1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
4  *
5  * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
6  * Copyright (c) 2015 Essensium NV
7  * Copyright (c) 2015 Melexis
8  *
9  * Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
10  *
11  * (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
12  *
13  * To wake up from sleep mode, the SDA line must be held low while SCL is high
14  * for at least 33ms.  This is achieved with an extra GPIO that can be connected
15  * directly to the SDA line.  In normal operation, the GPIO is set as input and
16  * will not interfere in I2C communication.  While the GPIO is driven low, the
17  * i2c adapter is locked since it cannot be used by other clients.  The SCL line
18  * always has a pull-up so we do not need an extra GPIO to drive it high.  If
19  * the "wakeup" GPIO is not given, power management will be disabled.
20  */
21 
22 #include <linux/err.h>
23 #include <linux/i2c.h>
24 #include <linux/module.h>
25 #include <linux/delay.h>
26 #include <linux/jiffies.h>
27 #include <linux/gpio/consumer.h>
28 #include <linux/pm_runtime.h>
29 
30 #include <linux/iio/iio.h>
31 #include <linux/iio/sysfs.h>
32 
33 #define MLX90614_OP_RAM		0x00
34 #define MLX90614_OP_EEPROM	0x20
35 #define MLX90614_OP_SLEEP	0xff
36 
37 /* RAM offsets with 16-bit data, MSB first */
38 #define MLX90614_RAW1	(MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
39 #define MLX90614_RAW2	(MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
40 #define MLX90614_TA	(MLX90614_OP_RAM | 0x06) /* ambient temperature */
41 #define MLX90614_TOBJ1	(MLX90614_OP_RAM | 0x07) /* object 1 temperature */
42 #define MLX90614_TOBJ2	(MLX90614_OP_RAM | 0x08) /* object 2 temperature */
43 
44 /* EEPROM offsets with 16-bit data, MSB first */
45 #define MLX90614_EMISSIVITY	(MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
46 #define MLX90614_CONFIG		(MLX90614_OP_EEPROM | 0x05) /* configuration register */
47 
48 /* Control bits in configuration register */
49 #define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
50 #define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
51 #define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
52 #define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
53 #define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
54 #define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
55 #define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
56 #define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
57 
58 /* Timings (in ms) */
59 #define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
60 #define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
61 #define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
62 
63 #define MLX90614_AUTOSLEEP_DELAY 5000 /* default autosleep delay */
64 
65 /* Magic constants */
66 #define MLX90614_CONST_OFFSET_DEC -13657 /* decimal part of the Kelvin offset */
67 #define MLX90614_CONST_OFFSET_REM 500000 /* remainder of offset (273.15*50) */
68 #define MLX90614_CONST_SCALE 20 /* Scale in milliKelvin (0.02 * 1000) */
69 #define MLX90614_CONST_RAW_EMISSIVITY_MAX 65535 /* max value for emissivity */
70 #define MLX90614_CONST_EMISSIVITY_RESOLUTION 15259 /* 1/65535 ~ 0.000015259 */
71 #define MLX90614_CONST_FIR 0x7 /* Fixed value for FIR part of low pass filter */
72 
73 struct mlx90614_data {
74 	struct i2c_client *client;
75 	struct mutex lock; /* for EEPROM access only */
76 	struct gpio_desc *wakeup_gpio; /* NULL to disable sleep/wake-up */
77 	unsigned long ready_timestamp; /* in jiffies */
78 };
79 
80 /* Bandwidth values for IIR filtering */
81 static const int mlx90614_iir_values[] = {77, 31, 20, 15, 723, 153, 110, 86};
82 static IIO_CONST_ATTR(in_temp_object_filter_low_pass_3db_frequency_available,
83 		      "0.15 0.20 0.31 0.77 0.86 1.10 1.53 7.23");
84 
85 static struct attribute *mlx90614_attributes[] = {
86 	&iio_const_attr_in_temp_object_filter_low_pass_3db_frequency_available.dev_attr.attr,
87 	NULL,
88 };
89 
90 static const struct attribute_group mlx90614_attr_group = {
91 	.attrs = mlx90614_attributes,
92 };
93 
94 /*
95  * Erase an address and write word.
