1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Hardware monitoring driver for Maxim MAX6620 |
4 | * |
5 | * Originally from L. Grunenberg. |
6 | * (C) 2012 by L. Grunenberg <contact@lgrunenberg.de> |
7 | * |
8 | * Copyright (c) 2021 Dell Inc. or its subsidiaries. All Rights Reserved. |
9 | * |
10 | * based on code written by : |
11 | * 2007 by Hans J. Koch <hjk@hansjkoch.de> |
12 | * John Morris <john.morris@spirentcom.com> |
13 | * Copyright (c) 2003 Spirent Communications |
14 | * and Claus Gindhart <claus.gindhart@kontron.com> |
15 | * |
16 | * This module has only been tested with the MAX6620 chip. |
17 | * |
18 | * The datasheet was last seen at: |
19 | * |
20 | * http://pdfserv.maxim-ic.com/en/ds/MAX6620.pdf |
21 | * |
22 | */ |
23 | |
24 | #include <linux/bits.h> |
25 | #include <linux/err.h> |
26 | #include <linux/hwmon.h> |
27 | #include <linux/i2c.h> |
28 | #include <linux/init.h> |
29 | #include <linux/jiffies.h> |
30 | #include <linux/module.h> |
31 | #include <linux/slab.h> |
32 | |
33 | /* |
34 | * MAX 6620 registers |
35 | */ |
36 | |
37 | #define MAX6620_REG_CONFIG 0x00 |
38 | #define MAX6620_REG_FAULT 0x01 |
39 | #define MAX6620_REG_CONF_FAN0 0x02 |
40 | #define MAX6620_REG_CONF_FAN1 0x03 |
41 | #define MAX6620_REG_CONF_FAN2 0x04 |
42 | #define MAX6620_REG_CONF_FAN3 0x05 |
43 | #define MAX6620_REG_DYN_FAN0 0x06 |
44 | #define MAX6620_REG_DYN_FAN1 0x07 |
45 | #define MAX6620_REG_DYN_FAN2 0x08 |
46 | #define MAX6620_REG_DYN_FAN3 0x09 |
47 | #define MAX6620_REG_TACH0 0x10 |
48 | #define MAX6620_REG_TACH1 0x12 |
49 | #define MAX6620_REG_TACH2 0x14 |
50 | #define MAX6620_REG_TACH3 0x16 |
51 | #define MAX6620_REG_VOLT0 0x18 |
52 | #define MAX6620_REG_VOLT1 0x1A |
53 | #define MAX6620_REG_VOLT2 0x1C |
54 | #define MAX6620_REG_VOLT3 0x1E |
55 | #define MAX6620_REG_TAR0 0x20 |
56 | #define MAX6620_REG_TAR1 0x22 |
57 | #define MAX6620_REG_TAR2 0x24 |
58 | #define MAX6620_REG_TAR3 0x26 |
59 | #define MAX6620_REG_DAC0 0x28 |
60 | #define MAX6620_REG_DAC1 0x2A |
61 | #define MAX6620_REG_DAC2 0x2C |
62 | #define MAX6620_REG_DAC3 0x2E |
63 | |
64 | /* |
65 | * Config register bits |
66 | */ |
67 | |
68 | #define MAX6620_CFG_RUN BIT(7) |
69 | #define MAX6620_CFG_POR BIT(6) |
70 | #define MAX6620_CFG_TIMEOUT BIT(5) |
71 | #define MAX6620_CFG_FULLFAN BIT(4) |
72 | #define MAX6620_CFG_OSC BIT(3) |
73 | #define MAX6620_CFG_WD_MASK (BIT(2) | BIT(1)) |
74 | #define MAX6620_CFG_WD_2 BIT(1) |
75 | #define MAX6620_CFG_WD_6 BIT(2) |
76 | #define MAX6620_CFG_WD10 (BIT(2) | BIT(1)) |
77 | #define MAX6620_CFG_WD BIT(0) |
78 | |
79 | /* |
80 | * Failure status register bits |
81 | */ |
82 | |
83 | #define MAX6620_FAIL_TACH0 BIT(4) |
84 | #define MAX6620_FAIL_TACH1 BIT(5) |
85 | #define MAX6620_FAIL_TACH2 BIT(6) |
86 | #define MAX6620_FAIL_TACH3 BIT(7) |
87 | #define MAX6620_FAIL_MASK0 BIT(0) |
88 | #define MAX6620_FAIL_MASK1 BIT(1) |
89 | #define MAX6620_FAIL_MASK2 BIT(2) |
90 | #define MAX6620_FAIL_MASK3 BIT(3) |
91 | |
92 | #define MAX6620_CLOCK_FREQ 8192 /* Clock frequency in Hz */ |
