sfc: Don't use enums as a bitmask.
[zen-stable.git] / drivers / hwmon / max6650.c
blob9a11532ecae84384d105e1f2c0b070a5107c0c3c
1 /*
2 * max6650.c - Part of lm_sensors, Linux kernel modules for hardware
3 * monitoring.
5 * (C) 2007 by Hans J. Koch <hjk@hansjkoch.de>
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>
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.
15 * The datasheet was last seen at:
17 * http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
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.
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.
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.
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>
44 * Addresses to scan. There are four disjoint possibilities, by pin config.
47 static const unsigned short normal_i2c[] = {0x1b, 0x1f, 0x48, 0x4b,
48 I2C_CLIENT_END};
51 * Insmod parameters
54 /* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */
55 static int fan_voltage;
56 /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
57 static int prescaler;
58 /* clock: The clock frequency of the chip the driver should assume */
59 static int clock = 254000;
61 module_param(fan_voltage, int, S_IRUGO);
62 module_param(prescaler, int, S_IRUGO);
63 module_param(clock, int, S_IRUGO);
66 * MAX 6650/6651 registers
69 #define MAX6650_REG_SPEED 0x00
70 #define MAX6650_REG_CONFIG 0x02
71 #define MAX6650_REG_GPIO_DEF 0x04
72 #define MAX6650_REG_DAC 0x06
73 #define MAX6650_REG_ALARM_EN 0x08
74 #define MAX6650_REG_ALARM 0x0A
75 #define MAX6650_REG_TACH0 0x0C
76 #define MAX6650_REG_TACH1 0x0E
77 #define MAX6650_REG_TACH2 0x10
78 #define MAX6650_REG_TACH3 0x12
79 #define MAX6650_REG_GPIO_STAT 0x14
80 #define MAX6650_REG_COUNT 0x16
83 * Config register bits
86 #define MAX6650_CFG_V12 0x08
87 #define MAX6650_CFG_PRESCALER_MASK 0x07
88 #define MAX6650_CFG_PRESCALER_2 0x01
89 #define MAX6650_CFG_PRESCALER_4 0x02
90 #define MAX6650_CFG_PRESCALER_8 0x03
91 #define MAX6650_CFG_PRESCALER_16 0x04
92 #define MAX6650_CFG_MODE_MASK 0x30
93 #define MAX6650_CFG_MODE_ON 0x00
94 #define MAX6650_CFG_MODE_OFF 0x10
95 #define MAX6650_CFG_MODE_CLOSED_LOOP 0x20
96 #define MAX6650_CFG_MODE_OPEN_LOOP 0x30
97 #define MAX6650_COUNT_MASK 0x03
100 * Alarm status register bits
103 #define MAX6650_ALRM_MAX 0x01
104 #define MAX6650_ALRM_MIN 0x02
105 #define MAX6650_ALRM_TACH 0x04
106 #define MAX6650_ALRM_GPIO1 0x08
107 #define MAX6650_ALRM_GPIO2 0x10
109 /* Minimum and maximum values of the FAN-RPM */
110 #define FAN_RPM_MIN 240
111 #define FAN_RPM_MAX 30000
113 #define DIV_FROM_REG(reg) (1 << (reg & 7))
115 static int max6650_probe(struct i2c_client *client,
116 const struct i2c_device_id *id);
117 static int max6650_detect(struct i2c_client *client,
118 struct i2c_board_info *info);
119 static int max6650_init_client(struct i2c_client *client);
120 static int max6650_remove(struct i2c_client *client);
121 static struct max6650_data *max6650_update_device(struct device *dev);
124 * Driver data (common to all clients)
127 static const struct i2c_device_id max6650_id[] = {
128 { "max6650", 0 },
131 MODULE_DEVICE_TABLE(i2c, max6650_id);
133 static struct i2c_driver max6650_driver = {
134 .class = I2C_CLASS_HWMON,
135 .driver = {
136 .name = "max6650",
138 .probe = max6650_probe,
139 .remove = max6650_remove,
140 .id_table = max6650_id,
141 .detect = max6650_detect,
142 .address_list = normal_i2c,
146 * Client data (each client gets its own)
149 struct max6650_data
151 struct device *hwmon_dev;
152 struct mutex update_lock;
153 char valid; /* zero until following fields are valid */
154 unsigned long last_updated; /* in jiffies */
156 /* register values */
157 u8 speed;
158 u8 config;
159 u8 tach[4];
160 u8 count;
161 u8 dac;
162 u8 alarm;
165 static ssize_t get_fan(struct device *dev, struct device_attribute *devattr,
166 char *buf)
168 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
169 struct max6650_data *data = max6650_update_device(dev);
170 int rpm;
173 * Calculation details:
175 * Each tachometer counts over an interval given by the "count"
176 * register (0.25, 0.5, 1 or 2 seconds). This module assumes
177 * that the fans produce two pulses per revolution (this seems
178 * to be the most common).
