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 	[IIO_CONCENTRATION] = "concentration",
79 	[IIO_RESISTANCE] = "resistance",
80 };
81 
82 static const char * const iio_modifier_names[] = {
83 	[IIO_MOD_X] = "x",
84 	[IIO_MOD_Y] = "y",
85 	[IIO_MOD_Z] = "z",
86 	[IIO_MOD_X_AND_Y] = "x&y",
87 	[IIO_MOD_X_AND_Z] = "x&z",
88 	[IIO_MOD_Y_AND_Z] = "y&z",
89 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
90 	[IIO_MOD_X_OR_Y] = "x|y",
91 	[IIO_MOD_X_OR_Z] = "x|z",
92 	[IIO_MOD_Y_OR_Z] = "y|z",
93 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
94 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
95 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
96 	[IIO_MOD_LIGHT_BOTH] = "both",
97 	[IIO_MOD_LIGHT_IR] = "ir",
98 	[IIO_MOD_LIGHT_CLEAR] = "clear",
99 	[IIO_MOD_LIGHT_RED] = "red",
100 	[IIO_MOD_LIGHT_GREEN] = "green",
101 	[IIO_MOD_LIGHT_BLUE] = "blue",
102 	[IIO_MOD_QUATERNION] = "quaternion",
103 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
104 	[IIO_MOD_TEMP_OBJECT] = "object",
105 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
106 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
107 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
108 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
109 	[IIO_MOD_RUNNING] = "running",
110 	[IIO_MOD_JOGGING] = "jogging",
111 	[IIO_MOD_WALKING] = "walking",
112 	[IIO_MOD_STILL] = "still",
113 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
114 	[IIO_MOD_I] = "i",
115 	[IIO_MOD_Q] = "q",
116 	[IIO_MOD_CO2] = "co2",
117 	[IIO_MOD_VOC] = "voc",
118 };
119 
120 /* relies on pairs of these shared then separate */
121 static const char * const iio_chan_info_postfix[] = {
122 	[IIO_CHAN_INFO_RAW] = "raw",
123 	[IIO_CHAN_INFO_PROCESSED] = "input",
124 	[IIO_CHAN_INFO_SCALE] = "scale",
125 	[IIO_CHAN_INFO_OFFSET] = "offset",
126 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
127 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
128 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
129 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
130 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
131 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
132 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
133 	= "filter_low_pass_3db_frequency",
134 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
135 	= "filter_high_pass_3db_frequency",
136 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
137 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
138 	[IIO_CHAN_INFO_PHASE] = "phase",
139 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
140 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
141 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
142 	[IIO_CHAN_INFO_ENABLE] = "en",
143 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
144 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
145 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
146 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
147 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
148 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
149 };
150 
151 /**
152  * iio_find_channel_from_si() - get channel from its scan index
153  * @indio_dev:		device
154  * @si:			scan index to match
155  */
156 const struct iio_chan_spec
157 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
158 {
159 	int i;
160 
161 	for (i = 0; i < indio_dev->num_channels; i++)
162 		if (indio_dev->channels[i].scan_index == si)
163 			return &indio_dev->channels[i];
164 	return NULL;
165 }
166 
167 /* This turns up an awful lot */
168 ssize_t iio_read_const_attr(struct device *dev,
169 			    struct device_attribute *attr,
170 			    char *buf)
171 {
172 	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
173 }
174 EXPORT_SYMBOL(iio_read_const_attr);
175 
176 static int __init iio_init(void)
177 {
178 	int ret;
179 
180 	/* Register sysfs bus */
181 	ret  = bus_register(&iio_bus_type);
182 	if (ret < 0) {
183 		pr_err("could not register bus type\n");
184 		goto error_nothing;
185 	}
186 
187 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
188 	if (ret < 0) {
189 		pr_err("failed to allocate char dev region\n");
190 		goto error_unregister_bus_type;
191 	}
192 
193 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
194 
195 	return 0;
196 
197 error_unregister_bus_type:
198 	bus_unregister(&iio_bus_type);
199 error_nothing:
200 	return ret;
201 }
202 
203 static void __exit iio_exit(void)
204 {
205 	if (iio_devt)
206 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
207 	bus_unregister(&iio_bus_type);
208 	debugfs_remove(iio_debugfs_dentry);
209 }
210 
211 #if defined(CONFIG_DEBUG_FS)
212 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
213 			      size_t count, loff_t *ppos)
214 {
215 	struct iio_dev *indio_dev = file->private_data;
216 	char buf[20];
217 	unsigned val = 0;
218 	ssize_t len;
219 	int ret;
220 
221 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
222 						  indio_dev->cached_reg_addr,
223 						  0, &val);
224 	if (ret)
225 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
226 
227 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
228 
