2 * Measurements Specialties driver common i2c functions
4 * Copyright (c) 2015 Measurement-Specialties
6 * Licensed under the GPL-2.
9 #include <linux/module.h>
10 #include <linux/iio/iio.h>
11 #include <linux/device.h>
12 #include <linux/delay.h>
14 #include "ms_sensors_i2c.h"
16 /* Conversion times in us */
17 static const u16 ms_sensors_ht_t_conversion_time
[] = { 50000, 25000,
19 static const u16 ms_sensors_ht_h_conversion_time
[] = { 16000, 3000,
21 static const u16 ms_sensors_tp_conversion_time
[] = { 500, 1100, 2100,
24 #define MS_SENSORS_SERIAL_READ_MSB 0xFA0F
25 #define MS_SENSORS_SERIAL_READ_LSB 0xFCC9
26 #define MS_SENSORS_CONFIG_REG_WRITE 0xE6
27 #define MS_SENSORS_CONFIG_REG_READ 0xE7
28 #define MS_SENSORS_HT_T_CONVERSION_START 0xF3
29 #define MS_SENSORS_HT_H_CONVERSION_START 0xF5
31 #define MS_SENSORS_TP_PROM_READ 0xA0
32 #define MS_SENSORS_TP_T_CONVERSION_START 0x50
33 #define MS_SENSORS_TP_P_CONVERSION_START 0x40
34 #define MS_SENSORS_TP_ADC_READ 0x00
36 #define MS_SENSORS_NO_READ_CMD 0xFF
39 * ms_sensors_reset() - Reset function
40 * @cli: pointer to device client
41 * @cmd: reset cmd. Depends on device in use
42 * @delay: usleep minimal delay after reset command is issued
44 * Generic I2C reset function for Measurement Specialties devices.
46 * Return: 0 on success, negative errno otherwise.
48 int ms_sensors_reset(void *cli
, u8 cmd
, unsigned int delay
)
51 struct i2c_client
*client
= cli
;
53 ret
= i2c_smbus_write_byte(client
, cmd
);
55 dev_err(&client
->dev
, "Failed to reset device\n");
58 usleep_range(delay
, delay
+ 1000);
62 EXPORT_SYMBOL(ms_sensors_reset
);
65 * ms_sensors_read_prom_word() - PROM word read function
66 * @cli: pointer to device client
67 * @cmd: PROM read cmd. Depends on device and prom id
68 * @word: pointer to word destination value
70 * Generic i2c prom word read function for Measurement Specialties devices.
72 * Return: 0 on success, negative errno otherwise.
74 int ms_sensors_read_prom_word(void *cli
, int cmd
, u16
*word
)
77 struct i2c_client
*client
= (struct i2c_client
*)cli
;
79 ret
= i2c_smbus_read_word_swapped(client
, cmd
);
81 dev_err(&client
->dev
, "Failed to read prom word\n");
88 EXPORT_SYMBOL(ms_sensors_read_prom_word
);
91 * ms_sensors_convert_and_read() - ADC conversion & read function
92 * @cli: pointer to device client
93 * @conv: ADC conversion command. Depends on device in use
94 * @rd: ADC read command. Depends on device in use
95 * @delay: usleep minimal delay after conversion command is issued
96 * @adc: pointer to ADC destination value
98 * Generic ADC conversion & read function for Measurement Specialties
100 * The function will issue conversion command, sleep appopriate delay, and
101 * issue command to read ADC.
103 * Return: 0 on success, negative errno otherwise.