93 | #define MAX6620_PULSE_PER_REV 2 /* Tachometer pulses per revolution */ |
94 | |
95 | /* Minimum and maximum values of the FAN-RPM */ |
96 | #define FAN_RPM_MIN 240 |
97 | #define FAN_RPM_MAX 30000 |
98 | |
99 | static const u8 config_reg[] = { |
100 | MAX6620_REG_CONF_FAN0, |
101 | MAX6620_REG_CONF_FAN1, |
102 | MAX6620_REG_CONF_FAN2, |
103 | MAX6620_REG_CONF_FAN3, |
104 | }; |
105 | |
106 | static const u8 dyn_reg[] = { |
107 | MAX6620_REG_DYN_FAN0, |
108 | MAX6620_REG_DYN_FAN1, |
109 | MAX6620_REG_DYN_FAN2, |
110 | MAX6620_REG_DYN_FAN3, |
111 | }; |
112 | |
113 | static const u8 tach_reg[] = { |
114 | MAX6620_REG_TACH0, |
115 | MAX6620_REG_TACH1, |
116 | MAX6620_REG_TACH2, |
117 | MAX6620_REG_TACH3, |
118 | }; |
119 | |
120 | static const u8 target_reg[] = { |
121 | MAX6620_REG_TAR0, |
122 | MAX6620_REG_TAR1, |
123 | MAX6620_REG_TAR2, |
124 | MAX6620_REG_TAR3, |
125 | }; |
126 | |
127 | /* |
128 | * Client data (each client gets its own) |
129 | */ |
130 | |
131 | struct max6620_data { |
132 | struct i2c_client *client; |
133 | struct mutex update_lock; |
134 | bool valid; /* false until following fields are valid */ |
135 | unsigned long last_updated; /* in jiffies */ |
136 | |
137 | /* register values */ |
138 | u8 fancfg[4]; |
139 | u8 fandyn[4]; |
140 | u8 fault; |
141 | u16 tach[4]; |
142 | u16 target[4]; |
143 | }; |
144 | |
145 | static u8 max6620_fan_div_from_reg(u8 val) |
146 | { |
147 | return BIT((val & 0xE0) >> 5); |
148 | } |
149 | |
150 | static u16 max6620_fan_rpm_to_tach(u8 div, int rpm) |
151 | { |
152 | return (60 * div * MAX6620_CLOCK_FREQ) / (rpm * MAX6620_PULSE_PER_REV); |
153 | } |
154 | |
155 | static int max6620_fan_tach_to_rpm(u8 div, u16 tach) |
156 | { |
157 | return (60 * div * MAX6620_CLOCK_FREQ) / (tach * MAX6620_PULSE_PER_REV); |
158 | } |
159 | |
160 | static int max6620_update_device(struct device *dev) |
161 | { |
162 | struct max6620_data *data = dev_get_drvdata(dev); |
163 | struct i2c_client *client = data->client; |
164 | int i; |
165 | int ret = 0; |
166 | |
167 | mutex_lock(&data->update_lock); |
168 | |
169 | if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { |
170 | for (i = 0; i < 4; i++) { |
171 | ret = i2c_smbus_read_byte_data(client, command: config_reg[i]); |
172 | if (ret < 0) |
173 | goto error; |
174 | data->fancfg[i] = ret; |
175 | |
176 | ret = i2c_smbus_read_byte_data(client, command: dyn_reg[i]); |
177 | if (ret < 0) |
178 | goto error; |
179 | data->fandyn[i] = ret; |
180 | |
181 | ret = i2c_smbus_read_byte_data(client, command: tach_reg[i]); |
182 | if (ret < 0) |
183 | goto error; |
184 | data->tach[i] = (ret << 3) & 0x7f8; |
185 | ret = i2c_smbus_read_byte_data(client, command: tach_reg[i] + 1); |
186 | if (ret < 0) |
187 | goto error; |
188 | data->tach[i] |= (ret >> 5) & 0x7; |
189 | |
190 | ret = i2c_smbus_read_byte_data(client, command: target_reg[i]); |
191 | if (ret < 0) |
192 | goto error; |
193 | data->target[i] = (ret << 3) & 0x7f8; |
