1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * The industrial I/O core
4  *
5  * Copyright (c) 2008 Jonathan Cameron
6  *
7  * Based on elements of hwmon and input subsystems.
8  */
9 
10 #define pr_fmt(fmt) "iio-core: " fmt
11 
12 #include <linux/anon_inodes.h>
13 #include <linux/cdev.h>
14 #include <linux/debugfs.h>
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/fs.h>
18 #include <linux/idr.h>
19 #include <linux/kdev_t.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/mutex.h>
23 #include <linux/poll.h>
24 #include <linux/property.h>
25 #include <linux/sched.h>
26 #include <linux/slab.h>
27 #include <linux/wait.h>
28 
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/buffer_impl.h>
31 #include <linux/iio/events.h>
32 #include <linux/iio/iio-opaque.h>
33 #include <linux/iio/iio.h>
34 #include <linux/iio/sysfs.h>
35 
36 #include "iio_core.h"
37 #include "iio_core_trigger.h"
38 
39 /* IDA to assign each registered device a unique id */
40 static DEFINE_IDA(iio_ida);
41 
42 static dev_t iio_devt;
43 
44 #define IIO_DEV_MAX 256
45 struct bus_type iio_bus_type = {
46 	.name = "iio",
47 };
48 EXPORT_SYMBOL(iio_bus_type);
49 
50 static struct dentry *iio_debugfs_dentry;
51 
52 static const char * const iio_direction[] = {
53 	[0] = "in",
54 	[1] = "out",
55 };
56 
57 static const char * const iio_chan_type_name_spec[] = {
58 	[IIO_VOLTAGE] = "voltage",
59 	[IIO_CURRENT] = "current",
60 	[IIO_POWER] = "power",
61 	[IIO_ACCEL] = "accel",
62 	[IIO_ANGL_VEL] = "anglvel",
63 	[IIO_MAGN] = "magn",
64 	[IIO_LIGHT] = "illuminance",
65 	[IIO_INTENSITY] = "intensity",
66 	[IIO_PROXIMITY] = "proximity",
67 	[IIO_TEMP] = "temp",
68 	[IIO_INCLI] = "incli",
69 	[IIO_ROT] = "rot",
70 	[IIO_ANGL] = "angl",
71 	[IIO_TIMESTAMP] = "timestamp",
72 	[IIO_CAPACITANCE] = "capacitance",
73 	[IIO_ALTVOLTAGE] = "altvoltage",
74 	[IIO_CCT] = "cct",
75 	[IIO_PRESSURE] = "pressure",
76 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
77 	[IIO_ACTIVITY] = "activity",
78 	[IIO_STEPS] = "steps",
79 	[IIO_ENERGY] = "energy",
80 	[IIO_DISTANCE] = "distance",
81 	[IIO_VELOCITY] = "velocity",
82 	[IIO_CONCENTRATION] = "concentration",
83 	[IIO_RESISTANCE] = "resistance",
84 	[IIO_PH] = "ph",
85 	[IIO_UVINDEX] = "uvindex",
86 	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
87 	[IIO_COUNT] = "count",
88 	[IIO_INDEX] = "index",
89 	[IIO_GRAVITY]  = "gravity",
90 	[IIO_POSITIONRELATIVE]  = "positionrelative",
91 	[IIO_PHASE] = "phase",
92 	[IIO_MASSCONCENTRATION] = "massconcentration",
93 };
94 
95 static const char * const iio_modifier_names[] = {
96 	[IIO_MOD_X] = "x",
97 	[IIO_MOD_Y] = "y",
98 	[IIO_MOD_Z] = "z",
99 	[IIO_MOD_X_AND_Y] = "x&y",
100 	[IIO_MOD_X_AND_Z] = "x&z",
101 	[IIO_MOD_Y_AND_Z] = "y&z",
102 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
103 	[IIO_MOD_X_OR_Y] = "x|y",
104 	[IIO_MOD_X_OR_Z] = "x|z",
105 	[IIO_MOD_Y_OR_Z] = "y|z",
106 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
107 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
108 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
109 	[IIO_MOD_LIGHT_BOTH] = "both",
110 	[IIO_MOD_LIGHT_IR] = "ir",
111 	[IIO_MOD_LIGHT_CLEAR] = "clear",
112 	[IIO_MOD_LIGHT_RED] = "red",
113 	[IIO_MOD_LIGHT_GREEN] = "green",
114 	[IIO_MOD_LIGHT_BLUE] = "blue",
115 	[IIO_MOD_LIGHT_UV] = "uv",
116 	[IIO_MOD_LIGHT_DUV] = "duv",
117 	[IIO_MOD_QUATERNION] = "quaternion",
118 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
119 	[IIO_MOD_TEMP_OBJECT] = "object",
120 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
121 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
122 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
123 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
124 	[IIO_MOD_RUNNING] = "running",
125 	[IIO_MOD_JOGGING] = "jogging",
126 	[IIO_MOD_WALKING] = "walking",
127 	[IIO_MOD_STILL] = "still",
128 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
129 	[IIO_MOD_I] = "i",
130 	[IIO_MOD_Q] = "q",
131 	[IIO_MOD_CO2] = "co2",
132 	[IIO_MOD_VOC] = "voc",
133 	[IIO_MOD_PM1] = "pm1",
134 	[IIO_MOD_PM2P5] = "pm2p5",
135 	[IIO_MOD_PM4] = "pm4",
136 	[IIO_MOD_PM10] = "pm10",
137 	[IIO_MOD_ETHANOL] = "ethanol",
138 	[IIO_MOD_H2] = "h2",
139 	[IIO_MOD_O2] = "o2",
140 	[IIO_MOD_LINEAR_X] = "linear_x",
141 	[IIO_MOD_LINEAR_Y] = "linear_y",
142 	[IIO_MOD_LINEAR_Z] = "linear_z",
143 	[IIO_MOD_PITCH] = "pitch",
144 	[IIO_MOD_YAW] = "yaw",
145 	[IIO_MOD_ROLL] = "roll",
146 };
147 
148 /* relies on pairs of these shared then separate */
149 static const char * const iio_chan_info_postfix[] = {
150 	[IIO_CHAN_INFO_RAW] = "raw",
151 	[IIO_CHAN_INFO_PROCESSED] = "input",
152 	[IIO_CHAN_INFO_SCALE] = "scale",
153 	[IIO_CHAN_INFO_OFFSET] = "offset",
154 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
155 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
156 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
157 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
158 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
159 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
160 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
161 	= "filter_low_pass_3db_frequency",
162 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
163 	= "filter_high_pass_3db_frequency",
164 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
165 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
166 	[IIO_CHAN_INFO_PHASE] = "phase",
167 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
168 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
169 	[IIO_CHAN_INFO_HYSTERESIS_RELATIVE] = "hysteresis_relative",
170 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
171 	[IIO_CHAN_INFO_ENABLE] = "en",
172 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
173 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
174 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
175 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
176 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
177 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
178 	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
179 	[IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
180 	[IIO_CHAN_INFO_ZEROPOINT] = "zeropoint",
181 };
182 /**
183  * iio_device_id() - query the unique ID for the device
184  * @indio_dev:		Device structure whose ID is being queried
185  *
186  * The IIO device ID is a unique index used for example for the naming
187  * of the character device /dev/iio\:device[ID].
188  *
189  * Returns: Unique ID for the device.
190  */
191 int iio_device_id(struct iio_dev *indio_dev)
192 {
193 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
194 
195 	return iio_dev_opaque->id;
196 }
197 EXPORT_SYMBOL_GPL(iio_device_id);
198 
199 /**
200  * iio_buffer_enabled() - helper function to test if the buffer is enabled
201  * @indio_dev:		IIO device structure for device
202  *
203  * Returns: True, if the buffer is enabled.
204  */
205 bool iio_buffer_enabled(struct iio_dev *indio_dev)
206 {
207 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
208 
209 	return iio_dev_opaque->currentmode &
210 	       (INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE |
211 		INDIO_BUFFER_TRIGGERED);
212 }
213 EXPORT_SYMBOL_GPL(iio_buffer_enabled);
214 
215 #if defined(CONFIG_DEBUG_FS)
216 /*
217  * There's also a CONFIG_DEBUG_FS guard in include/linux/iio/iio.h for
218  * iio_get_debugfs_dentry() to make it inline if CONFIG_DEBUG_FS is undefined
219  */
220 struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
221 {
222 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
223 
224 	return iio_dev_opaque->debugfs_dentry;
225 }
226 EXPORT_SYMBOL_GPL(iio_get_debugfs_dentry);
227 #endif
228 
229 /**
230  * iio_find_channel_from_si() - get channel from its scan index
231  * @indio_dev:		device
232  * @si:			scan index to match
233  *
234  * Returns:
235  * Constant pointer to iio_chan_spec, if scan index matches, NULL on failure.
