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aaf6fabf CP |
1 | /* |
2 | * tc654.c - Linux kernel modules for fan speed controller | |
3 | * | |
4 | * Copyright (C) 2016 Allied Telesis Labs NZ | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/bitops.h> | |
18 | #include <linux/err.h> | |
19 | #include <linux/hwmon.h> | |
20 | #include <linux/hwmon-sysfs.h> | |
21 | #include <linux/i2c.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/jiffies.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/mutex.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/util_macros.h> | |
28 | ||
29 | enum tc654_regs { | |
30 | TC654_REG_RPM1 = 0x00, /* RPM Output 1 */ | |
31 | TC654_REG_RPM2 = 0x01, /* RPM Output 2 */ | |
32 | TC654_REG_FAN_FAULT1 = 0x02, /* Fan Fault 1 Threshold */ | |
33 | TC654_REG_FAN_FAULT2 = 0x03, /* Fan Fault 2 Threshold */ | |
34 | TC654_REG_CONFIG = 0x04, /* Configuration */ | |
35 | TC654_REG_STATUS = 0x05, /* Status */ | |
36 | TC654_REG_DUTY_CYCLE = 0x06, /* Fan Speed Duty Cycle */ | |
37 | TC654_REG_MFR_ID = 0x07, /* Manufacturer Identification */ | |
38 | TC654_REG_VER_ID = 0x08, /* Version Identification */ | |
39 | }; | |
40 | ||
41 | /* Macros to easily index the registers */ | |
42 | #define TC654_REG_RPM(idx) (TC654_REG_RPM1 + (idx)) | |
43 | #define TC654_REG_FAN_FAULT(idx) (TC654_REG_FAN_FAULT1 + (idx)) | |
44 | ||
45 | /* Config register bits */ | |
46 | #define TC654_REG_CONFIG_RES BIT(6) /* Resolution Selection */ | |
47 | #define TC654_REG_CONFIG_DUTYC BIT(5) /* Duty Cycle Control */ | |
48 | #define TC654_REG_CONFIG_SDM BIT(0) /* Shutdown Mode */ | |
49 | ||
50 | /* Status register bits */ | |
51 | #define TC654_REG_STATUS_F2F BIT(1) /* Fan 2 Fault */ | |
52 | #define TC654_REG_STATUS_F1F BIT(0) /* Fan 1 Fault */ | |
53 | ||
54 | /* RPM resolution for RPM Output registers */ | |
55 | #define TC654_HIGH_RPM_RESOLUTION 25 /* 25 RPM resolution */ | |
56 | #define TC654_LOW_RPM_RESOLUTION 50 /* 50 RPM resolution */ | |
57 | ||
58 | /* Convert to the fan fault RPM threshold from register value */ | |
59 | #define TC654_FAN_FAULT_FROM_REG(val) ((val) * 50) /* 50 RPM resolution */ | |
60 | ||
61 | /* Convert to register value from the fan fault RPM threshold */ | |
62 | #define TC654_FAN_FAULT_TO_REG(val) (((val) / 50) & 0xff) | |
63 | ||
64 | /* Register data is read (and cached) at most once per second. */ | |
65 | #define TC654_UPDATE_INTERVAL HZ | |
66 | ||
67 | struct tc654_data { | |
68 | struct i2c_client *client; | |
69 | ||
70 | /* update mutex */ | |
71 | struct mutex update_lock; | |
72 | ||
73 | /* tc654 register cache */ | |
74 | bool valid; | |
75 | unsigned long last_updated; /* in jiffies */ | |
76 | ||
77 | u8 rpm_output[2]; /* The fan RPM data for fans 1 and 2 is then | |
78 | * written to registers RPM1 and RPM2 | |
79 | */ | |
80 | u8 fan_fault[2]; /* The Fan Fault Threshold Registers are used to | |
81 | * set the fan fault threshold levels for fan 1 | |
82 | * and fan 2 | |
83 | */ | |
84 | u8 config; /* The Configuration Register is an 8-bit read/ | |
85 | * writable multi-function control register | |
86 | * 7: Fan Fault Clear | |
87 | * 1 = Clear Fan Fault | |
88 | * 0 = Normal Operation (default) | |
89 | * 6: Resolution Selection for RPM Output Registers | |
90 | * RPM Output Registers (RPM1 and RPM2) will be | |
91 | * set for | |
92 | * 1 = 25 RPM (9-bit) resolution | |
93 | * 0 = 50 RPM (8-bit) resolution (default) | |
