1 /* 2 * max6650.c - Part of lm_sensors, Linux kernel modules for hardware 3 * monitoring. 4 * 5 * (C) 2007 by Hans J. Koch <hjk@hansjkoch.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 * The 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 * Insmod parameters 45 */ 46 47 /* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */ 48 static int fan_voltage; 49 /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */ 50 static int prescaler; 51 /* clock: The clock frequency of the chip the driver should assume */ 52 static int clock = 254000; 53 54 module_param(fan_voltage, int, S_IRUGO); 55 module_param(prescaler, int, S_IRUGO); 56 module_param(clock, int, S_IRUGO); 57 58 /* 59 * MAX 6650/6651 registers 60 */ 61 62 #define MAX6650_REG_SPEED 0x00 63 #define MAX6650_REG_CONFIG 0x02 64 #define MAX6650_REG_GPIO_DEF 0x04 65 #define MAX6650_REG_DAC 0x06 66 #define MAX6650_REG_ALARM_EN 0x08 67 #define MAX6650_REG_ALARM 0x0A 68 #define MAX6650_REG_TACH0 0x0C 69 #define MAX6650_REG_TACH1 0x0E 70 #define MAX6650_REG_TACH2 0x10 71 #define MAX6650_REG_TACH3 0x12 72 #define MAX6650_REG_GPIO_STAT 0x14 73 #define MAX6650_REG_COUNT 0x16 74 75 /* 76 * Config register bits 77 */ 78 79 #define MAX6650_CFG_V12 0x08 80 #define MAX6650_CFG_PRESCALER_MASK 0x07 81 #define MAX6650_CFG_PRESCALER_2 0x01 82 #define MAX6650_CFG_PRESCALER_4 0x02 83 #define MAX6650_CFG_PRESCALER_8 0x03 84 #define MAX6650_CFG_PRESCALER_16 0x04 85 #define MAX6650_CFG_MODE_MASK 0x30 86 #define MAX6650_CFG_MODE_ON 0x00 87 #define MAX6650_CFG_MODE_OFF 0x10 88 #define MAX6650_CFG_MODE_CLOSED_LOOP 0x20 89 #define MAX6650_CFG_MODE_OPEN_LOOP 0x30 90 #define MAX6650_COUNT_MASK 0x03 91 92 /* 93 * Alarm status register bits 94 */ 95 96 #define MAX6650_ALRM_MAX 0x01 97 #define MAX6650_ALRM_MIN 0x02 98 #define MAX6650_ALRM_TACH 0x04 99 #define MAX6650_ALRM_GPIO1 0x08 100 #define MAX6650_ALRM_GPIO2 0x10 101 102 /* Minimum and maximum values of the FAN-RPM */ 103 #define FAN_RPM_MIN 240 104 #define FAN_RPM_MAX 30000 105 106 #define DIV_FROM_REG(reg) (1 << (reg & 7)) 107 108 static int max6650_probe(struct i2c_client *client, 109 const struct i2c_device_id *id); 110 static int max6650_init_client(struct i2c_client *client); 111 static int max6650_remove(struct i2c_client *client); 112 static struct max6650_data *max6650_update_device(struct device *dev); 113 114 /* 115 * Driver data (common to all clients) 116 */ 117 118 static const struct i2c_device_id max6650_id[] = { 119 { "max6650", 1 }, 120 { "max6651", 4 }, 121 { } 122 }; 123 MODULE_DEVICE_TABLE(i2c, max6650_id); 124 125 static struct i2c_driver max6650_driver = { 126 .driver = { 127 .name = "max6650", 128 }, 129 .probe = max6650_probe, 130 .remove = max6650_remove, 131 .id_table = max6650_id, 132 }; 133 134 /* 135 * Client data (each client gets its own) 136 */ 137 138 struct max6650_data 139 { 140 struct device *hwmon_dev; 141 struct mutex update_lock; 142 int nr_fans; 143 char valid; /* zero until following fields are valid */ 144 unsigned long last_updated; /* in jiffies */ 145 146 /* register values */ 147 u8 speed; 148 u8 config; 149 u8 tach[4]; 150 u8 count; 151 u8 dac; 152 u8 alarm; 153 }; 154 155 static ssize_t get_fan(struct device *dev, struct device_attribute *devattr, 156 char *buf) 157 { 158 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 159 struct max6650_data *data = max6650_update_device(dev); 160 int rpm; 161 162 /* 163 * Calculation details: 164 * 165 * Each tachometer counts over an interval given by the "count" 166 * register (0.25, 0.5, 1 or 2 seconds). This module assumes 167 * that the fans produce two pulses per revolution (this seems 168 * to be the most common). 169 */ 170 171 rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count)); 172 return sprintf(buf, "%d\n", rpm); 173 } 174 175 /* 176 * Set the fan speed to the specified RPM (or read back the RPM setting). 177 * This works in closed loop mode only. Use pwm1 for open loop speed setting. 