1 /*
2  * mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
3  *
4  * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
5  * Copyright (c) 2015 Essensium NV
6  * Copyright (c) 2015 Melexis
7  *
8  * This file is subject to the terms and conditions of version 2 of
9  * the GNU General Public License.  See the file COPYING in the main
10  * directory of this archive for more details.
11  *
12  * Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
13  *
14  * (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
15  *
16  * To wake up from sleep mode, the SDA line must be held low while SCL is high
17  * for at least 33ms.  This is achieved with an extra GPIO that can be connected
18  * directly to the SDA line.  In normal operation, the GPIO is set as input and
19  * will not interfere in I2C communication.  While the GPIO is driven low, the
20  * i2c adapter is locked since it cannot be used by other clients.  The SCL line
21  * always has a pull-up so we do not need an extra GPIO to drive it high.  If
22  * the "wakeup" GPIO is not given, power management will be disabled.
23  *
24  */
25 
26 #include <linux/err.h>
27 #include <linux/i2c.h>
28 #include <linux/module.h>
29 #include <linux/delay.h>
30 #include <linux/jiffies.h>
31 #include <linux/gpio/consumer.h>
32 #include <linux/pm_runtime.h>
33 
34 #include <linux/iio/iio.h>
35 #include <linux/iio/sysfs.h>
36 
37 #define MLX90614_OP_RAM		0x00
38 #define MLX90614_OP_EEPROM	0x20
39 #define MLX90614_OP_SLEEP	0xff
40 
41 /* RAM offsets with 16-bit data, MSB first */
42 #define MLX90614_RAW1	(MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
43 #define MLX90614_RAW2	(MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
44 #define MLX90614_TA	(MLX90614_OP_RAM | 0x06) /* ambient temperature */
45 #define MLX90614_TOBJ1	(MLX90614_OP_RAM | 0x07) /* object 1 temperature */
46 #define MLX90614_TOBJ2	(MLX90614_OP_RAM | 0x08) /* object 2 temperature */
47 
48 /* EEPROM offsets with 16-bit data, MSB first */
49 #define MLX90614_EMISSIVITY	(MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
50 #define MLX90614_CONFIG		(MLX90614_OP_EEPROM | 0x05) /* configuration register */
51 
52 /* Control bits in configuration register */
53 #define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
54 #define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
55 #define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
56 #define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
57 #define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
58 #define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
59 #define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
60 #define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
61 
62 /* Timings (in ms) */
63 #define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
64 #define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
65 #define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
66 
67 #define MLX90614_AUTOSLEEP_DELAY 5000 /* default autosleep delay */
68 
69 /* Magic constants */
70 #define MLX90614_CONST_OFFSET_DEC -13657 /* decimal part of the Kelvin offset */
71 #define MLX90614_CONST_OFFSET_REM 500000 /* remainder of offset (273.15*50) */
72 #define MLX90614_CONST_SCALE 20 /* Scale in milliKelvin (0.02 * 1000) */
73 #define MLX90614_CONST_RAW_EMISSIVITY_MAX 65535 /* max value for emissivity */
74 #define MLX90614_CONST_EMISSIVITY_RESOLUTION 15259 /* 1/65535 ~ 0.000015259 */
75 #define MLX90614_CONST_FIR 0x7 /* Fixed value for FIR part of low pass filter */
76 
77 struct mlx90614_data {
78 	struct i2c_client *client;
79 	struct mutex lock; /* for EEPROM access only */
80 	struct gpio_desc *wakeup_gpio; /* NULL to disable sleep/wake-up */
81 	unsigned long ready_timestamp; /* in jiffies */
82 };
83 
84 /* Bandwidth values for IIR filtering */
85 static const int mlx90614_iir_values[] = {77, 31, 20, 15, 723, 153, 110, 86};
86 static IIO_CONST_ATTR(in_temp_object_filter_low_pass_3db_frequency_available,
87 		      "0.15 0.20 0.31 0.77 0.86 1.10 1.53 7.23");
88 
89 static struct attribute *mlx90614_attributes[] = {
90 	&iio_const_attr_in_temp_object_filter_low_pass_3db_frequency_available.dev_attr.attr,
91 	NULL,
92 };
93 
94 static const struct attribute_group mlx90614_attr_group = {
95 	.attrs = mlx90614_attributes,
96 };
97 
98 /*
99  * Erase an address and write word.
