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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.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 */
37static int fan_voltage;
38/* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
39static int prescaler;
40/* clock: The clock frequency of the chip (max6651 can be clocked externally) */
41static int clock = 254000;
42
43module_param(fan_voltage, int, 0444);
44module_param(prescaler, int, 0444);
45module_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#define DAC_LIMIT(v12) ((v12) ? 180 : 76)
97
98/*
99 * Client data (each client gets its own)
100 */
101
102struct max6650_data {
103 struct i2c_client *client;
104 struct mutex update_lock; /* protect alarm register updates */
105 int nr_fans;
106 bool valid; /* false until following fields are valid */
107 unsigned long last_updated; /* in jiffies */
108
109 /* register values */
110 u8 speed;
111 u8 config;
112 u8 tach[4];
113 u8 count;
114 u8 dac;
115 u8 alarm;
116 u8 alarm_en;
117 unsigned long cooling_dev_state;
118};
119
120static const u8 tach_reg[] = {
121 MAX6650_REG_TACH0,
122 MAX6650_REG_TACH1,
123 MAX6650_REG_TACH2,
124 MAX6650_REG_TACH3,
125};
126
127static 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};
138MODULE_DEVICE_TABLE(of, max6650_dt_match);
139
140static int dac_to_pwm(int dac, bool v12)
141{
142 /*
143 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
144 * Lower DAC values mean higher speeds.
145 */
146 return clamp_val(255 - (255 * dac) / DAC_LIMIT(v12), 0, 255);
147}
148
149static u8 pwm_to_dac(unsigned int pwm, bool v12)
150{
151 int limit = DAC_LIMIT(v12);
152
153 return limit - (limit * pwm) / 255;
154}
155
156static struct max6650_data *max6650_update_device(struct device *dev)
157{
158 struct max6650_data *data = dev_get_drvdata(dev);
159 struct i2c_client *client = data->client;
160 int reg, err = 0;
161 int i;
162
163 mutex_lock(&data->update_lock);
164
165 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
166 for (i = 0; i < data->nr_fans; i++) {
167 reg = i2c_smbus_read_byte_data(client, tach_reg[i]);
168 if (reg < 0) {
169 err = reg;
170 goto error;
171 }
172 data->tach[i] = reg;
173 }
174
175 /*
176 * Alarms are cleared on read in case the condition that
177 * caused the alarm is removed. Keep the value latched here
178 * for providing the register through different alarm files.
179 */
180 reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM);
181 if (reg < 0) {
182 err = reg;
183 goto error;
184 }
185 data->alarm |= reg;
186 data->last_updated = jiffies;
187 data->valid = true;
188 }
189
190error:
191 mutex_unlock(&data->update_lock);
192 if (err)
193 data = ERR_PTR(err);
194 return data;
195}
196
197/*
198 * Change the operating mode of the chip (if needed).
199 * mode is one of the MAX6650_CFG_MODE_* values.
200 */
201static int max6650_set_operating_mode(struct max6650_data *data, u8 mode)
202{
203 int result;
204 u8 config = data->config;
205
206 if (mode == (config & MAX6650_CFG_MODE_MASK))
207 return 0;
208
209 config = (config & ~MAX6650_CFG_MODE_MASK) | mode;
210
211 result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG,
212 config);
213 if (result < 0)
214 return result;
215
216 data->config = config;
217
218 return 0;
219}
220
221/*
222 * Set the fan speed to the specified RPM (or read back the RPM setting).
223 * This works in closed loop mode only. Use pwm1 for open loop speed setting.
224 *
225 * The MAX6650/1 will automatically control fan speed when in closed loop
226 * mode.
227 *
228 * Assumptions:
229 *
230 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use
231 * the clock module parameter if you need to fine tune this.
232 *
233 * 2) The prescaler (low three bits of the config register) has already
234 * been set to an appropriate value. Use the prescaler module parameter
235 * if your BIOS doesn't initialize the chip properly.
236 *
237 * The relevant equations are given on pages 21 and 22 of the datasheet.
238 *
239 * From the datasheet, the relevant equation when in regulation is:
240 *
241 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE
242 *
243 * where:
244 *
245 * fCLK is the oscillator frequency (either the 254kHz internal
246 * oscillator or the externally applied clock)
247 *
248 * KTACH is the value in the speed register
249 *
250 * FanSpeed is the speed of the fan in rps
251 *
252 * KSCALE is the prescaler value (1, 2, 4, 8, or 16)
253 *
254 * When reading, we need to solve for FanSpeed. When writing, we need to
255 * solve for KTACH.
256 *
257 * Note: this tachometer is completely separate from the tachometers
258 * used to measure the fan speeds. Only one fan's speed (fan1) is
259 * controlled.
