1 // SPDX-License-Identifier: GPL-2.0-only
2 /* The industrial I/O core
3  *
4  * Copyright (c) 2008 Jonathan Cameron
5  *
6  * Based on elements of hwmon and input subsystems.
7  */
8 
9 #define pr_fmt(fmt) "iio-core: " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/idr.h>
14 #include <linux/kdev_t.h>
15 #include <linux/err.h>
16 #include <linux/device.h>
17 #include <linux/fs.h>
18 #include <linux/poll.h>
19 #include <linux/property.h>
20 #include <linux/sched.h>
21 #include <linux/wait.h>
22 #include <linux/cdev.h>
23 #include <linux/slab.h>
24 #include <linux/anon_inodes.h>
25 #include <linux/debugfs.h>
26 #include <linux/mutex.h>
27 #include <linux/iio/iio.h>
28 #include <linux/iio/iio-opaque.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 #include <linux/iio/buffer_impl.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 	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
84 	[IIO_COUNT] = "count",
85 	[IIO_INDEX] = "index",
86 	[IIO_GRAVITY]  = "gravity",
87 	[IIO_POSITIONRELATIVE]  = "positionrelative",
88 	[IIO_PHASE] = "phase",
89 	[IIO_MASSCONCENTRATION] = "massconcentration",
90 };
91 
92 static const char * const iio_modifier_names[] = {
93 	[IIO_MOD_X] = "x",
94 	[IIO_MOD_Y] = "y",
95 	[IIO_MOD_Z] = "z",
96 	[IIO_MOD_X_AND_Y] = "x&y",
97 	[IIO_MOD_X_AND_Z] = "x&z",
98 	[IIO_MOD_Y_AND_Z] = "y&z",
99 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
100 	[IIO_MOD_X_OR_Y] = "x|y",
101 	[IIO_MOD_X_OR_Z] = "x|z",
102 	[IIO_MOD_Y_OR_Z] = "y|z",
103 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
104 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
105 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
106 	[IIO_MOD_LIGHT_BOTH] = "both",
107 	[IIO_MOD_LIGHT_IR] = "ir",
108 	[IIO_MOD_LIGHT_CLEAR] = "clear",
109 	[IIO_MOD_LIGHT_RED] = "red",
110 	[IIO_MOD_LIGHT_GREEN] = "green",
111 	[IIO_MOD_LIGHT_BLUE] = "blue",
112 	[IIO_MOD_LIGHT_UV] = "uv",
113 	[IIO_MOD_LIGHT_DUV] = "duv",
114 	[IIO_MOD_QUATERNION] = "quaternion",
115 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
116 	[IIO_MOD_TEMP_OBJECT] = "object",
117 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
118 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
119 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
120 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
121 	[IIO_MOD_RUNNING] = "running",
122 	[IIO_MOD_JOGGING] = "jogging",
123 	[IIO_MOD_WALKING] = "walking",
124 	[IIO_MOD_STILL] = "still",
125 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
126 	[IIO_MOD_I] = "i",
127 	[IIO_MOD_Q] = "q",
128 	[IIO_MOD_CO2] = "co2",
129 	[IIO_MOD_VOC] = "voc",
130 	[IIO_MOD_PM1] = "pm1",
131 	[IIO_MOD_PM2P5] = "pm2p5",
132 	[IIO_MOD_PM4] = "pm4",
133 	[IIO_MOD_PM10] = "pm10",
134 	[IIO_MOD_ETHANOL] = "ethanol",
135 	[IIO_MOD_H2] = "h2",
136 	[IIO_MOD_O2] = "o2",
137 };
138 
139 /* relies on pairs of these shared then separate */
140 static const char * const iio_chan_info_postfix[] = {
141 	[IIO_CHAN_INFO_RAW] = "raw",
142 	[IIO_CHAN_INFO_PROCESSED] = "input",
143 	[IIO_CHAN_INFO_SCALE] = "scale",
144 	[IIO_CHAN_INFO_OFFSET] = "offset",
145 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
146 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
147 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
148 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
149 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
150 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
151 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
152 	= "filter_low_pass_3db_frequency",
153 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
154 	= "filter_high_pass_3db_frequency",
155 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
156 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
157 	[IIO_CHAN_INFO_PHASE] = "phase",
158 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
159 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
160 	[IIO_CHAN_INFO_HYSTERESIS_RELATIVE] = "hysteresis_relative",
161 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
162 	[IIO_CHAN_INFO_ENABLE] = "en",
163 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
164 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
165 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
166 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
167 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
168 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
169 	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
170 	[IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
171 };
172 
173 /**
174  * iio_sysfs_match_string_with_gaps - matches given string in an array with gaps
175  * @array: array of strings
176  * @n: number of strings in the array
177  * @str: string to match with
178  *
179  * Returns index of @str in the @array or -EINVAL, similar to match_string().
180  * Uses sysfs_streq instead of strcmp for matching.
181  *
182  * This routine will look for a string in an array of strings.
183  * The search will continue until the element is found or the n-th element
184  * is reached, regardless of any NULL elements in the array.
185  */
186 static int iio_sysfs_match_string_with_gaps(const char * const *array, size_t n,
187 					    const char *str)
188 {
189 	const char *item;
190 	int index;
191 
192 	for (index = 0; index < n; index++) {
193 		item = array[index];
194 		if (!item)
195 			continue;
196 		if (sysfs_streq(item, str))
197 			return index;
198 	}
199 
200 	return -EINVAL;
201 }
202 
203 #if defined(CONFIG_DEBUG_FS)
204 /*
205  * There's also a CONFIG_DEBUG_FS guard in include/linux/iio/iio.h for
206  * iio_get_debugfs_dentry() to make it inline if CONFIG_DEBUG_FS is undefined
207  */
208 struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
209 {
210 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
211 	return iio_dev_opaque->debugfs_dentry;
212 }
213 EXPORT_SYMBOL_GPL(iio_get_debugfs_dentry);
214 #endif
215 
216 /**
217  * iio_find_channel_from_si() - get channel from its scan index
218  * @indio_dev:		device
219  * @si:			scan index to match
220  */
221 const struct iio_chan_spec
222 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
223 {
224 	int i;
225 
226 	for (i = 0; i < indio_dev->num_channels; i++)
227 		if (indio_dev->channels[i].scan_index == si)
228 			return &indio_dev->channels[i];
229 	return NULL;
230 }
231 
232 /* This turns up an awful lot */
233 ssize_t iio_read_const_attr(struct device *dev,
234 			    struct device_attribute *attr,
235 			    char *buf)
236 {
237 	return sysfs_emit(buf, "%s\n", to_iio_const_attr(attr)->string);
238 }
239 EXPORT_SYMBOL(iio_read_const_attr);
240 
241 /**
242  * iio_device_set_clock() - Set current timestamping clock for the device
243  * @indio_dev: IIO device structure containing the device
244  * @clock_id: timestamping clock posix identifier to set.
245  */
246 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
247 {
248 	int ret;
249 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
250 	const struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
251 
252 	ret = mutex_lock_interruptible(&indio_dev->mlock);
253 	if (ret)
254 		return ret;
255 	if ((ev_int && iio_event_enabled(ev_int)) ||
256 	    iio_buffer_enabled(indio_dev)) {
257 		mutex_unlock(&indio_dev->mlock);
258 		return -EBUSY;
259 	}
260 	indio_dev->clock_id = clock_id;
261 	mutex_unlock(&indio_dev->mlock);
262 
263 	return 0;
264 }
265 EXPORT_SYMBOL(iio_device_set_clock);
266 
267 /**
268  * iio_get_time_ns() - utility function to get a time stamp for events etc
269  * @indio_dev: device
270  */
271 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
272 {
273 	struct timespec64 tp;
274 
275 	switch (iio_device_get_clock(indio_dev)) {
276 	case CLOCK_REALTIME:
277 		return ktime_get_real_ns();
278 	case CLOCK_MONOTONIC:
279 		return ktime_get_ns();
280 	case CLOCK_MONOTONIC_RAW:
281 		return ktime_get_raw_ns();
282 	case CLOCK_REALTIME_COARSE:
283 		return ktime_to_ns(ktime_get_coarse_real());
284 	case CLOCK_MONOTONIC_COARSE:
285 		ktime_get_coarse_ts64(&tp);
286 		return timespec64_to_ns(&tp);
287 	case CLOCK_BOOTTIME:
288 		return ktime_get_boottime_ns();
289 	case CLOCK_TAI:
290 		return ktime_get_clocktai_ns();
291 	default:
292 		BUG();
293 	}
294 }
295 EXPORT_SYMBOL(iio_get_time_ns);
296 
297 /**
298  * iio_get_time_res() - utility function to get time stamp clock resolution in
299  *                      nano seconds.
