1 /* 2 * max6650.c - Part of lm_sensors, Linux kernel modules for hardware 3 * monitoring. 4 * 5 * (C) 2007 by Hans J. Koch <hjk@linutronix.de> 6 * 7 * based on code written by John Morris <john.morris@spirentcom.com> 8 * Copyright (c) 2003 Spirent Communications 9 * and Claus Gindhart <claus.gindhart@kontron.com> 10 * 11 * This module has only been tested with the MAX6650 chip. It should 12 * also work with the MAX6651. It does not distinguish max6650 and max6651 13 * chips. 14 * 15 * Tha datasheet was last seen at: 16 * 17 * http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf 18 * 19 * This program is free software; you can redistribute it and/or modify 20 * it under the terms of the GNU General Public License as published by 21 * the Free Software Foundation; either version 2 of the License, or 22 * (at your option) any later version. 23 * 24 * This program is distributed in the hope that it will be useful, 25 * but WITHOUT ANY WARRANTY; without even the implied warranty of 26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 27 * GNU General Public License for more details. 28 * 29 * You should have received a copy of the GNU General Public License 30 * along with this program; if not, write to the Free Software 31 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 32 */ 33 34 #include <linux/module.h> 35 #include <linux/init.h> 36 #include <linux/slab.h> 37 #include <linux/jiffies.h> 38 #include <linux/i2c.h> 39 #include <linux/hwmon.h> 40 #include <linux/hwmon-sysfs.h> 41 #include <linux/err.h> 42 43 /* 44 * Addresses to scan. There are four disjoint possibilities, by pin config. 45 */ 46 47 static unsigned short normal_i2c[] = {0x1b, 0x1f, 0x48, 0x4b, I2C_CLIENT_END}; 48 49 /* 50 * Insmod parameters 51 */ 52 53 /* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */ 54 static int fan_voltage; 55 /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */ 56 static int prescaler; 57 /* clock: The clock frequency of the chip the driver should assume */ 58 static int clock = 254000; 59 60 module_param(fan_voltage, int, S_IRUGO); 61 module_param(prescaler, int, S_IRUGO); 62 module_param(clock, int, S_IRUGO); 63 64 I2C_CLIENT_INSMOD_1(max6650); 65 66 /* 67 * MAX 6650/6651 registers 68 */ 69 70 #define MAX6650_REG_SPEED 0x00 71 #define MAX6650_REG_CONFIG 0x02 72 #define MAX6650_REG_GPIO_DEF 0x04 73 #define MAX6650_REG_DAC 0x06 74 #define MAX6650_REG_ALARM_EN 0x08 75 #define MAX6650_REG_ALARM 0x0A 76 #define MAX6650_REG_TACH0 0x0C 77 #define MAX6650_REG_TACH1 0x0E 78 #define MAX6650_REG_TACH2 0x10 79 #define MAX6650_REG_TACH3 0x12 80 #define MAX6650_REG_GPIO_STAT 0x14 81 #define MAX6650_REG_COUNT 0x16 82 83 /* 84 * Config register bits 85 */ 86 87 #define MAX6650_CFG_V12 0x08 88 #define MAX6650_CFG_PRESCALER_MASK 0x07 89 #define MAX6650_CFG_PRESCALER_2 0x01 90 #define MAX6650_CFG_PRESCALER_4 0x02 91 #define MAX6650_CFG_PRESCALER_8 0x03 92 #define MAX6650_CFG_PRESCALER_16 0x04 93 #define MAX6650_CFG_MODE_MASK 0x30 94 #define MAX6650_CFG_MODE_ON 0x00 95 #define MAX6650_CFG_MODE_OFF 0x10 96 #define MAX6650_CFG_MODE_CLOSED_LOOP 0x20 97 #define MAX6650_CFG_MODE_OPEN_LOOP 0x30 98 #define MAX6650_COUNT_MASK 0x03 99 100 /* Minimum and maximum values of the FAN-RPM */ 101 #define FAN_RPM_MIN 240 102 #define FAN_RPM_MAX 30000 103 104 #define DIV_FROM_REG(reg) (1 << (reg & 7)) 105 106 static int max6650_attach_adapter(struct i2c_adapter *adapter); 107 static int max6650_detect(struct i2c_adapter *adapter, int address, int kind); 108 static int max6650_init_client(struct i2c_client *client); 109 static int max6650_detach_client(struct i2c_client *client); 110 static struct max6650_data *max6650_update_device(struct device *dev); 111 112 /* 113 * Driver data (common to all clients) 114 */ 115 116 static struct i2c_driver max6650_driver = { 117 .driver = { 118 .name = "max6650", 119 }, 120 .attach_adapter = max6650_attach_adapter, 121 .detach_client = max6650_detach_client, 122 }; 123 124 /* 125 * Client data (each client gets its own) 126 */ 127 128 struct max6650_data 129 { 130 struct i2c_client client; 131 struct class_device *class_dev; 132 struct mutex update_lock; 133 char valid; /* zero until