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/anon_inodes.h>
12 #include <linux/cdev.h>
13 #include <linux/debugfs.h>
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/fs.h>
17 #include <linux/idr.h>
18 #include <linux/kdev_t.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/mutex.h>
22 #include <linux/poll.h>
23 #include <linux/property.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/wait.h>
27 
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/buffer_impl.h>
30 #include <linux/iio/events.h>
31 #include <linux/iio/iio-opaque.h>
32 #include <linux/iio/iio.h>
33 #include <linux/iio/sysfs.h>
34 
35 #include "iio_core.h"
36 #include "iio_core_trigger.h"
37 
38 /* IDA to assign each registered device a unique id */
39 static DEFINE_IDA(iio_ida);
40 
41 static dev_t iio_devt;
42 
43 #define IIO_DEV_MAX 256
44 struct bus_type iio_bus_type = {
45 	.name = "iio",
46 };
47 EXPORT_SYMBOL(iio_bus_type);
48 
49 static struct dentry *iio_debugfs_dentry;
50 
51 static const char * const iio_direction[] = {
52 	[0] = "in",
53 	[1] = "out",
54 };
55 
56 static const char * const iio_chan_type_name_spec[] = {
57 	[IIO_VOLTAGE] = "voltage",
58 	[IIO_CURRENT] = "current",
59 	[IIO_POWER] = "power",
60 	[IIO_ACCEL] = "accel",
61 	[IIO_ANGL_VEL] = "anglvel",
62 	[IIO_MAGN] = "magn",
63 	[IIO_LIGHT] = "illuminance",
64 	[IIO_INTENSITY] = "intensity",
65 	[IIO_PROXIMITY] = "proximity",
66 	[IIO_TEMP] = "temp",
67 	[IIO_INCLI] = "incli",
68 	[IIO_ROT] = "rot",
69 	[IIO_ANGL] = "angl",
70 	[IIO_TIMESTAMP] = "timestamp",
71 	[IIO_CAPACITANCE] = "capacitance",
72 	[IIO_ALTVOLTAGE] = "altvoltage",
73 	[IIO_CCT] = "cct",
74 	[IIO_PRESSURE] = "pressure",
75 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
76 	[IIO_ACTIVITY] = "activity",
77 	[IIO_STEPS] = "steps",
78 	[IIO_ENERGY] = "energy",
79 	[IIO_DISTANCE] = "distance",
80 	[IIO_VELOCITY] = "velocity",
81 	[IIO_CONCENTRATION] = "concentration",
82 	[IIO_RESISTANCE] = "resistance",
83 	[IIO_PH] = "ph",
84 	[IIO_UVINDEX] = "uvindex",
85 	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
86 	[IIO_COUNT] = "count",
87 	[IIO_INDEX] = "index",
88 	[IIO_GRAVITY]  = "gravity",
89 	[IIO_POSITIONRELATIVE]  = "positionrelative",
90 	[IIO_PHASE] = "phase",
91 	[IIO_MASSCONCENTRATION] = "massconcentration",
92 };
93 
94 static const char * const iio_modifier_names[] = {
95 	[IIO_MOD_X] = "x",
96 	[IIO_MOD_Y] = "y",
97 	[IIO_MOD_Z] = "z",
98 	[IIO_MOD_X_AND_Y] = "x&y",
99 	[IIO_MOD_X_AND_Z] = "x&z",
100 	[IIO_MOD_Y_AND_Z] = "y&z",
101 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
102 	[IIO_MOD_X_OR_Y] = "x|y",
103 	[IIO_MOD_X_OR_Z] = "x|z",
104 	[IIO_MOD_Y_OR_Z] = "y|z",
105 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
106 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
107 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
108 	[IIO_MOD_LIGHT_BOTH] = "both",
109 	[IIO_MOD_LIGHT_IR] = "ir",
110 	[IIO_MOD_LIGHT_CLEAR] = "clear",
111 	[IIO_MOD_LIGHT_RED] = "red",
112 	[IIO_MOD_LIGHT_GREEN] = "green",
113 	[IIO_MOD_LIGHT_BLUE] = "blue",
114 	[IIO_MOD_LIGHT_UV] = "uv",
115 	[IIO_MOD_LIGHT_DUV] = "duv",
116 	[IIO_MOD_QUATERNION] = "quaternion",
117 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
118 	[IIO_MOD_TEMP_OBJECT] = "object",
119 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
120 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
121 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
122 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
123 	[IIO_MOD_RUNNING] = "running",
124 	[IIO_MOD_JOGGING] = "jogging",
125 	[IIO_MOD_WALKING] = "walking",
126 	[IIO_MOD_STILL] = "still",
127 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
128 	[IIO_MOD_I] = "i",
129 	[IIO_MOD_Q] = "q",
130 	[IIO_MOD_CO2] = "co2",
131 	[IIO_MOD_VOC] = "voc",
132 	[IIO_MOD_PM1] = "pm1",
133 	[IIO_MOD_PM2P5] = "pm2p5",
134 	[IIO_MOD_PM4] = "pm4",
135 	[IIO_MOD_PM10] = "pm10",
136 	[IIO_MOD_ETHANOL] = "ethanol",
137 	[IIO_MOD_H2] = "h2",
138 	[IIO_MOD_O2] = "o2",
139 	[IIO_MOD_LINEAR_X] = "linear_x",
140 	[IIO_MOD_LINEAR_Y] = "linear_y",
141 	[IIO_MOD_LINEAR_Z] = "linear_z",
142 	[IIO_MOD_PITCH] = "pitch",
143 	[IIO_MOD_YAW] = "yaw",
144 	[IIO_MOD_ROLL] = "roll",
145 };
146 
147 /* relies on pairs of these shared then separate */
148 static const char * const iio_chan_info_postfix[] = {
149 	[IIO_CHAN_INFO_RAW] = "raw",
150 	[IIO_CHAN_INFO_PROCESSED] = "input",
151 	[IIO_CHAN_INFO_SCALE] = "scale",
152 	[IIO_CHAN_INFO_OFFSET] = "offset",
153 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
154 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
155 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
156 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
157 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
158 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
159 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
160 	= "filter_low_pass_3db_frequency",
161 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
162 	= "filter_high_pass_3db_frequency",
163 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
164 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
165 	[IIO_CHAN_INFO_PHASE] = "phase",
166 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
167 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
168 	[IIO_CHAN_INFO_HYSTERESIS_RELATIVE] = "hysteresis_relative",
169 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
170 	[IIO_CHAN_INFO_ENABLE] = "en",
171 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
172 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
173 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
174 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
175 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
176 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
177 	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
178 	[IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
179 	[IIO_CHAN_INFO_ZEROPOINT] = "zeropoint",
180 };
181 /**
182  * iio_device_id() - query the unique ID for the device
183  * @indio_dev:		Device structure whose ID is being queried
184  *
185  * The IIO device ID is a unique index used for example for the naming
186  * of the character device /dev/iio\:device[ID]
187  */
188 int iio_device_id(struct iio_dev *indio_dev)
189 {
190 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
191 
192 	return iio_dev_opaque->id;
193 }
194 EXPORT_SYMBOL_GPL(iio_device_id);
195 
196 /**
197  * iio_buffer_enabled() - helper function to test if the buffer is enabled
198  * @indio_dev:		IIO device structure for device
199  */
200 bool iio_buffer_enabled(struct iio_dev *indio_dev)
201 {
202 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
203 
204 	return iio_dev_opaque->currentmode
205 		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
206 		   INDIO_BUFFER_SOFTWARE);
207 }
208 EXPORT_SYMBOL_GPL(iio_buffer_enabled);
209 
210 #if defined(CONFIG_DEBUG_FS)
211 /*
212  * There's also a CONFIG_DEBUG_FS guard in include/linux/iio/iio.h for
213  * iio_get_debugfs_dentry() to make it inline if CONFIG_DEBUG_FS is undefined
214  */
215 struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
216 {
217 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
218 
219 	return iio_dev_opaque->debugfs_dentry;
220 }
221 EXPORT_SYMBOL_GPL(iio_get_debugfs_dentry);
222 #endif
223 
224 /**
225  * iio_find_channel_from_si() - get channel from its scan index
226  * @indio_dev:		device
227  * @si:			scan index to match
228  */
229 const struct iio_chan_spec
230 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
231 {
232 	int i;
233 
234 	for (i = 0; i < indio_dev->num_channels; i++)
235 		if (indio_dev->channels[i].scan_index == si)
236 			return &indio_dev->channels[i];
237 	return NULL;
238 }
239 
240 /* This turns up an awful lot */
241 ssize_t iio_read_const_attr(struct device *dev,
242 			    struct device_attribute *attr,
243 			    char *buf)
244 {
245 	return sysfs_emit(buf, "%s\n", to_iio_const_attr(attr)->string);
246 }
247 EXPORT_SYMBOL(iio_read_const_attr);
248 
249 /**
250  * iio_device_set_clock() - Set current timestamping clock for the device
251  * @indio_dev: IIO device structure containing the device
252  * @clock_id: timestamping clock posix identifier to set.