300  * @indio_dev: device
301  */
302 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
303 {
304 	switch (iio_device_get_clock(indio_dev)) {
305 	case CLOCK_REALTIME:
306 	case CLOCK_MONOTONIC:
307 	case CLOCK_MONOTONIC_RAW:
308 	case CLOCK_BOOTTIME:
309 	case CLOCK_TAI:
310 		return hrtimer_resolution;
311 	case CLOCK_REALTIME_COARSE:
312 	case CLOCK_MONOTONIC_COARSE:
313 		return LOW_RES_NSEC;
314 	default:
315 		BUG();
316 	}
317 }
318 EXPORT_SYMBOL(iio_get_time_res);
319 
320 static int __init iio_init(void)
321 {
322 	int ret;
323 
324 	/* Register sysfs bus */
325 	ret  = bus_register(&iio_bus_type);
326 	if (ret < 0) {
327 		pr_err("could not register bus type\n");
328 		goto error_nothing;
329 	}
330 
331 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
332 	if (ret < 0) {
333 		pr_err("failed to allocate char dev region\n");
334 		goto error_unregister_bus_type;
335 	}
336 
337 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
338 
339 	return 0;
340 
341 error_unregister_bus_type:
342 	bus_unregister(&iio_bus_type);
343 error_nothing:
344 	return ret;
345 }
346 
347 static void __exit iio_exit(void)
348 {
349 	if (iio_devt)
350 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
351 	bus_unregister(&iio_bus_type);
352 	debugfs_remove(iio_debugfs_dentry);
353 }
354 
355 #if defined(CONFIG_DEBUG_FS)
356 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
357 			      size_t count, loff_t *ppos)
358 {
359 	struct iio_dev *indio_dev = file->private_data;
360 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
361 	unsigned val = 0;
362 	int ret;
363 
364 	if (*ppos > 0)
365 		return simple_read_from_buffer(userbuf, count, ppos,
366 					       iio_dev_opaque->read_buf,
367 					       iio_dev_opaque->read_buf_len);
368 
369 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
370 						  iio_dev_opaque->cached_reg_addr,
371 						  0, &val);
372 	if (ret) {
373 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
374 		return ret;
375 	}
376 
377 	iio_dev_opaque->read_buf_len = snprintf(iio_dev_opaque->read_buf,
378 					      sizeof(iio_dev_opaque->read_buf),
379 					      "0x%X\n", val);
380 
381 	return simple_read_from_buffer(userbuf, count, ppos,
382 				       iio_dev_opaque->read_buf,
383 				       iio_dev_opaque->read_buf_len);
384 }
385 
386 static ssize_t iio_debugfs_write_reg(struct file *file,
387 		     const char __user *userbuf, size_t count, loff_t *ppos)
388 {
389 	struct iio_dev *indio_dev = file->private_data;
390 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
391 	unsigned reg, val;
392 	char buf[80];
393 	int ret;
394 
395 	count = min_t(size_t, count, (sizeof(buf)-1));
396 	if (copy_from_user(buf, userbuf, count))
397 		return -EFAULT;
398 
399 	buf[count] = 0;
400 
401 	ret = sscanf(buf, "%i %i", &reg, &val);
402 
403 	switch (ret) {
404 	case 1:
405 		iio_dev_opaque->cached_reg_addr = reg;
406 		break;
407 	case 2:
408 		iio_dev_opaque->cached_reg_addr = reg;
409 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
410 							  val, NULL);
411 		if (ret) {
412 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
413 				__func__);
414 			return ret;
415 		}
416 		break;
417 	default:
418 		return -EINVAL;
419 	}
420 
421 	return count;
422 }
423 
424 static const struct file_operations iio_debugfs_reg_fops = {
425 	.open = simple_open,
426 	.read = iio_debugfs_read_reg,
427 	.write = iio_debugfs_write_reg,
428 };
429 
430 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
431 {
432 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
433 	debugfs_remove_recursive(iio_dev_opaque->debugfs_dentry);
434 }
435 
436 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
437 {
438 	struct iio_dev_opaque *iio_dev_opaque;
439 
440 	if (indio_dev->info->debugfs_reg_access == NULL)
441 		return;
442 
443 	if (!iio_debugfs_dentry)
444 		return;
445 
446 	iio_dev_opaque = to_iio_dev_opaque(indio_dev);
447 
448 	iio_dev_opaque->debugfs_dentry =
449 		debugfs_create_dir(dev_name(&indio_dev->dev),
450 				   iio_debugfs_dentry);
451 
452 	debugfs_create_file("direct_reg_access", 0644,
453 			    iio_dev_opaque->debugfs_dentry, indio_dev,
454 			    &iio_debugfs_reg_fops);
455 }
456 #else
457 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
458 {
459 }
460 
461 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
462 {
463 }
464 #endif /* CONFIG_DEBUG_FS */
465 
466 static ssize_t iio_read_channel_ext_info(struct device *dev,
467 				     struct device_attribute *attr,
468 				     char *buf)
469 {
470 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
471 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
472 	const struct iio_chan_spec_ext_info *ext_info;
473 
474 	ext_info = &this_attr->c->ext_info[this_attr->address];
475 
476 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
477 }
478 
479 static ssize_t iio_write_channel_ext_info(struct device *dev,
480 				     struct device_attribute *attr,
481 				     const char *buf,
482 					 size_t len)
483 {
484 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
485 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
486 	const struct iio_chan_spec_ext_info *ext_info;
487 
488 	ext_info = &this_attr->c->ext_info[this_attr->address];
489 
490 	return ext_info->write(indio_dev, ext_info->private,
491 			       this_attr->c, buf, len);
492 }
493 
494 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
495 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
496 {
497 	const struct iio_enum *e = (const struct iio_enum *)priv;
498 	unsigned int i;
499 	size_t len = 0;
500 
501 	if (!e->num_items)
502 		return 0;
503 
504 	for (i = 0; i < e->num_items; ++i) {
505 		if (!e->items[i])
506 			continue;
507 		len += sysfs_emit_at(buf, len, "%s ", e->items[i]);
508 	}
509 
510 	/* replace last space with a newline */
511 	buf[len - 1] = '\n';
512 
513 	return len;
514 }
515 EXPORT_SYMBOL_GPL(iio_enum_available_read);
516 
517 ssize_t iio_enum_read(struct iio_dev *indio_dev,
518 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
519 {
520 	const struct iio_enum *e = (const struct iio_enum *)priv;
521 	int i;
522 
523 	if (!e->get)
524 		return -EINVAL;
525 
526 	i = e->get(indio_dev, chan);
527 	if (i < 0)
528 		return i;
529 	else if (i >= e->num_items || !e->items[i])
530 		return -EINVAL;
531 
532 	return sysfs_emit(buf, "%s\n", e->items[i]);
533 }
534 EXPORT_SYMBOL_GPL(iio_enum_read);
535 
536 ssize_t iio_enum_write(struct iio_dev *indio_dev,
537 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
538 	size_t len)
539 {
540 	const struct iio_enum *e = (const struct iio_enum *)priv;
541 	int ret;
542 
543 	if (!e->set)
544 		return -EINVAL;
545 
546 	ret = iio_sysfs_match_string_with_gaps(e->items, e->num_items, buf);
547 	if (ret < 0)
548 		return ret;
549 
550 	ret = e->set(indio_dev, chan, ret);
551 	return ret ? ret : len;
552 }
553 EXPORT_SYMBOL_GPL(iio_enum_write);
554 
555 static const struct iio_mount_matrix iio_mount_idmatrix = {
556 	.rotation = {
557 		"1", "0", "0",
558 		"0", "1", "0",
559 		"0", "0", "1"
560 	}
561 };
562 
563 static int iio_setup_mount_idmatrix(const struct device *dev,
564 				    struct iio_mount_matrix *matrix)
565 {
566 	*matrix = iio_mount_idmatrix;
567 	dev_info(dev, "mounting matrix not found: using identity...\n");
568 	return 0;
569 }
570 
571 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
572 			      const struct iio_chan_spec *chan, char *buf)
573 {
574 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
575 					      priv)(indio_dev, chan);
576 
577 	if (IS_ERR(mtx))
578 		return PTR_ERR(mtx);
579 
580 	if (!mtx)
581 		mtx = &iio_mount_idmatrix;
582 
583 	return sysfs_emit(buf, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
584 			  mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
585 			  mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
586 			  mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
587 }
588 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
589 
590 /**
591  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
592  *                           device "mount-matrix" property
593  * @dev:	device the mounting matrix property is assigned to
594  * @propname:	device specific mounting matrix property name
595  * @matrix:	where to store retrieved matrix
596  *
597  * If device is assigned no mounting matrix property, a default 3x3 identity
598  * matrix will be filled in.
