xref: /linux/drivers/iio/magnetometer/tmag5273.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for the TI TMAG5273 Low-Power Linear 3D Hall-Effect Sensor
4  *
5  * Copyright (C) 2022 WolfVision GmbH
6  *
7  * Author: Gerald Loacker <gerald.loacker@wolfvision.net>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/bits.h>
12 #include <linux/delay.h>
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/regmap.h>
16 #include <linux/pm_runtime.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 
21 #define TMAG5273_DEVICE_CONFIG_1	 0x00
22 #define TMAG5273_DEVICE_CONFIG_2	 0x01
23 #define TMAG5273_SENSOR_CONFIG_1	 0x02
24 #define TMAG5273_SENSOR_CONFIG_2	 0x03
25 #define TMAG5273_X_THR_CONFIG		 0x04
26 #define TMAG5273_Y_THR_CONFIG		 0x05
27 #define TMAG5273_Z_THR_CONFIG		 0x06
28 #define TMAG5273_T_CONFIG		 0x07
29 #define TMAG5273_INT_CONFIG_1		 0x08
30 #define TMAG5273_MAG_GAIN_CONFIG	 0x09
31 #define TMAG5273_MAG_OFFSET_CONFIG_1	 0x0A
32 #define TMAG5273_MAG_OFFSET_CONFIG_2	 0x0B
33 #define TMAG5273_I2C_ADDRESS		 0x0C
34 #define TMAG5273_DEVICE_ID		 0x0D
35 #define TMAG5273_MANUFACTURER_ID_LSB	 0x0E
36 #define TMAG5273_MANUFACTURER_ID_MSB	 0x0F
37 #define TMAG5273_T_MSB_RESULT		 0x10
38 #define TMAG5273_T_LSB_RESULT		 0x11
39 #define TMAG5273_X_MSB_RESULT		 0x12
40 #define TMAG5273_X_LSB_RESULT		 0x13
41 #define TMAG5273_Y_MSB_RESULT		 0x14
42 #define TMAG5273_Y_LSB_RESULT		 0x15
43 #define TMAG5273_Z_MSB_RESULT		 0x16
44 #define TMAG5273_Z_LSB_RESULT		 0x17
45 #define TMAG5273_CONV_STATUS		 0x18
46 #define TMAG5273_ANGLE_RESULT_MSB	 0x19
47 #define TMAG5273_ANGLE_RESULT_LSB	 0x1A
48 #define TMAG5273_MAGNITUDE_RESULT	 0x1B
49 #define TMAG5273_DEVICE_STATUS		 0x1C
50 #define TMAG5273_MAX_REG		 TMAG5273_DEVICE_STATUS
51 
52 #define TMAG5273_AUTOSLEEP_DELAY_MS	 5000
53 #define TMAG5273_MAX_AVERAGE             32
54 
55 /*
56  * bits in the TMAG5273_MANUFACTURER_ID_LSB / MSB register
57  * 16-bit unique manufacturer ID 0x49 / 0x54 = "TI"
58  */
59 #define TMAG5273_MANUFACTURER_ID	 0x5449
60 
61 /* bits in the TMAG5273_DEVICE_CONFIG_1 register */
62 #define TMAG5273_AVG_MODE_MASK		 GENMASK(4, 2)
63 #define TMAG5273_AVG_1_MODE		 FIELD_PREP(TMAG5273_AVG_MODE_MASK, 0)
64 #define TMAG5273_AVG_2_MODE		 FIELD_PREP(TMAG5273_AVG_MODE_MASK, 1)
65 #define TMAG5273_AVG_4_MODE		 FIELD_PREP(TMAG5273_AVG_MODE_MASK, 2)
66 #define TMAG5273_AVG_8_MODE		 FIELD_PREP(TMAG5273_AVG_MODE_MASK, 3)
67 #define TMAG5273_AVG_16_MODE		 FIELD_PREP(TMAG5273_AVG_MODE_MASK, 4)
68 #define TMAG5273_AVG_32_MODE		 FIELD_PREP(TMAG5273_AVG_MODE_MASK, 5)
69 
70 /* bits in the TMAG5273_DEVICE_CONFIG_2 register */
71 #define TMAG5273_OP_MODE_MASK		 GENMASK(1, 0)
72 #define TMAG5273_OP_MODE_STANDBY	 FIELD_PREP(TMAG5273_OP_MODE_MASK, 0)
73 #define TMAG5273_OP_MODE_SLEEP		 FIELD_PREP(TMAG5273_OP_MODE_MASK, 1)
74 #define TMAG5273_OP_MODE_CONT		 FIELD_PREP(TMAG5273_OP_MODE_MASK, 2)
75 #define TMAG5273_OP_MODE_WAKEUP		 FIELD_PREP(TMAG5273_OP_MODE_MASK, 3)
