1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * tc654.c - Linux kernel modules for fan speed controller |
4 | * |
5 | * Copyright (C) 2016 Allied Telesis Labs NZ |
6 | */ |
7 | |
8 | #include <linux/bitops.h> |
9 | #include <linux/err.h> |
10 | #include <linux/hwmon.h> |
11 | #include <linux/hwmon-sysfs.h> |
12 | #include <linux/i2c.h> |
13 | #include <linux/init.h> |
14 | #include <linux/jiffies.h> |
15 | #include <linux/module.h> |
16 | #include <linux/mutex.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/thermal.h> |
19 | #include <linux/util_macros.h> |
20 | |
21 | enum tc654_regs { |
22 | TC654_REG_RPM1 = 0x00, /* RPM Output 1 */ |
23 | TC654_REG_RPM2 = 0x01, /* RPM Output 2 */ |
24 | TC654_REG_FAN_FAULT1 = 0x02, /* Fan Fault 1 Threshold */ |
25 | TC654_REG_FAN_FAULT2 = 0x03, /* Fan Fault 2 Threshold */ |
26 | TC654_REG_CONFIG = 0x04, /* Configuration */ |
27 | TC654_REG_STATUS = 0x05, /* Status */ |
28 | TC654_REG_DUTY_CYCLE = 0x06, /* Fan Speed Duty Cycle */ |
29 | TC654_REG_MFR_ID = 0x07, /* Manufacturer Identification */ |
30 | TC654_REG_VER_ID = 0x08, /* Version Identification */ |
31 | }; |
32 | |
33 | /* Macros to easily index the registers */ |
34 | #define TC654_REG_RPM(idx) (TC654_REG_RPM1 + (idx)) |
35 | #define TC654_REG_FAN_FAULT(idx) (TC654_REG_FAN_FAULT1 + (idx)) |
36 | |
37 | /* Config register bits */ |
38 | #define TC654_REG_CONFIG_RES BIT(6) /* Resolution Selection */ |
39 | #define TC654_REG_CONFIG_DUTYC BIT(5) /* Duty Cycle Control */ |
40 | #define TC654_REG_CONFIG_SDM BIT(0) /* Shutdown Mode */ |
41 | |
42 | /* Status register bits */ |
43 | #define TC654_REG_STATUS_F2F BIT(1) /* Fan 2 Fault */ |
44 | #define TC654_REG_STATUS_F1F BIT(0) /* Fan 1 Fault */ |
45 | |
46 | /* RPM resolution for RPM Output registers */ |
47 | #define TC654_HIGH_RPM_RESOLUTION 25 /* 25 RPM resolution */ |
48 | #define TC654_LOW_RPM_RESOLUTION 50 /* 50 RPM resolution */ |
49 | |
50 | /* Convert to the fan fault RPM threshold from register value */ |
51 | #define TC654_FAN_FAULT_FROM_REG(val) ((val) * 50) /* 50 RPM resolution */ |
52 | |
53 | /* Convert to register value from the fan fault RPM threshold */ |
54 | #define TC654_FAN_FAULT_TO_REG(val) (((val) / 50) & 0xff) |
55 | |
56 | /* Register data is read (and cached) at most once per second. */ |
57 | #define TC654_UPDATE_INTERVAL HZ |
58 | |
59 | struct tc654_data { |
60 | struct i2c_client *client; |
61 | |
62 | /* update mutex */ |
63 | struct mutex update_lock; |
64 | |
65 | /* tc654 register cache */ |
66 | bool valid; |
67 | unsigned long last_updated; /* in jiffies */ |
68 | |
69 | u8 rpm_output[2]; /* The fan RPM data for fans 1 and 2 is then |
70 | * written to registers RPM1 and RPM2 |
71 | */ |
72 | u8 fan_fault[2]; /* The Fan Fault Threshold Registers are used to |
73 | * set the fan fault threshold levels for fan 1 |
74 | * and fan 2 |
75 | */ |
76 | u8 config; /* The Configuration Register is an 8-bit read/ |
77 | * writable multi-function control register |
78 | * 7: Fan Fault Clear |
79 | * 1 = Clear Fan Fault |
80 | * 0 = Normal Operation (default) |
81 | * 6: Resolution Selection for RPM Output Registers |