599  *
600  * Return: 0 if success, or a negative error code on failure.
601  */
602 int iio_read_mount_matrix(struct device *dev, const char *propname,
603 			  struct iio_mount_matrix *matrix)
604 {
605 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
606 	int err;
607 
608 	err = device_property_read_string_array(dev, propname,
609 						matrix->rotation, len);
610 	if (err == len)
611 		return 0;
612 
613 	if (err >= 0)
614 		/* Invalid number of matrix entries. */
615 		return -EINVAL;
616 
617 	if (err != -EINVAL)
618 		/* Invalid matrix declaration format. */
619 		return err;
620 
621 	/* Matrix was not declared at all: fallback to identity. */
622 	return iio_setup_mount_idmatrix(dev, matrix);
623 }
624 EXPORT_SYMBOL(iio_read_mount_matrix);
625 
626 static ssize_t __iio_format_value(char *buf, size_t offset, unsigned int type,
627 				  int size, const int *vals)
628 {
629 	int tmp0, tmp1;
630 	s64 tmp2;
631 	bool scale_db = false;
632 
633 	switch (type) {
634 	case IIO_VAL_INT:
635 		return sysfs_emit_at(buf, offset, "%d", vals[0]);
636 	case IIO_VAL_INT_PLUS_MICRO_DB:
637 		scale_db = true;
638 		fallthrough;
639 	case IIO_VAL_INT_PLUS_MICRO:
640 		if (vals[1] < 0)
641 			return sysfs_emit_at(buf, offset, "-%d.%06u%s",
642 					     abs(vals[0]), -vals[1],
643 					     scale_db ? " dB" : "");
644 		else
645 			return sysfs_emit_at(buf, offset, "%d.%06u%s", vals[0],
646 					     vals[1], scale_db ? " dB" : "");
647 	case IIO_VAL_INT_PLUS_NANO:
648 		if (vals[1] < 0)
649 			return sysfs_emit_at(buf, offset, "-%d.%09u",
650 					     abs(vals[0]), -vals[1]);
651 		else
652 			return sysfs_emit_at(buf, offset, "%d.%09u", vals[0],
653 					     vals[1]);
654 	case IIO_VAL_FRACTIONAL:
655 		tmp2 = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
656 		tmp1 = vals[1];
657 		tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
658 		if ((tmp2 < 0) && (tmp0 == 0))
659 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
660 		else
661 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
662 					     abs(tmp1));
663 	case IIO_VAL_FRACTIONAL_LOG2:
664 		tmp2 = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
665 		tmp0 = (int)div_s64_rem(tmp2, 1000000000LL, &tmp1);
666 		if (tmp0 == 0 && tmp2 < 0)
667 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
668 		else
669 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
670 					     abs(tmp1));
671 	case IIO_VAL_INT_MULTIPLE:
672 	{
673 		int i;
674 		int l = 0;
675 
676 		for (i = 0; i < size; ++i)
677 			l += sysfs_emit_at(buf, offset + l, "%d ", vals[i]);
678 		return l;
679 	}
680 	case IIO_VAL_CHAR:
681 		return sysfs_emit_at(buf, offset, "%c", (char)vals[0]);
682 	default:
683 		return 0;
684 	}
685 }
686 
687 /**
688  * iio_format_value() - Formats a IIO value into its string representation
689  * @buf:	The buffer to which the formatted value gets written
690  *		which is assumed to be big enough (i.e. PAGE_SIZE).
691  * @type:	One of the IIO_VAL_* constants. This decides how the val
692  *		and val2 parameters are formatted.
693  * @size:	Number of IIO value entries contained in vals
694  * @vals:	Pointer to the values, exact meaning depends on the
695  *		type parameter.
696  *
697  * Return: 0 by default, a negative number on failure or the
698  *	   total number of characters written for a type that belongs
699  *	   to the IIO_VAL_* constant.
700  */
701 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
702 {
703 	ssize_t len;
704 
705 	len = __iio_format_value(buf, 0, type, size, vals);
706 	if (len >= PAGE_SIZE - 1)
707 		return -EFBIG;
708 
709 	return len + sysfs_emit_at(buf, len, "\n");
710 }
711 EXPORT_SYMBOL_GPL(iio_format_value);
712 
713 static ssize_t iio_read_channel_label(struct device *dev,
714 				      struct device_attribute *attr,
715 				      char *buf)
716 {
717 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
718 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
719 
720 	if (!indio_dev->info->read_label)
721 		return -EINVAL;
722 
723 	return indio_dev->info->read_label(indio_dev, this_attr->c, buf);
724 }
725 
726 static ssize_t iio_read_channel_info(struct device *dev,
727 				     struct device_attribute *attr,
728 				     char *buf)
729 {
730 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
731 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
732 	int vals[INDIO_MAX_RAW_ELEMENTS];
733 	int ret;
734 	int val_len = 2;
735 
736 	if (indio_dev->info->read_raw_multi)
737 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
738 							INDIO_MAX_RAW_ELEMENTS,
739 							vals, &val_len,
740 							this_attr->address);
741 	else
742 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
743 				    &vals[0], &vals[1], this_attr->address);
744 
745 	if (ret < 0)
746 		return ret;
747 
748 	return iio_format_value(buf, ret, val_len, vals);
749 }
750 
751 static ssize_t iio_format_list(char *buf, const int *vals, int type, int length,
752 			       const char *prefix, const char *suffix)
753 {
754 	ssize_t len;
755 	int stride;
756 	int i;
757 
758 	switch (type) {
759 	case IIO_VAL_INT:
760 		stride = 1;
761 		break;
762 	default:
763 		stride = 2;
764 		break;
765 	}
766 
767 	len = sysfs_emit(buf, prefix);
768 
769 	for (i = 0; i <= length - stride; i += stride) {
770 		if (i != 0) {
771 			len += sysfs_emit_at(buf, len, " ");
772 			if (len >= PAGE_SIZE)
773 				return -EFBIG;
774 		}
775 
776 		len += __iio_format_value(buf, len, type, stride, &vals[i]);
777 		if (len >= PAGE_SIZE)
778 			return -EFBIG;
779 	}
780 
781 	len += sysfs_emit_at(buf, len, "%s\n", suffix);
782 
783 	return len;
784 }
785 
786 static ssize_t iio_format_avail_list(char *buf, const int *vals,
787 				     int type, int length)
788 {
789 
790 	return iio_format_list(buf, vals, type, length, "", "");
791 }
792 
793 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
794 {
795 	return iio_format_list(buf, vals, type, 3, "[", "]");
796 }
797 
798 static ssize_t iio_read_channel_info_avail(struct device *dev,
799 					   struct device_attribute *attr,
800 					   char *buf)
801 {
802 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
803 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
804 	const int *vals;
805 	int ret;
806 	int length;
807 	int type;
808 
809 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
810 					  &vals, &type, &length,
811 					  this_attr->address);
812 
813 	if (ret < 0)
814 		return ret;
815 	switch (ret) {
816 	case IIO_AVAIL_LIST:
817 		return iio_format_avail_list(buf, vals, type, length);
818 	case IIO_AVAIL_RANGE:
819 		return iio_format_avail_range(buf, vals, type);
820 	default:
821 		return -EINVAL;
822 	}
823 }
824 
825 /**
826  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
827  * @str: The string to parse
828  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
829  * @integer: The integer part of the number
830  * @fract: The fractional part of the number
831  * @scale_db: True if this should parse as dB
832  *
833  * Returns 0 on success, or a negative error code if the string could not be
834  * parsed.