following fields are valid */ 134 unsigned long last_updated; /* in jiffies */ 135 136 /* register values */ 137 u8 speed; 138 u8 config; 139 u8 tach[4]; 140 u8 count; 141 u8 dac; 142 }; 143 144 static ssize_t get_fan(struct device *dev, struct device_attribute *devattr, 145 char *buf) 146 { 147 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 148 struct max6650_data *data = max6650_update_device(dev); 149 int rpm; 150 151 /* 152 * Calculation details: 153 * 154 * Each tachometer counts over an interval given by the "count" 155 * register (0.25, 0.5, 1 or 2 seconds). This module assumes 156 * that the fans produce two pulses per revolution (this seems 157 * to be the most common). 158 */ 159 160 rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count)); 161 return sprintf(buf, "%d\n", rpm); 162 } 163 164 /* 165 * Set the fan speed to the specified RPM (or read back the RPM setting). 166 * This works in closed loop mode only. Use pwm1 for open loop speed setting. 167 * 168 * The MAX6650/1 will automatically control fan speed when in closed loop 169 * mode. 170 * 171 * Assumptions: 172 * 173 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use 174 * the clock module parameter if you need to fine tune this. 175 * 176 * 2) The prescaler (low three bits of the config register) has already 177 * been set to an appropriate value. Use the prescaler module parameter 178 * if your BIOS doesn't initialize the chip properly. 179 * 180 * The relevant equations are given on pages 21 and 22 of the datasheet. 181 * 182 * From the datasheet, the relevant equation when in regulation is: 183 * 184 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE 185 * 186 * where: 187 * 188 * fCLK is the oscillator frequency (either the 254kHz internal 189 * oscillator or the externally applied clock) 190 * 191 * KTACH is the value in the speed register 192 * 193 * FanSpeed is the speed of the fan in rps 194 * 195 * KSCALE is the prescaler value (1, 2, 4, 8, or 16) 196 * 197 * When reading, we need to solve for FanSpeed. When writing, we need to 198 * solve for KTACH. 199 * 200 * Note: this tachometer is completely separate from the tachometers 201 * used to measure the fan speeds. Only one fan's speed (fan1) is 202 * controlled. 203 */ 204 205 static ssize_t get_target(struct device *dev, struct device_attribute *devattr, 206 char *buf) 207 { 208 struct max6650_data *data = max6650_update_device(dev); 209 int kscale, ktach, rpm; 210 211 /* 212 * Use the datasheet equation: 213 * 214 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)] 215 * 216 * then multiply by 60 to give rpm. 217 */ 218 219 kscale = DIV_FROM_REG(data->config); 220 ktach = data->speed; 221 rpm = 60 * kscale * clock / (256 * (ktach + 1)); 222 return sprintf(buf, "%d\n", rpm); 223 } 224 225 static ssize_t set_target(struct device *dev, struct device_attribute *devattr, 226 const char *buf, size_t count) 227 { 228 struct i2c_client *client = to_i2c_client(dev); 229 struct max6650_data *data = i2c_get_clientdata(client); 230 int rpm = simple_strtoul(buf, NULL, 10); 231 int kscale, ktach; 232 233 rpm = SENSORS_LIMIT(rpm, FAN_RPM_MIN, FAN_RPM_MAX); 234 235 /* 236 * Divide the required speed by 60 to get from rpm to rps, then 237 * use the datasheet equation: 238 * 239 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1 240 */ 241 242 mutex_lock(&data->update_lock); 243 244 kscale = DIV_FROM_REG(data->config); 245 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1; 246 if (ktach < 0) 247 ktach = 0; 248 if (ktach > 255) 249 ktach = 255; 250 data->speed = ktach; 251 252 i2c_smbus_write_byte_data(client, MAX6650_REG_SPEED, data->speed); 253 254 mutex_unlock(&data->update_lock); 255 256 return count; 257 } 258 259 /* 260 * Get/set the fan speed in open loop mode using pwm1 sysfs file. 261 * Speed is given as a relative value from 0 to 255, where 255 is maximum 262 * speed. Note that this is done by writing directly to the chip's DAC, 263 * it won't change the closed loop speed set by fan1_target. 