94 | * 5: Duty Cycle Control Method | |
95 | * The V OUT duty cycle will be controlled via | |
96 | * 1 = the SMBus interface. | |
97 | * 0 = via the V IN analog input pin. (default) | |
98 | * 4,3: Fan 2 Pulses Per Rotation | |
99 | * 00 = 1 | |
100 | * 01 = 2 (default) | |
101 | * 10 = 4 | |
102 | * 11 = 8 | |
103 | * 2,1: Fan 1 Pulses Per Rotation | |
104 | * 00 = 1 | |
105 | * 01 = 2 (default) | |
106 | * 10 = 4 | |
107 | * 11 = 8 | |
108 | * 0: Shutdown Mode | |
109 | * 1 = Shutdown mode. | |
110 | * 0 = Normal operation. (default) | |
111 | */ | |
112 | u8 status; /* The Status register provides all the information | |
113 | * about what is going on within the TC654/TC655 | |
114 | * devices. | |
115 | * 7,6: Unimplemented, Read as '0' | |
116 | * 5: Over-Temperature Fault Condition | |
117 | * 1 = Over-Temperature condition has occurred | |
118 | * 0 = Normal operation. V IN is less than 2.6V | |
119 | * 4: RPM2 Counter Overflow | |
120 | * 1 = Fault condition | |
121 | * 0 = Normal operation | |
122 | * 3: RPM1 Counter Overflow | |
123 | * 1 = Fault condition | |
124 | * 0 = Normal operation | |
125 | * 2: V IN Input Status | |
126 | * 1 = V IN is open | |
127 | * 0 = Normal operation. voltage present at V IN | |
128 | * 1: Fan 2 Fault | |
129 | * 1 = Fault condition | |
130 | * 0 = Normal operation | |
131 | * 0: Fan 1 Fault | |
132 | * 1 = Fault condition | |
133 | * 0 = Normal operation | |
134 | */ | |
135 | u8 duty_cycle; /* The DUTY_CYCLE register is a 4-bit read/ | |
136 | * writable register used to control the duty | |
137 | * cycle of the V OUT output. | |
138 | */ | |
139 | }; | |
140 | ||
141 | /* helper to grab and cache data, at most one time per second */ | |
142 | static struct tc654_data *tc654_update_client(struct device *dev) | |
143 | { | |
144 | struct tc654_data *data = dev_get_drvdata(dev); | |
145 | struct i2c_client *client = data->client; | |
146 | int ret = 0; | |
147 | ||
148 | mutex_lock(&data->update_lock); | |
149 | if (time_before(jiffies, data->last_updated + TC654_UPDATE_INTERVAL) && | |
150 | likely(data->valid)) | |
151 | goto out; | |
152 | ||
153 | ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(0)); | |
154 | if (ret < 0) | |
155 | goto out; | |
156 | data->rpm_output[0] = ret; | |
157 | ||
158 | ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(1)); | |
159 | if (ret < 0) | |
160 | goto out; | |
161 | data->rpm_output[1] = ret; | |
162 | ||
163 | ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(0)); | |
164 | if (ret < 0) | |
165 | goto out; | |
166 | data->fan_fault[0] = ret; | |
167 | ||
168 | ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(1)); | |
169 | if (ret < 0) | |
170 | goto out; | |
171 | data->fan_fault[1] = ret; | |
172 | ||
173 | ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); | |
174 | if (ret < 0) | |
175 | goto out; | |
176 | data->config = ret; | |
177 | ||
178 | ret = i2c_smbus_read_byte_data(client, TC654_REG_STATUS); | |
179 | if (ret < 0) | |
180 | goto out; | |
181 | data->status = ret; | |
182 | ||
183 | ret = i2c_smbus_read_byte_data(client, TC654_REG_DUTY_CYCLE); | |
184 | if (ret < 0) | |
185 | goto out; | |
186 | data->duty_cycle = ret & 0x0f; | |
187 | ||
188 | data->last_updated = jiffies; | |
189 | data->valid = true; | |
190 | out: | |
191 | mutex_unlock(&data->update_lock); | |
192 | ||
193 | if (ret < 0) /* upon error, encode it in return value */ | |
194 | data = ERR_PTR(ret); | |