253  */
254 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
255 {
256 	int ret;
257 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
258 	const struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
259 
260 	ret = mutex_lock_interruptible(&iio_dev_opaque->mlock);
261 	if (ret)
262 		return ret;
263 	if ((ev_int && iio_event_enabled(ev_int)) ||
264 	    iio_buffer_enabled(indio_dev)) {
265 		mutex_unlock(&iio_dev_opaque->mlock);
266 		return -EBUSY;
267 	}
268 	iio_dev_opaque->clock_id = clock_id;
269 	mutex_unlock(&iio_dev_opaque->mlock);
270 
271 	return 0;
272 }
273 EXPORT_SYMBOL(iio_device_set_clock);
274 
275 /**
276  * iio_device_get_clock() - Retrieve current timestamping clock for the device
277  * @indio_dev: IIO device structure containing the device
278  */
279 clockid_t iio_device_get_clock(const struct iio_dev *indio_dev)
280 {
281 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
282 
283 	return iio_dev_opaque->clock_id;
284 }
285 EXPORT_SYMBOL(iio_device_get_clock);
286 
287 /**
288  * iio_get_time_ns() - utility function to get a time stamp for events etc
289  * @indio_dev: device
290  */
291 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
292 {
293 	struct timespec64 tp;
294 
295 	switch (iio_device_get_clock(indio_dev)) {
296 	case CLOCK_REALTIME:
297 		return ktime_get_real_ns();
298 	case CLOCK_MONOTONIC:
299 		return ktime_get_ns();
300 	case CLOCK_MONOTONIC_RAW:
301 		return ktime_get_raw_ns();
302 	case CLOCK_REALTIME_COARSE:
303 		return ktime_to_ns(ktime_get_coarse_real());
304 	case CLOCK_MONOTONIC_COARSE:
305 		ktime_get_coarse_ts64(&tp);
306 		return timespec64_to_ns(&tp);
307 	case CLOCK_BOOTTIME:
308 		return ktime_get_boottime_ns();
309 	case CLOCK_TAI:
310 		return ktime_get_clocktai_ns();
311 	default:
312 		BUG();
313 	}
314 }
315 EXPORT_SYMBOL(iio_get_time_ns);
316 
317 static int __init iio_init(void)
318 {
319 	int ret;
320 
321 	/* Register sysfs bus */
322 	ret  = bus_register(&iio_bus_type);
323 	if (ret < 0) {
324 		pr_err("could not register bus type\n");
325 		goto error_nothing;
326 	}
327 
328 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
329 	if (ret < 0) {
330 		pr_err("failed to allocate char dev region\n");
331 		goto error_unregister_bus_type;
332 	}
333 
334 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
335 
336 	return 0;
337 
338 error_unregister_bus_type:
339 	bus_unregister(&iio_bus_type);
340 error_nothing:
341 	return ret;
342 }
343 
344 static void __exit iio_exit(void)
345 {
346 	if (iio_devt)
347 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
348 	bus_unregister(&iio_bus_type);
349 	debugfs_remove(iio_debugfs_dentry);
350 }
351 
352 #if defined(CONFIG_DEBUG_FS)
353 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
354 			      size_t count, loff_t *ppos)
355 {
356 	struct iio_dev *indio_dev = file->private_data;
357 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
358 	unsigned int val = 0;
359 	int ret;
360 
361 	if (*ppos > 0)
362 		return simple_read_from_buffer(userbuf, count, ppos,
363 					       iio_dev_opaque->read_buf,
364 					       iio_dev_opaque->read_buf_len);
365 
366 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
367 						  iio_dev_opaque->cached_reg_addr,
368 						  0, &val);
369 	if (ret) {
370 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
371 		return ret;
372 	}
373 
374 	iio_dev_opaque->read_buf_len = snprintf(iio_dev_opaque->read_buf,
375 					      sizeof(iio_dev_opaque->read_buf),
376 					      "0x%X\n", val);
377 
378 	return simple_read_from_buffer(userbuf, count, ppos,
379 				       iio_dev_opaque->read_buf,
380 				       iio_dev_opaque->read_buf_len);
381 }
382 
383 static ssize_t iio_debugfs_write_reg(struct file *file,
384 		     const char __user *userbuf, size_t count, loff_t *ppos)
385 {
386 	struct iio_dev *indio_dev = file->private_data;
387 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
388 	unsigned int reg, val;
389 	char buf[80];
390 	int ret;
391 
392 	count = min_t(size_t, count, (sizeof(buf)-1));
393 	if (copy_from_user(buf, userbuf, count))
394 		return -EFAULT;
395 
396 	buf[count] = 0;
397 
398 	ret = sscanf(buf, "%i %i", &reg, &val);
399 
400 	switch (ret) {
401 	case 1:
402 		iio_dev_opaque->cached_reg_addr = reg;
403 		break;
404 	case 2:
405 		iio_dev_opaque->cached_reg_addr = reg;
406 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
407 							  val, NULL);
408 		if (ret) {
409 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
410 				__func__);
411 			return ret;
412 		}
413 		break;
414 	default:
415 		return -EINVAL;
416 	}
417 
418 	return count;
419 }
420 
421 static const struct file_operations iio_debugfs_reg_fops = {
422 	.open = simple_open,
423 	.read = iio_debugfs_read_reg,
424 	.write = iio_debugfs_write_reg,
425 };
426 
427 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
428 {
429 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
430 
431 	debugfs_remove_recursive(iio_dev_opaque->debugfs_dentry);
432 }
433 
434 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
435 {
436 	struct iio_dev_opaque *iio_dev_opaque;
437 
438 	if (indio_dev->info->debugfs_reg_access == NULL)
439 		return;
440 
441 	if (!iio_debugfs_dentry)
442 		return;
443 
444 	iio_dev_opaque = to_iio_dev_opaque(indio_dev);
445 
446 	iio_dev_opaque->debugfs_dentry =
447 		debugfs_create_dir(dev_name(&indio_dev->dev),
448 				   iio_debugfs_dentry);
449 
450 	debugfs_create_file("direct_reg_access", 0644,
451 			    iio_dev_opaque->debugfs_dentry, indio_dev,
452 			    &iio_debugfs_reg_fops);
453 }
454 #else
455 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
456 {
457 }
458 
459 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
460 {
461 }
462 #endif /* CONFIG_DEBUG_FS */
463 
464 static ssize_t iio_read_channel_ext_info(struct device *dev,
465 				     struct device_attribute *attr,
466 				     char *buf)
467 {
468 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
469 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
470 	const struct iio_chan_spec_ext_info *ext_info;
471 
472 	ext_info = &this_attr->c->ext_info[this_attr->address];
473 
474 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
475 }
476 
477 static ssize_t iio_write_channel_ext_info(struct device *dev,
478 				     struct device_attribute *attr,
479 				     const char *buf,
480 					 size_t len)
481 {
482 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
483 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
484 	const struct iio_chan_spec_ext_info *ext_info;
485 
486 	ext_info = &this_attr->c->ext_info[this_attr->address];
487 
488 	return ext_info->write(indio_dev, ext_info->private,
489 			       this_attr->c, buf, len);
490 }
491 
492 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
493 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
494 {
495 	const struct iio_enum *e = (const struct iio_enum *)priv;
496 	unsigned int i;
497 	size_t len = 0;
498 
499 	if (!e->num_items)
500 		return 0;
501 
502 	for (i = 0; i < e->num_items; ++i) {
503 		if (!e->items[i])
504 			continue;
505 		len += sysfs_emit_at(buf, len, "%s ", e->items[i]);
506 	}
507 
508 	/* replace last space with a newline */
509 	buf[len - 1] = '\n';
510 
511 	return len;
512 }
513 EXPORT_SYMBOL_GPL(iio_enum_available_read);
514 
515 ssize_t iio_enum_read(struct iio_dev *indio_dev,
516 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
517 {
518 	const struct iio_enum *e = (const struct iio_enum *)priv;
519 	int i;
520 
521 	if (!e->get)
522 		return -EINVAL;
523 
524 	i = e->get(indio_dev, chan);
525 	if (i < 0)
526 		return i;
527 	else if (i >= e->num_items || !e->items[i])
528 		return -EINVAL;
529 
530 	return sysfs_emit(buf, "%s\n", e->items[i]);
531 }
532 EXPORT_SYMBOL_GPL(iio_enum_read);
533 
534 ssize_t iio_enum_write(struct iio_dev *indio_dev,
535 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
536 	size_t len)
537 {
538 	const struct iio_enum *e = (const struct iio_enum *)priv;
539 	int ret;
540 
541 	if (!e->set)
542 		return -EINVAL;
543 
544 	ret = __sysfs_match_string(e->items, e->num_items, buf);
545 	if (ret < 0)
546 		return ret;
547 
548 	ret = e->set(indio_dev, chan, ret);
549 	return ret ? ret : len;
550 }
551 EXPORT_SYMBOL_GPL(iio_enum_write);
552 
553 static const struct iio_mount_matrix iio_mount_idmatrix = {
554 	.rotation = {
555 		"1", "0", "0",
556 		"0", "1", "0",
557 		"0", "0", "1"
558 	}
559 };
560 
561 static int iio_setup_mount_idmatrix(const struct device *dev,
562 				    struct iio_mount_matrix *matrix)
563 {
564 	*matrix = iio_mount_idmatrix;
565 	dev_info(dev, "mounting matrix not found: using identity...\n");
566 	return 0;
567 }
568 
569 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
570 			      const struct iio_chan_spec *chan, char *buf)
571 {
572 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
573 					      priv)(indio_dev, chan);
574 
575 	if (IS_ERR(mtx))
576 		return PTR_ERR(mtx);
577 
578 	if (!mtx)
579 		mtx = &iio_mount_idmatrix;
580 
581 	return sysfs_emit(buf, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
582 			  mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
583 			  mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
584 			  mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
585 }
586 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
587 
588 /**
589  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
590  *                           device "mount-matrix" property
591  * @dev:	device the mounting matrix property is assigned to
592  * @matrix:	where to store retrieved matrix
593  *
594  * If device is assigned no mounting matrix property, a default 3x3 identity
595  * matrix will be filled in.
