summaryrefslogtreecommitdiff
path: root/drivers/hwmon/mlxreg-fan.c
blob: a5f89aab3fb4d2c48ef08e7d759b3fefa5a2004c (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
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
//
// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
// Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/platform_data/mlxreg.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/thermal.h>

#define MLXREG_FAN_MAX_TACHO		24
#define MLXREG_FAN_MAX_PWM		4
#define MLXREG_FAN_PWM_NOT_CONNECTED	0xff
#define MLXREG_FAN_MAX_STATE		10
#define MLXREG_FAN_MIN_DUTY		51	/* 20% */
#define MLXREG_FAN_MAX_DUTY		255	/* 100% */
#define MLXREG_FAN_SPEED_MIN_LEVEL		2	/* 20 percent */
#define MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF	44
#define MLXREG_FAN_TACHO_DIV_MIN		283
#define MLXREG_FAN_TACHO_DIV_DEF		(MLXREG_FAN_TACHO_DIV_MIN * 4)
#define MLXREG_FAN_TACHO_DIV_SCALE_MAX	64
/*
 * FAN datasheet defines the formula for RPM calculations as RPM = 15/t-high.
 * The logic in a programmable device measures the time t-high by sampling the
 * tachometer every t-sample (with the default value 11.32 uS) and increment
 * a counter (N) as long as the pulse has not change:
 * RPM = 15 / (t-sample * (K + Regval)), where:
 * Regval: is the value read from the programmable device register;
 *  - 0xff - represents tachometer fault;
 *  - 0xfe - represents tachometer minimum value , which is 4444 RPM;
 *  - 0x00 - represents tachometer maximum value , which is 300000 RPM;
 * K: is 44 and it represents the minimum allowed samples per pulse;
 * N: is equal K + Regval;
 * In order to calculate RPM from the register value the following formula is
 * used: RPM = 15 / ((Regval + K) * 11.32) * 10^(-6)), which in  the
 * default case is modified to:
 * RPM = 15000000 * 100 / ((Regval + 44) * 1132);
 * - for Regval 0x00, RPM will be 15000000 * 100 / (44 * 1132) = 30115;
 * - for Regval 0xfe, RPM will be 15000000 * 100 / ((254 + 44) * 1132) = 4446;
 * In common case the formula is modified to:
 * RPM = 15000000 * 100 / ((Regval + samples) * divider).
 */
#define MLXREG_FAN_GET_RPM(rval, d, s)	(DIV_ROUND_CLOSEST(15000000 * 100, \
					 ((rval) + (s)) * (d)))
#define MLXREG_FAN_GET_FAULT(val, mask) ((val) == (mask))
#define MLXREG_FAN_PWM_DUTY2STATE(duty)	(DIV_ROUND_CLOSEST((duty) *	\
					 MLXREG_FAN_MAX_STATE,		\
					 MLXREG_FAN_MAX_DUTY))
#define MLXREG_FAN_PWM_STATE2DUTY(stat)	(DIV_ROUND_CLOSEST((stat) *	\
					 MLXREG_FAN_MAX_DUTY,		\
					 MLXREG_FAN_MAX_STATE))

struct mlxreg_fan;

/*
 * struct mlxreg_fan_tacho - tachometer data (internal use):
 *
 * @connected: indicates if tachometer is connected;
 * @reg: register offset;
 * @mask: fault mask;
 * @prsnt: present register offset;
 */
struct mlxreg_fan_tacho {
	bool connected;
	u32 reg;
	u32 mask;
	u32 prsnt;
};

/*
 * struct mlxreg_fan_pwm - PWM data (internal use):
 *
 * @fan: private data;
 * @connected: indicates if PWM is connected;
 * @reg: register offset;
 * @cooling: cooling device levels;
 * @last_hwmon_state: last cooling state set by hwmon subsystem;
 * @last_thermal_state: last cooling state set by thermal subsystem;
 * @cdev: cooling device;
 */
struct mlxreg_fan_pwm {
	struct mlxreg_fan *fan;
	bool connected;
	u32 reg;
	unsigned long last_hwmon_state;
	unsigned long last_thermal_state;
	struct thermal_cooling_device *cdev;
};

