summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/tc654.c
blob: 42a9658f1bc2b79bdae577ea46d466ebbc85a17c (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
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * tc654.c - Linux kernel modules for fan speed controller
 *
 * Copyright (C) 2016 Allied Telesis Labs NZ
 */

#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/thermal.h>
#include <linux/util_macros.h>

enum tc654_regs {
	TC654_REG_RPM1 = 0x00,	/* RPM Output 1 */
	TC654_REG_RPM2 = 0x01,	/* RPM Output 2 */
	TC654_REG_FAN_FAULT1 = 0x02,	/* Fan Fault 1 Threshold */
	TC654_REG_FAN_FAULT2 = 0x03,	/* Fan Fault 2 Threshold */
	TC654_REG_CONFIG = 0x04,	/* Configuration */
	TC654_REG_STATUS = 0x05,	/* Status */
	TC654_REG_DUTY_CYCLE = 0x06,	/* Fan Speed Duty Cycle */
	TC654_REG_MFR_ID = 0x07,	/* Manufacturer Identification */
	TC654_REG_VER_ID = 0x08,	/* Version Identification */
};

/* Macros to easily index the registers */
#define TC654_REG_RPM(idx)		(TC654_REG_RPM1 + (idx))
#define TC654_REG_FAN_FAULT(idx)	(TC654_REG_FAN_FAULT1 + (idx))

/* Config register bits */
#define TC654_REG_CONFIG_RES		BIT(6)	/* Resolution Selection */
#define TC654_REG_CONFIG_DUTYC		BIT(5)	/* Duty Cycle Control */
#define TC654_REG_CONFIG_SDM		BIT(0)	/* Shutdown Mode */

/* Status register bits */
#define TC654_REG_STATUS_F2F		BIT(1)	/* Fan 2 Fault */
#define TC654_REG_STATUS_F1F		BIT(0)	/* Fan 1 Fault */

/* RPM resolution for RPM Output registers */
#define TC654_HIGH_RPM_RESOLUTION	25	/* 25 RPM resolution */
#define TC654_LOW_RPM_RESOLUTION	50	/* 50 RPM resolution */

/* Convert to the fan fault RPM threshold from register value */
#define TC654_FAN_FAULT_FROM_REG(val)	((val) * 50)	/* 50 RPM resolution */

/* Convert to register value from the fan fault RPM threshold */
#define TC654_FAN_FAULT_TO_REG(val)	(((val) / 50) & 0xff)

/* Register data is read (and cached) at most once per second. */
#define TC654_UPDATE_INTERVAL		HZ

struct tc654_data {
	struct i2c_client *client;

	/* update mutex */
	struct mutex update_lock;

	/* tc654 register cache */
	bool valid;
	unsigned long last_updated;	/* in jiffies */

	u8 rpm_output[2];	/* The fan RPM data for fans 1 and 2 is then
				 * written to registers RPM1 and RPM2
				 */
	u8 fan_fault[2];	/* The Fan Fault Threshold Registers are used to
				 * set the fan fault threshold levels for fan 1
				 * and fan 2
				 */
	u8 config;	/* The Configuration Register is an 8-bit read/
			 * writable multi-function control register
			 *   7: Fan Fault Clear
			 *      1 = Clear Fan Fault
			 *      0 = Normal Operation (default)
			 *   6: Resolution Selection for RPM Output Registers
			 *      RPM Output Registers (RPM1 and RPM2) will be
			 *      set for
			 *      1 = 25 RPM (9-bit) resolution
			 *      0 = 50 RPM (8-bit) resolution (default)
			 *   5: Duty Cycle Control Method
			 *      The V OUT duty cycle will be controlled via
			 *      1 = the SMBus interface.
			 *      0 = via the V IN analog input pin. (default)
			 * 4,3: Fan 2 Pulses Per Rotation
			 *      00 = 1
			 *      01 = 2 (default)
			 *      10 = 4
			 *      11 = 8
			 * 2,1: Fan 1 Pulses Per Rotation
			 *      00 = 1
			 *      01 = 2 (default)
			 *      10 = 4
			 *      11 = 8
			 *   0: Shutdown Mode
			 *      1 = Shutdown mode.
			 *      0 = Normal operation. (default)
			 */
	u8 status;	/* The Status register provides all the information
			 * about what is going on within the TC654/TC655
			 * devices.
			 * 7,6: Unimplemented, Read as '0'
			 *   5: Over-Temperature Fault Condition
			 *      1 = Over-Temperature condition has occurred
			 *      0 = Normal operation. V IN is less than 2.6V
			 *   4: RPM2 Counter Overflow
			 *      1 = Fault condition
			 *      0 = Normal operation
			 *   3: RPM1 Counter Overflow
			 *      1 = Fault condition
			 *      0 = Normal operation
			 *   2: V IN Input Status
			 *      1 = V IN is open
			 *      0 = Normal operation. voltage present at V IN
			 *   1: Fan 2 Fault
			 *      1 = Fault condition
			 *      0 = Normal operation
			 *   0: Fan 1 Fault
			 *      1 = Fault condition
			 *      0 = Normal operation
			 */
	u8 duty_cycle;	/* The DUTY_CYCLE register is a 4-bit read/
			 * writable register used to control the duty
			 * cycle of the V OUT output.
			 */
};

