scd30_core.c 18 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Sensirion SCD30 carbon dioxide sensor core driver
  4. *
  5. * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com>
  6. */
  7. #include <linux/bits.h>
  8. #include <linux/completion.h>
  9. #include <linux/delay.h>
  10. #include <linux/device.h>
  11. #include <linux/errno.h>
  12. #include <linux/export.h>
  13. #include <linux/iio/buffer.h>
  14. #include <linux/iio/iio.h>
  15. #include <linux/iio/sysfs.h>
  16. #include <linux/iio/trigger.h>
  17. #include <linux/iio/trigger_consumer.h>
  18. #include <linux/iio/triggered_buffer.h>
  19. #include <linux/iio/types.h>
  20. #include <linux/interrupt.h>
  21. #include <linux/irqreturn.h>
  22. #include <linux/jiffies.h>
  23. #include <linux/kernel.h>
  24. #include <linux/module.h>
  25. #include <linux/mutex.h>
  26. #include <linux/regulator/consumer.h>
  27. #include <linux/string.h>
  28. #include <linux/sysfs.h>
  29. #include <linux/types.h>
  30. #include <asm/byteorder.h>
  31. #include "scd30.h"
  32. #define SCD30_PRESSURE_COMP_MIN_MBAR 700
  33. #define SCD30_PRESSURE_COMP_MAX_MBAR 1400
  34. #define SCD30_PRESSURE_COMP_DEFAULT 1013
  35. #define SCD30_MEAS_INTERVAL_MIN_S 2
  36. #define SCD30_MEAS_INTERVAL_MAX_S 1800
  37. #define SCD30_MEAS_INTERVAL_DEFAULT SCD30_MEAS_INTERVAL_MIN_S
  38. #define SCD30_FRC_MIN_PPM 400
  39. #define SCD30_FRC_MAX_PPM 2000
  40. #define SCD30_TEMP_OFFSET_MAX 655360
  41. #define SCD30_EXTRA_TIMEOUT_PER_S 250
  42. enum {
  43. SCD30_CONC,
  44. SCD30_TEMP,
  45. SCD30_HR,
  46. };
  47. static int scd30_command_write(struct scd30_state *state, enum scd30_cmd cmd, u16 arg)
  48. {
  49. return state->command(state, cmd, arg, NULL, 0);
  50. }
  51. static int scd30_command_read(struct scd30_state *state, enum scd30_cmd cmd, u16 *val)
  52. {
  53. __be16 tmp;
  54. int ret;
  55. ret = state->command(state, cmd, 0, &tmp, sizeof(tmp));
  56. *val = be16_to_cpup(&tmp);
  57. return ret;
  58. }
  59. static int scd30_reset(struct scd30_state *state)
  60. {
  61. int ret;
  62. u16 val;
  63. ret = scd30_command_write(state, CMD_RESET, 0);
  64. if (ret)
  65. return ret;
  66. /* sensor boots up within 2 secs */
  67. msleep(2000);
  68. /*
  69. * Power-on-reset causes sensor to produce some glitch on i2c bus and
  70. * some controllers end up in error state. Try to recover by placing
  71. * any data on the bus.
  72. */
  73. scd30_command_read(state, CMD_MEAS_READY, &val);
  74. return 0;
  75. }
  76. /* simplified float to fixed point conversion with a scaling factor of 0.01 */
  77. static int scd30_float_to_fp(int float32)
  78. {
  79. int fraction, shift,
  80. mantissa = float32 & GENMASK(22, 0),
  81. sign = (float32 & BIT(31)) ? -1 : 1,
  82. exp = (float32 & ~BIT(31)) >> 23;
  83. /* special case 0 */
  84. if (!exp && !mantissa)
  85. return 0;
  86. exp -= 127;
  87. if (exp < 0) {
  88. exp = -exp;
  89. /* return values ranging from 1 to 99 */
  90. return sign * ((((BIT(23) + mantissa) * 100) >> 23) >> exp);
  91. }
  92. /* return values starting at 100 */
  93. shift = 23 - exp;
  94. float32 = BIT(exp) + (mantissa >> shift);
  95. fraction = mantissa & GENMASK(shift - 1, 0);
  96. return sign * (float32 * 100 + ((fraction * 100) >> shift));
  97. }
  98. static int scd30_read_meas(struct scd30_state *state)
  99. {
  100. int i, ret;
  101. ret = state->command(state, CMD_READ_MEAS, 0, state->meas, sizeof(state->meas));
  102. if (ret)
  103. return ret;
  104. be32_to_cpu_array(state->meas, (__be32 *)state->meas, ARRAY_SIZE(state->meas));
  105. for (i = 0; i < ARRAY_SIZE(state->meas); i++)
  106. state->meas[i] = scd30_float_to_fp(state->meas[i]);
  107. /*
  108. * co2 is left unprocessed while temperature and humidity are scaled
  109. * to milli deg C and milli percent respectively.