178 * 179 * The MAX6650/1 will automatically control fan speed when in closed loop 180 * mode. 181 * 182 * Assumptions: 183 * 184 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use 185 * the clock module parameter if you need to fine tune this. 186 * 187 * 2) The prescaler (low three bits of the config register) has already 188 * been set to an appropriate value. Use the prescaler module parameter 189 * if your BIOS doesn't initialize the chip properly. 190 * 191 * The relevant equations are given on pages 21 and 22 of the datasheet. 192 * 193 * From the datasheet, the relevant equation when in regulation is: 194 * 195 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE 196 * 197 * where: 198 * 199 * fCLK is the oscillator frequency (either the 254kHz internal 200 * oscillator or the externally applied clock) 201 * 202 * KTACH is the value in the speed register 203 * 204 * FanSpeed is the speed of the fan in rps 205 * 206 * KSCALE is the prescaler value (1, 2, 4, 8, or 16) 207 * 208 * When reading, we need to solve for FanSpeed. When writing, we need to 209 * solve for KTACH. 210 * 211 * Note: this tachometer is completely separate from the tachometers 212 * used to measure the fan speeds. Only one fan's speed (fan1) is 213 * controlled. 214 */ 215 216 static ssize_t get_target(struct device *dev, struct device_attribute *devattr, 217 char *buf) 218 { 219 struct max6650_data *data = max6650_update_device(dev); 220 int kscale, ktach, rpm; 221 222 /* 223 * Use the datasheet equation: 224 * 225 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)] 226 * 227 * then multiply by 60 to give rpm. 228 */ 229 230 kscale = DIV_FROM_REG(data->config); 231 ktach = data->speed; 232 rpm = 60 * kscale * clock / (256 * (ktach + 1)); 233 return sprintf(buf, "%d\n", rpm); 234 } 235 236 static ssize_t set_target(struct device *dev, struct device_attribute *devattr, 237 const char *buf, size_t count) 238 { 239 struct i2c_client *client = to_i2c_client(dev); 240 struct max6650_data *data = i2c_get_clientdata(client); 241 int rpm = simple_strtoul(buf, NULL, 10); 242 int kscale, ktach; 243 244 rpm = SENSORS_LIMIT(rpm, FAN_RPM_MIN, FAN_RPM_MAX); 245 246 /* 247 * Divide the required speed by 60 to get from rpm to rps, then 248 * use the datasheet equation: 249 * 250 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1 251 */ 252 253 mutex_lock(&data->update_lock); 254 255 kscale = DIV_FROM_REG(data->config); 256 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1; 257 if (ktach < 0) 258 ktach = 0; 259 if (ktach > 255) 260 ktach = 255; 261 data->speed = ktach; 262 263 i2c_smbus_write_byte_data(client, MAX6650_REG_SPEED, data->speed); 264 265 mutex_unlock(&data->update_lock); 266 267 return count; 268 } 269 270 /* 271 * Get/set the fan speed in open loop mode using pwm1 sysfs file. 272 * Speed is given as a relative value from 0 to 255, where 255 is maximum 273 * speed. Note that this is done by writing directly to the chip's DAC, 274 * it won't change the closed loop speed set by fan1_target. 275 * Also note that due to rounding errors it is possible that you don't read 276 * back exactly the value you have set. 277 */ 278 279 static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr, 280 char *buf) 281 { 282 int pwm; 283 struct max6650_data *data = max6650_update_device(dev); 284 285 /* Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans. 286 Lower DAC values mean higher speeds. */ 287 if (data->config & MAX6650_CFG_V12) 288 pwm = 255 - (255 * (int)data->dac)/180; 289 else 290 pwm = 255 - (255 * (int)data->dac)/76; 291 292 if (pwm < 0) 293 pwm = 0; 294 295 return sprintf(buf, "%d\n", pwm); 296 } 297 298 static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr, 299 const char *buf, size_t count) 300 { 301 struct i2c_client *client = to_i2c_client(dev); 302 struct max6650_data *data = i2c_get_clientdata(client); 303 int pwm = simple_strtoul(buf, NULL, 10); 304 305 pwm = SENSORS_LIMIT(pwm, 0, 255); 306 307 mutex_lock(&data->update_lock); 308 309 if (data->config & MAX6650_CFG_V12) 310 data->dac = 180 - (180 * pwm)/255; 311 else 312 data->dac = 76 - (76 * pwm)/255; 313 314 i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); 315 316 mutex_unlock(&data->update_lock); 317 318 return count; 319 } 320 321 /* 322 * Get/Set controller mode: 323 * Possible values: 324 * 0 = Fan always on 325 * 1 = Open loop, Voltage is set according to speed, not regulated. 