summaryrefslogtreecommitdiff
path: root/drivers/iio/accel/bma180.c
blob: a7e68c81f89dd7203d4e2cc91f1872015801baf0 (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
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
/*
 * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
 *
 * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#define BMA180_DRV_NAME "bma180"
#define BMA180_IRQ_NAME "bma180_event"

/* Register set */
#define BMA180_CHIP_ID		0x00 /* Need to distinguish BMA180 from other */
#define BMA180_ACC_X_LSB	0x02 /* First of 6 registers of accel data */
#define BMA180_CTRL_REG0	0x0d
#define BMA180_RESET		0x10
#define BMA180_BW_TCS		0x20
#define BMA180_CTRL_REG3	0x21
#define BMA180_TCO_Z		0x30
#define BMA180_OFFSET_LSB1	0x35

/* BMA180_CTRL_REG0 bits */
#define BMA180_DIS_WAKE_UP	BIT(0) /* Disable wake up mode */
#define BMA180_SLEEP		BIT(1) /* 1 - chip will sleep */
#define BMA180_EE_W		BIT(4) /* Unlock writing to addr from 0x20 */
#define BMA180_RESET_INT	BIT(6) /* Reset pending interrupts */

/* BMA180_CTRL_REG3 bits */
#define BMA180_NEW_DATA_INT	BIT(1) /* Intr every new accel data is ready */

/* BMA180_OFFSET_LSB1 skipping mode bit */
#define BMA180_SMP_SKIP		BIT(0)

/* Bit masks for registers bit fields */
#define BMA180_RANGE		0x0e /* Range of measured accel values*/
#define BMA180_BW		0xf0 /* Accel bandwidth */
#define BMA180_MODE_CONFIG	0x03 /* Config operation modes */

/* We have to write this value in reset register to do soft reset */
#define BMA180_RESET_VAL	0xb6

#define BMA_180_ID_REG_VAL	0x03

/* Chip power modes */
#define BMA180_LOW_NOISE	0x00
#define BMA180_LOW_POWER	0x03

#define BMA180_LOW_NOISE_STR	"low_noise"
#define BMA180_LOW_POWER_STR	"low_power"

/* Defaults values */
#define BMA180_DEF_PMODE	0
#define BMA180_DEF_BW		20
#define BMA180_DEF_SCALE	250

/* Available values for sysfs */
#define BMA180_FLP_FREQ_AVAILABLE \
	"10 20 40 75 150 300"
#define BMA180_SCALE_AVAILABLE \
	"0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"

struct bma180_data {
	struct i2c_client *client;
	struct iio_trigger *trig;
	struct mutex mutex;
	int sleep_state;
	int scale;
	int bw;
	int pmode;
	char *buff;
};

enum bma180_axis {
	AXIS_X,
	AXIS_Y,
	AXIS_Z,
};

static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };

static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
{
	u8 reg = BMA180_ACC_X_LSB + axis * 2;
	int ret;

	if (data->sleep_state)
		return -EBUSY;

	ret = i2c_smbus_read_word_data(data->client, reg);
	if (ret < 0)
		dev_err(&data->client->dev,
			"failed to read accel_%c registers\n", 'x' + axis);

	return ret;
}

static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
{
	int ret = i2c_smbus_read_byte_data(data->client, reg);
	u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));

	if (ret < 0)
		return ret;

	return i2c_smbus_write_byte_data(data->client, reg, reg_val);
}

static int bma180_reset_intr(struct bma180_data *data)
{
	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);

	if (ret)
		dev_err(&data->client->dev, "failed to reset interrupt\n");

	return ret;
}

static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
{
	u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
	int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
			reg_val);

	if (ret)
		goto err;
	ret = bma180_reset_intr(data);
	if (ret)
		goto err;

	return 0;

err:
	dev_err(&data->client->dev,
		"failed to set new data interrupt state %d\n", state);
	return ret;
}