105 int ms_sensors_convert_and_read(void *cli
, u8 conv
, u8 rd
,
106 unsigned int delay
, u32
*adc
)
110 struct i2c_client
*client
= (struct i2c_client
*)cli
;
112 /* Trigger conversion */
113 ret
= i2c_smbus_write_byte(client
, conv
);
116 usleep_range(delay
, delay
+ 1000);
118 /* Retrieve ADC value */
119 if (rd
!= MS_SENSORS_NO_READ_CMD
)
120 ret
= i2c_smbus_read_i2c_block_data(client
, rd
, 3, (u8
*)&buf
);
122 ret
= i2c_master_recv(client
, (u8
*)&buf
, 3);
126 dev_dbg(&client
->dev
, "ADC raw value : %x\n", be32_to_cpu(buf
) >> 8);
127 *adc
= be32_to_cpu(buf
) >> 8;
131 dev_err(&client
->dev
, "Unable to make sensor adc conversion\n");
134 EXPORT_SYMBOL(ms_sensors_convert_and_read
);
137 * ms_sensors_crc_valid() - CRC check function
138 * @value: input and CRC compare value
140 * Cyclic Redundancy Check function used in TSYS02D, HTU21, MS8607.
141 * This function performs a x^8 + x^5 + x^4 + 1 polynomial CRC.
142 * The argument contains CRC value in LSB byte while the bytes 1 and 2
143 * are used for CRC computation.
145 * Return: 1 if CRC is valid, 0 otherwise.
147 static bool ms_sensors_crc_valid(u32 value
)
149 u32 polynom
= 0x988000; /* x^8 + x^5 + x^4 + 1 */
152 u32 result
= value
& 0xFFFF00;
153 u8 crc
= value
& 0xFF;
155 while (msb
!= 0x80) {
157 result
= ((result
^ polynom
) & mask
)
164 return result
== crc
;
168 * ms_sensors_read_serial() - Serial number read function
169 * @cli: pointer to i2c client
170 * @sn: pointer to 64-bits destination value
172 * Generic i2c serial number read function for Measurement Specialties devices.
173 * This function is used for TSYS02d, HTU21, MS8607 chipset.
174 * Refer to datasheet:
175 * http://www.meas-spec.com/downloads/HTU2X_Serial_Number_Reading.pdf
177 * Sensor raw MSB serial number format is the following :
178 * [ SNB3, CRC, SNB2, CRC, SNB1, CRC, SNB0, CRC]
179 * Sensor raw LSB serial number format is the following :
180 * [ X, X, SNC1, SNC0, CRC, SNA1, SNA0, CRC]
181 * The resulting serial number is following :
182 * [ SNA1, SNA0, SNB3, SNB2, SNB1, SNB0, SNC1, SNC0]
184 * Return: 0 on success, negative errno otherwise.
186 int ms_sensors_read_serial(struct i2c_client
*client
, u64
*sn
)
194 struct i2c_msg msg
[2] = {
196 .addr
= client
->addr
,
197 .flags
= client
->flags
,
199 .buf
= (__u8
*)&send_buf
,
202 .addr
= client
->addr
,
203 .flags
= client
->flags
| I2C_M_RD
,
204 .buf
= (__u8
*)&rcv_buf
,
208 /* Read MSB part of serial number */
209 send_buf
= cpu_to_be16(MS_SENSORS_SERIAL_READ_MSB
);
211 ret
= i2c_transfer(client
->adapter
, msg
, 2);
213 dev_err(&client
->dev
, "Unable to read device serial number");
217 rcv_val
= be64_to_cpu(rcv_buf
);
218 dev_dbg(&client
->dev
, "Serial MSB raw : %llx\n", rcv_val
);
220 for (i
= 0; i
< 64; i
+= 16) {
221 if (!ms_sensors_crc_valid((rcv_val
>> i
) & 0xFFFF))
225 *sn
= (((rcv_val
>> 32) & 0xFF000000) |
226 ((rcv_val
>> 24) & 0x00FF0000) |
227 ((rcv_val
>> 16) & 0x0000FF00) |
228 ((rcv_val
>> 8) & 0x000000FF)) << 16;
230 /* Read LSB part of serial number */
231 send_buf
= cpu_to_be16(MS_SENSORS_SERIAL_READ_LSB
);
234 ret
= i2c_transfer(client
->adapter
, msg
, 2);
236 dev_err(&client
->dev
, "Unable to read device serial number");
240 rcv_val
= be64_to_cpu(rcv_buf
) >> 16;
241 dev_dbg(&client
->dev
, "Serial MSB raw : %llx\n", rcv_val
);
243 for (i
= 0; i
< 48; i
+= 24) {
244 if (!ms_sensors_crc_valid((rcv_val
>> i
) & 0xFFFFFF))
248 *sn
|= (rcv_val
& 0xFFFF00) << 40 | (rcv_val
>> 32);
252 EXPORT_SYMBOL(ms_sensors_read_serial
);
254 static int ms_sensors_read_config_reg(struct i2c_client
*client
,
259 ret
= i2c_smbus_write_byte(client
, MS_SENSORS_CONFIG_REG_READ
);
261 dev_err(&client
->dev
, "Unable to read config register");
265 ret
= i2c_master_recv(client
, config_reg
, 1);
267 dev_err(&client
->dev
, "Unable to read config register");
270 dev_dbg(&client
->dev
, "Config register :%x\n", *config_reg
);
276 * ms_sensors_write_resolution() - Set resolution function
277 * @dev_data: pointer to temperature/humidity device data
278 * @i: resolution index to set
280 * This function will program the appropriate resolution based on the index
281 * provided when user space will set samp_freq channel.
