xref: /linux/drivers/iio/industrialio-core.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /* The industrial I/O core
2  *
3  * Copyright (c) 2008 Jonathan Cameron
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * Based on elements of hwmon and input subsystems.
10  */
11 
12 #define pr_fmt(fmt) "iio-core: " fmt
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/idr.h>
17 #include <linux/kdev_t.h>
18 #include <linux/err.h>
19 #include <linux/device.h>
20 #include <linux/fs.h>
21 #include <linux/poll.h>
22 #include <linux/sched.h>
23 #include <linux/wait.h>
24 #include <linux/cdev.h>
25 #include <linux/slab.h>
26 #include <linux/anon_inodes.h>
27 #include <linux/debugfs.h>
28 #include <linux/iio/iio.h>
29 #include "iio_core.h"
30 #include "iio_core_trigger.h"
31 #include <linux/iio/sysfs.h>
32 #include <linux/iio/events.h>
33 #include <linux/iio/buffer.h>
34 
35 /* IDA to assign each registered device a unique id */
36 static DEFINE_IDA(iio_ida);
37 
38 static dev_t iio_devt;
39 
40 #define IIO_DEV_MAX 256
41 struct bus_type iio_bus_type = {
42 	.name = "iio",
43 };
44 EXPORT_SYMBOL(iio_bus_type);
45 
46 static struct dentry *iio_debugfs_dentry;
47 
48 static const char * const iio_direction[] = {
49 	[0] = "in",
50 	[1] = "out",
51 };
52 
53 static const char * const iio_chan_type_name_spec[] = {
54 	[IIO_VOLTAGE] = "voltage",
55 	[IIO_CURRENT] = "current",
56 	[IIO_POWER] = "power",
57 	[IIO_ACCEL] = "accel",
58 	[IIO_ANGL_VEL] = "anglvel",
59 	[IIO_MAGN] = "magn",
60 	[IIO_LIGHT] = "illuminance",
61 	[IIO_INTENSITY] = "intensity",
62 	[IIO_PROXIMITY] = "proximity",
63 	[IIO_TEMP] = "temp",
64 	[IIO_INCLI] = "incli",
65 	[IIO_ROT] = "rot",
66 	[IIO_ANGL] = "angl",
67 	[IIO_TIMESTAMP] = "timestamp",
68 	[IIO_CAPACITANCE] = "capacitance",
69 	[IIO_ALTVOLTAGE] = "altvoltage",
70 	[IIO_CCT] = "cct",
71 	[IIO_PRESSURE] = "pressure",
72 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
73 	[IIO_ACTIVITY] = "activity",
74 	[IIO_STEPS] = "steps",
75 	[IIO_ENERGY] = "energy",
76 	[IIO_DISTANCE] = "distance",
77 	[IIO_VELOCITY] = "velocity",
78 };
79 
80 static const char * const iio_modifier_names[] = {
81 	[IIO_MOD_X] = "x",
82 	[IIO_MOD_Y] = "y",
83 	[IIO_MOD_Z] = "z",
84 	[IIO_MOD_X_AND_Y] = "x&y",
85 	[IIO_MOD_X_AND_Z] = "x&z",
86 	[IIO_MOD_Y_AND_Z] = "y&z",
87 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
88 	[IIO_MOD_X_OR_Y] = "x|y",
89 	[IIO_MOD_X_OR_Z] = "x|z",
90 	[IIO_MOD_Y_OR_Z] = "y|z",
91 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
92 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
93 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
94 	[IIO_MOD_LIGHT_BOTH] = "both",
95 	[IIO_MOD_LIGHT_IR] = "ir",
96 	[IIO_MOD_LIGHT_CLEAR] = "clear",
97 	[IIO_MOD_LIGHT_RED] = "red",
98 	[IIO_MOD_LIGHT_GREEN] = "green",
99 	[IIO_MOD_LIGHT_BLUE] = "blue",
100 	[IIO_MOD_QUATERNION] = "quaternion",
101 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
102 	[IIO_MOD_TEMP_OBJECT] = "object",
103 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
104 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
105 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
106 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
107 	[IIO_MOD_RUNNING] = "running",
108 	[IIO_MOD_JOGGING] = "jogging",
109 	[IIO_MOD_WALKING] = "walking",
110 	[IIO_MOD_STILL] = "still",
111 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
112 	[IIO_MOD_I] = "i",
113 	[IIO_MOD_Q] = "q",
114 };
115 
116 /* relies on pairs of these shared then separate */
117 static const char * const iio_chan_info_postfix[] = {
118 	[IIO_CHAN_INFO_RAW] = "raw",
119 	[IIO_CHAN_INFO_PROCESSED] = "input",
120 	[IIO_CHAN_INFO_SCALE] = "scale",
121 	[IIO_CHAN_INFO_OFFSET] = "offset",
122 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
123 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
124 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
125 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
126 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
127 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
128 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
129 	= "filter_low_pass_3db_frequency",
130 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
131 	= "filter_high_pass_3db_frequency",
132 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
133 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
134 	[IIO_CHAN_INFO_PHASE] = "phase",
135 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
136 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
137 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
138 	[IIO_CHAN_INFO_ENABLE] = "en",
139 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
140 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
141 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
142 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
143 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
144 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
145 };
146 
147 /**
