1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2011 Jonathan Cameron
4 *
5 * A reference industrial I/O driver to illustrate the functionality available.
6 *
7 * There are numerous real drivers to illustrate the finer points.
8 * The purpose of this driver is to provide a driver with far more comments
9 * and explanatory notes than any 'real' driver would have.
10 * Anyone starting out writing an IIO driver should first make sure they
11 * understand all of this driver except those bits specifically marked
12 * as being present to allow us to 'fake' the presence of hardware.
13 */
14#include <linux/kernel.h>
15#include <linux/slab.h>
16#include <linux/module.h>
17#include <linux/string.h>
18
19#include <linux/iio/iio.h>
20#include <linux/iio/sysfs.h>
21#include <linux/iio/events.h>
22#include <linux/iio/buffer.h>
23#include <linux/iio/sw_device.h>
24#include "iio_simple_dummy.h"
25
26static const struct config_item_type iio_dummy_type = {
27 .ct_owner = THIS_MODULE,
28};
29
30/**
31 * struct iio_dummy_accel_calibscale - realworld to register mapping
32 * @val: first value in read_raw - here integer part.
33 * @val2: second value in read_raw etc - here micro part.
34 * @regval: register value - magic device specific numbers.
35 */
36struct iio_dummy_accel_calibscale {
37 int val;
38 int val2;
39 int regval; /* what would be written to hardware */
40};
41
42static const struct iio_dummy_accel_calibscale dummy_scales[] = {
43 { 0, 100, 0x8 }, /* 0.000100 */
44 { 0, 133, 0x7 }, /* 0.000133 */
45 { 733, 13, 0x9 }, /* 733.000013 */
46};
47
48#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
49
50/*
51 * simple event - triggered when value rises above
52 * a threshold
53 */
54static const struct iio_event_spec iio_dummy_event = {
55 .type = IIO_EV_TYPE_THRESH,
56 .dir = IIO_EV_DIR_RISING,
57 .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
58};
59
60/*
61 * simple step detect event - triggered when a step is detected
62 */
63static const struct iio_event_spec step_detect_event = {
64 .type = IIO_EV_TYPE_CHANGE,
65 .dir = IIO_EV_DIR_NONE,
66 .mask_separate = BIT(IIO_EV_INFO_ENABLE),
67};
68
69/*
70 * simple transition event - triggered when the reported running confidence
71 * value rises above a threshold value
72 */
73static const struct iio_event_spec iio_running_event = {
74 .type = IIO_EV_TYPE_THRESH,
75 .dir = IIO_EV_DIR_RISING,
76 .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
77};
78
79/*
80 * simple transition event - triggered when the reported walking confidence
81 * value falls under a threshold value
82 */
83static const struct iio_event_spec iio_walking_event = {
84 .type = IIO_EV_TYPE_THRESH,
85 .dir = IIO_EV_DIR_FALLING,
86 .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
87};
88#endif
89
90/*
91 * iio_dummy_channels - Description of available channels
92 *
93 * This array of structures tells the IIO core about what the device
94 * actually provides for a given channel.
95 */
96static const struct iio_chan_spec iio_dummy_channels[] = {
97 /* indexed ADC channel in_voltage0_raw etc */
98 {
99 .type = IIO_VOLTAGE,
100 /* Channel has a numeric index of 0 */
101 .indexed = 1,
102 .channel = 0,
103 /* What other information is available? */
104 .info_mask_separate =
105 /*
106 * in_voltage0_raw
107 * Raw (unscaled no bias removal etc) measurement
108 * from the device.
