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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
aaf6fabf CP |
2 | /* |
3 | * tc654.c - Linux kernel modules for fan speed controller | |
4 | * | |
5 | * Copyright (C) 2016 Allied Telesis Labs NZ | |
aaf6fabf CP |
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/util_macros.h> | |
19 | ||
20 | enum tc654_regs { | |
21 | TC654_REG_RPM1 = 0x00, /* RPM Output 1 */ | |
22 | TC654_REG_RPM2 = 0x01, /* RPM Output 2 */ | |
23 | TC654_REG_FAN_FAULT1 = 0x02, /* Fan Fault 1 Threshold */ | |
24 | TC654_REG_FAN_FAULT2 = 0x03, /* Fan Fault 2 Threshold */ | |
25 | TC654_REG_CONFIG = 0x04, /* Configuration */ | |
26 | TC654_REG_STATUS = 0x05, /* Status */ | |
27 | TC654_REG_DUTY_CYCLE = 0x06, /* Fan Speed Duty Cycle */ | |
28 | TC654_REG_MFR_ID = 0x07, /* Manufacturer Identification */ | |
29 | TC654_REG_VER_ID = 0x08, /* Version Identification */ | |
30 | }; | |
31 | ||
32 | /* Macros to easily index the registers */ | |
33 | #define TC654_REG_RPM(idx) (TC654_REG_RPM1 + (idx)) | |
34 | #define TC654_REG_FAN_FAULT(idx) (TC654_REG_FAN_FAULT1 + (idx)) | |
35 | ||
36 | /* Config register bits */ | |
37 | #define TC654_REG_CONFIG_RES BIT(6) /* Resolution Selection */ | |
38 | #define TC654_REG_CONFIG_DUTYC BIT(5) /* Duty Cycle Control */ | |
39 | #define TC654_REG_CONFIG_SDM BIT(0) /* Shutdown Mode */ | |
40 | ||
41 | /* Status register bits */ | |
42 | #define TC654_REG_STATUS_F2F BIT(1) /* Fan 2 Fault */ | |
43 | #define TC654_REG_STATUS_F1F BIT(0) /* Fan 1 Fault */ | |
44 | ||
45 | /* RPM resolution for RPM Output registers */ | |
46 | #define TC654_HIGH_RPM_RESOLUTION 25 /* 25 RPM resolution */ | |
47 | #define TC654_LOW_RPM_RESOLUTION 50 /* 50 RPM resolution */ | |
48 | ||
49 | /* Convert to the fan fault RPM threshold from register value */ | |
50 | #define TC654_FAN_FAULT_FROM_REG(val) ((val) * 50) /* 50 RPM resolution */ | |
51 | ||
52 | /* Convert to register value from the fan fault RPM threshold */ | |
53 | #define TC654_FAN_FAULT_TO_REG(val) (((val) / 50) & 0xff) | |
54 | ||
55 | /* Register data is read (and cached) at most once per second. */ | |
56 | #define TC654_UPDATE_INTERVAL HZ | |
57 | ||
58 | struct tc654_data { | |
59 | struct i2c_client *client; | |
60 | ||
61 | /* update mutex */ | |
62 | struct mutex update_lock; | |
63 | ||
64 | /* tc654 register cache */ | |
65 | bool valid; | |
66 | unsigned long last_updated; /* in jiffies */ | |
67 | ||
68 | u8 rpm_output[2]; /* The fan RPM data for fans 1 and 2 is then | |
69 | * written to registers RPM1 and RPM2 | |
70 | */ | |
71 | u8 fan_fault[2]; /* The Fan Fault Threshold Registers are used to | |
72 | * set the fan fault threshold levels for fan 1 | |
73 | * and fan 2 | |
74 | */ | |
75 | u8 config; /* The Configuration Register is an 8-bit read/ | |
76 | * writable multi-function control register | |
77 | * 7: Fan Fault Clear | |
78 | * 1 = Clear Fan Fault | |
79 | * 0 = Normal Operation (default) | |
80 | * 6: Resolution Selection for RPM Output Registers | |
81 | * RPM Output Registers (RPM1 and RPM2) will be | |
82 | * set for | |
83 | * 1 = 25 RPM (9-bit) resolution | |
84 | * 0 = 50 RPM (8-bit) resolution (default) | |
85 | * 5: Duty Cycle Control Method | |
86 | * The V OUT duty cycle will be controlled via | |
87 | * 1 = the SMBus interface. | |
88 | * 0 = via the V IN analog input pin. (default) | |
