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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
4 * monitoring.
5 *
6 * (C) 2015 by Il Han <corone.il.han@gmail.com>
7 */
8
9#include <linux/err.h>
10#include <linux/hwmon.h>
11#include <linux/i2c.h>
12#include <linux/init.h>
13#include <linux/jiffies.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16
17/* MAX31790 registers */
18#define MAX31790_REG_GLOBAL_CONFIG 0x00
19#define MAX31790_REG_FAN_CONFIG(ch) (0x02 + (ch))
20#define MAX31790_REG_FAN_DYNAMICS(ch) (0x08 + (ch))
21#define MAX31790_REG_FAN_FAULT_STATUS2 0x10
22#define MAX31790_REG_FAN_FAULT_STATUS1 0x11
23#define MAX31790_REG_TACH_COUNT(ch) (0x18 + (ch) * 2)
24#define MAX31790_REG_PWM_DUTY_CYCLE(ch) (0x30 + (ch) * 2)
25#define MAX31790_REG_PWMOUT(ch) (0x40 + (ch) * 2)
26#define MAX31790_REG_TARGET_COUNT(ch) (0x50 + (ch) * 2)
27
28/* Fan Config register bits */
29#define MAX31790_FAN_CFG_RPM_MODE 0x80
30#define MAX31790_FAN_CFG_TACH_INPUT_EN 0x08
31#define MAX31790_FAN_CFG_TACH_INPUT 0x01
32
33/* Fan Dynamics register bits */
34#define MAX31790_FAN_DYN_SR_SHIFT 5
35#define MAX31790_FAN_DYN_SR_MASK 0xE0
36#define SR_FROM_REG(reg) (((reg) & MAX31790_FAN_DYN_SR_MASK) \
37 >> MAX31790_FAN_DYN_SR_SHIFT)
38
39#define FAN_RPM_MIN 120
40#define FAN_RPM_MAX 7864320
41
42#define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \
43 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
44 FAN_RPM_MAX)
45#define RPM_TO_REG(rpm, sr) ((60 * (sr) * 8192) / ((rpm) * 2))
46
47#define NR_CHANNEL 6
48
49/*
50 * Client data (each client gets its own)
51 */
52struct max31790_data {
53 struct i2c_client *client;
54 struct mutex update_lock;
55 bool valid; /* zero until following fields are valid */
56 unsigned long last_updated; /* in jiffies */
57
58 /* register values */
59 u8 fan_config[NR_CHANNEL];
60 u8 fan_dynamics[NR_CHANNEL];
61 u16 fault_status;
62 u16 tach[NR_CHANNEL * 2];
63 u16 pwm[NR_CHANNEL];
64 u16 target_count[NR_CHANNEL];
65};
66
67static struct max31790_data *max31790_update_device(struct device *dev)
68{
69 struct max31790_data *data = dev_get_drvdata(dev);
70 struct i2c_client *client = data->client;
71 struct max31790_data *ret = data;
72 int i;
73 int rv;
74
75 mutex_lock(&data->update_lock);
76
77 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
78 rv = i2c_smbus_read_byte_data(client,
79 MAX31790_REG_FAN_FAULT_STATUS1);
80 if (rv < 0)
81 goto abort;
82 data->fault_status = rv & 0x3F;
83
84 rv = i2c_smbus_read_byte_data(client,
85 MAX31790_REG_FAN_FAULT_STATUS2);
86 if (rv < 0)
87 goto abort;
88 data->fault_status |= (rv & 0x3F) << 6;
89
90 for (i = 0; i < NR_CHANNEL; i++) {
91 rv = i2c_smbus_read_word_swapped(client,
92 MAX31790_REG_TACH_COUNT(i));
93 if (rv < 0)
94 goto abort;
95 data->tach[i] = rv;
96
97 if (data->fan_config[i]
98 & MAX31790_FAN_CFG_TACH_INPUT) {
99 rv = i2c_smbus_read_word_swapped(client,
100 MAX31790_REG_TACH_COUNT(NR_CHANNEL
101 + i));
102 if (rv < 0)
103 goto abort;
104 data->tach[NR_CHANNEL + i] = rv;
105 } else {
106 rv = i2c_smbus_read_word_swapped(client,
107 MAX31790_REG_PWMOUT(i));
108 if (rv < 0)
109 goto abort;
110 data->pwm[i] = rv;
111
112 rv = i2c_smbus_read_word_swapped(client,
113 MAX31790_REG_TARGET_COUNT(i));
114 if (rv < 0)
115 goto abort;
116 data->target_count[i] = rv;
117 }
118 }
119
120 data->last_updated = jiffies;
121 data->valid = true;
122 }
123 goto done;
124
125abort:
126 data->valid = false;
127 ret = ERR_PTR(rv);
128
129done:
130 mutex_unlock(&data->update_lock);
131
132 return ret;
133}
134
135static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
136
137static u8 get_tach_period(u8 fan_dynamics)
138{
139 return tach_period[SR_FROM_REG(fan_dynamics)];
140}
141
142static u8 bits_for_tach_period(int rpm)
143{
144 u8 bits;
145
146 if (rpm < 500)
147 bits = 0x0;
148 else if (rpm < 1000)
149 bits = 0x1;
150 else if (rpm < 2000)
151 bits = 0x2;
152 else if (rpm < 4000)
153 bits = 0x3;
154 else if (rpm < 8000)
155 bits = 0x4;
156 else
157 bits = 0x5;
158
159 return bits;
160}
161
162static int max31790_read_fan(struct device *dev, u32 attr, int channel,
163 long *val)
164{
165 struct max31790_data *data = max31790_update_device(dev);
166 int sr, rpm;
167
168 if (IS_ERR(data))
169 return PTR_ERR(data);
170
171 switch (attr) {
172 case hwmon_fan_input:
173 sr = get_tach_period(data->fan_dynamics[channel]);
174 rpm = RPM_FROM_REG(data->tach[channel], sr);
175 *val = rpm;
176 return 0;
177 case hwmon_fan_target:
178 sr = get_tach_period(data->fan_dynamics[channel]);
179 rpm = RPM_FROM_REG(data->target_count[channel], sr);
180 *val = rpm;
181 return 0;
182 case hwmon_fan_fault:
183 *val = !!(data->fault_status & (1 << channel));
184 return 0;
185 default:
186 return -EOPNOTSUPP;
187 }
188}
189
190static int max31790_write_fan(struct device *dev, u32 attr, int channel,
191 long val)
192{
193 struct max31790_data *data = dev_get_drvdata(dev);
194 struct i2c_client *client = data->client;
195 int target_count;
196 int err = 0;
197 u8 bits;
198 int sr;
199
200 mutex_lock(&data->update_lock);
201
202 switch (attr) {
203 case hwmon_fan_target:
204 val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
205 bits = bits_for_tach_period(val);
206 data->fan_dynamics[channel] =
207 ((data->fan_dynamics[channel] &
208 ~MAX31790_FAN_DYN_SR_MASK) |
209 (bits << MAX31790_FAN_DYN_SR_SHIFT));
210 err = i2c_smbus_write_byte_data(client,
211 MAX31790_REG_FAN_DYNAMICS(channel),
212 data->fan_dynamics[channel]);
213 if (err < 0)
214 break;
215
216 sr = get_tach_period(data->fan_dynamics[channel]);
217 target_count = RPM_TO_REG(val, sr);
218 target_count = clamp_val(target_count, 0x1, 0x7FF);
219
220 data->target_count[channel] = target_count << 5;
221
222 err = i2c_smbus_write_word_swapped(client,
223 MAX31790_REG_TARGET_COUNT(channel),
224 data->target_count[channel]);
225 break;
226 default:
227 err = -EOPNOTSUPP;
228 break;
229 }
230
231 mutex_unlock(&data->update_lock);
232
233 return err;
234}
235
236static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
237{
238 const struct max31790_data *data = _data;
239 u8 fan_config = data->fan_config[channel % NR_CHANNEL];
240
241 switch (attr) {
242 case hwmon_fan_input:
243 case hwmon_fan_fault:
244 if (channel < NR_CHANNEL ||
245 (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
246 return 0444;
247 return 0;
248 case hwmon_fan_target:
249 if (channel < NR_CHANNEL &&
250 !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
251 return 0644;
252 return 0;
253 default:
254 return 0;
255 }
256}
257
258static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
259 long *val)
260{
261 struct max31790_data *data = max31790_update_device(dev);
262 u8 fan_config;
263
264 if (IS_ERR(data))
265 return PTR_ERR(data);
266
267 fan_config = data->fan_config[channel];
268
269 switch (attr) {
270 case hwmon_pwm_input:
271 *val = data->pwm[channel] >> 8;
272 return 0;
273 case hwmon_pwm_enable:
274 if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
275 *val = 2;
276 else if (fan_config & MAX31790_FAN_CFG_TACH_INPUT_EN)
277 *val = 1;
278 else
279 *val = 0;
280 return 0;
281 default:
282 return -EOPNOTSUPP;
283 }
284}
285
286static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
287 long val)
288{
289 struct max31790_data *data = dev_get_drvdata(dev);
290 struct i2c_client *client = data->client;
291 u8 fan_config;
292 int err = 0;
293
294 mutex_lock(&data->update_lock);
295
296 switch (attr) {
297 case hwmon_pwm_input:
298 if (val < 0 || val > 255) {
299 err = -EINVAL;
300 break;
301 }
302 data->pwm[channel] = val << 8;
303 err = i2c_smbus_write_word_swapped(client,
304 MAX31790_REG_PWMOUT(channel),
305 data->pwm[channel]);
306 break;
307 case hwmon_pwm_enable:
308 fan_config = data->fan_config[channel];
309 if (val == 0) {
310 fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
311 MAX31790_FAN_CFG_RPM_MODE);
312 } else if (val == 1) {
313 fan_config = (fan_config |
314 MAX31790_FAN_CFG_TACH_INPUT_EN) &
315 ~MAX31790_FAN_CFG_RPM_MODE;
316 } else if (val == 2) {
317 fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
318 MAX31790_FAN_CFG_RPM_MODE;
319 } else {
320 err = -EINVAL;
321 break;
322 }
323 data->fan_config[channel] = fan_config;
324 err = i2c_smbus_write_byte_data(client,
325 MAX31790_REG_FAN_CONFIG(channel),
326 fan_config);
327 break;
328 default:
329 err = -EOPNOTSUPP;
330 break;
331 }
332
333 mutex_unlock(&data->update_lock);
334
335 return err;
336}
337
338static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
339{
340 const struct max31790_data *data = _data;
341 u8 fan_config = data->fan_config[channel];
342
343 switch (attr) {
344 case hwmon_pwm_input:
345 case hwmon_pwm_enable:
346 if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
347 return 0644;
348 return 0;
349 default:
350 return 0;
351 }
352}
353
354static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
355 u32 attr, int channel, long *val)
356{
357 switch (type) {
358 case hwmon_fan:
359 return max31790_read_fan(dev, attr, channel, val);
360 case hwmon_pwm:
361 return max31790_read_pwm(dev, attr, channel, val);
362 default:
363 return -EOPNOTSUPP;
364 }
365}
366
367static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
368 u32 attr, int channel, long val)
369{
370 switch (type) {
371 case hwmon_fan:
372 return max31790_write_fan(dev, attr, channel, val);
373 case hwmon_pwm:
374 return max31790_write_pwm(dev, attr, channel, val);
375 default:
376 return -EOPNOTSUPP;
377 }
378}
379
380static umode_t max31790_is_visible(const void *data,
381 enum hwmon_sensor_types type,
382 u32 attr, int channel)
383{
384 switch (type) {
385 case hwmon_fan:
386 return max31790_fan_is_visible(data, attr, channel);
387 case hwmon_pwm:
388 return max31790_pwm_is_visible(data, attr, channel);
389 default:
390 return 0;
391 }
392}
393
394static const struct hwmon_channel_info *max31790_info[] = {
395 HWMON_CHANNEL_INFO(fan,
396 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
397 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
398 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
399 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
400 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
401 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
402 HWMON_F_INPUT | HWMON_F_FAULT,
403 HWMON_F_INPUT | HWMON_F_FAULT,
404 HWMON_F_INPUT | HWMON_F_FAULT,
405 HWMON_F_INPUT | HWMON_F_FAULT,
406 HWMON_F_INPUT | HWMON_F_FAULT,
407 HWMON_F_INPUT | HWMON_F_FAULT),
408 HWMON_CHANNEL_INFO(pwm,
409 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
410 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
411 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
412 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
413 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
414 HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
415 NULL
416};
417
418static const struct hwmon_ops max31790_hwmon_ops = {
419 .is_visible = max31790_is_visible,
420 .read = max31790_read,
421 .write = max31790_write,
422};
423
424static const struct hwmon_chip_info max31790_chip_info = {
425 .ops = &max31790_hwmon_ops,
426 .info = max31790_info,
427};
428
429static int max31790_init_client(struct i2c_client *client,
430 struct max31790_data *data)
431{
432 int i, rv;
433
434 for (i = 0; i < NR_CHANNEL; i++) {
435 rv = i2c_smbus_read_byte_data(client,
436 MAX31790_REG_FAN_CONFIG(i));
437 if (rv < 0)
438 return rv;
439 data->fan_config[i] = rv;
440
441 rv = i2c_smbus_read_byte_data(client,
442 MAX31790_REG_FAN_DYNAMICS(i));
443 if (rv < 0)
444 return rv;
445 data->fan_dynamics[i] = rv;
446 }
447
448 return 0;
449}
450
451static int max31790_probe(struct i2c_client *client,
452 const struct i2c_device_id *id)
453{
454 struct i2c_adapter *adapter = client->adapter;
455 struct device *dev = &client->dev;
456 struct max31790_data *data;
457 struct device *hwmon_dev;
458 int err;
459
460 if (!i2c_check_functionality(adapter,
461 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
462 return -ENODEV;
463
464 data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
465 if (!data)
466 return -ENOMEM;
467
468 data->client = client;
469 mutex_init(&data->update_lock);
470
471 /*
472 * Initialize the max31790 chip
473 */
474 err = max31790_init_client(client, data);
475 if (err)
476 return err;
477
478 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
479 data,
480 &max31790_chip_info,
481 NULL);
482
483 return PTR_ERR_OR_ZERO(hwmon_dev);
484}
485
486static const struct i2c_device_id max31790_id[] = {
487 { "max31790", 0 },
488 { }
489};
490MODULE_DEVICE_TABLE(i2c, max31790_id);
491
492static struct i2c_driver max31790_driver = {
493 .class = I2C_CLASS_HWMON,
494 .probe = max31790_probe,
495 .driver = {
496 .name = "max31790",
497 },
498 .id_table = max31790_id,
499};
500
501module_i2c_driver(max31790_driver);
502
503MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
504MODULE_DESCRIPTION("MAX31790 sensor driver");
505MODULE_LICENSE("GPL");