Bootlin logo

Elixir Cross Referencer

  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
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
/**
 * Copyright (c) 2011 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * A reference industrial I/O driver to illustrate the functionality available.
 *
 * There are numerous real drivers to illustrate the finer points.
 * The purpose of this driver is to provide a driver with far more comments
 * and explanatory notes than any 'real' driver would have.
 * Anyone starting out writing an IIO driver should first make sure they
 * understand all of this driver except those bits specifically marked
 * as being present to allow us to 'fake' the presence of hardware.
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/string.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/buffer.h>
#include <linux/iio/sw_device.h>
#include "iio_simple_dummy.h"

static struct config_item_type iio_dummy_type = {
	.ct_owner = THIS_MODULE,
};

/**
 * struct iio_dummy_accel_calibscale - realworld to register mapping
 * @val: first value in read_raw - here integer part.
 * @val2: second value in read_raw etc - here micro part.
 * @regval: register value - magic device specific numbers.
 */
struct iio_dummy_accel_calibscale {
	int val;
	int val2;
	int regval; /* what would be written to hardware */
};

static const struct iio_dummy_accel_calibscale dummy_scales[] = {
	{ 0, 100, 0x8 }, /* 0.000100 */
	{ 0, 133, 0x7 }, /* 0.000133 */
	{ 733, 13, 0x9 }, /* 733.000013 */
};

#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS

/*
 * simple event - triggered when value rises above
 * a threshold
 */
static const struct iio_event_spec iio_dummy_event = {
	.type = IIO_EV_TYPE_THRESH,
	.dir = IIO_EV_DIR_RISING,
	.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
};

/*
 * simple step detect event - triggered when a step is detected
 */
static const struct iio_event_spec step_detect_event = {
	.type = IIO_EV_TYPE_CHANGE,
	.dir = IIO_EV_DIR_NONE,
	.mask_separate = BIT(IIO_EV_INFO_ENABLE),
};

/*
 * simple transition event - triggered when the reported running confidence
 * value rises above a threshold value
 */
static const struct iio_event_spec iio_running_event = {
	.type = IIO_EV_TYPE_THRESH,
	.dir = IIO_EV_DIR_RISING,
	.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
};

/*
 * simple transition event - triggered when the reported walking confidence
 * value falls under a threshold value
 */
static const struct iio_event_spec iio_walking_event = {
	.type = IIO_EV_TYPE_THRESH,
	.dir = IIO_EV_DIR_FALLING,
	.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
};
#endif

