summaryrefslogtreecommitdiffstats
path: root/drivers/iio/accel/stk8ba50.c
blob: c70ddec29eb49ffebed0306e15cebed5e25c1f59 (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
// SPDX-License-Identifier: GPL-2.0-only
/**
 * Sensortek STK8BA50 3-Axis Accelerometer
 *
 * Copyright (c) 2015, Intel Corporation.
 *
 * STK8BA50 7-bit I2C address: 0x18.
 */

#include <linux/acpi.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>

#define STK8BA50_REG_XOUT			0x02
#define STK8BA50_REG_YOUT			0x04
#define STK8BA50_REG_ZOUT			0x06
#define STK8BA50_REG_RANGE			0x0F
#define STK8BA50_REG_BWSEL			0x10
#define STK8BA50_REG_POWMODE			0x11
#define STK8BA50_REG_SWRST			0x14
#define STK8BA50_REG_INTEN2			0x17
#define STK8BA50_REG_INTMAP2			0x1A

#define STK8BA50_MODE_NORMAL			0
#define STK8BA50_MODE_SUSPEND			1
#define STK8BA50_MODE_POWERBIT			BIT(7)
#define STK8BA50_DATA_SHIFT			6
#define STK8BA50_RESET_CMD			0xB6
#define STK8BA50_SR_1792HZ_IDX			7
#define STK8BA50_DREADY_INT_MASK		0x10
#define STK8BA50_DREADY_INT_MAP			0x81
#define STK8BA50_ALL_CHANNEL_MASK		7
#define STK8BA50_ALL_CHANNEL_SIZE		6

#define STK8BA50_DRIVER_NAME			"stk8ba50"
#define STK8BA50_IRQ_NAME			"stk8ba50_event"

#define STK8BA50_SCALE_AVAIL			"0.0384 0.0767 0.1534 0.3069"

/*
 * The accelerometer has four measurement ranges:
 * +/-2g; +/-4g; +/-8g; +/-16g
 *
 * Acceleration values are 10-bit, 2's complement.
 * Scales are calculated as following:
 *
 * scale1 = (2 + 2) * 9.81 / (2^10 - 1)   = 0.0384
 * scale2 = (4 + 4) * 9.81 / (2^10 - 1)   = 0.0767
 * etc.
 *
 * Scales are stored in this format:
 * { <register value>, <scale value> }
 *
 * Locally, the range is stored as a table index.
 */
static const struct {
	u8 reg_val;
	u32 scale_val;
} stk8ba50_scale_table[] = {
	{3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
};

/* Sample rates are stored as { <register value>, <Hz value> } */
static const struct {
	u8 reg_val;
	u16 samp_freq;
} stk8ba50_samp_freq_table[] = {
	{0x08, 14},  {0x09, 25},  {0x0A, 56},  {0x0B, 112},
	{0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
};

/* Used to map scan mask bits to their corresponding channel register. */
static const int stk8ba50_channel_table[] = {
	STK8BA50_REG_XOUT,
	STK8BA50_REG_YOUT,
	STK8BA50_REG_ZOUT
};

struct stk8ba50_data {
	struct i2c_client *client;
	struct mutex lock;
	int range;
	u8 sample_rate_idx;
	struct iio_trigger *dready_trig;
	bool dready_trigger_on;
	/*
	 * 3 x 16-bit channels (10-bit data, 6-bit padding) +
	 * 1 x 16 padding +
	 * 4 x 16 64-bit timestamp
	 */
	s16 buffer[8];
};

#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) {			\
	.type = IIO_ACCEL,						\
	.address = reg,							\
	.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_SAMP_FREQ),	\
	.scan_index = index,						\
	.scan_type = {							\
		.sign = 's',						\
		.realbits = 10,						\
		.storagebits = 16,					\
		.shift = STK8BA50_DATA_SHIFT,				\
		.endianness = IIO_CPU,					\
	},								\
}

static const struct iio_chan_spec stk8ba50_channels[] = {
	STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
	STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
	STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
	IIO_CHAN_SOFT_TIMESTAMP(3),
};

static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");

static struct attribute *stk8ba50_attributes[] = {
	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
	NULL,
};

static const struct attribute_group stk8ba50_attribute_group = {
	.attrs = stk8ba50_attributes
};

static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
{
	int ret;
	struct i2c_client *client = data->client;

	ret = i2c_smbus_read_word_data(client, reg);
	if (ret < 0) {
		dev_err(&client->dev, "register read failed\n");
		return ret;
	}

	return ret;
}

static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
					       bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct stk8ba50_data *data = iio_priv(indio_dev);
	int ret;

	if (state)
		ret = i2c_smbus_write_byte_data(data->client,
			STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
	else
		ret = i2c_smbus_write_byte_data(data->client,
			STK8BA50_REG_INTEN2, 0x00);

	if (ret < 0)
		dev_err(&data->client->dev, "failed to set trigger state\n");
	else
		data->dready_trigger_on = state;

	return ret;
}

static const struct iio_trigger_ops stk8ba50_trigger_ops = {
	.set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
};

static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
{
	int ret;
	u8 masked_reg;
	struct i2c_client *client = data->client;

	ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
	if (ret < 0)
		goto exit_err;

	if (mode)
		masked_reg = ret | STK8BA50_MODE_POWERBIT;
	else
		masked_reg = ret & (~STK8BA50_MODE_POWERBIT);

	ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
					masked_reg);
	if (ret < 0)
		goto exit_err;

	return ret;

exit_err:
	dev_err(&client->dev, "failed to change sensor mode\n");
	return ret;
}

static int stk8ba50_read_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int *val, int *val2, long mask)
{
	struct stk8ba50_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (iio_buffer_enabled(indio_dev))
			return -EBUSY;
		mutex_lock(&data->lock);
		ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
		if (ret < 0) {
			mutex_unlock(&data->lock);
			return -EINVAL;
		}
		ret = stk8ba50_read_accel(data, chan->address);
		if (ret < 0) {
			stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
			mutex_unlock(&data->lock);
			return -EINVAL;
		}
		*val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
		stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
		mutex_unlock(&data->lock);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = stk8ba50_scale_table[data->range].scale_val;
		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_SAMP_FREQ:
		*val = stk8ba50_samp_freq_table
				[data->sample_rate_idx].samp_freq;
		*val2 = 0;
		return IIO_VAL_INT;
	}

	return -EINVAL;
}

static int stk8ba50_write_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      int val, int val2, long mask)
{
	int ret;
	int i;
	int index = -1;
	struct stk8ba50_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
		if (val != 0)
			return -EINVAL;

		for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
			if (val2 == stk8ba50_scale_table[i].scale_val) {
				index = i;
				break;
			}
		if (index < 0)
			return -EINVAL;

		ret = i2c_smbus_write_byte_data(data->client,
				STK8BA50_REG_RANGE,
				stk8ba50_scale_table[index].reg_val);
		if (ret < 0)
			dev_err(&data->client->dev,
					"failed to set measurement range\n");
		else
			data->range = index;

		return ret;
	case IIO_CHAN_INFO_SAMP_FREQ:
		for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
			if (val == stk8ba50_samp_freq_table[i].samp_freq) {
				index = i;
				break;
			}
		if (index < 0)
			return -EINVAL;

		ret = i2c_smbus_write_byte_data(data->client,
				STK8BA50_REG_BWSEL,
				stk8ba50_samp_freq_table[index].reg_val);
		if (ret < 0)
			dev_err(&data->client->dev,
					"failed to set sampling rate\n");
		else
			data->sample_rate_idx = index;

		return ret;
	}

	return -EINVAL;
}

static const struct iio_info stk8ba50_info = {
	.read_raw		= stk8ba50_read_raw,
	.write_raw		= stk8ba50_write_raw,
	.attrs			= &stk8ba50_attribute_group,
};

static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct stk8ba50_data *data = iio_priv(indio_dev);
	int bit, ret, i = 0;

	mutex_lock(&data->lock);
	/*
	 * Do a bulk read if all channels are requested,
	 * from 0x02 (XOUT1) to 0x07 (ZOUT2)
	 */
	if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
		ret = i2c_smbus_read_i2c_block_data(data->client,
						    STK8BA50_REG_XOUT,
						    STK8BA50_ALL_CHANNEL_SIZE,
						    (u8 *)data->buffer);
		if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
			dev_err(&data->client->dev, "register read failed\n");
			goto err;
		}
	} else {
		for_each_set_bit(bit, indio_dev->active_scan_mask,
				 indio_dev->masklength) {
			ret = stk8ba50_read_accel(data,
						  stk8ba50_channel_table[bit]);
			if (ret < 0)
				goto err;

			data->buffer[i++] = ret;
		}
	}
	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
					   pf->timestamp);
err:
	mutex_unlock(&data->lock);
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
{
	struct iio_dev *indio_dev = private;
	struct stk8ba50_data *data = iio_priv(indio_dev);

	if (data->dready_trigger_on)
		iio_trigger_poll(data->dready_trig);