596  *
597  * Return: 0 if success, or a negative error code on failure.
598  */
599 int iio_read_mount_matrix(struct device *dev, struct iio_mount_matrix *matrix)
600 {
601 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
602 	int err;
603 
604 	err = device_property_read_string_array(dev, "mount-matrix", matrix->rotation, len);
605 	if (err == len)
606 		return 0;
607 
608 	if (err >= 0)
609 		/* Invalid number of matrix entries. */
610 		return -EINVAL;
611 
612 	if (err != -EINVAL)
613 		/* Invalid matrix declaration format. */
614 		return err;
615 
616 	/* Matrix was not declared at all: fallback to identity. */
617 	return iio_setup_mount_idmatrix(dev, matrix);
618 }
619 EXPORT_SYMBOL(iio_read_mount_matrix);
620 
621 static ssize_t __iio_format_value(char *buf, size_t offset, unsigned int type,
622 				  int size, const int *vals)
623 {
624 	int tmp0, tmp1;
625 	s64 tmp2;
626 	bool scale_db = false;
627 
628 	switch (type) {
629 	case IIO_VAL_INT:
630 		return sysfs_emit_at(buf, offset, "%d", vals[0]);
631 	case IIO_VAL_INT_PLUS_MICRO_DB:
632 		scale_db = true;
633 		fallthrough;
634 	case IIO_VAL_INT_PLUS_MICRO:
635 		if (vals[1] < 0)
636 			return sysfs_emit_at(buf, offset, "-%d.%06u%s",
637 					     abs(vals[0]), -vals[1],
638 					     scale_db ? " dB" : "");
639 		else
640 			return sysfs_emit_at(buf, offset, "%d.%06u%s", vals[0],
641 					     vals[1], scale_db ? " dB" : "");
642 	case IIO_VAL_INT_PLUS_NANO:
643 		if (vals[1] < 0)
644 			return sysfs_emit_at(buf, offset, "-%d.%09u",
645 					     abs(vals[0]), -vals[1]);
646 		else
647 			return sysfs_emit_at(buf, offset, "%d.%09u", vals[0],
648 					     vals[1]);
649 	case IIO_VAL_FRACTIONAL:
650 		tmp2 = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
651 		tmp1 = vals[1];
652 		tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
653 		if ((tmp2 < 0) && (tmp0 == 0))
654 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
655 		else
656 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
657 					     abs(tmp1));
658 	case IIO_VAL_FRACTIONAL_LOG2:
659 		tmp2 = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
660 		tmp0 = (int)div_s64_rem(tmp2, 1000000000LL, &tmp1);
661 		if (tmp0 == 0 && tmp2 < 0)
662 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
663 		else
664 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
665 					     abs(tmp1));
666 	case IIO_VAL_INT_MULTIPLE:
667 	{
668 		int i;
669 		int l = 0;
670 
671 		for (i = 0; i < size; ++i)
672 			l += sysfs_emit_at(buf, offset + l, "%d ", vals[i]);
673 		return l;
674 	}
675 	case IIO_VAL_CHAR:
676 		return sysfs_emit_at(buf, offset, "%c", (char)vals[0]);
677 	case IIO_VAL_INT_64:
678 		tmp2 = (s64)((((u64)vals[1]) << 32) | (u32)vals[0]);
679 		return sysfs_emit_at(buf, offset, "%lld", tmp2);
680 	default:
681 		return 0;
682 	}
683 }
684 
685 /**
686  * iio_format_value() - Formats a IIO value into its string representation
687  * @buf:	The buffer to which the formatted value gets written
688  *		which is assumed to be big enough (i.e. PAGE_SIZE).
689  * @type:	One of the IIO_VAL_* constants. This decides how the val
690  *		and val2 parameters are formatted.
691  * @size:	Number of IIO value entries contained in vals
692  * @vals:	Pointer to the values, exact meaning depends on the
693  *		type parameter.
694  *
695  * Return: 0 by default, a negative number on failure or the
696  *	   total number of characters written for a type that belongs
697  *	   to the IIO_VAL_* constant.
698  */
699 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
700 {
701 	ssize_t len;
702 
703 	len = __iio_format_value(buf, 0, type, size, vals);
704 	if (len >= PAGE_SIZE - 1)
705 		return -EFBIG;
706 
707 	return len + sysfs_emit_at(buf, len, "\n");
708 }
709 EXPORT_SYMBOL_GPL(iio_format_value);
710 
711 static ssize_t iio_read_channel_label(struct device *dev,
712 				      struct device_attribute *attr,
713 				      char *buf)
714 {
715 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
716 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
717 
718 	if (indio_dev->info->read_label)
719 		return indio_dev->info->read_label(indio_dev, this_attr->c, buf);
720 
721 	if (this_attr->c->extend_name)
722 		return sysfs_emit(buf, "%s\n", this_attr->c->extend_name);
723 
724 	return -EINVAL;
725 }
726 
727 static ssize_t iio_read_channel_info(struct device *dev,
728 				     struct device_attribute *attr,
729 				     char *buf)
730 {
731 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
732 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
733 	int vals[INDIO_MAX_RAW_ELEMENTS];
734 	int ret;
735 	int val_len = 2;
736 
737 	if (indio_dev->info->read_raw_multi)
738 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
739 							INDIO_MAX_RAW_ELEMENTS,
740 							vals, &val_len,
741 							this_attr->address);
742 	else
743 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
744 				    &vals[0], &vals[1], this_attr->address);
745 
746 	if (ret < 0)
747 		return ret;
748 
749 	return iio_format_value(buf, ret, val_len, vals);
750 }
751 
752 static ssize_t iio_format_list(char *buf, const int *vals, int type, int length,
753 			       const char *prefix, const char *suffix)
754 {
755 	ssize_t len;
756 	int stride;
757 	int i;
758 
759 	switch (type) {
760 	case IIO_VAL_INT:
761 		stride = 1;
762 		break;
763 	default:
764 		stride = 2;
765 		break;
766 	}
767 
768 	len = sysfs_emit(buf, prefix);
769 
770 	for (i = 0; i <= length - stride; i += stride) {
771 		if (i != 0) {
772 			len += sysfs_emit_at(buf, len, " ");
773 			if (len >= PAGE_SIZE)
774 				return -EFBIG;
775 		}
776 
777 		len += __iio_format_value(buf, len, type, stride, &vals[i]);
778 		if (len >= PAGE_SIZE)
779 			return -EFBIG;
780 	}
781 
782 	len += sysfs_emit_at(buf, len, "%s\n", suffix);
783 
784 	return len;
785 }
786 
787 static ssize_t iio_format_avail_list(char *buf, const int *vals,
788 				     int type, int length)
789 {
790 
791 	return iio_format_list(buf, vals, type, length, "", "");
792 }
793 
794 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
795 {
796 	int length;
797 
798 	/*
799 	 * length refers to the array size , not the number of elements.
