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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_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 */
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 = container_of(kobj, struct device, 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 *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 int max6650_probe(struct i2c_client *client,
761 const struct i2c_device_id *id)
762{
763 struct thermal_cooling_device *cooling_dev;
764 struct device *dev = &client->dev;
765 const struct of_device_id *of_id =
766 of_match_device(of_match_ptr(max6650_dt_match), dev);
767 struct max6650_data *data;
768 struct device *hwmon_dev;
769 int err;
770
771 data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL);
772 if (!data)
773 return -ENOMEM;
774
775 data->client = client;
776 i2c_set_clientdata(client, data);
777 mutex_init(&data->update_lock);
778 data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data;
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#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 */
49static int fan_voltage;
50/* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
51static int prescaler;
52/* clock: The clock frequency of the chip (max6651 can be clocked externally) */
53static int clock = 254000;
54
55module_param(fan_voltage, int, S_IRUGO);
56module_param(prescaler, int, S_IRUGO);
57module_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
113struct 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
130static const u8 tach_reg[] = {
131 MAX6650_REG_TACH0,
132 MAX6650_REG_TACH1,
133 MAX6650_REG_TACH2,
134 MAX6650_REG_TACH3,
135};
136
137static 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};
148MODULE_DEVICE_TABLE(of, max6650_dt_match);
149
150static 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 */
192static 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
212static 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
273static ssize_t fan1_target_show(struct device *dev,
274 struct device_attribute *devattr, 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
293static 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
321static ssize_t fan1_target_store(struct device *dev,
322 struct device_attribute *devattr,
323 const char *buf, size_t count)
324{
325 struct max6650_data *data = dev_get_drvdata(dev);
326 unsigned long rpm;
327 int err;
328
329 err = kstrtoul(buf, 10, &rpm);
330 if (err)
331 return err;
332
333 mutex_lock(&data->update_lock);
334
335 err = max6650_set_target(data, rpm);
336
337 mutex_unlock(&data->update_lock);
338
339 if (err < 0)
340 return err;
341
342 return count;
343}
344
345/*
346 * Get/set the fan speed in open loop mode using pwm1 sysfs file.
347 * Speed is given as a relative value from 0 to 255, where 255 is maximum
348 * speed. Note that this is done by writing directly to the chip's DAC,
349 * it won't change the closed loop speed set by fan1_target.
350 * Also note that due to rounding errors it is possible that you don't read
351 * back exactly the value you have set.
352 */
353
354static ssize_t pwm1_show(struct device *dev, struct device_attribute *devattr,
355 char *buf)
356{
357 int pwm;
358 struct max6650_data *data = max6650_update_device(dev);
359
360 /*
361 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
362 * Lower DAC values mean higher speeds.
363 */
364 if (data->config & MAX6650_CFG_V12)
365 pwm = 255 - (255 * (int)data->dac)/180;
366 else
367 pwm = 255 - (255 * (int)data->dac)/76;
368
369 if (pwm < 0)
370 pwm = 0;
371
372 return sprintf(buf, "%d\n", pwm);
373}
374
375static ssize_t pwm1_store(struct device *dev,
376 struct device_attribute *devattr, const char *buf,
377 size_t count)
378{
379 struct max6650_data *data = dev_get_drvdata(dev);
380 struct i2c_client *client = data->client;
381 unsigned long pwm;
382 int err;
383
384 err = kstrtoul(buf, 10, &pwm);
385 if (err)
386 return err;
387
388 pwm = clamp_val(pwm, 0, 255);
389
390 mutex_lock(&data->update_lock);
391
392 if (data->config & MAX6650_CFG_V12)
393 data->dac = 180 - (180 * pwm)/255;
394 else
395 data->dac = 76 - (76 * pwm)/255;
396 err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
397
398 mutex_unlock(&data->update_lock);
399
400 return err < 0 ? err : count;
401}
402
403/*
404 * Get/Set controller mode:
405 * Possible values:
406 * 0 = Fan always on
407 * 1 = Open loop, Voltage is set according to speed, not regulated.
