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 12
16 #define MLXREG_FAN_MAX_STATE 10
17 #define MLXREG_FAN_MIN_DUTY 51 /* 20% */
18 #define MLXREG_FAN_MAX_DUTY 255 /* 100% */
19 /*
20 * Minimum and maximum FAN allowed speed in percent: from 20% to 100%. Values
21 * MLXREG_FAN_MAX_STATE + x, where x is between 2 and 10 are used for
22 * setting FAN speed dynamic minimum. For example, if value is set to 14 (40%)
23 * cooling levels vector will be set to 4, 4, 4, 4, 4, 5, 6, 7, 8, 9, 10 to
24 * introduce PWM speed in percent: 40, 40, 40, 40, 40, 50, 60. 70, 80, 90, 100.
25 */
26 #define MLXREG_FAN_SPEED_MIN (MLXREG_FAN_MAX_STATE + 2)
27 #define MLXREG_FAN_SPEED_MAX (MLXREG_FAN_MAX_STATE * 2)
28 #define MLXREG_FAN_SPEED_MIN_LEVEL 2 /* 20 percent */
29 #define MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF 44
30 #define MLXREG_FAN_TACHO_DIV_MIN 283
31 #define MLXREG_FAN_TACHO_DIV_DEF (MLXREG_FAN_TACHO_DIV_MIN * 4)
32 #define MLXREG_FAN_TACHO_DIV_SCALE_MAX 64
33 /*
34 * FAN datasheet defines the formula for RPM calculations as RPM = 15/t-high.
35 * The logic in a programmable device measures the time t-high by sampling the
36 * tachometer every t-sample (with the default value 11.32 uS) and increment
37 * a counter (N) as long as the pulse has not change:
38 * RPM = 15 / (t-sample * (K + Regval)), where:
39 * Regval: is the value read from the programmable device register;
40 * - 0xff - represents tachometer fault;
41 * - 0xfe - represents tachometer minimum value , which is 4444 RPM;
42 * - 0x00 - represents tachometer maximum value , which is 300000 RPM;
43 * K: is 44 and it represents the minimum allowed samples per pulse;
44 * N: is equal K + Regval;
45 * In order to calculate RPM from the register value the following formula is
46 * used: RPM = 15 / ((Regval + K) * 11.32) * 10^(-6)), which in the
47 * default case is modified to:
48 * RPM = 15000000 * 100 / ((Regval + 44) * 1132);
49 * - for Regval 0x00, RPM will be 15000000 * 100 / (44 * 1132) = 30115;
50 * - for Regval 0xfe, RPM will be 15000000 * 100 / ((254 + 44) * 1132) = 4446;
51 * In common case the formula is modified to:
52 * RPM = 15000000 * 100 / ((Regval + samples) * divider).
53 */
54 #define MLXREG_FAN_GET_RPM(rval, d, s) (DIV_ROUND_CLOSEST(15000000 * 100, \
55 ((rval) + (s)) * (d)))
56 #define MLXREG_FAN_GET_FAULT(val, mask) ((val) == (mask))
57 #define MLXREG_FAN_PWM_DUTY2STATE(duty) (DIV_ROUND_CLOSEST((duty) * \
58 MLXREG_FAN_MAX_STATE, \
59 MLXREG_FAN_MAX_DUTY))
60 #define MLXREG_FAN_PWM_STATE2DUTY(stat) (DIV_ROUND_CLOSEST((stat) * \
61 MLXREG_FAN_MAX_DUTY, \
62 MLXREG_FAN_MAX_STATE))
63
64 /*
65 * struct mlxreg_fan_tacho - tachometer data (internal use):
66 *
67 * @connected: indicates if tachometer is connected;
68 * @reg: register offset;
69 * @mask: fault mask;
70 */
71 struct mlxreg_fan_tacho {
72 bool connected;
73 u32 reg;
74 u32 mask;
75 };
76
77 /*
78 * struct mlxreg_fan_pwm - PWM data (internal use):
79 *
80 * @connected: indicates if PWM is connected;
81 * @reg: register offset;
82 */
83 struct mlxreg_fan_pwm {
84 bool connected;
85 u32 reg;
86 };
87
88 /*
89 * struct mlxreg_fan - private data (internal use):
90 *
91 * @dev: basic device;
92 * @regmap: register map of parent device;
93 * @tacho: tachometer data;
94 * @pwm: PWM data;
95 * @samples: minimum allowed samples per pulse;
96 * @divider: divider value for tachometer RPM calculation;
97 * @cooling: cooling device levels;
98 * @cdev: cooling device;
99 */
100 struct mlxreg_fan {
101 struct device *dev;
102 void *regmap;
103 struct mlxreg_core_platform_data *pdata;
104 struct mlxreg_fan_tacho tacho[MLXREG_FAN_MAX_TACHO];
105 struct mlxreg_fan_pwm pwm;
106 int samples;
107 int divider;
108 u8 cooling_levels[MLXREG_FAN_MAX_STATE + 1];
109 struct thermal_cooling_device *cdev;
110 };
111
112 static int
mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val)113 mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
114 int channel, long *val)
115 {
116 struct mlxreg_fan *fan = dev_get_drvdata(dev);
117 struct mlxreg_fan_tacho *tacho;
118 u32 regval;
119 int err;
120
121 switch (type) {
122 case hwmon_fan:
123 tacho = &fan->tacho[channel];
124 switch (attr) {
125 case hwmon_fan_input:
126 err = regmap_read(fan->regmap, tacho->reg, ®val);
127 if (err)
128 return err;
129
130 if (MLXREG_FAN_GET_FAULT(regval, tacho->mask)) {
131 /* FAN is broken - return zero for FAN speed. */
132 *val = 0;
133 return 0;
134 }
135
136 *val = MLXREG_FAN_GET_RPM(regval, fan->divider,
137 fan->samples);
138 break;
139
140 case hwmon_fan_fault:
141 err = regmap_read(fan->regmap, tacho->reg, ®val);
142 if (err)
143 return err;
144
145 *val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
146 break;
147
148 default:
149 return -EOPNOTSUPP;
150 }
151 break;
152
153 case hwmon_pwm:
154 switch (attr) {
155 case hwmon_pwm_input:
156 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
157 if (err)
158 return err;
159
160 *val = regval;
161 break;
162
163 default:
164 return -EOPNOTSUPP;
165 }
166 break;
167
168 default:
169 return -EOPNOTSUPP;
170 }
171
172 return 0;
173 }
174
175 static int
mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val)176 mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
177 int channel, long val)
178 {
179 struct mlxreg_fan *fan = dev_get_drvdata(dev);
180
181 switch (type) {
182 case hwmon_pwm:
183 switch (attr) {
184 case hwmon_pwm_input:
185 if (val < MLXREG_FAN_MIN_DUTY ||
186 val > MLXREG_FAN_MAX_DUTY)
187 return -EINVAL;
188 return regmap_write(fan->regmap, fan->pwm.reg, val);
189 default:
190 return -EOPNOTSUPP;
191 }
192 break;
193
194 default:
195 return -EOPNOTSUPP;
196 }
197
198 return -EOPNOTSUPP;
199 }
200
201 static umode_t
mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel)202 mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
203 int channel)
204 {
205 switch (type) {
206 case hwmon_fan:
207 if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
208 return 0;
209
210 switch (attr) {
211 case hwmon_fan_input:
212 case hwmon_fan_fault:
213 return 0444;
214 default:
215 break;
216 }
217 break;
218
219 case hwmon_pwm:
220 if (!(((struct mlxreg_fan *)data)->pwm.connected))
221 return 0;
222
223 switch (attr) {
224 case hwmon_pwm_input:
225 return 0644;
226 default:
227 break;
228 }
229 break;
230
231 default:
232 break;
233 }
234
235 return 0;
236 }
237
238 static const struct hwmon_channel_info *mlxreg_fan_hwmon_info[] = {
239 HWMON_CHANNEL_INFO(fan,
240 HWMON_F_INPUT | HWMON_F_FAULT,
241 HWMON_F_INPUT | HWMON_F_FAULT,
242 HWMON_F_INPUT | HWMON_F_FAULT,
243 HWMON_F_INPUT | HWMON_F_FAULT,
244 HWMON_F_INPUT | HWMON_F_FAULT,
245 HWMON_F_INPUT | HWMON_F_FAULT,
246 HWMON_F_INPUT | HWMON_F_FAULT,
247 HWMON_F_INPUT | HWMON_F_FAULT,
248 HWMON_F_INPUT | HWMON_F_FAULT,
249 HWMON_F_INPUT | HWMON_F_FAULT,
250 HWMON_F_INPUT | HWMON_F_FAULT,
251 HWMON_F_INPUT | HWMON_F_FAULT),
252 HWMON_CHANNEL_INFO(pwm,
253 HWMON_PWM_INPUT),
254 NULL
255 };
256
257 static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
258 .is_visible = mlxreg_fan_is_visible,
259 .read = mlxreg_fan_read,
260 .write = mlxreg_fan_write,
261 };
262
263 static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
264 .ops = &mlxreg_fan_hwmon_hwmon_ops,
265 .info = mlxreg_fan_hwmon_info,
266 };
267
mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)268 static int mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev,
269 unsigned long *state)
270 {
271 *state = MLXREG_FAN_MAX_STATE;
272 return 0;
273 }
274
mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)275 static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
276 unsigned long *state)
277
278 {
279 struct mlxreg_fan *fan = cdev->devdata;
280 u32 regval;
281 int err;
282
283 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
284 if (err) {
285 dev_err(fan->dev, "Failed to query PWM duty\n");
286 return err;
287 }
288
289 *state = MLXREG_FAN_PWM_DUTY2STATE(regval);
290
291 return 0;
292 }
293
mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)294 static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
295 unsigned long state)
296
297 {
298 struct mlxreg_fan *fan = cdev->devdata;
299 unsigned long cur_state;
300 int i, config = 0;
301 u32 regval;
302 int err;
303
304 /*
305 * Verify if this request is for changing allowed FAN dynamical
306 * minimum. If it is - update cooling levels accordingly and update
307 * state, if current state is below the newly requested minimum state.