96  * The mutex must be locked before calling.
97  */
98 static s32 mlx90614_write_word(const struct i2c_client *client, u8 command,
99 			       u16 value)
100 {
101 	/*
102 	 * Note: The mlx90614 requires a PEC on writing but does not send us a
103 	 * valid PEC on reading.  Hence, we cannot set I2C_CLIENT_PEC in
104 	 * i2c_client.flags.  As a workaround, we use i2c_smbus_xfer here.
105 	 */
106 	union i2c_smbus_data data;
107 	s32 ret;
108 
109 	dev_dbg(&client->dev, "Writing 0x%x to address 0x%x", value, command);
110 
111 	data.word = 0x0000; /* erase command */
112 	ret = i2c_smbus_xfer(client->adapter, client->addr,
113 			     client->flags | I2C_CLIENT_PEC,
114 			     I2C_SMBUS_WRITE, command,
115 			     I2C_SMBUS_WORD_DATA, &data);
116 	if (ret < 0)
117 		return ret;
118 
119 	msleep(MLX90614_TIMING_EEPROM);
120 
121 	data.word = value; /* actual write */
122 	ret = i2c_smbus_xfer(client->adapter, client->addr,
123 			     client->flags | I2C_CLIENT_PEC,
124 			     I2C_SMBUS_WRITE, command,
125 			     I2C_SMBUS_WORD_DATA, &data);
126 
127 	msleep(MLX90614_TIMING_EEPROM);
128 
129 	return ret;
130 }
131 
132 /*
133  * Find the IIR value inside mlx90614_iir_values array and return its position
134  * which is equivalent to the bit value in sensor register
135  */
136 static inline s32 mlx90614_iir_search(const struct i2c_client *client,
137 				      int value)
138 {
139 	int i;
140 	s32 ret;
141 
142 	for (i = 0; i < ARRAY_SIZE(mlx90614_iir_values); ++i) {
143 		if (value == mlx90614_iir_values[i])
144 			break;
145 	}
146 
147 	if (i == ARRAY_SIZE(mlx90614_iir_values))
148 		return -EINVAL;
149 
150 	/*
151 	 * CONFIG register values must not be changed so
152 	 * we must read them before we actually write
153 	 * changes
154 	 */
155 	ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
156 	if (ret < 0)
157 		return ret;
158 
159 	ret &= ~MLX90614_CONFIG_FIR_MASK;
160 	ret |= MLX90614_CONST_FIR << MLX90614_CONFIG_FIR_SHIFT;
161 	ret &= ~MLX90614_CONFIG_IIR_MASK;
162 	ret |= i << MLX90614_CONFIG_IIR_SHIFT;
163 
164 	/* Write changed values */
165 	ret = mlx90614_write_word(client, MLX90614_CONFIG, ret);
166 	return ret;
167 }
168 
169 #ifdef CONFIG_PM
170 /*
171  * If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since
172  * the last wake-up.  This is normally only needed to get a valid temperature
173  * reading.  EEPROM access does not need such delay.
174  * Return 0 on success, <0 on error.