181 rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count));
182 return sprintf(buf, "%d\n", rpm);
186 * Set the fan speed to the specified RPM (or read back the RPM setting).
187 * This works in closed loop mode only. Use pwm1 for open loop speed setting.
189 * The MAX6650/1 will automatically control fan speed when in closed loop
190 * mode.
192 * Assumptions:
194 * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use
195 * the clock module parameter if you need to fine tune this.
197 * 2) The prescaler (low three bits of the config register) has already
198 * been set to an appropriate value. Use the prescaler module parameter
199 * if your BIOS doesn't initialize the chip properly.
201 * The relevant equations are given on pages 21 and 22 of the datasheet.
203 * From the datasheet, the relevant equation when in regulation is:
205 * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE
207 * where:
209 * fCLK is the oscillator frequency (either the 254kHz internal
210 * oscillator or the externally applied clock)
212 * KTACH is the value in the speed register
214 * FanSpeed is the speed of the fan in rps
216 * KSCALE is the prescaler value (1, 2, 4, 8, or 16)
218 * When reading, we need to solve for FanSpeed. When writing, we need to
219 * solve for KTACH.
221 * Note: this tachometer is completely separate from the tachometers
222 * used to measure the fan speeds. Only one fan's speed (fan1) is
223 * controlled.
226 static ssize_t get_target(struct device *dev, struct device_attribute *devattr,
227 char *buf)
229 struct max6650_data *data = max6650_update_device(dev);
230 int kscale, ktach, rpm;
233 * Use the datasheet equation:
235 * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
237 * then multiply by 60 to give rpm.
240 kscale = DIV_FROM_REG(data->config);
241 ktach = data->speed;
242 rpm = 60 * kscale * clock / (256 * (ktach + 1));
243 return sprintf(buf, "%d\n", rpm);
246 static ssize_t set_target(struct device *dev, struct device_attribute *devattr,
247 const char *buf, size_t count)
249 struct i2c_client *client = to_i2c_client(dev);
250 struct max6650_data *data = i2c_get_clientdata(client);
251 int rpm = simple_strtoul(buf, NULL, 10);
252 int kscale, ktach;
254 rpm = SENSORS_LIMIT(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
257 * Divide the required speed by 60 to get from rpm to rps, then
258 * use the datasheet equation:
260 * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1
263 mutex_lock(&data->update_lock);
265 kscale = DIV_FROM_REG(data->config);
266 ktach = ((clock * kscale) / (256 * rpm / 60)) - 1;
267 if (ktach < 0)
268 ktach = 0;
269 if (ktach > 255)
270 ktach = 255;
271 data->speed = ktach;
273 i2c_smbus_write_byte_data(client, MAX6650_REG_SPEED, data->speed);
275 mutex_unlock(&data->update_lock);
277 return count;
281 * Get/set the fan speed in open loop mode using pwm1 sysfs file.
282 * Speed is given as a relative value from 0 to 255, where 255 is maximum
283 * speed. Note that this is done by writing directly to the chip's DAC,
284 * it won't change the closed loop speed set by fan1_target.
285 * Also note that due to rounding errors it is possible that you don't read
286 * back exactly the value you have set.
