1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 //
3 // Copyright (c) 2018 Mellanox Technologies. All rights reserved.
4 // Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
5
6 #include <linux/bitops.h>
7 #include <linux/device.h>
8 #include <linux/hwmon.h>
9 #include <linux/module.h>
10 #include <linux/platform_data/mlxreg.h>
11 #include <linux/platform_device.h>
12 #include <linux/regmap.h>
13 #include <linux/thermal.h>
14
15 #define MLXREG_FAN_MAX_TACHO 24
16 #define MLXREG_FAN_MAX_PWM 4
17 #define MLXREG_FAN_PWM_NOT_CONNECTED 0xff
18 #define MLXREG_FAN_MAX_STATE 10
19 #define MLXREG_FAN_MIN_DUTY 51 /* 20% */
20 #define MLXREG_FAN_MAX_DUTY 255 /* 100% */
21 #define MLXREG_FAN_SPEED_MIN_LEVEL 2 /* 20 percent */
22 #define MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF 44
23 #define MLXREG_FAN_TACHO_DIV_MIN 283
24 #define MLXREG_FAN_TACHO_DIV_DEF (MLXREG_FAN_TACHO_DIV_MIN * 4)
25 #define MLXREG_FAN_TACHO_DIV_SCALE_MAX 64
26 /*
27 * FAN datasheet defines the formula for RPM calculations as RPM = 15/t-high.
28 * The logic in a programmable device measures the time t-high by sampling the
29 * tachometer every t-sample (with the default value 11.32 uS) and increment
30 * a counter (N) as long as the pulse has not change:
31 * RPM = 15 / (t-sample * (K + Regval)), where:
32 * Regval: is the value read from the programmable device register;
33 * - 0xff - represents tachometer fault;
34 * - 0xfe - represents tachometer minimum value , which is 4444 RPM;
35 * - 0x00 - represents tachometer maximum value , which is 300000 RPM;
36 * K: is 44 and it represents the minimum allowed samples per pulse;
37 * N: is equal K + Regval;
38 * In order to calculate RPM from the register value the following formula is
39 * used: RPM = 15 / ((Regval + K) * 11.32) * 10^(-6)), which in the
40 * default case is modified to:
41 * RPM = 15000000 * 100 / ((Regval + 44) * 1132);
42 * - for Regval 0x00, RPM will be 15000000 * 100 / (44 * 1132) = 30115;
43 * - for Regval 0xfe, RPM will be 15000000 * 100 / ((254 + 44) * 1132) = 4446;
44 * In common case the formula is modified to:
45 * RPM = 15000000 * 100 / ((Regval + samples) * divider).
46 */
47 #define MLXREG_FAN_GET_RPM(rval, d, s) (DIV_ROUND_CLOSEST(15000000 * 100, \
48 ((rval) + (s)) * (d)))
49 #define MLXREG_FAN_GET_FAULT(val, mask) ((val) == (mask))
50 #define MLXREG_FAN_PWM_DUTY2STATE(duty) (DIV_ROUND_CLOSEST((duty) * \
51 MLXREG_FAN_MAX_STATE, \
52 MLXREG_FAN_MAX_DUTY))
53 #define MLXREG_FAN_PWM_STATE2DUTY(stat) (DIV_ROUND_CLOSEST((stat) * \
54 MLXREG_FAN_MAX_DUTY, \
55 MLXREG_FAN_MAX_STATE))
56
57 struct mlxreg_fan;
58
59 /*
60 * struct mlxreg_fan_tacho - tachometer data (internal use):
61 *
62 * @connected: indicates if tachometer is connected;
63 * @reg: register offset;
64 * @mask: fault mask;
65 * @prsnt: present register offset;
66 * @shift: tacho presence bit shift;
67 */
68 struct mlxreg_fan_tacho {
69 bool connected;
70 u32 reg;
71 u32 mask;
72 u32 prsnt;
73 u32 shift;
74 };
75
76 /*
77 * struct mlxreg_fan_pwm - PWM data (internal use):
78 *
79 * @fan: private data;
80 * @connected: indicates if PWM is connected;
81 * @reg: register offset;
82 * @cooling: cooling device levels;
83 * @last_hwmon_state: last cooling state set by hwmon subsystem;
84 * @last_thermal_state: last cooling state set by thermal subsystem;
85 * @cdev: cooling device;
86 */
87 struct mlxreg_fan_pwm {
88 struct mlxreg_fan *fan;
89 bool connected;
90 u32 reg;
91 unsigned long last_hwmon_state;
92 unsigned long last_thermal_state;
93 struct thermal_cooling_device *cdev;