  110. */
  111. state->meas[SCD30_TEMP] *= 10;
  112. state->meas[SCD30_HR] *= 10;
  113. return 0;
  114. }
  115. static int scd30_wait_meas_irq(struct scd30_state *state)
  116. {
  117. int ret, timeout;
  118. reinit_completion(&state->meas_ready);
  119. enable_irq(state->irq);
  120. timeout = msecs_to_jiffies(state->meas_interval * (1000 + SCD30_EXTRA_TIMEOUT_PER_S));
  121. ret = wait_for_completion_interruptible_timeout(&state->meas_ready, timeout);
  122. if (ret > 0)
  123. ret = 0;
  124. else if (!ret)
  125. ret = -ETIMEDOUT;
  126. disable_irq(state->irq);
  127. return ret;
  128. }
  129. static int scd30_wait_meas_poll(struct scd30_state *state)
  130. {
  131. int timeout = state->meas_interval * SCD30_EXTRA_TIMEOUT_PER_S, tries = 5;
  132. do {
  133. int ret;
  134. u16 val;
  135. ret = scd30_command_read(state, CMD_MEAS_READY, &val);
  136. if (ret)
  137. return -EIO;
  138. /* new measurement available */
  139. if (val)
  140. break;
  141. msleep_interruptible(timeout);
  142. } while (--tries);
  143. return tries ? 0 : -ETIMEDOUT;
  144. }
  145. static int scd30_read_poll(struct scd30_state *state)
  146. {
  147. int ret;
  148. ret = scd30_wait_meas_poll(state);
  149. if (ret)
  150. return ret;
  151. return scd30_read_meas(state);
  152. }
  153. static int scd30_read(struct scd30_state *state)
  154. {
  155. if (state->irq > 0)
  156. return scd30_wait_meas_irq(state);
  157. return scd30_read_poll(state);
  158. }
  159. static int scd30_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
  160. int *val, int *val2, long mask)
  161. {
  162. struct scd30_state *state = iio_priv(indio_dev);
  163. int ret = -EINVAL;
  164. u16 tmp;
  165. mutex_lock(&state->lock);
  166. switch (mask) {
  167. case IIO_CHAN_INFO_RAW:
  168. case IIO_CHAN_INFO_PROCESSED:
  169. if (chan->output) {
  170. *val = state->pressure_comp;
  171. ret = IIO_VAL_INT;
  172. break;
  173. }
  174. ret = iio_device_claim_direct_mode(indio_dev);
  175. if (ret)
  176. break;
  177. ret = scd30_read(state);
  178. if (ret) {
  179. iio_device_release_direct_mode(indio_dev);
  180. break;
  181. }
  182. *val = state->meas[chan->address];
  183. iio_device_release_direct_mode(indio_dev);
  184. ret = IIO_VAL_INT;
  185. break;
  186. case IIO_CHAN_INFO_SCALE:
  187. *val = 0;
  188. *val2 = 1;
  189. ret = IIO_VAL_INT_PLUS_MICRO;
  190. break;
  191. case IIO_CHAN_INFO_SAMP_FREQ:
  192. ret = scd30_command_read(state, CMD_MEAS_INTERVAL, &tmp);
  193. if (ret)
  194. break;
  195. *val = 0;
  196. *val2 = 1000000000 / tmp;
  197. ret = IIO_VAL_INT_PLUS_NANO;
  198. break;
  199. case IIO_CHAN_INFO_CALIBBIAS:
  200. ret = scd30_command_read(state, CMD_TEMP_OFFSET, &tmp);
  201. if (ret)
  202. break;
  203. *val = tmp;
  204. ret = IIO_VAL_INT;
  205. break;
  206. }
  207. mutex_unlock(&state->lock);
  208. return ret;
  209. }