408 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer
409 * 3 = Fan off
410 */
411static ssize_t pwm1_enable_show(struct device *dev,
412 struct device_attribute *devattr, char *buf)
413{
414 struct max6650_data *data = max6650_update_device(dev);
415 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;
416 int sysfs_modes[4] = {0, 3, 2, 1};
417
418 return sprintf(buf, "%d\n", sysfs_modes[mode]);
419}
420
421static ssize_t pwm1_enable_store(struct device *dev,
422 struct device_attribute *devattr,
423 const char *buf, size_t count)
424{
425 struct max6650_data *data = dev_get_drvdata(dev);
426 unsigned long mode;
427 int err;
428 const u8 max6650_modes[] = {
429 MAX6650_CFG_MODE_ON,
430 MAX6650_CFG_MODE_OPEN_LOOP,
431 MAX6650_CFG_MODE_CLOSED_LOOP,
432 MAX6650_CFG_MODE_OFF,
433 };
434
435 err = kstrtoul(buf, 10, &mode);
436 if (err)
437 return err;
438
439 if (mode >= ARRAY_SIZE(max6650_modes))
440 return -EINVAL;
441
442 mutex_lock(&data->update_lock);
443
444 max6650_set_operating_mode(data, max6650_modes[mode]);
445
446 mutex_unlock(&data->update_lock);
447
448 return count;
449}
450
451/*
452 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such
453 * divider. We handle this by converting between divider and counttime:
454 *
455 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3
456 *
457 * Lower values of k allow to connect a faster fan without the risk of
458 * counter overflow. The price is lower resolution. You can also set counttime
459 * using the module parameter. Note that the module parameter "prescaler" also
460 * influences the behaviour. Unfortunately, there's no sysfs attribute
461 * defined for that. See the data sheet for details.
462 */
463
464static ssize_t fan1_div_show(struct device *dev,
465 struct device_attribute *devattr, char *buf)
466{
467 struct max6650_data *data = max6650_update_device(dev);
468
469 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count));
470}
471
472static ssize_t fan1_div_store(struct device *dev,
473 struct device_attribute *devattr,
474 const char *buf, size_t count)
475{
476 struct max6650_data *data = dev_get_drvdata(dev);
477 struct i2c_client *client = data->client;
478 unsigned long div;
479 int err;
480
481 err = kstrtoul(buf, 10, &div);
482 if (err)
483 return err;
484
485 mutex_lock(&data->update_lock);
486 switch (div) {
487 case 1:
488 data->count = 0;
489 break;
490 case 2:
491 data->count = 1;
492 break;
493 case 4:
494 data->count = 2;
495 break;
496 case 8:
497 data->count = 3;
498 break;
499 default:
500 mutex_unlock(&data->update_lock);
501 return -EINVAL;
502 }
503
504 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count);
505 mutex_unlock(&data->update_lock);
506
507 return count;
508}
509
510/*
511 * Get alarm stati:
512 * Possible values:
513 * 0 = no alarm
514 * 1 = alarm
515 */
516
517static ssize_t get_alarm(struct device *dev, struct device_attribute *devattr,
518 char *buf)
519{
520 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
521 struct max6650_data *data = max6650_update_device(dev);
522 struct i2c_client *client = data->client;
523 int alarm = 0;
524
525 if (data->alarm & attr->index) {
526 mutex_lock(&data->update_lock);
527 alarm = 1;
528 data->alarm &= ~attr->index;
529 data->alarm |= i2c_smbus_read_byte_data(client,
530 MAX6650_REG_ALARM);
531 mutex_unlock(&data->update_lock);
532 }
533
534 return sprintf(buf, "%d\n", alarm);
535}
536
537static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
538static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
539static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
540static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3);
541static DEVICE_ATTR_RW(fan1_target);
542static DEVICE_ATTR_RW(fan1_div);
543static DEVICE_ATTR_RW(pwm1_enable);
544static DEVICE_ATTR_RW(pwm1);
545static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL,
546 MAX6650_ALRM_MAX);
547static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL,
548 MAX6650_ALRM_MIN);
549static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL,
550 MAX6650_ALRM_TACH);
551static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL,
552 MAX6650_ALRM_GPIO1);
553static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL,
554 MAX6650_ALRM_GPIO2);
555
556static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a,
557 int n)
558{
559 struct device *dev = container_of(kobj, struct device, kobj);
560 struct max6650_data *data = dev_get_drvdata(dev);
561 struct i2c_client *client = data->client;
562 u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN);
563 struct device_attribute *devattr;
564
565 /*
566 * Hide the alarms that have not been enabled by the firmware
567 */
568
569 devattr = container_of(a, struct device_attribute, attr);
570 if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr
571 || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr
