1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * hdc3020.c - Support for the TI HDC3020,HDC3021 and HDC3022
4 * temperature + relative humidity sensors
5 *
6 * Copyright (C) 2023
7 *
8 * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH
9 *
10 * Datasheet: https://www.ti.com/lit/ds/symlink/hdc3020.pdf
11 */
12
13 #include <linux/bitfield.h>
14 #include <linux/bitops.h>
15 #include <linux/cleanup.h>
16 #include <linux/crc8.h>
17 #include <linux/delay.h>
18 #include <linux/gpio/consumer.h>
19 #include <linux/i2c.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/math64.h>
23 #include <linux/module.h>
24 #include <linux/mutex.h>
25 #include <linux/pm.h>
26 #include <linux/regulator/consumer.h>
27 #include <linux/units.h>
28
29 #include <linux/unaligned.h>
30
31 #include <linux/iio/events.h>
32 #include <linux/iio/iio.h>
33
34 #define HDC3020_S_AUTO_10HZ_MOD0 0x2737
35 #define HDC3020_S_STATUS 0x3041
36 #define HDC3020_HEATER_DISABLE 0x3066
37 #define HDC3020_HEATER_ENABLE 0x306D
38 #define HDC3020_HEATER_CONFIG 0x306E
39 #define HDC3020_EXIT_AUTO 0x3093
40 #define HDC3020_S_T_RH_THRESH_LOW 0x6100
41 #define HDC3020_S_T_RH_THRESH_LOW_CLR 0x610B
42 #define HDC3020_S_T_RH_THRESH_HIGH_CLR 0x6116
43 #define HDC3020_S_T_RH_THRESH_HIGH 0x611D
44 #define HDC3020_R_T_RH_AUTO 0xE000
45 #define HDC3020_R_T_LOW_AUTO 0xE002
46 #define HDC3020_R_T_HIGH_AUTO 0xE003
47 #define HDC3020_R_RH_LOW_AUTO 0xE004
48 #define HDC3020_R_RH_HIGH_AUTO 0xE005
49 #define HDC3020_R_T_RH_THRESH_LOW 0xE102
50 #define HDC3020_R_T_RH_THRESH_LOW_CLR 0xE109
51 #define HDC3020_R_T_RH_THRESH_HIGH_CLR 0xE114
52 #define HDC3020_R_T_RH_THRESH_HIGH 0xE11F
53 #define HDC3020_R_STATUS 0xF32D
54
55 #define HDC3020_THRESH_TEMP_MASK GENMASK(8, 0)
56 #define HDC3020_THRESH_TEMP_TRUNC_SHIFT 7
57 #define HDC3020_THRESH_HUM_MASK GENMASK(15, 9)
58 #define HDC3020_THRESH_HUM_TRUNC_SHIFT 9
59
60 #define HDC3020_STATUS_T_LOW_ALERT BIT(6)
61 #define HDC3020_STATUS_T_HIGH_ALERT BIT(7)
62 #define HDC3020_STATUS_RH_LOW_ALERT BIT(8)
63 #define HDC3020_STATUS_RH_HIGH_ALERT BIT(9)
64
65 #define HDC3020_READ_RETRY_TIMES 10
66 #define HDC3020_BUSY_DELAY_MS 10
67
68 #define HDC3020_CRC8_POLYNOMIAL 0x31
69
70 #define HDC3020_MIN_TEMP_MICRO -39872968
71 #define HDC3020_MAX_TEMP_MICRO 124875639
72 #define HDC3020_MAX_TEMP_HYST_MICRO 164748607
73 #define HDC3020_MAX_HUM_MICRO 99220264
74
75 /* Divide 65535 from the datasheet by 5 to avoid overflows */
76 #define HDC3020_THRESH_FRACTION (65535 / 5)
77
78 struct hdc3020_data {
79 struct i2c_client *client;
80 struct gpio_desc *reset_gpio;
81 struct regulator *vdd_supply;
82 /*
83 * Ensure that the sensor configuration (currently only heater is
84 * supported) will not be changed during the process of reading
85 * sensor data (this driver will try HDC3020_READ_RETRY_TIMES times
86 * if the device does not respond).
