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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
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
29#define MAX31790_FAN_CFG_RPM_MODE 0x80
30#define MAX31790_FAN_CFG_CTRL_MON 0x10
31#define MAX31790_FAN_CFG_TACH_INPUT_EN 0x08
32#define MAX31790_FAN_CFG_TACH_INPUT 0x01
33
34
35#define MAX31790_FAN_DYN_SR_SHIFT 5
36#define MAX31790_FAN_DYN_SR_MASK 0xE0
37#define SR_FROM_REG(reg) (((reg) & MAX31790_FAN_DYN_SR_MASK) \
38 >> MAX31790_FAN_DYN_SR_SHIFT)
39
40#define FAN_RPM_MIN 120
41#define FAN_RPM_MAX 7864320
42
43#define FAN_COUNT_REG_MAX 0xffe0
44
45#define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \
46 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
47 FAN_RPM_MAX)
48#define RPM_TO_REG(rpm, sr) ((60 * (sr) * 8192) / ((rpm) * 2))
49
50#define NR_CHANNEL 6
51
52
53
54
55struct max31790_data {
56 struct i2c_client *client;
57 struct mutex update_lock;
58 bool valid;
59 unsigned long last_updated;
60
61
62 u8 fan_config[NR_CHANNEL];
63 u8 fan_dynamics[NR_CHANNEL];
64 u16 fault_status;
65 u16 tach[NR_CHANNEL * 2];
66 u16 pwm[NR_CHANNEL];
67 u16 target_count[NR_CHANNEL];
68};
69
70static struct max31790_data *max31790_update_device(struct device *dev)
71{
72 struct max31790_data *data = dev_get_drvdata(dev);
73 struct i2c_client *client = data->client;
74 struct max31790_data *ret = data;
75 int i;
76 int rv;
77
78 mutex_lock(&data->update_lock);
79
80 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
81 rv = i2c_smbus_read_byte_data(client,
82 MAX31790_REG_FAN_FAULT_STATUS1);
83 if (rv < 0)
84 goto abort;
85 data->fault_status |= rv & 0x3F;
86
87 rv = i2c_smbus_read_byte_data(client,
88 MAX31790_REG_FAN_FAULT_STATUS2);
89 if (rv < 0)
90 goto abort;
91 data->fault_status |= (rv & 0x3F) << 6;
92
93 for (i = 0; i < NR_CHANNEL; i++) {
94 rv = i2c_smbus_read_word_swapped(client,
95 MAX31790_REG_TACH_COUNT(i));
96 if (rv < 0)
97 goto abort;
98 data->tach[i] = rv;
99
100 if (data->fan_config[i]
101 & MAX31790_FAN_CFG_TACH_INPUT) {
102 rv = i2c_smbus_read_word_swapped(client,
103 MAX31790_REG_TACH_COUNT(NR_CHANNEL
104 + i));
105 if (rv < 0)
106 goto abort;
107 data->tach[NR_CHANNEL + i] = rv;
108 } else {
109 rv = i2c_smbus_read_word_swapped(client,
110 MAX31790_REG_PWM_DUTY_CYCLE(i));
111 if (rv < 0)
112 goto abort;
113 data->pwm[i] = rv;
114
115 rv = i2c_smbus_read_word_swapped(client,
116 MAX31790_REG_TARGET_COUNT(i));
117 if (rv < 0)
118 goto abort;
119 data->target_count[i] = rv;
120 }
121 }
122
123 data->last_updated = jiffies;
124 data->valid = true;
125 }
126 goto done;
127
128abort:
129 data->valid = false;
130 ret = ERR_PTR(rv);
131
132done:
133 mutex_unlock(&data->update_lock);
134
135 return ret;
136}
137
138static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
139
140static u8 get_tach_period(u8 fan_dynamics)
141{
142 return tach_period[SR_FROM_REG(fan_dynamics)];
143}
144
145static u8 bits_for_tach_period(int rpm)
146{
147 u8 bits;
148
149 if (rpm < 500)
150 bits = 0x0;
151 else if (rpm < 1000)
152 bits = 0x1;
153 else if (rpm < 2000)
154 bits = 0x2;
155 else if (rpm < 4000)
156 bits = 0x3;
157 else if (rpm < 8000)
158 bits = 0x4;
159 else
160 bits = 0x5;
161
162 return bits;
163}
164
165static int max31790_read_fan(struct device *dev, u32 attr, int channel,
166 long *val)
167{
168 struct max31790_data *data = max31790_update_device(dev);
169 int sr, rpm;
170
171 if (IS_ERR(data))
172 return PTR_ERR(data);
173
174 switch (attr) {
175 case hwmon_fan_input:
176 sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]);
177 if (data->tach[channel] == FAN_COUNT_REG_MAX)
178 rpm = 0;
179 else
180 rpm = RPM_FROM_REG(data->tach[channel], sr);
181 *val = rpm;
182 return 0;
183 case hwmon_fan_target:
184 sr = get_tach_period(data->fan_dynamics[channel]);
185 rpm = RPM_FROM_REG(data->target_count[channel], sr);
186 *val = rpm;
187 return 0;
188 case hwmon_fan_fault:
189 mutex_lock(&data->update_lock);
190 *val = !!(data->fault_status & (1 << channel));
191 data->fault_status &= ~(1 << channel);
192
193
194
195
196
197 if (*val) {
198 int reg = MAX31790_REG_TARGET_COUNT(channel % NR_CHANNEL);
199
200 i2c_smbus_write_byte_data(data->client, reg,