236  */
237 const struct iio_chan_spec
238 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
239 {
240 	int i;
241 
242 	for (i = 0; i < indio_dev->num_channels; i++)
243 		if (indio_dev->channels[i].scan_index == si)
244 			return &indio_dev->channels[i];
245 	return NULL;
246 }
247 
248 /* This turns up an awful lot */
249 ssize_t iio_read_const_attr(struct device *dev,
250 			    struct device_attribute *attr,
251 			    char *buf)
252 {
253 	return sysfs_emit(buf, "%s\n", to_iio_const_attr(attr)->string);
254 }
255 EXPORT_SYMBOL(iio_read_const_attr);
256 
257 /**
258  * iio_device_set_clock() - Set current timestamping clock for the device
259  * @indio_dev: IIO device structure containing the device
260  * @clock_id: timestamping clock POSIX identifier to set.
261  *
262  * Returns: 0 on success, or a negative error code.
263  */
264 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
265 {
266 	int ret;
267 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
268 	const struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
269 
270 	ret = mutex_lock_interruptible(&iio_dev_opaque->mlock);
271 	if (ret)
272 		return ret;
273 	if ((ev_int && iio_event_enabled(ev_int)) ||
274 	    iio_buffer_enabled(indio_dev)) {
275 		mutex_unlock(&iio_dev_opaque->mlock);
276 		return -EBUSY;
277 	}
278 	iio_dev_opaque->clock_id = clock_id;
279 	mutex_unlock(&iio_dev_opaque->mlock);
280 
281 	return 0;
282 }
283 EXPORT_SYMBOL(iio_device_set_clock);
284 
285 /**
286  * iio_device_get_clock() - Retrieve current timestamping clock for the device
287  * @indio_dev: IIO device structure containing the device
288  *
289  * Returns: Clock ID of the current timestamping clock for the device.
290  */
291 clockid_t iio_device_get_clock(const struct iio_dev *indio_dev)
292 {
293 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
294 
295 	return iio_dev_opaque->clock_id;
296 }
297 EXPORT_SYMBOL(iio_device_get_clock);
298 
299 /**
300  * iio_get_time_ns() - utility function to get a time stamp for events etc
301  * @indio_dev: device
302  *
303  * Returns: Timestamp of the event in nanoseconds.
304  */
305 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
306 {
307 	struct timespec64 tp;
308 
309 	switch (iio_device_get_clock(indio_dev)) {
310 	case CLOCK_REALTIME:
311 		return ktime_get_real_ns();
312 	case CLOCK_MONOTONIC:
313 		return ktime_get_ns();
314 	case CLOCK_MONOTONIC_RAW:
315 		return ktime_get_raw_ns();
316 	case CLOCK_REALTIME_COARSE:
317 		return ktime_to_ns(ktime_get_coarse_real());
318 	case CLOCK_MONOTONIC_COARSE:
319 		ktime_get_coarse_ts64(&tp);
320 		return timespec64_to_ns(&tp);
321 	case CLOCK_BOOTTIME:
322 		return ktime_get_boottime_ns();
323 	case CLOCK_TAI:
324 		return ktime_get_clocktai_ns();
325 	default:
326 		BUG();
327 	}
328 }
329 EXPORT_SYMBOL(iio_get_time_ns);
330 
331 static int __init iio_init(void)
332 {
333 	int ret;
334 
335 	/* Register sysfs bus */
336 	ret  = bus_register(&iio_bus_type);
337 	if (ret < 0) {
338 		pr_err("could not register bus type\n");
339 		goto error_nothing;
340 	}
341 
342 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
343 	if (ret < 0) {
344 		pr_err("failed to allocate char dev region\n");
345 		goto error_unregister_bus_type;
346 	}
347 
348 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
349 
350 	return 0;
351 
352 error_unregister_bus_type:
353 	bus_unregister(&iio_bus_type);
354 error_nothing:
355 	return ret;
356 }
357 
358 static void __exit iio_exit(void)
359 {
360 	if (iio_devt)
361 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
362 	bus_unregister(&iio_bus_type);
363 	debugfs_remove(iio_debugfs_dentry);
364 }
365 
366 #if defined(CONFIG_DEBUG_FS)
367 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
368 			      size_t count, loff_t *ppos)
369 {
370 	struct iio_dev *indio_dev = file->private_data;
371 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
372 	unsigned int val = 0;
373 	int ret;
374 
375 	if (*ppos > 0)
376 		return simple_read_from_buffer(userbuf, count, ppos,
377 					       iio_dev_opaque->read_buf,
378 					       iio_dev_opaque->read_buf_len);
379 
380 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
381 						  iio_dev_opaque->cached_reg_addr,
382 						  0, &val);
383 	if (ret) {
384 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
385 		return ret;
386 	}
387 
388 	iio_dev_opaque->read_buf_len = snprintf(iio_dev_opaque->read_buf,
389 						sizeof(iio_dev_opaque->read_buf),
390 						"0x%X\n", val);
391 
392 	return simple_read_from_buffer(userbuf, count, ppos,
393 				       iio_dev_opaque->read_buf,
394 				       iio_dev_opaque->read_buf_len);
395 }
396 
397 static ssize_t iio_debugfs_write_reg(struct file *file,
398 		     const char __user *userbuf, size_t count, loff_t *ppos)
399 {
400 	struct iio_dev *indio_dev = file->private_data;
401 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
402 	unsigned int reg, val;
403 	char buf[80];
404 	int ret;
405 
406 	count = min(count, sizeof(buf) - 1);
407 	if (copy_from_user(buf, userbuf, count))
408 		return -EFAULT;
409 
410 	buf[count] = 0;
411 
412 	ret = sscanf(buf, "%i %i", &reg, &val);
413 
414 	switch (ret) {
415 	case 1:
416 		iio_dev_opaque->cached_reg_addr = reg;
417 		break;
418 	case 2:
419 		iio_dev_opaque->cached_reg_addr = reg;
420 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
421 							  val, NULL);
422 		if (ret) {
423 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
424 				__func__);
425 			return ret;
426 		}
427 		break;
428 	default:
429 		return -EINVAL;
430 	}
431 
432 	return count;
433 }
434 
435 static const struct file_operations iio_debugfs_reg_fops = {
436 	.open = simple_open,
437 	.read = iio_debugfs_read_reg,
438 	.write = iio_debugfs_write_reg,
439 };
440 
441 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
442 {
443 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
444 
445 	debugfs_remove_recursive(iio_dev_opaque->debugfs_dentry);
446 }
447 
448 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
449 {
450 	struct iio_dev_opaque *iio_dev_opaque;
451 
452 	if (indio_dev->info->debugfs_reg_access == NULL)
453 		return;
454 
455 	if (!iio_debugfs_dentry)
456 		return;
457 
458 	iio_dev_opaque = to_iio_dev_opaque(indio_dev);
459 
460 	iio_dev_opaque->debugfs_dentry =
461 		debugfs_create_dir(dev_name(&indio_dev->dev),
462 				   iio_debugfs_dentry);
463 
464 	debugfs_create_file("direct_reg_access", 0644,
465 			    iio_dev_opaque->debugfs_dentry, indio_dev,
466 			    &iio_debugfs_reg_fops);
467 }
468 #else
469 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
470 {
471 }
472 
473 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
474 {
475 }
476 #endif /* CONFIG_DEBUG_FS */
477 
478 static ssize_t iio_read_channel_ext_info(struct device *dev,
479 				     struct device_attribute *attr,
480 				     char *buf)
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->read(indio_dev, ext_info->private, this_attr->c, buf);
489 }
490 
491 static ssize_t iio_write_channel_ext_info(struct device *dev,
492 				     struct device_attribute *attr,
493 				     const char *buf, size_t len)
494 {
495 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
496 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
497 	const struct iio_chan_spec_ext_info *ext_info;
498 
499 	ext_info = &this_attr->c->ext_info[this_attr->address];
500 
501 	return ext_info->write(indio_dev, ext_info->private,
502 			       this_attr->c, buf, len);
503 }
504 
505 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
506 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
507 {
508 	const struct iio_enum *e = (const struct iio_enum *)priv;
509 	unsigned int i;
510 	size_t len = 0;
511 
512 	if (!e->num_items)
513 		return 0;
514 
515 	for (i = 0; i < e->num_items; ++i) {
516 		if (!e->items[i])
517 			continue;
518 		len += sysfs_emit_at(buf, len, "%s ", e->items[i]);
519 	}
520 
521 	/* replace last space with a newline */
522 	buf[len - 1] = '\n';
523 
524 	return len;
525 }
526 EXPORT_SYMBOL_GPL(iio_enum_available_read);
527 
528 ssize_t iio_enum_read(struct iio_dev *indio_dev,
529 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
530 {
531 	const struct iio_enum *e = (const struct iio_enum *)priv;
532 	int i;
533 
534 	if (!e->get)
535 		return -EINVAL;
536 
537 	i = e->get(indio_dev, chan);
538 	if (i < 0)
539 		return i;
540 	if (i >= e->num_items || !e->items[i])
541 		return -EINVAL;
542 
543 	return sysfs_emit(buf, "%s\n", e->items[i]);
544 }
545 EXPORT_SYMBOL_GPL(iio_enum_read);
546 
547 ssize_t iio_enum_write(struct iio_dev *indio_dev,
548 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
549 	size_t len)
550 {
551 	const struct iio_enum *e = (const struct iio_enum *)priv;
552 	int ret;
553 
554 	if (!e->set)
555 		return -EINVAL;
556 
557 	ret = __sysfs_match_string(e->items, e->num_items, buf);
558 	if (ret < 0)
559 		return ret;
560 
561 	ret = e->set(indio_dev, chan, ret);
562 	return ret ? ret : len;
563 }
564 EXPORT_SYMBOL_GPL(iio_enum_write);
565 
566 static const struct iio_mount_matrix iio_mount_idmatrix = {
567 	.rotation = {
568 		"1", "0", "0",
569 		"0", "1", "0",
570 		"0", "0", "1"
571 	}
572 };
573 
574 static int iio_setup_mount_idmatrix(const struct device *dev,
575 				    struct iio_mount_matrix *matrix)
576 {
577 	*matrix = iio_mount_idmatrix;
578 	dev_info(dev, "mounting matrix not found: using identity...\n");
579 	return 0;
580 }
581 
582 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
583 			      const struct iio_chan_spec *chan, char *buf)
584 {
585 	const struct iio_mount_matrix *mtx;
586 
587 	mtx = ((iio_get_mount_matrix_t *)priv)(indio_dev, chan);
588 	if (IS_ERR(mtx))
589 		return PTR_ERR(mtx);
590 
591 	if (!mtx)
592 		mtx = &iio_mount_idmatrix;
593 
594 	return sysfs_emit(buf, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
595 			  mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
596 			  mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
597 			  mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
598 }
599 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
600 
601 /**
602  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
603  *                           device "mount-matrix" property
604  * @dev:	device the mounting matrix property is assigned to
605  * @matrix:	where to store retrieved matrix
606  *
607  * If device is assigned no mounting matrix property, a default 3x3 identity
608  * matrix will be filled in.
