aboutsummaryrefslogtreecommitdiff
path: root/drivers/hwmon/max31790.c
blob: 7e9362f6dc29ee9c6ed79bd5c9973cedc43e937c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
 *             monitoring.
 *
 * (C) 2015 by Il Han <corone.il.han@gmail.com>
 */

#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/slab.h>

/* MAX31790 registers */
#define MAX31790_REG_GLOBAL_CONFIG	0x00
#define MAX31790_REG_FAN_CONFIG(ch)	(0x02 + (ch))
#define MAX31790_REG_FAN_DYNAMICS(ch)	(0x08 + (ch))
#define MAX31790_REG_FAN_FAULT_STATUS2	0x10
#define MAX31790_REG_FAN_FAULT_STATUS1	0x11
#define MAX31790_REG_TACH_COUNT(ch)	(0x18 + (ch) * 2)
#define MAX31790_REG_PWM_DUTY_CYCLE(ch)	(0x30 + (ch) * 2)
#define MAX31790_REG_PWMOUT(ch)		(0x40 + (ch) * 2)
#define MAX31790_REG_TARGET_COUNT(ch)	(0x50 + (ch) * 2)

/* Fan Config register bits */
#define MAX31790_FAN_CFG_RPM_MODE	0x80
#define MAX31790_FAN_CFG_CTRL_MON	0x10
#define MAX31790_FAN_CFG_TACH_INPUT_EN	0x08
#define MAX31790_FAN_CFG_TACH_INPUT	0x01

/* Fan Dynamics register bits */
#define MAX31790_FAN_DYN_SR_SHIFT	5
#define MAX31790_FAN_DYN_SR_MASK	0xE0
#define SR_FROM_REG(reg)		(((reg) & MAX31790_FAN_DYN_SR_MASK) \
					 >> MAX31790_FAN_DYN_SR_SHIFT)

#define FAN_RPM_MIN			120
#define FAN_RPM_MAX			7864320

#define FAN_COUNT_REG_MAX		0xffe0

#define RPM_FROM_REG(reg, sr)		(((reg) >> 4) ? \
					 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
					 FAN_RPM_MAX)
#define RPM_TO_REG(rpm, sr)		((60 * (sr) * 8192) / ((rpm) * 2))

#define NR_CHANNEL			6

/*
 * Client data (each client gets its own)
 */
struct max31790_data {
	struct i2c_client *client;
	struct mutex update_lock;
	bool valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* register values */
	u8 fan_config[NR_CHANNEL];
	u8 fan_dynamics[NR_CHANNEL];
	u16 fault_status;
	u16 tach[NR_CHANNEL * 2];
	u16 pwm[NR_CHANNEL];
	u16 target_count[NR_CHANNEL];
};

static struct max31790_data *max31790_update_device(struct device *dev)
{
	struct max31790_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	struct max31790_data *ret = data;
	int i;
	int rv;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
		rv = i2c_smbus_read_byte_data(client,
				MAX31790_REG_FAN_FAULT_STATUS1);
		if (rv < 0)
			goto abort;
		data->fault_status |= rv & 0x3F;

		rv = i2c_smbus_read_byte_data(client,
				MAX31790_REG_FAN_FAULT_STATUS2);
		if (rv < 0)
			goto abort;
		data->fault_status |= (rv & 0x3F) << 6;

		for (i = 0; i < NR_CHANNEL; i++) {
			rv = i2c_smbus_read_word_swapped(client,
					MAX31790_REG_TACH_COUNT(i));
			if (rv < 0)
				goto abort;
			data->tach[i] = rv;

			if (data->fan_config[i]
			    & MAX31790_FAN_CFG_TACH_INPUT) {
				rv = i2c_smbus_read_word_swapped(client,
					MAX31790_REG_TACH_COUNT(NR_CHANNEL
								+ i));
				if (rv < 0)
					goto abort;
				data->tach[NR_CHANNEL + i] = rv;
			} else {
				rv = i2c_smbus_read_word_swapped(client,
						MAX31790_REG_PWM_DUTY_CYCLE(i));
				if (rv < 0)
					goto abort;
				data->pwm[i] = rv;

				rv = i2c_smbus_read_word_swapped(client,
						MAX31790_REG_TARGET_COUNT(i));
				if (rv < 0)
					goto abort;
				data->target_count[i] = rv;
			}
		}

		data->last_updated = jiffies;
		data->valid = true;
	}
	goto done;

abort:
	data->valid = false;
	ret = ERR_PTR(rv);

done:
	mutex_unlock(&data->update_lock);

	return ret;
}

static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };

static u8 get_tach_period(u8 fan_dynamics)
{
	return tach_period[SR_FROM_REG(fan_dynamics)];
}

static u8 bits_for_tach_period(int rpm)
{
	u8 bits;

	if (rpm < 500)
		bits = 0x0;
	else if (rpm < 1000)
		bits = 0x1;
	else if (rpm < 2000)
		bits = 0x2;
	else if (rpm < 4000)
		bits = 0x3;
	else if (rpm < 8000)
		bits = 0x4;
	else
		bits = 0x5;

	return bits;
}

static int max31790_read_fan(struct device *dev, u32 attr, int channel,
			     long *val)
{
	struct max31790_data *data = max31790_update_device(dev);
	int sr, rpm;

	if (IS_ERR(data))
		return PTR_ERR(data);

	switch (attr) {
	case hwmon_fan_input:
		sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]);
		if (data->tach[channel] == FAN_COUNT_REG_MAX)
			rpm = 0;
		else
			rpm = RPM_FROM_REG(data->tach[channel], sr);
		*val = rpm;
		return 0;
	case hwmon_fan_target:
		sr = get_tach_period(data->fan_dynamics[channel]);
		rpm = RPM_FROM_REG(data->target_count[channel], sr);
		*val = rpm;
		return 0;
	case hwmon_fan_fault:
		mutex_lock(&data->update_lock);
		*val = !!(data->fault_status & (1 << channel));
		data->fault_status &= ~(1 << channel);
		/*
		 * If a fault bit is set, we need to write into one of the fan
		 * configuration registers to clear it. Note that this also
		 * clears the fault for the companion channel if enabled.
		 */
		if (*val) {
			int reg = MAX31790_REG_TARGET_COUNT(channel % NR_CHANNEL);

			i2c_smbus_write_byte_data(data->client, reg,
						  data->target_count[channel % NR_CHANNEL] >> 8);
		}
		mutex_unlock(&data->update_lock);
		return 0;
	default:
		return -EOPNOTSUPP;
	}
}

static int max31790_write_fan(struct device *dev, u32 attr, int channel,
			      long val)
{
	struct max31790_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int target_count;
	int err = 0;
	u8 bits;
	int sr;

	mutex_lock(&data->update_lock);

	switch (attr) {
	case hwmon_fan_target:
		val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
		bits = bits_for_tach_period(val);
		data->fan_dynamics[channel] =
			((data->fan_dynamics[channel] &
			  ~MAX31790_FAN_DYN_SR_MASK) |
			 (bits << MAX31790_FAN_DYN_SR_SHIFT));
		err = i2c_smbus_write_byte_data(client,
					MAX31790_REG_FAN_DYNAMICS(channel),
					data->fan_dynamics[channel]);
		if (err < 0)
			break;

		sr = get_tach_period(data->fan_dynamics[channel]);
		target_count = RPM_TO_REG(val, sr);
		target_count = clamp_val(target_count, 0x1, 0x7FF);

		data->target_count[channel] = target_count << 5;

		err = i2c_smbus_write_word_swapped(client,
					MAX31790_REG_TARGET_COUNT(channel),
					data->target_count[channel]);
		break;
	default:
		err = -EOPNOTSUPP;
		break;
	}

	mutex_unlock(&data->update_lock);

	return err;
}

static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
{
	const struct max31790_data *data = _data;
	u8 fan_config = data->fan_config[channel % NR_CHANNEL];

	switch (attr) {
	case hwmon_fan_input:
	case hwmon_fan_fault:
		if (channel < NR_CHANNEL ||
		    (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
			return 0444;
		return 0;
	case hwmon_fan_target:
		if (channel < NR_CHANNEL &&
		    !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
			return 0644;
		return 0;
	default:
		return 0;
	}
}

static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
			     long *val)
{
	struct max31790_data *data = max31790_update_device(dev);
	u8 fan_config;

	if (IS_ERR(data))
		return PTR_ERR(data);

	fan_config = data->fan_config[channel];

	switch (attr) {
	case hwmon_pwm_input:
		*val = data->pwm[channel] >> 8;
		return 0;
	case hwmon_pwm_enable:
		if (fan_config & MAX31790_FAN_CFG_CTRL_MON)
			*val = 0;
		else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
			*val = 2;
		else
			*val = 1;
		return 0;
	default:
		return -EOPNOTSUPP;
	}
}

static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
			      long val)
{
	struct max31790_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	u8 fan_config;
	int err = 0;

	mutex_lock(&data->update_lock);

