1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * max6650.c - Part of lm_sensors, Linux kernel modules for hardware 4 * monitoring. 5 * 6 * (C) 2007 by Hans J. Koch <hjk@hansjkoch.de> 7 * 8 * based on code written by John Morris <john.morris@spirentcom.com> 9 * Copyright (c) 2003 Spirent Communications 10 * and Claus Gindhart <claus.gindhart@kontron.com> 11 * 12 * This module has only been tested with the MAX6650 chip. It should 13 * also work with the MAX6651. It does not distinguish max6650 and max6651 14 * chips. 15 * 16 * The datasheet was last seen at: 17 * 18 * http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf 19 */ 20 21 #include <linux/module.h> 22 #include <linux/init.h> 23 #include <linux/slab.h> 24 #include <linux/jiffies.h> 25 #include <linux/i2c.h> 26 #include <linux/hwmon.h> 27 #include <linux/hwmon-sysfs.h> 28 #include <linux/err.h> 29 #include <linux/of_device.h> 30 #include <linux/thermal.h> 31 32 /* 33 * Insmod parameters 34 */ 35 36 /* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */ 37 static int fan_voltage; 38 /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */ 39 static int prescaler; 40 /* clock: The clock frequency of the chip (max6651 can be clocked externally) */ 41 static int clock = 254000; 42 43 module_param(fan_voltage, int, 0444); 44 module_param(prescaler, int, 0444); 45 module_param(clock, int, 0444); 46 47 /* 48 * MAX 6650/6651 registers 49 */ 50 51 #define MAX6650_REG_SPEED 0x00 52 #define MAX6650_REG_CONFIG 0x02 53 #define MAX6650_REG_GPIO_DEF 0x04 54 #define MAX6650_REG_DAC 0x06 55 #define MAX6650_REG_ALARM_EN 0x08 56 #define MAX6650_REG_ALARM 0x0A 57 #define MAX6650_REG_TACH0 0x0C 58 #define MAX6650_REG_TACH1 0x0E 59 #define MAX6650_REG_TACH2 0x10 60 #define MAX6650_REG_TACH3 0x12 61 #define MAX6650_REG_GPIO_STAT 0x14 62 #define MAX6650_REG_COUNT 0x16 63 64 /* 65 * Config register bits 66 */ 67 68 #define MAX6650_CFG_V12 0x08 69 #define MAX6650_CFG_PRESCALER_MASK 0x07 70 #define MAX6650_CFG_PRESCALER_2 0x01 71 #define MAX6650_CFG_PRESCALER_4 0x02 72 #define MAX6650_CFG_PRESCALER_8 0x03 73 #define MAX6650_CFG_PRESCALER_16 0x04 74 #define MAX6650_CFG_MODE_MASK 0x30 75 #define MAX6650_CFG_MODE_ON 0x00 76 #define MAX6650_CFG_MODE_OFF 0x10 77 #define MAX6650_CFG_MODE_CLOSED_LOOP 0x20 78 #define MAX6650_CFG_MODE_OPEN_LOOP 0x30 79 #define MAX6650_COUNT_MASK 0x03 80 81 /* 82 * Alarm status register bits 83 */ 84 85 #define MAX6650_ALRM_MAX 0x01 86 #define MAX6650_ALRM_MIN 0x02 87 #define MAX6650_ALRM_TACH 0x04 88 #define MAX6650_ALRM_GPIO1 0x08 89 #define MAX6650_ALRM_GPIO2 0x10 90 91 /* Minimum and maximum values of the FAN-RPM */ 92 #define FAN_RPM_MIN 240 93 #define FAN_RPM_MAX 30000 94 95 #define DIV_FROM_REG(reg) (1 << (reg & 7)) 96 97 /* 98 * Client data (each client gets its own) 99 */ 100 101 struct max6650_data { 102 struct i2c_client *client; 103 const struct attribute_group *groups[3]; 104 struct thermal_cooling_device *cooling_dev; 105 struct mutex update_lock; 106 int nr_fans; 107 char valid; /* zero until following fields are valid */ 108 unsigned long last_updated; /* in jiffies */ 109 110 /* register values */ 111 u8 speed; 112 u8 config; 113 u8 tach[4]; 114 u8 count; 115 u8 dac; 116 u8 alarm; 117 unsigned long cooling_dev_state; 118 }; 119 120 static const u8 tach_reg[] = { 121 MAX6650_REG_TACH0, 122 MAX6650_REG_TACH1, 123 MAX6650_REG_TACH2, 124 MAX6650_REG_TACH3, 125 }; 126 127 static const struct of_device_id __maybe_unused max6650_dt_match[] = { 128 { 129 .compatible = "maxim,max6650", 130 .data = (void *)1 131 }, 132 { 133 .compatible = "maxim,max6651", 134 .data = (void *)4 135 }, 136 { }, 137 }; 138 MODULE_DEVICE_TABLE(of, max6650_dt_match); 139 140 static struct max6650_data *max6650_update_device(struct device *dev) 141 { 142 struct max6650_data *data = dev_get_drvdata(dev); 143 struct i2c_client *client = data->client; 144 int i; 145 146 mutex_lock(&data->update_lock); 147 148 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 149 data->speed = i2c_smbus_read_byte_data(client, 150 MAX6650_REG_SPEED); 151 data->config = i2c_smbus_read_byte_data(client, 152 MAX6650_REG_CONFIG); 153 for (i = 0; i < data->nr_fans; i++) { 154 data->tach[i] = i2c_smbus_read_byte_data(client, 155 tach_reg[i]); 156 } 157 data->count = i2c_smbus_read_byte_data(client, 158 MAX6650_REG_COUNT); 159 data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC); 160 161 /* 162 * Alarms are cleared on read in case the condition that 163 * caused the alarm is removed. Keep the value latched here 164 * for providing the register through different alarm files. 165 */ 166 data->alarm |= i2c_smbus_read_byte_data(client, 167 MAX6650_REG_ALARM); 168 169 data->last_updated = jiffies; 170 data->valid = 1; 171 } 172 173 mutex_unlock(&data->update_lock); 174 175 return data; 176 } 177 178 /* 179 * Change the operating mode of the chip (if needed). 180 * mode is one of the MAX6650_CFG_MODE_* values. 181 */ 182 static int max6650_set_operating_mode(struct max6650_data *data, u8 mode) 183 { 184 int result; 185 u8 config = data->config; 186 187 if (mode == (config & MAX6650_CFG_MODE_MASK)) 188 return 0; 189 190 config = (config & ~MAX6650_CFG_MODE_MASK) | mode; 191 192 result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG, 193 config); 194 if (result < 0) 195 return result; 196 197 data->config = config; 198 199 return 0; 200 } 201 202 static ssize_t fan_show(struct device *dev, struct device_attribute *devattr, 203 char *buf) 204 { 205 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 206 struct max6650_data *data = max6650_update_device(dev); 207 int rpm; 208 209 /* 210 * Calculation details: 211 * 212 * Each tachometer counts over an interval given by the "count" 213 * register (0.25, 0.5, 1 or 2 seconds). This module assumes 214 * that the fans produce two pulses per revolution (this seems 215 * to be the most common). 216 */ 217 218 rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count)); 219 return sprintf(buf, "%d\n", rpm); 220 } 221 222 /* 223 * Set the fan speed to the specified RPM (or read back the RPM setting). 224 * This works in closed loop mode only. Use pwm1 for open loop speed setting. 225 * 226 * The MAX6650/1 will automatically control fan speed when in closed loop 227 * mode. 228 * 229 * Assumptions: 230 * 231 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use 232 * the clock module parameter if you need to fine tune this. 233 * 234 * 2) The prescaler (low three bits of the config register) has already 235 * been set to an appropriate value. Use the prescaler module parameter 236 * if your BIOS doesn't initialize the chip properly. 237 * 238 * The relevant equations are given on pages 21 and 22 of the datasheet. 239 * 240 * From the datasheet, the relevant equation when in regulation is: 241 * 242 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE 243 * 244 * where: 245 * 246 * fCLK is the oscillator frequency (either the 254kHz internal 247 * oscillator or the externally applied clock) 248 * 249 * KTACH is the value in the speed register 250 * 251 * FanSpeed is the speed of the fan in rps 252 * 253 * KSCALE is the prescaler value (1, 2, 4, 8, or 16) 254 * 255 * When reading, we need to solve for FanSpeed. When writing, we need to 256 * solve for KTACH. 257 * 258 * Note: this tachometer is completely separate from the tachometers 259 * used to measure the fan speeds. Only one fan's speed (fan1) is 260 * controlled. 