195 | ||
196 | return data; | |
197 | } | |
198 | ||
199 | /* | |
200 | * sysfs attributes | |
201 | */ | |
202 | ||
203 | static ssize_t show_fan(struct device *dev, struct device_attribute *da, | |
204 | char *buf) | |
205 | { | |
206 | int nr = to_sensor_dev_attr(da)->index; | |
207 | struct tc654_data *data = tc654_update_client(dev); | |
208 | int val; | |
209 | ||
210 | if (IS_ERR(data)) | |
211 | return PTR_ERR(data); | |
212 | ||
213 | if (data->config & TC654_REG_CONFIG_RES) | |
214 | val = data->rpm_output[nr] * TC654_HIGH_RPM_RESOLUTION; | |
215 | else | |
216 | val = data->rpm_output[nr] * TC654_LOW_RPM_RESOLUTION; | |
217 | ||
218 | return sprintf(buf, "%d\n", val); | |
219 | } | |
220 | ||
221 | static ssize_t show_fan_min(struct device *dev, struct device_attribute *da, | |
222 | char *buf) | |
223 | { | |
224 | int nr = to_sensor_dev_attr(da)->index; | |
225 | struct tc654_data *data = tc654_update_client(dev); | |
226 | ||
227 | if (IS_ERR(data)) | |
228 | return PTR_ERR(data); | |
229 | ||
230 | return sprintf(buf, "%d\n", | |
231 | TC654_FAN_FAULT_FROM_REG(data->fan_fault[nr])); | |
232 | } | |
233 | ||
234 | static ssize_t set_fan_min(struct device *dev, struct device_attribute *da, | |
235 | const char *buf, size_t count) | |
236 | { | |
237 | int nr = to_sensor_dev_attr(da)->index; | |
238 | struct tc654_data *data = dev_get_drvdata(dev); | |
239 | struct i2c_client *client = data->client; | |
240 | unsigned long val; | |
241 | int ret; | |
242 | ||
243 | if (kstrtoul(buf, 10, &val)) | |
244 | return -EINVAL; | |
245 | ||
246 | val = clamp_val(val, 0, 12750); | |
247 | ||
248 | mutex_lock(&data->update_lock); | |
249 | ||
250 | data->fan_fault[nr] = TC654_FAN_FAULT_TO_REG(val); | |
251 | ret = i2c_smbus_write_byte_data(client, TC654_REG_FAN_FAULT(nr), | |
252 | data->fan_fault[nr]); | |
253 | ||
254 | mutex_unlock(&data->update_lock); | |
255 | return ret < 0 ? ret : count; | |
256 | } | |
257 | ||
258 | static ssize_t show_fan_alarm(struct device *dev, struct device_attribute *da, | |
259 | char *buf) | |
260 | { | |
261 | int nr = to_sensor_dev_attr(da)->index; | |
262 | struct tc654_data *data = tc654_update_client(dev); | |
263 | int val; | |
264 | ||
265 | if (IS_ERR(data)) | |
266 | return PTR_ERR(data); | |
267 | ||
268 | if (nr == 0) | |
269 | val = !!(data->status & TC654_REG_STATUS_F1F); | |
270 | else | |
271 | val = !!(data->status & TC654_REG_STATUS_F2F); | |
272 | ||
273 | return sprintf(buf, "%d\n", val); | |
274 | } | |
275 | ||
276 | static const u8 TC654_FAN_PULSE_SHIFT[] = { 1, 3 }; | |
277 | ||
278 | static ssize_t show_fan_pulses(struct device *dev, struct device_attribute *da, | |
279 | char *buf) | |
280 | { | |
281 | int nr = to_sensor_dev_attr(da)->index; | |
282 | struct tc654_data *data = tc654_update_client(dev); | |
283 | u8 val; | |
284 | ||
285 | if (IS_ERR(data)) | |
286 | return PTR_ERR(data); | |
287 | ||
288 | val = BIT((data->config >> TC654_FAN_PULSE_SHIFT[nr]) & 0x03); | |
289 | return sprintf(buf, "%d\n", val); | |
290 | } | |
291 | ||
292 | static ssize_t set_fan_pulses(struct device *dev, struct device_attribute *da, | |
293 | const char *buf, size_t count) | |
294 | { | |
295 | int nr = to_sensor_dev_attr(da)->index; | |
296 | struct tc654_data *data = dev_get_drvdata(dev); | |
297 | struct i2c_client *client = data->client; | |
298 | u8 config; | |
299 | unsigned long val; | |
300 | int ret; | |
301 | ||
