1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Senseair Sunrise 006-0-0007 CO2 sensor driver. |
4 | * |
5 | * Copyright (C) 2021 Jacopo Mondi |
6 | * |
7 | * List of features not yet supported by the driver: |
8 | * - controllable EN pin |
9 | * - single-shot operations using the nDRY pin. |
10 | * - ABC/target calibration |
11 | */ |
12 | |
13 | #include <linux/bitops.h> |
14 | #include <linux/i2c.h> |
15 | #include <linux/kernel.h> |
16 | #include <linux/mod_devicetable.h> |
17 | #include <linux/module.h> |
18 | #include <linux/mutex.h> |
19 | #include <linux/regmap.h> |
20 | #include <linux/time64.h> |
21 | |
22 | #include <linux/iio/iio.h> |
23 | |
24 | #define DRIVER_NAME "sunrise_co2" |
25 | |
26 | #define SUNRISE_ERROR_STATUS_REG 0x00 |
27 | #define SUNRISE_CO2_FILTERED_COMP_REG 0x06 |
28 | #define SUNRISE_CHIP_TEMPERATURE_REG 0x08 |
29 | #define SUNRISE_CALIBRATION_STATUS_REG 0x81 |
30 | #define SUNRISE_CALIBRATION_COMMAND_REG 0x82 |
31 | #define SUNRISE_CALIBRATION_FACTORY_CMD 0x7c02 |
32 | #define SUNRISE_CALIBRATION_BACKGROUND_CMD 0x7c06 |
33 | /* |
34 | * The calibration timeout is not characterized in the datasheet. |
35 | * Use 30 seconds as a reasonable upper limit. |
36 | */ |
37 | #define SUNRISE_CALIBRATION_TIMEOUT_US (30 * USEC_PER_SEC) |
38 | |
39 | struct sunrise_dev { |
40 | struct i2c_client *client; |
41 | struct regmap *regmap; |
42 | /* Protects access to IIO attributes. */ |
43 | struct mutex lock; |
44 | bool ignore_nak; |
45 | }; |
46 | |
47 | /* Custom regmap read/write operations: perform unlocked access to the i2c bus. */ |
48 | |
49 | static int sunrise_regmap_read(void *context, const void *reg_buf, |
50 | size_t reg_size, void *val_buf, size_t val_size) |
51 | { |
52 | struct i2c_client *client = context; |
53 | struct sunrise_dev *sunrise = i2c_get_clientdata(client); |
54 | union i2c_smbus_data data; |
55 | int ret; |
56 | |
57 | if (reg_size != 1 || !val_size) |
58 | return -EINVAL; |
59 | |
60 | memset(&data, 0, sizeof(data)); |
61 | data.block[0] = val_size; |
62 | |
63 | /* |
64 | * Wake up sensor by sending sensor address: START, sensor address, |
65 | * STOP. Sensor will not ACK this byte. |
66 | * |
67 | * The chip enters a low power state after 15ms without |
68 | * communications or after a complete read/write sequence. |
69 | */ |
70 | __i2c_smbus_xfer(adapter: client->adapter, addr: client->addr, |
71 | flags: sunrise->ignore_nak ? I2C_M_IGNORE_NAK : 0, |
72 | I2C_SMBUS_WRITE, command: 0, I2C_SMBUS_BYTE_DATA, data: &data); |
73 | |
74 | usleep_range(min: 500, max: 1500); |
75 | |
76 | ret = __i2c_smbus_xfer(adapter: client->adapter, addr: client->addr, flags: client->flags, |
77 | I2C_SMBUS_READ, command: ((u8 *)reg_buf)[0], |
78 | I2C_SMBUS_I2C_BLOCK_DATA, data: &data); |
79 | if (ret < 0) |
80 | return ret; |
81 | |
82 | memcpy(val_buf, &data.block[1], data.block[0]); |
83 | |
84 | return 0; |
85 | } |
86 | |
87 | static int sunrise_regmap_write(void *context, const void *val_buf, size_t count) |
88 | { |
89 | struct i2c_client *client = context; |
90 | struct sunrise_dev *sunrise = i2c_get_clientdata(client); |
91 | union i2c_smbus_data data; |
92 | |
93 | /* Discard reg address from values count. */ |
94 | if (!count) |
95 | return -EINVAL; |
96 | count--; |
97 | |
98 | memset(&data, 0, sizeof(data)); |
99 | data.block[0] = count; |
100 | memcpy(&data.block[1], (u8 *)val_buf + 1, count); |
101 | |
102 | __i2c_smbus_xfer(adapter: client->adapter, addr: client->addr, |