800 	 * The purpose is to print the range [min , step ,max] so length should
801 	 * be 3 in case of int, and 6 for other types.
802 	 */
803 	switch (type) {
804 	case IIO_VAL_INT:
805 		length = 3;
806 		break;
807 	default:
808 		length = 6;
809 		break;
810 	}
811 
812 	return iio_format_list(buf, vals, type, length, "[", "]");
813 }
814 
815 static ssize_t iio_read_channel_info_avail(struct device *dev,
816 					   struct device_attribute *attr,
817 					   char *buf)
818 {
819 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
820 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
821 	const int *vals;
822 	int ret;
823 	int length;
824 	int type;
825 
826 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
827 					  &vals, &type, &length,
828 					  this_attr->address);
829 
830 	if (ret < 0)
831 		return ret;
832 	switch (ret) {
833 	case IIO_AVAIL_LIST:
834 		return iio_format_avail_list(buf, vals, type, length);
835 	case IIO_AVAIL_RANGE:
836 		return iio_format_avail_range(buf, vals, type);
837 	default:
838 		return -EINVAL;
839 	}
840 }
841 
842 /**
843  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
844  * @str: The string to parse
845  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
846  * @integer: The integer part of the number
847  * @fract: The fractional part of the number
848  * @scale_db: True if this should parse as dB
849  *
850  * Returns 0 on success, or a negative error code if the string could not be
851  * parsed.
852  */
853 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
854 				 int *integer, int *fract, bool scale_db)
855 {
856 	int i = 0, f = 0;
857 	bool integer_part = true, negative = false;
858 
859 	if (fract_mult == 0) {
860 		*fract = 0;
861 
862 		return kstrtoint(str, 0, integer);
863 	}
864 
865 	if (str[0] == '-') {
866 		negative = true;
867 		str++;
868 	} else if (str[0] == '+') {
869 		str++;
870 	}
871 
872 	while (*str) {
873 		if ('0' <= *str && *str <= '9') {
874 			if (integer_part) {
875 				i = i * 10 + *str - '0';
876 			} else {
877 				f += fract_mult * (*str - '0');
878 				fract_mult /= 10;
879 			}
880 		} else if (*str == '\n') {
881 			if (*(str + 1) == '\0')
882 				break;
883 			return -EINVAL;
884 		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
885 			/* Ignore the dB suffix */
886 			str += sizeof(" dB") - 1;
887 			continue;
888 		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
889 			/* Ignore the dB suffix */
890 			str += sizeof("dB") - 1;
891 			continue;
892 		} else if (*str == '.' && integer_part) {
893 			integer_part = false;
894 		} else {
895 			return -EINVAL;
896 		}
897 		str++;
898 	}
899 
900 	if (negative) {
901 		if (i)
902 			i = -i;
903 		else
904 			f = -f;
905 	}
906 
907 	*integer = i;
908 	*fract = f;
909 
910 	return 0;
911 }
912 
913 /**
914  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
915  * @str: The string to parse
916  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
917  * @integer: The integer part of the number
918  * @fract: The fractional part of the number
919  *
920  * Returns 0 on success, or a negative error code if the string could not be
921  * parsed.
922  */
923 int iio_str_to_fixpoint(const char *str, int fract_mult,
924 			int *integer, int *fract)
925 {
926 	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
927 }
928 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
929 
930 static ssize_t iio_write_channel_info(struct device *dev,
931 				      struct device_attribute *attr,
932 				      const char *buf,
933 				      size_t len)
934 {
935 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
936 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
937 	int ret, fract_mult = 100000;
938 	int integer, fract = 0;
939 	bool is_char = false;
940 	bool scale_db = false;
941 
942 	/* Assumes decimal - precision based on number of digits */
943 	if (!indio_dev->info->write_raw)
944 		return -EINVAL;
945 
946 	if (indio_dev->info->write_raw_get_fmt)
947 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
948 			this_attr->c, this_attr->address)) {
949 		case IIO_VAL_INT:
950 			fract_mult = 0;
951 			break;
952 		case IIO_VAL_INT_PLUS_MICRO_DB:
953 			scale_db = true;
954 			fallthrough;
955 		case IIO_VAL_INT_PLUS_MICRO:
956 			fract_mult = 100000;
957 			break;
958 		case IIO_VAL_INT_PLUS_NANO:
959 			fract_mult = 100000000;
960 			break;
961 		case IIO_VAL_CHAR:
962 			is_char = true;
963 			break;
964 		default:
965 			return -EINVAL;
966 		}
967 
968 	if (is_char) {
969 		char ch;
970 
971 		if (sscanf(buf, "%c", &ch) != 1)
972 			return -EINVAL;
973 		integer = ch;
974 	} else {
975 		ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
976 					    scale_db);
977 		if (ret)
978 			return ret;
979 	}
980 
981 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
982 					 integer, fract, this_attr->address);
983 	if (ret)
984 		return ret;
985 
986 	return len;
987 }
988 
989 static
990 int __iio_device_attr_init(struct device_attribute *dev_attr,
991 			   const char *postfix,
992 			   struct iio_chan_spec const *chan,
993 			   ssize_t (*readfunc)(struct device *dev,
994 					       struct device_attribute *attr,
995 					       char *buf),
996 			   ssize_t (*writefunc)(struct device *dev,
997 						struct device_attribute *attr,
998 						const char *buf,
999 						size_t len),
1000 			   enum iio_shared_by shared_by)
1001 {
1002 	int ret = 0;
1003 	char *name = NULL;
1004 	char *full_postfix;
1005 
1006 	sysfs_attr_init(&dev_attr->attr);
1007 
1008 	/* Build up postfix of <extend_name>_<modifier>_postfix */
1009 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
1010 		if (chan->extend_name)
1011 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
1012 						 iio_modifier_names[chan
1013 								    ->channel2],
1014 						 chan->extend_name,
1015 						 postfix);
1016 		else
1017 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
1018 						 iio_modifier_names[chan
1019 								    ->channel2],
1020 						 postfix);
1021 	} else {
1022 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
1023 			full_postfix = kstrdup(postfix, GFP_KERNEL);
1024 		else
1025 			full_postfix = kasprintf(GFP_KERNEL,
1026 						 "%s_%s",
1027 						 chan->extend_name,
1028 						 postfix);
1029 	}
1030 	if (full_postfix == NULL)
1031 		return -ENOMEM;
1032 
1033 	if (chan->differential) { /* Differential can not have modifier */
1034 		switch (shared_by) {
1035 		case IIO_SHARED_BY_ALL:
1036 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1037 			break;
1038 		case IIO_SHARED_BY_DIR:
1039 			name = kasprintf(GFP_KERNEL, "%s_%s",
1040 						iio_direction[chan->output],
1041 						full_postfix);
1042 			break;
1043 		case IIO_SHARED_BY_TYPE:
1044 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
1045 					    iio_direction[chan->output],
1046 					    iio_chan_type_name_spec[chan->type],
1047 					    iio_chan_type_name_spec[chan->type],
1048 					    full_postfix);
1049 			break;
1050 		case IIO_SEPARATE:
1051 			if (!chan->indexed) {
1052 				WARN(1, "Differential channels must be indexed\n");
1053 				ret = -EINVAL;
1054 				goto error_free_full_postfix;
1055 			}
1056 			name = kasprintf(GFP_KERNEL,
1057 					    "%s_%s%d-%s%d_%s",
1058 					    iio_direction[chan->output],
1059 					    iio_chan_type_name_spec[chan->type],
1060 					    chan->channel,
1061 					    iio_chan_type_name_spec[chan->type],
1062 					    chan->channel2,
1063 					    full_postfix);
1064 			break;
1065 		}
1066 	} else { /* Single ended */
1067 		switch (shared_by) {
1068 		case IIO_SHARED_BY_ALL:
1069 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1070 			break;
1071 		case IIO_SHARED_BY_DIR:
1072 			name = kasprintf(GFP_KERNEL, "%s_%s",
1073 						iio_direction[chan->output],
1074 						full_postfix);
1075 			break;
1076 		case IIO_SHARED_BY_TYPE:
1077 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1078 					    iio_direction[chan->output],
1079 					    iio_chan_type_name_spec[chan->type],
1080 					    full_postfix);
1081 			break;
1082 
1083 		case IIO_SEPARATE:
1084 			if (chan->indexed)
1085 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1086 						    iio_direction[chan->output],