229 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
230 }
231 
232 static ssize_t iio_debugfs_write_reg(struct file *file,
233 		     const char __user *userbuf, size_t count, loff_t *ppos)
234 {
235 	struct iio_dev *indio_dev = file->private_data;
236 	unsigned reg, val;
237 	char buf[80];
238 	int ret;
239 
240 	count = min_t(size_t, count, (sizeof(buf)-1));
241 	if (copy_from_user(buf, userbuf, count))
242 		return -EFAULT;
243 
244 	buf[count] = 0;
245 
246 	ret = sscanf(buf, "%i %i", &reg, &val);
247 
248 	switch (ret) {
249 	case 1:
250 		indio_dev->cached_reg_addr = reg;
251 		break;
252 	case 2:
253 		indio_dev->cached_reg_addr = reg;
254 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
255 							  val, NULL);
256 		if (ret) {
257 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
258 				__func__);
259 			return ret;
260 		}
261 		break;
262 	default:
263 		return -EINVAL;
264 	}
265 
266 	return count;
267 }
268 
269 static const struct file_operations iio_debugfs_reg_fops = {
270 	.open = simple_open,
271 	.read = iio_debugfs_read_reg,
272 	.write = iio_debugfs_write_reg,
273 };
274 
275 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
276 {
277 	debugfs_remove_recursive(indio_dev->debugfs_dentry);
278 }
279 
280 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
281 {
282 	struct dentry *d;
283 
284 	if (indio_dev->info->debugfs_reg_access == NULL)
285 		return 0;
286 
287 	if (!iio_debugfs_dentry)
288 		return 0;
289 
290 	indio_dev->debugfs_dentry =
291 		debugfs_create_dir(dev_name(&indio_dev->dev),
292 				   iio_debugfs_dentry);
293 	if (indio_dev->debugfs_dentry == NULL) {
294 		dev_warn(indio_dev->dev.parent,
295 			 "Failed to create debugfs directory\n");
296 		return -EFAULT;
297 	}
298 
299 	d = debugfs_create_file("direct_reg_access", 0644,
300 				indio_dev->debugfs_dentry,
301 				indio_dev, &iio_debugfs_reg_fops);
302 	if (!d) {
303 		iio_device_unregister_debugfs(indio_dev);
304 		return -ENOMEM;
305 	}
306 
307 	return 0;
308 }
309 #else
310 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
311 {
312 	return 0;
313 }
314 
315 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
316 {
317 }
318 #endif /* CONFIG_DEBUG_FS */
319 
320 static ssize_t iio_read_channel_ext_info(struct device *dev,
321 				     struct device_attribute *attr,
322 				     char *buf)
323 {
324 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
325 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
326 	const struct iio_chan_spec_ext_info *ext_info;
327 
328 	ext_info = &this_attr->c->ext_info[this_attr->address];
329 
330 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
331 }
332 
333 static ssize_t iio_write_channel_ext_info(struct device *dev,
334 				     struct device_attribute *attr,
335 				     const char *buf,
336 					 size_t len)
337 {
338 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
339 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
340 	const struct iio_chan_spec_ext_info *ext_info;
341 
342 	ext_info = &this_attr->c->ext_info[this_attr->address];
343 
344 	return ext_info->write(indio_dev, ext_info->private,
345 			       this_attr->c, buf, len);
346 }
347 
348 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
349 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
350 {
351 	const struct iio_enum *e = (const struct iio_enum *)priv;
352 	unsigned int i;
353 	size_t len = 0;
354 
355 	if (!e->num_items)
356 		return 0;
357 
358 	for (i = 0; i < e->num_items; ++i)
359 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
360 
361 	/* replace last space with a newline */
362 	buf[len - 1] = '\n';
363 
364 	return len;
365 }
366 EXPORT_SYMBOL_GPL(iio_enum_available_read);
367 
368 ssize_t iio_enum_read(struct iio_dev *indio_dev,
369 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
370 {
371 	const struct iio_enum *e = (const struct iio_enum *)priv;
372 	int i;
373 
374 	if (!e->get)
375 		return -EINVAL;
376 
377 	i = e->get(indio_dev, chan);
378 	if (i < 0)
379 		return i;
380 	else if (i >= e->num_items)
381 		return -EINVAL;
382 
383 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
384 }
385 EXPORT_SYMBOL_GPL(iio_enum_read);
386 
387 ssize_t iio_enum_write(struct iio_dev *indio_dev,
388 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
389 	size_t len)
390 {
391 	const struct iio_enum *e = (const struct iio_enum *)priv;
392 	unsigned int i;
393 	int ret;
394 
395 	if (!e->set)
396 		return -EINVAL;
397 
398 	for (i = 0; i < e->num_items; i++) {
399 		if (sysfs_streq(buf, e->items[i]))
400 			break;
401 	}
402 
403 	if (i == e->num_items)
404 		return -EINVAL;
405 
406 	ret = e->set(indio_dev, chan, i);
407 	return ret ? ret : len;
408 }
409 EXPORT_SYMBOL_GPL(iio_enum_write);
410 
411 /**
412  * iio_format_value() - Formats a IIO value into its string representation
413  * @buf:	The buffer to which the formatted value gets written
414  * @type:	One of the IIO_VAL_... constants. This decides how the val
415  *		and val2 parameters are formatted.
416  * @size:	Number of IIO value entries contained in vals
417  * @vals:	Pointer to the values, exact meaning depends on the
418  *		type parameter.