201 data->target_count[channel % NR_CHANNEL] >> 8);
202 }
203 mutex_unlock(&data->update_lock);
204 return 0;
205 default:
206 return -EOPNOTSUPP;
207 }
208}
209
210static int max31790_write_fan(struct device *dev, u32 attr, int channel,
211 long val)
212{
213 struct max31790_data *data = dev_get_drvdata(dev);
214 struct i2c_client *client = data->client;
215 int target_count;
216 int err = 0;
217 u8 bits;
218 int sr;
219
220 mutex_lock(&data->update_lock);
221
222 switch (attr) {
223 case hwmon_fan_target:
224 val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
225 bits = bits_for_tach_period(val);
226 data->fan_dynamics[channel] =
227 ((data->fan_dynamics[channel] &
228 ~MAX31790_FAN_DYN_SR_MASK) |
229 (bits << MAX31790_FAN_DYN_SR_SHIFT));
230 err = i2c_smbus_write_byte_data(client,
231 MAX31790_REG_FAN_DYNAMICS(channel),
232 data->fan_dynamics[channel]);
233 if (err < 0)
234 break;
235
236 sr = get_tach_period(data->fan_dynamics[channel]);
237 target_count = RPM_TO_REG(val, sr);
238 target_count = clamp_val(target_count, 0x1, 0x7FF);
239
240 data->target_count[channel] = target_count << 5;
241
242 err = i2c_smbus_write_word_swapped(client,
243 MAX31790_REG_TARGET_COUNT(channel),
244 data->target_count[channel]);
245 break;
246 default:
247 err = -EOPNOTSUPP;
248 break;
249 }
250
251 mutex_unlock(&data->update_lock);
252
253 return err;
254}
255
256static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
257{
258 const struct max31790_data *data = _data;
259 u8 fan_config = data->fan_config[channel % NR_CHANNEL];
260
261 switch (attr) {
262 case hwmon_fan_input:
263 case hwmon_fan_fault:
264 if (channel < NR_CHANNEL ||
265 (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
266 return 0444;
267 return 0;
268 case hwmon_fan_target:
269 if (channel < NR_CHANNEL &&
270 !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
271 return 0644;
272 return 0;
273 default:
274 return 0;
275 }
276}
277
278static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
279 long *val)
280{
281 struct max31790_data *data = max31790_update_device(dev);
282 u8 fan_config;
283
284 if (IS_ERR(data))
285 return PTR_ERR(data);
286
287 fan_config = data->fan_config[channel];
288
289 switch (attr) {
290 case hwmon_pwm_input:
291 *val = data->pwm[channel] >> 8;
292 return 0;
293 case hwmon_pwm_enable:
294 if (fan_config & MAX31790_FAN_CFG_CTRL_MON)
295 *val = 0;
296 else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
297 *val = 2;
298 else
299 *val = 1;
300 return 0;
301 default:
302 return -EOPNOTSUPP;
303 }
304}
305
306static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
307 long val)
308{
309 struct max31790_data *data = dev_get_drvdata(dev);
310 struct i2c_client *client = data->client;
311 u8 fan_config;
312 int err = 0;
313
314 mutex_lock(&data->update_lock);
315
316 switch (attr) {
317 case hwmon_pwm_input:
318 if (val < 0 || val > 255) {
319 err = -EINVAL;
320 break;
321 }
322 data->valid = false;
323 err = i2c_smbus_write_word_swapped(client,
324 MAX31790_REG_PWMOUT(channel),
325 val << 8);
326 break;
327 case hwmon_pwm_enable:
328 fan_config = data->fan_config[channel];
329 if (val == 0) {
330 fan_config |= MAX31790_FAN_CFG_CTRL_MON;
331
332
333
334
335 fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
336 } else if (val == 1) {
337 fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
338 } else if (val == 2) {
339 fan_config &= ~MAX31790_FAN_CFG_CTRL_MON;
340
341
342
343
344
345
346 fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);
347 } else {
348 err = -EINVAL;
349 break;
350 }
351 if (fan_config != data->fan_config[channel]) {
352 err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
353 fan_config);
354 if (!err)
355 data->fan_config[channel] = fan_config;
356 }
357 break;
358 default:
359 err = -EOPNOTSUPP;
360 break;
361 }
362
363 mutex_unlock(&data->update_lock);
364
365 return err;
366}
367
368static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
369{
370 const struct max31790_data *data = _data;
371 u8 fan_config = data->fan_config[channel];
372
373 switch (attr) {
374 case hwmon_pwm_input:
375 case hwmon_pwm_enable:
376 if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
