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drm: bridge: adv7511: remove s32 format from i2s capabilities
[drm/drm-misc.git] / drivers / iio / chemical / sgp30.c
blob21730d62b5c8dfc1796fcb474bd1734553d423f7
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * sgp30.c - Support for Sensirion SGP Gas Sensors
4 *
5 * Copyright (C) 2018 Andreas Brauchli <andreas.brauchli@sensirion.com>
6 *
7 * I2C slave address: 0x58
8 *
9 * Datasheets:
10 * https://www.sensirion.com/file/datasheet_sgp30
11 * https://www.sensirion.com/file/datasheet_sgpc3
12 *
13 * TODO:
14 * - baseline support
15 * - humidity compensation
16 * - power mode switching (SGPC3)
17 */
18
19 #include <linux/crc8.h>
20 #include <linux/delay.h>
21 #include <linux/kthread.h>
22 #include <linux/module.h>
23 #include <linux/mod_devicetable.h>
24 #include <linux/mutex.h>
25 #include <linux/i2c.h>
26 #include <linux/iio/iio.h>
27 #include <linux/iio/sysfs.h>
28
29 #define SGP_WORD_LEN 2
30 #define SGP_CRC8_POLYNOMIAL 0x31
31 #define SGP_CRC8_INIT 0xff
32 #define SGP_CRC8_LEN 1
33 #define SGP_CMD(cmd_word) cpu_to_be16(cmd_word)
34 #define SGP_CMD_DURATION_US 12000
35 #define SGP_MEASUREMENT_DURATION_US 50000
36 #define SGP_CMD_LEN SGP_WORD_LEN
37 #define SGP_CMD_MAX_BUF_SIZE (SGP_CMD_LEN + 2 * SGP_WORD_LEN)
38 #define SGP_MEASUREMENT_LEN 2
39 #define SGP30_MEASURE_INTERVAL_HZ 1
40 #define SGPC3_MEASURE_INTERVAL_HZ 2
41 #define SGP_VERS_PRODUCT(data) ((((data)->feature_set) & 0xf000) >> 12)
42 #define SGP_VERS_RESERVED(data) ((((data)->feature_set) & 0x0800) >> 11)
43 #define SGP_VERS_GEN(data) ((((data)->feature_set) & 0x0600) >> 9)
44 #define SGP_VERS_ENG_BIT(data) ((((data)->feature_set) & 0x0100) >> 8)
45 #define SGP_VERS_MAJOR(data) ((((data)->feature_set) & 0x00e0) >> 5)
46 #define SGP_VERS_MINOR(data) (((data)->feature_set) & 0x001f)
47
48 DECLARE_CRC8_TABLE(sgp_crc8_table);
49
50 enum sgp_product_id {
51 SGP30 = 0,
52 SGPC3,
53 };
54
55 enum sgp30_channel_idx {
56 SGP30_IAQ_TVOC_IDX = 0,
57 SGP30_IAQ_CO2EQ_IDX,
58 SGP30_SIG_ETOH_IDX,
59 SGP30_SIG_H2_IDX,
60 };
61
62 enum sgpc3_channel_idx {
63 SGPC3_IAQ_TVOC_IDX = 10,
64 SGPC3_SIG_ETOH_IDX,
65 };
66
67 enum sgp_cmd {
68 SGP_CMD_IAQ_INIT = SGP_CMD(0x2003),
69 SGP_CMD_IAQ_MEASURE = SGP_CMD(0x2008),
70 SGP_CMD_GET_FEATURE_SET = SGP_CMD(0x202f),
71 SGP_CMD_GET_SERIAL_ID = SGP_CMD(0x3682),
72
73 SGP30_CMD_MEASURE_SIGNAL = SGP_CMD(0x2050),
74
75 SGPC3_CMD_MEASURE_RAW = SGP_CMD(0x2046),
76 };
77
78 struct sgp_version {
79 u8 major;
80 u8 minor;
81 };
82
83 struct sgp_crc_word {
84 __be16 value;
85 u8 crc8;
86 } __attribute__((__packed__));
87
88 union sgp_reading {
89 u8 start;
90 struct sgp_crc_word raw_words[4];
91 };
92
93 enum _iaq_buffer_state {
94 IAQ_BUFFER_EMPTY = 0,
95 IAQ_BUFFER_DEFAULT_VALS,
96 IAQ_BUFFER_VALID,
97 };
98
99 struct sgp_data {
100 struct i2c_client *client;
101 struct task_struct *iaq_thread;
102 struct mutex data_lock;
103 unsigned long iaq_init_start_jiffies;
104 unsigned long iaq_defval_skip_jiffies;
105 u16 product_id;
106 u16 feature_set;
107 unsigned long measure_interval_jiffies;
108 enum sgp_cmd iaq_init_cmd;