/*
 * iio_dummy_channels - Description of available channels
 *
 * This array of structures tells the IIO core about what the device
 * actually provides for a given channel.
 */
static const struct iio_chan_spec iio_dummy_channels[] = {
	/* indexed ADC channel in_voltage0_raw etc */
	{
		.type = IIO_VOLTAGE,
		/* Channel has a numeric index of 0 */
		.indexed = 1,
		.channel = 0,
		/* What other information is available? */
		.info_mask_separate =
		/*
		 * in_voltage0_raw
		 * Raw (unscaled no bias removal etc) measurement
		 * from the device.
		 */
		BIT(IIO_CHAN_INFO_RAW) |
		/*
		 * in_voltage0_offset
		 * Offset for userspace to apply prior to scale
		 * when converting to standard units (microvolts)
		 */
		BIT(IIO_CHAN_INFO_OFFSET) |
		/*
		 * in_voltage0_scale
		 * Multipler for userspace to apply post offset
		 * when converting to standard units (microvolts)
		 */
		BIT(IIO_CHAN_INFO_SCALE),
		/*
		 * sampling_frequency
		 * The frequency in Hz at which the channels are sampled
		 */
		.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
		/* The ordering of elements in the buffer via an enum */
		.scan_index = DUMMY_INDEX_VOLTAGE_0,
		.scan_type = { /* Description of storage in buffer */
			.sign = 'u', /* unsigned */
			.realbits = 13, /* 13 bits */
			.storagebits = 16, /* 16 bits used for storage */
			.shift = 0, /* zero shift */
		},
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
		.event_spec = &iio_dummy_event,
		.num_event_specs = 1,
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
	},
	/* Differential ADC channel in_voltage1-voltage2_raw etc*/
	{
		.type = IIO_VOLTAGE,
		.differential = 1,
		/*
		 * Indexing for differential channels uses channel
		 * for the positive part, channel2 for the negative.
		 */
		.indexed = 1,
		.channel = 1,
		.channel2 = 2,
		/*
		 * in_voltage1-voltage2_raw
		 * Raw (unscaled no bias removal etc) measurement
		 * from the device.
		 */
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		/*
		 * in_voltage-voltage_scale
		 * Shared version of scale - shared by differential
		 * input channels of type IIO_VOLTAGE.
		 */
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
		/*
		 * sampling_frequency
		 * The frequency in Hz at which the channels are sampled
		 */
		.scan_index = DUMMY_INDEX_DIFFVOLTAGE_1M2,
		.scan_type = { /* Description of storage in buffer */
			.sign = 's', /* signed */
			.realbits = 12, /* 12 bits */
			.storagebits = 16, /* 16 bits used for storage */
			.shift = 0, /* zero shift */
		},
	},
	/* Differential ADC channel in_voltage3-voltage4_raw etc*/
	{
		.type = IIO_VOLTAGE,
		.differential = 1,
		.indexed = 1,
		.channel = 3,
		.channel2 = 4,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
		.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
		.scan_index = DUMMY_INDEX_DIFFVOLTAGE_3M4,
		.scan_type = {
			.sign = 's',
			.realbits = 11,
			.storagebits = 16,
			.shift = 0,
		},
	},
	/*
	 * 'modified' (i.e. axis specified) acceleration channel
	 * in_accel_z_raw
	 */
	{
		.type = IIO_ACCEL,
		.modified = 1,
		/* Channel 2 is use for modifiers */
		.channel2 = IIO_MOD_X,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
		/*
		 * Internal bias and gain correction values. Applied
		 * by the hardware or driver prior to userspace
		 * seeing the readings. Typically part of hardware
		 * calibration.
		 */
		BIT(IIO_CHAN_INFO_CALIBSCALE) |
		BIT(IIO_CHAN_INFO_CALIBBIAS),
		.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
		.scan_index = DUMMY_INDEX_ACCELX,
		.scan_type = { /* Description of storage in buffer */
			.sign = 's', /* signed */
			.realbits = 16, /* 16 bits */
			.storagebits = 16, /* 16 bits used for storage */
			.shift = 0, /* zero shift */
		},
	},
	/*
	 * Convenience macro for timestamps. 4 is the index in
	 * the buffer.
	 */
	IIO_CHAN_SOFT_TIMESTAMP(4),
	/* DAC channel out_voltage0_raw */
	{
		.type = IIO_VOLTAGE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.scan_index = -1, /* No buffer support */
		.output = 1,
		.indexed = 1,
		.channel = 0,
	},
	{
		.type = IIO_STEPS,
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_ENABLE) |
			BIT(IIO_CHAN_INFO_CALIBHEIGHT),
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.scan_index = -1, /* No buffer support */
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
		.event_spec = &step_detect_event,
		.num_event_specs = 1,
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
	},
	{
		.type = IIO_ACTIVITY,
		.modified = 1,
		.channel2 = IIO_MOD_RUNNING,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.scan_index = -1, /* No buffer support */
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
		.event_spec = &iio_running_event,
		.num_event_specs = 1,
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
	},
	{
		.type = IIO_ACTIVITY,
		.modified = 1,
		.channel2 = IIO_MOD_WALKING,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.scan_index = -1, /* No buffer support */
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
		.event_spec = &iio_walking_event,
		.num_event_specs = 1,
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
	},
};