87 */
88 struct mutex lock;
89 };
90
91 static const int hdc3020_heater_vals[] = {0, 1, 0x3FFF};
92
93 static const struct iio_event_spec hdc3020_t_rh_event[] = {
94 {
95 .type = IIO_EV_TYPE_THRESH,
96 .dir = IIO_EV_DIR_RISING,
97 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
98 BIT(IIO_EV_INFO_HYSTERESIS),
99 },
100 {
101 .type = IIO_EV_TYPE_THRESH,
102 .dir = IIO_EV_DIR_FALLING,
103 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
104 BIT(IIO_EV_INFO_HYSTERESIS),
105 },
106 };
107
108 static const struct iio_chan_spec hdc3020_channels[] = {
109 {
110 .type = IIO_TEMP,
111 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
112 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |
113 BIT(IIO_CHAN_INFO_TROUGH) | BIT(IIO_CHAN_INFO_OFFSET),
114 .event_spec = hdc3020_t_rh_event,
115 .num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event),
116 },
117 {
118 .type = IIO_HUMIDITYRELATIVE,
119 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
120 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |
121 BIT(IIO_CHAN_INFO_TROUGH),
122 .event_spec = hdc3020_t_rh_event,
123 .num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event),
124 },
125 {
126 /*
127 * For setting the internal heater, which can be switched on to
128 * prevent or remove any condensation that may develop when the
129 * ambient environment approaches its dew point temperature.
130 */
131 .type = IIO_CURRENT,
132 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
133 .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
134 .output = 1,
135 },
136 };
137
138 DECLARE_CRC8_TABLE(hdc3020_crc8_table);
139
hdc3020_write_bytes(struct hdc3020_data * data,u8 * buf,u8 len)140 static int hdc3020_write_bytes(struct hdc3020_data *data, u8 *buf, u8 len)
141 {
142 struct i2c_client *client = data->client;
143 struct i2c_msg msg;
144 int ret, cnt;
145
146 msg.addr = client->addr;
147 msg.flags = 0;
148 msg.buf = buf;
149 msg.len = len;
150
151 /*
152 * During the measurement process, HDC3020 will not return data.
153 * So wait for a while and try again
154 */
155 for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {
156 ret = i2c_transfer(client->adapter, &msg, 1);
157 if (ret == 1)
158 return 0;
159
160 mdelay(HDC3020_BUSY_DELAY_MS);
161 }
162 dev_err(&client->dev, "Could not write sensor command\n");
163
164 return -ETIMEDOUT;
165 }
166
167 static
hdc3020_read_bytes(struct hdc3020_data * data,u16 reg,u8 * buf,int len)168 int hdc3020_read_bytes(struct hdc3020_data *data, u16 reg, u8 *buf, int len)
169 {
170 u8 reg_buf[2];
171 int ret, cnt;
172 struct i2c_client *client = data->client;
173 struct i2c_msg msg[2] = {
174 [0] = {
175 .addr = client->addr,
176 .flags = 0,
177 .buf = reg_buf,
178 .len = 2,
179 },
180 [1] = {
181 .addr = client->addr,
182 .flags = I2C_M_RD,
183 .buf = buf,
184 .len = len,
185 },
186 };
187
188 put_unaligned_be16(reg, reg_buf);
189 /*
190 * During the measurement process, HDC3020 will not return data.