109 enum sgp_cmd measure_iaq_cmd;
110 enum sgp_cmd measure_gas_signals_cmd;
111 union sgp_reading buffer;
112 union sgp_reading iaq_buffer;
113 enum _iaq_buffer_state iaq_buffer_state;
114 };
115
116 struct sgp_device {
117 unsigned long product_id;
118 const struct iio_chan_spec *channels;
119 int num_channels;
120 };
121
122 static const struct sgp_version supported_versions_sgp30[] = {
123 {
124 .major = 1,
125 .minor = 0,
126 },
127 };
128
129 static const struct sgp_version supported_versions_sgpc3[] = {
130 {
131 .major = 0,
132 .minor = 4,
133 },
134 };
135
136 static const struct iio_chan_spec sgp30_channels[] = {
137 {
138 .type = IIO_CONCENTRATION,
139 .channel2 = IIO_MOD_VOC,
140 .modified = 1,
141 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
142 .address = SGP30_IAQ_TVOC_IDX,
143 },
144 {
145 .type = IIO_CONCENTRATION,
146 .channel2 = IIO_MOD_CO2,
147 .modified = 1,
148 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
149 .address = SGP30_IAQ_CO2EQ_IDX,
150 },
151 {
152 .type = IIO_CONCENTRATION,
153 .channel2 = IIO_MOD_ETHANOL,
154 .modified = 1,
155 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
156 .address = SGP30_SIG_ETOH_IDX,
157 },
158 {
159 .type = IIO_CONCENTRATION,
160 .channel2 = IIO_MOD_H2,
161 .modified = 1,
162 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
163 .address = SGP30_SIG_H2_IDX,
164 },
165 };
166
167 static const struct iio_chan_spec sgpc3_channels[] = {
168 {
169 .type = IIO_CONCENTRATION,
170 .channel2 = IIO_MOD_VOC,
171 .modified = 1,
172 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
173 .address = SGPC3_IAQ_TVOC_IDX,
174 },
175 {
176 .type = IIO_CONCENTRATION,
177 .channel2 = IIO_MOD_ETHANOL,
178 .modified = 1,
179 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
180 .address = SGPC3_SIG_ETOH_IDX,
181 },
182 };
183
184 static const struct sgp_device sgp_devices[] = {
185 [SGP30] = {
186 .product_id = SGP30,
187 .channels = sgp30_channels,
188 .num_channels = ARRAY_SIZE(sgp30_channels),
189 },
190 [SGPC3] = {
191 .product_id = SGPC3,
192 .channels = sgpc3_channels,
193 .num_channels = ARRAY_SIZE(sgpc3_channels),
194 },
195 };
196
197 /**
198 * sgp_verify_buffer() - verify the checksums of the data buffer words
199 *
200 * @data: SGP data
201 * @buf: Raw data buffer
202 * @word_count: Num data words stored in the buffer, excluding CRC bytes
203 *
204 * Return: 0 on success, negative error otherwise.
205 */
206 static int sgp_verify_buffer(const struct sgp_data *data,
207 union sgp_reading *buf, size_t word_count)
208 {
209 size_t size = word_count * (SGP_WORD_LEN + SGP_CRC8_LEN);
210 int i;
211 u8 crc;
212 u8 *data_buf = &buf->start;
213
214 for (i = 0; i < size; i += SGP_WORD_LEN + SGP_CRC8_LEN) {
215 crc = crc8(sgp_crc8_table, &data_buf[i], SGP_WORD_LEN,
216 SGP_CRC8_INIT);
217 if (crc != data_buf[i + SGP_WORD_LEN]) {
218 dev_err(&data->client->dev, "CRC error\n");
219 return -EIO;
220 }
221 }
222
223 return 0;
224 }
225
226 /**
227 * sgp_read_cmd() - reads data from sensor after issuing a command
228 * The caller must hold data->data_lock for the duration of the call.