76 
77 /* bits in the TMAG5273_SENSOR_CONFIG_1 register */
78 #define TMAG5273_MAG_CH_EN_MASK		 GENMASK(7, 4)
79 #define TMAG5273_MAG_CH_EN_X_Y_Z	 7
80 
81 /* bits in the TMAG5273_SENSOR_CONFIG_2 register */
82 #define TMAG5273_Z_RANGE_MASK		 BIT(0)
83 #define TMAG5273_X_Y_RANGE_MASK		 BIT(1)
84 #define TMAG5273_ANGLE_EN_MASK		 GENMASK(3, 2)
85 #define TMAG5273_ANGLE_EN_OFF		 0
86 #define TMAG5273_ANGLE_EN_X_Y		 1
87 #define TMAG5273_ANGLE_EN_Y_Z		 2
88 #define TMAG5273_ANGLE_EN_X_Z		 3
89 
90 /* bits in the TMAG5273_T_CONFIG register */
91 #define TMAG5273_T_CH_EN		 BIT(0)
92 
93 /* bits in the TMAG5273_DEVICE_ID register */
94 #define TMAG5273_VERSION_MASK		 GENMASK(1, 0)
95 
96 /* bits in the TMAG5273_CONV_STATUS register */
97 #define TMAG5273_CONV_STATUS_COMPLETE	 BIT(0)
98 
99 enum tmag5273_channels {
100 	TEMPERATURE = 0,
101 	AXIS_X,
102 	AXIS_Y,
103 	AXIS_Z,
104 	ANGLE,
105 	MAGNITUDE,
106 };
107 
108 enum tmag5273_scale_index {
109 	MAGN_RANGE_LOW = 0,
110 	MAGN_RANGE_HIGH,
111 	MAGN_RANGE_NUM
112 };
113 
114 /* state container for the TMAG5273 driver */
115 struct tmag5273_data {
116 	struct device *dev;
117 	unsigned int devid;
118 	unsigned int version;
119 	char name[16];
120 	unsigned int conv_avg;
121 	enum tmag5273_scale_index scale_index;
122 	unsigned int angle_measurement;
123 	struct regmap *map;
124 
125 	/*
126 	 * Locks the sensor for exclusive use during a measurement (which
127 	 * involves several register transactions so the regmap lock is not
128 	 * enough) so that measurements get serialized in a
129 	 * first-come-first-serve manner.
130 	 */
131 	struct mutex lock;
132 };
133 
134 static const char *const tmag5273_angle_names[] = { "off", "x-y", "y-z", "x-z" };
135 
136 /*
137  * Averaging enables additional sampling of the sensor data to reduce the noise
138  * effect, but also increases conversion time.
139  */
140 static const unsigned int tmag5273_avg_table[] = {
141 	1, 2, 4, 8, 16, 32,
142 };
143 
144 /*
145  * Magnetic resolution in Gauss for different TMAG5273 versions.
146  * Scale[Gauss] = Range[mT] * 1000 / 2^15 * 10, (1 mT = 10 Gauss)
147  * Only version 1 and 2 are valid, version 0 and 3 are reserved.
148  */
149 static const struct iio_val_int_plus_micro tmag5273_scale[][MAGN_RANGE_NUM] = {
150 	{ { 0,     0 }, { 0,     0 } },
151 	{ { 0, 12200 }, { 0, 24400 } },
152 	{ { 0, 40600 }, { 0, 81200 } },
153 	{ { 0,     0 }, { 0,     0 } },
154 };
155 
156 static int tmag5273_get_measure(struct tmag5273_data *data, s16 *t, s16 *x,
157 				s16 *y, s16 *z, u16 *angle, u16 *magnitude)
158 {
159 	unsigned int status, val;
160 	__be16 reg_data[4];
161 	int ret;
162 
163 	mutex_lock(&data->lock);
164 
165 	/*
166 	 * Max. conversion time is 2425 us in 32x averaging mode for all three
167 	 * channels. Since we are in continuous measurement mode, a measurement
168 	 * may already be there, so poll for completed measurement with
169 	 * timeout.