103 | flags: sunrise->ignore_nak ? I2C_M_IGNORE_NAK : 0, |
104 | I2C_SMBUS_WRITE, command: 0, I2C_SMBUS_BYTE_DATA, data: &data); |
105 | |
106 | usleep_range(min: 500, max: 1500); |
107 | |
108 | return __i2c_smbus_xfer(adapter: client->adapter, addr: client->addr, flags: client->flags, |
109 | I2C_SMBUS_WRITE, command: ((u8 *)val_buf)[0], |
110 | I2C_SMBUS_I2C_BLOCK_DATA, data: &data); |
111 | } |
112 | |
113 | /* |
114 | * Sunrise i2c read/write operations: lock the i2c segment to avoid losing the |
115 | * wake up session. Use custom regmap operations that perform unlocked access to |
116 | * the i2c bus. |
117 | */ |
118 | static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg) |
119 | { |
120 | const struct i2c_client *client = sunrise->client; |
121 | const struct device *dev = &client->dev; |
122 | unsigned int val; |
123 | int ret; |
124 | |
125 | i2c_lock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
126 | ret = regmap_read(map: sunrise->regmap, reg, val: &val); |
127 | i2c_unlock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
128 | if (ret) { |
129 | dev_err(dev, "Read byte failed: reg 0x%02x (%d)\n" , reg, ret); |
130 | return ret; |
131 | } |
132 | |
133 | return val; |
134 | } |
135 | |
136 | static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val) |
137 | { |
138 | const struct i2c_client *client = sunrise->client; |
139 | const struct device *dev = &client->dev; |
140 | __be16 be_val; |
141 | int ret; |
142 | |
143 | i2c_lock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
144 | ret = regmap_bulk_read(map: sunrise->regmap, reg, val: &be_val, val_count: sizeof(be_val)); |
145 | i2c_unlock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
146 | if (ret) { |
147 | dev_err(dev, "Read word failed: reg 0x%02x (%d)\n" , reg, ret); |
148 | return ret; |
149 | } |
150 | |
151 | *val = be16_to_cpu(be_val); |
152 | |
153 | return 0; |
154 | } |
155 | |
156 | static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val) |
157 | { |
158 | const struct i2c_client *client = sunrise->client; |
159 | const struct device *dev = &client->dev; |
160 | int ret; |
161 | |
162 | i2c_lock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
163 | ret = regmap_write(map: sunrise->regmap, reg, val); |
164 | i2c_unlock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
165 | if (ret) |
166 | dev_err(dev, "Write byte failed: reg 0x%02x (%d)\n" , reg, ret); |
167 | |
168 | return ret; |
169 | } |
170 | |
171 | static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data) |
172 | { |
173 | const struct i2c_client *client = sunrise->client; |
174 | const struct device *dev = &client->dev; |
175 | __be16 be_data = cpu_to_be16(data); |
176 | int ret; |
177 | |
178 | i2c_lock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
179 | ret = regmap_bulk_write(map: sunrise->regmap, reg, val: &be_data, val_count: sizeof(be_data)); |
180 | i2c_unlock_bus(adapter: client->adapter, I2C_LOCK_SEGMENT); |
181 | if (ret) |
182 | dev_err(dev, "Write word failed: reg 0x%02x (%d)\n" , reg, ret); |
183 | |
184 | return ret; |
185 | } |
186 | |
187 | /* Trigger a calibration cycle. */ |
188 | |
189 | enum { |
190 | SUNRISE_CALIBRATION_FACTORY, |
191 | SUNRISE_CALIBRATION_BACKGROUND, |
192 | }; |
193 | |
194 | static const struct sunrise_calib_data { |
195 | u16 cmd; |
196 | u8 bit; |
197 | const char * const name; |
198 | } calib_data[] = { |
199 | [SUNRISE_CALIBRATION_FACTORY] = { |
200 | SUNRISE_CALIBRATION_FACTORY_CMD, |