282 * This function is used for TSYS02D, HTU21 and MS8607 chipsets.
284 * Return: 0 on success, negative errno otherwise.
286 ssize_t
ms_sensors_write_resolution(struct ms_ht_dev
*dev_data
,
292 ret
= ms_sensors_read_config_reg(dev_data
->client
, &config_reg
);
297 config_reg
|= ((i
& 1) << 7) + ((i
& 2) >> 1);
299 return i2c_smbus_write_byte_data(dev_data
->client
,
300 MS_SENSORS_CONFIG_REG_WRITE
,
303 EXPORT_SYMBOL(ms_sensors_write_resolution
);
306 * ms_sensors_show_battery_low() - Show device battery low indicator
307 * @dev_data: pointer to temperature/humidity device data
308 * @buf: pointer to char buffer to write result
310 * This function will read battery indicator value in the device and
311 * return 1 if the device voltage is below 2.25V.
312 * This function is used for TSYS02D, HTU21 and MS8607 chipsets.
314 * Return: length of sprintf on success, negative errno otherwise.
316 ssize_t
ms_sensors_show_battery_low(struct ms_ht_dev
*dev_data
,
322 mutex_lock(&dev_data
->lock
);
323 ret
= ms_sensors_read_config_reg(dev_data
->client
, &config_reg
);
324 mutex_unlock(&dev_data
->lock
);
328 return sprintf(buf
, "%d\n", (config_reg
& 0x40) >> 6);
330 EXPORT_SYMBOL(ms_sensors_show_battery_low
);
333 * ms_sensors_show_heater() - Show device heater
334 * @dev_data: pointer to temperature/humidity device data
335 * @buf: pointer to char buffer to write result
337 * This function will read heater enable value in the device and
338 * return 1 if the heater is enabled.
339 * This function is used for HTU21 and MS8607 chipsets.
341 * Return: length of sprintf on success, negative errno otherwise.
343 ssize_t
ms_sensors_show_heater(struct ms_ht_dev
*dev_data
,
349 mutex_lock(&dev_data
->lock
);
350 ret
= ms_sensors_read_config_reg(dev_data
->client
, &config_reg
);
351 mutex_unlock(&dev_data
->lock
);
355 return sprintf(buf
, "%d\n", (config_reg
& 0x4) >> 2);
357 EXPORT_SYMBOL(ms_sensors_show_heater
);
360 * ms_sensors_write_heater() - Write device heater
361 * @dev_data: pointer to temperature/humidity device data
362 * @buf: pointer to char buffer from user space
363 * @len: length of buf
365 * This function will write 1 or 0 value in the device
366 * to enable or disable heater.
367 * This function is used for HTU21 and MS8607 chipsets.
369 * Return: length of buffer, negative errno otherwise.
