1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * tc654.c - Linux kernel modules for fan speed controller
5 * Copyright (C) 2016 Allied Telesis Labs NZ
8 #include <linux/bitops.h>
10 #include <linux/hwmon.h>
11 #include <linux/hwmon-sysfs.h>
12 #include <linux/i2c.h>
13 #include <linux/init.h>
14 #include <linux/jiffies.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/slab.h>
18 #include <linux/thermal.h>
19 #include <linux/util_macros.h>
22 TC654_REG_RPM1
= 0x00, /* RPM Output 1 */
23 TC654_REG_RPM2
= 0x01, /* RPM Output 2 */
24 TC654_REG_FAN_FAULT1
= 0x02, /* Fan Fault 1 Threshold */
25 TC654_REG_FAN_FAULT2
= 0x03, /* Fan Fault 2 Threshold */
26 TC654_REG_CONFIG
= 0x04, /* Configuration */
27 TC654_REG_STATUS
= 0x05, /* Status */
28 TC654_REG_DUTY_CYCLE
= 0x06, /* Fan Speed Duty Cycle */
29 TC654_REG_MFR_ID
= 0x07, /* Manufacturer Identification */
30 TC654_REG_VER_ID
= 0x08, /* Version Identification */
33 /* Macros to easily index the registers */
34 #define TC654_REG_RPM(idx) (TC654_REG_RPM1 + (idx))
35 #define TC654_REG_FAN_FAULT(idx) (TC654_REG_FAN_FAULT1 + (idx))
37 /* Config register bits */
38 #define TC654_REG_CONFIG_RES BIT(6) /* Resolution Selection */
39 #define TC654_REG_CONFIG_DUTYC BIT(5) /* Duty Cycle Control */
40 #define TC654_REG_CONFIG_SDM BIT(0) /* Shutdown Mode */
42 /* Status register bits */
43 #define TC654_REG_STATUS_F2F BIT(1) /* Fan 2 Fault */
44 #define TC654_REG_STATUS_F1F BIT(0) /* Fan 1 Fault */
46 /* RPM resolution for RPM Output registers */
47 #define TC654_HIGH_RPM_RESOLUTION 25 /* 25 RPM resolution */
48 #define TC654_LOW_RPM_RESOLUTION 50 /* 50 RPM resolution */
50 /* Convert to the fan fault RPM threshold from register value */
51 #define TC654_FAN_FAULT_FROM_REG(val) ((val) * 50) /* 50 RPM resolution */
53 /* Convert to register value from the fan fault RPM threshold */
54 #define TC654_FAN_FAULT_TO_REG(val) (((val) / 50) & 0xff)
56 /* Register data is read (and cached) at most once per second. */
57 #define TC654_UPDATE_INTERVAL HZ
60 struct i2c_client
*client
;
63 struct mutex update_lock
;
65 /* tc654 register cache */
67 unsigned long last_updated
; /* in jiffies */
69 u8 rpm_output
[2]; /* The fan RPM data for fans 1 and 2 is then
70 * written to registers RPM1 and RPM2
72 u8 fan_fault
[2]; /* The Fan Fault Threshold Registers are used to
73 * set the fan fault threshold levels for fan 1
76 u8 config
; /* The Configuration Register is an 8-bit read/
77 * writable multi-function control register
80 * 0 = Normal Operation (default)
81 * 6: Resolution Selection for RPM Output Registers
82 * RPM Output Registers (RPM1 and RPM2) will be
84 * 1 = 25 RPM (9-bit) resolution
85 * 0 = 50 RPM (8-bit) resolution (default)
86 * 5: Duty Cycle Control Method
87 * The V OUT duty cycle will be controlled via
88 * 1 = the SMBus interface.
89 * 0 = via the V IN analog input pin. (default)
90 * 4,3: Fan 2 Pulses Per Rotation
95 * 2,1: Fan 1 Pulses Per Rotation
102 * 0 = Normal operation. (default)
104 u8 status
; /* The Status register provides all the information
105 * about what is going on within the TC654/TC655
107 * 7,6: Unimplemented, Read as '0'
108 * 5: Over-Temperature Fault Condition
109 * 1 = Over-Temperature condition has occurred
110 * 0 = Normal operation. V IN is less than 2.6V
111 * 4: RPM2 Counter Overflow
112 * 1 = Fault condition
113 * 0 = Normal operation
114 * 3: RPM1 Counter Overflow
115 * 1 = Fault condition
116 * 0 = Normal operation
117 * 2: V IN Input Status
119 * 0 = Normal operation. voltage present at V IN
121 * 1 = Fault condition
122 * 0 = Normal operation
124 * 1 = Fault condition
125 * 0 = Normal operation
127 u8 duty_cycle
; /* The DUTY_CYCLE register is a 4-bit read/
128 * writable register used to control the duty
129 * cycle of the V OUT output.