835  */
836 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
837 				 int *integer, int *fract, bool scale_db)
838 {
839 	int i = 0, f = 0;
840 	bool integer_part = true, negative = false;
841 
842 	if (fract_mult == 0) {
843 		*fract = 0;
844 
845 		return kstrtoint(str, 0, integer);
846 	}
847 
848 	if (str[0] == '-') {
849 		negative = true;
850 		str++;
851 	} else if (str[0] == '+') {
852 		str++;
853 	}
854 
855 	while (*str) {
856 		if ('0' <= *str && *str <= '9') {
857 			if (integer_part) {
858 				i = i * 10 + *str - '0';
859 			} else {
860 				f += fract_mult * (*str - '0');
861 				fract_mult /= 10;
862 			}
863 		} else if (*str == '\n') {
864 			if (*(str + 1) == '\0')
865 				break;
866 			else
867 				return -EINVAL;
868 		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
869 			/* Ignore the dB suffix */
870 			str += sizeof(" dB") - 1;
871 			continue;
872 		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
873 			/* Ignore the dB suffix */
874 			str += sizeof("dB") - 1;
875 			continue;
876 		} else if (*str == '.' && integer_part) {
877 			integer_part = false;
878 		} else {
879 			return -EINVAL;
880 		}
881 		str++;
882 	}
883 
884 	if (negative) {
885 		if (i)
886 			i = -i;
887 		else
888 			f = -f;
889 	}
890 
891 	*integer = i;
892 	*fract = f;
893 
894 	return 0;
895 }
896 
897 /**
898  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
899  * @str: The string to parse
900  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
901  * @integer: The integer part of the number
902  * @fract: The fractional part of the number
903  *
904  * Returns 0 on success, or a negative error code if the string could not be
905  * parsed.
906  */
907 int iio_str_to_fixpoint(const char *str, int fract_mult,
908 			int *integer, int *fract)
909 {
910 	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
911 }
912 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
913 
914 static ssize_t iio_write_channel_info(struct device *dev,
915 				      struct device_attribute *attr,
916 				      const char *buf,
917 				      size_t len)
918 {
919 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
920 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
921 	int ret, fract_mult = 100000;
922 	int integer, fract = 0;
923 	bool is_char = false;
924 	bool scale_db = false;
925 
926 	/* Assumes decimal - precision based on number of digits */
927 	if (!indio_dev->info->write_raw)
928 		return -EINVAL;
929 
930 	if (indio_dev->info->write_raw_get_fmt)
931 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
932 			this_attr->c, this_attr->address)) {
933 		case IIO_VAL_INT:
934 			fract_mult = 0;
935 			break;
936 		case IIO_VAL_INT_PLUS_MICRO_DB:
937 			scale_db = true;
938 			fallthrough;
939 		case IIO_VAL_INT_PLUS_MICRO:
940 			fract_mult = 100000;
941 			break;
942 		case IIO_VAL_INT_PLUS_NANO:
943 			fract_mult = 100000000;
944 			break;
945 		case IIO_VAL_CHAR:
946 			is_char = true;
947 			break;
948 		default:
949 			return -EINVAL;
950 		}
951 
952 	if (is_char) {
953 		char ch;
954 
955 		if (sscanf(buf, "%c", &ch) != 1)
956 			return -EINVAL;
957 		integer = ch;
958 	} else {
959 		ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
960 					    scale_db);
961 		if (ret)
962 			return ret;
963 	}
964 
965 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
966 					 integer, fract, this_attr->address);
967 	if (ret)
968 		return ret;
969 
970 	return len;
971 }
972 
973 static
974 int __iio_device_attr_init(struct device_attribute *dev_attr,
975 			   const char *postfix,
976 			   struct iio_chan_spec const *chan,
977 			   ssize_t (*readfunc)(struct device *dev,
978 					       struct device_attribute *attr,
979 					       char *buf),
980 			   ssize_t (*writefunc)(struct device *dev,
981 						struct device_attribute *attr,
982 						const char *buf,
983 						size_t len),
984 			   enum iio_shared_by shared_by)
985 {
986 	int ret = 0;
987 	char *name = NULL;
988 	char *full_postfix;
989 	sysfs_attr_init(&dev_attr->attr);
990 
991 	/* Build up postfix of <extend_name>_<modifier>_postfix */
992 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
993 		if (chan->extend_name)
994 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
995 						 iio_modifier_names[chan
996 								    ->channel2],
997 						 chan->extend_name,
998 						 postfix);
999 		else
1000 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
1001 						 iio_modifier_names[chan
1002 								    ->channel2],
1003 						 postfix);
1004 	} else {
1005 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
1006 			full_postfix = kstrdup(postfix, GFP_KERNEL);
1007 		else
1008 			full_postfix = kasprintf(GFP_KERNEL,
1009 						 "%s_%s",
1010 						 chan->extend_name,
1011 						 postfix);
1012 	}
1013 	if (full_postfix == NULL)
1014 		return -ENOMEM;
1015 
1016 	if (chan->differential) { /* Differential can not have modifier */
1017 		switch (shared_by) {
1018 		case IIO_SHARED_BY_ALL:
1019 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1020 			break;
1021 		case IIO_SHARED_BY_DIR:
1022 			name = kasprintf(GFP_KERNEL, "%s_%s",
1023 						iio_direction[chan->output],
1024 						full_postfix);
1025 			break;
1026 		case IIO_SHARED_BY_TYPE:
1027 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
1028 					    iio_direction[chan->output],
1029 					    iio_chan_type_name_spec[chan->type],
1030 					    iio_chan_type_name_spec[chan->type],
1031 					    full_postfix);
1032 			break;
1033 		case IIO_SEPARATE:
1034 			if (!chan->indexed) {
1035 				WARN(1, "Differential channels must be indexed\n");
1036 				ret = -EINVAL;
1037 				goto error_free_full_postfix;
1038 			}
1039 			name = kasprintf(GFP_KERNEL,
1040 					    "%s_%s%d-%s%d_%s",
1041 					    iio_direction[chan->output],
1042 					    iio_chan_type_name_spec[chan->type],
1043 					    chan->channel,
1044 					    iio_chan_type_name_spec[chan->type],
1045 					    chan->channel2,
1046 					    full_postfix);
1047 			break;
1048 		}
1049 	} else { /* Single ended */
1050 		switch (shared_by) {
1051 		case IIO_SHARED_BY_ALL:
1052 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1053 			break;
1054 		case IIO_SHARED_BY_DIR:
1055 			name = kasprintf(GFP_KERNEL, "%s_%s",
1056 						iio_direction[chan->output],
1057 						full_postfix);
1058 			break;
1059 		case IIO_SHARED_BY_TYPE:
1060 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1061 					    iio_direction[chan->output],
1062 					    iio_chan_type_name_spec[chan->type],
1063 					    full_postfix);
1064 			break;
1065 
1066 		case IIO_SEPARATE:
1067 			if (chan->indexed)
1068 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1069 						    iio_direction[chan->output],
1070 						    iio_chan_type_name_spec[chan->type],
1071 						    chan->channel,
1072 						    full_postfix);
1073 			else
1074 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1075 						    iio_direction[chan->output],
1076 						    iio_chan_type_name_spec[chan->type],
1077 						    full_postfix);
1078 			break;
1079 		}
1080 	}
1081 	if (name == NULL) {