89 | * 4,3: Fan 2 Pulses Per Rotation | |
90 | * 00 = 1 | |
91 | * 01 = 2 (default) | |
92 | * 10 = 4 | |
93 | * 11 = 8 | |
94 | * 2,1: Fan 1 Pulses Per Rotation | |
95 | * 00 = 1 | |
96 | * 01 = 2 (default) | |
97 | * 10 = 4 | |
98 | * 11 = 8 | |
99 | * 0: Shutdown Mode | |
100 | * 1 = Shutdown mode. | |
101 | * 0 = Normal operation. (default) | |
102 | */ | |
103 | u8 status; /* The Status register provides all the information | |
104 | * about what is going on within the TC654/TC655 | |
105 | * devices. | |
106 | * 7,6: Unimplemented, Read as '0' | |
107 | * 5: Over-Temperature Fault Condition | |
108 | * 1 = Over-Temperature condition has occurred | |
109 | * 0 = Normal operation. V IN is less than 2.6V | |
110 | * 4: RPM2 Counter Overflow | |
111 | * 1 = Fault condition | |
112 | * 0 = Normal operation | |
113 | * 3: RPM1 Counter Overflow | |
114 | * 1 = Fault condition | |
115 | * 0 = Normal operation | |
116 | * 2: V IN Input Status | |
117 | * 1 = V IN is open | |
118 | * 0 = Normal operation. voltage present at V IN | |
119 | * 1: Fan 2 Fault | |
120 | * 1 = Fault condition | |
121 | * 0 = Normal operation | |
122 | * 0: Fan 1 Fault | |
123 | * 1 = Fault condition | |
124 | * 0 = Normal operation | |
125 | */ | |
126 | u8 duty_cycle; /* The DUTY_CYCLE register is a 4-bit read/ | |
127 | * writable register used to control the duty | |
128 | * cycle of the V OUT output. | |
129 | */ | |
130 | }; | |
131 | ||
132 | /* helper to grab and cache data, at most one time per second */ | |
133 | static struct tc654_data *tc654_update_client(struct device *dev) | |
134 | { | |
135 | struct tc654_data *data = dev_get_drvdata(dev); | |
136 | struct i2c_client *client = data->client; | |
137 | int ret = 0; | |
138 | ||
139 | mutex_lock(&data->update_lock); | |
140 | if (time_before(jiffies, data->last_updated + TC654_UPDATE_INTERVAL) && | |
141 | likely(data->valid)) | |
142 | goto out; | |
143 | ||
144 | ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(0)); | |
145 | if (ret < 0) | |
146 | goto out; | |
147 | data->rpm_output[0] = ret; | |
148 | ||
149 | ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(1)); | |
150 | if (ret < 0) | |
151 | goto out; | |
152 | data->rpm_output[1] = ret; | |
153 | ||
154 | ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(0)); | |
155 | if (ret < 0) | |
156 | goto out; | |
157 | data->fan_fault[0] = ret; | |
158 | ||
159 | ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(1)); | |
160 | if (ret < 0) | |
161 | goto out; | |
162 | data->fan_fault[1] = ret; | |
163 | ||
164 | ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); | |
165 | if (ret < 0) | |
166 | goto out; | |
167 | data->config = ret; | |
168 | ||
169 | ret = i2c_smbus_read_byte_data(client, TC654_REG_STATUS); | |
170 | if (ret < 0) | |
171 | goto out; | |
172 | data->status = ret; | |
173 | ||
174 | ret = i2c_smbus_read_byte_data(client, TC654_REG_DUTY_CYCLE); | |
175 | if (ret < 0) | |
176 | goto out; | |
177 | data->duty_cycle = ret & 0x0f; | |
178 | ||
179 | data->last_updated = jiffies; | |
180 | data->valid = true; | |
181 | out: | |
182 | mutex_unlock(&data->update_lock); | |
183 | ||
184 | if (ret < 0) /* upon error, encode it in return value */ | |
185 | data = ERR_PTR(ret); | |
186 | ||
187 | return data; | |
188 | } | |
189 | ||
190 | /* | |
191 | * sysfs attributes | |
192 | */ | |
193 | ||