100  * The mutex must be locked before calling.
101  */
102 static s32 mlx90614_write_word(const struct i2c_client *client, u8 command,
103 			       u16 value)
104 {
105 	/*
106 	 * Note: The mlx90614 requires a PEC on writing but does not send us a
107 	 * valid PEC on reading.  Hence, we cannot set I2C_CLIENT_PEC in
108 	 * i2c_client.flags.  As a workaround, we use i2c_smbus_xfer here.
109 	 */
110 	union i2c_smbus_data data;
111 	s32 ret;
112 
113 	dev_dbg(&client->dev, "Writing 0x%x to address 0x%x", value, command);
114 
115 	data.word = 0x0000; /* erase command */
116 	ret = i2c_smbus_xfer(client->adapter, client->addr,
117 			     client->flags | I2C_CLIENT_PEC,
118 			     I2C_SMBUS_WRITE, command,
119 			     I2C_SMBUS_WORD_DATA, &data);
120 	if (ret < 0)
121 		return ret;
122 
123 	msleep(MLX90614_TIMING_EEPROM);
124 
125 	data.word = value; /* actual write */
126 	ret = i2c_smbus_xfer(client->adapter, client->addr,
127 			     client->flags | I2C_CLIENT_PEC,
128 			     I2C_SMBUS_WRITE, command,
129 			     I2C_SMBUS_WORD_DATA, &data);
130 
131 	msleep(MLX90614_TIMING_EEPROM);
132 
133 	return ret;
134 }
135 
136 /*
137  * Find the IIR value inside mlx90614_iir_values array and return its position
138  * which is equivalent to the bit value in sensor register
139  */
140 static inline s32 mlx90614_iir_search(const struct i2c_client *client,
141 				      int value)
142 {
143 	int i;
144 	s32 ret;
145 
146 	for (i = 0; i < ARRAY_SIZE(mlx90614_iir_values); ++i) {
147 		if (value == mlx90614_iir_values[i])
148 			break;
149 	}
150 
151 	if (i == ARRAY_SIZE(mlx90614_iir_values))
152 		return -EINVAL;
153 
154 	/*
155 	 * CONFIG register values must not be changed so
156 	 * we must read them before we actually write
157 	 * changes
158 	 */
159 	ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
160 	if (ret < 0)
161 		return ret;
162 
163 	ret &= ~MLX90614_CONFIG_FIR_MASK;
164 	ret |= MLX90614_CONST_FIR << MLX90614_CONFIG_FIR_SHIFT;
165 	ret &= ~MLX90614_CONFIG_IIR_MASK;
166 	ret |= i << MLX90614_CONFIG_IIR_SHIFT;
167 
168 	/* Write changed values */
169 	ret = mlx90614_write_word(client, MLX90614_CONFIG, ret);
170 	return ret;
171 }
172 
173 #ifdef CONFIG_PM
174 /*
175  * If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since
176  * the last wake-up.  This is normally only needed to get a valid temperature
177  * reading.  EEPROM access does not need such delay.
178  * Return 0 on success, <0 on error.