371 ssize_t
ms_sensors_write_heater(struct ms_ht_dev
*dev_data
,
372 const char *buf
, size_t len
)
377 ret
= kstrtou8(buf
, 10, &val
);
384 mutex_lock(&dev_data
->lock
);
385 ret
= ms_sensors_read_config_reg(dev_data
->client
, &config_reg
);
387 mutex_unlock(&dev_data
->lock
);
392 config_reg
|= val
<< 2;
394 ret
= i2c_smbus_write_byte_data(dev_data
->client
,
395 MS_SENSORS_CONFIG_REG_WRITE
,
397 mutex_unlock(&dev_data
->lock
);
399 dev_err(&dev_data
->client
->dev
, "Unable to write config register\n");
405 EXPORT_SYMBOL(ms_sensors_write_heater
);
408 * ms_sensors_ht_read_temperature() - Read temperature
409 * @dev_data: pointer to temperature/humidity device data
410 * @temperature:pointer to temperature destination value
412 * This function will get temperature ADC value from the device,
413 * check the CRC and compute the temperature value.
414 * This function is used for TSYS02D, HTU21 and MS8607 chipsets.
416 * Return: 0 on success, negative errno otherwise.
418 int ms_sensors_ht_read_temperature(struct ms_ht_dev
*dev_data
,
425 mutex_lock(&dev_data
->lock
);
426 delay
= ms_sensors_ht_t_conversion_time
[dev_data
->res_index
];
427 ret
= ms_sensors_convert_and_read(dev_data
->client
,
428 MS_SENSORS_HT_T_CONVERSION_START
,
429 MS_SENSORS_NO_READ_CMD
,
431 mutex_unlock(&dev_data
->lock
);
435 if (!ms_sensors_crc_valid(adc
)) {
436 dev_err(&dev_data
->client
->dev
,
437 "Temperature read crc check error\n");
441 /* Temperature algorithm */
442 *temperature
= (((s64
)(adc
>> 8) * 175720) >> 16) - 46850;
446 EXPORT_SYMBOL(ms_sensors_ht_read_temperature
);
449 * ms_sensors_ht_read_humidity() - Read humidity
450 * @dev_data: pointer to temperature/humidity device data
451 * @humidity: pointer to humidity destination value
453 * This function will get humidity ADC value from the device,
454 * check the CRC and compute the temperature value.
455 * This function is used for HTU21 and MS8607 chipsets.
457 * Return: 0 on success, negative errno otherwise.
459 int ms_sensors_ht_read_humidity(struct ms_ht_dev
*dev_data
,
466 mutex_lock(&dev_data
->lock
);
467 delay
= ms_sensors_ht_h_conversion_time
[dev_data
->res_index
];
468 ret
= ms_sensors_convert_and_read(dev_data
->client
,
469 MS_SENSORS_HT_H_CONVERSION_START
,
470 MS_SENSORS_NO_READ_CMD
,
472 mutex_unlock(&dev_data
->lock
);
476 if (!ms_sensors_crc_valid(adc
)) {
477 dev_err(&dev_data
->client
->dev
,
478 "Humidity read crc check error\n");
482 /* Humidity algorithm */
483 *humidity
= (((s32
)(adc
>> 8) * 12500) >> 16) * 10 - 6000;
484 if (*humidity
>= 100000)
489 EXPORT_SYMBOL(ms_sensors_ht_read_humidity
);
492 * ms_sensors_tp_crc_valid() - CRC check function for
493 * Temperature and pressure devices.
494 * This function is only used when reading PROM coefficients
496 * @prom: pointer to PROM coefficients array
497 * @len: length of PROM coefficients array
499 * Return: True if CRC is ok.
501 static bool ms_sensors_tp_crc_valid(u16
*prom
, u8 len
)
503 unsigned int cnt
, n_bit
;
504 u16 n_rem
= 0x0000, crc_read
= prom
[0], crc
= (*prom
& 0xF000) >> 12;
507 prom
[0] &= 0x0FFF; /* Clear the CRC computation part */
509 for (cnt
= 0; cnt
< len
* 2; cnt
++) {
511 n_rem
^= prom
[cnt
>> 1] & 0x00FF;
513 n_rem
^= prom
[cnt
>> 1] >> 8;
515 for (n_bit
= 8; n_bit
> 0; n_bit
--) {
517 n_rem
= (n_rem
<< 1) ^ 0x3000;
529 * ms_sensors_tp_read_prom() - prom coeff read function
530 * @dev_data: pointer to temperature/pressure device data
532 * This function will read prom coefficients and check CRC.