133 /* helper to grab and cache data, at most one time per second */
134 static struct tc654_data
*tc654_update_client(struct device
*dev
)
136 struct tc654_data
*data
= dev_get_drvdata(dev
);
137 struct i2c_client
*client
= data
->client
;
140 mutex_lock(&data
->update_lock
);
141 if (time_before(jiffies
, data
->last_updated
+ TC654_UPDATE_INTERVAL
) &&
145 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_RPM(0));
148 data
->rpm_output
[0] = ret
;
150 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_RPM(1));
153 data
->rpm_output
[1] = ret
;
155 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_FAN_FAULT(0));
158 data
->fan_fault
[0] = ret
;
160 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_FAN_FAULT(1));
163 data
->fan_fault
[1] = ret
;
165 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_CONFIG
);
170 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_STATUS
);
175 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_DUTY_CYCLE
);
178 data
->duty_cycle
= ret
& 0x0f;
180 data
->last_updated
= jiffies
;
183 mutex_unlock(&data
->update_lock
);
185 if (ret
< 0) /* upon error, encode it in return value */
195 static ssize_t
fan_show(struct device
*dev
, struct device_attribute
*da
,
198 int nr
= to_sensor_dev_attr(da
)->index
;
199 struct tc654_data
*data
= tc654_update_client(dev
);
203 return PTR_ERR(data
);
205 if (data
->config
& TC654_REG_CONFIG_RES
)
206 val
= data
->rpm_output
[nr
] * TC654_HIGH_RPM_RESOLUTION
;
208 val
= data
->rpm_output
[nr
] * TC654_LOW_RPM_RESOLUTION
;
210 return sprintf(buf
, "%d\n", val
);
213 static ssize_t
fan_min_show(struct device
*dev
, struct device_attribute
*da
,
216 int nr
= to_sensor_dev_attr(da
)->index
;
217 struct tc654_data
*data
= tc654_update_client(dev
);
220 return PTR_ERR(data
);
222 return sprintf(buf
, "%d\n",
223 TC654_FAN_FAULT_FROM_REG(data
->fan_fault
[nr
]));
226 static ssize_t
fan_min_store(struct device
*dev
, struct device_attribute
*da
,
227 const char *buf
, size_t count
)
229 int nr
= to_sensor_dev_attr(da
)->index
;
230 struct tc654_data
*data
= dev_get_drvdata(dev
);
231 struct i2c_client
*client
= data
->client
;
235 if (kstrtoul(buf
, 10, &val
))
238 val
= clamp_val(val
, 0, 12750);
240 mutex_lock(&data
->update_lock
);
242 data
->fan_fault
[nr
] = TC654_FAN_FAULT_TO_REG(val
);
243 ret
= i2c_smbus_write_byte_data(client
, TC654_REG_FAN_FAULT(nr
),
244 data
->fan_fault
[nr
]);
246 mutex_unlock(&data
->update_lock
);
247 return ret
< 0 ? ret
: count
;
250 static ssize_t
fan_alarm_show(struct device
*dev
, struct device_attribute
*da
,
253 int nr
= to_sensor_dev_attr(da
)->index
;
254 struct tc654_data
*data
= tc654_update_client(dev
);
258 return PTR_ERR(data
);
261 val
= !!(data
->status
& TC654_REG_STATUS_F1F
);
263 val
= !!(data
->status
& TC654_REG_STATUS_F2F
);
265 return sprintf(buf
, "%d\n", val
);
268 static const u8 TC654_FAN_PULSE_SHIFT
[] = { 1, 3 };
270 static ssize_t
fan_pulses_show(struct device
*dev
,
271 struct device_attribute
*da
, char *buf
)
273 int nr
= to_sensor_dev_attr(da
)->index
;
274 struct tc654_data
*data
= tc654_update_client(dev
);
278 return PTR_ERR(data
);
280 val
= BIT((data
->config
>> TC654_FAN_PULSE_SHIFT
[nr
]) & 0x03);
281 return sprintf(buf
, "%d\n", val
);
284 static ssize_t
fan_pulses_store(struct device
*dev
,
285 struct device_attribute
*da
, const char *buf
,
288 int nr
= to_sensor_dev_attr(da
)->index
;
289 struct tc654_data
*data
= dev_get_drvdata(dev
);
290 struct i2c_client
*client
= data
->client
;
295 if (kstrtoul(buf
, 10, &val
))
315 mutex_lock(&data
->update_lock
);
317 data
->config
&= ~(0x03 << TC654_FAN_PULSE_SHIFT
