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 #include <linux/of_device.h> 43 44 /* 45 * Insmod parameters 46 */ 47 48 /* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */ 49 static int fan_voltage; 50 /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */ 51 static int prescaler; 52 /* clock: The clock frequency of the chip (max6651 can be clocked externally) */ 53 static int clock = 254000; 54 55 module_param(fan_voltage, int, S_IRUGO); 56 module_param(prescaler, int, S_IRUGO); 57 module_param(clock, int, S_IRUGO); 58 59 /* 60 * MAX 6650/6651 registers 61 */ 62 63 #define MAX6650_REG_SPEED 0x00 64 #define MAX6650_REG_CONFIG 0x02 65 #define MAX6650_REG_GPIO_DEF 0x04 66 #define MAX6650_REG_DAC 0x06 67 #define MAX6650_REG_ALARM_EN 0x08 68 #define MAX6650_REG_ALARM 0x0A 69 #define MAX6650_REG_TACH0 0x0C 70 #define MAX6650_REG_TACH1 0x0E 71 #define MAX6650_REG_TACH2 0x10 72 #define MAX6650_REG_TACH3 0x12 73 #define MAX6650_REG_GPIO_STAT 0x14 74 #define MAX6650_REG_COUNT 0x16 75 76 /* 77 * Config register bits 78 */ 79 80 #define MAX6650_CFG_V12 0x08 81 #define MAX6650_CFG_PRESCALER_MASK 0x07 82 #define MAX6650_CFG_PRESCALER_2 0x01 83 #define MAX6650_CFG_PRESCALER_4 0x02 84 #define MAX6650_CFG_PRESCALER_8 0x03 85 #define MAX6650_CFG_PRESCALER_16 0x04 86 #define MAX6650_CFG_MODE_MASK 0x30 87 #define MAX6650_CFG_MODE_ON 0x00 88 #define MAX6650_CFG_MODE_OFF 0x10 89 #define MAX6650_CFG_MODE_CLOSED_LOOP 0x20 90 #define MAX6650_CFG_MODE_OPEN_LOOP 0x30 91 #define MAX6650_COUNT_MASK 0x03 92 93 /* 94 * Alarm status register bits 95 */ 96 97 #define MAX6650_ALRM_MAX 0x01 98 #define MAX6650_ALRM_MIN 0x02 99 #define MAX6650_ALRM_TACH 0x04 100 #define MAX6650_ALRM_GPIO1 0x08 101 #define MAX6650_ALRM_GPIO2 0x10 102 103 /* Minimum and maximum values of the FAN-RPM */ 104 #define FAN_RPM_MIN 240 105 #define FAN_RPM_MAX 30000 106 107 #define DIV_FROM_REG(reg) (1 << (reg & 7)) 108 109 /* 110 * Client data (each client gets its own) 111 */ 112 113 struct max6650_data { 114 struct i2c_client *client; 115 const struct attribute_group *groups[3]; 116 struct mutex update_lock; 117 int nr_fans; 118 char valid; /* zero until following fields are valid */ 119 unsigned long last_updated; /* in jiffies */ 120 121 /* register values */ 122 u8 speed; 123 u8 config; 124 u8 tach[4]; 125 u8 count; 126 u8 dac; 127 u8 alarm; 128 }; 129 130 static const u8 tach_reg[] = { 131 MAX6650_REG_TACH0, 132 MAX6650_REG_TACH1, 133 MAX6650_REG_TACH2, 134 MAX6650_REG_TACH3, 135 }; 136 137 static const struct of_device_id max6650_dt_match[] = { 138 { 139 .compatible = "maxim,max6650", 140 .data = (void *)1 141 }, 142 { 143 .compatible = "maxim,max6651", 144 .data = (void *)4 145 }, 146 { }, 147 }; 148 MODULE_DEVICE_TABLE(of, max6650_dt_match); 149 150 static struct max6650_data *max6650_update_device(struct device *dev) 151 { 152 struct max6650_data *data = dev_get_drvdata(dev); 153 struct i2c_client *client = data->client; 154 int i; 155 156 mutex_lock(&data->update_lock); 157 158 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 159 data->speed = i2c_smbus_read_byte_data(client, 160 MAX6650_REG_SPEED); 161 data->config = i2c_smbus_read_byte_data(client, 162 MAX6650_REG_CONFIG); 163 for (i = 0; i < data->nr_fans; i++) { 164 data->tach[i] = i2c_smbus_read_byte_data(client, 165 tach_reg[i]); 166 } 167 data->count = i2c_smbus_read_byte_data(client, 168 MAX6650_REG_COUNT); 169 data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC); 170 171 /* 172 * Alarms are cleared on read in case the condition that 173 * caused the alarm is removed. Keep the value latched here 174 * for providing the register through different alarm files. 175 */ 176 data->alarm |= i2c_smbus_read_byte_data(client, 177 MAX6650_REG_ALARM); 178 179 data->last_updated = jiffies; 180 data->valid = 1; 181 } 182 183 mutex_unlock(&data->update_lock); 184 185 return data; 186 } 187 188 /* 189 * Change the operating mode of the chip (if needed). 190 * mode is one of the MAX6650_CFG_MODE_* values. 