/* helper to grab and cache data, at most one time per second */
static struct tc654_data *tc654_update_client(struct device *dev)
{
	struct tc654_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret = 0;

	mutex_lock(&data->update_lock);
	if (time_before(jiffies, data->last_updated + TC654_UPDATE_INTERVAL) &&
	    likely(data->valid))
		goto out;

	ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(0));
	if (ret < 0)
		goto out;
	data->rpm_output[0] = ret;

	ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(1));
	if (ret < 0)
		goto out;
	data->rpm_output[1] = ret;

	ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(0));
	if (ret < 0)
		goto out;
	data->fan_fault[0] = ret;

	ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(1));
	if (ret < 0)
		goto out;
	data->fan_fault[1] = ret;

	ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG);
	if (ret < 0)
		goto out;
	data->config = ret;

	ret = i2c_smbus_read_byte_data(client, TC654_REG_STATUS);
	if (ret < 0)
		goto out;
	data->status = ret;

	ret = i2c_smbus_read_byte_data(client, TC654_REG_DUTY_CYCLE);
	if (ret < 0)
		goto out;
	data->duty_cycle = ret & 0x0f;

	data->last_updated = jiffies;
	data->valid = true;
out:
	mutex_unlock(&data->update_lock);

	if (ret < 0)		/* upon error, encode it in return value */
		data = ERR_PTR(ret);

	return data;
}

/*
 * sysfs attributes
 */

static ssize_t fan_show(struct device *dev, struct device_attribute *da,
			char *buf)
{
	int nr = to_sensor_dev_attr(da)->index;
	struct tc654_data *data = tc654_update_client(dev);
	int val;

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

	if (data->config & TC654_REG_CONFIG_RES)
		val = data->rpm_output[nr] * TC654_HIGH_RPM_RESOLUTION;
	else
		val = data->rpm_output[nr] * TC654_LOW_RPM_RESOLUTION;

	return sprintf(buf, "%d\n", val);
}

static ssize_t fan_min_show(struct device *dev, struct device_attribute *da,
			    char *buf)
{
	int nr = to_sensor_dev_attr(da)->index;
	struct tc654_data *data = tc654_update_client(dev);

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

	return sprintf(buf, "%d\n",
		       TC654_FAN_FAULT_FROM_REG(data->fan_fault[nr]));
}

static ssize_t fan_min_store(struct device *dev, struct device_attribute *da,
			     const char *buf, size_t count)
{
	int nr = to_sensor_dev_attr(da)->index;
	struct tc654_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	unsigned long val;
	int ret;

	if (kstrtoul(buf, 10, &val))
		return -EINVAL;

	val = clamp_val(val, 0, 12750);

	mutex_lock(&data->update_lock);

	data->fan_fault[nr] = TC654_FAN_FAULT_TO_REG(val);
	ret = i2c_smbus_write_byte_data(client, TC654_REG_FAN_FAULT(nr),
					data->fan_fault[nr]);

	mutex_unlock(&data->update_lock);
	return ret < 0 ? ret : count;
}

static ssize_t fan_alarm_show(struct device *dev, struct device_attribute *da,
			      char *buf)
{
	int nr = to_sensor_dev_attr(da)->index;
	struct tc654_data *data = tc654_update_client(dev);
	int val;

