summaryrefslogtreecommitdiff
path: root/drivers/iio/magnetometer/mag3110.c
blob: b870ad8038626e7eed8fbe88409971544f49450e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
// SPDX-License-Identifier: GPL-2.0-only
/*
 * mag3110.c - Support for Freescale MAG3110 magnetometer sensor
 *
 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
 *
 * (7-bit I2C slave address 0x0e)
 *
 * TODO: irq, user offset, oversampling, continuous mode
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>

#define MAG3110_STATUS 0x00
#define MAG3110_OUT_X 0x01 /* MSB first */
#define MAG3110_OUT_Y 0x03
#define MAG3110_OUT_Z 0x05
#define MAG3110_WHO_AM_I 0x07
#define MAG3110_SYSMOD 0x08
#define MAG3110_OFF_X 0x09 /* MSB first */
#define MAG3110_OFF_Y 0x0b
#define MAG3110_OFF_Z 0x0d
#define MAG3110_DIE_TEMP 0x0f
#define MAG3110_CTRL_REG1 0x10
#define MAG3110_CTRL_REG2 0x11

#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))

#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
#define MAG3110_CTRL_DR_SHIFT 5
#define MAG3110_CTRL_DR_DEFAULT 0

#define MAG3110_SYSMOD_MODE_MASK GENMASK(1, 0)

#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */

#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */

#define MAG3110_DEVICE_ID 0xc4

/* Each client has this additional data */
struct mag3110_data {
	struct i2c_client *client;
	struct mutex lock;
	u8 ctrl_reg1;
	int sleep_val;
	struct regulator *vdd_reg;
	struct regulator *vddio_reg;
	/* Ensure natural alignment of timestamp */
	struct {
		__be16 channels[3];
		u8 temperature;
		s64 ts __aligned(8);
	} scan;
};

static int mag3110_request(struct mag3110_data *data)
{
	int ret, tries = 150;

	if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) {
		/* trigger measurement */
		ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
			data->ctrl_reg1 | MAG3110_CTRL_TM);
		if (ret < 0)
			return ret;
	}

	while (tries-- > 0) {
		ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
		if (ret < 0)
			return ret;
		/* wait for data ready */
		if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
			break;

		if (data->sleep_val <= 20)
			usleep_range(data->sleep_val * 250, data->sleep_val * 500);
		else
			msleep(20);
	}

	if (tries < 0) {
		dev_err(&data->client->dev, "data not ready\n");
		return -EIO;
	}

	return 0;
}

static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
{
	int ret;

	mutex_lock(&data->lock);
	ret = mag3110_request(data);
	if (ret < 0) {
		mutex_unlock(&data->lock);
		return ret;
	}
	ret = i2c_smbus_read_i2c_block_data(data->client,
		MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
	mutex_unlock(&data->lock);

	return ret;
}

static ssize_t mag3110_show_int_plus_micros(char *buf,
	const int (*vals)[2], int n)
{
	size_t len = 0;

	while (n-- > 0)
		len += scnprintf(buf + len, PAGE_SIZE - len,
			"%d.%06d ", vals[n][0], vals[n][1]);

	/* replace trailing space by newline */
	buf[len - 1] = '\n';

	return len;
}

static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
					int val, int val2)
{
	while (n-- > 0)
		if (val == vals[n][0] && val2 == vals[n][1])
			return n;

	return -EINVAL;
}

static const int mag3110_samp_freq[8][2] = {
	{80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
	{1, 250000}, {0, 625000}
};

static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
}

static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);

static int mag3110_get_samp_freq_index(struct mag3110_data *data,
	int val, int val2)
{
	return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
		val2);
}

static int mag3110_calculate_sleep(struct mag3110_data *data)
{
	int ret, i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;

	if (mag3110_samp_freq[i][0] > 0)
		ret = 1000 / mag3110_samp_freq[i][0];
	else
		ret = 1000;

	return ret == 0 ? 1 : ret;
}

static int mag3110_standby(struct mag3110_data *data)
{
	return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
		data->ctrl_reg1 & ~MAG3110_CTRL_AC);
}

static int mag3110_wait_standby(struct mag3110_data *data)
{
	int ret, tries = 30;