261 */ 262 263 static ssize_t fan1_target_show(struct device *dev, 264 struct device_attribute *devattr, char *buf) 265 { 266 struct max6650_data *data = max6650_update_device(dev); 267 int kscale, ktach, rpm; 268 269 /* 270 * Use the datasheet equation: 271 * 272 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)] 273 * 274 * then multiply by 60 to give rpm. 275 */ 276 277 kscale = DIV_FROM_REG(data->config); 278 ktach = data->speed; 279 rpm = 60 * kscale * clock / (256 * (ktach + 1)); 280 return sprintf(buf, "%d\n", rpm); 281 } 282 283 static int max6650_set_target(struct max6650_data *data, unsigned long rpm) 284 { 285 int kscale, ktach; 286 287 if (rpm == 0) 288 return max6650_set_operating_mode(data, MAX6650_CFG_MODE_OFF); 289 290 rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX); 291 292 /* 293 * Divide the required speed by 60 to get from rpm to rps, then 294 * use the datasheet equation: 295 * 296 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1 297 */ 298 299 kscale = DIV_FROM_REG(data->config); 300 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1; 301 if (ktach < 0) 302 ktach = 0; 303 if (ktach > 255) 304 ktach = 255; 305 data->speed = ktach; 306 307 return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED, 308 data->speed); 309 } 310 311 static ssize_t fan1_target_store(struct device *dev, 312 struct device_attribute *devattr, 313 const char *buf, size_t count) 314 { 315 struct max6650_data *data = dev_get_drvdata(dev); 316 unsigned long rpm; 317 int err; 318 319 err = kstrtoul(buf, 10, &rpm); 320 if (err) 321 return err; 322 323 mutex_lock(&data->update_lock); 324 325 err = max6650_set_target(data, rpm); 326 327 mutex_unlock(&data->update_lock); 328 329 if (err < 0) 330 return err; 331 332 return count; 333 } 334 335 /* 336 * Get/set the fan speed in open loop mode using pwm1 sysfs file. 337 * Speed is given as a relative value from 0 to 255, where 255 is maximum 338 * speed. Note that this is done by writing directly to the chip's DAC, 339 * it won't change the closed loop speed set by fan1_target. 340 * Also note that due to rounding errors it is possible that you don't read 341 * back exactly the value you have set. 342 */ 343 344 static ssize_t pwm1_show(struct device *dev, struct device_attribute *devattr, 345 char *buf) 346 { 347 int pwm; 348 struct max6650_data *data = max6650_update_device(dev); 349 350 /* 351 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans. 352 * Lower DAC values mean higher speeds. 353 */ 354 if (data->config & MAX6650_CFG_V12) 355 pwm = 255 - (255 * (int)data->dac)/180; 356 else 357 pwm = 255 - (255 * (int)data->dac)/76; 358 359 if (pwm < 0) 360 pwm = 0; 361 362 return sprintf(buf, "%d\n", pwm); 363 } 364 365 static ssize_t pwm1_store(struct device *dev, 366 struct device_attribute *devattr, const char *buf, 367 size_t count) 368 { 369 struct max6650_data *data = dev_get_drvdata(dev); 370 struct i2c_client *client = data->client; 371 unsigned long pwm; 372 int err; 373 374 err = kstrtoul(buf, 10, &pwm); 375 if (err) 376 return err; 377 378 pwm = clamp_val(pwm, 0, 255); 379 380 mutex_lock(&data->update_lock); 381 382 if (data->config & MAX6650_CFG_V12) 383 data->dac = 180 - (180 * pwm)/255; 384 else 385 data->dac = 76 - (76 * pwm)/255; 386 err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); 387 388 mutex_unlock(&data->update_lock); 389 390 return err < 0 ? err : count; 391 } 392 393 /* 394 * Get/Set controller mode: 395 * Possible values: 396 * 0 = Fan always on 397 * 1 = Open loop, Voltage is set according to speed, not regulated. 