148  * iio_find_channel_from_si() - get channel from its scan index
149  * @indio_dev:		device
150  * @si:			scan index to match
151  */
152 const struct iio_chan_spec
153 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
154 {
155 	int i;
156 
157 	for (i = 0; i < indio_dev->num_channels; i++)
158 		if (indio_dev->channels[i].scan_index == si)
159 			return &indio_dev->channels[i];
160 	return NULL;
161 }
162 
163 /* This turns up an awful lot */
164 ssize_t iio_read_const_attr(struct device *dev,
165 			    struct device_attribute *attr,
166 			    char *buf)
167 {
168 	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
169 }
170 EXPORT_SYMBOL(iio_read_const_attr);
171 
172 static int __init iio_init(void)
173 {
174 	int ret;
175 
176 	/* Register sysfs bus */
177 	ret  = bus_register(&iio_bus_type);
178 	if (ret < 0) {
179 		pr_err("could not register bus type\n");
180 		goto error_nothing;
181 	}
182 
183 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
184 	if (ret < 0) {
185 		pr_err("failed to allocate char dev region\n");
186 		goto error_unregister_bus_type;
187 	}
188 
189 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
190 
191 	return 0;
192 
193 error_unregister_bus_type:
194 	bus_unregister(&iio_bus_type);
195 error_nothing:
196 	return ret;
197 }
198 
199 static void __exit iio_exit(void)
200 {
201 	if (iio_devt)
202 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
203 	bus_unregister(&iio_bus_type);
204 	debugfs_remove(iio_debugfs_dentry);
205 }
206 
207 #if defined(CONFIG_DEBUG_FS)
208 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
209 			      size_t count, loff_t *ppos)
210 {
211 	struct iio_dev *indio_dev = file->private_data;
212 	char buf[20];
213 	unsigned val = 0;
214 	ssize_t len;
215 	int ret;
216 
217 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
218 						  indio_dev->cached_reg_addr,
219 						  0, &val);
220 	if (ret)
221 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
222 
223 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
224 
225 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
226 }
227 
228 static ssize_t iio_debugfs_write_reg(struct file *file,
229 		     const char __user *userbuf, size_t count, loff_t *ppos)
230 {
231 	struct iio_dev *indio_dev = file->private_data;
232 	unsigned reg, val;
233 	char buf[80];
234 	int ret;
235 
236 	count = min_t(size_t, count, (sizeof(buf)-1));
237 	if (copy_from_user(buf, userbuf, count))
238 		return -EFAULT;
239 
240 	buf[count] = 0;
241 
242 	ret = sscanf(buf, "%i %i", &reg, &val);
243 
244 	switch (ret) {
245 	case 1:
246 		indio_dev->cached_reg_addr = reg;
247 		break;
248 	case 2:
249 		indio_dev->cached_reg_addr = reg;
250 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
251 							  val, NULL);
252 		if (ret) {
253 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
254 				__func__);
255 			return ret;
256 		}
257 		break;
258 	default:
259 		return -EINVAL;
260 	}
261 
262 	return count;
263 }
264 
265 static const struct file_operations iio_debugfs_reg_fops = {
266 	.open = simple_open,
267 	.read = iio_debugfs_read_reg,
268 	.write = iio_debugfs_write_reg,
269 };
270 
271 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
272 {
273 	debugfs_remove_recursive(indio_dev->debugfs_dentry);
274 }
275 
276 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
277 {
278 	struct dentry *d;
279 
280 	if (indio_dev->info->debugfs_reg_access == NULL)
281 		return 0;
282 
283 	if (!iio_debugfs_dentry)
284 		return 0;
285 
286 	indio_dev->debugfs_dentry =
287 		debugfs_create_dir(dev_name(&indio_dev->dev),
288 				   iio_debugfs_dentry);
289 	if (indio_dev->debugfs_dentry == NULL) {
290 		dev_warn(indio_dev->dev.parent,
291 			 "Failed to create debugfs directory\n");
292 		return -EFAULT;
293 	}
294 
295 	d = debugfs_create_file("direct_reg_access", 0644,
296 				indio_dev->debugfs_dentry,
297 				indio_dev, &iio_debugfs_reg_fops);
298 	if (!d) {
299 		iio_device_unregister_debugfs(indio_dev);
300 		return -ENOMEM;
301 	}
302 
303 	return 0;
304 }
305 #else
306 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
307 {
308 	return 0;
309 }
310 
311 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
312 {
313 }
314 #endif /* CONFIG_DEBUG_FS */
315 
316 static ssize_t iio_read_channel_ext_info(struct device *dev,
317 				     struct device_attribute *attr,
318 				     char *buf)
319 {
320 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
321 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
322 	const struct iio_chan_spec_ext_info *ext_info;
323 
324 	ext_info = &this_attr->c->ext_info[this_attr->address];
325 
326 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
327 }
328 
329 static ssize_t iio_write_channel_ext_info(struct device *dev,
330 				     struct device_attribute *attr,
331 				     const char *buf,
332 					 size_t len)
333 {
334 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
335 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
336 	const struct iio_chan_spec_ext_info *ext_info;