191 * So wait for a while and try again
192 */
193 for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {
194 ret = i2c_transfer(client->adapter, msg, 2);
195 if (ret == 2)
196 return 0;
197
198 mdelay(HDC3020_BUSY_DELAY_MS);
199 }
200 dev_err(&client->dev, "Could not read sensor data\n");
201
202 return -ETIMEDOUT;
203 }
204
hdc3020_read_be16(struct hdc3020_data * data,u16 reg)205 static int hdc3020_read_be16(struct hdc3020_data *data, u16 reg)
206 {
207 u8 crc, buf[3];
208 int ret;
209
210 ret = hdc3020_read_bytes(data, reg, buf, 3);
211 if (ret < 0)
212 return ret;
213
214 crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
215 if (crc != buf[2])
216 return -EINVAL;
217
218 return get_unaligned_be16(buf);
219 }
220
hdc3020_exec_cmd(struct hdc3020_data * data,u16 reg)221 static int hdc3020_exec_cmd(struct hdc3020_data *data, u16 reg)
222 {
223 u8 reg_buf[2];
224
225 put_unaligned_be16(reg, reg_buf);
226 return hdc3020_write_bytes(data, reg_buf, 2);
227 }
228
hdc3020_read_measurement(struct hdc3020_data * data,enum iio_chan_type type,int * val)229 static int hdc3020_read_measurement(struct hdc3020_data *data,
230 enum iio_chan_type type, int *val)
231 {
232 u8 crc, buf[6];
233 int ret;
234
235 ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6);
236 if (ret < 0)
237 return ret;
238
239 /* CRC check of the temperature measurement */
240 crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
241 if (crc != buf[2])
242 return -EINVAL;
243
244 /* CRC check of the relative humidity measurement */
245 crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE);
246 if (crc != buf[5])
247 return -EINVAL;
248
249 if (type == IIO_TEMP)
250 *val = get_unaligned_be16(buf);
251 else if (type == IIO_HUMIDITYRELATIVE)
252 *val = get_unaligned_be16(&buf[3]);
253 else
254 return -EINVAL;
255
256 return 0;
257 }
258
hdc3020_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)259 static int hdc3020_read_raw(struct iio_dev *indio_dev,
260 struct iio_chan_spec const *chan, int *val,
261 int *val2, long mask)
262 {
263 struct hdc3020_data *data = iio_priv(indio_dev);
264 int ret;
265
266 if (chan->type != IIO_TEMP && chan->type != IIO_HUMIDITYRELATIVE)
267 return -EINVAL;
268
269 switch (mask) {
270 case IIO_CHAN_INFO_RAW: {
271 guard(mutex)(&data->lock);
272 ret = hdc3020_read_measurement(data, chan->type, val);
273 if (ret < 0)
274 return ret;
275
276 return IIO_VAL_INT;
277 }
278 case IIO_CHAN_INFO_PEAK: {
279 guard(mutex)(&data->lock);
280 if (chan->type == IIO_TEMP)
281 ret = hdc3020_read_be16(data, HDC3020_R_T_HIGH_AUTO);
282 else
283 ret = hdc3020_read_be16(data, HDC3020_R_RH_HIGH_AUTO);
284
285 if (ret < 0)
286 return ret;
287
288 *val = ret;
289 return IIO_VAL_INT;
290 }
291 case IIO_CHAN_INFO_TROUGH: {
292 guard(mutex)(&data->lock);
293 if (chan->type == IIO_TEMP)
294 ret = hdc3020_read_be16(data, HDC3020_R_T_LOW_AUTO);
295 else
296 ret = hdc3020_read_be16(data, HDC3020_R_RH_LOW_AUTO);
297
298 if (ret < 0)
299 return ret;
300
301 *val = ret;
302 return IIO_VAL_INT;
303 }
304 case IIO_CHAN_INFO_SCALE:
305 *val2 = 65536;
306 if (chan->type == IIO_TEMP)
307 *val = 175 * MILLI;
308 else
309 *val = 100 * MILLI;
310 return IIO_VAL_FRACTIONAL;
311
312 case IIO_CHAN_INFO_OFFSET:
313 if (chan->type != IIO_TEMP)
314 return -EINVAL;
315
316 *val = -16852;
317 return IIO_VAL_INT;
318
319 default:
320 return -EINVAL;
321 }
322 }
323
hdc3020_read_available(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)324 static int hdc3020_read_available(struct iio_dev *indio_dev,
325 struct iio_chan_spec const *chan,
326 const int **vals,
327 int *type, int *length, long mask)
328 {
329 if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_CURRENT)
330 return -EINVAL;
331
332 *vals = hdc3020_heater_vals;
333 *type = IIO_VAL_INT;
334
335 return IIO_AVAIL_RANGE;
336 }
337
hdc3020_update_heater(struct hdc3020_data * data,int val)338 static int hdc3020_update_heater(struct hdc3020_data *data, int val)
339 {
340 u8 buf[5];
341 int ret;
342
343 if (val < hdc3020_heater_vals[0] || val > hdc3020_heater_vals[2])
344 return -EINVAL;
345
346 if (!val)
347 hdc3020_exec_cmd(data, HDC3020_HEATER_DISABLE);
348
349 put_unaligned_be16(HDC3020_HEATER_CONFIG, buf);
350 put_unaligned_be16(val & GENMASK(13, 0), &buf[2]);
351 buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
352 ret = hdc3020_write_bytes(data, buf, 5);
353 if (ret < 0)
354 return ret;
355
356 return hdc3020_exec_cmd(data, HDC3020_HEATER_ENABLE);
357 }
358
hdc3020_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)359 static int hdc3020_write_raw(struct iio_dev *indio_dev,
360 struct iio_chan_spec const *chan,
361 int val, int val2, long mask)
362 {
363 struct hdc3020_data *data = iio_priv(indio_dev);
364
365 switch (mask) {
366 case IIO_CHAN_INFO_RAW:
367 if (chan->type != IIO_CURRENT)
368 return -EINVAL;
369
370 guard(mutex)(&data->lock);
371 return hdc3020_update_heater(data, val);
372 }
373
374 return -EINVAL;
375 }
376
hdc3020_thresh_get_temp(u16 thresh)377 static int hdc3020_thresh_get_temp(u16 thresh)
378 {
379 int temp;
380
381 /*
382 * Get the temperature threshold from 9 LSBs, shift them to get the
383 * truncated temperature threshold representation and calculate the
384 * threshold according to the explicit formula in the datasheet:
385 * T(C) = -45 + (175 * temp) / 65535.
