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/mutex.h>
29 #include <linux/iio/iio.h>
30 #include "iio_core.h"
31 #include "iio_core_trigger.h"
32 #include <linux/iio/sysfs.h>
33 #include <linux/iio/events.h>
34 #include <linux/iio/buffer.h>
35 
36 /* IDA to assign each registered device a unique id */
37 static DEFINE_IDA(iio_ida);
38 
39 static dev_t iio_devt;
40 
41 #define IIO_DEV_MAX 256
42 struct bus_type iio_bus_type = {
43 	.name = "iio",
44 };
45 EXPORT_SYMBOL(iio_bus_type);
46 
47 static struct dentry *iio_debugfs_dentry;
48 
49 static const char * const iio_direction[] = {
50 	[0] = "in",
51 	[1] = "out",
52 };
53 
54 static const char * const iio_chan_type_name_spec[] = {
55 	[IIO_VOLTAGE] = "voltage",
56 	[IIO_CURRENT] = "current",
57 	[IIO_POWER] = "power",
58 	[IIO_ACCEL] = "accel",
59 	[IIO_ANGL_VEL] = "anglvel",
60 	[IIO_MAGN] = "magn",
61 	[IIO_LIGHT] = "illuminance",
62 	[IIO_INTENSITY] = "intensity",
63 	[IIO_PROXIMITY] = "proximity",
64 	[IIO_TEMP] = "temp",
65 	[IIO_INCLI] = "incli",
66 	[IIO_ROT] = "rot",
67 	[IIO_ANGL] = "angl",
68 	[IIO_TIMESTAMP] = "timestamp",
69 	[IIO_CAPACITANCE] = "capacitance",
70 	[IIO_ALTVOLTAGE] = "altvoltage",
71 	[IIO_CCT] = "cct",
72 	[IIO_PRESSURE] = "pressure",
73 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
74 	[IIO_ACTIVITY] = "activity",
75 	[IIO_STEPS] = "steps",
76 	[IIO_ENERGY] = "energy",
77 	[IIO_DISTANCE] = "distance",
78 	[IIO_VELOCITY] = "velocity",
79 	[IIO_CONCENTRATION] = "concentration",
80 	[IIO_RESISTANCE] = "resistance",
81 	[IIO_PH] = "ph",
82 	[IIO_UVINDEX] = "uvindex",
83 };
84 
85 static const char * const iio_modifier_names[] = {
86 	[IIO_MOD_X] = "x",
87 	[IIO_MOD_Y] = "y",
88 	[IIO_MOD_Z] = "z",
89 	[IIO_MOD_X_AND_Y] = "x&y",
90 	[IIO_MOD_X_AND_Z] = "x&z",
91 	[IIO_MOD_Y_AND_Z] = "y&z",
92 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
93 	[IIO_MOD_X_OR_Y] = "x|y",
94 	[IIO_MOD_X_OR_Z] = "x|z",
95 	[IIO_MOD_Y_OR_Z] = "y|z",
96 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
97 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
98 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
99 	[IIO_MOD_LIGHT_BOTH] = "both",
100 	[IIO_MOD_LIGHT_IR] = "ir",
101 	[IIO_MOD_LIGHT_CLEAR] = "clear",
102 	[IIO_MOD_LIGHT_RED] = "red",
103 	[IIO_MOD_LIGHT_GREEN] = "green",
104 	[IIO_MOD_LIGHT_BLUE] = "blue",
105 	[IIO_MOD_LIGHT_UV] = "uv",
106 	[IIO_MOD_QUATERNION] = "quaternion",
107 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
108 	[IIO_MOD_TEMP_OBJECT] = "object",
109 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
110 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
111 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
112 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
113 	[IIO_MOD_RUNNING] = "running",
114 	[IIO_MOD_JOGGING] = "jogging",
115 	[IIO_MOD_WALKING] = "walking",
116 	[IIO_MOD_STILL] = "still",
117 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
118 	[IIO_MOD_I] = "i",
119 	[IIO_MOD_Q] = "q",
120 	[IIO_MOD_CO2] = "co2",
121 	[IIO_MOD_VOC] = "voc",
122 };
123 
124 /* relies on pairs of these shared then separate */
125 static const char * const iio_chan_info_postfix[] = {
126 	[IIO_CHAN_INFO_RAW] = "raw",
127 	[IIO_CHAN_INFO_PROCESSED] = "input",
128 	[IIO_CHAN_INFO_SCALE] = "scale",
129 	[IIO_CHAN_INFO_OFFSET] = "offset",
130 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
131 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
132 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
133 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
134 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
135 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
136 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
137 	= "filter_low_pass_3db_frequency",
138 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
139 	= "filter_high_pass_3db_frequency",
140 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
141 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
142 	[IIO_CHAN_INFO_PHASE] = "phase",
143 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
144 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
145 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
146 	[IIO_CHAN_INFO_ENABLE] = "en",
147 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
148 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
149 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
150 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
151 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
152 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
153 };
154 
155 /**
156  * iio_find_channel_from_si() - get channel from its scan index
157  * @indio_dev:		device
158  * @si:			scan index to match
159  */
160 const struct iio_chan_spec
161 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
162 {
163 	int i;
164 
165 	for (i = 0; i < indio_dev->num_channels; i++)
166 		if (indio_dev->channels[i].scan_index == si)
167 			return &indio_dev->channels[i];
168 	return NULL;
169 }
170 
171 /* This turns up an awful lot */
172 ssize_t iio_read_const_attr(struct device *dev,
173 			    struct device_attribute *attr,
174 			    char *buf)
175 {
176 	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
177 }
178 EXPORT_SYMBOL(iio_read_const_attr);
179 
180 static int __init iio_init(void)
181 {
182 	int ret;
183 
184 	/* Register sysfs bus */
185 	ret  = bus_register(&iio_bus_type);
186 	if (ret < 0) {
187 		pr_err("could not register bus type\n");
188 		goto error_nothing;
189 	}
190 
191 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
192 	if (ret < 0) {
193 		pr_err("failed to allocate char dev region\n");
194 		goto error_unregister_bus_type;
195 	}
196 
197 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
198 
199 	return 0;
200 
201 error_unregister_bus_type:
202 	bus_unregister(&iio_bus_type);
203 error_nothing:
204 	return ret;
205 }
206 
207 static void __exit iio_exit(void)
208 {
209 	if (iio_devt)
210 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
211 	bus_unregister(&iio_bus_type);
212 	debugfs_remove(iio_debugfs_dentry);
213 }
214 
215 #if defined(CONFIG_DEBUG_FS)
216 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
217 			      size_t count, loff_t *ppos)
218 {
219 	struct iio_dev *indio_dev = file->private_data;
220 	char buf[20];
221 	unsigned val = 0;
222 	ssize_t len;
223 	int ret;
224 
225 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