260 */
261
262static int max6650_set_target(struct max6650_data *data, unsigned long rpm)
263{
264 int kscale, ktach;
265
266 if (rpm == 0)
267 return max6650_set_operating_mode(data, MAX6650_CFG_MODE_OFF);
268
269 rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
270
271 /*
272 * Divide the required speed by 60 to get from rpm to rps, then
273 * use the datasheet equation:
274 *
275 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1
276 */
277
278 kscale = DIV_FROM_REG(data->config);
279 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1;
280 if (ktach < 0)
281 ktach = 0;
282 if (ktach > 255)
283 ktach = 255;
284 data->speed = ktach;
285
286 return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED,
287 data->speed);
288}
289
290/*
291 * Get gpio alarm status:
292 * Possible values:
293 * 0 = no alarm
294 * 1 = alarm
295 */
296
297static ssize_t alarm_show(struct device *dev,
298 struct device_attribute *devattr, char *buf)
299{
300 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
301 struct max6650_data *data = max6650_update_device(dev);
302 bool alarm;
303
304 if (IS_ERR(data))
305 return PTR_ERR(data);
306
307 alarm = data->alarm & attr->index;
308 if (alarm) {
309 mutex_lock(&data->update_lock);
310 data->alarm &= ~attr->index;
311 data->valid = false;
312 mutex_unlock(&data->update_lock);
313 }
314
315 return sprintf(buf, "%d\n", alarm);
316}
317
318static SENSOR_DEVICE_ATTR_RO(gpio1_alarm, alarm, MAX6650_ALRM_GPIO1);
319static SENSOR_DEVICE_ATTR_RO(gpio2_alarm, alarm, MAX6650_ALRM_GPIO2);
320
321static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a,
322 int n)
323{
324 struct device *dev = kobj_to_dev(kobj);
325 struct max6650_data *data = dev_get_drvdata(dev);
326 struct device_attribute *devattr;
327
328 /*
329 * Hide the alarms that have not been enabled by the firmware
330 */
331
332 devattr = container_of(a, struct device_attribute, attr);
333 if (devattr == &sensor_dev_attr_gpio1_alarm.dev_attr ||
334 devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) {
335 if (!(data->alarm_en & to_sensor_dev_attr(devattr)->index))
336 return 0;
337 }
338
339 return a->mode;
340}
341
342static struct attribute *max6650_attrs[] = {
343 &sensor_dev_attr_gpio1_alarm.dev_attr.attr,
344 &sensor_dev_attr_gpio2_alarm.dev_attr.attr,
345 NULL
346};
347
348static const struct attribute_group max6650_group = {
349 .attrs = max6650_attrs,
350 .is_visible = max6650_attrs_visible,
351};
352
353static const struct attribute_group *max6650_groups[] = {
354 &max6650_group,
355 NULL
356};
357
358static int max6650_init_client(struct max6650_data *data,
359 struct i2c_client *client)
360{
361 struct device *dev = &client->dev;
362 int reg;
363 int err;
364 u32 voltage;
365 u32 prescale;
366 u32 target_rpm;
367
368 if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt",
369 &voltage))
370 voltage = fan_voltage;
371 else
372 voltage /= 1000000; /* Microvolts to volts */
373 if (of_property_read_u32(dev->of_node, "maxim,fan-prescale",
374 &prescale))
375 prescale = prescaler;
376
377 reg = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
378 if (reg < 0) {
379 dev_err(dev, "Error reading config register, aborting.\n");
380 return reg;
381 }
382
383 switch (voltage) {
384 case 0:
385 break;
386 case 5:
387 reg &= ~MAX6650_CFG_V12;
388 break;
389 case 12:
390 reg |= MAX6650_CFG_V12;
391 break;
392 default:
393 dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage);
394 }
395
396 switch (prescale) {
397 case 0:
398 break;
399 case 1:
400 reg &= ~MAX6650_CFG_PRESCALER_MASK;
401 break;
402 case 2:
403 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
404 | MAX6650_CFG_PRESCALER_2;
405 break;
406 case 4:
407 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
408 | MAX6650_CFG_PRESCALER_4;
409 break;
410 case 8:
411 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
412 | MAX6650_CFG_PRESCALER_8;
413 break;
414 case 16:
415 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
416 | MAX6650_CFG_PRESCALER_16;
417 break;
418 default:
419 dev_err(dev, "illegal value for prescaler (%d)\n", prescale);
420 }
421