  210. static int scd30_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
  211. int val, int val2, long mask)
  212. {
  213. struct scd30_state *state = iio_priv(indio_dev);
  214. int ret = -EINVAL;
  215. mutex_lock(&state->lock);
  216. switch (mask) {
  217. case IIO_CHAN_INFO_SAMP_FREQ:
  218. if (val)
  219. break;
  220. val = 1000000000 / val2;
  221. if (val < SCD30_MEAS_INTERVAL_MIN_S || val > SCD30_MEAS_INTERVAL_MAX_S)
  222. break;
  223. ret = scd30_command_write(state, CMD_MEAS_INTERVAL, val);
  224. if (ret)
  225. break;
  226. state->meas_interval = val;
  227. break;
  228. case IIO_CHAN_INFO_RAW:
  229. switch (chan->type) {
  230. case IIO_PRESSURE:
  231. if (val < SCD30_PRESSURE_COMP_MIN_MBAR ||
  232. val > SCD30_PRESSURE_COMP_MAX_MBAR)
  233. break;
  234. ret = scd30_command_write(state, CMD_START_MEAS, val);
  235. if (ret)
  236. break;
  237. state->pressure_comp = val;
  238. break;
  239. default:
  240. break;
  241. }
  242. break;
  243. case IIO_CHAN_INFO_CALIBBIAS:
  244. if (val < 0 || val > SCD30_TEMP_OFFSET_MAX)
  245. break;
  246. /*
  247. * Manufacturer does not explicitly specify min/max sensible
  248. * values hence check is omitted for simplicity.
  249. */
  250. ret = scd30_command_write(state, CMD_TEMP_OFFSET / 10, val);
  251. }
  252. mutex_unlock(&state->lock);
  253. return ret;
  254. }
  255. static int scd30_write_raw_get_fmt(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
  256. long mask)
  257. {
  258. switch (mask) {
  259. case IIO_CHAN_INFO_SAMP_FREQ:
  260. return IIO_VAL_INT_PLUS_NANO;
  261. case IIO_CHAN_INFO_RAW:
  262. case IIO_CHAN_INFO_CALIBBIAS:
  263. return IIO_VAL_INT;
  264. }
  265. return -EINVAL;
  266. }
  267. static const int scd30_pressure_raw_available[] = {
  268. SCD30_PRESSURE_COMP_MIN_MBAR, 1, SCD30_PRESSURE_COMP_MAX_MBAR,
  269. };
  270. static const int scd30_temp_calibbias_available[] = {
  271. 0, 10, SCD30_TEMP_OFFSET_MAX,
  272. };
  273. static int scd30_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
  274. const int **vals, int *type, int *length, long mask)
  275. {
  276. switch (mask) {
  277. case IIO_CHAN_INFO_RAW:
  278. *vals = scd30_pressure_raw_available;
  279. *type = IIO_VAL_INT;
  280. return IIO_AVAIL_RANGE;
  281. case IIO_CHAN_INFO_CALIBBIAS:
  282. *vals = scd30_temp_calibbias_available;
  283. *type = IIO_VAL_INT;
  284. return IIO_AVAIL_RANGE;
  285. }
  286. return -EINVAL;
  287. }
  288. static ssize_t sampling_frequency_available_show(struct device *dev, struct device_attribute *attr,
  289. char *buf)
  290. {
  291. int i = SCD30_MEAS_INTERVAL_MIN_S;
  292. ssize_t len = 0;
  293. do {
  294. len += scnprintf(buf + len, PAGE_SIZE - len, "0.%09u ", 1000000000 / i);
  295. /*
  296. * Not all values fit PAGE_SIZE buffer hence print every 6th
  297. * (each frequency differs by 6s in time domain from the
  298. * adjacent). Unlisted but valid ones are still accepted.