static int bma180_set_sleep_state(struct bma180_data *data, int state)
{
	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);

	if (ret) {
		dev_err(&data->client->dev,
			"failed to set sleep state %d\n", state);
		return ret;
	}
	data->sleep_state = state;

	return 0;
}

static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
{
	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);

	if (ret)
		dev_err(&data->client->dev,
			"failed to set ee writing state %d\n", state);

	return ret;
}

static int bma180_set_bw(struct bma180_data *data, int val)
{
	int ret, i;

	if (data->sleep_state)
		return -EBUSY;

	for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
		if (bw_table[i] == val) {
			ret = bma180_set_bits(data,
					BMA180_BW_TCS, BMA180_BW, i);
			if (ret) {
				dev_err(&data->client->dev,
					"failed to set bandwidth\n");
				return ret;
			}
			data->bw = val;
			return 0;
		}
	}

	return -EINVAL;
}

static int bma180_set_scale(struct bma180_data *data, int val)
{
	int ret, i;

	if (data->sleep_state)
		return -EBUSY;

	for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
		if (scale_table[i] == val) {
			ret = bma180_set_bits(data,
					BMA180_OFFSET_LSB1, BMA180_RANGE, i);
			if (ret) {
				dev_err(&data->client->dev,
					"failed to set scale\n");
				return ret;
			}
			data->scale = val;
			return 0;
		}

	return -EINVAL;
}

static int bma180_set_pmode(struct bma180_data *data, int mode)
{
	u8 reg_val = mode ? BMA180_LOW_POWER : BMA180_LOW_NOISE;
	int ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG,
			reg_val);

	if (ret) {
		dev_err(&data->client->dev, "failed to set power mode\n");
		return ret;
	}
	data->pmode = mode;

	return 0;
}

static int bma180_soft_reset(struct bma180_data *data)
{
	int ret = i2c_smbus_write_byte_data(data->client,
			BMA180_RESET, BMA180_RESET_VAL);

	if (ret)
		dev_err(&data->client->dev, "failed to reset the chip\n");

	return ret;
}

static int bma180_chip_init(struct bma180_data *data)
{
	/* Try to read chip_id register. It must return 0x03. */
	int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);

	if (ret < 0)
		goto err;
	if (ret != BMA_180_ID_REG_VAL) {
		ret = -ENODEV;
		goto err;
	}

	ret = bma180_soft_reset(data);
	if (ret)
		goto err;
	/*
	 * No serial transaction should occur within minimum 10 us
	 * after soft_reset command
	 */
	msleep(20);

	ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
	if (ret)
		goto err;
	ret = bma180_set_ee_writing_state(data, 1);
	if (ret)
		goto err;
	ret = bma180_set_new_data_intr_state(data, 0);
	if (ret)
		goto err;
	ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
	if (ret)
		goto err;
	ret = bma180_set_pmode(data, BMA180_DEF_PMODE);
	if (ret)
		goto err;
	ret = bma180_set_bw(data, BMA180_DEF_BW);
	if (ret)
		goto err;
	ret = bma180_set_scale(data, BMA180_DEF_SCALE);
	if (ret)
		goto err;

	return 0;

err:
	dev_err(&data->client->dev, "failed to init the chip\n");
	return ret;
}

static void bma180_chip_disable(struct bma180_data *data)
{
	if (bma180_set_new_data_intr_state(data, 0))
		goto err;
	if (bma180_set_ee_writing_state(data, 0))
		goto err;
	if (bma180_set_sleep_state(data, 1))
		goto err;

	return;

err:
	dev_err(&data->client->dev, "failed to disable the chip\n");
}

static IIO_CONST_ATTR(in_accel_filter_low_pass_3db_frequency_available,
		BMA180_FLP_FREQ_AVAILABLE);
static IIO_CONST_ATTR(in_accel_scale_available, BMA180_SCALE_AVAILABLE);

static struct attribute *bma180_attributes[] = {
	&iio_const_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,
	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
	NULL,
};