82 | * RPM Output Registers (RPM1 and RPM2) will be |
83 | * set for |
84 | * 1 = 25 RPM (9-bit) resolution |
85 | * 0 = 50 RPM (8-bit) resolution (default) |
86 | * 5: Duty Cycle Control Method |
87 | * The V OUT duty cycle will be controlled via |
88 | * 1 = the SMBus interface. |
89 | * 0 = via the V IN analog input pin. (default) |
90 | * 4,3: Fan 2 Pulses Per Rotation |
91 | * 00 = 1 |
92 | * 01 = 2 (default) |
93 | * 10 = 4 |
94 | * 11 = 8 |
95 | * 2,1: Fan 1 Pulses Per Rotation |
96 | * 00 = 1 |
97 | * 01 = 2 (default) |
98 | * 10 = 4 |
99 | * 11 = 8 |
100 | * 0: Shutdown Mode |
101 | * 1 = Shutdown mode. |
102 | * 0 = Normal operation. (default) |
103 | */ |
104 | u8 status; /* The Status register provides all the information |
105 | * about what is going on within the TC654/TC655 |
106 | * devices. |
107 | * 7,6: Unimplemented, Read as '0' |
108 | * 5: Over-Temperature Fault Condition |
109 | * 1 = Over-Temperature condition has occurred |
110 | * 0 = Normal operation. V IN is less than 2.6V |
111 | * 4: RPM2 Counter Overflow |
112 | * 1 = Fault condition |
113 | * 0 = Normal operation |
114 | * 3: RPM1 Counter Overflow |
115 | * 1 = Fault condition |
116 | * 0 = Normal operation |
117 | * 2: V IN Input Status |
118 | * 1 = V IN is open |
119 | * 0 = Normal operation. voltage present at V IN |
120 | * 1: Fan 2 Fault |
121 | * 1 = Fault condition |
122 | * 0 = Normal operation |
123 | * 0: Fan 1 Fault |
124 | * 1 = Fault condition |
125 | * 0 = Normal operation |
126 | */ |
127 | u8 duty_cycle; /* The DUTY_CYCLE register is a 4-bit read/ |
128 | * writable register used to control the duty |
129 | * cycle of the V OUT output. |
130 | */ |
131 | }; |
132 | |
133 | /* helper to grab and cache data, at most one time per second */ |
134 | static struct tc654_data *tc654_update_client(struct device *dev) |
135 | { |
136 | struct tc654_data *data = dev_get_drvdata(dev); |
137 | struct i2c_client *client = data->client; |
138 | int ret = 0; |
139 | |
140 | mutex_lock(&data->update_lock); |
141 | if (time_before(jiffies, data->last_updated + TC654_UPDATE_INTERVAL) && |
142 | likely(data->valid)) |
143 | goto out; |
144 | |
145 | ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(0)); |
146 | if (ret < 0) |
147 | goto out; |
148 | data->rpm_output[0] = ret; |
149 | |
150 | ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(1)); |
151 | if (ret < 0) |
152 | goto out; |
153 | data->rpm_output[1] = ret; |
154 | |
155 | ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(0)); |
156 | if (ret < 0) |
157 | goto out; |
158 | data->fan_fault[0] = ret; |
159 | |
160 | ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(1)); |
161 | if (ret < 0) |
162 | goto out; |
163 | data->fan_fault[1] = ret; |
164 | |
165 | ret = i2c_smbus_read_byte_data(client, command: TC654_REG_CONFIG); |
166 | if (ret < 0) |
167 | goto out; |
168 | data->config = ret; |
169 | |
170 | ret = i2c_smbus_read_byte_data(client, command: TC654_REG_STATUS); |
171 | if (ret < 0) |
172 | goto out; |
173 | data->status = ret; |
174 | |
175 | ret = i2c_smbus_read_byte_data(client, command: TC654_REG_DUTY_CYCLE); |