609  *
610  * Returns: 0 if success, or a negative error code on failure.
611  */
612 int iio_read_mount_matrix(struct device *dev, struct iio_mount_matrix *matrix)
613 {
614 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
615 	int err;
616 
617 	err = device_property_read_string_array(dev, "mount-matrix", matrix->rotation, len);
618 	if (err == len)
619 		return 0;
620 
621 	if (err >= 0)
622 		/* Invalid number of matrix entries. */
623 		return -EINVAL;
624 
625 	if (err != -EINVAL)
626 		/* Invalid matrix declaration format. */
627 		return err;
628 
629 	/* Matrix was not declared at all: fallback to identity. */
630 	return iio_setup_mount_idmatrix(dev, matrix);
631 }
632 EXPORT_SYMBOL(iio_read_mount_matrix);
633 
634 static ssize_t __iio_format_value(char *buf, size_t offset, unsigned int type,
635 				  int size, const int *vals)
636 {
637 	int tmp0, tmp1;
638 	s64 tmp2;
639 	bool scale_db = false;
640 
641 	switch (type) {
642 	case IIO_VAL_INT:
643 		return sysfs_emit_at(buf, offset, "%d", vals[0]);
644 	case IIO_VAL_INT_PLUS_MICRO_DB:
645 		scale_db = true;
646 		fallthrough;
647 	case IIO_VAL_INT_PLUS_MICRO:
648 		if (vals[1] < 0)
649 			return sysfs_emit_at(buf, offset, "-%d.%06u%s",
650 					     abs(vals[0]), -vals[1],
651 					     scale_db ? " dB" : "");
652 		else
653 			return sysfs_emit_at(buf, offset, "%d.%06u%s", vals[0],
654 					     vals[1], scale_db ? " dB" : "");
655 	case IIO_VAL_INT_PLUS_NANO:
656 		if (vals[1] < 0)
657 			return sysfs_emit_at(buf, offset, "-%d.%09u",
658 					     abs(vals[0]), -vals[1]);
659 		else
660 			return sysfs_emit_at(buf, offset, "%d.%09u", vals[0],
661 					     vals[1]);
662 	case IIO_VAL_FRACTIONAL:
663 		tmp2 = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
664 		tmp1 = vals[1];
665 		tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
666 		if ((tmp2 < 0) && (tmp0 == 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_FRACTIONAL_LOG2:
672 		tmp2 = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
673 		tmp0 = (int)div_s64_rem(tmp2, 1000000000LL, &tmp1);
674 		if (tmp0 == 0 && tmp2 < 0)
675 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
676 		else
677 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
678 					     abs(tmp1));
679 	case IIO_VAL_INT_MULTIPLE:
680 	{
681 		int i;
682 		int l = 0;
683 
684 		for (i = 0; i < size; ++i)
685 			l += sysfs_emit_at(buf, offset + l, "%d ", vals[i]);
686 		return l;
687 	}
688 	case IIO_VAL_CHAR:
689 		return sysfs_emit_at(buf, offset, "%c", (char)vals[0]);
690 	case IIO_VAL_INT_64:
691 		tmp2 = (s64)((((u64)vals[1]) << 32) | (u32)vals[0]);
692 		return sysfs_emit_at(buf, offset, "%lld", tmp2);
693 	default:
694 		return 0;
695 	}
696 }
697 
698 /**
699  * iio_format_value() - Formats a IIO value into its string representation
700  * @buf:	The buffer to which the formatted value gets written
701  *		which is assumed to be big enough (i.e. PAGE_SIZE).
702  * @type:	One of the IIO_VAL_* constants. This decides how the val
703  *		and val2 parameters are formatted.
704  * @size:	Number of IIO value entries contained in vals
705  * @vals:	Pointer to the values, exact meaning depends on the
706  *		type parameter.
707  *
708  * Returns:
709  * 0 by default, a negative number on failure or the total number of characters
710  * written for a type that belongs to the IIO_VAL_* constant.
711  */
712 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
713 {
714 	ssize_t len;
715 
716 	len = __iio_format_value(buf, 0, type, size, vals);
717 	if (len >= PAGE_SIZE - 1)
718 		return -EFBIG;
719 
720 	return len + sysfs_emit_at(buf, len, "\n");
721 }
722 EXPORT_SYMBOL_GPL(iio_format_value);
723 
724 static ssize_t iio_read_channel_label(struct device *dev,
725 				      struct device_attribute *attr,
726 				      char *buf)
727 {
728 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
729 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
730 
731 	if (indio_dev->info->read_label)
732 		return indio_dev->info->read_label(indio_dev, this_attr->c, buf);
733 
734 	if (this_attr->c->extend_name)
735 		return sysfs_emit(buf, "%s\n", this_attr->c->extend_name);
736 
737 	return -EINVAL;
738 }
739 
740 static ssize_t iio_read_channel_info(struct device *dev,
741 				     struct device_attribute *attr,
742 				     char *buf)
743 {
744 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
745 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
746 	int vals[INDIO_MAX_RAW_ELEMENTS];
747 	int ret;
748 	int val_len = 2;
749 
750 	if (indio_dev->info->read_raw_multi)
751 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
752 							INDIO_MAX_RAW_ELEMENTS,
753 							vals, &val_len,
754 							this_attr->address);
755 	else if (indio_dev->info->read_raw)
756 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
757 				    &vals[0], &vals[1], this_attr->address);
758 	else
759 		return -EINVAL;
760 
761 	if (ret < 0)
762 		return ret;
763 
764 	return iio_format_value(buf, ret, val_len, vals);
765 }
766 
767 static ssize_t iio_format_list(char *buf, const int *vals, int type, int length,
768 			       const char *prefix, const char *suffix)
769 {
770 	ssize_t len;
771 	int stride;
772 	int i;
773 
774 	switch (type) {
775 	case IIO_VAL_INT:
776 		stride = 1;
777 		break;
778 	default:
779 		stride = 2;
780 		break;
781 	}
782 
783 	len = sysfs_emit(buf, prefix);
784 
785 	for (i = 0; i <= length - stride; i += stride) {
786 		if (i != 0) {
787 			len += sysfs_emit_at(buf, len, " ");
788 			if (len >= PAGE_SIZE)
789 				return -EFBIG;
790 		}
791 
792 		len += __iio_format_value(buf, len, type, stride, &vals[i]);
793 		if (len >= PAGE_SIZE)
794 			return -EFBIG;
795 	}
796 
797 	len += sysfs_emit_at(buf, len, "%s\n", suffix);
798 
799 	return len;
800 }
801 
802 static ssize_t iio_format_avail_list(char *buf, const int *vals,
803 				     int type, int length)
804 {
805 
806 	return iio_format_list(buf, vals, type, length, "", "");
807 }
808 
809 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
810 {
811 	int length;
812 
813 	/*
814 	 * length refers to the array size , not the number of elements.