109 */
110 BIT(IIO_CHAN_INFO_RAW) |
111 /*
112 * in_voltage0_offset
113 * Offset for userspace to apply prior to scale
114 * when converting to standard units (microvolts)
115 */
116 BIT(IIO_CHAN_INFO_OFFSET) |
117 /*
118 * in_voltage0_scale
119 * Multipler for userspace to apply post offset
120 * when converting to standard units (microvolts)
121 */
122 BIT(IIO_CHAN_INFO_SCALE),
123 /*
124 * sampling_frequency
125 * The frequency in Hz at which the channels are sampled
126 */
127 .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
128 /* The ordering of elements in the buffer via an enum */
129 .scan_index = DUMMY_INDEX_VOLTAGE_0,
130 .scan_type = { /* Description of storage in buffer */
131 .sign = 'u', /* unsigned */
132 .realbits = 13, /* 13 bits */
133 .storagebits = 16, /* 16 bits used for storage */
134 .shift = 0, /* zero shift */
135 },
136#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
137 .event_spec = &iio_dummy_event,
138 .num_event_specs = 1,
139#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
140 },
141 /* Differential ADC channel in_voltage1-voltage2_raw etc*/
142 {
143 .type = IIO_VOLTAGE,
144 .differential = 1,
145 /*
146 * Indexing for differential channels uses channel
147 * for the positive part, channel2 for the negative.
148 */
149 .indexed = 1,
150 .channel = 1,
151 .channel2 = 2,
152 /*
153 * in_voltage1-voltage2_raw
154 * Raw (unscaled no bias removal etc) measurement
155 * from the device.
156 */
157 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
158 /*
159 * in_voltage-voltage_scale
160 * Shared version of scale - shared by differential
161 * input channels of type IIO_VOLTAGE.
162 */
163 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
164 /*
165 * sampling_frequency
166 * The frequency in Hz at which the channels are sampled
167 */
168 .scan_index = DUMMY_INDEX_DIFFVOLTAGE_1M2,
169 .scan_type = { /* Description of storage in buffer */
170 .sign = 's', /* signed */
171 .realbits = 12, /* 12 bits */
172 .storagebits = 16, /* 16 bits used for storage */
173 .shift = 0, /* zero shift */
174 },
175 },
176 /* Differential ADC channel in_voltage3-voltage4_raw etc*/
177 {
178 .type = IIO_VOLTAGE,
179 .differential = 1,
180 .indexed = 1,
181 .channel = 3,
182 .channel2 = 4,
183 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
184 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
185 .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
186 .scan_index = DUMMY_INDEX_DIFFVOLTAGE_3M4,
187 .scan_type = {
188 .sign = 's',
189 .realbits = 11,
190 .storagebits = 16,
191 .shift = 0,
192 },
193 },
194 /*
195 * 'modified' (i.e. axis specified) acceleration channel
196 * in_accel_z_raw
197 */
198 {
199 .type = IIO_ACCEL,
200 .modified = 1,
201 /* Channel 2 is use for modifiers */
202 .channel2 = IIO_MOD_X,
203 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
204 /*
205 * Internal bias and gain correction values. Applied
206 * by the hardware or driver prior to userspace
207 * seeing the readings. Typically part of hardware
208 * calibration.
209 */
210 BIT(IIO_CHAN_INFO_CALIBSCALE) |
211 BIT(IIO_CHAN_INFO_CALIBBIAS),
212 .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
213 .scan_index = DUMMY_INDEX_ACCELX,
214 .scan_type = { /* Description of storage in buffer */
215 .sign = 's', /* signed */
216 .realbits = 16, /* 16 bits */
217 .storagebits = 16, /* 16 bits used for storage */
218 .shift = 0, /* zero shift */
219 },
220 },
221 /*
222 * Convenience macro for timestamps. 4 is the index in
223 * the buffer.