[nr
]);
318 data
->config
|= (config
<< TC654_FAN_PULSE_SHIFT
[nr
]);
319 ret
= i2c_smbus_write_byte_data(client
, TC654_REG_CONFIG
, data
->config
);
321 mutex_unlock(&data
->update_lock
);
322 return ret
< 0 ? ret
: count
;
325 static ssize_t
pwm_mode_show(struct device
*dev
, struct device_attribute
*da
,
328 struct tc654_data
*data
= tc654_update_client(dev
);
331 return PTR_ERR(data
);
333 return sprintf(buf
, "%d\n", !!(data
->config
& TC654_REG_CONFIG_DUTYC
));
336 static ssize_t
pwm_mode_store(struct device
*dev
, struct device_attribute
*da
,
337 const char *buf
, size_t count
)
339 struct tc654_data
*data
= dev_get_drvdata(dev
);
340 struct i2c_client
*client
= data
->client
;
344 if (kstrtoul(buf
, 10, &val
))
347 if (val
!= 0 && val
!= 1)
350 mutex_lock(&data
->update_lock
);
353 data
->config
|= TC654_REG_CONFIG_DUTYC
;
355 data
->config
&= ~TC654_REG_CONFIG_DUTYC
;
357 ret
= i2c_smbus_write_byte_data(client
, TC654_REG_CONFIG
, data
->config
);
359 mutex_unlock(&data
->update_lock
);
360 return ret
< 0 ? ret
: count
;
363 static const int tc654_pwm_map
[16] = { 77, 88, 102, 112, 124, 136, 148, 160,
364 172, 184, 196, 207, 219, 231, 243, 255};
366 static ssize_t
pwm_show(struct device
*dev
, struct device_attribute
*da
,
369 struct tc654_data
*data
= tc654_update_client(dev
);
373 return PTR_ERR(data
);
375 if (data
->config
& TC654_REG_CONFIG_SDM
)
378 pwm
= tc654_pwm_map
[data
->duty_cycle
];
380 return sprintf(buf
, "%d\n", pwm
);
383 static int _set_pwm(struct tc654_data
*data
, unsigned long val
)
385 struct i2c_client
*client
= data
->client
;
388 mutex_lock(&data
->update_lock
);
391 data
->config
|= TC654_REG_CONFIG_SDM
;
392 data
->duty_cycle
= 0;
394 data
->config
&= ~TC654_REG_CONFIG_SDM
;
395 data
->duty_cycle
= val
- 1;
398 ret
= i2c_smbus_write_byte_data(client
, TC654_REG_CONFIG
, data
->config
);
402 ret
= i2c_smbus_write_byte_data(client
, TC654_REG_DUTY_CYCLE
,
406 mutex_unlock(&data
->update_lock
);
410 static ssize_t
pwm_store(struct device
*dev
, struct device_attribute
*da
,
411 const char *buf
, size_t count
)
413 struct tc654_data
*data
= dev_get_drvdata(dev
);
417 if (kstrtoul(buf
, 10, &val
))
422 val
= find_closest(val
, tc654_pwm_map
, ARRAY_SIZE(tc654_pwm_map
)) + 1;
424 ret
= _set_pwm(data
, val
);
425 return ret
< 0 ? ret
: count
;
428 static SENSOR_DEVICE_ATTR_RO(fan1_input
, fan
, 0);
429 static SENSOR_DEVICE_ATTR_RO(fan2_input
, fan
, 1);
430 static SENSOR_DEVICE_ATTR_RW(fan1_min
, fan_min
, 0);
431 static SENSOR_DEVICE_ATTR_RW(fan2_min
, fan_min
, 1);
432 static SENSOR_DEVICE_ATTR_RO(fan1_alarm
, fan_alarm
, 0);
433 static SENSOR_DEVICE_ATTR_RO(fan2_alarm
, fan_alarm
, 1);
434 static SENSOR_DEVICE_ATTR_RW(fan1_pulses
, fan_pulses
, 0);
435 static SENSOR_DEVICE_ATTR_RW(fan2_pulses
, fan_pulses
, 1);
436 static SENSOR_DEVICE_ATTR_RW(pwm1_mode
, pwm_mode
, 0);
437 static SENSOR_DEVICE_ATTR_RW(pwm1
, pwm
, 0);
440 static struct attribute
*tc654_attrs
[] = {
441 &sensor_dev_attr_fan1_input
.dev_attr
.attr
,
442 &sensor_dev_attr_fan2_input
.dev_attr
.attr
,
443 &sensor_dev_attr_fan1_min
.dev_attr
.attr
,
444 &sensor_dev_attr_fan2_min
.dev_attr
.attr
,
445 &sensor_dev_attr_fan1_alarm
.dev_attr
.attr
,
446 &sensor_dev_attr_fan2_alarm
.dev_attr
.attr
,
447 &sensor_dev_attr_fan1_pulses
.dev_attr
.attr
,
448 &sensor_dev_attr_fan2_pulses
.dev_attr
.attr
,
449 &sensor_dev_attr_pwm1_mode
.dev_attr
.attr
,
450 &sensor_dev_attr_pwm1
.dev_attr
.attr
,
454 ATTRIBUTE_GROUPS(tc654
);
457 * thermal cooling device functions
459 * Account for the "ShutDown Mode (SDM)" state by offsetting
460 * the 16 PWM duty cycle states by 1.