226 						  indio_dev->cached_reg_addr,
227 						  0, &val);
228 	if (ret)
229 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
230 
231 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
232 
233 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
234 }
235 
236 static ssize_t iio_debugfs_write_reg(struct file *file,
237 		     const char __user *userbuf, size_t count, loff_t *ppos)
238 {
239 	struct iio_dev *indio_dev = file->private_data;
240 	unsigned reg, val;
241 	char buf[80];
242 	int ret;
243 
244 	count = min_t(size_t, count, (sizeof(buf)-1));
245 	if (copy_from_user(buf, userbuf, count))
246 		return -EFAULT;
247 
248 	buf[count] = 0;
249 
250 	ret = sscanf(buf, "%i %i", &reg, &val);
251 
252 	switch (ret) {
253 	case 1:
254 		indio_dev->cached_reg_addr = reg;
255 		break;
256 	case 2:
257 		indio_dev->cached_reg_addr = reg;
258 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
259 							  val, NULL);
260 		if (ret) {
261 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
262 				__func__);
263 			return ret;
264 		}
265 		break;
266 	default:
267 		return -EINVAL;
268 	}
269 
270 	return count;
271 }
272 
273 static const struct file_operations iio_debugfs_reg_fops = {
274 	.open = simple_open,
275 	.read = iio_debugfs_read_reg,
276 	.write = iio_debugfs_write_reg,
277 };
278 
279 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
280 {
281 	debugfs_remove_recursive(indio_dev->debugfs_dentry);
282 }
283 
284 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
285 {
286 	struct dentry *d;
287 
288 	if (indio_dev->info->debugfs_reg_access == NULL)
289 		return 0;
290 
291 	if (!iio_debugfs_dentry)
292 		return 0;
293 
294 	indio_dev->debugfs_dentry =
295 		debugfs_create_dir(dev_name(&indio_dev->dev),
296 				   iio_debugfs_dentry);
297 	if (indio_dev->debugfs_dentry == NULL) {
298 		dev_warn(indio_dev->dev.parent,
299 			 "Failed to create debugfs directory\n");
300 		return -EFAULT;
301 	}
302 
303 	d = debugfs_create_file("direct_reg_access", 0644,
304 				indio_dev->debugfs_dentry,
305 				indio_dev, &iio_debugfs_reg_fops);
306 	if (!d) {
307 		iio_device_unregister_debugfs(indio_dev);
308 		return -ENOMEM;
309 	}
310 
311 	return 0;
312 }
313 #else
314 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
315 {
316 	return 0;
317 }
318 
319 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
320 {
321 }
322 #endif /* CONFIG_DEBUG_FS */
323 
324 static ssize_t iio_read_channel_ext_info(struct device *dev,
325 				     struct device_attribute *attr,
326 				     char *buf)
327 {
328 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
329 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
330 	const struct iio_chan_spec_ext_info *ext_info;
331 
332 	ext_info = &this_attr->c->ext_info[this_attr->address];
333 
334 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
335 }
336 
337 static ssize_t iio_write_channel_ext_info(struct device *dev,
338 				     struct device_attribute *attr,
339 				     const char *buf,
340 					 size_t len)
341 {
342 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
343 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
344 	const struct iio_chan_spec_ext_info *ext_info;
345 
346 	ext_info = &this_attr->c->ext_info[this_attr->address];
347 
348 	return ext_info->write(indio_dev, ext_info->private,
349 			       this_attr->c, buf, len);
350 }
351 
352 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
353 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
354 {
355 	const struct iio_enum *e = (const struct iio_enum *)priv;
356 	unsigned int i;
357 	size_t len = 0;
358 
359 	if (!e->num_items)
360 		return 0;
361 
362 	for (i = 0; i < e->num_items; ++i)
363 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
364 
365 	/* replace last space with a newline */
366 	buf[len - 1] = '\n';
367 
368 	return len;
369 }
370 EXPORT_SYMBOL_GPL(iio_enum_available_read);
371 
372 ssize_t iio_enum_read(struct iio_dev *indio_dev,
373 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
374 {
375 	const struct iio_enum *e = (const struct iio_enum *)priv;
376 	int i;
377 
378 	if (!e->get)
379 		return -EINVAL;
380 
381 	i = e->get(indio_dev, chan);
382 	if (i < 0)
383 		return i;
384 	else if (i >= e->num_items)
385 		return -EINVAL;
386 
387 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
388 }
389 EXPORT_SYMBOL_GPL(iio_enum_read);
390 
391 ssize_t iio_enum_write(struct iio_dev *indio_dev,
392 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
393 	size_t len)
394 {
395 	const struct iio_enum *e = (const struct iio_enum *)priv;
396 	unsigned int i;
397 	int ret;
398 
399 	if (!e->set)
400 		return -EINVAL;
401 
402 	for (i = 0; i < e->num_items; i++) {
403 		if (sysfs_streq(buf, e->items[i]))
404 			break;
405 	}
406 
407 	if (i == e->num_items)
408 		return -EINVAL;
409 
410 	ret = e->set(indio_dev, chan, i);
411 	return ret ? ret : len;
412 }
413 EXPORT_SYMBOL_GPL(iio_enum_write);
414 
415 static const struct iio_mount_matrix iio_mount_idmatrix = {
416 	.rotation = {
417 		"1", "0", "0",
418 		"0", "1", "0",
419 		"0", "0", "1"
420 	}
421 };
422 
423 static int iio_setup_mount_idmatrix(const struct device *dev,
424 				    struct iio_mount_matrix *matrix)
425 {
426 	*matrix = iio_mount_idmatrix;
427 	dev_info(dev, "mounting matrix not found: using identity...\n");
428 	return 0;
429 }
430 
431 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
432 			      const struct iio_chan_spec *chan, char *buf)
433 {
434 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
435 					      priv)(indio_dev, chan);
436 
437 	if (IS_ERR(mtx))
438 		return PTR_ERR(mtx);
439 
440 	if (!mtx)
441 		mtx = &iio_mount_idmatrix;
442 
443 	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
444 			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
445 			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
446 			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
447 }
448 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
449 
450 /**
451  * of_iio_read_mount_matrix() - retrieve iio device mounting matrix from
452  *                              device-tree "mount-matrix" property
453  * @dev:	device the mounting matrix property is assigned to
454  * @propname:	device specific mounting matrix property name
455  * @matrix:	where to store retrieved matrix
456  *
457  * If device is assigned no mounting matrix property, a default 3x3 identity
458  * matrix will be filled in.