175  */
176 static int mlx90614_power_get(struct mlx90614_data *data, bool startup)
177 {
178 	unsigned long now;
179 
180 	if (!data->wakeup_gpio)
181 		return 0;
182 
183 	pm_runtime_get_sync(&data->client->dev);
184 
185 	if (startup) {
186 		now = jiffies;
187 		if (time_before(now, data->ready_timestamp) &&
188 		    msleep_interruptible(jiffies_to_msecs(
189 				data->ready_timestamp - now)) != 0) {
190 			pm_runtime_put_autosuspend(&data->client->dev);
191 			return -EINTR;
192 		}
193 	}
194 
195 	return 0;
196 }
197 
198 static void mlx90614_power_put(struct mlx90614_data *data)
199 {
200 	if (!data->wakeup_gpio)
201 		return;
202 
203 	pm_runtime_mark_last_busy(&data->client->dev);
204 	pm_runtime_put_autosuspend(&data->client->dev);
205 }
206 #else
207 static inline int mlx90614_power_get(struct mlx90614_data *data, bool startup)
208 {
209 	return 0;
210 }
211 
212 static inline void mlx90614_power_put(struct mlx90614_data *data)
213 {
214 }
215 #endif
216 
217 static int mlx90614_read_raw(struct iio_dev *indio_dev,
218 			    struct iio_chan_spec const *channel, int *val,
219 			    int *val2, long mask)
220 {
221 	struct mlx90614_data *data = iio_priv(indio_dev);
222 	u8 cmd;
223 	s32 ret;
224 
225 	switch (mask) {
226 	case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
227 		switch (channel->channel2) {
228 		case IIO_MOD_TEMP_AMBIENT:
229 			cmd = MLX90614_TA;
230 			break;
231 		case IIO_MOD_TEMP_OBJECT:
232 			switch (channel->channel) {
233 			case 0:
234 				cmd = MLX90614_TOBJ1;
235 				break;
236 			case 1:
237 				cmd = MLX90614_TOBJ2;
238 				break;
239 			default:
240 				return -EINVAL;
241 			}
242 			break;
243 		default:
244 			return -EINVAL;
245 		}
246 
247 		ret = mlx90614_power_get(data, true);
248 		if (ret < 0)
249 			return ret;
250 		ret = i2c_smbus_read_word_data(data->client, cmd);
251 		mlx90614_power_put(data);
252 
253 		if (ret < 0)
254 			return ret;
255 
256 		/* MSB is an error flag */
257 		if (ret & 0x8000)
258 			return -EIO;
259 
260 		*val = ret;
261 		return IIO_VAL_INT;
262 	case IIO_CHAN_INFO_OFFSET:
263 		*val = MLX90614_CONST_OFFSET_DEC;
264 		*val2 = MLX90614_CONST_OFFSET_REM;
265 		return IIO_VAL_INT_PLUS_MICRO;
266 	case IIO_CHAN_INFO_SCALE:
267 		*val = MLX90614_CONST_SCALE;
268 		return IIO_VAL_INT;
269 	case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
270 		mlx90614_power_get(data, false);
271 		mutex_lock(&data->lock);
272 		ret = i2c_smbus_read_word_data(data->client,
273 					       MLX90614_EMISSIVITY);
274 		mutex_unlock(&data->lock);
275 		mlx90614_power_put(data);
276 
277 		if (ret < 0)
278 			return ret;
279 
280 		if (ret == MLX90614_CONST_RAW_EMISSIVITY_MAX) {
281 			*val = 1;
282 			*val2 = 0;
283 		} else {
284 			*val = 0;
285 			*val2 = ret * MLX90614_CONST_EMISSIVITY_RESOLUTION;
286 		}
287 		return IIO_VAL_INT_PLUS_NANO;
288 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR setting with
289 							     FIR = 1024 */
290 		mlx90614_power_get(data, false);
291 		mutex_lock(&data->lock);
292 		ret = i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
293 		mutex_unlock(&data->lock);
294 		mlx90614_power_put(data);
295 
296 		if (ret < 0)
297 			return ret;
298 
299 		*val = mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] / 100;
300 		*val2 = (mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] % 100) *
301 			10000;
302 		return IIO_VAL_INT_PLUS_MICRO;
303 	default:
304 		return -EINVAL;
305 	}
306 }
307 
308 static int mlx90614_write_raw(struct iio_dev *indio_dev,
309 			     struct iio_chan_spec const *channel, int val,
310 			     int val2, long mask)
311 {
312 	struct mlx90614_data *data = iio_priv(indio_dev);
313 	s32 ret;
314 
315 	switch (mask) {
316 	case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
317 		if (val < 0 || val2 < 0 || val > 1 || (val == 1 && val2 != 0))
318 			return -EINVAL;