815 	 * The purpose is to print the range [min , step ,max] so length should
816 	 * be 3 in case of int, and 6 for other types.
817 	 */
818 	switch (type) {
819 	case IIO_VAL_INT:
820 		length = 3;
821 		break;
822 	default:
823 		length = 6;
824 		break;
825 	}
826 
827 	return iio_format_list(buf, vals, type, length, "[", "]");
828 }
829 
830 static ssize_t iio_read_channel_info_avail(struct device *dev,
831 					   struct device_attribute *attr,
832 					   char *buf)
833 {
834 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
835 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
836 	const int *vals;
837 	int ret;
838 	int length;
839 	int type;
840 
841 	if (!indio_dev->info->read_avail)
842 		return -EINVAL;
843 
844 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
845 					  &vals, &type, &length,
846 					  this_attr->address);
847 
848 	if (ret < 0)
849 		return ret;
850 	switch (ret) {
851 	case IIO_AVAIL_LIST:
852 		return iio_format_avail_list(buf, vals, type, length);
853 	case IIO_AVAIL_RANGE:
854 		return iio_format_avail_range(buf, vals, type);
855 	default:
856 		return -EINVAL;
857 	}
858 }
859 
860 /**
861  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
862  * @str: The string to parse
863  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
864  * @integer: The integer part of the number
865  * @fract: The fractional part of the number
866  * @scale_db: True if this should parse as dB
867  *
868  * Returns:
869  * 0 on success, or a negative error code if the string could not be parsed.
870  */
871 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
872 				 int *integer, int *fract, bool scale_db)
873 {
874 	int i = 0, f = 0;
875 	bool integer_part = true, negative = false;
876 
877 	if (fract_mult == 0) {
878 		*fract = 0;
879 
880 		return kstrtoint(str, 0, integer);
881 	}
882 
883 	if (str[0] == '-') {
884 		negative = true;
885 		str++;
886 	} else if (str[0] == '+') {
887 		str++;
888 	}
889 
890 	while (*str) {
891 		if ('0' <= *str && *str <= '9') {
892 			if (integer_part) {
893 				i = i * 10 + *str - '0';
894 			} else {
895 				f += fract_mult * (*str - '0');
896 				fract_mult /= 10;
897 			}
898 		} else if (*str == '\n') {
899 			if (*(str + 1) == '\0')
900 				break;
901 			return -EINVAL;
902 		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
903 			/* Ignore the dB suffix */
904 			str += sizeof(" dB") - 1;
905 			continue;
906 		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
907 			/* Ignore the dB suffix */
908 			str += sizeof("dB") - 1;
909 			continue;
910 		} else if (*str == '.' && integer_part) {
911 			integer_part = false;
912 		} else {
913 			return -EINVAL;
914 		}
915 		str++;
916 	}
917 
918 	if (negative) {
919 		if (i)
920 			i = -i;
921 		else
922 			f = -f;
923 	}
924 
925 	*integer = i;
926 	*fract = f;
927 
928 	return 0;
929 }
930 
931 /**
932  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
933  * @str: The string to parse
934  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
935  * @integer: The integer part of the number
936  * @fract: The fractional part of the number
937  *
938  * Returns:
939  * 0 on success, or a negative error code if the string could not be parsed.
940  */
941 int iio_str_to_fixpoint(const char *str, int fract_mult,
942 			int *integer, int *fract)
943 {
944 	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
945 }
946 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
947 
948 static ssize_t iio_write_channel_info(struct device *dev,
949 				      struct device_attribute *attr,
950 				      const char *buf,
951 				      size_t len)
952 {
953 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
954 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
955 	int ret, fract_mult = 100000;
956 	int integer, fract = 0;
957 	bool is_char = false;
958 	bool scale_db = false;
959 
960 	/* Assumes decimal - precision based on number of digits */
961 	if (!indio_dev->info->write_raw)
962 		return -EINVAL;
963 
964 	if (indio_dev->info->write_raw_get_fmt)
965 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
966 			this_attr->c, this_attr->address)) {
967 		case IIO_VAL_INT:
968 			fract_mult = 0;
969 			break;
970 		case IIO_VAL_INT_PLUS_MICRO_DB:
971 			scale_db = true;
972 			fallthrough;
973 		case IIO_VAL_INT_PLUS_MICRO:
974 			fract_mult = 100000;
975 			break;
976 		case IIO_VAL_INT_PLUS_NANO:
977 			fract_mult = 100000000;
978 			break;
979 		case IIO_VAL_CHAR:
980 			is_char = true;
981 			break;
982 		default:
983 			return -EINVAL;
984 		}
985 
986 	if (is_char) {
987 		char ch;
988 
989 		if (sscanf(buf, "%c", &ch) != 1)
990 			return -EINVAL;
991 		integer = ch;
992 	} else {
993 		ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
994 					    scale_db);
995 		if (ret)
996 			return ret;
997 	}
998 
999 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
1000 					 integer, fract, this_attr->address);
1001 	if (ret)
1002 		return ret;
1003 
1004 	return len;
1005 }
1006 
1007 static
1008 int __iio_device_attr_init(struct device_attribute *dev_attr,
1009 			   const char *postfix,
1010 			   struct iio_chan_spec const *chan,
1011 			   ssize_t (*readfunc)(struct device *dev,
1012 					       struct device_attribute *attr,
1013 					       char *buf),
1014 			   ssize_t (*writefunc)(struct device *dev,
1015 						struct device_attribute *attr,
1016 						const char *buf,
1017 						size_t len),
1018 			   enum iio_shared_by shared_by)
1019 {
1020 	int ret = 0;
1021 	char *name = NULL;
1022 	char *full_postfix;
1023 
1024 	sysfs_attr_init(&dev_attr->attr);
1025 
1026 	/* Build up postfix of <extend_name>_<modifier>_postfix */
1027 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
1028 		if (chan->extend_name)
1029 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
1030 						 iio_modifier_names[chan->channel2],
1031 						 chan->extend_name,
1032 						 postfix);
1033 		else
1034 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
1035 						 iio_modifier_names[chan->channel2],
1036 						 postfix);
1037 	} else {
1038 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
1039 			full_postfix = kstrdup(postfix, GFP_KERNEL);
1040 		else
1041 			full_postfix = kasprintf(GFP_KERNEL,
1042 						 "%s_%s",
1043 						 chan->extend_name,
1044 						 postfix);
1045 	}
1046 	if (full_postfix == NULL)
1047 		return -ENOMEM;
1048 
1049 	if (chan->differential) { /* Differential can not have modifier */
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_%s",
1061 					    iio_direction[chan->output],
1062 					    iio_chan_type_name_spec[chan->type],
1063 					    iio_chan_type_name_spec[chan->type],
1064 					    full_postfix);
1065 			break;
1066 		case IIO_SEPARATE:
1067 			if (!chan->indexed) {
1068 				WARN(1, "Differential channels must be indexed\n");
1069 				ret = -EINVAL;
1070 				goto error_free_full_postfix;
1071 			}
1072 			name = kasprintf(GFP_KERNEL,
1073 					    "%s_%s%d-%s%d_%s",
1074 					    iio_direction[chan->output],
1075 					    iio_chan_type_name_spec[chan->type],
1076 					    chan->channel,
1077 					    iio_chan_type_name_spec[chan->type],
1078 					    chan->channel2,
1079 					    full_postfix);
1080 			break;
1081 		}
1082 	} else { /* Single ended */
1083 		switch (shared_by) {
1084 		case IIO_SHARED_BY_ALL:
1085 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1086 			break;
1087 		case IIO_SHARED_BY_DIR:
1088 			name = kasprintf(GFP_KERNEL, "%s_%s",
1089 						iio_direction[chan->output],
1090 						full_postfix);
1091 			break;
1092 		case IIO_SHARED_BY_TYPE:
1093 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1094 					    iio_direction[chan->output],
1095 					    iio_chan_type_name_spec[chan->type],
1096 					    full_postfix);
1097 			break;
1098 
1099 		case IIO_SEPARATE:
1100 			if (chan->indexed)
1101 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1102 						    iio_direction[chan->output],
1103 						    iio_chan_type_name_spec[chan->type],
1104 						    chan->channel,
1105 						    full_postfix);