337 
338 	ext_info = &this_attr->c->ext_info[this_attr->address];
339 
340 	return ext_info->write(indio_dev, ext_info->private,
341 			       this_attr->c, buf, len);
342 }
343 
344 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
345 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
346 {
347 	const struct iio_enum *e = (const struct iio_enum *)priv;
348 	unsigned int i;
349 	size_t len = 0;
350 
351 	if (!e->num_items)
352 		return 0;
353 
354 	for (i = 0; i < e->num_items; ++i)
355 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
356 
357 	/* replace last space with a newline */
358 	buf[len - 1] = '\n';
359 
360 	return len;
361 }
362 EXPORT_SYMBOL_GPL(iio_enum_available_read);
363 
364 ssize_t iio_enum_read(struct iio_dev *indio_dev,
365 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
366 {
367 	const struct iio_enum *e = (const struct iio_enum *)priv;
368 	int i;
369 
370 	if (!e->get)
371 		return -EINVAL;
372 
373 	i = e->get(indio_dev, chan);
374 	if (i < 0)
375 		return i;
376 	else if (i >= e->num_items)
377 		return -EINVAL;
378 
379 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
380 }
381 EXPORT_SYMBOL_GPL(iio_enum_read);
382 
383 ssize_t iio_enum_write(struct iio_dev *indio_dev,
384 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
385 	size_t len)
386 {
387 	const struct iio_enum *e = (const struct iio_enum *)priv;
388 	unsigned int i;
389 	int ret;
390 
391 	if (!e->set)
392 		return -EINVAL;
393 
394 	for (i = 0; i < e->num_items; i++) {
395 		if (sysfs_streq(buf, e->items[i]))
396 			break;
397 	}
398 
399 	if (i == e->num_items)
400 		return -EINVAL;
401 
402 	ret = e->set(indio_dev, chan, i);
403 	return ret ? ret : len;
404 }
405 EXPORT_SYMBOL_GPL(iio_enum_write);
406 
407 /**
408  * iio_format_value() - Formats a IIO value into its string representation
409  * @buf:	The buffer to which the formatted value gets written
410  * @type:	One of the IIO_VAL_... constants. This decides how the val
411  *		and val2 parameters are formatted.
412  * @size:	Number of IIO value entries contained in vals
413  * @vals:	Pointer to the values, exact meaning depends on the
414  *		type parameter.
415  *
416  * Return: 0 by default, a negative number on failure or the
417  *	   total number of characters written for a type that belongs
418  *	   to the IIO_VAL_... constant.
419  */
420 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
421 {
422 	unsigned long long tmp;
423 	bool scale_db = false;
424 
425 	switch (type) {
426 	case IIO_VAL_INT:
427 		return sprintf(buf, "%d\n", vals[0]);
428 	case IIO_VAL_INT_PLUS_MICRO_DB:
429 		scale_db = true;
430 	case IIO_VAL_INT_PLUS_MICRO:
431 		if (vals[1] < 0)
432 			return sprintf(buf, "-%ld.%06u%s\n", abs(vals[0]),
433 					-vals[1],
434 				scale_db ? " dB" : "");
435 		else
436 			return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1],
437 				scale_db ? " dB" : "");
438 	case IIO_VAL_INT_PLUS_NANO:
439 		if (vals[1] < 0)
440 			return sprintf(buf, "-%ld.%09u\n", abs(vals[0]),
441 					-vals[1]);
442 		else
443 			return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
444 	case IIO_VAL_FRACTIONAL:
445 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
446 		vals[1] = do_div(tmp, 1000000000LL);
447 		vals[0] = tmp;
448 		return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
449 	case IIO_VAL_FRACTIONAL_LOG2:
450 		tmp = (s64)vals[0] * 1000000000LL >> vals[1];
451 		vals[1] = do_div(tmp, 1000000000LL);
452 		vals[0] = tmp;
453 		return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
454 	case IIO_VAL_INT_MULTIPLE:
455 	{
456 		int i;
457 		int len = 0;
458 
459 		for (i = 0; i < size; ++i)
460 			len += snprintf(&buf[len], PAGE_SIZE - len, "%d ",
461 								vals[i]);
462 		len += snprintf(&buf[len], PAGE_SIZE - len, "\n");
463 		return len;
464 	}
465 	default:
466 		return 0;
467 	}
468 }
469 
470 static ssize_t iio_read_channel_info(struct device *dev,
471 				     struct device_attribute *attr,
472 				     char *buf)
473 {
474 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
475 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
476 	int vals[INDIO_MAX_RAW_ELEMENTS];
477 	int ret;
478 	int val_len = 2;
479 
480 	if (indio_dev->info->read_raw_multi)
481 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
482 							INDIO_MAX_RAW_ELEMENTS,
483 							vals, &val_len,
484 							this_attr->address);
485 	else
486 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
487 				    &vals[0], &vals[1], this_attr->address);
488 
489 	if (ret < 0)
490 		return ret;
491 
492 	return iio_format_value(buf, ret, val_len, vals);
493 }
494 
495 /**
496  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
497  * @str: The string to parse
498  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
499  * @integer: The integer part of the number
500  * @fract: The fractional part of the number
501  *
502  * Returns 0 on success, or a negative error code if the string could not be
503  * parsed.