422 dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n",
423 (reg & MAX6650_CFG_V12) ? 12 : 5,
424 1 << (reg & MAX6650_CFG_PRESCALER_MASK));
425
426 err = i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, reg);
427 if (err) {
428 dev_err(dev, "Config write error, aborting.\n");
429 return err;
430 }
431 data->config = reg;
432
433 reg = i2c_smbus_read_byte_data(client, MAX6650_REG_SPEED);
434 if (reg < 0) {
435 dev_err(dev, "Failed to read speed register, aborting.\n");
436 return reg;
437 }
438 data->speed = reg;
439
440 reg = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
441 if (reg < 0) {
442 dev_err(dev, "Failed to read DAC register, aborting.\n");
443 return reg;
444 }
445 data->dac = reg;
446
447 reg = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
448 if (reg < 0) {
449 dev_err(dev, "Failed to read count register, aborting.\n");
450 return reg;
451 }
452 data->count = reg;
453
454 reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN);
455 if (reg < 0) {
456 dev_err(dev, "Failed to read alarm configuration, aborting.\n");
457 return reg;
458 }
459 data->alarm_en = reg;
460
461 if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm",
462 &target_rpm)) {
463 max6650_set_target(data, target_rpm);
464 max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP);
465 }
466
467 return 0;
468}
469
470static int max6650_get_max_state(struct thermal_cooling_device *cdev,
471 unsigned long *state)
472{
473 *state = 255;
474
475 return 0;
476}
477
478static int max6650_get_cur_state(struct thermal_cooling_device *cdev,
479 unsigned long *state)
480{
481 struct max6650_data *data = cdev->devdata;
482
483 *state = data->cooling_dev_state;
484
485 return 0;
486}
487
488static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
489 unsigned long state)
490{
491 struct max6650_data *data = cdev->devdata;
492 struct i2c_client *client = data->client;
493 int err;
494
495 state = clamp_val(state, 0, 255);
496
497 mutex_lock(&data->update_lock);
498
499 data->dac = pwm_to_dac(state, data->config & MAX6650_CFG_V12);
500 err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
501 if (!err) {
502 max6650_set_operating_mode(data, state ?
503 MAX6650_CFG_MODE_OPEN_LOOP :
504 MAX6650_CFG_MODE_OFF);
505 data->cooling_dev_state = state;
506 }
507
508 mutex_unlock(&data->update_lock);
509
510 return err;
511}
512
513static const struct thermal_cooling_device_ops max6650_cooling_ops = {
514 .get_max_state = max6650_get_max_state,
515 .get_cur_state = max6650_get_cur_state,
516 .set_cur_state = max6650_set_cur_state,
517};
518
519static int max6650_read(struct device *dev, enum hwmon_sensor_types type,
520 u32 attr, int channel, long *val)
521{
522 struct max6650_data *data = max6650_update_device(dev);
523 int mode;
524
525 if (IS_ERR(data))
526 return PTR_ERR(data);
527
528 switch (type) {
529 case hwmon_pwm:
530 switch (attr) {
531 case hwmon_pwm_input:
532 *val = dac_to_pwm(data->dac,
533 data->config & MAX6650_CFG_V12);
534 break;
535 case hwmon_pwm_enable:
536 /*
537 * Possible values:
538 * 0 = Fan always on
539 * 1 = Open loop, Voltage is set according to speed,
540 * not regulated.
541 * 2 = Closed loop, RPM for all fans regulated by fan1
542 * tachometer
543 * 3 = Fan off
544 */
545 mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;
546 *val = (4 - mode) & 3; /* {0 1 2 3} -> {0 3 2 1} */
547 break;
548 default:
549 return -EOPNOTSUPP;
550 }
551 break;
552 case hwmon_fan:
553 switch (attr) {
554 case hwmon_fan_input:
555 /*
556 * Calculation details:
557 *
558 * Each tachometer counts over an interval given by the
559 * "count" register (0.25, 0.5, 1 or 2 seconds).
560 * The driver assumes that the fans produce two pulses
561 * per revolution (this seems to be the most common).
562 */
563 *val = DIV_ROUND_CLOSEST(data->tach[channel] * 120,
564 DIV_FROM_REG(data->count));
565 break;
566 case hwmon_fan_div:
567 *val = DIV_FROM_REG(data->count);
568 break;
569 case hwmon_fan_target:
570 /*
571 * Use the datasheet equation:
572 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
573 * then multiply by 60 to give rpm.