170 	 */
171 	ret = regmap_read_poll_timeout(data->map, TMAG5273_CONV_STATUS, status,
172 				       status & TMAG5273_CONV_STATUS_COMPLETE,
173 				       100, 10000);
174 	if (ret) {
175 		dev_err(data->dev, "timeout waiting for measurement\n");
176 		goto out_unlock;
177 	}
178 
179 	ret = regmap_bulk_read(data->map, TMAG5273_T_MSB_RESULT, reg_data,
180 			       sizeof(reg_data));
181 	if (ret)
182 		goto out_unlock;
183 	*t = be16_to_cpu(reg_data[0]);
184 	*x = be16_to_cpu(reg_data[1]);
185 	*y = be16_to_cpu(reg_data[2]);
186 	*z = be16_to_cpu(reg_data[3]);
187 
188 	ret = regmap_bulk_read(data->map, TMAG5273_ANGLE_RESULT_MSB,
189 			       &reg_data[0], sizeof(reg_data[0]));
190 	if (ret)
191 		goto out_unlock;
192 	/*
193 	 * angle has 9 bits integer value and 4 bits fractional part
194 	 * 15 14 13 12 11 10 9  8  7  6  5  4  3  2  1  0
195 	 * 0  0  0  a  a  a  a  a  a  a  a  a  f  f  f  f
196 	 */
197 	*angle = be16_to_cpu(reg_data[0]);
198 
199 	ret = regmap_read(data->map, TMAG5273_MAGNITUDE_RESULT, &val);
200 	if (ret < 0)
201 		goto out_unlock;
202 	*magnitude = val;
203 
204 out_unlock:
205 	mutex_unlock(&data->lock);
206 	return ret;
207 }
208 
209 static int tmag5273_write_osr(struct tmag5273_data *data, int val)
210 {
211 	int i;
212 
213 	if (val == data->conv_avg)
214 		return 0;
215 
216 	for (i = 0; i < ARRAY_SIZE(tmag5273_avg_table); i++) {
217 		if (tmag5273_avg_table[i] == val)
218 			break;
219 	}
220 	if (i == ARRAY_SIZE(tmag5273_avg_table))
221 		return -EINVAL;
222 	data->conv_avg = val;
223 
224 	return regmap_update_bits(data->map, TMAG5273_DEVICE_CONFIG_1,
225 				  TMAG5273_AVG_MODE_MASK,
226 				  FIELD_PREP(TMAG5273_AVG_MODE_MASK, i));
227 }
228 
229 static int tmag5273_write_scale(struct tmag5273_data *data, int scale_micro)
230 {
231 	u32 value;
232 	int i;
233 
234 	for (i = 0; i < ARRAY_SIZE(tmag5273_scale[0]); i++) {
235 		if (tmag5273_scale[data->version][i].micro == scale_micro)
236 			break;
237 	}
238 	if (i == ARRAY_SIZE(tmag5273_scale[0]))
239 		return -EINVAL;
240 	data->scale_index = i;
241 
242 	if (data->scale_index == MAGN_RANGE_LOW)
243 		value = 0;
244 	else
245 		value = TMAG5273_Z_RANGE_MASK | TMAG5273_X_Y_RANGE_MASK;
246 
247 	return regmap_update_bits(data->map, TMAG5273_SENSOR_CONFIG_2,
248 				  TMAG5273_Z_RANGE_MASK | TMAG5273_X_Y_RANGE_MASK, value);
249 }
250 
251 static int tmag5273_read_avail(struct iio_dev *indio_dev,
252 			       struct iio_chan_spec const *chan,
253 			       const int **vals, int *type, int *length,
254 			       long mask)
255 {
256 	struct tmag5273_data *data = iio_priv(indio_dev);
257 
258 	switch (mask) {
259 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
260 		*vals = tmag5273_avg_table;
261 		*type = IIO_VAL_INT;
262 		*length = ARRAY_SIZE(tmag5273_avg_table);
263 		return IIO_AVAIL_LIST;
264 	case IIO_CHAN_INFO_SCALE:
265 		switch (chan->type) {
266 		case IIO_MAGN:
267 			*type = IIO_VAL_INT_PLUS_MICRO;
268 			*vals = (int *)tmag5273_scale[data->version];
269 			*length = ARRAY_SIZE(tmag5273_scale[data->version]) *
270 				  MAGN_RANGE_NUM;
271 			return IIO_AVAIL_LIST;
272 		default:
273 			return -EINVAL;
274 		}
275 	default:
276 		return -EINVAL;
277 	}
278 }
279 
280 static int tmag5273_read_raw(struct iio_dev *indio_dev,
281 			     const struct iio_chan_spec *chan, int *val,
282 			     int *val2, long mask)
283 {