1087 						    iio_chan_type_name_spec[chan->type],
1088 						    chan->channel,
1089 						    full_postfix);
1090 			else
1091 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1092 						    iio_direction[chan->output],
1093 						    iio_chan_type_name_spec[chan->type],
1094 						    full_postfix);
1095 			break;
1096 		}
1097 	}
1098 	if (name == NULL) {
1099 		ret = -ENOMEM;
1100 		goto error_free_full_postfix;
1101 	}
1102 	dev_attr->attr.name = name;
1103 
1104 	if (readfunc) {
1105 		dev_attr->attr.mode |= 0444;
1106 		dev_attr->show = readfunc;
1107 	}
1108 
1109 	if (writefunc) {
1110 		dev_attr->attr.mode |= 0200;
1111 		dev_attr->store = writefunc;
1112 	}
1113 
1114 error_free_full_postfix:
1115 	kfree(full_postfix);
1116 
1117 	return ret;
1118 }
1119 
1120 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1121 {
1122 	kfree(dev_attr->attr.name);
1123 }
1124 
1125 int __iio_add_chan_devattr(const char *postfix,
1126 			   struct iio_chan_spec const *chan,
1127 			   ssize_t (*readfunc)(struct device *dev,
1128 					       struct device_attribute *attr,
1129 					       char *buf),
1130 			   ssize_t (*writefunc)(struct device *dev,
1131 						struct device_attribute *attr,
1132 						const char *buf,
1133 						size_t len),
1134 			   u64 mask,
1135 			   enum iio_shared_by shared_by,
1136 			   struct device *dev,
1137 			   struct iio_buffer *buffer,
1138 			   struct list_head *attr_list)
1139 {
1140 	int ret;
1141 	struct iio_dev_attr *iio_attr, *t;
1142 
1143 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1144 	if (iio_attr == NULL)
1145 		return -ENOMEM;
1146 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1147 				     postfix, chan,
1148 				     readfunc, writefunc, shared_by);
1149 	if (ret)
1150 		goto error_iio_dev_attr_free;
1151 	iio_attr->c = chan;
1152 	iio_attr->address = mask;
1153 	iio_attr->buffer = buffer;
1154 	list_for_each_entry(t, attr_list, l)
1155 		if (strcmp(t->dev_attr.attr.name,
1156 			   iio_attr->dev_attr.attr.name) == 0) {
1157 			if (shared_by == IIO_SEPARATE)
1158 				dev_err(dev, "tried to double register : %s\n",
1159 					t->dev_attr.attr.name);
1160 			ret = -EBUSY;
1161 			goto error_device_attr_deinit;
1162 		}
1163 	list_add(&iio_attr->l, attr_list);
1164 
1165 	return 0;
1166 
1167 error_device_attr_deinit:
1168 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1169 error_iio_dev_attr_free:
1170 	kfree(iio_attr);
1171 	return ret;
1172 }
1173 
1174 static int iio_device_add_channel_label(struct iio_dev *indio_dev,
1175 					 struct iio_chan_spec const *chan)
1176 {
1177 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1178 	int ret;
1179 
1180 	if (!indio_dev->info->read_label && !chan->extend_name)
1181 		return 0;
1182 
1183 	ret = __iio_add_chan_devattr("label",
1184 				     chan,
1185 				     &iio_read_channel_label,
1186 				     NULL,
1187 				     0,
1188 				     IIO_SEPARATE,
1189 				     &indio_dev->dev,
1190 				     NULL,
1191 				     &iio_dev_opaque->channel_attr_list);
1192 	if (ret < 0)
1193 		return ret;
1194 
1195 	return 1;
1196 }
1197 
1198 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1199 					 struct iio_chan_spec const *chan,
1200 					 enum iio_shared_by shared_by,
1201 					 const long *infomask)
1202 {
1203 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1204 	int i, ret, attrcount = 0;
1205 
1206 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1207 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1208 			return -EINVAL;
1209 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1210 					     chan,
1211 					     &iio_read_channel_info,
1212 					     &iio_write_channel_info,
1213 					     i,
1214 					     shared_by,
1215 					     &indio_dev->dev,
1216 					     NULL,
1217 					     &iio_dev_opaque->channel_attr_list);
1218 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1219 			continue;
1220 		else if (ret < 0)
1221 			return ret;
1222 		attrcount++;
1223 	}
1224 
1225 	return attrcount;
1226 }
1227 
1228 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1229 					       struct iio_chan_spec const *chan,
1230 					       enum iio_shared_by shared_by,
1231 					       const long *infomask)
1232 {
1233 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1234 	int i, ret, attrcount = 0;
1235 	char *avail_postfix;
1236 
1237 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1238 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1239 			return -EINVAL;
1240 		avail_postfix = kasprintf(GFP_KERNEL,
1241 					  "%s_available",
1242 					  iio_chan_info_postfix[i]);
1243 		if (!avail_postfix)
1244 			return -ENOMEM;
1245 
1246 		ret = __iio_add_chan_devattr(avail_postfix,
1247 					     chan,
1248 					     &iio_read_channel_info_avail,
1249 					     NULL,
1250 					     i,
1251 					     shared_by,
1252 					     &indio_dev->dev,
1253 					     NULL,
1254 					     &iio_dev_opaque->channel_attr_list);
1255 		kfree(avail_postfix);
1256 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1257 			continue;
1258 		else if (ret < 0)
1259 			return ret;
1260 		attrcount++;
1261 	}
1262 
1263 	return attrcount;
1264 }
1265 
1266 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1267 					struct iio_chan_spec const *chan)
1268 {
1269 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1270 	int ret, attrcount = 0;
1271 	const struct iio_chan_spec_ext_info *ext_info;
1272 
1273 	if (chan->channel < 0)
1274 		return 0;
1275 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1276 					    IIO_SEPARATE,
1277 					    &chan->info_mask_separate);
1278 	if (ret < 0)
1279 		return ret;
1280 	attrcount += ret;
1281 
1282 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1283 						  IIO_SEPARATE,
1284 						  &chan->info_mask_separate_available);
1285 	if (ret < 0)
1286 		return ret;
1287 	attrcount += ret;
1288 
1289 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1290 					    IIO_SHARED_BY_TYPE,
1291 					    &chan->info_mask_shared_by_type);
1292 	if (ret < 0)
1293 		return ret;
1294 	attrcount += ret;
1295 
1296 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1297 						  IIO_SHARED_BY_TYPE,
1298 						  &chan->info_mask_shared_by_type_available);
1299 	if (ret < 0)
1300 		return ret;
1301 	attrcount += ret;
1302 
1303 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1304 					    IIO_SHARED_BY_DIR,
1305 					    &chan->info_mask_shared_by_dir);
1306 	if (ret < 0)
1307 		return ret;
1308 	attrcount += ret;
1309 
1310 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1311 						  IIO_SHARED_BY_DIR,
1312 						  &chan->info_mask_shared_by_dir_available);
1313 	if (ret < 0)
1314 		return ret;
1315 	attrcount += ret;
1316 
1317 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1318 					    IIO_SHARED_BY_ALL,
1319 					    &chan->info_mask_shared_by_all);
1320 	if (ret < 0)
1321 		return ret;
1322 	attrcount += ret;
1323 
1324 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1325 						  IIO_SHARED_BY_ALL,
1326 						  &chan->info_mask_shared_by_all_available);
1327 	if (ret < 0)
1328 		return ret;
1329 	attrcount += ret;
1330 
1331 	ret = iio_device_add_channel_label(indio_dev, chan);
1332 	if (ret < 0)
1333 		return ret;
1334 	attrcount += ret;
1335 
1336 	if (chan->ext_info) {
1337 		unsigned int i = 0;
1338 
1339 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1340 			ret = __iio_add_chan_devattr(ext_info->name,
1341 					chan,
1342 					ext_info->read ?
1343 					    &iio_read_channel_ext_info : NULL,
1344 					ext_info->write ?
1345 					    &iio_write_channel_ext_info : NULL,
1346 					i,
1347 					ext_info->shared,
1348 					&indio_dev->dev,
1349 					NULL,
1350 					&iio_dev_opaque->channel_attr_list);
1351 			i++;
1352 			if (ret == -EBUSY && ext_info->shared)
1353 				continue;
1354 
1355 			if (ret)
1356 				return ret;
1357 
1358 			attrcount++;
1359 		}
1360 	}
1361 
1362 	return attrcount;
1363 }
1364 
1365 /**
1366  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1367  * @attr_list: List of IIO device attributes
1368  *
1369  * This function frees the memory allocated for each of the IIO device
1370  * attributes in the list.