1082 		ret = -ENOMEM;
1083 		goto error_free_full_postfix;
1084 	}
1085 	dev_attr->attr.name = name;
1086 
1087 	if (readfunc) {
1088 		dev_attr->attr.mode |= S_IRUGO;
1089 		dev_attr->show = readfunc;
1090 	}
1091 
1092 	if (writefunc) {
1093 		dev_attr->attr.mode |= S_IWUSR;
1094 		dev_attr->store = writefunc;
1095 	}
1096 
1097 error_free_full_postfix:
1098 	kfree(full_postfix);
1099 
1100 	return ret;
1101 }
1102 
1103 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1104 {
1105 	kfree(dev_attr->attr.name);
1106 }
1107 
1108 int __iio_add_chan_devattr(const char *postfix,
1109 			   struct iio_chan_spec const *chan,
1110 			   ssize_t (*readfunc)(struct device *dev,
1111 					       struct device_attribute *attr,
1112 					       char *buf),
1113 			   ssize_t (*writefunc)(struct device *dev,
1114 						struct device_attribute *attr,
1115 						const char *buf,
1116 						size_t len),
1117 			   u64 mask,
1118 			   enum iio_shared_by shared_by,
1119 			   struct device *dev,
1120 			   struct iio_buffer *buffer,
1121 			   struct list_head *attr_list)
1122 {
1123 	int ret;
1124 	struct iio_dev_attr *iio_attr, *t;
1125 
1126 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1127 	if (iio_attr == NULL)
1128 		return -ENOMEM;
1129 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1130 				     postfix, chan,
1131 				     readfunc, writefunc, shared_by);
1132 	if (ret)
1133 		goto error_iio_dev_attr_free;
1134 	iio_attr->c = chan;
1135 	iio_attr->address = mask;
1136 	iio_attr->buffer = buffer;
1137 	list_for_each_entry(t, attr_list, l)
1138 		if (strcmp(t->dev_attr.attr.name,
1139 			   iio_attr->dev_attr.attr.name) == 0) {
1140 			if (shared_by == IIO_SEPARATE)
1141 				dev_err(dev, "tried to double register : %s\n",
1142 					t->dev_attr.attr.name);
1143 			ret = -EBUSY;
1144 			goto error_device_attr_deinit;
1145 		}
1146 	list_add(&iio_attr->l, attr_list);
1147 
1148 	return 0;
1149 
1150 error_device_attr_deinit:
1151 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1152 error_iio_dev_attr_free:
1153 	kfree(iio_attr);
1154 	return ret;
1155 }
1156 
1157 static int iio_device_add_channel_label(struct iio_dev *indio_dev,
1158 					 struct iio_chan_spec const *chan)
1159 {
1160 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1161 	int ret;
1162 
1163 	if (!indio_dev->info->read_label)
1164 		return 0;
1165 
1166 	ret = __iio_add_chan_devattr("label",
1167 				     chan,
1168 				     &iio_read_channel_label,
1169 				     NULL,
1170 				     0,
1171 				     IIO_SEPARATE,
1172 				     &indio_dev->dev,
1173 				     NULL,
1174 				     &iio_dev_opaque->channel_attr_list);
1175 	if (ret < 0)
1176 		return ret;
1177 
1178 	return 1;
1179 }
1180 
1181 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1182 					 struct iio_chan_spec const *chan,
1183 					 enum iio_shared_by shared_by,
1184 					 const long *infomask)
1185 {
1186 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1187 	int i, ret, attrcount = 0;
1188 
1189 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1190 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1191 			return -EINVAL;
1192 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1193 					     chan,
1194 					     &iio_read_channel_info,
1195 					     &iio_write_channel_info,
1196 					     i,
1197 					     shared_by,
1198 					     &indio_dev->dev,
1199 					     NULL,
1200 					     &iio_dev_opaque->channel_attr_list);
1201 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1202 			continue;
1203 		else if (ret < 0)
1204 			return ret;
1205 		attrcount++;
1206 	}
1207 
1208 	return attrcount;
1209 }
1210 
1211 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1212 					       struct iio_chan_spec const *chan,
1213 					       enum iio_shared_by shared_by,
1214 					       const long *infomask)
1215 {
1216 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1217 	int i, ret, attrcount = 0;
1218 	char *avail_postfix;
1219 
1220 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1221 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1222 			return -EINVAL;
1223 		avail_postfix = kasprintf(GFP_KERNEL,
1224 					  "%s_available",
1225 					  iio_chan_info_postfix[i]);
1226 		if (!avail_postfix)
1227 			return -ENOMEM;
1228 
1229 		ret = __iio_add_chan_devattr(avail_postfix,
1230 					     chan,
1231 					     &iio_read_channel_info_avail,
1232 					     NULL,
1233 					     i,
1234 					     shared_by,
1235 					     &indio_dev->dev,
1236 					     NULL,
1237 					     &iio_dev_opaque->channel_attr_list);
1238 		kfree(avail_postfix);
1239 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1240 			continue;
1241 		else if (ret < 0)
1242 			return ret;
1243 		attrcount++;
1244 	}
1245 
1246 	return attrcount;
1247 }
1248 
1249 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1250 					struct iio_chan_spec const *chan)
1251 {
1252 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1253 	int ret, attrcount = 0;
1254 	const struct iio_chan_spec_ext_info *ext_info;
1255 
1256 	if (chan->channel < 0)
1257 		return 0;
1258 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1259 					    IIO_SEPARATE,
1260 					    &chan->info_mask_separate);
1261 	if (ret < 0)
1262 		return ret;
1263 	attrcount += ret;
1264 
1265 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1266 						  IIO_SEPARATE,
1267 						  &chan->
1268 						  info_mask_separate_available);
1269 	if (ret < 0)
1270 		return ret;
1271 	attrcount += ret;
1272 
1273 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1274 					    IIO_SHARED_BY_TYPE,
1275 					    &chan->info_mask_shared_by_type);
1276 	if (ret < 0)
1277 		return ret;
1278 	attrcount += ret;
1279 
1280 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1281 						  IIO_SHARED_BY_TYPE,
1282 						  &chan->
1283 						  info_mask_shared_by_type_available);
1284 	if (ret < 0)
1285 		return ret;
1286 	attrcount += ret;
1287 
1288 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1289 					    IIO_SHARED_BY_DIR,
1290 					    &chan->info_mask_shared_by_dir);
1291 	if (ret < 0)
1292 		return ret;
1293 	attrcount += ret;
1294 
1295 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1296 						  IIO_SHARED_BY_DIR,
1297 						  &chan->info_mask_shared_by_dir_available);
1298 	if (ret < 0)
1299 		return ret;
1300 	attrcount += ret;
1301 
1302 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1303 					    IIO_SHARED_BY_ALL,
1304 					    &chan->info_mask_shared_by_all);
1305 	if (ret < 0)
1306 		return ret;
1307 	attrcount += ret;
1308 
1309 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1310 						  IIO_SHARED_BY_ALL,
1311 						  &chan->info_mask_shared_by_all_available);
1312 	if (ret < 0)
1313 		return ret;
1314 	attrcount += ret;
1315 
1316 	ret = iio_device_add_channel_label(indio_dev, chan);
1317 	if (ret < 0)
1318 		return ret;
1319 	attrcount += ret;
1320 
1321 	if (chan->ext_info) {
1322 		unsigned int i = 0;
1323 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1324 			ret = __iio_add_chan_devattr(ext_info->name,
1325 					chan,
1326 					ext_info->read ?
