 #define TEMP_FROM_REG(val_h, val_l) (((val_h) & 0x80 ? (val_h) - 0x100 : \ 84 (val_h)) * 1000 + (val_l) * 1000 / 256) 85 86 /* Functions declaration */ 87 static void lm95241_init_client(struct i2c_client *client); 88 static struct lm95241_data *lm95241_update_device(struct device *dev); 89 90 /* Client data (each client gets its own) */ 91 struct lm95241_data { 92 struct device *hwmon_dev; 93 struct mutex update_lock; 94 unsigned long last_updated, rate; /* in jiffies */ 95 char valid; /* zero until following fields are valid */ 96 /* registers values */ 97 u8 local_h, local_l; /* local */ 98 u8 remote1_h, remote1_l; /* remote1 */ 99 u8 remote2_h, remote2_l; /* remote2 */ 100 u8 config, model, trutherm; 101 }; 102 103 /* Sysfs stuff */ 104 #define show_temp(value) \ 105 static ssize_t show_##value(struct device *dev, \ 106 struct device_attribute *attr, char *buf) \ 107 { \ 108 struct lm95241_data *data = lm95241_update_device(dev); \ 109 snprintf(buf, PAGE_SIZE - 1, "%d\n", \ 110 TEMP_FROM_REG(data->value##_h, data->value##_l)); \ 111 return strlen(buf); \ 112 } 113 show_temp(local); 114 show_temp(remote1); 115 show_temp(remote2); 116 117 static ssize_t show_rate(struct device *dev, struct device_attribute *attr, 118 char *buf) 119 { 120 struct lm95241_data *data = lm95241_update_device(dev); 121 122 snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->rate / HZ); 123 return strlen(buf); 124 } 125 126 static ssize_t set_rate(struct device *dev, struct device_attribute *attr, 127 const char *buf, size_t count) 128 { 129 struct i2c_client *client = to_i2c_client(dev); 130 struct lm95241_data *data = i2c_get_clientdata(client); 131 132 strict_strtol(buf, 10, &data->rate); 133 data->rate = data->rate * HZ / 1000; 134 135 return count; 136 } 137 138 #define show_type(flag) \ 139 static ssize_t show_type##flag(struct device *dev, \ 140 struct device_attribute *attr, char *buf) \ 141 { \ 142 struct i2c_client *client = to_i2c_client(dev); \ 143 struct lm95241_data *data = i2c_get_clientdata(client); \ 144 \ 145 snprintf(buf, PAGE_SIZE - 1, \ 146 data->model & R##flag##MS_MASK ? "1\n" : "2\n"); \ 147 return strlen(buf); \ 148 } 149 show_type(1); 150 show_type(2); 151 152 #define show_min(flag) \ 153 static ssize_t show_min##flag(struct device *dev, \ 154 struct device_attribute *attr, char *buf) \ 155 { \ 156 struct i2c_client *client = to_i2c_client(dev); \ 157 struct lm95241_data *data = i2c_get_clientdata(client); \ 158 \ 159 snprintf(buf, PAGE_SIZE - 1, \ 160 data->config & R##flag##DF_MASK ? \ 161 "-127000\n" : "0\n"); \ 162 return strlen(buf); \ 163 } 164 show_min(1); 165 show_min(2); 166 167 #define show_max(flag) \ 168 static ssize_t show_max##flag(struct device *dev, \ 169 struct device_attribute *attr, char *buf) \ 170 { \ 171 struct i2c_client *client = to_i2c_client(dev); \ 172 struct lm95241_data *data = i2c_get_clientdata(client); \ 173 \ 174 snprintf(buf, PAGE_SIZE - 1, \ 175 data->config & R##flag##DF_MASK ? \ 176 "127000\n" : "255000\n"); \ 177 return strlen(buf); \ 178 } 179 show_max(1); 180 show_max(2); 181 182 #define set_type(flag) \ 183 static ssize_t set_type##flag(struct device *dev, \ 184 struct device_attribute *attr, \ 185 const char *buf, size_t count) \ 186 { \ 187 struct i2c_client *client = to_i2c_client(dev); \ 188 struct lm95241_data *data = i2c_get_clientdata(client); \ 189 \ 190 long val; \ 191 strict_strtol(buf, 10, &val); \ 192 \ 193 if ((val == 1) || (val == 2)) { \ 194 \ 195 mutex_lock(&data->update_lock); \ 196 \ 197 data->trutherm &= ~(TT_MASK << TT##flag##_SHIFT); \ 198 if (val == 1) { \ 199 data->model |= R##flag##MS_MASK; \ 200 data->trutherm |= (TT_ON << TT##flag##_SHIFT); \ 201 } \ 202 else { \ 203 data->model &= ~R##flag##MS_MASK; \ 204 data->trutherm |= (TT_OFF << TT##flag##_SHIFT); \ 205 } \ 206 \ 207 data->valid = 0; \ 208 \ 209 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, \ 210 data->model); \ 211 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, \ 212 data->trutherm); \ 213 \ 214 mutex_unlock(&data->update_lock); \ 215 \ 216 } \ 217 return count; \ 218 } 219 set_type(1); 220 set_type(2); 221 222 #define set_min(flag) \ 223 static ssize_t set_min##flag(struct device *dev, \ 224 struct device_attribute *devattr, const char *buf, size_t count) \ 225 { \ 226 struct i2c_client *client = to_i2c_client(dev); \ 227 struct lm95241_data *data = i2c_get_clientdata(client); \ 228 \ 229 long val; \ 230 strict_strtol(buf, 10, &val); \ 231 \ 232 mutex_lock(&data->update_lock); \ 233 \ 234 if (val < 0) \ 235 data->config |= R##flag##DF_MASK; \ 236 else \ 237 data->config &= ~R##flag##DF_MASK; \ 238 \ 239 data->valid = 0; \ 240 \ 241 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \ 242 data->config); \ 243 \ 244 mutex_unlock(&data->update_lock); \ 245 \ 246 return count; \ 247 } 248 set_min(1); 249 set_min(2); 250 251 #define set_max(flag) \ 252 static ssize_t set_max##flag(struct device *dev, \ 253 struct device_attribute *devattr, const char *buf, size_t count) \ 254 { \ 255 struct i2c_client *client = to_i2c_client(dev); \ 256 struct lm95241_data *data = i2c_get_clientdata(client); \ 257 \ 258 long val; \ 259 strict_strtol(buf, 10, &val); \ 260 \ 261 mutex_lock(&data->update_lock); \ 262 \ 263 if (val <= 127000) \ 264 data->config |= R##flag##DF_MASK; \ 265 else \ 266 data->config &= ~R##flag##DF_MASK; \ 267 \ 268 data->valid = 0; \ 269 \ 270 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \ 271 data->config); \ 272 \ 273 mutex_unlock(&data->update_lock); \ 274 \ 275 return count; \ 276 } 277 set_max(1); 278 set_max(2); 279 280 static DEVICE_ATTR(temp1_input, S_IRUGO, show_local, NULL); 281 static DEVICE_ATTR(temp2_input, S_IRUGO, show_remote1, NULL); 282 static DEVICE_ATTR(temp3_input, S_IRUGO, show_remote2, NULL); 283 static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type1, set_type1); 284 static DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type2, set_type2); 285 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min1, set_min1); 286 static DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min2, set_min2); 287 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max1, set_max1); 288 static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max2, set_max2); 289 static DEVICE_ATTR(rate, S_IWUSR | S_IRUGO, show_rate, set_rate); 290 291 static struct attribute *lm95241_attributes[] = { 292 &dev_attr_temp1_input.attr, 293 &dev_attr_temp2_input.attr, 294 &dev_attr_temp3_input.attr, 295 &dev_attr_temp2_type.attr, 296 &dev_attr_temp3_type.attr, 297 &dev_attr_temp2_min.attr, 298 &dev_attr_temp3_min.attr, 299 &dev_attr_temp2_max.attr, 300 &dev_attr_temp3_max.attr, 301 &dev_attr_rate.attr, 302 NULL 303 }; 304 305 static const struct attribute_group lm95241_group = { 306 .attrs = lm95241_attributes, 307 }; 308 309 /* Return 0 if detection is successful, -ENODEV otherwise */ 310 static int lm95241_detect(struct i2c_client *new_client, 311 struct i2c_board_info *info) 312 { 313 struct i2c_adapter *adapter = new_client->adapter; 314 int address = new_client->addr; 315 const char *name; 316 317 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 318 return -ENODEV; 319 320 if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID) 321 == MANUFACTURER_ID) 322 && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID) 323 >= DEFAULT_REVISION)) { 324 name = "lm95241"; 325 } else { 326 dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n", 327 address); 328 return -ENODEV; 329 } 330 331 /* Fill the i2c board info */ 332 strlcpy(info->type, name, I2C_NAME_SIZE); 333 return 0; 334 } 335 336 static int