1371  */
1372 void iio_free_chan_devattr_list(struct list_head *attr_list)
1373 {
1374 	struct iio_dev_attr *p, *n;
1375 
1376 	list_for_each_entry_safe(p, n, attr_list, l) {
1377 		kfree_const(p->dev_attr.attr.name);
1378 		list_del(&p->l);
1379 		kfree(p);
1380 	}
1381 }
1382 
1383 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
1384 			 char *buf)
1385 {
1386 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1387 
1388 	return sysfs_emit(buf, "%s\n", indio_dev->name);
1389 }
1390 
1391 static DEVICE_ATTR_RO(name);
1392 
1393 static ssize_t label_show(struct device *dev, struct device_attribute *attr,
1394 			  char *buf)
1395 {
1396 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1397 
1398 	return sysfs_emit(buf, "%s\n", indio_dev->label);
1399 }
1400 
1401 static DEVICE_ATTR_RO(label);
1402 
1403 static ssize_t current_timestamp_clock_show(struct device *dev,
1404 					    struct device_attribute *attr,
1405 					    char *buf)
1406 {
1407 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1408 	const clockid_t clk = iio_device_get_clock(indio_dev);
1409 	const char *name;
1410 	ssize_t sz;
1411 
1412 	switch (clk) {
1413 	case CLOCK_REALTIME:
1414 		name = "realtime\n";
1415 		sz = sizeof("realtime\n");
1416 		break;
1417 	case CLOCK_MONOTONIC:
1418 		name = "monotonic\n";
1419 		sz = sizeof("monotonic\n");
1420 		break;
1421 	case CLOCK_MONOTONIC_RAW:
1422 		name = "monotonic_raw\n";
1423 		sz = sizeof("monotonic_raw\n");
1424 		break;
1425 	case CLOCK_REALTIME_COARSE:
1426 		name = "realtime_coarse\n";
1427 		sz = sizeof("realtime_coarse\n");
1428 		break;
1429 	case CLOCK_MONOTONIC_COARSE:
1430 		name = "monotonic_coarse\n";
1431 		sz = sizeof("monotonic_coarse\n");
1432 		break;
1433 	case CLOCK_BOOTTIME:
1434 		name = "boottime\n";
1435 		sz = sizeof("boottime\n");
1436 		break;
1437 	case CLOCK_TAI:
1438 		name = "tai\n";
1439 		sz = sizeof("tai\n");
1440 		break;
1441 	default:
1442 		BUG();
1443 	}
1444 
1445 	memcpy(buf, name, sz);
1446 	return sz;
1447 }
1448 
1449 static ssize_t current_timestamp_clock_store(struct device *dev,
1450 					     struct device_attribute *attr,
1451 					     const char *buf, size_t len)
1452 {
1453 	clockid_t clk;
1454 	int ret;
1455 
1456 	if (sysfs_streq(buf, "realtime"))
1457 		clk = CLOCK_REALTIME;
1458 	else if (sysfs_streq(buf, "monotonic"))
1459 		clk = CLOCK_MONOTONIC;
1460 	else if (sysfs_streq(buf, "monotonic_raw"))
1461 		clk = CLOCK_MONOTONIC_RAW;
1462 	else if (sysfs_streq(buf, "realtime_coarse"))
1463 		clk = CLOCK_REALTIME_COARSE;
1464 	else if (sysfs_streq(buf, "monotonic_coarse"))
1465 		clk = CLOCK_MONOTONIC_COARSE;
1466 	else if (sysfs_streq(buf, "boottime"))
1467 		clk = CLOCK_BOOTTIME;
1468 	else if (sysfs_streq(buf, "tai"))
1469 		clk = CLOCK_TAI;
1470 	else
1471 		return -EINVAL;
1472 
1473 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1474 	if (ret)
1475 		return ret;
1476 
1477 	return len;
1478 }
1479 
1480 int iio_device_register_sysfs_group(struct iio_dev *indio_dev,
1481 				    const struct attribute_group *group)
1482 {
1483 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1484 	const struct attribute_group **new, **old = iio_dev_opaque->groups;
1485 	unsigned int cnt = iio_dev_opaque->groupcounter;
1486 
1487 	new = krealloc(old, sizeof(*new) * (cnt + 2), GFP_KERNEL);
1488 	if (!new)
1489 		return -ENOMEM;
1490 
1491 	new[iio_dev_opaque->groupcounter++] = group;
1492 	new[iio_dev_opaque->groupcounter] = NULL;
1493 
1494 	iio_dev_opaque->groups = new;
1495 
1496 	return 0;
1497 }
1498 
1499 static DEVICE_ATTR_RW(current_timestamp_clock);
1500 
1501 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1502 {
1503 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1504 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1505 	struct iio_dev_attr *p;
1506 	struct attribute **attr, *clk = NULL;
1507 
1508 	/* First count elements in any existing group */
1509 	if (indio_dev->info->attrs) {
1510 		attr = indio_dev->info->attrs->attrs;
1511 		while (*attr++ != NULL)
1512 			attrcount_orig++;
1513 	}
1514 	attrcount = attrcount_orig;
1515 	/*
1516 	 * New channel registration method - relies on the fact a group does
1517 	 * not need to be initialized if its name is NULL.
1518 	 */
1519 	if (indio_dev->channels)
1520 		for (i = 0; i < indio_dev->num_channels; i++) {
1521 			const struct iio_chan_spec *chan =
1522 				&indio_dev->channels[i];
1523 
1524 			if (chan->type == IIO_TIMESTAMP)
1525 				clk = &dev_attr_current_timestamp_clock.attr;
1526 
1527 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1528 			if (ret < 0)
1529 				goto error_clear_attrs;
1530 			attrcount += ret;
1531 		}
1532 
1533 	if (iio_dev_opaque->event_interface)
1534 		clk = &dev_attr_current_timestamp_clock.attr;
1535 
1536 	if (indio_dev->name)
1537 		attrcount++;
1538 	if (indio_dev->label)
1539 		attrcount++;
1540 	if (clk)
1541 		attrcount++;
1542 
1543 	iio_dev_opaque->chan_attr_group.attrs =
1544 		kcalloc(attrcount + 1,
1545 			sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
1546 			GFP_KERNEL);
1547 	if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
1548 		ret = -ENOMEM;
1549 		goto error_clear_attrs;
1550 	}
1551 	/* Copy across original attributes, and point to original binary attributes */
1552 	if (indio_dev->info->attrs) {
1553 		memcpy(iio_dev_opaque->chan_attr_group.attrs,
1554 		       indio_dev->info->attrs->attrs,
1555 		       sizeof(iio_dev_opaque->chan_attr_group.attrs[0])
1556 		       *attrcount_orig);
1557 		iio_dev_opaque->chan_attr_group.is_visible =
1558 			indio_dev->info->attrs->is_visible;
1559 		iio_dev_opaque->chan_attr_group.bin_attrs =
1560 			indio_dev->info->attrs->bin_attrs;
1561 	}
1562 	attrn = attrcount_orig;
1563 	/* Add all elements from the list. */
1564 	list_for_each_entry(p, &iio_dev_opaque->channel_attr_list, l)
1565 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1566 	if (indio_dev->name)
1567 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1568 	if (indio_dev->label)
1569 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1570 	if (clk)
1571 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk;
1572 
1573 	ret = iio_device_register_sysfs_group(indio_dev,
1574 					      &iio_dev_opaque->chan_attr_group);
1575 	if (ret)
1576 		goto error_clear_attrs;
1577 
1578 	return 0;
1579 
1580 error_clear_attrs:
1581 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1582 
1583 	return ret;
1584 }
1585 
1586 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1587 {
1588 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1589 
1590 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1591 	kfree(iio_dev_opaque->chan_attr_group.attrs);
1592 	iio_dev_opaque->chan_attr_group.attrs = NULL;
1593 	kfree(iio_dev_opaque->groups);
1594 	iio_dev_opaque->groups = NULL;
1595 }
1596 
1597 static void iio_dev_release(struct device *device)
1598 {
1599 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1600 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1601 
1602 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1603 		iio_device_unregister_trigger_consumer(indio_dev);
1604 	iio_device_unregister_eventset(indio_dev);
1605 	iio_device_unregister_sysfs(indio_dev);
1606 
1607 	iio_device_detach_buffers(indio_dev);
1608 
1609 	lockdep_unregister_key(&iio_dev_opaque->mlock_key);
1610 
1611 	ida_free(&iio_ida, iio_dev_opaque->id);
1612 	kfree(iio_dev_opaque);
1613 }
1614 
1615 const struct device_type iio_device_type = {
1616 	.name = "iio_device",
1617 	.release = iio_dev_release,
1618 };
1619 
1620 /**
1621  * iio_device_alloc() - allocate an iio_dev from a driver
1622  * @parent:		Parent device.