284 	struct tmag5273_data *data = iio_priv(indio_dev);
285 	s16 t, x, y, z;
286 	u16 angle, magnitude;
287 	int ret;
288 
289 	switch (mask) {
290 	case IIO_CHAN_INFO_PROCESSED:
291 	case IIO_CHAN_INFO_RAW:
292 		ret = pm_runtime_resume_and_get(data->dev);
293 		if (ret < 0)
294 			return ret;
295 
296 		ret = tmag5273_get_measure(data, &t, &x, &y, &z, &angle, &magnitude);
297 
298 		pm_runtime_mark_last_busy(data->dev);
299 		pm_runtime_put_autosuspend(data->dev);
300 
301 		if (ret)
302 			return ret;
303 
304 		switch (chan->address) {
305 		case TEMPERATURE:
306 			*val = t;
307 			return IIO_VAL_INT;
308 		case AXIS_X:
309 			*val = x;
310 			return IIO_VAL_INT;
311 		case AXIS_Y:
312 			*val = y;
313 			return IIO_VAL_INT;
314 		case AXIS_Z:
315 			*val = z;
316 			return IIO_VAL_INT;
317 		case ANGLE:
318 			*val = angle;
319 			return IIO_VAL_INT;
320 		case MAGNITUDE:
321 			*val = magnitude;
322 			return IIO_VAL_INT;
323 		default:
324 			return -EINVAL;
325 		}
326 	case IIO_CHAN_INFO_SCALE:
327 		switch (chan->type) {
328 		case IIO_TEMP:
329 			/*
330 			 * Convert device specific value to millicelsius.
331 			 * Resolution from the sensor is 60.1 LSB/celsius and
332 			 * the reference value at 25 celsius is 17508 LSBs.
333 			 */
334 			*val = 10000;
335 			*val2 = 601;
336 			return IIO_VAL_FRACTIONAL;
337 		case IIO_MAGN:
338 			/* Magnetic resolution in uT */
339 			*val = 0;
340 			*val2 = tmag5273_scale[data->version]
341 					      [data->scale_index].micro;
342 			return IIO_VAL_INT_PLUS_MICRO;
343 		case IIO_ANGL:
344 			/*
345 			 * Angle is in degrees and has four fractional bits,
346 			 * therefore use 1/16 * pi/180 to convert to radians.
347 			 */
348 			*val = 1000;
349 			*val2 = 916732;
350 			return IIO_VAL_FRACTIONAL;
351 		default:
352 			return -EINVAL;
353 		}
354 	case IIO_CHAN_INFO_OFFSET:
355 		switch (chan->type) {
356 		case IIO_TEMP:
357 			*val = -16005;
358 			return IIO_VAL_INT;
359 		default:
360 			return -EINVAL;
361 		}
362 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
363 		*val = data->conv_avg;
364 		return IIO_VAL_INT;
365 
366 	default:
367 		return -EINVAL;
368 	}
369 }
370 
371 static int tmag5273_write_raw(struct iio_dev *indio_dev,
372 			      struct iio_chan_spec const *chan, int val,
373 			      int val2, long mask)
374 {
375 	struct tmag5273_data *data = iio_priv(indio_dev);
376 
377 	switch (mask) {
378 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
379 		return tmag5273_write_osr(data, val);
380 	case IIO_CHAN_INFO_SCALE:
381 		switch (chan->type) {
382 		case IIO_MAGN:
383 			if (val)
384 				return -EINVAL;
385 			return tmag5273_write_scale(data, val2);
386 		default:
387 			return -EINVAL;
388 		}
389 	default:
390 		return -EINVAL;
391 	}
392 }
393 
394 #define TMAG5273_AXIS_CHANNEL(axis, index)				     \
395 	{								     \
396 		.type = IIO_MAGN,					     \
397 		.modified = 1,						     \
398 		.channel2 = IIO_MOD_##axis,				     \
399 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		     \
400 				      BIT(IIO_CHAN_INFO_SCALE),		     \
401 		.info_mask_shared_by_type_available =			     \
402 				      BIT(IIO_CHAN_INFO_SCALE),		     \
403 		.info_mask_shared_by_all =				     \
404 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
405 		.info_mask_shared_by_all_available =			     \
406 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