194 | ret = i2c_smbus_read_byte_data(client, command: target_reg[i] + 1); |
195 | if (ret < 0) |
196 | goto error; |
197 | data->target[i] |= (ret >> 5) & 0x7; |
198 | } |
199 | |
200 | /* |
201 | * Alarms are cleared on read in case the condition that |
202 | * caused the alarm is removed. Keep the value latched here |
203 | * for providing the register through different alarm files. |
204 | */ |
205 | ret = i2c_smbus_read_byte_data(client, MAX6620_REG_FAULT); |
206 | if (ret < 0) |
207 | goto error; |
208 | data->fault |= (ret >> 4) & (ret & 0x0F); |
209 | |
210 | data->last_updated = jiffies; |
211 | data->valid = true; |
212 | } |
213 | |
214 | error: |
215 | mutex_unlock(lock: &data->update_lock); |
216 | return ret; |
217 | } |
218 | |
219 | static umode_t |
220 | max6620_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, |
221 | int channel) |
222 | { |
223 | switch (type) { |
224 | case hwmon_fan: |
225 | switch (attr) { |
226 | case hwmon_fan_alarm: |
227 | case hwmon_fan_input: |
228 | return 0444; |
229 | case hwmon_fan_div: |
230 | case hwmon_fan_target: |
231 | return 0644; |
232 | default: |
233 | break; |
234 | } |
235 | break; |
236 | default: |
237 | break; |
238 | } |
239 | |
240 | return 0; |
241 | } |
242 | |
243 | static int |
244 | max6620_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, |
245 | int channel, long *val) |
246 | { |
247 | struct max6620_data *data; |
248 | struct i2c_client *client; |
249 | int ret; |
250 | u8 div; |
251 | u8 val1; |
252 | u8 val2; |
253 | |
254 | ret = max6620_update_device(dev); |
255 | if (ret < 0) |
256 | return ret; |
257 | data = dev_get_drvdata(dev); |
258 | client = data->client; |
259 | |
260 | switch (type) { |
261 | case hwmon_fan: |
262 | switch (attr) { |
263 | case hwmon_fan_alarm: |
264 | mutex_lock(&data->update_lock); |
265 | *val = !!(data->fault & BIT(channel)); |
266 | |
267 | /* Setting TACH count to re-enable fan fault detection */ |
268 | if (*val == 1) { |
269 | val1 = (data->target[channel] >> 3) & 0xff; |
270 | val2 = (data->target[channel] << 5) & 0xe0; |
271 | ret = i2c_smbus_write_byte_data(client, |
272 | command: target_reg[channel], value: val1); |
273 | if (ret < 0) { |
274 | mutex_unlock(lock: &data->update_lock); |
275 | return ret; |
276 | } |
277 | ret = i2c_smbus_write_byte_data(client, |
278 | command: target_reg[channel] + 1, value: val2); |
279 | if (ret < 0) { |
280 | mutex_unlock(lock: &data->update_lock); |
281 | return ret; |
282 | } |
283 | |
284 | data->fault &= ~BIT(channel); |
285 | } |
286 | mutex_unlock(lock: &data->update_lock); |
287 | |
288 | break; |
289 | case hwmon_fan_div: |
290 | *val = max6620_fan_div_from_reg(val: data->fandyn[channel]); |
291 | break; |
292 | case hwmon_fan_input: |
293 | if (data->tach[channel] == 0) { |
294 | *val = 0; |
295 | } else { |
296 | div = max6620_fan_div_from_reg(val: data->fandyn[channel]); |
297 | *val = max6620_fan_tach_to_rpm(div, tach: data->tach[channel]); |
298 | } |
299 | break; |
300 | case hwmon_fan_target: |