319 		val = val * MLX90614_CONST_RAW_EMISSIVITY_MAX +
320 			val2 / MLX90614_CONST_EMISSIVITY_RESOLUTION;
321 
322 		mlx90614_power_get(data, false);
323 		mutex_lock(&data->lock);
324 		ret = mlx90614_write_word(data->client, MLX90614_EMISSIVITY,
325 					  val);
326 		mutex_unlock(&data->lock);
327 		mlx90614_power_put(data);
328 
329 		return ret;
330 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR Filter setting */
331 		if (val < 0 || val2 < 0)
332 			return -EINVAL;
333 
334 		mlx90614_power_get(data, false);
335 		mutex_lock(&data->lock);
336 		ret = mlx90614_iir_search(data->client,
337 					  val * 100 + val2 / 10000);
338 		mutex_unlock(&data->lock);
339 		mlx90614_power_put(data);
340 
341 		return ret;
342 	default:
343 		return -EINVAL;
344 	}
345 }
346 
347 static int mlx90614_write_raw_get_fmt(struct iio_dev *indio_dev,
348 				     struct iio_chan_spec const *channel,
349 				     long mask)
350 {
351 	switch (mask) {
352 	case IIO_CHAN_INFO_CALIBEMISSIVITY:
353 		return IIO_VAL_INT_PLUS_NANO;
354 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
355 		return IIO_VAL_INT_PLUS_MICRO;
356 	default:
357 		return -EINVAL;
358 	}
359 }
360 
361 static const struct iio_chan_spec mlx90614_channels[] = {
362 	{
363 		.type = IIO_TEMP,
364 		.modified = 1,
365 		.channel2 = IIO_MOD_TEMP_AMBIENT,
366 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
367 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
368 		    BIT(IIO_CHAN_INFO_SCALE),
369 	},
370 	{
371 		.type = IIO_TEMP,
372 		.modified = 1,
373 		.channel2 = IIO_MOD_TEMP_OBJECT,
374 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
375 		    BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
376 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
377 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
378 		    BIT(IIO_CHAN_INFO_SCALE),
379 	},
380 	{
381 		.type = IIO_TEMP,
382 		.indexed = 1,
383 		.modified = 1,
384 		.channel = 1,
385 		.channel2 = IIO_MOD_TEMP_OBJECT,
386 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
387 		    BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) |
388 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
389 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
390 		    BIT(IIO_CHAN_INFO_SCALE),
391 	},
392 };
393 
394 static const struct iio_info mlx90614_info = {
395 	.read_raw = mlx90614_read_raw,
396 	.write_raw = mlx90614_write_raw,
397 	.write_raw_get_fmt = mlx90614_write_raw_get_fmt,
398 	.attrs = &mlx90614_attr_group,
399 };
400 
401 #ifdef CONFIG_PM
402 static int mlx90614_sleep(struct mlx90614_data *data)
403 {
404 	s32 ret;
405 
406 	if (!data->wakeup_gpio) {
407 		dev_dbg(&data->client->dev, "Sleep disabled");
408 		return -ENOSYS;
409 	}
410 
411 	dev_dbg(&data->client->dev, "Requesting sleep");
412 
413 	mutex_lock(&data->lock);
414 	ret = i2c_smbus_xfer(data->client->adapter, data->client->addr,
415 			     data->client->flags | I2C_CLIENT_PEC,
416 			     I2C_SMBUS_WRITE, MLX90614_OP_SLEEP,
417 			     I2C_SMBUS_BYTE, NULL);
418 	mutex_unlock(&data->lock);
419 
420 	return ret;
421 }
422 
423 static int mlx90614_wakeup(struct mlx90614_data *data)
424 {
425 	if (!data->wakeup_gpio) {
426 		dev_dbg(&data->client->dev, "Wake-up disabled");
427 		return -ENOSYS;
428 	}
429 
430 	dev_dbg(&data->client->dev, "Requesting wake-up");
431 
432 	i2c_lock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
433 	gpiod_direction_output(data->wakeup_gpio, 0);
434 	msleep(MLX90614_TIMING_WAKEUP);
435 	gpiod_direction_input(data->wakeup_gpio);
436 	i2c_unlock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
437 
438 	data->ready_timestamp = jiffies +
439 			msecs_to_jiffies(MLX90614_TIMING_STARTUP);
440 
441 	/*
442 	 * Quirk: the i2c controller may get confused right after the
443 	 * wake-up signal has been sent.  As a workaround, do a dummy read.