326 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer 327 */ 328 329 static ssize_t get_enable(struct device *dev, struct device_attribute *devattr, 330 char *buf) 331 { 332 struct max6650_data *data = max6650_update_device(dev); 333 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4; 334 int sysfs_modes[4] = {0, 1, 2, 1}; 335 336 return sprintf(buf, "%d\n", sysfs_modes[mode]); 337 } 338 339 static ssize_t set_enable(struct device *dev, struct device_attribute *devattr, 340 const char *buf, size_t count) 341 { 342 struct i2c_client *client = to_i2c_client(dev); 343 struct max6650_data *data = i2c_get_clientdata(client); 344 int mode = simple_strtoul(buf, NULL, 10); 345 int max6650_modes[3] = {0, 3, 2}; 346 347 if ((mode < 0)||(mode > 2)) { 348 dev_err(&client->dev, 349 "illegal value for pwm1_enable (%d)\n", mode); 350 return -EINVAL; 351 } 352 353 mutex_lock(&data->update_lock); 354 355 data->config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 356 data->config = (data->config & ~MAX6650_CFG_MODE_MASK) 357 | (max6650_modes[mode] << 4); 358 359 i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, data->config); 360 361 mutex_unlock(&data->update_lock); 362 363 return count; 364 } 365 366 /* 367 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such 368 * divider. We handle this by converting between divider and counttime: 369 * 370 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3 371 * 372 * Lower values of k allow to connect a faster fan without the risk of 373 * counter overflow. The price is lower resolution. You can also set counttime 374 * using the module parameter. Note that the module parameter "prescaler" also 375 * influences the behaviour. Unfortunately, there's no sysfs attribute 376 * defined for that. See the data sheet for details. 377 */ 378 379 static ssize_t get_div(struct device *dev, struct device_attribute *devattr, 380 char *buf) 381 { 382 struct max6650_data *data = max6650_update_device(dev); 383 384 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count)); 385 } 386 387 static ssize_t set_div(struct device *dev, struct device_attribute *devattr, 388 const char *buf, size_t count) 389 { 390 struct i2c_client *client = to_i2c_client(dev); 391 struct max6650_data *data = i2c_get_clientdata(client); 392 int div = simple_strtoul(buf, NULL, 10); 393 394 mutex_lock(&data->update_lock); 395 switch (div) { 396 case 1: 397 data->count = 0; 398 break; 399 case 2: 400 data->count = 1; 401 break; 402 case 4: 403 data->count = 2; 404 break; 405 case 8: 406 data->count = 3; 407 break; 408 default: 409 mutex_unlock(&data->update_lock); 410 dev_err(&client->dev, 411 "illegal value for fan divider (%d)\n", div); 412 return -EINVAL; 413 } 414 415 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count); 416 mutex_unlock(&data->update_lock); 417 418 return count; 419 } 420 421 /* 422 * Get alarm stati: 423 * Possible values: 424 * 0 = no alarm 425 * 1 = alarm 426 */ 427 428 static ssize_t get_alarm(struct device *dev, struct device_attribute *devattr, 429 char *buf) 430 { 431 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 432 struct max6650_data *data = max6650_update_device(dev); 433 struct i2c_client *client = to_i2c_client(dev); 434 int alarm = 0; 435 436 if (data->alarm & attr->index) { 437 mutex_lock(&data->update_lock); 438 alarm = 1; 439 data->alarm &= ~attr->index; 440 data->alarm |= i2c_smbus_read_byte_data(client, 441 MAX6650_REG_ALARM); 442 mutex_unlock(&data->update_lock); 443 } 444 445 return sprintf(buf, "%d\n", alarm); 446 } 447 448 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0); 449 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1); 450 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2); 451 static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3); 452 