/*
 * struct mlxreg_fan - private data (internal use):
 *
 * @dev: basic device;
 * @regmap: register map of parent device;
 * @tacho: tachometer data;
 * @pwm: PWM data;
 * @tachos_per_drwr - number of tachometers per drawer;
 * @samples: minimum allowed samples per pulse;
 * @divider: divider value for tachometer RPM calculation;
 */
struct mlxreg_fan {
	struct device *dev;
	void *regmap;
	struct mlxreg_core_platform_data *pdata;
	struct mlxreg_fan_tacho tacho[MLXREG_FAN_MAX_TACHO];
	struct mlxreg_fan_pwm pwm[MLXREG_FAN_MAX_PWM];
	int tachos_per_drwr;
	int samples;
	int divider;
};

static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
				    unsigned long state);

static int
mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
		int channel, long *val)
{
	struct mlxreg_fan *fan = dev_get_drvdata(dev);
	struct mlxreg_fan_tacho *tacho;
	struct mlxreg_fan_pwm *pwm;
	u32 regval;
	int err;

	switch (type) {
	case hwmon_fan:
		tacho = &fan->tacho[channel];
		switch (attr) {
		case hwmon_fan_input:
			/*
			 * Check FAN presence: FAN related bit in presence register is one,
			 * if FAN is physically connected, zero - otherwise.
			 */
			if (tacho->prsnt && fan->tachos_per_drwr) {
				err = regmap_read(fan->regmap, tacho->prsnt, &regval);
				if (err)
					return err;

				/*
				 * Map channel to presence bit - drawer can be equipped with
				 * one or few FANs, while presence is indicated per drawer.
				 */
				if (BIT(channel / fan->tachos_per_drwr) & regval) {
					/* FAN is not connected - return zero for FAN speed. */
					*val = 0;
					return 0;
				}
			}

			err = regmap_read(fan->regmap, tacho->reg, &regval);
			if (err)
				return err;

			if (MLXREG_FAN_GET_FAULT(regval, tacho->mask)) {
				/* FAN is broken - return zero for FAN speed. */
				*val = 0;
				return 0;
			}

			*val = MLXREG_FAN_GET_RPM(regval, fan->divider,
						  fan->samples);
			break;

		case hwmon_fan_fault:
			err = regmap_read(fan->regmap, tacho->reg, &regval);
			if (err)
				return err;

			*val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
			break;

		default:
			return -EOPNOTSUPP;
		}
		break;

	case hwmon_pwm:
		pwm = &fan->pwm[channel];
		switch (attr) {
		case hwmon_pwm_input:
			err = regmap_read(fan->regmap, pwm->reg, &regval);
			if (err)
				return err;

			*val = regval;
			break;

		default:
			return -EOPNOTSUPP;
		}
		break;

	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int
mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
		 int channel, long val)
{
	struct mlxreg_fan *fan = dev_get_drvdata(dev);
	struct mlxreg_fan_pwm *pwm;

	switch (type) {
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
			if (val < MLXREG_FAN_MIN_DUTY ||
			    val > MLXREG_FAN_MAX_DUTY)
				return -EINVAL;
			pwm = &fan->pwm[channel];
			/* If thermal is configured - handle PWM limit setting. */
			if (IS_REACHABLE(CONFIG_THERMAL)) {
				pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(val);
				/*
				 * Update PWM only in case requested state is not less than the
				 * last thermal state.
				 */
				if (pwm->last_hwmon_state >= pwm->last_thermal_state)
					return mlxreg_fan_set_cur_state(pwm->cdev,
									pwm->last_hwmon_state);
				return 0;
			}
			return regmap_write(fan->regmap, pwm->reg, val);
		default:
			return -EOPNOTSUPP;
		}
		break;

	default:
		return -EOPNOTSUPP;
	}

	return -EOPNOTSUPP;
}

static umode_t
mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
		      int channel)
{
	switch (type) {
	case hwmon_fan:
		if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
			return 0;

		switch (attr) {
		case hwmon_fan_input:
		case hwmon_fan_fault:
			return 0444;
		default:
			break;
		}
		break;

	case hwmon_pwm:
		if (!(((struct mlxreg_fan *)data)->pwm[channel].connected))
			return 0;

		switch (attr) {
		case hwmon_pwm_input:
			return 0644;
		default:
			break;
		}
		break;

	default:
		break;
	}

	return 0;
}

static char *mlxreg_fan_name[] = {
	"mlxreg_fan",
	"mlxreg_fan1",
	"mlxreg_fan2",
	"mlxreg_fan3",
};

static const struct hwmon_channel_info * const mlxreg_fan_hwmon_info[] = {
	HWMON_CHANNEL_INFO(fan,
			   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_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_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_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_INPUT,
			   HWMON_PWM_INPUT,
			   HWMON_PWM_INPUT),
	NULL
};

static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
	.is_visible = mlxreg_fan_is_visible,
	.read = mlxreg_fan_read,
	.write = mlxreg_fan_write,
};

static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
	.ops = &mlxreg_fan_hwmon_hwmon_ops,
	.info = mlxreg_fan_hwmon_info,
};