179  */
180 static int mlx90614_power_get(struct mlx90614_data *data, bool startup)
181 {
182 	unsigned long now;
183 
184 	if (!data->wakeup_gpio)
185 		return 0;
186 
187 	pm_runtime_get_sync(&data->client->dev);
188 
189 	if (startup) {
190 		now = jiffies;
191 		if (time_before(now, data->ready_timestamp) &&
192 		    msleep_interruptible(jiffies_to_msecs(
193 				data->ready_timestamp - now)) != 0) {
194 			pm_runtime_put_autosuspend(&data->client->dev);
195 			return -EINTR;
196 		}
197 	}
198 
199 	return 0;
200 }
201 
202 static void mlx90614_power_put(struct mlx90614_data *data)
203 {
204 	if (!data->wakeup_gpio)
205 		return;
206 
207 	pm_runtime_mark_last_busy(&data->client->dev);
208 	pm_runtime_put_autosuspend(&data->client->dev);
209 }
210 #else
211 static inline int mlx90614_power_get(struct mlx90614_data *data, bool startup)
212 {
213 	return 0;
214 }
215 
216 static inline void mlx90614_power_put(struct mlx90614_data *data)
217 {
218 }
219 #endif
220 
221 static int mlx90614_read_raw(struct iio_dev *indio_dev,
222 			    struct iio_chan_spec const *channel, int *val,
223 			    int *val2, long mask)
224 {
225 	struct mlx90614_data *data = iio_priv(indio_dev);
226 	u8 cmd;
227 	s32 ret;
228 
229 	switch (mask) {
230 	case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
231 		switch (channel->channel2) {
232 		case IIO_MOD_TEMP_AMBIENT:
233 			cmd = MLX90614_TA;
234 			break;
235 		case IIO_MOD_TEMP_OBJECT:
236 			switch (channel->channel) {
237 			case 0:
238 				cmd = MLX90614_TOBJ1;
239 				break;
240 			case 1:
241 				cmd = MLX90614_TOBJ2;
242 				break;
243 			default:
244 				return -EINVAL;
245 			}
246 			break;
247 		default:
248 			return -EINVAL;
249 		}
250 
251 		ret = mlx90614_power_get(data, true);
252 		if (ret < 0)
253 			return ret;
254 		ret = i2c_smbus_read_word_data(data->client, cmd);
255 		mlx90614_power_put(data);
256 
257 		if (ret < 0)
258 			return ret;
259 
260 		/* MSB is an error flag */
261 		if (ret & 0x8000)
262 			return -EIO;
263 
264 		*val = ret;
265 		return IIO_VAL_INT;
266 	case IIO_CHAN_INFO_OFFSET:
267 		*val = MLX90614_CONST_OFFSET_DEC;
268 		*val2 = MLX90614_CONST_OFFSET_REM;
269 		return IIO_VAL_INT_PLUS_MICRO;
270 	case IIO_CHAN_INFO_SCALE:
271 		*val = MLX90614_CONST_SCALE;
272 		return IIO_VAL_INT;
273 	case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
274 		mlx90614_power_get(data, false);
275 		mutex_lock(&data->lock);
276 		ret = i2c_smbus_read_word_data(data->client,
277 					       MLX90614_EMISSIVITY);
278 		mutex_unlock(&data->lock);
279 		mlx90614_power_put(data);
280 
281 		if (ret < 0)
282 			return ret;
283 
284 		if (ret == MLX90614_CONST_RAW_EMISSIVITY_MAX) {
285 			*val = 1;
286 			*val2 = 0;
287 		} else {
288 			*val = 0;
289 			*val2 = ret * MLX90614_CONST_EMISSIVITY_RESOLUTION;
290 		}
291 		return IIO_VAL_INT_PLUS_NANO;
292 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR setting with
293 							     FIR = 1024 */
294 		mlx90614_power_get(data, false);
295 		mutex_lock(&data->lock);
296 		ret = i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
297 		mutex_unlock(&data->lock);
298 		mlx90614_power_put(data);
299 
300 		if (ret < 0)
301 			return ret;
302 
303 		*val = mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] / 100;
304 		*val2 = (mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] % 100) *
305 			10000;
306 		return IIO_VAL_INT_PLUS_MICRO;
307 	default:
308 		return -EINVAL;
309 	}
310 }
311 
312 static int mlx90614_write_raw(struct iio_dev *indio_dev,
313 			     struct iio_chan_spec const *channel, int val,
314 			     int val2, long mask)
315 {
316 	struct mlx90614_data *data = iio_priv(indio_dev);
317 	s32 ret;
318 
319 	switch (mask) {
320 	case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
321 		if (val < 0 || val2 < 0 || val > 1 || (val == 1 && val2 != 0))