176 | if (ret < 0) |
177 | goto out; |
178 | data->duty_cycle = ret & 0x0f; |
179 | |
180 | data->last_updated = jiffies; |
181 | data->valid = true; |
182 | out: |
183 | mutex_unlock(lock: &data->update_lock); |
184 | |
185 | if (ret < 0) /* upon error, encode it in return value */ |
186 | data = ERR_PTR(error: ret); |
187 | |
188 | return data; |
189 | } |
190 | |
191 | /* |
192 | * sysfs attributes |
193 | */ |
194 | |
195 | static ssize_t fan_show(struct device *dev, struct device_attribute *da, |
196 | char *buf) |
197 | { |
198 | int nr = to_sensor_dev_attr(da)->index; |
199 | struct tc654_data *data = tc654_update_client(dev); |
200 | int val; |
201 | |
202 | if (IS_ERR(ptr: data)) |
203 | return PTR_ERR(ptr: data); |
204 | |
205 | if (data->config & TC654_REG_CONFIG_RES) |
206 | val = data->rpm_output[nr] * TC654_HIGH_RPM_RESOLUTION; |
207 | else |
208 | val = data->rpm_output[nr] * TC654_LOW_RPM_RESOLUTION; |
209 | |
210 | return sprintf(buf, fmt: "%d\n" , val); |
211 | } |
212 | |
213 | static ssize_t fan_min_show(struct device *dev, struct device_attribute *da, |
214 | char *buf) |
215 | { |
216 | int nr = to_sensor_dev_attr(da)->index; |
217 | struct tc654_data *data = tc654_update_client(dev); |
218 | |
219 | if (IS_ERR(ptr: data)) |
220 | return PTR_ERR(ptr: data); |
221 | |
222 | return sprintf(buf, fmt: "%d\n" , |
223 | TC654_FAN_FAULT_FROM_REG(data->fan_fault[nr])); |
224 | } |
225 | |
226 | static ssize_t fan_min_store(struct device *dev, struct device_attribute *da, |
227 | const char *buf, size_t count) |
228 | { |
229 | int nr = to_sensor_dev_attr(da)->index; |
230 | struct tc654_data *data = dev_get_drvdata(dev); |
231 | struct i2c_client *client = data->client; |
232 | unsigned long val; |
233 | int ret; |
234 | |
235 | if (kstrtoul(s: buf, base: 10, res: &val)) |
236 | return -EINVAL; |
237 | |
238 | val = clamp_val(val, 0, 12750); |
239 | |
240 | mutex_lock(&data->update_lock); |
241 | |
242 | data->fan_fault[nr] = TC654_FAN_FAULT_TO_REG(val); |
243 | ret = i2c_smbus_write_byte_data(client, TC654_REG_FAN_FAULT(nr), |
244 | value: data->fan_fault[nr]); |
245 | |
246 | mutex_unlock(lock: &data->update_lock); |
247 | return ret < 0 ? ret : count; |
248 | } |
249 | |
250 | static ssize_t fan_alarm_show(struct device *dev, struct device_attribute *da, |
251 | char *buf) |
252 | { |
253 | int nr = to_sensor_dev_attr(da)->index; |
254 | struct tc654_data *data = tc654_update_client(dev); |
255 | int val; |
256 | |
257 | if (IS_ERR(ptr: data)) |
258 | return PTR_ERR(ptr: data); |
259 | |
260 | if (nr == 0) |
261 | val = !!(data->status & TC654_REG_STATUS_F1F); |
262 | else |
263 | val = !!(data->status & TC654_REG_STATUS_F2F); |
264 | |
265 | return sprintf(buf, fmt: "%d\n" , val); |
266 | } |
267 | |
268 | static const u8 TC654_FAN_PULSE_SHIFT[] = { 1, 3 }; |
269 | |
270 | static ssize_t fan_pulses_show(struct device *dev, |
271 | struct device_attribute *da, char *buf) |
272 | { |
273 | int nr = to_sensor_dev_attr(da)->index; |
274 | struct tc654_data *data = tc654_update_client(dev); |
275 | u8 val; |
276 | |
277 | if (IS_ERR(ptr: data)) |