1327 					    &iio_read_channel_ext_info : NULL,
1328 					ext_info->write ?
1329 					    &iio_write_channel_ext_info : NULL,
1330 					i,
1331 					ext_info->shared,
1332 					&indio_dev->dev,
1333 					NULL,
1334 					&iio_dev_opaque->channel_attr_list);
1335 			i++;
1336 			if (ret == -EBUSY && ext_info->shared)
1337 				continue;
1338 
1339 			if (ret)
1340 				return ret;
1341 
1342 			attrcount++;
1343 		}
1344 	}
1345 
1346 	return attrcount;
1347 }
1348 
1349 /**
1350  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1351  * @attr_list: List of IIO device attributes
1352  *
1353  * This function frees the memory allocated for each of the IIO device
1354  * attributes in the list.
1355  */
1356 void iio_free_chan_devattr_list(struct list_head *attr_list)
1357 {
1358 	struct iio_dev_attr *p, *n;
1359 
1360 	list_for_each_entry_safe(p, n, attr_list, l) {
1361 		kfree_const(p->dev_attr.attr.name);
1362 		list_del(&p->l);
1363 		kfree(p);
1364 	}
1365 }
1366 
1367 static ssize_t iio_show_dev_name(struct device *dev,
1368 				 struct device_attribute *attr,
1369 				 char *buf)
1370 {
1371 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1372 	return sysfs_emit(buf, "%s\n", indio_dev->name);
1373 }
1374 
1375 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1376 
1377 static ssize_t iio_show_dev_label(struct device *dev,
1378 				 struct device_attribute *attr,
1379 				 char *buf)
1380 {
1381 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1382 	return sysfs_emit(buf, "%s\n", indio_dev->label);
1383 }
1384 
1385 static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
1386 
1387 static ssize_t iio_show_timestamp_clock(struct device *dev,
1388 					struct device_attribute *attr,
1389 					char *buf)
1390 {
1391 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1392 	const clockid_t clk = iio_device_get_clock(indio_dev);
1393 	const char *name;
1394 	ssize_t sz;
1395 
1396 	switch (clk) {
1397 	case CLOCK_REALTIME:
1398 		name = "realtime\n";
1399 		sz = sizeof("realtime\n");
1400 		break;
1401 	case CLOCK_MONOTONIC:
1402 		name = "monotonic\n";
1403 		sz = sizeof("monotonic\n");
1404 		break;
1405 	case CLOCK_MONOTONIC_RAW:
1406 		name = "monotonic_raw\n";
1407 		sz = sizeof("monotonic_raw\n");
1408 		break;
1409 	case CLOCK_REALTIME_COARSE:
1410 		name = "realtime_coarse\n";
1411 		sz = sizeof("realtime_coarse\n");
1412 		break;
1413 	case CLOCK_MONOTONIC_COARSE:
1414 		name = "monotonic_coarse\n";
1415 		sz = sizeof("monotonic_coarse\n");
1416 		break;
1417 	case CLOCK_BOOTTIME:
1418 		name = "boottime\n";
1419 		sz = sizeof("boottime\n");
1420 		break;
1421 	case CLOCK_TAI:
1422 		name = "tai\n";
1423 		sz = sizeof("tai\n");
1424 		break;
1425 	default:
1426 		BUG();
1427 	}
1428 
1429 	memcpy(buf, name, sz);
1430 	return sz;
1431 }
1432 
1433 static ssize_t iio_store_timestamp_clock(struct device *dev,
1434 					 struct device_attribute *attr,
1435 					 const char *buf, size_t len)
1436 {
1437 	clockid_t clk;
1438 	int ret;
1439 
1440 	if (sysfs_streq(buf, "realtime"))
1441 		clk = CLOCK_REALTIME;
1442 	else if (sysfs_streq(buf, "monotonic"))
1443 		clk = CLOCK_MONOTONIC;
1444 	else if (sysfs_streq(buf, "monotonic_raw"))
1445 		clk = CLOCK_MONOTONIC_RAW;
1446 	else if (sysfs_streq(buf, "realtime_coarse"))
1447 		clk = CLOCK_REALTIME_COARSE;
1448 	else if (sysfs_streq(buf, "monotonic_coarse"))
1449 		clk = CLOCK_MONOTONIC_COARSE;
1450 	else if (sysfs_streq(buf, "boottime"))
1451 		clk = CLOCK_BOOTTIME;
1452 	else if (sysfs_streq(buf, "tai"))
1453 		clk = CLOCK_TAI;
1454 	else
1455 		return -EINVAL;
1456 
1457 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1458 	if (ret)
1459 		return ret;
1460 
1461 	return len;
1462 }
1463 
1464 int iio_device_register_sysfs_group(struct iio_dev *indio_dev,
1465 				    const struct attribute_group *group)
1466 {
1467 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1468 	const struct attribute_group **new, **old = iio_dev_opaque->groups;
1469 	unsigned int cnt = iio_dev_opaque->groupcounter;
1470 
1471 	new = krealloc(old, sizeof(*new) * (cnt + 2), GFP_KERNEL);
1472 	if (!new)
1473 		return -ENOMEM;
1474 
1475 	new[iio_dev_opaque->groupcounter++] = group;
1476 	new[iio_dev_opaque->groupcounter] = NULL;
1477 
1478 	iio_dev_opaque->groups = new;
1479 
1480 	return 0;
1481 }
1482 
1483 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1484 		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1485 
1486 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1487 {
1488 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1489 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1490 	struct iio_dev_attr *p;
1491 	struct attribute **attr, *clk = NULL;
1492 
1493 	/* First count elements in any existing group */
1494 	if (indio_dev->info->attrs) {
1495 		attr = indio_dev->info->attrs->attrs;
1496 		while (*attr++ != NULL)
1497 			attrcount_orig++;
1498 	}
1499 	attrcount = attrcount_orig;
1500 	/*
1501 	 * New channel registration method - relies on the fact a group does
1502 	 * not need to be initialized if its name is NULL.