322 			return -EINVAL;
323 		val = val * MLX90614_CONST_RAW_EMISSIVITY_MAX +
324 			val2 / MLX90614_CONST_EMISSIVITY_RESOLUTION;
325 
326 		mlx90614_power_get(data, false);
327 		mutex_lock(&data->lock);
328 		ret = mlx90614_write_word(data->client, MLX90614_EMISSIVITY,
329 					  val);
330 		mutex_unlock(&data->lock);
331 		mlx90614_power_put(data);
332 
333 		return ret;
334 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR Filter setting */
335 		if (val < 0 || val2 < 0)
336 			return -EINVAL;
337 
338 		mlx90614_power_get(data, false);
339 		mutex_lock(&data->lock);
340 		ret = mlx90614_iir_search(data->client,
341 					  val * 100 + val2 / 10000);
342 		mutex_unlock(&data->lock);
343 		mlx90614_power_put(data);
344 
345 		return ret;
346 	default:
347 		return -EINVAL;
348 	}
349 }
350 
351 static int mlx90614_write_raw_get_fmt(struct iio_dev *indio_dev,
352 				     struct iio_chan_spec const *channel,
353 				     long mask)
354 {
355 	switch (mask) {
356 	case IIO_CHAN_INFO_CALIBEMISSIVITY:
357 		return IIO_VAL_INT_PLUS_NANO;
358 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
359 		return IIO_VAL_INT_PLUS_MICRO;
360 	default:
361 		return -EINVAL;
362 	}
363 }
364 
365 static const struct iio_chan_spec mlx90614_channels[] = {
366 	{
367 		.type = IIO_TEMP,
368 		.modified = 1,
369 		.channel2 = IIO_MOD_TEMP_AMBIENT,
370 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
371 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
372 		    BIT(IIO_CHAN_INFO_SCALE),
373 	},
374 	{
375 		.type = IIO_TEMP,
376 		.modified = 1,
377 		.channel2 = IIO_MOD_TEMP_OBJECT,
378 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
379 		    BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
380 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
381 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
382 		    BIT(IIO_CHAN_INFO_SCALE),
383 	},
384 	{
385 		.type = IIO_TEMP,
386 		.indexed = 1,
387 		.modified = 1,
388 		.channel = 1,
389 		.channel2 = IIO_MOD_TEMP_OBJECT,
390 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
391 		    BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
392 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
393 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
394 		    BIT(IIO_CHAN_INFO_SCALE),
395 	},
396 };
397 
398 static const struct iio_info mlx90614_info = {
399 	.read_raw = mlx90614_read_raw,
400 	.write_raw = mlx90614_write_raw,
401 	.write_raw_get_fmt = mlx90614_write_raw_get_fmt,
402 	.attrs = &mlx90614_attr_group,
403 };
404 
405 #ifdef CONFIG_PM
406 static int mlx90614_sleep(struct mlx90614_data *data)
407 {
408 	s32 ret;
409 
410 	if (!data->wakeup_gpio) {
411 		dev_dbg(&data->client->dev, "Sleep disabled");
412 		return -ENOSYS;
413 	}
414 
415 	dev_dbg(&data->client->dev, "Requesting sleep");
416 
417 	mutex_lock(&data->lock);
418 	ret = i2c_smbus_xfer(data->client->adapter, data->client->addr,
419 			     data->client->flags | I2C_CLIENT_PEC,
420 			     I2C_SMBUS_WRITE, MLX90614_OP_SLEEP,
421 			     I2C_SMBUS_BYTE, NULL);
422 	mutex_unlock(&data->lock);
423 
424 	return ret;
425 }
426 
427 static int mlx90614_wakeup(struct mlx90614_data *data)
428 {
429 	if (!data->wakeup_gpio) {
430 		dev_dbg(&data->client->dev, "Wake-up disabled");
431 		return -ENOSYS;
432 	}
433 
434 	dev_dbg(&data->client->dev, "Requesting wake-up");
435 
436 	i2c_lock_adapter(data->client->adapter);
437 	gpiod_direction_output(data->wakeup_gpio, 0);
438 	msleep(MLX90614_TIMING_WAKEUP);
439 	gpiod_direction_input(data->wakeup_gpio);
440 	i2c_unlock_adapter(data->client->adapter);
441 
442 	data->ready_timestamp = jiffies +
443 			msecs_to_jiffies(MLX90614_TIMING_STARTUP);
444 
445 	/*
446 	 * Quirk: the i2c controller may get confused right after the
447 	 * wake-up signal has been sent.  As a workaround, do a dummy read.
