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 *val = MLXREG_FAN_GET_RPM(regval, fan->divider,
131 fan->samples);
132 break;
133
134 case hwmon_fan_fault:
135 err = regmap_read(fan->regmap, tacho->reg, ®val);
136 if (err)
137 return err;
138
139 *val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
140 break;
141
142 default:
143 return -EOPNOTSUPP;
144 }
145 break;
146
147 case hwmon_pwm:
148 switch (attr) {
149 case hwmon_pwm_input:
150 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
151 if (err)
152 return err;
153
154 *val = regval;
155 break;
156
157 default:
158 return -EOPNOTSUPP;
159 }
160 break;
161
162 default:
163 return -EOPNOTSUPP;
164 }
165
166 return 0;
167 }
168
169 static int
mlxreg_fan_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)170 mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
171 int channel, long val)
172 {
173 struct mlxreg_fan *fan = dev_get_drvdata(dev);
174
175 switch (type) {
176 case hwmon_pwm:
177 switch (attr) {
178 case hwmon_pwm_input:
179 if (val < MLXREG_FAN_MIN_DUTY ||
180 val > MLXREG_FAN_MAX_DUTY)
181 return -EINVAL;
182 return regmap_write(fan->regmap, fan->pwm.reg, val);
183 default:
184 return -EOPNOTSUPP;
185 }
186 break;
187
188 default:
189 return -EOPNOTSUPP;
190 }
191
192 return -EOPNOTSUPP;
193 }
194
195 static umode_t
mlxreg_fan_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)196 mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
197 int channel)
198 {
199 switch (type) {
200 case hwmon_fan:
201 if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
202 return 0;
203
204 switch (attr) {
205 case hwmon_fan_input:
206 case hwmon_fan_fault:
207 return 0444;
208 default:
209 break;
210 }
211 break;
212
213 case hwmon_pwm:
214 if (!(((struct mlxreg_fan *)data)->pwm.connected))
215 return 0;
216
217 switch (attr) {
218 case hwmon_pwm_input:
219 return 0644;
220 default:
221 break;
222 }
223 break;
224
225 default:
226 break;
227 }
228
229 return 0;
230 }
231
232 static const struct hwmon_channel_info *mlxreg_fan_hwmon_info[] = {
233 HWMON_CHANNEL_INFO(fan,
234 HWMON_F_INPUT | HWMON_F_FAULT,
235 HWMON_F_INPUT | HWMON_F_FAULT,
236 HWMON_F_INPUT | HWMON_F_FAULT,
237 HWMON_F_INPUT | HWMON_F_FAULT,
238 HWMON_F_INPUT | HWMON_F_FAULT,
239 HWMON_F_INPUT | HWMON_F_FAULT,
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_CHANNEL_INFO(pwm,
247 HWMON_PWM_INPUT),
248 NULL
249 };
250
251 static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
252 .is_visible = mlxreg_fan_is_visible,
253 .read = mlxreg_fan_read,
254 .write = mlxreg_fan_write,
255 };
256
257 static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
258 .ops = &mlxreg_fan_hwmon_hwmon_ops,
259 .info = mlxreg_fan_hwmon_info,
260 };
261
mlxreg_fan_get_max_state(struct thermal_cooling_device * cdev,unsigned long * state)262 static int mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev,
263 unsigned long *state)
264 {
265 *state = MLXREG_FAN_MAX_STATE;
266 return 0;
267 }
268
mlxreg_fan_get_cur_state(struct thermal_cooling_device * cdev,unsigned long * state)269 static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
270 unsigned long *state)
271
272 {
273 struct mlxreg_fan *fan = cdev->devdata;
274 u32 regval;
275 int err;
276
277 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
278 if (err) {
279 dev_err(fan->dev, "Failed to query PWM duty\n");
280 return err;
281 }
282
283 *state = MLXREG_FAN_PWM_DUTY2STATE(regval);
284
285 return 0;
286 }
287
mlxreg_fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state)288 static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
289 unsigned long state)
290
291 {
292 struct mlxreg_fan *fan = cdev->devdata;
293 unsigned long cur_state;
294 int i, config = 0;
295 u32 regval;
296 int err;
297
298 /*
299 * Verify if this request is for changing allowed FAN dynamical
300 * minimum. If it is - update cooling levels accordingly and update
301 * state, if current state is below the newly requested minimum state.