407 		.address = index,					     \
408 		.scan_index = index,					     \
409 		.scan_type = {						     \
410 			.sign = 's',					     \
411 			.realbits = 16,					     \
412 			.storagebits = 16,				     \
413 			.endianness = IIO_CPU,				     \
414 		},							     \
415 	}
416 
417 static const struct iio_chan_spec tmag5273_channels[] = {
418 	{
419 		.type = IIO_TEMP,
420 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
421 			BIT(IIO_CHAN_INFO_SCALE) |
422 			BIT(IIO_CHAN_INFO_OFFSET),
423 		.address = TEMPERATURE,
424 		.scan_index = TEMPERATURE,
425 		.scan_type = {
426 			.sign = 'u',
427 			.realbits = 16,
428 			.storagebits = 16,
429 			.endianness = IIO_CPU,
430 		},
431 	},
432 	TMAG5273_AXIS_CHANNEL(X, AXIS_X),
433 	TMAG5273_AXIS_CHANNEL(Y, AXIS_Y),
434 	TMAG5273_AXIS_CHANNEL(Z, AXIS_Z),
435 	{
436 		.type = IIO_ANGL,
437 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
438 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
439 		.info_mask_shared_by_all =
440 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
441 		.info_mask_shared_by_all_available =
442 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
443 		.address = ANGLE,
444 		.scan_index = ANGLE,
445 		.scan_type = {
446 			.sign = 'u',
447 			.realbits = 16,
448 			.storagebits = 16,
449 			.endianness = IIO_CPU,
450 		},
451 	},
452 	{
453 		.type = IIO_DISTANCE,
454 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
455 		.info_mask_shared_by_all =
456 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
457 		.info_mask_shared_by_all_available =
458 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
459 		.address = MAGNITUDE,
460 		.scan_index = MAGNITUDE,
461 		.scan_type = {
462 			.sign = 'u',
463 			.realbits = 16,
464 			.storagebits = 16,
465 			.endianness = IIO_CPU,
466 		},
467 	},
468 	IIO_CHAN_SOFT_TIMESTAMP(6),
469 };
470 
471 static const struct iio_info tmag5273_info = {
472 	.read_avail = tmag5273_read_avail,
473 	.read_raw = tmag5273_read_raw,
474 	.write_raw = tmag5273_write_raw,
475 };
476 
477 static bool tmag5273_volatile_reg(struct device *dev, unsigned int reg)
478 {
479 	return reg >= TMAG5273_T_MSB_RESULT && reg <= TMAG5273_MAGNITUDE_RESULT;
480 }
481 
482 static const struct regmap_config tmag5273_regmap_config = {
483 	.reg_bits = 8,
484 	.val_bits = 8,
485 	.max_register = TMAG5273_MAX_REG,
486 	.volatile_reg = tmag5273_volatile_reg,
487 };
488 
489 static int tmag5273_set_operating_mode(struct tmag5273_data *data,
490 				       unsigned int val)
491 {
492 	return regmap_write(data->map, TMAG5273_DEVICE_CONFIG_2, val);
493 }
494 
495 static void tmag5273_read_device_property(struct tmag5273_data *data)
496 {
497 	struct device *dev = data->dev;
498 	int ret;
499 
500 	data->angle_measurement = TMAG5273_ANGLE_EN_X_Y;
501 
502 	ret = device_property_match_property_string(dev, "ti,angle-measurement",
503 						    tmag5273_angle_names,
504 						    ARRAY_SIZE(tmag5273_angle_names));
505 	if (ret >= 0)
506 		data->angle_measurement = ret;
507 }
508 
509 static void tmag5273_wake_up(struct tmag5273_data *data)
510 {
511 	int val;
512 
513 	/* Wake up the chip by sending a dummy I2C command */
514 	regmap_read(data->map, TMAG5273_DEVICE_ID, &val);
515 	/*
516 	 * Time to go to stand-by mode from sleep mode is 50us
517 	 * typically, during this time no I2C access is possible.
