1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
6 * (C) 2015 by Il Han <corone.il.han@gmail.com>
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>
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)
28 /* Fan Config register bits */
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
34 /* Fan Dynamics register bits */
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)
40 #define FAN_RPM_MIN 120
41 #define FAN_RPM_MAX 7864320
43 #define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \
44 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
46 #define RPM_TO_REG(rpm, sr) ((60 * (sr) * 8192) / ((rpm) * 2))
51 * Client data (each client gets its own)
53 struct max31790_data {
54 struct i2c_client *client;
55 struct mutex update_lock;
56 bool valid; /* zero until following fields are valid */
57 unsigned long last_updated; /* in jiffies */
60 u8 fan_config[NR_CHANNEL];
61 u8 fan_dynamics[NR_CHANNEL];
63 u16 tach[NR_CHANNEL * 2];
65 u16 target_count[NR_CHANNEL];
68 static struct max31790_data *max31790_update_device(struct device *dev)
70 struct max31790_data *data = dev_get_drvdata(dev);
71 struct i2c_client *client = data->client;
72 struct max31790_data *ret = data;
76 mutex_lock(&data->update_lock);
78 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
79 rv = i2c_smbus_read_byte_data(client,
80 MAX31790_REG_FAN_FAULT_STATUS1);
83 data->fault_status = rv & 0x3F;
85 rv = i2c_smbus_read_byte_data(client,
86 MAX31790_REG_FAN_FAULT_STATUS2);
89 data->fault_status |= (rv & 0x3F) << 6;
91 for (i = 0; i < NR_CHANNEL; i++) {
92 rv = i2c_smbus_read_word_swapped(client,
93 MAX31790_REG_TACH_COUNT(i));
98 if (data->fan_config[i]
99 & MAX31790_FAN_CFG_TACH_INPUT) {
100 rv = i2c_smbus_read_word_swapped(client,
101 MAX31790_REG_TACH_COUNT(NR_CHANNEL
105 data->tach[NR_CHANNEL + i] = rv;
107 rv = i2c_smbus_read_word_swapped(client,
108 MAX31790_REG_PWM_DUTY_CYCLE(i));
113 rv = i2c_smbus_read_word_swapped(client,
114 MAX31790_REG_TARGET_COUNT(i));
117 data->target_count[i] = rv;
121 data->last_updated = jiffies;
131 mutex_unlock(&data->update_lock);
136 static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
138 static u8 get_tach_period(u8 fan_dynamics)
140 return tach_period[SR_FROM_REG(fan_dynamics)];
143 static u8 bits_for_tach_period(int rpm)
163 static int max31790_read_fan(struct device *dev, u32 attr, int channel,
166 struct max31790_data *data = max31790_update_device(dev);
170 return PTR_ERR(data);
173 case hwmon_fan_input:
174 sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]);
175 rpm = RPM_FROM_REG(data->tach[channel], sr);
178 case hwmon_fan_target:
179 sr = get_tach_period(data->fan_dynamics[channel]);
180 rpm = RPM_FROM_REG(data->target_count[channel], sr);
183 case hwmon_fan_fault:
184 *val = !!(data->fault_status & (1 << channel));
191 static int max31790_write_fan(struct device *dev, u32 attr, int channel,
194 struct max31790_data *data = dev_get_drvdata(dev);
195 struct i2c_client *client = data->client;
201 mutex_lock(&data->update_lock);
204 case hwmon_fan_target:
205 val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
206 bits = bits_for_tach_period(val);
207 data->fan_dynamics[channel] =
208 ((data->fan_dynamics[channel] &
209 ~MAX31790_FAN_DYN_SR_MASK) |
210 (bits << MAX31790_FAN_DYN_SR_SHIFT));
211 err = i2c_smbus_write_byte_data(client,
212 MAX31790_REG_FAN_DYNAMICS(channel),
213 data->fan_dynamics[channel]);
217 sr = get_tach_period(data->fan_dynamics[channel]);
218 target_count = RPM_TO_REG(val, sr);
219 target_count = clamp_val(target_count, 0x1, 0x7FF);
221 data->target_count[channel] = target_count << 5;
223 err = i2c_smbus_write_word_swapped(client,
224 MAX31790_REG_TARGET_COUNT(channel),
225 data->target_count[channel]);
232 mutex_unlock(&data->update_lock);
237 static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
239 const struct max31790_data *data = _data;
240 u8 fan_config = data->fan_config[channel % NR_CHANNEL];
243 case hwmon_fan_input:
244 case hwmon_fan_fault:
245 if (channel < NR_CHANNEL ||
246 (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
249 case hwmon_fan_target:
250 if (channel < NR_CHANNEL &&
251 !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
259 static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
262 struct max31790_data *data = max31790_update_device(dev);
266 return PTR_ERR(data);
268 fan_config = data->fan_config[channel];
271 case hwmon_pwm_input:
272 *val = data->pwm[channel] >> 8;
274 case hwmon_pwm_enable:
275 if (fan_config & MAX31790_FAN_CFG_CTRL_MON)
277 else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
287 static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
290 struct max31790_data *data = dev_get_drvdata(dev);
291 struct i2c_client *client = data->client;
295 mutex_lock(&data->update_lock);
298 case hwmon_pwm_input:
299 if (val < 0 || val > 255) {
304 err = i2c_smbus_write_word_swapped(client,
305 MAX31790_REG_PWMOUT(channel),
308 case hwmon_pwm_enable:
309 fan_config = data->fan_config[channel];
311 fan_config |= MAX31790_FAN_CFG_CTRL_MON;
313 * Disable RPM mode; otherwise disabling fan speed
314 * monitoring is not possible.