574 */
575 *val = 60 * DIV_FROM_REG(data->config) * clock /
576 (256 * (data->speed + 1));
577 break;
578 case hwmon_fan_min_alarm:
579 *val = !!(data->alarm & MAX6650_ALRM_MIN);
580 data->alarm &= ~MAX6650_ALRM_MIN;
581 data->valid = false;
582 break;
583 case hwmon_fan_max_alarm:
584 *val = !!(data->alarm & MAX6650_ALRM_MAX);
585 data->alarm &= ~MAX6650_ALRM_MAX;
586 data->valid = false;
587 break;
588 case hwmon_fan_fault:
589 *val = !!(data->alarm & MAX6650_ALRM_TACH);
590 data->alarm &= ~MAX6650_ALRM_TACH;
591 data->valid = false;
592 break;
593 default:
594 return -EOPNOTSUPP;
595 }
596 break;
597 default:
598 return -EOPNOTSUPP;
599 }
600 return 0;
601}
602
603static const u8 max6650_pwm_modes[] = {
604 MAX6650_CFG_MODE_ON,
605 MAX6650_CFG_MODE_OPEN_LOOP,
606 MAX6650_CFG_MODE_CLOSED_LOOP,
607 MAX6650_CFG_MODE_OFF,
608};
609
610static int max6650_write(struct device *dev, enum hwmon_sensor_types type,
611 u32 attr, int channel, long val)
612{
613 struct max6650_data *data = dev_get_drvdata(dev);
614 int ret = 0;
615 u8 reg;
616
617 mutex_lock(&data->update_lock);
618
619 switch (type) {
620 case hwmon_pwm:
621 switch (attr) {
622 case hwmon_pwm_input:
623 reg = pwm_to_dac(clamp_val(val, 0, 255),
624 data->config & MAX6650_CFG_V12);
625 ret = i2c_smbus_write_byte_data(data->client,
626 MAX6650_REG_DAC, reg);
627 if (ret)
628 break;
629 data->dac = reg;
630 break;
631 case hwmon_pwm_enable:
632 if (val < 0 || val >= ARRAY_SIZE(max6650_pwm_modes)) {
633 ret = -EINVAL;
634 break;
635 }
636 ret = max6650_set_operating_mode(data,
637 max6650_pwm_modes[val]);
638 break;
639 default:
640 ret = -EOPNOTSUPP;
641 break;
642 }
643 break;
644 case hwmon_fan:
645 switch (attr) {
646 case hwmon_fan_div:
647 switch (val) {
648 case 1:
649 reg = 0;
650 break;
651 case 2:
652 reg = 1;
653 break;
654 case 4:
655 reg = 2;
656 break;
657 case 8:
658 reg = 3;
659 break;
660 default:
661 ret = -EINVAL;
662 goto error;
663 }
664 ret = i2c_smbus_write_byte_data(data->client,
665 MAX6650_REG_COUNT, reg);
666 if (ret)
667 break;
668 data->count = reg;
669 break;
670 case hwmon_fan_target:
671 if (val < 0) {
672 ret = -EINVAL;
673 break;
674 }
675 ret = max6650_set_target(data, val);
676 break;
677 default:
678 ret = -EOPNOTSUPP;
679 break;
680 }
681 break;
682 default:
683 ret = -EOPNOTSUPP;
684 break;
685 }
686
687error:
688 mutex_unlock(&data->update_lock);
689 return ret;
690}
691
692static umode_t max6650_is_visible(const void *_data,
693 enum hwmon_sensor_types type, u32 attr,
694 int channel)
695{
696 const struct max6650_data *data = _data;
697
698 if (channel && (channel >= data->nr_fans || type != hwmon_fan))
699 return 0;
700
701 switch (type) {
702 case hwmon_fan:
703 switch (attr) {
704 case hwmon_fan_input:
705 return 0444;
706 case hwmon_fan_target:
707 case hwmon_fan_div:
708 return 0644;
709 case hwmon_fan_min_alarm:
710 if (data->alarm_en & MAX6650_ALRM_MIN)
711 return 0444;
712 break;
713 case hwmon_fan_max_alarm:
714 if (data->alarm_en & MAX6650_ALRM_MAX)
715 return 0444;
716 break;
717 case hwmon_fan_fault:
718 if (data->alarm_en & MAX6650_ALRM_TACH)
719 return 0444;
720 break;
721 default:
722 break;
723 }
724 break;
725 case hwmon_pwm:
726 switch (attr) {
727 case hwmon_pwm_input:
728 case hwmon_pwm_enable:
729 return 0644;
730 default:
731 break;
732 }
733 break;
734 default:
735 break;
736 }
737 return 0;
738}
739
740static const struct hwmon_channel_info * const max6650_info[] = {
741 HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_DIV |
742 HWMON_F_MIN_ALARM | HWMON_F_MAX_ALARM |
743 HWMON_F_FAULT,
744 HWMON_F_INPUT, HWMON_F_INPUT, HWMON_F_INPUT),
745 HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
746 NULL
747};
748
749static const struct hwmon_ops max6650_hwmon_ops = {
750 .read = max6650_read,
751 .write = max6650_write,
752 .is_visible = max6650_is_visible,
753};
754
755static const struct hwmon_chip_info max6650_chip_info = {
756 .ops = &max6650_hwmon_ops,
757 .info = max6650_info,
758};
759
760static const struct i2c_device_id max6650_id[];
761
762static int max6650_probe(struct i2c_client *client)
763{
764 struct thermal_cooling_device *cooling_dev;
765 struct device *dev = &client->dev;
766 struct max6650_data *data;
767 struct device *hwmon_dev;
768 int err;
769
770 data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL);
771 if (!data)