448 	 * If the read fails, the controller will probably be reset so that
449 	 * further reads will work.
450 	 */
451 	i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
452 
453 	return 0;
454 }
455 
456 /* Return wake-up GPIO or NULL if sleep functionality should be disabled. */
457 static struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
458 {
459 	struct gpio_desc *gpio;
460 
461 	if (!i2c_check_functionality(client->adapter,
462 						I2C_FUNC_SMBUS_WRITE_BYTE)) {
463 		dev_info(&client->dev,
464 			 "i2c adapter does not support SMBUS_WRITE_BYTE, sleep disabled");
465 		return NULL;
466 	}
467 
468 	gpio = devm_gpiod_get_optional(&client->dev, "wakeup", GPIOD_IN);
469 
470 	if (IS_ERR(gpio)) {
471 		dev_warn(&client->dev,
472 			 "gpio acquisition failed with error %ld, sleep disabled",
473 			 PTR_ERR(gpio));
474 		return NULL;
475 	} else if (!gpio) {
476 		dev_info(&client->dev,
477 			 "wakeup-gpio not found, sleep disabled");
478 	}
479 
480 	return gpio;
481 }
482 #else
483 static inline int mlx90614_sleep(struct mlx90614_data *data)
484 {
485 	return -ENOSYS;
486 }
487 static inline int mlx90614_wakeup(struct mlx90614_data *data)
488 {
489 	return -ENOSYS;
490 }
491 static inline struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
492 {
493 	return NULL;
494 }
495 #endif
496 
497 /* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
498 static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
499 {
500 	s32 ret;
501 
502 	ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
503 
504 	if (ret < 0)
505 		return ret;
506 
507 	return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
508 }
509 
510 static int mlx90614_probe(struct i2c_client *client,
511 			 const struct i2c_device_id *id)
512 {
513 	struct iio_dev *indio_dev;
514 	struct mlx90614_data *data;
515 	int ret;
516 
517 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
518 		return -EOPNOTSUPP;
519 
520 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
521 	if (!indio_dev)
522 		return -ENOMEM;
523 
524 	data = iio_priv(indio_dev);
525 	i2c_set_clientdata(client, indio_dev);
526 	data->client = client;
527 	mutex_init(&data->lock);
528 	data->wakeup_gpio = mlx90614_probe_wakeup(client);
529 
530 	mlx90614_wakeup(data);
531 
532 	indio_dev->dev.parent = &client->dev;
533 	indio_dev->name = id->name;
534 	indio_dev->modes = INDIO_DIRECT_MODE;
535 	indio_dev->info = &mlx90614_info;
536 
537 	ret = mlx90614_probe_num_ir_sensors(client);
538 	switch (ret) {
539 	case 0:
540 		dev_dbg(&client->dev, "Found single sensor");
541 		indio_dev->channels = mlx90614_channels;
542 		indio_dev->num_channels = 2;
543 		break;
544 	case 1:
545 		dev_dbg(&client->dev, "Found dual sensor");
546 		indio_dev->channels = mlx90614_channels;
547 		indio_dev->num_channels = 3;
548 		break;
549 	default:
550 		return ret;
551 	}
552 
553 	if (data->wakeup_gpio) {
554 		pm_runtime_set_autosuspend_delay(&client->dev,
555 						 MLX90614_AUTOSLEEP_DELAY);
556 		pm_runtime_use_autosuspend(&client->dev);