278 | return PTR_ERR(ptr: data); |
279 | |
280 | val = BIT((data->config >> TC654_FAN_PULSE_SHIFT[nr]) & 0x03); |
281 | return sprintf(buf, fmt: "%d\n" , val); |
282 | } |
283 | |
284 | static ssize_t fan_pulses_store(struct device *dev, |
285 | struct device_attribute *da, const char *buf, |
286 | size_t count) |
287 | { |
288 | int nr = to_sensor_dev_attr(da)->index; |
289 | struct tc654_data *data = dev_get_drvdata(dev); |
290 | struct i2c_client *client = data->client; |
291 | u8 config; |
292 | unsigned long val; |
293 | int ret; |
294 | |
295 | if (kstrtoul(s: buf, base: 10, res: &val)) |
296 | return -EINVAL; |
297 | |
298 | switch (val) { |
299 | case 1: |
300 | config = 0; |
301 | break; |
302 | case 2: |
303 | config = 1; |
304 | break; |
305 | case 4: |
306 | config = 2; |
307 | break; |
308 | case 8: |
309 | config = 3; |
310 | break; |
311 | default: |
312 | return -EINVAL; |
313 | } |
314 | |
315 | mutex_lock(&data->update_lock); |
316 | |
317 | data->config &= ~(0x03 << TC654_FAN_PULSE_SHIFT[nr]); |
318 | data->config |= (config << TC654_FAN_PULSE_SHIFT[nr]); |
319 | ret = i2c_smbus_write_byte_data(client, command: TC654_REG_CONFIG, value: data->config); |
320 | |
321 | mutex_unlock(lock: &data->update_lock); |
322 | return ret < 0 ? ret : count; |
323 | } |
324 | |
325 | static ssize_t pwm_mode_show(struct device *dev, struct device_attribute *da, |
326 | char *buf) |
327 | { |
328 | struct tc654_data *data = tc654_update_client(dev); |
329 | |
330 | if (IS_ERR(ptr: data)) |
331 | return PTR_ERR(ptr: data); |
332 | |
333 | return sprintf(buf, fmt: "%d\n" , !!(data->config & TC654_REG_CONFIG_DUTYC)); |
334 | } |
335 | |
336 | static ssize_t pwm_mode_store(struct device *dev, struct device_attribute *da, |
337 | const char *buf, size_t count) |
338 | { |
339 | struct tc654_data *data = dev_get_drvdata(dev); |
340 | struct i2c_client *client = data->client; |
341 | unsigned long val; |
342 | int ret; |
343 | |
344 | if (kstrtoul(s: buf, base: 10, res: &val)) |
345 | return -EINVAL; |
346 | |
347 | if (val != 0 && val != 1) |
348 | return -EINVAL; |
349 | |
350 | mutex_lock(&data->update_lock); |
351 | |
352 | if (val) |
353 | data->config |= TC654_REG_CONFIG_DUTYC; |
354 | else |
355 | data->config &= ~TC654_REG_CONFIG_DUTYC; |
356 | |
357 | ret = i2c_smbus_write_byte_data(client, command: TC654_REG_CONFIG, value: data->config); |
358 | |
359 | mutex_unlock(lock: &data->update_lock); |
360 | return ret < 0 ? ret : count; |
361 | } |
362 | |
363 | static const int tc654_pwm_map[16] = { 77, 88, 102, 112, 124, 136, 148, 160, |
364 | 172, 184, 196, 207, 219, 231, 243, 255}; |
365 | |
366 | static ssize_t pwm_show(struct device *dev, struct device_attribute *da, |
367 | char *buf) |
368 | { |
369 | struct tc654_data *data = tc654_update_client(dev); |
370 | int pwm; |
371 | |
372 | if (IS_ERR(ptr: data)) |
373 | return PTR_ERR(ptr: data); |
374 | |
375 | if (data->config & TC654_REG_CONFIG_SDM) |
376 | pwm = 0; |
377 | else |
378 | pwm = tc654_pwm_map[data->duty_cycle]; |
379 | |
380 | return sprintf(buf, fmt: "%d\n" , pwm); |
381 | } |
382 | |