224 */
225 IIO_CHAN_SOFT_TIMESTAMP(4),
226 /* DAC channel out_voltage0_raw */
227 {
228 .type = IIO_VOLTAGE,
229 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
230 .scan_index = -1, /* No buffer support */
231 .output = 1,
232 .indexed = 1,
233 .channel = 0,
234 },
235 {
236 .type = IIO_STEPS,
237 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_ENABLE) |
238 BIT(IIO_CHAN_INFO_CALIBHEIGHT),
239 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
240 .scan_index = -1, /* No buffer support */
241#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
242 .event_spec = &step_detect_event,
243 .num_event_specs = 1,
244#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
245 },
246 {
247 .type = IIO_ACTIVITY,
248 .modified = 1,
249 .channel2 = IIO_MOD_RUNNING,
250 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
251 .scan_index = -1, /* No buffer support */
252#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
253 .event_spec = &iio_running_event,
254 .num_event_specs = 1,
255#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
256 },
257 {
258 .type = IIO_ACTIVITY,
259 .modified = 1,
260 .channel2 = IIO_MOD_WALKING,
261 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
262 .scan_index = -1, /* No buffer support */
263#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
264 .event_spec = &iio_walking_event,
265 .num_event_specs = 1,
266#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
267 },
268};
269
270/**
271 * iio_dummy_read_raw() - data read function.
272 * @indio_dev: the struct iio_dev associated with this device instance
273 * @chan: the channel whose data is to be read
274 * @val: first element of returned value (typically INT)
275 * @val2: second element of returned value (typically MICRO)
276 * @mask: what we actually want to read as per the info_mask_*
277 * in iio_chan_spec.
278 */
279static int iio_dummy_read_raw(struct iio_dev *indio_dev,
280 struct iio_chan_spec const *chan,
281 int *val,
282 int *val2,
283 long mask)
284{
285 struct iio_dummy_state *st = iio_priv(indio_dev);
286
287 switch (mask) {
288 case IIO_CHAN_INFO_RAW: /* magic value - channel value read */
289 iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
290 guard(mutex)(T: &st->lock);
291 switch (chan->type) {
292 case IIO_VOLTAGE:
293 if (chan->output) {
294 /* Set integer part to cached value */
295 *val = st->dac_val;
296 return IIO_VAL_INT;
297 } else if (chan->differential) {
298 if (chan->channel == 1)
299 *val = st->differential_adc_val[0];
300 else
301 *val = st->differential_adc_val[1];
302 return IIO_VAL_INT;
303 } else {
304 *val = st->single_ended_adc_val;
305 return IIO_VAL_INT;
306 }
307
308 case IIO_ACCEL:
309 *val = st->accel_val;
310 return IIO_VAL_INT;
311 default:
312 return -EINVAL;
313 }
314 }
315 unreachable();
316 case IIO_CHAN_INFO_PROCESSED:
317 iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
318 guard(mutex)(T: &st->lock);
319 switch (chan->type) {
320 case IIO_STEPS:
321 *val = st->steps;
322 return IIO_VAL_INT;
323 case IIO_ACTIVITY:
324 switch (chan->channel2) {
325 case IIO_MOD_RUNNING:
326 *val = st->activity_running;
327 return IIO_VAL_INT;
328 case IIO_MOD_WALKING:
329 *val = st->activity_walking;
330 return IIO_VAL_INT;
331 default:
332 return -EINVAL;
333 }
334 default:
335 return -EINVAL;
336 }
337 }
338 unreachable();
339 case IIO_CHAN_INFO_OFFSET:
340 /* only single ended adc -> 7 */
341 *val = 7;
342 return IIO_VAL_INT;
343 case IIO_CHAN_INFO_SCALE:
344 switch (chan->type) {
345 case IIO_VOLTAGE:
346 switch (chan->differential) {
347 case 0:
348 /* only single ended adc -> 0.001333 */
349 *val = 0;
350 *val2 = 1333;
351 return IIO_VAL_INT_PLUS_MICRO;
352 case 1:
353 /* all differential adc -> 0.000001344 */