1acd2e29 | 194 | static ssize_t fan_show(struct device *dev, struct device_attribute *da, |
aaf6fabf CP |
195 | char *buf) |
196 | { | |
197 | int nr = to_sensor_dev_attr(da)->index; | |
198 | struct tc654_data *data = tc654_update_client(dev); | |
199 | int val; | |
200 | ||
201 | if (IS_ERR(data)) | |
202 | return PTR_ERR(data); | |
203 | ||
204 | if (data->config & TC654_REG_CONFIG_RES) | |
205 | val = data->rpm_output[nr] * TC654_HIGH_RPM_RESOLUTION; | |
206 | else | |
207 | val = data->rpm_output[nr] * TC654_LOW_RPM_RESOLUTION; | |
208 | ||
209 | return sprintf(buf, "%d\n", val); | |
210 | } | |
211 | ||
1acd2e29 | 212 | static ssize_t fan_min_show(struct device *dev, struct device_attribute *da, |
aaf6fabf CP |
213 | char *buf) |
214 | { | |
215 | int nr = to_sensor_dev_attr(da)->index; | |
216 | struct tc654_data *data = tc654_update_client(dev); | |
217 | ||
218 | if (IS_ERR(data)) | |
219 | return PTR_ERR(data); | |
220 | ||
221 | return sprintf(buf, "%d\n", | |
222 | TC654_FAN_FAULT_FROM_REG(data->fan_fault[nr])); | |
223 | } | |
224 | ||
1acd2e29 GR |
225 | static ssize_t fan_min_store(struct device *dev, struct device_attribute *da, |
226 | const char *buf, size_t count) | |
aaf6fabf CP |
227 | { |
228 | int nr = to_sensor_dev_attr(da)->index; | |
229 | struct tc654_data *data = dev_get_drvdata(dev); | |
230 | struct i2c_client *client = data->client; | |
231 | unsigned long val; | |
232 | int ret; | |
233 | ||
234 | if (kstrtoul(buf, 10, &val)) | |
235 | return -EINVAL; | |
236 | ||
237 | val = clamp_val(val, 0, 12750); | |
238 | ||
239 | mutex_lock(&data->update_lock); | |
240 | ||
241 | data->fan_fault[nr] = TC654_FAN_FAULT_TO_REG(val); | |
242 | ret = i2c_smbus_write_byte_data(client, TC654_REG_FAN_FAULT(nr), | |
243 | data->fan_fault[nr]); | |
244 | ||
245 | mutex_unlock(&data->update_lock); | |
246 | return ret < 0 ? ret : count; | |
247 | } | |
248 | ||
1acd2e29 | 249 | static ssize_t fan_alarm_show(struct device *dev, struct device_attribute *da, |
aaf6fabf CP |
250 | char *buf) |
251 | { | |
252 | int nr = to_sensor_dev_attr(da)->index; | |
253 | struct tc654_data *data = tc654_update_client(dev); | |
254 | int val; | |
255 | ||
256 | if (IS_ERR(data)) | |
257 | return PTR_ERR(data); | |
258 | ||
259 | if (nr == 0) | |
260 | val = !!(data->status & TC654_REG_STATUS_F1F); | |
261 | else | |
262 | val = !!(data->status & TC654_REG_STATUS_F2F); | |
263 | ||
264 | return sprintf(buf, "%d\n", val); | |
265 | } | |
266 | ||
267 | static const u8 TC654_FAN_PULSE_SHIFT[] = { 1, 3 }; | |
268 | ||
1acd2e29 GR |
269 | static ssize_t fan_pulses_show(struct device *dev, |
270 | struct device_attribute *da, char *buf) | |
aaf6fabf CP |
271 | { |
272 | int nr = to_sensor_dev_attr(da)->index; | |
273 | struct tc654_data *data = tc654_update_client(dev); | |
274 | u8 val; | |
275 | ||
276 | if (IS_ERR(data)) | |
277 | return PTR_ERR(data); | |
278 | ||
279 | val = BIT((data->config >> TC654_FAN_PULSE_SHIFT[nr]) & 0x03); | |
280 | return sprintf(buf, "%d\n", val); | |
281 | } | |
282 | ||
1acd2e29 GR |
283 | static ssize_t fan_pulses_store(struct device *dev, |
284 | struct device_attribute *da, const char *buf, | |
285 | size_t count) | |
aaf6fabf CP |
286 | { |
287 | int nr = to_sensor_dev_attr(da)->index; | |
288 | struct tc654_data *data = dev_get_drvdata(dev); | |
289 | struct i2c_client *client = data->client; | |
290 | u8 config; | |
291 | unsigned long val; | |