533 * This function is used for MS5637 and MS8607 chipsets.
535 * Return: 0 on success, negative errno otherwise.
537 int ms_sensors_tp_read_prom(struct ms_tp_dev
*dev_data
)
541 for (i
= 0; i
< MS_SENSORS_TP_PROM_WORDS_NB
; i
++) {
542 ret
= ms_sensors_read_prom_word(
544 MS_SENSORS_TP_PROM_READ
+ (i
<< 1),
551 if (!ms_sensors_tp_crc_valid(dev_data
->prom
,
552 MS_SENSORS_TP_PROM_WORDS_NB
+ 1)) {
553 dev_err(&dev_data
->client
->dev
,
554 "Calibration coefficients crc check error\n");
560 EXPORT_SYMBOL(ms_sensors_tp_read_prom
);
563 * ms_sensors_read_temp_and_pressure() - read temp and pressure
564 * @dev_data: pointer to temperature/pressure device data
565 * @temperature:pointer to temperature destination value
566 * @pressure: pointer to pressure destination value
568 * This function will read ADC and compute pressure and temperature value.
569 * This function is used for MS5637 and MS8607 chipsets.
571 * Return: 0 on success, negative errno otherwise.
573 int ms_sensors_read_temp_and_pressure(struct ms_tp_dev
*dev_data
,
575 unsigned int *pressure
)
580 s64 off
, sens
, t2
, off2
, sens2
;
581 u16
*prom
= dev_data
->prom
, delay
;
583 mutex_lock(&dev_data
->lock
);
584 delay
= ms_sensors_tp_conversion_time
[dev_data
->res_index
];
586 ret
= ms_sensors_convert_and_read(
588 MS_SENSORS_TP_T_CONVERSION_START
+
589 dev_data
->res_index
* 2,
590 MS_SENSORS_TP_ADC_READ
,
593 mutex_unlock(&dev_data
->lock
);
597 ret
= ms_sensors_convert_and_read(
599 MS_SENSORS_TP_P_CONVERSION_START
+
600 dev_data
->res_index
* 2,
601 MS_SENSORS_TP_ADC_READ
,
603 mutex_unlock(&dev_data
->lock
);
607 dt
= (s32
)t_adc
- (prom
[5] << 8);
609 /* Actual temperature = 2000 + dT * TEMPSENS */
610 temp
= 2000 + (((s64
)dt
* prom
[6]) >> 23);
612 /* Second order temperature compensation */
614 s64 tmp
= (s64
)temp
- 2000;
616 t2
= (3 * ((s64
)dt
* (s64
)dt
)) >> 33;
617 off2
= (61 * tmp
* tmp
) >> 4;
618 sens2
= (29 * tmp
* tmp
) >> 4;
621 s64 tmp
= (s64
)temp
+ 1500;
623 off2
+= 17 * tmp
* tmp
;
624 sens2
+= 9 * tmp
* tmp
;
627 t2
= (5 * ((s64
)dt
* (s64
)dt
)) >> 38;
632 /* OFF = OFF_T1 + TCO * dT */
633 off
= (((s64
)prom
[2]) << 17) + ((((s64
)prom
[4]) * (s64
)dt
) >> 6);
636 /* Sensitivity at actual temperature = SENS_T1 + TCS * dT */
637 sens
= (((s64
)prom
[1]) << 16) + (((s64
)prom
[3] * dt
) >> 7);
640 /* Temperature compensated pressure = D1 * SENS - OFF */
641 *temperature
= (temp
- t2
) * 10;
642 *pressure
= (u32
)(((((s64
)p_adc
* sens
) >> 21) - off
) >> 15);
646 EXPORT_SYMBOL(ms_sensors_read_temp_and_pressure
);
648 MODULE_DESCRIPTION("Measurement-Specialties common i2c driver");
649 MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
650 MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
651 MODULE_LICENSE("GPL v2");