	switch (attr) {
	case hwmon_pwm_input:
		if (val < 0 || val > 255) {
			err = -EINVAL;
			break;
		}
		data->valid = false;
		err = i2c_smbus_write_word_swapped(client,
						   MAX31790_REG_PWMOUT(channel),
						   val << 8);
		break;
	case hwmon_pwm_enable:
		fan_config = data->fan_config[channel];
		if (val == 0) {
			fan_config |= MAX31790_FAN_CFG_CTRL_MON;
			/*
			 * Disable RPM mode; otherwise disabling fan speed
			 * monitoring is not possible.
			 */
			fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
		} else if (val == 1) {
			fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
		} else if (val == 2) {
			fan_config &= ~MAX31790_FAN_CFG_CTRL_MON;
			/*
			 * The chip sets MAX31790_FAN_CFG_TACH_INPUT_EN on its
			 * own if MAX31790_FAN_CFG_RPM_MODE is set.
			 * Do it here as well to reflect the actual register
			 * value in the cache.
			 */
			fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);
		} else {
			err = -EINVAL;
			break;
		}
		if (fan_config != data->fan_config[channel]) {
			err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
							fan_config);
			if (!err)
				data->fan_config[channel] = fan_config;
		}
		break;
	default:
		err = -EOPNOTSUPP;
		break;
	}

	mutex_unlock(&data->update_lock);

	return err;
}

static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
{
	const struct max31790_data *data = _data;
	u8 fan_config = data->fan_config[channel];

	switch (attr) {
	case hwmon_pwm_input:
	case hwmon_pwm_enable:
		if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
			return 0644;
		return 0;
	default:
		return 0;
	}
}

static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
			 u32 attr, int channel, long *val)
{
	switch (type) {
	case hwmon_fan:
		return max31790_read_fan(dev, attr, channel, val);
	case hwmon_pwm:
		return max31790_read_pwm(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
			  u32 attr, int channel, long val)
{
	switch (type) {
	case hwmon_fan:
		return max31790_write_fan(dev, attr, channel, val);
	case hwmon_pwm:
		return max31790_write_pwm(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static umode_t max31790_is_visible(const void *data,
				   enum hwmon_sensor_types type,
				   u32 attr, int channel)
{
	switch (type) {
	case hwmon_fan:
		return max31790_fan_is_visible(data, attr, channel);
	case hwmon_pwm:
		return max31790_pwm_is_visible(data, attr, channel);
	default:
		return 0;
	}
}

static const struct hwmon_channel_info *max31790_info[] = {
	HWMON_CHANNEL_INFO(fan,
			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_FAULT,
			   HWMON_F_INPUT | HWMON_F_FAULT),
	HWMON_CHANNEL_INFO(pwm,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
	NULL
};

static const struct hwmon_ops max31790_hwmon_ops = {
	.is_visible = max31790_is_visible,
	.read = max31790_read,
	.write = max31790_write,
};

static const struct hwmon_chip_info max31790_chip_info = {
	.ops = &max31790_hwmon_ops,
	.info = max31790_info,
};

static int max31790_init_client(struct i2c_client *client,
				struct max31790_data *data)
{
	int i, rv;

	for (i = 0; i < NR_CHANNEL; i++) {
		rv = i2c_smbus_read_byte_data(client,
				MAX31790_REG_FAN_CONFIG(i));
		if (rv < 0)
			return rv;
		data->fan_config[i] = rv;

		rv = i2c_smbus_read_byte_data(client,
				MAX31790_REG_FAN_DYNAMICS(i));
		if (rv < 0)
			return rv;
		data->fan_dynamics[i] = rv;
	}

	return 0;
}

static int max31790_probe(struct i2c_client *client)
{
	struct i2c_adapter *adapter = client->adapter;
	struct device *dev = &client->dev;
	struct max31790_data *data;
	struct device *hwmon_dev;
	int err;

	if (!i2c_check_functionality(adapter,
			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->client = client;
	mutex_init(&data->update_lock);

	/*
	 * Initialize the max31790 chip
	 */
	err = max31790_init_client(client, data);
	if (err)
		return err;

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 data,
							 &max31790_chip_info,
							 NULL);

	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id max31790_id[] = {
	{ "max31790", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, max31790_id);

static struct i2c_driver max31790_driver = {
	.class		= I2C_CLASS_HWMON,
	.probe_new	= max31790_probe,
	.driver = {
		.name	= "max31790",
	},
	.id_table	= max31790_id,
};

module_i2c_driver(max31790_driver);

MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
MODULE_DESCRIPTION("MAX31790 sensor driver");
MODULE_LICENSE("GPL");