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1/*
2 * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
3 * monitoring.
4 *
5 * (C) 2015 by Il Han <corone.il.han@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/err.h>
19#include <linux/hwmon.h>
20#include <linux/i2c.h>
21#include <linux/init.h>
22#include <linux/jiffies.h>
23#include <linux/module.h>
24#include <linux/slab.h>
25
26/* MAX31790 registers */
27#define MAX31790_REG_GLOBAL_CONFIG 0x00
28#define MAX31790_REG_FAN_CONFIG(ch) (0x02 + (ch))
29#define MAX31790_REG_FAN_DYNAMICS(ch) (0x08 + (ch))
30#define MAX31790_REG_FAN_FAULT_STATUS2 0x10
31#define MAX31790_REG_FAN_FAULT_STATUS1 0x11
32#define MAX31790_REG_TACH_COUNT(ch) (0x18 + (ch) * 2)
33#define MAX31790_REG_PWM_DUTY_CYCLE(ch) (0x30 + (ch) * 2)
34#define MAX31790_REG_PWMOUT(ch) (0x40 + (ch) * 2)
35#define MAX31790_REG_TARGET_COUNT(ch) (0x50 + (ch) * 2)
36
37/* Fan Config register bits */
38#define MAX31790_FAN_CFG_RPM_MODE 0x80
39#define MAX31790_FAN_CFG_TACH_INPUT_EN 0x08
40#define MAX31790_FAN_CFG_TACH_INPUT 0x01
41
42/* Fan Dynamics register bits */
43#define MAX31790_FAN_DYN_SR_SHIFT 5
44#define MAX31790_FAN_DYN_SR_MASK 0xE0
45#define SR_FROM_REG(reg) (((reg) & MAX31790_FAN_DYN_SR_MASK) \
46 >> MAX31790_FAN_DYN_SR_SHIFT)
47
48#define FAN_RPM_MIN 120
49#define FAN_RPM_MAX 7864320
50
51#define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \
52 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
53 FAN_RPM_MAX)
54#define RPM_TO_REG(rpm, sr) ((60 * (sr) * 8192) / ((rpm) * 2))
55
56#define NR_CHANNEL 6
57
58/*
59 * Client data (each client gets its own)
60 */
61struct max31790_data {
62 struct i2c_client *client;
63 struct mutex update_lock;
64 bool valid; /* zero until following fields are valid */
65 unsigned long last_updated; /* in jiffies */
66
67 /* register values */
68 u8 fan_config[NR_CHANNEL];
69 u8 fan_dynamics[NR_CHANNEL];
70 u16 fault_status;
71 u16 tach[NR_CHANNEL * 2];
72 u16 pwm[NR_CHANNEL];
73 u16 target_count[NR_CHANNEL];
74};
75
76static struct max31790_data *max31790_update_device(struct device *dev)
77{
78 struct max31790_data *data = dev_get_drvdata(dev);
79 struct i2c_client *client = data->client;
80 struct max31790_data *ret = data;
81 int i;
82 int rv;
83
84 mutex_lock(&data->update_lock);
85
86 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
87 rv = i2c_smbus_read_byte_data(client,
88 MAX31790_REG_FAN_FAULT_STATUS1);
89 if (rv < 0)
90 goto abort;
91 data->fault_status = rv & 0x3F;
92
93 rv = i2c_smbus_read_byte_data(client,
94 MAX31790_REG_FAN_FAULT_STATUS2);
95 if (rv < 0)
96 goto abort;
97 data->fault_status |= (rv & 0x3F) << 6;
98
99 for (i = 0; i < NR_CHANNEL; i++) {
100 rv = i2c_smbus_read_word_swapped(client,
101 MAX31790_REG_TACH_COUNT(i));
102 if (rv < 0)
103 goto abort;
104 data->tach[i] = rv;
105
106 if (data->fan_config[i]
107 & MAX31790_FAN_CFG_TACH_INPUT) {
108 rv = i2c_smbus_read_word_swapped(client,
109 MAX31790_REG_TACH_COUNT(NR_CHANNEL
110 + i));
111 if (rv < 0)
112 goto abort;
113 data->tach[NR_CHANNEL + i] = rv;
114 } else {
115 rv = i2c_smbus_read_word_swapped(client,
116 MAX31790_REG_PWMOUT(i));
117 if (rv < 0)
118 goto abort;
119 data->pwm[i] = rv;
120
121 rv = i2c_smbus_read_word_swapped(client,
122 MAX31790_REG_TARGET_COUNT(i));
123 if (rv < 0)
124 goto abort;
125 data->target_count[i] = rv;
126 }