  299. */
  300. i += 6;
  301. } while (i <= SCD30_MEAS_INTERVAL_MAX_S);
  302. buf[len - 1] = '\n';
  303. return len;
  304. }
  305. static ssize_t calibration_auto_enable_show(struct device *dev, struct device_attribute *attr,
  306. char *buf)
  307. {
  308. struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  309. struct scd30_state *state = iio_priv(indio_dev);
  310. int ret;
  311. u16 val;
  312. mutex_lock(&state->lock);
  313. ret = scd30_command_read(state, CMD_ASC, &val);
  314. mutex_unlock(&state->lock);
  315. return ret ?: sprintf(buf, "%d\n", val);
  316. }
  317. static ssize_t calibration_auto_enable_store(struct device *dev, struct device_attribute *attr,
  318. const char *buf, size_t len)
  319. {
  320. struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  321. struct scd30_state *state = iio_priv(indio_dev);
  322. bool val;
  323. int ret;
  324. ret = kstrtobool(buf, &val);
  325. if (ret)
  326. return ret;
  327. mutex_lock(&state->lock);
  328. ret = scd30_command_write(state, CMD_ASC, val);
  329. mutex_unlock(&state->lock);
  330. return ret ?: len;
  331. }
  332. static ssize_t calibration_forced_value_show(struct device *dev, struct device_attribute *attr,
  333. char *buf)
  334. {
  335. struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  336. struct scd30_state *state = iio_priv(indio_dev);
  337. int ret;
  338. u16 val;
  339. mutex_lock(&state->lock);
  340. ret = scd30_command_read(state, CMD_FRC, &val);
  341. mutex_unlock(&state->lock);
  342. return ret ?: sprintf(buf, "%d\n", val);
  343. }
  344. static ssize_t calibration_forced_value_store(struct device *dev, struct device_attribute *attr,
  345. const char *buf, size_t len)
  346. {
  347. struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  348. struct scd30_state *state = iio_priv(indio_dev);
  349. int ret;
  350. u16 val;
  351. ret = kstrtou16(buf, 0, &val);
  352. if (ret)
  353. return ret;
  354. if (val < SCD30_FRC_MIN_PPM || val > SCD30_FRC_MAX_PPM)
  355. return -EINVAL;
  356. mutex_lock(&state->lock);
  357. ret = scd30_command_write(state, CMD_FRC, val);
  358. mutex_unlock(&state->lock);
  359. return ret ?: len;
  360. }
  361. static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0);
  362. static IIO_DEVICE_ATTR_RW(calibration_auto_enable, 0);
  363. static IIO_DEVICE_ATTR_RW(calibration_forced_value, 0);
  364. static struct attribute *scd30_attrs[] = {
  365. &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
  366. &iio_dev_attr_calibration_auto_enable.dev_attr.attr,
  367. &iio_dev_attr_calibration_forced_value.dev_attr.attr,
  368. NULL
  369. };
  370. static const struct attribute_group scd30_attr_group = {
  371. .attrs = scd30_attrs,
  372. };
  373. static const struct iio_info scd30_info = {
  374. .attrs = &scd30_attr_group,
  375. .read_raw = scd30_read_raw,
  376. .write_raw = scd30_write_raw,
  377. .write_raw_get_fmt = scd30_write_raw_get_fmt,
  378. .read_avail = scd30_read_avail,
  379. };
  380. #define SCD30_CHAN_SCAN_TYPE(_sign, _realbits) .scan_type = { \
  381. .sign = _sign, \
  382. .realbits = _realbits, \
  383. .storagebits = 32, \
  384. .endianness = IIO_CPU, \
  385. }
  386. static const struct iio_chan_spec scd30_channels[] = {
  387. {
  388. /*
  389. * this channel is special in a sense we are pretending that
  390. * sensor is able to change measurement chamber pressure but in
  391. * fact we're just setting pressure compensation value
  392. */
  393. .type = IIO_PRESSURE,
  394. .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  395. .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
  396. .output = 1,
  397. .scan_index = -1,
  398. },
  399. {
  400. .type = IIO_CONCENTRATION,
  401. .channel2 = IIO_MOD_CO2,
  402. .address = SCD30_CONC,
  403. .scan_index = SCD30_CONC,
  404. .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  405. BIT(IIO_CHAN_INFO_SCALE),
  406. .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
  407. .modified = 1,
  408. SCD30_CHAN_SCAN_TYPE('u', 20),
  409. },
  410. {
  411. .type = IIO_TEMP,
  412. .address = SCD30_TEMP,
  413. .scan_index = SCD30_TEMP,
  414. .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
  415. BIT(IIO_CHAN_INFO_CALIBBIAS),
  416. .info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS),
  417. .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
  418. SCD30_CHAN_SCAN_TYPE('s', 18),
  419. },
  420. {