504  */
505 int iio_str_to_fixpoint(const char *str, int fract_mult,
506 	int *integer, int *fract)
507 {
508 	int i = 0, f = 0;
509 	bool integer_part = true, negative = false;
510 
511 	if (str[0] == '-') {
512 		negative = true;
513 		str++;
514 	} else if (str[0] == '+') {
515 		str++;
516 	}
517 
518 	while (*str) {
519 		if ('0' <= *str && *str <= '9') {
520 			if (integer_part) {
521 				i = i * 10 + *str - '0';
522 			} else {
523 				f += fract_mult * (*str - '0');
524 				fract_mult /= 10;
525 			}
526 		} else if (*str == '\n') {
527 			if (*(str + 1) == '\0')
528 				break;
529 			else
530 				return -EINVAL;
531 		} else if (*str == '.' && integer_part) {
532 			integer_part = false;
533 		} else {
534 			return -EINVAL;
535 		}
536 		str++;
537 	}
538 
539 	if (negative) {
540 		if (i)
541 			i = -i;
542 		else
543 			f = -f;
544 	}
545 
546 	*integer = i;
547 	*fract = f;
548 
549 	return 0;
550 }
551 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
552 
553 static ssize_t iio_write_channel_info(struct device *dev,
554 				      struct device_attribute *attr,
555 				      const char *buf,
556 				      size_t len)
557 {
558 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
559 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
560 	int ret, fract_mult = 100000;
561 	int integer, fract;
562 
563 	/* Assumes decimal - precision based on number of digits */
564 	if (!indio_dev->info->write_raw)
565 		return -EINVAL;
566 
567 	if (indio_dev->info->write_raw_get_fmt)
568 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
569 			this_attr->c, this_attr->address)) {
570 		case IIO_VAL_INT_PLUS_MICRO:
571 			fract_mult = 100000;
572 			break;
573 		case IIO_VAL_INT_PLUS_NANO:
574 			fract_mult = 100000000;
575 			break;
576 		default:
577 			return -EINVAL;
578 		}
579 
580 	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
581 	if (ret)
582 		return ret;
583 
584 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
585 					 integer, fract, this_attr->address);
586 	if (ret)
587 		return ret;
588 
589 	return len;
590 }
591 
592 static
593 int __iio_device_attr_init(struct device_attribute *dev_attr,
594 			   const char *postfix,
595 			   struct iio_chan_spec const *chan,
596 			   ssize_t (*readfunc)(struct device *dev,
597 					       struct device_attribute *attr,
598 					       char *buf),
599 			   ssize_t (*writefunc)(struct device *dev,
600 						struct device_attribute *attr,
601 						const char *buf,
602 						size_t len),
603 			   enum iio_shared_by shared_by)
604 {
605 	int ret = 0;
606 	char *name = NULL;
607 	char *full_postfix;
608 	sysfs_attr_init(&dev_attr->attr);
609 
610 	/* Build up postfix of <extend_name>_<modifier>_postfix */
611 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
612 		if (chan->extend_name)
613 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
614 						 iio_modifier_names[chan
615 								    ->channel2],
616 						 chan->extend_name,
617 						 postfix);
618 		else
619 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
620 						 iio_modifier_names[chan
621 								    ->channel2],
622 						 postfix);
623 	} else {
624 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
625 			full_postfix = kstrdup(postfix, GFP_KERNEL);
626 		else
627 			full_postfix = kasprintf(GFP_KERNEL,
628 						 "%s_%s",
629 						 chan->extend_name,
630 						 postfix);
631 	}
632 	if (full_postfix == NULL)
633 		return -ENOMEM;
634 
635 	if (chan->differential) { /* Differential can not have modifier */
636 		switch (shared_by) {
637 		case IIO_SHARED_BY_ALL:
638 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
639 			break;
640 		case IIO_SHARED_BY_DIR:
641 			name = kasprintf(GFP_KERNEL, "%s_%s",
642 						iio_direction[chan->output],
643 						full_postfix);
644 			break;
645 		case IIO_SHARED_BY_TYPE:
646 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
647 					    iio_direction[chan->output],
648 					    iio_chan_type_name_spec[chan->type],
649 					    iio_chan_type_name_spec[chan->type],
650 					    full_postfix);
651 			break;
652 		case IIO_SEPARATE:
653 			if (!chan->indexed) {
654 				WARN_ON("Differential channels must be indexed\n");
655 				ret = -EINVAL;
656 				goto error_free_full_postfix;
657 			}
658 			name = kasprintf(GFP_KERNEL,
659 					    "%s_%s%d-%s%d_%s",
660 					    iio_direction[chan->output],
661 					    iio_chan_type_name_spec[chan->type],
662 					    chan->channel,
663 					    iio_chan_type_name_spec[chan->type],
664 					    chan->channel2,
665 					    full_postfix);
666 			break;
667 		}
668 	} else { /* Single ended */
669 		switch (shared_by) {
670 		case IIO_SHARED_BY_ALL:
671 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
672 			break;
673 		case IIO_SHARED_BY_DIR:
674 			name = kasprintf(GFP_KERNEL, "%s_%s",
675 						iio_direction[chan->output],
676 						full_postfix);
677 			break;
678 		case IIO_SHARED_BY_TYPE:
679 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
680 					    iio_direction[chan->output],
681 					    iio_chan_type_name_spec[chan->type],
682 					    full_postfix);
683 			break;
684 
685 		case IIO_SEPARATE:
686 			if (chan->indexed)
687 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
688 						    iio_direction[chan->output],
689 						    iio_chan_type_name_spec[chan->type],
690 						    chan->channel,
691 						    full_postfix);
692 			else
693 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
694 						    iio_direction[chan->output],
695 						    iio_chan_type_name_spec[chan->type],
696 						    full_postfix);
697 			break;
698 		}
699 	}
700 	if (name == NULL) {
701 		ret = -ENOMEM;
702 		goto error_free_full_postfix;
703 	}
704 	dev_attr->attr.name = name;
705 
706 	if (readfunc) {
707 		dev_attr->attr.mode |= S_IRUGO;
708 		dev_attr->show = readfunc;
709 	}
710 
711 	if (writefunc) {
712 		dev_attr->attr.mode |= S_IWUSR;
713 		dev_attr->store = writefunc;
714 	}
715 
716 error_free_full_postfix:
717 	kfree(full_postfix);
718 
719 	return ret;
720 }
721 
722 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
723 {
724 	kfree(dev_attr->attr.name);
725 }
726 
727 int __iio_add_chan_devattr(const char *postfix,
728 			   struct iio_chan_spec const *chan,
729 			   ssize_t (*readfunc)(struct device *dev,
730 					       struct device_attribute *attr,
731 					       char *buf),
732 			   ssize_t (*writefunc)(struct device *dev,
733 						struct device_attribute *attr,
734 						const char *buf,
735 						size_t len),
736 			   u64 mask,
737 			   enum iio_shared_by shared_by,
738 			   struct device *dev,
739 			   struct list_head *attr_list)
740 {
741 	int ret;
742 	struct iio_dev_attr *iio_attr, *t;
743 
744 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
745 	if (iio_attr == NULL)
746 		return -ENOMEM;
747 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
748 				     postfix, chan,
749 				     readfunc, writefunc, shared_by);
750 	if (ret)
751 		goto error_iio_dev_attr_free;
752 	iio_attr->c = chan;
753 	iio_attr->address = mask;
754 	list_for_each_entry(t, attr_list, l)
755 		if (strcmp(t->dev_attr.attr.name,
756 			   iio_attr->dev_attr.attr.name) == 0) {
757 			if (shared_by == IIO_SEPARATE)
758 				dev_err(dev, "tried to double register : %s\n",
759 					t->dev_attr.attr.name);
760 			ret = -EBUSY;
761 			goto error_device_attr_deinit;
762 		}
763 	list_add(&iio_attr->l, attr_list);
764 
765 	return 0;
766 
767 error_device_attr_deinit:
768 	__iio_device_attr_deinit(&iio_attr->dev_attr);
769 error_iio_dev_attr_free:
770 	kfree(iio_attr);
771 	return ret;
772 }
773 
774 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
775 					 struct iio_chan_spec const *chan,
776 					 enum iio_shared_by shared_by,
777 					 const long *infomask)
778 {
779 	int i, ret, attrcount = 0;
780 
781 	for_each_set_bit(i, infomask, sizeof(infomask)*8) {
782 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
783 			return -EINVAL;
784 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
785 					     chan,
786 					     &iio_read_channel_info,
787 					     &iio_write_channel_info,
788 					     i,
789 					     shared_by,
790 					     &indio_dev->dev,
791 					     &indio_dev->channel_attr_list);
792 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
793 			continue;
794 		else if (ret < 0)
795 			return ret;
796 		attrcount++;
797 	}
798 
799 	return attrcount;
800 }
801 
802 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
803 					struct iio_chan_spec const *chan)
804 {
805 	int ret, attrcount = 0;
806 	const struct iio_chan_spec_ext_info *ext_info;
807 
808 	if (chan->channel < 0)
809 		return 0;
810 	ret = iio_device_add_info_mask_type(indio_dev, chan,
811 					    IIO_SEPARATE,
812 					    &chan->info_mask_separate);
813 	if (ret < 0)
814 		return ret;
815 	attrcount += ret;
816 
817 	ret = iio_device_add_info_mask_type(indio_dev, chan,
818 					    IIO_SHARED_BY_TYPE,
819 					    &chan->info_mask_shared_by_type);
820 	if (ret < 0)
821 		return ret;
822 	attrcount += ret;
823 
824 	ret = iio_device_add_info_mask_type(indio_dev, chan,
825 					    IIO_SHARED_BY_DIR,
826 					    &chan->info_mask_shared_by_dir);
827 	if (ret < 0)
828 		return ret;
829 	attrcount += ret;
830 
831 	ret = iio_device_add_info_mask_type(indio_dev, chan,
832 					    IIO_SHARED_BY_ALL,
833 					    &chan->info_mask_shared_by_all);
834 	if (ret < 0)
835 		return ret;
836 	attrcount += ret;
837 
838 	if (chan->ext_info) {
839 		unsigned int i = 0;
840 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
841 			ret = __iio_add_chan_devattr(ext_info->name,
842 					chan,
843 					ext_info->read ?
844 					    &iio_read_channel_ext_info : NULL,
845 					ext_info->write ?
846 					    &iio_write_channel_ext_info : NULL,
847 					i,
848 					ext_info->shared,
849 					&indio_dev->dev,
850 					&indio_dev->channel_attr_list);
851 			i++;
852 			if (ret == -EBUSY && ext_info->shared)
853 				continue;
854 
855 			if (ret)
856 				return ret;
857 
858 			attrcount++;
859 		}
860 	}
861 
862 	return attrcount;
863 }
864 
865 /**
866  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
867  * @attr_list: List of IIO device attributes
868  *
869  * This function frees the memory allocated for each of the IIO device
870  * attributes in the list.