289 static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr,
290 char *buf)
292 int pwm;
293 struct max6650_data *data = max6650_update_device(dev);
295 /* Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
296 Lower DAC values mean higher speeds. */
297 if (data->config & MAX6650_CFG_V12)
298 pwm = 255 - (255 * (int)data->dac)/180;
299 else
300 pwm = 255 - (255 * (int)data->dac)/76;
302 if (pwm < 0)
303 pwm = 0;
305 return sprintf(buf, "%d\n", pwm);
308 static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr,
309 const char *buf, size_t count)
311 struct i2c_client *client = to_i2c_client(dev);
312 struct max6650_data *data = i2c_get_clientdata(client);
313 int pwm = simple_strtoul(buf, NULL, 10);
315 pwm = SENSORS_LIMIT(pwm, 0, 255);
317 mutex_lock(&data->update_lock);
319 if (data->config & MAX6650_CFG_V12)
320 data->dac = 180 - (180 * pwm)/255;
321 else
322 data->dac = 76 - (76 * pwm)/255;
324 i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
326 mutex_unlock(&data->update_lock);
328 return count;
332 * Get/Set controller mode:
333 * Possible values:
334 * 0 = Fan always on
335 * 1 = Open loop, Voltage is set according to speed, not regulated.
336 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer
339 static ssize_t get_enable(struct device *dev, struct device_attribute *devattr,
340 char *buf)
342 struct max6650_data *data = max6650_update_device(dev);
343 int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;
344 int sysfs_modes[4] = {0, 1, 2, 1};
346 return sprintf(buf, "%d\n", sysfs_modes[mode]);
349 static ssize_t set_enable(struct device *dev, struct device_attribute *devattr,
350 const char *buf, size_t count)
352 struct i2c_client *client = to_i2c_client(dev);
353 struct max6650_data *data = i2c_get_clientdata(client);
354 int mode = simple_strtoul(buf, NULL, 10);
355 int max6650_modes[3] = {0, 3, 2};
357 if ((mode < 0)||(mode > 2)) {
358 dev_err(&client->dev,
359 "illegal value for pwm1_enable (%d)\n", mode);
360 return -EINVAL;
363 mutex_lock(&data->update_lock);
365 data->config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
366 data->config = (data->config & ~MAX6650_CFG_MODE_MASK)
367 | (max6650_modes[mode] << 4);
369 i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, data->config);
371 mutex_unlock(&data->update_lock);
373 return count;
377 * Read/write functions for fan1_div sysfs file. The MAX6650 has no such
378 * divider. We handle this by converting between divider and counttime:
380 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3
382 * Lower values of k allow to connect a faster fan without the risk of
383 * counter overflow. The price is lower resolution. You can also set counttime
384 * using the module parameter. Note that the module parameter "prescaler" also
385 * influences the behaviour. Unfortunately, there's no sysfs attribute
386 * defined for that. See the data sheet for details.
389 static ssize_t get_div(struct device *dev, struct device_attribute *devattr,
390 char *buf)
392 struct max6650_data *data = max6650_update_device(dev);
394 return sprintf(buf, "%d\n", DIV_FROM_REG(data->count));
397 static ssize_t set_div(struct device *dev, struct device_attribute *devattr,
398 const char *buf, size_t count)
400 struct i2c_client *client = to_i2c_client(dev);
401 struct max6650_data *data = i2c_get_clientdata(client);
402 int div = simple_strtoul(buf, NULL, 10);
404 mutex_lock(&data->update_lock);
405 switch (div) {
406 case 1:
407 data->count = 0;
408 break;
409 case 2:
410 data->count = 1;
411 break;
412 case 4:
413 data->count = 2;
414 break;
415 case 8:
416 data->count = 3;
417 break;
418 default:
419 mutex_unlock(&data->update_lock);
420 dev_err(&client->dev,
421 "illegal value for fan divider (%d)\n", div);
422 return -EINVAL;
425 i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count);
426 mutex_unlock(&data->update_lock);
428 return count;
432 * Get alarm stati:
433 * Possible values:
434 * 0 = no alarm
435 * 1 = alarm
438 static ssize_t get_alarm(struct device *dev, struct device_attribute *devattr,
439 char *buf)
441 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
442 struct max6650_data *data = max6650_update_device(dev);
443 struct i2c_client *client = to_i2c_client(dev);
444 int alarm = 0;
446 if (data->alarm & attr->index) {
447 mutex_lock(&data->update_lock);
448 alarm = 1;