772 return -ENOMEM;
773
774 data->client = client;
775 i2c_set_clientdata(client, data);
776 mutex_init(&data->update_lock);
777
778 data->nr_fans = (uintptr_t)i2c_get_match_data(client);
779
780 /*
781 * Initialize the max6650 chip
782 */
783 err = max6650_init_client(data, client);
784 if (err)
785 return err;
786
787 hwmon_dev = devm_hwmon_device_register_with_info(dev,
788 client->name, data,
789 &max6650_chip_info,
790 max6650_groups);
791 err = PTR_ERR_OR_ZERO(hwmon_dev);
792 if (err)
793 return err;
794
795 if (IS_ENABLED(CONFIG_THERMAL)) {
796 cooling_dev = devm_thermal_of_cooling_device_register(dev,
797 dev->of_node, client->name,
798 data, &max6650_cooling_ops);
799 if (IS_ERR(cooling_dev)) {
800 dev_warn(dev, "thermal cooling device register failed: %ld\n",
801 PTR_ERR(cooling_dev));
802 }
803 }
804
805 return 0;
806}
807
808static const struct i2c_device_id max6650_id[] = {
809 { "max6650", 1 },
810 { "max6651", 4 },
811 { }
812};
813MODULE_DEVICE_TABLE(i2c, max6650_id);
814
815static struct i2c_driver max6650_driver = {
816 .driver = {
817 .name = "max6650",
818 .of_match_table = of_match_ptr(max6650_dt_match),
819 },
820 .probe = max6650_probe,
821 .id_table = max6650_id,
822};
823
824module_i2c_driver(max6650_driver);
825
826MODULE_AUTHOR("Hans J. Koch");
827MODULE_DESCRIPTION("MAX6650 sensor driver");
828MODULE_LICENSE("GPL");
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 */
48static int fan_voltage;
49/* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
50static int prescaler;
51/* clock: The clock frequency of the chip the driver should assume */
52static int clock = 254000;
53
54module_param(fan_voltage, int, S_IRUGO);
55module_param(prescaler, int, S_IRUGO);
56module_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/*
109 * Client data (each client gets its own)
110 */
111
112struct max6650_data {
113 struct i2c_client *client;
114 const struct attribute_group *groups[3];
115 struct mutex update_lock;
116 int nr_fans;
117 char valid; /* zero until following fields are valid */
118 unsigned long last_updated; /* in jiffies */
119
120 /* register values */
121 u8 speed;
122 u8 config;
123 u8 tach[4];
124 u8 count;
125 u8 dac;
126 u8 alarm;
127};
128
129static const u8 tach_reg[] = {
130 MAX6650_REG_TACH0,
131 MAX6650_REG_TACH1,
132 MAX6650_REG_TACH2,
133 MAX6650_REG_TACH3,
134};
135
136static struct max6650_data *max6650_update_device(struct device *dev)
137{
138 struct max6650_data *data = dev_get_drvdata(dev);
139 struct i2c_client *client = data->client;
140 int i;
141
142 mutex_lock(&data->update_lock);
143
144 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
145 data->speed = i2c_smbus_read_byte_data(client,
146 MAX6650_REG_SPEED);
147 data->config = i2c_smbus_read_byte_data(client,
148 MAX6650_REG_CONFIG);
149 for (i = 0; i < data->nr_fans; i++) {
150 data->tach[i] = i2c_smbus_read_byte_data(client,
151 tach_reg[i]);
152 }
153 data->count = i2c_smbus_read_byte_data(client,
154 MAX6650_REG_COUNT);
155 data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
156
157 /*
158 * Alarms are cleared on read in case the condition that
159 * caused the alarm is removed. Keep the value latched here
160 * for providing the register through different alarm files.
161 */
162 data->alarm |= i2c_smbus_read_byte_data(client,
163 MAX6650_REG_ALARM);
164
165 data->last_updated = jiffies;
166 data->valid = 1;
167 }
168
169 mutex_unlock(&data->update_lock);
170
171 return data;
172}
173
174static ssize_t get_fan(struct device *dev, struct device_attribute *devattr,
175 char *buf)
176{
177 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
178 struct max6650_data *data = max6650_update_device(dev);
179 int rpm;
180
181 /*
182 * Calculation details:
183 *
184 * Each tachometer counts over an interval given by the "count"
185 * register (0.25, 0.5, 1 or 2 seconds). This module assumes
186 * that the fans produce two pulses per revolution (this seems
187 * to be the most common).
188 */
189
190 rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count));
191 return sprintf(buf, "%d\n", rpm);
192}
193
194/*
195 * Set the fan speed to the specified RPM (or read back the RPM setting).
196 * This works in closed loop mode only. Use pwm1 for open loop speed setting.
197 *
198 * The MAX6650/1 will automatically control fan speed when in closed loop
199 * mode.