572 || devattr == &sensor_dev_attr_fan1_fault.dev_attr
573 || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr
574 || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) {
575 if (!(alarm_en & to_sensor_dev_attr(devattr)->index))
576 return 0;
577 }
578
579 return a->mode;
580}
581
582static struct attribute *max6650_attrs[] = {
583 &sensor_dev_attr_fan1_input.dev_attr.attr,
584 &dev_attr_fan1_target.attr,
585 &dev_attr_fan1_div.attr,
586 &dev_attr_pwm1_enable.attr,
587 &dev_attr_pwm1.attr,
588 &sensor_dev_attr_fan1_max_alarm.dev_attr.attr,
589 &sensor_dev_attr_fan1_min_alarm.dev_attr.attr,
590 &sensor_dev_attr_fan1_fault.dev_attr.attr,
591 &sensor_dev_attr_gpio1_alarm.dev_attr.attr,
592 &sensor_dev_attr_gpio2_alarm.dev_attr.attr,
593 NULL
594};
595
596static const struct attribute_group max6650_group = {
597 .attrs = max6650_attrs,
598 .is_visible = max6650_attrs_visible,
599};
600
601static struct attribute *max6651_attrs[] = {
602 &sensor_dev_attr_fan2_input.dev_attr.attr,
603 &sensor_dev_attr_fan3_input.dev_attr.attr,
604 &sensor_dev_attr_fan4_input.dev_attr.attr,
605 NULL
606};
607
608static const struct attribute_group max6651_group = {
609 .attrs = max6651_attrs,
610};
611
612/*
613 * Real code
614 */
615
616static int max6650_init_client(struct max6650_data *data,
617 struct i2c_client *client)
618{
619 struct device *dev = &client->dev;
620 int config;
621 int err = -EIO;
622 u32 voltage;
623 u32 prescale;
624 u32 target_rpm;
625
626 if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt",
627 &voltage))
628 voltage = fan_voltage;
629 else
630 voltage /= 1000000; /* Microvolts to volts */
631 if (of_property_read_u32(dev->of_node, "maxim,fan-prescale",
632 &prescale))
633 prescale = prescaler;
634
635 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
636
637 if (config < 0) {
638 dev_err(dev, "Error reading config, aborting.\n");
639 return err;
640 }
641
642 switch (voltage) {
643 case 0:
644 break;
645 case 5:
646 config &= ~MAX6650_CFG_V12;
647 break;
648 case 12:
649 config |= MAX6650_CFG_V12;
650 break;
651 default:
652 dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage);
653 }
654
655 switch (prescale) {
656 case 0:
657 break;
658 case 1:
659 config &= ~MAX6650_CFG_PRESCALER_MASK;
660 break;
661 case 2:
662 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
663 | MAX6650_CFG_PRESCALER_2;
664 break;
665 case 4:
666 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
667 | MAX6650_CFG_PRESCALER_4;
668 break;
669 case 8:
670 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
671 | MAX6650_CFG_PRESCALER_8;
672 break;
673 case 16:
674 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
675 | MAX6650_CFG_PRESCALER_16;
676 break;
677 default:
678 dev_err(dev, "illegal value for prescaler (%d)\n", prescale);
679 }
680
681 dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n",
682 (config & MAX6650_CFG_V12) ? 12 : 5,
683 1 << (config & MAX6650_CFG_PRESCALER_MASK));
684
685 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) {
686 dev_err(dev, "Config write error, aborting.\n");
687 return err;
688 }
689
690 data->config = config;
691 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
692
693 if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm",
694 &target_rpm)) {
695 max6650_set_target(data, target_rpm);
696 max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP);
697 }
698
699 return 0;
700}
701
702static int max6650_probe(struct i2c_client *client,
703 const struct i2c_device_id *id)
704{
705 struct device *dev = &client->dev;
706 const struct of_device_id *of_id =
707 of_match_device(of_match_ptr(max6650_dt_match), dev);
708 struct max6650_data *data;
709 struct device *hwmon_dev;
710 int err;
711
712 data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL);
713 if (!data)
714 return -ENOMEM;
715
716 data->client = client;
717 mutex_init(&data->update_lock);
718 data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data;
719
720 /*
721 * Initialize the max6650 chip
722 */
723 err = max6650_init_client(data, client);
724 if (err)
725 return err;
726
727 data->groups[0] = &max6650_group;
728 /* 3 additional fan inputs for the MAX6651 */
729 if (data->nr_fans == 4)
730 data->groups[1] = &max6651_group;
731
732 hwmon_dev = devm_hwmon_device_register_with_groups(dev,
733 client->name, data,
734 data->groups);
735 return PTR_ERR_OR_ZERO(hwmon_dev);
736}
737
738static const struct i2c_device_id max6650_id[] = {
739 { "max6650", 1 },
740 { "max6651", 4 },
741 { }
742};
743MODULE_DEVICE_TABLE(i2c, max6650_id);
744
745static struct i2c_driver max6650_driver = {
746 .driver = {
747 .name = "max6650",
748 .of_match_table = of_match_ptr(max6650_dt_match),
749 },
750 .probe = max6650_probe,
751 .id_table = max6650_id,
752};
753
754module_i2c_driver(max6650_driver);
755
756MODULE_AUTHOR("Hans J. Koch");
757MODULE_DESCRIPTION("MAX6650 sensor driver");
758MODULE_LICENSE("GPL");