201 | BIT(2), |
202 | "factory_calibration" , |
203 | }, |
204 | [SUNRISE_CALIBRATION_BACKGROUND] = { |
205 | SUNRISE_CALIBRATION_BACKGROUND_CMD, |
206 | BIT(5), |
207 | .name: "background_calibration" , |
208 | }, |
209 | }; |
210 | |
211 | static int sunrise_calibrate(struct sunrise_dev *sunrise, |
212 | const struct sunrise_calib_data *data) |
213 | { |
214 | unsigned int status; |
215 | int ret; |
216 | |
217 | /* Reset the calibration status reg. */ |
218 | ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, val: 0x00); |
219 | if (ret) |
220 | return ret; |
221 | |
222 | /* Write a calibration command and poll the calibration status bit. */ |
223 | ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG, data: data->cmd); |
224 | if (ret) |
225 | return ret; |
226 | |
227 | dev_dbg(&sunrise->client->dev, "%s in progress\n" , data->name); |
228 | |
229 | /* |
230 | * Calibration takes several seconds, so the sleep time between reads |
231 | * can be pretty relaxed. |
232 | */ |
233 | return read_poll_timeout(sunrise_read_byte, status, status & data->bit, |
234 | 200000, SUNRISE_CALIBRATION_TIMEOUT_US, false, |
235 | sunrise, SUNRISE_CALIBRATION_STATUS_REG); |
236 | } |
237 | |
238 | static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev, |
239 | uintptr_t private, |
240 | const struct iio_chan_spec *chan, |
241 | const char *buf, size_t len) |
242 | { |
243 | struct sunrise_dev *sunrise = iio_priv(indio_dev: iiodev); |
244 | bool enable; |
245 | int ret; |
246 | |
247 | ret = kstrtobool(s: buf, res: &enable); |
248 | if (ret) |
249 | return ret; |
250 | |
251 | if (!enable) |
252 | return len; |
253 | |
254 | mutex_lock(&sunrise->lock); |
255 | ret = sunrise_calibrate(sunrise, data: &calib_data[SUNRISE_CALIBRATION_FACTORY]); |
256 | mutex_unlock(lock: &sunrise->lock); |
257 | if (ret) |
258 | return ret; |
259 | |
260 | return len; |
261 | } |
262 | |
263 | static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev, |
264 | uintptr_t private, |
265 | const struct iio_chan_spec *chan, |
266 | const char *buf, size_t len) |
267 | { |
268 | struct sunrise_dev *sunrise = iio_priv(indio_dev: iiodev); |
269 | bool enable; |
270 | int ret; |
271 | |
272 | ret = kstrtobool(s: buf, res: &enable); |
273 | if (ret) |
274 | return ret; |
275 | |
276 | if (!enable) |
277 | return len; |
278 | |
279 | mutex_lock(&sunrise->lock); |
280 | ret = sunrise_calibrate(sunrise, data: &calib_data[SUNRISE_CALIBRATION_BACKGROUND]); |
281 | mutex_unlock(lock: &sunrise->lock); |
282 | if (ret) |
283 | return ret; |
284 | |
285 | return len; |
286 | } |
287 | |
288 | /* Enumerate and retrieve the chip error status. */ |
289 | enum { |
290 | SUNRISE_ERROR_FATAL, |
291 | SUNRISE_ERROR_I2C, |
292 | SUNRISE_ERROR_ALGORITHM, |
293 | SUNRISE_ERROR_CALIBRATION, |
294 | SUNRISE_ERROR_SELF_DIAGNOSTIC, |
295 | SUNRISE_ERROR_OUT_OF_RANGE, |
296 | SUNRISE_ERROR_MEMORY, |
297 | SUNRISE_ERROR_NO_MEASUREMENT, |
298 | SUNRISE_ERROR_LOW_VOLTAGE, |
299 | SUNRISE_ERROR_MEASUREMENT_TIMEOUT, |
300 | }; |
301 | |
302 | static const char * const sunrise_error_statuses[] = { |
303 | [SUNRISE_ERROR_FATAL] = "error_fatal" , |
304 | [SUNRISE_ERROR_I2C] = "error_i2c" , |
305 | [SUNRISE_ERROR_ALGORITHM] = "error_algorithm" , |
306 | [SUNRISE_ERROR_CALIBRATION] = "error_calibration" , |
307 | [SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic" , |
308 | [SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range" , |