398 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer 399 * 3 = Fan off 400 */ 401 static ssize_t pwm1_enable_show(struct device *dev, 402 struct device_attribute *devattr, char *buf) 403 { 404 struct max6650_data *data = max6650_update_device(dev); 405 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4; 406 int sysfs_modes[4] = {0, 3, 2, 1}; 407 408 return sprintf(buf, "%d\n", sysfs_modes[mode]); 409 } 410 411 static ssize_t pwm1_enable_store(struct device *dev, 412 struct device_attribute *devattr, 413 const char *buf, size_t count) 414 { 415 struct max6650_data *data = dev_get_drvdata(dev); 416 unsigned long mode; 417 int err; 418 const u8 max6650_modes[] = { 419 MAX6650_CFG_MODE_ON, 420 MAX6650_CFG_MODE_OPEN_LOOP, 421 MAX6650_CFG_MODE_CLOSED_LOOP, 422 MAX6650_CFG_MODE_OFF, 423 }; 424 425 err = kstrtoul(buf, 10, &mode); 426 if (err) 427 return err; 428 429 if (mode >= ARRAY_SIZE(max6650_modes)) 430 return -EINVAL; 431 432 mutex_lock(&data->update_lock); 433 434 max6650_set_operating_mode(data, max6650_modes[mode]); 435 436 mutex_unlock(&data->update_lock); 437 438 return count; 439 } 440 441 /* 442 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such 443 * divider. We handle this by converting between divider and counttime: 444 * 445 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3 446 * 447 * Lower values of k allow to connect a faster fan without the risk of 448 * counter overflow. The price is lower resolution. You can also set counttime 449 * using the module parameter. Note that the module parameter "prescaler" also 450 * influences the behaviour. Unfortunately, there's no sysfs attribute 451 * defined for that. See the data sheet for details. 452 */ 453 454 static ssize_t fan1_div_show(struct device *dev, 455 struct device_attribute *devattr, char *buf) 456 { 457 struct max6650_data *data = max6650_update_device(dev); 458 459 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count)); 460 } 461 462 static ssize_t fan1_div_store(struct device *dev, 463 struct device_attribute *devattr, 464 const char *buf, size_t count) 465 { 466 struct max6650_data *data = dev_get_drvdata(dev); 467 struct i2c_client *client = data->client; 468 unsigned long div; 469 int err; 470 471 err = kstrtoul(buf, 10, &div); 472 if (err) 473 return err; 474 475 mutex_lock(&data->update_lock); 476 switch (div) { 477 case 1: 478 data->count = 0; 479 break; 480 case 2: 481 data->count = 1; 482 break; 483 case 4: 484 data->count = 2; 485 break; 486 case 8: 487 data->count = 3; 488 break; 489 default: 490 mutex_unlock(&data->update_lock); 491 return -EINVAL; 492 } 493 494 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count); 495 mutex_unlock(&data->update_lock); 496 497 return count; 498 } 499 500 /* 501 * Get alarm stati: 502 * Possible values: 503 * 0 = no alarm 504 * 1 = alarm 505 */ 506 507 static ssize_t alarm_show(struct device *dev, 508 struct device_attribute *devattr, char *buf) 509 { 510 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 511 struct max6650_data *data = max6650_update_device(dev); 512 struct i2c_client *client = data->client; 513 int alarm = 0; 514 515 if (data->alarm & attr->index) { 516 mutex_lock(&data->update_lock); 517 alarm = 1; 518 data->alarm &= ~attr->index; 519 data->alarm |= i2c_smbus_read_byte_data(client, 520 MAX6650_REG_ALARM); 521 mutex_unlock(&data->update_lock); 522 } 523 524 return sprintf(buf, "%d\n", alarm); 525 } 526 527 static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0); 528 static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1); 529 static SENSOR_DEVICE_ATTR_RO(fan3_input, fan, 2); 530 static SENSOR_DEVICE_ATTR_RO(fan4_input, fan, 3); 531 static DEVICE_ATTR_RW(fan1_target); 532 static DEVICE_ATTR_RW(fan1_div); 533 static DEVICE_ATTR_RW(pwm1_enable); 534 static DEVICE_ATTR_RW(pwm1); 535 static SENSOR_DEVICE_ATTR_RO(fan1_max_alarm, alarm, MAX6650_ALRM_MAX); 536 static SENSOR_DEVICE_ATTR_RO(fan1_min_alarm, alarm, MAX6650_ALRM_MIN); 537 static SENSOR_DEVICE_ATTR_RO(fan1_fault, alarm, MAX6650_ALRM_TACH); 538 static SENSOR_DEVICE_ATTR_RO(gpio1_alarm, alarm, MAX6650_ALRM_GPIO1); 539 static SENSOR_DEVICE_ATTR_RO(gpio2_alarm, alarm, MAX6650_ALRM_GPIO2); 540 541 