386 * Additionally scale by HDC3020_THRESH_FRACTION to avoid precision loss
387 * when calculating threshold and hysteresis values. Result is degree
388 * celsius scaled by HDC3020_THRESH_FRACTION.
389 */
390 temp = FIELD_GET(HDC3020_THRESH_TEMP_MASK, thresh) <<
391 HDC3020_THRESH_TEMP_TRUNC_SHIFT;
392
393 return -2949075 / 5 + (175 / 5 * temp);
394 }
395
hdc3020_thresh_get_hum(u16 thresh)396 static int hdc3020_thresh_get_hum(u16 thresh)
397 {
398 int hum;
399
400 /*
401 * Get the humidity threshold from 7 MSBs, shift them to get the
402 * truncated humidity threshold representation and calculate the
403 * threshold according to the explicit formula in the datasheet:
404 * RH(%) = 100 * hum / 65535.
405 * Additionally scale by HDC3020_THRESH_FRACTION to avoid precision loss
406 * when calculating threshold and hysteresis values. Result is percent
407 * scaled by HDC3020_THRESH_FRACTION.
408 */
409 hum = FIELD_GET(HDC3020_THRESH_HUM_MASK, thresh) <<
410 HDC3020_THRESH_HUM_TRUNC_SHIFT;
411
412 return hum * 100 / 5;
413 }
414
hdc3020_thresh_set_temp(int s_temp,u16 curr_thresh)415 static u16 hdc3020_thresh_set_temp(int s_temp, u16 curr_thresh)
416 {
417 u64 temp;
418 u16 thresh;
419
420 /*
421 * Calculate temperature threshold, shift it down to get the
422 * truncated threshold representation in the 9LSBs while keeping
423 * the current humidity threshold in the 7 MSBs.
424 */
425 temp = (u64)(s_temp + 45000000) * 65535ULL;
426 temp = div_u64(temp, 1000000 * 175) >> HDC3020_THRESH_TEMP_TRUNC_SHIFT;
427 thresh = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, temp);
428 thresh |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, curr_thresh) <<
429 HDC3020_THRESH_HUM_TRUNC_SHIFT);
430
431 return thresh;
432 }
433
hdc3020_thresh_set_hum(int s_hum,u16 curr_thresh)434 static u16 hdc3020_thresh_set_hum(int s_hum, u16 curr_thresh)
435 {
436 u64 hum;
437 u16 thresh;
438
439 /*
440 * Calculate humidity threshold, shift it down and up to get the
441 * truncated threshold representation in the 7MSBs while keeping
442 * the current temperature threshold in the 9 LSBs.
443 */
444 hum = (u64)(s_hum) * 65535ULL;
445 hum = div_u64(hum, 1000000 * 100) >> HDC3020_THRESH_HUM_TRUNC_SHIFT;
446 thresh = FIELD_PREP(HDC3020_THRESH_HUM_MASK, hum);
447 thresh |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, curr_thresh);
448
449 return thresh;
450 }
451
452 static
hdc3020_thresh_clr(s64 s_thresh,s64 s_hyst,enum iio_event_direction dir)453 int hdc3020_thresh_clr(s64 s_thresh, s64 s_hyst, enum iio_event_direction dir)
454 {
455 s64 s_clr;
456
457 /*
458 * Include directions when calculation the clear value,
459 * since hysteresis is unsigned by definition and the
460 * clear value is an absolute value which is signed.