127 }
128
129 data->last_updated = jiffies;
130 data->valid = true;
131 }
132 goto done;
133
134abort:
135 data->valid = false;
136 ret = ERR_PTR(rv);
137
138done:
139 mutex_unlock(&data->update_lock);
140
141 return ret;
142}
143
144static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
145
146static u8 get_tach_period(u8 fan_dynamics)
147{
148 return tach_period[SR_FROM_REG(fan_dynamics)];
149}
150
151static u8 bits_for_tach_period(int rpm)
152{
153 u8 bits;
154
155 if (rpm < 500)
156 bits = 0x0;
157 else if (rpm < 1000)
158 bits = 0x1;
159 else if (rpm < 2000)
160 bits = 0x2;
161 else if (rpm < 4000)
162 bits = 0x3;
163 else if (rpm < 8000)
164 bits = 0x4;
165 else
166 bits = 0x5;
167
168 return bits;
169}
170
171static int max31790_read_fan(struct device *dev, u32 attr, int channel,
172 long *val)
173{
174 struct max31790_data *data = max31790_update_device(dev);
175 int sr, rpm;
176
177 if (IS_ERR(data))
178 return PTR_ERR(data);
179
180 switch (attr) {
181 case hwmon_fan_input:
182 sr = get_tach_period(data->fan_dynamics[channel]);
183 rpm = RPM_FROM_REG(data->tach[channel], sr);
184 *val = rpm;
185 return 0;
186 case hwmon_fan_target:
187 sr = get_tach_period(data->fan_dynamics[channel]);
188 rpm = RPM_FROM_REG(data->target_count[channel], sr);
189 *val = rpm;
190 return 0;
191 case hwmon_fan_fault:
192 *val = !!(data->fault_status & (1 << channel));
193 return 0;
194 default:
195 return -EOPNOTSUPP;
196 }
197}
198
199static int max31790_write_fan(struct device *dev, u32 attr, int channel,
200 long val)
201{
202 struct max31790_data *data = dev_get_drvdata(dev);
203 struct i2c_client *client = data->client;
204 int target_count;
205 int err = 0;
206 u8 bits;
207 int sr;
208
209 mutex_lock(&data->update_lock);
210
211 switch (attr) {
212 case hwmon_fan_target:
213 val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
214 bits = bits_for_tach_period(val);
215 data->fan_dynamics[channel] =
216 ((data->fan_dynamics[channel] &
217 ~MAX31790_FAN_DYN_SR_MASK) |
218 (bits << MAX31790_FAN_DYN_SR_SHIFT));
219 err = i2c_smbus_write_byte_data(client,
220 MAX31790_REG_FAN_DYNAMICS(channel),
221 data->fan_dynamics[channel]);
222 if (err < 0)
223 break;
224
225 sr = get_tach_period(data->fan_dynamics[channel]);
226 target_count = RPM_TO_REG(val, sr);
227 target_count = clamp_val(target_count, 0x1, 0x7FF);
228
229 data->target_count[channel] = target_count << 5;
230
231 err = i2c_smbus_write_word_swapped(client,
232 MAX31790_REG_TARGET_COUNT(channel),
233 data->target_count[channel]);
234 break;
235 default:
236 err = -EOPNOTSUPP;
237 break;
238 }
239
240 mutex_unlock(&data->update_lock);
241
242 return err;
243}
244
245static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
246{
247 const struct max31790_data *data = _data;
248 u8 fan_config = data->fan_config[channel % NR_CHANNEL];
249
250 switch (attr) {
251 case hwmon_fan_input:
252 case hwmon_fan_fault:
253 if (channel < NR_CHANNEL ||
254 (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
255 return S_IRUGO;
256 return 0;
257 case hwmon_fan_target:
258 if (channel < NR_CHANNEL &&
259 !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
260 return S_IRUGO | S_IWUSR;
261 return 0;
262 default:
263 return 0;
264 }
265}
266
267static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
268 long *val)
269{