302 | if (kstrtoul(buf, 10, &val)) | |
303 | return -EINVAL; | |
304 | ||
305 | switch (val) { | |
306 | case 1: | |
307 | config = 0; | |
308 | break; | |
309 | case 2: | |
310 | config = 1; | |
311 | break; | |
312 | case 4: | |
313 | config = 2; | |
314 | break; | |
315 | case 8: | |
316 | config = 3; | |
317 | break; | |
318 | default: | |
319 | return -EINVAL; | |
320 | } | |
321 | ||
322 | mutex_lock(&data->update_lock); | |
323 | ||
324 | data->config &= ~(0x03 << TC654_FAN_PULSE_SHIFT[nr]); | |
325 | data->config |= (config << TC654_FAN_PULSE_SHIFT[nr]); | |
326 | ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); | |
327 | ||
328 | mutex_unlock(&data->update_lock); | |
329 | return ret < 0 ? ret : count; | |
330 | } | |
331 | ||
332 | static ssize_t show_pwm_mode(struct device *dev, | |
333 | struct device_attribute *da, char *buf) | |
334 | { | |
335 | struct tc654_data *data = tc654_update_client(dev); | |
336 | ||
337 | if (IS_ERR(data)) | |
338 | return PTR_ERR(data); | |
339 | ||
340 | return sprintf(buf, "%d\n", !!(data->config & TC654_REG_CONFIG_DUTYC)); | |
341 | } | |
342 | ||
343 | static ssize_t set_pwm_mode(struct device *dev, | |
344 | struct device_attribute *da, | |
345 | const char *buf, size_t count) | |
346 | { | |
347 | struct tc654_data *data = dev_get_drvdata(dev); | |
348 | struct i2c_client *client = data->client; | |
349 | unsigned long val; | |
350 | int ret; | |
351 | ||
352 | if (kstrtoul(buf, 10, &val)) | |
353 | return -EINVAL; | |
354 | ||
355 | if (val != 0 && val != 1) | |
356 | return -EINVAL; | |
357 | ||
358 | mutex_lock(&data->update_lock); | |
359 | ||
360 | if (val) | |
361 | data->config |= TC654_REG_CONFIG_DUTYC; | |
362 | else | |
363 | data->config &= ~TC654_REG_CONFIG_DUTYC; | |
364 | ||
365 | ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); | |
366 | ||
367 | mutex_unlock(&data->update_lock); | |
368 | return ret < 0 ? ret : count; | |
369 | } | |
370 | ||
371 | static const int tc654_pwm_map[16] = { 77, 88, 102, 112, 124, 136, 148, 160, | |
372 | 172, 184, 196, 207, 219, 231, 243, 255}; | |
373 | ||
374 | static ssize_t show_pwm(struct device *dev, struct device_attribute *da, | |
375 | char *buf) | |
376 | { | |
377 | struct tc654_data *data = tc654_update_client(dev); | |
378 | int pwm; | |
379 | ||
380 | if (IS_ERR(data)) | |
381 | return PTR_ERR(data); | |
382 | ||
383 | if (data->config & TC654_REG_CONFIG_SDM) | |
384 | pwm = 0; | |
385 | else | |
386 | pwm = tc654_pwm_map[data->duty_cycle]; | |
387 | ||
388 | return sprintf(buf, "%d\n", pwm); | |
389 | } | |
390 | ||
391 | static ssize_t set_pwm(struct device *dev, struct device_attribute *da, | |
392 | const char *buf, size_t count) | |
393 | { | |
394 | struct tc654_data *data = dev_get_drvdata(dev); | |
395 | struct i2c_client *client = data->client; | |
396 | unsigned long val; | |
397 | int ret; | |
398 | ||
399 | if (kstrtoul(buf, 10, &val)) | |
400 | return -EINVAL; | |
401 | if (val > 255) | |
402 | return -EINVAL; | |
403 | ||
404 | mutex_lock(&data->update_lock); | |
405 | ||
406 | if (val == 0) | |
407 | data->config |= TC654_REG_CONFIG_SDM; | |
408 | else | |
409 | data->config &= ~TC654_REG_CONFIG_SDM; | |
410 | ||
411 | data->duty_cycle = find_closest(val, tc654_pwm_map, | |
412 | ARRAY_SIZE(tc654_pwm_map)); | |
413 | ||
414 | ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); | |
415 | if (ret < 0) | |
416 | goto out; | |
417 | ||