191 */ 192 static int max6650_set_operating_mode(struct max6650_data *data, u8 mode) 193 { 194 int result; 195 u8 config = data->config; 196 197 if (mode == (config & MAX6650_CFG_MODE_MASK)) 198 return 0; 199 200 config = (config & ~MAX6650_CFG_MODE_MASK) | mode; 201 202 result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG, 203 config); 204 if (result < 0) 205 return result; 206 207 data->config = config; 208 209 return 0; 210 } 211 212 static ssize_t get_fan(struct device *dev, struct device_attribute *devattr, 213 char *buf) 214 { 215 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 216 struct max6650_data *data = max6650_update_device(dev); 217 int rpm; 218 219 /* 220 * Calculation details: 221 * 222 * Each tachometer counts over an interval given by the "count" 223 * register (0.25, 0.5, 1 or 2 seconds). This module assumes 224 * that the fans produce two pulses per revolution (this seems 225 * to be the most common). 226 */ 227 228 rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count)); 229 return sprintf(buf, "%d\n", rpm); 230 } 231 232 /* 233 * Set the fan speed to the specified RPM (or read back the RPM setting). 234 * This works in closed loop mode only. Use pwm1 for open loop speed setting. 235 * 236 * The MAX6650/1 will automatically control fan speed when in closed loop 237 * mode. 238 * 239 * Assumptions: 240 * 241 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use 242 * the clock module parameter if you need to fine tune this. 243 * 244 * 2) The prescaler (low three bits of the config register) has already 245 * been set to an appropriate value. Use the prescaler module parameter 246 * if your BIOS doesn't initialize the chip properly. 247 * 248 * The relevant equations are given on pages 21 and 22 of the datasheet. 249 * 250 * From the datasheet, the relevant equation when in regulation is: 251 * 252 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE 253 * 254 * where: 255 * 256 * fCLK is the oscillator frequency (either the 254kHz internal 257 * oscillator or the externally applied clock) 258 * 259 * KTACH is the value in the speed register 260 * 261 * FanSpeed is the speed of the fan in rps 262 * 263 * KSCALE is the prescaler value (1, 2, 4, 8, or 16) 264 * 265 * When reading, we need to solve for FanSpeed. When writing, we need to 266 * solve for KTACH. 267 * 268 * Note: this tachometer is completely separate from the tachometers 269 * used to measure the fan speeds. Only one fan's speed (fan1) is 270 * controlled. 271 */ 272 273 static ssize_t get_target(struct device *dev, struct device_attribute *devattr, 274 char *buf) 275 { 276 struct max6650_data *data = max6650_update_device(dev); 277 int kscale, ktach, rpm; 278 279 /* 280 * Use the datasheet equation: 281 * 282 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)] 283 * 284 * then multiply by 60 to give rpm. 285 */ 286 287 kscale = DIV_FROM_REG(data->config); 288 ktach = data->speed; 289 rpm = 60 * kscale * clock / (256 * (ktach + 1)); 290 return sprintf(buf, "%d\n", rpm); 291 } 292 293 static int max6650_set_target(struct max6650_data *data, unsigned long rpm) 294 { 295 int kscale, ktach; 296 297 if (rpm == 0) 298 return max6650_set_operating_mode(data, MAX6650_CFG_MODE_OFF); 299 300 rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX); 301 302 /* 303 * Divide the required speed by 60 to get from rpm to rps, then 304 * use the datasheet equation: 305 * 306 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1 307 */ 308 309 kscale = DIV_FROM_REG(data->config); 310 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1; 311 if (ktach < 0) 312 ktach = 0; 313 if (ktach > 255) 314 ktach = 255; 315 data->speed = ktach; 316 317 return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED, 318 data->speed); 319 } 320 321 static ssize_t set_target(struct device *dev, struct device_attribute *devattr, 322 const char *buf, size_t count) 323 { 324 struct max6650_data *data = dev_get_drvdata(dev); 325 unsigned long rpm; 326 int err; 327 328 err = kstrtoul(buf, 10, &rpm); 329 if (err) 330 return err; 331 332 mutex_lock(&data->update_lock); 333 334 err = max6650_set_target(data, rpm); 335 336 mutex_unlock(&data->update_lock); 337 338 if (err < 0) 339 return err; 340 341 return count; 342 } 343 344 /* 345 * Get/set the fan speed in open loop mode using pwm1 sysfs file. 346 * Speed is given as a relative value from 0 to 255, where 255 is maximum 347 * speed. Note that this is done by writing directly to the chip's DAC, 348 * it won't change the closed loop speed set by fan1_target. 