354 *val = 0;
355 *val2 = 1344;
356 return IIO_VAL_INT_PLUS_NANO;
357 default:
358 return -EINVAL;
359 }
360 default:
361 return -EINVAL;
362 }
363 case IIO_CHAN_INFO_CALIBBIAS: {
364 guard(mutex)(T: &st->lock);
365 /* only the acceleration axis - read from cache */
366 *val = st->accel_calibbias;
367 return IIO_VAL_INT;
368 }
369 case IIO_CHAN_INFO_CALIBSCALE: {
370 guard(mutex)(T: &st->lock);
371 *val = st->accel_calibscale->val;
372 *val2 = st->accel_calibscale->val2;
373 return IIO_VAL_INT_PLUS_MICRO;
374 }
375 case IIO_CHAN_INFO_SAMP_FREQ:
376 *val = 3;
377 *val2 = 33;
378 return IIO_VAL_INT_PLUS_NANO;
379 case IIO_CHAN_INFO_ENABLE: {
380 guard(mutex)(T: &st->lock);
381 switch (chan->type) {
382 case IIO_STEPS:
383 *val = st->steps_enabled;
384 return IIO_VAL_INT;
385 default:
386 return -EINVAL;
387 }
388 }
389 case IIO_CHAN_INFO_CALIBHEIGHT: {
390 guard(mutex)(T: &st->lock);
391 switch (chan->type) {
392 case IIO_STEPS:
393 *val = st->height;
394 return IIO_VAL_INT;
395 default:
396 return -EINVAL;
397 }
398 }
399 default:
400 return -EINVAL;
401 }
402}
403
404/**
405 * iio_dummy_write_raw() - data write function.
406 * @indio_dev: the struct iio_dev associated with this device instance
407 * @chan: the channel whose data is to be written
408 * @val: first element of value to set (typically INT)
409 * @val2: second element of value to set (typically MICRO)
410 * @mask: what we actually want to write as per the info_mask_*
411 * in iio_chan_spec.
412 *
413 * Note that all raw writes are assumed IIO_VAL_INT and info mask elements
414 * are assumed to be IIO_INT_PLUS_MICRO unless the callback write_raw_get_fmt
415 * in struct iio_info is provided by the driver.
416 */
417static int iio_dummy_write_raw(struct iio_dev *indio_dev,
418 struct iio_chan_spec const *chan,
419 int val,
420 int val2,
421 long mask)
422{
423 int i;
424 struct iio_dummy_state *st = iio_priv(indio_dev);
425
426 switch (mask) {
427 case IIO_CHAN_INFO_RAW:
428 switch (chan->type) {
429 case IIO_VOLTAGE:
430 if (chan->output == 0)
431 return -EINVAL;
432
433 scoped_guard(mutex, &st->lock) {
434 /* Locking not required as writing single value */
435 st->dac_val = val;
436 }
437 return 0;
438 default:
439 return -EINVAL;
440 }
441 case IIO_CHAN_INFO_PROCESSED:
442 switch (chan->type) {
443 case IIO_STEPS:
444 scoped_guard(mutex, &st->lock) {
445 st->steps = val;
446 }
447 return 0;
448 case IIO_ACTIVITY:
449 if (val < 0)
450 val = 0;
451 if (val > 100)
452 val = 100;
453 switch (chan->channel2) {
454 case IIO_MOD_RUNNING:
455 st->activity_running = val;
456 return 0;
457 case IIO_MOD_WALKING:
458 st->activity_walking = val;
459 return 0;
460 default:
461 return -EINVAL;
462 }
463 break;
464 default:
465 return -EINVAL;
466 }
467 case IIO_CHAN_INFO_CALIBSCALE: {
468 guard(mutex)(T: &st->lock);
469 /* Compare against table - hard matching here */
470 for (i = 0; i < ARRAY_SIZE(dummy_scales); i++)
471 if (val == dummy_scales[i].val &&
472 val2 == dummy_scales[i].val2)
473 break;
474 if (i == ARRAY_SIZE(dummy_scales))
475 return -EINVAL;
476 st->accel_calibscale = &dummy_scales[i];
477 return 0;
478 }
479 case IIO_CHAN_INFO_CALIBBIAS:
480 scoped_guard(mutex, &st->lock) {
481 st->accel_calibbias = val;
482 }
483 return 0;
484 case IIO_CHAN_INFO_ENABLE:
485 switch (chan->type) {
486 case IIO_STEPS:
487 scoped_guard(mutex, &st->lock) {
488 st->steps_enabled = val;
489 }
490 return 0;
491 default:
492 return -EINVAL;
493 }
494 case IIO_CHAN_INFO_CALIBHEIGHT:
495 switch (chan->type) {
496 case IIO_STEPS:
497 st->height = val;
498 return 0;
499 default:
500 return -EINVAL;
501 }
502
503 default:
504 return -EINVAL;
505 }
506}
507
508/*
509 * Device type specific information.