1106 			else
1107 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1108 						    iio_direction[chan->output],
1109 						    iio_chan_type_name_spec[chan->type],
1110 						    full_postfix);
1111 			break;
1112 		}
1113 	}
1114 	if (name == NULL) {
1115 		ret = -ENOMEM;
1116 		goto error_free_full_postfix;
1117 	}
1118 	dev_attr->attr.name = name;
1119 
1120 	if (readfunc) {
1121 		dev_attr->attr.mode |= 0444;
1122 		dev_attr->show = readfunc;
1123 	}
1124 
1125 	if (writefunc) {
1126 		dev_attr->attr.mode |= 0200;
1127 		dev_attr->store = writefunc;
1128 	}
1129 
1130 error_free_full_postfix:
1131 	kfree(full_postfix);
1132 
1133 	return ret;
1134 }
1135 
1136 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1137 {
1138 	kfree(dev_attr->attr.name);
1139 }
1140 
1141 int __iio_add_chan_devattr(const char *postfix,
1142 			   struct iio_chan_spec const *chan,
1143 			   ssize_t (*readfunc)(struct device *dev,
1144 					       struct device_attribute *attr,
1145 					       char *buf),
1146 			   ssize_t (*writefunc)(struct device *dev,
1147 						struct device_attribute *attr,
1148 						const char *buf,
1149 						size_t len),
1150 			   u64 mask,
1151 			   enum iio_shared_by shared_by,
1152 			   struct device *dev,
1153 			   struct iio_buffer *buffer,
1154 			   struct list_head *attr_list)
1155 {
1156 	int ret;
1157 	struct iio_dev_attr *iio_attr, *t;
1158 
1159 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1160 	if (iio_attr == NULL)
1161 		return -ENOMEM;
1162 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1163 				     postfix, chan,
1164 				     readfunc, writefunc, shared_by);
1165 	if (ret)
1166 		goto error_iio_dev_attr_free;
1167 	iio_attr->c = chan;
1168 	iio_attr->address = mask;
1169 	iio_attr->buffer = buffer;
1170 	list_for_each_entry(t, attr_list, l)
1171 		if (strcmp(t->dev_attr.attr.name,
1172 			   iio_attr->dev_attr.attr.name) == 0) {
1173 			if (shared_by == IIO_SEPARATE)
1174 				dev_err(dev, "tried to double register : %s\n",
1175 					t->dev_attr.attr.name);
1176 			ret = -EBUSY;
1177 			goto error_device_attr_deinit;
1178 		}
1179 	list_add(&iio_attr->l, attr_list);
1180 
1181 	return 0;
1182 
1183 error_device_attr_deinit:
1184 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1185 error_iio_dev_attr_free:
1186 	kfree(iio_attr);
1187 	return ret;
1188 }
1189 
1190 static int iio_device_add_channel_label(struct iio_dev *indio_dev,
1191 					 struct iio_chan_spec const *chan)
1192 {
1193 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1194 	int ret;
1195 
1196 	if (!indio_dev->info->read_label && !chan->extend_name)
1197 		return 0;
1198 
1199 	ret = __iio_add_chan_devattr("label",
1200 				     chan,
1201 				     &iio_read_channel_label,
1202 				     NULL,
1203 				     0,
1204 				     IIO_SEPARATE,
1205 				     &indio_dev->dev,
1206 				     NULL,
1207 				     &iio_dev_opaque->channel_attr_list);
1208 	if (ret < 0)
1209 		return ret;
1210 
1211 	return 1;
1212 }
1213 
1214 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1215 					 struct iio_chan_spec const *chan,
1216 					 enum iio_shared_by shared_by,
1217 					 const long *infomask)
1218 {
1219 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1220 	int i, ret, attrcount = 0;
1221 
1222 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1223 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1224 			return -EINVAL;
1225 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1226 					     chan,
1227 					     &iio_read_channel_info,
1228 					     &iio_write_channel_info,
1229 					     i,
1230 					     shared_by,
1231 					     &indio_dev->dev,
1232 					     NULL,
1233 					     &iio_dev_opaque->channel_attr_list);
1234 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1235 			continue;
1236 		if (ret < 0)
1237 			return ret;
1238 		attrcount++;
1239 	}
1240 
1241 	return attrcount;
1242 }
1243 
1244 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1245 					       struct iio_chan_spec const *chan,
1246 					       enum iio_shared_by shared_by,
1247 					       const long *infomask)
1248 {
1249 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1250 	int i, ret, attrcount = 0;
1251 	char *avail_postfix;
1252 
1253 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1254 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1255 			return -EINVAL;
1256 		avail_postfix = kasprintf(GFP_KERNEL,
1257 					  "%s_available",
1258 					  iio_chan_info_postfix[i]);
1259 		if (!avail_postfix)
1260 			return -ENOMEM;
1261 
1262 		ret = __iio_add_chan_devattr(avail_postfix,
1263 					     chan,
1264 					     &iio_read_channel_info_avail,
1265 					     NULL,
1266 					     i,
1267 					     shared_by,
1268 					     &indio_dev->dev,
1269 					     NULL,
1270 					     &iio_dev_opaque->channel_attr_list);
1271 		kfree(avail_postfix);
1272 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1273 			continue;
1274 		if (ret < 0)
1275 			return ret;
1276 		attrcount++;
1277 	}
1278 
1279 	return attrcount;
1280 }
1281 
1282 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1283 					struct iio_chan_spec const *chan)
1284 {
1285 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1286 	int ret, attrcount = 0;
1287 	const struct iio_chan_spec_ext_info *ext_info;
1288 
1289 	if (chan->channel < 0)
1290 		return 0;
1291 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1292 					    IIO_SEPARATE,
1293 					    &chan->info_mask_separate);
1294 	if (ret < 0)
1295 		return ret;
1296 	attrcount += ret;
1297 
1298 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1299 						  IIO_SEPARATE,
1300 						  &chan->info_mask_separate_available);
1301 	if (ret < 0)
1302 		return ret;
1303 	attrcount += ret;
1304 
1305 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1306 					    IIO_SHARED_BY_TYPE,
1307 					    &chan->info_mask_shared_by_type);
1308 	if (ret < 0)
1309 		return ret;
1310 	attrcount += ret;
1311 
1312 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1313 						  IIO_SHARED_BY_TYPE,
1314 						  &chan->info_mask_shared_by_type_available);
1315 	if (ret < 0)
1316 		return ret;
1317 	attrcount += ret;
1318 
1319 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1320 					    IIO_SHARED_BY_DIR,
1321 					    &chan->info_mask_shared_by_dir);
1322 	if (ret < 0)
1323 		return ret;
1324 	attrcount += ret;
1325 
1326 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1327 						  IIO_SHARED_BY_DIR,
1328 						  &chan->info_mask_shared_by_dir_available);
1329 	if (ret < 0)
1330 		return ret;
1331 	attrcount += ret;
1332 
1333 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1334 					    IIO_SHARED_BY_ALL,
1335 					    &chan->info_mask_shared_by_all);
1336 	if (ret < 0)
1337 		return ret;
1338 	attrcount += ret;
1339 
1340 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1341 						  IIO_SHARED_BY_ALL,
1342 						  &chan->info_mask_shared_by_all_available);
1343 	if (ret < 0)
1344 		return ret;
1345 	attrcount += ret;
1346 
1347 	ret = iio_device_add_channel_label(indio_dev, chan);
1348 	if (ret < 0)
1349 		return ret;
1350 	attrcount += ret;
1351 
1352 	if (chan->ext_info) {
1353 		unsigned int i = 0;
1354 
1355 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1356 			ret = __iio_add_chan_devattr(ext_info->name,
1357 					chan,
1358 					ext_info->read ?
1359 					    &iio_read_channel_ext_info : NULL,
1360 					ext_info->write ?
1361 					    &iio_write_channel_ext_info : NULL,
1362 					i,
1363 					ext_info->shared,
1364 					&indio_dev->dev,
1365 					NULL,
1366 					&iio_dev_opaque->channel_attr_list);
1367 			i++;
1368 			if (ret == -EBUSY && ext_info->shared)
1369 				continue;
1370 
1371 			if (ret)
1372 				return ret;
1373 
1374 			attrcount++;
1375 		}
1376 	}
1377 
1378 	return attrcount;
1379 }
1380 
1381 /**
1382  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1383  * @attr_list: List of IIO device attributes
1384  *
1385  * This function frees the memory allocated for each of the IIO device
1386  * attributes in the list.