309 | [SUNRISE_ERROR_MEMORY] = "error_memory" , |
310 | [SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement" , |
311 | [SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage" , |
312 | [SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout" , |
313 | }; |
314 | |
315 | static const struct iio_enum sunrise_error_statuses_enum = { |
316 | .items = sunrise_error_statuses, |
317 | .num_items = ARRAY_SIZE(sunrise_error_statuses), |
318 | }; |
319 | |
320 | static ssize_t sunrise_error_status_read(struct iio_dev *iiodev, |
321 | uintptr_t private, |
322 | const struct iio_chan_spec *chan, |
323 | char *buf) |
324 | { |
325 | struct sunrise_dev *sunrise = iio_priv(indio_dev: iiodev); |
326 | unsigned long errors; |
327 | ssize_t len = 0; |
328 | u16 value; |
329 | int ret; |
330 | u8 i; |
331 | |
332 | mutex_lock(&sunrise->lock); |
333 | ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, val: &value); |
334 | if (ret) { |
335 | mutex_unlock(lock: &sunrise->lock); |
336 | return ret; |
337 | } |
338 | |
339 | errors = value; |
340 | for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses)) |
341 | len += sysfs_emit_at(buf, at: len, fmt: "%s " , sunrise_error_statuses[i]); |
342 | |
343 | if (len) |
344 | buf[len - 1] = '\n'; |
345 | |
346 | mutex_unlock(lock: &sunrise->lock); |
347 | |
348 | return len; |
349 | } |
350 | |
351 | static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = { |
352 | /* Calibration triggers. */ |
353 | { |
354 | .name = "calibration_factory" , |
355 | .write = sunrise_cal_factory_write, |
356 | .shared = IIO_SEPARATE, |
357 | }, |
358 | { |
359 | .name = "calibration_background" , |
360 | .write = sunrise_cal_background_write, |
361 | .shared = IIO_SEPARATE, |
362 | }, |
363 | |
364 | /* Error statuses. */ |
365 | { |
366 | .name = "error_status" , |
367 | .read = sunrise_error_status_read, |
368 | .shared = IIO_SHARED_BY_ALL, |
369 | }, |
370 | { |
371 | .name = "error_status_available" , |
372 | .shared = IIO_SHARED_BY_ALL, |
373 | .read = iio_enum_available_read, |
374 | .private = (uintptr_t)&sunrise_error_statuses_enum, |
375 | }, |
376 | {} |
377 | }; |
378 | |
379 | static const struct iio_chan_spec sunrise_channels[] = { |
380 | { |
381 | .type = IIO_CONCENTRATION, |
382 | .modified = 1, |
383 | .channel2 = IIO_MOD_CO2, |
384 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
385 | BIT(IIO_CHAN_INFO_SCALE), |
386 | .ext_info = sunrise_concentration_ext_info, |
387 | }, |
388 | { |
389 | .type = IIO_TEMP, |
390 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
391 | BIT(IIO_CHAN_INFO_SCALE), |
392 | }, |
393 | }; |
394 | |
395 | static int sunrise_read_raw(struct iio_dev *iio_dev, |
396 | const struct iio_chan_spec *chan, |
397 | int *val, int *val2, long mask) |
398 | { |
399 | struct sunrise_dev *sunrise = iio_priv(indio_dev: iio_dev); |
400 | u16 value; |
401 | int ret; |
402 | |
403 | switch (mask) { |
404 | case IIO_CHAN_INFO_RAW: |
405 | switch (chan->type) { |
406 | case IIO_CONCENTRATION: |
407 | mutex_lock(&sunrise->lock); |
408 | ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG, |
409 | val: &value); |
410 | mutex_unlock(lock: &sunrise->lock); |
411 | |
412 | if (ret) |
413 | return ret; |
414 | |
415 | *val = value; |
416 | return IIO_VAL_INT; |
417 | |
418 | case IIO_TEMP: |
419 | mutex_lock(&sunrise->lock); |
420 | ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG, |
421 | val: &value); |
422 | mutex_unlock(lock: &sunrise->lock); |
423 | |
424 | if (ret) |