419  *
420  * Return: 0 by default, a negative number on failure or the
421  *	   total number of characters written for a type that belongs
422  *	   to the IIO_VAL_... constant.
423  */
424 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
425 {
426 	unsigned long long tmp;
427 	bool scale_db = false;
428 
429 	switch (type) {
430 	case IIO_VAL_INT:
431 		return sprintf(buf, "%d\n", vals[0]);
432 	case IIO_VAL_INT_PLUS_MICRO_DB:
433 		scale_db = true;
434 	case IIO_VAL_INT_PLUS_MICRO:
435 		if (vals[1] < 0)
436 			return sprintf(buf, "-%d.%06u%s\n", abs(vals[0]),
437 				       -vals[1], scale_db ? " dB" : "");
438 		else
439 			return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1],
440 				scale_db ? " dB" : "");
441 	case IIO_VAL_INT_PLUS_NANO:
442 		if (vals[1] < 0)
443 			return sprintf(buf, "-%d.%09u\n", abs(vals[0]),
444 				       -vals[1]);
445 		else
446 			return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
447 	case IIO_VAL_FRACTIONAL:
448 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
449 		vals[1] = do_div(tmp, 1000000000LL);
450 		vals[0] = tmp;
451 		return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
452 	case IIO_VAL_FRACTIONAL_LOG2:
453 		tmp = (s64)vals[0] * 1000000000LL >> vals[1];
454 		vals[1] = do_div(tmp, 1000000000LL);
455 		vals[0] = tmp;
456 		return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
457 	case IIO_VAL_INT_MULTIPLE:
458 	{
459 		int i;
460 		int len = 0;
461 
462 		for (i = 0; i < size; ++i)
463 			len += snprintf(&buf[len], PAGE_SIZE - len, "%d ",
464 								vals[i]);
465 		len += snprintf(&buf[len], PAGE_SIZE - len, "\n");
466 		return len;
467 	}
468 	default:
469 		return 0;
470 	}
471 }
472 EXPORT_SYMBOL_GPL(iio_format_value);
473 
474 static ssize_t iio_read_channel_info(struct device *dev,
475 				     struct device_attribute *attr,
476 				     char *buf)
477 {
478 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
479 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
480 	int vals[INDIO_MAX_RAW_ELEMENTS];
481 	int ret;
482 	int val_len = 2;
483 
484 	if (indio_dev->info->read_raw_multi)
485 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
486 							INDIO_MAX_RAW_ELEMENTS,
487 							vals, &val_len,
488 							this_attr->address);
489 	else
490 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
491 				    &vals[0], &vals[1], this_attr->address);
492 
493 	if (ret < 0)
494 		return ret;
495 
496 	return iio_format_value(buf, ret, val_len, vals);
497 }
498 
499 /**
500  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
501  * @str: The string to parse
502  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
503  * @integer: The integer part of the number
504  * @fract: The fractional part of the number
505  *
506  * Returns 0 on success, or a negative error code if the string could not be
507  * parsed.
508  */
509 int iio_str_to_fixpoint(const char *str, int fract_mult,
510 	int *integer, int *fract)
511 {
512 	int i = 0, f = 0;
513 	bool integer_part = true, negative = false;
514 
515 	if (fract_mult == 0) {
516 		*fract = 0;
517 
518 		return kstrtoint(str, 0, integer);
519 	}
520 
521 	if (str[0] == '-') {
522 		negative = true;
523 		str++;
524 	} else if (str[0] == '+') {
525 		str++;
526 	}
527 
528 	while (*str) {
529 		if ('0' <= *str && *str <= '9') {
530 			if (integer_part) {
531 				i = i * 10 + *str - '0';
532 			} else {
533 				f += fract_mult * (*str - '0');
534 				fract_mult /= 10;
535 			}
536 		} else if (*str == '\n') {
537 			if (*(str + 1) == '\0')
538 				break;
539 			else
540 				return -EINVAL;
541 		} else if (*str == '.' && integer_part) {
542 			integer_part = false;
543 		} else {
544 			return -EINVAL;
545 		}
546 		str++;
547 	}
548 
549 	if (negative) {
550 		if (i)
551 			i = -i;
552 		else
553 			f = -f;
554 	}
555 
556 	*integer = i;
557 	*fract = f;
558 
559 	return 0;
560 }
561 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
562 
563 static ssize_t iio_write_channel_info(struct device *dev,
564 				      struct device_attribute *attr,
565 				      const char *buf,
566 				      size_t len)
567 {
568 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
569 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
570 	int ret, fract_mult = 100000;
571 	int integer, fract;
572 
573 	/* Assumes decimal - precision based on number of digits */
574 	if (!indio_dev->info->write_raw)
575 		return -EINVAL;
576 
577 	if (indio_dev->info->write_raw_get_fmt)
578 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
579 			this_attr->c, this_attr->address)) {
580 		case IIO_VAL_INT:
581 			fract_mult = 0;
582 			break;
583 		case IIO_VAL_INT_PLUS_MICRO:
584 			fract_mult = 100000;
585 			break;
586 		case IIO_VAL_INT_PLUS_NANO:
587 			fract_mult = 100000000;
588 			break;
589 		default:
590 			return -EINVAL;
591 		}
592 
593 	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
594 	if (ret)
595 		return ret;
596 
597 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
598 					 integer, fract, this_attr->address);
599 	if (ret)
600 		return ret;
601 
602 	return len;
603 }
604 
605 static
606 int __iio_device_attr_init(struct device_attribute *dev_attr,
607 			   const char *postfix,
608 			   struct iio_chan_spec const *chan,
609 			   ssize_t (*readfunc)(struct device *dev,
610 					       struct device_attribute *attr,
611 					       char *buf),
612 			   ssize_t (*writefunc)(struct device *dev,
613 						struct device_attribute *attr,
614 						const char *buf,
615 						size_t len),
616 			   enum iio_shared_by shared_by)
617 {
618 	int ret = 0;
619 	char *name = NULL;
620 	char *full_postfix;
621 	sysfs_attr_init(&dev_attr->attr);
622 
623 	/* Build up postfix of <extend_name>_<modifier>_postfix */
624 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
625 		if (chan->extend_name)
626 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
627 						 iio_modifier_names[chan
628 								    ->channel2],
629 						 chan->extend_name,
630 						 postfix);
631 		else
632 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
633 						 iio_modifier_names[chan
634 								    ->channel2],
635 						 postfix);
636 	} else {
637 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
638 			full_postfix = kstrdup(postfix, GFP_KERNEL);
639 		else
640 			full_postfix = kasprintf(GFP_KERNEL,
641 						 "%s_%s",
642 						 chan->extend_name,
643 						 postfix);
644 	}
645 	if (full_postfix == NULL)
646 		return -ENOMEM;
647 
648 	if (chan->differential) { /* Differential can not have modifier */
649 		switch (shared_by) {
650 		case IIO_SHARED_BY_ALL:
651 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
652 			break;
653 		case IIO_SHARED_BY_DIR:
654 			name = kasprintf(GFP_KERNEL, "%s_%s",
655 						iio_direction[chan->output],
656 						full_postfix);
657 			break;
658 		case IIO_SHARED_BY_TYPE:
659 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
660 					    iio_direction[chan->output],
661 					    iio_chan_type_name_spec[chan->type],
662 					    iio_chan_type_name_spec[chan->type],
663 					    full_postfix);
664 			break;
665 		case IIO_SEPARATE:
666 			if (!chan->indexed) {
667 				WARN(1, "Differential channels must be indexed\n");
668 				ret = -EINVAL;
669 				goto error_free_full_postfix;
670 			}
671 			name = kasprintf(GFP_KERNEL,
672 					    "%s_%s%d-%s%d_%s",
673 					    iio_direction[chan->output],
674 					    iio_chan_type_name_spec[chan->type],
675 					    chan->channel,
676 					    iio_chan_type_name_spec[chan->type],
677 					    chan->channel2,
678 					    full_postfix);
679 			break;
680 		}
681 	} else { /* Single ended */
682 		switch (shared_by) {
683 		case IIO_SHARED_BY_ALL:
684 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
685 			break;
686 		case IIO_SHARED_BY_DIR:
687 			name = kasprintf(GFP_KERNEL, "%s_%s",
688 						iio_direction[chan->output],
689 						full_postfix);
690 			break;
691 		case IIO_SHARED_BY_TYPE:
692 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
693 					    iio_direction[chan->output],
694 					    iio_chan_type_name_spec[chan->type],
695 					    full_postfix);
696 			break;
697 
698 		case IIO_SEPARATE:
699 			if (chan->indexed)
700 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
701 						    iio_direction[chan->output],
702 						    iio_chan_type_name_spec[chan->type],
703 						    chan->channel,
704 						    full_postfix);
705 			else
706 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
707 						    iio_direction[chan->output],
708 						    iio_chan_type_name_spec[chan->type],
709 						    full_postfix);
710 			break;
711 		}
712 	}
713 	if (name == NULL) {
714 		ret = -ENOMEM;
715 		goto error_free_full_postfix;
716 	}
717 	dev_attr->attr.name = name;
718 
719 	if (readfunc) {
720 		dev_attr->attr.mode |= S_IRUGO;
721 		dev_attr->show = readfunc;
722 	}
723 
724 	if (writefunc) {
725 		dev_attr->attr.mode |= S_IWUSR;
726 		dev_attr->store = writefunc;
727 	}
728 
729 error_free_full_postfix:
730 	kfree(full_postfix);
731 
732 	return ret;
733 }
734 
735 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
736 {
737 	kfree(dev_attr->attr.name);
738 }
739 
740 int __iio_add_chan_devattr(const char *postfix,
741 			   struct iio_chan_spec const *chan,
742 			   ssize_t (*readfunc)(struct device *dev,
743 					       struct device_attribute *attr,
744 					       char *buf),
745 			   ssize_t (*writefunc)(struct device *dev,
746 						struct device_attribute *attr,
747 						const char *buf,
748 						size_t len),
749 			   u64 mask,
750 			   enum iio_shared_by shared_by,
751 			   struct device *dev,