229 * @data: SGP data
230 * @cmd: SGP Command to issue
231 * @buf: Raw data buffer to use
232 * @word_count: Num words to read, excluding CRC bytes
233 * @duration_us: Time taken to sensor to take a reading and data to be ready.
234 *
235 * Return: 0 on success, negative error otherwise.
236 */
237 static int sgp_read_cmd(struct sgp_data *data, enum sgp_cmd cmd,
238 union sgp_reading *buf, size_t word_count,
239 unsigned long duration_us)
240 {
241 int ret;
242 struct i2c_client *client = data->client;
243 size_t size = word_count * (SGP_WORD_LEN + SGP_CRC8_LEN);
244 u8 *data_buf;
245
246 ret = i2c_master_send(client, (const char *)&cmd, SGP_CMD_LEN);
247 if (ret != SGP_CMD_LEN)
248 return -EIO;
249 usleep_range(duration_us, duration_us + 1000);
250
251 if (word_count == 0)
252 return 0;
253
254 data_buf = &buf->start;
255 ret = i2c_master_recv(client, data_buf, size);
256 if (ret < 0)
257 return ret;
258 if (ret != size)
259 return -EIO;
260
261 return sgp_verify_buffer(data, buf, word_count);
262 }
263
264 /**
265 * sgp_measure_iaq() - measure and retrieve IAQ values from sensor
266 * The caller must hold data->data_lock for the duration of the call.
267 * @data: SGP data
268 *
269 * Return: 0 on success, -EBUSY on default values, negative error
270 * otherwise.
271 */
272
273 static int sgp_measure_iaq(struct sgp_data *data)
274 {
275 int ret;
276 /* data contains default values */
277 bool default_vals = !time_after(jiffies, data->iaq_init_start_jiffies +
278 data->iaq_defval_skip_jiffies);
279
280 ret = sgp_read_cmd(data, data->measure_iaq_cmd, &data->iaq_buffer,
281 SGP_MEASUREMENT_LEN, SGP_MEASUREMENT_DURATION_US);
282 if (ret < 0)
283 return ret;
284
285 data->iaq_buffer_state = IAQ_BUFFER_DEFAULT_VALS;
286
287 if (default_vals)
288 return -EBUSY;
289
290 data->iaq_buffer_state = IAQ_BUFFER_VALID;
291
292 return 0;
293 }
294
295 static void sgp_iaq_thread_sleep_until(const struct sgp_data *data,
296 unsigned long sleep_jiffies)
297 {
298 const long IAQ_POLL = 50000;
299
300 while (!time_after(jiffies, sleep_jiffies)) {
301 usleep_range(IAQ_POLL, IAQ_POLL + 10000);
302 if (kthread_should_stop() || data->iaq_init_start_jiffies == 0)
303 return;
304 }
305 }
306
307 static int sgp_iaq_threadfn(void *p)
308 {
309 struct sgp_data *data = (struct sgp_data *)p;
310 unsigned long next_update_jiffies;
311 int ret;
312
313 while (!kthread_should_stop()) {
314 mutex_lock(&data->data_lock);
315 if (data->iaq_init_start_jiffies == 0) {
316 ret = sgp_read_cmd(data, data->iaq_init_cmd, NULL, 0,
317 SGP_CMD_DURATION_US);
318 if (ret < 0)
319 goto unlock_sleep_continue;
320 data->iaq_init_start_jiffies = jiffies;
321 }
322
323 ret = sgp_measure_iaq(data);
324 if (ret && ret != -EBUSY) {
325 dev_warn(&data->client->dev,
326 "IAQ measurement error [%d]\n", ret);
327 }
328 unlock_sleep_continue:
329 next_update_jiffies = jiffies + data->measure_interval_jiffies;
330 mutex_unlock(&data->data_lock);
331 sgp_iaq_thread_sleep_until(data, next_update_jiffies);
332 }
333
334 return 0;
335 }
336
337 static int sgp_read_raw(struct iio_dev *indio_dev,
338 struct iio_chan_spec const *chan, int *val,
339 int *val2, long mask)
340 {
341 struct sgp_data *data = iio_priv(indio_dev);
342 struct sgp_crc_word *words;
343 int ret;
344
345 switch (mask) {
346 case IIO_CHAN_INFO_PROCESSED:
347 mutex_lock(&data->data_lock);
348 if (data->iaq_buffer_state != IAQ_BUFFER_VALID) {
349 mutex_unlock(&data->data_lock);
350 return -EBUSY;
351 }
352 words = data->iaq_buffer.raw_words;
353 switch (chan->address) {
354 case SGP30_IAQ_TVOC_IDX:
355 case SGPC3_IAQ_TVOC_IDX:
356 *val = 0;
357 *val2 = be16_to_cpu(words[1].value);
358 ret = IIO_VAL_INT_PLUS_NANO;
359 break;
360 case SGP30_IAQ_CO2EQ_IDX:
361 *val = 0;
362 *val2 = be16_to_cpu(words[0].value);
363 ret = IIO_VAL_INT_PLUS_MICRO;
364 break;
365 default:
366 ret = -EINVAL;
367 break;
368 }
369 mutex_unlock(&data->data_lock);
370 break;
371 case IIO_CHAN_INFO_RAW:
372 mutex_lock(&data->data_lock);
373 if (chan->address == SGPC3_SIG_ETOH_IDX) {
374 if (data->iaq_buffer_state == IAQ_BUFFER_EMPTY)
375 ret = -EBUSY;
376 else
377 ret = 0;
378 words = data->iaq_buffer.raw_words;
379 } else {
380 ret = sgp_read_cmd(data, data->measure_gas_signals_cmd,
381 &data->buffer, SGP_MEASUREMENT_LEN,
382 SGP_MEASUREMENT_DURATION_US);
383 words = data->buffer.raw_words;
384 }
385 if (ret) {
386 mutex_unlock(&data->data_lock);
387 return ret;
388 }
389
390 switch (chan->address) {
391 case SGP30_SIG_ETOH_IDX:
392 *val = be16_to_cpu(words[1].value);
393 ret = IIO_VAL_INT;
394 break;
395 case SGPC3_SIG_ETOH_IDX:
396 case SGP30_SIG_H2_IDX:
397 *val = be16_to_cpu(words[0].value);
398 ret = IIO_VAL_INT;
399 break;
400 default:
401 ret = -EINVAL;
402 break;
403 }
404 mutex_unlock(&data->data_lock);
405 break;
406 default:
407 return -EINVAL;
408 }
409
410 return ret;
411 }
412
413 static int sgp_check_compat(struct sgp_data *data,
414 unsigned int product_id)
415 {
416 struct device *dev = &data->client->dev;
417 const struct sgp_version *supported_versions;
418 u16 ix, num_fs;
419 u16 product, generation, major, minor;
420
421 /* driver does not match product */
422 generation = SGP_VERS_GEN(data);
423 if (generation != 0) {
424 dev_err(dev,
425 "incompatible product generation %d != 0", generation);
426 return -ENODEV;
427 }
428
429 product = SGP_VERS_PRODUCT(data);
430 if (product != product_id) {
431 dev_err(dev, "sensor reports a different product: 0x%04x\n",
432 product);
433 return -ENODEV;
434 }
435
436 if (SGP_VERS_RESERVED(data))
437 dev_warn(dev, "reserved bit is set\n");
438
439 /* engineering samples are not supported: no interface guarantees */
440 if (SGP_VERS_ENG_BIT(data))
441 return -ENODEV;
442
443 switch (product) {
444 case SGP30:
445 supported_versions = supported_versions_sgp30;
446 num_fs = ARRAY_SIZE(supported_versions_sgp30);
447 break;
448 case SGPC3:
449 supported_versions = supported_versions_sgpc3;
450 num_fs = ARRAY_SIZE(supported_versions_sgpc3);
451 break;
452 default:
453 return -ENODEV;
454 }
455
456 major = SGP_VERS_MAJOR(data);
457 minor = SGP_VERS_MINOR(data);
458 for (ix = 0; ix < num_fs; ix++) {
459 if (major == supported_versions[ix].major &&
460 minor >= supported_versions[ix].minor)
461 return 0;
462 }
463 dev_err(dev, "unsupported sgp version: %d.%d\n", major, minor);
464
465 return -ENODEV;
466 }
467
468 static void sgp_init(struct sgp_data *data)
469 {
470 data->iaq_init_cmd = SGP_CMD_IAQ_INIT;
471 data->iaq_init_start_jiffies = 0;
472 data->iaq_buffer_state = IAQ_BUFFER_EMPTY;
473 switch (SGP_VERS_PRODUCT(data)) {
474 case SGP30:
475 data->measure_interval_jiffies = SGP30_MEASURE_INTERVAL_HZ * HZ;
