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 struct device *hwmon_dev; 140 struct mutex update_lock; 141 int nr_fans; 142 char valid; /* zero until following fields are valid */ 143 unsigned long last_updated; /* in jiffies */ 144 145 /* register values */ 146 u8 speed; 147 u8 config; 148 u8 tach[4]; 149 u8 count; 150 u8 dac; 151 u8 alarm; 152 }; 153 154 static ssize_t get_fan(struct device *dev, struct device_attribute *devattr, 155 char *buf) 156 { 157 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 158 struct max6650_data *data = max6650_update_device(dev); 159 int rpm; 160 161 /* 162 * Calculation details: 163 * 164 * Each tachometer counts over an interval given by the "count" 165 * register (0.25, 0.5, 1 or 2 seconds). This module assumes 166 * that the fans produce two pulses per revolution (this seems 167 * to be the most common). 168 */ 169 170 rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count)); 171 return sprintf(buf, "%d\n", rpm); 172 } 173 174 /* 175 * Set the fan speed to the specified RPM (or read back the RPM setting). 176 * This works in closed loop mode only. Use pwm1 for open loop speed setting. 177 * 178 * The MAX6650/1 will automatically control fan speed when in closed loop 179 * mode. 180 * 181 * Assumptions: 182 * 183 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use 184 * the clock module parameter if you need to fine tune this. 185 * 186 * 2) The prescaler (low three bits of the config register) has already 187 * been set to an appropriate value. Use the prescaler module parameter 188 * if your BIOS doesn't initialize the chip properly. 189 * 190 * The relevant equations are given on pages 21 and 22 of the datasheet. 191 * 192 * From the datasheet, the relevant equation when in regulation is: 193 * 194 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE 195 * 196 * where: 197 * 198 * fCLK is the oscillator frequency (either the 254kHz internal 199 * oscillator or the externally applied clock) 200 * 201 * KTACH is the value in the speed register 202 * 203 * FanSpeed is the speed of the fan in rps 204 * 205 * KSCALE is the prescaler value (1, 2, 4, 8, or 16) 206 * 207 * When reading, we need to solve for FanSpeed. When writing, we need to 208 * solve for KTACH. 209 * 210 * Note: this tachometer is completely separate from the tachometers 211 * used to measure the fan speeds. Only one fan's speed (fan1) is 212 * controlled. 213 */ 214 215 static ssize_t get_target(struct device *dev, struct device_attribute *devattr, 216 char *buf) 217 { 218 struct max6650_data *data = max6650_update_device(dev); 219 int kscale, ktach, rpm; 220 221 /* 222 * Use the datasheet equation: 223 * 224 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)] 225 * 226 * then multiply by 60 to give rpm. 227 */ 228 229 kscale = DIV_FROM_REG(data->config); 230 ktach = data->speed; 231 rpm = 60 * kscale * clock / (256 * (ktach + 1)); 232 return sprintf(buf, "%d\n", rpm); 233 } 234 235 static ssize_t set_target(struct device *dev, struct device_attribute *devattr, 236 const char *buf, size_t count) 237 { 238 struct i2c_client *client = to_i2c_client(dev); 239 struct max6650_data *data = i2c_get_clientdata(client); 240 int kscale, ktach; 241 unsigned long rpm; 242 int err; 243 244 err = kstrtoul(buf, 10, &rpm); 245 if (err) 246 return err; 247 248 rpm = SENSORS_LIMIT(rpm, FAN_RPM_MIN, FAN_RPM_MAX); 249 250 /* 251 * Divide the required speed by 60 to get from rpm to rps, then 252 * use the datasheet equation: 253 * 254 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1 255 */ 256 257 mutex_lock(&data->update_lock); 258 259 kscale = DIV_FROM_REG(data->config); 260 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1; 261 if (ktach < 0) 262 ktach = 0; 263 if (ktach > 255) 264 ktach = 255; 265 data->speed = ktach; 266 267 i2c_smbus_write_byte_data(client, MAX6650_REG_SPEED, data->speed); 268 269 mutex_unlock(&data->update_lock); 270 271 return count; 272 } 273 274 /* 275 * Get/set the fan speed in open loop mode using pwm1 sysfs file. 276 * Speed is given as a relative value from 0 to 255, where 255 is maximum 277 * speed. Note that this is done by writing directly to the chip's DAC, 278 * it won't change the closed loop speed set by fan1_target. 