459  *
460  * Return: 0 if success, or a negative error code on failure.
461  */
462 #ifdef CONFIG_OF
463 int of_iio_read_mount_matrix(const struct device *dev,
464 			     const char *propname,
465 			     struct iio_mount_matrix *matrix)
466 {
467 	if (dev->of_node) {
468 		int err = of_property_read_string_array(dev->of_node,
469 				propname, matrix->rotation,
470 				ARRAY_SIZE(iio_mount_idmatrix.rotation));
471 
472 		if (err == ARRAY_SIZE(iio_mount_idmatrix.rotation))
473 			return 0;
474 
475 		if (err >= 0)
476 			/* Invalid number of matrix entries. */
477 			return -EINVAL;
478 
479 		if (err != -EINVAL)
480 			/* Invalid matrix declaration format. */
481 			return err;
482 	}
483 
484 	/* Matrix was not declared at all: fallback to identity. */
485 	return iio_setup_mount_idmatrix(dev, matrix);
486 }
487 #else
488 int of_iio_read_mount_matrix(const struct device *dev,
489 			     const char *propname,
490 			     struct iio_mount_matrix *matrix)
491 {
492 	return iio_setup_mount_idmatrix(dev, matrix);
493 }
494 #endif
495 EXPORT_SYMBOL(of_iio_read_mount_matrix);
496 
497 /**
498  * iio_format_value() - Formats a IIO value into its string representation
499  * @buf:	The buffer to which the formatted value gets written
500  * @type:	One of the IIO_VAL_... constants. This decides how the val
501  *		and val2 parameters are formatted.
502  * @size:	Number of IIO value entries contained in vals
503  * @vals:	Pointer to the values, exact meaning depends on the
504  *		type parameter.
505  *
506  * Return: 0 by default, a negative number on failure or the
507  *	   total number of characters written for a type that belongs
508  *	   to the IIO_VAL_... constant.
509  */
510 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
511 {
512 	unsigned long long tmp;
513 	bool scale_db = false;
514 
515 	switch (type) {
516 	case IIO_VAL_INT:
517 		return sprintf(buf, "%d\n", vals[0]);
518 	case IIO_VAL_INT_PLUS_MICRO_DB:
519 		scale_db = true;
520 	case IIO_VAL_INT_PLUS_MICRO:
521 		if (vals[1] < 0)
522 			return sprintf(buf, "-%d.%06u%s\n", abs(vals[0]),
523 				       -vals[1], scale_db ? " dB" : "");
524 		else
525 			return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1],
526 				scale_db ? " dB" : "");
527 	case IIO_VAL_INT_PLUS_NANO:
528 		if (vals[1] < 0)
529 			return sprintf(buf, "-%d.%09u\n", abs(vals[0]),
530 				       -vals[1]);
531 		else
532 			return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
533 	case IIO_VAL_FRACTIONAL:
534 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
535 		vals[1] = do_div(tmp, 1000000000LL);
536 		vals[0] = tmp;
537 		return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
538 	case IIO_VAL_FRACTIONAL_LOG2:
539 		tmp = (s64)vals[0] * 1000000000LL >> vals[1];
540 		vals[1] = do_div(tmp, 1000000000LL);
541 		vals[0] = tmp;
542 		return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
543 	case IIO_VAL_INT_MULTIPLE:
544 	{
545 		int i;
546 		int len = 0;
547 
548 		for (i = 0; i < size; ++i)
549 			len += snprintf(&buf[len], PAGE_SIZE - len, "%d ",
550 								vals[i]);
551 		len += snprintf(&buf[len], PAGE_SIZE - len, "\n");
552 		return len;
553 	}
554 	default:
555 		return 0;
556 	}
557 }
558 EXPORT_SYMBOL_GPL(iio_format_value);
559 
560 static ssize_t iio_read_channel_info(struct device *dev,
561 				     struct device_attribute *attr,
562 				     char *buf)
563 {
564 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
565 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
566 	int vals[INDIO_MAX_RAW_ELEMENTS];
567 	int ret;
568 	int val_len = 2;
569 
570 	if (indio_dev->info->read_raw_multi)
571 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
572 							INDIO_MAX_RAW_ELEMENTS,
573 							vals, &val_len,
574 							this_attr->address);
575 	else
576 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
577 				    &vals[0], &vals[1], this_attr->address);
578 
579 	if (ret < 0)
580 		return ret;
581 
582 	return iio_format_value(buf, ret, val_len, vals);
583 }
584 
585 /**
586  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
587  * @str: The string to parse
588  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
589  * @integer: The integer part of the number
590  * @fract: The fractional part of the number
591  *
592  * Returns 0 on success, or a negative error code if the string could not be
593  * parsed.