302 * For example, if current state is 5, and minimal state is to be
303 * changed from 4 to 6, fan->cooling_levels[0 to 5] will be changed all
304 * from 4 to 6. And state 5 (fan->cooling_levels[4]) should be
305 * overwritten.
306 */
307 if (state >= MLXREG_FAN_SPEED_MIN && state <= MLXREG_FAN_SPEED_MAX) {
308 /*
309 * This is configuration change, which is only supported through sysfs.
310 * For configuration non-zero value is to be returned to avoid thermal
311 * statistics update.
312 */
313 config = 1;
314 state -= MLXREG_FAN_MAX_STATE;
315 for (i = 0; i < state; i++)
316 fan->cooling_levels[i] = state;
317 for (i = state; i <= MLXREG_FAN_MAX_STATE; i++)
318 fan->cooling_levels[i] = i;
319
320 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
321 if (err) {
322 dev_err(fan->dev, "Failed to query PWM duty\n");
323 return err;
324 }
325
326 cur_state = MLXREG_FAN_PWM_DUTY2STATE(regval);
327 if (state < cur_state)
328 return config;
329
330 state = cur_state;
331 }
332
333 if (state > MLXREG_FAN_MAX_STATE)
334 return -EINVAL;
335
336 /* Normalize the state to the valid speed range. */
337 state = fan->cooling_levels[state];
338 err = regmap_write(fan->regmap, fan->pwm.reg,
339 MLXREG_FAN_PWM_STATE2DUTY(state));
340 if (err) {
341 dev_err(fan->dev, "Failed to write PWM duty\n");
342 return err;
343 }
344 return config;
345 }
346
347 static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
348 .get_max_state = mlxreg_fan_get_max_state,
349 .get_cur_state = mlxreg_fan_get_cur_state,
350 .set_cur_state = mlxreg_fan_set_cur_state,
351 };
352
mlxreg_fan_connect_verify(struct mlxreg_fan * fan,struct mlxreg_core_data * data)353 static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
354 struct mlxreg_core_data *data)
355 {
356 u32 regval;
357 int err;
358
359 err = regmap_read(fan->regmap, data->capability, ®val);
360 if (err) {
361 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
362 data->capability);
363 return err;
364 }
365
366 return !!(regval & data->bit);
367 }
368
mlxreg_fan_speed_divider_get(struct mlxreg_fan * fan,struct mlxreg_core_data * data)369 static int mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan,
370 struct mlxreg_core_data *data)
371 {
372 u32 regval;
373 int err;
374
375 err = regmap_read(fan->regmap, data->capability, ®val);
376 if (err) {
377 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
378 data->capability);
379 return err;
380 }
381
382 /*
383 * Set divider value according to the capability register, in case it
384 * contains valid value. Otherwise use default value. The purpose of
385 * this validation is to protect against the old hardware, in which
386 * this register can return zero.