static const struct attribute_group bma180_attrs_group = {
	.attrs = bma180_attributes,
};

static int bma180_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan, int *val, int *val2,
		long mask)
{
	struct bma180_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&data->mutex);
		if (iio_buffer_enabled(indio_dev))
			ret = -EBUSY;
		else
			ret = bma180_get_acc_reg(data, chan->scan_index);
		mutex_unlock(&data->mutex);
		if (ret < 0)
			return ret;
		*val = (s16)ret >> chan->scan_type.shift;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
		*val = data->bw;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = data->scale;
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		return -EINVAL;
	}
}

static int bma180_write_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan, int val, int val2, long mask)
{
	struct bma180_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
		if (val)
			return -EINVAL;
		mutex_lock(&data->mutex);
		ret = bma180_set_scale(data, val2);
		mutex_unlock(&data->mutex);
		return ret;
	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
		mutex_lock(&data->mutex);
		ret = bma180_set_bw(data, val);
		mutex_unlock(&data->mutex);
		return ret;
	default:
		return -EINVAL;
	}
}

static int bma180_update_scan_mode(struct iio_dev *indio_dev,
		const unsigned long *scan_mask)
{
	struct bma180_data *data = iio_priv(indio_dev);

	if (data->buff)
		devm_kfree(&indio_dev->dev, data->buff);
	data->buff = devm_kzalloc(&indio_dev->dev,
			indio_dev->scan_bytes, GFP_KERNEL);
	if (!data->buff)
		return -ENOMEM;

	return 0;
}

static const struct iio_info bma180_info = {
	.attrs			= &bma180_attrs_group,
	.read_raw		= bma180_read_raw,
	.write_raw		= bma180_write_raw,
	.update_scan_mode	= bma180_update_scan_mode,
	.driver_module		= THIS_MODULE,
};

static const char * const bma180_power_modes[] = {
	BMA180_LOW_NOISE_STR,
	BMA180_LOW_POWER_STR,
};

static int bma180_get_power_mode(struct iio_dev *indio_dev,
		const struct iio_chan_spec *chan)
{
	struct bma180_data *data = iio_priv(indio_dev);

	return data->pmode;
}

static int bma180_set_power_mode(struct iio_dev *indio_dev,
		const struct iio_chan_spec *chan, unsigned int mode)
{
	struct bma180_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = bma180_set_pmode(data, mode);
	mutex_unlock(&data->mutex);

	return ret;
}

static const struct iio_enum bma180_power_mode_enum = {
	.items = bma180_power_modes,
	.num_items = ARRAY_SIZE(bma180_power_modes),
	.get = bma180_get_power_mode,
	.set = bma180_set_power_mode,
};

static const struct iio_chan_spec_ext_info bma180_ext_info[] = {
	IIO_ENUM("power_mode", true, &bma180_power_mode_enum),
	IIO_ENUM_AVAILABLE("power_mode", &bma180_power_mode_enum),
	{ },
};

#define BMA180_CHANNEL(_axis) {					\
	.type = IIO_ACCEL,						\
	.modified = 1,							\
	.channel2 = IIO_MOD_##_axis,					\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
	.scan_index = AXIS_##_axis,					\
	.scan_type = {							\
		.sign = 's',						\
		.realbits = 14,						\
		.storagebits = 16,					\
		.shift = 2,						\
	},								\
	.ext_info = bma180_ext_info,					\
}

static const struct iio_chan_spec bma180_channels[] = {
	BMA180_CHANNEL(X),
	BMA180_CHANNEL(Y),
	BMA180_CHANNEL(Z),
	IIO_CHAN_SOFT_TIMESTAMP(3),
};

static irqreturn_t bma180_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct bma180_data *data = iio_priv(indio_dev);
	int64_t time_ns = iio_get_time_ns();
	int bit, ret, i = 0;

	mutex_lock(&data->mutex);