461 */
462 if (dir == IIO_EV_DIR_RISING)
463 s_clr = s_thresh - s_hyst;
464 else
465 s_clr = s_thresh + s_hyst;
466
467 /* Divide by HDC3020_THRESH_FRACTION to get units of micro */
468 return div_s64(s_clr, HDC3020_THRESH_FRACTION);
469 }
470
_hdc3020_write_thresh(struct hdc3020_data * data,u16 reg,u16 val)471 static int _hdc3020_write_thresh(struct hdc3020_data *data, u16 reg, u16 val)
472 {
473 u8 buf[5];
474
475 put_unaligned_be16(reg, buf);
476 put_unaligned_be16(val, buf + 2);
477 buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
478
479 return hdc3020_write_bytes(data, buf, 5);
480 }
481
hdc3020_write_thresh(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int val,int val2)482 static int hdc3020_write_thresh(struct iio_dev *indio_dev,
483 const struct iio_chan_spec *chan,
484 enum iio_event_type type,
485 enum iio_event_direction dir,
486 enum iio_event_info info,
487 int val, int val2)
488 {
489 struct hdc3020_data *data = iio_priv(indio_dev);
490 u16 reg, reg_val, reg_thresh_rd, reg_clr_rd, reg_thresh_wr, reg_clr_wr;
491 s64 s_thresh, s_hyst, s_clr;
492 int s_val, thresh, clr, ret;
493
494 /* Select threshold registers */
495 if (dir == IIO_EV_DIR_RISING) {
496 reg_thresh_rd = HDC3020_R_T_RH_THRESH_HIGH;
497 reg_thresh_wr = HDC3020_S_T_RH_THRESH_HIGH;
498 reg_clr_rd = HDC3020_R_T_RH_THRESH_HIGH_CLR;
499 reg_clr_wr = HDC3020_S_T_RH_THRESH_HIGH_CLR;
500 } else {
501 reg_thresh_rd = HDC3020_R_T_RH_THRESH_LOW;
502 reg_thresh_wr = HDC3020_S_T_RH_THRESH_LOW;
503 reg_clr_rd = HDC3020_R_T_RH_THRESH_LOW_CLR;
504 reg_clr_wr = HDC3020_S_T_RH_THRESH_LOW_CLR;
505 }
506
507 guard(mutex)(&data->lock);
508 ret = hdc3020_read_be16(data, reg_thresh_rd);
509 if (ret < 0)
510 return ret;
511
512 thresh = ret;
513 ret = hdc3020_read_be16(data, reg_clr_rd);
514 if (ret < 0)
515 return ret;
516
517 clr = ret;
518 /* Scale value to include decimal part into calculations */
519 s_val = (val < 0) ? (val * 1000 - val2) : (val * 1000 + val2);
520 switch (chan->type) {
521 case IIO_TEMP:
522 switch (info) {
523 case IIO_EV_INFO_VALUE:
524 s_val = max(s_val, HDC3020_MIN_TEMP_MICRO);
525 s_val = min(s_val, HDC3020_MAX_TEMP_MICRO);
526 reg = reg_thresh_wr;
527 reg_val = hdc3020_thresh_set_temp(s_val, thresh);
528 ret = _hdc3020_write_thresh(data, reg, reg_val);
529 if (ret < 0)
530 return ret;
531
532 /* Calculate old hysteresis */
533 s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;
534 s_clr = (s64)hdc3020_thresh_get_temp(clr) * 1000000;
535 s_hyst = div_s64(abs(s_thresh - s_clr),
536 HDC3020_THRESH_FRACTION);
537 /* Set new threshold */
538 thresh = reg_val;
539 /* Set old hysteresis */
540 s_val = s_hyst;
541 fallthrough;
542 case IIO_EV_INFO_HYSTERESIS:
543 /*
544 * Function hdc3020_thresh_get_temp returns temperature
545 * in degree celsius scaled by HDC3020_THRESH_FRACTION.
546 * Scale by 1000000 to be able to subtract scaled
547 * hysteresis value.
548 */
549 s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;
550 /*
551 * Units of s_val are in micro degree celsius, scale by
552 * HDC3020_THRESH_FRACTION to get same units as s_thresh.