557 		pm_runtime_set_active(&client->dev);
558 		pm_runtime_enable(&client->dev);
559 	}
560 
561 	return iio_device_register(indio_dev);
562 }
563 
564 static int mlx90614_remove(struct i2c_client *client)
565 {
566 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
567 	struct mlx90614_data *data = iio_priv(indio_dev);
568 
569 	iio_device_unregister(indio_dev);
570 
571 	if (data->wakeup_gpio) {
572 		pm_runtime_disable(&client->dev);
573 		if (!pm_runtime_status_suspended(&client->dev))
574 			mlx90614_sleep(data);
575 		pm_runtime_set_suspended(&client->dev);
576 	}
577 
578 	return 0;
579 }
580 
581 static const struct i2c_device_id mlx90614_id[] = {
582 	{ "mlx90614", 0 },
583 	{ }
584 };
585 MODULE_DEVICE_TABLE(i2c, mlx90614_id);
586 
587 static const struct of_device_id mlx90614_of_match[] = {
588 	{ .compatible = "melexis,mlx90614" },
589 	{ }
590 };
591 MODULE_DEVICE_TABLE(of, mlx90614_of_match);
592 
593 #ifdef CONFIG_PM_SLEEP
594 static int mlx90614_pm_suspend(struct device *dev)
595 {
596 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
597 	struct mlx90614_data *data = iio_priv(indio_dev);
598 
599 	if (data->wakeup_gpio && pm_runtime_active(dev))
600 		return mlx90614_sleep(data);
601 
602 	return 0;
603 }
604 
605 static int mlx90614_pm_resume(struct device *dev)
606 {
607 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
608 	struct mlx90614_data *data = iio_priv(indio_dev);
609 	int err;
610 
611 	if (data->wakeup_gpio) {
612 		err = mlx90614_wakeup(data);
613 		if (err < 0)
614 			return err;
615 
616 		pm_runtime_disable(dev);
617 		pm_runtime_set_active(dev);
618 		pm_runtime_enable(dev);
619 	}
620 
621 	return 0;
622 }
623 #endif
624 
625 #ifdef CONFIG_PM
626 static int mlx90614_pm_runtime_suspend(struct device *dev)
627 {
628 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
629 	struct mlx90614_data *data = iio_priv(indio_dev);
630 
631 	return mlx90614_sleep(data);
632 }
633 
634 static int mlx90614_pm_runtime_resume(struct device *dev)
635 {
636 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
637 	struct mlx90614_data *data = iio_priv(indio_dev);
638 
639 	return mlx90614_wakeup(data);
640 }
641 #endif
642 
643 static const struct dev_pm_ops mlx90614_pm_ops = {
644 	SET_SYSTEM_SLEEP_PM_OPS(mlx90614_pm_suspend, mlx90614_pm_resume)
645 	SET_RUNTIME_PM_OPS(mlx90614_pm_runtime_suspend,
646 			   mlx90614_pm_runtime_resume, NULL)
647 };
648 
649 static struct i2c_driver mlx90614_driver = {
650 	.driver = {
651 		.name	= "mlx90614",
652 		.of_match_table = mlx90614_of_match,
653 		.pm	= &mlx90614_pm_ops,
654 	},
655 	.probe = mlx90614_probe,
656 	.remove = mlx90614_remove,
657 	.id_table = mlx90614_id,
658 };
659 module_i2c_driver(mlx90614_driver);
660 
661 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
662 MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
663 MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
664 MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
665 MODULE_LICENSE("GPL");
666