/**
 * iio_dummy_read_raw() - data read function.
 * @indio_dev:	the struct iio_dev associated with this device instance
 * @chan:	the channel whose data is to be read
 * @val:	first element of returned value (typically INT)
 * @val2:	second element of returned value (typically MICRO)
 * @mask:	what we actually want to read as per the info_mask_*
 *		in iio_chan_spec.
 */
static int iio_dummy_read_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      int *val,
			      int *val2,
			      long mask)
{
	struct iio_dummy_state *st = iio_priv(indio_dev);
	int ret = -EINVAL;

	mutex_lock(&st->lock);
	switch (mask) {
	case IIO_CHAN_INFO_RAW: /* magic value - channel value read */
		switch (chan->type) {
		case IIO_VOLTAGE:
			if (chan->output) {
				/* Set integer part to cached value */
				*val = st->dac_val;
				ret = IIO_VAL_INT;
			} else if (chan->differential) {
				if (chan->channel == 1)
					*val = st->differential_adc_val[0];
				else
					*val = st->differential_adc_val[1];
				ret = IIO_VAL_INT;
			} else {
				*val = st->single_ended_adc_val;
				ret = IIO_VAL_INT;
			}
			break;
		case IIO_ACCEL:
			*val = st->accel_val;
			ret = IIO_VAL_INT;
			break;
		default:
			break;
		}
		break;
	case IIO_CHAN_INFO_PROCESSED:
		switch (chan->type) {
		case IIO_STEPS:
			*val = st->steps;
			ret = IIO_VAL_INT;
			break;
		case IIO_ACTIVITY:
			switch (chan->channel2) {
			case IIO_MOD_RUNNING:
				*val = st->activity_running;
				ret = IIO_VAL_INT;
				break;
			case IIO_MOD_WALKING:
				*val = st->activity_walking;
				ret = IIO_VAL_INT;
				break;
			default:
				break;
			}
			break;
		default:
			break;
		}
		break;
	case IIO_CHAN_INFO_OFFSET:
		/* only single ended adc -> 7 */
		*val = 7;
		ret = IIO_VAL_INT;
		break;
	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_VOLTAGE:
			switch (chan->differential) {
			case 0:
				/* only single ended adc -> 0.001333 */
				*val = 0;
				*val2 = 1333;
				ret = IIO_VAL_INT_PLUS_MICRO;
				break;
			case 1:
				/* all differential adc -> 0.000001344 */
				*val = 0;
				*val2 = 1344;
				ret = IIO_VAL_INT_PLUS_NANO;
			}
			break;
		default:
			break;
		}
		break;
	case IIO_CHAN_INFO_CALIBBIAS:
		/* only the acceleration axis - read from cache */
		*val = st->accel_calibbias;
		ret = IIO_VAL_INT;
		break;
	case IIO_CHAN_INFO_CALIBSCALE:
		*val = st->accel_calibscale->val;
		*val2 = st->accel_calibscale->val2;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;
	case IIO_CHAN_INFO_SAMP_FREQ:
		*val = 3;
		*val2 = 33;
		ret = IIO_VAL_INT_PLUS_NANO;
		break;
	case IIO_CHAN_INFO_ENABLE:
		switch (chan->type) {
		case IIO_STEPS:
			*val = st->steps_enabled;
			ret = IIO_VAL_INT;
			break;
		default:
			break;
		}
		break;
	case IIO_CHAN_INFO_CALIBHEIGHT:
		switch (chan->type) {
		case IIO_STEPS:
			*val = st->height;
			ret = IIO_VAL_INT;
			break;
		default:
			break;
		}
		break;

	default:
		break;
	}
	mutex_unlock(&st->lock);
	return ret;
}

/**
 * iio_dummy_write_raw() - data write function.
 * @indio_dev:	the struct iio_dev associated with this device instance
 * @chan:	the channel whose data is to be written
 * @val:	first element of value to set (typically INT)
 * @val2:	second element of value to set (typically MICRO)
 * @mask:	what we actually want to write as per the info_mask_*
 *		in iio_chan_spec.
 *
 * Note that all raw writes are assumed IIO_VAL_INT and info mask elements
 * are assumed to be IIO_INT_PLUS_MICRO unless the callback write_raw_get_fmt
 * in struct iio_info is provided by the driver.
 */
static int iio_dummy_write_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan,
			       int val,
			       int val2,
			       long mask)
{
	int i;
	int ret = 0;
	struct iio_dummy_state *st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		switch (chan->type) {
		case IIO_VOLTAGE:
			if (chan->output == 0)
				return -EINVAL;