752 			   struct list_head *attr_list)
753 {
754 	int ret;
755 	struct iio_dev_attr *iio_attr, *t;
756 
757 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
758 	if (iio_attr == NULL)
759 		return -ENOMEM;
760 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
761 				     postfix, chan,
762 				     readfunc, writefunc, shared_by);
763 	if (ret)
764 		goto error_iio_dev_attr_free;
765 	iio_attr->c = chan;
766 	iio_attr->address = mask;
767 	list_for_each_entry(t, attr_list, l)
768 		if (strcmp(t->dev_attr.attr.name,
769 			   iio_attr->dev_attr.attr.name) == 0) {
770 			if (shared_by == IIO_SEPARATE)
771 				dev_err(dev, "tried to double register : %s\n",
772 					t->dev_attr.attr.name);
773 			ret = -EBUSY;
774 			goto error_device_attr_deinit;
775 		}
776 	list_add(&iio_attr->l, attr_list);
777 
778 	return 0;
779 
780 error_device_attr_deinit:
781 	__iio_device_attr_deinit(&iio_attr->dev_attr);
782 error_iio_dev_attr_free:
783 	kfree(iio_attr);
784 	return ret;
785 }
786 
787 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
788 					 struct iio_chan_spec const *chan,
789 					 enum iio_shared_by shared_by,
790 					 const long *infomask)
791 {
792 	int i, ret, attrcount = 0;
793 
794 	for_each_set_bit(i, infomask, sizeof(infomask)*8) {
795 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
796 			return -EINVAL;
797 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
798 					     chan,
799 					     &iio_read_channel_info,
800 					     &iio_write_channel_info,
801 					     i,
802 					     shared_by,
803 					     &indio_dev->dev,
804 					     &indio_dev->channel_attr_list);
805 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
806 			continue;
807 		else if (ret < 0)
808 			return ret;
809 		attrcount++;
810 	}
811 
812 	return attrcount;
813 }
814 
815 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
816 					struct iio_chan_spec const *chan)
817 {
818 	int ret, attrcount = 0;
819 	const struct iio_chan_spec_ext_info *ext_info;
820 
821 	if (chan->channel < 0)
822 		return 0;
823 	ret = iio_device_add_info_mask_type(indio_dev, chan,
824 					    IIO_SEPARATE,
825 					    &chan->info_mask_separate);
826 	if (ret < 0)
827 		return ret;
828 	attrcount += ret;
829 
830 	ret = iio_device_add_info_mask_type(indio_dev, chan,
831 					    IIO_SHARED_BY_TYPE,
832 					    &chan->info_mask_shared_by_type);
833 	if (ret < 0)
834 		return ret;
835 	attrcount += ret;
836 
837 	ret = iio_device_add_info_mask_type(indio_dev, chan,
838 					    IIO_SHARED_BY_DIR,
839 					    &chan->info_mask_shared_by_dir);
840 	if (ret < 0)
841 		return ret;
842 	attrcount += ret;
843 
844 	ret = iio_device_add_info_mask_type(indio_dev, chan,
845 					    IIO_SHARED_BY_ALL,
846 					    &chan->info_mask_shared_by_all);
847 	if (ret < 0)
848 		return ret;
849 	attrcount += ret;
850 
851 	if (chan->ext_info) {
852 		unsigned int i = 0;
853 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
854 			ret = __iio_add_chan_devattr(ext_info->name,
855 					chan,
856 					ext_info->read ?
857 					    &iio_read_channel_ext_info : NULL,
858 					ext_info->write ?
859 					    &iio_write_channel_ext_info : NULL,
860 					i,
861 					ext_info->shared,
862 					&indio_dev->dev,
863 					&indio_dev->channel_attr_list);
864 			i++;
865 			if (ret == -EBUSY && ext_info->shared)
866 				continue;
867 
868 			if (ret)
869 				return ret;
870 
871 			attrcount++;
872 		}
873 	}
874 
875 	return attrcount;
876 }
877 
878 /**
879  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
880  * @attr_list: List of IIO device attributes
881  *
882  * This function frees the memory allocated for each of the IIO device
883  * attributes in the list.
884  */
885 void iio_free_chan_devattr_list(struct list_head *attr_list)
886 {
887 	struct iio_dev_attr *p, *n;
888 
889 	list_for_each_entry_safe(p, n, attr_list, l) {
890 		kfree(p->dev_attr.attr.name);
891 		list_del(&p->l);
892 		kfree(p);
893 	}
894 }
895 
896 static ssize_t iio_show_dev_name(struct device *dev,
897 				 struct device_attribute *attr,
898 				 char *buf)
899 {
900 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
901 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
902 }
903 
904 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
905 
906 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
907 {
908 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
909 	struct iio_dev_attr *p;
910 	struct attribute **attr;
911 
912 	/* First count elements in any existing group */
913 	if (indio_dev->info->attrs) {
914 		attr = indio_dev->info->attrs->attrs;
915 		while (*attr++ != NULL)
916 			attrcount_orig++;
917 	}
918 	attrcount = attrcount_orig;
919 	/*
920 	 * New channel registration method - relies on the fact a group does
921 	 * not need to be initialized if its name is NULL.