462 * State 0 = 0% PWM | Shutdown - Fan(s) are off
463 * State 1 = 30% PWM | duty_cycle = 0
464 * State 2 = ~35% PWM | duty_cycle = 1
466 * State 15 = ~95% PWM | duty_cycle = 14
467 * State 16 = 100% PWM | duty_cycle = 15
469 #define TC654_MAX_COOLING_STATE 16
471 static int tc654_get_max_state(struct thermal_cooling_device
*cdev
, unsigned long *state
)
473 *state
= TC654_MAX_COOLING_STATE
;
477 static int tc654_get_cur_state(struct thermal_cooling_device
*cdev
, unsigned long *state
)
479 struct tc654_data
*data
= tc654_update_client(cdev
->devdata
);
482 return PTR_ERR(data
);
484 if (data
->config
& TC654_REG_CONFIG_SDM
)
485 *state
= 0; /* FAN is off */
487 *state
= data
->duty_cycle
+ 1; /* offset PWM States by 1 */
492 static int tc654_set_cur_state(struct thermal_cooling_device
*cdev
, unsigned long state
)
494 struct tc654_data
*data
= tc654_update_client(cdev
->devdata
);
497 return PTR_ERR(data
);
499 return _set_pwm(data
, clamp_val(state
, 0, TC654_MAX_COOLING_STATE
));
502 static const struct thermal_cooling_device_ops tc654_fan_cool_ops
= {
503 .get_max_state
= tc654_get_max_state
,
504 .get_cur_state
= tc654_get_cur_state
,
505 .set_cur_state
= tc654_set_cur_state
,
509 * device probe and removal
512 static int tc654_probe(struct i2c_client
*client
)
514 struct device
*dev
= &client
->dev
;
515 struct tc654_data
*data
;
516 struct device
*hwmon_dev
;
519 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_SMBUS_BYTE_DATA
))
522 data
= devm_kzalloc(dev
, sizeof(struct tc654_data
), GFP_KERNEL
);
526 data
->client
= client
;
527 mutex_init(&data
->update_lock
);
529 ret
= i2c_smbus_read_byte_data(client
, TC654_REG_CONFIG
);
536 devm_hwmon_device_register_with_groups(dev
, client
->name
, data
,
538 if (IS_ERR(hwmon_dev
))
539 return PTR_ERR(hwmon_dev
);
541 if (IS_ENABLED(CONFIG_THERMAL
)) {
542 struct thermal_cooling_device
*cdev
;
544 cdev
= devm_thermal_of_cooling_device_register(dev
, dev
->of_node
, client
->name
,
545 hwmon_dev
, &tc654_fan_cool_ops
);
546 return PTR_ERR_OR_ZERO(cdev
);
552 static const struct i2c_device_id tc654_id
[] = {
558 MODULE_DEVICE_TABLE(i2c
, tc654_id
);
560 static struct i2c_driver tc654_driver
= {
564 .probe
= tc654_probe
,
565 .id_table
= tc654_id
,
568 module_i2c_driver(tc654_driver
);
570 MODULE_AUTHOR("Allied Telesis Labs");
571 MODULE_DESCRIPTION("Microchip TC654/TC655 driver");
572 MODULE_LICENSE("GPL");