lm95241_probe(struct i2c_client *new_client, 337 const struct i2c_device_id *id) 338 { 339 struct lm95241_data *data; 340 int err; 341 342 data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL); 343 if (!data) { 344 err = -ENOMEM; 345 goto exit; 346 } 347 348 i2c_set_clientdata(new_client, data); 349 mutex_init(&data->update_lock); 350 351 /* Initialize the LM95241 chip */ 352 lm95241_init_client(new_client); 353 354 /* Register sysfs hooks */ 355 err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group); 356 if (err) 357 goto exit_free; 358 359 data->hwmon_dev = hwmon_device_register(&new_client->dev); 360 if (IS_ERR(data->hwmon_dev)) { 361 err = PTR_ERR(data->hwmon_dev); 362 goto exit_remove_files; 363 } 364 365 return 0; 366 367 exit_remove_files: 368 sysfs_remove_group(&new_client->dev.kobj, &lm95241_group); 369 exit_free: 370 kfree(data); 371 exit: 372 return err; 373 } 374 375 static void lm95241_init_client(struct i2c_client *client) 376 { 377 struct lm95241_data *data = i2c_get_clientdata(client); 378 379 data->rate = HZ; /* 1 sec default */ 380 data->valid = 0; 381 data->config = CFG_CR0076; 382 data->model = 0; 383 data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT); 384 385 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, 386 data->config); 387 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER, 388 R1FE_MASK | R2FE_MASK); 389 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, 390 data->trutherm); 391 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, 392 data->model); 393 } 394 395 static int lm95241_remove(struct i2c_client *client) 396 { 397 struct lm95241_data *data = i2c_get_clientdata(client); 398 399 hwmon_device_unregister(data->hwmon_dev); 400 sysfs_remove_group(&client->dev.kobj, &lm95241_group); 401 402 i2c_set_clientdata(client, NULL); 403 kfree(data); 404 return 0; 405 } 406 407 static struct lm95241_data *lm95241_update_device(struct device *dev) 408 { 409 struct i2c_client *client = to_i2c_client(dev); 410 struct lm95241_data *data = i2c_get_clientdata(client); 411 412 mutex_lock(&data->update_lock); 413 414 if (time_after(jiffies, data->last_updated + data->rate) || 415 !data->valid) { 416 dev_dbg(&client->dev, "Updating lm95241 data.\n"); 417 data->local_h = 418 i2c_smbus_read_byte_data(client, 419 LM95241_REG_R_LOCAL_TEMPH); 420 data->local_l = 421 i2c_smbus_read_byte_data(client, 422 LM95241_REG_R_LOCAL_TEMPL); 423 data->remote1_h = 424 i2c_smbus_read_byte_data(client, 425 LM95241_REG_R_REMOTE1_TEMPH); 426 data->remote1_l = 427 i2c_smbus_read_byte_data(client, 428 LM95241_REG_R_REMOTE1_TEMPL); 429 data->remote2_h = 430 i2c_smbus_read_byte_data(client, 431 LM95241_REG_R_REMOTE2_TEMPH); 432 data->remote2_l = 433 i2c_smbus_read_byte_data(client, 434 LM95241_REG_R_REMOTE2_TEMPL); 435 data->last_updated = jiffies; 436 data->valid = 1; 437 } 438 439 mutex_unlock(&data->update_lock); 440 441 return data; 442 } 443 444 /* Driver data (common to all clients) */ 445 static const struct i2c_device_id lm95241_id[] = { 446 { "lm95241", 0 }, 447 { } 448 }; 449 MODULE_DEVICE_TABLE(i2c, lm95241_id); 450 451 static struct i2c_driver lm95241_driver = { 452 .class = I2C_CLASS_HWMON, 453 .driver = { 454 .name = "lm95241", 455 }, 456 .probe = lm95241_probe, 457 .remove = lm95241_remove, 458 .id_table = lm95241_id, 459 .detect = lm95241_detect, 460 .address_list = normal_i2c, 461 }; 462 463 static int __init sensors_lm95241_init(void) 464 { 465 return i2c_add_driver(&lm95241_driver); 466 } 467 468 static void __exit sensors_lm95241_exit(void) 469 { 470 i2c_del_driver(&lm95241_driver); 471 } 472 473 MODULE_AUTHOR("Davide Rizzo <elpa-rizzo@gmail.com>"); 474 MODULE_DESCRIPTION("LM95241 sensor driver"); 475 MODULE_LICENSE("GPL"); 476 477 module_init(sensors_lm95241_init); 478 module_exit(sensors_lm95241_exit); 479