871  */
872 void iio_free_chan_devattr_list(struct list_head *attr_list)
873 {
874 	struct iio_dev_attr *p, *n;
875 
876 	list_for_each_entry_safe(p, n, attr_list, l) {
877 		kfree(p->dev_attr.attr.name);
878 		list_del(&p->l);
879 		kfree(p);
880 	}
881 }
882 
883 static ssize_t iio_show_dev_name(struct device *dev,
884 				 struct device_attribute *attr,
885 				 char *buf)
886 {
887 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
888 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
889 }
890 
891 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
892 
893 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
894 {
895 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
896 	struct iio_dev_attr *p;
897 	struct attribute **attr;
898 
899 	/* First count elements in any existing group */
900 	if (indio_dev->info->attrs) {
901 		attr = indio_dev->info->attrs->attrs;
902 		while (*attr++ != NULL)
903 			attrcount_orig++;
904 	}
905 	attrcount = attrcount_orig;
906 	/*
907 	 * New channel registration method - relies on the fact a group does
908 	 * not need to be initialized if its name is NULL.
909 	 */
910 	if (indio_dev->channels)
911 		for (i = 0; i < indio_dev->num_channels; i++) {
912 			ret = iio_device_add_channel_sysfs(indio_dev,
913 							   &indio_dev
914 							   ->channels[i]);
915 			if (ret < 0)
916 				goto error_clear_attrs;
917 			attrcount += ret;
918 		}
919 
920 	if (indio_dev->name)
921 		attrcount++;
922 
923 	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
924 						   sizeof(indio_dev->chan_attr_group.attrs[0]),
925 						   GFP_KERNEL);
926 	if (indio_dev->chan_attr_group.attrs == NULL) {
927 		ret = -ENOMEM;
928 		goto error_clear_attrs;
929 	}
930 	/* Copy across original attributes */
931 	if (indio_dev->info->attrs)
932 		memcpy(indio_dev->chan_attr_group.attrs,
933 		       indio_dev->info->attrs->attrs,
934 		       sizeof(indio_dev->chan_attr_group.attrs[0])
935 		       *attrcount_orig);
936 	attrn = attrcount_orig;
937 	/* Add all elements from the list. */
938 	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
939 		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
940 	if (indio_dev->name)
941 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
942 
943 	indio_dev->groups[indio_dev->groupcounter++] =
944 		&indio_dev->chan_attr_group;
945 
946 	return 0;
947 
948 error_clear_attrs:
949 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
950 
951 	return ret;
952 }
953 
954 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
955 {
956 
957 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
958 	kfree(indio_dev->chan_attr_group.attrs);
959 	indio_dev->chan_attr_group.attrs = NULL;
960 }
961 
962 static void iio_dev_release(struct device *device)
963 {
964 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
965 	if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
966 		iio_device_unregister_trigger_consumer(indio_dev);
967 	iio_device_unregister_eventset(indio_dev);
968 	iio_device_unregister_sysfs(indio_dev);
969 
970 	iio_buffer_put(indio_dev->buffer);
971 
972 	ida_simple_remove(&iio_ida, indio_dev->id);
973 	kfree(indio_dev);
974 }
975 
976 struct device_type iio_device_type = {
977 	.name = "iio_device",
978 	.release = iio_dev_release,
979 };
980 
981 /**
982  * iio_device_alloc() - allocate an iio_dev from a driver
983  * @sizeof_priv:	Space to allocate for private structure.
984  **/
985 struct iio_dev *iio_device_alloc(int sizeof_priv)
986 {
987 	struct iio_dev *dev;
988 	size_t alloc_size;
989 
990 	alloc_size = sizeof(struct iio_dev);
991 	if (sizeof_priv) {
992 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
993 		alloc_size += sizeof_priv;
994 	}
995 	/* ensure 32-byte alignment of whole construct ? */
996 	alloc_size += IIO_ALIGN - 1;
997 
998 	dev = kzalloc(alloc_size, GFP_KERNEL);
999 
1000 	if (dev) {
1001 		dev->dev.groups = dev->groups;
1002 		dev->dev.type = &iio_device_type;
1003 		dev->dev.bus = &iio_bus_type;
1004 		device_initialize(&dev->dev);
1005 		dev_set_drvdata(&dev->dev, (void *)dev);
1006 		mutex_init(&dev->mlock);
1007 		mutex_init(&dev->info_exist_lock);
1008 		INIT_LIST_HEAD(&dev->channel_attr_list);
1009 
1010 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1011 		if (dev->id < 0) {
1012 			/* cannot use a dev_err as the name isn't available */
1013 			pr_err("failed to get device id\n");
1014 			kfree(dev);
1015 			return NULL;
1016 		}
1017 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1018 		INIT_LIST_HEAD(&dev->buffer_list);
1019 	}
1020 
1021 	return dev;
1022 }
1023 EXPORT_SYMBOL(iio_device_alloc);
1024 
1025 /**
1026  * iio_device_free() - free an iio_dev from a driver
1027  * @dev:		the iio_dev associated with the device
1028  **/
1029 void iio_device_free(struct iio_dev *dev)
1030 {
1031 	if (dev)
1032 		put_device(&dev->dev);
1033 }
1034 EXPORT_SYMBOL(iio_device_free);
1035 
1036 static void devm_iio_device_release(struct device *dev, void *res)
1037 {
1038 	iio_device_free(*(struct iio_dev **)res);
1039 }
1040 
1041 static int devm_iio_device_match(struct device *dev, void *res, void *data)
1042 {
1043 	struct iio_dev **r = res;
1044 	if (!r || !*r) {
1045 		WARN_ON(!r || !*r);
1046 		return 0;
1047 	}
1048 	return *r == data;
1049 }
1050 
1051 /**
1052  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1053  * @dev:		Device to allocate iio_dev for
1054  * @sizeof_priv:	Space to allocate for private structure.