518 	 */
519 	usleep_range(80, 200);
520 }
521 
522 static int tmag5273_chip_init(struct tmag5273_data *data)
523 {
524 	int ret;
525 
526 	ret = regmap_write(data->map, TMAG5273_DEVICE_CONFIG_1,
527 			   TMAG5273_AVG_32_MODE);
528 	if (ret)
529 		return ret;
530 	data->conv_avg = 32;
531 
532 	ret = regmap_write(data->map, TMAG5273_DEVICE_CONFIG_2,
533 			   TMAG5273_OP_MODE_CONT);
534 	if (ret)
535 		return ret;
536 
537 	ret = regmap_write(data->map, TMAG5273_SENSOR_CONFIG_1,
538 			   FIELD_PREP(TMAG5273_MAG_CH_EN_MASK,
539 				      TMAG5273_MAG_CH_EN_X_Y_Z));
540 	if (ret)
541 		return ret;
542 
543 	ret = regmap_write(data->map, TMAG5273_SENSOR_CONFIG_2,
544 			   FIELD_PREP(TMAG5273_ANGLE_EN_MASK,
545 				      data->angle_measurement));
546 	if (ret)
547 		return ret;
548 	data->scale_index = MAGN_RANGE_LOW;
549 
550 	return regmap_write(data->map, TMAG5273_T_CONFIG, TMAG5273_T_CH_EN);
551 }
552 
553 static int tmag5273_check_device_id(struct tmag5273_data *data)
554 {
555 	__le16 devid;
556 	int val, ret;
557 
558 	ret = regmap_read(data->map, TMAG5273_DEVICE_ID, &val);
559 	if (ret)
560 		return dev_err_probe(data->dev, ret, "failed to power on device\n");
561 	data->version = FIELD_PREP(TMAG5273_VERSION_MASK, val);
562 
563 	ret = regmap_bulk_read(data->map, TMAG5273_MANUFACTURER_ID_LSB, &devid,
564 			       sizeof(devid));
565 	if (ret)
566 		return dev_err_probe(data->dev, ret, "failed to read device ID\n");
567 	data->devid = le16_to_cpu(devid);
568 
569 	switch (data->devid) {
570 	case TMAG5273_MANUFACTURER_ID:
571 		/*
572 		 * The device name matches the orderable part number. 'x' stands
573 		 * for A, B, C or D devices, which have different I2C addresses.
574 		 * Versions 1 or 2 (0 and 3 is reserved) stands for different
575 		 * magnetic strengths.
576 		 */
577 		snprintf(data->name, sizeof(data->name), "tmag5273x%1u", data->version);
578 		if (data->version < 1 || data->version > 2)
579 			dev_warn(data->dev, "Unsupported device %s\n", data->name);
580 		return 0;
581 	default:
582 		/*
583 		 * Only print warning in case of unknown device ID to allow
584 		 * fallback compatible in device tree.
585 		 */
586 		dev_warn(data->dev, "Unknown device ID 0x%x\n", data->devid);
587 		return 0;
588 	}
589 }
590 
591 static void tmag5273_power_down(void *data)
592 {
593 	tmag5273_set_operating_mode(data, TMAG5273_OP_MODE_SLEEP);
594 }
595 
596 static int tmag5273_probe(struct i2c_client *i2c)
597 {
598 	struct device *dev = &i2c->dev;
599 	struct tmag5273_data *data;
600 	struct iio_dev *indio_dev;
601 	int ret;
602 
603 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
604 	if (!indio_dev)
605 		return -ENOMEM;
606 
607 	data = iio_priv(indio_dev);
608 	data->dev = dev;
609 	i2c_set_clientdata(i2c, indio_dev);
610 
611 	data->map = devm_regmap_init_i2c(i2c, &tmag5273_regmap_config);
612 	if (IS_ERR(data->map))
613 		return dev_err_probe(dev, PTR_ERR(data->map),
614 				     "failed to allocate register map\n");
615 
616 	mutex_init(&data->lock);
617 
618 	ret = devm_regulator_get_enable(dev, "vcc");
619 	if (ret)
620 		return dev_err_probe(dev, ret, "failed to enable regulator\n");
621 
622 	tmag5273_wake_up(data);
623 
624 	ret = tmag5273_check_device_id(data);
625 	if (ret)
626 		return ret;
627 
628 	ret = tmag5273_set_operating_mode(data, TMAG5273_OP_MODE_CONT);
629 	if (ret)
630 		return dev_err_probe(dev, ret, "failed to power on device\n");
631 
632 	/*
633 	 * Register powerdown deferred callback which suspends the chip
634 	 * after module unloaded.