922 	 */
923 	if (indio_dev->channels)
924 		for (i = 0; i < indio_dev->num_channels; i++) {
925 			ret = iio_device_add_channel_sysfs(indio_dev,
926 							   &indio_dev
927 							   ->channels[i]);
928 			if (ret < 0)
929 				goto error_clear_attrs;
930 			attrcount += ret;
931 		}
932 
933 	if (indio_dev->name)
934 		attrcount++;
935 
936 	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
937 						   sizeof(indio_dev->chan_attr_group.attrs[0]),
938 						   GFP_KERNEL);
939 	if (indio_dev->chan_attr_group.attrs == NULL) {
940 		ret = -ENOMEM;
941 		goto error_clear_attrs;
942 	}
943 	/* Copy across original attributes */
944 	if (indio_dev->info->attrs)
945 		memcpy(indio_dev->chan_attr_group.attrs,
946 		       indio_dev->info->attrs->attrs,
947 		       sizeof(indio_dev->chan_attr_group.attrs[0])
948 		       *attrcount_orig);
949 	attrn = attrcount_orig;
950 	/* Add all elements from the list. */
951 	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
952 		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
953 	if (indio_dev->name)
954 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
955 
956 	indio_dev->groups[indio_dev->groupcounter++] =
957 		&indio_dev->chan_attr_group;
958 
959 	return 0;
960 
961 error_clear_attrs:
962 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
963 
964 	return ret;
965 }
966 
967 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
968 {
969 
970 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
971 	kfree(indio_dev->chan_attr_group.attrs);
972 	indio_dev->chan_attr_group.attrs = NULL;
973 }
974 
975 static void iio_dev_release(struct device *device)
976 {
977 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
978 	if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
979 		iio_device_unregister_trigger_consumer(indio_dev);
980 	iio_device_unregister_eventset(indio_dev);
981 	iio_device_unregister_sysfs(indio_dev);
982 
983 	iio_buffer_put(indio_dev->buffer);
984 
985 	ida_simple_remove(&iio_ida, indio_dev->id);
986 	kfree(indio_dev);
987 }
988 
989 struct device_type iio_device_type = {
990 	.name = "iio_device",
991 	.release = iio_dev_release,
992 };
993 
994 /**
995  * iio_device_alloc() - allocate an iio_dev from a driver
996  * @sizeof_priv:	Space to allocate for private structure.
997  **/
998 struct iio_dev *iio_device_alloc(int sizeof_priv)
999 {
1000 	struct iio_dev *dev;
1001 	size_t alloc_size;
1002 
1003 	alloc_size = sizeof(struct iio_dev);
1004 	if (sizeof_priv) {
1005 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1006 		alloc_size += sizeof_priv;
1007 	}
1008 	/* ensure 32-byte alignment of whole construct ? */
1009 	alloc_size += IIO_ALIGN - 1;
1010 
1011 	dev = kzalloc(alloc_size, GFP_KERNEL);
1012 
1013 	if (dev) {
1014 		dev->dev.groups = dev->groups;
1015 		dev->dev.type = &iio_device_type;
1016 		dev->dev.bus = &iio_bus_type;
1017 		device_initialize(&dev->dev);
1018 		dev_set_drvdata(&dev->dev, (void *)dev);
1019 		mutex_init(&dev->mlock);
1020 		mutex_init(&dev->info_exist_lock);
1021 		INIT_LIST_HEAD(&dev->channel_attr_list);
1022 
1023 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1024 		if (dev->id < 0) {
1025 			/* cannot use a dev_err as the name isn't available */
1026 			pr_err("failed to get device id\n");
1027 			kfree(dev);
1028 			return NULL;
1029 		}
1030 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1031 		INIT_LIST_HEAD(&dev->buffer_list);
1032 	}
1033 
1034 	return dev;
1035 }
1036 EXPORT_SYMBOL(iio_device_alloc);
1037 
1038 /**
1039  * iio_device_free() - free an iio_dev from a driver
1040  * @dev:		the iio_dev associated with the device
1041  **/
1042 void iio_device_free(struct iio_dev *dev)
1043 {
1044 	if (dev)
1045 		put_device(&dev->dev);
1046 }
1047 EXPORT_SYMBOL(iio_device_free);
1048 
1049 static void devm_iio_device_release(struct device *dev, void *res)
1050 {
1051 	iio_device_free(*(struct iio_dev **)res);
1052 }
1053 
1054 static int devm_iio_device_match(struct device *dev, void *res, void *data)
1055 {
1056 	struct iio_dev **r = res;
1057 	if (!r || !*r) {
1058 		WARN_ON(!r || !*r);
1059 		return 0;
1060 	}
1061 	return *r == data;
1062 }
1063 
1064 /**
1065  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1066  * @dev:		Device to allocate iio_dev for
1067  * @sizeof_priv:	Space to allocate for private structure.