1055  *
1056  * Managed iio_device_alloc. iio_dev allocated with this function is
1057  * automatically freed on driver detach.
1058  *
1059  * If an iio_dev allocated with this function needs to be freed separately,
1060  * devm_iio_device_free() must be used.
1061  *
1062  * RETURNS:
1063  * Pointer to allocated iio_dev on success, NULL on failure.
1064  */
1065 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1066 {
1067 	struct iio_dev **ptr, *iio_dev;
1068 
1069 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1070 			   GFP_KERNEL);
1071 	if (!ptr)
1072 		return NULL;
1073 
1074 	iio_dev = iio_device_alloc(sizeof_priv);
1075 	if (iio_dev) {
1076 		*ptr = iio_dev;
1077 		devres_add(dev, ptr);
1078 	} else {
1079 		devres_free(ptr);
1080 	}
1081 
1082 	return iio_dev;
1083 }
1084 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1085 
1086 /**
1087  * devm_iio_device_free - Resource-managed iio_device_free()
1088  * @dev:		Device this iio_dev belongs to
1089  * @iio_dev:		the iio_dev associated with the device
1090  *
1091  * Free iio_dev allocated with devm_iio_device_alloc().
1092  */
1093 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1094 {
1095 	int rc;
1096 
1097 	rc = devres_release(dev, devm_iio_device_release,
1098 			    devm_iio_device_match, iio_dev);
1099 	WARN_ON(rc);
1100 }
1101 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1102 
1103 /**
1104  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1105  * @inode:	Inode structure for identifying the device in the file system
1106  * @filp:	File structure for iio device used to keep and later access
1107  *		private data
1108  *
1109  * Return: 0 on success or -EBUSY if the device is already opened
1110  **/
1111 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1112 {
1113 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1114 						struct iio_dev, chrdev);
1115 
1116 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1117 		return -EBUSY;
1118 
1119 	iio_device_get(indio_dev);
1120 
1121 	filp->private_data = indio_dev;
1122 
1123 	return 0;
1124 }
1125 
1126 /**
1127  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1128  * @inode:	Inode structure pointer for the char device
1129  * @filp:	File structure pointer for the char device
1130  *
1131  * Return: 0 for successful release
1132  */
1133 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1134 {
1135 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1136 						struct iio_dev, chrdev);
1137 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1138 	iio_device_put(indio_dev);
1139 
1140 	return 0;
1141 }
1142 
1143 /* Somewhat of a cross file organization violation - ioctls here are actually
1144  * event related */
1145 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1146 {
1147 	struct iio_dev *indio_dev = filp->private_data;
1148 	int __user *ip = (int __user *)arg;
1149 	int fd;
1150 
1151 	if (!indio_dev->info)
1152 		return -ENODEV;
1153 
1154 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1155 		fd = iio_event_getfd(indio_dev);
1156 		if (copy_to_user(ip, &fd, sizeof(fd)))
1157 			return -EFAULT;
1158 		return 0;
1159 	}
1160 	return -EINVAL;
1161 }
1162 
1163 static const struct file_operations iio_buffer_fileops = {
1164 	.read = iio_buffer_read_first_n_outer_addr,
1165 	.release = iio_chrdev_release,
1166 	.open = iio_chrdev_open,
1167 	.poll = iio_buffer_poll_addr,
1168 	.owner = THIS_MODULE,
1169 	.llseek = noop_llseek,
1170 	.unlocked_ioctl = iio_ioctl,
1171 	.compat_ioctl = iio_ioctl,
1172 };
1173 
1174 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1175 {
1176 	int i, j;
1177 	const struct iio_chan_spec *channels = indio_dev->channels;
1178 
1179 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1180 		return 0;
1181 
1182 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1183 		if (channels[i].scan_index < 0)
1184 			continue;
1185 		for (j = i + 1; j < indio_dev->num_channels; j++)
1186 			if (channels[i].scan_index == channels[j].scan_index) {
1187 				dev_err(&indio_dev->dev,
1188 					"Duplicate scan index %d\n",
1189 					channels[i].scan_index);
1190 				return -EINVAL;
1191 			}
1192 	}
1193 
1194 	return 0;
1195 }
1196 
1197 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1198 
1199 /**
1200  * iio_device_register() - register a device with the IIO subsystem
1201  * @indio_dev:		Device structure filled by the device driver
1202  **/
1203 int iio_device_register(struct iio_dev *indio_dev)
1204 {
1205 	int ret;
1206 
1207 	/* If the calling driver did not initialize of_node, do it here */
1208 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1209 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1210 
1211 	ret = iio_check_unique_scan_index(indio_dev);
1212 	if (ret < 0)
1213 		return ret;
1214 