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

	if (nr == 0)
		val = !!(data->status & TC654_REG_STATUS_F1F);
	else
		val = !!(data->status & TC654_REG_STATUS_F2F);

	return sprintf(buf, "%d\n", val);
}

static const u8 TC654_FAN_PULSE_SHIFT[] = { 1, 3 };

static ssize_t fan_pulses_show(struct device *dev,
			       struct device_attribute *da, char *buf)
{
	int nr = to_sensor_dev_attr(da)->index;
	struct tc654_data *data = tc654_update_client(dev);
	u8 val;

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

	val = BIT((data->config >> TC654_FAN_PULSE_SHIFT[nr]) & 0x03);
	return sprintf(buf, "%d\n", val);
}

static ssize_t fan_pulses_store(struct device *dev,
				struct device_attribute *da, const char *buf,
				size_t count)
{
	int nr = to_sensor_dev_attr(da)->index;
	struct tc654_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	u8 config;
	unsigned long val;
	int ret;

	if (kstrtoul(buf, 10, &val))
		return -EINVAL;

	switch (val) {
	case 1:
		config = 0;
		break;
	case 2:
		config = 1;
		break;
	case 4:
		config = 2;
		break;
	case 8:
		config = 3;
		break;
	default:
		return -EINVAL;
	}

	mutex_lock(&data->update_lock);

	data->config &= ~(0x03 << TC654_FAN_PULSE_SHIFT[nr]);
	data->config |= (config << TC654_FAN_PULSE_SHIFT[nr]);
	ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);

	mutex_unlock(&data->update_lock);
	return ret < 0 ? ret : count;
}

static ssize_t pwm_mode_show(struct device *dev, struct device_attribute *da,
			     char *buf)
{
	struct tc654_data *data = tc654_update_client(dev);

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

	return sprintf(buf, "%d\n", !!(data->config & TC654_REG_CONFIG_DUTYC));
}

static ssize_t pwm_mode_store(struct device *dev, struct device_attribute *da,
			      const char *buf, size_t count)
{
	struct tc654_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	unsigned long val;
	int ret;

	if (kstrtoul(buf, 10, &val))
		return -EINVAL;

	if (val != 0 && val != 1)
		return -EINVAL;

	mutex_lock(&data->update_lock);

	if (val)
		data->config |= TC654_REG_CONFIG_DUTYC;
	else
		data->config &= ~TC654_REG_CONFIG_DUTYC;

	ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);

	mutex_unlock(&data->update_lock);
	return ret < 0 ? ret : count;
}

static const int tc654_pwm_map[16] = { 77,  88, 102, 112, 124, 136, 148, 160,
				      172, 184, 196, 207, 219, 231, 243, 255};

static ssize_t pwm_show(struct device *dev, struct device_attribute *da,
			char *buf)
{
	struct tc654_data *data = tc654_update_client(dev);
	int pwm;

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

	if (data->config & TC654_REG_CONFIG_SDM)
		pwm = 0;
	else
		pwm = tc654_pwm_map[data->duty_cycle];

	return sprintf(buf, "%d\n", pwm);
}

static int _set_pwm(struct tc654_data *data, unsigned long val)
{
	struct i2c_client *client = data->client;
	int ret;

	mutex_lock(&data->update_lock);

	if (val == 0) {
		data->config |= TC654_REG_CONFIG_SDM;
		data->duty_cycle = 0;
	} else {
		data->config &= ~TC654_REG_CONFIG_SDM;
		data->duty_cycle = val - 1;
	}

	ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);
	if (ret < 0)
		goto out;

	ret = i2c_smbus_write_byte_data(client, TC654_REG_DUTY_CYCLE,
					data->duty_cycle);

out:
	mutex_unlock(&data->update_lock);
	return ret;
}

static ssize_t pwm_store(struct device *dev, struct device_attribute *da,
			 const char *buf, size_t count)
{
	struct tc654_data *data = dev_get_drvdata(dev);
	unsigned long val;
	int ret;

	if (kstrtoul(buf, 10, &val))
		return -EINVAL;
	if (val > 255)
		return -EINVAL;
	if (val > 0)
		val = find_closest(val, tc654_pwm_map, ARRAY_SIZE(tc654_pwm_map)) + 1;