308 * For example, if current state is 5, and minimal state is to be
309 * changed from 4 to 6, fan->cooling_levels[0 to 5] will be changed all
310 * from 4 to 6. And state 5 (fan->cooling_levels[4]) should be
311 * overwritten.
312 */
313 if (state >= MLXREG_FAN_SPEED_MIN && state <= MLXREG_FAN_SPEED_MAX) {
314 /*
315 * This is configuration change, which is only supported through sysfs.
316 * For configuration non-zero value is to be returned to avoid thermal
317 * statistics update.
318 */
319 config = 1;
320 state -= MLXREG_FAN_MAX_STATE;
321 for (i = 0; i < state; i++)
322 fan->cooling_levels[i] = state;
323 for (i = state; i <= MLXREG_FAN_MAX_STATE; i++)
324 fan->cooling_levels[i] = i;
325
326 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
327 if (err) {
328 dev_err(fan->dev, "Failed to query PWM duty\n");
329 return err;
330 }
331
332 cur_state = MLXREG_FAN_PWM_DUTY2STATE(regval);
333 if (state < cur_state)
334 return config;
335
336 state = cur_state;
337 }
338
339 if (state > MLXREG_FAN_MAX_STATE)
340 return -EINVAL;
341
342 /* Normalize the state to the valid speed range. */
343 state = fan->cooling_levels[state];
344 err = regmap_write(fan->regmap, fan->pwm.reg,
345 MLXREG_FAN_PWM_STATE2DUTY(state));
346 if (err) {
347 dev_err(fan->dev, "Failed to write PWM duty\n");
348 return err;
349 }
350 return config;
351 }
352
353 static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
354 .get_max_state = mlxreg_fan_get_max_state,
355 .get_cur_state = mlxreg_fan_get_cur_state,
356 .set_cur_state = mlxreg_fan_set_cur_state,
357 };
358
mlxreg_fan_connect_verify(struct mlxreg_fan *fan, struct mlxreg_core_data *data)359 static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
360 struct mlxreg_core_data *data)
361 {
362 u32 regval;
363 int err;
364
365 err = regmap_read(fan->regmap, data->capability, ®val);
366 if (err) {
367 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
368 data->capability);
369 return err;
370 }
371
372 return !!(regval & data->bit);
373 }
374
mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan, struct mlxreg_core_data *data)375 static int mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan,
376 struct mlxreg_core_data *data)
377 {
378 u32 regval;
379 int err;
380
381 err = regmap_read(fan->regmap, data->capability, ®val);
382 if (err) {
383 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
384 data->capability);
385 return err;
386 }
387
388 /*
389 * Set divider value according to the capability register, in case it
390 * contains valid value. Otherwise use default value. The purpose of
391 * this validation is to protect against the old hardware, in which
392 * this register can return zero.