418 | ret = i2c_smbus_write_byte_data(client, TC654_REG_DUTY_CYCLE, | |
419 | data->duty_cycle); | |
420 | ||
421 | out: | |
422 | mutex_unlock(&data->update_lock); | |
423 | return ret < 0 ? ret : count; | |
424 | } | |
425 | ||
426 | static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0); | |
427 | static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1); | |
428 | static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan_min, | |
429 | set_fan_min, 0); | |
430 | static SENSOR_DEVICE_ATTR(fan2_min, S_IWUSR | S_IRUGO, show_fan_min, | |
431 | set_fan_min, 1); | |
432 | static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL, 0); | |
433 | static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_fan_alarm, NULL, 1); | |
434 | static SENSOR_DEVICE_ATTR(fan1_pulses, S_IWUSR | S_IRUGO, show_fan_pulses, | |
435 | set_fan_pulses, 0); | |
436 | static SENSOR_DEVICE_ATTR(fan2_pulses, S_IWUSR | S_IRUGO, show_fan_pulses, | |
437 | set_fan_pulses, 1); | |
438 | static SENSOR_DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, | |
439 | show_pwm_mode, set_pwm_mode, 0); | |
440 | static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, | |
441 | set_pwm, 0); | |
442 | ||
443 | /* Driver data */ | |
444 | static struct attribute *tc654_attrs[] = { | |
445 | &sensor_dev_attr_fan1_input.dev_attr.attr, | |
446 | &sensor_dev_attr_fan2_input.dev_attr.attr, | |
447 | &sensor_dev_attr_fan1_min.dev_attr.attr, | |
448 | &sensor_dev_attr_fan2_min.dev_attr.attr, | |
449 | &sensor_dev_attr_fan1_alarm.dev_attr.attr, | |
450 | &sensor_dev_attr_fan2_alarm.dev_attr.attr, | |
451 | &sensor_dev_attr_fan1_pulses.dev_attr.attr, | |
452 | &sensor_dev_attr_fan2_pulses.dev_attr.attr, | |
453 | &sensor_dev_attr_pwm1_mode.dev_attr.attr, | |
454 | &sensor_dev_attr_pwm1.dev_attr.attr, | |
455 | NULL | |
456 | }; | |
457 | ||
458 | ATTRIBUTE_GROUPS(tc654); | |
459 | ||
460 | /* | |
461 | * device probe and removal | |
462 | */ | |
463 | ||
464 | static int tc654_probe(struct i2c_client *client, | |
465 | const struct i2c_device_id *id) | |
466 | { | |
467 | struct device *dev = &client->dev; | |
468 | struct tc654_data *data; | |
469 | struct device *hwmon_dev; | |
470 | int ret; | |
471 | ||
472 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
473 | return -ENODEV; | |
474 | ||
475 | data = devm_kzalloc(dev, sizeof(struct tc654_data), GFP_KERNEL); | |
476 | if (!data) | |
477 | return -ENOMEM; | |
478 | ||
479 | data->client = client; | |
480 | mutex_init(&data->update_lock); | |
481 | ||
482 | ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); | |
483 | if (ret < 0) | |
484 | return ret; | |
485 | ||
486 | data->config = ret; | |
487 | ||
488 | hwmon_dev = | |
489 | devm_hwmon_device_register_with_groups(dev, client->name, data, | |
490 | tc654_groups); | |
491 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
492 | } | |
493 | ||
494 | static const struct i2c_device_id tc654_id[] = { | |
495 | {"tc654", 0}, | |
496 | {"tc655", 0}, | |
497 | {} | |
498 | }; | |
499 | ||
500 | MODULE_DEVICE_TABLE(i2c, tc654_id); | |
501 | ||
502 | static struct i2c_driver tc654_driver = { | |
503 | .driver = { | |
504 | .name = "tc654", | |
505 | }, | |
506 | .probe = tc654_probe, | |
507 | .id_table = tc654_id, | |
508 | }; | |
509 | ||
510 | module_i2c_driver(tc654_driver); | |
511 | ||
512 | MODULE_AUTHOR("Allied Telesis Labs"); | |
513 | MODULE_DESCRIPTION("Microchip TC654/TC655 driver"); | |
514 | MODULE_LICENSE("GPL"); |