270 struct max31790_data *data = max31790_update_device(dev);
271 u8 fan_config;
272
273 if (IS_ERR(data))
274 return PTR_ERR(data);
275
276 fan_config = data->fan_config[channel];
277
278 switch (attr) {
279 case hwmon_pwm_input:
280 *val = data->pwm[channel] >> 8;
281 return 0;
282 case hwmon_pwm_enable:
283 if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
284 *val = 2;
285 else if (fan_config & MAX31790_FAN_CFG_TACH_INPUT_EN)
286 *val = 1;
287 else
288 *val = 0;
289 return 0;
290 default:
291 return -EOPNOTSUPP;
292 }
293}
294
295static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
296 long val)
297{
298 struct max31790_data *data = dev_get_drvdata(dev);
299 struct i2c_client *client = data->client;
300 u8 fan_config;
301 int err = 0;
302
303 mutex_lock(&data->update_lock);
304
305 switch (attr) {
306 case hwmon_pwm_input:
307 if (val < 0 || val > 255) {
308 err = -EINVAL;
309 break;
310 }
311 data->pwm[channel] = val << 8;
312 err = i2c_smbus_write_word_swapped(client,
313 MAX31790_REG_PWMOUT(channel),
314 val);
315 break;
316 case hwmon_pwm_enable:
317 fan_config = data->fan_config[channel];
318 if (val == 0) {
319 fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
320 MAX31790_FAN_CFG_RPM_MODE);
321 } else if (val == 1) {
322 fan_config = (fan_config |
323 MAX31790_FAN_CFG_TACH_INPUT_EN) &
324 ~MAX31790_FAN_CFG_RPM_MODE;
325 } else if (val == 2) {
326 fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
327 MAX31790_FAN_CFG_RPM_MODE;
328 } else {
329 err = -EINVAL;
330 break;
331 }
332 data->fan_config[channel] = fan_config;
333 err = i2c_smbus_write_byte_data(client,
334 MAX31790_REG_FAN_CONFIG(channel),
335 fan_config);
336 break;
337 default:
338 err = -EOPNOTSUPP;
339 break;
340 }
341
342 mutex_unlock(&data->update_lock);
343
344 return err;
345}
346
347static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
348{
349 const struct max31790_data *data = _data;
350 u8 fan_config = data->fan_config[channel];
351
352 switch (attr) {
353 case hwmon_pwm_input:
354 case hwmon_pwm_enable:
355 if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
356 return S_IRUGO | S_IWUSR;
357 return 0;
358 default:
359 return 0;
360 }
361}
362
363static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
364 u32 attr, int channel, long *val)
365{
366 switch (type) {
367 case hwmon_fan:
368 return max31790_read_fan(dev, attr, channel, val);
369 case hwmon_pwm:
370 return max31790_read_pwm(dev, attr, channel, val);
371 default:
372 return -EOPNOTSUPP;
373 }
374}
375
376static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
377 u32 attr, int channel, long val)
378{
379 switch (type) {
380 case hwmon_fan:
381 return max31790_write_fan(dev, attr, channel, val);
382 case hwmon_pwm:
383 return max31790_write_pwm(dev, attr, channel, val);
384 default:
385 return -EOPNOTSUPP;
386 }
387}
388
389static umode_t max31790_is_visible(const void *data,
390 enum hwmon_sensor_types type,
391 u32 attr, int channel)
392{
393 switch (type) {
394 case hwmon_fan:
395 return max31790_fan_is_visible(data, attr, channel);
396 case hwmon_pwm:
397 return max31790_pwm_is_visible(data, attr, channel);
398 default:
399 return 0;
400 }
401}
402
403static const u32 max31790_fan_config[] = {
404 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
405 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