  421. .type = IIO_HUMIDITYRELATIVE,
  422. .address = SCD30_HR,
  423. .scan_index = SCD30_HR,
  424. .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
  425. .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
  426. SCD30_CHAN_SCAN_TYPE('u', 17),
  427. },
  428. IIO_CHAN_SOFT_TIMESTAMP(3),
  429. };
  430. int __maybe_unused scd30_suspend(struct device *dev)
  431. {
  432. struct iio_dev *indio_dev = dev_get_drvdata(dev);
  433. struct scd30_state *state = iio_priv(indio_dev);
  434. int ret;
  435. ret = scd30_command_write(state, CMD_STOP_MEAS, 0);
  436. if (ret)
  437. return ret;
  438. return regulator_disable(state->vdd);
  439. }
  440. EXPORT_SYMBOL(scd30_suspend);
  441. int __maybe_unused scd30_resume(struct device *dev)
  442. {
  443. struct iio_dev *indio_dev = dev_get_drvdata(dev);
  444. struct scd30_state *state = iio_priv(indio_dev);
  445. int ret;
  446. ret = regulator_enable(state->vdd);
  447. if (ret)
  448. return ret;
  449. return scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
  450. }
  451. EXPORT_SYMBOL(scd30_resume);
  452. static void scd30_stop_meas(void *data)
  453. {
  454. struct scd30_state *state = data;
  455. scd30_command_write(state, CMD_STOP_MEAS, 0);
  456. }
  457. static void scd30_disable_regulator(void *data)
  458. {
  459. struct scd30_state *state = data;
  460. regulator_disable(state->vdd);
  461. }
  462. static irqreturn_t scd30_irq_handler(int irq, void *priv)
  463. {
  464. struct iio_dev *indio_dev = priv;
  465. if (iio_buffer_enabled(indio_dev)) {
  466. iio_trigger_poll(indio_dev->trig);
  467. return IRQ_HANDLED;
  468. }
  469. return IRQ_WAKE_THREAD;
  470. }
  471. static irqreturn_t scd30_irq_thread_handler(int irq, void *priv)
  472. {
  473. struct iio_dev *indio_dev = priv;
  474. struct scd30_state *state = iio_priv(indio_dev);
  475. int ret;
  476. ret = scd30_read_meas(state);
  477. if (ret)
  478. goto out;
  479. complete_all(&state->meas_ready);
  480. out:
  481. return IRQ_HANDLED;
  482. }
  483. static irqreturn_t scd30_trigger_handler(int irq, void *p)
  484. {
  485. struct iio_poll_func *pf = p;
  486. struct iio_dev *indio_dev = pf->indio_dev;
  487. struct scd30_state *state = iio_priv(indio_dev);
  488. struct {
  489. int data[SCD30_MEAS_COUNT];
  490. s64 ts __aligned(8);
  491. } scan;
  492. int ret;
  493. mutex_lock(&state->lock);
  494. if (!iio_trigger_using_own(indio_dev))
  495. ret = scd30_read_poll(state);
  496. else
  497. ret = scd30_read_meas(state);
  498. memset(&scan, 0, sizeof(scan));
  499. memcpy(scan.data, state->meas, sizeof(state->meas));
  500. mutex_unlock(&state->lock);
  501. if (ret)
  502. goto out;
  503. iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev));
  504. out:
  505. iio_trigger_notify_done(indio_dev->trig);
  506. return IRQ_HANDLED;
  507. }
  508. static int scd30_set_trigger_state(struct iio_trigger *trig, bool state)
  509. {
  510. struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
  511. struct scd30_state *st = iio_priv(indio_dev);
  512. if (state)
  513. enable_irq(st->irq);
  514. else
  515. disable_irq(st->irq);
  516. return 0;
  517. }
  518. static const struct iio_trigger_ops scd30_trigger_ops = {
  519. .set_trigger_state = scd30_set_trigger_state,
  520. .validate_device = iio_trigger_validate_own_device,
  521. };
  522. static int scd30_setup_trigger(struct iio_dev *indio_dev)
  523. {
  524. struct scd30_state *state = iio_priv(indio_dev);
  525. struct device *dev = indio_dev->dev.parent;
  526. struct iio_trigger *trig;
  527. int ret;
  528. trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, indio_dev->id);
  529. if (!trig) {
  530. dev_err(dev, "failed to allocate trigger\n");
  531. return -ENOMEM;
  532. }
  533. trig->dev.parent = dev;
  534. trig->ops = &scd30_trigger_ops;
  535. iio_trigger_set_drvdata(trig, indio_dev);
  536. ret = devm_iio_trigger_register(dev, trig);
  537. if (ret)
  538. return ret;
  539. indio_dev->trig = iio_trigger_get(trig);
  540. ret = devm_request_threaded_irq(dev, state->irq, scd30_irq_handler,
  541. scd30_irq_thread_handler, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
  542. indio_dev->name, indio_dev);
  543. if (ret)
  544. dev_err(dev, "failed to request irq\n");
  545. /*
  546. * Interrupt is enabled just before taking a fresh measurement
  547. * and disabled afterwards. This means we need to disable it here
  548. * to keep calls to enable/disable balanced.