1068  *
1069  * Managed iio_device_alloc. iio_dev allocated with this function is
1070  * automatically freed on driver detach.
1071  *
1072  * If an iio_dev allocated with this function needs to be freed separately,
1073  * devm_iio_device_free() must be used.
1074  *
1075  * RETURNS:
1076  * Pointer to allocated iio_dev on success, NULL on failure.
1077  */
1078 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1079 {
1080 	struct iio_dev **ptr, *iio_dev;
1081 
1082 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1083 			   GFP_KERNEL);
1084 	if (!ptr)
1085 		return NULL;
1086 
1087 	iio_dev = iio_device_alloc(sizeof_priv);
1088 	if (iio_dev) {
1089 		*ptr = iio_dev;
1090 		devres_add(dev, ptr);
1091 	} else {
1092 		devres_free(ptr);
1093 	}
1094 
1095 	return iio_dev;
1096 }
1097 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1098 
1099 /**
1100  * devm_iio_device_free - Resource-managed iio_device_free()
1101  * @dev:		Device this iio_dev belongs to
1102  * @iio_dev:		the iio_dev associated with the device
1103  *
1104  * Free iio_dev allocated with devm_iio_device_alloc().
1105  */
1106 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1107 {
1108 	int rc;
1109 
1110 	rc = devres_release(dev, devm_iio_device_release,
1111 			    devm_iio_device_match, iio_dev);
1112 	WARN_ON(rc);
1113 }
1114 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1115 
1116 /**
1117  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1118  * @inode:	Inode structure for identifying the device in the file system
1119  * @filp:	File structure for iio device used to keep and later access
1120  *		private data
1121  *
1122  * Return: 0 on success or -EBUSY if the device is already opened
1123  **/
1124 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1125 {
1126 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1127 						struct iio_dev, chrdev);
1128 
1129 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1130 		return -EBUSY;
1131 
1132 	iio_device_get(indio_dev);
1133 
1134 	filp->private_data = indio_dev;
1135 
1136 	return 0;
1137 }
1138 
1139 /**
1140  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1141  * @inode:	Inode structure pointer for the char device
1142  * @filp:	File structure pointer for the char device
1143  *
1144  * Return: 0 for successful release
1145  */
1146 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1147 {
1148 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1149 						struct iio_dev, chrdev);
1150 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1151 	iio_device_put(indio_dev);
1152 
1153 	return 0;
1154 }
1155 
1156 /* Somewhat of a cross file organization violation - ioctls here are actually
1157  * event related */
1158 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1159 {
1160 	struct iio_dev *indio_dev = filp->private_data;
1161 	int __user *ip = (int __user *)arg;
1162 	int fd;
1163 
1164 	if (!indio_dev->info)
1165 		return -ENODEV;
1166 
1167 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1168 		fd = iio_event_getfd(indio_dev);
1169 		if (fd < 0)
1170 			return fd;
1171 		if (copy_to_user(ip, &fd, sizeof(fd)))
1172 			return -EFAULT;
1173 		return 0;
1174 	}
1175 	return -EINVAL;
1176 }
1177 
1178 static const struct file_operations iio_buffer_fileops = {
1179 	.read = iio_buffer_read_first_n_outer_addr,
1180 	.release = iio_chrdev_release,
1181 	.open = iio_chrdev_open,
1182 	.poll = iio_buffer_poll_addr,
1183 	.owner = THIS_MODULE,
1184 	.llseek = noop_llseek,
1185 	.unlocked_ioctl = iio_ioctl,
1186 	.compat_ioctl = iio_ioctl,
1187 };
1188 
1189 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1190 {
1191 	int i, j;
1192 	const struct iio_chan_spec *channels = indio_dev->channels;
1193 
1194 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1195 		return 0;
1196 
1197 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1198 		if (channels[i].scan_index < 0)
1199 			continue;
1200 		for (j = i + 1; j < indio_dev->num_channels; j++)
1201 			if (channels[i].scan_index == channels[j].scan_index) {
1202 				dev_err(&indio_dev->dev,
1203 					"Duplicate scan index %d\n",
1204 					channels[i].scan_index);
1205 				return -EINVAL;
1206 			}
1207 	}
1208 
1209 	return 0;
1210 }
1211 
1212 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1213 
1214 /**
1215  * iio_device_register() - register a device with the IIO subsystem
1216  * @indio_dev:		Device structure filled by the device driver
1217  **/
1218 int iio_device_register(struct iio_dev *indio_dev)
1219 {
1220 	int ret;
1221 
1222 	/* If the calling driver did not initialize of_node, do it here */
1223 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1224 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1225 
1226 	ret = iio_check_unique_scan_index(indio_dev);
1227 	if (ret < 0)
1228 		return ret;
1229 