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

static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
				    unsigned long *state)

{
	struct mlxreg_fan_pwm *pwm = cdev->devdata;
	struct mlxreg_fan *fan = pwm->fan;
	u32 regval;
	int err;

	err = regmap_read(fan->regmap, pwm->reg, &regval);
	if (err) {
		dev_err(fan->dev, "Failed to query PWM duty\n");
		return err;
	}

	*state = MLXREG_FAN_PWM_DUTY2STATE(regval);

	return 0;
}

static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
				    unsigned long state)

{
	struct mlxreg_fan_pwm *pwm = cdev->devdata;
	struct mlxreg_fan *fan = pwm->fan;
	int err;

	if (state > MLXREG_FAN_MAX_STATE)
		return -EINVAL;

	/* Save thermal state. */
	pwm->last_thermal_state = state;

	state = max_t(unsigned long, state, pwm->last_hwmon_state);
	err = regmap_write(fan->regmap, pwm->reg,
			   MLXREG_FAN_PWM_STATE2DUTY(state));
	if (err) {
		dev_err(fan->dev, "Failed to write PWM duty\n");
		return err;
	}
	return 0;
}

static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
	.get_max_state	= mlxreg_fan_get_max_state,
	.get_cur_state	= mlxreg_fan_get_cur_state,
	.set_cur_state	= mlxreg_fan_set_cur_state,
};

static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
				     struct mlxreg_core_data *data)
{
	u32 regval;
	int err;

	err = regmap_read(fan->regmap, data->capability, &regval);
	if (err) {
		dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
			data->capability);
		return err;
	}

	return !!(regval & data->bit);
}

static int mlxreg_pwm_connect_verify(struct mlxreg_fan *fan,
				     struct mlxreg_core_data *data)
{
	u32 regval;
	int err;

	err = regmap_read(fan->regmap, data->reg, &regval);
	if (err) {
		dev_err(fan->dev, "Failed to query pwm register 0x%08x\n",
			data->reg);
		return err;
	}

	return regval != MLXREG_FAN_PWM_NOT_CONNECTED;
}

static int mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan,
					struct mlxreg_core_data *data)
{
	u32 regval;
	int err;

	err = regmap_read(fan->regmap, data->capability, &regval);
	if (err) {
		dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
			data->capability);
		return err;
	}

	/*
	 * Set divider value according to the capability register, in case it
	 * contains valid value. Otherwise use default value. The purpose of
	 * this validation is to protect against the old hardware, in which
	 * this register can return zero.
	 */
	if (regval > 0 && regval <= MLXREG_FAN_TACHO_DIV_SCALE_MAX)
		fan->divider = regval * MLXREG_FAN_TACHO_DIV_MIN;

	return 0;
}

static int mlxreg_fan_config(struct mlxreg_fan *fan,
			     struct mlxreg_core_platform_data *pdata)
{
	int tacho_num = 0, tacho_avail = 0, pwm_num = 0, i;
	struct mlxreg_core_data *data = pdata->data;
	bool configured = false;
	int err;

	fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
	fan->divider = MLXREG_FAN_TACHO_DIV_DEF;
	for (i = 0; i < pdata->counter; i++, data++) {
		if (strnstr(data->label, "tacho", sizeof(data->label))) {
			if (tacho_num == MLXREG_FAN_MAX_TACHO) {
				dev_err(fan->dev, "too many tacho entries: %s\n",
					data->label);
				return -EINVAL;
			}

			if (data->capability) {
				err = mlxreg_fan_connect_verify(fan, data);
				if (err < 0)
					return err;
				else if (!err) {
					tacho_num++;
					continue;
				}
			}

			fan->tacho[tacho_num].reg = data->reg;
			fan->tacho[tacho_num].mask = data->mask;
			fan->tacho[tacho_num].prsnt = data->reg_prsnt;
			fan->tacho[tacho_num++].connected = true;
			tacho_avail++;
		} else if (strnstr(data->label, "pwm", sizeof(data->label))) {
			if (pwm_num == MLXREG_FAN_MAX_TACHO) {
				dev_err(fan->dev, "too many pwm entries: %s\n",
					data->label);
				return -EINVAL;
			}