393 */
394 if (regval > 0 && regval <= MLXREG_FAN_TACHO_DIV_SCALE_MAX)
395 fan->divider = regval * MLXREG_FAN_TACHO_DIV_MIN;
396
397 return 0;
398 }
399
mlxreg_fan_config(struct mlxreg_fan *fan, struct mlxreg_core_platform_data *pdata)400 static int mlxreg_fan_config(struct mlxreg_fan *fan,
401 struct mlxreg_core_platform_data *pdata)
402 {
403 struct mlxreg_core_data *data = pdata->data;
404 bool configured = false;
405 int tacho_num = 0, i;
406 int err;
407
408 fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
409 fan->divider = MLXREG_FAN_TACHO_DIV_DEF;
410 for (i = 0; i < pdata->counter; i++, data++) {
411 if (strnstr(data->label, "tacho", sizeof(data->label))) {
412 if (tacho_num == MLXREG_FAN_MAX_TACHO) {
413 dev_err(fan->dev, "too many tacho entries: %s\n",
414 data->label);
415 return -EINVAL;
416 }
417
418 if (data->capability) {
419 err = mlxreg_fan_connect_verify(fan, data);
420 if (err < 0)
421 return err;
422 else if (!err) {
423 tacho_num++;
424 continue;
425 }
426 }
427
428 fan->tacho[tacho_num].reg = data->reg;
429 fan->tacho[tacho_num].mask = data->mask;
430 fan->tacho[tacho_num++].connected = true;
431 } else if (strnstr(data->label, "pwm", sizeof(data->label))) {
432 if (fan->pwm.connected) {
433 dev_err(fan->dev, "duplicate pwm entry: %s\n",
434 data->label);
435 return -EINVAL;
436 }
437 fan->pwm.reg = data->reg;
438 fan->pwm.connected = true;
439 } else if (strnstr(data->label, "conf", sizeof(data->label))) {
440 if (configured) {
441 dev_err(fan->dev, "duplicate conf entry: %s\n",
442 data->label);
443 return -EINVAL;
444 }
445 /* Validate that conf parameters are not zeros. */
446 if (!data->mask && !data->bit && !data->capability) {
447 dev_err(fan->dev, "invalid conf entry params: %s\n",
448 data->label);
449 return -EINVAL;
450 }
451 if (data->capability) {
452 err = mlxreg_fan_speed_divider_get(fan, data);
453 if (err)
454 return err;
455 } else {
456 if (data->mask)
457 fan->samples = data->mask;
458 if (data->bit)
459 fan->divider = data->bit;
460 }
461 configured = true;
462 } else {
463 dev_err(fan->dev, "invalid label: %s\n", data->label);
464 return -EINVAL;
465 }
466 }
467
468 /* Init cooling levels per PWM state. */
469 for (i = 0; i < MLXREG_FAN_SPEED_MIN_LEVEL; i++)
470 fan->cooling_levels[i] = MLXREG_FAN_SPEED_MIN_LEVEL;
471 for (i = MLXREG_FAN_SPEED_MIN_LEVEL; i <= MLXREG_FAN_MAX_STATE; i++)
472 fan->cooling_levels[i] = i;
473
474 return 0;
475 }
476
mlxreg_fan_probe(struct platform_device *pdev)477 static int mlxreg_fan_probe(struct platform_device *pdev)
478 {
479 struct mlxreg_core_platform_data *pdata;
480 struct device *dev = &pdev->dev;
481 struct mlxreg_fan *fan;
482 struct device *hwm;
483 int err;
484
485 pdata = dev_get_platdata(dev);
486 if (!pdata) {
487 dev_err(dev, "Failed to get platform data.\n");
488 return -EINVAL;
489 }
490
491 fan = devm_kzalloc(dev, sizeof(*fan), GFP_KERNEL);
492 if (!fan)
493 return -ENOMEM;
494
495 fan->dev = dev;
496 fan->regmap = pdata->regmap;
497
498 err = mlxreg_fan_config(fan, pdata);
499 if (err)
500 return err;
501
502 hwm = devm_hwmon_device_register_with_info(dev, "mlxreg_fan",
503 fan,
504 &mlxreg_fan_hwmon_chip_info,
505 NULL);
506 if (IS_ERR(hwm)) {
507 dev_err(dev, "Failed to register hwmon device\n");
508 return PTR_ERR(hwm);
509 }
510
511 if (IS_REACHABLE(CONFIG_THERMAL)) {
512 fan->cdev = devm_thermal_of_cooling_device_register(dev,
513 NULL, "mlxreg_fan", fan, &mlxreg_fan_cooling_ops);
514 if (IS_ERR(fan->cdev)) {
515 dev_err(dev, "Failed to register cooling device\n");
516 return PTR_ERR(fan->cdev);
517 }
518 }
519
520 return 0;
521 }
522
523 static struct platform_driver mlxreg_fan_driver = {
524 .driver = {
525 .name = "mlxreg-fan",
526 },
527 .probe = mlxreg_fan_probe,
528 };
529
530 module_platform_driver(mlxreg_fan_driver);
531
532 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
533 MODULE_DESCRIPTION("Mellanox FAN driver");
534 MODULE_LICENSE("GPL");
535 MODULE_ALIAS("platform:mlxreg-fan");
536