594  */
595 int iio_str_to_fixpoint(const char *str, int fract_mult,
596 	int *integer, int *fract)
597 {
598 	int i = 0, f = 0;
599 	bool integer_part = true, negative = false;
600 
601 	if (fract_mult == 0) {
602 		*fract = 0;
603 
604 		return kstrtoint(str, 0, integer);
605 	}
606 
607 	if (str[0] == '-') {
608 		negative = true;
609 		str++;
610 	} else if (str[0] == '+') {
611 		str++;
612 	}
613 
614 	while (*str) {
615 		if ('0' <= *str && *str <= '9') {
616 			if (integer_part) {
617 				i = i * 10 + *str - '0';
618 			} else {
619 				f += fract_mult * (*str - '0');
620 				fract_mult /= 10;
621 			}
622 		} else if (*str == '\n') {
623 			if (*(str + 1) == '\0')
624 				break;
625 			else
626 				return -EINVAL;
627 		} else if (*str == '.' && integer_part) {
628 			integer_part = false;
629 		} else {
630 			return -EINVAL;
631 		}
632 		str++;
633 	}
634 
635 	if (negative) {
636 		if (i)
637 			i = -i;
638 		else
639 			f = -f;
640 	}
641 
642 	*integer = i;
643 	*fract = f;
644 
645 	return 0;
646 }
647 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
648 
649 static ssize_t iio_write_channel_info(struct device *dev,
650 				      struct device_attribute *attr,
651 				      const char *buf,
652 				      size_t len)
653 {
654 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
655 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
656 	int ret, fract_mult = 100000;
657 	int integer, fract;
658 
659 	/* Assumes decimal - precision based on number of digits */
660 	if (!indio_dev->info->write_raw)
661 		return -EINVAL;
662 
663 	if (indio_dev->info->write_raw_get_fmt)
664 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
665 			this_attr->c, this_attr->address)) {
666 		case IIO_VAL_INT:
667 			fract_mult = 0;
668 			break;
669 		case IIO_VAL_INT_PLUS_MICRO:
670 			fract_mult = 100000;
671 			break;
672 		case IIO_VAL_INT_PLUS_NANO:
673 			fract_mult = 100000000;
674 			break;
675 		default:
676 			return -EINVAL;
677 		}
678 
679 	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
680 	if (ret)
681 		return ret;
682 
683 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
684 					 integer, fract, this_attr->address);
685 	if (ret)
686 		return ret;
687 
688 	return len;
689 }
690 
691 static
692 int __iio_device_attr_init(struct device_attribute *dev_attr,
693 			   const char *postfix,
694 			   struct iio_chan_spec const *chan,
695 			   ssize_t (*readfunc)(struct device *dev,
696 					       struct device_attribute *attr,
697 					       char *buf),
698 			   ssize_t (*writefunc)(struct device *dev,
699 						struct device_attribute *attr,
700 						const char *buf,
701 						size_t len),
702 			   enum iio_shared_by shared_by)
703 {
704 	int ret = 0;
705 	char *name = NULL;
706 	char *full_postfix;
707 	sysfs_attr_init(&dev_attr->attr);
708 
709 	/* Build up postfix of <extend_name>_<modifier>_postfix */
710 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
711 		if (chan->extend_name)
712 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
713 						 iio_modifier_names[chan
714 								    ->channel2],
715 						 chan->extend_name,
716 						 postfix);
717 		else
718 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
719 						 iio_modifier_names[chan
720 								    ->channel2],
721 						 postfix);
722 	} else {
723 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
724 			full_postfix = kstrdup(postfix, GFP_KERNEL);
725 		else
726 			full_postfix = kasprintf(GFP_KERNEL,
727 						 "%s_%s",
728 						 chan->extend_name,
729 						 postfix);
730 	}
731 	if (full_postfix == NULL)
732 		return -ENOMEM;
733 
734 	if (chan->differential) { /* Differential can not have modifier */
735 		switch (shared_by) {
736 		case IIO_SHARED_BY_ALL:
737 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
738 			break;
739 		case IIO_SHARED_BY_DIR:
740 			name = kasprintf(GFP_KERNEL, "%s_%s",
741 						iio_direction[chan->output],
742 						full_postfix);
743 			break;
744 		case IIO_SHARED_BY_TYPE:
745 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
746 					    iio_direction[chan->output],
747 					    iio_chan_type_name_spec[chan->type],
748 					    iio_chan_type_name_spec[chan->type],
749 					    full_postfix);
750 			break;
751 		case IIO_SEPARATE:
752 			if (!chan->indexed) {
753 				WARN(1, "Differential channels must be indexed\n");
754 				ret = -EINVAL;
755 				goto error_free_full_postfix;
756 			}
757 			name = kasprintf(GFP_KERNEL,
758 					    "%s_%s%d-%s%d_%s",
759 					    iio_direction[chan->output],
760 					    iio_chan_type_name_spec[chan->type],
761 					    chan->channel,
762 					    iio_chan_type_name_spec[chan->type],
763 					    chan->channel2,
764 					    full_postfix);
765 			break;
766 		}
767 	} else { /* Single ended */
768 		switch (shared_by) {
769 		case IIO_SHARED_BY_ALL:
770 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
771 			break;
772 		case IIO_SHARED_BY_DIR:
773 			name = kasprintf(GFP_KERNEL, "%s_%s",
774 						iio_direction[chan->output],
775 						full_postfix);
776 			break;
777 		case IIO_SHARED_BY_TYPE:
778 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
779 					    iio_direction[chan->output],
780 					    iio_chan_type_name_spec[chan->type],