200 *
201 * Assumptions:
202 *
203 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use
204 * the clock module parameter if you need to fine tune this.
205 *
206 * 2) The prescaler (low three bits of the config register) has already
207 * been set to an appropriate value. Use the prescaler module parameter
208 * if your BIOS doesn't initialize the chip properly.
209 *
210 * The relevant equations are given on pages 21 and 22 of the datasheet.
211 *
212 * From the datasheet, the relevant equation when in regulation is:
213 *
214 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE
215 *
216 * where:
217 *
218 * fCLK is the oscillator frequency (either the 254kHz internal
219 * oscillator or the externally applied clock)
220 *
221 * KTACH is the value in the speed register
222 *
223 * FanSpeed is the speed of the fan in rps
224 *
225 * KSCALE is the prescaler value (1, 2, 4, 8, or 16)
226 *
227 * When reading, we need to solve for FanSpeed. When writing, we need to
228 * solve for KTACH.
229 *
230 * Note: this tachometer is completely separate from the tachometers
231 * used to measure the fan speeds. Only one fan's speed (fan1) is
232 * controlled.
233 */
234
235static ssize_t get_target(struct device *dev, struct device_attribute *devattr,
236 char *buf)
237{
238 struct max6650_data *data = max6650_update_device(dev);
239 int kscale, ktach, rpm;
240
241 /*
242 * Use the datasheet equation:
243 *
244 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
245 *
246 * then multiply by 60 to give rpm.
247 */
248
249 kscale = DIV_FROM_REG(data->config);
250 ktach = data->speed;
251 rpm = 60 * kscale * clock / (256 * (ktach + 1));
252 return sprintf(buf, "%d\n", rpm);
253}
254
255static ssize_t set_target(struct device *dev, struct device_attribute *devattr,
256 const char *buf, size_t count)
257{
258 struct max6650_data *data = dev_get_drvdata(dev);
259 struct i2c_client *client = data->client;
260 int kscale, ktach;
261 unsigned long rpm;
262 int err;
263
264 err = kstrtoul(buf, 10, &rpm);
265 if (err)
266 return err;
267
268 rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
269
270 /*
271 * Divide the required speed by 60 to get from rpm to rps, then
272 * use the datasheet equation:
273 *
274 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1
275 */
276
277 mutex_lock(&data->update_lock);
278
279 kscale = DIV_FROM_REG(data->config);
280 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1;
281 if (ktach < 0)
282 ktach = 0;
283 if (ktach > 255)
284 ktach = 255;
285 data->speed = ktach;
286
287 i2c_smbus_write_byte_data(client, MAX6650_REG_SPEED, data->speed);
288
289 mutex_unlock(&data->update_lock);
290
291 return count;
292}
293
294/*
295 * Get/set the fan speed in open loop mode using pwm1 sysfs file.
296 * Speed is given as a relative value from 0 to 255, where 255 is maximum
297 * speed. Note that this is done by writing directly to the chip's DAC,
298 * it won't change the closed loop speed set by fan1_target.
299 * Also note that due to rounding errors it is possible that you don't read
300 * back exactly the value you have set.
301 */
302
303static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr,
304 char *buf)
305{
306 int pwm;
307 struct max6650_data *data = max6650_update_device(dev);
308
309 /*
310 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
311 * Lower DAC values mean higher speeds.
312 */
313 if (data->config & MAX6650_CFG_V12)
314 pwm = 255 - (255 * (int)data->dac)/180;
315 else
316 pwm = 255 - (255 * (int)data->dac)/76;
317
318 if (pwm < 0)
319 pwm = 0;
320
321 return sprintf(buf, "%d\n", pwm);
322}
323
324static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr,
325 const char *buf, size_t count)
326{
327 struct max6650_data *data = dev_get_drvdata(dev);
328 struct i2c_client *client = data->client;
329 unsigned long pwm;
330 int err;
331
332 err = kstrtoul(buf, 10, &pwm);
333 if (err)
334 return err;
335
336 pwm = clamp_val(pwm, 0, 255);
337
338 mutex_lock(&data->update_lock);
339
340 if (data->config & MAX6650_CFG_V12)
341 data->dac = 180 - (180 * pwm)/255;
342 else
343 data->dac = 76 - (76 * pwm)/255;
344
345 i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
346
347 mutex_unlock(&data->update_lock);
348
349 return count;
350}
351
352/*
353 * Get/Set controller mode:
354 * Possible values:
355 * 0 = Fan always on
356 * 1 = Open loop, Voltage is set according to speed, not regulated.