static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target); 453 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div); 454 static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable); 455 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm); 456 static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL, 457 MAX6650_ALRM_MAX); 458 static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL, 459 MAX6650_ALRM_MIN); 460 static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL, 461 MAX6650_ALRM_TACH); 462 static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL, 463 MAX6650_ALRM_GPIO1); 464 static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL, 465 MAX6650_ALRM_GPIO2); 466 467 static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a, 468 int n) 469 { 470 struct device *dev = container_of(kobj, struct device, kobj); 471 struct i2c_client *client = to_i2c_client(dev); 472 u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN); 473 struct device_attribute *devattr; 474 475 /* 476 * Hide the alarms that have not been enabled by the firmware 477 */ 478 479 devattr = container_of(a, struct device_attribute, attr); 480 if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr 481 || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr 482 || devattr == &sensor_dev_attr_fan1_fault.dev_attr 483 || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr 484 || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) { 485 if (!(alarm_en & to_sensor_dev_attr(devattr)->index)) 486 return 0; 487 } 488 489 return a->mode; 490 } 491 492 static struct attribute *max6650_attrs[] = { 493 &sensor_dev_attr_fan1_input.dev_attr.attr, 494 &dev_attr_fan1_target.attr, 495 &dev_attr_fan1_div.attr, 496 &dev_attr_pwm1_enable.attr, 497 &dev_attr_pwm1.attr, 498 &sensor_dev_attr_fan1_max_alarm.dev_attr.attr, 499 &sensor_dev_attr_fan1_min_alarm.dev_attr.attr, 500 &sensor_dev_attr_fan1_fault.dev_attr.attr, 501 &sensor_dev_attr_gpio1_alarm.dev_attr.attr, 502 &sensor_dev_attr_gpio2_alarm.dev_attr.attr, 503 NULL 504 }; 505 506 static struct attribute_group max6650_attr_grp = { 507 .attrs = max6650_attrs, 508 .is_visible = max6650_attrs_visible, 509 }; 510 511 static struct attribute *max6651_attrs[] = { 512 &sensor_dev_attr_fan2_input.dev_attr.attr, 513 &sensor_dev_attr_fan3_input.dev_attr.attr, 514 &sensor_dev_attr_fan4_input.dev_attr.attr, 515 NULL 516 }; 517 518 static const struct attribute_group max6651_attr_grp = { 519 .attrs = max6651_attrs, 520 }; 521 522 /* 523 * Real code 524 */ 525 526 static int max6650_probe(struct i2c_client *client, 527 const struct i2c_device_id *id) 528 { 529 struct max6650_data *data; 530 int err; 531 532 if (!(data = kzalloc(sizeof(struct max6650_data), GFP_KERNEL))) { 533 dev_err(&client->dev, "out of memory.\n"); 534 return -ENOMEM; 535 } 536 537 i2c_set_clientdata(client, data); 538 mutex_init(&data->update_lock); 539 data->nr_fans = id->driver_data; 540 541 /* 542 * Initialize the max6650 chip 543 */ 544 err = max6650_init_client(client); 545 if (err) 546 goto err_free; 547 548 err = sysfs_create_group(&client->dev.kobj, &max6650_attr_grp); 549 if (err) 550 goto err_free; 551 /* 3 additional fan inputs for the MAX6651 */ 552 if (data->nr_fans == 4) { 553 err = sysfs_create_group(&client->dev.kobj, &max6651_attr_grp); 554 if (err) 555 goto err_remove; 556 } 557 558 data->hwmon_dev = hwmon_device_register(&client->dev); 559 if (!IS_ERR(data->hwmon_dev)) 560 return 0; 561 562 err = PTR_ERR(data->hwmon_dev); 563 dev_err(&client->dev, "error registering hwmon device.\n"); 564 if (data->nr_fans == 4) 565 sysfs_remove_group(&client->dev.kobj, &max6651_attr_grp); 566 err_remove: 567 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp); 568 err_free: 569 kfree(data); 570 return err; 571 } 572 573 static int max6650_remove(struct i2c_client *client) 574 { 575 struct max6650_data *data = i2c_get_clientdata(client); 576 577 hwmon_device_unregister(data->hwmon_dev); 578 if (data->nr_fans == 4) 579 sysfs_remove_group(&client->dev.kobj, &max6651_attr_grp); 580 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp); 581 kfree(data); 582 return 0; 583 } 584 585 static int max6650_init_client(struct i2c_client *client) 586 { 587 struct max6650_data *data = i2c_get_clientdata(client); 588 int config; 589 int err = -EIO; 590 591 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 592 593 if (config < 0) { 594 dev_err(&client->dev, "Error reading config, aborting.