781 					    full_postfix);
782 			break;
783 
784 		case IIO_SEPARATE:
785 			if (chan->indexed)
786 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
787 						    iio_direction[chan->output],
788 						    iio_chan_type_name_spec[chan->type],
789 						    chan->channel,
790 						    full_postfix);
791 			else
792 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
793 						    iio_direction[chan->output],
794 						    iio_chan_type_name_spec[chan->type],
795 						    full_postfix);
796 			break;
797 		}
798 	}
799 	if (name == NULL) {
800 		ret = -ENOMEM;
801 		goto error_free_full_postfix;
802 	}
803 	dev_attr->attr.name = name;
804 
805 	if (readfunc) {
806 		dev_attr->attr.mode |= S_IRUGO;
807 		dev_attr->show = readfunc;
808 	}
809 
810 	if (writefunc) {
811 		dev_attr->attr.mode |= S_IWUSR;
812 		dev_attr->store = writefunc;
813 	}
814 
815 error_free_full_postfix:
816 	kfree(full_postfix);
817 
818 	return ret;
819 }
820 
821 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
822 {
823 	kfree(dev_attr->attr.name);
824 }
825 
826 int __iio_add_chan_devattr(const char *postfix,
827 			   struct iio_chan_spec const *chan,
828 			   ssize_t (*readfunc)(struct device *dev,
829 					       struct device_attribute *attr,
830 					       char *buf),
831 			   ssize_t (*writefunc)(struct device *dev,
832 						struct device_attribute *attr,
833 						const char *buf,
834 						size_t len),
835 			   u64 mask,
836 			   enum iio_shared_by shared_by,
837 			   struct device *dev,
838 			   struct list_head *attr_list)
839 {
840 	int ret;
841 	struct iio_dev_attr *iio_attr, *t;
842 
843 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
844 	if (iio_attr == NULL)
845 		return -ENOMEM;
846 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
847 				     postfix, chan,
848 				     readfunc, writefunc, shared_by);
849 	if (ret)
850 		goto error_iio_dev_attr_free;
851 	iio_attr->c = chan;
852 	iio_attr->address = mask;
853 	list_for_each_entry(t, attr_list, l)
854 		if (strcmp(t->dev_attr.attr.name,
855 			   iio_attr->dev_attr.attr.name) == 0) {
856 			if (shared_by == IIO_SEPARATE)
857 				dev_err(dev, "tried to double register : %s\n",
858 					t->dev_attr.attr.name);
859 			ret = -EBUSY;
860 			goto error_device_attr_deinit;
861 		}
862 	list_add(&iio_attr->l, attr_list);
863 
864 	return 0;
865 
866 error_device_attr_deinit:
867 	__iio_device_attr_deinit(&iio_attr->dev_attr);
868 error_iio_dev_attr_free:
869 	kfree(iio_attr);
870 	return ret;
871 }
872 
873 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
874 					 struct iio_chan_spec const *chan,
875 					 enum iio_shared_by shared_by,
876 					 const long *infomask)
877 {
878 	int i, ret, attrcount = 0;
879 
880 	for_each_set_bit(i, infomask, sizeof(infomask)*8) {
881 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
882 			return -EINVAL;
883 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
884 					     chan,
885 					     &iio_read_channel_info,
886 					     &iio_write_channel_info,
887 					     i,
888 					     shared_by,
889 					     &indio_dev->dev,
890 					     &indio_dev->channel_attr_list);
891 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
892 			continue;
893 		else if (ret < 0)
894 			return ret;
895 		attrcount++;
896 	}
897 
898 	return attrcount;
899 }
900 
901 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
902 					struct iio_chan_spec const *chan)
903 {
904 	int ret, attrcount = 0;
905 	const struct iio_chan_spec_ext_info *ext_info;
906 
907 	if (chan->channel < 0)
908 		return 0;
909 	ret = iio_device_add_info_mask_type(indio_dev, chan,
910 					    IIO_SEPARATE,
911 					    &chan->info_mask_separate);
912 	if (ret < 0)
913 		return ret;
914 	attrcount += ret;
915 
916 	ret = iio_device_add_info_mask_type(indio_dev, chan,
917 					    IIO_SHARED_BY_TYPE,
918 					    &chan->info_mask_shared_by_type);
919 	if (ret < 0)
920 		return ret;
921 	attrcount += ret;
922 
923 	ret = iio_device_add_info_mask_type(indio_dev, chan,
924 					    IIO_SHARED_BY_DIR,
925 					    &chan->info_mask_shared_by_dir);
926 	if (ret < 0)
927 		return ret;
928 	attrcount += ret;
929 
930 	ret = iio_device_add_info_mask_type(indio_dev, chan,
931 					    IIO_SHARED_BY_ALL,
932 					    &chan->info_mask_shared_by_all);
933 	if (ret < 0)
934 		return ret;
935 	attrcount += ret;
936 
937 	if (chan->ext_info) {
938 		unsigned int i = 0;
939 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
940 			ret = __iio_add_chan_devattr(ext_info->name,
941 					chan,
942 					ext_info->read ?
943 					    &iio_read_channel_ext_info : NULL,
944 					ext_info->write ?
945 					    &iio_write_channel_ext_info : NULL,
946 					i,
947 					ext_info->shared,
948 					&indio_dev->dev,
949 					&indio_dev->channel_attr_list);
950 			i++;
951 			if (ret == -EBUSY && ext_info->shared)
952 				continue;
953 
954 			if (ret)
955 				return ret;
956 
957 			attrcount++;
958 		}
959 	}
960 
961 	return attrcount;
962 }
963 
964 /**
965  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
966  * @attr_list: List of IIO device attributes
967  *
968  * This function frees the memory allocated for each of the IIO device
969  * attributes in the list.