	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
			 indio_dev->masklength) {
		ret = bma180_get_acc_reg(data, bit);
		if (ret < 0) {
			mutex_unlock(&data->mutex);
			goto err;
		}
		((s16 *)data->buff)[i++] = ret;
	}
	mutex_unlock(&data->mutex);

	iio_push_to_buffers_with_timestamp(indio_dev, data->buff, time_ns);
err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
		bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct bma180_data *data = iio_priv(indio_dev);

	return bma180_set_new_data_intr_state(data, state);
}

static int bma180_trig_try_reen(struct iio_trigger *trig)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct bma180_data *data = iio_priv(indio_dev);

	return bma180_reset_intr(data);
}

static const struct iio_trigger_ops bma180_trigger_ops = {
	.set_trigger_state = bma180_data_rdy_trigger_set_state,
	.try_reenable = bma180_trig_try_reen,
	.owner = THIS_MODULE,
};

static int bma180_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
{
	struct bma180_data *data;
	struct iio_dev *indio_dev;
	struct iio_trigger *trig;
	int ret;

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

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;

	ret = bma180_chip_init(data);
	if (ret < 0)
		goto err_chip_disable;

	mutex_init(&data->mutex);

	indio_dev->dev.parent = &client->dev;
	indio_dev->channels = bma180_channels;
	indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
	indio_dev->name = BMA180_DRV_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &bma180_info;

	trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
	if (!trig) {
		ret = -ENOMEM;
		goto err_chip_disable;
	}

	ret = devm_request_irq(&client->dev, client->irq,
			iio_trigger_generic_data_rdy_poll,
			IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
	if (ret) {
		dev_err(&client->dev, "unable to request IRQ\n");
		goto err_trigger_free;
	}

	trig->dev.parent = &client->dev;
	trig->ops = &bma180_trigger_ops;
	iio_trigger_set_drvdata(trig, indio_dev);
	data->trig = trig;
	indio_dev->trig = trig;

	ret = iio_trigger_register(trig);
	if (ret)
		goto err_trigger_free;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
			bma180_trigger_handler, NULL);
	if (ret < 0) {
		dev_err(&client->dev, "unable to setup iio triggered buffer\n");
		goto err_trigger_unregister;
	}

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(&client->dev, "unable to register iio device\n");
		goto err_buffer_cleanup;
	}

	return 0;

err_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
err_trigger_unregister:
	iio_trigger_unregister(trig);
err_trigger_free:
	iio_trigger_free(trig);
err_chip_disable:
	bma180_chip_disable(data);

	return ret;
}

static int bma180_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct bma180_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	iio_trigger_unregister(data->trig);
	iio_trigger_free(data->trig);

	mutex_lock(&data->mutex);
	bma180_chip_disable(data);
	mutex_unlock(&data->mutex);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int bma180_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct bma180_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = bma180_set_sleep_state(data, 1);
	mutex_unlock(&data->mutex);

	return ret;
}

static int bma180_resume(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct bma180_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = bma180_set_sleep_state(data, 0);
	mutex_unlock(&data->mutex);

	return ret;
}

static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
#define BMA180_PM_OPS (&bma180_pm_ops)
#else
#define BMA180_PM_OPS NULL
#endif

static struct i2c_device_id bma180_id[] = {
	{ BMA180_DRV_NAME, 0 },
	{ }
};

MODULE_DEVICE_TABLE(i2c, bma180_id);

static struct i2c_driver bma180_driver = {
	.driver = {
		.name	= BMA180_DRV_NAME,
		.owner	= THIS_MODULE,
		.pm	= BMA180_PM_OPS,
	},
	.probe		= bma180_probe,
	.remove		= bma180_remove,
	.id_table	= bma180_id,
};

module_i2c_driver(bma180_driver);

MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
MODULE_AUTHOR("Texas Instruments, Inc.");
MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
MODULE_LICENSE("GPL");