	ret = _set_pwm(data, val);
	return ret < 0 ? ret : count;
}

static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1);
static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0);
static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1);
static SENSOR_DEVICE_ATTR_RO(fan1_alarm, fan_alarm, 0);
static SENSOR_DEVICE_ATTR_RO(fan2_alarm, fan_alarm, 1);
static SENSOR_DEVICE_ATTR_RW(fan1_pulses, fan_pulses, 0);
static SENSOR_DEVICE_ATTR_RW(fan2_pulses, fan_pulses, 1);
static SENSOR_DEVICE_ATTR_RW(pwm1_mode, pwm_mode, 0);
static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);

/* Driver data */
static struct attribute *tc654_attrs[] = {
	&sensor_dev_attr_fan1_input.dev_attr.attr,
	&sensor_dev_attr_fan2_input.dev_attr.attr,
	&sensor_dev_attr_fan1_min.dev_attr.attr,
	&sensor_dev_attr_fan2_min.dev_attr.attr,
	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
	&sensor_dev_attr_fan1_pulses.dev_attr.attr,
	&sensor_dev_attr_fan2_pulses.dev_attr.attr,
	&sensor_dev_attr_pwm1_mode.dev_attr.attr,
	&sensor_dev_attr_pwm1.dev_attr.attr,
	NULL
};

ATTRIBUTE_GROUPS(tc654);

/*
 * thermal cooling device functions
 *
 * Account for the "ShutDown Mode (SDM)" state by offsetting
 * the 16 PWM duty cycle states by 1.
 *
 * State  0 =   0% PWM | Shutdown - Fan(s) are off
 * State  1 =  30% PWM | duty_cycle =  0
 * State  2 = ~35% PWM | duty_cycle =  1
 * [...]
 * State 15 = ~95% PWM | duty_cycle = 14
 * State 16 = 100% PWM | duty_cycle = 15
 */
#define TC654_MAX_COOLING_STATE	16

static int tc654_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
{
	*state = TC654_MAX_COOLING_STATE;
	return 0;
}

static int tc654_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
{
	struct tc654_data *data = tc654_update_client(cdev->devdata);

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

	if (data->config & TC654_REG_CONFIG_SDM)
		*state = 0;	/* FAN is off */
	else
		*state = data->duty_cycle + 1;	/* offset PWM States by 1 */

	return 0;
}

static int tc654_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
{
	struct tc654_data *data = tc654_update_client(cdev->devdata);

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

	return _set_pwm(data, clamp_val(state, 0, TC654_MAX_COOLING_STATE));
}

static const struct thermal_cooling_device_ops tc654_fan_cool_ops = {
	.get_max_state = tc654_get_max_state,
	.get_cur_state = tc654_get_cur_state,
	.set_cur_state = tc654_set_cur_state,
};

/*
 * device probe and removal
 */

static int tc654_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct tc654_data *data;
	struct device *hwmon_dev;
	int ret;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -ENODEV;

	data = devm_kzalloc(dev, sizeof(struct tc654_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG);
	if (ret < 0)
		return ret;

	data->config = ret;

	hwmon_dev =
	    devm_hwmon_device_register_with_groups(dev, client->name, data,
						   tc654_groups);
	if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);

	if (IS_ENABLED(CONFIG_THERMAL)) {
		struct thermal_cooling_device *cdev;

		cdev = devm_thermal_of_cooling_device_register(dev, dev->of_node, client->name,
							       hwmon_dev, &tc654_fan_cool_ops);
		return PTR_ERR_OR_ZERO(cdev);
	}

	return 0;
}

static const struct i2c_device_id tc654_id[] = {
	{"tc654", 0},
	{"tc655", 0},
	{}
};

MODULE_DEVICE_TABLE(i2c, tc654_id);

static struct i2c_driver tc654_driver = {
	.driver = {
		   .name = "tc654",
		   },
	.probe = tc654_probe,
	.id_table = tc654_id,
};

module_i2c_driver(tc654_driver);

MODULE_AUTHOR("Allied Telesis Labs");
MODULE_DESCRIPTION("Microchip TC654/TC655 driver");
MODULE_LICENSE("GPL");