970  */
971 void iio_free_chan_devattr_list(struct list_head *attr_list)
972 {
973 	struct iio_dev_attr *p, *n;
974 
975 	list_for_each_entry_safe(p, n, attr_list, l) {
976 		kfree(p->dev_attr.attr.name);
977 		list_del(&p->l);
978 		kfree(p);
979 	}
980 }
981 
982 static ssize_t iio_show_dev_name(struct device *dev,
983 				 struct device_attribute *attr,
984 				 char *buf)
985 {
986 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
987 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
988 }
989 
990 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
991 
992 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
993 {
994 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
995 	struct iio_dev_attr *p;
996 	struct attribute **attr;
997 
998 	/* First count elements in any existing group */
999 	if (indio_dev->info->attrs) {
1000 		attr = indio_dev->info->attrs->attrs;
1001 		while (*attr++ != NULL)
1002 			attrcount_orig++;
1003 	}
1004 	attrcount = attrcount_orig;
1005 	/*
1006 	 * New channel registration method - relies on the fact a group does
1007 	 * not need to be initialized if its name is NULL.
1008 	 */
1009 	if (indio_dev->channels)
1010 		for (i = 0; i < indio_dev->num_channels; i++) {
1011 			ret = iio_device_add_channel_sysfs(indio_dev,
1012 							   &indio_dev
1013 							   ->channels[i]);
1014 			if (ret < 0)
1015 				goto error_clear_attrs;
1016 			attrcount += ret;
1017 		}
1018 
1019 	if (indio_dev->name)
1020 		attrcount++;
1021 
1022 	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1023 						   sizeof(indio_dev->chan_attr_group.attrs[0]),
1024 						   GFP_KERNEL);
1025 	if (indio_dev->chan_attr_group.attrs == NULL) {
1026 		ret = -ENOMEM;
1027 		goto error_clear_attrs;
1028 	}
1029 	/* Copy across original attributes */
1030 	if (indio_dev->info->attrs)
1031 		memcpy(indio_dev->chan_attr_group.attrs,
1032 		       indio_dev->info->attrs->attrs,
1033 		       sizeof(indio_dev->chan_attr_group.attrs[0])
1034 		       *attrcount_orig);
1035 	attrn = attrcount_orig;
1036 	/* Add all elements from the list. */
1037 	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1038 		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1039 	if (indio_dev->name)
1040 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1041 
1042 	indio_dev->groups[indio_dev->groupcounter++] =
1043 		&indio_dev->chan_attr_group;
1044 
1045 	return 0;
1046 
1047 error_clear_attrs:
1048 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1049 
1050 	return ret;
1051 }
1052 
1053 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1054 {
1055 
1056 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1057 	kfree(indio_dev->chan_attr_group.attrs);
1058 	indio_dev->chan_attr_group.attrs = NULL;
1059 }
1060 
1061 static void iio_dev_release(struct device *device)
1062 {
1063 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1064 	if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1065 		iio_device_unregister_trigger_consumer(indio_dev);
1066 	iio_device_unregister_eventset(indio_dev);
1067 	iio_device_unregister_sysfs(indio_dev);
1068 
1069 	iio_buffer_put(indio_dev->buffer);
1070 
1071 	ida_simple_remove(&iio_ida, indio_dev->id);
1072 	kfree(indio_dev);
1073 }
1074 
1075 struct device_type iio_device_type = {
1076 	.name = "iio_device",
1077 	.release = iio_dev_release,
1078 };
1079 
1080 /**
1081  * iio_device_alloc() - allocate an iio_dev from a driver
1082  * @sizeof_priv:	Space to allocate for private structure.
1083  **/
1084 struct iio_dev *iio_device_alloc(int sizeof_priv)
1085 {
1086 	struct iio_dev *dev;
1087 	size_t alloc_size;
1088 
1089 	alloc_size = sizeof(struct iio_dev);
1090 	if (sizeof_priv) {
1091 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1092 		alloc_size += sizeof_priv;
1093 	}
1094 	/* ensure 32-byte alignment of whole construct ? */
1095 	alloc_size += IIO_ALIGN - 1;
1096 
1097 	dev = kzalloc(alloc_size, GFP_KERNEL);
1098 
1099 	if (dev) {
1100 		dev->dev.groups = dev->groups;
1101 		dev->dev.type = &iio_device_type;
1102 		dev->dev.bus = &iio_bus_type;
1103 		device_initialize(&dev->dev);
1104 		dev_set_drvdata(&dev->dev, (void *)dev);
1105 		mutex_init(&dev->mlock);
1106 		mutex_init(&dev->info_exist_lock);
1107 		INIT_LIST_HEAD(&dev->channel_attr_list);
1108 
1109 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1110 		if (dev->id < 0) {
1111 			/* cannot use a dev_err as the name isn't available */
1112 			pr_err("failed to get device id\n");
1113 			kfree(dev);
1114 			return NULL;
1115 		}
1116 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1117 		INIT_LIST_HEAD(&dev->buffer_list);
1118 	}
1119 
1120 	return dev;
1121 }
1122 EXPORT_SYMBOL(iio_device_alloc);
1123 
1124 /**
1125  * iio_device_free() - free an iio_dev from a driver
1126  * @dev:		the iio_dev associated with the device
1127  **/
1128 void iio_device_free(struct iio_dev *dev)
1129 {
1130 	if (dev)
1131 		put_device(&dev->dev);
1132 }
1133 EXPORT_SYMBOL(iio_device_free);
1134 
1135 static void devm_iio_device_release(struct device *dev, void *res)
1136 {
1137 	iio_device_free(*(struct iio_dev **)res);
1138 }
1139 
1140 static int devm_iio_device_match(struct device *dev, void *res, void *data)
1141 {
1142 	struct iio_dev **r = res;
1143 	if (!r || !*r) {
1144 		WARN_ON(!r || !*r);
1145 		return 0;
1146 	}
1147 	return *r == data;
1148 }
1149 
1150 /**
1151  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1152  * @dev:		Device to allocate iio_dev for
1153  * @sizeof_priv:	Space to allocate for private structure.