444 	 * If the read fails, the controller will probably be reset so that
445 	 * further reads will work.
446 	 */
447 	i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
448 
449 	return 0;
450 }
451 
452 /* Return wake-up GPIO or NULL if sleep functionality should be disabled. */
453 static struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
454 {
455 	struct gpio_desc *gpio;
456 
457 	if (!i2c_check_functionality(client->adapter,
458 						I2C_FUNC_SMBUS_WRITE_BYTE)) {
459 		dev_info(&client->dev,
460 			 "i2c adapter does not support SMBUS_WRITE_BYTE, sleep disabled");
461 		return NULL;
462 	}
463 
464 	gpio = devm_gpiod_get_optional(&client->dev, "wakeup", GPIOD_IN);
465 
466 	if (IS_ERR(gpio)) {
467 		dev_warn(&client->dev,
468 			 "gpio acquisition failed with error %ld, sleep disabled",
469 			 PTR_ERR(gpio));
470 		return NULL;
471 	} else if (!gpio) {
472 		dev_info(&client->dev,
473 			 "wakeup-gpio not found, sleep disabled");
474 	}
475 
476 	return gpio;
477 }
478 #else
479 static inline int mlx90614_sleep(struct mlx90614_data *data)
480 {
481 	return -ENOSYS;
482 }
483 static inline int mlx90614_wakeup(struct mlx90614_data *data)
484 {
485 	return -ENOSYS;
486 }
487 static inline struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
488 {
489 	return NULL;
490 }
491 #endif
492 
493 /* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
494 static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
495 {
496 	s32 ret;
497 
498 	ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
499 
500 	if (ret < 0)
501 		return ret;
502 
503 	return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
504 }
505 
506 static int mlx90614_probe(struct i2c_client *client,
507 			 const struct i2c_device_id *id)
508 {
509 	struct iio_dev *indio_dev;
510 	struct mlx90614_data *data;
511 	int ret;
512 
513 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
514 		return -EOPNOTSUPP;
515 
516 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
517 	if (!indio_dev)
518 		return -ENOMEM;
519 
520 	data = iio_priv(indio_dev);
521 	i2c_set_clientdata(client, indio_dev);
522 	data->client = client;
523 	mutex_init(&data->lock);
524 	data->wakeup_gpio = mlx90614_probe_wakeup(client);
525 
526 	mlx90614_wakeup(data);
527 
528 	indio_dev->dev.parent = &client->dev;
529 	indio_dev->name = id->name;
530 	indio_dev->modes = INDIO_DIRECT_MODE;
531 	indio_dev->info = &mlx90614_info;
532 
533 	ret = mlx90614_probe_num_ir_sensors(client);
534 	switch (ret) {
535 	case 0:
536 		dev_dbg(&client->dev, "Found single sensor");
537 		indio_dev->channels = mlx90614_channels;
538 		indio_dev->num_channels = 2;
539 		break;
540 	case 1:
541 		dev_dbg(&client->dev, "Found dual sensor");
542 		indio_dev->channels = mlx90614_channels;
543 		indio_dev->num_channels = 3;
544 		break;
545 	default:
546 		return ret;
547 	}
548 
549 	if (data->wakeup_gpio) {
550 		pm_runtime_set_autosuspend_delay(&client->dev,
551 						 MLX90614_AUTOSLEEP_DELAY);
552 		pm_runtime_use_autosuspend(&client->dev);