1623  * @sizeof_priv:	Space to allocate for private structure.
1624  **/
1625 struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
1626 {
1627 	struct iio_dev_opaque *iio_dev_opaque;
1628 	struct iio_dev *indio_dev;
1629 	size_t alloc_size;
1630 
1631 	alloc_size = sizeof(struct iio_dev_opaque);
1632 	if (sizeof_priv) {
1633 		alloc_size = ALIGN(alloc_size, IIO_DMA_MINALIGN);
1634 		alloc_size += sizeof_priv;
1635 	}
1636 
1637 	iio_dev_opaque = kzalloc(alloc_size, GFP_KERNEL);
1638 	if (!iio_dev_opaque)
1639 		return NULL;
1640 
1641 	indio_dev = &iio_dev_opaque->indio_dev;
1642 	indio_dev->priv = (char *)iio_dev_opaque +
1643 		ALIGN(sizeof(struct iio_dev_opaque), IIO_DMA_MINALIGN);
1644 
1645 	indio_dev->dev.parent = parent;
1646 	indio_dev->dev.type = &iio_device_type;
1647 	indio_dev->dev.bus = &iio_bus_type;
1648 	device_initialize(&indio_dev->dev);
1649 	mutex_init(&iio_dev_opaque->mlock);
1650 	mutex_init(&iio_dev_opaque->info_exist_lock);
1651 	INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
1652 
1653 	iio_dev_opaque->id = ida_alloc(&iio_ida, GFP_KERNEL);
1654 	if (iio_dev_opaque->id < 0) {
1655 		/* cannot use a dev_err as the name isn't available */
1656 		pr_err("failed to get device id\n");
1657 		kfree(iio_dev_opaque);
1658 		return NULL;
1659 	}
1660 
1661 	if (dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id)) {
1662 		ida_free(&iio_ida, iio_dev_opaque->id);
1663 		kfree(iio_dev_opaque);
1664 		return NULL;
1665 	}
1666 
1667 	INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
1668 	INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);
1669 
1670 	lockdep_register_key(&iio_dev_opaque->mlock_key);
1671 	lockdep_set_class(&iio_dev_opaque->mlock, &iio_dev_opaque->mlock_key);
1672 
1673 	return indio_dev;
1674 }
1675 EXPORT_SYMBOL(iio_device_alloc);
1676 
1677 /**
1678  * iio_device_free() - free an iio_dev from a driver
1679  * @dev:		the iio_dev associated with the device
1680  **/
1681 void iio_device_free(struct iio_dev *dev)
1682 {
1683 	if (dev)
1684 		put_device(&dev->dev);
1685 }
1686 EXPORT_SYMBOL(iio_device_free);
1687 
1688 static void devm_iio_device_release(void *iio_dev)
1689 {
1690 	iio_device_free(iio_dev);
1691 }
1692 
1693 /**
1694  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1695  * @parent:		Device to allocate iio_dev for, and parent for this IIO device
1696  * @sizeof_priv:	Space to allocate for private structure.
1697  *
1698  * Managed iio_device_alloc. iio_dev allocated with this function is
1699  * automatically freed on driver detach.
1700  *
1701  * RETURNS:
1702  * Pointer to allocated iio_dev on success, NULL on failure.
1703  */
1704 struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
1705 {
1706 	struct iio_dev *iio_dev;
1707 	int ret;
1708 
1709 	iio_dev = iio_device_alloc(parent, sizeof_priv);
1710 	if (!iio_dev)
1711 		return NULL;
1712 
1713 	ret = devm_add_action_or_reset(parent, devm_iio_device_release,
1714 				       iio_dev);
1715 	if (ret)
1716 		return NULL;
1717 
1718 	return iio_dev;
1719 }
1720 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1721 
1722 /**
1723  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1724  * @inode:	Inode structure for identifying the device in the file system
1725  * @filp:	File structure for iio device used to keep and later access
1726  *		private data
1727  *
1728  * Return: 0 on success or -EBUSY if the device is already opened
1729  **/
1730 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1731 {
1732 	struct iio_dev_opaque *iio_dev_opaque =
1733 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1734 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1735 	struct iio_dev_buffer_pair *ib;
1736 
1737 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags))
1738 		return -EBUSY;
1739 
1740 	iio_device_get(indio_dev);
1741 
1742 	ib = kmalloc(sizeof(*ib), GFP_KERNEL);
1743 	if (!ib) {
1744 		iio_device_put(indio_dev);
1745 		clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1746 		return -ENOMEM;
1747 	}
1748 
1749 	ib->indio_dev = indio_dev;
1750 	ib->buffer = indio_dev->buffer;
1751 
1752 	filp->private_data = ib;
1753 
1754 	return 0;
1755 }
1756 
1757 /**
1758  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1759  * @inode:	Inode structure pointer for the char device
1760  * @filp:	File structure pointer for the char device
1761  *
1762  * Return: 0 for successful release
1763  */
1764 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1765 {
1766 	struct iio_dev_buffer_pair *ib = filp->private_data;
1767 	struct iio_dev_opaque *iio_dev_opaque =
1768 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1769 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1770 
1771 	kfree(ib);
1772 	clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1773 	iio_device_put(indio_dev);
1774 
1775 	return 0;
1776 }
1777 
1778 void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
1779 				       struct iio_ioctl_handler *h)
1780 {
1781 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1782 
1783 	list_add_tail(&h->entry, &iio_dev_opaque->ioctl_handlers);
1784 }
1785 
1786 void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h)
1787 {
1788 	list_del(&h->entry);
1789 }
1790 
1791 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1792 {
1793 	struct iio_dev_buffer_pair *ib = filp->private_data;
1794 	struct iio_dev *indio_dev = ib->indio_dev;
1795 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1796 	struct iio_ioctl_handler *h;
1797 	int ret = -ENODEV;
1798 
1799 	mutex_lock(&iio_dev_opaque->info_exist_lock);
1800 
1801 	/**
1802 	 * The NULL check here is required to prevent crashing when a device
1803 	 * is being removed while userspace would still have open file handles
1804 	 * to try to access this device.