279 * Also note that due to rounding errors it is possible that you don't read 280 * back exactly the value you have set. 281 */ 282 283 static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr, 284 char *buf) 285 { 286 int pwm; 287 struct max6650_data *data = max6650_update_device(dev); 288 289 /* 290 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans. 291 * Lower DAC values mean higher speeds. 292 */ 293 if (data->config & MAX6650_CFG_V12) 294 pwm = 255 - (255 * (int)data->dac)/180; 295 else 296 pwm = 255 - (255 * (int)data->dac)/76; 297 298 if (pwm < 0) 299 pwm = 0; 300 301 return sprintf(buf, "%d\n", pwm); 302 } 303 304 static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr, 305 const char *buf, size_t count) 306 { 307 struct i2c_client *client = to_i2c_client(dev); 308 struct max6650_data *data = i2c_get_clientdata(client); 309 unsigned long pwm; 310 int err; 311 312 err = kstrtoul(buf, 10, &pwm); 313 if (err) 314 return err; 315 316 pwm = SENSORS_LIMIT(pwm, 0, 255); 317 318 mutex_lock(&data->update_lock); 319 320 if (data->config & MAX6650_CFG_V12) 321 data->dac = 180 - (180 * pwm)/255; 322 else 323 data->dac = 76 - (76 * pwm)/255; 324 325 i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); 326 327 mutex_unlock(&data->update_lock); 328 329 return count; 330 } 331 332 /* 333 * Get/Set controller mode: 334 * Possible values: 335 * 0 = Fan always on 336 * 1 = Open loop, Voltage is set according to speed, not regulated. 337 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer 338 */ 339 340 static ssize_t get_enable(struct device *dev, struct device_attribute *devattr, 341 char *buf) 342 { 343 struct max6650_data *data = max6650_update_device(dev); 344 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4; 345 int sysfs_modes[4] = {0, 1, 2, 1}; 346 347 return sprintf(buf, "%d\n", sysfs_modes[mode]); 348 } 349 350 static ssize_t set_enable(struct device *dev, struct device_attribute *devattr, 351 const char *buf, size_t count) 352 { 353 struct i2c_client *client = to_i2c_client(dev); 354 struct max6650_data *data = i2c_get_clientdata(client); 355 int max6650_modes[3] = {0, 3, 2}; 356 unsigned long mode; 357 int err; 358 359 err = kstrtoul(buf, 10, &mode); 360 if (err) 361 return err; 362 363 if (mode > 2) 364 return -EINVAL; 365 366 mutex_lock(&data->update_lock); 367 368 data->config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 369 data->config = (data->config & ~MAX6650_CFG_MODE_MASK) 370 | (max6650_modes[mode] << 4); 371 372 i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, data->config); 373 374 mutex_unlock(&data->update_lock); 375 376 return count; 377 } 378 379 /* 380 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such 381 * divider. We handle this by converting between divider and counttime: 382 * 383 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3 384 * 385 * Lower values of k allow to connect a faster fan without the risk of 386 * counter overflow. The price is lower resolution. You can also set counttime 387 * using the module parameter. Note that the module parameter "prescaler" also 388 * influences the behaviour. Unfortunately, there's no sysfs attribute 389 * defined for that. See the data sheet for details. 390 */ 391 392 static ssize_t get_div(struct device *dev, struct device_attribute *devattr, 393 char *buf) 394 { 395 struct max6650_data *data = max6650_update_device(dev); 396 397 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count)); 398 } 399 400 static ssize_t set_div(struct device *dev, struct device_attribute *devattr, 401 const char *buf, size_t count) 402 { 403 struct i2c_client *client = to_i2c_client(dev); 404 struct max6650_data *data = i2c_get_clientdata(client); 405 unsigned long div; 406 int err; 407 408 err = kstrtoul(buf, 10, &div); 409 if (err) 410 return err; 411 412 mutex_lock(&data->update_lock); 413 switch (div) { 414 case 1: 415 data->count = 0; 416 break; 417 case 2: 418 data->count = 1; 419 break; 420 case 4: 421 data->count = 2; 422 break; 423 case 8: 424 data->count = 3; 425 break; 426 default: 427 mutex_unlock(&data->update_lock); 428 return -EINVAL; 429 } 430 431 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count); 432 mutex_unlock(&data->update_lock); 433 434 return count; 435 } 436 437 /* 438 * Get alarm stati: 439 * Possible values: 440 * 0 = no alarm 441 * 1 = alarm 442 */ 443 444 static ssize_t get_alarm(struct device *dev, struct device_attribute *devattr, 