301 | if (data->target[channel] == 0) { |
302 | *val = 0; |
303 | } else { |
304 | div = max6620_fan_div_from_reg(val: data->fandyn[channel]); |
305 | *val = max6620_fan_tach_to_rpm(div, tach: data->target[channel]); |
306 | } |
307 | break; |
308 | default: |
309 | return -EOPNOTSUPP; |
310 | } |
311 | break; |
312 | |
313 | default: |
314 | return -EOPNOTSUPP; |
315 | } |
316 | |
317 | return 0; |
318 | } |
319 | |
320 | static int |
321 | max6620_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, |
322 | int channel, long val) |
323 | { |
324 | struct max6620_data *data; |
325 | struct i2c_client *client; |
326 | int ret; |
327 | u8 div; |
328 | u16 tach; |
329 | u8 val1; |
330 | u8 val2; |
331 | |
332 | ret = max6620_update_device(dev); |
333 | if (ret < 0) |
334 | return ret; |
335 | data = dev_get_drvdata(dev); |
336 | client = data->client; |
337 | mutex_lock(&data->update_lock); |
338 | |
339 | switch (type) { |
340 | case hwmon_fan: |
341 | switch (attr) { |
342 | case hwmon_fan_div: |
343 | switch (val) { |
344 | case 1: |
345 | div = 0; |
346 | break; |
347 | case 2: |
348 | div = 1; |
349 | break; |
350 | case 4: |
351 | div = 2; |
352 | break; |
353 | case 8: |
354 | div = 3; |
355 | break; |
356 | case 16: |
357 | div = 4; |
358 | break; |
359 | case 32: |
360 | div = 5; |
361 | break; |
362 | default: |
363 | ret = -EINVAL; |
364 | goto error; |
365 | } |
366 | data->fandyn[channel] &= 0x1F; |
367 | data->fandyn[channel] |= div << 5; |
368 | ret = i2c_smbus_write_byte_data(client, command: dyn_reg[channel], |
369 | value: data->fandyn[channel]); |
370 | break; |
371 | case hwmon_fan_target: |
372 | val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX); |
373 | div = max6620_fan_div_from_reg(val: data->fandyn[channel]); |
374 | tach = max6620_fan_rpm_to_tach(div, rpm: val); |
375 | val1 = (tach >> 3) & 0xff; |
376 | val2 = (tach << 5) & 0xe0; |
377 | ret = i2c_smbus_write_byte_data(client, command: target_reg[channel], value: val1); |
378 | if (ret < 0) |
379 | break; |
380 | ret = i2c_smbus_write_byte_data(client, command: target_reg[channel] + 1, value: val2); |
381 | if (ret < 0) |
382 | break; |
383 | |
384 | /* Setting TACH count re-enables fan fault detection */ |
385 | data->fault &= ~BIT(channel); |
386 | |
387 | break; |
388 | default: |
389 | ret = -EOPNOTSUPP; |
390 | break; |
391 | } |
392 | break; |
393 | |
394 | default: |
395 | ret = -EOPNOTSUPP; |
396 | break; |
397 | } |
398 | |
399 | error: |
400 | mutex_unlock(lock: &data->update_lock); |
401 | return ret; |
402 | } |
403 | |
404 | static const struct hwmon_channel_info * const max6620_info[] = { |
405 | HWMON_CHANNEL_INFO(fan, |
406 | HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM, |
407 | HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM, |
408 | HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM, |
409 | HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM), |
410 | NULL |
411 | }; |
412 | |
413 | static const struct hwmon_ops max6620_hwmon_ops = { |