264 * Also note that due to rounding errors it is possible that you don't read 265 * back exactly the value you have set. 266 */ 267 268 static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr, 269 char *buf) 270 { 271 int pwm; 272 struct max6650_data *data = max6650_update_device(dev); 273 274 /* Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans. 275 Lower DAC values mean higher speeds. */ 276 if (data->config & MAX6650_CFG_V12) 277 pwm = 255 - (255 * (int)data->dac)/180; 278 else 279 pwm = 255 - (255 * (int)data->dac)/76; 280 281 if (pwm < 0) 282 pwm = 0; 283 284 return sprintf(buf, "%d\n", pwm); 285 } 286 287 static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr, 288 const char *buf, size_t count) 289 { 290 struct i2c_client *client = to_i2c_client(dev); 291 struct max6650_data *data = i2c_get_clientdata(client); 292 int pwm = simple_strtoul(buf, NULL, 10); 293 294 pwm = SENSORS_LIMIT(pwm, 0, 255); 295 296 mutex_lock(&data->update_lock); 297 298 if (data->config & MAX6650_CFG_V12) 299 data->dac = 180 - (180 * pwm)/255; 300 else 301 data->dac = 76 - (76 * pwm)/255; 302 303 i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); 304 305 mutex_unlock(&data->update_lock); 306 307 return count; 308 } 309 310 /* 311 * Get/Set controller mode: 312 * Possible values: 313 * 0 = Fan always on 314 * 1 = Open loop, Voltage is set according to speed, not regulated. 315 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer 316 */ 317 318 static ssize_t get_enable(struct device *dev, struct device_attribute *devattr, 319 char *buf) 320 { 321 struct max6650_data *data = max6650_update_device(dev); 322 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4; 323 int sysfs_modes[4] = {0, 1, 2, 1}; 324 325 return sprintf(buf, "%d\n", sysfs_modes[mode]); 326 } 327 328 static ssize_t set_enable(struct device *dev, struct device_attribute *devattr, 329 const char *buf, size_t count) 330 { 331 struct i2c_client *client = to_i2c_client(dev); 332 struct max6650_data *data = i2c_get_clientdata(client); 333 int mode = simple_strtoul(buf, NULL, 10); 334 int max6650_modes[3] = {0, 3, 2}; 335 336 if ((mode < 0)||(mode > 2)) { 337 dev_err(&client->dev, 338 "illegal value for pwm1_enable (%d)\n", mode); 339 return -EINVAL; 340 } 341 342 mutex_lock(&data->update_lock); 343 344 data->config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 345 data->config = (data->config & ~MAX6650_CFG_MODE_MASK) 346 | (max6650_modes[mode] << 4); 347 348 i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, data->config); 349 350 mutex_unlock(&data->update_lock); 351 352 return count; 353 } 354 355 /* 356 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such 357 * divider. We handle this by converting between divider and counttime: 358 * 359 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3 360 * 361 * Lower values of k allow to connect a faster fan without the risk of 362 * counter overflow. The price is lower resolution. You can also set counttime 363 * using the module parameter. Note that the module parameter "prescaler" also 364 * influences the behaviour. Unfortunately, there's no sysfs attribute 365 * defined for that. See the data sheet for details. 366 */ 367 368 static ssize_t get_div(struct device *dev, struct device_attribute *devattr, 369 char *buf) 370 { 371 struct max6650_data *data = max6650_update_device(dev); 372 373 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count)); 374 } 375 376 static ssize_t set_div(struct device *dev, struct device_attribute *devattr, 377 const char *buf, size_t count) 378 { 379 struct i2c_client *client = to_i2c_client(dev); 380 struct max6650_data *data = i2c_get_clientdata(client); 381 int div = simple_strtoul(buf, NULL, 10); 382 383 mutex_lock(&data->update_lock); 384 switch (div) { 385 case 1: 386 data->count = 0; 387 break; 388 case 2: 389 data->count = 1; 390 break; 391 case 4: 392 data->count = 2; 393 break; 394 case 8: 395 data->count = 3; 396 break; 397 default: 398 dev_err(&client->dev, 399 "illegal value for fan divider (%d)\n", div); 400 return -EINVAL; 401 } 402 403 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count); 404 mutex_unlock(&data->update_lock); 405 406 return count; 407 } 408 409 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0); 410 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1); 