	/*
	 * Takes up to 1/ODR to come out of active mode into stby
	 * Longest expected period is 12.5seconds.
	 * We'll sleep for 500ms between checks
	 */
	while (tries-- > 0) {
		ret = i2c_smbus_read_byte_data(data->client, MAG3110_SYSMOD);
		if (ret < 0) {
			dev_err(&data->client->dev, "i2c error\n");
			return ret;
		}
		/* wait for standby */
		if ((ret & MAG3110_SYSMOD_MODE_MASK) == 0)
			break;

		msleep_interruptible(500);
	}

	if (tries < 0) {
		dev_err(&data->client->dev, "device not entering standby mode\n");
		return -EIO;
	}

	return 0;
}

static int mag3110_active(struct mag3110_data *data)
{
	return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
					 data->ctrl_reg1);
}

/* returns >0 if active, 0 if in standby and <0 on error */
static int mag3110_is_active(struct mag3110_data *data)
{
	int reg;

	reg = i2c_smbus_read_byte_data(data->client, MAG3110_CTRL_REG1);
	if (reg < 0)
		return reg;

	return reg & MAG3110_CTRL_AC;
}

static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)
{
	int ret;
	int is_active;

	mutex_lock(&data->lock);

	is_active = mag3110_is_active(data);
	if (is_active < 0) {
		ret = is_active;
		goto fail;
	}

	/* config can only be changed when in standby */
	if (is_active > 0) {
		ret = mag3110_standby(data);
		if (ret < 0)
			goto fail;
	}

	/*
	 * After coming out of active we must wait for the part
	 * to transition to STBY. This can take up to 1 /ODR to occur
	 */
	ret = mag3110_wait_standby(data);
	if (ret < 0)
		goto fail;

	ret = i2c_smbus_write_byte_data(data->client, reg, val);
	if (ret < 0)
		goto fail;

	if (is_active > 0) {
		ret = mag3110_active(data);
		if (ret < 0)
			goto fail;
	}

	ret = 0;
fail:
	mutex_unlock(&data->lock);

	return ret;
}

static int mag3110_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
{
	struct mag3110_data *data = iio_priv(indio_dev);
	__be16 buffer[3];
	int i, ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = iio_device_claim_direct_mode(indio_dev);
		if (ret)
			return ret;

		switch (chan->type) {
		case IIO_MAGN: /* in 0.1 uT / LSB */
			ret = mag3110_read(data, buffer);
			if (ret < 0)
				goto release;
			*val = sign_extend32(
				be16_to_cpu(buffer[chan->scan_index]),
					    chan->scan_type.realbits - 1);
			ret = IIO_VAL_INT;
			break;
		case IIO_TEMP: /* in 1 C / LSB */
			mutex_lock(&data->lock);
			ret = mag3110_request(data);
			if (ret < 0) {
				mutex_unlock(&data->lock);
				goto release;
			}
			ret = i2c_smbus_read_byte_data(data->client,
				MAG3110_DIE_TEMP);
			mutex_unlock(&data->lock);
			if (ret < 0)
				goto release;
			*val = sign_extend32(ret,
					     chan->scan_type.realbits - 1);
			ret = IIO_VAL_INT;
			break;
		default:
			ret = -EINVAL;
		}
release:
		iio_device_release_direct_mode(indio_dev);
		return ret;