383 | static int _set_pwm(struct tc654_data *data, unsigned long val) |
384 | { |
385 | struct i2c_client *client = data->client; |
386 | int ret; |
387 | |
388 | mutex_lock(&data->update_lock); |
389 | |
390 | if (val == 0) { |
391 | data->config |= TC654_REG_CONFIG_SDM; |
392 | data->duty_cycle = 0; |
393 | } else { |
394 | data->config &= ~TC654_REG_CONFIG_SDM; |
395 | data->duty_cycle = val - 1; |
396 | } |
397 | |
398 | ret = i2c_smbus_write_byte_data(client, command: TC654_REG_CONFIG, value: data->config); |
399 | if (ret < 0) |
400 | goto out; |
401 | |
402 | ret = i2c_smbus_write_byte_data(client, command: TC654_REG_DUTY_CYCLE, |
403 | value: data->duty_cycle); |
404 | |
405 | out: |
406 | mutex_unlock(lock: &data->update_lock); |
407 | return ret; |
408 | } |
409 | |
410 | static ssize_t pwm_store(struct device *dev, struct device_attribute *da, |
411 | const char *buf, size_t count) |
412 | { |
413 | struct tc654_data *data = dev_get_drvdata(dev); |
414 | unsigned long val; |
415 | int ret; |
416 | |
417 | if (kstrtoul(s: buf, base: 10, res: &val)) |
418 | return -EINVAL; |
419 | if (val > 255) |
420 | return -EINVAL; |
421 | if (val > 0) |
422 | val = find_closest(val, tc654_pwm_map, ARRAY_SIZE(tc654_pwm_map)) + 1; |
423 | |
424 | ret = _set_pwm(data, val); |
425 | return ret < 0 ? ret : count; |
426 | } |
427 | |
428 | static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0); |
429 | static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1); |
430 | static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0); |
431 | static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1); |
432 | static SENSOR_DEVICE_ATTR_RO(fan1_alarm, fan_alarm, 0); |
433 | static SENSOR_DEVICE_ATTR_RO(fan2_alarm, fan_alarm, 1); |
434 | static SENSOR_DEVICE_ATTR_RW(fan1_pulses, fan_pulses, 0); |
435 | static SENSOR_DEVICE_ATTR_RW(fan2_pulses, fan_pulses, 1); |
436 | static SENSOR_DEVICE_ATTR_RW(pwm1_mode, pwm_mode, 0); |
437 | static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0); |
438 | |
439 | /* Driver data */ |
440 | static struct attribute *tc654_attrs[] = { |
441 | &sensor_dev_attr_fan1_input.dev_attr.attr, |
442 | &sensor_dev_attr_fan2_input.dev_attr.attr, |
443 | &sensor_dev_attr_fan1_min.dev_attr.attr, |
444 | &sensor_dev_attr_fan2_min.dev_attr.attr, |
445 | &sensor_dev_attr_fan1_alarm.dev_attr.attr, |
446 | &sensor_dev_attr_fan2_alarm.dev_attr.attr, |
447 | &sensor_dev_attr_fan1_pulses.dev_attr.attr, |
448 | &sensor_dev_attr_fan2_pulses.dev_attr.attr, |
449 | &sensor_dev_attr_pwm1_mode.dev_attr.attr, |
450 | &sensor_dev_attr_pwm1.dev_attr.attr, |
451 | NULL |
452 | }; |
453 | |
454 | ATTRIBUTE_GROUPS(tc654); |
455 | |
456 | /* |
457 | * thermal cooling device functions |
458 | * |
459 | * Account for the "ShutDown Mode (SDM)" state by offsetting |
460 | * the 16 PWM duty cycle states by 1. |
461 | * |
462 | * State 0 = 0% PWM | Shutdown - Fan(s) are off |
463 | * State 1 = 30% PWM | duty_cycle = 0 |
464 | * State 2 = ~35% PWM | duty_cycle = 1 |
465 | * [...] |
466 | * State 15 = ~95% PWM | duty_cycle = 14 |
467 | * State 16 = 100% PWM | duty_cycle = 15 |
468 | */ |