553 */
554 s_val = min(abs(s_val), HDC3020_MAX_TEMP_HYST_MICRO);
555 s_hyst = (s64)s_val * HDC3020_THRESH_FRACTION;
556 s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);
557 s_clr = max(s_clr, HDC3020_MIN_TEMP_MICRO);
558 s_clr = min(s_clr, HDC3020_MAX_TEMP_MICRO);
559 reg = reg_clr_wr;
560 reg_val = hdc3020_thresh_set_temp(s_clr, clr);
561 break;
562 default:
563 return -EOPNOTSUPP;
564 }
565 break;
566 case IIO_HUMIDITYRELATIVE:
567 s_val = (s_val < 0) ? 0 : min(s_val, HDC3020_MAX_HUM_MICRO);
568 switch (info) {
569 case IIO_EV_INFO_VALUE:
570 reg = reg_thresh_wr;
571 reg_val = hdc3020_thresh_set_hum(s_val, thresh);
572 ret = _hdc3020_write_thresh(data, reg, reg_val);
573 if (ret < 0)
574 return ret;
575
576 /* Calculate old hysteresis */
577 s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;
578 s_clr = (s64)hdc3020_thresh_get_hum(clr) * 1000000;
579 s_hyst = div_s64(abs(s_thresh - s_clr),
580 HDC3020_THRESH_FRACTION);
581 /* Set new threshold */
582 thresh = reg_val;
583 /* Try to set old hysteresis */
584 s_val = min(abs(s_hyst), HDC3020_MAX_HUM_MICRO);
585 fallthrough;
586 case IIO_EV_INFO_HYSTERESIS:
587 /*
588 * Function hdc3020_thresh_get_hum returns relative
589 * humidity in percent scaled by HDC3020_THRESH_FRACTION.
590 * Scale by 1000000 to be able to subtract scaled
591 * hysteresis value.
592 */
593 s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;
594 /*
595 * Units of s_val are in micro percent, scale by
596 * HDC3020_THRESH_FRACTION to get same units as s_thresh.
597 */
598 s_hyst = (s64)s_val * HDC3020_THRESH_FRACTION;
599 s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);
600 s_clr = max(s_clr, 0);
601 s_clr = min(s_clr, HDC3020_MAX_HUM_MICRO);
602 reg = reg_clr_wr;
603 reg_val = hdc3020_thresh_set_hum(s_clr, clr);
604 break;
605 default:
606 return -EOPNOTSUPP;
607 }
608 break;
609 default:
610 return -EOPNOTSUPP;
611 }
612
613 return _hdc3020_write_thresh(data, reg, reg_val);
614 }
615
hdc3020_read_thresh(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int * val,int * val2)616 static int hdc3020_read_thresh(struct iio_dev *indio_dev,
617 const struct iio_chan_spec *chan,
618 enum iio_event_type type,
619 enum iio_event_direction dir,
620 enum iio_event_info info,
621 int *val, int *val2)
622 {
623 struct hdc3020_data *data = iio_priv(indio_dev);
624 u16 reg_thresh, reg_clr;
625 int thresh, clr, ret;
626
627 /* Select threshold registers */
628 if (dir == IIO_EV_DIR_RISING) {
629 reg_thresh = HDC3020_R_T_RH_THRESH_HIGH;
630 reg_clr = HDC3020_R_T_RH_THRESH_HIGH_CLR;
631 } else {
632 reg_thresh = HDC3020_R_T_RH_THRESH_LOW;
633 reg_clr = HDC3020_R_T_RH_THRESH_LOW_CLR;
634 }
635
636 guard(mutex)(&data->lock);
637 ret = hdc3020_read_be16(data, reg_thresh);
638 if (ret < 0)
639 return ret;
640
641 switch (chan->type) {
642 case IIO_TEMP:
643 thresh = hdc3020_thresh_get_temp(ret);
644 switch (info) {
645 case IIO_EV_INFO_VALUE:
646 *val = thresh * MILLI;
647 break;
648 case IIO_EV_INFO_HYSTERESIS:
649 ret = hdc3020_read_be16(data, reg_clr);
650 if (ret < 0)
651 return ret;
652
653 clr = hdc3020_thresh_get_temp(ret);
654 *val = abs(thresh - clr) * MILLI;