	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_MAGN:
			*val = 0;
			*val2 = 1000;
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_TEMP:
			*val = 1000;
			return IIO_VAL_INT;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_SAMP_FREQ:
		i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
		*val = mag3110_samp_freq[i][0];
		*val2 = mag3110_samp_freq[i][1];
		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_CALIBBIAS:
		ret = i2c_smbus_read_word_swapped(data->client,
			MAG3110_OFF_X +	2 * chan->scan_index);
		if (ret < 0)
			return ret;
		*val = sign_extend32(ret >> 1, 14);
		return IIO_VAL_INT;
	}
	return -EINVAL;
}

static int mag3110_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long mask)
{
	struct mag3110_data *data = iio_priv(indio_dev);
	int rate, ret;

	ret = iio_device_claim_direct_mode(indio_dev);
	if (ret)
		return ret;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		rate = mag3110_get_samp_freq_index(data, val, val2);
		if (rate < 0) {
			ret = -EINVAL;
			break;
		}
		data->ctrl_reg1 &= 0xff & ~MAG3110_CTRL_DR_MASK
					& ~MAG3110_CTRL_AC;
		data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
		data->sleep_val = mag3110_calculate_sleep(data);
		if (data->sleep_val < 40)
			data->ctrl_reg1 |= MAG3110_CTRL_AC;

		ret = mag3110_change_config(data, MAG3110_CTRL_REG1,
					    data->ctrl_reg1);
		break;
	case IIO_CHAN_INFO_CALIBBIAS:
		if (val < -10000 || val > 10000) {
			ret = -EINVAL;
			break;
		}
		ret = i2c_smbus_write_word_swapped(data->client,
			MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
		break;
	default:
		ret = -EINVAL;
		break;
	}
	iio_device_release_direct_mode(indio_dev);
	return ret;
}

static irqreturn_t mag3110_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct mag3110_data *data = iio_priv(indio_dev);
	int ret;

	ret = mag3110_read(data, data->scan.channels);
	if (ret < 0)
		goto done;

	if (test_bit(3, indio_dev->active_scan_mask)) {
		ret = i2c_smbus_read_byte_data(data->client,
			MAG3110_DIE_TEMP);
		if (ret < 0)
			goto done;
		data->scan.temperature = ret;
	}

	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
		iio_get_time_ns(indio_dev));

done:
	iio_trigger_notify_done(indio_dev->trig);
	return IRQ_HANDLED;
}

#define MAG3110_CHANNEL(axis, idx) { \
	.type = IIO_MAGN, \
	.modified = 1, \
	.channel2 = IIO_MOD_##axis, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
		BIT(IIO_CHAN_INFO_CALIBBIAS), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
		BIT(IIO_CHAN_INFO_SCALE), \
	.scan_index = idx, \
	.scan_type = { \
		.sign = 's', \
		.realbits = 16, \
		.storagebits = 16, \
		.endianness = IIO_BE, \
	}, \
}

static const struct iio_chan_spec mag3110_channels[] = {
	MAG3110_CHANNEL(X, 0),
	MAG3110_CHANNEL(Y, 1),
	MAG3110_CHANNEL(Z, 2),
	{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
			BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = 3,
		.scan_type = {
			.sign = 's',
			.realbits = 8,
			.storagebits = 8,
			},
	},
	IIO_CHAN_SOFT_TIMESTAMP(4),
};

static struct attribute *mag3110_attributes[] = {
	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
	NULL
};

static const struct attribute_group mag3110_group = {
	.attrs = mag3110_attributes,
};

static const struct iio_info mag3110_info = {
	.attrs = &mag3110_group,
	.read_raw = &mag3110_read_raw,
	.write_raw = &mag3110_write_raw,
};

static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};

static int mag3110_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct mag3110_data *data;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	data = iio_priv(indio_dev);

	data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
	if (IS_ERR(data->vdd_reg))
		return dev_err_probe(&client->dev, PTR_ERR(data->vdd_reg),
				     "failed to get VDD regulator!\n");

	data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
	if (IS_ERR(data->vddio_reg))
		return dev_err_probe(&client->dev, PTR_ERR(data->vddio_reg),
				     "failed to get VDDIO regulator!\n");

	ret = regulator_enable(data->vdd_reg);
	if (ret) {
		dev_err(&client->dev, "failed to enable VDD regulator!\n");
		return ret;
	}

	ret = regulator_enable(data->vddio_reg);
	if (ret) {
		dev_err(&client->dev, "failed to enable VDDIO regulator!\n");
		goto disable_regulator_vdd;
	}

	ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
	if (ret < 0)
		goto disable_regulators;
	if (ret != MAG3110_DEVICE_ID) {
		ret = -ENODEV;
		goto disable_regulators;
	}

	data->client = client;
	mutex_init(&data->lock);

	i2c_set_clientdata(client, indio_dev);
	indio_dev->info = &mag3110_info;
	indio_dev->name = id->name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mag3110_channels;
	indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
	indio_dev->available_scan_masks = mag3110_scan_masks;

	data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;
	data->sleep_val = mag3110_calculate_sleep(data);
	if (data->sleep_val < 40)
		data->ctrl_reg1 |= MAG3110_CTRL_AC;

	ret = mag3110_change_config(data, MAG3110_CTRL_REG1, data->ctrl_reg1);
	if (ret < 0)
		goto disable_regulators;

	ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
		MAG3110_CTRL_AUTO_MRST_EN);
	if (ret < 0)
		goto standby_on_error;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
		mag3110_trigger_handler, NULL);
	if (ret < 0)
		goto standby_on_error;

	ret = iio_device_register(indio_dev);
	if (ret < 0)
		goto buffer_cleanup;
	return 0;

buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
standby_on_error:
	mag3110_standby(iio_priv(indio_dev));
disable_regulators:
	regulator_disable(data->vddio_reg);
disable_regulator_vdd:
	regulator_disable(data->vdd_reg);

	return ret;
}

static void mag3110_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct mag3110_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	mag3110_standby(iio_priv(indio_dev));
	regulator_disable(data->vddio_reg);
	regulator_disable(data->vdd_reg);
}

static int mag3110_suspend(struct device *dev)
{
	struct mag3110_data *data = iio_priv(i2c_get_clientdata(
		to_i2c_client(dev)));
	int ret;

	ret = mag3110_standby(iio_priv(i2c_get_clientdata(
		to_i2c_client(dev))));
	if (ret)
		return ret;

	ret = regulator_disable(data->vddio_reg);
	if (ret) {
		dev_err(dev, "failed to disable VDDIO regulator\n");
		return ret;
	}

	ret = regulator_disable(data->vdd_reg);
	if (ret) {
		dev_err(dev, "failed to disable VDD regulator\n");
		return ret;
	}

	return 0;
}

static int mag3110_resume(struct device *dev)
{
	struct mag3110_data *data = iio_priv(i2c_get_clientdata(
		to_i2c_client(dev)));
	int ret;

	ret = regulator_enable(data->vdd_reg);
	if (ret) {
		dev_err(dev, "failed to enable VDD regulator\n");
		return ret;
	}

	ret = regulator_enable(data->vddio_reg);
	if (ret) {
		dev_err(dev, "failed to enable VDDIO regulator\n");
		regulator_disable(data->vdd_reg);
		return ret;
	}

	return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
		data->ctrl_reg1);
}

static DEFINE_SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend,
				mag3110_resume);

static const struct i2c_device_id mag3110_id[] = {
	{ "mag3110", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mag3110_id);

static const struct of_device_id mag3110_of_match[] = {
	{ .compatible = "fsl,mag3110" },
	{ }
};
MODULE_DEVICE_TABLE(of, mag3110_of_match);

static struct i2c_driver mag3110_driver = {
	.driver = {
		.name	= "mag3110",
		.of_match_table = mag3110_of_match,
		.pm	= pm_sleep_ptr(&mag3110_pm_ops),
	},
	.probe = mag3110_probe,
	.remove = mag3110_remove,
	.id_table = mag3110_id,
};
module_i2c_driver(mag3110_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
MODULE_LICENSE("GPL");