414 | .read = max6620_read, |
415 | .write = max6620_write, |
416 | .is_visible = max6620_is_visible, |
417 | }; |
418 | |
419 | static const struct hwmon_chip_info max6620_chip_info = { |
420 | .ops = &max6620_hwmon_ops, |
421 | .info = max6620_info, |
422 | }; |
423 | |
424 | static int max6620_init_client(struct max6620_data *data) |
425 | { |
426 | struct i2c_client *client = data->client; |
427 | int config; |
428 | int err; |
429 | int i; |
430 | int reg; |
431 | |
432 | config = i2c_smbus_read_byte_data(client, MAX6620_REG_CONFIG); |
433 | if (config < 0) { |
434 | dev_err(&client->dev, "Error reading config, aborting.\n" ); |
435 | return config; |
436 | } |
437 | |
438 | /* |
439 | * Set bit 4, disable other fans from going full speed on a fail |
440 | * failure. |
441 | */ |
442 | err = i2c_smbus_write_byte_data(client, MAX6620_REG_CONFIG, value: config | 0x10); |
443 | if (err < 0) { |
444 | dev_err(&client->dev, "Config write error, aborting.\n" ); |
445 | return err; |
446 | } |
447 | |
448 | for (i = 0; i < 4; i++) { |
449 | reg = i2c_smbus_read_byte_data(client, command: config_reg[i]); |
450 | if (reg < 0) |
451 | return reg; |
452 | data->fancfg[i] = reg; |
453 | |
454 | /* Enable RPM mode */ |
455 | data->fancfg[i] |= 0xa8; |
456 | err = i2c_smbus_write_byte_data(client, command: config_reg[i], value: data->fancfg[i]); |
457 | if (err < 0) |
458 | return err; |
459 | |
460 | /* 2 counts (001) and Rate change 100 (0.125 secs) */ |
461 | data->fandyn[i] = 0x30; |
462 | err = i2c_smbus_write_byte_data(client, command: dyn_reg[i], value: data->fandyn[i]); |
463 | if (err < 0) |
464 | return err; |
465 | } |
466 | return 0; |
467 | } |
468 | |
469 | static int max6620_probe(struct i2c_client *client) |
470 | { |
471 | struct device *dev = &client->dev; |
472 | struct max6620_data *data; |
473 | struct device *hwmon_dev; |
474 | int err; |
475 | |
476 | data = devm_kzalloc(dev, size: sizeof(struct max6620_data), GFP_KERNEL); |
477 | if (!data) |
478 | return -ENOMEM; |
479 | |
480 | data->client = client; |
481 | mutex_init(&data->update_lock); |
482 | |
483 | err = max6620_init_client(data); |
484 | if (err) |
485 | return err; |
486 | |
487 | hwmon_dev = devm_hwmon_device_register_with_info(dev, name: client->name, |
488 | drvdata: data, |
489 | info: &max6620_chip_info, |
490 | NULL); |
491 | |
492 | return PTR_ERR_OR_ZERO(ptr: hwmon_dev); |
493 | } |
494 | |
495 | static const struct i2c_device_id max6620_id[] = { |
496 | { "max6620" , 0 }, |
497 | { } |
498 | }; |
499 | MODULE_DEVICE_TABLE(i2c, max6620_id); |
500 | |
501 | static struct i2c_driver max6620_driver = { |
502 | .class = I2C_CLASS_HWMON, |
503 | .driver = { |
504 | .name = "max6620" , |
505 | }, |
506 | .probe = max6620_probe, |
507 | .id_table = max6620_id, |
508 | }; |
509 | |
510 | module_i2c_driver(max6620_driver); |
511 | |
512 | MODULE_AUTHOR("Lucas Grunenberg" ); |
513 | MODULE_DESCRIPTION("MAX6620 sensor driver" ); |
514 | MODULE_LICENSE("GPL" ); |
515 | |