635 	 *
636 	 * TMAG5273 should be in SUSPEND mode in the two cases:
637 	 * 1) When driver is loaded, but we do not have any data or
638 	 *    configuration requests to it (we are solving it using
639 	 *    autosuspend feature).
640 	 * 2) When driver is unloaded and device is not used (devm action is
641 	 *    used in this case).
642 	 */
643 	ret = devm_add_action_or_reset(dev, tmag5273_power_down, data);
644 	if (ret)
645 		return dev_err_probe(dev, ret, "failed to add powerdown action\n");
646 
647 	ret = pm_runtime_set_active(dev);
648 	if (ret < 0)
649 		return ret;
650 
651 	ret = devm_pm_runtime_enable(dev);
652 	if (ret)
653 		return ret;
654 
655 	pm_runtime_get_noresume(dev);
656 	pm_runtime_set_autosuspend_delay(dev, TMAG5273_AUTOSLEEP_DELAY_MS);
657 	pm_runtime_use_autosuspend(dev);
658 
659 	tmag5273_read_device_property(data);
660 
661 	ret = tmag5273_chip_init(data);
662 	if (ret)
663 		return dev_err_probe(dev, ret, "failed to init device\n");
664 
665 	indio_dev->info = &tmag5273_info;
666 	indio_dev->modes = INDIO_DIRECT_MODE;
667 	indio_dev->name = data->name;
668 	indio_dev->channels = tmag5273_channels;
669 	indio_dev->num_channels = ARRAY_SIZE(tmag5273_channels);
670 
671 	pm_runtime_mark_last_busy(dev);
672 	pm_runtime_put_autosuspend(dev);
673 
674 	ret = devm_iio_device_register(dev, indio_dev);
675 	if (ret)
676 		return dev_err_probe(dev, ret, "device register failed\n");
677 
678 	return 0;
679 }
680 
681 static int tmag5273_runtime_suspend(struct device *dev)
682 {
683 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
684 	struct tmag5273_data *data = iio_priv(indio_dev);
685 	int ret;
686 
687 	ret = tmag5273_set_operating_mode(data, TMAG5273_OP_MODE_SLEEP);
688 	if (ret)
689 		dev_err(dev, "failed to power off device (%pe)\n", ERR_PTR(ret));
690 
691 	return ret;
692 }
693 
694 static int tmag5273_runtime_resume(struct device *dev)
695 {
696 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
697 	struct tmag5273_data *data = iio_priv(indio_dev);
698 	int ret;
699 
700 	tmag5273_wake_up(data);
701 
702 	ret = tmag5273_set_operating_mode(data, TMAG5273_OP_MODE_CONT);
703 	if (ret)
704 		dev_err(dev, "failed to power on device (%pe)\n", ERR_PTR(ret));
705 
706 	return ret;
707 }
708 
709 static DEFINE_RUNTIME_DEV_PM_OPS(tmag5273_pm_ops,
710 				 tmag5273_runtime_suspend, tmag5273_runtime_resume,
711 				 NULL);
712 
713 static const struct i2c_device_id tmag5273_id[] = {
714 	{ "tmag5273" },
715 	{ /* sentinel */ }
716 };
717 MODULE_DEVICE_TABLE(i2c, tmag5273_id);
718 
719 static const struct of_device_id tmag5273_of_match[] = {
720 	{ .compatible = "ti,tmag5273" },
721 	{ /* sentinel */ }
722 };
723 MODULE_DEVICE_TABLE(of, tmag5273_of_match);
724 
725 static struct i2c_driver tmag5273_driver = {
726 	.driver	 = {
727 		.name = "tmag5273",
728 		.of_match_table = tmag5273_of_match,
729 		.pm = pm_ptr(&tmag5273_pm_ops),
730 	},
731 	.probe = tmag5273_probe,
732 	.id_table = tmag5273_id,
733 };
734 module_i2c_driver(tmag5273_driver);
735 
736 MODULE_DESCRIPTION("TI TMAG5273 Low-Power Linear 3D Hall-Effect Sensor driver");
737 MODULE_AUTHOR("Gerald Loacker <gerald.loacker@wolfvision.net>");
738 MODULE_LICENSE("GPL");
739