94 };
95
96 /*
97 * struct mlxreg_fan - private data (internal use):
98 *
99 * @dev: basic device;
100 * @regmap: register map of parent device;
101 * @tacho: tachometer data;
102 * @pwm: PWM data;
103 * @tachos_per_drwr - number of tachometers per drawer;
104 * @samples: minimum allowed samples per pulse;
105 * @divider: divider value for tachometer RPM calculation;
106 */
107 struct mlxreg_fan {
108 struct device *dev;
109 void *regmap;
110 struct mlxreg_core_platform_data *pdata;
111 struct mlxreg_fan_tacho tacho[MLXREG_FAN_MAX_TACHO];
112 struct mlxreg_fan_pwm pwm[MLXREG_FAN_MAX_PWM];
113 int tachos_per_drwr;
114 int samples;
115 int divider;
116 };
117
118 static int _mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
119 unsigned long state, bool thermal);
120
121 static int
mlxreg_fan_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)122 mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
123 int channel, long *val)
124 {
125 struct mlxreg_fan *fan = dev_get_drvdata(dev);
126 struct mlxreg_fan_tacho *tacho;
127 struct mlxreg_fan_pwm *pwm;
128 u32 regval;
129 int err;
130
131 switch (type) {
132 case hwmon_fan:
133 tacho = &fan->tacho[channel];
134 switch (attr) {
135 case hwmon_fan_input:
136 /*
137 * Check FAN presence: FAN related bit in presence register is one,
138 * if FAN is physically connected, zero - otherwise.
139 */
140 if (tacho->prsnt && fan->tachos_per_drwr) {
141 err = regmap_read(fan->regmap, tacho->prsnt, ®val);
142 if (err)
143 return err;
144
145 /*
146 * Map channel to presence bit - drawer can be equipped with
147 * one or few FANs, while presence is indicated per drawer.
148 * Shift channel value if necessary to align with register value.
149 */
150 if (BIT(rol32(channel, tacho->shift) / fan->tachos_per_drwr) &
151 regval) {
152 /* FAN is not connected - return zero for FAN speed. */
153 *val = 0;
154 return 0;
155 }
156 }
157
158 err = regmap_read(fan->regmap, tacho->reg, ®val);
159 if (err)
160 return err;
161
162 if (MLXREG_FAN_GET_FAULT(regval, tacho->mask)) {
163 /* FAN is broken - return zero for FAN speed. */
164 *val = 0;
165 return 0;
166 }
167
168 *val = MLXREG_FAN_GET_RPM(regval, fan->divider,
169 fan->samples);
170 break;
171
172 case hwmon_fan_fault:
173 err = regmap_read(fan->regmap, tacho->reg, ®val);
174 if (err)
175 return err;
176
177 *val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
178 break;
179
180 default:
181 return -EOPNOTSUPP;
182 }
183 break;
184
185 case hwmon_pwm:
186 pwm = &fan->pwm[channel];
187 switch (attr) {
188 case hwmon_pwm_input:
189 err = regmap_read(fan->regmap, pwm->reg, ®val);
190 if (err)
191 return err;
192
193 *val = regval;
194 break;
195
196 default:
197 return -EOPNOTSUPP;
198 }
199 break;
200
201 default:
202 return -EOPNOTSUPP;
203 }
204
205 return 0;
206 }
207
208 static int
mlxreg_fan_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)209 mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
210 int channel, long val)
211 {
212 struct mlxreg_fan *fan = dev_get_drvdata(dev);
213 struct mlxreg_fan_pwm *pwm;
214
215 switch (type) {
216 case hwmon_pwm:
217 switch (attr) {
218 case hwmon_pwm_input:
219 if (val < MLXREG_FAN_MIN_DUTY ||
220 val > MLXREG_FAN_MAX_DUTY)
221 return -EINVAL;
222 pwm = &fan->pwm[channel];
223 /* If thermal is configured - handle PWM limit setting. */
224 if (IS_REACHABLE(CONFIG_THERMAL)) {
225 pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(val);
226 /*
227 * Update PWM only in case requested state is not less than the
228 * last thermal state.