349 * Also note that due to rounding errors it is possible that you don't read 350 * back exactly the value you have set. 351 */ 352 353 static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr, 354 char *buf) 355 { 356 int pwm; 357 struct max6650_data *data = max6650_update_device(dev); 358 359 /* 360 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans. 361 * Lower DAC values mean higher speeds. 362 */ 363 if (data->config & MAX6650_CFG_V12) 364 pwm = 255 - (255 * (int)data->dac)/180; 365 else 366 pwm = 255 - (255 * (int)data->dac)/76; 367 368 if (pwm < 0) 369 pwm = 0; 370 371 return sprintf(buf, "%d\n", pwm); 372 } 373 374 static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr, 375 const char *buf, size_t count) 376 { 377 struct max6650_data *data = dev_get_drvdata(dev); 378 struct i2c_client *client = data->client; 379 unsigned long pwm; 380 int err; 381 382 err = kstrtoul(buf, 10, &pwm); 383 if (err) 384 return err; 385 386 pwm = clamp_val(pwm, 0, 255); 387 388 mutex_lock(&data->update_lock); 389 390 if (data->config & MAX6650_CFG_V12) 391 data->dac = 180 - (180 * pwm)/255; 392 else 393 data->dac = 76 - (76 * pwm)/255; 394 err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); 395 396 mutex_unlock(&data->update_lock); 397 398 return err < 0 ? err : count; 399 } 400 401 /* 402 * Get/Set controller mode: 403 * Possible values: 404 * 0 = Fan always on 405 * 1 = Open loop, Voltage is set according to speed, not regulated. 406 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer 407 * 3 = Fan off 408 */ 409 static ssize_t get_enable(struct device *dev, struct device_attribute *devattr, 410 char *buf) 411 { 412 struct max6650_data *data = max6650_update_device(dev); 413 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4; 414 int sysfs_modes[4] = {0, 3, 2, 1}; 415 416 return sprintf(buf, "%d\n", sysfs_modes[mode]); 417 } 418 419 static ssize_t set_enable(struct device *dev, struct device_attribute *devattr, 420 const char *buf, size_t count) 421 { 422 struct max6650_data *data = dev_get_drvdata(dev); 423 unsigned long mode; 424 int err; 425 const u8 max6650_modes[] = { 426 MAX6650_CFG_MODE_ON, 427 MAX6650_CFG_MODE_OPEN_LOOP, 428 MAX6650_CFG_MODE_CLOSED_LOOP, 429 MAX6650_CFG_MODE_OFF, 430 }; 431 432 err = kstrtoul(buf, 10, &mode); 433 if (err) 434 return err; 435 436 if (mode >= ARRAY_SIZE(max6650_modes)) 437 return -EINVAL; 438 439 mutex_lock(&data->update_lock); 440 441 max6650_set_operating_mode(data, max6650_modes[mode]); 442 443 mutex_unlock(&data->update_lock); 444 445 return count; 446 } 447 448 /* 449 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such 450 * divider. We handle this by converting between divider and counttime: 451 * 452 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3 453 * 454 * Lower values of k allow to connect a faster fan without the risk of 455 * counter overflow. The price is lower resolution. You can also set counttime 456 * using the module parameter. Note that the module parameter "prescaler" also 457 * influences the behaviour. Unfortunately, there's no sysfs attribute 458 * defined for that. See the data sheet for details. 