655 break;
656 default:
657 return -EOPNOTSUPP;
658 }
659 *val2 = HDC3020_THRESH_FRACTION;
660 return IIO_VAL_FRACTIONAL;
661 case IIO_HUMIDITYRELATIVE:
662 thresh = hdc3020_thresh_get_hum(ret);
663 switch (info) {
664 case IIO_EV_INFO_VALUE:
665 *val = thresh * MILLI;
666 break;
667 case IIO_EV_INFO_HYSTERESIS:
668 ret = hdc3020_read_be16(data, reg_clr);
669 if (ret < 0)
670 return ret;
671
672 clr = hdc3020_thresh_get_hum(ret);
673 *val = abs(thresh - clr) * MILLI;
674 break;
675 default:
676 return -EOPNOTSUPP;
677 }
678 *val2 = HDC3020_THRESH_FRACTION;
679 return IIO_VAL_FRACTIONAL;
680 default:
681 return -EOPNOTSUPP;
682 }
683 }
684
hdc3020_interrupt_handler(int irq,void * private)685 static irqreturn_t hdc3020_interrupt_handler(int irq, void *private)
686 {
687 struct iio_dev *indio_dev = private;
688 struct hdc3020_data *data;
689 s64 time;
690 int ret;
691
692 data = iio_priv(indio_dev);
693 ret = hdc3020_read_be16(data, HDC3020_R_STATUS);
694 if (ret < 0)
695 return IRQ_HANDLED;
696
697 if (!(ret & (HDC3020_STATUS_T_HIGH_ALERT | HDC3020_STATUS_T_LOW_ALERT |
698 HDC3020_STATUS_RH_HIGH_ALERT | HDC3020_STATUS_RH_LOW_ALERT)))
699 return IRQ_NONE;
700
701 time = iio_get_time_ns(indio_dev);
702 if (ret & HDC3020_STATUS_T_HIGH_ALERT)
703 iio_push_event(indio_dev,
704 IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
705 IIO_NO_MOD,
706 IIO_EV_TYPE_THRESH,
707 IIO_EV_DIR_RISING),
708 time);
709
710 if (ret & HDC3020_STATUS_T_LOW_ALERT)
711 iio_push_event(indio_dev,
712 IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
713 IIO_NO_MOD,
714 IIO_EV_TYPE_THRESH,
715 IIO_EV_DIR_FALLING),
716 time);
717
718 if (ret & HDC3020_STATUS_RH_HIGH_ALERT)
719 iio_push_event(indio_dev,
720 IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0,
721 IIO_NO_MOD,
722 IIO_EV_TYPE_THRESH,
723 IIO_EV_DIR_RISING),
724 time);
725
726 if (ret & HDC3020_STATUS_RH_LOW_ALERT)
727 iio_push_event(indio_dev,
728 IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0,
729 IIO_NO_MOD,
730 IIO_EV_TYPE_THRESH,
731 IIO_EV_DIR_FALLING),
732 time);
733
734 return IRQ_HANDLED;
735 }
736
737 static const struct iio_info hdc3020_info = {
738 .read_raw = hdc3020_read_raw,
739 .write_raw = hdc3020_write_raw,
740 .read_avail = hdc3020_read_available,
741 .read_event_value = hdc3020_read_thresh,
742 .write_event_value = hdc3020_write_thresh,
743 };
744
hdc3020_power_off(struct hdc3020_data * data)745 static int hdc3020_power_off(struct hdc3020_data *data)
746 {
747 hdc3020_exec_cmd(data, HDC3020_EXIT_AUTO);
748
749 if (data->reset_gpio)
750 gpiod_set_value_cansleep(data->reset_gpio, 1);
751
752 return regulator_disable(data->vdd_supply);
753 }
754
hdc3020_power_on(struct hdc3020_data * data)755 static int hdc3020_power_on(struct hdc3020_data *data)
756 {
757 int ret;
758
759 ret = regulator_enable(data->vdd_supply);
760 if (ret)
761 return ret;
762
763 fsleep(5000);
764
765 if (data->reset_gpio) {
766 gpiod_set_value_cansleep(data->reset_gpio, 0);
767 fsleep(3000);
768 }
769
770 if (data->client->irq) {
771 /*
772 * The alert output is activated by default upon power up,
773 * hardware reset, and soft reset. Clear the status register.