1503 	 */
1504 	if (indio_dev->channels)
1505 		for (i = 0; i < indio_dev->num_channels; i++) {
1506 			const struct iio_chan_spec *chan =
1507 				&indio_dev->channels[i];
1508 
1509 			if (chan->type == IIO_TIMESTAMP)
1510 				clk = &dev_attr_current_timestamp_clock.attr;
1511 
1512 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1513 			if (ret < 0)
1514 				goto error_clear_attrs;
1515 			attrcount += ret;
1516 		}
1517 
1518 	if (iio_dev_opaque->event_interface)
1519 		clk = &dev_attr_current_timestamp_clock.attr;
1520 
1521 	if (indio_dev->name)
1522 		attrcount++;
1523 	if (indio_dev->label)
1524 		attrcount++;
1525 	if (clk)
1526 		attrcount++;
1527 
1528 	iio_dev_opaque->chan_attr_group.attrs =
1529 		kcalloc(attrcount + 1,
1530 			sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
1531 			GFP_KERNEL);
1532 	if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
1533 		ret = -ENOMEM;
1534 		goto error_clear_attrs;
1535 	}
1536 	/* Copy across original attributes */
1537 	if (indio_dev->info->attrs) {
1538 		memcpy(iio_dev_opaque->chan_attr_group.attrs,
1539 		       indio_dev->info->attrs->attrs,
1540 		       sizeof(iio_dev_opaque->chan_attr_group.attrs[0])
1541 		       *attrcount_orig);
1542 		iio_dev_opaque->chan_attr_group.is_visible =
1543 			indio_dev->info->attrs->is_visible;
1544 	}
1545 	attrn = attrcount_orig;
1546 	/* Add all elements from the list. */
1547 	list_for_each_entry(p, &iio_dev_opaque->channel_attr_list, l)
1548 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1549 	if (indio_dev->name)
1550 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1551 	if (indio_dev->label)
1552 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1553 	if (clk)
1554 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk;
1555 
1556 	ret = iio_device_register_sysfs_group(indio_dev,
1557 					      &iio_dev_opaque->chan_attr_group);
1558 	if (ret)
1559 		goto error_clear_attrs;
1560 
1561 	return 0;
1562 
1563 error_clear_attrs:
1564 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1565 
1566 	return ret;
1567 }
1568 
1569 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1570 {
1571 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1572 
1573 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1574 	kfree(iio_dev_opaque->chan_attr_group.attrs);
1575 	iio_dev_opaque->chan_attr_group.attrs = NULL;
1576 	kfree(iio_dev_opaque->groups);
1577 }
1578 
1579 static void iio_dev_release(struct device *device)
1580 {
1581 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1582 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1583 
1584 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1585 		iio_device_unregister_trigger_consumer(indio_dev);
1586 	iio_device_unregister_eventset(indio_dev);
1587 	iio_device_unregister_sysfs(indio_dev);
1588 
1589 	iio_device_detach_buffers(indio_dev);
1590 
1591 	ida_simple_remove(&iio_ida, indio_dev->id);
1592 	kfree(iio_dev_opaque);
1593 }
1594 
1595 struct device_type iio_device_type = {
1596 	.name = "iio_device",
1597 	.release = iio_dev_release,
1598 };
1599 
1600 /**
1601  * iio_device_alloc() - allocate an iio_dev from a driver
1602  * @parent:		Parent device.
1603  * @sizeof_priv:	Space to allocate for private structure.
1604  **/
1605 struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
1606 {
1607 	struct iio_dev_opaque *iio_dev_opaque;
1608 	struct iio_dev *indio_dev;
1609 	size_t alloc_size;
1610 
1611 	alloc_size = sizeof(struct iio_dev_opaque);
1612 	if (sizeof_priv) {
1613 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1614 		alloc_size += sizeof_priv;
1615 	}
1616 
1617 	iio_dev_opaque = kzalloc(alloc_size, GFP_KERNEL);
1618 	if (!iio_dev_opaque)
1619 		return NULL;
1620 
1621 	indio_dev = &iio_dev_opaque->indio_dev;
1622 	indio_dev->priv = (char *)iio_dev_opaque +
1623 		ALIGN(sizeof(struct iio_dev_opaque), IIO_ALIGN);
1624 
1625 	indio_dev->dev.parent = parent;
1626 	indio_dev->dev.type = &iio_device_type;
1627 	indio_dev->dev.bus = &iio_bus_type;
1628 	device_initialize(&indio_dev->dev);
1629 	iio_device_set_drvdata(indio_dev, (void *)indio_dev);
1630 	mutex_init(&indio_dev->mlock);
1631 	mutex_init(&indio_dev->info_exist_lock);
1632 	INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
1633 
1634 	indio_dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1635 	if (indio_dev->id < 0) {
1636 		/* cannot use a dev_err as the name isn't available */
1637 		pr_err("failed to get device id\n");
1638 		kfree(iio_dev_opaque);
1639 		return NULL;
1640 	}
1641 	dev_set_name(&indio_dev->dev, "iio:device%d", indio_dev->id);
1642 	INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
1643 	INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);
1644 
1645 	return indio_dev;
1646 }
1647 EXPORT_SYMBOL(iio_device_alloc);
1648 
1649 /**
1650  * iio_device_free() - free an iio_dev from a driver
1651  * @dev:		the iio_dev associated with the device
1652  **/
1653 void iio_device_free(struct iio_dev *dev)
1654 {
1655 	if (dev)
1656 		put_device(&dev->dev);
1657 }
1658 EXPORT_SYMBOL(iio_device_free);
1659 
1660 static void devm_iio_device_release(struct device *dev, void *res)
1661 {
1662 	iio_device_free(*(struct iio_dev **)res);
1663 }
1664 
1665 /**
1666  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1667  * @parent:		Device to allocate iio_dev for, and parent for this IIO device
1668  * @sizeof_priv:	Space to allocate for private structure.
1669  *
1670  * Managed iio_device_alloc. iio_dev allocated with this function is
1671  * automatically freed on driver detach.
1672  *
1673  * RETURNS:
1674  * Pointer to allocated iio_dev on success, NULL on failure.
1675  */
1676 struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
1677 {
1678 	struct iio_dev **ptr, *iio_dev;
1679 
1680 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1681 			   GFP_KERNEL);
1682 	if (!ptr)
1683 		return NULL;
1684 
1685 	iio_dev = iio_device_alloc(parent, sizeof_priv);
1686 	if (iio_dev) {
1687 		*ptr = iio_dev;
1688 		devres_add(parent, ptr);
1689 	} else {
1690 		devres_free(ptr);
1691 	}
1692 
1693 	return iio_dev;
1694 }
1695 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1696 
1697 /**
1698  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1699  * @inode:	Inode structure for identifying the device in the file system
1700  * @filp:	File structure for iio device used to keep and later access
1701  *		private data
1702  *
1703  * Return: 0 on success or -EBUSY if the device is already opened
1704  **/
1705 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1706 {
1707 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1708 						struct iio_dev, chrdev);
1709 	struct iio_dev_buffer_pair *ib;
1710 
1711 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1712 		return -EBUSY;
1713 
1714 	iio_device_get(indio_dev);
1715 
1716 	ib = kmalloc(sizeof(*ib), GFP_KERNEL);
1717 	if (!ib) {
1718 		iio_device_put(indio_dev);
1719 		clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1720 		return -ENOMEM;
1721 	}
1722 
1723 	ib->indio_dev = indio_dev;
1724 	ib->buffer = indio_dev->buffer;
1725 
1726 	filp->private_data = ib;
1727 
1728 	return 0;
1729 }
1730 
1731 /**
1732  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1733  * @inode:	Inode structure pointer for the char device
1734  * @filp:	File structure pointer for the char device
1735  *
1736  * Return: 0 for successful release
1737  */
1738 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1739 {
1740 	struct iio_dev_buffer_pair *ib = filp->private_data;
1741 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1742 						struct iio_dev, chrdev);
1743 	kfree(ib);
1744 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1745 	iio_device_put(indio_dev);
1746 
1747 	return 0;
1748 }
1749 
1750 void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
1751 				       struct iio_ioctl_handler *h)
1752 {
1753 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1754 
1755 	list_add_tail(&h->entry, &iio_dev_opaque->ioctl_handlers);
1756 }
1757 
1758 void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h)
1759 {
1760 	list_del(&h->entry);
1761 }
1762 
1763 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1764 {
1765 	struct iio_dev_buffer_pair *ib = filp->private_data;
1766 	struct iio_dev *indio_dev = ib->indio_dev;
1767 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1768 	struct iio_ioctl_handler *h;
1769 	int ret = -ENODEV;
1770 
1771 	mutex_lock(&indio_dev->info_exist_lock);
1772 
1773 	/**
1774 	 * The NULL check here is required to prevent crashing when a device
1775 	 * is being removed while userspace would still have open file handles
1776 	 * to try to access this device.