459 */ 460 461 static ssize_t get_div(struct device *dev, struct device_attribute *devattr, 462 char *buf) 463 { 464 struct max6650_data *data = max6650_update_device(dev); 465 466 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count)); 467 } 468 469 static ssize_t set_div(struct device *dev, struct device_attribute *devattr, 470 const char *buf, size_t count) 471 { 472 struct max6650_data *data = dev_get_drvdata(dev); 473 struct i2c_client *client = data->client; 474 unsigned long div; 475 int err; 476 477 err = kstrtoul(buf, 10, &div); 478 if (err) 479 return err; 480 481 mutex_lock(&data->update_lock); 482 switch (div) { 483 case 1: 484 data->count = 0; 485 break; 486 case 2: 487 data->count = 1; 488 break; 489 case 4: 490 data->count = 2; 491 break; 492 case 8: 493 data->count = 3; 494 break; 495 default: 496 mutex_unlock(&data->update_lock); 497 return -EINVAL; 498 } 499 500 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count); 501 mutex_unlock(&data->update_lock); 502 503 return count; 504 } 505 506 /* 507 * Get alarm stati: 508 * Possible values: 509 * 0 = no alarm 510 * 1 = alarm 511 */ 512 513 static ssize_t get_alarm(struct device *dev, struct device_attribute *devattr, 514 char *buf) 515 { 516 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 517 struct max6650_data *data = max6650_update_device(dev); 518 struct i2c_client *client = data->client; 519 int alarm = 0; 520 521 if (data->alarm & attr->index) { 522 mutex_lock(&data->update_lock); 523 alarm = 1; 524 data->alarm &= ~attr->index; 525 data->alarm |= i2c_smbus_read_byte_data(client, 526 MAX6650_REG_ALARM); 527 mutex_unlock(&data->update_lock); 528 } 529 530 return sprintf(buf, "%d\n", alarm); 531 } 532 533 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0); 534 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1); 535 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2); 536 static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3); 537 static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target); 538 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div); 539 static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable); 540 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm); 541 static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL, 542 MAX6650_ALRM_MAX); 543 static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL, 544 MAX6650_ALRM_MIN); 545 static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL, 546 MAX6650_ALRM_TACH); 547 static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL, 548 MAX6650_ALRM_GPIO1); 549 static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL, 550 MAX6650_ALRM_GPIO2); 551 552 static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a, 553 int n) 554 { 555 struct device *dev = container_of(kobj, struct device, kobj); 556 struct max6650_data *data = dev_get_drvdata(dev); 557 struct i2c_client *client = data->client; 558 u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN); 559 struct device_attribute *devattr; 560 561 /* 562 * Hide the alarms that have not been enabled by the firmware 563 */ 564 565 devattr = container_of(a, struct device_attribute, attr); 566 if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr 567 || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr 568 || devattr == &sensor_dev_attr_fan1_fault.dev_attr 569 || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr 570 || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) { 571 if (!(alarm_en & to_sensor_dev_attr(devattr)->index)) 572 return 0; 573 } 574 575 return a->mode; 576 } 577 578 static struct attribute *max6650_attrs[] = { 579 &sensor_dev_attr_fan1_input.dev_attr.attr, 580 &dev_attr_fan1_target.attr, 581 &dev_attr_fan1_div.attr, 582 &dev_attr_pwm1_enable.attr, 583 &dev_attr_pwm1.attr, 584 &sensor_dev_attr_fan1_max_alarm.dev_attr.attr, 585 &sensor_dev_attr_fan1_min_alarm.dev_attr.attr, 586 &sensor_dev_attr_fan1_fault.dev_attr.attr, 587 &sensor_dev_attr_gpio1_alarm.dev_attr.attr, 588 &sensor_dev_attr_gpio2_alarm.dev_attr.attr, 589 NULL 590 }; 591 592 static const struct attribute_group max6650_group = { 593 .attrs = max6650_attrs, 594 .is_visible = max6650_attrs_visible, 595 }; 596 597 static struct attribute *max6651_attrs[] = { 