static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a, 542 int n) 543 { 544 struct device *dev = container_of(kobj, struct device, kobj); 545 struct max6650_data *data = dev_get_drvdata(dev); 546 struct i2c_client *client = data->client; 547 u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN); 548 struct device_attribute *devattr; 549 550 /* 551 * Hide the alarms that have not been enabled by the firmware 552 */ 553 554 devattr = container_of(a, struct device_attribute, attr); 555 if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr 556 || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr 557 || devattr == &sensor_dev_attr_fan1_fault.dev_attr 558 || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr 559 || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) { 560 if (!(alarm_en & to_sensor_dev_attr(devattr)->index)) 561 return 0; 562 } 563 564 return a->mode; 565 } 566 567 static struct attribute *max6650_attrs[] = { 568 &sensor_dev_attr_fan1_input.dev_attr.attr, 569 &dev_attr_fan1_target.attr, 570 &dev_attr_fan1_div.attr, 571 &dev_attr_pwm1_enable.attr, 572 &dev_attr_pwm1.attr, 573 &sensor_dev_attr_fan1_max_alarm.dev_attr.attr, 574 &sensor_dev_attr_fan1_min_alarm.dev_attr.attr, 575 &sensor_dev_attr_fan1_fault.dev_attr.attr, 576 &sensor_dev_attr_gpio1_alarm.dev_attr.attr, 577 &sensor_dev_attr_gpio2_alarm.dev_attr.attr, 578 NULL 579 }; 580 581 static const struct attribute_group max6650_group = { 582 .attrs = max6650_attrs, 583 .is_visible = max6650_attrs_visible, 584 }; 585 586 static struct attribute *max6651_attrs[] = { 587 &sensor_dev_attr_fan2_input.dev_attr.attr, 588 &sensor_dev_attr_fan3_input.dev_attr.attr, 589 &sensor_dev_attr_fan4_input.dev_attr.attr, 590 NULL 591 }; 592 593 static const struct attribute_group max6651_group = { 594 .attrs = max6651_attrs, 595 }; 596 597 /* 598 * Real code 599 */ 600 601 static int max6650_init_client(struct max6650_data *data, 602 struct i2c_client *client) 603 { 604 struct device *dev = &client->dev; 605 int config; 606 int err = -EIO; 607 u32 voltage; 608 u32 prescale; 609 u32 target_rpm; 610 611 if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt", 612 &voltage)) 613 voltage = fan_voltage; 614 else 615 voltage /= 1000000; /* Microvolts to volts */ 616 if (of_property_read_u32(dev->of_node, "maxim,fan-prescale", 617 &prescale)) 618 prescale = prescaler; 619 620 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); 621 622 if (config < 0) { 623 dev_err(dev, "Error reading config, aborting.\n"); 624 return err; 625 } 626 627 switch (voltage) { 628 case 0: 629 break; 630 case 5: 631 config &= ~MAX6650_CFG_V12; 632 break; 633 case 12: 634 config |= MAX6650_CFG_V12; 635 break; 636 default: 637 dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage); 638 } 639 640 switch (prescale) { 641 case 0: 642 break; 643 case 1: 644 config &= ~MAX6650_CFG_PRESCALER_MASK; 645 break; 646 case 2: 647 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 648 | MAX6650_CFG_PRESCALER_2; 649 break; 650 case 4: 651 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 652 | MAX6650_CFG_PRESCALER_4; 653 break; 654 case 8: 655 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 656 | MAX6650_CFG_PRESCALER_8; 657 break; 658 case 16: 659 config = (config & ~MAX6650_CFG_PRESCALER_MASK) 660 | MAX6650_CFG_PRESCALER_16; 661 break; 662 default: 663 dev_err(dev, "illegal value for prescaler (%d)\n", prescale); 664 } 665 666 dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n", 667 (config & MAX6650_CFG_V12) ? 12 : 5, 668 1 << (config & MAX6650_CFG_PRESCALER_MASK)); 669 670 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) { 671 dev_err(dev, "Config write error, aborting.