292 | int ret; | |
293 | ||
294 | if (kstrtoul(buf, 10, &val)) | |
295 | return -EINVAL; | |
296 | ||
297 | switch (val) { | |
298 | case 1: | |
299 | config = 0; | |
300 | break; | |
301 | case 2: | |
302 | config = 1; | |
303 | break; | |
304 | case 4: | |
305 | config = 2; | |
306 | break; | |
307 | case 8: | |
308 | config = 3; | |
309 | break; | |
310 | default: | |
311 | return -EINVAL; | |
312 | } | |
313 | ||
314 | mutex_lock(&data->update_lock); | |
315 | ||
316 | data->config &= ~(0x03 << TC654_FAN_PULSE_SHIFT[nr]); | |
317 | data->config |= (config << TC654_FAN_PULSE_SHIFT[nr]); | |
318 | ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); | |
319 | ||
320 | mutex_unlock(&data->update_lock); | |
321 | return ret < 0 ? ret : count; | |
322 | } | |
323 | ||
1acd2e29 GR |
324 | static ssize_t pwm_mode_show(struct device *dev, struct device_attribute *da, |
325 | char *buf) | |
aaf6fabf CP |
326 | { |
327 | struct tc654_data *data = tc654_update_client(dev); | |
328 | ||
329 | if (IS_ERR(data)) | |
330 | return PTR_ERR(data); | |
331 | ||
332 | return sprintf(buf, "%d\n", !!(data->config & TC654_REG_CONFIG_DUTYC)); | |
333 | } | |
334 | ||
1acd2e29 GR |
335 | static ssize_t pwm_mode_store(struct device *dev, struct device_attribute *da, |
336 | const char *buf, size_t count) | |
aaf6fabf CP |
337 | { |
338 | struct tc654_data *data = dev_get_drvdata(dev); | |
339 | struct i2c_client *client = data->client; | |
340 | unsigned long val; | |
341 | int ret; | |
342 | ||
343 | if (kstrtoul(buf, 10, &val)) | |
344 | return -EINVAL; | |
345 | ||
346 | if (val != 0 && val != 1) | |
347 | return -EINVAL; | |
348 | ||
349 | mutex_lock(&data->update_lock); | |
350 | ||
351 | if (val) | |
352 | data->config |= TC654_REG_CONFIG_DUTYC; | |
353 | else | |
354 | data->config &= ~TC654_REG_CONFIG_DUTYC; | |
355 | ||
356 | ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); | |
357 | ||
358 | mutex_unlock(&data->update_lock); | |
359 | return ret < 0 ? ret : count; | |
360 | } | |
361 | ||
362 | static const int tc654_pwm_map[16] = { 77, 88, 102, 112, 124, 136, 148, 160, | |
363 | 172, 184, 196, 207, 219, 231, 243, 255}; | |
364 | ||
1acd2e29 | 365 | static ssize_t pwm_show(struct device *dev, struct device_attribute *da, |
aaf6fabf CP |
366 | char *buf) |
367 | { | |
368 | struct tc654_data *data = tc654_update_client(dev); | |
369 | int pwm; | |
370 | ||
371 | if (IS_ERR(data)) | |
372 | return PTR_ERR(data); | |
373 | ||
374 | if (data->config & TC654_REG_CONFIG_SDM) | |
375 | pwm = 0; | |
376 | else | |
377 | pwm = tc654_pwm_map[data->duty_cycle]; | |
378 | ||
379 | return sprintf(buf, "%d\n", pwm); | |
380 | } | |
381 | ||
1acd2e29 GR |
382 | static ssize_t pwm_store(struct device *dev, struct device_attribute *da, |
383 | const char *buf, size_t count) | |
aaf6fabf CP |
384 | { |
385 | struct tc654_data *data = dev_get_drvdata(dev); | |
386 | struct i2c_client *client = data->client; | |
387 | unsigned long val; | |
388 | int ret; | |
389 | ||
390 | if (kstrtoul(buf, 10, &val)) | |
391 | return -EINVAL; | |
392 | if (val > 255) | |
393 | return -EINVAL; | |
394 | ||
395 | mutex_lock(&data->update_lock); | |
396 | ||
397 | if (val == 0) | |
398 | data->config |= TC654_REG_CONFIG_SDM; | |
399 | else | |
400 | data->config &= ~TC654_REG_CONFIG_SDM; | |
401 | ||
402 | data->duty_cycle = find_closest(val, tc654_pwm_map, | |