1387  */
1388 void iio_free_chan_devattr_list(struct list_head *attr_list)
1389 {
1390 	struct iio_dev_attr *p, *n;
1391 
1392 	list_for_each_entry_safe(p, n, attr_list, l) {
1393 		kfree_const(p->dev_attr.attr.name);
1394 		list_del(&p->l);
1395 		kfree(p);
1396 	}
1397 }
1398 
1399 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
1400 			 char *buf)
1401 {
1402 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1403 
1404 	return sysfs_emit(buf, "%s\n", indio_dev->name);
1405 }
1406 
1407 static DEVICE_ATTR_RO(name);
1408 
1409 static ssize_t label_show(struct device *dev, struct device_attribute *attr,
1410 			  char *buf)
1411 {
1412 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1413 
1414 	return sysfs_emit(buf, "%s\n", indio_dev->label);
1415 }
1416 
1417 static DEVICE_ATTR_RO(label);
1418 
1419 static const char * const clock_names[] = {
1420 	[CLOCK_REALTIME]	 	= "realtime",
1421 	[CLOCK_MONOTONIC]	 	= "monotonic",
1422 	[CLOCK_PROCESS_CPUTIME_ID]	= "process_cputime_id",
1423 	[CLOCK_THREAD_CPUTIME_ID]	= "thread_cputime_id",
1424 	[CLOCK_MONOTONIC_RAW]	 	= "monotonic_raw",
1425 	[CLOCK_REALTIME_COARSE]	 	= "realtime_coarse",
1426 	[CLOCK_MONOTONIC_COARSE] 	= "monotonic_coarse",
1427 	[CLOCK_BOOTTIME]	 	= "boottime",
1428 	[CLOCK_REALTIME_ALARM]		= "realtime_alarm",
1429 	[CLOCK_BOOTTIME_ALARM]		= "boottime_alarm",
1430 	[CLOCK_SGI_CYCLE]		= "sgi_cycle",
1431 	[CLOCK_TAI]		 	= "tai",
1432 };
1433 
1434 static ssize_t current_timestamp_clock_show(struct device *dev,
1435 					    struct device_attribute *attr,
1436 					    char *buf)
1437 {
1438 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1439 	const clockid_t clk = iio_device_get_clock(indio_dev);
1440 
1441 	switch (clk) {
1442 	case CLOCK_REALTIME:
1443 	case CLOCK_MONOTONIC:
1444 	case CLOCK_MONOTONIC_RAW:
1445 	case CLOCK_REALTIME_COARSE:
1446 	case CLOCK_MONOTONIC_COARSE:
1447 	case CLOCK_BOOTTIME:
1448 	case CLOCK_TAI:
1449 		break;
1450 	default:
1451 		BUG();
1452 	}
1453 
1454 	return sysfs_emit(buf, "%s\n", clock_names[clk]);
1455 }
1456 
1457 static ssize_t current_timestamp_clock_store(struct device *dev,
1458 					     struct device_attribute *attr,
1459 					     const char *buf, size_t len)
1460 {
1461 	clockid_t clk;
1462 	int ret;
1463 
1464 	ret = sysfs_match_string(clock_names, buf);
1465 	if (ret < 0)
1466 		return ret;
1467 	clk = ret;
1468 
1469 	switch (clk) {
1470 	case CLOCK_REALTIME:
1471 	case CLOCK_MONOTONIC:
1472 	case CLOCK_MONOTONIC_RAW:
1473 	case CLOCK_REALTIME_COARSE:
1474 	case CLOCK_MONOTONIC_COARSE:
1475 	case CLOCK_BOOTTIME:
1476 	case CLOCK_TAI:
1477 		break;
1478 	default:
1479 		return -EINVAL;
1480 	}
1481 
1482 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1483 	if (ret)
1484 		return ret;
1485 
1486 	return len;
1487 }
1488 
1489 int iio_device_register_sysfs_group(struct iio_dev *indio_dev,
1490 				    const struct attribute_group *group)
1491 {
1492 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1493 	const struct attribute_group **new, **old = iio_dev_opaque->groups;
1494 	unsigned int cnt = iio_dev_opaque->groupcounter;
1495 
1496 	new = krealloc_array(old, cnt + 2, sizeof(*new), GFP_KERNEL);
1497 	if (!new)
1498 		return -ENOMEM;
1499 
1500 	new[iio_dev_opaque->groupcounter++] = group;
1501 	new[iio_dev_opaque->groupcounter] = NULL;
1502 
1503 	iio_dev_opaque->groups = new;
1504 
1505 	return 0;
1506 }
1507 
1508 static DEVICE_ATTR_RW(current_timestamp_clock);
1509 
1510 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1511 {
1512 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1513 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1514 	struct iio_dev_attr *p;
1515 	struct attribute **attr, *clk = NULL;
1516 
1517 	/* First count elements in any existing group */
1518 	if (indio_dev->info->attrs) {
1519 		attr = indio_dev->info->attrs->attrs;
1520 		while (*attr++ != NULL)
1521 			attrcount_orig++;
1522 	}
1523 	attrcount = attrcount_orig;
1524 	/*
1525 	 * New channel registration method - relies on the fact a group does
1526 	 * not need to be initialized if its name is NULL.
1527 	 */
1528 	if (indio_dev->channels)
1529 		for (i = 0; i < indio_dev->num_channels; i++) {
1530 			const struct iio_chan_spec *chan =
1531 				&indio_dev->channels[i];
1532 
1533 			if (chan->type == IIO_TIMESTAMP)
1534 				clk = &dev_attr_current_timestamp_clock.attr;
1535 
1536 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1537 			if (ret < 0)
1538 				goto error_clear_attrs;
1539 			attrcount += ret;
1540 		}
1541 
1542 	if (iio_dev_opaque->event_interface)
1543 		clk = &dev_attr_current_timestamp_clock.attr;
1544 
1545 	if (indio_dev->name)
1546 		attrcount++;
1547 	if (indio_dev->label)
1548 		attrcount++;
1549 	if (clk)
1550 		attrcount++;
1551 
1552 	iio_dev_opaque->chan_attr_group.attrs =
1553 		kcalloc(attrcount + 1,
1554 			sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
1555 			GFP_KERNEL);
1556 	if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
1557 		ret = -ENOMEM;
1558 		goto error_clear_attrs;
1559 	}
1560 	/* Copy across original attributes, and point to original binary attributes */
1561 	if (indio_dev->info->attrs) {
1562 		memcpy(iio_dev_opaque->chan_attr_group.attrs,
1563 		       indio_dev->info->attrs->attrs,
1564 		       sizeof(iio_dev_opaque->chan_attr_group.attrs[0])
1565 		       *attrcount_orig);
1566 		iio_dev_opaque->chan_attr_group.is_visible =
1567 			indio_dev->info->attrs->is_visible;
1568 		iio_dev_opaque->chan_attr_group.bin_attrs =
1569 			indio_dev->info->attrs->bin_attrs;
1570 	}
1571 	attrn = attrcount_orig;
1572 	/* Add all elements from the list. */
1573 	list_for_each_entry(p, &iio_dev_opaque->channel_attr_list, l)
1574 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1575 	if (indio_dev->name)
1576 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1577 	if (indio_dev->label)
1578 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1579 	if (clk)
1580 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk;
1581 
1582 	ret = iio_device_register_sysfs_group(indio_dev,
1583 					      &iio_dev_opaque->chan_attr_group);
1584 	if (ret)
1585 		goto error_free_chan_attrs;
1586 
1587 	return 0;
1588 
1589 error_free_chan_attrs:
1590 	kfree(iio_dev_opaque->chan_attr_group.attrs);
1591 	iio_dev_opaque->chan_attr_group.attrs = NULL;
1592 error_clear_attrs:
1593 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1594 
1595 	return ret;
1596 }
1597 
1598 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1599 {
1600 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1601 
1602 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1603 	kfree(iio_dev_opaque->chan_attr_group.attrs);
1604 	iio_dev_opaque->chan_attr_group.attrs = NULL;
1605 	kfree(iio_dev_opaque->groups);
1606 	iio_dev_opaque->groups = NULL;
1607 }
1608 
1609 static void iio_dev_release(struct device *device)
1610 {
1611 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1612 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1613 
1614 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1615 		iio_device_unregister_trigger_consumer(indio_dev);
1616 	iio_device_unregister_eventset(indio_dev);
1617 	iio_device_unregister_sysfs(indio_dev);
1618 
1619 	iio_device_detach_buffers(indio_dev);
1620 
1621 	lockdep_unregister_key(&iio_dev_opaque->mlock_key);
1622 
1623 	ida_free(&iio_ida, iio_dev_opaque->id);
1624 	kfree(iio_dev_opaque);
1625 }
1626 
1627 const struct device_type iio_device_type = {
1628 	.name = "iio_device",
1629 	.release = iio_dev_release,
1630 };
1631 
1632 /**
1633  * iio_device_alloc() - allocate an iio_dev from a driver
1634  * @parent:		Parent device.