229 */
230 if (pwm->last_hwmon_state >= pwm->last_thermal_state)
231 return _mlxreg_fan_set_cur_state(pwm->cdev,
232 pwm->last_hwmon_state,
233 false);
234 return 0;
235 }
236 return regmap_write(fan->regmap, pwm->reg, val);
237 default:
238 return -EOPNOTSUPP;
239 }
240 break;
241
242 default:
243 return -EOPNOTSUPP;
244 }
245
246 return -EOPNOTSUPP;
247 }
248
249 static umode_t
mlxreg_fan_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)250 mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
251 int channel)
252 {
253 switch (type) {
254 case hwmon_fan:
255 if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
256 return 0;
257
258 switch (attr) {
259 case hwmon_fan_input:
260 case hwmon_fan_fault:
261 return 0444;
262 default:
263 break;
264 }
265 break;
266
267 case hwmon_pwm:
268 if (!(((struct mlxreg_fan *)data)->pwm[channel].connected))
269 return 0;
270
271 switch (attr) {
272 case hwmon_pwm_input:
273 return 0644;
274 default:
275 break;
276 }
277 break;
278
279 default:
280 break;
281 }
282
283 return 0;
284 }
285
286 static char *mlxreg_fan_name[] = {
287 "mlxreg_fan",
288 "mlxreg_fan1",
289 "mlxreg_fan2",
290 "mlxreg_fan3",
291 };
292
293 static const struct hwmon_channel_info * const mlxreg_fan_hwmon_info[] = {
294 HWMON_CHANNEL_INFO(fan,
295 HWMON_F_INPUT | HWMON_F_FAULT,
296 HWMON_F_INPUT | HWMON_F_FAULT,
297 HWMON_F_INPUT | HWMON_F_FAULT,
298 HWMON_F_INPUT | HWMON_F_FAULT,
299 HWMON_F_INPUT | HWMON_F_FAULT,
300 HWMON_F_INPUT | HWMON_F_FAULT,
301 HWMON_F_INPUT | HWMON_F_FAULT,
302 HWMON_F_INPUT | HWMON_F_FAULT,
303 HWMON_F_INPUT | HWMON_F_FAULT,
304 HWMON_F_INPUT | HWMON_F_FAULT,
305 HWMON_F_INPUT | HWMON_F_FAULT,
306 HWMON_F_INPUT | HWMON_F_FAULT,
307 HWMON_F_INPUT | HWMON_F_FAULT,
308 HWMON_F_INPUT | HWMON_F_FAULT,
309 HWMON_F_INPUT | HWMON_F_FAULT,
310 HWMON_F_INPUT | HWMON_F_FAULT,
311 HWMON_F_INPUT | HWMON_F_FAULT,
312 HWMON_F_INPUT | HWMON_F_FAULT,
313 HWMON_F_INPUT | HWMON_F_FAULT,
314 HWMON_F_INPUT | HWMON_F_FAULT,
315 HWMON_F_INPUT | HWMON_F_FAULT,
316 HWMON_F_INPUT | HWMON_F_FAULT,
317 HWMON_F_INPUT | HWMON_F_FAULT,
318 HWMON_F_INPUT | HWMON_F_FAULT),
319 HWMON_CHANNEL_INFO(pwm,
320 HWMON_PWM_INPUT,
321 HWMON_PWM_INPUT,
322 HWMON_PWM_INPUT,
323 HWMON_PWM_INPUT),
324 NULL
325 };
326
327 static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
328 .is_visible = mlxreg_fan_is_visible,
329 .read = mlxreg_fan_read,
330 .write = mlxreg_fan_write,
331 };
332
333 static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
334 .ops = &mlxreg_fan_hwmon_hwmon_ops,
335 .info = mlxreg_fan_hwmon_info,
336 };
337
mlxreg_fan_get_max_state(struct thermal_cooling_device * cdev,unsigned long * state)338 static int mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev,
339 unsigned long *state)
340 {
341 *state = MLXREG_FAN_MAX_STATE;
342 return 0;
343 }
344
mlxreg_fan_get_cur_state(struct thermal_cooling_device * cdev,unsigned long * state)345 static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
346 unsigned long *state)
347
348 {
349 struct mlxreg_fan_pwm *pwm = cdev->devdata;