\n"); 672 return err; 673 } 674 675 data->config = config; 676 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT); 677 678 if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm", 679 &target_rpm)) { 680 max6650_set_target(data, target_rpm); 681 max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP); 682 } 683 684 return 0; 685 } 686 687 #if IS_ENABLED(CONFIG_THERMAL) 688 689 static int max6650_get_max_state(struct thermal_cooling_device *cdev, 690 unsigned long *state) 691 { 692 *state = 255; 693 694 return 0; 695 } 696 697 static int max6650_get_cur_state(struct thermal_cooling_device *cdev, 698 unsigned long *state) 699 { 700 struct max6650_data *data = cdev->devdata; 701 702 *state = data->cooling_dev_state; 703 704 return 0; 705 } 706 707 static int max6650_set_cur_state(struct thermal_cooling_device *cdev, 708 unsigned long state) 709 { 710 struct max6650_data *data = cdev->devdata; 711 struct i2c_client *client = data->client; 712 int err; 713 714 state = clamp_val(state, 0, 255); 715 716 mutex_lock(&data->update_lock); 717 718 if (data->config & MAX6650_CFG_V12) 719 data->dac = 180 - (180 * state)/255; 720 else 721 data->dac = 76 - (76 * state)/255; 722 723 err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); 724 725 if (!err) { 726 max6650_set_operating_mode(data, state ? 727 MAX6650_CFG_MODE_OPEN_LOOP : 728 MAX6650_CFG_MODE_OFF); 729 data->cooling_dev_state = state; 730 } 731 732 mutex_unlock(&data->update_lock); 733 734 return err < 0 ? err : 0; 735 } 736 737 static const struct thermal_cooling_device_ops max6650_cooling_ops = { 738 .get_max_state = max6650_get_max_state, 739 .get_cur_state = max6650_get_cur_state, 740 .set_cur_state = max6650_set_cur_state, 741 }; 742 #endif 743 744 static int max6650_probe(struct i2c_client *client, 745 const struct i2c_device_id *id) 746 { 747 struct device *dev = &client->dev; 748 const struct of_device_id *of_id = 749 of_match_device(of_match_ptr(max6650_dt_match), dev); 750 struct max6650_data *data; 751 struct device *hwmon_dev; 752 int err; 753 754 data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL); 755 if (!data) 756 return -ENOMEM; 757 758 data->client = client; 759 i2c_set_clientdata(client, data); 760 mutex_init(&data->update_lock); 761 data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data; 762 763 /* 764 * Initialize the max6650 chip 765 */ 766 err = max6650_init_client(data, client); 767 if (err) 768 return err; 769 770 data->groups[0] = &max6650_group; 771 /* 3 additional fan inputs for the MAX6651 */ 772 if (data->nr_fans == 4) 773 data->groups[1] = &max6651_group; 774 775 hwmon_dev = devm_hwmon_device_register_with_groups(dev, 776 client->name, data, 777 data->groups); 778 err = PTR_ERR_OR_ZERO(hwmon_dev); 779 if (err) 780 return err; 781 782 #if IS_ENABLED(CONFIG_THERMAL) 783 data->cooling_dev = 784 thermal_of_cooling_device_register(client->dev.of_node, 785 client->name, data, 786 &max6650_cooling_ops); 787 if (IS_ERR(data->cooling_dev)) 788 dev_warn(&client->dev, 789 "thermal cooling device register failed: %ld\n", 790 PTR_ERR(data->cooling_dev)); 791 #endif 792 return 0; 793 } 794 795 static int max6650_remove(struct i2c_client *client) 796 { 797 struct max6650_data *data = i2c_get_clientdata(client); 798 799 if (!IS_ERR(data->cooling_dev)) 800 thermal_cooling_device_unregister(data->cooling_dev); 801 802 return 0; 803 } 804 805 static const struct i2c_device_id max6650_id[] = { 806 { "max6650", 1 }, 807 { "max6651", 4 }, 808 { } 809 }; 810 MODULE_DEVICE_TABLE(i2c, max6650_id); 811 812 static struct i2c_driver max6650_driver = { 813 .driver = { 814 .name = "max6650", 815 .of_match_table = of_match_ptr(max6650_dt_match), 816 }, 817 .probe = max6650_probe, 818 .remove = max6650_remove, 819 .id_table = max6650_id, 820 }; 821 822 module_i2c_driver(max6650_driver); 823 824 MODULE_AUTHOR("Hans J. Koch"); 825 MODULE_DESCRIPTION("MAX6650 sensor driver"); 826 MODULE_LICENSE("GPL"); 827