1635  * @sizeof_priv:	Space to allocate for private structure.
1636  *
1637  * Returns:
1638  * Pointer to allocated iio_dev on success, NULL on failure.
1639  */
1640 struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
1641 {
1642 	struct iio_dev_opaque *iio_dev_opaque;
1643 	struct iio_dev *indio_dev;
1644 	size_t alloc_size;
1645 
1646 	alloc_size = sizeof(struct iio_dev_opaque);
1647 	if (sizeof_priv) {
1648 		alloc_size = ALIGN(alloc_size, IIO_DMA_MINALIGN);
1649 		alloc_size += sizeof_priv;
1650 	}
1651 
1652 	iio_dev_opaque = kzalloc(alloc_size, GFP_KERNEL);
1653 	if (!iio_dev_opaque)
1654 		return NULL;
1655 
1656 	indio_dev = &iio_dev_opaque->indio_dev;
1657 
1658 	if (sizeof_priv)
1659 		indio_dev->priv = (char *)iio_dev_opaque +
1660 			ALIGN(sizeof(*iio_dev_opaque), IIO_DMA_MINALIGN);
1661 
1662 	indio_dev->dev.parent = parent;
1663 	indio_dev->dev.type = &iio_device_type;
1664 	indio_dev->dev.bus = &iio_bus_type;
1665 	device_initialize(&indio_dev->dev);
1666 	mutex_init(&iio_dev_opaque->mlock);
1667 	mutex_init(&iio_dev_opaque->info_exist_lock);
1668 	INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
1669 
1670 	iio_dev_opaque->id = ida_alloc(&iio_ida, GFP_KERNEL);
1671 	if (iio_dev_opaque->id < 0) {
1672 		/* cannot use a dev_err as the name isn't available */
1673 		pr_err("failed to get device id\n");
1674 		kfree(iio_dev_opaque);
1675 		return NULL;
1676 	}
1677 
1678 	if (dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id)) {
1679 		ida_free(&iio_ida, iio_dev_opaque->id);
1680 		kfree(iio_dev_opaque);
1681 		return NULL;
1682 	}
1683 
1684 	INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
1685 	INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);
1686 
1687 	lockdep_register_key(&iio_dev_opaque->mlock_key);
1688 	lockdep_set_class(&iio_dev_opaque->mlock, &iio_dev_opaque->mlock_key);
1689 
1690 	return indio_dev;
1691 }
1692 EXPORT_SYMBOL(iio_device_alloc);
1693 
1694 /**
1695  * iio_device_free() - free an iio_dev from a driver
1696  * @dev:		the iio_dev associated with the device
1697  */
1698 void iio_device_free(struct iio_dev *dev)
1699 {
1700 	if (dev)
1701 		put_device(&dev->dev);
1702 }
1703 EXPORT_SYMBOL(iio_device_free);
1704 
1705 static void devm_iio_device_release(void *iio_dev)
1706 {
1707 	iio_device_free(iio_dev);
1708 }
1709 
1710 /**
1711  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1712  * @parent:		Device to allocate iio_dev for, and parent for this IIO device
1713  * @sizeof_priv:	Space to allocate for private structure.
1714  *
1715  * Managed iio_device_alloc. iio_dev allocated with this function is
1716  * automatically freed on driver detach.
1717  *
1718  * Returns:
1719  * Pointer to allocated iio_dev on success, NULL on failure.
1720  */
1721 struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
1722 {
1723 	struct iio_dev *iio_dev;
1724 	int ret;
1725 
1726 	iio_dev = iio_device_alloc(parent, sizeof_priv);
1727 	if (!iio_dev)
1728 		return NULL;
1729 
1730 	ret = devm_add_action_or_reset(parent, devm_iio_device_release,
1731 				       iio_dev);
1732 	if (ret)
1733 		return NULL;
1734 
1735 	return iio_dev;
1736 }
1737 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1738 
1739 /**
1740  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1741  * @inode:	Inode structure for identifying the device in the file system
1742  * @filp:	File structure for iio device used to keep and later access
1743  *		private data
1744  *
1745  * Returns: 0 on success or -EBUSY if the device is already opened
1746  */
1747 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1748 {
1749 	struct iio_dev_opaque *iio_dev_opaque =
1750 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1751 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1752 	struct iio_dev_buffer_pair *ib;
1753 
1754 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags))
1755 		return -EBUSY;
1756 
1757 	iio_device_get(indio_dev);
1758 
1759 	ib = kmalloc(sizeof(*ib), GFP_KERNEL);
1760 	if (!ib) {
1761 		iio_device_put(indio_dev);
1762 		clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1763 		return -ENOMEM;
1764 	}
1765 
1766 	ib->indio_dev = indio_dev;
1767 	ib->buffer = indio_dev->buffer;
1768 
1769 	filp->private_data = ib;
1770 
1771 	return 0;
1772 }
1773 
1774 /**
1775  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1776  * @inode:	Inode structure pointer for the char device
1777  * @filp:	File structure pointer for the char device
1778  *
1779  * Returns: 0 for successful release.
1780  */
1781 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1782 {
1783 	struct iio_dev_buffer_pair *ib = filp->private_data;
1784 	struct iio_dev_opaque *iio_dev_opaque =
1785 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1786 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1787 
1788 	kfree(ib);
1789 	clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1790 	iio_device_put(indio_dev);
1791 
1792 	return 0;
1793 }
1794 
1795 void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
1796 				       struct iio_ioctl_handler *h)
1797 {
1798 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1799 
1800 	list_add_tail(&h->entry, &iio_dev_opaque->ioctl_handlers);
1801 }
1802 
1803 void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h)
1804 {
1805 	list_del(&h->entry);
1806 }
1807 
1808 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1809 {
1810 	struct iio_dev_buffer_pair *ib = filp->private_data;
1811 	struct iio_dev *indio_dev = ib->indio_dev;
1812 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1813 	struct iio_ioctl_handler *h;
1814 	int ret = -ENODEV;
1815 
1816 	mutex_lock(&iio_dev_opaque->info_exist_lock);
1817 
1818 	/*
1819 	 * The NULL check here is required to prevent crashing when a device
1820 	 * is being removed while userspace would still have open file handles
1821 	 * to try to access this device.