449 data->alarm &= ~attr->index;
450 data->alarm |= i2c_smbus_read_byte_data(client,
451 MAX6650_REG_ALARM);
452 mutex_unlock(&data->update_lock);
455 return sprintf(buf, "%d\n", alarm);
458 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
459 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
460 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
461 static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3);
462 static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target);
463 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div);
464 static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable);
465 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
466 static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL,
467 MAX6650_ALRM_MAX);
468 static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL,
469 MAX6650_ALRM_MIN);
470 static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL,
471 MAX6650_ALRM_TACH);
472 static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL,
473 MAX6650_ALRM_GPIO1);
474 static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL,
475 MAX6650_ALRM_GPIO2);
477 static mode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a,
478 int n)
480 struct device *dev = container_of(kobj, struct device, kobj);
481 struct i2c_client *client = to_i2c_client(dev);
482 u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN);
483 struct device_attribute *devattr;
486 * Hide the alarms that have not been enabled by the firmware
489 devattr = container_of(a, struct device_attribute, attr);
490 if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr
491 || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr
492 || devattr == &sensor_dev_attr_fan1_fault.dev_attr
493 || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr
494 || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) {
495 if (!(alarm_en & to_sensor_dev_attr(devattr)->index))
496 return 0;
499 return a->mode;
502 static struct attribute *max6650_attrs[] = {
503 &sensor_dev_attr_fan1_input.dev_attr.attr,
504 &sensor_dev_attr_fan2_input.dev_attr.attr,
505 &sensor_dev_attr_fan3_input.dev_attr.attr,
506 &sensor_dev_attr_fan4_input.dev_attr.attr,
507 &dev_attr_fan1_target.attr,
508 &dev_attr_fan1_div.attr,
509 &dev_attr_pwm1_enable.attr,
510 &dev_attr_pwm1.attr,
511 &sensor_dev_attr_fan1_max_alarm.dev_attr.attr,
512 &sensor_dev_attr_fan1_min_alarm.dev_attr.attr,
513 &sensor_dev_attr_fan1_fault.dev_attr.attr,
514 &sensor_dev_attr_gpio1_alarm.dev_attr.attr,
515 &sensor_dev_attr_gpio2_alarm.dev_attr.attr,
516 NULL
519 static struct attribute_group max6650_attr_grp = {
520 .attrs = max6650_attrs,
521 .is_visible = max6650_attrs_visible,
525 * Real code
528 /* Return 0 if detection is successful, -ENODEV otherwise */
529 static int max6650_detect(struct i2c_client *client,
530 struct i2c_board_info *info)
532 struct i2c_adapter *adapter = client->adapter;
533 int address = client->addr;
535 dev_dbg(&adapter->dev, "max6650_detect called\n");
537 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
538 dev_dbg(&adapter->dev, "max6650: I2C bus doesn't support "
539 "byte read mode, skipping.\n");
540 return -ENODEV;
543 if (((i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG) & 0xC0)
544 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_GPIO_STAT) & 0xE0)
545 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN) & 0xE0)
546 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM) & 0xE0)
547 ||(i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT) & 0xFC))) {
548 dev_dbg(&adapter->dev,
549 "max6650: detection failed at 0x%02x.\n", address);
550 return -ENODEV;
553 dev_info(&adapter->dev, "max6650: chip found at 0x%02x.\n", address);
555 strlcpy(info->type, "max6650", I2C_NAME_SIZE);
557 return 0;
560 static int max6650_probe(struct i2c_client *client,
561 const struct i2c_device_id *id)
563 struct max6650_data *data;
564 int err;
566 if (!(data = kzalloc(sizeof(struct max6650_data), GFP_KERNEL))) {
567 dev_err(&client->dev, "out of memory.\n");
568 return -ENOMEM;
571 i2c_set_clientdata(client, data);
572 mutex_init(&data->update_lock);
575 * Initialize the max6650 chip
577 err = max6650_init_client(client);
578 if (err)
579 goto err_free;
581 err = sysfs_create_group(&client->dev.kobj, &max6650_attr_grp);
582 if (err)
583 goto err_free;