387 */
388 if (regval > 0 && regval <= MLXREG_FAN_TACHO_DIV_SCALE_MAX)
389 fan->divider = regval * MLXREG_FAN_TACHO_DIV_MIN;
390
391 return 0;
392 }
393
mlxreg_fan_config(struct mlxreg_fan * fan,struct mlxreg_core_platform_data * pdata)394 static int mlxreg_fan_config(struct mlxreg_fan *fan,
395 struct mlxreg_core_platform_data *pdata)
396 {
397 struct mlxreg_core_data *data = pdata->data;
398 bool configured = false;
399 int tacho_num = 0, i;
400 int err;
401
402 fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
403 fan->divider = MLXREG_FAN_TACHO_DIV_DEF;
404 for (i = 0; i < pdata->counter; i++, data++) {
405 if (strnstr(data->label, "tacho", sizeof(data->label))) {
406 if (tacho_num == MLXREG_FAN_MAX_TACHO) {
407 dev_err(fan->dev, "too many tacho entries: %s\n",
408 data->label);
409 return -EINVAL;
410 }
411
412 if (data->capability) {
413 err = mlxreg_fan_connect_verify(fan, data);
414 if (err < 0)
415 return err;
416 else if (!err) {
417 tacho_num++;
418 continue;
419 }
420 }
421
422 fan->tacho[tacho_num].reg = data->reg;
423 fan->tacho[tacho_num].mask = data->mask;
424 fan->tacho[tacho_num++].connected = true;
425 } else if (strnstr(data->label, "pwm", sizeof(data->label))) {
426 if (fan->pwm.connected) {
427 dev_err(fan->dev, "duplicate pwm entry: %s\n",
428 data->label);
429 return -EINVAL;
430 }
431 fan->pwm.reg = data->reg;
432 fan->pwm.connected = true;
433 } else if (strnstr(data->label, "conf", sizeof(data->label))) {
434 if (configured) {
435 dev_err(fan->dev, "duplicate conf entry: %s\n",
436 data->label);
437 return -EINVAL;
438 }
439 /* Validate that conf parameters are not zeros. */
440 if (!data->mask && !data->bit && !data->capability) {
441 dev_err(fan->dev, "invalid conf entry params: %s\n",
442 data->label);
443 return -EINVAL;
444 }
445 if (data->capability) {
446 err = mlxreg_fan_speed_divider_get(fan, data);
447 if (err)
448 return err;
449 } else {
450 if (data->mask)
451 fan->samples = data->mask;
452 if (data->bit)
453 fan->divider = data->bit;
454 }
455 configured = true;
456 } else {
457 dev_err(fan->dev, "invalid label: %s\n", data->label);
458 return -EINVAL;
459 }
460 }
461
462 /* Init cooling levels per PWM state. */
463 for (i = 0; i < MLXREG_FAN_SPEED_MIN_LEVEL; i++)
464 fan->cooling_levels[i] = MLXREG_FAN_SPEED_MIN_LEVEL;
465 for (i = MLXREG_FAN_SPEED_MIN_LEVEL; i <= MLXREG_FAN_MAX_STATE; i++)
466 fan->cooling_levels[i] = i;
467
468 return 0;
469 }
470
mlxreg_fan_probe(struct platform_device * pdev)471 static int mlxreg_fan_probe(struct platform_device *pdev)
472 {
473 struct mlxreg_core_platform_data *pdata;
474 struct device *dev = &pdev->dev;
475 struct mlxreg_fan *fan;
476 struct device *hwm;
477 int err;
478
479 pdata = dev_get_platdata(dev);
480 if (!pdata) {
481 dev_err(dev, "Failed to get platform data.\n");
482 return -EINVAL;
483 }
484
485 fan = devm_kzalloc(dev, sizeof(*fan), GFP_KERNEL);
486 if (!fan)
487 return -ENOMEM;
488
489 fan->dev = dev;
490 fan->regmap = pdata->regmap;
491
492 err = mlxreg_fan_config(fan, pdata);
493 if (err)
494 return err;
495
496 hwm = devm_hwmon_device_register_with_info(dev, "mlxreg_fan",
497 fan,
498 &mlxreg_fan_hwmon_chip_info,
499 NULL);
500 if (IS_ERR(hwm)) {
501 dev_err(dev, "Failed to register hwmon device\n");
502 return PTR_ERR(hwm);
503 }
504
505 if (IS_REACHABLE(CONFIG_THERMAL)) {
506 fan->cdev = devm_thermal_of_cooling_device_register(dev,
507 NULL, "mlxreg_fan", fan, &mlxreg_fan_cooling_ops);
508 if (IS_ERR(fan->cdev)) {
509 dev_err(dev, "Failed to register cooling device\n");
510 return PTR_ERR(fan->cdev);
511 }
512 }
513
514 return 0;
515 }
516
517 static struct platform_driver mlxreg_fan_driver = {
518 .driver = {
519 .name = "mlxreg-fan",
520 },
521 .probe = mlxreg_fan_probe,
522 };
523
524 module_platform_driver(mlxreg_fan_driver);
525
526 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
527 MODULE_DESCRIPTION("Mellanox FAN driver");
528 MODULE_LICENSE("GPL");
529 MODULE_ALIAS("platform:mlxreg-fan");
530