510 */
511static const struct iio_info iio_dummy_info = {
512 .read_raw = &iio_dummy_read_raw,
513 .write_raw = &iio_dummy_write_raw,
514#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
515 .read_event_config = &iio_simple_dummy_read_event_config,
516 .write_event_config = &iio_simple_dummy_write_event_config,
517 .read_event_value = &iio_simple_dummy_read_event_value,
518 .write_event_value = &iio_simple_dummy_write_event_value,
519#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
520};
521
522/**
523 * iio_dummy_init_device() - device instance specific init
524 * @indio_dev: the iio device structure
525 *
526 * Most drivers have one of these to set up default values,
527 * reset the device to known state etc.
528 */
529static int iio_dummy_init_device(struct iio_dev *indio_dev)
530{
531 struct iio_dummy_state *st = iio_priv(indio_dev);
532
533 st->dac_val = 0;
534 st->single_ended_adc_val = 73;
535 st->differential_adc_val[0] = 33;
536 st->differential_adc_val[1] = -34;
537 st->accel_val = 34;
538 st->accel_calibbias = -7;
539 st->accel_calibscale = &dummy_scales[0];
540 st->steps = 47;
541 st->activity_running = 98;
542 st->activity_walking = 4;
543
544 return 0;
545}
546
547/**
548 * iio_dummy_probe() - device instance probe
549 * @name: name of this instance.
550 *
551 * Arguments are bus type specific.
552 * I2C: iio_dummy_probe(struct i2c_client *client,
553 * const struct i2c_device_id *id)
554 * SPI: iio_dummy_probe(struct spi_device *spi)
555 */
556static struct iio_sw_device *iio_dummy_probe(const char *name)
557{
558 int ret;
559 struct iio_dev *indio_dev;
560 struct iio_dummy_state *st;
561 struct iio_sw_device *swd;
562 struct device *parent = NULL;
563
564 /*
565 * With hardware: Set the parent device.
566 * parent = &spi->dev;
567 * parent = &client->dev;
568 */
569
570 swd = kzalloc(size: sizeof(*swd), GFP_KERNEL);
571 if (!swd)
572 return ERR_PTR(error: -ENOMEM);
573
574 /*
575 * Allocate an IIO device.
576 *
577 * This structure contains all generic state
578 * information about the device instance.
579 * It also has a region (accessed by iio_priv()
580 * for chip specific state information.
581 */
582 indio_dev = iio_device_alloc(parent, sizeof_priv: sizeof(*st));
583 if (!indio_dev) {
584 ret = -ENOMEM;
585 goto error_free_swd;
586 }
587
588 st = iio_priv(indio_dev);
589 mutex_init(&st->lock);
590
591 iio_dummy_init_device(indio_dev);
592
593 /*
594 * Make the iio_dev struct available to remove function.
595 * Bus equivalents
596 * i2c_set_clientdata(client, indio_dev);
597 * spi_set_drvdata(spi, indio_dev);
598 */
599 swd->device = indio_dev;
600
601 /*
602 * Set the device name.