585 data->hwmon_dev = hwmon_device_register(&client->dev);
586 if (!IS_ERR(data->hwmon_dev))
587 return 0;
589 err = PTR_ERR(data->hwmon_dev);
590 dev_err(&client->dev, "error registering hwmon device.\n");
591 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp);
592 err_free:
593 kfree(data);
594 return err;
597 static int max6650_remove(struct i2c_client *client)
599 struct max6650_data *data = i2c_get_clientdata(client);
601 sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp);
602 hwmon_device_unregister(data->hwmon_dev);
603 kfree(data);
604 return 0;
607 static int max6650_init_client(struct i2c_client *client)
609 struct max6650_data *data = i2c_get_clientdata(client);
610 int config;
611 int err = -EIO;
613 config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
615 if (config < 0) {
616 dev_err(&client->dev, "Error reading config, aborting.\n");
617 return err;
620 switch (fan_voltage) {
621 case 0:
622 break;
623 case 5:
624 config &= ~MAX6650_CFG_V12;
625 break;
626 case 12:
627 config |= MAX6650_CFG_V12;
628 break;
629 default:
630 dev_err(&client->dev,
631 "illegal value for fan_voltage (%d)\n",
632 fan_voltage);
635 dev_info(&client->dev, "Fan voltage is set to %dV.\n",
636 (config & MAX6650_CFG_V12) ? 12 : 5);
638 switch (prescaler) {
639 case 0:
640 break;
641 case 1:
642 config &= ~MAX6650_CFG_PRESCALER_MASK;
643 break;
644 case 2:
645 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
646 | MAX6650_CFG_PRESCALER_2;
647 break;
648 case 4:
649 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
650 | MAX6650_CFG_PRESCALER_4;
651 break;
652 case 8:
653 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
654 | MAX6650_CFG_PRESCALER_8;
655 break;
656 case 16:
657 config = (config & ~MAX6650_CFG_PRESCALER_MASK)
658 | MAX6650_CFG_PRESCALER_16;
659 break;
660 default:
661 dev_err(&client->dev,
662 "illegal value for prescaler (%d)\n",
663 prescaler);
666 dev_info(&client->dev, "Prescaler is set to %d.\n",
667 1 << (config & MAX6650_CFG_PRESCALER_MASK));
669 /* If mode is set to "full off", we change it to "open loop" and
670 * set DAC to 255, which has the same effect. We do this because
671 * there's no "full off" mode defined in hwmon specifcations.
674 if ((config & MAX6650_CFG_MODE_MASK) == MAX6650_CFG_MODE_OFF) {
675 dev_dbg(&client->dev, "Change mode to open loop, full off.\n");
676 config = (config & ~MAX6650_CFG_MODE_MASK)
677 | MAX6650_CFG_MODE_OPEN_LOOP;
678 if (i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, 255)) {
679 dev_err(&client->dev, "DAC write error, aborting.\n");
680 return err;
684 if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) {
685 dev_err(&client->dev, "Config write error, aborting.\n");
686 return err;
689 data->config = config;
690 data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
692 return 0;
695 static const u8 tach_reg[] = {
696 MAX6650_REG_TACH0,
697 MAX6650_REG_TACH1,
698 MAX6650_REG_TACH2,
699 MAX6650_REG_TACH3,
702 static struct max6650_data *max6650_update_device(struct device *dev)
704 int i;
705 struct i2c_client *client = to_i2c_client(dev);
706 struct max6650_data *data = i2c_get_clientdata(client);
708 mutex_lock(&data->update_lock);
710 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
711 data->speed = i2c_smbus_read_byte_data(client,
712 MAX6650_REG_SPEED);
713 data->config = i2c_smbus_read_byte_data(client,
714 MAX6650_REG_CONFIG);
715 for (i = 0; i < 4; i++) {
716 data->tach[i] = i2c_smbus_read_byte_data(client,
717 tach_reg[i]);
719 data->count = i2c_smbus_read_byte_data(client,
720 MAX6650_REG_COUNT);
721 data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
723 /* Alarms are cleared on read in case the condition that
724 * caused the alarm is removed. Keep the value latched here
725 * for providing the register through different alarm files. */
726 data->alarm |= i2c_smbus_read_byte_data(client,
727 MAX6650_REG_ALARM);
729 data->last_updated = jiffies;
730 data->valid = 1;
733 mutex_unlock(&data->update_lock);
735 return data;
738 static int __init sensors_max6650_init(void)
740 return i2c_add_driver(&max6650_driver);
743 static void __exit sensors_max6650_exit(void)
745 i2c_del_driver(&max6650_driver);
748 MODULE_AUTHOR("Hans J. Koch");
749 MODULE_DESCRIPTION("MAX6650 sensor driver");
750 MODULE_LICENSE("GPL");
752 module_init(sensors_max6650_init);
753 module_exit(sensors_max6650_exit);