			/* Locking not required as writing single value */
			mutex_lock(&st->lock);
			st->dac_val = val;
			mutex_unlock(&st->lock);
			return 0;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_PROCESSED:
		switch (chan->type) {
		case IIO_STEPS:
			mutex_lock(&st->lock);
			st->steps = val;
			mutex_unlock(&st->lock);
			return 0;
		case IIO_ACTIVITY:
			if (val < 0)
				val = 0;
			if (val > 100)
				val = 100;
			switch (chan->channel2) {
			case IIO_MOD_RUNNING:
				st->activity_running = val;
				return 0;
			case IIO_MOD_WALKING:
				st->activity_walking = val;
				return 0;
			default:
				return -EINVAL;
			}
			break;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_CALIBSCALE:
		mutex_lock(&st->lock);
		/* Compare against table - hard matching here */
		for (i = 0; i < ARRAY_SIZE(dummy_scales); i++)
			if (val == dummy_scales[i].val &&
			    val2 == dummy_scales[i].val2)
				break;
		if (i == ARRAY_SIZE(dummy_scales))
			ret = -EINVAL;
		else
			st->accel_calibscale = &dummy_scales[i];
		mutex_unlock(&st->lock);
		return ret;
	case IIO_CHAN_INFO_CALIBBIAS:
		mutex_lock(&st->lock);
		st->accel_calibbias = val;
		mutex_unlock(&st->lock);
		return 0;
	case IIO_CHAN_INFO_ENABLE:
		switch (chan->type) {
		case IIO_STEPS:
			mutex_lock(&st->lock);
			st->steps_enabled = val;
			mutex_unlock(&st->lock);
			return 0;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_CALIBHEIGHT:
		switch (chan->type) {
		case IIO_STEPS:
			st->height = val;
			return 0;
		default:
			return -EINVAL;
		}

	default:
		return -EINVAL;
	}
}

/*
 * Device type specific information.
 */
static const struct iio_info iio_dummy_info = {
	.driver_module = THIS_MODULE,
	.read_raw = &iio_dummy_read_raw,
	.write_raw = &iio_dummy_write_raw,
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
	.read_event_config = &iio_simple_dummy_read_event_config,
	.write_event_config = &iio_simple_dummy_write_event_config,
	.read_event_value = &iio_simple_dummy_read_event_value,
	.write_event_value = &iio_simple_dummy_write_event_value,
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
};

/**
 * iio_dummy_init_device() - device instance specific init
 * @indio_dev: the iio device structure
 *
 * Most drivers have one of these to set up default values,
 * reset the device to known state etc.
 */
static int iio_dummy_init_device(struct iio_dev *indio_dev)
{
	struct iio_dummy_state *st = iio_priv(indio_dev);

	st->dac_val = 0;
	st->single_ended_adc_val = 73;
	st->differential_adc_val[0] = 33;
	st->differential_adc_val[1] = -34;
	st->accel_val = 34;
	st->accel_calibbias = -7;
	st->accel_calibscale = &dummy_scales[0];
	st->steps = 47;
	st->activity_running = 98;
	st->activity_walking = 4;

	return 0;
}

/**
 * iio_dummy_probe() - device instance probe
 * @index: an id number for this instance.
 *
 * Arguments are bus type specific.
 * I2C: iio_dummy_probe(struct i2c_client *client,
 *                      const struct i2c_device_id *id)
 * SPI: iio_dummy_probe(struct spi_device *spi)
 */
static struct iio_sw_device *iio_dummy_probe(const char *name)
{
	int ret;
	struct iio_dev *indio_dev;
	struct iio_dummy_state *st;
	struct iio_sw_device *swd;

	swd = kzalloc(sizeof(*swd), GFP_KERNEL);
	if (!swd) {
		ret = -ENOMEM;
		goto error_kzalloc;
	}
	/*
	 * Allocate an IIO device.
	 *
	 * This structure contains all generic state
	 * information about the device instance.
	 * It also has a region (accessed by iio_priv()
	 * for chip specific state information.
	 */
	indio_dev = iio_device_alloc(sizeof(*st));
	if (!indio_dev) {
		ret = -ENOMEM;
		goto error_ret;
	}

	st = iio_priv(indio_dev);
	mutex_init(&st->lock);

	iio_dummy_init_device(indio_dev);
	/*
	 * With hardware: Set the parent device.
	 * indio_dev->dev.parent = &spi->dev;
	 * indio_dev->dev.parent = &client->dev;
	 */