350 struct mlxreg_fan *fan = pwm->fan;
351 u32 regval;
352 int err;
353
354 err = regmap_read(fan->regmap, pwm->reg, ®val);
355 if (err) {
356 dev_err(fan->dev, "Failed to query PWM duty\n");
357 return err;
358 }
359
360 *state = MLXREG_FAN_PWM_DUTY2STATE(regval);
361
362 return 0;
363 }
364
_mlxreg_fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state,bool thermal)365 static int _mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
366 unsigned long state, bool thermal)
367 {
368 struct mlxreg_fan_pwm *pwm = cdev->devdata;
369 struct mlxreg_fan *fan = pwm->fan;
370 int err;
371
372 if (state > MLXREG_FAN_MAX_STATE)
373 return -EINVAL;
374
375 /* Save thermal state. */
376 if (thermal)
377 pwm->last_thermal_state = state;
378
379 state = max_t(unsigned long, state, pwm->last_hwmon_state);
380 err = regmap_write(fan->regmap, pwm->reg,
381 MLXREG_FAN_PWM_STATE2DUTY(state));
382 if (err) {
383 dev_err(fan->dev, "Failed to write PWM duty\n");
384 return err;
385 }
386 return 0;
387 }
388
mlxreg_fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state)389 static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
390 unsigned long state)
391
392 {
393 return _mlxreg_fan_set_cur_state(cdev, state, true);
394 }
395
396 static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
397 .get_max_state = mlxreg_fan_get_max_state,
398 .get_cur_state = mlxreg_fan_get_cur_state,
399 .set_cur_state = mlxreg_fan_set_cur_state,
400 };
401
mlxreg_fan_connect_verify(struct mlxreg_fan * fan,struct mlxreg_core_data * data)402 static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
403 struct mlxreg_core_data *data)
404 {
405 u32 regval;
406 int err;
407
408 err = regmap_read(fan->regmap, data->capability, ®val);
409 if (err) {
410 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
411 data->capability);
412 return err;
413 }
414
415 return data->slot ? (data->slot <= regval ? 1 : 0) : !!(regval & data->bit);
416 }
417
mlxreg_pwm_connect_verify(struct mlxreg_fan * fan,struct mlxreg_core_data * data)418 static int mlxreg_pwm_connect_verify(struct mlxreg_fan *fan,
419 struct mlxreg_core_data *data)
420 {
421 u32 regval;
422 int err;
423
424 err = regmap_read(fan->regmap, data->reg, ®val);
425 if (err) {
426 dev_err(fan->dev, "Failed to query pwm register 0x%08x\n",
427 data->reg);
428 return err;
429 }
430
431 return regval != MLXREG_FAN_PWM_NOT_CONNECTED;
432 }
433
mlxreg_fan_speed_divider_get(struct mlxreg_fan * fan,struct mlxreg_core_data * data)434 static int mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan,
435 struct mlxreg_core_data *data)
436 {
437 u32 regval;
438 int err;
439
440 err = regmap_read(fan->regmap, data->capability, ®val);
441 if (err) {
442 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
443 data->capability);
444 return err;
445 }
446
447 /*
448 * Set divider value according to the capability register, in case it
449 * contains valid value. Otherwise use default value. The purpose of
450 * this validation is to protect against the old hardware, in which
451 * this register can return zero.