1154  *
1155  * Managed iio_device_alloc. iio_dev allocated with this function is
1156  * automatically freed on driver detach.
1157  *
1158  * If an iio_dev allocated with this function needs to be freed separately,
1159  * devm_iio_device_free() must be used.
1160  *
1161  * RETURNS:
1162  * Pointer to allocated iio_dev on success, NULL on failure.
1163  */
1164 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1165 {
1166 	struct iio_dev **ptr, *iio_dev;
1167 
1168 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1169 			   GFP_KERNEL);
1170 	if (!ptr)
1171 		return NULL;
1172 
1173 	iio_dev = iio_device_alloc(sizeof_priv);
1174 	if (iio_dev) {
1175 		*ptr = iio_dev;
1176 		devres_add(dev, ptr);
1177 	} else {
1178 		devres_free(ptr);
1179 	}
1180 
1181 	return iio_dev;
1182 }
1183 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1184 
1185 /**
1186  * devm_iio_device_free - Resource-managed iio_device_free()
1187  * @dev:		Device this iio_dev belongs to
1188  * @iio_dev:		the iio_dev associated with the device
1189  *
1190  * Free iio_dev allocated with devm_iio_device_alloc().
1191  */
1192 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1193 {
1194 	int rc;
1195 
1196 	rc = devres_release(dev, devm_iio_device_release,
1197 			    devm_iio_device_match, iio_dev);
1198 	WARN_ON(rc);
1199 }
1200 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1201 
1202 /**
1203  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1204  * @inode:	Inode structure for identifying the device in the file system
1205  * @filp:	File structure for iio device used to keep and later access
1206  *		private data
1207  *
1208  * Return: 0 on success or -EBUSY if the device is already opened
1209  **/
1210 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1211 {
1212 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1213 						struct iio_dev, chrdev);
1214 
1215 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1216 		return -EBUSY;
1217 
1218 	iio_device_get(indio_dev);
1219 
1220 	filp->private_data = indio_dev;
1221 
1222 	return 0;
1223 }
1224 
1225 /**
1226  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1227  * @inode:	Inode structure pointer for the char device
1228  * @filp:	File structure pointer for the char device
1229  *
1230  * Return: 0 for successful release
1231  */
1232 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1233 {
1234 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1235 						struct iio_dev, chrdev);
1236 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1237 	iio_device_put(indio_dev);
1238 
1239 	return 0;
1240 }
1241 
1242 /* Somewhat of a cross file organization violation - ioctls here are actually
1243  * event related */
1244 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1245 {
1246 	struct iio_dev *indio_dev = filp->private_data;
1247 	int __user *ip = (int __user *)arg;
1248 	int fd;
1249 
1250 	if (!indio_dev->info)
1251 		return -ENODEV;
1252 
1253 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1254 		fd = iio_event_getfd(indio_dev);
1255 		if (fd < 0)
1256 			return fd;
1257 		if (copy_to_user(ip, &fd, sizeof(fd)))
1258 			return -EFAULT;
1259 		return 0;
1260 	}
1261 	return -EINVAL;
1262 }
1263 
1264 static const struct file_operations iio_buffer_fileops = {
1265 	.read = iio_buffer_read_first_n_outer_addr,
1266 	.release = iio_chrdev_release,
1267 	.open = iio_chrdev_open,
1268 	.poll = iio_buffer_poll_addr,
1269 	.owner = THIS_MODULE,
1270 	.llseek = noop_llseek,
1271 	.unlocked_ioctl = iio_ioctl,
1272 	.compat_ioctl = iio_ioctl,
1273 };
1274 
1275 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1276 {
1277 	int i, j;
1278 	const struct iio_chan_spec *channels = indio_dev->channels;
1279 
1280 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1281 		return 0;
1282 
1283 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1284 		if (channels[i].scan_index < 0)
1285 			continue;
1286 		for (j = i + 1; j < indio_dev->num_channels; j++)
1287 			if (channels[i].scan_index == channels[j].scan_index) {
1288 				dev_err(&indio_dev->dev,
1289 					"Duplicate scan index %d\n",
1290 					channels[i].scan_index);
1291 				return -EINVAL;
1292 			}
1293 	}
1294 
1295 	return 0;
1296 }
1297 
1298 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1299 
1300 /**
1301  * iio_device_register() - register a device with the IIO subsystem
1302  * @indio_dev:		Device structure filled by the device driver
1303  **/
1304 int iio_device_register(struct iio_dev *indio_dev)
1305 {
1306 	int ret;
1307 
1308 	/* If the calling driver did not initialize of_node, do it here */
1309 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1310 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1311 
1312 	ret = iio_check_unique_scan_index(indio_dev);
1313 	if (ret < 0)
1314 		return ret;
1315 
1316 	/* configure elements for the chrdev */
1317 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1318 
1319 	ret = iio_device_register_debugfs(indio_dev);
1320 	if (ret) {
1321 		dev_err(indio_dev->dev.parent,
1322 			"Failed to register debugfs interfaces\n");
1323 		return ret;
1324 	}
1325 
1326 	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1327 	if (ret) {
1328 		dev_err(indio_dev->dev.parent,
1329 			"Failed to create buffer sysfs interfaces\n");
1330 		goto error_unreg_debugfs;
1331 	}
1332 
1333 	ret = iio_device_register_sysfs(indio_dev);
1334 	if (ret) {
1335 		dev_err(indio_dev->dev.parent,
1336 			"Failed to register sysfs interfaces\n");
1337 		goto error_buffer_free_sysfs;
1338 	}
1339 	ret = iio_device_register_eventset(indio_dev);
1340 	if (ret) {
1341 		dev_err(indio_dev->dev.parent,
1342 			"Failed to register event set\n");
1343 		goto error_free_sysfs;
1344 	}
1345 	if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1346 		iio_device_register_trigger_consumer(indio_dev);
1347 
1348 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1349 		indio_dev->setup_ops == NULL)
1350 		indio_dev->setup_ops = &noop_ring_setup_ops;
1351 
1352 	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1353 	indio_dev->chrdev.owner = indio_dev->info->driver_module;
1354 	indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1355 	ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1356 	if (ret < 0)
1357 		goto error_unreg_eventset;
1358 
1359 	ret = device_add(&indio_dev->dev);
1360 	if (ret < 0)
1361 		goto error_cdev_del;
1362 
1363 	return 0;
1364 error_cdev_del:
1365 	cdev_del(&indio_dev->chrdev);
1366 error_unreg_eventset:
1367 	iio_device_unregister_eventset(indio_dev);
1368 error_free_sysfs:
1369 	iio_device_unregister_sysfs(indio_dev);
1370 error_buffer_free_sysfs:
1371 	iio_buffer_free_sysfs_and_mask(indio_dev);
1372 error_unreg_debugfs:
1373 	iio_device_unregister_debugfs(indio_dev);
1374 	return ret;
1375 }
1376 EXPORT_SYMBOL(iio_device_register);
1377 
1378 /**
1379  * iio_device_unregister() - unregister a device from the IIO subsystem
1380  * @indio_dev:		Device structure representing the device.