1215 	/* configure elements for the chrdev */
1216 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1217 
1218 	ret = iio_device_register_debugfs(indio_dev);
1219 	if (ret) {
1220 		dev_err(indio_dev->dev.parent,
1221 			"Failed to register debugfs interfaces\n");
1222 		return ret;
1223 	}
1224 
1225 	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1226 	if (ret) {
1227 		dev_err(indio_dev->dev.parent,
1228 			"Failed to create buffer sysfs interfaces\n");
1229 		goto error_unreg_debugfs;
1230 	}
1231 
1232 	ret = iio_device_register_sysfs(indio_dev);
1233 	if (ret) {
1234 		dev_err(indio_dev->dev.parent,
1235 			"Failed to register sysfs interfaces\n");
1236 		goto error_buffer_free_sysfs;
1237 	}
1238 	ret = iio_device_register_eventset(indio_dev);
1239 	if (ret) {
1240 		dev_err(indio_dev->dev.parent,
1241 			"Failed to register event set\n");
1242 		goto error_free_sysfs;
1243 	}
1244 	if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
1245 		iio_device_register_trigger_consumer(indio_dev);
1246 
1247 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1248 		indio_dev->setup_ops == NULL)
1249 		indio_dev->setup_ops = &noop_ring_setup_ops;
1250 
1251 	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1252 	indio_dev->chrdev.owner = indio_dev->info->driver_module;
1253 	indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1254 	ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1255 	if (ret < 0)
1256 		goto error_unreg_eventset;
1257 
1258 	ret = device_add(&indio_dev->dev);
1259 	if (ret < 0)
1260 		goto error_cdev_del;
1261 
1262 	return 0;
1263 error_cdev_del:
1264 	cdev_del(&indio_dev->chrdev);
1265 error_unreg_eventset:
1266 	iio_device_unregister_eventset(indio_dev);
1267 error_free_sysfs:
1268 	iio_device_unregister_sysfs(indio_dev);
1269 error_buffer_free_sysfs:
1270 	iio_buffer_free_sysfs_and_mask(indio_dev);
1271 error_unreg_debugfs:
1272 	iio_device_unregister_debugfs(indio_dev);
1273 	return ret;
1274 }
1275 EXPORT_SYMBOL(iio_device_register);
1276 
1277 /**
1278  * iio_device_unregister() - unregister a device from the IIO subsystem
1279  * @indio_dev:		Device structure representing the device.
1280  **/
1281 void iio_device_unregister(struct iio_dev *indio_dev)
1282 {
1283 	mutex_lock(&indio_dev->info_exist_lock);
1284 
1285 	device_del(&indio_dev->dev);
1286 
1287 	if (indio_dev->chrdev.dev)
1288 		cdev_del(&indio_dev->chrdev);
1289 	iio_device_unregister_debugfs(indio_dev);
1290 
1291 	iio_disable_all_buffers(indio_dev);
1292 
1293 	indio_dev->info = NULL;
1294 
1295 	iio_device_wakeup_eventset(indio_dev);
1296 	iio_buffer_wakeup_poll(indio_dev);
1297 
1298 	mutex_unlock(&indio_dev->info_exist_lock);
1299 
1300 	iio_buffer_free_sysfs_and_mask(indio_dev);
1301 }
1302 EXPORT_SYMBOL(iio_device_unregister);
1303 
1304 static void devm_iio_device_unreg(struct device *dev, void *res)
1305 {
1306 	iio_device_unregister(*(struct iio_dev **)res);
1307 }
1308 
1309 /**
1310  * devm_iio_device_register - Resource-managed iio_device_register()
1311  * @dev:	Device to allocate iio_dev for
1312  * @indio_dev:	Device structure filled by the device driver
1313  *
1314  * Managed iio_device_register.  The IIO device registered with this
1315  * function is automatically unregistered on driver detach. This function
1316  * calls iio_device_register() internally. Refer to that function for more
1317  * information.
1318  *
1319  * If an iio_dev registered with this function needs to be unregistered
1320  * separately, devm_iio_device_unregister() must be used.
1321  *
1322  * RETURNS:
1323  * 0 on success, negative error number on failure.
1324  */
1325 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1326 {
1327 	struct iio_dev **ptr;
1328 	int ret;
1329 
1330 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1331 	if (!ptr)
1332 		return -ENOMEM;
1333 
1334 	*ptr = indio_dev;
1335 	ret = iio_device_register(indio_dev);
1336 	if (!ret)
1337 		devres_add(dev, ptr);
1338 	else
1339 		devres_free(ptr);
1340 
1341 	return ret;
1342 }
1343 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1344 
1345 /**
1346  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1347  * @dev:	Device this iio_dev belongs to
1348  * @indio_dev:	the iio_dev associated with the device
1349  *
1350  * Unregister iio_dev registered with devm_iio_device_register().
1351  */
1352 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1353 {
1354 	int rc;
1355 
1356 	rc = devres_release(dev, devm_iio_device_unreg,
1357 			    devm_iio_device_match, indio_dev);
1358 	WARN_ON(rc);
1359 }
1360 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1361 
1362 subsys_initcall(iio_init);
1363 module_exit(iio_exit);
1364 
1365 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1366 MODULE_DESCRIPTION("Industrial I/O core");
1367 MODULE_LICENSE("GPL");
1368