445 char *buf) 446 { 447 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 448 struct max6650_data *data = max6650_update_device(dev); 449 struct i2c_client *client = to_i2c_client(dev); 450 int alarm = 0; 451 452 if (data->alarm & attr->index) { 453 mutex_lock(&data->update_lock); 454 alarm = 1; 455 data->alarm &= ~attr->index; 456 data->alarm |= i2c_smbus_read_byte_data(client, 457 MAX6650_REG_ALARM); 458 mutex_unlock(&data->update_lock); 459 } 460 461 return sprintf(buf, "%d\n", alarm); 462 } 463 464 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0); 465 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1); 466 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2); 467 static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3); 468 static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target); 469 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div); 470 static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable); 471 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm); 472 static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL, 473 MAX6650_ALRM_MAX); 474 static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL, 475 MAX6650_ALRM_MIN); 476 static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL, 477 MAX6650_ALRM_TACH); 478 static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL, 479 MAX6650_ALRM_GPIO1); 480 static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL, 481 MAX6650_ALRM_GPIO2); 482 483 static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a, 484 int n) 485 { 486 struct device *dev = container_of(kobj, struct device, kobj); 487 struct i2c_client *client = to_i2c_client(dev); 488 u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN); 489 struct device_attribute *devattr; 490 491 /* 492 * Hide the alarms that have not been enabled by the firmware 493 */ 494 495 devattr = container_of(a, struct device_attribute, attr); 496 if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr 497 || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr 498 || devattr == &sensor_dev_attr_fan1_fault.dev_attr 499 || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr 500 || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) { 501 if (!(alarm_en & to_sensor_dev_attr(devattr)->index)) 502 return 0; 503 } 504 505 return a->mode; 506 } 507 508 static struct attribute *max6650_attrs[] = { 509 &sensor_dev_attr_fan1_input.dev_attr.attr, 510 &dev_attr_fan1_target.attr, 511 &dev_attr_fan1_div.attr, 512 &dev_attr_pwm1_enable.attr, 513 &dev_attr_pwm1.attr, 514 &sensor_dev_attr_fan1_max_alarm.dev_attr.attr, 515 &sensor_dev_attr_fan1_min_alarm.dev_attr.attr, 516 &sensor_dev_attr_fan1_fault.dev_attr.attr, 517 &sensor_dev_attr_gpio1_alarm.dev_attr.attr, 518 &sensor_dev_attr_gpio2_alarm.dev_attr.attr, 519 NULL 520 }; 521 522 static struct attribute_group max6650_attr_grp = { 523 .attrs = max6650_attrs, 524 .is_visible = max6650_attrs_visible, 525 }; 526 527 static struct attribute *max6651_attrs[] = { 528 &sensor_dev_attr_fan2_input.dev_attr.attr, 529 &sensor_dev_attr_fan3_input.dev_attr.attr, 530 &sensor_dev_attr_fan4_input.dev_attr.attr, 531 NULL 532 }; 533 534 static const struct attribute_group max6651_attr_grp = { 535 .attrs = max6651_attrs, 536 }; 537 538 /* 539 * Real code 540 */ 541 542 static int max6650_probe(struct i2c_client *client, 543 const struct i2c_device_id *id) 544 { 545 struct max6650_data *data; 546 int err; 547 548 data = kzalloc(sizeof(struct max6650_data), GFP_KERNEL); 549 if (!data) { 550 dev_err(&client->dev, "out of memory.\n"); 551 return -ENOMEM; 552 } 553 554 i2c_set_clientdata(client, data); 555 mutex_init(&data->update_lock); 556 data->nr_fans = id->driver_data; 557 558 /* 559 * Initialize the max6650 chip 560 */ 561 err = max6650_init_client(client); 562 if (err) 563 goto err_free; 564 565 err = sysfs_create_group(&client->dev.kobj, &max6650_attr_grp); 566 if (err) 567 goto err_free; 568 /* 3 additional fan inputs for the MAX6651 */ 569 if (data->nr_fans == 4) { 570 err = sysfs_create_group(&client->dev.kobj, &max6651_attr_grp); 571 if (err) 572 goto err_remove; 573 } 574 575 data->hwmon_dev = hwmon_device_register(&client->dev); 576 if (!IS_ERR(data->hwmon_dev)) 577 return 0; 578 579 err = PTR_ERR(data->hwmon_dev); 580 dev_err(&client->dev, "error registering hwmon device.