603 *
604 * This is typically a part number and obtained from the module
605 * id table.
606 * e.g. for i2c and spi:
607 * indio_dev->name = id->name;
608 * indio_dev->name = spi_get_device_id(spi)->name;
609 */
610 indio_dev->name = kstrdup(s: name, GFP_KERNEL);
611 if (!indio_dev->name) {
612 ret = -ENOMEM;
613 goto error_free_device;
614 }
615
616 /* Provide description of available channels */
617 indio_dev->channels = iio_dummy_channels;
618 indio_dev->num_channels = ARRAY_SIZE(iio_dummy_channels);
619
620 /*
621 * Provide device type specific interface functions and
622 * constant data.
623 */
624 indio_dev->info = &iio_dummy_info;
625
626 /* Specify that device provides sysfs type interfaces */
627 indio_dev->modes = INDIO_DIRECT_MODE;
628
629 ret = iio_simple_dummy_events_register(indio_dev);
630 if (ret < 0)
631 goto error_free_name;
632
633 ret = iio_simple_dummy_configure_buffer(indio_dev);
634 if (ret < 0)
635 goto error_unregister_events;
636
637 ret = iio_device_register(indio_dev);
638 if (ret < 0)
639 goto error_unconfigure_buffer;
640
641 iio_swd_group_init_type_name(d: swd, name, type: &iio_dummy_type);
642
643 return swd;
644error_unconfigure_buffer:
645 iio_simple_dummy_unconfigure_buffer(indio_dev);
646error_unregister_events:
647 iio_simple_dummy_events_unregister(indio_dev);
648error_free_name:
649 kfree(objp: indio_dev->name);
650error_free_device:
651 iio_device_free(indio_dev);
652error_free_swd:
653 kfree(objp: swd);
654 return ERR_PTR(error: ret);
655}
656
657/**
658 * iio_dummy_remove() - device instance removal function
659 * @swd: pointer to software IIO device abstraction
660 *
661 * Parameters follow those of iio_dummy_probe for buses.
662 */
663static int iio_dummy_remove(struct iio_sw_device *swd)
664{
665 /*
666 * Get a pointer to the device instance iio_dev structure
667 * from the bus subsystem. E.g.
668 * struct iio_dev *indio_dev = i2c_get_clientdata(client);
669 * struct iio_dev *indio_dev = spi_get_drvdata(spi);
670 */
671 struct iio_dev *indio_dev = swd->device;
672
673 /* Unregister the device */
674 iio_device_unregister(indio_dev);
675
676 /* Device specific code to power down etc */
677
678 /* Buffered capture related cleanup */
679 iio_simple_dummy_unconfigure_buffer(indio_dev);
680
681 iio_simple_dummy_events_unregister(indio_dev);
682
683 /* Free all structures */
684 kfree(objp: indio_dev->name);
685 iio_device_free(indio_dev);
686
687 return 0;
688}
689
690/*
691 * module_iio_sw_device_driver() - device driver registration
692 *
693 * Varies depending on bus type of the device. As there is no device
694 * here, call probe directly. For information on device registration
695 * i2c:
696 * Documentation/i2c/writing-clients.rst
697 * spi:
698 * Documentation/spi/spi-summary.rst
699 */
700static const struct iio_sw_device_ops iio_dummy_device_ops = {
701 .probe = iio_dummy_probe,
702 .remove = iio_dummy_remove,
703};
704
705static struct iio_sw_device_type iio_dummy_device = {
706 .name = "dummy",
707 .owner = THIS_MODULE,
708 .ops = &iio_dummy_device_ops,
709};
710
711module_iio_sw_device_driver(iio_dummy_device);
712
713MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
714MODULE_DESCRIPTION("IIO dummy driver");
715MODULE_LICENSE("GPL v2");
716

source code of linux/drivers/iio/dummy/iio_simple_dummy.c