1230 	/* configure elements for the chrdev */
1231 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1232 
1233 	ret = iio_device_register_debugfs(indio_dev);
1234 	if (ret) {
1235 		dev_err(indio_dev->dev.parent,
1236 			"Failed to register debugfs interfaces\n");
1237 		return ret;
1238 	}
1239 
1240 	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1241 	if (ret) {
1242 		dev_err(indio_dev->dev.parent,
1243 			"Failed to create buffer sysfs interfaces\n");
1244 		goto error_unreg_debugfs;
1245 	}
1246 
1247 	ret = iio_device_register_sysfs(indio_dev);
1248 	if (ret) {
1249 		dev_err(indio_dev->dev.parent,
1250 			"Failed to register sysfs interfaces\n");
1251 		goto error_buffer_free_sysfs;
1252 	}
1253 	ret = iio_device_register_eventset(indio_dev);
1254 	if (ret) {
1255 		dev_err(indio_dev->dev.parent,
1256 			"Failed to register event set\n");
1257 		goto error_free_sysfs;
1258 	}
1259 	if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1260 		iio_device_register_trigger_consumer(indio_dev);
1261 
1262 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1263 		indio_dev->setup_ops == NULL)
1264 		indio_dev->setup_ops = &noop_ring_setup_ops;
1265 
1266 	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1267 	indio_dev->chrdev.owner = indio_dev->info->driver_module;
1268 	indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1269 	ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1270 	if (ret < 0)
1271 		goto error_unreg_eventset;
1272 
1273 	ret = device_add(&indio_dev->dev);
1274 	if (ret < 0)
1275 		goto error_cdev_del;
1276 
1277 	return 0;
1278 error_cdev_del:
1279 	cdev_del(&indio_dev->chrdev);
1280 error_unreg_eventset:
1281 	iio_device_unregister_eventset(indio_dev);
1282 error_free_sysfs:
1283 	iio_device_unregister_sysfs(indio_dev);
1284 error_buffer_free_sysfs:
1285 	iio_buffer_free_sysfs_and_mask(indio_dev);
1286 error_unreg_debugfs:
1287 	iio_device_unregister_debugfs(indio_dev);
1288 	return ret;
1289 }
1290 EXPORT_SYMBOL(iio_device_register);
1291 
1292 /**
1293  * iio_device_unregister() - unregister a device from the IIO subsystem
1294  * @indio_dev:		Device structure representing the device.
1295  **/
1296 void iio_device_unregister(struct iio_dev *indio_dev)
1297 {
1298 	mutex_lock(&indio_dev->info_exist_lock);
1299 
1300 	device_del(&indio_dev->dev);
1301 
1302 	if (indio_dev->chrdev.dev)
1303 		cdev_del(&indio_dev->chrdev);
1304 	iio_device_unregister_debugfs(indio_dev);
1305 
1306 	iio_disable_all_buffers(indio_dev);
1307 
1308 	indio_dev->info = NULL;
1309 
1310 	iio_device_wakeup_eventset(indio_dev);
1311 	iio_buffer_wakeup_poll(indio_dev);
1312 
1313 	mutex_unlock(&indio_dev->info_exist_lock);
1314 
1315 	iio_buffer_free_sysfs_and_mask(indio_dev);
1316 }
1317 EXPORT_SYMBOL(iio_device_unregister);
1318 
1319 static void devm_iio_device_unreg(struct device *dev, void *res)
1320 {
1321 	iio_device_unregister(*(struct iio_dev **)res);
1322 }
1323 
1324 /**
1325  * devm_iio_device_register - Resource-managed iio_device_register()
1326  * @dev:	Device to allocate iio_dev for
1327  * @indio_dev:	Device structure filled by the device driver
1328  *
1329  * Managed iio_device_register.  The IIO device registered with this
1330  * function is automatically unregistered on driver detach. This function
1331  * calls iio_device_register() internally. Refer to that function for more
1332  * information.
1333  *
1334  * If an iio_dev registered with this function needs to be unregistered
1335  * separately, devm_iio_device_unregister() must be used.
1336  *
1337  * RETURNS:
1338  * 0 on success, negative error number on failure.
1339  */
1340 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1341 {
1342 	struct iio_dev **ptr;
1343 	int ret;
1344 
1345 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1346 	if (!ptr)
1347 		return -ENOMEM;
1348 
1349 	*ptr = indio_dev;
1350 	ret = iio_device_register(indio_dev);
1351 	if (!ret)
1352 		devres_add(dev, ptr);
1353 	else
1354 		devres_free(ptr);
1355 
1356 	return ret;
1357 }
1358 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1359 
1360 /**
1361  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1362  * @dev:	Device this iio_dev belongs to
1363  * @indio_dev:	the iio_dev associated with the device
1364  *
1365  * Unregister iio_dev registered with devm_iio_device_register().
1366  */
1367 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1368 {
1369 	int rc;
1370 
1371 	rc = devres_release(dev, devm_iio_device_unreg,
1372 			    devm_iio_device_match, indio_dev);
1373 	WARN_ON(rc);
1374 }
1375 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1376 
1377 subsys_initcall(iio_init);
1378 module_exit(iio_exit);
1379 
1380 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1381 MODULE_DESCRIPTION("Industrial I/O core");
1382 MODULE_LICENSE("GPL");
1383