406 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
407 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
408 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
409 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
410 HWMON_F_INPUT | HWMON_F_FAULT,
411 HWMON_F_INPUT | HWMON_F_FAULT,
412 HWMON_F_INPUT | HWMON_F_FAULT,
413 HWMON_F_INPUT | HWMON_F_FAULT,
414 HWMON_F_INPUT | HWMON_F_FAULT,
415 HWMON_F_INPUT | HWMON_F_FAULT,
416 0
417};
418
419static const struct hwmon_channel_info max31790_fan = {
420 .type = hwmon_fan,
421 .config = max31790_fan_config,
422};
423
424static const u32 max31790_pwm_config[] = {
425 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
426 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
427 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
428 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
429 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
430 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
431 0
432};
433
434static const struct hwmon_channel_info max31790_pwm = {
435 .type = hwmon_pwm,
436 .config = max31790_pwm_config,
437};
438
439static const struct hwmon_channel_info *max31790_info[] = {
440 &max31790_fan,
441 &max31790_pwm,
442 NULL
443};
444
445static const struct hwmon_ops max31790_hwmon_ops = {
446 .is_visible = max31790_is_visible,
447 .read = max31790_read,
448 .write = max31790_write,
449};
450
451static const struct hwmon_chip_info max31790_chip_info = {
452 .ops = &max31790_hwmon_ops,
453 .info = max31790_info,
454};
455
456static int max31790_init_client(struct i2c_client *client,
457 struct max31790_data *data)
458{
459 int i, rv;
460
461 for (i = 0; i < NR_CHANNEL; i++) {
462 rv = i2c_smbus_read_byte_data(client,
463 MAX31790_REG_FAN_CONFIG(i));
464 if (rv < 0)
465 return rv;
466 data->fan_config[i] = rv;
467
468 rv = i2c_smbus_read_byte_data(client,
469 MAX31790_REG_FAN_DYNAMICS(i));
470 if (rv < 0)
471 return rv;
472 data->fan_dynamics[i] = rv;
473 }
474
475 return 0;
476}
477
478static int max31790_probe(struct i2c_client *client,
479 const struct i2c_device_id *id)
480{
481 struct i2c_adapter *adapter = client->adapter;
482 struct device *dev = &client->dev;
483 struct max31790_data *data;
484 struct device *hwmon_dev;
485 int err;
486
487 if (!i2c_check_functionality(adapter,
488 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
489 return -ENODEV;
490
491 data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
492 if (!data)
493 return -ENOMEM;
494
495 data->client = client;
496 mutex_init(&data->update_lock);
497
498 /*
499 * Initialize the max31790 chip
500 */
501 err = max31790_init_client(client, data);
502 if (err)
503 return err;
504
505 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
506 data,
507 &max31790_chip_info,
508 NULL);
509
510 return PTR_ERR_OR_ZERO(hwmon_dev);
511}
512
513static const struct i2c_device_id max31790_id[] = {
514 { "max31790", 0 },
515 { }
516};
517MODULE_DEVICE_TABLE(i2c, max31790_id);
518
519static struct i2c_driver max31790_driver = {
520 .class = I2C_CLASS_HWMON,
521 .probe = max31790_probe,
522 .driver = {
523 .name = "max31790",
524 },
525 .id_table = max31790_id,
526};
527
528module_i2c_driver(max31790_driver);
529
530MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
531MODULE_DESCRIPTION("MAX31790 sensor driver");
532MODULE_LICENSE("GPL");