425 | return ret; |
426 | |
427 | *val = value; |
428 | return IIO_VAL_INT; |
429 | |
430 | default: |
431 | return -EINVAL; |
432 | } |
433 | |
434 | case IIO_CHAN_INFO_SCALE: |
435 | switch (chan->type) { |
436 | case IIO_CONCENTRATION: |
437 | /* |
438 | * 1 / 10^4 to comply with IIO scale for CO2 |
439 | * (percentage). The chip CO2 reading range is [400 - |
440 | * 5000] ppm which corresponds to [0,004 - 0,5] %. |
441 | */ |
442 | *val = 1; |
443 | *val2 = 10000; |
444 | return IIO_VAL_FRACTIONAL; |
445 | |
446 | case IIO_TEMP: |
447 | /* x10 to comply with IIO scale (millidegrees celsius). */ |
448 | *val = 10; |
449 | return IIO_VAL_INT; |
450 | |
451 | default: |
452 | return -EINVAL; |
453 | } |
454 | |
455 | default: |
456 | return -EINVAL; |
457 | } |
458 | } |
459 | |
460 | static const struct iio_info sunrise_info = { |
461 | .read_raw = sunrise_read_raw, |
462 | }; |
463 | |
464 | static const struct regmap_bus sunrise_regmap_bus = { |
465 | .read = sunrise_regmap_read, |
466 | .write = sunrise_regmap_write, |
467 | }; |
468 | |
469 | static const struct regmap_config sunrise_regmap_config = { |
470 | .reg_bits = 8, |
471 | .val_bits = 8, |
472 | }; |
473 | |
474 | static int sunrise_probe(struct i2c_client *client) |
475 | { |
476 | struct sunrise_dev *sunrise; |
477 | struct iio_dev *iio_dev; |
478 | |
479 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
480 | I2C_FUNC_SMBUS_BLOCK_DATA)) { |
481 | dev_err(&client->dev, |
482 | "Adapter does not support required functionalities\n" ); |
483 | return -EOPNOTSUPP; |
484 | } |
485 | |
486 | iio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*sunrise)); |
487 | if (!iio_dev) |
488 | return -ENOMEM; |
489 | |
490 | sunrise = iio_priv(indio_dev: iio_dev); |
491 | sunrise->client = client; |
492 | mutex_init(&sunrise->lock); |
493 | |
494 | i2c_set_clientdata(client, data: sunrise); |
495 | |
496 | sunrise->regmap = devm_regmap_init(&client->dev, &sunrise_regmap_bus, |
497 | client, &sunrise_regmap_config); |
498 | if (IS_ERR(ptr: sunrise->regmap)) { |
499 | dev_err(&client->dev, "Failed to initialize regmap\n" ); |
500 | return PTR_ERR(ptr: sunrise->regmap); |
501 | } |
502 | |
503 | /* |
504 | * The chip nacks the wake up message. If the adapter does not support |
505 | * protocol mangling do not set the I2C_M_IGNORE_NAK flag at the expense |
506 | * of possible cruft in the logs. |
507 | */ |
508 | if (i2c_check_functionality(adap: client->adapter, I2C_FUNC_PROTOCOL_MANGLING)) |
509 | sunrise->ignore_nak = true; |
510 | |
511 | iio_dev->info = &sunrise_info; |
512 | iio_dev->name = DRIVER_NAME; |
513 | iio_dev->channels = sunrise_channels; |
514 | iio_dev->num_channels = ARRAY_SIZE(sunrise_channels); |
515 | iio_dev->modes = INDIO_DIRECT_MODE; |
516 | |
517 | return devm_iio_device_register(&client->dev, iio_dev); |
518 | } |
519 | |
520 | static const struct of_device_id sunrise_of_match[] = { |
521 | { .compatible = "senseair,sunrise-006-0-0007" }, |
522 | {} |
523 | }; |
524 | MODULE_DEVICE_TABLE(of, sunrise_of_match); |
525 | |
526 | static struct i2c_driver sunrise_driver = { |
527 | .driver = { |
528 | .name = DRIVER_NAME, |
529 | .of_match_table = sunrise_of_match, |
530 | }, |
531 | .probe = sunrise_probe, |
532 | }; |
533 | module_i2c_driver(sunrise_driver); |
534 | |
535 | MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>" ); |
536 | MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver" ); |
537 | MODULE_LICENSE("GPL v2" ); |
538 | |