411 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2); 412 static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3); 413 static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target); 414 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div); 415 static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable); 416 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm); 417 418 419 static struct attribute *max6650_attrs[] = { 420 &sensor_dev_attr_fan1_input.dev_attr.attr, 421 &sensor_dev_attr_fan2_input.dev_attr.attr, 422 &sensor_dev_attr_fan3_input.dev_attr.attr, 423 &sensor_dev_attr_fan4_input.dev_attr.attr, 424 &dev_attr_fan1_target.attr, 425 &dev_attr_fan1_div.attr, 426 &dev_attr_pwm1_enable.attr, 427 &dev_attr_pwm1.attr, 428 NULL 429 }; 430 431 static struct attribute_group max6650_attr_grp = { 432 .attrs = max6650_attrs, 433 }; 434 435 /* 436 * Real code 437 */ 438 439 static int max6650_attach_adapter(struct i2c_adapter *adapter) 440 { 441 if (!(adapter->class & I2C_CLASS_HWMON)) { 442 dev_dbg(&adapter->dev, 443 "FATAL: max6650_attach_adapter class HWMON not set\n"); 444 return 0; 445 } 446 447 return i2c_probe(adapter, &addr_data, max6650_detect); 448 } 449 450 /* 451 * The following function does more than just detection. If detection 452 * succeeds, it also registers the new chip. 453 */ 454 455 static int max6650_detect(struct i2c_adapter *adapter, int address, int kind) 456 { 457 struct i2c_client *client; 458 struct max6650_data *data; 459 int err = -ENODEV; 460 461 dev_dbg(&adapter->dev, "max6650_detect called, kind = %d\n", kind); 462 463 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) { 464 dev_dbg(&adapter->dev, "max6650: I2C bus doesn't support " 465 "byte read mode, skipping.\n"); 466 return 0; 467 } 468 469 if (!(data = kzalloc(sizeof(struct max6650_data), GFP_KERNEL))) { 470 dev_err(&adapter->dev, "max6650: out of memory.\n"); 471 return -ENOMEM; 472 } 473 474 client = &data->client; 475 i2c_set_clientdata(client, data); 476 client->addr = address; 477 client->adapter = adapter; 478 client->driver = &max6650_driver; 479 480 /* 481 * Now we do the remaining detection. A negative kind means that 482 * the driver was loaded with no force parameter (default), so we 483 * must both detect and identify the chip (actually there is only 484 * one possible kind of chip for now, max6650). A zero kind means that 485 * the driver was loaded with the force parameter, the detection 486 * step shall be skipped. A positive kind means that the driver 487 * was loaded with the force parameter and a given kind of chip is 488 * requested, so both the detection and the identification steps 489 * are skipped. 490 * 491 * Currently I can find no way to distinguish between a MAX6650 and 492 * a MAX6651. This driver has only been tried on the former. 493 */ 494 495 if ((kind < 0) && 496 ( (i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG) & 0xC0) 497 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_GPIO_STAT) & 0xE0) 498 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN) & 0xE0) 499 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM) & 0xE0) 500 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT) & 0xFC))) { 501 dev_dbg(&adapter->dev, 502 "max6650: detection failed at 0x%02x.\n", address); 503 goto err_free; 504 } 505 506 dev_info(&adapter->dev, "max6650: chip found at 0x%02x.\n", address); 507 508 strlcpy(client->name, "max6650", I2C_NAME_SIZE); 509 mutex_init(&data->update_lock); 510 511 if ((err = i2c_attach_client(client))) { 512 dev_err(&adapter->dev, "max6650: failed to attach client.\n"); 513 goto err_free; 514 } 515 516 /* 517 * Initialize the max6650 chip 518 */ 519 if (max6650_init_client(client)) 520 goto err_detach; 521 522 err = sysfs_create_group(&client->dev.kobj, &max6650_attr_grp); 523 if (err) 524 goto err_detach; 525 526 data->class_dev = hwmon_device_register(&client->dev); 527 if (!IS_ERR(data->class_dev)) 528 return 0; 529 530 err = PTR_ERR(data->class_dev); 531 dev_err(&client->dev, "error registering hwmon device.