	 /*
	 * Make the iio_dev struct available to remove function.
	 * Bus equivalents
	 * i2c_set_clientdata(client, indio_dev);
	 * spi_set_drvdata(spi, indio_dev);
	 */
	swd->device = indio_dev;

	/*
	 * Set the device name.
	 *
	 * This is typically a part number and obtained from the module
	 * id table.
	 * e.g. for i2c and spi:
	 *    indio_dev->name = id->name;
	 *    indio_dev->name = spi_get_device_id(spi)->name;
	 */
	indio_dev->name = kstrdup(name, GFP_KERNEL);

	/* Provide description of available channels */
	indio_dev->channels = iio_dummy_channels;
	indio_dev->num_channels = ARRAY_SIZE(iio_dummy_channels);

	/*
	 * Provide device type specific interface functions and
	 * constant data.
	 */
	indio_dev->info = &iio_dummy_info;

	/* Specify that device provides sysfs type interfaces */
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = iio_simple_dummy_events_register(indio_dev);
	if (ret < 0)
		goto error_free_device;

	ret = iio_simple_dummy_configure_buffer(indio_dev);
	if (ret < 0)
		goto error_unregister_events;

	ret = iio_device_register(indio_dev);
	if (ret < 0)
		goto error_unconfigure_buffer;

	iio_swd_group_init_type_name(swd, name, &iio_dummy_type);

	return swd;
error_unconfigure_buffer:
	iio_simple_dummy_unconfigure_buffer(indio_dev);
error_unregister_events:
	iio_simple_dummy_events_unregister(indio_dev);
error_free_device:
	iio_device_free(indio_dev);
error_ret:
	kfree(swd);
error_kzalloc:
	return ERR_PTR(ret);
}

/**
 * iio_dummy_remove() - device instance removal function
 * @swd: pointer to software IIO device abstraction
 *
 * Parameters follow those of iio_dummy_probe for buses.
 */
static int iio_dummy_remove(struct iio_sw_device *swd)
{
	/*
	 * Get a pointer to the device instance iio_dev structure
	 * from the bus subsystem. E.g.
	 * struct iio_dev *indio_dev = i2c_get_clientdata(client);
	 * struct iio_dev *indio_dev = spi_get_drvdata(spi);
	 */
	struct iio_dev *indio_dev = swd->device;

	/* Unregister the device */
	iio_device_unregister(indio_dev);

	/* Device specific code to power down etc */

	/* Buffered capture related cleanup */
	iio_simple_dummy_unconfigure_buffer(indio_dev);

	iio_simple_dummy_events_unregister(indio_dev);

	/* Free all structures */
	kfree(indio_dev->name);
	iio_device_free(indio_dev);

	return 0;
}
/**
 * module_iio_sw_device_driver() -  device driver registration
 *
 * Varies depending on bus type of the device. As there is no device
 * here, call probe directly. For information on device registration
 * i2c:
 * Documentation/i2c/writing-clients
 * spi:
 * Documentation/spi/spi-summary
 */
static const struct iio_sw_device_ops iio_dummy_device_ops = {
	.probe = iio_dummy_probe,
	.remove = iio_dummy_remove,
};

static struct iio_sw_device_type iio_dummy_device = {
	.name = "dummy",
	.owner = THIS_MODULE,
	.ops = &iio_dummy_device_ops,
};

module_iio_sw_device_driver(iio_dummy_device);

MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("IIO dummy driver");
MODULE_LICENSE("GPL v2");