			/* Validate if more then one PWM is connected. */
			if (pwm_num) {
				err = mlxreg_pwm_connect_verify(fan, data);
				if (err < 0)
					return err;
				else if (!err)
					continue;
			}

			fan->pwm[pwm_num].reg = data->reg;
			fan->pwm[pwm_num].connected = true;
			pwm_num++;
		} else if (strnstr(data->label, "conf", sizeof(data->label))) {
			if (configured) {
				dev_err(fan->dev, "duplicate conf entry: %s\n",
					data->label);
				return -EINVAL;
			}
			/* Validate that conf parameters are not zeros. */
			if (!data->mask && !data->bit && !data->capability) {
				dev_err(fan->dev, "invalid conf entry params: %s\n",
					data->label);
				return -EINVAL;
			}
			if (data->capability) {
				err = mlxreg_fan_speed_divider_get(fan, data);
				if (err)
					return err;
			} else {
				if (data->mask)
					fan->samples = data->mask;
				if (data->bit)
					fan->divider = data->bit;
			}
			configured = true;
		} else {
			dev_err(fan->dev, "invalid label: %s\n", data->label);
			return -EINVAL;
		}
	}

	if (pdata->capability) {
		int drwr_avail;
		u32 regval;

		/* Obtain the number of FAN drawers, supported by system. */
		err = regmap_read(fan->regmap, pdata->capability, &regval);
		if (err) {
			dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
				pdata->capability);
			return err;
		}

		drwr_avail = hweight32(regval);
		if (!tacho_avail || !drwr_avail || tacho_avail < drwr_avail) {
			dev_err(fan->dev, "Configuration is invalid: drawers num %d tachos num %d\n",
				drwr_avail, tacho_avail);
			return -EINVAL;
		}

		/* Set the number of tachometers per one drawer. */
		fan->tachos_per_drwr = tacho_avail / drwr_avail;
	}

	return 0;
}

static int mlxreg_fan_cooling_config(struct device *dev, struct mlxreg_fan *fan)
{
	int i;

	for (i = 0; i < MLXREG_FAN_MAX_PWM; i++) {
		struct mlxreg_fan_pwm *pwm = &fan->pwm[i];

		if (!pwm->connected)
			continue;
		pwm->fan = fan;
		pwm->cdev = devm_thermal_of_cooling_device_register(dev, NULL, mlxreg_fan_name[i],
								    pwm, &mlxreg_fan_cooling_ops);
		if (IS_ERR(pwm->cdev)) {
			dev_err(dev, "Failed to register cooling device\n");
			return PTR_ERR(pwm->cdev);
		}

		/* Set minimal PWM speed. */
		pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(MLXREG_FAN_MIN_DUTY);
	}

	return 0;
}

static int mlxreg_fan_probe(struct platform_device *pdev)
{
	struct mlxreg_core_platform_data *pdata;
	struct device *dev = &pdev->dev;
	struct mlxreg_fan *fan;
	struct device *hwm;
	int err;

	pdata = dev_get_platdata(dev);
	if (!pdata) {
		dev_err(dev, "Failed to get platform data.\n");
		return -EINVAL;
	}

	fan = devm_kzalloc(dev, sizeof(*fan), GFP_KERNEL);
	if (!fan)
		return -ENOMEM;

	fan->dev = dev;
	fan->regmap = pdata->regmap;

	err = mlxreg_fan_config(fan, pdata);
	if (err)
		return err;

	hwm = devm_hwmon_device_register_with_info(dev, "mlxreg_fan",
						   fan,
						   &mlxreg_fan_hwmon_chip_info,
						   NULL);
	if (IS_ERR(hwm)) {
		dev_err(dev, "Failed to register hwmon device\n");
		return PTR_ERR(hwm);
	}

	if (IS_REACHABLE(CONFIG_THERMAL))
		err = mlxreg_fan_cooling_config(dev, fan);

	return err;
}

static struct platform_driver mlxreg_fan_driver = {
	.driver = {
	    .name = "mlxreg-fan",
	},
	.probe = mlxreg_fan_probe,
};

module_platform_driver(mlxreg_fan_driver);

MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
MODULE_DESCRIPTION("Mellanox FAN driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mlxreg-fan");