\n"); 532 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp); 533 err_detach: 534 i2c_detach_client(client); 535 err_free: 536 kfree(data); 537 return err; 538 } 539 540 static int max6650_detach_client(struct i2c_client *client) 541 { 542 struct max6650_data *data = i2c_get_clientdata(client); 543 int err; 544 545 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp); 546 hwmon_device_unregister(data->class_dev); 547 err = i2c_detach_client(client); 548 if (!err) 549 kfree(data); 550 return err; 551 } 552 553 static int max6650_init_client(struct i2c_client *client) 554 { 555 struct max6650_data *data = i2c_get_clientdata(client); 556 int config; 557 int err = -EIO; 558 559 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 560 561 if (config < 0) { 562 dev_err(&client->dev, "Error reading config, aborting.\n"); 563 return err; 564 } 565 566 switch (fan_voltage) { 567 case 0: 568 break; 569 case 5: 570 config &= ~MAX6650_CFG_V12; 571 break; 572 case 12: 573 config |= MAX6650_CFG_V12; 574 break; 575 default: 576 dev_err(&client->dev, 577 "illegal value for fan_voltage (%d)\n", 578 fan_voltage); 579 } 580 581 dev_info(&client->dev, "Fan voltage is set to %dV.\n", 582 (config & MAX6650_CFG_V12) ? 12 : 5); 583 584 switch (prescaler) { 585 case 0: 586 break; 587 case 1: 588 config &= ~MAX6650_CFG_PRESCALER_MASK; 589 break; 590 case 2: 591 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 592 | MAX6650_CFG_PRESCALER_2; 593 break; 594 case 4: 595 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 596 | MAX6650_CFG_PRESCALER_4; 597 break; 598 case 8: 599 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 600 | MAX6650_CFG_PRESCALER_8; 601 break; 602 case 16: 603 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 604 | MAX6650_CFG_PRESCALER_16; 605 break; 606 default: 607 dev_err(&client->dev, 608 "illegal value for prescaler (%d)\n", 609 prescaler); 610 } 611 612 dev_info(&client->dev, "Prescaler is set to %d.\n", 613 1 << (config & MAX6650_CFG_PRESCALER_MASK)); 614 615 /* If mode is set to "full off", we change it to "open loop" and 616 * set DAC to 255, which has the same effect. We do this because 617 * there's no "full off" mode defined in hwmon specifcations. 618 */ 619 620 if ((config & MAX6650_CFG_MODE_MASK) == MAX6650_CFG_MODE_OFF) { 621 dev_dbg(&client->dev, "Change mode to open loop, full off.\n"); 622 config = (config & ~MAX6650_CFG_MODE_MASK) 623 | MAX6650_CFG_MODE_OPEN_LOOP; 624 if (i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, 255)) { 625 dev_err(&client->dev, "DAC write error, aborting.\n"); 626 return err; 627 } 628 } 629 630 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) { 631 dev_err(&client->dev, "Config write error, aborting.\n"); 632 return err; 633 } 634 635 data->config = config; 636 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT); 637 638 return 0; 639 } 640 641 static const u8 tach_reg[] = { 642 MAX6650_REG_TACH0, 643 MAX6650_REG_TACH1, 644 MAX6650_REG_TACH2, 645 MAX6650_REG_TACH3, 646 }; 647 648 static struct max6650_data *max6650_update_device(struct device *dev) 649 { 650 int i; 651 struct i2c_client *client = to_i2c_client(dev); 652 struct max6650_data *data = i2c_get_clientdata(client); 653 654 mutex_lock(&data->update_lock); 655 656 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 657 data->speed = i2c_smbus_read_byte_data(client, 658 MAX6650_REG_SPEED); 659 data->config = i2c_smbus_read_byte_data(client, 660 MAX6650_REG_CONFIG); 661 for (i = 0; i < 4; i++) { 662 data->tach[i] = i2c_smbus_read_byte_data(client, 663 tach_reg[i]); 664 } 665 data->count = i2c_smbus_read_byte_data(client, 666 MAX6650_REG_COUNT); 667 data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC); 668 669 data->last_updated = jiffies; 670 data->valid = 1; 671 } 672 673 mutex_unlock(&data->update_lock); 674 675 return data; 676 } 677 678 static int __init sensors_max6650_init(void) 679 { 680 return i2c_add_driver(&max6650_driver); 681 } 682 683 static void __exit sensors_max6650_exit(void) 684 { 685 i2c_del_driver(&max6650_driver); 686 } 687 688 MODULE_AUTHOR("Hans J. Koch"); 689 MODULE_DESCRIPTION("MAX6650 sensor driver"); 690 MODULE_LICENSE("GPL"); 691 692 module_init(sensors_max6650_init); 693 module_exit(sensors_max6650_exit); 694