  549. */
  550. disable_irq(state->irq);
  551. return ret;
  552. }
  553. int scd30_probe(struct device *dev, int irq, const char *name, void *priv,
  554. scd30_command_t command)
  555. {
  556. static const unsigned long scd30_scan_masks[] = { 0x07, 0x00 };
  557. struct scd30_state *state;
  558. struct iio_dev *indio_dev;
  559. int ret;
  560. u16 val;
  561. indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
  562. if (!indio_dev)
  563. return -ENOMEM;
  564. state = iio_priv(indio_dev);
  565. state->dev = dev;
  566. state->priv = priv;
  567. state->irq = irq;
  568. state->pressure_comp = SCD30_PRESSURE_COMP_DEFAULT;
  569. state->meas_interval = SCD30_MEAS_INTERVAL_DEFAULT;
  570. state->command = command;
  571. mutex_init(&state->lock);
  572. init_completion(&state->meas_ready);
  573. dev_set_drvdata(dev, indio_dev);
  574. indio_dev->info = &scd30_info;
  575. indio_dev->name = name;
  576. indio_dev->channels = scd30_channels;
  577. indio_dev->num_channels = ARRAY_SIZE(scd30_channels);
  578. indio_dev->modes = INDIO_DIRECT_MODE;
  579. indio_dev->available_scan_masks = scd30_scan_masks;
  580. state->vdd = devm_regulator_get(dev, "vdd");
  581. if (IS_ERR(state->vdd))
  582. return dev_err_probe(dev, PTR_ERR(state->vdd), "failed to get regulator\n");
  583. ret = regulator_enable(state->vdd);
  584. if (ret)
  585. return ret;
  586. ret = devm_add_action_or_reset(dev, scd30_disable_regulator, state);
  587. if (ret)
  588. return ret;
  589. ret = scd30_reset(state);
  590. if (ret) {
  591. dev_err(dev, "failed to reset device: %d\n", ret);
  592. return ret;
  593. }
  594. if (state->irq > 0) {
  595. ret = scd30_setup_trigger(indio_dev);
  596. if (ret) {
  597. dev_err(dev, "failed to setup trigger: %d\n", ret);
  598. return ret;
  599. }
  600. }
  601. ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, scd30_trigger_handler, NULL);
  602. if (ret)
  603. return ret;
  604. ret = scd30_command_read(state, CMD_FW_VERSION, &val);
  605. if (ret) {
  606. dev_err(dev, "failed to read firmware version: %d\n", ret);
  607. return ret;
  608. }
  609. dev_info(dev, "firmware version: %d.%d\n", val >> 8, (char)val);
  610. ret = scd30_command_write(state, CMD_MEAS_INTERVAL, state->meas_interval);
  611. if (ret) {
  612. dev_err(dev, "failed to set measurement interval: %d\n", ret);
  613. return ret;
  614. }
  615. ret = scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
  616. if (ret) {
  617. dev_err(dev, "failed to start measurement: %d\n", ret);
  618. return ret;
  619. }
  620. ret = devm_add_action_or_reset(dev, scd30_stop_meas, state);
  621. if (ret)
  622. return ret;
  623. return devm_iio_device_register(dev, indio_dev);
  624. }
  625. EXPORT_SYMBOL(scd30_probe);
  626. MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>");
  627. MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor core driver");
  628. MODULE_LICENSE("GPL v2");