377 return 0644;
378 return 0;
379 default:
380 return 0;
381 }
382}
383
384static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
385 u32 attr, int channel, long *val)
386{
387 switch (type) {
388 case hwmon_fan:
389 return max31790_read_fan(dev, attr, channel, val);
390 case hwmon_pwm:
391 return max31790_read_pwm(dev, attr, channel, val);
392 default:
393 return -EOPNOTSUPP;
394 }
395}
396
397static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
398 u32 attr, int channel, long val)
399{
400 switch (type) {
401 case hwmon_fan:
402 return max31790_write_fan(dev, attr, channel, val);
403 case hwmon_pwm:
404 return max31790_write_pwm(dev, attr, channel, val);
405 default:
406 return -EOPNOTSUPP;
407 }
408}
409
410static umode_t max31790_is_visible(const void *data,
411 enum hwmon_sensor_types type,
412 u32 attr, int channel)
413{
414 switch (type) {
415 case hwmon_fan:
416 return max31790_fan_is_visible(data, attr, channel);
417 case hwmon_pwm:
418 return max31790_pwm_is_visible(data, attr, channel);
419 default:
420 return 0;
421 }
422}
423
424static const struct hwmon_channel_info *max31790_info[] = {
425 HWMON_CHANNEL_INFO(fan,
426 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
427 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
428 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
429 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
430 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
431 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
432 HWMON_F_INPUT | HWMON_F_FAULT,
433 HWMON_F_INPUT | HWMON_F_FAULT,
434 HWMON_F_INPUT | HWMON_F_FAULT,
435 HWMON_F_INPUT | HWMON_F_FAULT,
436 HWMON_F_INPUT | HWMON_F_FAULT,
437 HWMON_F_INPUT | HWMON_F_FAULT),
438 HWMON_CHANNEL_INFO(pwm,
439 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
440 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
441 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
442 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
443 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
444 HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
445 NULL
446};
447
448static const struct hwmon_ops max31790_hwmon_ops = {
449 .is_visible = max31790_is_visible,
450 .read = max31790_read,
451 .write = max31790_write,
452};
453
454static const struct hwmon_chip_info max31790_chip_info = {
455 .ops = &max31790_hwmon_ops,
456 .info = max31790_info,
457};
458
459static int max31790_init_client(struct i2c_client *client,
460 struct max31790_data *data)
461{
462 int i, rv;
463
464 for (i = 0; i < NR_CHANNEL; i++) {
465 rv = i2c_smbus_read_byte_data(client,
466 MAX31790_REG_FAN_CONFIG(i));
467 if (rv < 0)
468 return rv;
469 data->fan_config[i] = rv;
470
471 rv = i2c_smbus_read_byte_data(client,
472 MAX31790_REG_FAN_DYNAMICS(i));
473 if (rv < 0)
474 return rv;
475 data->fan_dynamics[i] = rv;
476 }
477
478 return 0;
479}
480
481static int max31790_probe(struct i2c_client *client)
482{
483 struct i2c_adapter *adapter = client->adapter;
484 struct device *dev = &client->dev;
485 struct max31790_data *data;
486 struct device *hwmon_dev;
487 int err;
488
489 if (!i2c_check_functionality(adapter,
490 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
491 return -ENODEV;
492
493 data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
494 if (!data)
495 return -ENOMEM;
496
497 data->client = client;
498 mutex_init(&data->update_lock);
499
500
501
502
503 err = max31790_init_client(client, data);
504 if (err)
505 return err;
506
507 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
508 data,
509 &max31790_chip_info,
510 NULL);
511
512 return PTR_ERR_OR_ZERO(hwmon_dev);
513}
514
515static const struct i2c_device_id max31790_id[] = {
516 { "max31790", 0 },
517 { }
518};
519MODULE_DEVICE_TABLE(i2c, max31790_id);
520
521static struct i2c_driver max31790_driver = {
522 .class = I2C_CLASS_HWMON,
523 .probe_new = max31790_probe,
524 .driver = {
525 .name = "max31790",
526 },
527 .id_table = max31790_id,
528};
529
530module_i2c_driver(max31790_driver);
531
532MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
533MODULE_DESCRIPTION("MAX31790 sensor driver");
534MODULE_LICENSE("GPL");
535