1822 	 */
1823 	if (!indio_dev->info)
1824 		goto out_unlock;
1825 
1826 	list_for_each_entry(h, &iio_dev_opaque->ioctl_handlers, entry) {
1827 		ret = h->ioctl(indio_dev, filp, cmd, arg);
1828 		if (ret != IIO_IOCTL_UNHANDLED)
1829 			break;
1830 	}
1831 
1832 	if (ret == IIO_IOCTL_UNHANDLED)
1833 		ret = -ENODEV;
1834 
1835 out_unlock:
1836 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
1837 
1838 	return ret;
1839 }
1840 
1841 static const struct file_operations iio_buffer_fileops = {
1842 	.owner = THIS_MODULE,
1843 	.llseek = noop_llseek,
1844 	.read = iio_buffer_read_outer_addr,
1845 	.write = iio_buffer_write_outer_addr,
1846 	.poll = iio_buffer_poll_addr,
1847 	.unlocked_ioctl = iio_ioctl,
1848 	.compat_ioctl = compat_ptr_ioctl,
1849 	.open = iio_chrdev_open,
1850 	.release = iio_chrdev_release,
1851 };
1852 
1853 static const struct file_operations iio_event_fileops = {
1854 	.owner = THIS_MODULE,
1855 	.llseek = noop_llseek,
1856 	.unlocked_ioctl = iio_ioctl,
1857 	.compat_ioctl = compat_ptr_ioctl,
1858 	.open = iio_chrdev_open,
1859 	.release = iio_chrdev_release,
1860 };
1861 
1862 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1863 {
1864 	int i, j;
1865 	const struct iio_chan_spec *channels = indio_dev->channels;
1866 
1867 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1868 		return 0;
1869 
1870 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1871 		if (channels[i].scan_index < 0)
1872 			continue;
1873 		for (j = i + 1; j < indio_dev->num_channels; j++)
1874 			if (channels[i].scan_index == channels[j].scan_index) {
1875 				dev_err(&indio_dev->dev,
1876 					"Duplicate scan index %d\n",
1877 					channels[i].scan_index);
1878 				return -EINVAL;
1879 			}
1880 	}
1881 
1882 	return 0;
1883 }
1884 
1885 static int iio_check_extended_name(const struct iio_dev *indio_dev)
1886 {
1887 	unsigned int i;
1888 
1889 	if (!indio_dev->info->read_label)
1890 		return 0;
1891 
1892 	for (i = 0; i < indio_dev->num_channels; i++) {
1893 		if (indio_dev->channels[i].extend_name) {
1894 			dev_err(&indio_dev->dev,
1895 				"Cannot use labels and extend_name at the same time\n");
1896 			return -EINVAL;
1897 		}
1898 	}
1899 
1900 	return 0;
1901 }
1902 
1903 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1904 
1905 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1906 {
1907 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1908 	struct fwnode_handle *fwnode = NULL;
1909 	int ret;
1910 
1911 	if (!indio_dev->info)
1912 		return -EINVAL;
1913 
1914 	iio_dev_opaque->driver_module = this_mod;
1915 
1916 	/* If the calling driver did not initialize firmware node, do it here */
1917 	if (dev_fwnode(&indio_dev->dev))
1918 		fwnode = dev_fwnode(&indio_dev->dev);
1919 	/* The default dummy IIO device has no parent */
1920 	else if (indio_dev->dev.parent)
1921 		fwnode = dev_fwnode(indio_dev->dev.parent);
1922 	device_set_node(&indio_dev->dev, fwnode);
1923 
1924 	fwnode_property_read_string(fwnode, "label", &indio_dev->label);
1925 
1926 	ret = iio_check_unique_scan_index(indio_dev);
1927 	if (ret < 0)
1928 		return ret;
1929 
1930 	ret = iio_check_extended_name(indio_dev);
1931 	if (ret < 0)
1932 		return ret;
1933 
1934 	iio_device_register_debugfs(indio_dev);
1935 
1936 	ret = iio_buffers_alloc_sysfs_and_mask(indio_dev);
1937 	if (ret) {
1938 		dev_err(indio_dev->dev.parent,
1939 			"Failed to create buffer sysfs interfaces\n");
1940 		goto error_unreg_debugfs;
1941 	}
1942 
1943 	ret = iio_device_register_sysfs(indio_dev);
1944 	if (ret) {
1945 		dev_err(indio_dev->dev.parent,
1946 			"Failed to register sysfs interfaces\n");
1947 		goto error_buffer_free_sysfs;
1948 	}
1949 	ret = iio_device_register_eventset(indio_dev);
1950 	if (ret) {
1951 		dev_err(indio_dev->dev.parent,
1952 			"Failed to register event set\n");
1953 		goto error_free_sysfs;
1954 	}
1955 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1956 		iio_device_register_trigger_consumer(indio_dev);
1957 
1958 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1959 		indio_dev->setup_ops == NULL)
1960 		indio_dev->setup_ops = &noop_ring_setup_ops;
1961 
1962 	if (iio_dev_opaque->attached_buffers_cnt)
1963 		cdev_init(&iio_dev_opaque->chrdev, &iio_buffer_fileops);
1964 	else if (iio_dev_opaque->event_interface)
1965 		cdev_init(&iio_dev_opaque->chrdev, &iio_event_fileops);
1966 
1967 	if (iio_dev_opaque->attached_buffers_cnt || iio_dev_opaque->event_interface) {
1968 		indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), iio_dev_opaque->id);
1969 		iio_dev_opaque->chrdev.owner = this_mod;
1970 	}
1971 
1972 	/* assign device groups now; they should be all registered now */
1973 	indio_dev->dev.groups = iio_dev_opaque->groups;
1974 
1975 	ret = cdev_device_add(&iio_dev_opaque->chrdev, &indio_dev->dev);
1976 	if (ret < 0)
1977 		goto error_unreg_eventset;
1978 
1979 	return 0;
1980 
1981 error_unreg_eventset:
1982 	iio_device_unregister_eventset(indio_dev);
1983 error_free_sysfs:
1984 	iio_device_unregister_sysfs(indio_dev);
1985 error_buffer_free_sysfs:
1986 	iio_buffers_free_sysfs_and_mask(indio_dev);
1987 error_unreg_debugfs:
1988 	iio_device_unregister_debugfs(indio_dev);
1989 	return ret;
1990 }
1991 EXPORT_SYMBOL(__iio_device_register);
1992 
1993 /**
1994  * iio_device_unregister() - unregister a device from the IIO subsystem
1995  * @indio_dev:		Device structure representing the device.
1996  */
1997 void iio_device_unregister(struct iio_dev *indio_dev)
1998 {
1999 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2000 
2001 	cdev_device_del(&iio_dev_opaque->chrdev, &indio_dev->dev);
2002 
2003 	mutex_lock(&iio_dev_opaque->info_exist_lock);
2004 
2005 	iio_device_unregister_debugfs(indio_dev);
2006 
2007 	iio_disable_all_buffers(indio_dev);
2008 
2009 	indio_dev->info = NULL;
2010 
2011 	iio_device_wakeup_eventset(indio_dev);
2012 	iio_buffer_wakeup_poll(indio_dev);
2013 
2014 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
2015 
2016 	iio_buffers_free_sysfs_and_mask(indio_dev);
2017 }
2018 EXPORT_SYMBOL(iio_device_unregister);
2019 
2020 static void devm_iio_device_unreg(void *indio_dev)
2021 {
2022 	iio_device_unregister(indio_dev);
2023 }
2024 
2025 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
2026 			       struct module *this_mod)
2027 {
2028 	int ret;
2029 
2030 	ret = __iio_device_register(indio_dev, this_mod);
2031 	if (ret)
2032 		return ret;
2033 
2034 	return devm_add_action_or_reset(dev, devm_iio_device_unreg, indio_dev);
2035 }
2036 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
2037 
2038 /**
2039  * iio_device_claim_direct_mode - Keep device in direct mode
2040  * @indio_dev:	the iio_dev associated with the device
2041  *
2042  * If the device is in direct mode it is guaranteed to stay
2043  * that way until iio_device_release_direct_mode() is called.
2044  *
2045  * Use with iio_device_release_direct_mode()
2046  *
2047  * Returns: 0 on success, -EBUSY on failure.
2048  */
2049 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
2050 {
2051 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2052 
2053 	mutex_lock(&iio_dev_opaque->mlock);
2054 
2055 	if (iio_buffer_enabled(indio_dev)) {
2056 		mutex_unlock(&iio_dev_opaque->mlock);
2057 		return -EBUSY;
2058 	}
2059 	return 0;
2060 }
2061 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
2062 
2063 /**
2064  * iio_device_release_direct_mode - releases claim on direct mode
2065  * @indio_dev:	the iio_dev associated with the device
2066  *
2067  * Release the claim. Device is no longer guaranteed to stay
2068  * in direct mode.
2069  *
2070  * Use with iio_device_claim_direct_mode()
2071  */
2072 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
2073 {
2074 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2075 }
2076 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
2077 
2078 /**
2079  * iio_device_claim_buffer_mode - Keep device in buffer mode
2080  * @indio_dev:	the iio_dev associated with the device
2081  *
2082  * If the device is in buffer mode it is guaranteed to stay
2083  * that way until iio_device_release_buffer_mode() is called.
2084  *
2085  * Use with iio_device_release_buffer_mode().
2086  *
2087  * Returns: 0 on success, -EBUSY on failure.
2088  */
2089 int iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
2090 {
2091 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2092 
2093 	mutex_lock(&iio_dev_opaque->mlock);
2094 
2095 	if (iio_buffer_enabled(indio_dev))
2096 		return 0;
2097 
2098 	mutex_unlock(&iio_dev_opaque->mlock);
2099 	return -EBUSY;
2100 }
2101 EXPORT_SYMBOL_GPL(iio_device_claim_buffer_mode);
2102 
2103 /**
2104  * iio_device_release_buffer_mode - releases claim on buffer mode
2105  * @indio_dev:	the iio_dev associated with the device
2106  *
2107  * Release the claim. Device is no longer guaranteed to stay
2108  * in buffer mode.
2109  *
2110  * Use with iio_device_claim_buffer_mode().
2111  */
2112 void iio_device_release_buffer_mode(struct iio_dev *indio_dev)
2113 {
2114 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2115 }
2116 EXPORT_SYMBOL_GPL(iio_device_release_buffer_mode);
2117 
2118 /**
2119  * iio_device_get_current_mode() - helper function providing read-only access to
2120  *				   the opaque @currentmode variable
2121  * @indio_dev:			   IIO device structure for device
2122  */
2123 int iio_device_get_current_mode(struct iio_dev *indio_dev)
2124 {
2125 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2126 
2127 	return iio_dev_opaque->currentmode;
2128 }
2129 EXPORT_SYMBOL_GPL(iio_device_get_current_mode);
2130 
2131 subsys_initcall(iio_init);
2132 module_exit(iio_exit);
2133 
2134 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
2135 MODULE_DESCRIPTION("Industrial I/O core");
2136 MODULE_LICENSE("GPL");
2137