774 */
775 ret = hdc3020_exec_cmd(data, HDC3020_S_STATUS);
776 if (ret) {
777 hdc3020_power_off(data);
778 return ret;
779 }
780 }
781
782 ret = hdc3020_exec_cmd(data, HDC3020_S_AUTO_10HZ_MOD0);
783 if (ret)
784 hdc3020_power_off(data);
785
786 return ret;
787 }
788
hdc3020_exit(void * data)789 static void hdc3020_exit(void *data)
790 {
791 hdc3020_power_off(data);
792 }
793
hdc3020_probe(struct i2c_client * client)794 static int hdc3020_probe(struct i2c_client *client)
795 {
796 struct iio_dev *indio_dev;
797 struct hdc3020_data *data;
798 int ret;
799
800 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
801 return -EOPNOTSUPP;
802
803 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
804 if (!indio_dev)
805 return -ENOMEM;
806
807 dev_set_drvdata(&client->dev, indio_dev);
808
809 data = iio_priv(indio_dev);
810 data->client = client;
811 mutex_init(&data->lock);
812
813 crc8_populate_msb(hdc3020_crc8_table, HDC3020_CRC8_POLYNOMIAL);
814
815 indio_dev->name = "hdc3020";
816 indio_dev->modes = INDIO_DIRECT_MODE;
817 indio_dev->info = &hdc3020_info;
818 indio_dev->channels = hdc3020_channels;
819 indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels);
820
821 data->vdd_supply = devm_regulator_get(&client->dev, "vdd");
822 if (IS_ERR(data->vdd_supply))
823 return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
824 "Unable to get VDD regulator\n");
825
826 data->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
827 GPIOD_OUT_HIGH);
828 if (IS_ERR(data->reset_gpio))
829 return dev_err_probe(&client->dev, PTR_ERR(data->reset_gpio),
830 "Cannot get reset GPIO\n");
831
832 ret = hdc3020_power_on(data);
833 if (ret)
834 return dev_err_probe(&client->dev, ret, "Power on failed\n");
835
836 ret = devm_add_action_or_reset(&data->client->dev, hdc3020_exit, data);
837 if (ret)
838 return ret;
839
840 if (client->irq) {
841 ret = devm_request_threaded_irq(&client->dev, client->irq,
842 NULL, hdc3020_interrupt_handler,
843 IRQF_ONESHOT, "hdc3020",
844 indio_dev);
845 if (ret)
846 return dev_err_probe(&client->dev, ret,
847 "Failed to request IRQ\n");
848 }
849
850 ret = devm_iio_device_register(&data->client->dev, indio_dev);
851 if (ret)
852 return dev_err_probe(&client->dev, ret, "Failed to add device");
853
854 return 0;
855 }
856
hdc3020_suspend(struct device * dev)857 static int hdc3020_suspend(struct device *dev)
858 {
859 struct iio_dev *iio_dev = dev_get_drvdata(dev);
860 struct hdc3020_data *data = iio_priv(iio_dev);
861
862 return hdc3020_power_off(data);
863 }
864
hdc3020_resume(struct device * dev)865 static int hdc3020_resume(struct device *dev)
866 {
867 struct iio_dev *iio_dev = dev_get_drvdata(dev);
868 struct hdc3020_data *data = iio_priv(iio_dev);
869
870 return hdc3020_power_on(data);
871 }
872
873 static DEFINE_SIMPLE_DEV_PM_OPS(hdc3020_pm_ops, hdc3020_suspend, hdc3020_resume);
874
875 static const struct i2c_device_id hdc3020_id[] = {
876 { "hdc3020" },
877 { "hdc3021" },
878 { "hdc3022" },
879 { }
880 };
881 MODULE_DEVICE_TABLE(i2c, hdc3020_id);
882
883 static const struct of_device_id hdc3020_dt_ids[] = {
884 { .compatible = "ti,hdc3020" },
885 { .compatible = "ti,hdc3021" },
886 { .compatible = "ti,hdc3022" },
887 { }
888 };
889 MODULE_DEVICE_TABLE(of, hdc3020_dt_ids);
890
891 static struct i2c_driver hdc3020_driver = {
892 .driver = {
893 .name = "hdc3020",
894 .pm = pm_sleep_ptr(&hdc3020_pm_ops),
895 .of_match_table = hdc3020_dt_ids,
896 },
897 .probe = hdc3020_probe,
898 .id_table = hdc3020_id,
899 };
900 module_i2c_driver(hdc3020_driver);
901
902 MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");
903 MODULE_AUTHOR("Li peiyu <579lpy@gmail.com>");
904 MODULE_DESCRIPTION("TI HDC3020 humidity and temperature sensor driver");
905 MODULE_LICENSE("GPL");
906