357 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer
358 */
359
360static ssize_t get_enable(struct device *dev, struct device_attribute *devattr,
361 char *buf)
362{
363 struct max6650_data *data = max6650_update_device(dev);
364 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;
365 int sysfs_modes[4] = {0, 1, 2, 1};
366
367 return sprintf(buf, "%d\n", sysfs_modes[mode]);
368}
369
370static ssize_t set_enable(struct device *dev, struct device_attribute *devattr,
371 const char *buf, size_t count)
372{
373 struct max6650_data *data = dev_get_drvdata(dev);
374 struct i2c_client *client = data->client;
375 int max6650_modes[3] = {0, 3, 2};
376 unsigned long mode;
377 int err;
378
379 err = kstrtoul(buf, 10, &mode);
380 if (err)
381 return err;
382
383 if (mode > 2)
384 return -EINVAL;
385
386 mutex_lock(&data->update_lock);
387
388 data->config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
389 data->config = (data->config & ~MAX6650_CFG_MODE_MASK)
390 | (max6650_modes[mode] << 4);
391
392 i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, data->config);
393
394 mutex_unlock(&data->update_lock);
395
396 return count;
397}
398
399/*
400 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such
401 * divider. We handle this by converting between divider and counttime:
402 *
403 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3
404 *
405 * Lower values of k allow to connect a faster fan without the risk of
406 * counter overflow. The price is lower resolution. You can also set counttime
407 * using the module parameter. Note that the module parameter "prescaler" also
408 * influences the behaviour. Unfortunately, there's no sysfs attribute
409 * defined for that. See the data sheet for details.
410 */
411
412static ssize_t get_div(struct device *dev, struct device_attribute *devattr,
413 char *buf)
414{
415 struct max6650_data *data = max6650_update_device(dev);
416
417 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count));
418}
419
420static ssize_t set_div(struct device *dev, struct device_attribute *devattr,
421 const char *buf, size_t count)
422{
423 struct max6650_data *data = dev_get_drvdata(dev);
424 struct i2c_client *client = data->client;
425 unsigned long div;
426 int err;
427
428 err = kstrtoul(buf, 10, &div);
429 if (err)
430 return err;
431
432 mutex_lock(&data->update_lock);
433 switch (div) {
434 case 1:
435 data->count = 0;
436 break;
437 case 2:
438 data->count = 1;
439 break;
440 case 4:
441 data->count = 2;
442 break;
443 case 8:
444 data->count = 3;
445 break;
446 default:
447 mutex_unlock(&data->update_lock);
448 return -EINVAL;
449 }
450
451 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count);
452 mutex_unlock(&data->update_lock);
453
454 return count;
455}
456
457/*
458 * Get alarm stati:
459 * Possible values:
460 * 0 = no alarm
461 * 1 = alarm
462 */
463
464static ssize_t get_alarm(struct device *dev, struct device_attribute *devattr,
465 char *buf)
466{
467 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
468 struct max6650_data *data = max6650_update_device(dev);
469 struct i2c_client *client = data->client;
470 int alarm = 0;
471
472 if (data->alarm & attr->index) {
473 mutex_lock(&data->update_lock);
474 alarm = 1;
475 data->alarm &= ~attr->index;
476 data->alarm |= i2c_smbus_read_byte_data(client,
477 MAX6650_REG_ALARM);
478 mutex_unlock(&data->update_lock);
479 }
480
481 return sprintf(buf, "%d\n", alarm);
482}
483
484static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
485static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
486static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
487static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3);
488static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target);
489static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div);
490static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable);
491static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
492static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL,
493 MAX6650_ALRM_MAX);
494static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL,
495 MAX6650_ALRM_MIN);
496static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL,
497 MAX6650_ALRM_TACH);
498static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL,
499 MAX6650_ALRM_GPIO1);
500static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL,
501 MAX6650_ALRM_GPIO2);
502
503static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a,
504 int n)
505{
506 struct device *dev = container_of(kobj, struct device, kobj);
507 struct max6650_data *data = dev_get_drvdata(dev);
508 struct i2c_client *client = data->client;
509 u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN);
510 struct device_attribute *devattr;
511
512 /*
513 * Hide the alarms that have not been enabled by the firmware
514 */
515
516 devattr = container_of(a, struct device_attribute, attr);