476 data->measure_iaq_cmd = SGP_CMD_IAQ_MEASURE;
477 data->measure_gas_signals_cmd = SGP30_CMD_MEASURE_SIGNAL;
478 data->product_id = SGP30;
479 data->iaq_defval_skip_jiffies = 15 * HZ;
480 break;
481 case SGPC3:
482 data->measure_interval_jiffies = SGPC3_MEASURE_INTERVAL_HZ * HZ;
483 data->measure_iaq_cmd = SGPC3_CMD_MEASURE_RAW;
484 data->measure_gas_signals_cmd = SGPC3_CMD_MEASURE_RAW;
485 data->product_id = SGPC3;
486 data->iaq_defval_skip_jiffies =
487 43 * data->measure_interval_jiffies;
488 break;
489 }
490 }
491
492 static const struct iio_info sgp_info = {
493 .read_raw = sgp_read_raw,
494 };
495
496 static const struct of_device_id sgp_dt_ids[] = {
497 { .compatible = "sensirion,sgp30", .data = &sgp_devices[SGP30] },
498 { .compatible = "sensirion,sgpc3", .data = &sgp_devices[SGPC3] },
499 { }
500 };
501
502 static int sgp_probe(struct i2c_client *client)
503 {
504 const struct i2c_device_id *id = i2c_client_get_device_id(client);
505 const struct sgp_device *match_data;
506 struct device *dev = &client->dev;
507 struct iio_dev *indio_dev;
508 struct sgp_data *data;
509 int ret;
510
511 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
512 if (!indio_dev)
513 return -ENOMEM;
514
515 match_data = i2c_get_match_data(client);
516
517 data = iio_priv(indio_dev);
518 i2c_set_clientdata(client, indio_dev);
519 data->client = client;
520 crc8_populate_msb(sgp_crc8_table, SGP_CRC8_POLYNOMIAL);
521 mutex_init(&data->data_lock);
522
523 /* get feature set version and write it to client data */
524 ret = sgp_read_cmd(data, SGP_CMD_GET_FEATURE_SET, &data->buffer, 1,
525 SGP_CMD_DURATION_US);
526 if (ret < 0)
527 return ret;
528
529 data->feature_set = be16_to_cpu(data->buffer.raw_words[0].value);
530
531 ret = sgp_check_compat(data, match_data->product_id);
532 if (ret)
533 return ret;
534
535 indio_dev->info = &sgp_info;
536 indio_dev->name = id->name;
537 indio_dev->modes = INDIO_DIRECT_MODE;
538 indio_dev->channels = match_data->channels;
539 indio_dev->num_channels = match_data->num_channels;
540
541 sgp_init(data);
542
543 ret = devm_iio_device_register(dev, indio_dev);
544 if (ret) {
545 dev_err(dev, "failed to register iio device\n");
546 return ret;
547 }
548
549 data->iaq_thread = kthread_run(sgp_iaq_threadfn, data,
550 "%s-iaq", data->client->name);
551
552 return 0;
553 }
554
555 static void sgp_remove(struct i2c_client *client)
556 {
557 struct iio_dev *indio_dev = i2c_get_clientdata(client);
558 struct sgp_data *data = iio_priv(indio_dev);
559
560 if (data->iaq_thread)
561 kthread_stop(data->iaq_thread);
562 }
563
564 static const struct i2c_device_id sgp_id[] = {
565 { "sgp30", (kernel_ulong_t)&sgp_devices[SGP30] },
566 { "sgpc3", (kernel_ulong_t)&sgp_devices[SGPC3] },
567 { }
568 };
569
570 MODULE_DEVICE_TABLE(i2c, sgp_id);
571 MODULE_DEVICE_TABLE(of, sgp_dt_ids);
572
573 static struct i2c_driver sgp_driver = {
574 .driver = {
575 .name = "sgp30",
576 .of_match_table = sgp_dt_ids,
577 },
578 .probe = sgp_probe,
579 .remove = sgp_remove,
580 .id_table = sgp_id,
581 };
582 module_i2c_driver(sgp_driver);
583
584 MODULE_AUTHOR("Andreas Brauchli <andreas.brauchli@sensirion.com>");
585 MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>");
586 MODULE_DESCRIPTION("Sensirion SGP gas sensors");
587 MODULE_LICENSE("GPL v2");
Kernel DRM miscellaneous fixes and cross-tree changes