403 | ARRAY_SIZE(tc654_pwm_map)); | |
404 | ||
405 | ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); | |
406 | if (ret < 0) | |
407 | goto out; | |
408 | ||
409 | ret = i2c_smbus_write_byte_data(client, TC654_REG_DUTY_CYCLE, | |
410 | data->duty_cycle); | |
411 | ||
412 | out: | |
413 | mutex_unlock(&data->update_lock); | |
414 | return ret < 0 ? ret : count; | |
415 | } | |
416 | ||
1acd2e29 GR |
417 | static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0); |
418 | static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1); | |
419 | static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0); | |
420 | static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1); | |
421 | static SENSOR_DEVICE_ATTR_RO(fan1_alarm, fan_alarm, 0); | |
422 | static SENSOR_DEVICE_ATTR_RO(fan2_alarm, fan_alarm, 1); | |
423 | static SENSOR_DEVICE_ATTR_RW(fan1_pulses, fan_pulses, 0); | |
424 | static SENSOR_DEVICE_ATTR_RW(fan2_pulses, fan_pulses, 1); | |
425 | static SENSOR_DEVICE_ATTR_RW(pwm1_mode, pwm_mode, 0); | |
426 | static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0); | |
aaf6fabf CP |
427 | |
428 | /* Driver data */ | |
429 | static struct attribute *tc654_attrs[] = { | |
430 | &sensor_dev_attr_fan1_input.dev_attr.attr, | |
431 | &sensor_dev_attr_fan2_input.dev_attr.attr, | |
432 | &sensor_dev_attr_fan1_min.dev_attr.attr, | |
433 | &sensor_dev_attr_fan2_min.dev_attr.attr, | |
434 | &sensor_dev_attr_fan1_alarm.dev_attr.attr, | |
435 | &sensor_dev_attr_fan2_alarm.dev_attr.attr, | |
436 | &sensor_dev_attr_fan1_pulses.dev_attr.attr, | |
437 | &sensor_dev_attr_fan2_pulses.dev_attr.attr, | |
438 | &sensor_dev_attr_pwm1_mode.dev_attr.attr, | |
439 | &sensor_dev_attr_pwm1.dev_attr.attr, | |
440 | NULL | |
441 | }; | |
442 | ||
443 | ATTRIBUTE_GROUPS(tc654); | |
444 | ||
445 | /* | |
446 | * device probe and removal | |
447 | */ | |
448 | ||
449 | static int tc654_probe(struct i2c_client *client, | |
450 | const struct i2c_device_id *id) | |
451 | { | |
452 | struct device *dev = &client->dev; | |
453 | struct tc654_data *data; | |
454 | struct device *hwmon_dev; | |
455 | int ret; | |
456 | ||
457 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
458 | return -ENODEV; | |
459 | ||
460 | data = devm_kzalloc(dev, sizeof(struct tc654_data), GFP_KERNEL); | |
461 | if (!data) | |
462 | return -ENOMEM; | |
463 | ||
464 | data->client = client; | |
465 | mutex_init(&data->update_lock); | |
466 | ||
467 | ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); | |
468 | if (ret < 0) | |
469 | return ret; | |
470 | ||
471 | data->config = ret; | |
472 | ||
473 | hwmon_dev = | |
474 | devm_hwmon_device_register_with_groups(dev, client->name, data, | |
475 | tc654_groups); | |
476 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
477 | } | |
478 | ||
479 | static const struct i2c_device_id tc654_id[] = { | |
480 | {"tc654", 0}, | |
481 | {"tc655", 0}, | |
482 | {} | |
483 | }; | |
484 | ||
485 | MODULE_DEVICE_TABLE(i2c, tc654_id); | |
486 | ||
487 | static struct i2c_driver tc654_driver = { | |
488 | .driver = { | |
489 | .name = "tc654", | |
490 | }, | |
491 | .probe = tc654_probe, | |
492 | .id_table = tc654_id, | |
493 | }; | |
494 | ||
495 | module_i2c_driver(tc654_driver); | |
496 | ||
497 | MODULE_AUTHOR("Allied Telesis Labs"); | |
498 | MODULE_DESCRIPTION("Microchip TC654/TC655 driver"); | |
499 | MODULE_LICENSE("GPL"); |