469 | #define TC654_MAX_COOLING_STATE 16 |
470 | |
471 | static int tc654_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state) |
472 | { |
473 | *state = TC654_MAX_COOLING_STATE; |
474 | return 0; |
475 | } |
476 | |
477 | static int tc654_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state) |
478 | { |
479 | struct tc654_data *data = tc654_update_client(dev: cdev->devdata); |
480 | |
481 | if (IS_ERR(ptr: data)) |
482 | return PTR_ERR(ptr: data); |
483 | |
484 | if (data->config & TC654_REG_CONFIG_SDM) |
485 | *state = 0; /* FAN is off */ |
486 | else |
487 | *state = data->duty_cycle + 1; /* offset PWM States by 1 */ |
488 | |
489 | return 0; |
490 | } |
491 | |
492 | static int tc654_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) |
493 | { |
494 | struct tc654_data *data = tc654_update_client(dev: cdev->devdata); |
495 | |
496 | if (IS_ERR(ptr: data)) |
497 | return PTR_ERR(ptr: data); |
498 | |
499 | return _set_pwm(data, clamp_val(state, 0, TC654_MAX_COOLING_STATE)); |
500 | } |
501 | |
502 | static const struct thermal_cooling_device_ops tc654_fan_cool_ops = { |
503 | .get_max_state = tc654_get_max_state, |
504 | .get_cur_state = tc654_get_cur_state, |
505 | .set_cur_state = tc654_set_cur_state, |
506 | }; |
507 | |
508 | /* |
509 | * device probe and removal |
510 | */ |
511 | |
512 | static int tc654_probe(struct i2c_client *client) |
513 | { |
514 | struct device *dev = &client->dev; |
515 | struct tc654_data *data; |
516 | struct device *hwmon_dev; |
517 | int ret; |
518 | |
519 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
520 | return -ENODEV; |
521 | |
522 | data = devm_kzalloc(dev, size: sizeof(struct tc654_data), GFP_KERNEL); |
523 | if (!data) |
524 | return -ENOMEM; |
525 | |
526 | data->client = client; |
527 | mutex_init(&data->update_lock); |
528 | |
529 | ret = i2c_smbus_read_byte_data(client, command: TC654_REG_CONFIG); |
530 | if (ret < 0) |
531 | return ret; |
532 | |
533 | data->config = ret; |
534 | |
535 | hwmon_dev = |
536 | devm_hwmon_device_register_with_groups(dev, name: client->name, drvdata: data, |
537 | groups: tc654_groups); |
538 | if (IS_ERR(ptr: hwmon_dev)) |
539 | return PTR_ERR(ptr: hwmon_dev); |
540 | |
541 | if (IS_ENABLED(CONFIG_THERMAL)) { |
542 | struct thermal_cooling_device *cdev; |
543 | |
544 | cdev = devm_thermal_of_cooling_device_register(dev, np: dev->of_node, type: client->name, |
545 | devdata: hwmon_dev, ops: &tc654_fan_cool_ops); |
546 | return PTR_ERR_OR_ZERO(ptr: cdev); |
547 | } |
548 | |
549 | return 0; |
550 | } |
551 | |
552 | static const struct i2c_device_id tc654_id[] = { |
553 | {"tc654" , 0}, |
554 | {"tc655" , 0}, |
555 | {} |
556 | }; |
557 | |
558 | MODULE_DEVICE_TABLE(i2c, tc654_id); |
559 | |
560 | static struct i2c_driver tc654_driver = { |
561 | .driver = { |
562 | .name = "tc654" , |
563 | }, |
564 | .probe = tc654_probe, |
565 | .id_table = tc654_id, |
566 | }; |
567 | |
568 | module_i2c_driver(tc654_driver); |
569 | |
570 | MODULE_AUTHOR("Allied Telesis Labs" ); |
571 | MODULE_DESCRIPTION("Microchip TC654/TC655 driver" ); |
572 | MODULE_LICENSE("GPL" ); |
573 | |