1805 	 */
1806 	if (!indio_dev->info)
1807 		goto out_unlock;
1808 
1809 	list_for_each_entry(h, &iio_dev_opaque->ioctl_handlers, entry) {
1810 		ret = h->ioctl(indio_dev, filp, cmd, arg);
1811 		if (ret != IIO_IOCTL_UNHANDLED)
1812 			break;
1813 	}
1814 
1815 	if (ret == IIO_IOCTL_UNHANDLED)
1816 		ret = -ENODEV;
1817 
1818 out_unlock:
1819 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
1820 
1821 	return ret;
1822 }
1823 
1824 static const struct file_operations iio_buffer_fileops = {
1825 	.owner = THIS_MODULE,
1826 	.llseek = noop_llseek,
1827 	.read = iio_buffer_read_outer_addr,
1828 	.write = iio_buffer_write_outer_addr,
1829 	.poll = iio_buffer_poll_addr,
1830 	.unlocked_ioctl = iio_ioctl,
1831 	.compat_ioctl = compat_ptr_ioctl,
1832 	.open = iio_chrdev_open,
1833 	.release = iio_chrdev_release,
1834 };
1835 
1836 static const struct file_operations iio_event_fileops = {
1837 	.owner = THIS_MODULE,
1838 	.llseek = noop_llseek,
1839 	.unlocked_ioctl = iio_ioctl,
1840 	.compat_ioctl = compat_ptr_ioctl,
1841 	.open = iio_chrdev_open,
1842 	.release = iio_chrdev_release,
1843 };
1844 
1845 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1846 {
1847 	int i, j;
1848 	const struct iio_chan_spec *channels = indio_dev->channels;
1849 
1850 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1851 		return 0;
1852 
1853 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1854 		if (channels[i].scan_index < 0)
1855 			continue;
1856 		for (j = i + 1; j < indio_dev->num_channels; j++)
1857 			if (channels[i].scan_index == channels[j].scan_index) {
1858 				dev_err(&indio_dev->dev,
1859 					"Duplicate scan index %d\n",
1860 					channels[i].scan_index);
1861 				return -EINVAL;
1862 			}
1863 	}
1864 
1865 	return 0;
1866 }
1867 
1868 static int iio_check_extended_name(const struct iio_dev *indio_dev)
1869 {
1870 	unsigned int i;
1871 
1872 	if (!indio_dev->info->read_label)
1873 		return 0;
1874 
1875 	for (i = 0; i < indio_dev->num_channels; i++) {
1876 		if (indio_dev->channels[i].extend_name) {
1877 			dev_err(&indio_dev->dev,
1878 				"Cannot use labels and extend_name at the same time\n");
1879 			return -EINVAL;
1880 		}
1881 	}
1882 
1883 	return 0;
1884 }
1885 
1886 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1887 
1888 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1889 {
1890 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1891 	struct fwnode_handle *fwnode;
1892 	int ret;
1893 
1894 	if (!indio_dev->info)
1895 		return -EINVAL;
1896 
1897 	iio_dev_opaque->driver_module = this_mod;
1898 
1899 	/* If the calling driver did not initialize firmware node, do it here */
1900 	if (dev_fwnode(&indio_dev->dev))
1901 		fwnode = dev_fwnode(&indio_dev->dev);
1902 	else
1903 		fwnode = dev_fwnode(indio_dev->dev.parent);
1904 	device_set_node(&indio_dev->dev, fwnode);
1905 
1906 	fwnode_property_read_string(fwnode, "label", &indio_dev->label);
1907 
1908 	ret = iio_check_unique_scan_index(indio_dev);
1909 	if (ret < 0)
1910 		return ret;
1911 
1912 	ret = iio_check_extended_name(indio_dev);
1913 	if (ret < 0)
1914 		return ret;
1915 
1916 	iio_device_register_debugfs(indio_dev);
1917 
1918 	ret = iio_buffers_alloc_sysfs_and_mask(indio_dev);
1919 	if (ret) {
1920 		dev_err(indio_dev->dev.parent,
1921 			"Failed to create buffer sysfs interfaces\n");
1922 		goto error_unreg_debugfs;
1923 	}
1924 
1925 	ret = iio_device_register_sysfs(indio_dev);
1926 	if (ret) {
1927 		dev_err(indio_dev->dev.parent,
1928 			"Failed to register sysfs interfaces\n");
1929 		goto error_buffer_free_sysfs;
1930 	}
1931 	ret = iio_device_register_eventset(indio_dev);
1932 	if (ret) {
1933 		dev_err(indio_dev->dev.parent,
1934 			"Failed to register event set\n");
1935 		goto error_free_sysfs;
1936 	}
1937 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1938 		iio_device_register_trigger_consumer(indio_dev);
1939 
1940 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1941 		indio_dev->setup_ops == NULL)
1942 		indio_dev->setup_ops = &noop_ring_setup_ops;
1943 
1944 	if (iio_dev_opaque->attached_buffers_cnt)
1945 		cdev_init(&iio_dev_opaque->chrdev, &iio_buffer_fileops);
1946 	else if (iio_dev_opaque->event_interface)
1947 		cdev_init(&iio_dev_opaque->chrdev, &iio_event_fileops);
1948 
1949 	if (iio_dev_opaque->attached_buffers_cnt || iio_dev_opaque->event_interface) {
1950 		indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), iio_dev_opaque->id);
1951 		iio_dev_opaque->chrdev.owner = this_mod;
1952 	}
1953 
1954 	/* assign device groups now; they should be all registered now */
1955 	indio_dev->dev.groups = iio_dev_opaque->groups;
1956 
1957 	ret = cdev_device_add(&iio_dev_opaque->chrdev, &indio_dev->dev);
1958 	if (ret < 0)
1959 		goto error_unreg_eventset;
1960 
1961 	return 0;
1962 
1963 error_unreg_eventset:
1964 	iio_device_unregister_eventset(indio_dev);
1965 error_free_sysfs:
1966 	iio_device_unregister_sysfs(indio_dev);
1967 error_buffer_free_sysfs:
1968 	iio_buffers_free_sysfs_and_mask(indio_dev);
1969 error_unreg_debugfs:
1970 	iio_device_unregister_debugfs(indio_dev);
1971 	return ret;
1972 }
1973 EXPORT_SYMBOL(__iio_device_register);
1974 
1975 /**
1976  * iio_device_unregister() - unregister a device from the IIO subsystem
1977  * @indio_dev:		Device structure representing the device.
1978  **/
1979 void iio_device_unregister(struct iio_dev *indio_dev)
1980 {
1981 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1982 
1983 	cdev_device_del(&iio_dev_opaque->chrdev, &indio_dev->dev);
1984 
1985 	mutex_lock(&iio_dev_opaque->info_exist_lock);
1986 
1987 	iio_device_unregister_debugfs(indio_dev);
1988 
1989 	iio_disable_all_buffers(indio_dev);
1990 
1991 	indio_dev->info = NULL;
1992 
1993 	iio_device_wakeup_eventset(indio_dev);
1994 	iio_buffer_wakeup_poll(indio_dev);
1995 
1996 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
1997 
1998 	iio_buffers_free_sysfs_and_mask(indio_dev);
1999 }
2000 EXPORT_SYMBOL(iio_device_unregister);
2001 
2002 static void devm_iio_device_unreg(void *indio_dev)
2003 {
2004 	iio_device_unregister(indio_dev);
2005 }
2006 
2007 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
2008 			       struct module *this_mod)
2009 {
2010 	int ret;
2011 
2012 	ret = __iio_device_register(indio_dev, this_mod);
2013 	if (ret)
2014 		return ret;
2015 
2016 	return devm_add_action_or_reset(dev, devm_iio_device_unreg, indio_dev);
2017 }
2018 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
2019 
2020 /**
2021  * iio_device_claim_direct_mode - Keep device in direct mode
2022  * @indio_dev:	the iio_dev associated with the device
2023  *
2024  * If the device is in direct mode it is guaranteed to stay
2025  * that way until iio_device_release_direct_mode() is called.
2026  *
2027  * Use with iio_device_release_direct_mode()
2028  *
2029  * Returns: 0 on success, -EBUSY on failure
2030  */
2031 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
2032 {
2033 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2034 
2035 	mutex_lock(&iio_dev_opaque->mlock);
2036 
2037 	if (iio_buffer_enabled(indio_dev)) {
2038 		mutex_unlock(&iio_dev_opaque->mlock);
2039 		return -EBUSY;
2040 	}
2041 	return 0;
2042 }
2043 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
2044 
2045 /**
2046  * iio_device_release_direct_mode - releases claim on direct mode
2047  * @indio_dev:	the iio_dev associated with the device
2048  *
2049  * Release the claim. Device is no longer guaranteed to stay
2050  * in direct mode.
2051  *
2052  * Use with iio_device_claim_direct_mode()
2053  */
2054 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
2055 {
2056 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2057 }
2058 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
2059 
2060 /**
2061  * iio_device_claim_buffer_mode - Keep device in buffer mode
2062  * @indio_dev:	the iio_dev associated with the device
2063  *
2064  * If the device is in buffer mode it is guaranteed to stay
2065  * that way until iio_device_release_buffer_mode() is called.
2066  *
2067  * Use with iio_device_release_buffer_mode().
2068  *
2069  * Returns: 0 on success, -EBUSY on failure.
2070  */
2071 int iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
2072 {
2073 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2074 
2075 	mutex_lock(&iio_dev_opaque->mlock);
2076 
2077 	if (iio_buffer_enabled(indio_dev))
2078 		return 0;
2079 
2080 	mutex_unlock(&iio_dev_opaque->mlock);
2081 	return -EBUSY;
2082 }
2083 EXPORT_SYMBOL_GPL(iio_device_claim_buffer_mode);
2084 
2085 /**
2086  * iio_device_release_buffer_mode - releases claim on buffer mode
2087  * @indio_dev:	the iio_dev associated with the device
2088  *
2089  * Release the claim. Device is no longer guaranteed to stay
2090  * in buffer mode.
2091  *
2092  * Use with iio_device_claim_buffer_mode().
2093  */
2094 void iio_device_release_buffer_mode(struct iio_dev *indio_dev)
2095 {
2096 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2097 }
2098 EXPORT_SYMBOL_GPL(iio_device_release_buffer_mode);
2099 
2100 /**
2101  * iio_device_get_current_mode() - helper function providing read-only access to
2102  *				   the opaque @currentmode variable
2103  * @indio_dev:			   IIO device structure for device
2104  */
2105 int iio_device_get_current_mode(struct iio_dev *indio_dev)
2106 {
2107 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2108 
2109 	return iio_dev_opaque->currentmode;
2110 }
2111 EXPORT_SYMBOL_GPL(iio_device_get_current_mode);
2112 
2113 subsys_initcall(iio_init);
2114 module_exit(iio_exit);
2115 
2116 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
2117 MODULE_DESCRIPTION("Industrial I/O core");
2118 MODULE_LICENSE("GPL");
2119