598 &sensor_dev_attr_fan2_input.dev_attr.attr, 599 &sensor_dev_attr_fan3_input.dev_attr.attr, 600 &sensor_dev_attr_fan4_input.dev_attr.attr, 601 NULL 602 }; 603 604 static const struct attribute_group max6651_group = { 605 .attrs = max6651_attrs, 606 }; 607 608 /* 609 * Real code 610 */ 611 612 static int max6650_init_client(struct max6650_data *data, 613 struct i2c_client *client) 614 { 615 struct device *dev = &client->dev; 616 int config; 617 int err = -EIO; 618 u32 voltage; 619 u32 prescale; 620 u32 target_rpm; 621 622 if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt", 623 &voltage)) 624 voltage = fan_voltage; 625 else 626 voltage /= 1000000; /* Microvolts to volts */ 627 if (of_property_read_u32(dev->of_node, "maxim,fan-prescale", 628 &prescale)) 629 prescale = prescaler; 630 631 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 632 633 if (config < 0) { 634 dev_err(dev, "Error reading config, aborting.\n"); 635 return err; 636 } 637 638 switch (voltage) { 639 case 0: 640 break; 641 case 5: 642 config &= ~MAX6650_CFG_V12; 643 break; 644 case 12: 645 config |= MAX6650_CFG_V12; 646 break; 647 default: 648 dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage); 649 } 650 651 switch (prescale) { 652 case 0: 653 break; 654 case 1: 655 config &= ~MAX6650_CFG_PRESCALER_MASK; 656 break; 657 case 2: 658 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 659 | MAX6650_CFG_PRESCALER_2; 660 break; 661 case 4: 662 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 663 | MAX6650_CFG_PRESCALER_4; 664 break; 665 case 8: 666 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 667 | MAX6650_CFG_PRESCALER_8; 668 break; 669 case 16: 670 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 671 | MAX6650_CFG_PRESCALER_16; 672 break; 673 default: 674 dev_err(dev, "illegal value for prescaler (%d)\n", prescale); 675 } 676 677 dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n", 678 (config & MAX6650_CFG_V12) ? 12 : 5, 679 1 << (config & MAX6650_CFG_PRESCALER_MASK)); 680 681 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) { 682 dev_err(dev, "Config write error, aborting.\n"); 683 return err; 684 } 685 686 data->config = config; 687 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT); 688 689 if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm", 690 &target_rpm)) { 691 max6650_set_target(data, target_rpm); 692 max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP); 693 } 694 695 return 0; 696 } 697 698 static int max6650_probe(struct i2c_client *client, 699 const struct i2c_device_id *id) 700 { 701 struct device *dev = &client->dev; 702 const struct of_device_id *of_id = 703 of_match_device(of_match_ptr(max6650_dt_match), dev); 704 struct max6650_data *data; 705 struct device *hwmon_dev; 706 int err; 707 708 data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL); 709 if (!data) 710 return -ENOMEM; 711 712 data->client = client; 713 mutex_init(&data->update_lock); 714 data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data; 715 716 /* 717 * Initialize the max6650 chip 718 */ 719 err = max6650_init_client(data, client); 720 if (err) 721 return err; 722 723 data->groups[0] = &max6650_group; 724 /* 3 additional fan inputs for the MAX6651 */ 725 if (data->nr_fans == 4) 726 data->groups[1] = &max6651_group; 727 728 hwmon_dev = devm_hwmon_device_register_with_groups(dev, 729 client->name, data, 730 data->groups); 731 return PTR_ERR_OR_ZERO(hwmon_dev); 732 } 733 734 static const struct i2c_device_id max6650_id[] = { 735 { "max6650", 1 }, 736 { "max6651", 4 }, 737 { } 738 }; 739 MODULE_DEVICE_TABLE(i2c, max6650_id); 740 741 static struct i2c_driver max6650_driver = { 742 .driver = { 743 .name = "max6650", 744 .of_match_table = of_match_ptr(max6650_dt_match), 745 }, 746 .probe = max6650_probe, 747 .id_table = max6650_id, 748 }; 749 750 module_i2c_driver(max6650_driver); 751 752 MODULE_AUTHOR("Hans J. Koch"); 753 MODULE_DESCRIPTION("MAX6650 sensor driver"); 754 MODULE_LICENSE("GPL"); 755