517 if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr
518 || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr
519 || devattr == &sensor_dev_attr_fan1_fault.dev_attr
520 || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr
521 || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) {
522 if (!(alarm_en & to_sensor_dev_attr(devattr)->index))
523 return 0;
524 }
525
526 return a->mode;
527}
528
529static struct attribute *max6650_attrs[] = {
530 &sensor_dev_attr_fan1_input.dev_attr.attr,
531 &dev_attr_fan1_target.attr,
532 &dev_attr_fan1_div.attr,
533 &dev_attr_pwm1_enable.attr,
534 &dev_attr_pwm1.attr,
535 &sensor_dev_attr_fan1_max_alarm.dev_attr.attr,
536 &sensor_dev_attr_fan1_min_alarm.dev_attr.attr,
537 &sensor_dev_attr_fan1_fault.dev_attr.attr,
538 &sensor_dev_attr_gpio1_alarm.dev_attr.attr,
539 &sensor_dev_attr_gpio2_alarm.dev_attr.attr,
540 NULL
541};
542
543static const struct attribute_group max6650_group = {
544 .attrs = max6650_attrs,
545 .is_visible = max6650_attrs_visible,
546};
547
548static struct attribute *max6651_attrs[] = {
549 &sensor_dev_attr_fan2_input.dev_attr.attr,
550 &sensor_dev_attr_fan3_input.dev_attr.attr,
551 &sensor_dev_attr_fan4_input.dev_attr.attr,
552 NULL
553};
554
555static const struct attribute_group max6651_group = {
556 .attrs = max6651_attrs,
557};
558
559/*
560 * Real code
561 */
562
563static int max6650_init_client(struct max6650_data *data,
564 struct i2c_client *client)
565{
566 struct device *dev = &client->dev;
567 int config;
568 int err = -EIO;
569
570 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
571
572 if (config < 0) {
573 dev_err(dev, "Error reading config, aborting.\n");
574 return err;
575 }
576
577 switch (fan_voltage) {
578 case 0:
579 break;
580 case 5:
581 config &= ~MAX6650_CFG_V12;
582 break;
583 case 12:
584 config |= MAX6650_CFG_V12;
585 break;
586 default:
587 dev_err(dev, "illegal value for fan_voltage (%d)\n",
588 fan_voltage);
589 }
590
591 dev_info(dev, "Fan voltage is set to %dV.\n",
592 (config & MAX6650_CFG_V12) ? 12 : 5);
593
594 switch (prescaler) {
595 case 0:
596 break;
597 case 1:
598 config &= ~MAX6650_CFG_PRESCALER_MASK;
599 break;
600 case 2:
601 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
602 | MAX6650_CFG_PRESCALER_2;
603 break;
604 case 4:
605 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
606 | MAX6650_CFG_PRESCALER_4;
607 break;
608 case 8:
609 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
610 | MAX6650_CFG_PRESCALER_8;
611 break;
612 case 16:
613 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
614 | MAX6650_CFG_PRESCALER_16;
615 break;
616 default:
617 dev_err(dev, "illegal value for prescaler (%d)\n", prescaler);
618 }
619
620 dev_info(dev, "Prescaler is set to %d.\n",
621 1 << (config & MAX6650_CFG_PRESCALER_MASK));
622
623 /*
624 * If mode is set to "full off", we change it to "open loop" and
625 * set DAC to 255, which has the same effect. We do this because
626 * there's no "full off" mode defined in hwmon specifications.
627 */
628
629 if ((config & MAX6650_CFG_MODE_MASK) == MAX6650_CFG_MODE_OFF) {
630 dev_dbg(dev, "Change mode to open loop, full off.\n");
631 config = (config & ~MAX6650_CFG_MODE_MASK)
632 | MAX6650_CFG_MODE_OPEN_LOOP;
633 if (i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, 255)) {
634 dev_err(dev, "DAC write error, aborting.\n");
635 return err;
636 }
637 }
638
639 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) {
640 dev_err(dev, "Config write error, aborting.\n");
641 return err;
642 }
643
644 data->config = config;
645 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
646
647 return 0;
648}
649
650static int max6650_probe(struct i2c_client *client,
651 const struct i2c_device_id *id)
652{
653 struct device *dev = &client->dev;
654 struct max6650_data *data;
655 struct device *hwmon_dev;
656 int err;
657
658 data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL);
659 if (!data)
660 return -ENOMEM;
661
662 data->client = client;
663 mutex_init(&data->update_lock);
664 data->nr_fans = id->driver_data;
665
666 /*
667 * Initialize the max6650 chip
668 */
669 err = max6650_init_client(data, client);
670 if (err)
671 return err;
672
673 data->groups[0] = &max6650_group;
674 /* 3 additional fan inputs for the MAX6651 */
675 if (data->nr_fans == 4)
676 data->groups[1] = &max6651_group;
677
678 hwmon_dev = devm_hwmon_device_register_with_groups(dev,
679 client->name, data,
680 data->groups);
681 return PTR_ERR_OR_ZERO(hwmon_dev);
682}
683
684static const struct i2c_device_id max6650_id[] = {
685 { "max6650", 1 },
686 { "max6651", 4 },
687 { }
688};
689MODULE_DEVICE_TABLE(i2c, max6650_id);
690
691static struct i2c_driver max6650_driver = {
692 .driver = {
693 .name = "max6650",
694 },
695 .probe = max6650_probe,
696 .id_table = max6650_id,
697};
698
699module_i2c_driver(max6650_driver);
700
701MODULE_AUTHOR("Hans J. Koch");
702MODULE_DESCRIPTION("MAX6650 sensor driver");
703MODULE_LICENSE("GPL");