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 FAN_COUNT_REG_MAX 0xffe0
45 #define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \
46 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
48 #define RPM_TO_REG(rpm, sr) ((60 * (sr) * 8192) / ((rpm) * 2))
52 #define PWM_INPUT_SCALE 255
53 #define MAX31790_REG_PWMOUT_SCALE 511
56 * Client data (each client gets its own)
58 struct max31790_data {
59 struct i2c_client *client;
60 struct mutex update_lock;
61 bool valid; /* zero until following fields are valid */
62 unsigned long last_updated; /* in jiffies */
65 u8 fan_config[NR_CHANNEL];
66 u8 fan_dynamics[NR_CHANNEL];
68 u16 tach[NR_CHANNEL * 2];
70 u16 target_count[NR_CHANNEL];
73 static struct max31790_data *max31790_update_device(struct device *dev)
75 struct max31790_data *data = dev_get_drvdata(dev);
76 struct i2c_client *client = data->client;
77 struct max31790_data *ret = data;
81 mutex_lock(&data->update_lock);
83 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
84 rv = i2c_smbus_read_byte_data(client,
85 MAX31790_REG_FAN_FAULT_STATUS1);
88 data->fault_status |= rv & 0x3F;
90 rv = i2c_smbus_read_byte_data(client,
91 MAX31790_REG_FAN_FAULT_STATUS2);
94 data->fault_status |= (rv & 0x3F) << 6;
96 for (i = 0; i < NR_CHANNEL; i++) {
97 rv = i2c_smbus_read_word_swapped(client,
98 MAX31790_REG_TACH_COUNT(i));
103 if (data->fan_config[i]
104 & MAX31790_FAN_CFG_TACH_INPUT) {
105 rv = i2c_smbus_read_word_swapped(client,
106 MAX31790_REG_TACH_COUNT(NR_CHANNEL
110 data->tach[NR_CHANNEL + i] = rv;
112 rv = i2c_smbus_read_word_swapped(client,
113 MAX31790_REG_PWM_DUTY_CYCLE(i));
118 rv = i2c_smbus_read_word_swapped(client,
119 MAX31790_REG_TARGET_COUNT(i));
122 data->target_count[i] = rv;
126 data->last_updated = jiffies;
136 mutex_unlock(&data->update_lock);
141 static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
143 static u8 get_tach_period(u8 fan_dynamics)
145 return tach_period[SR_FROM_REG(fan_dynamics)];
148 static u8 bits_for_tach_period(int rpm)
168 static int max31790_read_fan(struct device *dev, u32 attr, int channel,
171 struct max31790_data *data = max31790_update_device(dev);
175 return PTR_ERR(data);
178 case hwmon_fan_input:
179 sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]);
180 if (data->tach[channel] == FAN_COUNT_REG_MAX)
183 rpm = RPM_FROM_REG(data->tach[channel], sr);
186 case hwmon_fan_target:
187 sr = get_tach_period(data->fan_dynamics[channel]);
188 rpm = RPM_FROM_REG(data->target_count[channel], sr);
191 case hwmon_fan_fault:
192 mutex_lock(&data->update_lock);
193 *val = !!(data->fault_status & (1 << channel));
194 data->fault_status &= ~(1 << channel);
196 * If a fault bit is set, we need to write into one of the fan
197 * configuration registers to clear it. Note that this also
198 * clears the fault for the companion channel if enabled.
201 int reg = MAX31790_REG_TARGET_COUNT(channel % NR_CHANNEL);
203 i2c_smbus_write_byte_data(data->client, reg,
204 data->target_count[channel % NR_CHANNEL] >> 8);
206 mutex_unlock(&data->update_lock);
208 case hwmon_fan_enable:
209 *val = !!(data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN);
216 static int max31790_write_fan(struct device *dev, u32 attr, int channel,
219 struct max31790_data *data = dev_get_drvdata(dev);
220 struct i2c_client *client = data->client;
226 mutex_lock(&data->update_lock);
229 case hwmon_fan_target:
230 val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
231 bits = bits_for_tach_period(val);
232 data->fan_dynamics[channel] =
233 ((data->fan_dynamics[channel] &
234 ~MAX31790_FAN_DYN_SR_MASK) |
235 (bits << MAX31790_FAN_DYN_SR_SHIFT));
236 err = i2c_smbus_write_byte_data(client,
237 MAX31790_REG_FAN_DYNAMICS(channel),
238 data->fan_dynamics[channel]);
242 sr = get_tach_period(data->fan_dynamics[channel]);
243 target_count = RPM_TO_REG(val, sr);
244 target_count = clamp_val(target_count, 0x1, 0x7FF);
246 data->target_count[channel] = target_count << 5;
248 err = i2c_smbus_write_word_swapped(client,
249 MAX31790_REG_TARGET_COUNT(channel),
250 data->target_count[channel]);
252 case hwmon_fan_enable:
253 fan_config = data->fan_config[channel];
255 fan_config &= ~MAX31790_FAN_CFG_TACH_INPUT_EN;
256 } else if (val == 1) {
257 fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN;
262 if (fan_config != data->fan_config[channel]) {
263 err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
266 data->fan_config[channel] = fan_config;
274 mutex_unlock(&data->update_lock);
279 static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
281 const struct max31790_data *data = _data;
282 u8 fan_config = data->fan_config[channel % NR_CHANNEL];
285 case hwmon_fan_input:
286 case hwmon_fan_fault:
287 if (channel < NR_CHANNEL ||
288 (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
291 case hwmon_fan_target:
292 if (channel < NR_CHANNEL &&
293 !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
296 case hwmon_fan_enable:
297 if (channel < NR_CHANNEL)
305 static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
308 struct max31790_data *data = max31790_update_device(dev);
312 return PTR_ERR(data);
314 fan_config = data->fan_config[channel];
317 case hwmon_pwm_input:
318 *val = data->pwm[channel] >> 8;
320 case hwmon_pwm_enable:
321 if (fan_config & MAX31790_FAN_CFG_CTRL_MON)
323 else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
333 static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
336 struct max31790_data *data = dev_get_drvdata(dev);
337 struct i2c_client *client = data->client;
341 mutex_lock(&data->update_lock);
344 case hwmon_pwm_input:
345 if (val < 0 || val > 255) {
350 val = DIV_ROUND_CLOSEST(val * MAX31790_REG_PWMOUT_SCALE,
353 err = i2c_smbus_write_word_swapped(client,
354 MAX31790_REG_PWMOUT(channel),
357 case hwmon_pwm_enable:
358 fan_config = data->fan_config[channel];
360 fan_config |= MAX31790_FAN_CFG_CTRL_MON;
362 * Disable RPM mode; otherwise disabling fan speed
363 * monitoring is not possible.