1777 	 */
1778 	if (!indio_dev->info)
1779 		goto out_unlock;
1780 
1781 	ret = -EINVAL;
1782 	list_for_each_entry(h, &iio_dev_opaque->ioctl_handlers, entry) {
1783 		ret = h->ioctl(indio_dev, filp, cmd, arg);
1784 		if (ret != IIO_IOCTL_UNHANDLED)
1785 			break;
1786 	}
1787 
1788 	if (ret == IIO_IOCTL_UNHANDLED)
1789 		ret = -EINVAL;
1790 
1791 out_unlock:
1792 	mutex_unlock(&indio_dev->info_exist_lock);
1793 
1794 	return ret;
1795 }
1796 
1797 static const struct file_operations iio_buffer_fileops = {
1798 	.owner = THIS_MODULE,
1799 	.llseek = noop_llseek,
1800 	.read = iio_buffer_read_outer_addr,
1801 	.poll = iio_buffer_poll_addr,
1802 	.unlocked_ioctl = iio_ioctl,
1803 	.compat_ioctl = compat_ptr_ioctl,
1804 	.open = iio_chrdev_open,
1805 	.release = iio_chrdev_release,
1806 };
1807 
1808 static const struct file_operations iio_event_fileops = {
1809 	.owner = THIS_MODULE,
1810 	.llseek = noop_llseek,
1811 	.unlocked_ioctl = iio_ioctl,
1812 	.compat_ioctl = compat_ptr_ioctl,
1813 	.open = iio_chrdev_open,
1814 	.release = iio_chrdev_release,
1815 };
1816 
1817 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1818 {
1819 	int i, j;
1820 	const struct iio_chan_spec *channels = indio_dev->channels;
1821 
1822 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1823 		return 0;
1824 
1825 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1826 		if (channels[i].scan_index < 0)
1827 			continue;
1828 		for (j = i + 1; j < indio_dev->num_channels; j++)
1829 			if (channels[i].scan_index == channels[j].scan_index) {
1830 				dev_err(&indio_dev->dev,
1831 					"Duplicate scan index %d\n",
1832 					channels[i].scan_index);
1833 				return -EINVAL;
1834 			}
1835 	}
1836 
1837 	return 0;
1838 }
1839 
1840 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1841 
1842 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1843 {
1844 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1845 	const char *label;
1846 	int ret;
1847 
1848 	if (!indio_dev->info)
1849 		return -EINVAL;
1850 
1851 	indio_dev->driver_module = this_mod;
1852 	/* If the calling driver did not initialize of_node, do it here */
1853 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1854 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1855 
1856 	label = of_get_property(indio_dev->dev.of_node, "label", NULL);
1857 	if (label)
1858 		indio_dev->label = label;
1859 
1860 	ret = iio_check_unique_scan_index(indio_dev);
1861 	if (ret < 0)
1862 		return ret;
1863 
1864 	iio_device_register_debugfs(indio_dev);
1865 
1866 	ret = iio_buffers_alloc_sysfs_and_mask(indio_dev);
1867 	if (ret) {
1868 		dev_err(indio_dev->dev.parent,
1869 			"Failed to create buffer sysfs interfaces\n");
1870 		goto error_unreg_debugfs;
1871 	}
1872 
1873 	ret = iio_device_register_sysfs(indio_dev);
1874 	if (ret) {
1875 		dev_err(indio_dev->dev.parent,
1876 			"Failed to register sysfs interfaces\n");
1877 		goto error_buffer_free_sysfs;
1878 	}
1879 	ret = iio_device_register_eventset(indio_dev);
1880 	if (ret) {
1881 		dev_err(indio_dev->dev.parent,
1882 			"Failed to register event set\n");
1883 		goto error_free_sysfs;
1884 	}
1885 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1886 		iio_device_register_trigger_consumer(indio_dev);
1887 
1888 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1889 		indio_dev->setup_ops == NULL)
1890 		indio_dev->setup_ops = &noop_ring_setup_ops;
1891 
1892 	if (iio_dev_opaque->attached_buffers_cnt)
1893 		cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1894 	else if (iio_dev_opaque->event_interface)
1895 		cdev_init(&indio_dev->chrdev, &iio_event_fileops);
1896 
1897 	if (iio_dev_opaque->attached_buffers_cnt || iio_dev_opaque->event_interface) {
1898 		indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1899 		indio_dev->chrdev.owner = this_mod;
1900 	}
1901 
1902 	/* assign device groups now; they should be all registered now */
1903 	indio_dev->dev.groups = iio_dev_opaque->groups;
1904 
1905 	ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1906 	if (ret < 0)
1907 		goto error_unreg_eventset;
1908 
1909 	return 0;
1910 
1911 error_unreg_eventset:
1912 	iio_device_unregister_eventset(indio_dev);
1913 error_free_sysfs:
1914 	iio_device_unregister_sysfs(indio_dev);
1915 error_buffer_free_sysfs:
1916 	iio_buffers_free_sysfs_and_mask(indio_dev);
1917 error_unreg_debugfs:
1918 	iio_device_unregister_debugfs(indio_dev);
1919 	return ret;
1920 }
1921 EXPORT_SYMBOL(__iio_device_register);
1922 
1923 /**
1924  * iio_device_unregister() - unregister a device from the IIO subsystem
1925  * @indio_dev:		Device structure representing the device.
1926  **/
1927 void iio_device_unregister(struct iio_dev *indio_dev)
1928 {
1929 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1930 	struct iio_ioctl_handler *h, *t;
1931 
1932 	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1933 
1934 	mutex_lock(&indio_dev->info_exist_lock);
1935 
1936 	iio_device_unregister_debugfs(indio_dev);
1937 
1938 	iio_disable_all_buffers(indio_dev);
1939 
1940 	indio_dev->info = NULL;
1941 
1942 	list_for_each_entry_safe(h, t, &iio_dev_opaque->ioctl_handlers, entry)
1943 		list_del(&h->entry);
1944 
1945 	iio_device_wakeup_eventset(indio_dev);
1946 	iio_buffer_wakeup_poll(indio_dev);
1947 
1948 	mutex_unlock(&indio_dev->info_exist_lock);
1949 
1950 	iio_buffers_free_sysfs_and_mask(indio_dev);
1951 }
1952 EXPORT_SYMBOL(iio_device_unregister);
1953 
1954 static void devm_iio_device_unreg(struct device *dev, void *res)
1955 {
1956 	iio_device_unregister(*(struct iio_dev **)res);
1957 }
1958 
1959 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1960 			       struct module *this_mod)
1961 {
1962 	struct iio_dev **ptr;
1963 	int ret;
1964 
1965 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1966 	if (!ptr)
1967 		return -ENOMEM;
1968 
1969 	*ptr = indio_dev;
1970 	ret = __iio_device_register(indio_dev, this_mod);
1971 	if (!ret)
1972 		devres_add(dev, ptr);
1973 	else
1974 		devres_free(ptr);
1975 
1976 	return ret;
1977 }
1978 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1979 
1980 /**
1981  * iio_device_claim_direct_mode - Keep device in direct mode
1982  * @indio_dev:	the iio_dev associated with the device
1983  *
1984  * If the device is in direct mode it is guaranteed to stay
1985  * that way until iio_device_release_direct_mode() is called.
1986  *
1987  * Use with iio_device_release_direct_mode()
1988  *
1989  * Returns: 0 on success, -EBUSY on failure
1990  */
1991 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1992 {
1993 	mutex_lock(&indio_dev->mlock);
1994 
1995 	if (iio_buffer_enabled(indio_dev)) {
1996 		mutex_unlock(&indio_dev->mlock);
1997 		return -EBUSY;
1998 	}
1999 	return 0;
2000 }
2001 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
2002 
2003 /**
2004  * iio_device_release_direct_mode - releases claim on direct mode
2005  * @indio_dev:	the iio_dev associated with the device
2006  *
2007  * Release the claim. Device is no longer guaranteed to stay
2008  * in direct mode.
2009  *
2010  * Use with iio_device_claim_direct_mode()
2011  */
2012 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
2013 {
2014 	mutex_unlock(&indio_dev->mlock);
2015 }
2016 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
2017 
2018 subsys_initcall(iio_init);
2019 module_exit(iio_exit);
2020 
2021 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
2022 MODULE_DESCRIPTION("Industrial I/O core");
2023 MODULE_LICENSE("GPL");
2024