553 		pm_runtime_set_active(&client->dev);
554 		pm_runtime_enable(&client->dev);
555 	}
556 
557 	return iio_device_register(indio_dev);
558 }
559 
560 static int mlx90614_remove(struct i2c_client *client)
561 {
562 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
563 	struct mlx90614_data *data = iio_priv(indio_dev);
564 
565 	iio_device_unregister(indio_dev);
566 
567 	if (data->wakeup_gpio) {
568 		pm_runtime_disable(&client->dev);
569 		if (!pm_runtime_status_suspended(&client->dev))
570 			mlx90614_sleep(data);
571 		pm_runtime_set_suspended(&client->dev);
572 	}
573 
574 	return 0;
575 }
576 
577 static const struct i2c_device_id mlx90614_id[] = {
578 	{ "mlx90614", 0 },
579 	{ }
580 };
581 MODULE_DEVICE_TABLE(i2c, mlx90614_id);
582 
583 static const struct of_device_id mlx90614_of_match[] = {
584 	{ .compatible = "melexis,mlx90614" },
585 	{ }
586 };
587 MODULE_DEVICE_TABLE(of, mlx90614_of_match);
588 
589 #ifdef CONFIG_PM_SLEEP
590 static int mlx90614_pm_suspend(struct device *dev)
591 {
592 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
593 	struct mlx90614_data *data = iio_priv(indio_dev);
594 
595 	if (data->wakeup_gpio && pm_runtime_active(dev))
596 		return mlx90614_sleep(data);
597 
598 	return 0;
599 }
600 
601 static int mlx90614_pm_resume(struct device *dev)
602 {
603 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
604 	struct mlx90614_data *data = iio_priv(indio_dev);
605 	int err;
606 
607 	if (data->wakeup_gpio) {
608 		err = mlx90614_wakeup(data);
609 		if (err < 0)
610 			return err;
611 
612 		pm_runtime_disable(dev);
613 		pm_runtime_set_active(dev);
614 		pm_runtime_enable(dev);
615 	}
616 
617 	return 0;
618 }
619 #endif
620 
621 #ifdef CONFIG_PM
622 static int mlx90614_pm_runtime_suspend(struct device *dev)
623 {
624 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
625 	struct mlx90614_data *data = iio_priv(indio_dev);
626 
627 	return mlx90614_sleep(data);
628 }
629 
630 static int mlx90614_pm_runtime_resume(struct device *dev)
631 {
632 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
633 	struct mlx90614_data *data = iio_priv(indio_dev);
634 
635 	return mlx90614_wakeup(data);
636 }
637 #endif
638 
639 static const struct dev_pm_ops mlx90614_pm_ops = {
640 	SET_SYSTEM_SLEEP_PM_OPS(mlx90614_pm_suspend, mlx90614_pm_resume)
641 	SET_RUNTIME_PM_OPS(mlx90614_pm_runtime_suspend,
642 			   mlx90614_pm_runtime_resume, NULL)
643 };
644 
645 static struct i2c_driver mlx90614_driver = {
646 	.driver = {
647 		.name	= "mlx90614",
648 		.of_match_table = mlx90614_of_match,
649 		.pm	= &mlx90614_pm_ops,
650 	},
651 	.probe = mlx90614_probe,
652 	.remove = mlx90614_remove,
653 	.id_table = mlx90614_id,
654 };
655 module_i2c_driver(mlx90614_driver);
656 
657 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
658 MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
659 MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
660 MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
661 MODULE_LICENSE("GPL");
662