452 */
453 if (regval > 0 && regval <= MLXREG_FAN_TACHO_DIV_SCALE_MAX)
454 fan->divider = regval * MLXREG_FAN_TACHO_DIV_MIN;
455
456 return 0;
457 }
458
mlxreg_fan_config(struct mlxreg_fan * fan,struct mlxreg_core_platform_data * pdata)459 static int mlxreg_fan_config(struct mlxreg_fan *fan,
460 struct mlxreg_core_platform_data *pdata)
461 {
462 int tacho_num = 0, tacho_avail = 0, pwm_num = 0, i;
463 struct mlxreg_core_data *data = pdata->data;
464 bool configured = false;
465 int err;
466
467 fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
468 fan->divider = MLXREG_FAN_TACHO_DIV_DEF;
469 for (i = 0; i < pdata->counter; i++, data++) {
470 if (strnstr(data->label, "tacho", sizeof(data->label))) {
471 if (tacho_num == MLXREG_FAN_MAX_TACHO) {
472 dev_err(fan->dev, "too many tacho entries: %s\n",
473 data->label);
474 return -EINVAL;
475 }
476
477 if (data->capability) {
478 err = mlxreg_fan_connect_verify(fan, data);
479 if (err < 0)
480 return err;
481 else if (!err) {
482 tacho_num++;
483 continue;
484 }
485 }
486
487 fan->tacho[tacho_num].reg = data->reg;
488 fan->tacho[tacho_num].mask = data->mask;
489 fan->tacho[tacho_num].prsnt = data->reg_prsnt;
490 fan->tacho[tacho_num++].connected = true;
491 tacho_avail++;
492 } else if (strnstr(data->label, "pwm", sizeof(data->label))) {
493 if (pwm_num == MLXREG_FAN_MAX_TACHO) {
494 dev_err(fan->dev, "too many pwm entries: %s\n",
495 data->label);
496 return -EINVAL;
497 }
498
499 /* Validate if more then one PWM is connected. */
500 if (pwm_num) {
501 err = mlxreg_pwm_connect_verify(fan, data);
502 if (err < 0)
503 return err;
504 else if (!err)
505 continue;
506 }
507
508 fan->pwm[pwm_num].reg = data->reg;
509 fan->pwm[pwm_num].connected = true;
510 pwm_num++;
511 } else if (strnstr(data->label, "conf", sizeof(data->label))) {
512 if (configured) {
513 dev_err(fan->dev, "duplicate conf entry: %s\n",
514 data->label);
515 return -EINVAL;
516 }
517 /* Validate that conf parameters are not zeros. */
518 if (!data->mask && !data->bit && !data->capability) {
519 dev_err(fan->dev, "invalid conf entry params: %s\n",
520 data->label);
521 return -EINVAL;
522 }
523 if (data->capability) {
524 err = mlxreg_fan_speed_divider_get(fan, data);
525 if (err)
526 return err;
527 } else {
528 if (data->mask)
529 fan->samples = data->mask;
530 if (data->bit)
531 fan->divider = data->bit;
532 }
533 configured = true;
534 } else {
535 dev_err(fan->dev, "invalid label: %s\n", data->label);
536 return -EINVAL;
537 }
538 }
539
540 if (pdata->capability) {
541 int drwr_avail;
542 u32 regval;
543
544 /* Obtain the number of FAN drawers, supported by system. */
545 err = regmap_read(fan->regmap, pdata->capability, ®val);
546 if (err) {
547 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
548 pdata->capability);
549 return err;
550 }
551
552 /*
553 * The number of drawers could be specified in registers by counters for newer
554 * systems, or by bitmasks for older systems. In case the data is provided by
555 * counter, it is indicated through 'version' field.