316 fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
317 } else if (val == 1) {
318 fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
319 } else if (val == 2) {
320 fan_config &= ~MAX31790_FAN_CFG_CTRL_MON;
322 * The chip sets MAX31790_FAN_CFG_TACH_INPUT_EN on its
323 * own if MAX31790_FAN_CFG_RPM_MODE is set.
324 * Do it here as well to reflect the actual register
325 * value in the cache.
327 fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);
332 if (fan_config != data->fan_config[channel]) {
333 err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
336 data->fan_config[channel] = fan_config;
344 mutex_unlock(&data->update_lock);
349 static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
351 const struct max31790_data *data = _data;
352 u8 fan_config = data->fan_config[channel];
355 case hwmon_pwm_input:
356 case hwmon_pwm_enable:
357 if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
365 static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
366 u32 attr, int channel, long *val)
370 return max31790_read_fan(dev, attr, channel, val);
372 return max31790_read_pwm(dev, attr, channel, val);
378 static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
379 u32 attr, int channel, long val)
383 return max31790_write_fan(dev, attr, channel, val);
385 return max31790_write_pwm(dev, attr, channel, val);
391 static umode_t max31790_is_visible(const void *data,
392 enum hwmon_sensor_types type,
393 u32 attr, int channel)
397 return max31790_fan_is_visible(data, attr, channel);
399 return max31790_pwm_is_visible(data, attr, channel);
405 static const struct hwmon_channel_info *max31790_info[] = {
406 HWMON_CHANNEL_INFO(fan,
407 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
408 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
409 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
410 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
411 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
412 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
413 HWMON_F_INPUT | HWMON_F_FAULT,
414 HWMON_F_INPUT | HWMON_F_FAULT,
415 HWMON_F_INPUT | HWMON_F_FAULT,
416 HWMON_F_INPUT | HWMON_F_FAULT,
417 HWMON_F_INPUT | HWMON_F_FAULT,
418 HWMON_F_INPUT | HWMON_F_FAULT),
419 HWMON_CHANNEL_INFO(pwm,
420 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
421 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
422 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
423 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
424 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
425 HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
429 static const struct hwmon_ops max31790_hwmon_ops = {
430 .is_visible = max31790_is_visible,
431 .read = max31790_read,
432 .write = max31790_write,
435 static const struct hwmon_chip_info max31790_chip_info = {
436 .ops = &max31790_hwmon_ops,
437 .info = max31790_info,
440 static int max31790_init_client(struct i2c_client *client,
441 struct max31790_data *data)
445 for (i = 0; i < NR_CHANNEL; i++) {
446 rv = i2c_smbus_read_byte_data(client,
447 MAX31790_REG_FAN_CONFIG(i));
450 data->fan_config[i] = rv;
452 rv = i2c_smbus_read_byte_data(client,
453 MAX31790_REG_FAN_DYNAMICS(i));
456 data->fan_dynamics[i] = rv;
462 static int max31790_probe(struct i2c_client *client)
464 struct i2c_adapter *adapter = client->adapter;
465 struct device *dev = &client->dev;
466 struct max31790_data *data;
467 struct device *hwmon_dev;
470 if (!i2c_check_functionality(adapter,
471 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
474 data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
478 data->client = client;
479 mutex_init(&data->update_lock);
482 * Initialize the max31790 chip
484 err = max31790_init_client(client, data);
488 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
493 return PTR_ERR_OR_ZERO(hwmon_dev);
496 static const struct i2c_device_id max31790_id[] = {
500 MODULE_DEVICE_TABLE(i2c, max31790_id);
502 static struct i2c_driver max31790_driver = {
503 .class = I2C_CLASS_HWMON,
504 .probe_new = max31790_probe,
508 .id_table = max31790_id,
511 module_i2c_driver(max31790_driver);
513 MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
514 MODULE_DESCRIPTION("MAX31790 sensor driver");
515 MODULE_LICENSE("GPL");