365 fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
366 } else if (val == 1) {
367 fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
368 } else if (val == 2) {
369 fan_config &= ~MAX31790_FAN_CFG_CTRL_MON;
371 * The chip sets MAX31790_FAN_CFG_TACH_INPUT_EN on its
372 * own if MAX31790_FAN_CFG_RPM_MODE is set.
373 * Do it here as well to reflect the actual register
374 * value in the cache.
376 fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);
381 if (fan_config != data->fan_config[channel]) {
382 err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
385 data->fan_config[channel] = fan_config;
393 mutex_unlock(&data->update_lock);
398 static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
400 const struct max31790_data *data = _data;
401 u8 fan_config = data->fan_config[channel];
404 case hwmon_pwm_input:
405 case hwmon_pwm_enable:
406 if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
414 static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
415 u32 attr, int channel, long *val)
419 return max31790_read_fan(dev, attr, channel, val);
421 return max31790_read_pwm(dev, attr, channel, val);
427 static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
428 u32 attr, int channel, long val)
432 return max31790_write_fan(dev, attr, channel, val);
434 return max31790_write_pwm(dev, attr, channel, val);
440 static umode_t max31790_is_visible(const void *data,
441 enum hwmon_sensor_types type,
442 u32 attr, int channel)
446 return max31790_fan_is_visible(data, attr, channel);
448 return max31790_pwm_is_visible(data, attr, channel);
454 static const struct hwmon_channel_info * const max31790_info[] = {
455 HWMON_CHANNEL_INFO(fan,
456 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
457 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
458 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
459 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
460 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
461 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
462 HWMON_F_INPUT | HWMON_F_FAULT,
463 HWMON_F_INPUT | HWMON_F_FAULT,
464 HWMON_F_INPUT | HWMON_F_FAULT,
465 HWMON_F_INPUT | HWMON_F_FAULT,
466 HWMON_F_INPUT | HWMON_F_FAULT,
467 HWMON_F_INPUT | HWMON_F_FAULT),
468 HWMON_CHANNEL_INFO(pwm,
469 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
470 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
471 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
472 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
473 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
474 HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
478 static const struct hwmon_ops max31790_hwmon_ops = {
479 .is_visible = max31790_is_visible,
480 .read = max31790_read,
481 .write = max31790_write,
484 static const struct hwmon_chip_info max31790_chip_info = {
485 .ops = &max31790_hwmon_ops,
486 .info = max31790_info,
489 static int max31790_init_client(struct i2c_client *client,
490 struct max31790_data *data)
494 for (i = 0; i < NR_CHANNEL; i++) {
495 rv = i2c_smbus_read_byte_data(client,
496 MAX31790_REG_FAN_CONFIG(i));
499 data->fan_config[i] = rv;
501 rv = i2c_smbus_read_byte_data(client,
502 MAX31790_REG_FAN_DYNAMICS(i));
505 data->fan_dynamics[i] = rv;
511 static int max31790_probe(struct i2c_client *client)
513 struct i2c_adapter *adapter = client->adapter;
514 struct device *dev = &client->dev;
515 struct max31790_data *data;
516 struct device *hwmon_dev;
519 if (!i2c_check_functionality(adapter,
520 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
523 data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
527 data->client = client;
528 mutex_init(&data->update_lock);
531 * Initialize the max31790 chip
533 err = max31790_init_client(client, data);
537 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
542 return PTR_ERR_OR_ZERO(hwmon_dev);
545 static const struct i2c_device_id max31790_id[] = {
549 MODULE_DEVICE_TABLE(i2c, max31790_id);
551 static struct i2c_driver max31790_driver = {
552 .probe = max31790_probe,
556 .id_table = max31790_id,
559 module_i2c_driver(max31790_driver);
561 MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
562 MODULE_DESCRIPTION("MAX31790 sensor driver");
563 MODULE_LICENSE("GPL");