556 */
557 if (pdata->version)
558 drwr_avail = regval;
559 else
560 drwr_avail = hweight32(regval);
561 if (!tacho_avail || !drwr_avail || tacho_avail < drwr_avail) {
562 dev_err(fan->dev, "Configuration is invalid: drawers num %d tachos num %d\n",
563 drwr_avail, tacho_avail);
564 return -EINVAL;
565 }
566
567 /* Set the number of tachometers per one drawer. */
568 fan->tachos_per_drwr = tacho_avail / drwr_avail;
569 }
570
571 return 0;
572 }
573
mlxreg_fan_cooling_config(struct device * dev,struct mlxreg_fan * fan)574 static int mlxreg_fan_cooling_config(struct device *dev, struct mlxreg_fan *fan)
575 {
576 int i;
577
578 for (i = 0; i < MLXREG_FAN_MAX_PWM; i++) {
579 struct mlxreg_fan_pwm *pwm = &fan->pwm[i];
580
581 if (!pwm->connected)
582 continue;
583 pwm->fan = fan;
584 /* Set minimal PWM speed. */
585 pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(MLXREG_FAN_MIN_DUTY);
586 pwm->cdev = devm_thermal_of_cooling_device_register(dev, NULL, mlxreg_fan_name[i],
587 pwm, &mlxreg_fan_cooling_ops);
588 if (IS_ERR(pwm->cdev)) {
589 dev_err(dev, "Failed to register cooling device\n");
590 return PTR_ERR(pwm->cdev);
591 }
592 }
593
594 return 0;
595 }
596
mlxreg_fan_probe(struct platform_device * pdev)597 static int mlxreg_fan_probe(struct platform_device *pdev)
598 {
599 struct mlxreg_core_platform_data *pdata;
600 struct device *dev = &pdev->dev;
601 struct mlxreg_fan *fan;
602 struct device *hwm;
603 int err;
604
605 pdata = dev_get_platdata(dev);
606 if (!pdata) {
607 dev_err(dev, "Failed to get platform data.\n");
608 return -EINVAL;
609 }
610
611 fan = devm_kzalloc(dev, sizeof(*fan), GFP_KERNEL);
612 if (!fan)
613 return -ENOMEM;
614
615 fan->dev = dev;
616 fan->regmap = pdata->regmap;
617
618 err = mlxreg_fan_config(fan, pdata);
619 if (err)
620 return err;
621
622 hwm = devm_hwmon_device_register_with_info(dev, "mlxreg_fan",
623 fan,
624 &mlxreg_fan_hwmon_chip_info,
625 NULL);
626 if (IS_ERR(hwm)) {
627 dev_err(dev, "Failed to register hwmon device\n");
628 return PTR_ERR(hwm);
629 }
630
631 if (IS_REACHABLE(CONFIG_THERMAL))
632 err = mlxreg_fan_cooling_config(dev, fan);
633
634 return err;
635 }
636
637 static struct platform_driver mlxreg_fan_driver = {
638 .driver = {
639 .name = "mlxreg-fan",
640 },
641 .probe = mlxreg_fan_probe,
642 };
643
644 module_platform_driver(mlxreg_fan_driver);
645
646 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
647 MODULE_DESCRIPTION("Mellanox FAN driver");
648 MODULE_LICENSE("GPL");
649 MODULE_ALIAS("platform:mlxreg-fan");
650