1381  **/
1382 void iio_device_unregister(struct iio_dev *indio_dev)
1383 {
1384 	mutex_lock(&indio_dev->info_exist_lock);
1385 
1386 	device_del(&indio_dev->dev);
1387 
1388 	if (indio_dev->chrdev.dev)
1389 		cdev_del(&indio_dev->chrdev);
1390 	iio_device_unregister_debugfs(indio_dev);
1391 
1392 	iio_disable_all_buffers(indio_dev);
1393 
1394 	indio_dev->info = NULL;
1395 
1396 	iio_device_wakeup_eventset(indio_dev);
1397 	iio_buffer_wakeup_poll(indio_dev);
1398 
1399 	mutex_unlock(&indio_dev->info_exist_lock);
1400 
1401 	iio_buffer_free_sysfs_and_mask(indio_dev);
1402 }
1403 EXPORT_SYMBOL(iio_device_unregister);
1404 
1405 static void devm_iio_device_unreg(struct device *dev, void *res)
1406 {
1407 	iio_device_unregister(*(struct iio_dev **)res);
1408 }
1409 
1410 /**
1411  * devm_iio_device_register - Resource-managed iio_device_register()
1412  * @dev:	Device to allocate iio_dev for
1413  * @indio_dev:	Device structure filled by the device driver
1414  *
1415  * Managed iio_device_register.  The IIO device registered with this
1416  * function is automatically unregistered on driver detach. This function
1417  * calls iio_device_register() internally. Refer to that function for more
1418  * information.
1419  *
1420  * If an iio_dev registered with this function needs to be unregistered
1421  * separately, devm_iio_device_unregister() must be used.
1422  *
1423  * RETURNS:
1424  * 0 on success, negative error number on failure.
1425  */
1426 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1427 {
1428 	struct iio_dev **ptr;
1429 	int ret;
1430 
1431 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1432 	if (!ptr)
1433 		return -ENOMEM;
1434 
1435 	*ptr = indio_dev;
1436 	ret = iio_device_register(indio_dev);
1437 	if (!ret)
1438 		devres_add(dev, ptr);
1439 	else
1440 		devres_free(ptr);
1441 
1442 	return ret;
1443 }
1444 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1445 
1446 /**
1447  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1448  * @dev:	Device this iio_dev belongs to
1449  * @indio_dev:	the iio_dev associated with the device
1450  *
1451  * Unregister iio_dev registered with devm_iio_device_register().
1452  */
1453 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1454 {
1455 	int rc;
1456 
1457 	rc = devres_release(dev, devm_iio_device_unreg,
1458 			    devm_iio_device_match, indio_dev);
1459 	WARN_ON(rc);
1460 }
1461 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1462 
1463 /**
1464  * iio_device_claim_direct_mode - Keep device in direct mode
1465  * @indio_dev:	the iio_dev associated with the device
1466  *
1467  * If the device is in direct mode it is guaranteed to stay
1468  * that way until iio_device_release_direct_mode() is called.
1469  *
1470  * Use with iio_device_release_direct_mode()
1471  *
1472  * Returns: 0 on success, -EBUSY on failure
1473  */
1474 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1475 {
1476 	mutex_lock(&indio_dev->mlock);
1477 
1478 	if (iio_buffer_enabled(indio_dev)) {
1479 		mutex_unlock(&indio_dev->mlock);
1480 		return -EBUSY;
1481 	}
1482 	return 0;
1483 }
1484 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1485 
1486 /**
1487  * iio_device_release_direct_mode - releases claim on direct mode
1488  * @indio_dev:	the iio_dev associated with the device
1489  *
1490  * Release the claim. Device is no longer guaranteed to stay
1491  * in direct mode.
1492  *
1493  * Use with iio_device_claim_direct_mode()
1494  */
1495 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1496 {
1497 	mutex_unlock(&indio_dev->mlock);
1498 }
1499 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1500 
1501 subsys_initcall(iio_init);
1502 module_exit(iio_exit);
1503 
1504 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1505 MODULE_DESCRIPTION("Industrial I/O core");
1506 MODULE_LICENSE("GPL");
1507