	return IRQ_HANDLED;
}

static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
{
	struct stk8ba50_data *data = iio_priv(indio_dev);

	return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
}

static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
{
	struct stk8ba50_data *data = iio_priv(indio_dev);

	return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
}

static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
	.preenable   = stk8ba50_buffer_preenable,
	.postenable  = iio_triggered_buffer_postenable,
	.predisable  = iio_triggered_buffer_predisable,
	.postdisable = stk8ba50_buffer_postdisable,
};

static int stk8ba50_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	int ret;
	struct iio_dev *indio_dev;
	struct stk8ba50_data *data;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev) {
		dev_err(&client->dev, "iio allocation failed!\n");
		return -ENOMEM;
	}

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

	indio_dev->dev.parent = &client->dev;
	indio_dev->info = &stk8ba50_info;
	indio_dev->name = STK8BA50_DRIVER_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = stk8ba50_channels;
	indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);

	/* Reset all registers on startup */
	ret = i2c_smbus_write_byte_data(client,
			STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
	if (ret < 0) {
		dev_err(&client->dev, "failed to reset sensor\n");
		goto err_power_off;
	}

	/* The default range is +/-2g */
	data->range = 0;

	/* The default sampling rate is 1792 Hz (maximum) */
	data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;

	/* Set up interrupts */
	ret = i2c_smbus_write_byte_data(client,
			STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
	if (ret < 0) {
		dev_err(&client->dev, "failed to set up interrupts\n");
		goto err_power_off;
	}
	ret = i2c_smbus_write_byte_data(client,
			STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
	if (ret < 0) {
		dev_err(&client->dev, "failed to set up interrupts\n");
		goto err_power_off;
	}

	if (client->irq > 0) {
		ret = devm_request_threaded_irq(&client->dev, client->irq,
						stk8ba50_data_rdy_trig_poll,
						NULL,
						IRQF_TRIGGER_RISING |
						IRQF_ONESHOT,
						STK8BA50_IRQ_NAME,
						indio_dev);
		if (ret < 0) {
			dev_err(&client->dev, "request irq %d failed\n",
				client->irq);
			goto err_power_off;
		}

		data->dready_trig = devm_iio_trigger_alloc(&client->dev,
							   "%s-dev%d",
							   indio_dev->name,
							   indio_dev->id);
		if (!data->dready_trig) {
			ret = -ENOMEM;
			goto err_power_off;
		}

		data->dready_trig->dev.parent = &client->dev;
		data->dready_trig->ops = &stk8ba50_trigger_ops;
		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
		ret = iio_trigger_register(data->dready_trig);
		if (ret) {
			dev_err(&client->dev, "iio trigger register failed\n");
			goto err_power_off;
		}
	}

	ret = iio_triggered_buffer_setup(indio_dev,
					 iio_pollfunc_store_time,
					 stk8ba50_trigger_handler,
					 &stk8ba50_buffer_setup_ops);
	if (ret < 0) {
		dev_err(&client->dev, "iio triggered buffer setup failed\n");
		goto err_trigger_unregister;
	}

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(&client->dev, "device_register failed\n");
		goto err_buffer_cleanup;
	}

	return ret;

err_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
err_trigger_unregister:
	if (data->dready_trig)
		iio_trigger_unregister(data->dready_trig);
err_power_off:
	stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
	return ret;
}

static int stk8ba50_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct stk8ba50_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);

	if (data->dready_trig)
		iio_trigger_unregister(data->dready_trig);

	return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
}

#ifdef CONFIG_PM_SLEEP
static int stk8ba50_suspend(struct device *dev)
{
	struct stk8ba50_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
}

static int stk8ba50_resume(struct device *dev)
{
	struct stk8ba50_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
}

static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume);

#define STK8BA50_PM_OPS (&stk8ba50_pm_ops)
#else
#define STK8BA50_PM_OPS NULL
#endif

static const struct i2c_device_id stk8ba50_i2c_id[] = {
	{"stk8ba50", 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);

static const struct acpi_device_id stk8ba50_acpi_id[] = {
	{"STK8BA50", 0},
	{}
};

MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);

static struct i2c_driver stk8ba50_driver = {
	.driver = {
		.name = "stk8ba50",
		.pm = STK8BA50_PM_OPS,
		.acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
	},
	.probe =            stk8ba50_probe,
	.remove =           stk8ba50_remove,
	.id_table =         stk8ba50_i2c_id,
};

module_i2c_driver(stk8ba50_driver);

MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");