\n"); 595 return err; 596 } 597 598 switch (fan_voltage) { 599 case 0: 600 break; 601 case 5: 602 config &= ~MAX6650_CFG_V12; 603 break; 604 case 12: 605 config |= MAX6650_CFG_V12; 606 break; 607 default: 608 dev_err(&client->dev, 609 "illegal value for fan_voltage (%d)\n", 610 fan_voltage); 611 } 612 613 dev_info(&client->dev, "Fan voltage is set to %dV.\n", 614 (config & MAX6650_CFG_V12) ? 12 : 5); 615 616 switch (prescaler) { 617 case 0: 618 break; 619 case 1: 620 config &= ~MAX6650_CFG_PRESCALER_MASK; 621 break; 622 case 2: 623 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 624 | MAX6650_CFG_PRESCALER_2; 625 break; 626 case 4: 627 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 628 | MAX6650_CFG_PRESCALER_4; 629 break; 630 case 8: 631 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 632 | MAX6650_CFG_PRESCALER_8; 633 break; 634 case 16: 635 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 636 | MAX6650_CFG_PRESCALER_16; 637 break; 638 default: 639 dev_err(&client->dev, 640 "illegal value for prescaler (%d)\n", 641 prescaler); 642 } 643 644 dev_info(&client->dev, "Prescaler is set to %d.\n", 645 1 << (config & MAX6650_CFG_PRESCALER_MASK)); 646 647 /* If mode is set to "full off", we change it to "open loop" and 648 * set DAC to 255, which has the same effect. We do this because 649 * there's no "full off" mode defined in hwmon specifcations. 650 */ 651 652 if ((config & MAX6650_CFG_MODE_MASK) == MAX6650_CFG_MODE_OFF) { 653 dev_dbg(&client->dev, "Change mode to open loop, full off.\n"); 654 config = (config & ~MAX6650_CFG_MODE_MASK) 655 | MAX6650_CFG_MODE_OPEN_LOOP; 656 if (i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, 255)) { 657 dev_err(&client->dev, "DAC write error, aborting.\n"); 658 return err; 659 } 660 } 661 662 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) { 663 dev_err(&client->dev, "Config write error, aborting.\n"); 664 return err; 665 } 666 667 data->config = config; 668 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT); 669 670 return 0; 671 } 672 673 static const u8 tach_reg[] = { 674 MAX6650_REG_TACH0, 675 MAX6650_REG_TACH1, 676 MAX6650_REG_TACH2, 677 MAX6650_REG_TACH3, 678 }; 679 680 static struct max6650_data *max6650_update_device(struct device *dev) 681 { 682 int i; 683 struct i2c_client *client = to_i2c_client(dev); 684 struct max6650_data *data = i2c_get_clientdata(client); 685 686 mutex_lock(&data->update_lock); 687 688 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 689 data->speed = i2c_smbus_read_byte_data(client, 690 MAX6650_REG_SPEED); 691 data->config = i2c_smbus_read_byte_data(client, 692 MAX6650_REG_CONFIG); 693 for (i = 0; i < data->nr_fans; i++) { 694 data->tach[i] = i2c_smbus_read_byte_data(client, 695 tach_reg[i]); 696 } 697 data->count = i2c_smbus_read_byte_data(client, 698 MAX6650_REG_COUNT); 699 data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC); 700 701 /* Alarms are cleared on read in case the condition that 702 * caused the alarm is removed. Keep the value latched here 703 * for providing the register through different alarm files. */ 704 data->alarm |= i2c_smbus_read_byte_data(client, 705 MAX6650_REG_ALARM); 706 707 data->last_updated = jiffies; 708 data->valid = 1; 709 } 710 711 mutex_unlock(&data->update_lock); 712 713 return data; 714 } 715 716 static int __init sensors_max6650_init(void) 717 { 718 return i2c_add_driver(&max6650_driver); 719 } 720 721 static void __exit sensors_max6650_exit(void) 722 { 723 i2c_del_driver(&max6650_driver); 724 } 725 726 MODULE_AUTHOR("Hans J. Koch"); 727 MODULE_DESCRIPTION("MAX6650 sensor driver"); 728 MODULE_LICENSE("GPL"); 729 730 module_init(sensors_max6650_init); 731 module_exit(sensors_max6650_exit); 732