\n"); 581 if (data->nr_fans == 4) 582 sysfs_remove_group(&client->dev.kobj, &max6651_attr_grp); 583 err_remove: 584 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp); 585 err_free: 586 kfree(data); 587 return err; 588 } 589 590 static int max6650_remove(struct i2c_client *client) 591 { 592 struct max6650_data *data = i2c_get_clientdata(client); 593 594 hwmon_device_unregister(data->hwmon_dev); 595 if (data->nr_fans == 4) 596 sysfs_remove_group(&client->dev.kobj, &max6651_attr_grp); 597 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp); 598 kfree(data); 599 return 0; 600 } 601 602 static int max6650_init_client(struct i2c_client *client) 603 { 604 struct max6650_data *data = i2c_get_clientdata(client); 605 int config; 606 int err = -EIO; 607 608 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 609 610 if (config < 0) { 611 dev_err(&client->dev, "Error reading config, aborting.\n"); 612 return err; 613 } 614 615 switch (fan_voltage) { 616 case 0: 617 break; 618 case 5: 619 config &= ~MAX6650_CFG_V12; 620 break; 621 case 12: 622 config |= MAX6650_CFG_V12; 623 break; 624 default: 625 dev_err(&client->dev, "illegal value for fan_voltage (%d)\n", 626 fan_voltage); 627 } 628 629 dev_info(&client->dev, "Fan voltage is set to %dV.\n", 630 (config & MAX6650_CFG_V12) ? 12 : 5); 631 632 switch (prescaler) { 633 case 0: 634 break; 635 case 1: 636 config &= ~MAX6650_CFG_PRESCALER_MASK; 637 break; 638 case 2: 639 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 640 | MAX6650_CFG_PRESCALER_2; 641 break; 642 case 4: 643 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 644 | MAX6650_CFG_PRESCALER_4; 645 break; 646 case 8: 647 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 648 | MAX6650_CFG_PRESCALER_8; 649 break; 650 case 16: 651 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 652 | MAX6650_CFG_PRESCALER_16; 653 break; 654 default: 655 dev_err(&client->dev, "illegal value for prescaler (%d)\n", 656 prescaler); 657 } 658 659 dev_info(&client->dev, "Prescaler is set to %d.\n", 660 1 << (config & MAX6650_CFG_PRESCALER_MASK)); 661 662 /* 663 * If mode is set to "full off", we change it to "open loop" and 664 * set DAC to 255, which has the same effect. We do this because 665 * there's no "full off" mode defined in hwmon specifcations. 666 */ 667 668 if ((config & MAX6650_CFG_MODE_MASK) == MAX6650_CFG_MODE_OFF) { 669 dev_dbg(&client->dev, "Change mode to open loop, full off.\n"); 670 config = (config & ~MAX6650_CFG_MODE_MASK) 671 | MAX6650_CFG_MODE_OPEN_LOOP; 672 if (i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, 255)) { 673 dev_err(&client->dev, "DAC write error, aborting.\n"); 674 return err; 675 } 676 } 677 678 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) { 679 dev_err(&client->dev, "Config write error, aborting.\n"); 680 return err; 681 } 682 683 data->config = config; 684 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT); 685 686 return 0; 687 } 688 689 static const u8 tach_reg[] = { 690 MAX6650_REG_TACH0, 691 MAX6650_REG_TACH1, 692 MAX6650_REG_TACH2, 693 MAX6650_REG_TACH3, 694 }; 695 696 static struct max6650_data *max6650_update_device(struct device *dev) 697 { 698 int i; 699 struct i2c_client *client = to_i2c_client(dev); 700 struct max6650_data *data = i2c_get_clientdata(client); 701 702 mutex_lock(&data->update_lock); 703 704 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 705 data->speed = i2c_smbus_read_byte_data(client, 706 MAX6650_REG_SPEED); 707 data->config = i2c_smbus_read_byte_data(client, 708 MAX6650_REG_CONFIG); 709 for (i = 0; i < data->nr_fans; i++) { 710 data->tach[i] = i2c_smbus_read_byte_data(client, 711 tach_reg[i]); 712 } 713 data->count = i2c_smbus_read_byte_data(client, 714 MAX6650_REG_COUNT); 715 data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC); 716 717 /* 718 * Alarms are cleared on read in case the condition that 719 * caused the alarm is removed. Keep the value latched here 720 * for providing the register through different alarm files. 721 */ 722 data->alarm |= i2c_smbus_read_byte_data(client, 723 MAX6650_REG_ALARM); 724 725 data->last_updated = jiffies; 726 data->valid = 1; 727 } 728 729 mutex_unlock(&data->update_lock); 730 731 return data; 732 } 733 734 module_i2c_driver(max6650_driver); 735 736 MODULE_AUTHOR("Hans J. Koch"); 737 MODULE_DESCRIPTION("MAX6650 sensor driver"); 738 MODULE_LICENSE("GPL"); 739